CRTC2 and PROM1 expression in non-small cell lung cancer: analysis by Western blot and immunohistochemistry.

Accumulating evidence supports that genetic factors are another risk factors for lung cancer. Previously, we used whole exome sequencing with sanger sequencing to search for genetic-related mutations in one of four individuals from a pedigree with lung cancer history. Then, we used PCR-RFLP and direct-sequence in the sample size of 318 individuals with lung cancer (cases) and 272 controls. Recently, we detected two new genes including CRTC2 (CREB regulated transcription coactivator 2) and PROM1(human prominin-1,CD133). We investigated the CRTC2 mutation and PROM1 mutation of surgically resected NSCLC tissues (n=200). The presence or absence of CRTC2 and PROM1 mutation was analyzed by direct sequencing. The expression of CRTC2 and PROM1 was studied by western blot and immunohistochemical analysis of the lung cancer tissues which had the mutation of the two genes(cases), the samples without mutations(controls) and the normal lung tissue(controls). CRTC2 and PROM1 mutations in 5 NSCLC tissues and 3 NSCLC tissues out of the samples were identified. The positive results were closely correlated with clinicopathological features, such as male gender, adenocarcinoma, smoker status, and older age (≥55). We found that the CRTC2 and PROM1 expression were significantly higher in tissues of NSCLS with mutations than that without mutations and the normal lung tissue. The results imply that the high expression of CRTC2 and PROM1 may play an important role in the development and hereditary of NSCLC.