RETRACTED ARTICLE: Cancer-derived exosomal miR-221-3p promotes angiogenesis by targeting THBS2 in cervical squamous cell carcinoma

• Published in: Angiogenesis (London) Vol. 22; no. 3; pp. 397 - 410
• Main Authors: Wu, Xiang-Guang, Zhou, Chen-Fei, Zhang, Yan-Mei, Yan, Rui-Ming, Wei, Wen-Fei, Chen, Xiao-Jing, Yi, Hong-Yan, Liang, Luo-Jiao, Fan, Liang-sheng, Liang, Li, Wu, Sha, Wang, Wei
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 15.08.2019; Springer Nature B.V
• Subjects: Biomedical and Life Sciences; Biomedicine; Cancer Research; Cardiology; Cell Biology; Oncology; Ophthalmology; Original Paper; Angiogenesis; Thrombospondin-2; miR-221-3p; Cervical squamous cell carcinoma; Exosome
• ISSN: 0969-6970; 1573-7209
• DOI: 10.1007/s10456-019-09665-1

Aims Recently, cancer-derived exosomes were shown to have pro-metastasis function in cancer, but the mechanism remains unclear. Angiogenesis is essential for tumor progression and is a great promising therapeutic target for advanced cervical cancer. Here, we investigated the role of cervical cancer cell-secreted exosomal miR-221-3p in tumor angiogenesis. Methods and results miR-221-3p was found to be closely correlated with microvascular density in cervical squamous cell carcinoma (CSCC) by evaluating the microvascular density with immunohistochemistry and miR-221-3p expression with in situ hybridization in clinical specimens. Using the groups of CSCC cell lines (SiHa and C33A) with miR-221-3p overexpression and silencing, the CSCC exosomes were characterized by electron microscopy, western blotting, and fluorescence microscopy. The enrichment of miR-221-3p in CSCC exosomes and its transfer into human umbilical vein endothelial cells (HUVECs) were confirmed by qRT-PCR. CSCC exosomal miR-221-3p promoted angiogenesis in vitro in Matrigel tube formation assay, spheroid sprouting assay, migration assay, and wound healing assay. Then, exosome intratumoral injection indicated that CSCC exosomal miR-221-3p promoted tumor growth in vivo. Thrombospondin-2 (THBS2) was bioinformatically predicted to be a direct target of miR-221-3p, and this was verified by using the in vitro and in vivo experiments described above. Additionally, overexpression of THBS2 in HUVECs rescued the angiogenic function of miR-221-3p. Conclusions Our results suggest that CSCC exosomes transport miR-221-3p from cancer cells to vessel endothelial cells and promote angiogenesis by downregulating THBS2. Therefore, CSCC-derived exosomal miR-221-3p could be a possible novel diagnostic biomarker and therapeutic target for CSCC progression.