Establishment and characterization of adriamycin-resistant human colorectal adenocarcinoma HCT-15 cell lines with multidrug resistance.
The multidrug resistance (MDR) phenotype, either intrinsic and/or acquired, is discussed in relation to several MDR-associated markers such as P-glycoprotein (P-gp) encoded by mdr1, multidrug-resistance-associated protein (MRP) encoded by MRP and lung-resistance-associated protein (LRP) encoded by LRP. Well-characterized in vitro models are required to elucidate the mechanisms of MDR. The aim of the present study is the establishment of a drug-resistant subline from human colorectal adenocarcinoma HCT-15 that intrinsically expresses moderate levels of P-gp, MRP and LRP. Three adriamycin-resistant sublines (HCT-15/ADM1, HCT-15/ADM2 and HCT-15/ADM2-2) were established by stepwise exposure in growth medium that was supplemented with 25-200 ng/ml adriamycin-resulting in a 2.2- to 7.8-fold increase in IC(50) values by using the XTT assay. They were cross-resistant to MDR-related drugs, epirubicin, mitoxantrone, vincristine, etoposide and taxol, but not the MDR-unrelated drug, mytomycin C. The resistance to adriamycin was confirmed in vivo by a lack of sensitivity in athymic nude mice. Gene expression data for mdr1/P-gp, MRP/MRP and LRP/LRP on both mRNA and protein levels demonstrated that the molecules contributing to MDR in resistant sublines are mainly P-gp and partially MRP. The newly established adriamycin-resistant sublines of HCT-15 will provide clinically relevant tools to investigate how to overcome drug resistance and elucidate possible mechanisms of acquired MDR in human colon cancer.
Uchiyama-Kokubu
N
N
Tsukuba Research Institute, Novartis Pharma KK, Ohkubo 8, Tsukuba-shi, Ibaraki 300-2611, Japan. Noriko.Uchiyama@Pharma.Novartis.com
Watanabe
T
T
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism; D000230:Adenocarcinoma / Q000188:drug therapy*; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D015179:Colorectal Neoplasms / Q000188:drug therapy*; D004317:Doxorubicin / Q000494:pharmacology*; D019008:Drug Resistance, Neoplasm; D005260:Female; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000378:metabolism; D009363:Neoplasm Proteins / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured; D020394:Vault Ribonucleoprotein Particles / Q000378:metabolism; D000099187:Major Vault Protein
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents; D004317:Doxorubicin; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D020394:Vault Ribonucleoprotein Particles; D000099187:Major Vault Protein