[Expression of PTEN, p16, p21, and p53 proteins in lung cancer using tissue microarray and their clinical significance].

BACKGROUND & OBJECTIVE: The genesis of lung cancer was associated with mutation or abnormal expression of PTEN, p16, p21, and p53. Tissue microarray provides a high throughout tool for genes expression. But little is reported about expression of PTEN, p16, p21, and p53 in lung cancers with tissue microarray. The aim of this study was to investigate the expression of PTEN, p16, p21, and p53 proteins and to analyze their relationship with the pathogenesis, invasion, and metastasis in lung cancer. METHODS: The expression of the antioncogene proteins in 100 cases of lung cancer and corresponding adjacent tissues were determined by tissue microarray combined with immunohistochemistry. RESULTS: The positive expression rates of PTEN, p16, p21, and p53 proteins were 31% (31/100), 38% (38/100), 42% (42/100), 53% (53/100) in lung cancer tissues, and were 85% (85/100), 72% (72/100), 80% (80/100), and 23% (23/100) in the adjacent cancer tissues, respectively, showing a low expression of PTEN, p16, p21 in cancer tissues, and high expression of p53 outside of them (P< 0.05, P< 0.01). Furthermore, the expression of PTEN, P16, and p53 proteins showed positive correlation with the clinical degrees and pathological stages of lung squamous carcinomas and adenocarcinomas (P< 0.05,P< 0.01). In lung cancer with lymph node metastasis, the expression of PTEN, p16, and p21 were low, but the expression of p53 increased significantly (P< 0.05, P< 0.01). CONCLUSION: Tissue microarray provided a useful high-throughout tool for multigene expression in large-scale investigations. There existed low expression of PTEN, p16, p21 proteins and over-expression of mutated p53 protein. Coexpression of these antioncogenes played an important role in invasion and metastasis in lung cancer.