The epidermal growth factor receptor (EGFR) and type 1 insulin-like growth factor receptor (type 1 IGF receptor or IGF1R) have played an important role in the growth and apoptosis of cancer. The RNA interference (RNAi) technique can suppress gene expression, but the effects of dual silencing of EGFR and type 1 IGF receptor have not been well understood.

pU6-EGFR-shRNA-1, pU6-EGFR-shRNA-2, pU6-IGF1R-shRNA-1 and pU6-IGF-1R-shRNA-2 plasimd vectors were transfected to the nasopharyngeal cancer cells. Seven groups were selected for the study. The protein and downstream protein expression were assessed by Western blot. Apoptosis was determined via flow cytometry. Meanwhile, chemosensitivity of nasopharyngeal cancer cell lines transfeced to chemotherapeutic drugs were carried out by MTT.

In dual silencing of EGFR and IGF-1R, the protein expression much more was decreased than single silencing of EGFR or IGF-1R, but the cell apoptosis much more is increased than single silencing EGFR or IGF-1R. Dual silencing of EGFR and IGF-1R enhanced chemosensitivity to anticancer drugs, compared with single silencing of EGFR or IGF-1R.

Dual silencing of EGFR and IGF-1R are capable of suppressing EGFR and IGF-1R expression of the nasopharyngeal cancer cell and can promote apoptosis and increase the cell sensitivity of anticancer drug. The dual silencing of genes RNAi technique is significantly better than a single gene.