Overexpression and activation of HER-2/neu (also known as c-erbB-2), a proto-oncogene, was found in about 30% of human breast cancers, promoting cancer growth and making cancer cells resistant to chemo- and radio-ther...Overexpression and activation of HER-2/neu (also known as c-erbB-2), a proto-oncogene, was found in about 30% of human breast cancers, promoting cancer growth and making cancer cells resistant to chemo- and radio-therapy. Wild-type p53 is crucial in regulating cell growth and apoptosis and is found to be mutated or deleted in 60-70% of human cancers. And some cancers with a wild-type p53 do not have normal p53 function, suggesting that it is implicated in a complex process regulated by many factors. In the present study, we showed that the overexpression of HER-2/neu could decrease the amount of wild-type p53 protein via activating PI3K pathway, as well as inducing MDM2 nuclear translocation in MCF7 human breast cancer cells. Blockage of PI3K pathway with its specific inhibitor LY294002 caused Gl-S phase arrest, decreased cell growth rate and increased chemo- and radio-therapeutic sensitivity in MCF7 cells expressing wild-type p53. However, it did not increase the sensitivity to adriamycin in MDA-MB-453 breast cancer cells containing mutant p53. Our study indicates that blocking PI3K pathway activation mediated by HER-2/neu overexpression may be useful in the treatment of breast tumors with HER-2/neu overexpression and wild-type p53.展开更多
目的探讨用荧光原位杂交(fluorescent in situ hybridization,FISH)方法检测乳腺癌HER-2/neu基因表达的临床意义。方法应用FISH法对2008年1月至2008年7月在首都医科大学附属北京天坛医院就诊的33例女性新发乳腺癌患者进行HER-2/neu基因...目的探讨用荧光原位杂交(fluorescent in situ hybridization,FISH)方法检测乳腺癌HER-2/neu基因表达的临床意义。方法应用FISH法对2008年1月至2008年7月在首都医科大学附属北京天坛医院就诊的33例女性新发乳腺癌患者进行HER-2/neu基因检测,分析基因表达程度与临床病理特征之间的关系,比较基因和免疫组化(IHC)法蛋白表达的差别。结果33位受试者中HER-2/neu基因过表达率为39.4%,其过表达与肿瘤大小、绝经与否、临床分期之间差异无统计学意义(P>0.05)。该基因在有腋淋巴结转移组显著高于无淋巴结转移组(P<0.05),ER阴性组高于ER阳性组,差异有统计学意义(P<0.01)。PR阴性组与阳性组间差异无统计学意义。P53基因阳性组显著高于阴性组(P<0.05)。HER-2/neu基因过表达者11例为免疫组化HER-2蛋白强阳性病例;2例为中度阳性病例。结论FISH技术可稳定检测乳腺癌中HER-2/neu基因的表达程度,其过表达与绝经与否、肿瘤大小、临床分期无关,与腋淋巴结转移和P53基因表达成正相关,与ER呈密切负相关。HER-2蛋白高强度表达(3+)与基因扩增有极好的一致性,而中等强度表达(2+)必须进一步行FISH法基因检测。展开更多
文摘Overexpression and activation of HER-2/neu (also known as c-erbB-2), a proto-oncogene, was found in about 30% of human breast cancers, promoting cancer growth and making cancer cells resistant to chemo- and radio-therapy. Wild-type p53 is crucial in regulating cell growth and apoptosis and is found to be mutated or deleted in 60-70% of human cancers. And some cancers with a wild-type p53 do not have normal p53 function, suggesting that it is implicated in a complex process regulated by many factors. In the present study, we showed that the overexpression of HER-2/neu could decrease the amount of wild-type p53 protein via activating PI3K pathway, as well as inducing MDM2 nuclear translocation in MCF7 human breast cancer cells. Blockage of PI3K pathway with its specific inhibitor LY294002 caused Gl-S phase arrest, decreased cell growth rate and increased chemo- and radio-therapeutic sensitivity in MCF7 cells expressing wild-type p53. However, it did not increase the sensitivity to adriamycin in MDA-MB-453 breast cancer cells containing mutant p53. Our study indicates that blocking PI3K pathway activation mediated by HER-2/neu overexpression may be useful in the treatment of breast tumors with HER-2/neu overexpression and wild-type p53.
文摘目的探讨用荧光原位杂交(fluorescent in situ hybridization,FISH)方法检测乳腺癌HER-2/neu基因表达的临床意义。方法应用FISH法对2008年1月至2008年7月在首都医科大学附属北京天坛医院就诊的33例女性新发乳腺癌患者进行HER-2/neu基因检测,分析基因表达程度与临床病理特征之间的关系,比较基因和免疫组化(IHC)法蛋白表达的差别。结果33位受试者中HER-2/neu基因过表达率为39.4%,其过表达与肿瘤大小、绝经与否、临床分期之间差异无统计学意义(P>0.05)。该基因在有腋淋巴结转移组显著高于无淋巴结转移组(P<0.05),ER阴性组高于ER阳性组,差异有统计学意义(P<0.01)。PR阴性组与阳性组间差异无统计学意义。P53基因阳性组显著高于阴性组(P<0.05)。HER-2/neu基因过表达者11例为免疫组化HER-2蛋白强阳性病例;2例为中度阳性病例。结论FISH技术可稳定检测乳腺癌中HER-2/neu基因的表达程度,其过表达与绝经与否、肿瘤大小、临床分期无关,与腋淋巴结转移和P53基因表达成正相关,与ER呈密切负相关。HER-2蛋白高强度表达(3+)与基因扩增有极好的一致性,而中等强度表达(2+)必须进一步行FISH法基因检测。
