LncRNA GNAS-AS1 facilitates ER+ breast cancer cells progression by promoting M2 macrophage polarization via regulating miR-433-3p/GATA3 axis.

Objective: ER+ breast cancer is the most common type of breast cancer, which seriously affects the physical and mental health of women. Recently, lncRNAs mediated tumor-associated macrophages (TAM) were identified to involve in tumorigenesis. Therefore, the present study aimed at demonstrating the regulatory network of GNAS-AS1 in TAM-mediated ER+ breast cancer progress.

Methods: The expression levels of genes were evaluated using qRT-PCR. The proportions of polarized macrophages (M1, M2) were assessed by flow cytometry. Cell proliferation, migration and invasion were evaluated by CCK-8, wound healing and transwell assay, respectively. Double-luciferase reporter system was used to detect the interaction between molecules. Western blot was applied to test protein levels.

Results: The expression of GNAS-AS1 was obviously increased in ER+ breast cancer tissues and cell lines, as well as M2 macrophages. GNAS-AS1 facilitated the capabilities of proliferation, migration and invasion of ER+ breast cancer cells by accelerating M2 macrophage polarization via directly sponging miR-433-3p. GATA3, as a target of miR-433-3p, could positively regulate by GNAS-AS1. Furthermore, either miR-433-3p overexpression or GATA3 knockdown impaired the effects of GNAS-AS1 on M2 macrophage polarization and ER+ breast cancer cells progression.

Conclusion: GNAS-AS1/miR-433-3p/GATA3 axis promoted proliferation, metastasis of ER+ breast cancer cells by accelerating M2 macrophage polarization. The mechanism may provide a new strategy and target for ER+ breast cancer treatment.