Long noncoding RNA KB-1980E6.3 promotes breast cancer progression through the PI3K/AKT signalling pathway

This research aims to investigate the effect of lncRNA KB-1980E6.3 on the biological behaviour of breast cancer cells under normoxic conditions and the underlying molecular mechanism. The expression of KB-1980E6.3 in breast cancer tissues and cells was detected by RT-qPCR. The proliferation, migration and invasion of cells were evaluated by CCK-8, colony formation, scratch and Transwell assays; KB-1980E6.3-related xenograft models were established for in vivo studies. The protein expression of PI3K, p-PI3K, AKT and p-AKT was validated by western blotting analysis. The levels of KB-1980E6.3 are significantly upregulated in breast cancer tissues and cells and are related to the poor prognosis. Functional research both in vivo and in vitro revealed that the downregulation of KB-1980E6.3 expression significantly decreased cell proliferation, invasion and migration, while ectopic KB-1980E6.3 expression obviously promoted these biological phenotypes. In terms of the mechanism, KB-1980E6.3 is involved in the activation of the PI3K/AKT signalling pathway. Knockdown of KB-1980E6.3 reduced the expression of the p-PI3K and p-AKT proteins, whereas KB-1980E6.3 overexpression showed the opposite result. The agonist 740Y-P and inhibitor LY294002 reversed the effect of KB-1980E6.3 knockdown and overexpression on the PI3K/AKT pathway in BC cells. KB-1980E6.3 promotes the proliferation, invasion and migration of breast cancer cells by activating PI3K/AKT signalling, which can be used as a potential target for breast cancer therapy.