Pro-apoptotic Effect Of Resveratrol Research Articles

Resveratrol induces apoptosis by modulating the reciprocal crosstalk between p53 and Sirt-1 in the CRC tumor microenvironment.

P53 represents a key player in apoptosis-induction in cancers including colorectal cancer (CRC) that ranks third worldwide in cancer prevalence as well as mortality statistics. Although a pro-apoptotic effect of resveratrol has been repeatedly proven in CRC cells, its pathway mechanisms are not completely understood, as there are controversial statements in the literature regarding its activation or inhibition of the counteracting proteins Sirt-1 and p53. CRC cells as wild-type (HCT-116 WT) or p53-deficient (HCT-116 p53-/-) were cultured using multicellular tumor microenvironment (TME) cultures containing T-lymphocytes and fibroblasts to elucidate the role of p53/Sirt-1 modulation in resveratrol's concentration-dependent, pro-apoptotic, and thus anti-cancer effects. Resveratrol dose-dependently inhibited viability, proliferation, plasticity as well as migration, and induced apoptosis in HCT-116 WT more effectively than in HCT-116 p53-/- cells. Moreover, resveratrol stimulated Sirt-1 expression when administered at low concentrations (<5µM) but suppressed it when added at high concentrations (>10µM) to CRC-TME. In parallel, similar to the knockdown of Sirt-1 at the mRNA level, treatment with high-concentration resveratrol boosted the acetylation of p53, the expression of p21, Bax, cytochrome C, caspase-3, and ultimately induced apoptosis in CRC WT but not in CRC p53-/- cells. Notably, increasing concentrations of resveratrol were found to promote hyperacetylation of p53 and FOXO3a as post-translational substrates of Sirt-1, indicating a negative regulatory loop between Sirt-1 and p53. These results demonstrate for the first time, a negative reciprocal crosstalk between the regulatory circuits of p53 and Sirt-1, consequently, apoptosis induction by higher resveratrol concentrations in CRC-TME.

Cytotoxic and Proapoptotic Effects of Resveratrol in In Vitro Studies on Selected Types of Gastrointestinal Cancers.

Cancer diseases are currently one of the greatest health challenges in clinical medicine worldwide. Classic methods of treatment often lead to numerous side effects, including the development of multidrug resistance. For this reason, increasing hope is being placed on compounds of natural origin, mainly due to their pleiotropic effect on different types of cells, protective effect on normal cells and toxic effect on cancerous ones. The most studied group are the polyphenolic compounds, which include resveratrol. The effectiveness of polyphenols in the treatment and prevention of many diseases, including cancer of various origins, has become the basis of many scientific studies. The anticancer effect of resveratrol has been demonstrated at all stages of the carcinogenesis process. Additionally, whether administered by itself or in combination with cytostatics, it may play a significant role in the process of reversing multidrug resistance. A review of the effects of resveratrol in in vitro conditions proves that it has a stronger or weaker antiproliferative and proapoptotic effect on the cells of certain neoplasms of the gastrointestinal tract. Despite the differences in the effect of this compound on different types of cancer, a similar tendency can be observed especially regarding the correlation between the concentration of the compound and the incubation time on the one hand and the antitumour effect on the other hand. The information included in this review may prove helpful in planning in vivo and clinical studies in the future.

Notch-1 activation-dependent p53 restoration contributes to resveratrol-induced apoptosis in glioblastoma cells

Glioblastoma is the most malignant form of adult brain tumor and is associated with a dismal prognosis. Emerging data suggest that Notch signaling participates principally in the formation and malignant progression of glioblastoma. Resveratrol is a terpenoid that exhibits broad pro-apoptotic activity in various types of cancers, including glioblastoma. However, the effects of resveratrol on Notch signaling in glioblastomas have not yet been fully elucidated. We demonstrated that resveratrol strongly suppressed cell growth and induced apoptosis in A172 and T98G glioblastoma cells, which have low active Notch-1 expression and a heterozygous p53 mutation. Our results suggest that resveratrol significantly activates intracellular Notch-1 and restores wild-type p53 expression in a time-dependent manner. Significant de-phosphorylation of Akt, increased Bax expression, decreased Bcl-2 expression and cleavage of caspase-3 were also observed in resveratrol-induced apoptosis in glioblastoma cells. Moreover, simultaneous treatment with resveratrol and a Notch-1 inhibitor (MRK-003) partially attenuated the apoptosis and completely blocked the activation of Notch-1 and the increase in wild-type p53. This suggests that restoration of wild-type p53 expression depends on Notch-1 activation. In addition, the de-phosphorylation of Akt, increased expression of Bax and cleavage of caspase-3 were not fully reversed by MRK-003 treatment, suggesting that p53 restoration is not the only mechanism underlying resveratrol-induced apoptosis. Taken together, we confirmed the anti-proliferative and pro-apoptotic effects of resveratrol on glioblastoma cells and revealed Notch-1 activation-dependent restoration of p53 as an important causative mechanism.

Abstract 3708: Resveratrol induces DNA damage independent of Smad4 expression in its efficacy against human head and neck carcinoma cells

Abstract Resveratrol is a non-toxic natural product present in grape skin, red wine, peanuts etc. Extensive research in almost last two-decades has established that resveratrol possesses a broad range of health benefits including anti-cancer, anti-oxidant, anti aging and cardio protective properties; however, its efficacy and associated mechanisms is not examined in head and neck squamous cell carcinomas (HNSCC), which is the sixth most common human malignancy largely associated with tobacco and alcohol use. Molecular mechanistic studies have established that frequent alterations in Smad4 signaling pathway is common in HNSCC due to frequent mutations in TGF-β type II receptor. Smad4 loss has also been shown to cause genomic instability in mice and to induce HNSCC, suggesting that the agents are needed to control HNSCC that could target both Smad4 dependent and independent pathways. Accordingly, here we evaluated the efficacy of resveratrol against a panel of human HNSCC cell lines, namely FaDu (homologous deletion of Smad4), Cal27 (harbors nonsense mutation in Smad4), and Det562 (wild type Smad4). Resveratrol treatment at 5-50µM concentrations for 24 hrs significantly suppressed cell proliferation and induced DNA damage in FaDu and Cal27 cell lines; however, Det562 cells were more resistant to such treatments even at comparatively higher dose (100 µM). Cal27 cells transfected to Smad4 (Cal27-Smad4) showed similar resveratrol effects as parent line (Cal27) indicating that a lack of resveratrol effect in Det562 cells was independent of Smad4 status in these cells. Same resveratrol treatments also did not induce DNA damage in normal human epidermal keratinocytes and fibroblasts, showing its selective efficacy only in HNSCC cells. In other studies, resveratrol also caused a strong S phase arrest and induced apoptotic death of FaDu and Cal27 cells together with induction in Brca1 and H2AX nuclear foci formation. These finding for the first time established the efficacy of resveratrol in inducing DNA damage mediated cell death, which was independent of Smad4 expression in HNSCC. Further in an in vivo study, resveratrol (50 mg/kg body weight) treatment for 30 days, inhibited the tumor volume (48%; P&amp;lt;.01) and tumor weight (62%; p&amp;lt;.01) in ectopically growing human FaDu tumor xenografts in athymic nude mice. H2AX (ser 139) and cleaved caspase 3 expression was strongly increased in tumor xenograft from resveratrol-treated mice compared to controls. Together, these results clearly establish the anti-proliferative, DNA damaging and pro-apoptotic effects of resveratrol in HNSCC cells independent of Smad4 status, both in vitro and in vivo. Based on these findings, more studies are needed in future to evaluate both anti-cancer and chemopreventive efficacy of resveratrol in relevant pre-clinical models to establish its potential usefulness against human head and neck cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3708. doi:10.1158/1538-7445.AM2011-3708

Resveratrol induces growth arrest and apoptosis through activation of FOXO transcription factors in prostate cancer cells.

BackgroundResveratrol, a naturally occurring phytopolyphenol compound, has attracted extensive interest in recent years because of its diverse pharmacological characteristics. Although resveratrol possesses chemopreventive properties against several cancers, the molecular mechanisms by which it inhibits cell growth and induces apoptosis have not been clearly understood. The present study was carried out to examine whether PI3K/AKT/FOXO pathway mediates the biological effects of resveratrol.Methodology/Principal FindingsResveratrol inhibited the phosphorylation of PI3K, AKT and mTOR. Resveratrol, PI3K inhibitors (LY294002 and Wortmannin) and AKT inhibitor alone slightly induced apoptosis in LNCaP cells. These inhibitors further enhanced the apoptosis-inducing potential of resveratrol. Overexpression of wild-type PTEN slightly induced apoptosis. Wild type PTEN and PTEN-G129E enhanced resveratrol-induced apoptosis, whereas PTEN-G129R had no effect on proapoptotic effects of resveratrol. Furthermore, apoptosis-inducing potential of resveratrol was enhanced by dominant negative AKT, and inhibited by wild-type AKT and constitutively active AKT. Resveratrol has no effect on the expression of FKHR, FKHRL1 and AFX genes. The inhibition of FOXO phosphorylation by resveratrol resulted in its nuclear translocation, DNA binding and transcriptional activity. The inhibition of PI3K/AKT pathway induced FOXO transcriptional activity resulting in induction of Bim, TRAIL, p27/KIP1, DR4 and DR5, and inhibition of cyclin D1. Similarly, resveratrol-induced FOXO transcriptional activity was further enhanced when activation of PI3K/AKT pathway was blocked. Over-expression of phosphorylation deficient mutants of FOXO proteins (FOXO1-TM, FOXO3A-TM and FOXO4-TM) induced FOXO transcriptional activity, which was further enhanced by resveratrol. Inhibition of FOXO transcription factors by shRNA blocked resveratrol-induced upregulation of Bim, TRAIL, DR4, DR5, p27/KIP1 and apoptosis, and inhibition of cyclin D1 by resveratrol.Conclusion/SignificanceThese data suggest that FOXO transcription factors mediate anti-proliferative and pro-apoptotic effects of resveratrol, in part due to activation of extrinsic apoptosis pathway.

Resveratrol inhibits proliferation and promotes apoptosis of osteosarcoma cells

The phytoalexin resveratrol has been described to have chemopreventive and chemotherapeutic effects in several tumor models while its effects on osteosarcoma have not been extensively studied. Additionally, resveratrol is a potent activator of the Sirt1/Sir2 (silent information regulator 2) family of NAD-dependent deacetylases which plays a role in calorie restriction-mediated tumor suppression. In the present study, we evaluated the effect of resveratrol on growth and apoptosis in four osteosarcoma cell lines (HOS, Saos-2, U-2 OS and MG-63) and a normal human osteoblast cell line (NHOst). We found that Sirt1 protein was relatively higher expressed in the tumor cells than normal osteoblasts. Consistently, resveratrol induced apoptosis in a dose-dependent fashion in the osteosarcoma cells but had minor effect on normal osteoblasts. Also, a similar effect could be elicited by another Sirt1 activator, isonicotinamide. In addition, the pro-apoptotic effect of resveratrol could be enhanced by nutrition restriction elicited by l-asparaginase. We postulate that these effects by resveratrol are mediated via Sirt1 but further studies are needed to confirm or refute this theory.

Resveratrol inhibits cell growth by inducing cell cycle arrest in activated hepatic stellate cells

Resveratrol (RSV) exerts anti-proliferative and pro-apoptotic actions in different cell lines. Hepatic stellate cells (HSCs) are major fibrogenic cell types that contribute to collagen accumulation during chronic liver disease. In the present study, the inhibitory effects of RSV on cell proliferation, cell cycle, and apoptosis were evaluated in the mouse hepatic stellate cell line GRX. Cells treated with 1 nM-1 muM of RSV demonstrated a decrease in cell growth of about 35% after 5 days. GRX cells, treated with RSV (100 nM or 1 muM), were analyzed by flow cytometry; RSV induced an increase in the number of GRX cells in the S- and sub-G1 phases. The increase in sub-G1 phase cells and the nuclear condensation and fragmentation shown by DAPI staining identified a possible pro-apoptotic effect of RSV on GRX cells. Furthermore, the RSV anti-proliferative effects could be explained by an S-phase accumulation caused by a decrease in the progression through the cell cycle or an inhibition of S or G2 phase transition. It is notable that these RSV actions are mediated at nanomolar levels, compatible with the concentrations of free RSV in biological fluids after ingestion of polyphenol-rich foods, suggesting a possible effect of these foods as an adjuvant treatment in chronic liver diseases.

Evaluation of antitumor effects of two vine stalk oligomers of resveratrol on a panel of lymphoid and myeloid cell lines: Comparison with resveratrol

This study aims to evaluate and compare the antiproliferative and proapoptotic effects of resveratrol ( trans-3,4′,5-trihydoxystilbene) with two of its naturally occurring oligomers, ɛ-viniferin (a dimer) and miyabenol C (a trimer). Proliferation assays performed on myeloid and lymphoid cell lines show that the three compounds inhibit cell growth of all cell types tested, with miyabenol C being the most efficient (IC50 ranging from 10.8 to 29.4 μM). Further analysis performed on the multiple myeloma cell line U266 shows that all compounds modify cell cycle distribution probably via actions on different targets. Whereas cells treated with resveratrol accumulate in S phase, cells treated with ɛ-viniferin and miyabenol C accumulate in G2/M and G0/G1, respectively. Miyabenol C is also the most efficient at inducing cell death in U266 cells. All compounds induce apoptosis of U266 cells via mechanisms entirely dependent on caspase activation and associated with mitochondrial membrane potential disruption. Compounds do not act directly on the mitochondrial membrane, but could induce activation of upstream caspases such as caspase 8 and/or caspase 2, depending on the compound. In no case did upstream caspase 8 activation involve Fas/FasL interaction. Taken together, these results show that ɛ-viniferin and, more importantly, miyabenol C represent potent antitumor agents that require further investigation, either alone or in combination with resveratrol.

Resveratrol at High Doses Acts as an Apoptotic Inducer in Endothelial Cells

Resveratrol is a phenolic compound found in grapes and other food products. In order to assess the availability of resveratrol as an angio-inhibiting drug, we examined whether resveratrol plays an important role in bovine aortic endothelial cells (BAECs) for cell apoptosis and cell migration. Endothelial cell apoptosis was observed as detected by the Hoechst staining and the caspase-3 activity. Additionally, Western blotting was performed for monitoring the activities of various cell signaling molecules. Resveratrol was shown to act as a pro-apoptotic agent. The pro-apoptotic effect of resveratrol was as great as that of etoposide, a well-known anti-cancer drug. In addition, resveratrol had an inhibitory effect on endothelial cell migration. The demonstrated efficacy of resveratrol suggests that resveratrol may be utilized as an anti-angiogenic drug. To determine the underlying mechanisms, we further investigated which signaling molecules are activated by resveratrol. Extracellular signal-regulated kinase (ERK) was activated by the treatment with resveratrol in BAECs, whereas endothelial nitric oxide synthetase (eNOS), Akt, and Jun N-terminal kinase (JNK) were inhibited. The pretreatment with PD compound, an ERK inhibitor, had no effect on the pro-apoptosis induced by resveratrol. Resveratrol plays an important role in endothelial cell apoptosis, indicating that resveratrol can be utilized as a potent anti-angiogenic drug.

Resveratrol Induces Cell Cycle Arrest in the OCI-LY18 B-Cell Lymphoma.

Resveratrol is a polyphenolic compound with well-documented anti-tumor properties. Despite reports of its efficacy in chronic B lymphocytic leukemia, little is known regarding the antiproliferative and/or proapoptotic effects of resveratrol in other B-cell malignancies. Diffuse large B cell lymphoma (DLBCL) has recently been subdivided into three major categories or subtypes, each with apparently distinct etiologies, gene expression profiles, and responses to conventional chemotherapy. These three DLBCLs comprise germinal center B cell (GC), activated B cell (ABC), and primary mediastinal DLBCL. Herein, we report that treatment of the OCI-LY18 B-cell lymphoma with resveratrol induced cell cycle arrest and apoptosis in a dose-dependant manner. Preliminary analyses suggest that OCI-LY18 exhibits a surface immunophenotype indicative of a GC DLBCL. The molecular mechanisms underlying cell cycle arrest by resveratrol were also investigated. We report herein that resveratrol induced the expression of p27 concomitant with inhibition of cdk2 and a decreased phosphorylation of the retinoblastoma protein (pRb). Resveratrol also induced the up-regulation of p53. In addition, resveratrol treatment resulted in the phosphorylation of p53 on Ser15/37, modifications that corresponded to the upregulation of p53. These data suggest that resveratrol induces growth arrest in OCI-LY18 via a mechanism that involves upregulation of p27 and p53. These results suggest that resveratrol might be beneficial as a novel treatment of GC DLBCL.

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