Cloning and analysis of PTEN2 gene

RACE克隆的PTEN2 cDNA片段是位于染色体9q上的假基因。我们研究了PTEN mRNA在食管、胃和乳腺原发性癌和细胞系中的突变和表达。在食管癌和乳腺癌中未发现突变，但在胃癌细胞系中仅发现1个突变。在一个胃癌细胞系和一个乳腺癌细胞系中观察到PTEN基因的高甲基化失活。在两个细胞系中观察到过表达。原发肿瘤的显微解剖结果显示PTEN基因失活，AKT基因过表达。这些癌均为硬结性癌。这些结果表明PTEN基因失活可能在这些类型的肿瘤细胞中起重要作用。

The cDNA fragments of PTEN2 cloned by RACE was a pseudogene located on the chromosome 9q. We investigated mutations and expression of PTEN mRNA in primary carcinomas and cell lines of the esophagus, stomach and breast. No mutations were found in esophageal and breast carcinomas, but only one mutation was confirmed in gastric cancer cell line. Inactivation of PTEN gene by hypermethylation was observed in a gastric and a breast cancer cell lines. 0verexpression was observed in two cell lines. Microdissected materials obtained from primary tumors showed inactivation of PTEN gene and overexpression of AKT gene. These carcinomas were all scirrhous type of carcinomas. These results indicated that inactivation of PTEN gene may play a significant role in these type of tumor cells.