DETECTION OF PREMALIGNANT STAGES IN CERVICAL SMEARS WITH A BIOTINYLATED PROBE FOR CHROMOSOME-1

Fluorescence in situ hybridization with (peri-)centromeric probes is a n easy method to detect numerical aberrations in nonmitotic and mitoti c cells. In this study, cervical smears of premalignant and malignant stages (26 controls, 15 CIN I, 12 CIN II, and 15 CIN III cervical smea rs) were analyzed for the presence of numerical aberrations of chromos ome 1 with a centromeric DNA probe (1q12). With more severe stages a d ecrease of disomy was observed, merely due to a gain of extra copies o f chromosome 1; in some cases, however, monosomy was detected. The Fre quencies of disomy for chromosome 1 ranged from 65.3% to 95.0% in the controls, from 71.3% to 94.3% in CIN I, from 59.2% to 91.5% in CIN II, and from 23% to 96.2% in CIN III. Polysomy ranged from 0% to 5.7% in the controls, from 0% to 14.4% in CIN I, from 0.9% to 30.8% in CIN II, and from 0.8% to 69.6% in CIN III. Monosomy ranged from 2.6% to 34.1% in the controls, from 0% to 17.5% in CIN I, from 3.6% to 27.5% in CIN II, and from 0.9% to 31.4% in CIN III. The results show that screenin g for aneuploidy of chromosome 1 allows a good discrimination between control samples and dysplasia. These data suggest that chromosome 1 ma y be a marker chromosome. They are in accordance with previous cytoden sitometric analyses, where already in the preneoplastic stages an incr eased DNA content (polyploidization with subsequent aneuploidization) is observed.