cyclin-d1 and tanshinone

Although the cardiovascular pharmacological actions of Tanshinone IIA (TanIIA) have been extensively studied, research on its roles in cardiac regeneration is still insufficient. The present study employed the cardiac myoblast cell line H9c2 to evaluate the possible roles of TanIIA in cardiac regeneration. It was found that certain concentration of TanIIA inhibited cell proliferation by suppressing the expression of proteins related to the cell cycle [cyclin dependent kinase (CDK)4, CDK6 and cyclin D1] and proliferation [c‑Myc, octamer‑binding transcription factor 4 (Oct4) and proliferating cell nuclear antigen (PCNA)] without inducing apoptosis. In this process, the expression of cardiac troponin in the treated cells was significantly increased and the migration of the treated cells toward the wound area was significantly enhanced. Meanwhile, TanIIA inhibited the canonical signaling pathway through increasing the expression of glycogen synthase kinase 3β (GSK‑3β) and adenomatous polyposis coli (APC) and increased the expression of Wnt11 and Wnt5a in the noncanonical Wnt signaling pathway. Following β‑catenin agonist WAY‑262611 intervention, the effect of TanIIA on the promotion of cardiac differentiation and improved cell migration was significantly reduced. In conclusion, it was hypothesized that TanIIA could promote cardiac differentiation and improve cell motility by modulating the Wnt/β‑catenin signaling pathway. These results suggest that TanIIA may play beneficial roles in myocardial regeneration following stem cell transplantation.

Topics: Abietanes; Animals; Cell Differentiation; Cell Line; Cell Movement; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Myocytes, Cardiac; Rats; Wnt Signaling Pathway

Tanshinone I (TAN I) as one of the naturally occurring diterpenes from Salvia miltiorrhizae Bunge (Danshen) has been reported to exhibit an anti-cancer activity. However, the underlying mechanisms are still poorly understood. Thus, we performed in vitro study to elucidate the biological mechanism by which TAN I may induce the inhibition of cell growth in human colorectal cancer cells. The treatment of TAN I suppressed the cell proliferation in HCT116 and SW480 cells and decreased the level of cyclin D1 protein. However, the mRNA level of cyclin D1 did not changed by TAN I treatment. Inhibition of proteasomal degradation by MG132 blocked TAN I-mediated cyclin D1 downregulation and the half-life of cyclin D1 was decreased in the cells treated with TAN I. In addition, phosphorylation of cyclin D1 at threonine-286 was increased by TAN I and a point mutation of threonine-286 to alanine attenuated TAN I-mediated cyclin D1 downregulation. Inhibition of ERK1/2 suppressed cyclin D1 phosphorylation and subsequent downregulation by TAN I. From these results, we suggest that TAN I-mediated cyclin D1 downregulation may result from proteasomal degradation through its ERK1/2-mediated phosphorylation of threonine-286. In conclusion, the current study provides new mechanistic link between TAN I, cyclin D1 downregulation and cell growth in human colorectal cancer cells.

Topics: Abietanes; Antineoplastic Agents, Phytogenic; Cell Line, Tumor; Cell Proliferation; Colorectal Neoplasms; Cyclin D1; Down-Regulation; Humans; MAP Kinase Signaling System; Phosphorylation; Proteasome Endopeptidase Complex

Signal transducer and activator of transcription 3 (STAT3) is usually constitutively activated in a variety of malignancies. Thus, STAT3 may be a promising target for treatment of tumor cells. Recently, Tanshinone IIA (Tan IIA), a major active constituent from the root of Salvia miltiorrhiza Bunge, was reported to have apoptosis inducing effects on a large variety of cancer cells. In this study, we evaluate the anti-proliferation and apoptosis inducing effects of Tan IIA on C6 glioma cells. Cell growth and proliferation were measured by MTT assay, cell apoptosis was observed by flow cytometry and DNA-fragmentation analysis. Further more, we investigated inhibitory effects of Tan IIA on STAT3 activity and its downstream targets: Bcl-XL, cyclin D1. Alteration of STAT3 activity was examined by measuring their DNA binding activity and tyrosine phosphorylation. Changes in the expression levels of Bcl-XL and cyclin D1 were examined by Western blot analysis. We found that the cellular growth were inhibited and cell apoptosis were observed after the treatment with Tan IIA. The STAT3 activity was significantly reduced by Tan IIA parallel with a significant attenuation of expression of Bcl-XL and cyclin D1. These results suggest that Tan IIA may serve as an effective adjunctive reagent in the treatment of glioma for its targeting of constitutive STAT3 signaling.

Topics: Abietanes; Animals; Antineoplastic Agents, Phytogenic; Apoptosis; bcl-X Protein; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cyclin D1; DNA Fragmentation; Dose-Response Relationship, Drug; Glioma; Phenanthrenes; Rats; STAT3 Transcription Factor; Time Factors

Tanshinone IIA (TSN) is a monomer extracted from the Chinese herb Danshen. In this study, we examined the effect of Tanshinone IIA on adriamycin (ADR)-induced apoptosis in neonatal rat cardiomyocytes and underlying molecular mechanisms. Primary cultured cardiomyocytes were treated with 1 micromol/L of adriamycin for 24 h with or without pretreatment with Tanshinone IIA (0.5-2 micromol/L) for 2 h. 3-(4,5-dimethyl thiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT) assay, Hoechst staining, and flow cytometry measurement were used to assess cell viability and apoptosis. Fluorescent probes 2',7'-dichlorofluorescein diacetate and dihydroethidium were used to detect the production of reactive oxygen species. Western blotting was used to evaluate the expression of Bcl-2 and Bax proteins. Adriamycin significantly induced apoptosis in cardiomyocytes. Tanshinone IIA (0.5-2 micromol/L) ameliorated apoptosis induced by adriamycin in a dose-dependent manner. Tanshinone IIA (2 micromol/L) markedly attenuated adriamycin-induced reactive oxygen species production. Western blotting revealed that Tanshinone IIA prevented the adriamycin-mediated reduction of the ratio of Bcl-2/Bax. In conclusion, Tanshinone IIA significantly inhibits adriamycin-induced cardiomyocyte apoptosis in a dose-dependent manner, and this effect is at least partly caused by its antioxidant properties.

Topics: Abietanes; Animals; Animals, Newborn; Antineoplastic Agents; Antioxidants; Apoptosis; bcl-2-Associated X Protein; Cell Nucleus; Cell Survival; Cells, Cultured; Chemoprevention; Cyclin D1; Dose-Response Relationship, Drug; Doxorubicin; Drugs, Chinese Herbal; Formazans; Myocytes, Cardiac; Phenanthrenes; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Tetrazolium Salts

Tanshinone (Tan) is one of the active components of Radix Salvia miltiorrhiza (Lamiaceae), which is clinically used to treat cardiovascular diseases in China. The aim of this study was to estimate the effect of Tan on the proliferation of cultured vascular smooth muscle cells (VSMCs) induced by fatal bovine serum (FBS). It was shown that various concentrations of Tan inhibited the VSMCs proliferation in a dose-dependent manner. Tan significantly blocked VSMCs cell cycle in G(0)/G(1) phase. The anti-proliferative effect of Tan was associated with the inhibition of the extracellular signal-regulated kinase1/2 (ERK1/2). On the other hand, the decrement of Tan on the cyclin D1 protein may be related to the high expression of p21(waf/cip1). The data suggest that the anti-proliferative effect of Tan on VSMCs proliferation was associated with ERK1/2 signaling pathway.

Topics: Abietanes; Angiogenesis Inhibitors; Animals; Antineoplastic Agents, Phytogenic; Blotting, Western; Cell Cycle; Cell Cycle Proteins; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Flow Cytometry; Male; Muscle, Smooth, Vascular; Phenanthrenes; Phosphorylation; Rats; Rats, Wistar; Signal Transduction; Tetrazolium Salts; Thiazoles