GATA3/MiR-199a-3p Suppresses Glycometabolism in Breast Cancer by Inhibiting PFKFB3 Expression

Abstract

Background: Dysregulation of glycometabolism is considered an important marker for cancer, and the glycolytic components may be targets for cancer therapy. Hence, we aimed to explore the mechanism by which miR-199a-3p influences breast cancer (BC) glycolysis. Methods: Cell glucose and phosphofructokinase (PFK) levels in miR-199a-3p over-expressing BC cells were determined using the PFK assay kit. Glucose consumption and adenosine-triphosphate (ATP) levels were measured in miR-199a-3p over-expressing BC cells with a Glucose assay kit and ATP detection kit. The expressions of miR-199a-3p, 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) and GATA binding protein 3 (GATA3) were measured using qPCR in GATA3 over-expressing or knockdown BC cell lines. The expressions of glucose transporter type 5 (GLUT5), lactate dehydrogenase A (LDHA), pyruvate kinase M2 (PKM2) and PFKFB3 were examined using western blotting in two miR-199a-3p over-expressing BC cell lines. Chromatin immunoprecipitation quantitative PCR (ChIP-qPCR) was used to confirm that GATA3 bound to the specific region of the miR-199a-3p promoter in BC cells. Results: Our results showed that miR-199a-3p suppressed PFKFB3 mRNA and protein expression in BC cells (p < 0.05). Mechanistically, luciferase assays demonstrated that miR-199a-3p reduced PFKFB3 by targeting the PFKFB3 3′ untranslated region (3′-UTR) directly. Furthermore, a recovery assay indicated that PFKFB3 overexpression reversed the suppressing effects of miR-199a-3p on aerobic glycolysis (AG) (p < 0.05). More importantly, miR-199a-3p was modulated by the GATA3 transcription element by binding to the promoter. Conclusions: The GATA3/miR-199a-3p axis might be involved in BC cell glycometabolism through regulating PFKFB3 expression, which may provide a good prognosis for breast cancer.