Many long noncoding RNAs(lncRNAs)have been identified through siRNA-based screening as essential regulators of embryonic stem cell(ESC)pluripotency.However,the biological and molecular functions of most lncRNAs remain...Many long noncoding RNAs(lncRNAs)have been identified through siRNA-based screening as essential regulators of embryonic stem cell(ESC)pluripotency.However,the biological and molecular functions of most lncRNAs remain unclear.Here,we employed CRISPR/Cas9-mediated knockout technology to explore the functions of 8 lncRNAs previously reported to promote pluripotency in mouse ESCs.Unexpectedly,all of these lncRNAs were dispensable for pluripotency maintenance and proliferation in mouse ESCs when disrupted individually or in combination.Single-cell transcriptomic analysis also showed that the knockout of these lncRNAs has a minimal impact on pluripotency gene expression and cell identity.We further showed that several small hairpin RNAs(shRNAs)previously used to knock down lncRNAs caused the downregulation of pluripotency genes in the corresponding lncRNA-knockout ESCs,indicating that off-target effects likely responsible for the pluripotency defects caused by these shRNAs.Interestingly,linc1343-knockout and linc1343-knockdown ESCs failed to form cystic structures and exhibited high expression of pluripotency genes during embryoid body(EB)differentiation.By reintroducing RNA products generated from the linc1343 locus,we found that two snoRNAs,Snora73a and Snora73b,but not lncRNAs,could rescue pluripotency silencing defects during EB differentiation of linc1343 knockout ESCs.Our results suggest that the 8 previously annotated pluripotency-regulating lncRNAs have no overt functions in conventional ESC culture;however,we identified snoRNA products derived from an annotated lncRNA locus as essential regulators for silencing pluripotency genes.展开更多
Thousands of long non-coding RNAs(lncRNAs)have been discovered in human genomes by gene chip,next-generation sequencing,and/or other methods in recent years,which represent a significant subset of the universal genes ...Thousands of long non-coding RNAs(lncRNAs)have been discovered in human genomes by gene chip,next-generation sequencing,and/or other methods in recent years,which represent a significant subset of the universal genes involved in a wide range of biological functions.An abnormal expression of lncRNAs is associated with the growth,invasion,and metastasis of various types of human cancers,including hepatocellular carcinoma(HCC),which is an aggressive,highly malignant,and invasive tumor,and a poor prognosis in China.With a more in-depth understanding of lncRNA research for HCC and the emergence of new moleculartargeted therapies,the diagnosis,treatment,and prognosis of HCC will be considerably improved.Therefore,this review is expected to provide recommendations and directions for future lncRNA research for HCC.展开更多
Deletion of chromosome 6q is frequent in breast cancer, and the deletion often involves a region in 6q 14-q 16. At present, however, the underlying tumor suppressor gene has not been established. Based on a recent stu...Deletion of chromosome 6q is frequent in breast cancer, and the deletion often involves a region in 6q 14-q 16. At present, however, the underlying tumor suppressor gene has not been established. Based on a recent study identifying snoRNA U50 as a candidate for the 6q14-16 tumor suppressor gene in prostate cancer, we investigated whether U50 is also involved in breast cancer. PCR-based approaches showed that U50 underwent frequent genomic deletion and transcriptional downregulation in cell lines derived from breast cancer. Mutation screening identified the same 2-bp deletion of U50 as in prostate cancer in both cell lines and primary tumors from breast cancer, and the deletion was both somatic and in germline. Genotyping of a cohort of breast cancer cases and controls for the mutation demonstrated that, while homozygous genotype of the mutation was rare, its heterozygous genotype occurred more frequently in women with breast cancer. Functionally, re-expression of U50 resulted in the inhibition of colony formation in breast cancer cell lines. These results suggest that noncoding snoRNA U50 plays a role in the development and/or progression of breast cancer.展开更多
核仁小分子RNA(snoRNA)是一类广泛分布于真核生物细胞核仁的小分子非编码RNA,具有保守的结构元件,并以此划分为3大类:box C/D snoRNA、box H/ACA snoRNA和MRP RNA。其中box C/D和box H/ACA是已知snoRNA的主要类型,以碱基配对的方式分别...核仁小分子RNA(snoRNA)是一类广泛分布于真核生物细胞核仁的小分子非编码RNA,具有保守的结构元件,并以此划分为3大类:box C/D snoRNA、box H/ACA snoRNA和MRP RNA。其中box C/D和box H/ACA是已知snoRNA的主要类型,以碱基配对的方式分别指导着核糖体RNA的甲基化和假尿嘧啶化修饰。研究发现,s n o R N A除了在核糖体R N A的生物合成中发挥作用之外,还能够指导snRNA、tR N A和m R N A的转录后修饰。此外,还有相当数量的snoRNA功能不明,被称为孤儿snoRNA(orphan snoRNA)。在哺乳动物的孤儿snoRNA中,印迹snoRNA(imprinted snoRNA)是最为特殊的一群,由基因组印迹区编码,具有明显的组织表达特异性。原核生物古细菌中类snoRNA的鉴定表明这些非编码RNA家族成员的古老起源;而哺乳动物中大量的snoRNA反转座子的存在更为人们探索snoRNA在基因组中扩增和功能进化提供了新的思路。展开更多
Small nucleolar RNA （snoRNA） dysfunctions have been associated with cancer development. SNORD126 is an orphan C/D box snoRNA that is encoded within introns 5-6 of its host gene, cyclin Bl-interacting protein 1 （CCN...Small nucleolar RNA （snoRNA） dysfunctions have been associated with cancer development. SNORD126 is an orphan C/D box snoRNA that is encoded within introns 5-6 of its host gene, cyclin Bl-interacting protein 1 （CCNBIIP1）. The cancer-associated molecular mechanisms triggered by SNORD126 are not fully understood. Here, we demonstrate that SNORD126 is highly expressed in hepatoceUular carcinoma （HCC） and colorectal cancer （CRC） patient samples. SNORD126 increased Huh-7 and SW480 cell growth and tumorigenicity in nude mice. Knockdown of SNORD126 inhibited HepG2 and LS174T cell growth. We veri- fied that SNORD126 was not processed into small RNAs with miRNA activity. Moreover, SNORD126 did not show a significant expression correlation with CCNBIlP1 in HCC samples or regulate CCNBIlP1 expression. Our gene expression profile analysis indicated that SNORD126-upregulated genes frequently mapped to the PI3K-AKT pathway. SNORD126 overexpression increased the levels of phosphorylated AKT, GSK-3p, and p7056K and elevated fibroblast growth factor receptor 2 （FGFR2） expression. siRNA-mediated knockdown or AZD4547-mediated inactivation of FGFR2 in SNORD126-overexpressing Huh-7 cells inhibited AKT phosphorylation and suppressed cell growth. These findings indicate an oncogenic role for SNORD126 in cancer and suggest its potential as a therapeutic target.展开更多
基金supported by the National Natural Science Foundation of China(31900447,32070792 and 91940302)the Startup Foundation of Dermatology Hospital,Southern Medical University(2019RC06)。
文摘Many long noncoding RNAs(lncRNAs)have been identified through siRNA-based screening as essential regulators of embryonic stem cell(ESC)pluripotency.However,the biological and molecular functions of most lncRNAs remain unclear.Here,we employed CRISPR/Cas9-mediated knockout technology to explore the functions of 8 lncRNAs previously reported to promote pluripotency in mouse ESCs.Unexpectedly,all of these lncRNAs were dispensable for pluripotency maintenance and proliferation in mouse ESCs when disrupted individually or in combination.Single-cell transcriptomic analysis also showed that the knockout of these lncRNAs has a minimal impact on pluripotency gene expression and cell identity.We further showed that several small hairpin RNAs(shRNAs)previously used to knock down lncRNAs caused the downregulation of pluripotency genes in the corresponding lncRNA-knockout ESCs,indicating that off-target effects likely responsible for the pluripotency defects caused by these shRNAs.Interestingly,linc1343-knockout and linc1343-knockdown ESCs failed to form cystic structures and exhibited high expression of pluripotency genes during embryoid body(EB)differentiation.By reintroducing RNA products generated from the linc1343 locus,we found that two snoRNAs,Snora73a and Snora73b,but not lncRNAs,could rescue pluripotency silencing defects during EB differentiation of linc1343 knockout ESCs.Our results suggest that the 8 previously annotated pluripotency-regulating lncRNAs have no overt functions in conventional ESC culture;however,we identified snoRNA products derived from an annotated lncRNA locus as essential regulators for silencing pluripotency genes.
基金This study was supported by the National Natural Science Foundation of China(grant number 81871653),the Program for Innovation Team of Higher Education in Chongqing(grant number CXTDX201601015)and the Natural Science Foundation of Chongqing(grant number cstc2016jcyjA0269).
文摘Thousands of long non-coding RNAs(lncRNAs)have been discovered in human genomes by gene chip,next-generation sequencing,and/or other methods in recent years,which represent a significant subset of the universal genes involved in a wide range of biological functions.An abnormal expression of lncRNAs is associated with the growth,invasion,and metastasis of various types of human cancers,including hepatocellular carcinoma(HCC),which is an aggressive,highly malignant,and invasive tumor,and a poor prognosis in China.With a more in-depth understanding of lncRNA research for HCC and the emergence of new moleculartargeted therapies,the diagnosis,treatment,and prognosis of HCC will be considerably improved.Therefore,this review is expected to provide recommendations and directions for future lncRNA research for HCC.
基金This work was supported by the National Natural Science Foundation of China(Grant No.30230200)the Fund for Distinguished Young Scholars from the Ministry of Education of China.
基金supported in part by a grant from the National Cancer Institute,USA (No. R01CA085560)
文摘Deletion of chromosome 6q is frequent in breast cancer, and the deletion often involves a region in 6q 14-q 16. At present, however, the underlying tumor suppressor gene has not been established. Based on a recent study identifying snoRNA U50 as a candidate for the 6q14-16 tumor suppressor gene in prostate cancer, we investigated whether U50 is also involved in breast cancer. PCR-based approaches showed that U50 underwent frequent genomic deletion and transcriptional downregulation in cell lines derived from breast cancer. Mutation screening identified the same 2-bp deletion of U50 as in prostate cancer in both cell lines and primary tumors from breast cancer, and the deletion was both somatic and in germline. Genotyping of a cohort of breast cancer cases and controls for the mutation demonstrated that, while homozygous genotype of the mutation was rare, its heterozygous genotype occurred more frequently in women with breast cancer. Functionally, re-expression of U50 resulted in the inhibition of colony formation in breast cancer cell lines. These results suggest that noncoding snoRNA U50 plays a role in the development and/or progression of breast cancer.
文摘核仁小分子RNA(snoRNA)是一类广泛分布于真核生物细胞核仁的小分子非编码RNA,具有保守的结构元件,并以此划分为3大类:box C/D snoRNA、box H/ACA snoRNA和MRP RNA。其中box C/D和box H/ACA是已知snoRNA的主要类型,以碱基配对的方式分别指导着核糖体RNA的甲基化和假尿嘧啶化修饰。研究发现,s n o R N A除了在核糖体R N A的生物合成中发挥作用之外,还能够指导snRNA、tR N A和m R N A的转录后修饰。此外,还有相当数量的snoRNA功能不明,被称为孤儿snoRNA(orphan snoRNA)。在哺乳动物的孤儿snoRNA中,印迹snoRNA(imprinted snoRNA)是最为特殊的一群,由基因组印迹区编码,具有明显的组织表达特异性。原核生物古细菌中类snoRNA的鉴定表明这些非编码RNA家族成员的古老起源;而哺乳动物中大量的snoRNA反转座子的存在更为人们探索snoRNA在基因组中扩增和功能进化提供了新的思路。
文摘Small nucleolar RNA （snoRNA） dysfunctions have been associated with cancer development. SNORD126 is an orphan C/D box snoRNA that is encoded within introns 5-6 of its host gene, cyclin Bl-interacting protein 1 （CCNBIIP1）. The cancer-associated molecular mechanisms triggered by SNORD126 are not fully understood. Here, we demonstrate that SNORD126 is highly expressed in hepatoceUular carcinoma （HCC） and colorectal cancer （CRC） patient samples. SNORD126 increased Huh-7 and SW480 cell growth and tumorigenicity in nude mice. Knockdown of SNORD126 inhibited HepG2 and LS174T cell growth. We veri- fied that SNORD126 was not processed into small RNAs with miRNA activity. Moreover, SNORD126 did not show a significant expression correlation with CCNBIlP1 in HCC samples or regulate CCNBIlP1 expression. Our gene expression profile analysis indicated that SNORD126-upregulated genes frequently mapped to the PI3K-AKT pathway. SNORD126 overexpression increased the levels of phosphorylated AKT, GSK-3p, and p7056K and elevated fibroblast growth factor receptor 2 （FGFR2） expression. siRNA-mediated knockdown or AZD4547-mediated inactivation of FGFR2 in SNORD126-overexpressing Huh-7 cells inhibited AKT phosphorylation and suppressed cell growth. These findings indicate an oncogenic role for SNORD126 in cancer and suggest its potential as a therapeutic target.
