311P - Blockade of vascular endothelial growth factor receptors by tivozanib inhibits growth and restores chemosensitivity in human ovarian carcinoma cells

Date 18 December 2016
Event ESMO Asia 2016 Congress
Session Poster lunch
Topics Anti-Cancer Agents & Biologic Therapy
Ovarian Cancer
Presenter Ghazaleh Zarrinrad
Citation Annals of Oncology (2016) 27 (suppl_9): ix94-ix103. 10.1093/annonc/mdw585
Authors G. Zarrinrad, M. Momeny, Z. Sabourinejad, F. Moghaddaskho, H. Eyvani, H. Yousefi, A. Poursheikhani, F. Barghi, F. Esmaeilii, M. Yaghmaiee, K. Alimoghaddam, A. Ghavamzadeh, S. Ghaffari
  • Hematology/oncology, HORC-SCT, TUMS-Shariati Hospital, 141144114 - Tehran/IR

Abstract

Background

Epithelial ovarian cancer (EOC) is the most fatal gynecological malignancy worldwide. Despite initial therapeutic response, the majority of advanced-stage patients relapse and succumb to chemoresistant disease. Therapy-resistant EOC is an incurable malignancy and overcoming drug resistance is the key to successful treatment. Members of vascular endothelial growth factor (VEGF) family of ligands and receptors are over-expressed in EOC and play key roles in its malignant progression though the exact contribution of this pathway in development of the chemoresistant disease remains largely elusive.

Methods

Cell proliferation, colony formation and anoikis resistance assays were performed to evaluate the effects of tivozasnib on cell viability. Quantitative reverse transcription-PCR was conducted to measure the effects of tivozanib on expression of IL6, IL8, CCNB1, BIRC5, CDK1, CDK2, CHEK1, CHEK2, CDKN1A and SFN. To investigate changes in expression of WEE1, cyclin B1, CDC25C, BCL2, BAX, P21 and survivin after tivozanib treatment, Western blot analysis was done. Propium iodide staining was performed to measure cell cycle distribution and a caspase 3 activation assay was used to investigate the effects of tivozanib on induction of apoptosis. Zymoanaylsis, uPA activity assay and cell migration/invasion assays were done to explore the effects of tivozanib treatment on MMP-2 activity, uPA enzymatic levels and motility of the chemoresistant ovarian carcinoma cells. All data were evaluated in triplicate against untreated control cells and collected from three independent experiments. Data were graphed and analysed using GraphPad Prism Software 6.0 using one-way ANOVA and the unpaired two-tailed Student's t test. All data are presented as mean ± standard deviation (SD).

Results

In this report, we showed that expression of the VEGF family members is higher in therapy-resistant EOC cells compared to sensitive ones. Over-expression of VEGFA, VEGFC and VEGFR2 correlated with dug resistance and tivozanib, a pan-inhibitor of VEGF receptors, reduced proliferation of the chemoresistant EOC cells through a G2/M cell cycle arrest. Tivozanib decreased adhesive and invasive potential of these cells via reduction of intercellular adhesion molecule-1 (ICAM-1) and enzymatic activity of urokinase plasminogen activator (uPA) as well as matrix metalloproteinase-2 (MMP-2). Moreover, tivozanib synergistically enhanced anti-tumor effects of EGFR-directed therapies including erlotinib, gefitinib and cetuximab via down-regulation of anti-apoptotic proteins survivin and Bcl-2.

Conclusions

Altogether, these findings suggest that the VEGF/VEGFR pathway may have potential as an attractive therapeutic target in therapy-resistant EOC and VEGFR blockade by tivozanib may yield stronger anti-tumor efficacy and circumvent resistance to EGFR-directed therapies.

Clinical trial indentification

N/A

Legal entity responsible for the study

Dr. Majid Momeny

Funding

Tehran University of Medical Sciences

Disclosure

All authors have declared no conflicts of interest.