Objective: To study the growth inhibitory and chemo-sensitizing effects of adenovirus E1A gene on HER2/neu-overexpressing tumor cell lines.
Methods: E1A was transfected in vitro and in vivo by adenovirus vector into HER2/neu overexpressing human mammary cancer cell lines MDA-MB-453 and SKBR3 and their growth was monitored. The chemo-sensitizing effect was examined by MTT assay.
Results: E1A greatly inhibited growth of HER2/neu-overexpressing tumor and prolonged the survival time of tumor-bearing mice. Western blot and immunohistochemical analysis both showed suppression of p185 protein expression in E1A-transfected HER2/neu overexpressing cancer cell lines. E1A could sensitize HER2/neu-overexpressing human breast cancer cells to Taxotere by repressing HER2/neu expression.
Conclusion: Adenovirus E1A inhibits tumor growth and sensitizes tumor cells to chemotherapeutic agent via down regulation of HER2/neu expression.