Effect of Insulin growth factor 1 binding protein 2 (IGF2BP1) knock down on the expression of multidrug resistance proteins in HepG2 cells.

BUCCI MUÑOZ M; SEMENIUK M; LIVORE V; BANCHIO C; MOTTINO AD; CEBALLOS MP; RUIZ ML

Congreso; Reunión Anual SAFIS 2019; 2019

Background and aim: Multidrug resistance associated protein 3 (MRP3/ABCC3) and Breast cancer resistance protein (BCRP/ABCG2) are export pumps that extrude endo- and xenobiotics out of the cells, such as chemotherapeutic drugs. MRP3 and BCRP overexpression leads to chemoresistance in tumoral cells. IGF2BP1 is an oncoprotein highly expressed in tumoral cells, which modulates protein expression by binding and stabilizing mRNAs. The aim of this study is to evaluate if IGF2BP1 regulates MRP3 and BCRP expression in HepG2 cells.Methods: A specific shRNA targeting human IGF2BP1 was designed and cloned into pSR-GFP/Neo. The control shRNA (scrambled, SC) was designed by scrambling the nucleotides of the specific sequence. HepG2 cells were cultured and transiently transfected with plasmids encoding IGF2BP1 shRNA (IGF2BP1-KD) or SC shRNA for 72 h with lipofectamine. The KD of IGF2BP1 was evaluated by Western blotting. MRP3 and BCRP protein levels were evaluated in IGF2BP1 KD cells and SC cells by Western blotting.Results: IGF2BP1 protein expression was decreased in HepG2 cells transfected with IGF2BP1 shRNA (SC: 100 ± 9 %, IGF2BP1 KD: 68 ± 2 %*). MRP3 and BCRP protein expression also decreased in HepG2 cells transfected with IGF2BP1 shRNA (MRP3: SC: 100 ± 3 %, IGF2BP1 KD: 80 ± 5 %*. BCRP: SC: 100 ± 14 %, IGF2BP1 KD: 47 ± 3 %*). All results are presented as mean ± SD, n = 5-6, *p < 0.05 vs. SC.Discussion: The IGF2BP1 knock down resulted in a downregulation of MRP3 and BCRP. This finding suggests that targeting IGF2BP1 could be a useful tool to modulate multidrug associated resistance proteins, at least BCRP and MRP3, in order to minimize the development of chemoresistance in tumoral cells.