Transforming growth factor β1 upregulates 6‐phosphofructo‐ 2‐kinase/fructose 2,6‐bisphosphatase‐4 expression in A549 and MCF‐10A cells

Abstract

Transforming growth factor beta 1 (TGF beta 1) induces a cellular process known as epithelial-mesenchymal transition (EMT) associated with metabolic reprogramming, including enhanced glycolysis. Given the involvement of 6-phosphofructo-2-kinase/ fructose 2,6-bisphosphatase (PFKFB) enzymes in glycolysis, we aimed to investigate whether TGF beta 1 regulates expressions of PFKFB genes and if PFKFBs are required for TGF beta 1-driven phenotypes. A549 and MCF-10A cell lines were used as TGF beta 1driven EMT models. Messenger RNA expressions of PFKFB and EMT genes were determined by real-time quantitative polymerase chain reaction. A small interfering RNA approach was used to deplete PFKFB4 expression. A Matrigel invasion assay was conducted to assess the effect of PFKFB4 silencing on the TGF ss 1-enhanced invasion of A549 cells. F2,6BP levels were analyzed using an enzyme-coupled assay. Glucose and lactate concentrations were determined using colorimetric assays. TGF beta 1 robustly induced expression of the fourth isoform of PFKFBs, PFKFB4, in both cell lines. PFKFB4 depletion partially inhibits mesenchymal transdifferentiation caused by TGF beta 1 in A549 cells, as assessed by microscopy. Inductions of Snail in MCF-10A cells and Fibronectin in A549 cells and repressions of E-cadherin in both cell lines by TGF beta 1 are attenuated by PFKFB4 silencing. PFKFB4 silencing reduces F2,6BP and glycolytic activity, although TGF beta 1 alone does not affect these parameters. Finally, PFKFB4 depletion suppresses the TGF beta 1-driven invasion of A549 cells through Matrigel. Presented data suggest that TGF ss 1 induces the expression of PFKFB4 in A549 and MCF-10 cells, and PFKFB4 may be required for TGF beta 1-driven phenotypes such as EMT and invasion in these models.