Inhibition of tumor growth of non-small cell lung cancer by small interfering RNA targeting to HER2/neu gene

AIM: To construct RNA interference (RNAi) vector to down-regulate HER2/neu gene and study the RNAi effect on the cell cycle and tumor growth of non-small cell lung cancer. METHODS: Oligonucleotides of 64 base pairs for hairpin RNA targeting HER2/neu were designed, chemically synthesized and annealed, and cloned into pSUPER vector.After identified by restriction digestion,the right vectors were transiently transfected into SPC-A-1 cells, a human lung adenocarcinoma cell line. The HER2 mRNA was detected by RT-PCR, and the protein detected by Western blot and indirect immunofluorescence staining. FCM analysis and MTT method were applied to measure cell cycle and cell growth respectively. RESULTS: SPC-A-1 cells had an overexpression of HER2. The vector of RNAi which can interfere HER2/neu gene was successfully constructed, and compared with parent cells, the vector can increase the number of cells in G0/G1 phase by 9.9%, and inhibit the tumor cell growth (P0.05). CONCLUSION: We successfully constructed an expressing hairpin RNA against HER2/neu vector. The vector can effectively silence HER2/neu gene, increase the number of cells in G0/G1 phase, and then slow down the growth of tumor cells.This may be a useful therapeutic strategy for NSCLC over-expressing HER2/neu.