Enhanced antitumor effect of axitinib synergistic interaction with AG490 via VEGFR2/JAK2/STAT3 signaling mediated epithelial-mesenchymal transition in cervical cancer in vitro

Background: Epithelial to mesenchymal transition (EMT) not only confers tumor cells with a distinct advantage for metastatic dissemination, but also it provides tumor cells for proliferation and chemotherapy resistance. Thus, inhibiting this process using single or multiple agents, remains a field of intensive research. The development of EMT has been implicated in not only conferring cancer cells distant metastasis, but also providing tumor cells advantages for proliferation and chemotherapy resistance.

Objective: We investigated whether axitinib synergistic interaction with AG490 could effectively block the growth and EMT-mediated tumor metastasis in cervical cancer in vitro.

Methods: We addressed synergism effects on tumor growth, axitinib, AG490 alone and in any possible combinations on cell viability, apoptosis and cell cycle distribution were evaluated by XTT assay, Annexin V/propidium iodide staining and flow cytometric analysis. To assess how combination therapy affected chemotactic motility in tumor cells, wound-healing migration and the Boyden chamber invasion assays were applied in vitro. Further, using western blots, the key signaling molecules and pathways in response to axitinib and AG490 combination treatment in anti tumor growth and anti EMT-mediated tumor metastasis were analyzed in Hela cells.

Results: Therapy with axitinib and AG490 resulted in strong synergistic inhibition of proliferation, migration and cell cycle arrest without potently effect on apoptosis induction relative to AG490 monotherapy and control in vitro. Furthermore, phosphorylation of VEGFR2 (Tyr¹¹⁷⁵), JAK2 (Tyr¹⁰⁰⁷/¹⁰⁰⁸) and STAT3 (Tyr⁷⁰⁵) was completely blocked in parallel with significant reduction expressions of N-cadherin and obvious enhancement levels of E-cadherin through down-regulating Snail responding to combination treatment in cervical cancer cells.

Conclusion:We first provided evidences that combination therapy of axitinib and AG490 significantly enhances anti-tumor effect via VEGFR2/JAK2/STAT3 signaling mediated growth arrest and EMT-mediated tumor metastasis inhibition, holds promise for an efficacious treatment of these advanced patients.