Replication pattern of the p53 and 21q22 loci in the premalignant and malignant stages of carcinoma of the cervix

BACKGROUND. Loss of replication synchrony during the S-phase of the cell cycle has been shown to be associated with aneuploidy in malignant cells. METHODS. The replication pattern of cervical cells obtained from normal patients and from patients with preinvasive and invasive carcinoma of the cervix was evaluated. The fluorescence in situ hybridization technique was applied to Papanicolaou smear slides using p53 and 21q22 loci. Asynchrony was determined by the presence of one single and one set of double dots in the same cell. RESULTS. The rate of asynchrony in low grade squamous intraepithelial lesions was not significantly different from that of normal controls. However, the rate of asynchrony was significantly higher in the high grade squamous intraepithelial lesions and even higher in the invasive carcinoma. CONCLUSIONS. The authors believe these results reflect impairment of the replication control of homologous loci and that this phenomenon may be correlated to the phenotype of the tumor.