ABSTRACT
Objective To investigate the expression and clinical significance of DNMT1 and CCNA1 in different grades of cervical lesions. Methods Cervical tissues were selected from normal cervical(NC),low-grade cervical intraepithelial lesion(LSIL),high-grade cervical intraepithelial lesion(HSIL)and cervical squa-mous cell carcinoma(SCC)from each thirty patients.The expression of DNMT1 and CCNA1 mRNA and protein was examined by Western Blot analysis and qRT-PCR in cervical tissues. Results The expression of DNMT1 mRNA and protein in LSIL,HSIL and SCC was higher than in NC(F=117.93,P<0.05;F=61.24,P<0.05). Expression of DNMT1 mRNA and protein was increased steadily according to severity of cervical lesions(χ2trend=26.25,P<0.05;χ2trend=26.60,P<0.05).The expression of CCNA1 mRNA and protein in HSIL and SCC was lower than that in NC and LSIL(F = 77.04,P < 0.05;F = 57.15,P < 0.05). Expression of CCNA1 mRNA and protein was decreased steadily according to severity of cervical lesions(χ2trend=64.19,P<0.05;χ2trend=60.24,P<0.05). There was a negative correlation between expression of DNMT1 and CCNA1 protein in LSIL,HSIL,SCC (r=-0.75,-0.56,P<0.05). Conclusion In DNMT1 mRNA there is high expression of protein and in CCNA1 mRNA there is low expression of protein,but both may be related to the occurrence and development of cervical cancer.
ABSTRACT
Besides its function as a pathogenicity determinant, the Tombusvirus P19 also serves as a suppressor of RNA interference (RNAi) by sequestering intracellular small RNAs such as the small interfering RNAs (siRNAs) and microRNAs (miRNAs). However, the effect of P19 on mammalian cells has not been evaluated before. A human embryonic kidney 293 cell line that stably expressed p19 (HEK293-p19) was generated. Flow cytometric analysis revealed that over-expression of P19 caused a significant accumulation of G2/M phase cells. Cell proliferation assays demonstrated a reduced DNA replication and cell growth in HEK293-p19 cells. Moreover, p19 altered the expression profiles of a number of cell cycle regulators in HEK293 cells, such as upregulafion of cyclin A1, CDK2, CDK4, CDK6, p18, cyclin D2, p19INK4d and E2F1, and downregulation of p15, cyclin A2, cyclin B1 and cyclin E1. Thus, the data strongly indicate that p19 might influence multiple G2/M regulators to cause G2/M arrest.