Elevated expression levels of the 14-3-3 family of proteins in lung cancer tissues

Abstract

Immunochemical staining of lung cancer sections with a murine monoclonal anti-14-3-3 antibody showed a sharp discrimination of the cancer tissue from neighboring normal counterparts in 88 of 121 primary lung cancer tissue specimens of all four major lung cancer histologies; specifically, 32 of 48 adenocarcinomas, 36 of 44 squamous cell carcinomas, 10 of 13 large cell carcinomas, and 10 of 16 small cell carcinomas, respectively, were stained positively. Sets of the 10,000 × g supernatants of normal and cancerous lung tissue homogenates, each set prepared from surgically dissected tissues of the cancer and its surrounding normal part, were assayed for 14-3-3 proteins by the sandwich enzyme-linked immunosorbent assay using two different monoclonal antibodies to 14-3-3 proteins. The results of the assay demonstrated 7.2 times higher 14-3-3-protein content in the lung cancer tissue (378±200 ng ml⁻¹) as compared with the normal lung (54±35 ng ml⁻¹). These results indicate that the 14-3-3 family of proteins can be an effective marker for lung cancer diagnosis such as sputum cytodiagnosis and that 14-3-3 proteins might be involved in the development of lung cancers.