Long non‑coding RNA PITPNA‑AS1 silencing suppresses proliferation, metastasis and epithelial‑mesenchymal transition in non‑small cell lung cancer cells by targeting microRNA‑32‑5p.

Abstract

Lung cancer is one of the most common types of cancer and has a high mortality rate, worldwide. The major histopathological subtype is non-small cell lung cancer (NSCLC). The aim of the present study was to investigate the role of long non-coding (lnc) RNA PITPNA antisense RNA 1 (PITPNA-AS1) in NSCLC and elucidate its potential mechanisms. The expression of PITPNA-AS1 was determined in several NSCLC cell lines. Following PITPNA-AS1-silencing, cell proliferation, invasion and migration were evaluated using Cell Counting Kit-8, colony formation, Transwell assay and wound healing assays, respectively. The expression levels of proliferation-, migration- and epithelial-mesenchymal transition (EMT)-associated proteins were examined using immunofluorescence assay or western blot analysis. A luciferase reporter assay was conducted to verify the potential interaction between PITPNA-AS1 and microRNA(miR)-32-5p. Subsequently, rescue assays were performed to investigate the effects of PITPNA-AS1 and miR-32-5p on NSCLC progression. The results demonstrated that PITPNA-AS1 was highly expressed in NSCLC tissues and cell lines. It was found that PITPNA-AS1 silencing inhibited the proliferation, invasion and migration of NSCLC cells. Furthermore, the protein expression of E-cadherin was upregulated, while the expression levels N-cadherin and vimentin were downregulated. The luciferase reporter assay confirmed that miR-32-5p was a direct target of PITPNA-AS1. The rescue experiments suggested that a miR-32-5p inhibitor significantly reversed the inhibitory effects of PITPNA-AS1 silencing on proliferation, invasion, migration and EMT in NSCLC cells. Collectively, the present results demonstrated that PITPNA-AS1 silencing could suppress the progression of NSCLC by targeting miR-32-5p, suggesting a promising biomarker in NSCLC diagnosis and treatment.