SVIL Promotes Ovarian Cancer Progression and Epithelial-Mesenchymal Transition under Hypoxic Conditions Through the TGF-β/Smad Pathway

Objective Ovarian cancer is the malignant tumor with the highest mortality rate in gynecology. We aimed to identify novel genes that promote ovarian cancer progression and epithelial-mesenchymal transition under hypoxic conditions. Methods We screened SVIL as a hypoxia-associated target in ovarian cancer and explored the related molecular mechanisms. We assessed the effects of SVIL on ovarian cancer progression and metastasis in clinical samples and cellular hypoxia models. Further, we investigated the relevant pathways of SVIL and confirmed the effects of SVIL on ovarian cancer progression by using nude mouse in situ tumor models. Results We found that SVIL was significantly highly expressed in the hypoxic environment of ovarian cancer, and SVIL expression correlated with patient prognosis.CCK8, Wound-healing assay, Transwell assay, Western Blot, and apoptosis assays revealed that knockdown of SVIL inhibited the activation of the TGFβ1/smad2/3 pathway, which attenuated the progression and epithelial-mesenchymal transition(EMT) of ovarian cancer and alleviated cisplatin resistance by increasing cisplatin-induced apoptosis. Furthermore, in a nude mouse ovarian cancer in situ model, we found that the knockdown of SVIL significantly inhibited tumor growth and metastasis. Conclusion SVIL highly expressed in the hypoxic microenvironment can increase ovarian cancer progression and cisplatin resistance by activating TGFβ1/smad2/3 pathway. Our study demonstrated that SVIL may be a novel target for the treatment of ovarian cancer.