Lipid metabolism associated PLPP4 gene drives oncogenic and adipogenic potential in breast cancer cells

Abstract

Lipid metabolic reprogramming plays a pivotal role in cancer cell evolution and causing subsequent cancer growth, metastasis and therapy resistance. Cancer associated adipocyte and/or cancer derived adipocyte-like cells often supply fuels and various factors to fulfill the cells bioenergetics to enhance oncogenic potential. This study intends to find out a set of dysregulated genes involved in lipid metabolism in breast cancer studies and uncovers the role of unexplored dysregulated gene in cancer potential. Cancer database analysis determines seven seed signature genes (PLPP2, PLPP4, CDS1, ASAH2, LCLAT1, LPCAT1 and LASS6/CERS6) concluded from relative expression and survival analysis. Furthermore, experimental analysis unveils the gene PLPP4 (Phospholipid Phosphatase 4) as oncogene confirmed by knockdown and overexpression studies in MDA-MB 231 and MCF-7 breast cancer cells. PLPP4 enzyme is involved in regulation of triacyl glycerol metabolism. Lipid accumulation along with other studies documented enhanced lipid droplets, TAG formation and glycerol release with concomitant increased expressions of various adipogenic markers (e.g., PPARγ, perilipin 1 and leptin) in breast cancer cells transfected with PLPP4 gene expressing plasmid whereas downregulation of PLPP4 gene diminished lipid accumulation and adipocyte marker gene expressions. Our findings also revealed that BMP2 induced adipogenic potential in breast cancer cells was mitigated in response to downregulation of PLPP4 gene expression. All these findings together, for first time, demonstrated that BMP2 drives PLPP4 to enhance both oncogenic and adipogenic potential in breast cancer cells. This article uncovers the perturbed lipid metabolism associated PLPP4 acts as oncogene presumably by modulating adipogenic activity in cancer cells.