Growth inhibition of breast cancer cell line MCF-7 by siRNA silencing of Wilms tumor 1 gene.

BACKGROUND: RNA interference (RNAi) is sequence-specific inhibition of gene expression induced by double-stranded RNA. OBJECTIVE: Define the role of Wilms tumor 1 gene (WT1) in breast cancer oncogenesis using RNAi. MATERIAL AND METHOD: MCF-7 breast cancer cells, which express a high level of WT1, were transfected with synthetic small interfering RNA (siRNA) targeting WT1 (siRNA(WT1)) resulting in inhibition of WTI expression, as well as growth, in a dose- and time-dependent manner. RESULT: The minimum concentration of siRNA(WT1) for growth inhibition and WT1 silencing was 25 nM and 50 nM respectively. WT1 expression was completely abolished at 200 nM siRNA,. CONCLUSION: These data suggest that WTI1is indispensable for the survival of breast cancer MCF-7 cell line.

Hepatocellular carcinoma: Correlation of histological grading with immunohistochemical identification of proliferative hepatocytes with PC 10.

Sections from 31 liver needle biopsies of hepatocellular carcinomas(HCCs) were exa-mined for the histological grading of tumors with the expression of a labelling index, using monoclonal antibodies to proliferating cell nuclear antigen PC-10. The correlation between histological grading and the labelling index showed a statistically significant increase in the labelling index in grades III to IV of HCCs. A cut-off point of the labelling index at 49 per cent was proposed to indicate the prognosis of the patient. HCCs with a labelling index below 49 per cent has a better prognosis than HCCs with a labelling index above 49 per cent. A combination of histological grading and the labelling index indicated the prognosis of the patients with HCCs.