AIM: Ursolic acid (UA) and oleanolic acid (OA) are triperpene acids having a similar chemical structure and are distributed wildly in plants all over the world. In recent years, it was found that they had marked anti-...AIM: Ursolic acid (UA) and oleanolic acid (OA) are triperpene acids having a similar chemical structure and are distributed wildly in plants all over the world. In recent years, it was found that they had marked anti-tumor effects. There is little literature currently available regarding their effects on colon carcinoma cells. The present study was designed to investigate their inhibitory effects on human colon carcinoma cell line HCT15. METHODS: HCT15 cells were cultured with different drugs. The treated cells were stained with hematoxylin-eosin and their morphologic changes observed under a light microscope. The cytotoxicity of these drugs was evaluated by tetrazolium dye assay. Cell cycle analysis was performed by flow cytometry (FCM). Data were expressed as means +/-SEM and Analysis of variance and Student' t-test for individual comparisons. RESULTS: Twenty-four to 72 h after UA or OA 60 micromol/L treatment, the numbers of dead cells and cell fragments were increased and most cells were dead at the 72nd hour. The cytotoxicity of UA was stronger than that of OA. Seventy-eight hours after 30 micromol/L of UA or OA treatment, a number of cells were degenerated, but cell fragments were rarely seen. The IC(50) values for UA and OA were 30 and 60 micromol/L, respectively. Proliferation assay showed that proliferation of UA and OA-treated cells was slightly increased at 24h and significantly decreased at 48 h and 60 h, whereas untreated control cells maintained an exponential growth curve. Cell cycle analysis by FCM showed HCT15 cells treated with UA 30 and OA 60 for 36 h and 72 h gradually accumulated in G(0)/G(1) phase (both drugs P【0.05 for 72 h), with a concomitant decrease of cell populations in S phase (both drugs P【0.01 for 72 h) and no detectable apoptotic fraction. CONCLUSION: UA and OA have significant anti-tumor activity. The effect of UA is stronger than that of OA. The possible mechanism of action is that both drugs have an inhibitory effect on tumor cell proliferation through cell-cycle arrest.展开更多
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
AIM: To investigate the correlation between clinicopathology and expression of heat shock protein 70 (HSP70) and glucose-regulated protein 94 (grp94) in human colonic carcinoma. METHODS: The expression of HSP70 and gr...AIM: To investigate the correlation between clinicopathology and expression of heat shock protein 70 (HSP70) and glucose-regulated protein 94 (grp94) in human colonic carcinoma. METHODS: The expression of HSP70 and grp94 was studied in 80 human colonic cancers with or without metastasis as well as in their adjacent mucous membrane by way of immunohistochemistry and pathology photograph analysis. RESULTS: The expression of HSP70 and grp94 was significantly higher in cancer than that in adjacent mucous membrane (92.5%, 85.0% vs 56.3%, 42.5%, P<0.01). HSP70 and grp94 expressed higher in moderately- and poorly-differentiated colonic cancers than that in their adjacent tissues (93.7%, 87.5%; 100%, 90% vs56.3%, 42.5%;P<0.01). Dukes C and D stages of colonic cancers showed higher positive rates than Dukes A and B stage groups (97.1%, 91.2%; 100%, 90.9%; vs 80%, 70%; 78.6%, 71.4%; P<0.05). There were definite differences in HSP70 and grp94 expression between metastasis groups and non-metastasis groups (100% vs 75%, 100% CONCLUSION: The HSP70 and grp94 expression rates in colonic cancer groups are significantly higher than that in their adjacent mucous membrane. The HSP70 and grp94 expression in poorly-differentiated colonic cancers with metastasis is significantly higher than well-differentiated cancers without metastasis. The overexpression of HSP70 and grp94 can be used as diagnostic or prognostic markers for colonic cancer.展开更多
AIM： To investigate the anti-inflammatory mechanism of oxymatrine in dextran sulfate sodium （DSS）-induced colitis of rats. METHODS： Acute colitis was induced by giving 2% DSS orally in drinking water for 8 d. Twen...AIM： To investigate the anti-inflammatory mechanism of oxymatrine in dextran sulfate sodium （DSS）-induced colitis of rats. METHODS： Acute colitis was induced by giving 2% DSS orally in drinking water for 8 d. Twenty-six male rats were randomized into oxymatrine-treated group （group A, 10 rats）, DSS control （group B, 10 rats） and normal control （group C, 6 rats）. The rats in group A were injected muscularly with oxymatrine at the dosage of 63 mg/（kg·d） from d 1 to 11 and drank 2% DSS solution from d 4 to 11. The rats in group B were treated with 0.9% saline in an equal volume as group A and drank 2% DSS solution from d 4 to 11. The rats in group C were treated with 0.9% saline as group B from d 1 to 11 and drank water normally. Diarrhea and bloody stool as well as colonic histology were observed. The levels of serum tumor necrosis factor-α （TNF-α） and interleukin-6 （IL-6） were determined by ELISA, and nuclear factor-κB （NF-κB） activity and the expression of inter-cellular adhesion molecule-1 （ICAM-1） in colonic mucosa were detected by immunohistochemistry method. RESULTS： Compared with DSS control group, the inflammatory symptoms and histological damages of colonic mucosa in oxymatrine-treated group were significantly improved, the serum levels of TNF-α, IL-6, and the expression of NF-κB, ICAM-1 in colonic mucosa were significantly reduced. CONCLUSION： The fact that oxymatrine can reduce the serum levels of TNF-α, IL-6, and the expression of NF-κB and ICAM-1 in colonic mucosa in DSS-induced colitis of rats indicates that oxymatrine may ameliorate the colonic inflammation and thus alleviate diarrhea and bloody stool.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
文摘AIM: Ursolic acid (UA) and oleanolic acid (OA) are triperpene acids having a similar chemical structure and are distributed wildly in plants all over the world. In recent years, it was found that they had marked anti-tumor effects. There is little literature currently available regarding their effects on colon carcinoma cells. The present study was designed to investigate their inhibitory effects on human colon carcinoma cell line HCT15. METHODS: HCT15 cells were cultured with different drugs. The treated cells were stained with hematoxylin-eosin and their morphologic changes observed under a light microscope. The cytotoxicity of these drugs was evaluated by tetrazolium dye assay. Cell cycle analysis was performed by flow cytometry (FCM). Data were expressed as means +/-SEM and Analysis of variance and Student' t-test for individual comparisons. RESULTS: Twenty-four to 72 h after UA or OA 60 micromol/L treatment, the numbers of dead cells and cell fragments were increased and most cells were dead at the 72nd hour. The cytotoxicity of UA was stronger than that of OA. Seventy-eight hours after 30 micromol/L of UA or OA treatment, a number of cells were degenerated, but cell fragments were rarely seen. The IC(50) values for UA and OA were 30 and 60 micromol/L, respectively. Proliferation assay showed that proliferation of UA and OA-treated cells was slightly increased at 24h and significantly decreased at 48 h and 60 h, whereas untreated control cells maintained an exponential growth curve. Cell cycle analysis by FCM showed HCT15 cells treated with UA 30 and OA 60 for 36 h and 72 h gradually accumulated in G(0)/G(1) phase (both drugs P【0.05 for 72 h), with a concomitant decrease of cell populations in S phase (both drugs P【0.01 for 72 h) and no detectable apoptotic fraction. CONCLUSION: UA and OA have significant anti-tumor activity. The effect of UA is stronger than that of OA. The possible mechanism of action is that both drugs have an inhibitory effect on tumor cell proliferation through cell-cycle arrest.
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 the Research Fund for Young Scholars of Beijing,No. 02120031
文摘AIM: To investigate the correlation between clinicopathology and expression of heat shock protein 70 (HSP70) and glucose-regulated protein 94 (grp94) in human colonic carcinoma. METHODS: The expression of HSP70 and grp94 was studied in 80 human colonic cancers with or without metastasis as well as in their adjacent mucous membrane by way of immunohistochemistry and pathology photograph analysis. RESULTS: The expression of HSP70 and grp94 was significantly higher in cancer than that in adjacent mucous membrane (92.5%, 85.0% vs 56.3%, 42.5%, P<0.01). HSP70 and grp94 expressed higher in moderately- and poorly-differentiated colonic cancers than that in their adjacent tissues (93.7%, 87.5%; 100%, 90% vs56.3%, 42.5%;P<0.01). Dukes C and D stages of colonic cancers showed higher positive rates than Dukes A and B stage groups (97.1%, 91.2%; 100%, 90.9%; vs 80%, 70%; 78.6%, 71.4%; P<0.05). There were definite differences in HSP70 and grp94 expression between metastasis groups and non-metastasis groups (100% vs 75%, 100% CONCLUSION: The HSP70 and grp94 expression rates in colonic cancer groups are significantly higher than that in their adjacent mucous membrane. The HSP70 and grp94 expression in poorly-differentiated colonic cancers with metastasis is significantly higher than well-differentiated cancers without metastasis. The overexpression of HSP70 and grp94 can be used as diagnostic or prognostic markers for colonic cancer.
基金Supported by the University Science and Technology Development Foundation of Shanghai, No.00B07
文摘AIM： To investigate the anti-inflammatory mechanism of oxymatrine in dextran sulfate sodium （DSS）-induced colitis of rats. METHODS： Acute colitis was induced by giving 2% DSS orally in drinking water for 8 d. Twenty-six male rats were randomized into oxymatrine-treated group （group A, 10 rats）, DSS control （group B, 10 rats） and normal control （group C, 6 rats）. The rats in group A were injected muscularly with oxymatrine at the dosage of 63 mg/（kg·d） from d 1 to 11 and drank 2% DSS solution from d 4 to 11. The rats in group B were treated with 0.9% saline in an equal volume as group A and drank 2% DSS solution from d 4 to 11. The rats in group C were treated with 0.9% saline as group B from d 1 to 11 and drank water normally. Diarrhea and bloody stool as well as colonic histology were observed. The levels of serum tumor necrosis factor-α （TNF-α） and interleukin-6 （IL-6） were determined by ELISA, and nuclear factor-κB （NF-κB） activity and the expression of inter-cellular adhesion molecule-1 （ICAM-1） in colonic mucosa were detected by immunohistochemistry method. RESULTS： Compared with DSS control group, the inflammatory symptoms and histological damages of colonic mucosa in oxymatrine-treated group were significantly improved, the serum levels of TNF-α, IL-6, and the expression of NF-κB, ICAM-1 in colonic mucosa were significantly reduced. CONCLUSION： The fact that oxymatrine can reduce the serum levels of TNF-α, IL-6, and the expression of NF-κB and ICAM-1 in colonic mucosa in DSS-induced colitis of rats indicates that oxymatrine may ameliorate the colonic inflammation and thus alleviate diarrhea and bloody stool.
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.
