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Liu Y, Liu A, Xu Z, Yu W, Wang H, Li C, Lin J. XZH-5 inhibits STAT3 phosphorylation and causes apoptosis in human hepatocellular carcinoma cells. Apoptosis 2011; 16:502-10. [PMID: 21311975 DOI: 10.1007/s10495-011-0578-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Growing evidence has demonstrated that signal transducer and activator of transcription 3 (STAT3), which is constitutively activated in patients with hepatocellular carcinoma (HCC), plays an important role in HCC development, progression, and prognosis. Interleukin-6 (IL-6) is a multifunctional inflammatory cytokine, which may induce STAT3 activation in a variety of human cancers. In this study, we demonstrated that blocking STAT3 phosphorylation with STAT3 small molecule inhibitors SD-1029 and Stattic caused apoptosis in HCC cells. Then we characterized the inhibitory effects of a novel small molecule XZH-5 on STAT3 phosphorylation in HCC cell lines. XZH-5 reduced constitutive STAT3 phosphorylation at Tyr705 and the expression of STAT3 downstream genes. The inhibition of STAT3 in HCC cells resulted in the induction of apoptosis and reduction of colony forming ability. In addition, XZH-5 also inhibited IL-6-induced STAT3 phosphorylation, nuclear translocation and STAT3 DNA binding activity. In contrast, it had no effect on IFN-γ-induced STAT1 phosphorylation, indicating the more selective effects on STAT3. These results suggested that XZH-5 may serve as a lead compound for further development of STAT3 specific small molecule inhibitors for HCC therapy.
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Affiliation(s)
- Yan Liu
- Center for Childhood Cancer, Department of Pediatrics, College of Medicine, The Ohio State University, Columbus, 43205, USA
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152
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Liu Y, Liu A, Li H, Li C, Lin J. Celecoxib inhibits interleukin-6/interleukin-6 receptor-induced JAK2/STAT3 phosphorylation in human hepatocellular carcinoma cells. Cancer Prev Res (Phila) 2011; 4:1296-305. [PMID: 21490132 DOI: 10.1158/1940-6207.capr-10-0317] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Growing evidence shows an association between chronic liver inflammation and hepatocellular carcinoma (HCC) development. STAT3, which is associated with inflammation and cellular transformation, is constitutively activated in human HCC tissues but not in normal human liver tissues. Although interleukin-6 (IL-6) is elevated in the serum of patients with HCC, it is not fully understood whether STAT3 constitutive activation is positively correlated with autocrine IL-6 secreted by HCC cells. Here, we reported that in HCC cells, the elevated levels of both IL-6 and IL-6 receptor (IL-6R, gp80), not IL-6 alone, correlated with STAT3 activation. We also explored whether the anticancer effects of celecoxib, an anti-inflammatory drug, may be due to the inhibition of the IL-6/STAT3 pathway in HCC cells. Our results showed that celecoxib decreased STAT3 phosphorylation by reducing Janus-activated kinase (JAK2) phosphorylation and caused apoptosis in HCC cells. Celecoxib could also block exogenous IL-6-induced STAT3 phosphorylation and nuclear translocation. Moreover, we observed more significant inhibition of cell viability when celecoxib was combined with doxorubicin or sorafenib. We conclude that the elevated levels of IL-6/IL-6R may be correlated with STAT3 activation in HCC cells. Celecoxib may be a candidate for HCC therapy through blocking IL-6/STAT3 pathway and can be combined with other anticancer drugs to reduce drug resistance caused by IL-6/STAT3 signals.
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Affiliation(s)
- Yan Liu
- Center for Childhood Cancer, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
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153
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Mankan AK, Greten FR. Inhibiting signal transducer and activator of transcription 3: rationality and rationale design of inhibitors. Expert Opin Investig Drugs 2011; 20:1263-75. [PMID: 21751940 DOI: 10.1517/13543784.2011.601739] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
INTRODUCTION Signal transducer and activator of transcription 3 (STAT3) controls a key signaling pathway in the development of many malignant diseases. Several genetic studies have proven its central role in the regulation of apoptosis, proliferation, angiogenesis and immune responses making it an attractive target for cancer therapy. AREAS COVERED This article addresses the role of STAT3 in immune response modulation and highlights the contribution of STAT3 in inflammation-mediated tumorigenesis. We also review the rationale to use novel STAT3 inhibitors and list some of these inhibitors such as STA-21, IS3 295, S3I- M2001 and small molecule JAK2 inhibitors AZD1480 and AZ960 that have been found to be efficient against tumors. We summarize the efforts that have been made so far in identifying promising compounds and mention the barriers that need to be overcome for successful application of STAT3 inhibitors in clinics. EXPERT OPINION STAT3 is an important target in tumor biology based on its frequent activation in various tumors and its pleiotropic effects on different cell types. Screening large libraries of logically synthesized small molecule inhibitors is one way to rapidly generate many potential molecules, which can then be tested in different biologically relevant models. The stage is, therefore, set for the identification and development of novel STAT3 inhibitors that will, in the very near future, enter the clinical realm.
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Affiliation(s)
- Arun K Mankan
- Institute of Molecular Immunology, Klinikum rechts der Isar, Technische Universität München, Ismaningerstr. 22, 81675 München, Germany.
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154
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Liu A, Liu Y, Xu Z, Yu W, Wang H, Li C, Lin J. Novel small molecule, XZH-5, inhibits constitutive and interleukin-6-induced STAT3 phosphorylation in human rhabdomyosarcoma cells. Cancer Sci 2011; 102:1381-7. [PMID: 21435102 PMCID: PMC11158026 DOI: 10.1111/j.1349-7006.2011.01932.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Signal transducers and activators of transcription 3 (STAT3) signaling is constitutively activated in many types of human cancers and cancer cell lines and represents a promising target for cancer therapy. We previously reported that the STAT3 signaling pathway is constitutively activated in human rhabodomyosarcoma cell lines (RH28, RH30 and RD2). We also demonstrated that inhibition of the STAT3 pathway led to apoptosis in human rhabdomyosarcoma cells. In the present study, we investigated the inhibitory effects of a novel small molecule, XZH-5, on the STAT3 signaling pathway in human rhabdomyosarcoma cells. XZH-5 was designed based on STAT3 structure, and our idea was to design peptide mimics to bind to the phosphorylated Tyr705 site and the side pocket. We found that XZH-5 downregulated STAT3 phosphorylation. The inhibition of STAT3 by XZH-5 was confirmed by the inhibition of STAT3 DNA binding ability and the downregulation of STAT3 downstream genes, such as Bcl-2, Bcl-xL, Cyclin D1 and Survivin; we also demonstrated that blockade of STAT3 phosphorylation in human rhabdomyosarcoma cells with XZH-5 caused apoptosis and suppressed colony-forming ability and cell migration. In addition to reducing constitutive STAT3 phosphorylation, XZH-5 also exhibited the potency to block interleukin-6 (IL-6)-induced STAT3 phosphorylation and nuclear translocation but did not inhibit the stimulation of STAT1 phosphorylation by interferon (IFN)-γ. Our findings indicate that XZH-5 has the potential for targeting human rhabdomyosarcoma cells expressing constitutive STAT3.
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Affiliation(s)
- Aiguo Liu
- Center for Childhood Cancer, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
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155
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Abstract
BACKGROUND Persistent activation of signal transducers and activators of transcription 3 (STAT3) is commonly detected in many types of cancer, including colon cancer. To date, whether STAT3 is activated and the effects of STAT3 inhibition by a newly developed curcumin analogue, GO-Y030, in colon cancer stem cells are still unknown. METHODS Flow cytometry was used to isolate colon cancer stem cells, which are characterised by both aldehyde dehydrogenase (ALDH)-positive and CD133-positive subpopulations (ALDH(+)/CD133(+)). The levels of STAT3 phosphorylation and the effects of STAT3 inhibition by a newly developed curcumin analogue, GO-Y030, that targets STAT3 in colon cancer stem cells were examined. RESULTS Our results observed that ALDH(+)/CD133(+) colon cancer cells expressed higher levels of phosphorylated STAT3 than ALDH-negative/CD133-negative colon cancer cells, suggesting that STAT3 is activated in colon cancer stem cells. GO-Y030 and curcumin inhibited STAT3 phosphorylation, cell viability, tumoursphere formation in colon cancer stem cells. GO-Y030 also reduced STAT3 downstream target gene expression and induced apoptosis in colon cancer stem cells. Furthermore, GO-Y030 suppressed tumour growth of cancer stem cells from both SW480 and HCT-116 colon cancer cell lines in the mouse model. CONCLUSION Our results indicate that STAT3 is a novel therapeutic target in colon cancer stem cells, and inhibition of activated STAT3 in cancer stem cells by GO-Y030 may offer an effective treatment for colorectal cancer.
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156
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Trefoil factor 3 is oncogenic and mediates anti-estrogen resistance in human mammary carcinoma. Neoplasia 2011; 12:1041-53. [PMID: 21170268 DOI: 10.1593/neo.10916] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2010] [Revised: 08/12/2010] [Accepted: 08/24/2010] [Indexed: 01/05/2023] Open
Abstract
We report herein that trefoil factor 3 (TFF3) is oncogenic and mediates anti-estrogen resistance in human mammary carcinoma. Forced expression of TFF3 in mammary carcinoma cells increased cell proliferation and survival, enhanced anchorage-independent growth, and promoted migration and invasion. Moreover, forced expression of TFF3 increased tumor size in xenograft models. Conversely, depletion of endogenous TFF3 with small interfering RNA (siRNA) decreased the oncogenicity and invasiveness of mammary carcinoma cells. Neutralization of secreted TFF3 by antibody promoted apoptosis, decreased cell growth in vitro, and arrested mammary carcinoma xenograft growth. TFF3 expression was significantly correlated to decreased survival of estrogen receptor (ER)-positive breast cancer patients treated with tamoxifen. Forced expression of TFF3 in mammary carcinoma cells increased ER transcriptional activity, promoted estrogen-independent growth, and produced resistance to tamoxifen and fulvestrant in vitro and to tamoxifen in xenograft models. siRNA-mediated depletion or antibody inhibition of TFF3 significantly enhanced the efficacy of antiestrogens. Increased TFF3 expression was observed in tamoxifen-resistant (TAMR) cells and antibody inhibition of TFF3 in TAMR cells improved tamoxifen sensitivity. Functional antagonism of TFF3 therefore warrants consideration as a novel therapeutic strategy for mammary carcinoma.
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157
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Ishdorj G, Johnston JB, Gibson SB. Inhibition of constitutive activation of STAT3 by curcurbitacin-I (JSI-124) sensitized human B-leukemia cells to apoptosis. Mol Cancer Ther 2011; 9:3302-14. [PMID: 21159613 DOI: 10.1158/1535-7163.mct-10-0550] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Phosphorylation of STAT3 on serine 727 regulates gene expression and is found to be elevated in many B-leukemia cells including chronic lymphocytic leukemia (CLL). It is, however, unclear whether targeting STAT3 will be an effective antileukemia therapy. In this study, we assessed in vitro antileukemia activity of the STAT3 inhibitor JSI-124 (cucurbitacin I). JSI-124 potently induces apoptosis in 3 B-leukemia cell lines (BJAB, I-83, and NALM-6) and in primary CLL cells and was associated with a reduction in serine 727 phosphorylation of STAT3. Similarly, knockdown of STAT3 expression induced apoptosis in these leukemia cells. In addition, we found that JSI-124 and knockdown of STAT3 decreased antiapoptotic protein XIAP expression and overexpression of XIAP blocked JSI-124-induced apoptosis. Furthermore, we found that combined treatment of JSI-124 and TRAIL increased apoptosis associated with an increase in death receptor 4 expression. Besides apoptosis, we found that JSI-124 also induced cell-cycle arrest prior to apoptosis in B-leukemia cells. This corresponded with reduced expression of the cell-cycle regulatory gene, cdc-2. Thus, we present here for the first time that JSI-124 induced suppression of serine 727 phosphorylation of STAT3, leading to apoptosis and cell-cycle arrest through alterations in gene transcription in B-leukemia cells.
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Affiliation(s)
- Ganchimeg Ishdorj
- Departments of Biochemistry and Medical Genetics, Manitoba Institute of Cell Biology, University of Manitoba, Winnipeg, Manitoba, Canada
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158
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Gupta SC, Kannappan R, Reuter S, Kim JH, Aggarwal BB. Chemosensitization of tumors by resveratrol. Ann N Y Acad Sci 2011; 1215:150-60. [PMID: 21261654 DOI: 10.1111/j.1749-6632.2010.05852.x] [Citation(s) in RCA: 224] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Because tumors develop resistance to chemotherapeutic agents, the cancer research community continues to search for effective chemosensitizers. One promising possibility is to use dietary agents that sensitize tumors to the chemotherapeutics. In this review, we discuss that the use of resveratrol can sensitize tumor cells to chemotherapeutic agents. The tumors shown to be sensitized by resveratrol include lung carcinoma, acute myeloid leukemia, promyelocytic leukemia, multiple myeloma, prostate cancer, oral epidermoid carcinoma, and pancreatic cancer. The chemotherapeutic agents include vincristine, adriamycin, paclitaxel, doxorubicin, cisplatin, gefitinib, 5-fluorouracil, velcade, and gemcitabine. The chemosensitization of tumor cells by resveratrol appears to be mediated through its ability to modulate multiple cell-signaling molecules, including drug transporters, cell survival proteins, cell proliferative proteins, and members of the NF-κB and STAT3 signaling pathways. Interestingly, this nutraceutical has also been reported to suppress apoptosis induced by paclitaxel, vincristine, and daunorubicin in some tumor cells. The potential mechanisms underlying this dual effect are discussed. Overall, studies suggest that resveratrol can be used to sensitize tumors to standard cancer chemotherapeutics.
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Affiliation(s)
- Subash C Gupta
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, 77030, USA
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159
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Proietti CJ, Béguelin W, Flaqué MCD, Cayrol F, Rivas MA, Tkach M, Charreau EH, Schillaci R, Elizalde PV. Novel role of signal transducer and activator of transcription 3 as a progesterone receptor coactivator in breast cancer. Steroids 2011; 76:381-92. [PMID: 21184768 DOI: 10.1016/j.steroids.2010.12.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2010] [Revised: 12/13/2010] [Accepted: 12/14/2010] [Indexed: 12/19/2022]
Abstract
Interactions between progesterone receptor (PR) and signal transducer and activator of transcription 3 (Stat3)-mediated signaling pathways have already been described. In the present study, we explored the capacity of Stat3 to functionally interact with progesterone receptor (PR) and modulate PR transcriptional activation in breast cancer cells. We found that the synthetic progestin medroxyprogesterone acetate (MPA) induced the association of a PR/Stat3 complex in which Stat3 acts as a coactivator of PR. We demonstrated that Stat3 activation is required for MPA modulation of the endogenous genes bcl-X and p21(CIP1) which are involved in MPA-induced cell cycle regulation. Stat3 activity as a coactivator of PR was observed in both the classical and nonclassical ligand activated-PR transcriptional mechanisms, since the effects described were identified in the bcl-X promoter which contains a progesterone responsive element and in the p21(CIP1) promoter which carries Sp1 binding sites where PR is recruited via the transcription factor Sp1. The data herein presented identifies a potential therapeutic intervention for PR-positive breast tumors consisting of targeting Stat3 function or PR/Stat3 interaction which will result in the inhibition of PR function.
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Affiliation(s)
- Cecilia J Proietti
- Instituto de Biología y Medicina Experimental (IBYME), CONICET, Vuelta de Obligado 2490, Buenos Aires C1428ADN, Argentina.
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160
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Small molecules, LLL12 and FLLL32, inhibit STAT3 and exhibit potent growth suppressive activity in osteosarcoma cells and tumor growth in mice. Invest New Drugs 2011; 30:916-26. [DOI: 10.1007/s10637-011-9645-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Accepted: 02/08/2011] [Indexed: 12/15/2022]
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161
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Lee ES, Ko KK, Joe YA, Kang SG, Hong YK. Inhibition of STAT3 reverses drug resistance acquired in temozolomide-resistant human glioma cells. Oncol Lett 2010; 2:115-121. [PMID: 22870139 DOI: 10.3892/ol.2010.210] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Accepted: 10/12/2010] [Indexed: 01/22/2023] Open
Abstract
The alkylating agent temozolomide (TMZ) is an effective drug used for the treatment of malignant gliomas. However, tumor relapse combined with the development of drug resistance remains a significant problem. To clarify the mechanism of the resistance of glioma cells to TMZ chemotherapy, TMZ-resistant glioma cell lines (TR cells) were generated using U373 and U251 human glioma cells, and TMZ-resistance was confirmed via viability and apoptosis assays. The TMZ-resistance of TR cells was not associated with the TMZ-resistance molecule O(6)-methylguanine-DNA-methyltransferase. Notably, the expression level of signal transducers and activators of transcription 3 (STAT3) and serine 727-phosphorylated STAT3 (pSTAT3-Ser727) was highly increased in TR cells, while that of 705-phosphorylated STAT3 (pSTAT3-Tyr705) was decreased. The inhibition of STAT3 expression by small interfering RNA enhanced TR cell TMZ sensitivity. These results suggest that STAT3 contributes to TMZ-resistance in gliomas and is a potential target for the reversal of TMZ-resistance in patients with a recurrent glioma.
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Affiliation(s)
- Eun-Sang Lee
- Cancer Research Institute, The Catholic University of Korea, Seoul 137-701, Korea
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162
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Li X, Wang H, Lu X, DI B. Silencing STAT3 with short hairpin RNA enhances radiosensitivity of human laryngeal squamous cell carcinoma xenografts in vivo. Exp Ther Med 2010; 1:947-953. [PMID: 22993624 DOI: 10.3892/etm.2010.156] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2010] [Accepted: 09/20/2010] [Indexed: 11/05/2022] Open
Abstract
Short hairpin RNA (shRNA) targeting signal transducer and activator of transcription 3 (STAT3) potentiate the radiosensitivity of human laryngeal squamous carcinoma cells in vitro. In the present study, we investigated the inhibitory effect of STAT3 shRNA plus radiotherapy on nude mouse laryngeal squamous cell carcinoma xenografts. The xenotransplanted tumors were treated with STAT3 shRNA, with or without radiation, following a planned scheme. The inhibition rate for tumor growth was calculated and the tumor growth curve was plotted. In addition, the expression of p-STAT3, B cell lymphoma 2 (Bcl-2), p53, vascular endothelial growth factor (VEGF) protein and intratumoral microvessel density (MVD) was determined by immunohistochemistry. Flow cytometry was used to detect the rate of cell apoptosis. The results revealed that STAT3 shRNA transfection plus radiotherapy significantly minimized tumor volume and increased the rate of tumor inhibition. p-STAT3 protein expression and intratumoral MVD were observed to be down-regulated, whereas apoptosis was increased. There was a positive correlation between the expression of p-STAT3 and Bcl-2, and also between the expression of p53 and VEGF, and MVD. These findings indicate that STAT3 shRNA potentiate the radiosensitivity of laryngeal carcinoma xenografts in vivo by regulating downstream signaling proteins in the STAT3 pathway.
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Affiliation(s)
- Xiaoming Li
- Department of Otolaryngology-Head and Neck Surgery, Bethune International Peace Hospital, Shijiazhuang, Hebei 050082
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163
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Saydmohammed M, Joseph D, Syed V. Curcumin suppresses constitutive activation of STAT-3 by up-regulating protein inhibitor of activated STAT-3 (PIAS-3) in ovarian and endometrial cancer cells. J Cell Biochem 2010; 110:447-56. [PMID: 20235152 DOI: 10.1002/jcb.22558] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Signal transducer and activator of transcription-3 (STAT-3) is constitutively activated in ovarian and endometrial cancers and is implicated in uncontrolled cell growth. Thus, its disruption could be an effective approach to control tumorigenesis. Curcumin is a dihydroxyphenolic compound, with proven anti-cancer efficacy in various cancer models. We examined the anti-tumor mechanism of curcumin on STAT-3 and on the negative regulators of STAT-3, including suppressors of cytokine signaling proteins (SOCS-1 and SOCS-3), protein inhibitors of activated STAT (PIAS-1 and PIAS-3), and SH2 domain-containing phosphatases (SHP-1 and SHP-2) in ovarian and endometrial cancer cell lines. Treatment of cancer cells with curcumin induced a dose- and time-dependent decrease of constitutive IL-6 expression and of constitutive and IL-6-induced STAT-3 phosphorylation, which is associated with decreased cell viability and increased cleavage of caspase-3. The inhibition of STAT-3 activation by curcumin was reversible, and phosphorylated STAT-3 levels returned to control levels 24 h after curcumin removal. Compared to normal cells baseline expression of SOCS-3 was high in cancer cells and a marked decrease in SOCS-3 expression was seen following curcumin treatment. Overexpression of SOCS-3 in curcumin-treated cells increased expression of phosphorylated STAT-3 and resulted in increased cell viability. Normal ovarian and endometrial cells exhibited high expression of PIAS-3 protein, whereas in cancer cells the expression was greatly reduced. Curcumin increased PIAS-3 expression in cancer cells. Of significance, siRNA-mediated knockdown of PIAS-3 overcomes the inhibitory effect of curcumin on STAT-3 phosphorylation and cell viability. In conclusion, curcumin suppresses JAK-STAT signaling via activation of PIAS-3, thus attenuating STAT-3 phosphorylation and tumor cell growth.
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Affiliation(s)
- Manush Saydmohammed
- Department of Obstetrics and Gynecology, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814-4799, USA
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164
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Choi CH, Song SY, Kang H, Lee YY, Kim CJ, Lee JW, Kim TJ, Kim BG, Lee JH, Bae DS. Prognostic significance of p-STAT3 in patients with bulky cervical carcinoma undergoing neoadjuvant chemotherapy. J Obstet Gynaecol Res 2010; 36:304-10. [PMID: 20492381 DOI: 10.1111/j.1447-0756.2009.01131.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
AIM To better predict treatment responses for managing bulky cervical carcinoma with neoadjuvant chemotherapy (NAC). METHODS The expression of p-STAT3 was analyzed by immunohistochemistry using paraffin-embedded pretreatment cervical biopsy tissues. The study included 29 patients with bulky IB to IIA cervical squamous cell carcinoma treated with NAC. RESULTS Twenty (69.0%) of 29 patients were scored as p-STAT3-positive. Pathological response to chemotherapy (complete response or residual tumor with less than 3 mm stromal invasion) was observed in eight patients (27.6%). The p-STAT3-positive patients had a longer disease-free survival compared to p-STAT3-negative patients (P = 0.03), though they had more frequent clinical nodal involvement (P = 0.046). CONCLUSION Pretreatment assessment of p-STAT3 expression may provide additional information for the identification of patients with cervical cancer who have a favorable prognosis.
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Affiliation(s)
- Chel Hun Choi
- Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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165
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Lee J, Hahm ER, Singh SV. Withaferin A inhibits activation of signal transducer and activator of transcription 3 in human breast cancer cells. Carcinogenesis 2010; 31:1991-8. [PMID: 20724373 DOI: 10.1093/carcin/bgq175] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have shown previously that withaferin A (WA), a promising anticancer constituent of Ayurvedic medicine plant Withania somnifera, inhibits growth of human breast cancer cells in culture and in vivo in association with apoptosis induction. The present study builds on these observations and demonstrates that WA inhibits constitutive as well as interleukin-6 (IL-6)-inducible activation of signal transducer and activator of transcription 3 (STAT3), which is an oncogenic transcription factor activated in many human malignancies including breast cancer. The WA treatment (2 and 4 μM) decreased constitutive (MDA-MB-231) and/or IL-6-inducible (MDA-MB-231 and MCF-7) phosphorylation of STAT3 (Tyr(705)) and its upstream regulator Janus-activated kinase 2 (JAK2; Tyr(1007/1008)) in MDA-MB-231, which was accompanied by suppression of their protein levels especially at the higher concentration. Exposure of MDA-MB-231 or MCF-7 cells to WA also resulted in suppression of (i) transcriptional activity of STAT3 with or without IL-6 stimulation in both cells; (ii) dimerization of STAT3 (MDA-MB-231) and (iii) nuclear translocation of Tyr(705)-phosphorylated STAT3 in both cells. To our surprise, the IL-6-stimulation, either before or after WA treatment, did not have an appreciable effect on WA-mediated apoptosis in MDA-MB-231 or MCF-7 cell line. The IL-6-stimulated activation of STAT3 conferred a modest protection against WA-mediated suppression of MDA-MB-231 cell invasion. General implication of these findings is that WA can trigger apoptosis and largely inhibit cell migration/invasion of breast cancer cells even after IL-6-induced activation of STAT3, which should be viewed as a therapeutic advantage for this agent.
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Affiliation(s)
- Joomin Lee
- Department of Pharmacology & Chemical Biology, and University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, 5117 Centre Avenue, Pittsburgh, PA 15213, USA
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166
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Rho O, Kim DJ, Kiguchi K, Digiovanni J. Growth factor signaling pathways as targets for prevention of epithelial carcinogenesis. Mol Carcinog 2010; 50:264-79. [PMID: 20648549 DOI: 10.1002/mc.20665] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Revised: 06/09/2010] [Accepted: 06/10/2010] [Indexed: 10/24/2022]
Abstract
Growth factor receptor (GFR) signaling controls epithelial cell growth by responding to various endogenous or exogenous stimuli and subsequently activating downstream signaling pathways including Stat3, PI3K/Akt/mTOR, MAPK, and c-Src. Environmental chemical toxicants and UVB irradiation cause enhanced and prolonged activation of GFR signaling and downstream pathways that contributes to epithelial cancer development including skin cancer. Recent studies, especially those with tissue-specific transgenic mouse models, have demonstrated that GFRs and their downstream signaling pathways contribute to all three stages of epithelial carcinogenesis by regulating a wide variety of biological functions including proliferation, apoptosis, angiogenesis, cell adhesion, and migration. Inhibiting these signaling pathways early in the carcinogenic process results in reduced cell proliferation and survival, leading to decreased tumor formation. Collectively, these studies suggest that GFR signaling and subsequent downstream signaling pathways are potential targets for the prevention of epithelial cancers including skin cancer.
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Affiliation(s)
- Okkyung Rho
- Division of Pharmacology & Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, Texas 78723-3092, USA
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167
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Liu Y, Li PK, Li C, Lin J. Inhibition of STAT3 signaling blocks the anti-apoptotic activity of IL-6 in human liver cancer cells. J Biol Chem 2010; 285:27429-27439. [PMID: 20562100 DOI: 10.1074/jbc.m110.142752] [Citation(s) in RCA: 133] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Interleukin-6 (IL-6) is a multifunctional cytokine, which may block apoptosis during inflammation to protect cells under very toxic conditions. However, IL-6 also activates STAT3 in many types of human cancer. Recent studies demonstrate that high levels of IL-6 are associated with hepatocellular carcinoma, the most common type of liver cancer. Here we reported that IL-6 promoted survival of human liver cancer cells through activating STAT3 in response to doxorubicin treatment. Endogenous IL-6 levels in SNU-449 cells were higher than in Hep3B cells. Meanwhile, SNU-449 cells were more resistant to doxorubicin than Hep3B cells. Addition of IL-6 induced STAT3 activation in Hep3B cells and led to protection against doxorubicin. In contrast, neutralizing IL-6 with anti-IL-6 antibody decreased survival of SNU-449 cells in response to doxorubicin. To elucidate the mechanism of the anti-apoptotic function of IL-6, we investigated if STAT3 mediated this drug resistance. Targeting STAT3 with STAT3 siRNA reduced the protection of IL-6 against doxorubicin-induced apoptosis, indicating that STAT3 signaling contributed to the anti-apoptotic effect of IL-6. Moreover, we further explored if a STAT3 small molecule inhibitor could abolish this anti-apoptotic effect. LLL12, a STAT3 small molecule inhibitor, blocked IL-6-induced STAT3 phosphorylation, resulting in attenuation of the anti-apoptotic activity of IL-6. Finally, neutralization of endogenous IL-6 with anti-IL-6 antibody or blockade of STAT3 with LLL12 lowered the recovery in SNU-449 cells after doxorubicin treatment. Therefore, our results demonstrated that targeting STAT3 signaling could interrupt the anti-apoptotic function of IL-6 in human liver cancer cells.
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Affiliation(s)
- Yan Liu
- Department of Pediatrics, Center for Childhood Cancer, The Research Institute at Nationwide Children's Hospital, The Ohio State University Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43205
| | - Pui-Kai Li
- Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43205
| | - Chenglong Li
- Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43205
| | - Jiayuh Lin
- Department of Pediatrics, Center for Childhood Cancer, The Research Institute at Nationwide Children's Hospital, The Ohio State University Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43205; Experimental Therapeutics Program, The Ohio State University Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43205.
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168
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A novel small molecule, LLL12, inhibits STAT3 phosphorylation and activities and exhibits potent growth-suppressive activity in human cancer cells. Neoplasia 2010; 12:39-50. [PMID: 20072652 DOI: 10.1593/neo.91196] [Citation(s) in RCA: 158] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Revised: 10/08/2009] [Accepted: 10/09/2009] [Indexed: 01/17/2023] Open
Abstract
Constitutive activation of signal transducer and activator of transcription 3 (STAT3) signaling is frequently detected in cancer, promoting its emergence as a promising target for cancer treatment. Inhibiting constitutive STAT3 signaling represents a potential therapeutic approach. We used structure-based design to develop a nonpeptide, cell-permeable, small molecule, termed as LLL12, which targets STAT3. LLL12 was found to inhibit STAT3 phosphorylation (tyrosine 705) and induce apoptosis as indicated by the increases of cleaved caspase-3 and poly (ADP-ribose) polymerase in various breast, pancreatic, and glioblastoma cancer cell lines expressing elevated levels of STAT3 phosphorylation. LLL12 could also inhibit STAT3 phosphorylation induced by interleukin-6 in MDA-MB-453 breast cancer cells. The inhibition of STAT3 by LLL12 was confirmed by the inhibition of STAT3 DNA binding activity and STAT3-dependent transcriptional luciferase activity. Downstream targets of STAT3, cyclin D1, Bcl-2, and survivin were also downregulated by LLL12 at both protein and messenger RNA levels. LLL12 is a potent inhibitor of cell viability, with half-maximal inhibitory concentrations values ranging between 0.16 and 3.09 microM, which are lower than the reported JAK2 inhibitor WP1066 and STAT3 inhibitor S3I-201 in six cancer cell lines expressing elevated levels of STAT3 phosphorylation. In addition, LLL12 inhibits colony formation and cell migration and works synergistically with doxorubicin and gemcitabine. Furthermore, LLL12 demonstrated a potent inhibitory activity on breast and glioblastoma tumor growth in a mouse xenograft model. Our results indicate that LLL12 may be a potential therapeutic agent for human cancer cells expressing constitutive STAT3 signaling.
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169
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Lin L, Hutzen B, Zuo M, Ball S, Deangelis S, Foust E, Pandit B, Ihnat MA, Shenoy SS, Kulp S, Li PK, Li C, Fuchs J, Lin J. Novel STAT3 phosphorylation inhibitors exhibit potent growth-suppressive activity in pancreatic and breast cancer cells. Cancer Res 2010; 70:2445-54. [PMID: 20215512 DOI: 10.1158/0008-5472.can-09-2468] [Citation(s) in RCA: 178] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The constitutive activation of signal transducer and activator of transcription 3 (STAT3) is frequently detected in most types of human cancer where it plays important roles in survival, drug resistance, angiogenesis, and other functions. Targeting constitutive STAT3 signaling is thus an attractive therapeutic approach for these cancers. We have recently developed novel small-molecule STAT3 inhibitors, known as FLLL31 and FLLL32, which are derived from curcumin (the primary bioactive compound of turmeric). These compounds are designed to bind selectively to Janus kinase 2 and the STAT3 Src homology-2 domain, which serve crucial roles in STAT3 dimerization and signal transduction. Here we show that FLLL31 and FLLL32 are effective inhibitors of STAT3 phosphorylation, DNA-binding activity, and transactivation in vitro, leading to the impediment of multiple oncogenic processes and the induction of apoptosis in pancreatic and breast cancer cell lines. FLLL31 and FLLL32 also inhibit colony formation in soft agar and cell invasion and exhibit synergy with the anticancer drug doxorubicin against breast cancer cells. In addition, we show that FLLL32 can inhibit the induction of STAT3 phosphorylation by IFNalpha and interleukin-6 in breast cancer cells. We also show that administration of FLLL32 can inhibit tumor growth and vascularity in chicken embryo xenografts as well as substantially reduce tumor volumes in mouse xenografts. Our findings highlight the potential of these new compounds and their efficacy in targeting pancreatic and breast cancers that exhibit constitutive STAT3 signaling.
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Affiliation(s)
- Li Lin
- Department of Pediatrics, Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, Ohio 43205, USA.
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170
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Zhang X, Yue P, Fletcher S, Zhao W, Gunning PT, Turkson J. A novel small-molecule disrupts Stat3 SH2 domain-phosphotyrosine interactions and Stat3-dependent tumor processes. Biochem Pharmacol 2010; 79:1398-409. [PMID: 20067773 DOI: 10.1016/j.bcp.2010.01.001] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2009] [Revised: 12/10/2009] [Accepted: 01/04/2010] [Indexed: 10/20/2022]
Abstract
The molecular modeling of the phosphotyrosine (pTyr)-SH2 domain interaction in the Stat3:Stat3 dimerization, combined with in silico structural analysis of the Stat3 dimerization disruptor, S3I-201, has furnished a diverse set of analogs. We present evidence from in vitro biochemical and biophysical studies that the structural analog, S3I-201.1066 directly interacts with Stat3 or the SH2 domain, with an affinity (K(D)) of 2.74microM, and disrupts the binding of Stat3 to the cognate pTyr-peptide, GpYLPQTV-NH(2), with an IC(50) of 23microM. Moreover, S3I-201.1066 selectively blocks the association of Stat3 with the epidermal growth factor receptor (EGFR), and inhibits Stat3 tyrosine phosphorylation and nuclear translocation in EGF-stimulated mouse fibroblasts. In cancer cells that harbor aberrant Stat3 activity, S3I-201.1066 inhibits constitutive Stat3 DNA-binding and transcriptional activities. By contrast, S3I-201.1066 has no effect on Src activation or the EGFR-mediated activation of the Erk1/2(MAPK) pathway. S3I-201.1066 selectively suppresses the viability, survival, and malignant transformation of the human breast and pancreatic cancer lines and the v-Src-transformed mouse fibroblasts harboring persistently active Stat3. Treatment with S3I-201.1066 of malignant cells harboring aberrantly active Stat3 down-regulated the expression of c-Myc, Bcl-xL, Survivin, the matrix metalloproteinase 9, and VEGF. The in vivo administration of S3I-201.1066-induced significant antitumor response in mouse models of human breast cancer, which correlates with the inhibition of constitutively active Stat3 and the suppression of known Stat3-regulated genes. Our studies identify a novel small-molecule that binds with a high affinity to Stat3, blocks Stat3 activation and function, and thereby induces antitumor response in human breast tumor xenografts harboring persistently active Stat3.
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Affiliation(s)
- Xiaolei Zhang
- University of Central Florida College of Medicine, Orlando, 32827, USA
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171
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Inhibition of the JAK-STAT3 pathway by andrographolide enhances chemosensitivity of cancer cells to doxorubicin. Biochem Pharmacol 2009; 79:1242-50. [PMID: 20026083 DOI: 10.1016/j.bcp.2009.12.014] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2009] [Revised: 12/05/2009] [Accepted: 12/10/2009] [Indexed: 11/21/2022]
Abstract
Andrographolide (Andro), a diterpenoid lactone isolated from a traditional herbal medicine Andrographis paniculata, is known to possess potent anti-inflammatory and anticancer properties. In this study, we sought to examine the effect of Andro on signal transducer and activator of transcription 3 (STAT3) pathway and evaluate whether suppression of STAT3 activity by Andro could sensitize cancer cells to a chemotherapeutic drug doxorubicin. First, we demonstrated that Andro is able to significantly suppress both constitutively activated and IL-6-induced STAT3 phosphorylation and subsequent nuclear translocation in cancer cells. Such inhibition is found to be achieved through suppression of Janus-activated kinase (JAK)1/2 and interaction between STAT3 and gp130. For understanding the biological significance of the inhibitory effect of Andro on STAT3, we next investigated the effect of Andro on doxorubicin-induced apoptosis in human cancer cells. In our study the constitutive activation level of STAT3 was found to be correlated to the resistance of cancer cells to doxorubicin-induced apoptosis. Both the short-term MTT assay and the long-term colony formation assay showed that Andro dramatically promoted doxorubicin-induced cell death in cancer cells, indicating that Andro enhances the sensitivity of cancer cells to doxorubicin mainly via STAT3 suppression. These observations thus reveal a novel anticancer function of Andro and suggest a potential therapeutic strategy of using Andro in combination with chemotherapeutic agents for treatment of cancer.
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172
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Implication of protein tyrosine phosphatase 1B in MCF-7 cell proliferation and resistance to 4-OH tamoxifen. Biochem Biophys Res Commun 2009; 387:748-53. [DOI: 10.1016/j.bbrc.2009.07.105] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2009] [Accepted: 07/22/2009] [Indexed: 12/12/2022]
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173
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Aggarwal BB, Kunnumakkara AB, Harikumar KB, Gupta SR, Tharakan ST, Koca C, Dey S, Sung B. Signal transducer and activator of transcription-3, inflammation, and cancer: how intimate is the relationship? Ann N Y Acad Sci 2009. [PMID: 19723038 DOI: 10.1111/j.1749-6632.2009.04911.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/29/2022]
Abstract
Signal transducer and activator of transcription-3 (STAT-3) is one of six members of a family of transcription factors. It was discovered almost 15 years ago as an acute-phase response factor. This factor has now been associated with inflammation, cellular transformation, survival, proliferation, invasion, angiogenesis, and metastasis of cancer. Various types of carcinogens, radiation, viruses, growth factors, oncogenes, and inflammatory cytokines have been found to activate STAT-3. STAT-3 is constitutively active in most tumor cells but not in normal cells. Phosphorylation of STAT-3 at tyrosine 705 leads to its dimerization, nuclear translocation, DNA binding, and gene transcription. The phosphorylation of STAT-3 at serine 727 may regulate its activity negatively or positively. STAT-3 regulates the expression of genes that mediate survival (survivin, bcl-xl, mcl-1, cellular FLICE-like inhibitory protein), proliferation (c-fos, c-myc, cyclin D1), invasion (matrix metalloproteinase-2), and angiogenesis (vascular endothelial growth factor). STAT-3 activation has also been associated with both chemoresistance and radioresistance. STAT-3 mediates these effects through its collaboration with various other transcription factors, including nuclear factor-kappaB, hypoxia-inducible factor-1, and peroxisome proliferator activated receptor-gamma. Because of its critical role in tumorigenesis, inhibitors of this factor's activation are being sought for both prevention and therapy of cancer. This has led to identification of small peptides, oligonucleotides, and small molecules as potential STAT-3 inhibitors. Several of these small molecules are chemopreventive agents derived from plants. This review discusses the intimate relationship between STAT-3, inflammation, and cancer in more detail.
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Affiliation(s)
- Bharat B Aggarwal
- Department of Experimental Therapeutics, Cytokine Research Laboratory, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA.
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174
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Aggarwal BB, Kunnumakkara AB, Harikumar KB, Gupta SR, Tharakan ST, Koca C, Dey S, Sung B. Signal transducer and activator of transcription-3, inflammation, and cancer: how intimate is the relationship? Ann N Y Acad Sci 2009; 1171:59-76. [PMID: 19723038 DOI: 10.1111/j.1749-6632.2009.04911.x] [Citation(s) in RCA: 533] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Signal transducer and activator of transcription-3 (STAT-3) is one of six members of a family of transcription factors. It was discovered almost 15 years ago as an acute-phase response factor. This factor has now been associated with inflammation, cellular transformation, survival, proliferation, invasion, angiogenesis, and metastasis of cancer. Various types of carcinogens, radiation, viruses, growth factors, oncogenes, and inflammatory cytokines have been found to activate STAT-3. STAT-3 is constitutively active in most tumor cells but not in normal cells. Phosphorylation of STAT-3 at tyrosine 705 leads to its dimerization, nuclear translocation, DNA binding, and gene transcription. The phosphorylation of STAT-3 at serine 727 may regulate its activity negatively or positively. STAT-3 regulates the expression of genes that mediate survival (survivin, bcl-xl, mcl-1, cellular FLICE-like inhibitory protein), proliferation (c-fos, c-myc, cyclin D1), invasion (matrix metalloproteinase-2), and angiogenesis (vascular endothelial growth factor). STAT-3 activation has also been associated with both chemoresistance and radioresistance. STAT-3 mediates these effects through its collaboration with various other transcription factors, including nuclear factor-kappaB, hypoxia-inducible factor-1, and peroxisome proliferator activated receptor-gamma. Because of its critical role in tumorigenesis, inhibitors of this factor's activation are being sought for both prevention and therapy of cancer. This has led to identification of small peptides, oligonucleotides, and small molecules as potential STAT-3 inhibitors. Several of these small molecules are chemopreventive agents derived from plants. This review discusses the intimate relationship between STAT-3, inflammation, and cancer in more detail.
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Affiliation(s)
- Bharat B Aggarwal
- Department of Experimental Therapeutics, Cytokine Research Laboratory, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA.
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175
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Lin L, Hutzen B, Ball S, Foust E, Sobo M, Deangelis S, Pandit B, Friedman L, Li C, Li PK, Fuchs J, Lin J. New curcumin analogues exhibit enhanced growth-suppressive activity and inhibit AKT and signal transducer and activator of transcription 3 phosphorylation in breast and prostate cancer cells. Cancer Sci 2009; 100:1719-27. [PMID: 19558577 PMCID: PMC11158315 DOI: 10.1111/j.1349-7006.2009.01220.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2009] [Revised: 05/06/2009] [Accepted: 05/09/2009] [Indexed: 12/23/2022] Open
Abstract
Curcumin, the active component of turmeric, has been shown to protect against carcinogenesis and prevent tumor development in cancer. To enhance its potency, we tested the efficacy of synthetic curcumin analogues, known as FLLL11 and FLLL12, in cancer cells. We examined the impact of FLLL11 and FLLL12 on cell viability in eight different breast and prostate cancer cell lines. FLLL11 and FLLL12 (IC(50) values 0.3-5.7 and 0.3-3.8 micromol/L, respectively) were substantially more potent than curcumin (IC(50) values between 14.4-50 micromol/L). FLLL11 and FLLL12 were also found to inhibit AKT phosphorylation and downregulate the expression of HER2/neu. In addition, we demonstrate for the first time that FLLL11 and FLLL12 inhibit phosphorylation of signal transducer and activator of transcription (STAT) 3, an oncogene frequently found to be persistently active in many cancer types. The inhibition of STAT3 signaling was confirmed by the inhibition of STAT3 DNA binding and STAT3 transcriptional activity. Furthermore, FLLL11 and FLLL12 were more effective than curcumin in inhibiting cell migration and colony formation in soft agar as well as inducing apoptosis in cancer cells. These results indicate that FLLL11 and FLLL12 exhibit more potent activities than curcumin on the inhibition of STAT3, AKT, and HER-2/neu, as well as inhibit cancer cell growth and migration, and may thus have translational potential as chemopreventive or therapeutic agents for breast and prostate cancers.
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Affiliation(s)
- Li Lin
- Department of Pediatrics, College of Pharmacy, The Ohio State University, Columbus, OH , USA
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176
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Hutzen B, Willis W, Jones S, Cen L, Deangelis S, Fuh B, Lin J. Dietary agent, benzyl isothiocyanate inhibits signal transducer and activator of transcription 3 phosphorylation and collaborates with sulforaphane in the growth suppression of PANC-1 cancer cells. Cancer Cell Int 2009; 9:24. [PMID: 19712481 PMCID: PMC3224892 DOI: 10.1186/1475-2867-9-24] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2008] [Accepted: 08/27/2009] [Indexed: 12/15/2022] Open
Abstract
The Signal Transducer and Activator of Transcription (STAT) proteins comprise a family of latent transcription factors with diverse functions. STAT3 has well established roles in cell proliferation, growth and survival, and its persistent activation has been detected with high frequency in many human cancers. As constitutive activation of STAT3 appears to be vital for the continued survival of these cancerous cells, it has emerged as an attractive target for chemotherapeutics. We examined whether the inhibitory activities of bioactive compounds from cruciferous vegetables, such as Benzyl isothiocyanate (BITC) and sulforaphane, extended to STAT3 activation in PANC-1 human pancreatic cancer cells. BITC and sulforaphane were both capable of inhibiting cell viability and inducing apoptosis in PANC-1. Sulforaphane had minimal effect on the direct inhibition of STAT3 tyrosine phosphorylation, however, suggesting its inhibitory activities are most likely STAT3-independent. Conversely, BITC was shown to inhibit the tyrosine phosphorylation of STAT3, but not the phosphorylation of ERK1/2, MAPK and p70S6 kinase. These results suggest that STAT3 may be one of the targets of BITC-mediated inhibition of cell viability in PANC-1 cancer cells. In addition, we show that BITC can prevent the induction of STAT3 activation by Interleukin-6 in MDA-MB-453 breast cancer cells. Furthermore, combinations of BITC and sulforaphane inhibited cell viability and STAT3 phosphorylation more dramatically than either agent alone. These findings suggest that the combination of the dietary agents BITC and sulforaphane has potent inhibitory activity in pancreatic cancer cells and that they may have translational potential as chemopreventative or therapeutic agents.
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Affiliation(s)
- Brian Hutzen
- Department of Pediatrics, The Research Institute at Nationwide Childrens' Hospital, Columbus, OH, USA.
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177
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Hawthorne VS, Huang WC, Neal CL, Tseng LM, Hung MC, Yu D. ErbB2-mediated Src and signal transducer and activator of transcription 3 activation leads to transcriptional up-regulation of p21Cip1 and chemoresistance in breast cancer cells. Mol Cancer Res 2009; 7:592-600. [PMID: 19372587 DOI: 10.1158/1541-7786.mcr-08-0316] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Overexpression of the ErbB2 receptor tyrosine kinase is prevalent in approximately 30% of human breast cancers and confers Taxol resistance. Our previous work has shown that ErbB2 inhibits Taxol-induced apoptosis in breast cancer cells by transcriptionally up-regulating p21(Cip1). However, the mechanism of ErbB2-mediated p21(Cip1) up-regulation is unclear. Here, we show that ErbB2 up-regulates p21(Cip1) transcription through increased Src activity in ErbB2-overexpressing cells. Src activation further activated signal transducer and activator of transcription 3 (STAT3) that recognizes a SIE binding site on the p21(Cip1) promoter required for ErbB2-mediated p21(Cip1) transcriptional up-regulation. Both Src and STAT3 inhibitors restored Taxol sensitivity in resistant ErbB2-overexpressing breast cancer cells. Our data suggest that ErbB2 overexpression can activate STAT3 through Src leading to transcriptional up-regulation of p21(Cip1) that confers Taxol resistance of breast cancer cells. Our study suggests a potential clinical application of Src and STAT3 inhibitors in Taxol sensitization of ErbB2-overexpressing breast cancers.
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Affiliation(s)
- Valerie S Hawthorne
- Department of Molecular and Cellular Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA
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178
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Fuh B, Sobo M, Cen L, Josiah D, Hutzen B, Cisek K, Bhasin D, Regan N, Lin L, Chan C, Caldas H, DeAngelis S, Li C, Li PK, Lin J. LLL-3 inhibits STAT3 activity, suppresses glioblastoma cell growth and prolongs survival in a mouse glioblastoma model. Br J Cancer 2009; 100:106-12. [PMID: 19127268 PMCID: PMC2634692 DOI: 10.1038/sj.bjc.6604793] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Persistent activation of the signal transducer and activator of transcription 3 (STAT3) signalling has been linked to oncogenesis and the development of chemotherapy resistance in glioblastoma and other cancers. Inhibition of the STAT3 pathway thus represents an attractive therapeutic approach for cancer. In this study, we investigated the inhibitory effects of a small molecule compound known as LLL-3, which is a structural analogue of the earlier reported STAT3 inhibitor, STA-21, on the cell viability of human glioblastoma cells, U87, U373, and U251 expressing constitutively activated STAT3. We also investigated the inhibitory effects of LLL-3 on U87 glioblastoma cell growth in a mouse tumour model as well as the impact it had on the survival time of the treated mice. We observed that LLL-3 inhibited STAT3-dependent transcriptional and DNA binding activities. LLL-3 also inhibited viability of U87, U373, and U251 glioblastoma cells as well as induced apoptosis of these glioblastoma cell lines as evidenced by increased poly (ADP-ribose) polymerase (PARP) and caspase-3 cleavages. Furthermore, the U87 glioblastoma tumour-bearing mice treated with LLL-3 exhibited prolonged survival relative to vehicle-treated mice (28.5 vs 16 days) and had smaller intracranial tumours and no evidence of contralateral invasion. These results suggest that LLL-3 may be a potential therapeutic agent in the treatment of glioblastoma with constitutive STAT3 activation.
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Affiliation(s)
- B Fuh
- Department of Pediatrics, BSOM, East Carolina University, Greenville, NC 27834, USA
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179
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Activation of Stat3 by heregulin/ErbB-2 through the co-option of progesterone receptor signaling drives breast cancer growth. Mol Cell Biol 2008; 29:1249-65. [PMID: 19103753 DOI: 10.1128/mcb.00853-08] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Cross talk between the steroid hormone receptors for estrogen and progesterone (PR) and the ErbB family of receptor tyrosine kinases appears to be a hallmark of breast cancer growth, but its underlying mechanism remains poorly explored. Here we have highlighted signal transducer and activator of transcription 3 (Stat3) as a key protein activated by heregulin (HRG), a ligand of the ErbB receptors, through co-opted, ligand-independent PR function as a signaling molecule. Stat3 activation was an absolute requirement in HRG-induced mammary tumor growth, and targeting Stat3 effectively inhibited growth of breast cancer cells with activated HRG/ErbB-2 and PR. Our findings unravel a novel potential therapeutic intervention in PR- and ErbB-2-positive breast tumors, involving the specific blockage of PR signaling activity.
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180
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Sayyah J, Magis A, Ostrov DA, Allan RW, Braylan RC, Sayeski PP. Z3, a novel Jak2 tyrosine kinase small-molecule inhibitor that suppresses Jak2-mediated pathologic cell growth. Mol Cancer Ther 2008; 7:2308-18. [PMID: 18723478 DOI: 10.1158/1535-7163.mct-08-0279] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Jak2 tyrosine kinase is essential for animal development and hyperkinetic Jak2 function has been linked to a host of human diseases. Control of this pathway using Jak2-specific inhibitors would therefore potentially serve as a useful research tool and/or therapeutic agent. Here, we used a high-throughput program called DOCK to predict the ability of 20,000 small molecules to interact with a structural pocket adjacent to the ATP-binding site of murine Jak2. One small molecule, 2-methyl-1-phenyl-4-pyridin-2-yl-2-(2-pyridin-2-ylethyl)butan-1-one (herein designated as Z3), bound to Jak2 with a favorable energy score. Z3 inhibited Jak2-V617F and Jak2-WT autophosphorylation in a dose-dependent manner but was not cytotoxic to cells at concentrations that inhibited kinase activity. Z3 selectively inhibited Jak2 kinase function with no effect on Tyk2 or c-Src kinase function. Z3 significantly inhibited proliferation of the Jak2-V617F-expressing, human erythroleukemia cell line, HEL 92.1.7. The Z3-mediated reduction in cell proliferation correlated with reduced Jak2 and STAT3 tyrosine phosphorylation levels as well as marked cell cycle arrest. Finally, Z3 inhibited the growth of hematopoietic progenitor cells isolated from the bone marrow of an essential thrombocythemia patient harboring the Jak2-V617F mutation and a polycythemia vera patient carrying a Jak2-F537I mutation. Collectively, the data suggest that Z3 is a novel specific inhibitor of Jak2 tyrosine kinase.
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Affiliation(s)
- Jacqueline Sayyah
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL 32610, USA
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181
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Kruser TJ, Armstrong EA, Ghia AJ, Huang S, Wheeler DL, Radinsky R, Freeman DJ, Harari PM. Augmentation of radiation response by panitumumab in models of upper aerodigestive tract cancer. Int J Radiat Oncol Biol Phys 2008; 72:534-42. [PMID: 18793955 DOI: 10.1016/j.ijrobp.2008.06.1490] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2008] [Revised: 05/26/2008] [Accepted: 06/01/2008] [Indexed: 12/25/2022]
Abstract
PURPOSE To examine the interaction between panitumumab, a fully human anti-epidermal growth factor receptor monoclonal antibody, and radiation in head-and-neck squamous cell carcinoma and non-small-cell lung cancer cell lines and xenografts. METHODS AND MATERIALS The head-and-neck squamous cell carcinoma lines UM-SCC1 and SCC-1483, as well as the non-small-cell lung cancer line H226, were studied. Tumor xenografts in athymic nude mice were used to assess the in vivo activity of panitumumab alone and combined with radiation. In vitro assays were performed to assess the effect of panitumumab on radiation-induced cell signaling, apoptosis, and DNA damage. RESULTS Panitumumab increased the radiosensitivity as measured by the clonogenic survival assay. Radiation-induced epidermal growth factor receptor phosphorylation and downstream signaling through mitogen-activated protein kinase (MAPK) and signal transducer and activator of transcription 3 (STAT3) was inhibited by panitumumab. Panitumumab augmented radiation-induced DNA damage by 1.2-1.6-fold in each of the cell lines studied as assessed by residual gamma-H(2)AX foci after radiation. Radiation-induced apoptosis was increased 1.4-1.9-fold by panitumumab, as evidenced by Annexin V-fluorescein isothiocyanate staining and flow cytometry. In vivo, the combination therapy of panitumumab and radiation was superior to panitumumab or radiation alone in the H226 xenografts (p = 0.01) and showed a similar trend in the SCC-1483 xenografts (p = 0.08). In vivo, immunohistochemistry demonstrated the ability of panitumumab to augment the antiproliferative and antiangiogenic effects of radiation. CONCLUSION These studies have identified a favorable interaction in the combination of radiation and panitumumab in upper aerodigestive tract tumor models, both in vitro and in vivo. These data suggest that clinical investigations examining the combination of radiation and panitumumab in the treatment of epithelial tumors warrant additional pursuit.
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Affiliation(s)
- Tim J Kruser
- Department of Human Oncology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
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182
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Chen CL, Cen L, Kohout J, Hutzen B, Chan C, Hsieh FC, Loy A, Huang V, Cheng G, Lin J. Signal transducer and activator of transcription 3 activation is associated with bladder cancer cell growth and survival. Mol Cancer 2008; 7:78. [PMID: 18939995 PMCID: PMC2577686 DOI: 10.1186/1476-4598-7-78] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2007] [Accepted: 10/21/2008] [Indexed: 01/01/2023] Open
Abstract
Background Constitutive activation of signal transducer and activator of transcription 3 (Stat3) signaling pathway plays an important role in several human cancers. Activation of Stat3 is dependent on the phosphorylation at the tyrosine residue 705 by upstream kinases and subsequent nuclear translocation after dimerization. It remains unclear whether oncogenic Stat3 signaling pathway is involved in the oncogenesis of bladder cancer. Results We found that elevated Stat3 phosphorylation in 19 of 100 (19%) bladder cancer tissues as well as bladder cancer cell lines, WH, UMUC-3 and 253J. To explore whether Stat3 activation is associated with cell growth and survival of bladder cancer, we targeted the Stat3 signaling pathway in bladder cancer cells using an adenovirus-mediated dominant-negative Stat3 (Y705F) and a small molecule compound, STA-21. Both prohibited cell growth and induction of apoptosis in these bladder cancer cell lines but not in normal bladder smooth muscle cell (BdSMC). The survival inhibition might be mediated through apoptotic caspase 3, 8 and 9 pathways. Moreover, down-regulation of anti-apoptotic genes (Bcl-2, Bcl-xL and survivin) and a cell cycle regulating gene (cyclin D1) was associated with the cell growth inhibition and apoptosis. Conclusion These results indicated that activation of Stat3 is crucial for bladder cancer cell growth and survival. Therefore, interference of Stat3 signaling pathway emerges as a potential therapeutic approach for bladder cancer.
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Affiliation(s)
- Chun-Liang Chen
- Center for Childhood Cancer, The Research Institute at Nationwide Children's Hospital, Columbus, OH 43205, USA.
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183
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Lieblein JC, Ball S, Hutzen B, Sasser AK, Lin HJ, Huang TH, Hall BM, Lin J. STAT3 can be activated through paracrine signaling in breast epithelial cells. BMC Cancer 2008; 8:302. [PMID: 18939993 PMCID: PMC2582243 DOI: 10.1186/1471-2407-8-302] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2008] [Accepted: 10/21/2008] [Indexed: 01/09/2023] Open
Abstract
Background Many cancers, including breast cancer, have been identified with increased levels of phosphorylated or the active form of Signal Transducers and Activators of Transcription 3 (STAT3) protein. However, whether the tumor microenvironment plays a role in this activation is still poorly understood. Methods Conditioned media, which contains soluble factors from MDA-MB-231 and MDA-MB-468 breast cancer cells and breast cancer associated fibroblasts, was added to MCF-10A breast epithelial and MDA-MB-453 breast cancer cells. The stimulation of phosphorylated STAT3 (p-STAT3) levels by conditioned media was assayed by Western blot in the presence or absence of neutralized IL-6 antibody, or a JAK/STAT3 inhibitor, JSI-124. The stimulation of cell proliferation in MCF-10A cells by conditioned media in the presence or absence of JSI-124 was subjected to MTT analysis. IL-6, IL-10, and VEGF levels were determined by ELISA analysis. Results Our results demonstrated that conditioned media from cell lines with constitutively active STAT3 are sufficient to induce p-STAT3 levels in various recipients that do not possess elevated p-STAT3 levels. This signaling occurs through the JAK/STAT3 pathway, leading to STAT3 phosphorylation as early as 30 minutes and is persistent for at least 24 hours. ELISA analysis confirmed a correlation between elevated levels of IL-6 production and p-STAT3. Neutralization of the IL-6 ligand or gp130 was sufficient to block increased levels of p-STAT3 (Y705) in treated cells. Furthermore, soluble factors within the MDA-MB-231 conditioned media were also sufficient to stimulate an increase in IL-6 production from MCF-10A cells. Conclusion These results demonstrate STAT3 phosphorylation in breast epithelial cells can be stimulated by paracrine signaling through soluble factors from both breast cancer cells and breast cancer associated fibroblasts with elevated STAT3 phosphorylation. The induction of STAT3 phosphorylation is through the IL-6/JAK pathway and appears to be associated with cell proliferation. Understanding how IL-6 and other soluble factors may lead to STAT3 activation via the tumor microenvironment will provide new therapeutic regimens for breast carcinomas and other cancers with elevated p-STAT3 levels.
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Rogers D, Nylander KD, Mi Z, Hu T, Schor NF. Molecular predictors of human nervous system cancer responsiveness to enediyne chemotherapy. Cancer Chemother Pharmacol 2008; 62:699-706. [PMID: 18338171 PMCID: PMC2575071 DOI: 10.1007/s00280-008-0725-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2008] [Accepted: 02/26/2008] [Indexed: 11/25/2022]
Abstract
PURPOSE To identify and mathematically model molecular predictors of response to the enediyne chemotherapeutic agent, neocarzinostatin, in nervous system cancer cell lines. METHODS Human neuroblastoma, breast cancer, glioma, and medulloblastoma cell lines were maintained in culture. Content of caspase-3 and Bcl-2, respectively, was determined relative to actin content for each cell line by Western blotting and optical densitometry. For each cell line, sensitivity to neocarzinostatin was determined. Brain tumor cell lines were stably transfected with human Bcl-2 cDNA cloned into the pcDNA3 plasmid vector. RESULTS In human tumor cell lines of different tissue origins, sensitivity to neocarzinostatin is proportional to the product of the relative contents of Bcl-2 and caspase-3 (r (2) = 0.9; P < 0.01). Neuroblastoma and brain tumor cell lines are particularly sensitive to neocarzinostatin; the sensitivity of brain tumor lines to neocarzinostatin is enhanced by transfection with an expression construct for Bcl-2 and is proportional in transfected cells to the product of the relative contents of Bcl-2 and caspase-3 (r (2) = 0.7). CONCLUSION These studies underscore the potential of molecular profiling in identifying effective chemotherapeutic paradigms for cancer in general and tumors of the nervous system in particular.
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Affiliation(s)
- Danny Rogers
- Departments of Pediatrics, Neurology, and Neurobiology & Anatomy, University of Rochester Medical Center, Rochester, NY
| | - Karen D. Nylander
- Pediatric Center for Neuroscience, Children’s Hospital of Pittsburgh, Pittsburgh, PA
| | - Zhiping Mi
- Departments of Pediatrics, Neurology, and Neurobiology & Anatomy, University of Rochester Medical Center, Rochester, NY
| | - Tong Hu
- Departments of Pediatrics, Neurology, and Neurobiology & Anatomy, University of Rochester Medical Center, Rochester, NY
| | - Nina F. Schor
- Departments of Pediatrics, Neurology, and Neurobiology & Anatomy, University of Rochester Medical Center, Rochester, NY
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Dhillon N, Aggarwal BB, Newman RA, Wolff RA, Kunnumakkara AB, Abbruzzese JL, Ng CS, Badmaev V, Kurzrock R. Phase II Trial of Curcumin in Patients with Advanced Pancreatic Cancer. Clin Cancer Res 2008; 14:4491-9. [DOI: 10.1158/1078-0432.ccr-08-0024] [Citation(s) in RCA: 932] [Impact Index Per Article: 58.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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186
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Zhang L, Gao L, Li Y, Lin G, Shao Y, Ji K, Yu H, Hu J, Kalvakolanu DV, Kopecko DJ, Zhao X, Xu DQ. Effects of plasmid-based Stat3-specific short hairpin RNA and GRIM-19 on PC-3M tumor cell growth. Clin Cancer Res 2008; 14:559-68. [PMID: 18223232 DOI: 10.1158/1078-0432.ccr-07-1176] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Persistent activation of signal transducers and activators of transcription 3 (Stat3) and its overexpression contribute to the progression and metastasis of several different tumor types. For this reason, Stat3 is a reasonable target for RNA interference-mediated growth inhibition. Blockade of Stat3 using specific short hairpin RNAs (shRNA) can significantly reduce prostate tumor growth in mice. However, RNA interference does not fully ablate target gene expression in vivo, owing to the idiosyncrasies associated with shRNAs and their targets. To enhance the therapeutic efficacy of Stat3-specific shRNA, we applied a combination treatment involving gene associated with retinoid-IFN-induced mortality 19 (GRIM-19), another inhibitor of STAT3, along with shRNA. EXPERIMENTAL DESIGN The coding sequences for GRIM-19, a cellular STAT3-specific inhibitor, and Stat3-specific shRNAs were used to create a dual expression plasmid vector and used for prostate cancer therapy in vitro and in mouse xenograft models in vivo. RESULTS The coexpressed Stat3-specific shRNA and GRIM-19 synergistically and more effectively suppressed prostate tumor growth and metastases when compared with treatment with either single agent alone. CONCLUSION The simultaneous use of two specific, but mechanistically different, inhibitors of STAT3 activity exerts enhanced antitumor effects.
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Affiliation(s)
- Ling Zhang
- Prostate Diseases Prevention and Treatment Research Center and Department of Pathophysiology, School of Basic Medicine, Jilin University, Changchun, PR China
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187
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STAT3 as a target for inducing apoptosis in solid and hematological tumors. Cell Res 2008; 18:254-67. [PMID: 18227858 DOI: 10.1038/cr.2008.18] [Citation(s) in RCA: 387] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Studies in the past few years have provided compelling evidence for the critical role of aberrant Signal Transducer and Activator of Transcription 3 (STAT3) in malignant transformation and tumorigenesis. Thus, it is now generally accepted that STAT3 is one of the critical players in human cancer formation and represents a valid target for novel anticancer drug design. This review focuses on aberrant STAT3 and its role in promoting tumor cell survival and supporting the malignant phenotype. A brief evaluation of the current strategies targeting STAT3 for the development of novel anticancer agents against human tumors harboring constitutively active STAT3 will also be presented.
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188
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Ma Z, Molavi O, Haddadi A, Lai R, Gossage RA, Lavasanifar A. Resveratrol analog trans 3,4,5,4'-tetramethoxystilbene (DMU-212) mediates anti-tumor effects via mechanism different from that of resveratrol. Cancer Chemother Pharmacol 2008; 63:27-35. [PMID: 18286288 DOI: 10.1007/s00280-008-0704-z] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2007] [Accepted: 02/06/2008] [Indexed: 12/23/2022]
Abstract
PURPOSE Resveratrol is a well-known chemopreventive and chemotherapeutic agent. Among all of the resveratrol analogs synthesized, 3,4,5,4'-tetramethoxystilbene (DMU-212) shows high activity and selectivity against various cancer cell types. The objective of this study is to investigate why DMU-212 has higher anti-tumor activity than resveratrol. METHODS The effects of DMU-212 and resveratrol on cell viability, cell cycle, Stat3 activation, and microtubule dynamic were investigated and compared using MTT assay, cell cycle analysis, Western blot, tubulin polymerization assay, respectively, in MDA-MB-435 and MCF-7 human breast cancer cells. RESULTS Compared to resveratrol, DMU-212 exerted a significantly higher growth inhibition in both cell lines. Further studies demonstrated that DMU-212 acted via different mechanisms from resveratrol. First, DMU-212 induced predominantly G2/M arrest whereas resveratrol induced G0/G1 arrest in both cell lines. Correlating with these findings, resveratrol induced more dramatic changes in the expression of Cyclin D1 compared to DMU-212. Second, DMU-212 induced apoptosis and reduced the expression of multiple anti-apoptotic proteins more appreciably than resveratrol. Third, while both agents inhibited Stat3 phosphorylation, treatments of DMU-212 but not resveratrol led to a significant increase in tubulin polymerization. The higher sensitivity to DMU-122 in MDA-MB-435 correlated with the more prominent effects seen in these parameters in this cell line, as compared to MCF7. CONCLUSION Compared to resveratrol, the novel stilbene derivative, DMU-212, had higher anti-tumor effects, which are likely owing to its modulation of multiple cellular targets.
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Affiliation(s)
- Zengshuan Ma
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
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189
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Zhang YQ, Herman B. Expression and modification of ARC (apoptosis repressor with a CARD domain) is distinctly regulated by oxidative stress in cancer cells. J Cell Biochem 2008; 104:818-25. [DOI: 10.1002/jcb.21666] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Germain D, Frank DA. Targeting the cytoplasmic and nuclear functions of signal transducers and activators of transcription 3 for cancer therapy. Clin Cancer Res 2007; 13:5665-9. [PMID: 17908954 DOI: 10.1158/1078-0432.ccr-06-2491] [Citation(s) in RCA: 174] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Signal transducers and activators of transcription (STAT) are a highly conserved family of transcription factors that are activated by phosphorylation in the cytoplasm, after which they translocate to the nucleus to regulate gene expression. Among the seven STATs, STAT3 is of particular interest due to its constitutive phosphorylation in a large proportion of human cancers and its ability to induce neoplastic transformation. Inhibition of STAT3 can reverse tumor growth in experimental systems while having few effects in normal cells. These findings have implicated STAT3 as a potentially important target for therapeutic intervention. In addition to its well-described role as a transcription factor, STAT3 has been found recently to have important effects in the cytoplasm. Collectively, these functions of STAT3 directly contribute to tumorigenesis, invasion, and metastasis. Given the potential importance of STAT3 as a target for cancer therapy, molecules have been developed that can block STAT3 function at a variety of steps. These drugs show promise as anticancer agents in model systems of a variety of common human cancers. Thus, elucidating the functions of STAT3 and developing agents to inhibit this protein remain important scientific and clinical challenges.
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Affiliation(s)
- Doris Germain
- Division of Hematology/Oncology, Department of Medicine, Mount Sinai School of Medicine, New York, New York, USA
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191
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Fontalba A, Gutierrez O, Fernandez-Luna JL. NLRP2, an Inhibitor of the NF-κB Pathway, Is Transcriptionally Activated by NF-κB and Exhibits a Nonfunctional Allelic Variant. THE JOURNAL OF IMMUNOLOGY 2007; 179:8519-24. [DOI: 10.4049/jimmunol.179.12.8519] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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192
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Inhibition of Stat3 increases doxorubicin sensitivity in a human metastatic breast cancer cell line. Cancer Lett 2007; 258:181-8. [DOI: 10.1016/j.canlet.2007.08.019] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2007] [Revised: 08/23/2007] [Accepted: 08/31/2007] [Indexed: 11/18/2022]
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193
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Abstract
Recent studies have revealed that the regulated death of bacterial cells is important for biofilm development. Following cell death, a sub-population of the dead bacteria lyse and release genomic DNA, which then has an essential role in intercellular adhesion and biofilm stability. This Opinion focuses on the role of regulated cell death and lysis in biofilm development and provides a functional comparison between bacterial programmed cell death and apoptosis. The hypothesis that the differential regulation of these processes during biofilm development contributes to the antibiotic tolerance of biofilm cells is also explored.
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Affiliation(s)
- Kenneth W Bayles
- Department of Pathology & Microbiology, University of Nebraska Medical Center, 986,495 Nebraska Medical Center, Omaha, Nebraska, USA.
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194
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Kusaba M, Nakao K, Goto T, Nishimura D, Kawashimo H, Shibata H, Motoyoshi Y, Taura N, Ichikawa T, Hamasaki K, Eguchi K. Abrogation of constitutive STAT3 activity sensitizes human hepatoma cells to TRAIL-mediated apoptosis. J Hepatol 2007; 47:546-55. [PMID: 17602782 DOI: 10.1016/j.jhep.2007.04.017] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2006] [Revised: 04/24/2007] [Accepted: 04/26/2007] [Indexed: 12/04/2022]
Abstract
BACKGROUND/AIMS Signal transducer and activator of transcription 3 (STAT3) is constitutively activated and regulates cell growth and survival of various cancer cells. We investigated the anti-tumor effect of AG490, a Janus kinase 2 specific inhibitor, inhuman hepatoma cells. METHODS Effects of AG490 on STAT3 activation, on cell-growth and survival, and on the expression of cell-cycle- and apoptosis-related proteins were evaluated in Huh-1, Huh-7, HepG2 and Hep3B cells. Next, whether AG490 renders hepatoma cells susceptible to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) was examined in vitro and in vivo. RESULTS Constitutively activated STAT3 through tyrosine phosphorylation was detected in all hepatoma cells. AG490 inhibited the phosphorylation of STAT3 and its activity. AG490 induced cell cycle arrest in Huh-1, Huh-7 and HepG2 through cyclin D1 downregulation, and induced marked apoptosis in Hep3B. AG490 downregulated at least one of the anti-apoptotic proteins, Bcl-xL, survivin or XIAP in all hepatoma cells. AG490 sensitized Huh-1, Huh-7 and HepG2 to TRAIL-induced apoptosis in vitro. Intraperitoneal injection of AG490, the combination of AG490 and TRAIL more greatly, repressed the growth of subcutaneous Huh-7 tumors in athymic mice. CONCLUSIONS Abrogation of constitutive activation of STAT3 by AG490 enhances the anti-tumor activity of TRAIL against human hepatoma cells.
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Affiliation(s)
- Mariko Kusaba
- First Department of Internal Medicine, Nagasaki University School of Medicine, 1-7-1, Sakamoto, Nagasaki 852-8501, Japan
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195
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Kim DJ, Chan KS, Sano S, Digiovanni J. Signal transducer and activator of transcription 3 (Stat3) in epithelial carcinogenesis. Mol Carcinog 2007; 46:725-31. [PMID: 17610223 DOI: 10.1002/mc.20342] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Signal transducer and activator of transcription 3 (Stat3) is one of a family of cytoplasmic proteins that participate in normal cellular responses to cytokines and growth factors as transcription factors. Stat3 modulates various physiological functions including cell survival, cell-cycle regulation, and angiogenesis through regulation of gene expression, and its constitutive activation is associated with a number of human epithelial cancers. Recent studies with skin-specific gain and loss of Stat3 function transgenic mice have shown that Stat3 plays critical roles in skin carcinogenesis. Multistage skin carcinogenesis bioassays performed with these transgenic mice clearly demonstrate that Stat3 is required for both tumor initiation and promotion through regulation of genes involved in survival and proliferation, respectively. Stat3 also plays a role in malignant progression of skin tumors by regulating genes that are involved in angiogenesis and invasion. Further studies have revealed that Stat3 plays a critical role in epidermal cell proliferation and survival following exposure to ultraviolet B (UVB) irradiation. In addition, Stat3 is constitutively active in UVB-induced skin tumors from both mice and humans. Collectively, these studies suggest that Stat3 may be a potential target for both the prevention and treatment of human epithelial cancers including skin cancer.
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Affiliation(s)
- Dae Joon Kim
- Department of Carcinogenesis, The University of Texas M.D. Anderson Cancer Center, Science Park--Research Division, Smithville, Texas 78957, USA
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196
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Chen CL, Hsieh FC, Lieblein JC, Brown J, Chan C, Wallace JA, Cheng G, Hall BM, Lin J. Stat3 activation in human endometrial and cervical cancers. Br J Cancer 2007; 96:591-9. [PMID: 17311011 PMCID: PMC2360038 DOI: 10.1038/sj.bjc.6603597] [Citation(s) in RCA: 139] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The activation of signal transducer and activator of transcription 3 (Stat3) has been implicated in the oncogenesis of cancer and is regarded as a novel target for cancer therapy. Stat3 is classified as a proto-oncogene, because an activated form of Stat3 can mediate oncogenic transformation in cultured cells and tumour formation in nude mice. The constitutive activation of Stat3 has been frequently detected in various types of human cancers. However, the constitutive activation of Stat3 in endometrial and cervical cancers has not been studied. We examined tyrosine phosphorylation of Stat3 (activated form of Stat3) in multiple endometrial and cervical cancer tissues using tissue microarray slides as well as cancer cell lines to explore the possible activation of Stat3. Our results indicated that elevated phosphorylation of Stat3 was detected in cervical and endometrial cancer cell lines. Our results also showed that elevated levels of phosphorylation of Stat3 protein were detected in the endometrial and cervical cancer specimens. This is the first study to demonstrate that Stat3 is activated in human endometrial and cervical cancer tissues. Immunohistochemical staining showed that activated Stat3 is associated with increased expression of downstream antiapoptotic genes, Bcl-xL, survivin, and Mcl-1 in these tissues. Expression of a dominant-negative Stat3 mutant using adenovirus-mediated gene transfer inhibited cell growth and induced apoptosis in HeLa and SiHa cervical cancer cell lines expressing elevated levels of Stat3 phosphorylation. Further, a JAK/Stat3 small molecular inhibitor, JSI-124, induced apoptosis more selectively in HeLa and SiHa cancer cell lines than Ishikawa cell line without elevated levels of Stat3 phosphorylation. These results indicate that Stat3 is activated in human endometrial and cervical cancers and the inhibition of constitutive Stat3 signaling may be an effective target for cancer intervention in these two cancers.
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Affiliation(s)
- C-L Chen
- Center for Childhood Cancer, Columbus Children's Research Institute, Columbus, OH, USA
| | - F-C Hsieh
- Center for Childhood Cancer, Columbus Children's Research Institute, Columbus, OH, USA
| | - J C Lieblein
- Ohio State Biochemistry Program, Columbus, OH, USA
| | - J Brown
- Ohio State Biochemistry Program, Columbus, OH, USA
| | - C Chan
- Center for Childhood Cancer, Columbus Children's Research Institute, Columbus, OH, USA
| | - J A Wallace
- Graduate Program in Molecular, Cellular & Developmental Biology, Columbus, OH, USA
| | - G Cheng
- Center for Childhood Cancer, Columbus Children's Research Institute, Columbus, OH, USA
| | - B M Hall
- Center for Childhood Cancer, Columbus Children's Research Institute, Columbus, OH, USA
- Ohio State University Comprehensive Cancer Center, Ohio State University, Columbus, OH, USA
| | - J Lin
- Center for Childhood Cancer, Columbus Children's Research Institute, Columbus, OH, USA
- Ohio State Biochemistry Program, Columbus, OH, USA
- Graduate Program in Molecular, Cellular & Developmental Biology, Columbus, OH, USA
- Ohio State University Comprehensive Cancer Center, Ohio State University, Columbus, OH, USA
- WA 5020, Center for Childhood Cancer, Columbus Children's Research Institute, The Ohio State University, Columbus, OH 43205, USA. E-mail:
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Abstract
The abilities of tumor cells to proliferate uncontrollably, resist apoptosis, induce vasculature formation, and invade distant organs are well-recognized hallmarks of cancer. More recently, the capability of tumors to evade immune surveillance and avoid destruction by the immune system has also gained significant acceptance in the cancer research field. However, the initial explanation for the lack of antitumor immune responses was ascribed to mutations affecting tumor-associated antigen expression, antigen processing, and presentation. Although these mutations undoubtedly facilitate tumor immune evasion, they cannot account for how tumors remain undetected before the occurrence of these genetic alterations. Moreover, the tumor microenvironment, whose pivotal role in immune paralysis is gaining appreciation, does not seem to directly cause these mutations. In addition, many tumors retain intact genes encoding major histocompatibility complex, costimulatory molecules and tumor antigens, but with reduced expression levels in the presence of tumor-secreted factors. Discoveries from several recent studies support the hypothesis that oncogenesis itself, as a result of overactivity of growth factor receptors, cytokine receptors, or oncoproteins, coordinates immune evasion. In particular, signal transducer and transcription activator 3 (Stat3), which is a point of convergence for many oncogenic pathways, has emerged as a critical mediator of tumor immune evasion at multiple levels. As a result, molecules involved in the oncogenic signaling pathways, particularly Stat3, provide targets for cancer immunotherapy.
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Affiliation(s)
- Marcin Kortylewski
- Division of Cancer Immunotherapeutics and Tumor Immunology, The Beckman Research Institute of City of Hope National Medical Center, Duarte, CA 91010, USA
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Williams C, Edvardsson K, Lewandowski SA, Ström A, Gustafsson JA. A genome-wide study of the repressive effects of estrogen receptor beta on estrogen receptor alpha signaling in breast cancer cells. Oncogene 2007; 27:1019-32. [PMID: 17700529 DOI: 10.1038/sj.onc.1210712] [Citation(s) in RCA: 178] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Transcriptional effects of estrogen result from its activation of two estrogen receptor (ER) isoforms; ERalpha that drives proliferation and ERbeta that is antiproliferative. Expression of ERbeta in xenograft tumors from the T47D breast cancer cell line reduces tumor growth and angiogenesis. If ERbeta can halt tumor growth, its introduction into cancers may be a novel therapeutic approach to the treatment of estrogen-responsive cancers. To assess the complete impact of ERbeta on transcription, we have made a full transcriptome analysis of ERalpha- and ERbeta-mediated gene regulation in T47D cell line with Tet-Off regulated ERbeta expression. Of the 35 000 genes and transcripts analysed, 4.1% (1434) were altered by ERalpha activation. Tet withdrawal and subsequent ERbeta expression inhibited the ERalpha regulation of 998 genes and, in addition, altered expression of 152 non-ERalpha-regulated genes. ERalpha-induced and ERbeta-repressed genes were involved in proliferation, steroid/xenobiotic metabolism and ion transport. The ERbeta repressive effect was further confirmed by proliferation assays, where ERbeta was shown to completely oppose the ERalpha-E2 induced proliferation. Additional analysis of ERbeta with a mutated DNA-binding domain revealed that this mutant, at least for a quantity of genes, antagonizes ERalpha even more strongly than ERbeta wt. From an examination of the genes regulated by ERalpha and ERbeta, we suggest that introduction of ERbeta may be an alternative therapeutic approach to the treatment of certain cancers.
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Affiliation(s)
- C Williams
- Department of Biosciences and Nutrition at Novum, Karolinska Institutet, Huddinge, Sweden.
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Redell MS, Tsimelzon A, Hilsenbeck SG, Tweardy DJ. Conditional overexpression of Stat3alpha in differentiating myeloid cells results in neutrophil expansion and induces a distinct, antiapoptotic and pro-oncogenic gene expression pattern. J Leukoc Biol 2007; 82:975-85. [PMID: 17634277 DOI: 10.1189/jlb.1206766] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Normal neutrophil development requires G-CSF signaling, which includes activation of Stat3. Studies of G-CSF-mediated Stat3 signaling in cell culture and transgenic mice have yielded conflicting data regarding the role of Stat3 in myelopoiesis. The specific functions of Stat3 remain unclear, in part, because two isoforms, Stat3alpha and Stat3beta, are expressed in myeloid cells. To understand the contribution of each Stat3 isoform to myelopoiesis, we conditionally overexpressed Stat3alpha or Stat3beta in the murine myeloid cell line 32Dcl3 (32D) and examined the consequences of overexpression on cell survival and differentiation. 32D cells induced to overexpress Stat3alpha, but not Stat3beta, generated a markedly higher number of neutrophils in response to G-CSF. This effect was a result of decreased apoptosis but not of increased proliferation. Comparison of gene expression profiles of G-CSF-stimulated, Stat3alpha-overexpressing 32D cells with those of cells with normal Stat3alpha expression revealed novel Stat3 gene targets, which may contribute to neutrophil expansion and improved survival, most notably Slc28a2, a purine nucleoside transporter, which is critical for maintenance of intracellular nucleotide levels and prevention of apoptosis, and Gpr65, an acid-sensing, G protein-coupled receptor with pro-oncogenic and antiapoptotic functions.
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Affiliation(s)
- Michele S Redell
- Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
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Petterino C, Ratto A, Podestà G, Drigo M, Pellegrino C. Immunohistochemical evaluation of STAT3-p-tyr705 expression in feline mammary gland tumours and correlation with histologic grade. Res Vet Sci 2007; 82:218-24. [PMID: 16934302 DOI: 10.1016/j.rvsc.2006.06.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2006] [Accepted: 06/12/2006] [Indexed: 11/26/2022]
Abstract
STAT3 (signal transducer and activator of transcription 3) is a cytoplasmic transcription factor that plays a role in the G1 to S phase cell-cycle transition and is induced by cytokines and growth factors. The expression of STAT3 phosphorylated on tyrosine 705 (STAT3-p-tyr705) in normal, hyperplastic and neoplastic feline mammary gland tissue was assessed by immunohistochemistry in 45 cats. The samples included 4 normal mammary non-lactating tissues, 9 hyperplastic tissues (5 fibroepithelial hyperplasia and 4 lobular epithelial hyperplasia), 2 benign tumours (1 complex adenoma, and 1 simple adenoma), and 30 carcinomas (18 simple tubular papillary, 6 simple tubular, 2 simple solid, 3 cribriform, and 1 adenosquamous carcinoma). For immunohistochemistry, tissue sections were incubated with an anti-STAT3-p-tyr705 monoclonal antibody and visualized with EnVision-DAB polymer. STAT3-p-tyr705 positivity was quantified in a semi-quantitative manner. All positive samples showed cytoplasmic and/or nuclear positivity. Normal non-lactating mammary tissue showed a low number of positive cells, similar to hyperplastic tissue. In neoplastic tissues, a high number of positive cells with a moderate to intense reaction was observed. Moreover, a correlation was observed between nuclear positivity for STAT3-p-tyr705 and histologic grade (P=0.013; r=0.447), tubular formation (P=0.043; r=0.820), and mitotic activity (P<0.0001; r=0.689). In contrast, no such correlations were observed for cytoplasmic reactivity of STAT3-p-tyr705. A significant difference was observed between malignant lesions and hyperplasia with regards to expression of STAT3-p-tyr 705 in the cytoplasm (P=0.008; U=59.00) and nuclei (P=0.002; U=47.00). These results confirm previous our data and reinforce the potential role of STAT3 in malignancy as reported for human breast cancer and other sporadic tumours.
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Affiliation(s)
- Claudio Petterino
- Department of Public Health, Comparative Pathology and Veterinary Hygiene School of Veterinary Medicine, University of Padua, Agripolis, Legnaro, Italy.
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