Novel nuclear localization of multidrug resistance associated protein 4 (MRP4/ABCC4) in human cancer cell lines

RODRIGO LAGOS; SAMANTA GANCEDO; CARLOS DAVIO; ANA SAHORES; BETINA GONZÁLEZ ; CAROLINA GHANEM; NATALIA GÓMEZ; JULIETA IMPERIALE; RODRIGO LAGOS; SAMANTA GANCEDO; CARLOS DAVIO; ANA SAHORES; BETINA GONZÁLEZ ; CAROLINA GHANEM; NATALIA GÓMEZ; JULIETA IMPERIALE

Mar del Plata

Congreso; LXIV Reunión Anual de la Sociedad Argentina de Investigación Clínica (SAIC); 2019

The member of ATP Binding Cassette (ABC) family, MRP4 is responsible forsubstance extrusion, as cAMP, and typically located in plasma membrane. MRP4is overexpressed in pancreatic and hepatocellular cancer. In pancreatic ductaladenocarcinomas (PDACs) a correlation between MRP4 overexpression and poorprognosis of the disease has been stablished in patients. Preliminary results seem to show an increase in the nuclear MRP4 staining in human PDACs. Therefore, the aim of this study was to determine de novel presence of Mrp4 in nuclei of human cancer cell lines. We used pancreatic cancer cell line BxPC-3 and thehepatocellular cancer cell line HepG2. MRP4 Western-blot (WB) were performed inenriched nuclei, total membrane and cytosolic fractions isolated (50 ug/lane) byultracentrifugation. The enrichment was evaluated by histone, actin and GAPDHdetection respectively. Then immune co-localization of Mrp4, GAPDH and DAPI incells and the isolated nuclear fraction was determined by confocal microscopy.Results were expressed asmediaSEM, analyzed by student-t test. Mrp4 wasdetected in the nuclear fraction of both cell lines but Nuclear/total ratio was 1.3 in BxPC-3 and 0.3 in HepG2. Total Mrp4 expression in HepG2 was half of BxPC-3 (P