Estrogen plays a critical role in AAV2-mediated gene transfer in ovarian cancer
Aim: The aim of our study was to develop an effective gene delivery system for ovarian cancer gene therapy. Methods: The expression of heparin sulfate proteoglycan (HSPG) and integrins α3 and α5 were analyzed with flow cytometry on 2 human ovarian cancer cell lines (OVCAR-3 and SKOV-3ip). The gene transduction efficiencies were evaluated with recombinant adeno-associated viral vector (rAAV)2–green fluorescent protein or rAAV2–lactase Z followed by flow cytometry or cytohistochemistry staining. The effect of 17-estradiol on ovarian cancer cell proliferation, HSPG, the expressions of integrins α3 and α5, and adeno-associated viral vector (AAV)2-mediated gene transduction were determined. Results: In the present study, we found: (1) a variation in HSPG and the expressions of integrins α3 and α5 between OVCAR-3 and SKOV-3ip; (2) that 17-estradiol was shown to significantly stimulate cell proliferation and integrin 5 expression in certain ovarian cancer cell lines; and (3) integrin-targeted A520/N584RGD–rAAV2, which has alternative interactivity with integrins and abrogates the binding capacity HSPG, showed much higher gene transduction efficiency in ovarian cancer cells than rAAV2 in the presence/absence of 17-estradiol. Moreover, this RGD-modified rAAV2 exerted more efficient transduction in ovarian cancer cells in response to 17-estradiol. Conclusion: Our findings implied that A520/N584RGD-rAAV2 may offer great potential for ovarian cancer treatment in vivo.