DLD-1 AND HCT-15 CELL-LINES DERIVED SEPARATELY FROM COLORECTAL CARCINOMAS HAVE TOTALLY DIFFERENT CHROMOSOME CHANGES BUT THE SAME GENETIC-ORIGIN

Aneuploid DLD-1 and HCT-15 cell lines independently derived from a colon carcinoma by two researchers lacked a common marker chromosome or a concurrent numerical change. To further look into the genetic identity of these two cell lines, we used chromosome painting with fluorescence in situ hybridization (FISH) and confirmed the G-band identification on all chromosome changes. We have also found comparable results between these two cell lines on C-/Q- polymorphic bands of several chromosomes, and electrophoretic patterns of restriction fragment-length polymorphisms (RFLPs) from eight Y-chromosome-specific DNA probes with 13 restriction enzymes. These results strongly suggest that DLD-1 and HCT-15 are identical genetically. Clearly, cell lines bearing totally unrelated changes in karotypes can be generated from the same cancer specimen.