Therapeutic potential of combination therapy of soluble VEGF receptor 1 and conventional chemotherapy for ovarian cancer growth

Abstract

Aim This study aimed at evaluating the additional anti‐tumor effects of exogenous rVEGFR1 (sFlt1) on conventional chemotherapy in ovarian cancer cell lines. Methods We utilized cells from two ovarian cancer cell lines, SKOV3 and HeyA8, and treated them with a combination of rVEGFR1 (sFlt1) and carboplatin as well as rVEGFR1 (sFlt1) alone. First, we evaluated cell survival after treatment by using cell counting and MTS assays. Next, we performed Ki67 staining for evaluating the inhibitory effects of the treatment on cell proliferation, and a lactate dehydrogenase (LDH) assay for evaluating cytotoxicity. Finally, to determine whether MAP kinase signaling is involved in this process, we performed western blot analysis of extracellular signal‐regulated kinase (ERK), phospho‐ERK, c‐jun n‐terminal kinase (JNK) and phospho‐JNK. Results The cytotoxic and growth‐restriction effects were more pronounced in the group co‐administered with rVEGFR1 (sFlt1) and carboplatin than in cells treated with either rVEGFR1 (sFlt1) or carboplatin alone. Quantitative analysis of Ki67‐positive cells also showed a decreased proportion of Ki67‐positive cells in SKOV3 cells treated with a combination of exogeneous rVEGFR1 (sFlt1) and carboplatin compared to that in cells treated with either rVEGFR1 (sFlt1) or carboplatin alone. In the LDH assay, we also found significantly enhanced cell toxicity from the combination therapy. Finally, western blotting analysis showed that the MAPK signaling pathway was not affected by sFlt1 treatment. Conclusion This study confirmed the additive effects of rVEGFR1 (sFlt1) combined with conventional chemotherapy for ovarian cancer growth in in vitro assays, thus suggesting the combination of rVEGFR1 (sFlt1) and carboplatin as a potential novel therapeutic option for ovarian cancer.