Circular RNA hsa_circ_0103552 Promotes Proliferation, Migration, and Invasion of Breast Cancer Cells through Upregulating Cysteine-Rich Angiogenic Inducer 61 (CYR61) Expression via Sponging MicroRNA-515-5p

Qi Huang,¹ Yujun He,¹ Xiaohua Zhang¹ and Lingji Guo¹

¹Department of Breast and Thyroid Surgery, Daping Hospital, Army Medical University, Chongqing, China

Circular RNAs (circRNAs) exert a significant regulatory function on tumor progression. This work intends to probe into the biological function and regulatory mechanism of circRNA_0103552 (circ_0103552) in breast cancer carcinogenesis. In this study, circ_0103552, microRNA-515-5p (miR-515-5p), and cysteine-rich angiogenic inducer 61 (CYR61) mRNA expressions in breast cancer cells and tissues were determined by quantitative real-time polymerase chain reaction, followed by cell counting kit 8 and Transwell experiments to examine the multiplication, migration, and invasion of breast cancer cells. Circular RNA Interactome database and StarBase database were searched, and dual-luciferase reporter gene experiments were applied to verify the targeting relationship between circ_0103552 and miR-515-5p, and between miR-515-5p and CYR61, and Western blot was adopted to the regulatory function of circ_0103552 and miR-515-5p on CYR61 protein expression. Circ_0103552 expression was found to be remarkably up-modulated in breast cancer tissues and cells, and circ_0103552 overexpression facilitated the multiplication, migration, and invasion of breast cancer cells, while knocking down circ_0103552 induced the opposite effects. Mechanistically, circ_0103552 could sponge miR-515-5p and restrained its expression in breast cancer cells. MiR-515-5p could counteract the functions of circ_0103552 in breast cancer cells. Additionally, CYR61 was revealed to be a downstream target of miR-515-5p in breast cancer cells. In summary, this study shows that migration, and invasion of breast cancer cells.

Keywords —— breast cancer; circular RNA; circ_0103552; cysteine-rich angiogenic inducer 61 (CYR61); microRNA-515-5p

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Tohoku J. Exp. Med 2021, 255, 171-181.

Correspondence: Xiaohua Zhang, Department of Breast and Thyroid Surgery, Daping Hospital, Army Medical University, No.2 Changjiang Road No.10, Yuzhong District, Chongqing 400042, China.

e-mail: vlb361114@163.com