Vascular endothelial growth factor C promotes cervical cancer cell invasiveness via regulation of microRNA-326/cortactin expression

Abstract

Vascular endothelial growth factor C (VEGF-C) accelerates cervical cancer metastasis, while the detailed mechanism remains largely unknown. Recent evidence indicates that microRNA play a crucial role in controlling cancer cell invasiveness. In the present study, we investigated the role of miR-326 in VEGF-C-induced cervical cancer cell invasion. VEGF-C expression was higher and miR-326 was much lower in primary cervical cancer specimens than that in non-cancerous specimens, and a negative correlation between VEGF-C and miR-326 was found. On cervical carcinoma cell line SiHa cells, treatment with VEGF-C downregulated miR-326 level and increased cortactin protein expression. Transfection with miR-326 mimic reversed cortactin expression induced by VEGF-C, suggesting that VEGF-C increased cortactin via downregulation of miR-326. VEGF-C activated c-Src and c-Src inhibitor PP2 abolished VEGF-C effect on miR-326 and cortactin expression, implying that VEGF-C regulated miR-326/cortactin via c-Src signaling. VEGF-C promoted SiHa cell invasion index, which was largely inhibited by transfection with miR-326 antagonist or by siRNA against cortactin. In conclusion, our findings implied that VEGF-C reduced miR-326 expression and increased cortactin expression through c-Src signaling, leading to enhanced cervical cancer invasiveness. This may shed light on potential therapeutic strategies for cervical cancer therapy.

Chinese abstract

血管内皮生长因子C (VEGF-C) 加速宫颈癌的转移, 然而机制不明。最新的证据表明microRNA在调控癌细胞侵袭力方面起着重要作用。我们研究了miR-326在VEGF-C介导的宫颈癌侵袭的作用, 原发宫颈癌的标本与非癌症的标本比较, VEGF-C的表达偏高而miR-326的表达偏低, 两者呈负相关。在宫颈癌细胞株SiHa细胞中, 用VEGF-C可以降低miR-326的表达并增加皮层蛋白的表达。转染miR-326模拟反向的VEGF-C诱导皮层蛋白表达, 提示VEGF-C通过下调miR-326来增加皮层蛋白。VEGF-C激活c-Src, c-Src抑制剂PP2消除了VEGF-C对miR-326和皮层蛋白表达的影响, VEGF-C提升了SiHa细胞侵袭指数,但这种提升能力可以通过转染miR-326拮抗剂或抗皮层蛋白的siRNA被很大程度地抑制。综上所述, 我们的发现表明VEGF-C通过c-Src信号抑制miR-326表达, 增加皮层蛋白表达, 导致宫颈癌的侵袭性增强。这可能有助于阐明宫颈癌潜在的治疗策略。

Keywords:

• VEGF-C
• cervical cancer
• miR-326
• cortactin
• invasiveness

Disclosure statement

The authors of this manuscript have nothing to disclose.

Additional information

Funding

This work was supported by the Medical Scientific Research Foundation of Guangdong Province (to Y. Cheng, No. A2015058) and by the National Natural Science Foundation of China (to J.X. Liu, No. 81502226).