PTEN/MMAC1/TEP1在肺癌中的丢失和失活

目的 了解抑制癌基因ＰＴＥＮ／ＭＭＡＣ１／ＴＥＰ１（以下简称ＰＴＥＮ）在肺癌中的缺失和失活。方法 选用２４例具有正常对照的肺癌新鲜标本,１８例小细胞肺癌石蜡切片,用聚合酶链反应及杂合性丢失分析法检测ＰＴＥＮ的杂合笥丢失;并采用原位杂交法、免疫组化化学染色法、Ｗｅｓｔｅｍ ｂｌｏｔ法观察肺癌标本中ＰＴＥＮ ｍＲＮＡ和蛋白水平的表达。对１株肺腺癌和３株小细胞肺癌系进行ＰＴＥＮ的Ｓｏｕｔｈｅｒｎ、Ｎｏｒ

Loss and inactivation of PTEN/MMAC1/TEP1 gene in lung cancer

Objective The recently identified PTEN/MMAC1/TEP1 gene is the first tumor suppressor encoding a phosphatase,which mutated in multiple tumors. Our research aims to detect loss of heterozygosity and inactivation of PTEN in lung cancer. Methods 24 lung cancer fresh samples paired with normal tissue, 18 archival paraffinembedded sections of small cell lung cancer (SCLC) were included. For 24 fresh samples, PCRLOH was used to detect Loss of heterozygosity (LOH) in or near PTEN loci. In situ hybridization, Western blot and or immunohistochemistry were proceeded for mRNA and protein expression of PTEN in lung cancer samples. Southern, Northern and Western blot were done to exam PTEN abnormality in one NSCLC and three SCLC cell lines. Results Among these 24 fresh samples PTEN LOH was detected in 11 out of 24 cases(45.8%) and 6 cases had no PTEN mRNA and protein expression. Results in situ hybridization were in conformity with that of immunohistochemistry/Western blot in our research. No protein expression was detected in 8/18(44%) archival paraffin cases of SCLC. Southern,Northern and Western blot confirmed homozygous deletion in one SCLC cell line. Conclusion Lung cancers had LOH and inactivation of PTEN.