D. Couturier et Mh. Couturierturpin, GENETIC ALTERATIONS IN HUMAN COLORECTAL T UMORS - DELETIONS AT CHROMOSOME-1 SHORT ARM AN EARLY EVENT, Bulletin de l'Academie nationale de medecine, 181(8), 1997, pp. 1651-1662
Cytogenetic anomalies described in cole-rectal tumors are numerous. De
spite the complexity and the number of the anomalies observed, a combi
ned study of their frequency and of the stage of prognosis of the tumo
rs suggests that the evolution from colonic adenoma to carcinoma often
follows a sequence of events comprising a 5q15-22 deletion (DCC), and
a 17p deletion (P53). It even seems likely that in many cases, these
events are not constant and that others might lead to the same phenoty
pic transformation. Chromosome 1 involvement in structural rearrangeme
nts has been demonstrated in numerous forms of cancers, malignant bloo
d disorders and in solid tumors. In colorectal adenocarcinoma anomalie
s have been described on short and/or long amis. In a case of adenoma,
vith mild dysplasia a deletion of the distal part of the short arm of
chromosome 1 rr as observed as an isolated cytogenetic anomaly suggest
ing it would be an early, perhaps triggering, event for the tumour dev
elopment. A cytogenetic study in a series of colo-rectal tumours, rese
archs on loss heterozygoty and microsatellite instability lead to cons
ider deletions at chromosome 1p as an early event in human colorectal
tumourigenesis.