Downregulation of human epidermal growth factor receptor 2 by short hairpin RNA increases chemosensitivity of human ovarian cancer cells.

The aim of the current study was to investigate the suppressive effects of pSilencer T7-human epidermal growth factor receptor 2 (HER2)-short hairpin RNA (shRNA) recombinant plasmids on human SKOV3 ovarian cancer cell growth and sensitivity to carboplatin (CBP). Three different pairs of shRNAs (shRNAa, shRNAb and shRNAc), targeting the HER2 gene, were selected and transfected into human SKOV3 cells, respectively. The expression levels of HER2 were then detected by immunohistochemical (IHC), semi-quantitative reverse transcription-polymerase chain reaction and western blot analyses. In addition, cell cycle and cell growth were investigated using cell counting kit-8 (CCK-8). The results of the IHC and western blot analyses revealed that shRNAb significantly inhibited HER2 protein expression in SKOV3 cells. shRNAb exhibited an improved effect on HER2 expression compared with shRNAa (P<0.01), while shRNAc did not affect HER2 expression. Nontransfected and nonspecific shRNA groups were used as the negative controls. Knockdown of HER2 expression by shRNA was initiated at 24 h following transfection, achieving an optimum effect at 48 h and lasting for at least 72 h after the treatment. The CCK-8 cell growth assay indicated that the knockdown of HER2 expression in the SKOV3 cell line resulted in significant growth suppression and cell cycle arrest. In addition, inhibition of HER2 significantly increased SKOV3 cell sensitivity to CBP treatment. In conclusion, pSilencer T7-HER2-shRNA significantly inhibited HER2 expression in human ovarian cancer cells in vitro and induced chemotherapeutic sensitivity to CBP.