The PVT1/miR-216b/Beclin-1 regulates cisplatin sensitivity of NSCLC cells via modulating autophagy and apoptosis

Abstract

Purpose: The efficacy of cisplatin-based chemotherapy remains an open question for chemo-resistance in non-small cell lung cancer (NSCLC). This study aimed to explore the role and mechanism of long noncoding RNA plasmacytoma variant translocation 1 (PVT1) in cisplatin sensitivity of NSCLC.

Methods: Paired tumor and adjacent tissues were collected from forty patients with NSCLC. The clinical value of PVT1 was investigated according to clinicopathological parameters of patients. Cisplatin-sensitive or -resistant cells (A549 or A549/DDP) were used for in vitro experiments. Cell viability, apoptosis, autophagy and animal experiments were conducted to investigate cisplatin sensitivity. The expressions of PVT1, microRNA-216b (miR-216b) and apoptosis- or autophagy-related proteins were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR) or western blot assay, respectively. Luciferase reporter assay and RNA immunoprecipitation (RIP) assay were conducted to probe the interaction between miR-216b and PVT1 or Beclin-1.

Results: PVT1 was highly expressed and associated with poor prognosis of NSCLC patients (^*P < 0.05). PVT1 knockdown enhanced cisplatin-induced viability inhibition and apoptosis induction in A549/DDP cells, but addition of PVT1 caused an opposite effect in A549 cells (^*P < 0.05, ^#P < 0.05). Moreover, accumulation of PVT1 facilitated autophagy of NSCLC cells and tumor growth in vivo (^*P < 0.05, ^#P < 0.05). In addition, miR-216b interacted with PVT1 or Beclin-1. Beclin-1 reversed miR-216b-mediated effect on autophagy and apoptosis of NSCLC cells (^*P < 0.05,^#P < 0.05). Besides, Beclin-1 protein expression was regulated by PVT1 and miR-216b (^*P < 0.05, ^#P < 0.05).

Conclusions: PVT1 may function as a competing endogenous RNA for miR-216b to inhibit cisplatin sensitivity of NSCLC through regulating apoptosis and autophagy via miR-216b/Beclin-1 pathway, providing a novel target for improving chemo-therapy efficacy of NSCLC.

Keywords: Autophagy; Beclin-1; Cisplatin sensitivity; NSCLC; PVT1; miR-216b.