Objective: To investigate the mode of cell division and Numb expression in cervical squamous cells. Method: We measured the cleavage angles of cervical squamous epithelia basal cells and Numb protein expression in 50 cases of cervical squamous cell carcinomas (CSCC), 59 cervical intraepithelial neoplasias (CIN) grade II-III, 21 CIN grade I and 48 controls. Results: We found an increase in horizontal divisions in CIN grade I and a decrease in horizontal divisions in CIN grade II-III. Numb

more »

... ion had a tendency to be stronger from control to CSCC. In CSCC there was a significantly higher expression of mRNA for the Numb-PRR L isoform but not for the Numb-PRR S isoform. Conclusion: Our findings suggest that in the initial stage of CSCC, carcinomatous cells may acquire an increase of symmetric division by altering cleavage orientation and proliferation. Expression of Numb protein in Cervical squamous epithelia and an increased expression of Numb-PRR L isoforms may be among the mechanisms involved in the genesis of CSCC.