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1.
Nat Med ; 12(8): 933-8, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16862154

RESUMO

CD82, also known as KAI1, was recently identified as a prostate cancer metastasis suppressor gene on human chromosome 11p1.2 (ref. 1). The product of CD82 is KAI1, a 40- to 75-kDa tetraspanin cell-surface protein also known as the leukocyte cell-surface marker CD82 (refs. 1,2). Downregulation of KAI1 has been found to be clinically associated with metastatic progression in a variety of cancers, whereas overexpression of CD82 specifically suppresses tumor metastasis in various animal models. To define the mechanism of action of KAI1, we used a yeast two-hybrid screen and identified an endothelial cell-surface protein, DARC (also known as gp-Fy), as an interacting partner of KAI1. Our results indicate that the cancer cells expressing KAI1 attach to vascular endothelial cells through direct interaction between KAI1 and DARC, and that this interaction leads to inhibition of tumor cell proliferation and induction of senescence by modulating the expression of TBX2 and p21. Furthermore, the metastasis-suppression activity of KAI1 was significantly compromised in DARC knockout mice, whereas KAI1 completely abrogated pulmonary metastasis in wild-type and heterozygous littermates. These results provide direct evidence that DARC is essential for the function of CD82 as a suppressor of metastasis.


Assuntos
Sistema do Grupo Sanguíneo Duffy/metabolismo , Endotélio Vascular/metabolismo , Proteína Kangai-1/metabolismo , Neoplasias Pulmonares/patologia , Glicoproteínas de Membrana/metabolismo , Metástase Neoplásica/prevenção & controle , Receptores de Superfície Celular/metabolismo , Alelos , Sequência de Aminoácidos , Animais , Sequência de Bases , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Senescência Celular/fisiologia , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Sistema do Grupo Sanguíneo Duffy/química , Feminino , Heterozigoto , Humanos , Proteína Kangai-1/química , Masculino , Glicoproteínas de Membrana/química , Glicoproteínas de Membrana/genética , Camundongos , Camundongos Knockout , Dados de Sequência Molecular , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Estrutura Terciária de Proteína , Ratos , Receptores de Superfície Celular/química , Proteínas com Domínio T/metabolismo
2.
J Biol Chem ; 286(21): 18949-59, 2011 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-21454613

RESUMO

NDRG1 and KAI1 belong to metastasis suppressor genes, which impede the dissemination of tumor cells from primary tumors to distant organs. Previously, we identified the metastasis promoting transcription factor, ATF3, as a downstream target of NDRG1. Further analysis revealed that the KAI1 promoter contained a consensus binding motif of ATF3, suggesting a possibility that NDRG1 suppresses metastasis through inhibition of ATF3 expression followed by activation of the KAI1 gene. In this report, we found that ectopic expression of NDRG1 was able to augment endogenous KAI1 gene expression in prostate cancer cell lines, whereas silencing NDRG1 was accompanied with significant decrease in KAI1 expression in vitro and in vivo. In addition, our results of ChIP analysis indicate that ATF3 indeed bound to the promoter of the KAI1 gene. Importantly, our promoter-based analysis revealed that ATF3 modulated KAI1 transcription through cooperation with other endogenous transcription factor as co-activator (ATF3-JunB) or co-repressor (ATF3-NFκB). Moreover, loss of KAI1 expression significantly abrogated NDRG1-mediated metastatic suppression in vitro as well as in a spontaneous metastasis animal model, indicating that KA11 is a functional downstream target of the NDRG1 pathway. Our result of immunohistochemical analysis showed that loss of NDRG1 and KAI1 occurs in parallel as prostate cancer progresses. We also found that a combined expression status of these two genes serves as a strong independent prognostic marker to predict metastasis-free survival of prostate cancer patients. Taken together, our result revealed a novel regulatory network of two metastasis suppressor genes, NDRG1 and KAI1, which together concerted metastasis-suppressive activities through an intrinsic transcriptional cascade.


Assuntos
Fator 3 Ativador da Transcrição/metabolismo , Proteínas de Ciclo Celular/biossíntese , Regulação Neoplásica da Expressão Gênica , Proteína Kangai-1/metabolismo , NF-kappa B/metabolismo , Neoplasias da Próstata/metabolismo , Fator 3 Ativador da Transcrição/genética , Animais , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteína Kangai-1/genética , Masculino , NF-kappa B/genética , Metástase Neoplásica , Regiões Promotoras Genéticas/genética , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Proteínas Proto-Oncogênicas c-jun/genética , Proteínas Proto-Oncogênicas c-jun/metabolismo , Ratos , Transcrição Gênica/genética
3.
Breast Cancer Res Treat ; 128(1): 57-68, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20665104

RESUMO

We previously isolated cacalol as a free radical-scavenging compound from Cacalia delphiniifolia which is a traditional Asian herbal plant and is believed to have medicinal effects on cancer. In this report, we demonstrated that cacalol has strong anti-proliferation effect on breast cancer cells and induces apoptosis by activating a pro-apoptotic pathway. We also found that a combination of cacalol and other chemotherapeutic drugs (Taxol and cyclophosphamide) synergistically induced apoptosis and partially overcame chemo-resistance. To further gain a mechanistic insight, we tested a potential inhibitory effect of cacalol on fatty acid synthase gene (FAS) in breast cancer cells, and found that cacalol significantly modulated the expression of the FAS gene, which resulted in apoptosis through activation of DAPK2 and caspase 3. We have also shown that cacalol significantly suppressed the Akt-sterol regulatory element-binding proteins (SREBP) signaling pathway and concomitant transcriptional activation of FAS. In a xenograft model of nude mouse, when cacalol was administered intraperitoneally, tumor growth was significantly suppressed. Importantly, oral administration of cacalol before implanting tumors showed significant preventive effect on tumor growth in the same animal model. Furthermore, the treatment of mice with a combination of low dose of Taxol and cacalol significantly suppressed the tumor growth. Taken together, our results indicate that cacalol induces apoptosis in breast cancer cells and impairs mammary tumor growth in vivo by blocking the expression of the FAS gene through modulation of Akt-SREBP pathway, suggesting that cacalol has potential utility as a chemopreventive and chemotherapeutic agent for breast cancer.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Ácido Graxo Sintases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Sesquiterpenos/farmacologia , Proteínas de Ligação a Elemento Regulador de Esterol/metabolismo , Animais , Antineoplásicos/efeitos adversos , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Neoplasias da Mama , Proteínas Quinases Dependentes de Cálcio-Calmodulina/genética , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Caspase 3/metabolismo , Linhagem Celular Tumoral , Ciclofosfamida/farmacologia , Proteínas Quinases Associadas com Morte Celular , Sinergismo Farmacológico , Ativação Enzimática , Ácido Graxo Sintases/genética , Feminino , Genes Reporter , Humanos , Luciferases de Renilla/biossíntese , Luciferases de Renilla/genética , Camundongos , Camundongos Nus , Paclitaxel/farmacologia , Regiões Promotoras Genéticas , Sesquiterpenos/efeitos adversos , Transdução de Sinais , Transcrição Gênica , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
4.
Breast Cancer Res Treat ; 130(2): 387-98, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21188630

RESUMO

Resveratrol is a natural polyphenolic compound and has been shown to exhibit cardio-protective as well as anti-neoplastic effects on various types of cancers. However, the exact mechanism of its anti-tumor effect is not clearly defined. Resveratrol has been shown to have strong hypolipidemic effect on normal adipocytes and as hyper-lipogenesis is a hallmark of cancer cell physiology, the effect of resveratrol on lipid synthesis in cancer stem-like cells (CD24(-)/CD44(+)/ESA(+)) that were isolated from both ER+ and ER- breast cancer cell lines was examined. The authors found that resveratrol significantly reduced the cell viability and mammosphere formation followed by inducing apoptosis in cancer stem-like cells. This inhibitory effect of resveratrol is accompanied by a significant reduction in lipid synthesis which is caused by the down-regulation of the fatty acid synthase (FAS) gene followed by up-regulation of pro-apoptotic genes, DAPK2 and BNIP3. The activation of apoptotic pathway in the cancer stem-like cells was suppressed by TOFA and by Fumonisin B1, suggesting that resveratrol-induced apoptosis is indeed through the modulation of FAS-mediated cell survival signaling. Importantly, resveratrol was able to significantly suppress the growth of cancer stem-like cells in an animal model of xenograft without showing apparental toxicity. Taken together, the results of this study indicate that resveratrol is capable of inducing apoptosis in the cancer stem-like cells through suppression of lipogenesis by modulating FAS expression, which highlights a novel mechanism of anti-tumor effect of resveratrol.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Ácido Graxo Sintases/antagonistas & inibidores , Células-Tronco Neoplásicas/efeitos dos fármacos , Estilbenos/farmacologia , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Proteínas Quinases Dependentes de Cálcio-Calmodulina/genética , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Proteínas Quinases Associadas com Morte Celular , Ácido Graxo Sintases/genética , Ácido Graxo Sintases/metabolismo , Feminino , Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Lipogênese/efeitos dos fármacos , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Nus , Células-Tronco Neoplásicas/metabolismo , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Interferência de RNA , Resveratrol , Ensaios Antitumorais Modelo de Xenoenxerto
5.
Biochim Biophys Acta ; 1786(2): 87-104, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18692117

RESUMO

It is well recognized that the majority of cancer related deaths is caused by metastatic diseases. Therefore, there is an urgent need for the development of therapeutic intervention specifically targeted to the metastatic process. In the last decade, significant progress has been made in this research field, and many new concepts have emerged that shed light on the molecular mechanism of metastasis cascade which is often portrayed as a succession of six distinct steps; localized invasion, intravasation, translocation, extravasation, micrometastasis and colonization. Successful metastasis is dependent on the balance and complex interplay of both the metastasis promoters and suppressors in each step. Therefore, the basic strategy of our interventions is aimed at either blocking the promoters or potentiating the suppressors in this disease process. Toward this goal, various kinds of antibodies and small molecules have been designed. These include agents that block the ligand-recepter interaction of metastasis promoters (HGF/c-Met), antagonize the metastasis-promoting enzymes (AMF, uPA and MMP) and inhibit the transcriptional activity of metastasis promoter (beta-Catenin). On the other hand, the intriguing roles of metastasis suppressors and their signal pathways have been extensively studied and various attempts have been made to potentiate these factors. Small molecules have been developed to restore the expression or mimic the function of metastasis-suppressor genes such as NM23, E-cadherin, Kiss-1, MKK4 and NDRG1, and some of them are under clinical trials. This review summarizes our current understanding of the molecular pathway of tumor metastasis and discusses strategies and recent development of anti-metastatic drugs.


Assuntos
Antineoplásicos/uso terapêutico , Genes Supressores de Tumor/fisiologia , Metástase Neoplásica/tratamento farmacológico , Metástase Neoplásica/genética , Neoplasias/tratamento farmacológico , Carcinógenos/antagonistas & inibidores , Sistemas de Liberação de Medicamentos , Humanos , Modelos Biológicos , Neoplasias/genética , Neoplasias/patologia , Transdução de Sinais/efeitos da radiação , Proteínas Supressoras de Tumor/uso terapêutico
6.
Cancer Res ; 66(11): 5934-40, 2006 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-16740734

RESUMO

Fatty acid synthase (FAS) has been found to be overexpressed in a wide range of epithelial tumors, including breast cancer. Pharmacologic inhibitors of FAS cause apoptosis of breast cancer cells and result in decreased tumor size in vivo. However, how the inhibition of FAS induces apoptosis in tumor cells remains largely unknown. To understand the apoptotic pathway resulting from direct inhibition of FAS, we treated breast tumor cells with or without FAS small interfering RNA (siRNA) followed by a microarray analysis. Our results indicated that the proapoptotic genes BNIP3, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), and death-associated protein kinase 2 (DAPK2) were significantly up-regulated on direct inhibition of the FAS gene. We also found that the knockdown of FAS expression significantly increased ceramide level in the tumor cells, and this increase was abrogated by acetyl-CoA carboxylase inhibitor. In addition, carnitine palmitoyltransferase-1 (CPT-1) inhibitor up-regulated the ceramide and BNIP3 levels in these cells, whereas treatment of tumor cells with FAS siRNA in the presence of a ceramide synthase inhibitor abrogated the up-regulation of BNIP3 and inhibited apoptosis. Furthermore, we found that treatment of cells with BNIP3 siRNA significantly counteracted the effect of FAS siRNA-mediated apoptosis. Consistent with these results, a significant inverse correlation was observed in the expression of FAS and BNIP3 in clinical samples of human breast cancer. Collectively, our results indicate that inhibition of FAS in breast cancer cells causes accumulation of malonyl-CoA, which leads to inhibition of CPT-1 and up-regulation of ceramide and induction of the proapoptotic genes BNIP3, TRAIL, and DAPK2, resulting in apoptosis.


Assuntos
Apoptose/fisiologia , Neoplasias da Mama/enzimologia , Ácido Graxo Sintases/antagonistas & inibidores , Apoptose/genética , Proteínas Reguladoras de Apoptose/genética , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Proteínas Quinases Dependentes de Cálcio-Calmodulina/genética , Linhagem Celular Tumoral , Proteínas Quinases Associadas com Morte Celular , Ácido Graxo Sintases/genética , Humanos , Glicoproteínas de Membrana/genética , Proteínas de Membrana/biossíntese , Proteínas de Membrana/genética , Proteínas Proto-Oncogênicas/biossíntese , Proteínas Proto-Oncogênicas/genética , RNA Interferente Pequeno/genética , Ligante Indutor de Apoptose Relacionado a TNF , Fator de Necrose Tumoral alfa/genética , Regulação para Cima
7.
Cancer Res ; 66(24): 11983-90, 2006 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-17178897

RESUMO

The tumor metastasis suppressor gene Drg-1 has been shown to suppress metastasis without affecting tumorigenicity in immunodeficient mouse models of prostate and colon cancer. Expression of Drg-1 has also been found to have a significant inverse correlation with metastasis or invasiveness in various types of human cancer. However, how Drg-1 exerts its metastasis suppressor function remains unknown. In the present study, to elucidate the mechanism of action of the Drg-1 gene, we did a microarray analysis and found that induction of Drg-1 significantly inhibited the expression of activating transcription factor (ATF) 3, a member of the ATF/cyclic AMP-responsive element binding protein family of transcription factors. We also showed that Drg-1 attenuated the endogenous level of ATF3 mRNA and protein in prostate cancer cells, whereas Drg-1 small interfering RNA up-regulated the ATF3 expression. Furthermore, Drg-1 suppressed the promoter activity of the ATF3 gene, indicating that Drg-1 regulates ATF3 expression at the transcriptional level. Our immunohistochemical analysis on prostate cancer specimens revealed that nuclear expression of ATF3 was inversely correlated to Drg-1 expression and positively correlated to metastases. Consistently, we have found that ATF3 overexpression promoted invasiveness of prostate tumor cells in vitro, whereas Drg-1 suppressed the invasive ability of these cells. More importantly, overexpression of ATF3 in prostate cancer cells significantly enhanced spontaneous lung metastasis of these cells without affecting primary tumorigenicity in a severe combined immunodeficient mouse model. Taken together, our results strongly suggest that Drg-1 suppresses metastasis of prostate tumor cells, at least in part, by inhibiting the invasive ability of the cells via down-regulation of the expression of the ATF3 gene.


Assuntos
Fator 3 Ativador da Transcrição/genética , Proteínas de Ligação ao GTP/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias da Próstata/genética , Linhagem Celular Tumoral , Humanos , Masculino , Metástase Neoplásica/genética , Metástase Neoplásica/prevenção & controle , Plasmídeos , Neoplasias da Próstata/patologia , Mapeamento por Restrição , Transfecção
8.
Oncogene ; 24(34): 5389-95, 2005 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-15897909

RESUMO

Fatty acid synthase (FAS), a key enzyme of the fatty acid biosynthetic pathway, has been shown to be overexpressed in various types of human cancer and is, therefore, considered to be an attractive target for anticancer therapy. However, the exact mechanism of overexpression of the FAS gene in tumor cells is not well understood. In this report, we demonstrate that the expression of the tumor suppressor gene PTEN has a significant inverse correlation with FAS expression in the case of prostate cancer in the clinical setting, and inhibition of the PTEN gene leads to the overexpression of FAS in vitro. We also found that the combination of the expression status of these two genes is a better prognostic marker than either gene alone. Furthermore, our results indicate that the specific inhibition of FAS gene by siRNA leads to apoptosis of prostate tumor cells, and inhibition of PI 3-kinase pathway synergizes with FAS siRNA to enhance tumor cell death. These results provide a strong rationale for exploring the therapeutic use of an inhibitor of the PTEN signaling pathway in conjunction with the FAS siRNA to inhibit prostate tumor growth.


Assuntos
Apoptose , Ácido Graxo Sintases/metabolismo , Regulação Neoplásica da Expressão Gênica , Fosfatidilinositol 3-Quinases/metabolismo , Monoéster Fosfórico Hidrolases/biossíntese , Neoplasias da Próstata/genética , Proteínas Supressoras de Tumor/biossíntese , Idoso , Idoso de 80 Anos ou mais , Ácido Graxo Sintases/biossíntese , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , PTEN Fosfo-Hidrolase , Prognóstico , Neoplasias da Próstata/patologia , Interferência de RNA , Transdução de Sinais , Análise de Sobrevida
9.
Cancer Res ; 63(8): 1731-6, 2003 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-12702552

RESUMO

Drg-1 was previously identified (N. van Belzen et al., Lab. Investig., 77: 85-92, 1997) as a gene that was up-regulated by the induction of differentiation in a colon carcinoma cell line in vitro. Subsequently, this gene was found to be regulated by several factors including hypoxia, androgen, p53, and N-myc. Recently, Drg-1 has also been shown to be involved in tumor progression in animals, although the clinical significance of its involvement remains to be investigated. To clarify the functional role of Drg-1 in prostate cancer, we examined a clinical archive of cancer specimens for the expression of Drg-1 by immunohistochemistry. We found that the expression of Drg-1 had a significant inverse correlation with the Gleason grading and the overall survival rate of patients. In particular, the gene expression in patients with lymph node or bone metastasis was significantly reduced as compared with those with localized prostate cancer, suggesting that the function of Drg-1 is negatively involved in metastatic progression of the disease. To further clarify the function of this gene in the advancement of prostate cancer, a spontaneous metastasis assay was performed in a severe combined immunodeficient (SCID) mouse model. We found that Drg-1 almost completely inhibited lung colonization of highly metastatic prostate cancer cells without affecting the growth of the primary tumors. These results strongly suggest that Drg-1 is a candidate metastasis suppressor gene for prostate cancer and may serve as a useful prognostic marker.


Assuntos
Proteínas de Ciclo Celular/genética , Genes Supressores de Tumor , Neoplasias da Próstata/genética , Idoso , Idoso de 80 Anos ou mais , Animais , Proteínas de Ciclo Celular/biossíntese , Modelos Animais de Doenças , Regulação Neoplásica da Expressão Gênica , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/secundário , Masculino , Camundongos , Camundongos SCID , Pessoa de Meia-Idade , Invasividade Neoplásica , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Transfecção
10.
Cancer Res ; 64(21): 7655-60, 2004 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-15520163

RESUMO

PTEN (phosphatase and tensin homologue deleted on chromosome 10) has been shown to be inactivated in a wide variety of cancers, and the role of this gene as a tumor suppressor has been well established. On the other hand, results of recent animal studies as well as clinical evidence indicate that PTEN is also involved in tumor metastasis suppression. Although PTEN is known to play a key role in controlling cell growth and apoptosis, how PTEN exerts the metastasis suppressor function remains largely unknown. Recently, a microarray analysis identified the Drg-1 gene (differentiation related gene 1) as one of the potential targets of PTEN. The Drg-1 gene has been shown to suppress tumor metastasis in animal models of prostate and colon cancer, and the expression of this gene is significantly reduced with advancement of prostate and breast cancers in clinical setting. In this study, we explored the possibility that PTEN controls tumor metastasis by regulating the expression of the Drg-1 gene. Our results indicate that overexpression of PTEN significantly augments the endogenous expression of Drg-1 protein, whereas inhibition of PTEN by small interfering RNA decreases Drg-1 in a dose- and time-dependent manner. We also found that the control of the Drg-1 gene by PTEN seems to be at the transcriptional level, and that a phospho-Akt inhibitor restores the Drg-1 expression, indicating that PTEN controls Drg-1 by an Akt-dependent pathway. Consistent with these results, our immunohistochemical analysis revealed that PTEN expression correlates significantly with Drg-1 in both prostate and breast cancer cases. Furthermore, combination of the two markers, PTEN and Drg-1, emerged as a significantly better predictor of prostate and breast cancer patient survival than either marker alone.


Assuntos
Neoplasias da Mama/genética , Proteínas de Ciclo Celular/genética , Genes Supressores de Tumor , Monoéster Fosfórico Hidrolases/fisiologia , Neoplasias da Próstata/genética , Proteínas Supressoras de Tumor/fisiologia , Neoplasias da Mama/mortalidade , Linhagem Celular Tumoral , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Masculino , PTEN Fosfo-Hidrolase , Neoplasias da Próstata/mortalidade , Taxa de Sobrevida , Regulação para Cima
11.
Oncogene ; 23(33): 5675-81, 2004 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-15184886

RESUMO

The differentiation-related gene-1 (Drg-1) was first identified as a gene strongly upregulated by induction of differentiation in colon carcinoma cells in vitro, and later the same gene was shown to suppress tumorigenicity of human bladder cancer cells in vivo. On the other hand, we and others have demonstrated that the Drg-1 gene suppresses prostate and colon cancer metastases in mouse models. In the context of such potential organ-specific differential function of the Drg-1 gene, the present study was designed to clarify the expression status, regulation and function of Drg-1 in the case of human breast cancer. We found that the expression of the Drg-1 protein was significantly reduced in breast tumor cells, particularly in patients with lymph node or bone metastasis as compared to those with localized breast cancer. Drg-1 expression also exhibited significant inverse correlation with the disease-free survival rate of patients and emerged as an independent prognostic factor. The downregulation of the Drg-1 gene appeared to be largely at the RNA level, and the DNA methylation inhibitor, 5-Azacytidine, significantly elevated the Drg-1 gene expression in various breast tumor cell lines. Furthermore, we found that overexpression of the Drg-1 gene suppresses the invasiveness of breast cancer cells in vitro, and this suppression was also achieved by treatment of cells with 5-Azacytidine. Together, our results strongly suggest functional involvement of the Drg-1 gene in suppressing the metastatic advancement of human breast cancer.


Assuntos
Neoplasias da Mama/genética , Proteínas de Ligação ao GTP/genética , Metilação de DNA , Progressão da Doença , Intervalo Livre de Doença , Feminino , Regulação Neoplásica da Expressão Gênica , Genes Supressores de Tumor , Humanos , Metástase Neoplásica , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Tumorais Cultivadas
12.
Cancer Res ; 73(4): 1434-44, 2013 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-23384942

RESUMO

Despite significant improvement in survival rates of patients with breast cancer, prognosis of metastatic disease is still dismal. Cancer stem-like cells (CSC) are considered to play a role in metastatic progression of breast cancer; however, the exact pathologic role of CSCs is yet to be elucidated. In this report, we found that CSCs (CD24(-)/CD44(+)/ESA(+)) isolated from metastatic breast cell lines are significantly more metastatic than non-CSC populations in an organ-specific manner. The results of our microRNA (miRNA) profile analysis for these cells revealed that CSCs that are highly metastatic to bone and brain expressed significantly lower level of miR-7 and that this miRNA was capable of modulating one of the essential genes for induced pluripotent stem cell, KLF4. Interestingly, high expression of KLF4 was significantly and inversely correlated to brain but not bone metastasis-free survival of patients with breast cancer, and we indeed found that the expression of miR-7 significantly suppressed the ability of CSCs to metastasize to brain but not to bone in our animal model. We also examined the expression of miR-7 and KLF4 in brain-metastatic lesions and found that these genes were significantly down- or upregulated, respectively, in the tumor cells in brain. Furthermore, the results of our in vitro experiments indicate that miR-7 attenuates the abilities of invasion and self-renewal of CSCs by modulating KLF4 expression. These results suggest that miR-7 and KLF4 may serve as biomarkers or therapeutic targets for brain metastasis of breast cancer.


Assuntos
Neoplasias Encefálicas/genética , Neoplasias da Mama/genética , Fatores de Transcrição Kruppel-Like/genética , MicroRNAs/genética , Células-Tronco Neoplásicas/metabolismo , Animais , Western Blotting , Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Neoplasias Encefálicas/secundário , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Células HEK293 , Humanos , Estimativa de Kaplan-Meier , Fator 4 Semelhante a Kruppel , Células MCF-7 , Neoplasias Mamárias Experimentais/genética , Neoplasias Mamárias Experimentais/patologia , Camundongos , Camundongos Nus , Células-Tronco Neoplásicas/patologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transplante Heterólogo
13.
EMBO Mol Med ; 5(3): 384-96, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23495140

RESUMO

Brain metastasis of breast cancer profoundly affects the cognitive and sensory functions as well as morbidity of patients, and the 1 year survival rate among these patients remains less than 20%. However, the pathological mechanism of brain metastasis is as yet poorly understood. In this report, we found that metastatic breast tumour cells in the brain highly expressed IL-1ß which then 'activated' surrounding astrocytes. This activation significantly augmented the expression of JAG1 in the astrocytes, and the direct interaction of the reactivated astrocytes and cancer stem-like cells (CSCs) significantly stimulated Notch signalling in CSCs. We also found that the activated Notch signalling in CSCs up-regulated HES5 followed by promoting self-renewal of CSCs. Furthermore, we have shown that the blood-brain barrier permeable Notch inhibitor, Compound E, can significantly suppress the brain metastasis in vivo. These results represent a novel paradigm for the understanding of how metastatic breast CSCs re-establish their niche for their self-renewal in a totally different microenvironment, which opens a new avenue to identify a novel and specific target for the brain metastatic disease.


Assuntos
Astrócitos/metabolismo , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/secundário , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Proliferação de Células , Células-Tronco Neoplásicas/metabolismo , Receptores Notch/metabolismo , Transdução de Sinais , Animais , Antineoplásicos/farmacologia , Astrócitos/patologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/prevenção & controle , Neoplasias da Mama/genética , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , Comunicação Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Meios de Cultivo Condicionados/metabolismo , Feminino , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Proteína Jagged-1 , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Células NIH 3T3 , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/patologia , Interferência de RNA , Ratos , Receptores Notch/antagonistas & inibidores , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Proteínas Serrate-Jagged , Transdução de Sinais/efeitos dos fármacos , Nicho de Células-Tronco , Fatores de Tempo , Transfecção , Microambiente Tumoral , Ensaios Antitumorais Modelo de Xenoenxerto
14.
EMBO Mol Med ; 4(2): 93-108, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22246988

RESUMO

Wnt signalling has pivotal roles in tumour progression and metastasis; however, the exact molecular mechanism of Wnt signalling in the metastatic process is as yet poorly defined. Here we demonstrate that the tumour metastasis suppressor gene, NDRG1, interacts with the Wnt receptor, LRP6, followed by blocking of the Wnt signalling, and therefore, orchestrates a cellular network that impairs the metastatic progression of tumour cells. Importantly, restoring NDRG1 expression by a small molecule compound significantly suppressed the capability of otherwise highly metastatic tumour cells to thrive in circulation and distant organs in animal models. In addition, our analysis of clinical cohorts data indicate that Wnt+/NDRG-/LRP+ signature has a strong predictable value for recurrence-free survival of cancer patients. Collectively, we have identified NDRG1 as a novel negative master regulator of Wnt signalling during the metastatic progression, which opens an opportunity to define a potential therapeutic target for metastatic disease.


Assuntos
Metástase Neoplásica/genética , Transdução de Sinais/genética , Proteínas Wnt/genética , beta Catenina/genética , Animais , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Células Cultivadas , Genes myc , Células HEK293 , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Camundongos , Camundongos SCID , Transfecção , Proteínas Wnt/metabolismo , beta Catenina/metabolismo
15.
Cancer Res ; 72(2): 537-47, 2012 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-22113945

RESUMO

The molecular mechanisms that operate within the organ microenvironment to support metastatic progression remain unclear. Here, we report that upregulation of hyaluronan synthase 2 (HAS2) occurs in highly metastatic breast cancer stem-like cells (CSC) defined by CD44(+)/CD24(-)/ESA(+) phenotype, where it plays a critical role in the generation of a prometastatic microenvironment in breast cancer. HAS2 was critical for the interaction of CSCs with tumor-associated macrophages (TAM), leading to enhanced secretion of platelet-derived growth factor-BB from TAMs, which then activated stromal cells and enhanced CSC self-renewal. Loss of HAS2 in CSCs or treatment with 4-methylumbelliferone, an inhibitor of HAS, which blocks hyaluronan production, drastically reduced the incidence and growth of metastatic lesions in vitro or in vivo, respectively. Taken together, our findings show a critical role of HAS2 in the development of a prometastatic microenvironment and suggest that HAS2 inhibitors can act as antimetastatic agents that disrupt a paracrine growth factor loop within this microenvironment.


Assuntos
Neoplasias Ósseas/enzimologia , Neoplasias da Mama/enzimologia , Glucuronosiltransferase/metabolismo , Macrófagos/patologia , Células-Tronco Neoplásicas/patologia , Células Estromais/patologia , Animais , Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Neoplasias Ósseas/secundário , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Adesão Celular/fisiologia , Movimento Celular/fisiologia , Progressão da Doença , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Glucuronosiltransferase/antagonistas & inibidores , Humanos , Hialuronan Sintases , Himecromona/análogos & derivados , Himecromona/farmacologia , Macrófagos/enzimologia , Camundongos , Camundongos Nus , Invasividade Neoplásica , Células-Tronco Neoplásicas/enzimologia , Células Estromais/enzimologia , Regulação para Cima
16.
J Exp Med ; 208(13): 2641-55, 2011 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-22124112

RESUMO

Metastatic disease is the major cause of cancer deaths, and recurrent tumors at distant organs are a critical issue. However, how metastatic tumor cells become dormant and how and why tumors recur in target organs are not well understood. In this study, we demonstrate that BMP7 (bone morphogenetic protein 7) secreted from bone stromal cells induces senescence in prostate cancer stem-like cells (CSCs) by activating p38 mitogen-activated protein kinase and increasing expression of the cell cycle inhibitor, p21, and the metastasis suppressor gene, NDRG1 (N-myc downstream-regulated gene 1). This effect of BMP7 depended on BMPR2 (BMP receptor 2), and BMPR2 expression inversely correlated with recurrence and bone metastasis in prostate cancer patients. Importantly, this BMP7-induced senescence in CSCs was reversible upon withdrawal of BMP7. Furthermore, treatment of mice with BMP7 significantly suppressed the growth of CSCs in bone, whereas the withdrawal of BMP7 restarted growth of these cells. These results suggest that the BMP7-BMPR2-p38-NDRG1 axis plays a critical role in dormancy and recurrence of prostate CSCs in bone and suggest a potential therapeutic utility of BMP7 for recurrent metastatic disease.


Assuntos
Proteína Morfogenética Óssea 7/metabolismo , Neoplasias Ósseas/metabolismo , Proteínas de Neoplasias/metabolismo , Células-Tronco Neoplásicas/metabolismo , Neoplasias da Próstata/metabolismo , Animais , Receptores de Proteínas Morfogenéticas Ósseas Tipo II/biossíntese , Neoplasias Ósseas/patologia , Neoplasias Ósseas/secundário , Neoplasias Ósseas/terapia , Proteínas de Ciclo Celular/biossíntese , Inibidor de Quinase Dependente de Ciclina p27/biossíntese , Regulação Neoplásica da Expressão Gênica , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Masculino , Camundongos , Metástase Neoplásica , Transplante de Neoplasias , Células-Tronco Neoplásicas/patologia , Neoplasias da Próstata/patologia , Neoplasias da Próstata/terapia , Transplante Heterólogo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
17.
Cancer Res ; 68(18): 7613-20, 2008 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-18794150

RESUMO

RhoC is a member of the Ras-homologous family of genes which have been implicated in tumorigenesis and tumor progression. However, the exact role of RhoC is controversial and is yet to be clarified. We have examined the effect of RhoC on prostate tumor cells and found that RhoC had no effect on cell proliferation in vitro or on tumor growth in mice. However, RhoC significantly enhanced the metastatic ability of the tumor cells in these animals, suggesting that RhoC affects only the metastasis but not the growth of prostate tumor cells. The results of our immunohistochemical analyses on tumor specimens from 63 patients with prostate cancer indicate that RhoC expression had no significant correlation with Gleason grade. However, the expression of RhoC showed significant positive correlation with both lymph node and distant metastasis, and it was inversely correlated with patient survival. We also found that RhoC significantly augmented the invasion and motility of prostate tumor cells by activating matrix metalloproteinases 2 and 9 (MMP2 and MMP9) in vitro. The results of our antibody array analysis for signal molecules revealed that RhoC significantly activated kinases including mitogen-activated protein kinase (MAPK), focal adhesion kinase (FAK), Akt, and Pyk2. Inhibition of Pyk2 kinase blocked the RhoC-dependent activation of FAK, MAPK, and Akt, followed by the suppression of MMP2 and MMP9. Inhibitors of both MAPK and Akt also significantly blocked the activities of these MMPs. Therefore, our results indicate that RhoC promotes tumor metastasis in prostate cancer by sequential activation of Pyk2, FAK, MAPK, and Akt followed by the up-regulation of MMP2 and MMP9, which results in the stimulation of invasiveness of tumor cells.


Assuntos
Quinase 2 de Adesão Focal/metabolismo , Neoplasias da Próstata/metabolismo , Proteínas rho de Ligação ao GTP/metabolismo , Animais , Processos de Crescimento Celular/fisiologia , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Ativação Enzimática , Quinase 1 de Adesão Focal/metabolismo , Humanos , Masculino , Metaloproteinase 2 da Matriz/biossíntese , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 9 da Matriz/biossíntese , Metaloproteinase 9 da Matriz/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Metástase Neoplásica , Neoplasias da Próstata/enzimologia , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Ratos , Transdução de Sinais , Regulação para Cima , Proteínas rho de Ligação ao GTP/biossíntese , Proteína de Ligação a GTP rhoC
18.
Cancer Res ; 68(4): 1003-11, 2008 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-18281474

RESUMO

The fatty acid synthase (FAS) gene is significantly up-regulated in various types of cancers, and blocking the FAS expression results in apoptosis of tumor cells. Therefore, FAS is considered to be an attractive target for anticancer therapy. However, the molecular mechanism by which the FAS gene is up-regulated in tumor cells is poorly understood. We found that FAS was significantly up-regulated by hypoxia, which was also accompanied by reactive oxygen species (ROS) generation in human breast cancer cell lines. The FAS expression was also activated by H(2)O(2), whereas N-acetyl-L-cystein, a ROS inhibitor, suppressed the expression. We also found that the hypoxia significantly up-regulated sterol regulatory-element binding protein (SREBP)-1, the major transcriptional regulator of the FAS gene, via phosphorylation of Akt followed by activation of hypoxia-inducible factor 1 (HIF1). Moreover, our results of reporter assay and chromatin immunoprecipitation analysis indicate that SREBP-1 strongly bound to the SREBP binding site/E-box sequence on the FAS promoter under hypoxia. In our xenograft mouse model, FAS was strongly expressed in the hypoxic regions of the tumor. In addition, our results of immunohistochemical analysis for human breast tumor specimens indicate that the expressions of both FAS and SREBP-1 were colocalized with hypoxic regions in the tumors. Furthermore, we found that hypoxia-induced chemoresistance to cyclophosphamide was partially blocked by a combination of FAS inhibitor and cyclophosphamide. Taken together, our results indicate that FAS gene is up-regulated by hypoxia via activation of the Akt and HIF1 followed by the induction of the SREBP-1 gene, and that hypoxia-induced chemoresistance is partly due to the up-regulation of FAS.


Assuntos
Neoplasias da Mama/enzimologia , Neoplasias da Mama/genética , Ácido Graxo Sintases/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Hipóxia Celular/genética , Linhagem Celular Tumoral , Ciclofosfamida/administração & dosagem , Ciclofosfamida/farmacologia , Resistencia a Medicamentos Antineoplásicos , Ativação Enzimática , Inibidores Enzimáticos/administração & dosagem , Ácido Graxo Sintases/antagonistas & inibidores , Ácido Graxo Sintases/biossíntese , Feminino , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Fator 1 Induzível por Hipóxia/biossíntese , Fator 1 Induzível por Hipóxia/genética , Camundongos , Camundongos Nus , Espécies Reativas de Oxigênio/metabolismo , Regulação para Cima
19.
Nutr Cancer ; 43(1): 76-81, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12467138

RESUMO

Solidago virgaurea (goldenrod) has traditionally been used as an anti-inflammatory herbal medicine for the treatment of various symptoms, including prostatic diseases. The plant has also been reported to have antibacterial, spasmolytic, and carminative properties. During the course of our screening for antineoplastic activities in various herbal plants, we found that the extract of S. virgaurea exhibits strong cytotoxic activities on various tumor cell lines. The active component mostly resides in the leaves of the plant and is soluble in water. When the extract was fractionated by a Sephadex G-100 column, the active fraction corresponded to a molecular weight of approximately 40,000. This cytotoxic activity is effective on various tumor cell lines, including human prostate (PC3), breast (MDA435), melanoma (C8161), and small cell lung carcinoma (H520). To examine the effect of the cytotoxic activity on tumor cells in vivo, we used the rat prostate cell line (AT6.1) and an SCID mouse model. AT6.1 cells were injected into the flank of SCID mice, and then the G-100 fraction of S. virgaurea was administered intraperitoneally or subcutaneously every 3 days. The size of the tumor was measured for up to 25 days. The growth of the tumor was significantly suppressed by the G-100 fraction at 5 mg/kg without any apparent side effects. Therefore, S. virgaurea is considered to be promising as an antineoplastic medicine with minimal toxicities.


Assuntos
Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Modelos Animais de Doenças , Fitoterapia , Extratos Vegetais/uso terapêutico , Neoplasias da Próstata/tratamento farmacológico , Solidago , Animais , Caspase 3 , Caspases/análise , Divisão Celular/efeitos dos fármacos , Citometria de Fluxo , Masculino , Camundongos , Camundongos SCID , Células Tumorais Cultivadas/efeitos dos fármacos
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