In addition, CCND3 was correlated to reduced OS in breast cancer patients (HR = 1.64, 95% CI: 1.07-2.52) and shorter DFS/PFS/RFS in bladder cancer patients (HR = 4.60, 95% CI: 1.89-12.57).
Analysis of the primary breast cancer cell lines with HER2 overexpression further confirmed that 5a significantly inhibited Akt Ser473 and Bad Ser136 phosphorylation and reduced cyclin D3 expression.
Interestingly, levels of In1-ghrelin variant expression in breast cancer samples were 8-times higher than those of normal mammary tissue, and showed a strong correlation in breast tumors with GOAT (p = 0.0001), ghrelin receptor-type 1b (GHSR1b; p = 0.049) and cyclin-D3 (a cell-cycle inducer/proliferation marker; p = 0.009), but not with native-ghrelin or GHSR1a expression.
Furthermore, we found that Nic-induced human breast cancer (MDA-MB-231) cell proliferation was inhibited by 1 μM of garcinol (Gar), isolated from the edible fruit Garcinia indica, through down-regulation of α9-nAChR and cyclin D3 expression.
Cyclin CCND3 and CCNE1 along with CDK2 and CDK6 regulate this checkpoint, and genetic changes, detectable by fluorescence in situ hybridization, are hypothesized to increase the aggressiveness of breast cancer, thereby influencing patient survival.
In this study, we analyzed 3 polymorphisms E2F2_-5368_A>G, CCND1_870_A>G and CCND3_-677_C>T located in genes involved in cell cycle regulation in the GENICA population-based and age-matched breast cancer case-control study from Germany.
These results indicate that cyclin D1 and cyclin D3 share a common mechanism of degradation and we propose that the coordinate increase of D-type cyclins observed in primary breast cancers reflects a defect in their proteolysis.