Neuron specific enolase promoter for suicide gene therapy in small cell lung carcinoma.

To investigate the specific transduction of a suicide gene into human small cell lung carcinoma (SCLC) cells, we explored the promoter region of the neuron specific enolase (NSE) gene as a tumor-specific promoter. In Northern blot analysis, NSE mRNA was expressed more abundantly in the SBC3 human SCLC cell line than in the RERF human SCLC cell line, the A549 human lung adenocarcinoma cell line and the HeLa human uterine cervix epitheloid carcinoma cell line. A reporting vector containing the NSE promoter (pNSE-LUC) exhibited higher luciferase activity in SBC3 than in the other three cell lines. After transfecting an expression vector containing the NSE promoter-bound HSV-TK gene (pNSE-TK) into the cells, we measured their sensitivity to ganciclovir (GCV). In SBC3, pNSE-TK transfected cells showed about the same sensitivity to GCV as non-transfected (parental) cells. Though the NSE promoter itself is not optimal for use in suicide gene transfer to SCLC cells, it might be applied as a tumor-specific promoter after enhancement of its activity.