Overexpression of lncRNA NLIPMT Inhibits Colorectal Cancer Cell Migration and Invasion by Downregulating TGF-β1

Background: NLIPMT, as a tumor suppressive lncRNA, has only been investigated in breast cancer, while its roles in other types of cancer remain unknown. This study aimed to explore the role of NLIPMT in colorectal cancer (CRC). Methods: Expression levels of NLIPMT and TGF-beta 1 in two types of CRC tissue (Non-tumor tissues and tumor tissues) were measured and compared by qRT-PCR and paired t-test, respectively. Correlations between the expression of NLIPMT and TGF-beta 1 were analyzed by performing linear regression. The effects of transfections on cell invasion and migration were evaluated by Transwell assays. Results: We found that NLIPMT was downregulated, while TGF-beta 1 was upregulated in CRC. In CRC tumor, a negative correlation was found between the expression of NLIPMT and TGF-beta 1. In CRC cells, overexpression of NLIPMT resulted in downregulation, while silencing of NLIPMT resulted in upregulation of TGF-beta 1. Analysis of cell invasion and migration showed that overexpression of NLIPMT suppressed the tumor cell invasion and migration. In contrast, overexpression of TGF-beta 1 could promote CRC cell invasion and migration and also reduce the role of NLIPMT. Through the overall survival evaluation, NLIPMT-high groups of CRC represented better survival rate compared to that of the NLIPMT-low group patients. Conclusion: The expression of lncRNA NLIPMT was negatively correlated with TGF-ss 1 in CRC. Overexpression of NLIPMT inhibited the colorectal cancer cell migration and invasion by downregulating TGF-beta 1. Furthermore, the expression of NLIPMT in CRC patients predicted better prognosis, which suggested that NLIPMT could be considered as a novel diagnosis biomarker.