MicroRNA-365 promotes lung carcinogenesis by downregulating the USP33/SLIT2/ROBO1 signalling pathway

Yuhuan Wang,Shukun Mu,Baishen Zhang,Hao Ma,Hejing Bao,Shudong Ma,Shuhua Zhang

doi:10.1186/s12935-018-0563-6

Abstract

BackgroundAbnormal microRNA expression is closely related to cancer occurrence and development. miR-365a-3p plays an oncogenic role in skin cancer, but its role in lung cancer remains unclear. In this study, we aimed to investigate its role and underlying molecular mechanisms in lung cancer.MethodsWestern blot and real-time quantitative PCR (qPCR) were used to detect the expression of miR-365a-3p in lung adenocarcinoma and lung cancer cell lines. The effects of miR-365a-3p on lung cancer cell proliferation, migration, and invasion were also explored in vitro. The potential miR-365a-3p that targets USP33 was determined by dual luciferase reporter assay and verified by qPCR and western blot analysis. miR-365a-3p acts as an oncogene by promoting lung carcinogenesis via the downregulation of the miR-365a/USP33/SLIT2/ROBO1 axis based on western blot analysis. Subcutaneous tumourigenesis further demonstrated that miR-365a-3p promotes tumour formation in vivo.ResultsmiR-365a-3p was upregulated in lung adenocarcinoma and lung cancer cell lines. Overexpression of miR-365a-3p promoted and inhibition of miR-365a-3p suppressed the proliferation, migration, and invasion of lung cancer cells. We identified USP33 as the downstream target of miR-365a-3p and observed a negative correlation between miR-365a-3p and USP33 expression in lung adenocarcinoma patients. The miR-365/USP33/SLIT2/ROBO1 axis, a new mechanism, was reported to inhibit the invasion and metastasis of lung cancer. A nude mouse model of lung cancer further verified these findings.ConclusionsIn summary, miR-365a-3p acts as an oncogene by promoting lung carcinogenesis via the downregulation of the USP33/SLIT2/ROBO1 signalling pathway, making the miR-365/USP33/SLIT2/ROBO1 axis a new mechanism of lung cancer promotion and a novel therapeutic target for predicting prognosis and response to gene therapy.

Highlights

Abnormal microRNA expression is closely related to cancer occurrence and development. miR-365a-3p plays an oncogenic role in skin cancer, but its role in lung cancer remains unclear
Results miR‐365a‐3p is upregulated in non-small cell lung cancer (NSCLC) tissues and cell lines To evaluate the expression of miR-365a-3p in lung adenocarcinoma cells, qRT-PCR assays were performed in 20 patients with lung adenocarcinoma and matched paracancerous tissues
The expression levels of miR-365a-3p were analysed in various lung cancer cell lines. qRT-PCR results demonstrated that higher expression levels of miR-365a-3p were present in A549, SPC-A-1, H1299, and PC9 lung cancer cell lines than in 16HBE normal lung epithelial cells

Summary

Introduction

Abnormal microRNA expression is closely related to cancer occurrence and development. miR-365a-3p plays an oncogenic role in skin cancer, but its role in lung cancer remains unclear. MicroRNAs (miRNAs) are small, highly conserved, noncoding RNAs of approximately 19–25 nucleotides that regulate gene expression at the post-transcriptional level by base-pairing with the 3′ UTRs of target mRNAs [8,9,10,11]. They play key roles in human biological processes, such as migration, cellular metabolism, cell proliferation, apoptosis, and epithelial–mesenchymal transition (EMT) [12,13,14,15,16,17]. The roles of miR-365a-3p in lung cancer cells remain unclear and require further study

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