AIM： To observe the growth inhibitory effect of wild-type Kras2 gene on a colonic adenocarcinoma cell line Caco-2. METHODS： Recombinant plasmid pCI-neo-Kras2 with wild type Kras2 open reading frame was constructed. ...AIM： To observe the growth inhibitory effect of wild-type Kras2 gene on a colonic adenocarcinoma cell line Caco-2. METHODS： Recombinant plasmid pCI-neo-Kras2 with wild type Kras2 open reading frame was constructed. The Caco-2 cells were transfected with either pCI-neo or pCI-neo-Kras2 using Upofectamine 2000. The expression of wild type Kras2 was examined by Northern blot analysis. And the expression of wild type Kras2 protein was examined by Western blot analysis. The effects of wild-type Kras2 on cell proliferation were analyzed by monotetrazolium （MTT） assay, meanwhile analyses of cell cycle and spontaneous apoptosis rate were carried out by flow cytometry （FCM）. RESULTS： The plasmid of pCI-neo-Kras2 was successfully established. The growth rate of cells transfected with pCI-neo-Kras2 was significantly lower than the control cells transfected with the empty pCI- neo vector （P 〈 0.05）. Cell cycle analysis revealed arrest of the pCI-neo-Kras2 transfected cells in G0/G1 phases, decreased DNA synthesis and decreased fractions of cells in S phase. The proliferative index of cells transfected with pCI-neo-Kras2 was decreased compared with the control cells （49.78% vs 64.21%）, while the apoptotic rate of Caco-2 cells with stable Kras2 expression increased （0.30% vs 0.02%）. CONCLUSION： The wild-type Kras2 gene effectively inhibits the growth of the colonic adenocarcinoma cell line Caco-2.展开更多
AIM： To study the loss of heterozygosity （LOH） on 12p12-13 in Chinese colon carcinoma patients.METHODS： DNA was extracted from 10 specimens of cancer tissue, 10 specimens of adjacent tissue and 10 specimens of nor...AIM： To study the loss of heterozygosity （LOH） on 12p12-13 in Chinese colon carcinoma patients.METHODS： DNA was extracted from 10 specimens of cancer tissue, 10 specimens of adjacent tissue and 10 specimens of normal tissue, respectively. LOH of Kras2 gene was analyzed by polymerase chain reaction （PCR） and denaturing polyacrylamide gel electrophoresis using 11 microsatellite markers on 12p-12-13.RESULTS： LOH of Kras gene was detected at least on one marker of 12p-12-13 in 30% （3/10） of adjacent tissue specimens. The highest frequency of LOH was identified on D12S1034 in 28.57% （2]7） of adjacent tissue specimens. LOH was detected at least on one marker of 12p12-13 in 60% （6/10） of carcinoma tissue specimens, the most frequent LOH was found on D12S1034 and D12S1591 in 42.86% （3/7） of carcinoma tissue specimens. LOH was detected in 30% （3/10） of carcinoma tissue specimens, 30% （3/10） of adjacent tissue specimens, and no signal in 1% （1/0） carcinoma tissue specimen. The occurrence of LOH did not correlate with sex, age, tumor size and lymph node metastasis.CONCLUSION： Genomic instability may occur on 12p-12-13 of Kras2 gene in the development and progression of colon carcinoma. The high LOH of Kras2 gene may directly influence the transcription and translation of wild type Kras2 gene.展开更多
Gut杂志上的一份报告指出:大多数结直肠肿瘤患者术前血清中都能发现KRAS2突变体,但是在手术后该突变体再被检出则有力地预示着疾病的复发。 荷兰Maastricht大学医院Dr.B. M. Ryan及其同事,分别评价了78名术前结直肠肿瘤患者和94名已接...Gut杂志上的一份报告指出:大多数结直肠肿瘤患者术前血清中都能发现KRAS2突变体,但是在手术后该突变体再被检出则有力地预示着疾病的复发。 荷兰Maastricht大学医院Dr.B. M. Ryan及其同事,分别评价了78名术前结直肠肿瘤患者和94名已接受肿瘤切除手术的病人(连续三年内每月三次对这94名患者进行采血检查),对他们肿瘤和血清样本中第12、13号密码子的KRAS2突变体情况进行了分析。 他们发现,在78名术前患者中,41人(53％)的肿瘤样本和32人(41％)的血清样本中检出KRAS2突变体。41名在肿瘤中检出有KRAS2突变体患者中的31名(76％)病人血清中也发现了突变体。展开更多
目的通过对中国人结肠癌染色体12p12-13杂合性丢失(loss of heterozygosity,LOH)分析,了解KRAS2基因与结肠癌发生发展的关系。方法从10例结肠癌手术切除标本中,提取肿瘤、癌旁及相应正常组织的DNA,用PCR-变性聚丙烯酰胺凝胶电泳-免疫荧...目的通过对中国人结肠癌染色体12p12-13杂合性丢失(loss of heterozygosity,LOH)分析,了解KRAS2基因与结肠癌发生发展的关系。方法从10例结肠癌手术切除标本中,提取肿瘤、癌旁及相应正常组织的DNA,用PCR-变性聚丙烯酰胺凝胶电泳-免疫荧光标记多重微卫星PCR法,对染色体12p12-13杂合性丢失进行分析。结果10例癌旁组织中有3例(30%)在12p12-13处至少有一个位点出现杂合性丢失,其中D12S1034出现频率最高,为28.57%(2/7);10例原发性结肠癌标本中6例(60%)在12p12-13处至少有一个位点出现有杂合性丢失,D12S1034和D12S1591是高频率丢失集中的区域,均占42.86%(3/7);癌旁组织、癌组织均发生LOH的标本有3例,占30%(3/10);仅在癌组织中发生LOH的标本有3例,占30%(3/10);仅在癌旁组织中发生LOH,癌组织无信号的标本1例;杂合性丢失的频率与肿瘤患者的年龄、性别、肿瘤大小、肿瘤部位及淋巴结转移均无关。结论KRAS2基因所在的12p12-13区域在结肠癌发生发展过程中出现基因组不稳定,该区域的高频杂合性丢失可能直接影响野生型KRAS2基因的转录与翻译。展开更多
基金a grant from National Natural Science Foundation of China for Young Scholars, No. 30200326
文摘AIM： To observe the growth inhibitory effect of wild-type Kras2 gene on a colonic adenocarcinoma cell line Caco-2. METHODS： Recombinant plasmid pCI-neo-Kras2 with wild type Kras2 open reading frame was constructed. The Caco-2 cells were transfected with either pCI-neo or pCI-neo-Kras2 using Upofectamine 2000. The expression of wild type Kras2 was examined by Northern blot analysis. And the expression of wild type Kras2 protein was examined by Western blot analysis. The effects of wild-type Kras2 on cell proliferation were analyzed by monotetrazolium （MTT） assay, meanwhile analyses of cell cycle and spontaneous apoptosis rate were carried out by flow cytometry （FCM）. RESULTS： The plasmid of pCI-neo-Kras2 was successfully established. The growth rate of cells transfected with pCI-neo-Kras2 was significantly lower than the control cells transfected with the empty pCI- neo vector （P 〈 0.05）. Cell cycle analysis revealed arrest of the pCI-neo-Kras2 transfected cells in G0/G1 phases, decreased DNA synthesis and decreased fractions of cells in S phase. The proliferative index of cells transfected with pCI-neo-Kras2 was decreased compared with the control cells （49.78% vs 64.21%）, while the apoptotic rate of Caco-2 cells with stable Kras2 expression increased （0.30% vs 0.02%）. CONCLUSION： The wild-type Kras2 gene effectively inhibits the growth of the colonic adenocarcinoma cell line Caco-2.
基金Supported by the National Natural Science Foundation of China,No.30200326
文摘AIM： To study the loss of heterozygosity （LOH） on 12p12-13 in Chinese colon carcinoma patients.METHODS： DNA was extracted from 10 specimens of cancer tissue, 10 specimens of adjacent tissue and 10 specimens of normal tissue, respectively. LOH of Kras2 gene was analyzed by polymerase chain reaction （PCR） and denaturing polyacrylamide gel electrophoresis using 11 microsatellite markers on 12p-12-13.RESULTS： LOH of Kras gene was detected at least on one marker of 12p-12-13 in 30% （3/10） of adjacent tissue specimens. The highest frequency of LOH was identified on D12S1034 in 28.57% （2]7） of adjacent tissue specimens. LOH was detected at least on one marker of 12p12-13 in 60% （6/10） of carcinoma tissue specimens, the most frequent LOH was found on D12S1034 and D12S1591 in 42.86% （3/7） of carcinoma tissue specimens. LOH was detected in 30% （3/10） of carcinoma tissue specimens, 30% （3/10） of adjacent tissue specimens, and no signal in 1% （1/0） carcinoma tissue specimen. The occurrence of LOH did not correlate with sex, age, tumor size and lymph node metastasis.CONCLUSION： Genomic instability may occur on 12p-12-13 of Kras2 gene in the development and progression of colon carcinoma. The high LOH of Kras2 gene may directly influence the transcription and translation of wild type Kras2 gene.
文摘Gut杂志上的一份报告指出:大多数结直肠肿瘤患者术前血清中都能发现KRAS2突变体,但是在手术后该突变体再被检出则有力地预示着疾病的复发。 荷兰Maastricht大学医院Dr.B. M. Ryan及其同事,分别评价了78名术前结直肠肿瘤患者和94名已接受肿瘤切除手术的病人(连续三年内每月三次对这94名患者进行采血检查),对他们肿瘤和血清样本中第12、13号密码子的KRAS2突变体情况进行了分析。 他们发现,在78名术前患者中,41人(53％)的肿瘤样本和32人(41％)的血清样本中检出KRAS2突变体。41名在肿瘤中检出有KRAS2突变体患者中的31名(76％)病人血清中也发现了突变体。
文摘目的通过对中国人结肠癌染色体12p12-13杂合性丢失(loss of heterozygosity,LOH)分析,了解KRAS2基因与结肠癌发生发展的关系。方法从10例结肠癌手术切除标本中,提取肿瘤、癌旁及相应正常组织的DNA,用PCR-变性聚丙烯酰胺凝胶电泳-免疫荧光标记多重微卫星PCR法,对染色体12p12-13杂合性丢失进行分析。结果10例癌旁组织中有3例(30%)在12p12-13处至少有一个位点出现杂合性丢失,其中D12S1034出现频率最高,为28.57%(2/7);10例原发性结肠癌标本中6例(60%)在12p12-13处至少有一个位点出现有杂合性丢失,D12S1034和D12S1591是高频率丢失集中的区域,均占42.86%(3/7);癌旁组织、癌组织均发生LOH的标本有3例,占30%(3/10);仅在癌组织中发生LOH的标本有3例,占30%(3/10);仅在癌旁组织中发生LOH,癌组织无信号的标本1例;杂合性丢失的频率与肿瘤患者的年龄、性别、肿瘤大小、肿瘤部位及淋巴结转移均无关。结论KRAS2基因所在的12p12-13区域在结肠癌发生发展过程中出现基因组不稳定,该区域的高频杂合性丢失可能直接影响野生型KRAS2基因的转录与翻译。
