Regulation of Multidrug Resistance Proteins by Genistein in a Hepatocarcinoma Cell Line: Impact on Sorafenib Cytotoxicity

Abstract

Hepatocellular carcinoma (HCC) is the fifth most frequent cancer worldwide. Sorafenib is the only drug available that improves the overall survival of HCC patients. P-glycoprotein (P-gp), Multidrug resistance-associated proteins 2 and 3 (MRP2 and 3) and Breast cancer resistance protein (BCRP) are efflux pumps that play a key role in cancer chemoresistance. Their modulation by dietary compounds may affect the intracellular accumulation and therapeutic efficacy of drugs that are substrates of these transporters. Genistein (GNT) is a phytoestrogen abundant in soybean that exerts its genomic effects through Estrogen-Receptors and Pregnane-X-Receptor (PXR), which are involved in the regulation of the above-mentioned transporters. We evaluated the effect of GNT on the expression and activity of P-gp, MRP2, MRP3 and BCRP in HCC-derived HepG2 cells. GNT (at 1.0 and 10 μM) increased P-gp and MRP2 protein expression and activity, correlating well with an increased resistance to sorafenib cytotoxicity as detected by the methylthiazole tetrazolium (MTT) assay. GNT induced P-gp and MRP2 mRNA expression at 10 but not at 1.0 μM concentration suggesting a different pattern of regulation depending on the concentration. Induction of both transporters by 1.0 μM GNT was prevented by cycloheximide, suggesting translational regulation. Downregulation of expression of the miR-379 by GNT could be associated with translational regulation of MRP2. Silencing of PXR abolished P-gp induction by GNT (at 1.0 and 10 μM) and MRP2 induction by GNT (only at 10 μM), suggesting partial mediation of GNT effects by PXR. Taken together, the data suggest the possibility of nutrient-drug interactions leading to enhanced chemoresistance in HCC when GNT is ingested with soy rich diets or dietary supplements.

Non-digestible stachyose promotes bioavailability of genistein through inhibiting intestinal degradation and first-pass metabolism of genistein in mice

“…Instead, they highly depend on the activity of membrane bound ATP binding cassette transport proteins (such as P-gp, MRP1, and MRP2) to over the intestinal epithelium [25,31]. A previous study has reported that efflux transporters' (P-gp, MRP1, and MRP2) expression of cancer cells is improved in a dose-dependent manner by genistein treatment for a long time [32], which would strengthen the first-pass metabolism of genistein (Figure 4). Interestingly, in the present study, co-treatment of stachyose could decrease the levels of P-gp, MRP1, and MRP2 in the small intestine with the increase of treatment doses when the mice were co-administrated for four consecutive weeks (Figure 4), suggesting that stachyose could inhibit efflux transportation of phase II metabolites of genistein in the intestine of mice, which contributed to promote bioavailability of genistein.…”

The trypanocidal benznidazole promotes adaptive response to oxidative injury: Involvement of the nuclear factor-erythroid 2-related factor-2 (Nrf2) and multidrug resistance associated protein 2 (MRP2)

“…HepG2 cells were grown in Dulbecco’s modified Eagle’s medium (DMEM) and Ham’s F-12 medium (Invitrogen, Carlsbad, CA, USA) at a 1:1 proportion supplemented with 10% fetal bovine serum (PAA, Pasching, Austria), 2 mM L-glutamine, antibiotics (5 mg/ml penicillin, 5 mg/ml streptomycin and 10 mg/ml neomycin) and 0,1 mg% insulin (Invitrogen). Cells were incubated at 37°C in a humidified atmosphere containing 5% CO 2 as described (Rigalli et al 2015). Unless otherwise stated, treatments were performed in 6-well plates.…”

Risks and benefits related to alimentary exposure to xenoestrogens

“…This combination produced an augmented lethality in vivo and an increased toxicity in isolated cardiomyocytes, when compared to the administration of Sunitinib alone (Harvey and Lainwand, 2015). Genistein intake was correlated with an enhanced multidrug chemoresistance in hepatocellular carcinoma (Rigalli et al, 2015). Pharmacokinetic interactions of genistein and imatinib were evaluated in rats and genistein seems to decrease imatinib plasma levels probably through effects on cytochrome CYP3A4; however the clinical significance of the pharmacokinetic interaction between imatinib and genistein still needs to be confirmed through further studies (Wang et al, 2015).…”