The Cotransporter NaPi-IIb: characteristics, regulation and its role in carcinogenesis

ABSTRACT

Inorganic phosphate (Pi) presents a crucial role in cellular metabolism, with the kidney and intestine as the principal regulating organs of the homeostasis of this nutrient. Maintaining phosphate balance results from the activity of different subtype of transporters of sodium-dependent phosphate that use the electrochemical gradient of sodium ions to carry out cotransport. Several diseases have been related to dysfunctions of phosphate cotransporters, including in the area of oncology. A study using the SAGE technique pointed to a possible role of the type IIb sodium-phosphate cotransporter (NaPi-IIb), encoded by the SLC34A2 gene, in ovarian carcinogenesis. More recently, such protein was associated with the development of other carcinomas and some of the components that regulate its function were determined. It is believed that in the future, the analysis of SLC34A2 expression in tumor samples will help in the choice of treatment, evaluation of prognosis and be a possible target for new therapeutic strategies.