[LINC00668 is Highly Expressed in Lung Squamous Cell Carcinoma and 
Promotes Tumor Cell Migration and Invasion]

A lack of effective treatment for lung squamous cell carcinoma (LUSC) makes it an important factor restricting the 5-year survival rate of non-small cell lung cancer (NSCLC). Long non-coding RNA 00668 (LINC00668) was reported to play crucial regulatory roles in the tumorigenesis and progression of various cancers; however, its role in LUSC is unclear. The aim of this study was to investigate the prognosis value and biological function of LINC00668 in NSCLC, especially in LUSC.

The expression pattern of LINC00668 and its relationship with clinical characteristics and prognosis of patients were investigated in the NSCLC especially LUSC based on The Cancer Genome Altas (TCGA) database. Its function in LUSC cells was explored in vitro.

LINC00668 expression was significantly up-regulated in LUSC patients and high expression level of LINC00668 was associated with advanced tumor-node-metastasis (TMN) stage. Moreover, the expression of LINC00668 significantly increased in smoking patients, and was a prognostic indicator for overall survival (OS) of smoking patients with LUSC. In vitro experiments showed that LINC00668 has significantly higher expression level in LUSC cell lines and tissues compared to normal bronchial epithelial cell and para-tumor tissues; meanwhile, functional assay indicated knockdown of LINC00668 effectively inhibited the migration and invasion of LUSC cells.

LINC00668 might closely relate to the development of LUSC, and inhibition of LINC00668 may reduce the metastasis of LUSC.