Long non-coding RNA PVT1 as a novel biomarker for diagnosis and prognosis of non-small cell lung cancer

Accumulating evidence has indicated that long non-coding RNA PVT1 is upregulated in various human cancers. However, it remains unclear whether PVT1 is involved in the development and progression of non-small cell lung cancer (NSCLC). The present study was designed to investigate the expression, biological role, and clinical significance of PVT1 in NSCLC. Our results indicated that PVT1 expression was significantly increased in NSCLC tissues and cell lines, and its upregulation was associated with advanced T-stage and tumor-node-metastasis (TNM) stage and regional lymph node metastasis. PVT1 expression levels were robust in differentiating NSCLC tissues from controls. Kaplan-Meier curve and Cox regression analysis showed that high expression of PVT1 was associated with poor overall survival and disease-free survival in NSCLC patients. The results of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and colony formation assays indicated that knockdown of PVT1 remarkably inhibited NSCLC cell proliferation, whereas overexpression of PVT1 significantly promoted cellular proliferation. In addition, PVT1 knockdown increased the number of cells in the G0/G1 phase and reduced the number of cells in the S phase, while overexpression of PVT1 could promote cell cycle progression. Furthermore, our findings also revealed that the messenger RNA (mRNA) and protein expression of P15 and P21 was significantly upregulated in NSCLC cells transfected with PVT1 small interfering RNA (siRNA) and downregulated in cells transfected with pcDNA3.1-PVT1. In conclusion, our study demonstrated that PVT1 might serve as a promising biomarker for diagnosis and prognosis of NSCLC, and it could promote the proliferation of NSCLC cells by downregulating p15 and p21 expression.