To solve the problem of immune incompatibility, nuclear transplantation has been envisaged as a means to produce cells or tissues for human autologous transplantation. Here we have derived embryonic stem cells by the ...To solve the problem of immune incompatibility, nuclear transplantation has been envisaged as a means to produce cells or tissues for human autologous transplantation. Here we have derived embryonic stem cells by the transfer of human somatic nuclei into rabbit oocytes. The number of blastocysts that developed from the fused nuclear transfer was comparable among nuclear donors at ages of 5, 42, 52 and 60 years, and nuclear transfer (NT) embryonic stem cells (ntES cells) were subsequently derived from each of the four age groups. These results suggest that human somatic nuclei can form ntES cells independent of the age of the donor. The derived ntES cells are human based on karyotype, isogenicity, in situ hybridization, PCR and immunocytochemistry with probes that distinguish between the various species. The ntES cells maintain the capability of sustained growth in an undifferentiated state, and form embryoid bodies, which, on further induction, give rise to cell types such as neuron and muscle, as well as mixed cell populations that express markers representative of all three germ layers. Thus, ntES cells derived from human somatic cells by NT to rabbit eggs retain phenotypes similar to those of conventional human ES cells, including the ability to undergo multilineage cellular differentiation.展开更多
Lung cancer is one of the leading causes of death with one of the lowest survival rates. However, a subset of lung cancer patients who are of Asian origin and carry somatic mutations in epidermal growth factor recepto...Lung cancer is one of the leading causes of death with one of the lowest survival rates. However, a subset of lung cancer patients who are of Asian origin and carry somatic mutations in epidermal growth factor receptor or EGFR have responded remarkable well to two tyrosine kinase inhibitors, gefitinib and erlotinib. While EGFR mutation profiles have been reported from Japan, South Korea, and Taiwan, there is no such report from mainland of China where the largest pool of patients reside. In this report, we identified ten somatic mutations from a total of 41 lung cancer patients in China. Among them, seven mutations were found in 17 adenocarcinomas. In contrast to previous reports, eight of these mutations are deletions in exon 19 and two of these deletions are homozygous. These results suggest that a large portion of Chinese adenocarcinoma patients could benefit from gefitinib or erlotinib. This unique mutation profile provides a rationale to develop the next generation of EGFR inhibitors more suitable for the Chinese population.展开更多
Transforming growth factor （TGF）-βs and their family members, including bone morphogenetic proteins （BMPs）, Nodal and activins, have been implicated in the development and maintenance of various organs, in which ...Transforming growth factor （TGF）-βs and their family members, including bone morphogenetic proteins （BMPs）, Nodal and activins, have been implicated in the development and maintenance of various organs, in which stem cells play important roles. Stem cells are characterized by their ability to self-renew and to generate differentiated cells of a particular tissue, and are classified into embryonic and somatic stem cells. Embryonic stem （ES） cells self-renew indefinitely and contribute to derivatives of all three primary germ layers. In contrast, somatic stem cells, which can be identified in various adult organs, exhibit limited abilities for self-renewal and differentiation in most cases. The multi-lineage differentiation capacity of ES ceils and somatic stem cells has opened possibilities for cell replacement therapies for genetic, malignant and degenerative diseases. In order to utilize stem cells for therapeutic applications, it is essential to understand the extrinsic and intrinsic factors regulating self-renewal and differentiation of stem cells. More recently, induced pluripotent stem （iPS） cells have been generated from mouse and human fibroblasts that resemble ES cells via ectopic expression of four transcription factors, iPS cells may have an advantage in regenerative medicine, since they overcome the immunogenicity and ethical controversy of ES cells. Moreover, recent studies have highlighted the involvement of cancer stem cells during the formation and progression of various types of cancers, including leukemia, glioma, and breast cancer. Here, we illustrate the roles of TGF-β family members in the maintenance and differentiation of ES cells, somatic stem cells, and cancer stem cells.展开更多
Protoplasts isolated from cotyledon-derived calli of Actinidia chinensis var. chinensis (2n = 2x=58) were fused by the PEG method with cotyledon-callus protoplasts of A. deliciosa var. deliciosa (2n = 6x = 174) or wit...Protoplasts isolated from cotyledon-derived calli of Actinidia chinensis var. chinensis (2n = 2x=58) were fused by the PEG method with cotyledon-callus protoplasts of A. deliciosa var. deliciosa (2n = 6x = 174) or with mesophyll protoplasts of A. kolomikta (2n = 2x = 58), respectively. Randomly amplified polymorphic DNA (RAPD) markers and flow cytometry was used to confirm the occurrence of somatic hybrids. RAPD results with some primers surveyed indicated that one clone (A. chinensis + A. deliciosa) and four clones (A. chinensis + A. kolomikta) had RAPD banding patterns which combined the parental banding profiles. Ploidy levels of the (A. chinensis + A. deliciosa) clone were deduced as octoploid (2n = 8x), and the (A. chinensis + A. kolomikta) clones were tetraploid (2n = 4x), triploid (2n = 3x) or pentaploid (2n = 5x). The clones were confirmed as interspecific somatic hybrids in Actinidia.展开更多
Background Molecular targeted drugs is now widely used in non-small cell lung cancer （NSCLC） clinical treatment. Icotinib hydrochloride is a new type of oral epidermal growth factor receptor （EGFR） tyrosine kinase...Background Molecular targeted drugs is now widely used in non-small cell lung cancer （NSCLC） clinical treatment. Icotinib hydrochloride is a new type of oral epidermal growth factor receptor （EGFR） tyrosine kinase inhibitors （EGFR-TKIs）. In this study, we examined the role of EGFR, K-RAS, B-RAF somatic mutations and EGFR mRNA expression in tumor specimens from advanced NSCLC patients as predicators of the efficacy of icotinib hydrochloride. Methods We analyzed tumor paraffin-embedded specimens, which were obtained from 14 of 40 patients with advanced NSCLC who enrolled in the stage I clinical trial of icotinib hydrochloride. Somatic mutations were evaluated by mutant-enriched liquidchip （MEL） technology, and EGFR mRNA expression was measured by branched DNA liquidchip （MBL） technology. Results In the 14 specimens, seven patients showed EGFR mutations, exon 19 deletion （3/7） and exon 21 point mutation （4/7）; and two patients showed K-RAS mutation. No mutations in EGFR exon 20. or B-RAF were detected. In patients with EGFR mutation, one patient developed progress disease （PD）, three patients had stable disease （SD）, two patients had partial responses （PR） and one patient had a complete response （CR）. In patients with wild-type EGFR, four patients had PD, three patients acquired SD, and none had PR/CR （P=-0.0407）. EGFR mutations were associated with better progress-free survival （PFS） （141 days vs. 61 days） but without a statistically significant difference （P=0.8597）, and median overall survival （OS） （-〉449 days vs. 140 days）. EGFR mRNA expression levels were evaluated （three high, eight moderate, one low, and two that can not be measured due to insufficient tumor tissue） and no statistically significant relationships was observed with response, PFS or OS. Conclusions The EGFR mutation rate was consistent with that reported in the Asian population, so the MEL technology is reliable for measuring EGFR mutation with high throughput and rapidity展开更多
Formation of somatic embryos from non-germline cells is unique to higher plants and can be manipulated in a variety of species. Previous studies revealed that overexpression of several Arabidopsis genes, including WUS...Formation of somatic embryos from non-germline cells is unique to higher plants and can be manipulated in a variety of species. Previous studies revealed that overexpression of several Arabidopsis genes, including WUSCHEL （WUS）/PLANT GROWTH ACTIVATOR6 （PGA6）, BABY BOOM, LEAFY COTYLEDON1 （LEC1）, and LEC2, is able to cause vegetative-to-embryonic transition or the formation of somatic embryos. Here, we report that a gain-offunction mutation in the Arabidopsis PGA37 gene, encoding the MYBI18 transcription factor, induced vegetative-toembryonic transition, the formation of somatic embryos from root explants, and an elevated LEC1 expression level. Double mutant analysis showed that WUS was not required for induction of somatic embryos by PGA37/MYB118. In addition, overexpression of MYBll5, a homolog of PGA37/MYB118, caused a pga37-like phenotype. A myb118 myb115 double mutant did not show apparent developmental abnormalities. Collectively, these results suggest that PGA37/ MYB118 and MYB115 promote vegetative-to-embryonic transition, through a signaling pathway independent of WUS.展开更多
The evaluation on the callus embryogenesis capacity of 15 genotypes of citrus showed that stress treatments were conducive to somatic embryogenesis and could enhance the recovery of the missed capacity of embryogenes...The evaluation on the callus embryogenesis capacity of 15 genotypes of citrus showed that stress treatments were conducive to somatic embryogenesis and could enhance the recovery of the missed capacity of embryogenesis for some genotypes. Randomly amplified polymorphic DNA (RAPD) and methylation sensitive amplified polymorphism (MSAP) analysis indicated that there existed significant differences in DNA methylation status between the callus capable of producing somatic embryoids and that which missed the embryogenesis capacity of the same genotype Newhall navel orange ( Citrus sinensis Osb. cv. Newhall). The DNA methylation level of the former was lower than that of the latter. However, RAPD profiles did not show any difference between these two kinds of callus.展开更多
The present study examined the effects of genetic manipulation to the donor cell and different types of transgenic donor cells on developmental potential of bovine nuclear trans-fer (NT) embryos. Four types of bovine ...The present study examined the effects of genetic manipulation to the donor cell and different types of transgenic donor cells on developmental potential of bovine nuclear trans-fer (NT) embryos. Four types of bovine somatic cells, including granulosa cells, fetal fibroblasts, fetal oviduct epithelial cells and fetal ovary epithelial cells, were transfected with a plasmid (pCE-EGFP-Ires-Neo-dNdB) containing the enhanced green fluorescent protein (EGFP) and neomycin-resistant (Neor) genes by electroporation. After 14 days selection with 800 mg/mL G418, transgenic cell lines from each type of somatic cells were obtained. Nontransgenic granulosa cells and all 4 types of transgenic somatic cells were used as nuclear donor to produce transgenic embryos by NT. There was no significant difference in development rates to the blas-tocyst stage for NT embryos from transgenic and nontransgenic granulosa cells (44.6% and 42.8%, respectively), and transfer of NT embryos derived from transgenic and nontransgenic granulosa cells to recipients resulted in similar pregnancy rates on day 90 (19% and 25%, re-spectively). The development rates to the blastocyst stage of NT embryos were significantly dif-ferent among different types of transgenic donor cells (P<0.05). Blastocyst rates from fetal ovi-duct epithelial cell and granulosa cell (49.1% and 44.6%, respectively) were higher than those from fetal fibroblast (32.7%) and fetal ovary epithelial cell (22.5%). These results suggest that (i) genetic manipulation to donor cells has no negative effect on in vitro and early in vivo develop-mental competence of bovine NT embryos and (ii) granulosa and fetal oviduct epithelial cells can be used to produce transgenic bovine NT embryos more efficiently. In addition, GFP can be used to select transgenic NT embryos as a non-invasive selective marker.展开更多
The rice XA21 immune receptor kinase and the structurally related XA3 receptor confer immunity to Xanthomonas oryzae pv. oryzae （Xoo）, the causal agent of bacterial leaf blight. Here we report the isolation of OsSER...The rice XA21 immune receptor kinase and the structurally related XA3 receptor confer immunity to Xanthomonas oryzae pv. oryzae （Xoo）, the causal agent of bacterial leaf blight. Here we report the isolation of OsSERK2 （rice somatic embryogenesis receptor kinase 2） and demonstrate that OsSERK2 positively regulates immunity mediated by XA21 and XA3 as well as the rice immune receptor FLS2 （OsFLS2）. Rice plants silenced for OsSerk2 display altered morphology and reduced sensitivity to the hormone brassinolide. OsSERK2 interacts with the intracellular domains of each immune receptor in the yeast two-hybrid system in a kinase activity-dependent manner. OsSERK2 undergoes bidi- rectional transphosphorylation with XA21 in vitro and forms a constitutive complex with XA21 in vivo. These results demonstrate an essential role for OsSERK2 in the function of three rice immune receptors and suggest that direct interaction with the rice immune receptors is critical for their function. Taken together, our findings suggest that the mechanism of OsSERK2-meditated regulation of rice XA21, XA3, and FLS2 differs from that of AtSERK3/BAK1-mediated regulation of Arabidopsis FLS2 and EFR.展开更多
Polycomb group genes play crucial roles in the maintenance of the transcriptionally silenced state of genes for proper cell differentiation in animals and plants. While components of the polycomb repressive complex2 ...Polycomb group genes play crucial roles in the maintenance of the transcriptionally silenced state of genes for proper cell differentiation in animals and plants. While components of the polycomb repressive complex2 （PRC2） are evolutionarily conserved and their functions are extensively studied in plants, PRCI differs considerably between animals and plants, and its functions in plants are as yet not well described. Previous studies have identified the Arabidopsis AtRINGla and AtRINGlb as homologues of the animal PRC1 subunit RING1. Here, we show that the Atringla Atringlb double mutant exhibits derepression of embryonic traits during vegetative growth. Accordingly, several key regulatory genes involved in embryogenesis and stem cell activity are ectopically expressed in the mutant. Furthermore, we show that the mutant phenotypes and increased expression of regulatory genes are enhanced by the PRC2 mutant c/f. Finally, we show that three homologues of the animal PRCl-subunit ring-finger protein BMI1, AtBMIIa, AtBMIlb and AtBMIlc, can bind with AtRINGla or AtRINGIb, and in addition, AtBMIlc can bind with LHP1. The Atbmila Atbmilb double mutant shows derepression of embryonic traits similar to that of the Atringla Atringlb double mutant. Interestingly, expression levels of AtBMIla, AtBMIlb and AtBMIlc are elevated in the Atringla Atringlb mutant and those of AtBMIlc, AtRINGla and AtRINGlb are elevated in the Atbmila Atbmilb mu- tant, suggesting a self-regulatory feedback mechanism. Taken together, our results illuminate crucial functions of the PRCl-like ring-finger components in stable repression of embryonic traits and regulatory genes for proper somatic growth.展开更多
Generating B cell-deficient mutant is the first step to produce human antibody repertoires in large animal models. In this study, we applied the clustered regularly interspaced short palindromic repeat （CRISPR）/CRIS...Generating B cell-deficient mutant is the first step to produce human antibody repertoires in large animal models. In this study, we applied the clustered regularly interspaced short palindromic repeat （CRISPR）/CRISPR-associated （Cas） system to target the JH region of the pig IgM heavy chain gene which is crucial for B cell development and differentiation. Transfection of IgM-targeting Cas9 plasmid in primary porcine fetal fibroblasts （PFFs） enabled inducing gene knock out （KO） in up to 53.3% of colonies analyzed, a quarter of which harbored biallelic modification, which was much higher than that of the traditional homologous recombination （HR）. With the aid of somatic cell nuclear transfer （SCNT） technology, three piglets with the biallelic lgM heavy chain gene mutation were produced. The piglets showed no antibody-producing B cells which indicated that the biallelic mutation of the lgM heavy chain gene effectively knocked out the function of the IgM and resulted in a B cell-deficient phenotype. Our study suggests that the CRISPR/Cas9 system combined with SCNT technology is an efficient genome-editing approach in pigs.展开更多
Normal and neoplastic growth of the prostate gland are dependent on androgen receptor （AR） expression and function. Androgenic activation of the AR, in association with its coregulatory factors, is the classical pat...Normal and neoplastic growth of the prostate gland are dependent on androgen receptor （AR） expression and function. Androgenic activation of the AR, in association with its coregulatory factors, is the classical pathway that leads to transcriptional activity of AR target genes. Alternatively, cytoplasmic signaling crosstalk of AR by growth factors, neurotrophic peptides, cytokines or nonandrogenic hormones may have important roles in prostate carcinogenesis and in metastatic or androgen-independent （AI） progression of the disease. In addition, cross-modulation by various nuclear transcription factors acting through basal transcriptional machinery could positively or negatively affect the AR or AR target genes expression and activity. Androgen ablation leads to an initial favorable response in a significant number of patients; however, almost invariably patients relapse with an aggressive form of the disease known as castration-resistant or hormone-refractory prostate cancer （PCa）. Understanding critical molecular events that lead PCa cells to resist androgen-deprivation therapy is essential in developing successful treatments for hormone-refractory disease. In a significant number of hormone-refractory patients, the AR is overexpressed, mutated or genomically amplified. These genetic alterations maintain an active presence for a highly sensitive AR, which is responsive to androgens, antiandrogens or nonandrogenic hormones and collectively confer a selective growth advantage to PCa cells. This review provides a brief synopsis of the AR structure, AR coregulators, posttranslational modifications of AR, duality of AR function in prostate epithelial and stromal cells, AR-dependent signaling, genetic changes in the form of somatic and germline mutations and their known functional significance in PCa cells and tissues.展开更多
This review describes the conceptual and clinical relations between irritable bowel syndrome (IBS), other functional, somatoform, and mental disorders, and points to appropriate future conceptualizations. IBS is consi...This review describes the conceptual and clinical relations between irritable bowel syndrome (IBS), other functional, somatoform, and mental disorders, and points to appropriate future conceptualizations. IBS is considered to be a functional somatic syndrome (FSS) with a considerable symptom overlap with other FSSs like chronic fatigue syndrome or fibromyalgia syndrome. IBS patients show an increased prevalence of psychiatric symptoms and disorders, especially depression and anxiety. IBS is largely congruent with the concepts of somatoform and somatic symptom disorders. Roughly 50% of IBS patients complain of gastrointestinal symptoms only and have no psychiatric comorbidity. IBS concepts, treatment approaches, as well as health care structures should acknowledge its variability and multidimensionality by: (1) awareness of additional extraintestinal and psychobehavioral symptoms in patients with IBS; (2) general and collaborative care rather than specialist and separated care; and (3) implementation of “interface disorders” to abandon the dualistic classification of purely organic or purely mental disorders.展开更多
Protoplasts of Valencia sweet orange ( Citrus sinensis Osb.),irradiated by X_ray with a dose rate of 3.8 krad/min for 45 min, were electrically fused with protoplasts of Murcott tangor ( C. reticulata×C. sin...Protoplasts of Valencia sweet orange ( Citrus sinensis Osb.),irradiated by X_ray with a dose rate of 3.8 krad/min for 45 min, were electrically fused with protoplasts of Murcott tangor ( C. reticulata×C. sinensis ) that were treated with 0.25 mmol/L iodoacetic acid for 15 min. It took nearly 15 months for the fusion_derived calli to develop into embryoids that were only originated in the medium of MT supplemented with 2% glycerol. The shoots were recalcitrant to rooting in the root_induction medium. In vitro grafting was employed to produce whole plants though one self_rooting plant was obtained. Cytological determination of root and shoot tips showed mainly diploid and aneuploid cells, together with few tetraploid cells in some plants. RAPD (random amplified polymorphism DNA) analysis with 10_mer primers demonstrated that bands specific to the fusion parents were detected in the regenerated plants, indicating that interspecific somatic hybrids have been obtained via protoplast asymmetric fusion in Citrus .展开更多
Novel bacterial blight (BB) resistance gene(s) for rice was (were) introduced into a cultivated japonica rice variety Oryza sativa (cv. 8411), via somatic hybridization using the wild rice Oryza meyeriana as the donor...Novel bacterial blight (BB) resistance gene(s) for rice was (were) introduced into a cultivated japonica rice variety Oryza sativa (cv. 8411), via somatic hybridization using the wild rice Oryza meyeriana as the donor of the resistance gene(s). Twenty-nine progenies of somatically hybridized plants were obtained. Seven somatically hybridized plants and their parents were used for AFLP (amplified fragment length polymorphism) analysis using 8 primer pairs. Results confirmed that these plants were somatic hybrids containing the characteristic bands of both parents. The morphology of the regenerated rice showed characters of both O.sativa and O.meyeriana. Two somatic hybrids showed highest BB resistance and the other 8 plants showed moderate resistance. The new germplasms with highest resistance have been used in the rice breeding program for the improvement of bacterial blight resistance.展开更多
Induced pluripotent stem(iPS) cells are derived from somatic cells by ectopic expression of few transcription factors.Like embryonic stem(ES) cells,iPS cells are able to self-renew indefinitely and to differentiate in...Induced pluripotent stem(iPS) cells are derived from somatic cells by ectopic expression of few transcription factors.Like embryonic stem(ES) cells,iPS cells are able to self-renew indefinitely and to differentiate into all types of cells in the body.iPS cells hold great promise for regenerative medicine,because iPS cells circumvent not only immunological rejection but also ethical issues.Since the first report on the derivation of iPS cells in 2006,many laboratories all over the world started research on iPS cells and have made significant progress.This paper reviews recent progress in iPS cell research,including the methods to generate iPS cells,the molecular mechanism of reprogramming in the formation of iPS cells,and the potential applications of iPS cells in cell replacement therapy.Current problems that need to be addressed and the prospects for iPS research are also discussed.展开更多
Background:Treatment guidelines for a variety of cancers have been increasingly used in clinical practice,and have resulted in major improvement in patient outcomes.However,recommended regimens(even first-line treat-m...Background:Treatment guidelines for a variety of cancers have been increasingly used in clinical practice,and have resulted in major improvement in patient outcomes.However,recommended regimens(even first-line treat-ments)are clearly not ideal for every patients.In the present study,we used mini patient-derived xenograft(mini-PDX)and next-generation sequencing to develop personalized treatment in a patient with metastatic duodenal adenocarcinoma.Methods:Resected metachronous metastatic tumor tissues were implanted into SCID mice to determine the sensitivity to a variety of drug regimens.Mutation profiles were assessed using both DNA whole-exome sequencing(DNA-WES)and RNA sequencing.The results of the analyses were used to select optimal treatment for the patient with metastatic duodenal adenocarcinoma.Results:Assessment with mini-PDX models took only 7 days.The results showed high sensitivity to S-1 plus cis-platin,gemcitabine plus cisplatin and everolimus alone.The patient received gemcitabine plus cisplatin initially,but the treatment was terminated due to toxicity.The patient was then switched to treatment with S-1 alone.The overall disease-free survival was 34 months.DNA-WES and RNA sequencing identified KRAS mutation(A146T),TP53(C229Yfs*10)and RICTOR amplification in the metastatic duodenal adenocarcinoma.These findings provided further support to the results of the mini-PDX,and suggest mTOR inhibitors should be used if and when relapse eventually occurs in this patient.Conclusions:Mini-PDX model combined with WES/RNA sequencing can rapidly assess drug sensitivity in cancer patients and reveal key genetic alterations.Further research on this technology for personalized therapy in patients with refractory malignant tumors is warranted.展开更多
Somatic embryogenesis is an important experimental model for studying cellular and molecular mechanisms of early embryo development. Although it has long been known that removal of exogenous auxin from medium results ...Somatic embryogenesis is an important experimental model for studying cellular and molecular mechanisms of early embryo development. Although it has long been known that removal of exogenous auxin from medium results in somatic embryogenesis, the mechanisms underlying the initiation of somatic embryos （SEs） are poorly understood. In this study, we showed that YUCCAs （YUCs） encoding key enzymes in auxin biosynthesis are required for SE induction in Arabidopsis. To identify other factors mediating SE initiation, we performed transcriptional profiling and gene expres- sion analysis. The results showed that genes involved in ethylene biosynthesis and its responses were down-regulated during SE initiation. Ethylene level decreased progressively during SE initiation, whereas treatment with the metabolic precursor of ethylene, 1-aminocyclopropane-l-carboxylic acid （ACC）, or mutation of ETHYLENE-OVERPRODUCTION1 （ET01） disrupted SE induction, suggesting that ethylene plays a role in this process. Suppression of SE induction was also observed in the constitutive triple response 1 （ctrl） mutant, in which ethylene signaling was enhanced. These results indicate that down-regulation of not only ethylene biosynthesis, but also ethylene response is critical for SE induction. We further showed that ethylene disturbed SE initiation through inhibiting YUC expression that might be involved in local auxin biosynthesis and subsequent auxin distribution. Our results provide new information on the mechanisms of hormone-regulated SE initiation.展开更多
Hepatocellular carcinoma(HCC) is one of the leading causes of cancer-related deaths worldwide. Although recent advances in therapeutic approaches for treating HCC have improved the prognoses of patients with HCC, this...Hepatocellular carcinoma(HCC) is one of the leading causes of cancer-related deaths worldwide. Although recent advances in therapeutic approaches for treating HCC have improved the prognoses of patients with HCC, this cancer is still associated with a poor survival rate mainly due to late diagnosis. Therefore, a diagnosis must be made sufficiently early to perform curative and effective treatments. There is a need for a deeper understanding of the molecular mechanisms underlying the initiation and progression of HCC because these mechanisms are critical for making early diagnoses and developing novel therapeutic strategies. Over the past decade, much progress has been made in elucidating the molecular mechanisms underlying hepatocarcinogenesis. In particular, recent advances in next-generation sequencing technologies have revealed numerous genetic alterations, including recurrently mutated genes and dysregulated signaling pathways in HCC. A better understanding of the genetic alterations in HCC could contribute to identifying potential driver mutations and discovering novel therapeutic targets in the future. In this article, we summarize the current advances in research on the genetic alterations, including genomic instability, single-nucleotide polymorphisms, somatic mutations and deregulated signaling pathways, implicated in the initiation and progression of HCC. We also attempt to elucidate some of the genetic mechanisms that contribute to making early diagnoses of and developing molecularly targeted therapies for HCC.展开更多
基金supported by grants from the Major State Basic Research Development Program of China(No.001CB5099)the National High Technology Research and Development Program of China(No.2001AA216121)+3 种基金National Natural Science Foundation of China(No.30040003)Projects of Shanghai Science&Technology Development Foundation(No.99DJ14002,00DJ14033,01DJ14003)the Chinese Academy of Sciences(No.KSCX-2-3-08)Shanghai Municipal Education Commission and by Shanghai Second Medical University
文摘To solve the problem of immune incompatibility, nuclear transplantation has been envisaged as a means to produce cells or tissues for human autologous transplantation. Here we have derived embryonic stem cells by the transfer of human somatic nuclei into rabbit oocytes. The number of blastocysts that developed from the fused nuclear transfer was comparable among nuclear donors at ages of 5, 42, 52 and 60 years, and nuclear transfer (NT) embryonic stem cells (ntES cells) were subsequently derived from each of the four age groups. These results suggest that human somatic nuclei can form ntES cells independent of the age of the donor. The derived ntES cells are human based on karyotype, isogenicity, in situ hybridization, PCR and immunocytochemistry with probes that distinguish between the various species. The ntES cells maintain the capability of sustained growth in an undifferentiated state, and form embryoid bodies, which, on further induction, give rise to cell types such as neuron and muscle, as well as mixed cell populations that express markers representative of all three germ layers. Thus, ntES cells derived from human somatic cells by NT to rabbit eggs retain phenotypes similar to those of conventional human ES cells, including the ability to undergo multilineage cellular differentiation.
基金supported by the GIBH funds provided by the Chinese Academy of Sciences,the City of Guangzhou and Guangdong Province
文摘Lung cancer is one of the leading causes of death with one of the lowest survival rates. However, a subset of lung cancer patients who are of Asian origin and carry somatic mutations in epidermal growth factor receptor or EGFR have responded remarkable well to two tyrosine kinase inhibitors, gefitinib and erlotinib. While EGFR mutation profiles have been reported from Japan, South Korea, and Taiwan, there is no such report from mainland of China where the largest pool of patients reside. In this report, we identified ten somatic mutations from a total of 41 lung cancer patients in China. Among them, seven mutations were found in 17 adenocarcinomas. In contrast to previous reports, eight of these mutations are deletions in exon 19 and two of these deletions are homozygous. These results suggest that a large portion of Chinese adenocarcinoma patients could benefit from gefitinib or erlotinib. This unique mutation profile provides a rationale to develop the next generation of EGFR inhibitors more suitable for the Chinese population.
文摘Transforming growth factor （TGF）-βs and their family members, including bone morphogenetic proteins （BMPs）, Nodal and activins, have been implicated in the development and maintenance of various organs, in which stem cells play important roles. Stem cells are characterized by their ability to self-renew and to generate differentiated cells of a particular tissue, and are classified into embryonic and somatic stem cells. Embryonic stem （ES） cells self-renew indefinitely and contribute to derivatives of all three primary germ layers. In contrast, somatic stem cells, which can be identified in various adult organs, exhibit limited abilities for self-renewal and differentiation in most cases. The multi-lineage differentiation capacity of ES ceils and somatic stem cells has opened possibilities for cell replacement therapies for genetic, malignant and degenerative diseases. In order to utilize stem cells for therapeutic applications, it is essential to understand the extrinsic and intrinsic factors regulating self-renewal and differentiation of stem cells. More recently, induced pluripotent stem （iPS） cells have been generated from mouse and human fibroblasts that resemble ES cells via ectopic expression of four transcription factors, iPS cells may have an advantage in regenerative medicine, since they overcome the immunogenicity and ethical controversy of ES cells. Moreover, recent studies have highlighted the involvement of cancer stem cells during the formation and progression of various types of cancers, including leukemia, glioma, and breast cancer. Here, we illustrate the roles of TGF-β family members in the maintenance and differentiation of ES cells, somatic stem cells, and cancer stem cells.
基金The research is supported by grant from the National Natural Science Foundation of China.
文摘Protoplasts isolated from cotyledon-derived calli of Actinidia chinensis var. chinensis (2n = 2x=58) were fused by the PEG method with cotyledon-callus protoplasts of A. deliciosa var. deliciosa (2n = 6x = 174) or with mesophyll protoplasts of A. kolomikta (2n = 2x = 58), respectively. Randomly amplified polymorphic DNA (RAPD) markers and flow cytometry was used to confirm the occurrence of somatic hybrids. RAPD results with some primers surveyed indicated that one clone (A. chinensis + A. deliciosa) and four clones (A. chinensis + A. kolomikta) had RAPD banding patterns which combined the parental banding profiles. Ploidy levels of the (A. chinensis + A. deliciosa) clone were deduced as octoploid (2n = 8x), and the (A. chinensis + A. kolomikta) clones were tetraploid (2n = 4x), triploid (2n = 3x) or pentaploid (2n = 5x). The clones were confirmed as interspecific somatic hybrids in Actinidia.
文摘Background Molecular targeted drugs is now widely used in non-small cell lung cancer （NSCLC） clinical treatment. Icotinib hydrochloride is a new type of oral epidermal growth factor receptor （EGFR） tyrosine kinase inhibitors （EGFR-TKIs）. In this study, we examined the role of EGFR, K-RAS, B-RAF somatic mutations and EGFR mRNA expression in tumor specimens from advanced NSCLC patients as predicators of the efficacy of icotinib hydrochloride. Methods We analyzed tumor paraffin-embedded specimens, which were obtained from 14 of 40 patients with advanced NSCLC who enrolled in the stage I clinical trial of icotinib hydrochloride. Somatic mutations were evaluated by mutant-enriched liquidchip （MEL） technology, and EGFR mRNA expression was measured by branched DNA liquidchip （MBL） technology. Results In the 14 specimens, seven patients showed EGFR mutations, exon 19 deletion （3/7） and exon 21 point mutation （4/7）; and two patients showed K-RAS mutation. No mutations in EGFR exon 20. or B-RAF were detected. In patients with EGFR mutation, one patient developed progress disease （PD）, three patients had stable disease （SD）, two patients had partial responses （PR） and one patient had a complete response （CR）. In patients with wild-type EGFR, four patients had PD, three patients acquired SD, and none had PR/CR （P=-0.0407）. EGFR mutations were associated with better progress-free survival （PFS） （141 days vs. 61 days） but without a statistically significant difference （P=0.8597）, and median overall survival （OS） （-〉449 days vs. 140 days）. EGFR mRNA expression levels were evaluated （three high, eight moderate, one low, and two that can not be measured due to insufficient tumor tissue） and no statistically significant relationships was observed with response, PFS or OS. Conclusions The EGFR mutation rate was consistent with that reported in the Asian population, so the MEL technology is reliable for measuring EGFR mutation with high throughput and rapidity
文摘Formation of somatic embryos from non-germline cells is unique to higher plants and can be manipulated in a variety of species. Previous studies revealed that overexpression of several Arabidopsis genes, including WUSCHEL （WUS）/PLANT GROWTH ACTIVATOR6 （PGA6）, BABY BOOM, LEAFY COTYLEDON1 （LEC1）, and LEC2, is able to cause vegetative-to-embryonic transition or the formation of somatic embryos. Here, we report that a gain-offunction mutation in the Arabidopsis PGA37 gene, encoding the MYBI18 transcription factor, induced vegetative-toembryonic transition, the formation of somatic embryos from root explants, and an elevated LEC1 expression level. Double mutant analysis showed that WUS was not required for induction of somatic embryos by PGA37/MYB118. In addition, overexpression of MYBll5, a homolog of PGA37/MYB118, caused a pga37-like phenotype. A myb118 myb115 double mutant did not show apparent developmental abnormalities. Collectively, these results suggest that PGA37/ MYB118 and MYB115 promote vegetative-to-embryonic transition, through a signaling pathway independent of WUS.
文摘The evaluation on the callus embryogenesis capacity of 15 genotypes of citrus showed that stress treatments were conducive to somatic embryogenesis and could enhance the recovery of the missed capacity of embryogenesis for some genotypes. Randomly amplified polymorphic DNA (RAPD) and methylation sensitive amplified polymorphism (MSAP) analysis indicated that there existed significant differences in DNA methylation status between the callus capable of producing somatic embryoids and that which missed the embryogenesis capacity of the same genotype Newhall navel orange ( Citrus sinensis Osb. cv. Newhall). The DNA methylation level of the former was lower than that of the latter. However, RAPD profiles did not show any difference between these two kinds of callus.
文摘The present study examined the effects of genetic manipulation to the donor cell and different types of transgenic donor cells on developmental potential of bovine nuclear trans-fer (NT) embryos. Four types of bovine somatic cells, including granulosa cells, fetal fibroblasts, fetal oviduct epithelial cells and fetal ovary epithelial cells, were transfected with a plasmid (pCE-EGFP-Ires-Neo-dNdB) containing the enhanced green fluorescent protein (EGFP) and neomycin-resistant (Neor) genes by electroporation. After 14 days selection with 800 mg/mL G418, transgenic cell lines from each type of somatic cells were obtained. Nontransgenic granulosa cells and all 4 types of transgenic somatic cells were used as nuclear donor to produce transgenic embryos by NT. There was no significant difference in development rates to the blas-tocyst stage for NT embryos from transgenic and nontransgenic granulosa cells (44.6% and 42.8%, respectively), and transfer of NT embryos derived from transgenic and nontransgenic granulosa cells to recipients resulted in similar pregnancy rates on day 90 (19% and 25%, re-spectively). The development rates to the blastocyst stage of NT embryos were significantly dif-ferent among different types of transgenic donor cells (P<0.05). Blastocyst rates from fetal ovi-duct epithelial cell and granulosa cell (49.1% and 44.6%, respectively) were higher than those from fetal fibroblast (32.7%) and fetal ovary epithelial cell (22.5%). These results suggest that (i) genetic manipulation to donor cells has no negative effect on in vitro and early in vivo develop-mental competence of bovine NT embryos and (ii) granulosa and fetal oviduct epithelial cells can be used to produce transgenic bovine NT embryos more efficiently. In addition, GFP can be used to select transgenic NT embryos as a non-invasive selective marker.
文摘The rice XA21 immune receptor kinase and the structurally related XA3 receptor confer immunity to Xanthomonas oryzae pv. oryzae （Xoo）, the causal agent of bacterial leaf blight. Here we report the isolation of OsSERK2 （rice somatic embryogenesis receptor kinase 2） and demonstrate that OsSERK2 positively regulates immunity mediated by XA21 and XA3 as well as the rice immune receptor FLS2 （OsFLS2）. Rice plants silenced for OsSerk2 display altered morphology and reduced sensitivity to the hormone brassinolide. OsSERK2 interacts with the intracellular domains of each immune receptor in the yeast two-hybrid system in a kinase activity-dependent manner. OsSERK2 undergoes bidi- rectional transphosphorylation with XA21 in vitro and forms a constitutive complex with XA21 in vivo. These results demonstrate an essential role for OsSERK2 in the function of three rice immune receptors and suggest that direct interaction with the rice immune receptors is critical for their function. Taken together, our findings suggest that the mechanism of OsSERK2-meditated regulation of rice XA21, XA3, and FLS2 differs from that of AtSERK3/BAK1-mediated regulation of Arabidopsis FLS2 and EFR.
文摘Polycomb group genes play crucial roles in the maintenance of the transcriptionally silenced state of genes for proper cell differentiation in animals and plants. While components of the polycomb repressive complex2 （PRC2） are evolutionarily conserved and their functions are extensively studied in plants, PRCI differs considerably between animals and plants, and its functions in plants are as yet not well described. Previous studies have identified the Arabidopsis AtRINGla and AtRINGlb as homologues of the animal PRC1 subunit RING1. Here, we show that the Atringla Atringlb double mutant exhibits derepression of embryonic traits during vegetative growth. Accordingly, several key regulatory genes involved in embryogenesis and stem cell activity are ectopically expressed in the mutant. Furthermore, we show that the mutant phenotypes and increased expression of regulatory genes are enhanced by the PRC2 mutant c/f. Finally, we show that three homologues of the animal PRCl-subunit ring-finger protein BMI1, AtBMIIa, AtBMIlb and AtBMIlc, can bind with AtRINGla or AtRINGIb, and in addition, AtBMIlc can bind with LHP1. The Atbmila Atbmilb double mutant shows derepression of embryonic traits similar to that of the Atringla Atringlb double mutant. Interestingly, expression levels of AtBMIla, AtBMIlb and AtBMIlc are elevated in the Atringla Atringlb mutant and those of AtBMIlc, AtRINGla and AtRINGlb are elevated in the Atbmila Atbmilb mu- tant, suggesting a self-regulatory feedback mechanism. Taken together, our results illuminate crucial functions of the PRCl-like ring-finger components in stable repression of embryonic traits and regulatory genes for proper somatic growth.
基金supported by a grant from the Jiangsu Key Laboratory of Xenotransplantation (BM2012116)
文摘Generating B cell-deficient mutant is the first step to produce human antibody repertoires in large animal models. In this study, we applied the clustered regularly interspaced short palindromic repeat （CRISPR）/CRISPR-associated （Cas） system to target the JH region of the pig IgM heavy chain gene which is crucial for B cell development and differentiation. Transfection of IgM-targeting Cas9 plasmid in primary porcine fetal fibroblasts （PFFs） enabled inducing gene knock out （KO） in up to 53.3% of colonies analyzed, a quarter of which harbored biallelic modification, which was much higher than that of the traditional homologous recombination （HR）. With the aid of somatic cell nuclear transfer （SCNT） technology, three piglets with the biallelic lgM heavy chain gene mutation were produced. The piglets showed no antibody-producing B cells which indicated that the biallelic mutation of the lgM heavy chain gene effectively knocked out the function of the IgM and resulted in a B cell-deficient phenotype. Our study suggests that the CRISPR/Cas9 system combined with SCNT technology is an efficient genome-editing approach in pigs.
文摘Normal and neoplastic growth of the prostate gland are dependent on androgen receptor （AR） expression and function. Androgenic activation of the AR, in association with its coregulatory factors, is the classical pathway that leads to transcriptional activity of AR target genes. Alternatively, cytoplasmic signaling crosstalk of AR by growth factors, neurotrophic peptides, cytokines or nonandrogenic hormones may have important roles in prostate carcinogenesis and in metastatic or androgen-independent （AI） progression of the disease. In addition, cross-modulation by various nuclear transcription factors acting through basal transcriptional machinery could positively or negatively affect the AR or AR target genes expression and activity. Androgen ablation leads to an initial favorable response in a significant number of patients; however, almost invariably patients relapse with an aggressive form of the disease known as castration-resistant or hormone-refractory prostate cancer （PCa）. Understanding critical molecular events that lead PCa cells to resist androgen-deprivation therapy is essential in developing successful treatments for hormone-refractory disease. In a significant number of hormone-refractory patients, the AR is overexpressed, mutated or genomically amplified. These genetic alterations maintain an active presence for a highly sensitive AR, which is responsive to androgens, antiandrogens or nonandrogenic hormones and collectively confer a selective growth advantage to PCa cells. This review provides a brief synopsis of the AR structure, AR coregulators, posttranslational modifications of AR, duality of AR function in prostate epithelial and stromal cells, AR-dependent signaling, genetic changes in the form of somatic and germline mutations and their known functional significance in PCa cells and tissues.
文摘This review describes the conceptual and clinical relations between irritable bowel syndrome (IBS), other functional, somatoform, and mental disorders, and points to appropriate future conceptualizations. IBS is considered to be a functional somatic syndrome (FSS) with a considerable symptom overlap with other FSSs like chronic fatigue syndrome or fibromyalgia syndrome. IBS patients show an increased prevalence of psychiatric symptoms and disorders, especially depression and anxiety. IBS is largely congruent with the concepts of somatoform and somatic symptom disorders. Roughly 50% of IBS patients complain of gastrointestinal symptoms only and have no psychiatric comorbidity. IBS concepts, treatment approaches, as well as health care structures should acknowledge its variability and multidimensionality by: (1) awareness of additional extraintestinal and psychobehavioral symptoms in patients with IBS; (2) general and collaborative care rather than specialist and separated care; and (3) implementation of “interface disorders” to abandon the dualistic classification of purely organic or purely mental disorders.
基金TheNational Natural Science Foundation of China(3983026039625017)the International Foundation for Science(D/3001_1)
文摘Protoplasts of Valencia sweet orange ( Citrus sinensis Osb.),irradiated by X_ray with a dose rate of 3.8 krad/min for 45 min, were electrically fused with protoplasts of Murcott tangor ( C. reticulata×C. sinensis ) that were treated with 0.25 mmol/L iodoacetic acid for 15 min. It took nearly 15 months for the fusion_derived calli to develop into embryoids that were only originated in the medium of MT supplemented with 2% glycerol. The shoots were recalcitrant to rooting in the root_induction medium. In vitro grafting was employed to produce whole plants though one self_rooting plant was obtained. Cytological determination of root and shoot tips showed mainly diploid and aneuploid cells, together with few tetraploid cells in some plants. RAPD (random amplified polymorphism DNA) analysis with 10_mer primers demonstrated that bands specific to the fusion parents were detected in the regenerated plants, indicating that interspecific somatic hybrids have been obtained via protoplast asymmetric fusion in Citrus .
文摘Novel bacterial blight (BB) resistance gene(s) for rice was (were) introduced into a cultivated japonica rice variety Oryza sativa (cv. 8411), via somatic hybridization using the wild rice Oryza meyeriana as the donor of the resistance gene(s). Twenty-nine progenies of somatically hybridized plants were obtained. Seven somatically hybridized plants and their parents were used for AFLP (amplified fragment length polymorphism) analysis using 8 primer pairs. Results confirmed that these plants were somatic hybrids containing the characteristic bands of both parents. The morphology of the regenerated rice showed characters of both O.sativa and O.meyeriana. Two somatic hybrids showed highest BB resistance and the other 8 plants showed moderate resistance. The new germplasms with highest resistance have been used in the rice breeding program for the improvement of bacterial blight resistance.
基金Supported by the National Key Basic Research and Development Program of China (Grant No. 2009CB941000)the Ministry of Science and Technology of China, and the transgenic program (Grant No. 2009ZX08006-010B)+1 种基金the National Natural Science Foundation of China (Grant No. 90919009)the Ministry of Agriculture of China (Grant No. 2009ZX08006-011B)
文摘Induced pluripotent stem(iPS) cells are derived from somatic cells by ectopic expression of few transcription factors.Like embryonic stem(ES) cells,iPS cells are able to self-renew indefinitely and to differentiate into all types of cells in the body.iPS cells hold great promise for regenerative medicine,because iPS cells circumvent not only immunological rejection but also ethical issues.Since the first report on the derivation of iPS cells in 2006,many laboratories all over the world started research on iPS cells and have made significant progress.This paper reviews recent progress in iPS cell research,including the methods to generate iPS cells,the molecular mechanism of reprogramming in the formation of iPS cells,and the potential applications of iPS cells in cell replacement therapy.Current problems that need to be addressed and the prospects for iPS research are also discussed.
基金the National Natural Science Foundation of China(No.81472346)the National Key Research and Development Program of China(No.2017ZX10203205).
文摘Background:Treatment guidelines for a variety of cancers have been increasingly used in clinical practice,and have resulted in major improvement in patient outcomes.However,recommended regimens(even first-line treat-ments)are clearly not ideal for every patients.In the present study,we used mini patient-derived xenograft(mini-PDX)and next-generation sequencing to develop personalized treatment in a patient with metastatic duodenal adenocarcinoma.Methods:Resected metachronous metastatic tumor tissues were implanted into SCID mice to determine the sensitivity to a variety of drug regimens.Mutation profiles were assessed using both DNA whole-exome sequencing(DNA-WES)and RNA sequencing.The results of the analyses were used to select optimal treatment for the patient with metastatic duodenal adenocarcinoma.Results:Assessment with mini-PDX models took only 7 days.The results showed high sensitivity to S-1 plus cis-platin,gemcitabine plus cisplatin and everolimus alone.The patient received gemcitabine plus cisplatin initially,but the treatment was terminated due to toxicity.The patient was then switched to treatment with S-1 alone.The overall disease-free survival was 34 months.DNA-WES and RNA sequencing identified KRAS mutation(A146T),TP53(C229Yfs*10)and RICTOR amplification in the metastatic duodenal adenocarcinoma.These findings provided further support to the results of the mini-PDX,and suggest mTOR inhibitors should be used if and when relapse eventually occurs in this patient.Conclusions:Mini-PDX model combined with WES/RNA sequencing can rapidly assess drug sensitivity in cancer patients and reveal key genetic alterations.Further research on this technology for personalized therapy in patients with refractory malignant tumors is warranted.
文摘Somatic embryogenesis is an important experimental model for studying cellular and molecular mechanisms of early embryo development. Although it has long been known that removal of exogenous auxin from medium results in somatic embryogenesis, the mechanisms underlying the initiation of somatic embryos （SEs） are poorly understood. In this study, we showed that YUCCAs （YUCs） encoding key enzymes in auxin biosynthesis are required for SE induction in Arabidopsis. To identify other factors mediating SE initiation, we performed transcriptional profiling and gene expres- sion analysis. The results showed that genes involved in ethylene biosynthesis and its responses were down-regulated during SE initiation. Ethylene level decreased progressively during SE initiation, whereas treatment with the metabolic precursor of ethylene, 1-aminocyclopropane-l-carboxylic acid （ACC）, or mutation of ETHYLENE-OVERPRODUCTION1 （ET01） disrupted SE induction, suggesting that ethylene plays a role in this process. Suppression of SE induction was also observed in the constitutive triple response 1 （ctrl） mutant, in which ethylene signaling was enhanced. These results indicate that down-regulation of not only ethylene biosynthesis, but also ethylene response is critical for SE induction. We further showed that ethylene disturbed SE initiation through inhibiting YUC expression that might be involved in local auxin biosynthesis and subsequent auxin distribution. Our results provide new information on the mechanisms of hormone-regulated SE initiation.
文摘Hepatocellular carcinoma(HCC) is one of the leading causes of cancer-related deaths worldwide. Although recent advances in therapeutic approaches for treating HCC have improved the prognoses of patients with HCC, this cancer is still associated with a poor survival rate mainly due to late diagnosis. Therefore, a diagnosis must be made sufficiently early to perform curative and effective treatments. There is a need for a deeper understanding of the molecular mechanisms underlying the initiation and progression of HCC because these mechanisms are critical for making early diagnoses and developing novel therapeutic strategies. Over the past decade, much progress has been made in elucidating the molecular mechanisms underlying hepatocarcinogenesis. In particular, recent advances in next-generation sequencing technologies have revealed numerous genetic alterations, including recurrently mutated genes and dysregulated signaling pathways in HCC. A better understanding of the genetic alterations in HCC could contribute to identifying potential driver mutations and discovering novel therapeutic targets in the future. In this article, we summarize the current advances in research on the genetic alterations, including genomic instability, single-nucleotide polymorphisms, somatic mutations and deregulated signaling pathways, implicated in the initiation and progression of HCC. We also attempt to elucidate some of the genetic mechanisms that contribute to making early diagnoses of and developing molecularly targeted therapies for HCC.
