StarD7 siRNA modulates ABCG2 expression, cell migration and proliferation in epitelial cell lines

JESICA FLORES- MARTÍN; VIVIANA RENA; MÁRQUEZ S; GRACIELA PANZETTA -DUTARI; SUSANA GENTI DE RAIMONDI

Mendoza

Encuentro; 48 Annual Meeting XLVIII Reunión Anual th Argentine Society for Biochemistry and Molecular Biology; 2012

SAIB

StAR-related lipid transfer domain containing 7 (StarD7) belongs to the family of START proteins ubiquitously expressed, which are implicated in lipid transport, metabolism, and signalling. Previous results indicate that StarD7 silencing decreases ABCG2 multidrug transporter level, cell migration, proliferation, and reduction in phospholipid synthesis; whereas an increase in biochemical and morphological differentiation marker expression was detected in the epithelial choriocarcinoma JEG-3 cells. The present study was undertaken to extend these data to other epithelial tumour cells to establish the StarD7 function. In order to do this, we performed StarD7 knockdown in hepatoma HepG2 and colon adenocarcinoma HT-29 cells, two cell lines in which we previously demonstrated higher StarD7 expression levels. StarD7 silencing, confirmed by qRT-PCR and western blot, led to a decrease in the xenobiotic/ lipid transporter ABCG2 at both the mRNA and protein levels. Also a concomitant reduction in bromodeoxyuridine uptake was detected. Wound healing and transwell assays revealed that HepG2 and HT- 29 cell migration was significantly diminished. Altogether these findings provide evidence for a role of StarD7 in cell physiology suggesting that it has a conserved function. Current work is in progress to establish the mechanisms involved in these findings