Establishment of cell lines derived from chronic lymphocytic leukaemic cells by transfection with myc and ras.

Seventy-one samples from 37 cases of chronic lymphocytic leukaemia (CLL) were transfected with human c-myc and/or N-ras. In only three cases did the CLL cells further transform and four cell lines were established following transfection with myc plus ras. Surface marker profiles and immunoglobulin gene rearrangement studies confirm that all cell lines have arisen from the original CLL cells. The cell lines are EBNA positive but negative for EBV latent membrane protein (LMP). Karyotyping of the cell lines is as follows: SA4, 46,XY; SA4-2, 45,XY, 20; RK4, 48,XY,+ 5,+ 12; EHC4, 47,XY, t(14;18)(q32;q21), + 12. Although the majority of CLL cells appear resistant to transformation in vitro with myc and ras with the methods used, it does occur in a small percentage (about 8%). There appeared to be no correlation between the ability to transform in vitro and clinical behaviour.