SLC37A1 Gene expression is up-regulated by epidermal growth factor in breast cancer cells

Phospholipid biosynthesis exerts an importantrole in the proliferation of tumor cells; however, the regulationof the proteins involved in this context still remains tobe fully evaluated. SLC37A1 protein belongs to a smallfamily of sugar-phosphate/phosphate exchangers. Thesequence homology with the bacterial glycerol-3-phosphatetransporter (30%) suggests that SLC37A1 might be able tocatalyze an exchange of glycerol-3-phosphate againstphosphate. Glycerol-3-phosphate, found in different cellularcompartments, is a fundamental substrate in phospholipidbiosynthesis. In the present study, we demonstrate forthe first time that epidermal growth factor (EGF) transactivatesSLC37A1 promoter sequence and induces SLC37A1mRNA, and protein expression through the EGFR/MAPK/Fos transduction pathway in ER-negative SkBr3 breastcancer cells. These findings were corroborated by comparableresults obtained in ER-positive endometrial Ishikawatumor cells. Interestingly, we also show that SLC37A1protein localizes in the endoplasmic reticulum, hence supportingits possible involvement in phospholipid biosynthesis.On the basis of our data, the up-regulation ofSLC37A1 gene expression should be included among thewell-known stimulatory action exerted by EGF in breastcancer cells. In addition, further studies are required toprovide evidence concerning the potential role of EGFmediatedSLC37A1 induction in breast tumor cells.