Ischemic colitis is the most common form of ischemic injury of the gastrointestinal tract and can present either as an occlusive or a non-occlusive form. It accounts for 1 in 1000 hospitalizations but its incidence is...Ischemic colitis is the most common form of ischemic injury of the gastrointestinal tract and can present either as an occlusive or a non-occlusive form. It accounts for 1 in 1000 hospitalizations but its incidence is underesti- mated because it often has a mild and transient nature. The etiology of ischemic colitis is multifactorial and the clinical presentation variable. The diagnosis is based on a combination of clinical suspicion, radiographic, endo- scopic and histological findings. Therapy and outcome depends on the severity of the disease. Most cases of the non-gangrenous form are transient and resolve spontaneously without complications. On the other hand, high morbidity and mortality and urgent operative intervention are the hallmarks of gangrenous ischemic colitis.展开更多
The multiple beneficial effects on human health of the short-chain fatty acid butyrate,synthesized from nonabsorbed carbohydrate by colonic microbiota,are well documented.At the intestinal level,butyrate plays a regul...The multiple beneficial effects on human health of the short-chain fatty acid butyrate,synthesized from nonabsorbed carbohydrate by colonic microbiota,are well documented.At the intestinal level,butyrate plays a regulatory role on the transepithelial fluid transport,ameliorates mucosal inflammation and oxidative status,reinforces the epithelial defense barrier,and modulates visceral sensitivity and intestinal motility.In addition,a growing number of studies have stressed the role of butyrate in the prevention and inhibition of colorectal cancer.At the extraintestinal level,butyrate exerts potentially useful effects on many conditions,including hemoglobinopathies,genetic metabolic diseases,hypercholesterolemia,insulin resistance,and ischemic stroke.The mechanisms of action of butyrate are different;many of these are related to its potent regulatory effects on gene expression.These data suggest a wide spectrum of positive effects exerted by butyrate,with a high potential for a therapeutic use in human medicine.展开更多
AIM:To investigate the roles and mechanism of signal transducer and activator of transcription 3 (STAT3) in invasion of human colon cancer cells by RNA interference. METHODS: Small interfering RNA (siRNA) targeting Si...AIM:To investigate the roles and mechanism of signal transducer and activator of transcription 3 (STAT3) in invasion of human colon cancer cells by RNA interference. METHODS: Small interfering RNA (siRNA) targeting Signal transducer and activator of transcription 3 (STAT3) was transfected into HT29 colon cancer cells. STAT3 protein level and DNA-binding activity of STAT3 was evaluated by western blotting and electrophoretic mobility shift assay (EMSA), respectively. We studied the anchorage-independent growth using colony formation in soft agar, and invasion using the boyden chamber model, anoikis using DNA fragmentation assay and terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling (TUNEL), respectively. Western blot assay was used to observe the protein expression of Bcl-xL and survivin in colon cancer HT29 cells. RESULTS: RNA interference (RNAi) mediated by siRNA leads to suppression of STAT3 expression in colon cancer cell lines. Suppression of STAT3 expression by siRNA could inhibit anchorage-independent growth, and invasion ability, and induces anoikis in the colon cancer cell line HT29. It has been shown that knockdown of STAT3 expression by siRNA results in a reduction in expression of Bcl-xL and survivin in HT29 cells. CONCLUSION: These results suggest that STAT3 siRNA can inhibit the invasion ability of colon cancer cells through inducing anoikis, which antiapoptotic genes survivin and Bcl-xL contribute to regulation of anoikis.These studies indicate STAT3 siRNA could be a useful therapeutic tool for the treatment of colon cancer.展开更多
The human intestinal microbiome plays a major role in human health and diseases, including colorectal cancer. Colorectal carcinogenesis represents a heterogeneous process with a differing set of somatic molecular alte...The human intestinal microbiome plays a major role in human health and diseases, including colorectal cancer. Colorectal carcinogenesis represents a heterogeneous process with a differing set of somatic molecular alterations, influenced by diet, environmental and microbial exposures, and host immunity. Fusobacterium species are part of the human oral and intestinal microbiota. Metagenomic analyses have shown an enrichment of Fusobacterium nucleatum(F. nucleatum) in colorectal carcinoma tissue. Using 511 colorectal carcinomas from Japanese patients, we assessed the presence of F. nucleatum. Our results showed that the frequency of F. nucleatum positivity in the Japanese colorectal cancer was 8.6%(44/511), which was lower than that in United States cohort studies(13%). Similar to the United States studies, F. nucleatum positivityin Japanese colorectal cancers was significantly associated with microsatellite instability(MSI)-high status. Regarding the immune response in colorectal cancer, high levels of infiltrating T-cell subsets(i.e., CD3+, CD8+, CD45RO+, and FOXP3+ cells) have been associated with better patient prognosis. There is also evidence to indicate that molecular features of colorectal cancer, especially MSI, influence T-cell-mediated adaptive immunity. Concerning the association between the gut microbiome and immunity, F. nucleatum has been shown to expand myeloid-derived immune cells, which inhibit T-cell proliferation and induce T-cell apoptosis in colorectal cancer. This finding indicates that F. nucleatum possesses immunosuppressive activities by inhibiting human T-cell responses. Certain micro RNAs are induced during the macrophage inflammatory response and have the ability to regulate host-cell responses to pathogens. Micro RNA-21 increases the levels of IL-10 and prostaglandin E2, which suppress antitumor T-cell-mediated adaptive immunity through the inhibition of the antigen-presenting capacities of dendritic cells and T-cell proliferation in colorectal cancer cells. Thus, emerging evidence may 展开更多
The aim of this study is to assess the effects of DNA methylation and historic acetylation, alone or in combination, on the expression of several tumor-associated genes and cell cycle progression in two established hu...The aim of this study is to assess the effects of DNA methylation and historic acetylation, alone or in combination, on the expression of several tumor-associated genes and cell cycle progression in two established human colon cancer cell lines: Colo-320 and SW1116. Treatments with 5-aza-2'-deoxycytidine (5-aza-dC) and trichostatin A, alone or in combination, were applied respectively. The methylation status of the CDKN2A promoter was determined by methyla-tion-specific PCR, and the acetylated status of the histones associated with the p21WAF1 and CDKN2A genes was examined by chromatin immunoprecipitation. The expression of the CDKN2A, p21WAF1, p53, p73, APC, c-myc, c-Ki-ras and survivin genes was detected by real-time RT-PCR and RT-PCR. The cell cycle profile was established by flow cytometry. We found that along with the demethylation of the CDKN2A gene promoter in both cell lines induced by 5-aza-dC alone or in combination with TSA, the expression of both CDKN2A and APC genes increased. The treatment of TSA or sodium butyrate up-regulated the transcription of p21WAF1 significantly by inducing the acetylation of histones H4 and H3, but failed to alter the acetylation level of CDKN2A-associated histones. No changes in transcription of p53, p73, c-myc, c-Ki-ras and survivin genes were observed. In addition, TSA or sodium butyrate was shown to arrest cells at the G1 phase. However, 5-aza-dC was not able to affect the cell cycle progression. In conclusion, regulation by epigenetic modification of the transcription of tumor-associated genes and the cell cycle progression in both human colon cancer cell lines Colo-320 and SW1116 is gene-specific.展开更多
Bile acids are implicated as etiologic agents in cancer of the gastrointestinal (GI) tract, including cancer of the esophagus, stomach, small intestine, liver, biliary tract, pancreas and colon/rectum. Deleterious eff...Bile acids are implicated as etiologic agents in cancer of the gastrointestinal (GI) tract, including cancer of the esophagus, stomach, small intestine, liver, biliary tract, pancreas and colon/rectum. Deleterious effects of bile acid exposure, likely related to carcinogenesis, include: induction of reactive oxygen and reactive nitrogen species; induction of DNA damage; stimulation of mutation; induction of apoptosis in the short term, and selection for apoptosis resistance in the long term. These deleterious effects have, so far, been reported most consistently in relation to esophageal and colorectal cancer, but also to some extent in relation to cancer of other organs. In addition, evidence is reviewed for an association of increased bile acid exposure with cancer risk in human populations, in specific human genetic conditions, and in animal experiments. A model for the role of bile acids in GI carcinogenesis is presented from a Darwinian perspective that offers an explanation for how the observed effects of bile acids on cells contribute to cancer development.展开更多
The colon is derived from the embryological midgut and hindgut separately,with the right colon and left colon having different features with regards to both anatomical and physiological characteristics.Cancers located...The colon is derived from the embryological midgut and hindgut separately,with the right colon and left colon having different features with regards to both anatomical and physiological characteristics.Cancers located in the right and left colon are referred to as right colon cancer(RCC) and left colon cancer(LCC),respectively,based on their apparent anatomical positions.Increasing evidence supports the notion that not only are there differences in treatment strategies when dealing with RCC and LCC,but molecular features also vary between them,not to mention the distinguishing clinical manifestations.Disease-free survival after radical surgery of both RCC and LCC are similar.In the treatment of RCC,the benefit gained from adjuvant FOLFIRI chemotherapy is superior,or at least similar,to LCC,but inferior to LCC if FOLFOX regimen is applied.On the other hand,metastatic LCC exhibits longer survival than that of RCC in a palliative chemotherapy setting.For KRAS wild-type cancers,LCC benefits more from cetuximab treatment than RCC.Moreover,advanced LCC shows a higher sensitivity to bevacizumab treatment in comparison with advanced RCC.Significant varieties exist at the molecular level between RCC and LCC,which may serve as the cause of all apparent differences.With respect to carcinogenesis mechanisms,RCC is associated with known gene types,such as MMR,KRAS,BRAF,and mi RNA-31,while LCC is associated with CIN,p53,NRAS,mi RNA-146 a,mi RNA-147 b,and mi RNA-1288.Regarding protein expression,RCC is related to GNAS,NQO1,telomerase activity,P-PDH,and annexin A10,while LCC is related to Topo I,TS,and EGFR.In addition,separated pathways dominate progressionto relapse in RCC and LCC.Therefore,RCC and LCC should be regarded as two heterogeneous entities,with this heterogeneity being used to stratify patients in order for them to have the optimal,current,and novel therapeutic strategies in clinical practice.Additional research is needed to uncover further differences between RCC and LCC.展开更多
AIM: To observe the gene silencing mediated by the specific shRNA targeted against β-catenin and its effect on cell proliferation and cycle distribution in the human colon cancer cell line Colo205. METHODS: Two shRNA...AIM: To observe the gene silencing mediated by the specific shRNA targeted against β-catenin and its effect on cell proliferation and cycle distribution in the human colon cancer cell line Colo205. METHODS: Two shRNA plasmid vectors against β-catenin were constructed and transfected into Colo205 cells with LipofectamineTM2000. The down-regulations of β-catenin, c-myc and cyclinD1 expressions were detected by RT-PCR and western blot analysis. The cell proliferation inhibitions were determined by MTT assay and soft agar colony formation assay. The effect of these two β-catenin shRNAs on cell cycle distribution and apoptosis was examined by flow cytometry. RESULTS: These two shRNA vectors targeted against β-catenin efficiently suppressed the expression of β-catenin and its down stream genes, c-myc and cyclinD1. The expression inhibition rates were around 40%-50% either at the mRNA or at the protein level. The shRNA-mediated gene silencing of β-catenin resulted in significant inhibition of cell growth both on the culture plates and in the soft agar. Moreover, the cancer cells showed significant G0/G1 arrest and increased apoptosis at 72 h post transfection due to gene silencing. CONCLUSION: These specific shRNAs targeted against β-catenin could have a gene silencing effect and block the WNT signaling pathway. They could inhibit cell growth, increase apoptosis, and induce cell cycle arrest in Colo205 cells. ShRNA interference against β-catenin is of potential value in gene therapy of colon cancer.展开更多
AIM: Laparoscopic surgery, especially laparoscopic rectal surgery, for colorectal cancer has been developed considerably. However, due to relatively complicated anatomy and high requirements for surgery techniques, la...AIM: Laparoscopic surgery, especially laparoscopic rectal surgery, for colorectal cancer has been developed considerably. However, due to relatively complicated anatomy and high requirements for surgery techniques, laparoscopic right colectomy develops relatively slowly. This study was designed to compare the outcomes of laparoscopic right hemicolectomy (LRH) with open right hemicolectomy (ORH) in the treatment of colon carcinoma. METHODS: Between September 2000 and February 2003, 30 patients with colon cancer who underwent LRH were compared with 34 controls treated by ORH in the same period. All patients were evaluated with respect to surgery related complications, postoperative recovery, recurrence and metastasis rate, cost-effectiveness and survival. RESULTS: Among 30 LRH, 2 (6.7%) were converted to open procedure. No significant differences were observed in terms of mean operation time, blood loss, post-operative complications, and hospital cost between LRH and ORH groups. Mean time for bowel movement, hospital stay, and time to resum?early activity in the LRH group were significantly shorter than those in the ORH group (2.24±0.56 vs 3.25±1.29 d, 13.94?.5 vs 18.25±5.96 d, 3.94±1.64 vs 5.45±1.82 d respectively, P<0.05). As to the lymph node yield, the specimen length and total cost for operation and drugs, there was no significant difference between the two groups. Local recurrence rate and metachronous metastasis rate had no marked difference between the two groups. Cumulative survival probability at 40 mo in LRH group (76.50%) was not obviously different compared to the ORH group (74.04%). CONCLUSION: LRH in patients with colon cancer has statistically and clinically significant advantages over ORH. Thus, LRH can be regarded as a safe and effective procedure.展开更多
Patients with long-standing inflammatory bowel disease (IBD) have an increased risk of developing colorectal cancer (CRC). Many of the molecular alterations responsible for sporadic colorectal cancer, namely chromosom...Patients with long-standing inflammatory bowel disease (IBD) have an increased risk of developing colorectal cancer (CRC). Many of the molecular alterations responsible for sporadic colorectal cancer, namely chromosomal instability, microsatellite instability, and hypermethylation, also play a role in colitis-associated colon carcinogenesis. Colon cancer risk in inflammatory bowel disease increases with longer duration of colitis, greater anatomic extent of colitis, the presence of primary sclerosing cholangitis, family history of CRC and degree of inflammation of the bowel. Chemoprevention includes aminosalicylates, ursodeoxycholic acid, and possibly folic acid and statins. To reduce CRC mortality in IBD, colonoscopic surveillance with random biopsies remains the major way to detect early mucosal dysplasia. When dysplasia is confirmed, proctocolectomy is considered for these patients. Patients with small intestinal Crohn’s disease are at increased risk of small bowel adenocarcinoma. Ulcerative colitis patients with total proctocolectomy and ileal pouch anal- anastomosis have a rather low risk of dysplasia in the ileal pouch, but the anal transition zone should be monitored periodically. Other extra intestinal cancers, such as hepatobiliary and hematopoietic cancer, have shown variable incidence rates. New endoscopic and molecular screening approaches may further refine our current surveillance guidelines and our understanding of the natural history of dysplasia.展开更多
AIM:To increase the understanding,diagnosis and treatment of pneumatosis cystoides intestinalis(PCI)and to find the characteristics and potential cause of the disease in China.METHODS:We report here one case of PCI in...AIM:To increase the understanding,diagnosis and treatment of pneumatosis cystoides intestinalis(PCI)and to find the characteristics and potential cause of the disease in China.METHODS:We report here one case of PCI in a 70-year-old male patient who received a variety of treatment methods.Then,we systematically searched the PCI eligible literature published from an available Chinese database from May 2002 to May 2012,including CBM,CBMDisc,CMCC,VIP,Wanfang,and CNKI.The key words were pneumatosis cystoides intestinalis,pneumatosis,pneumatosis intestinalis,pneumatosis coli and mucosal gas.The patients' information,histories,therapies,courses,and outcomes were reviewed.RESULTS:The study group consisted of 239 PCI cases(male:female = 2.4:1)from 77 reported incidents.The mean age was 45.3 ± 15.6 years,and the median illness course was 6 mo.One hundred and sixty patients(66.9%)were in high altitude areas.In addition,43.5%(104/239)of the patients had potential PCI-related disease,and 16.3% had complications with intestinal obstruction and perforation.The most common symptom was abdominal pain(53.9%),followed by diarrhea(53.0%),distention(42.4%),nausea and vomiting(14.3%),bloody stool(12.9%),mucous stool(12.0%)and constipation(7.8%).Most multiple pneumocysts developed in the submucosa of the colon(69.9%).The efficacy of the treatments by combined modalities,surgery,endoscopic treatment,conservative approach,oxygen,and antibiotics were 100%,100%,100%,93.3%,68.3% and 26.3%,respectively.CONCLUSION:PCI can be safely managed by conservative treatments,presents more frequently in males,in the large bowel and submucosa,than in females,in the small intestine and subserosa.High altitude residence maybe associated with the PCI etiology.展开更多
Drug resistance develops in nearly all patients with colon cancer, leading to a decrease in the therapeutic efficacies of anticancer agents. This review provides an up-to-date summary on over-expression of ATPbinding ...Drug resistance develops in nearly all patients with colon cancer, leading to a decrease in the therapeutic efficacies of anticancer agents. This review provides an up-to-date summary on over-expression of ATPbinding cassette(ABC) transporters and evasion of apoptosis, two representatives of transport-based and non-transport-based mechanisms of drug resistance, as well as their therapeutic strategies. Different ABC transporters were found to be up-regulated in colon cancer, which can facilitate the efflux of anticancer drugs out of cancer cells and decrease their therapeutic effects. Inhibition of ABC transporters by suppressing their protein expressions or co-administration of modulators has been proven as an effective approach to sensitize drug-resistant cancer cells to anticancer drugs in vitro. On the other hand, evasion of apoptosis observed in drug-resistant cancers also results in drug resistance to anticancer agents, especially to apoptosis inducers. Restoration of apoptotic signals by BH3 mimetics or epidermal growth factor receptor inhibitors and inhibition of cancer cell growth by alternative cell death pathways, such as autophagy, are effective means to treat such resistant cancer types. Given that the drug resistance mechanisms are different among colon cancer patients and may change even in a single patient at different stages, personalized and specific combination therapy is proposed to be more effective and safer for the reversal of drug resistance in clinics.展开更多
文摘Ischemic colitis is the most common form of ischemic injury of the gastrointestinal tract and can present either as an occlusive or a non-occlusive form. It accounts for 1 in 1000 hospitalizations but its incidence is underesti- mated because it often has a mild and transient nature. The etiology of ischemic colitis is multifactorial and the clinical presentation variable. The diagnosis is based on a combination of clinical suspicion, radiographic, endo- scopic and histological findings. Therapy and outcome depends on the severity of the disease. Most cases of the non-gangrenous form are transient and resolve spontaneously without complications. On the other hand, high morbidity and mortality and urgent operative intervention are the hallmarks of gangrenous ischemic colitis.
基金Supported by A Grant from Agenzia Italiana del Farmaco(AIFA) grant code FARM6FJ728
文摘The multiple beneficial effects on human health of the short-chain fatty acid butyrate,synthesized from nonabsorbed carbohydrate by colonic microbiota,are well documented.At the intestinal level,butyrate plays a regulatory role on the transepithelial fluid transport,ameliorates mucosal inflammation and oxidative status,reinforces the epithelial defense barrier,and modulates visceral sensitivity and intestinal motility.In addition,a growing number of studies have stressed the role of butyrate in the prevention and inhibition of colorectal cancer.At the extraintestinal level,butyrate exerts potentially useful effects on many conditions,including hemoglobinopathies,genetic metabolic diseases,hypercholesterolemia,insulin resistance,and ischemic stroke.The mechanisms of action of butyrate are different;many of these are related to its potent regulatory effects on gene expression.These data suggest a wide spectrum of positive effects exerted by butyrate,with a high potential for a therapeutic use in human medicine.
基金the Program of Science and Technology, Zhenjiang City, No. SH2006019
文摘AIM:To investigate the roles and mechanism of signal transducer and activator of transcription 3 (STAT3) in invasion of human colon cancer cells by RNA interference. METHODS: Small interfering RNA (siRNA) targeting Signal transducer and activator of transcription 3 (STAT3) was transfected into HT29 colon cancer cells. STAT3 protein level and DNA-binding activity of STAT3 was evaluated by western blotting and electrophoretic mobility shift assay (EMSA), respectively. We studied the anchorage-independent growth using colony formation in soft agar, and invasion using the boyden chamber model, anoikis using DNA fragmentation assay and terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling (TUNEL), respectively. Western blot assay was used to observe the protein expression of Bcl-xL and survivin in colon cancer HT29 cells. RESULTS: RNA interference (RNAi) mediated by siRNA leads to suppression of STAT3 expression in colon cancer cell lines. Suppression of STAT3 expression by siRNA could inhibit anchorage-independent growth, and invasion ability, and induces anoikis in the colon cancer cell line HT29. It has been shown that knockdown of STAT3 expression by siRNA results in a reduction in expression of Bcl-xL and survivin in HT29 cells. CONCLUSION: These results suggest that STAT3 siRNA can inhibit the invasion ability of colon cancer cells through inducing anoikis, which antiapoptotic genes survivin and Bcl-xL contribute to regulation of anoikis.These studies indicate STAT3 siRNA could be a useful therapeutic tool for the treatment of colon cancer.
基金Supported by Japanese Society of Gastroenterology Research Foundation(to Nosho K)Pancreas Research Foundation of Japan(to Nosho K)+4 种基金Medical Research Encouragement Prize of The Japan Medical Association(to Nosho K)The Japan Society for the Promotion of Science Challenging Exploratory Researchgrant No.25670371(to Shinomura Y)Ono Cancer Research Foundation(to Ito M)
文摘The human intestinal microbiome plays a major role in human health and diseases, including colorectal cancer. Colorectal carcinogenesis represents a heterogeneous process with a differing set of somatic molecular alterations, influenced by diet, environmental and microbial exposures, and host immunity. Fusobacterium species are part of the human oral and intestinal microbiota. Metagenomic analyses have shown an enrichment of Fusobacterium nucleatum(F. nucleatum) in colorectal carcinoma tissue. Using 511 colorectal carcinomas from Japanese patients, we assessed the presence of F. nucleatum. Our results showed that the frequency of F. nucleatum positivity in the Japanese colorectal cancer was 8.6%(44/511), which was lower than that in United States cohort studies(13%). Similar to the United States studies, F. nucleatum positivityin Japanese colorectal cancers was significantly associated with microsatellite instability(MSI)-high status. Regarding the immune response in colorectal cancer, high levels of infiltrating T-cell subsets(i.e., CD3+, CD8+, CD45RO+, and FOXP3+ cells) have been associated with better patient prognosis. There is also evidence to indicate that molecular features of colorectal cancer, especially MSI, influence T-cell-mediated adaptive immunity. Concerning the association between the gut microbiome and immunity, F. nucleatum has been shown to expand myeloid-derived immune cells, which inhibit T-cell proliferation and induce T-cell apoptosis in colorectal cancer. This finding indicates that F. nucleatum possesses immunosuppressive activities by inhibiting human T-cell responses. Certain micro RNAs are induced during the macrophage inflammatory response and have the ability to regulate host-cell responses to pathogens. Micro RNA-21 increases the levels of IL-10 and prostaglandin E2, which suppress antitumor T-cell-mediated adaptive immunity through the inhibition of the antigen-presenting capacities of dendritic cells and T-cell proliferation in colorectal cancer cells. Thus, emerging evidence may
基金This work was supported in part by National Natural Science Foundation of China(No.30170413)the Foundation for Jing Yuan FANG of National Excellent Doctoral Dissertation of China(No.199946)the Foundation of Shanghai Education Committee(Shuguang Plan,No.02SG45).
文摘The aim of this study is to assess the effects of DNA methylation and historic acetylation, alone or in combination, on the expression of several tumor-associated genes and cell cycle progression in two established human colon cancer cell lines: Colo-320 and SW1116. Treatments with 5-aza-2'-deoxycytidine (5-aza-dC) and trichostatin A, alone or in combination, were applied respectively. The methylation status of the CDKN2A promoter was determined by methyla-tion-specific PCR, and the acetylated status of the histones associated with the p21WAF1 and CDKN2A genes was examined by chromatin immunoprecipitation. The expression of the CDKN2A, p21WAF1, p53, p73, APC, c-myc, c-Ki-ras and survivin genes was detected by real-time RT-PCR and RT-PCR. The cell cycle profile was established by flow cytometry. We found that along with the demethylation of the CDKN2A gene promoter in both cell lines induced by 5-aza-dC alone or in combination with TSA, the expression of both CDKN2A and APC genes increased. The treatment of TSA or sodium butyrate up-regulated the transcription of p21WAF1 significantly by inducing the acetylation of histones H4 and H3, but failed to alter the acetylation level of CDKN2A-associated histones. No changes in transcription of p53, p73, c-myc, c-Ki-ras and survivin genes were observed. In addition, TSA or sodium butyrate was shown to arrest cells at the G1 phase. However, 5-aza-dC was not able to affect the cell cycle progression. In conclusion, regulation by epigenetic modification of the transcription of tumor-associated genes and the cell cycle progression in both human colon cancer cell lines Colo-320 and SW1116 is gene-specific.
基金Supported by Grants from the NIH (R21CA111513-01A1, 5 RO1 CA119087, and SPORE Grant 1 P50CA95060)grants from the Arizona Biomedical Research Commission (#0012 & #0803)by Biomedical Diagnostics & Research In., Tucson Arizona, and by a VA Merit Review Grant
文摘Bile acids are implicated as etiologic agents in cancer of the gastrointestinal (GI) tract, including cancer of the esophagus, stomach, small intestine, liver, biliary tract, pancreas and colon/rectum. Deleterious effects of bile acid exposure, likely related to carcinogenesis, include: induction of reactive oxygen and reactive nitrogen species; induction of DNA damage; stimulation of mutation; induction of apoptosis in the short term, and selection for apoptosis resistance in the long term. These deleterious effects have, so far, been reported most consistently in relation to esophageal and colorectal cancer, but also to some extent in relation to cancer of other organs. In addition, evidence is reviewed for an association of increased bile acid exposure with cancer risk in human populations, in specific human genetic conditions, and in animal experiments. A model for the role of bile acids in GI carcinogenesis is presented from a Darwinian perspective that offers an explanation for how the observed effects of bile acids on cells contribute to cancer development.
基金Supported by Grants from Key Projects in the National Science and Technology Pillar Program during the Twelfth Five-year Plan Period,No.2014BAI09B07grants from the National Natural Science Foundation of China,No.81101580 and No.81201640
文摘The colon is derived from the embryological midgut and hindgut separately,with the right colon and left colon having different features with regards to both anatomical and physiological characteristics.Cancers located in the right and left colon are referred to as right colon cancer(RCC) and left colon cancer(LCC),respectively,based on their apparent anatomical positions.Increasing evidence supports the notion that not only are there differences in treatment strategies when dealing with RCC and LCC,but molecular features also vary between them,not to mention the distinguishing clinical manifestations.Disease-free survival after radical surgery of both RCC and LCC are similar.In the treatment of RCC,the benefit gained from adjuvant FOLFIRI chemotherapy is superior,or at least similar,to LCC,but inferior to LCC if FOLFOX regimen is applied.On the other hand,metastatic LCC exhibits longer survival than that of RCC in a palliative chemotherapy setting.For KRAS wild-type cancers,LCC benefits more from cetuximab treatment than RCC.Moreover,advanced LCC shows a higher sensitivity to bevacizumab treatment in comparison with advanced RCC.Significant varieties exist at the molecular level between RCC and LCC,which may serve as the cause of all apparent differences.With respect to carcinogenesis mechanisms,RCC is associated with known gene types,such as MMR,KRAS,BRAF,and mi RNA-31,while LCC is associated with CIN,p53,NRAS,mi RNA-146 a,mi RNA-147 b,and mi RNA-1288.Regarding protein expression,RCC is related to GNAS,NQO1,telomerase activity,P-PDH,and annexin A10,while LCC is related to Topo I,TS,and EGFR.In addition,separated pathways dominate progressionto relapse in RCC and LCC.Therefore,RCC and LCC should be regarded as two heterogeneous entities,with this heterogeneity being used to stratify patients in order for them to have the optimal,current,and novel therapeutic strategies in clinical practice.Additional research is needed to uncover further differences between RCC and LCC.
基金Supported by the Guangdong Provincial Scientific Research Grants: No. 2004B30301002, No. 2007B030702012 and No. 04300330
文摘AIM: To observe the gene silencing mediated by the specific shRNA targeted against β-catenin and its effect on cell proliferation and cycle distribution in the human colon cancer cell line Colo205. METHODS: Two shRNA plasmid vectors against β-catenin were constructed and transfected into Colo205 cells with LipofectamineTM2000. The down-regulations of β-catenin, c-myc and cyclinD1 expressions were detected by RT-PCR and western blot analysis. The cell proliferation inhibitions were determined by MTT assay and soft agar colony formation assay. The effect of these two β-catenin shRNAs on cell cycle distribution and apoptosis was examined by flow cytometry. RESULTS: These two shRNA vectors targeted against β-catenin efficiently suppressed the expression of β-catenin and its down stream genes, c-myc and cyclinD1. The expression inhibition rates were around 40%-50% either at the mRNA or at the protein level. The shRNA-mediated gene silencing of β-catenin resulted in significant inhibition of cell growth both on the culture plates and in the soft agar. Moreover, the cancer cells showed significant G0/G1 arrest and increased apoptosis at 72 h post transfection due to gene silencing. CONCLUSION: These specific shRNAs targeted against β-catenin could have a gene silencing effect and block the WNT signaling pathway. They could inhibit cell growth, increase apoptosis, and induce cell cycle arrest in Colo205 cells. ShRNA interference against β-catenin is of potential value in gene therapy of colon cancer.
基金Supported by Science and Technology Development Foundation of Shanghai,No. 024119106
文摘AIM: Laparoscopic surgery, especially laparoscopic rectal surgery, for colorectal cancer has been developed considerably. However, due to relatively complicated anatomy and high requirements for surgery techniques, laparoscopic right colectomy develops relatively slowly. This study was designed to compare the outcomes of laparoscopic right hemicolectomy (LRH) with open right hemicolectomy (ORH) in the treatment of colon carcinoma. METHODS: Between September 2000 and February 2003, 30 patients with colon cancer who underwent LRH were compared with 34 controls treated by ORH in the same period. All patients were evaluated with respect to surgery related complications, postoperative recovery, recurrence and metastasis rate, cost-effectiveness and survival. RESULTS: Among 30 LRH, 2 (6.7%) were converted to open procedure. No significant differences were observed in terms of mean operation time, blood loss, post-operative complications, and hospital cost between LRH and ORH groups. Mean time for bowel movement, hospital stay, and time to resum?early activity in the LRH group were significantly shorter than those in the ORH group (2.24±0.56 vs 3.25±1.29 d, 13.94?.5 vs 18.25±5.96 d, 3.94±1.64 vs 5.45±1.82 d respectively, P<0.05). As to the lymph node yield, the specimen length and total cost for operation and drugs, there was no significant difference between the two groups. Local recurrence rate and metachronous metastasis rate had no marked difference between the two groups. Cumulative survival probability at 40 mo in LRH group (76.50%) was not obviously different compared to the ORH group (74.04%). CONCLUSION: LRH in patients with colon cancer has statistically and clinically significant advantages over ORH. Thus, LRH can be regarded as a safe and effective procedure.
文摘Patients with long-standing inflammatory bowel disease (IBD) have an increased risk of developing colorectal cancer (CRC). Many of the molecular alterations responsible for sporadic colorectal cancer, namely chromosomal instability, microsatellite instability, and hypermethylation, also play a role in colitis-associated colon carcinogenesis. Colon cancer risk in inflammatory bowel disease increases with longer duration of colitis, greater anatomic extent of colitis, the presence of primary sclerosing cholangitis, family history of CRC and degree of inflammation of the bowel. Chemoprevention includes aminosalicylates, ursodeoxycholic acid, and possibly folic acid and statins. To reduce CRC mortality in IBD, colonoscopic surveillance with random biopsies remains the major way to detect early mucosal dysplasia. When dysplasia is confirmed, proctocolectomy is considered for these patients. Patients with small intestinal Crohn’s disease are at increased risk of small bowel adenocarcinoma. Ulcerative colitis patients with total proctocolectomy and ileal pouch anal- anastomosis have a rather low risk of dysplasia in the ileal pouch, but the anal transition zone should be monitored periodically. Other extra intestinal cancers, such as hepatobiliary and hematopoietic cancer, have shown variable incidence rates. New endoscopic and molecular screening approaches may further refine our current surveillance guidelines and our understanding of the natural history of dysplasia.
文摘AIM:To increase the understanding,diagnosis and treatment of pneumatosis cystoides intestinalis(PCI)and to find the characteristics and potential cause of the disease in China.METHODS:We report here one case of PCI in a 70-year-old male patient who received a variety of treatment methods.Then,we systematically searched the PCI eligible literature published from an available Chinese database from May 2002 to May 2012,including CBM,CBMDisc,CMCC,VIP,Wanfang,and CNKI.The key words were pneumatosis cystoides intestinalis,pneumatosis,pneumatosis intestinalis,pneumatosis coli and mucosal gas.The patients' information,histories,therapies,courses,and outcomes were reviewed.RESULTS:The study group consisted of 239 PCI cases(male:female = 2.4:1)from 77 reported incidents.The mean age was 45.3 ± 15.6 years,and the median illness course was 6 mo.One hundred and sixty patients(66.9%)were in high altitude areas.In addition,43.5%(104/239)of the patients had potential PCI-related disease,and 16.3% had complications with intestinal obstruction and perforation.The most common symptom was abdominal pain(53.9%),followed by diarrhea(53.0%),distention(42.4%),nausea and vomiting(14.3%),bloody stool(12.9%),mucous stool(12.0%)and constipation(7.8%).Most multiple pneumocysts developed in the submucosa of the colon(69.9%).The efficacy of the treatments by combined modalities,surgery,endoscopic treatment,conservative approach,oxygen,and antibiotics were 100%,100%,100%,93.3%,68.3% and 26.3%,respectively.CONCLUSION:PCI can be safely managed by conservative treatments,presents more frequently in males,in the large bowel and submucosa,than in females,in the small intestine and subserosa.High altitude residence maybe associated with the PCI etiology.
文摘Drug resistance develops in nearly all patients with colon cancer, leading to a decrease in the therapeutic efficacies of anticancer agents. This review provides an up-to-date summary on over-expression of ATPbinding cassette(ABC) transporters and evasion of apoptosis, two representatives of transport-based and non-transport-based mechanisms of drug resistance, as well as their therapeutic strategies. Different ABC transporters were found to be up-regulated in colon cancer, which can facilitate the efflux of anticancer drugs out of cancer cells and decrease their therapeutic effects. Inhibition of ABC transporters by suppressing their protein expressions or co-administration of modulators has been proven as an effective approach to sensitize drug-resistant cancer cells to anticancer drugs in vitro. On the other hand, evasion of apoptosis observed in drug-resistant cancers also results in drug resistance to anticancer agents, especially to apoptosis inducers. Restoration of apoptotic signals by BH3 mimetics or epidermal growth factor receptor inhibitors and inhibition of cancer cell growth by alternative cell death pathways, such as autophagy, are effective means to treat such resistant cancer types. Given that the drug resistance mechanisms are different among colon cancer patients and may change even in a single patient at different stages, personalized and specific combination therapy is proposed to be more effective and safer for the reversal of drug resistance in clinics.
