title: Diminished drug transport and augmented radiation sensitivity caused by loss of RLIP76.
abstract: This study was undertaken to characterize the consequences of Ral-interacting protein (RLIP76)-loss with respect to drug resistance, transport, radiation resistance, and alternative transport mechanisms in mouse embryonic fibroblasts (MEFs). MEFs were derived from RLIP76+/+, RLIP76+/- and RLIP76-/- mice. The transport of doxorubicin (DOX), colchicine (COL), leukotriene C4 and dinitrophenyl S-glutathione (DNP-SG) was analyzed in inside-out vesicles (IOVs) prepared from MEFs. We used immuno-titration of transport activity to determine the contribution of RLIP76, MRP1, and p-glycoprotein (Pgp) towards total transport activity. Loss of RLIP76 alleles resulted in significant sensitization to radiation, DOX, cisplatin, and vinorelbine (VRL). In IOVs prepared from MEFs, we observed a stepwise loss of transport activity. Loss of RLIP76 confers sensitivity to xenobiotics and radiation due to the loss of a common transport mechanism for glutathione-electrophile conjugates and xenobiotics.
authors.affiliation: Department of Molecular Biology and Immunology, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, EAD RM No. 542, Fort Worth, TX 76107-2699, United States. ssinghal@hsc.unt.edu
authors.forename: Sharad S
authors.initials: SS
authors.lastname: Singhal
authors.forename: Sushma
authors.initials: S
authors.lastname: Yadav
authors.forename: Jyotsana
authors.initials: J
authors.lastname: Singhal
authors.forename: Mukesh
authors.initials: M
authors.lastname: Sahu
authors.forename: Archana
authors.initials: A
authors.lastname: Sehrawat
authors.forename: Sanjay
authors.initials: S
authors.lastname: Awasthi
mesh_terms: D000477:Alkylating Agents / Q000378:metabolism / Q000633:toxicity; D000818:Animals; D018943:Anthracyclines / Q000378:metabolism / Q000633:toxicity; D001692:Biological Transport / Q000235:genetics; D004317:Doxorubicin / Q000378:metabolism / Q000633:toxicity; D019008:Drug Resistance, Neoplasm / Q000235:genetics; D004705:Endocytosis / Q000235:genetics; D020690:GTPase-Activating Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007328:Insulin / Q000378:metabolism; D051379:Mice; D008817:Mice, Mutant Strains; D018384:Oxidative Stress; D045663:Quantum Dots; D011836:Radiation Tolerance / Q000235:genetics; D012235:Rhodamines / Q000378:metabolism; D015262:Xenobiotics / Q000378:metabolism* / Q000633:toxicity
chemical_list: D000477:Alkylating Agents; D018943:Anthracyclines; D020690:GTPase-Activating Proteins; D007328:Insulin; C490620:Ralbp1 protein, mouse; D012235:Rhodamines; D015262:Xenobiotics; D004317:Doxorubicin
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