XIAP和Smac/DIABLO在乳腺癌发生、发展中的表达及意义

目的：探讨XIAP、Smac/DIABLO基因的表达及二者的相对关系在乳腺癌发生和发展中的作用。方法：采用实时定量PCR方法检测正常乳腺组织（6例）、乳腺增生组织（16例）、乳腺癌组织（62例）中XIAP mRNA和Smac/DIABLO mRNA的表达,并分析其与乳腺癌临床病理特征的关系。结果：在所有标本中均检测到了XIAP和Smac/DIABLO的表达,乳腺癌组织中的XIAP mRNA水平和XIAP/Smac比值明显高于正常乳腺组织和乳腺增生组织（P〈0.05）;从原位癌到浸润性乳腺癌,XIAP mRNA水平和XIAP/Smac比值无明显提高（P〉0.05）;Smac/DIABLO mRNA水平在正常乳腺组织、乳腺增生组织和乳腺癌组织中基本保持恒定。发生淋巴结转移的乳腺癌组织中的XIAP/Smac比值明显高于无淋巴结转移的乳腺癌组织（P〈0.05）。结论：XIAP和Smac/DIABLO间的平衡在乳腺癌发生、发展过程中被逐渐打破,XIAP的相对高表达诱导凋亡抵抗,对乳腺癌的发生、发展起促进作用。

Expressions and significances of XIAP and Smac/DIABLO in carcinogenesis and progression of breast cancer

Objective： To explore the relevance of antiapoptotic XIAP and proapoptotic Smac/DIABLO for tumour progression in breast cancer.Methods： We analyzed XIAP and Smac/DIABLO mRNA expression in 6 normal breast tissues,16 nonatypical hyperplasia tissues and 62 breast cancer tissues by SYBR Green Quantitative Real-time PCR.The relationships between XIAP expression,Smac/DIABLO expression,XIAP/Smac and clinically pathological features of breast cancer were assessed.Results： XIAP and Smac/DIABLO mRNA expression was found in all tis-sues.The XIAP mRNA expression levels significantly increased from normal or nonatypical hyper-plasia tissues to breast cancer（P0.05）,but did not increase from ductal carcinoma in situ or lobular carcinoma in situ to invasive breast cancers.In contrast,mRNA expression levels of Smac/DIABLO did not significantly change from normal or nonatypical hyperplasia tissues to breast cancers.Consequently,the mRNA expression ratio between antiapoptotic XIAP and proapoptotic Smac/DIABLO markedly increased during progression from normal or nonatypical hyperplasia tissues to breast cancers（P0.05）.Moreover,breast cancers with lymph nodes metastasis exhibited a significantly higher XIAP to Smac/DIABLO expression ratio when compared with breast cancers without lymph nodesmetastasis（P0.05）.Conclusions： The delicate balance between XIAP and Smac/DIABLO expression is gradually disturbed during progression from normal,nonatypical hyperplasia tissue tobreast cancer,resulting in a relative increase of antiapoptotic XIAP over proapoptotic Smac/DIABLO,thereby probably contributing to the marked apoptosis resistance of breast cancer.