AIM: To correlate the length of the telomere to microsatellite instability (MSI) and loss of heterozygosity (LOH) of APC, MCC and DCC genes in gastric carcinomas. METHODS: Telomeric restriction fragment (TRF) length o...AIM: To correlate the length of the telomere to microsatellite instability (MSI) and loss of heterozygosity (LOH) of APC, MCC and DCC genes in gastric carcinomas. METHODS: Telomeric restriction fragment (TRF) length of gastric cancer was measured with Southern blot. LOH of APC, MCC and DCC genes, microsatellite instability (MSI) and frameshift mutation of hMSH6, TGF-betaRII and BAX genes were analyzed by PCR-based methods. RESULTS: Sixty-eight cases of sporadic gastric carcinoma were studied for MSI using five microsatellite markers. MSI in at least one locus was detected in 17 (25%) of 68 tumors analyzed. Frameshift mutations of hMSH6, TGF-betaRII and BAX were detected in 2,6 and 3 of gastric carcinomas respectively showing high MSI (】 or = 2 loci, n = 8), but none was found in those showing low MSI (only one locus, n = 9) or MSS (tumor lacking MSI or stable, n = 51). Thirty-five cases, including all high MSI and low MSI, were studied for TRF. The mean TRF length was not correlated with clinicopathological parameters. No association was observed between TRF length and MSI or frameshift mutation. On the contrary, LOH at the DCC locus was related to telomere shortening (P【0.01). This tendency was also observed in APC and MCC genes, although there was no statistical significance. CONCLUSION: The development of gastric cancer can arise through two different genetic pathways. In high MSI gastric cancers, defective mismatch repair allows mutations to accumulate and generate the high MSI phenotype. In gastric cancers showing either low MSI or MSS, multiple deletions may represent the LOH pathway. Telomere erosion is independent of high MSI phenotype but related to the LOH pathway in gastric cancer.展开更多
AIM: The transcription factor EGR-1 (early growth response gene-1) plays an important role in cell growth, differentiation and development. It has identified that EGR-1 has significant transformation suppression activ...AIM: The transcription factor EGR-1 (early growth response gene-1) plays an important role in cell growth, differentiation and development. It has identified that EGR-1 has significant transformation suppression activity in some neoplasms, such as fibrosarcoma, breast carcinoma. This experiment was designed to investigate the role of egr-1 in the cancerous process of hepatocellular carcinoma (HCC) and esophageal carcinoma (EC), and then to appraise the effects of EGR-1 on the growth of these tumor cells. METHODS: Firstly, the transcription and expression of egr-1 in HCC and EC, paracancerous tissues and their normal counterpart parts were detected by in situ hybridization and immunohistochemistry, with normal human breast and mouse brain tissues as positive controls. Egr-1 gene was then transfected into HCC (HHCC, SMMC7721) and EC (ECa109) cell lines in which no egr-1 transcription and expression were present. The cell growth speed, FCM cell cycle, plate clone formation and tumorigenicity in nude mice were observed and the controls were the cell lines transfected with vector only. RESULTS: Little or no egr-1 transcription and expression were detected in HCC, EC and normal liver tissues. The expression of egr-1 were found higher in hepatocellular paracancerous tissue (transcription level P=0.000; expression level P=0.143, probably because fewer in number of cases) and dysplastic tissue of esophageal cancer (transcription level P=0.000; expression level P=0.001). The growth rate of egr-1-transfected HHCC (HCC cell line) cells and ECa109 (EC cell line) cells was much slower than that of the controls. The proportion of S phase cell, clone formation and tumorigenicity were significantly lower than these of the controls' (decreased 45.5% in HHCC cells and 34.1% in ECa109 cells; 46.6% and 41.8%; 80.4% and 72.6% respectively). There were no obvious differences between SMMC7721 (HCC) egr-1-transfected cells and the controls with regard to the above items. CONCLUSION: The decreased expression of egr-1 might play a role in 展开更多
AIM: To explore the association of methylation of the CpG island in the promotor of the p16 tumor suppressor gene with the clinicopathological characteristics of the colorectal cancers. METHODS: Methylation-specific P...AIM: To explore the association of methylation of the CpG island in the promotor of the p16 tumor suppressor gene with the clinicopathological characteristics of the colorectal cancers. METHODS: Methylation-specific PCR (MSP) was used to detect p16 methylation of 62 sporadic colorectal cancer specimens. RESULTS: p16 methylation was detected in 42% of the tumors.Dukes'staging was associated with p16 methylation status.p16 methylation occurred more frequently in Dukes'C and D patients (75.9%) than in Dukes'A and B patients (12.1%). CONCLUSION: p16 methylation plays a role in the carcinogenesis of a subset of colorectal cancer, and it might be linked to poor prognosis.展开更多
AIM: To investigate the role of TR3 in induction of apoptosis in gastric cancer cells. METHODS: Human gastric cancer cell line, MGC80-3, was used. Expression of TR3 mRNA and its protein was detected by Northern blot a...AIM: To investigate the role of TR3 in induction of apoptosis in gastric cancer cells. METHODS: Human gastric cancer cell line, MGC80-3, was used. Expression of TR3 mRNA and its protein was detected by Northern blot and Western blot. Localization of TR3 protein was showed by immunofluorescence analysis under laser-scanning confocal microscope. Apoptotic morphology was observed by DAPI fluorescence staining, and apoptotic index was counted among 1000 cells randomly. Stable transfection assay was carried out by Lipofectamine. RESULTS: Treatment of MGC80-3 cells with TPA and VP-16 resulted in apoptosis, accompanied by the repression of Bcl-2 protein in a time-dependent manner. At the same time, TPA and VP-16 also up-regulated expression level of TR3 mRNA in MGC80-3 cells that expressed TR3 mRNA. When antisense-TR3 expression vector was transfected into the cells, expression of TR3 protein was repressed. In this case, TPA and VP-16 did not induce apoptosis. In addition, TPA and VP-16-induced apoptosis involved in translocation of TR3. In MGC80-3 cells, TR3 localized concentrative in nucleus, after treatment of cells with TPA and VP-16, TR3 translocated from nucleus to cytosol obviously. However, when this nuclear translocation was blocked by LMB, apoptosis was not occurred in MGC80-3 cells even in the presence of TPA and VP-16. CONCLUSION: Induction of apoptosis by TPA and VP-16 is through induction of TR3 expression and translocation of TR3 from nucleus to cytosol, which may be a novel signal pathway for TR3, and represent the new biological function of TR3 to exert its effect on apoptosis in gastric cancer cells.展开更多
目的:探讨二甲双胍是否能够逆转卵巢癌细胞对顺铂的耐药性,以及其可能的作用机制。方法:CCK-8法检测二甲双胍作用后卵巢癌细胞顺铂耐药株C13K和CP70细胞对顺铂的耐药性变化,以及转染针对切除修复交叉互补基因1(excision repair cross-co...目的:探讨二甲双胍是否能够逆转卵巢癌细胞对顺铂的耐药性,以及其可能的作用机制。方法:CCK-8法检测二甲双胍作用后卵巢癌细胞顺铂耐药株C13K和CP70细胞对顺铂的耐药性变化,以及转染针对切除修复交叉互补基因1(excision repair cross-complemention 1,ERCC1)的特异性小干扰RNA(small interfering RNA,si RNA)后C13K和CP70细胞耐药性的变化。实时荧光定量PCR法检测不同浓度二甲双胍作用后,C13K和CP70细胞中ERCC1基因表达的变化。蛋白质印迹法检测二甲双胍作用后C13K和CP70细胞中腺苷酸活化蛋白激酶(AMP-activated protein kinase,AMPK)信号通路的激活和p38丝裂原活化蛋白激酶(p38 mitogen-activated protein kinase,p38MAPK)信号通路的抑制情况,以及联合或不联合AMPK信号通路阻断剂Compound C作用后ERCC1蛋白的表达情况。同时,蛋白质印迹法检测p38MAPK信号通路抑制剂SB203580作用后耐药细胞中ERCC1蛋白表达的变化,以及二甲双胍作用联合p38MAPK si RNA转染前后耐药细胞中ERCC1蛋白的表达变化。结果:二甲双胍能够逆转C13K和CP70细胞对顺铂的耐药性(P<0.05)。二甲双胍作用能够降低C13K和CP70细胞中ERCC1 m RNA和蛋白的表达水平(P<0.05),并激活AMPK信号通路(P<0.05);而联合应用AMPK信号通路阻断剂Compound C可以阻断二甲双胍的这种作用(即ERCC1蛋白表达水平升高)(P<0.01)。p38MAPK信号通路抑制剂SB203580作用后,C13K和CP70细胞中ERCC1蛋白表达水平降低(P<0.05);而二甲双胍作用可降低p38MAPK的磷酸化水平(P<0.01),抑制p38MAPK信号通路。二甲双胍作用转染了p38MAPK si RNA的C13K和CP70细胞后,ERCC1蛋白的表达水平无明显变化(P>0.05)。结论:二甲双胍可能逆转卵巢癌顺铂耐药株对顺铂的耐药性,并且这一作用可能是通过抑制p38MAPK信号通路和降低细胞中ERCC1的表达而实现的。展开更多
基金National Natural Science Foundation of China,No.30070043"10.5"Scientific Research Foundation of PLA,No.01Z075
文摘AIM: To correlate the length of the telomere to microsatellite instability (MSI) and loss of heterozygosity (LOH) of APC, MCC and DCC genes in gastric carcinomas. METHODS: Telomeric restriction fragment (TRF) length of gastric cancer was measured with Southern blot. LOH of APC, MCC and DCC genes, microsatellite instability (MSI) and frameshift mutation of hMSH6, TGF-betaRII and BAX genes were analyzed by PCR-based methods. RESULTS: Sixty-eight cases of sporadic gastric carcinoma were studied for MSI using five microsatellite markers. MSI in at least one locus was detected in 17 (25%) of 68 tumors analyzed. Frameshift mutations of hMSH6, TGF-betaRII and BAX were detected in 2,6 and 3 of gastric carcinomas respectively showing high MSI (】 or = 2 loci, n = 8), but none was found in those showing low MSI (only one locus, n = 9) or MSS (tumor lacking MSI or stable, n = 51). Thirty-five cases, including all high MSI and low MSI, were studied for TRF. The mean TRF length was not correlated with clinicopathological parameters. No association was observed between TRF length and MSI or frameshift mutation. On the contrary, LOH at the DCC locus was related to telomere shortening (P【0.01). This tendency was also observed in APC and MCC genes, although there was no statistical significance. CONCLUSION: The development of gastric cancer can arise through two different genetic pathways. In high MSI gastric cancers, defective mismatch repair allows mutations to accumulate and generate the high MSI phenotype. In gastric cancers showing either low MSI or MSS, multiple deletions may represent the LOH pathway. Telomere erosion is independent of high MSI phenotype but related to the LOH pathway in gastric cancer.
基金the National Natural Scientific Foundation of China,No.39670298
文摘AIM: The transcription factor EGR-1 (early growth response gene-1) plays an important role in cell growth, differentiation and development. It has identified that EGR-1 has significant transformation suppression activity in some neoplasms, such as fibrosarcoma, breast carcinoma. This experiment was designed to investigate the role of egr-1 in the cancerous process of hepatocellular carcinoma (HCC) and esophageal carcinoma (EC), and then to appraise the effects of EGR-1 on the growth of these tumor cells. METHODS: Firstly, the transcription and expression of egr-1 in HCC and EC, paracancerous tissues and their normal counterpart parts were detected by in situ hybridization and immunohistochemistry, with normal human breast and mouse brain tissues as positive controls. Egr-1 gene was then transfected into HCC (HHCC, SMMC7721) and EC (ECa109) cell lines in which no egr-1 transcription and expression were present. The cell growth speed, FCM cell cycle, plate clone formation and tumorigenicity in nude mice were observed and the controls were the cell lines transfected with vector only. RESULTS: Little or no egr-1 transcription and expression were detected in HCC, EC and normal liver tissues. The expression of egr-1 were found higher in hepatocellular paracancerous tissue (transcription level P=0.000; expression level P=0.143, probably because fewer in number of cases) and dysplastic tissue of esophageal cancer (transcription level P=0.000; expression level P=0.001). The growth rate of egr-1-transfected HHCC (HCC cell line) cells and ECa109 (EC cell line) cells was much slower than that of the controls. The proportion of S phase cell, clone formation and tumorigenicity were significantly lower than these of the controls' (decreased 45.5% in HHCC cells and 34.1% in ECa109 cells; 46.6% and 41.8%; 80.4% and 72.6% respectively). There were no obvious differences between SMMC7721 (HCC) egr-1-transfected cells and the controls with regard to the above items. CONCLUSION: The decreased expression of egr-1 might play a role in
基金Supported by the grants from Mjnistry of Public Health of China,No.98-1-303The Educational Committee of Shanghai,No.2000B02.
文摘AIM: To explore the association of methylation of the CpG island in the promotor of the p16 tumor suppressor gene with the clinicopathological characteristics of the colorectal cancers. METHODS: Methylation-specific PCR (MSP) was used to detect p16 methylation of 62 sporadic colorectal cancer specimens. RESULTS: p16 methylation was detected in 42% of the tumors.Dukes'staging was associated with p16 methylation status.p16 methylation occurred more frequently in Dukes'C and D patients (75.9%) than in Dukes'A and B patients (12.1%). CONCLUSION: p16 methylation plays a role in the carcinogenesis of a subset of colorectal cancer, and it might be linked to poor prognosis.
基金the National Outstanding Youth Science foundation of China (B type,39825502)the National Natural Science Foundation of China (39880015,30170477)the Natural Science Foundation of Fujian Province (C0110004).
文摘AIM: To investigate the role of TR3 in induction of apoptosis in gastric cancer cells. METHODS: Human gastric cancer cell line, MGC80-3, was used. Expression of TR3 mRNA and its protein was detected by Northern blot and Western blot. Localization of TR3 protein was showed by immunofluorescence analysis under laser-scanning confocal microscope. Apoptotic morphology was observed by DAPI fluorescence staining, and apoptotic index was counted among 1000 cells randomly. Stable transfection assay was carried out by Lipofectamine. RESULTS: Treatment of MGC80-3 cells with TPA and VP-16 resulted in apoptosis, accompanied by the repression of Bcl-2 protein in a time-dependent manner. At the same time, TPA and VP-16 also up-regulated expression level of TR3 mRNA in MGC80-3 cells that expressed TR3 mRNA. When antisense-TR3 expression vector was transfected into the cells, expression of TR3 protein was repressed. In this case, TPA and VP-16 did not induce apoptosis. In addition, TPA and VP-16-induced apoptosis involved in translocation of TR3. In MGC80-3 cells, TR3 localized concentrative in nucleus, after treatment of cells with TPA and VP-16, TR3 translocated from nucleus to cytosol obviously. However, when this nuclear translocation was blocked by LMB, apoptosis was not occurred in MGC80-3 cells even in the presence of TPA and VP-16. CONCLUSION: Induction of apoptosis by TPA and VP-16 is through induction of TR3 expression and translocation of TR3 from nucleus to cytosol, which may be a novel signal pathway for TR3, and represent the new biological function of TR3 to exert its effect on apoptosis in gastric cancer cells.
文摘目的:探讨二甲双胍是否能够逆转卵巢癌细胞对顺铂的耐药性,以及其可能的作用机制。方法:CCK-8法检测二甲双胍作用后卵巢癌细胞顺铂耐药株C13K和CP70细胞对顺铂的耐药性变化,以及转染针对切除修复交叉互补基因1(excision repair cross-complemention 1,ERCC1)的特异性小干扰RNA(small interfering RNA,si RNA)后C13K和CP70细胞耐药性的变化。实时荧光定量PCR法检测不同浓度二甲双胍作用后,C13K和CP70细胞中ERCC1基因表达的变化。蛋白质印迹法检测二甲双胍作用后C13K和CP70细胞中腺苷酸活化蛋白激酶(AMP-activated protein kinase,AMPK)信号通路的激活和p38丝裂原活化蛋白激酶(p38 mitogen-activated protein kinase,p38MAPK)信号通路的抑制情况,以及联合或不联合AMPK信号通路阻断剂Compound C作用后ERCC1蛋白的表达情况。同时,蛋白质印迹法检测p38MAPK信号通路抑制剂SB203580作用后耐药细胞中ERCC1蛋白表达的变化,以及二甲双胍作用联合p38MAPK si RNA转染前后耐药细胞中ERCC1蛋白的表达变化。结果:二甲双胍能够逆转C13K和CP70细胞对顺铂的耐药性(P<0.05)。二甲双胍作用能够降低C13K和CP70细胞中ERCC1 m RNA和蛋白的表达水平(P<0.05),并激活AMPK信号通路(P<0.05);而联合应用AMPK信号通路阻断剂Compound C可以阻断二甲双胍的这种作用(即ERCC1蛋白表达水平升高)(P<0.01)。p38MAPK信号通路抑制剂SB203580作用后,C13K和CP70细胞中ERCC1蛋白表达水平降低(P<0.05);而二甲双胍作用可降低p38MAPK的磷酸化水平(P<0.01),抑制p38MAPK信号通路。二甲双胍作用转染了p38MAPK si RNA的C13K和CP70细胞后,ERCC1蛋白的表达水平无明显变化(P>0.05)。结论:二甲双胍可能逆转卵巢癌顺铂耐药株对顺铂的耐药性,并且这一作用可能是通过抑制p38MAPK信号通路和降低细胞中ERCC1的表达而实现的。
