Long Noncoding RNA Brain Cytoplasmic RNA 1 Induces Cisplatin-Resistance of Cervical Cancer Cells by Sponging MicroRNA-330-5p and Upregulating High-Mobility Group Box 3.

ABSTRACT

OBJECTIVES: The aim of the study was to find out the function of long noncoding RNA brain cytoplasmic RNA 1 (BCYRN1) in cisplatin (DDP)-resistance of cervical cancer (CC) cells. Design and Materials, Setting, Methods: BCYRN1 expression in CC and DDP-resistant cells was evaluated, with the association of BCYRN1 and prognosis analyzed. Then, DDP-resistant cells with BCYRN1 knockdown were established and the DDP-resistance of these cells was assessed. BCYRN1 subcellular localization was detected and confirmed. Besides, the binding relations of BCYRN1 and microRNA (miR)-330-5p and between miR-330-5p and high-mobility group box 3 (HMGB3) were examined and verified. Moreover, the role of miR-330-5p and HMGB3 in the mechanism of BCYRN1 modulating DDP-resistance of CC cells was detected. In addition, xenograft transplantation was conducted to confirm the effect of BCYRN1 in CC cell DDP-resistance. RESULTS: BCYRN1 was overexpressed in CC, which resulted in poor prognosis and DDP-resistance. BCYRN1 knockdown in DDP-resistant cells downregulated DDP-resistance. Mechanically, BCYRN1 sponged miR-330-5p to strengthen HMGB3 mRNA level. Besides, miR-330-5p underexpression or HMGB3 overexpression reversed the function of BCYRN1 knockdown in inhibiting DDP-resistance of CC cells. Eventually, BCYRN1 knockdown reduced the DDP-resistance of CC cells in vivo. LIMITATIONS: There are still some deficiencies in the research; for example, whether there are other miRs working as the downstream genes of BCYRN1 in the competing endogenous RNA interaction is not fully clarified, nor the other downstream mechanisms of miR-330-5p. Besides, the experimental findings and their application into practice need extensive validation. CONCLUSIONS: BCYRN1 knockdown could disrupt the DDP-resistance of CC cells through upregulating miR-330-5p to suppress HMGB3 mRNA level.