Antitumor Effects Of Resveratrol Research Articles

Resveratrol ameliorates glioblastoma inflammatory response by reducing NLRP3 inflammasome activation through inhibition of the JAK2/STAT3 pathway

ObjectivesThe aim of this study was to investigate the anti-tumor effect of resveratrol (RSV) on glioblastoma (GBM) and its specific mechanism in improving the inflammatory response of the tumor microenvironment. The tumor microenvironment of GBM is highly neuroinflammatory, inducing tumor immunosuppression. Therefore, ameliorating the inflammatory response is an important focus for anti-tumor research.MethodsThe anti-tumor effect of RSV on GBM was demonstrated through in vitro cellular assays, including CCK-8, EdU, PI staining, Transwell, wound healing assay, and flow cytometry. Potential mechanisms of RSV's anti-GBM effects were identified through network pharmacological analysis. In addition, the relationship of RSV with the JAK2/STAT3 signaling pathway and the inflammasome NLRP3 was verified using Western blot.ResultsRSV significantly inhibited cell viability in GBM cell lines LN-229 and U87-MG. Furthermore, it inhibited the proliferation and invasive migration ability of GBM cells, while promoting apoptosis. Network pharmacological analysis revealed a close association between the anti-GBM effects of RSV and the JAK/STAT signaling pathway, as well as inflammatory responses. Western blot analysis confirmed that RSV inhibited the over-activation of the inflammasome NLRP3 through the JAK2/STAT3 signaling pathway. Partial reversal of RSV's inhibition of inflammasome NLRP3 was observed with the addition of the JAK/STAT agonist RO8191.ConclusionsIn vitro, RSV can exert anti-tumor effects on GBM and improve the inflammatory response in the GBM microenvironment by inhibiting the activation of the JAK2/STAT3 signaling pathway. These findings provide new insights into potential therapeutic targets for GBM.

Retracted] Antitumor effect of resveratrol on chondrosarcoma cells via phosphoinositide 3‑kinase/AKT and p38 mitogen‑activated protein kinase pathways.

Following the publication of this paper, it was drawn to the Editors' attention by a concerned reader that the cell apoptotic data shown in Fig.2 were strikingly similar to data appearing in different form in other articles by different authors. Owing to the fact that the contentious data in the above article had already been published elsewhere, or were already under consideration for publication, prior to its submission to Molecular Medicine Reports, the Editor has decided that this paper should be retracted from the Journal. After having been in contact with the authors, they agreed with the decision to retract the paper. The Editor apologizes to the readership for any inconvenience caused. [the original article was published in Molecular Medicine Reports 12: 3151-3155, 2015; DOI: 10.3892/mmr.2015.3683].

Abstract P6-06-16: Resveratrol enhanced chemosensitivity by reversing macrophage polarization in breast cancer

Abstract Background: Resveratrol is a naturally occurring polyphenolic compound in Polygonum cuspidatum and is well known for its antitumor effect by targeting several cancer-related inflammatory pathways. However, limited data is available on the effect of resveratrol in the tumor microenvironment (TME). Tumor-associated macrophages (TAMs) are the most abundant leukocyte population within the tumors and are associated with poor prognosis in over 80% of breast cancer cases. This study aimed to investigate the effect of resveratrol on TAM polarization in breast cancer progression. Methods: The antitumor effect of resveratrol was examined in MDA-MB-231(MB231), cisplatin resistance MDA-MB-231 (cisR) cells, and T47D by cell proliferation assay using MTT. Gene expressions of M1 and M2 markers in macrophages derived from THP-1 cells were examined by qPCR and immunofluorescence staining after treated with tumor-conditioned medium (TCM) with or without resveratrol (25μM). Cytokine profile of TCM was examined by Qiagen Multi-Analyte ELISArray and expression of cytokines in TCM was validated by qPCR and ELISA. The effect of resveratrol and its downstream targets on macrophage polarization were investigated by supplementing resveratrol with interferon gamma (IFN-γ, 20ng/ml) and lipopolysaccharide (LPS, 100ng/ml) for M1 macrophage polarization or IL-4 (20ng/ml) and IL-13 (20ng/ml)for M2 macrophage polarization. NOD/SCID mice were used to investigate the potential use of resveratrol in treating breast cancer and chemotherapy as complementary treatment in vivo. Results: Our preliminary data demonstrated that resveratrol significantly reduced cell proliferation and enhanced chemosensitivity in MB231, cisR, and T47D cells. Resveratrol inhibited CD163 (M2 marker) and increased CXCL10 (M1 marker) expression. In addition, resveratrol decreased exogenous IL-6 levels in TCM, thus inhibited breast cancer cell proliferation by promoting M1/M2 macrophage polarization ratio and supressing IL-6/pSTAT3 pathway. Combined use of resveratrol and cisplatin significantly decreased tumor size in vivo. Conclusion: Our data demonstrated that resveratrol enhanced chemosensitivity in vivo and in vitro by promoting M1/M2 macrophage polarization ratio and supressing STAT3 activation through reducing exogenous IL-6 levels. This study revealed a novel mechanism on resveratrol-mediated macrophage polarization on breast cancer progression. Correspondence: akwong@asiabreastregistry.com Citation Format: Isabella Wai Yin Cheuk, Jiawei Chen, Man Ting Siu, Sau Wing Lam, Jue Wang, Vivian Yvonne Shin, Ava Kwong. Resveratrol enhanced chemosensitivity by reversing macrophage polarization in breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-06-16.

Resveratrol exerts antitumor effects by downregulating CD8+CD122+ Tregs in murine hepatocellular carcinoma

ABSTRACT CD4+Foxp3+ regulatory T cells (Tregs) in the tumor microenvironment restrain antitumor immunity, resulting in tumor aggression and poor survival in hepatocellular carcinoma (HCC). CD8+CD122+ Tregs have been previously shown to be more potent in immunosuppression than are CD4+Foxp3+ Tregs. Previous studies have demonstrated that resveratrol exerts its anti-cancer effects by downregulating CD4+Foxp3+ and M2-like macrophages, two key immunoregulatory cells that maintain the immunosuppressive tumor microenvironment. In this study, we found that resveratrol inhibited the tumor growth in a subcutaneous Hepa1-6 HCC model and decreased the frequency of CD8+CD122+ Tregs in the tumor as well as lymph nodes and spleen of the tumor-bearing mice. It also increased the percentage of IFN-γ-expressing CD8+ T cells in the tumor and peripheral lymphoid organs. The antitumor effects of resveratrol were partially reversed by the adoptive transfer of exogenous CD8+CD122+ Tregs into the tumor-bearing mice. Meanwhile, resveratrol treatment downregulated immunosuppressive cytokines, including TGF-β1 and interleukin-10, in the tumor while elevating antitumor cytokines, TNF-α and IFN-γ. It also inhibited the activation of STAT3 signaling in the tumor. As expected, resveratrol reduced the percentage of M2-like macrophages in the mice. Importantly, resveratrol suppressed orthotopic H22 tumor growth and decreased the frequency of CD8+CD122+ Tregs and M2-like macrophages in the tumor-bearing mice. Furthermore, our studies showed that resveratrol, at non-cytotoxic concentrations, inhibited CD8+CD122+ Treg differentiation from CD8+CD122− T cells in vitro. Thus, our studies unveiled a new immune mechanism underlying the immunosuppressive tumor microenvironment and demonstrated that resveratrol could help reverse it by diminishing CD8+CD122+ Tregs.

Resveratrol inhibits the proliferation of estrogen receptor-positive breast cancer cells by suppressing EZH2 through the modulation of ERK1/2 signaling.

Enhancer of zeste homolog 2 (EZH2) is frequently overexpressed in breast cancer and plays an important role in maintaining the cell proliferative capacity. However, the mechanisms underlying the transcriptional regulation of EZH2 in estrogen receptor (ER)-positive breast cancer cells remain unclear. The antitumor effects of resveratrol have been reported. However, whether EZH2 was involved in these effects needs further exploration. Here, we showed that EZH2 is required for estrogen-induced cell proliferation in ER-positive breast cancer. Exposure to 17β-estradiol (E2) upregulated EZH2 via ERα signaling, and this effect was blocked by U0126, a MEK inhibiter. Resveratrol inhibited the proliferation and colony formation in ER-positive breast cancer cells and downregulated EZH2 through inhibition of phospho-ERK1/2. These findings indicated that ERK1/2 and ER signaling-mediated EZH2 upregulation is crucial for the proliferation of ER-positive breast cancer cells. The suppression of EZH2 expression by ERK1/2 dephosphorylation is important for the antiproliferative activities of resveratrol against ER-positive breast cancer cells.

Anti-tumor effects of resveratrol on malignant melanoma is associated with promoter demethylation of RUNX3 gene.

The natural phytoalexin resveratrol (RES) has exhibited excellent anti-tumor effects on a variety of tumors including malignant melanoma. However, its specific mechanism of anti-melanoma needs to be further explored. It has been reported, that the expression of tumor suppressor gene RUNX3 was lost or substantially decreased in melanoma. Whether RES exerts its anti-tumor effect by regulating the expression of RUNX3 gene in melanoma is worthy of study. In the present study, we found the RUNX3 promoter is hypermethylated and the expression of RUNX3 mRNA and protein are absent in melanoma cells B16F10. After intervention with RES, promoter hypermethylation of RUNX3 in B16F10 cells could be significantly decreased and mRNA and protein expression of it was upregulated in a dose-dependent manner. We further investigated the effects of RES on B16F10 xenograft models. The intervention of RES and treatment of melanoma positive drug dacarbazine (DTIC) both could significantly inhibit tumor growth in xenograft mice, but only RES could upregulate the expression of RUNX3 mRNA and protein in peripheral blood and tumor tissues. Therefore, the upregulation of mRNA and protein expression of RUNX3 resulting from promoter demethylation might be one of the mechanisms of RES inhibiting melanoma. This research has revealed a novel mechanism for RES against melanoma from the epigenetic perspective, which is helpful to improve the understanding of the anti-tumor mechanism of RES and provide new insights for the treatment of melanoma.

The antitumor effect of resveratrol on nasopharyngeal carcinoma cells.

The anti-tumor effect of resveratrol has been observed in many cancers. Here, we examined the anti-tumor activity of resveratrol in human nasopharyngeal carcinoma (NPC) cells. Resveratrol, in a dose-dependent manner, inhibited proliferation related proteins (Ki67, PCNA), and cell proliferation, and reduced apoptosis related proteins (cleaved caspase-3, cleaved caspase-9) and apoptosis in nasopharyngeal carcinoma cells. Resveratrol treatment inhibited the increased-expression of Survivin in NPC cells, while the overexpressed Survivin counteracted the effect of resveratrol on cell proliferation and apoptosis in NPC cells, thus establishing Resveratrol-induced reduction in increased-survivin in NPC cells as the underlying mechanism. These findings show that resveratrol can be used to modify the cell growth and death in NPC cells.

Resveratrol inhibits STAT5 activation through the induction of SHP-1 and SHP-2 tyrosine phosphatases in chronic myelogenous leukemia cells.

STAT5 is an important transcription factor that is constitutively activated in various types of malignancies, including chronic myelogenous leukemia (CML). Whether the antitumor effects of resveratrol (RES) are linked to its capability to inhibit STAT5 activation in CML cells was investigated. We found that RES inhibited STAT5 activation in K562 and KU812 cell lines; RES also reduced the STAT5 concentration in the nucleus of K562 and KU812 cells. Protein tyrosine phosphatase (PTP) inhibitor, sodium pervanadate, reversed the RES-induced downregulation of STAT5, suggesting the involvement of a PTP. Indeed, we observed that RES decreased the expression of tyrosine phosphatase SHP-1 and SHP-2; moreover, the deletion of SHP-1 and SHP-2 genes by siRNA abolished the ability of RES to inhibit STAT5 activation, which suggested the critical role of both SHP-1 and SHP-2 in its possible mechanism of action. RES downregulated the expression of STAT5-regulated gene products such as Bcl-xL, Bcl-2, Cyclin D1, and Mcl-1, and increased the expression of Bax. This correlated with the suppression of proliferation and induction of apoptosis. Overall, our results suggest that RES is a blocker of STAT5 activation and thus may be potentially useful for the treatment of CML.

Resveratrol represses estrogen-induced mammary carcinogenesis through NRF2-UGT1A8-estrogen metabolic axis activation

Estrogen plays a pivotal role in the pathological development of breast cancer. Resveratrol has chemo-preventive effects against breast cancer, whereas, the mechanism of antitumor activities of resveratrol remains unanswered. In this study, we showed that estrogen homeostasis profile was disturbed in both breast cancer patients and in experimental breast cancer model rats, with carcinogenic catechol estrogens significantly accumulated in the mammary tissues. UDP-glucuronosyltransferase 1A8 (UGT1A8) is an important phase II drug-metabolizing enzymes which involved in the metabolism of catechol estrogens. Here we found that the mammary nuclear factor erythroid 2-related factor 2 (NRF2) – UGT1A8 signaling was down-regulated in breast cancer rats, whereas treatment with resveratrol could upregulate the expression of NRF2 and UGT1A8, accelerate metabolic elimination of catechol estrogens, inhibit estrogen-induced DNA damage and suppress the pathological development of breast cancer. In addition, luciferase reporter assay suggested that resveratrol activated the expression of UGT1A8 by up-regulating the transcriptional activity of NRF2. Small-interfering RNA-mediated silencing of NRF2 abolished resveratrol-mediated preventive effects indicated that the antitumor effect of resveratrol is based on NRF2-UGT1A8-estrogen metabolism axis. Taken together, we established the resveratrol regulating potential on estrogen homeostasis based on NRF2-UGT1A8 signaling pathway, and also provided a novel link between estrogen glucuronidation metabolism and breast cancer pathological development.

Resveratrol induces mitochondrial respiration and apoptosis in SW620 colon cancer cells

BackgroundThe polyphenol resveratrol (RSV) is found in the skin of red grapes and has been reported to exhibit anticancer properties. The antitumor effects of RSV in the gastrointestinal tract have gained considerable interest due to the high exposure of this tissue to this dietary compound. One of the hallmarks of cancer cells is their particular metabolism mainly relying on glycolysis for ATP production rather than mitochondrial oxidative phosphorylation. Although RSV has been described to act as a calorie-restriction mimetic, modulating energy metabolism in normal tissues, little efforts have been done to study the effects of this polyphenol in the metabolism of cancer cells. Taking this into account, the aim of this study was to explore metabolic effects of this polyphenol in colon cancer. MethodsOxygen consumption, ATP levels, Western blotting and other molecular biology techniques were carried out to characterize the metabolic signature of RSV in SW620 colon cancer cells. ResultsParadoxically, the cytotoxic effects of RSV were associated with an increase in oxygen consumption supported by mitochondrial biogenesis and increased fatty acid oxidation. This partial reversion of the Warburg effect was followed by hyperpolarization of mitochondrial membrane and ROS production, leading to an increased apoptosis. ConclusionsOur results propose that the anticancer mechanisms of RSV could reside in targeting cancer cell metabolism, promoting mitochondrial electron transport chain overload and, ultimately, increasing ROS production. General significanceThese results shed new light into the anticancer mechanism of RSV supporting the ability of this compound in potentiating the effects of chemotherapy.

Sirt1 Is Required for Resveratrol-Mediated Chemopreventive Effects in Colorectal Cancer Cells.

Sirt1 is a NAD+-dependent protein-modifying enzyme involved in regulating gene expression, DNA damage repair, metabolism and survival, as well as acts as an important subcellular target of resveratrol. The complex mechanisms underlying Sirt1 signaling during carcinogenesis remain controversial, as it can serve both as a tumor promoter and suppressor. Whether resveratrol-mediated chemopreventive effects are mediated via Sirt1 in CRC growth and metastasis remains unclear; which was the subject of this study. We found that resveratrol suppressed proliferation and invasion of two different human CRC cells in a dose-dependent manner, and interestingly, this was accompanied with a significant decrease in Ki-67 expression. By transient transfection of CRC cells with Sirt1-ASO, we demonstrated that the anti-tumor effects of resveratrol on cells was abolished, suggesting the essential role of this enzyme in the resveratrol signaling pathway. Moreover, resveratrol downregulated nuclear localization of NF-κB, NF-κB phosphorylation and its acetylation, causing attenuation of NF-κB-regulated gene products (MMP-9, CXCR4) involved in tumor-invasion and metastasis. Finally, Sirt1 was found to interact directly with NF-κB, and resveratrol did not suppress Sirt1-ASO-induced NF-κB phosphorylation, acetylation and NF-κB-regulated gene products. Overall, our results demonstrate that resveratrol can suppress tumorigenesis, at least in part by targeting Sirt1 and suppression of NF-κB activation.

Antitumor effect of resveratrol on chondrosarcoma cells via phosphoinositide 3-kinase/AKT and p38 mitogen-activated protein kinase pathways.

Chondrosarcoma is one of the most common types of primary bone cancer that develops in cartilage cells. Resveratrol (Res), a natural polyphenol compound isolated from various fruits, has a suppressive effect on various human malignancies. It has been shown that Res inhibits matrix metalloproteinase (MMP)-induced differentiation in chondrosarcoma cells. However, the effects of Res on cell proliferation, apoptosis and invasion of chondrosarcoma cells, as well as the underlying mechanisms, remain largely unknown. To the best of our knowledge, the present study showed for the first time that Res inhibited proliferation and induced apoptosis in chondrosarcoma cells in a dose-dependent manner. Furthermore, it was shown that Res also suppressed chondrosarcoma cell invasion in a dose-dependent manner, probably via the inhibition of MMP2 and MMP9 protein expression. Molecular mechanism investigations revealed that Res could inhibit the activity of phosphoinositide 3-kinase/AKT and p38 mitogen-activated protein kinase signaling pathways, which has been demonstrated to be important in the regulation of proliferation, apoptosis and invasion in various cancer cell types. In conclusion, this study suggests that Res may serve as a promising agent for the treatment of chondrosarcoma.

Resveratrol-loaded polymeric nanoparticles suppress glucose metabolism and tumor growth in vitro and in vivo

Resveratrol (RSV) is a natural phenol with promising anti-tumor activities, but its use for in vivo cancer treatment is limited by low aqueous solubility and poor stability. In this study, we prepared RSV-loaded polyethylene glycol–polylactic acid (PEG–PLA; M.W. 5000-5000) polymer nanoparticles (NPs) for improved stability and controlled delivery, and investigated its metabolic and anti-tumor effect in vitro and in vivo. CT26 colon cancer cells displayed significantly reduced cell number to 5.6% and colony forming capacity to 6.3% of controls by 72h treatment with 40 and 20μM of RSV-NP, respectively. Flow cytometry and western blots demonstrated increased apoptotic cell death, and 18F FDG uptake and reactive oxygen species was significantly reduced by RSV-NP. All of these effects were comparable to or greater in potency compared to free RSV. When RSV-NP was intravenously administered to CT26 tumor bearing mice, there was a reduction of 18F FDG uptake on PET/CT by day 4. Longer treatment led to retardation of tumor growth accompanied by an improvement in survival compared to empty NP-injected controls. These results demonstrate that the in vitro and in vivo metabolic and anti-tumor effects of RSV is preserved by PEG–PLA NP loading, and provide an encouraging outlook on the potential of polymeric NPs as an effective method to deliver RSV for cancer therapy.

Effects of resveratrol on cell growth and prolactin synthesis in GH3 cells

Resveratrol (RE), a phytoestrogen, has antiestrogenic properties. Estrogen plays a key role in the development and progression of pituitary prolactinoma. Moreover, RE is a potent cancer chemopreventive agent that inhibits the initiation, promotion and progression of carcinogenesis. The present study investigated the antitumor effects of RE on GH3 pituitary tumor cells. A concentration- and treatment duration-dependent biphasic effect of RE on the proliferation of the GH3 cells was demonstrated. After three days of treatment, RE stimulated proliferation at low concentrations and inhibited proliferation at high concentrations. However, when the treatment duration was reduced to 6 h, RE inhibited proliferation in a concentration-dependent manner. In addition, RE induced apoptosis with the activation of caspase-3 and -8, and decreased the percentage of prolactin (PRL)-immunopositive GH3 cells. Furthermore, RE suppressed expression of the PRL gene and inhibited the cell proliferation and PRL synthesis induced by 17β-estradiol (E2). In GH3 cells, the proliferation response exhibited higher sensitivity to E2 compared with the PRL response; by contrast, the PRL response was more sensitive to RE than the proliferation response was. These results indicate that RE, an antiestrogenic compound, exerts its antitumor effect on GH3 cells through the suppression of GH3 cell growth and through the inhibition of PRL synthesis. The RE-induced cell apoptosis was shown to be caspase-dependent. Therefore, the present study provides support for the use of RE in the chemoprevention and chemotherapy of pituitary prolactinoma.

Resveratrol Inhibits Invasion and Metastasis of Colorectal Cancer Cells via MALAT1 Mediated Wnt/β-Catenin Signal Pathway

Resveratrol, extracted from Chinese herbal medicine Polygonum cuspidatum, is known to inhibit invasion and metastasis of human colorectal cancer (CRC), in which long non-coding Metastasis Associated Lung Adenocarcinoma Transcript 1 (RNA-MALAT1) also plays an important role. Using MALAT1 lentiviral shRNA and over-expression constructs in CRC derived cell lines, LoVo and HCT116, we demonstrated that the anti-tumor effects of resveratrol on CRC are through inhibiting Wnt/β-catenin signaling, thus the expression of its target genes such as c-Myc, MMP-7, as well as the expression of MALAT1. In detail, resveratrol down-regulates MALAT1, resulting in decreased nuclear localization of β-catenin thus attenuated Wnt/β-catenin signaling, which leads to the inhibition of CRC invasion and metastasis. This finding of ours surely provides important pre-clinical evidence supporting future use of resveratrol in prevention and treatment of CRC.

Abstract 4516: Targeted delivery of resveratrol to improve therapeutic outcome in prostate cancer.

Abstract Conventional chemotherapeutics offered to treat prostate cancer (PCa) are not selectively targeted and due to this fact they are toxic to the normal cells. Thus, it is imperative to identify new anti-cancer agents and/or methods to selectively target PCa cells without affecting normal cells. In this regard, resveratrol (trans-3, 5, 4’-trihydroxystilbene), a plant polyphenol, has shown very promising results. Despite the proven anti-tumor effects of resveratrol, clinical use of this compound is restricted due to its poor bioavailability. To surmount these problems, we developed nanoparticles, loaded with resveratrol, using a planetary-balled milling (PBM) technique and tagged them with folate for targeted delivery to PCa cells, which express high affinity folate receptors. Image Stream multispectral imaging was used to measure the response of resveratrol-loaded PBM nanoparticles, and free resveratrol on various PCa cell lines. Resveratrol-loaded folic acid-coated PBM nanoparticles selectively targeted PCa cells and induced apoptosis. Furthermore, our results indicate that targeted delivery of resveratrol using PBM nanoparticles was 70-85% more effective in killing PCa cells at concentrations lower than the IC50 of free resveratrol. Citation Format: Rajesh Singh, Pranav Gupta, Shailesh Singh, James W. Lillard. Targeted delivery of resveratrol to improve therapeutic outcome in prostate cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4516. doi:10.1158/1538-7445.AM2013-4516

Study of apoptosis related factors regulatory mechanism of resveratrol to human skin squamous cell carcinoma A431 xenograft in nude mice

To explore the anti-tumor effects of resveratrol (Res) upon human skin squamous cell carcinoma A431 xenograft in nude mice and elucidate the regulatory mechanisms of survivin and caspase-3. The model of human skin squamous cell carcinoma (A431) xenograft in nude mice was established. And the animals were randomly divided into saline-negative control, cyclophosphamide (CTX) positive control, Res high-, medium- and low-dosage and blank control groups (n = 10 each). After drug intervention, tumor-bearing mice were sacrificed. The tumor growth curve was plotted and the Res inhibition rate calculated by terminal tumor weight. The morphological changes of tumor cell among groups were observed by hematoxylin and eosin staining; cell apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling TUNEL; the impact of Res upon the protein expressions of survivin and caspase-3 in tumor issues was observed by Western blot. Analysis of variance and Pearson's correlation were employed for statistical analyses. (1) By the end of treatment, the tumor volume of CTX, Res high-, medium-, low-dosage, saline-negative control and blank control groups were (1154 ± 255), (1002 ± 115), (1207 ± 176), (1342 ± 211), (1642 ± 226), (1564 ± 156) mm(3) respectively, and tumor weight of CTX, Res high-, medium-, low-dosage, saline-negative control and blank control groups (1.84 ± 0.30), (1.72 ± 0.39), (1.96 ± 0.40), (2.67 ± 0.73), (3.16 ± 0.52), (3.33 ± 0.59) g respectively. Through analysis of variance, the tumor volume and weight of Res high-, medium-, low-dosage groups were smaller than those of saline-negative control and blank control groups (all P < 0.05). The inhibition rate of Res high-, medium- and low-dosage groups were 45.57%, 37.97% and 15.51% respectively. (2) The apoptosis index of the above groups were 36.79% ± 8.86%, 33.15% ± 6.00%, 18.09% ± 3.92%, 10.53% ± 4.20%, 3.87% ± 1.63%, 2.73% ± 1.61%. Through analysis of variance, the apoptosis index of Res groups were higher than those of saline-negative control and blank control groups (all P < 0.05). (3) The protein expression of survivin/β-actin of each group were 0.48 ± 0.20, 0.19 ± 0.11, 0.22 ± 0.12, 0.28 ± 0.24, 0.98 ± 0.41, 0.85 ± 0.34. The protein expression of caspase-3/β-actin of each group were 0.42 ± 0.09, 0.31 ± 0.10, 0.31 ± 0.07, 0.22 ± 0.08, 0.14 ± 0.04, 0.13 ± 0.05 respectively. Through analysis of variance, the protein expression of survivin of Res groups was lower than those of the saline-negative control and blank control groups (all P < 0.05). And the protein expression of caspase-3 of Res groups were higher than those of the saline-negative control and blank control group (all P < 0.05). Through Pearson's analysis, the protein expression of survivin and caspase-3 had no correlation (r = -0.279, P > 0.05). Res inhibits the growth of human skin squamous cell carcinoma A431 xenograft in nude mice. And its mechanism may be associated with the apoptosis of tumor cell through the depression of survivin and the activation of caspase-3.

Abstract 1093: Resveratrol inhibits prostate cancer metastasis by targeting microRNA-21

Abstract Introduction: Most prostate cancer-related deaths are due to the metastatic form of the disease. Despite multimodal therapy, no effective treatment exists for metastatic prostate cancer. Resveratrol, a phytoalexin, has been reported to possess anticancer properties against various cancers. However, the exact mechanism underlying this beneficial effect is not clearly known. MicroRNA (miR)-21, an oncomir, is found to be up-regulated in prostate cancer and its levels are positively linked to cancer cell invasion and metastasis. In this study, we propose that resveratrol inhibition of miR-21 could account, in part, for its reduction in invasiveness and metastasis of prostate cancer cells. Methods: PC3-MM cells were treated with resveratrol and the levels of miR-21 and its target proteins, programmed cell death 4 (PDCD4) and maspin, were assessed by TaqMan assay and Western blotting, respectively. Cell viability was assessed by MTS assay, while invasion and migration were assessed by Boyden chamber assay and wound healing assay, respectively. Annexin-FITC and PI staining were performed to assess cell apoptosis. Microarray analyses were performed to identify different miRs which are regulated by resveratrol. Transient transfection of pre-miR-21 or PDCD4 siRNA was performed to elucidate the molecular mechanisms of resveratrol's antitumor action. Severe combined immunodeficient (SCID) mice were utilized to study the effect of oral administration of resveratrol on tumor growth and lung metastasis using subcutaneous and intravenous injections of PC3-MM cells. Results: Resveratrol significantly reduced PC3-MM cell viability and inhibited its invasion and migration in a dose-dependent manner. These anti-tumor effects of resveratrol were due to inhibition of miR-21 and increased expression of PDCD4, because transfection of PC3-MM cells with pre-miR-21 and PDCD4 siRNA reversed the anti-tumor effects of resveratrol. Resveratrol also decreased both serum and insulin growth factor 1 (IGF1)-activated Akt1 (p-Akt), a known regulator of miR-21. Inhibition of PI3 kinase by LY294002 mimicked resveratrol's response on cell viability and invasiveness. Furthermore, studies in SCID mice demonstrated that oral administration of resveratrol reduced PC3-MM tumor growth by inhibiting miR-21 and p-Akt and also reduced the ability of these cells to metastasize to the lung. Conclusion: We conclude that resveratrol inhibits PC3-MM prostate cancer cell viability, invasion and migration by suppressing miR-21 expression via a growth factor/Akt sensitive pathway. We propose that oral administration of resveratrol inhibits prostate cancer growth and metastasis by abrogating a growth factor/Akt signaling pathway for induction of miR-21. These data support the use of resveratrol as a miR-21 inhibitor for the treatment of metastatic prostate cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1093. doi:1538-7445.AM2012-1093

Resveratrol inhibits LPS-induced epithelial-mesenchymal transition in mouse melanoma model

Epithelial to mesenchymal transition (EMT) has been linked to metastasis. Resveratrol exhibits potential antitumor activities; however, the inhibitory effects of resveratrol on the EMT of melanoma have not been demonstrated. Here, a new role for LPS in promoting EMT is described. LPS-induced EMT was identified by examining the markers of EMT. To assess the activation of NF-κB signal transduction pathway, we performed a reporter assay by using tumor cells transfected with the luciferase gene under the control of NF-κB response elements. The antitumor effects of resveratrol were evaluated in an experimental mouse metastasis tumor model. LPS increased N-cadherin and Snail expression and decreased zonula occludens-1 expression in a dose- and time-dependent manner. Meanwhile, LPS stimulated cell migration through activation of TLR4/NF-κB signal pathway. LPS-induced EMT is critical for inflammation-initiated metastasis. Nuclear translocation and transcriptional activity of p65 NF-κB, an important inducer of EMT, were inhibited by resveratrol. Resveratrol inhibited LPS-induced tumor migration and markers of EMT, significantly prolonged animal survival and reduced the tumor size. Thus, resveratrol plays an important role in the inhibition of LPS-induced EMT in mouse melanoma through the down-regulation of NF-κB activity. The data provide an insight into the mechanisms on the function of resveratrol during the processes of EMT.

Application of liposome encapsulation technique to improve anti-carcinoma effect of resveratrol

Aim: The promising anti-tumor effect of resveratrol (RES) has aroused much interest in recent years, but its clinical application was seriously hindered due to its poor solubility in water. The aim of this study was to improve the water solubility of RES by liposome encapsulation technique for effective tumor treatment.Methods: This study develops two liposomal formulations to solubilize RES by reverse-phase evaporation method with or without poly(ethylene glycol-2000)-grafted distearolyl phosphatidylethanolamine (DSPE-PEG2000). The effect of different formulation factors on the encapsulation efficiency (EE) and the particle sizes were investigated. These factors included the mass ratio of drug to soybean phosphatidylcholine (drug/SPC), the mass ratio of cholesterol to soybean phosphatidylcholine (chol/SPC), the volume ratio of water phase/organic phase and the microfluidization process. The drug release studies were performed in various media, simulating the desired application conditions. The cytotoxicity study was carried out by MTT assay on HeLa and Hep G2 cell lines.Results: The RES EE of 95% was obtained when using drug/SPC (1:40 mass ratio), Chol/SPC (1:10 mass ratio), water phase/oil phase (1:2 volume ratio), microfluidization process (entrance pressure 6 kpa, two times of cycle time). The addition of DSPE-PEG2000 into the formulation showed little effect on the formation and properties of RES liposome. The release of RES was pH-independent. RES liposomes and PEG-modified liposomes performed significant inhibition effects on both cells growth due to the solubilized RES.Conclusion: RES can be effectively loaded into liposomes and its anti-cancer effect was evidently improved by the application of liposome encapsulation technique.