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Cellosaurus publication CLPUB00028

Publication number CLPUB00028
Authors Mini E., Medina W.D., Srimatkandada S., Moroson B.A., Bertino J.R.
Title Establishment and characterization of methotrexate-resistant human cell lines and effects of folate antagonists.
Citation Clin. Res. 31:509A-509A(1983)
Abstract The human T-cell lymphoblast line CCRF-CEM was grown in progressively higher concentrations of methotrexate (MTX) over a period of several months. Multistep selection resulted in the establishment of CEM/R1 and CEM/R3 sublines able to grow in 0.2 and 2.0 muM MTX, respectively. Both resistant cell lines had a dihydrofolate reductase (MR) activity 10-20 fold elevated over that of the sensitive line. Resistance in CEM/R3 cells was also associated with a marked decreasee in 3H-MTX transport. Southern blot analysis of restriction enzyme digested DNAs from sensitive and CEM/R1 cells, using 32P, nick-translated human DHFR cDNA probe, demonstrated amplification of DHFR genes in the CEM/R1 line. Cytogenetic analysis showed that CEM/R1 cells contained an elongated marker chromosome having a homogeneous staining region not present in the sensitive cells. The inhibitory effect of two new folate antagonists was evaluated in these resistant sublines, as well as in CEM/R4, a HTX resistant subline (obtained from H. Lazarus) characterized by impaired HTX transport but normal levels of DHFR. The drugs studied were trimetrezate (JB-11, TMQ, 2,4-diamino-S-methyl-6[(3,4,5-trimethoxyanilino)methyl]quinazoline) and triazinate (TZT, Baker's anti-fol), now in clinical trial.
Cell lines CVCL_S649; CCRF-CEM/R1
CVCL_S651; CCRF-CEM/R3