The research for the classification by molecular biology and the development of a novel therapy in squamous cell carcinomas of the skin

皮肤鳞状细胞癌（SCCs）的发展是一个多步骤的过程，涉及人类皮肤角质形成细胞中原癌基因的激活和/或肿瘤抑制基因的失活。近年来，除了基因突变和染色体异常外，癌症相关基因DNA启动子甲基化异常引起的表观遗传失活已被发现是几种癌症的共同和重要特征。在本研究中，我们利用20例皮肤SCCs的DNA样本，采用亚硫酸根PCR方法分析了E-cadherin、p16^<INK4a>、p14^<ARF>、p15、pRb、DAPK、MGMT、RASSF1A、RIZ1和PTEN的启动子甲基化状态。分别在19/20（95%）、4/20（20%）、3/20（15%）、1/20（5%）、1/20（5%）、3/20（15%）、3/20（15%）、1/20（5%）、0/20（0%）和0/20（0%）中检测到启动子甲基化。这些发现表明，癌症相关基因的表观遗传失活可能是皮肤鳞状细胞癌的共同特征，并与皮肤鳞状细胞癌的发生有关。

Squamous cell carcinomas (SCCs) of the skin are supposed to develop through the multistep process that involves activation of proto-oncogenes and/or inactivation of tumor suppressor genes in the human skin keratinocytes. Recently, in addition to gene mutations and chromosomal abnormalities, epigenetic inactivation due to aberrant DNA promoter methylation of cancer-related genes has been revealed to be a common and important feature of several cancers. In this study, we analyzed promoter methylation status of E-cadherin, p16^<INK4a>, p14^<ARF>, p15, pRb, DAPK, MGMT, RASSF1A, RIZ1, and PTEN by means of bisulfite PCR using DNA samples from 20 cases of SCCs of the skin. Promoter methylation was detected in 19/20 (95%), 4/20 (20%), 3/20 (15%), 1/20 (5%), 1/20 (5%), 3/20 (15%), 3/20 (15%), 1/20 (5%), 0/20 (0%), and 0/20 (0%), respectively. These findings indicate that epigenetic inactivation of cancer-related genes might be a common feature of SCCs of the skin and have some relevance to the carcinogenesis in SCCs of the skin.