stevioside and Breast-Neoplasms

Background: CPUK02 (15-Oxosteviol benzyl ester) is a new ent-kaurenoid derivative of stevioside and exhibits\ strong anti-cancer activity. Nowadays, the pattern of epigenetic in cancer has been topic of many studies and DNA\ methylation targeting represents a relevant strategy for cancer treatment. Since, no study conducted to this mechanism, we\ attempt to evaluate whether CPUK02 induce its anti-cancer effects via alteration the level of mRNA DNMT3B, DNMT3A\ expression and ESR1 methylation pattern in breast cancer cells line. Methods: MCF-7 (ER +) and MDA-MB231 (ER-)\ cell lines were treated for 24, 48 hours with 1 μM CPUK02 and 5-AZA-CdR (DNA methyltransferase inhibitor).\ Quantitative expression of DNMT3B and DNMT3A genes and ESR1 promoter methylation was assessed by Real-Time\ PCR and MS-PCR, respectively. Results: CPUK02 restored ESR1 promoter unmethylated allele in MDA-MB 231\ cells. Also treatment with CPUK02 decreased the expression of both DNMT3A and DNMT3B genes like 5-AZA.\ The expression of DNMT genes were diminished by half compared with control cells. Conclusions: These results showed\ that CPUK02 has an anticancer effect on MDA-MB 231 cells which this effect can be done through several pathways.

Topics: Antineoplastic Agents; Breast Neoplasms; Cell Proliferation; Diterpenes, Kaurane; DNA Methylation; Estrogen Receptor alpha; Female; Gene Expression Regulation, Neoplastic; Glucosides; Humans; Promoter Regions, Genetic; Tumor Cells, Cultured

Stevioside is a diterpene glycoside found in the leaf of Stevia rebaudiana, a traditional oriental medicinal herb, which has been shown to have various biological and ethno-medicinal activities including antitumor activity. In this study, we investigated the effects of stevioside on the cytotoxicity, induction of apoptosis, and the putative pathways of its action in human breast cancer cells (MCF-7). For the analysis of apoptotic pathway, measurement of reactive oxygen species (ROS) and assessment of mitochondrial transmembrane potential (MTP) were achieved. We showed that stevioside was a potent inducer of apoptosis and it conveyed the apoptotic signal via intracellular ROS generation; thereby inducing change in MTP and induction of mitochondrial mediated apoptotic pathway. Taken together, our data indicated that stevioside induces the ROS-mediated mitochondrial permeability transition and results in the increased expression of apoptotic proteins such as Bax, Bcl-2 and Caspase-9. Effect of stevioside on stress-related transcription factors like NF-E2-related factor-2 opens up a new vista for further studies. This is the first report on the mechanism of the antibreast cancer (in vitro) activity of stevioside.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; bcl-2-Associated X Protein; Blotting, Western; Breast Neoplasms; Caspase 9; Cell Cycle; Cell Proliferation; Cell Survival; Diterpenes, Kaurane; Dose-Response Relationship, Drug; Female; Glucosides; Humans; MCF-7 Cells; Membrane Potentials; Mitochondria; NF-E2-Related Factor 1; Reactive Oxygen Species; Signal Transduction