Low LINC00599 expression is a poor prognostic factor in glioma

LINC00599 has been suggested to be involved in physiological and pathological processes including carcinogenesis. However, the clinical and prognostic significance of LINC00599 in glioma patients and the effect of LINC00599 on glioma cell migration and invasion remain unknown. In our results, we first observe the expression of LINC00599 in 31 types of human cancers including tumor tissues and corresponding normal tissues at The Cancer Genome Atlas (TCGA) database, and found that LINC00599 expression levels were only reduced in lower grade glioma (LGG) tissues and glioblastoma multiforme (GBM) tissues compared with normal brain tissues. Moreover, we confirmed levels of LINC00599 expression were decreased in glioma tissues and cell lines compared with matched adjacent normal tissues and normal human astrocytes (NHAs), respectively. Meanwhile, we found that glioma tissues with WHO III-IV grade exhibited lower levels of LINC00599 expression than glioma tissues with I-II grade. The survival analysis at TCGA data showed low LINC00599 expression was associated with poor disease-free survival and overall survival in glioma patients. In vitro study suggested up-regulation of LINC00599 depressed glioma cell migration and invasion through regulating epithelial–mesenchymal transition (EMT) process. In conclusion, LINC00599 acts as a tumor-suppressing long non-coding RNA (lncRNA) in glioma.