Distinct chromosomal alterations associated with TP53 status of LoVo cellsunder PALA selective pressure: a parallel with cytogenetic pathways of colorectal cancers

This study investigates the chromosomal alterations involved in the acquisi tion of PALA resistance of LoVo colorectal cancer cells homozygous for wild -type TP53 before and after transfection with a 143Ala-mutated TP53 gene. P ALA resistance was always associated with an increased number of CAD gene c opies, but gene amplification sensu stricto was rarely observed, Interestin gly, distinct chromosome patterns were found in relation to the TP53 status of the cells. In parental LoVo cells, the CAD copy number was increased th rough gains of normal chromosome 2 whereas in transfectant clones, resistan ce mostly occurred through chromosome rearrangements. The relationship with the two different cytogenetic patterns described in colorectal tumors is d iscussed.