This study investigates whether curcumin inhibits Skp2-mediated p27 ubiquitination in Her2/Skp2-overexpressing cancer cell lines (MDA-MB-231/Her2 cells).
Collectively, our findings support the hypothesis that Cks1 supports hepatocarcinogenesis by NF-κB-mediated regulation of IL-8 expression, broadening the function of Cks1 in cancer beyond its role as a Skp2 cofactor in p27 ubiquitination.
Our data provide proof-of-principle that the screening platform we developed, using endogenous nuclear p27 as an endpoint, presents an effective means of identifying bioactive molecules with cancer selective antiproliferative activity.
Moreover, a significant positive correlation between p27 gene expression and rapamycin anti-tumor activity was also observed in mice bearing different human cancer cell xenografts.
These findings, overall, suggest that Skp2 may play an important role in ACC development through the down-regulation of p27 and that Skp2 siRNA can be a novel modality of cancer gene therapy for suppression of p27 down-regulation in ACC.
Therefore, knockdown of Skp2 expression by RNAi inhibits breast cancer cell growth and enhances the effect of epirubicin. siRNA-mediated gene silencing of Skp2 could be a novel cancer gene therapy for the suppression of p27 down regulation.
Due to the role of p27 in maintaining cellular quiescence, however, loss of its expression can still be a useful partial indicator of the aggressiveness of cancer.
The study aimed at the assessment of expression levels of cyclins D1 and E in surgically removed gastric cancers, including the analysis of this prognostic value parameter, and attempted to determine some correlations between the expression of the examined cyclins and selected histoclinical and molecular parameters such as: patients' age and gender, histological type according to the Lauren classification, cancer stage (TNM), degree of histological malignancy (G) and level of expression of the cell-cycle regulatory genes protein products--P53, P21, P27.
Thus, this novel chimeric molecule is more potent and capable of killing a broader spectrum of tumors than the parental p16 and p27 molecules independent of the tumor cell p53 and phenotype and represents a powerful new therapeutic agent for cancer gene therapy.