抗凋亡的“原癌基因”Bcl-2实为抗癌基因
The antiapoptotic “oncogene” Bcl-2 is a de facto tumor suppressor

长期以来，细胞凋亡减少被认为是肿瘤发生的重要原因和机制，具有抗凋亡作用的基因被认为是癌基因。Bcl-2是在滤泡性B细胞淋巴瘤中分离出来的具有很强抗凋亡作用的基因，是这类癌基因的原型。吊诡的是，Bcl-2对肿瘤的发生和发展有很强的抑制作用。这种作用包括三个方面：①在培养细胞，Bcl-2的过表达可抑制细胞的生长和集落的形成；②在转基因动物，Bcl-2的过表达可抑制化学致癌物和其他癌基因诱发的肿瘤发生和生长；③在多种肿瘤，Bcl-2的过表达与患者的预后好相关。Bcl-2的这种生物学作用提示我们应该对癌基
The antiapoptotic genes have long been taken as a type of oncogenes, since reduced cell death has beenregarded as an important mechanism of oncogenesis and cancer development. Bcl-2 is a prototype of the antiapoptoticgenes originally isolated from the follicular B cell lymphoma. Paradoxically, Bcl-2 has a strong tumor suppressing effect,which is showed in the following aspects: ① overexpressed Bcl-2 inhibits the focus formation and cell growth ex vivo;②overexpressed Bcl-2 inhibits carcinogenesis induced by chemical carcinogens and other oncogenes in transgenicanimal studies; ③the overexpression is positively associated with favorable clinical outcomes of cancer patients. Theseparadoxical functions of Bcl-2 drive us to reconsider the concepts of oncogenes and tumor suppressor genes. We suggestputting Bcl-2 and other antiapoptotic genes in the tumor suppressor genes, instead of oncogenes. Further, instead ofblocking Bcl-2, a reverse strategy of mimicking the effects of Bcl-2 can be adopted in the cancer treatment