title: Copper transporters and chaperones CTR1, CTR2, ATOX1, and CCS as determinants of cisplatin sensitivity.
abstract: The development of resistance to cisplatin (cDDP) is commonly accompanied by reduced drug uptake or increased efflux. Previous studies in yeast and murine embryonic fibroblasts have reported that the copper (Cu) transporters and chaperones participate in the uptake, efflux, and intracellular distribution of cDDP. However, there is conflicting data from studies in human cells. We used CRISPR-Cas9 genome editing to individually knock out the human copper transporters CTR1 and CTR2 and the copper chaperones ATOX1 and CCS. Isogenic knockout cell lines were generated in both human HEK-293T and ovarian carcinoma OVCAR8 cells. All knockout cell lines had slowed growth compared to parental cells, small changes in basal Cu levels, and varying sensitivities to Cu depending on the gene targeted. However, all of the knockouts demonstrated only modest 2 to 5-fold changes in cDDP sensitivity that did not differ from the range of sensitivities of 10 wild type clones grown from the same parental cell population. We conclude that, under basal conditions, loss of CTR1, CTR2, ATOX1, or CCS does not produce a change in cisplatin sensitivity that exceeds the variance found within the parental population, suggesting that they are not essential to the mechanism by which cDDP enters these cell lines and is transported to the nucleus.
authors.affiliation: Moores Cancer Center, University of California, San Diego, 3855 Health Sciences Drive, Mail Code 0819, La Jolla, CA 92093, USA. showell@ucsd.edu.
authors.forename: Kristin M
authors.initials: KM
authors.lastname: Bompiani
authors.forename: Cheng-Yu
authors.initials: CY
authors.lastname: Tsai
authors.forename: Felix P
authors.initials: FP
authors.lastname: Achatz
authors.forename: Janika K
authors.initials: JK
authors.lastname: Liebig
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Howell
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D027682:Cation Transport Proteins / Q000378:metabolism*; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D002945:Cisplatin / Q000494:pharmacology*; D003300:Copper / Q000378:metabolism*; D000079922:Copper Transport Proteins; D000079923:Copper Transporter 1; D019008:Drug Resistance, Neoplasm; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D018832:Molecular Chaperones / Q000378:metabolism*; D010051:Ovarian Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D000080083:SLC31 Proteins; D023041:Xenograft Model Antitumor Assays
chemical_list: D000970:Antineoplastic Agents; C499247:Atox1 protein, mouse; D027682:Cation Transport Proteins; C491962:Ccs protein, mouse; D000079922:Copper Transport Proteins; D000079923:Copper Transporter 1; D018832:Molecular Chaperones; D000080083:SLC31 Proteins; C490077:Slc31a1 protein, mouse; C585492:Slc31a2 protein, mouse; D003300:Copper; D002945:Cisplatin