HIN-1, an inhibitor of cell growth, invasion, and AKT activation.

The HIN-1 gene encoding a small, secreted protein is silenced due to methylation in a substantial fraction of breast, prostate, lung, and pancreatic carcinomas, suggesting a potential tumor suppressor function. The receptor of HIN-1 is unknown, but ligand-binding studies indicate the presence of high-affinity cell surface HIN-1 binding on epithelial cells. Here, we report that HIN-1 is a potent inhibitor of anchorage-dependent and anchorage-independent cell growth, cell migration, and invasion.

Frequent HIN-1 promoter methylation and lack of expression in multiple human tumor types.

HIN-1 (high in normal-1) is a candidate tumor suppressor identified as a gene silenced by methylation in the majority of breast carcinomas. HIN-1 is highly expressed in the mammary gland, trachea, lung, prostate, pancreas, and salivary gland, and in the lung, its expression is primarily restricted to bronchial epithelial cells. In this report, we show that, correlating with the secretory nature of HIN-1, high levels of HIN-1 protein are detected in bronchial lavage, saliva, plasma, and serum.

Polyamine-mediated post-transcriptional regulation of COX-2.

Polyamines are involved in various cellular processes including embryonic development, cell growth and cell cycle regulation, apoptosis and carcinogenesis. Growing evidence suggests the importance of RNA processing and stability mediated by oncogenes and tumor suppressor genes in the development of cancer. Polyamines, which are found to be increased in neoplastic cells and tissues compared to normal, bind to RNA to influence its structure and function.

Selenomethionine inhibits growth and suppresses cyclooxygenase-2 (COX-2) protein expression in human colon cancer cell lines.

Currently, selenium (in the form of high selenium containing yeast or selenomethionine) is being evaluated for anticancer effects against both human colon polyp recurrence and human prostate cancer, respectively. Chemical speciation analysis of the high selenium containing yeast indicates that selenomethionine (SeMet) is a major constituent of selenized yeast. We tested the hypothesis that SeMet might affect colon cancer cell growth by mechanisms involving cyclooxygenases (COX).