cyclin-d1 and lupeol

The compound 29-(4-methylpiperazine)-luepol (M22), a novel derivative of lupeol has shown anti-proliferative effects against the human non-small cell lung cancer A549 cell line. M22 showed significant anti-proliferative activity at 6.80 μM and increased accumulation of G1 cells and effectively suppressed expression of the G1 arrest-related genes cyclins D1 and E1, CDK2 and CDC25A. This was further confirmed by Western blotting demonstrating decreased cyclin D1 and CDC25A protein levels. Furthermore, M22 caused induction of apoptosis that downregulated the anti-apoptotic BCL-2 gene and increased expression of BAX, CASP3 and CASP9 as well as the APAF1 gene. The effect of caspase-induced apoptosis was confirmed by an increase in reactive oxygen species (ROS), loss of mitochondrial membrane potential (MMP). Taken together, our findings indicated that M22 possessed potent anti-proliferative and apoptotic activities.

Topics: A549 Cells; Antineoplastic Agents, Phytogenic; Apoptosis; Apoptotic Protease-Activating Factor 1; bcl-2-Associated X Protein; Caspase 3; Caspase 9; cdc25 Phosphatases; Cell Line, Tumor; Cyclin D1; Cyclin E; Cyclin-Dependent Kinase 2; G1 Phase Cell Cycle Checkpoints; Gene Expression Regulation, Neoplastic; HeLa Cells; Hep G2 Cells; Humans; Inhibitory Concentration 50; Membrane Potential, Mitochondrial; Oncogene Proteins; Pentacyclic Triterpenes; Piperazines; Proto-Oncogene Proteins c-bcl-2; Reactive Oxygen Species; Signal Transduction

Lupeol, a dietary triterpene, was shown to decrease serum prostate-specific antigen levels and inhibit the tumorigenicity of prostate cancer (CaP) cells in vivo. Here, we show that Lupeol inhibits the proliferative potential of CaP cells and delineated its mechanism of action. Employing a focused microarray of human CaP-associated genes, we found that Lupeol significantly modulates the expression level of genes such as ERBB2, tissue inhibitor of metalloproteinases-3, cyclin D1 and matrix metalloproteinase (MMP)-2 that are known to be associated with proliferation and survival. A common feature of these genes is that all of them are known to either regulate or act as downstream target of beta-catenin signaling that is highly aberrant in CaP patients. Lupeol treatment significantly (1) reduced levels of beta-catenin in the cytoplasmic and nuclear fractions, (2) modulated expression levels of glycogen synthase kinase 3 beta (GSK3beta)-axin complex (regulator of beta-catenin stability), (3) decreased the expression level and enzymatic activity of MMP-2 (downstream target of beta-catenin), (4) reduced the transcriptional activation of T Cell Factor (TCF) responsive element (marker for beta-catenin signaling) in pTK-TCF-Luc-transfected cells and (5) decreased the transcriptional activation of MMP-2 gene in pGL2-MMP-2-Luc-transfected cells. Effects of Lupeol treatment on beta-catenin degradation were significantly reduced in CaP cells where axin is knocked down through small interfering RNA transfection and GSK3beta activity is blocked. Collectively, these data suggest the multitarget efficacy of Lupeol on beta-catenin-signaling network thus resulting in the inhibition CaP cell proliferation. We suggest that Lupeol could be developed as an agent for chemoprevention as well as chemotherapy of human CaP.

Topics: Anti-Inflammatory Agents; beta Catenin; Cell Division; Cyclin D1; Gene Expression Regulation; Gene Expression Regulation, Neoplastic; Humans; Male; Matrix Metalloproteinase 2; Oligonucleotide Array Sequence Analysis; Pentacyclic Triterpenes; Prostatic Neoplasms; Signal Transduction; Tissue Inhibitor of Metalloproteinase-3; Triterpenes