RESUMEN
Emerging evidence suggests that gamma-tocotrienol (γ-T3), a vitamin E isomer, has potent anti-cancer properties against a wide-range of cancers. γ-T3 not only inhibited the growth and survival of cancer cells in vitro, but also suppressed angiogenesis and tumour metastasis under in vivo conditions. Recently, γ-T3 was found to target cancer stem cells (CSCs), leading to suppression of tumour formation and chemosensitisation. Despite its promising anti-cancer potential, the exact mechanisms responsible for the effects of γ-T3 are still largely unknown. Here, we report the identification of Ang-1 (Angiopoietin-1)/Tie-2 as a novel γ-T3 downstream target. In prostate cancer cells, γ-T3 treatment leads to the suppression of Ang-1 at both the mRNA transcript and protein levels. Supplementing the cells with Ang-1 was found to protect them against the anti-CSC effect of γ-T3. Intriguingly, inactivation of Tie-2, a member receptor that mediates the effect of Ang-1, was found to significantly enhance the cytotoxic effect of γ-T3 through activation of AMP-activated protein kinase (AMPK) and subsequent interruption of autophagy. Our results highlighted the therapeutic potential of using γ-T3 in combination with a Tie-2 inhibitor to treat advanced prostate cancer.
Asunto(s)
Cromanos/farmacología , Neoplasias de la Próstata/metabolismo , Transducción de Señal/efectos de los fármacos , Vitamina E/análogos & derivados , Angiopoyetina 1/genética , Angiopoyetina 1/metabolismo , Autofagia , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Regulación hacia Abajo , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Masculino , Neoplasias de la Próstata/tratamiento farmacológico , Neoplasias de la Próstata/genética , Receptor TIE-2/genética , Receptor TIE-2/metabolismo , Vitamina E/farmacologíaRESUMEN
Whether and how garlic-derived S-allylmercaptocysteine (SAMC) inhibits hepatocellular carcinoma (HCC) is largely unknown. In the current study, the role of low-density lipoprotein receptor (LDLR)-related protein 6 (LRP6) in HCC progression and the anti-HCC mechanism of SAMC was examined in clinical sample, cell model and xenograft/orthotopic mouse models. We demonstrated that SAMC inhibited cell proliferation and tumorigenesis, while induced apoptosis of human HCC cells without influencing normal hepatocytes. SAMC directly interacted with Wnt-pathway co-receptor LRP6 on the cell membrane. LRP6 was frequently over-expressed in the tumor tissue of human HCC patients (66.7% of 48 patients) and its over-expression only correlated with the over-expression of ß-catenin, but not with age, gender, tumor size, stage and metastasis. Deficiency or over-expression of LRP6 in hepatoma cells could partly mimic or counteract the anti-tumor properties of SAMC, respectively. In vivo administration of SAMC significantly suppressed the growth of Huh-7 xenograft/orthotopic HCC tumor without causing undesirable side effects. In addition, stable down-regulation of LRP6 in Huh-7 facilitated the anti-HCC effects of SAMC. In conclusion, LRP6 can be a potential therapeutic target of HCC. SAMC is a promising specific anti-tumor agent for treating HCC subtypes with Wnt activation at the hepatoma cell surface.
RESUMEN
The medicinal mushroom Trametes versicolor has been well recognized for its activity in maintaining the general health of the population and in managing and treating human diseases in various cultures. Its use has been recently gaining acceptance and popularity in Western countries. The reported health benefits of T. versicolor led to a search for the identity of its bioactive ingredients. These efforts have resulted in the isolation of the polysaccharopeptide PSP from cultured mycelia of strain Cov-1, which expresses large amounts of PSP. The availability of highly purified PSP was followed by studies of its biological activities using tissue culture models and limited human clinical trials. In this review we summarize recent advances in the antitumorigenic and immunomodulatory effects of PSP, elimination of prostate cancer stem cells and control of the intestinal microbiome, and its interplay with host cells as a prebiotic. These findings may have implications for widening and repurposing the use of PSP.
Asunto(s)
Antibacterianos/farmacología , Antineoplásicos/farmacología , Microbioma Gastrointestinal/efectos de los fármacos , Células Madre Neoplásicas/efectos de los fármacos , Proteoglicanos/farmacología , Trametes/química , Antibacterianos/química , Antineoplásicos/química , Humanos , Proteoglicanos/químicaRESUMEN
BACKGROUND: Despite the introduction of 21st-century surgical and neoadjuvant treatment modalities, survival of patients with osteosarcoma (OS) has not improved in two decades. Advances will depend in part on the development of clinically relevant and reliable animal models. This report describes the engineering and validation of a humanized tissue-engineered bone organ (hTEBO) for preclinical research on primary bone tumors in order to minimize false-positive and false-negative results due to interspecies differences in current xenograft models. METHODS: Pelvic bone and marrow fragments were harvested from patients during reaming of the acetabulum during hip arthroplasty. HTEBOs were engineered by embedding fragments in a fibrin matrix containing bone morphogenetic protein-7 (BMP-7) and implanted into NOD-scid mice. After 10 weeks of subcutaneous growth, one group of hTEBOs was harvested to analyze the degree of humanization. A second group was injected with human luciferase-labeled OS (Luc-SAOS-2) cells. Tumor growth was followed in vivo with bioluminescence imaging. After 5 weeks, the OS tumors were harvested and analyzed. They were also compared with tumors created via intratibial injection. RESULTS: After 10 weeks of in vivo growth, a new bone organ containing human bone matrix as well as viable and functional human hematopoietic cells developed. Five weeks after injection of Luc-SAOS-2 cells into this humanized bone microenvironment, spontaneous metastatic spread to the lung was evident. Relevant prognostic markers such as vascular endothelial growth factor (VEGF) and periostin were found to be positive in OS tumors grown within the humanized microenvironment but not in tumors created in murine tibial bones. Hypoxia-inducible transcription factor-2α (HIF-2α) was detected only in the humanized OS. CONCLUSIONS: We report an in vivo model that contains human bone matrix and marrow components in one organ. BMP-7 made it possible to maintain viable mesenchymal and hematopoietic stem cells and created a bone microenvironment mimicking human physiology. CLINICAL RELEVANCE: This novel platform enables preclinical research on primary bone tumors in order to test new treatment options.
Asunto(s)
Proteína Morfogenética Ósea 7/metabolismo , Neoplasias Óseas/patología , Modelos Animales de Enfermedad , Animales , Neoplasias Óseas/metabolismo , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Ratones , Ratones Endogámicos NOD , Factor A de Crecimiento Endotelial Vascular/metabolismoRESUMEN
Skeletal metastases present a major clinical challenge for prostate cancer patient care, inflicting distinctive mixed osteoblastic and osteolytic lesions that cause morbidity and refractory skeletal complications. Macrophages are abundant in bone and bone marrow and can influence both osteoblast and osteoclast function in physiology and pathology. Herein, we examined the role of macrophages in prostate cancer bone lesions, particularly the osteoblastic response. First, macrophage and lymphocyte distributions were qualitatively assessed in patient's prostate cancer skeletal lesions by immunohistochemistry. Second, macrophage functional contributions to prostate tumour growth in bone were explored using an immune-competent mouse model combined with two independent approaches to achieve in vivo macrophage depletion: liposome encapsulated clodronate that depletes phagocytic cells (including macrophages and osteoclasts); and targeted depletion of CD169(+) macrophages using a suicide gene knock-in model. Immunohistochemistry and histomorphometric analysis were performed to quantitatively assess cancer-induced bone changes. In human bone metastasis specimens, CD68(+) macrophages were consistently located within the tumour mass. Osteal macrophages (osteomacs) were associated with pathological woven bone within the metastatic lesions. In contrast, lymphocytes were inconsistently present in prostate cancer skeletal lesions and when detected, had varied distributions. In the immune-competent mouse model, CD169(+) macrophage ablation significantly inhibited prostate cancer-induced woven bone formation, suggesting that CD169(+) macrophages within pathological woven bone are integral to tumour-induced bone formation. In contrast, pan-phagocytic cell, but not targeted CD169(+) macrophage depletion resulted in increased tumour mass, indicating that CD169(-) macrophage subset(s) and/or osteoclasts influenced tumour growth. In summary, these observations indicate a prominent role for macrophages in prostate cancer bone metastasis that may be therapeutically targetable to reduce the negative skeletal impacts of this malignancy, including tumour-induced bone modelling. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Asunto(s)
Neoplasias Óseas/secundario , Macrófagos/inmunología , Neoplasias de la Próstata/inmunología , Lectina 1 Similar a Ig de Unión al Ácido Siálico/inmunología , Anciano , Anciano de 80 o más Años , Animales , Neoplasias Óseas/inmunología , Neoplasias Óseas/patología , Línea Celular Tumoral , Modelos Animales de Enfermedad , Humanos , Macrófagos/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Metástasis de la Neoplasia , Osteoblastos/inmunología , Osteoblastos/patología , Osteoclastos/inmunología , Osteoclastos/patología , Próstata/inmunología , Próstata/patología , Neoplasias de la Próstata/patología , Lectina 1 Similar a Ig de Unión al Ácido Siálico/metabolismoRESUMEN
Ample evidence supports that prostate tumor metastasis originates from a rare population of cancer cells, known as cancer stem cells (CSCs). Unfortunately, little is known about the identity of these cells, making it difficult to target the metastatic prostate tumor. Here, for the first time, we report the identification of a rare population of prostate cancer cells that express the Tie-2 protein. We found that this Tie-2High population exists mainly in prostate cancer cell lines that are capable of metastasizing to the bone. These cells not only express a higher level of CSC markers but also demonstrate enhanced resistance to the chemotherapeutic drug Cabazitaxel. In addition, knockdown of the expression of the Tie-2 ligand angiopoietin (Ang-1) led to suppression of CSC markers, suggesting that the Ang-1/Tie-2 signaling pathway functions as an autocrine loop for the maintenance of prostate CSCs. More importantly, we found that Tie-2High prostate cancer cells are more adhesive than the Tie-2Low population to both osteoblasts and endothelial cells. Moreover, only the Tie-2High, but not the Tie-2Low cells developed tumor metastasis in vivo when injected at a low number. Taken together, our data suggest that Tie-2 may play an important role during the development of prostate tumor metastasis.
Asunto(s)
Adhesión Celular , Endotelio Vascular/patología , Células Madre Neoplásicas/patología , Osteoblastos/patología , Neoplasias de la Próstata/secundario , Receptor TIE-2/metabolismo , Células del Estroma/patología , Animales , Apoptosis , Proliferación Celular , Endotelio Vascular/metabolismo , Humanos , Técnicas para Inmunoenzimas , Masculino , Ratones , Ratones Endogámicos NOD , Ratones SCID , Células Madre Neoplásicas/metabolismo , Osteoblastos/metabolismo , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/metabolismo , ARN Mensajero/genética , ARN Interferente Pequeño/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Receptor TIE-2/antagonistas & inhibidores , Receptor TIE-2/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células del Estroma/metabolismo , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Obesity has long been linked with prostate cancer progression, although the underlying mechanism is still largely unknown. Here, we report that adipocytes promote the enrichment of prostate cancer stem cells (CSCs) through a vicious cycle of autocrine amplification. In the presence of adipocytes, prostate cancer cells actively secrete the peptide hormone cholecystokinin (CCK), which not only stimulates prostate CSC self-renewal, but also induces cathepsin B (CTSB) production of the adipocytes. In return, CTSB facilitates further CCK secretion by the cancer cells. More importantly, inactivation of CCK receptor not only suppresses CTSB secretion by the adipocytes, but also synergizes the inhibitory effect of CTSB inhibitor on adipocyte-promoted prostate CSC self-renewal. In summary, we have uncovered a novel mechanism underlying the mutual interplay between adipocytes and prostate CSCs, which may help explaining the role of adipocytes in prostate cancer progression and provide opportunities for effective intervention.
Asunto(s)
Adipocitos/patología , Comunicación Autocrina , Proliferación Celular/efectos de los fármacos , Autorrenovación de las Células/efectos de los fármacos , Colecistoquinina/farmacología , Células Madre Neoplásicas/patología , Neoplasias de la Próstata/patología , Células 3T3-L1 , Adipocitos/efectos de los fármacos , Adipocitos/metabolismo , Animales , Apoptosis/efectos de los fármacos , Western Blotting , Células Cultivadas , Cromatografía Liquida , Citometría de Flujo , Humanos , Técnicas para Inmunoenzimas , Masculino , Ratones , Células Madre Neoplásicas/efectos de los fármacos , Células Madre Neoplásicas/metabolismo , Neoplasias de la Próstata/tratamiento farmacológico , Neoplasias de la Próstata/metabolismo , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Espectrometría de Masas en TándemRESUMEN
Mushroom extracts have been extensively studied for their medicinal effects. They can stimulate immune responses and thus have been explored in cancer treatment. Recently, it has also been shown that some mushroom extracts can produce direct cytotoxic effect on cancer cells. In this review, we summarize the cytotoxic effect of mushroom extracts in cancer treatment revealed by both in vitro and in vivo studies. We also summarize the current understanding of the mechanisms associated with such an effect with an emphasis on the mitochondrial apoptotic pathway. The recent finding that mushroom extracts have direct cytotoxic effects supplements their known immune stimulating effects. Thus, novel anticancer agents based on new findings from mushroom extracts may soon be added to the present pool of anticancer drugs. Specifically, we propose that nanodelivery of the bioactive compounds of mushroom extracts to mitochondria will further increase their potential treatment efficacy.
Asunto(s)
Agaricales/química , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Mitocondrias/efectos de los fármacos , Neoplasias/tratamiento farmacológico , Neoplasias/patología , Extractos Vegetales/farmacología , Humanos , Mitocondrias/patologíaRESUMEN
Infection with Human papillomaviruses (HPVs) leads to the development of a wide-range of cancers, accounting for 5% of all human cancers. A prominent example is cervical cancer, one of the leading causes of cancer death in women worldwide. It has been well established that tumor development and progression induced by HPV infection is driven by the sustained expression of two oncogenes E6 and E7. The expression of E6 and E7 not only inhibits the tumor suppressors p53 and Rb, but also alters additional signalling pathways that may be equally important for transformation. Among these pathways, the phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signalling cascade plays a very important role in HPV-induced carcinogenesis by acting through multiple cellular and molecular events. In this review, we summarize the frequent amplification of PI3K/Akt/mTOR signals in HPV-induced cancers and discuss how HPV oncogenes E6/E7/E5 activate the PI3K/Akt/mTOR signalling pathway to modulate tumor initiation and progression and affect patient outcome. Improvement of our understanding of the mechanism by which the PI3K/Akt/mTOR signalling pathway contributes to the immortalization and carcinogenesis of HPV-transduced cells will assist in devising novel strategies for preventing and treating HPV-induced cancers.
Asunto(s)
Neoplasias/etiología , Neoplasias/metabolismo , Papillomaviridae/fisiología , Infecciones por Papillomavirus/complicaciones , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal , Serina-Treonina Quinasas TOR/metabolismo , Animales , Proteínas de la Ataxia Telangiectasia Mutada/metabolismo , Transformación Celular Viral , Humanos , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Estadios del Ciclo de Vida , Infecciones por Papillomavirus/virología , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismoRESUMEN
AIM: To evaluate the potential of newly-developed, biocompatible iron oxide magnetic nanoparticles (MNPs) conjugated with J591, an antibody to an extracellular epitope of PSMA, to enhance MRI of prostate cancer. MATERIALS & METHODS: Specific binding to PSMA by J591-MNP was investigated in vitro. MRI studies were performed on orthotopic tumor-bearing NOD.SCID mice 2 h and 24 h after intravenous injection of J591-MNPs, or non-targeting MNPs. RESULTS & CONCLUSION: In vitro, MNPs did not affect prostate cancer cell viability, and conjugation to J591 did not compromise antibody specificity and enhanced cellular iron uptake. Magnetic resonance contrast of tumors was increased in vivo using PSMA-targeting MNPs, but not by non-targeting MNPs. This provides proof-of-concept that PSMA-targeting MNPs have potential to enhance magnetic resonance detection/localization of prostate cancer.
Asunto(s)
Antígenos de Superficie/análisis , Medios de Contraste , Compuestos Férricos , Glutamato Carboxipeptidasa II/análisis , Nanopartículas de Magnetita , Neoplasias de la Próstata/diagnóstico , Animales , Línea Celular Tumoral , Humanos , Imagen por Resonancia Magnética , Masculino , Ratones Endogámicos NOD , Ratones SCID , Próstata/patologíaRESUMEN
BACKGROUND: Prostate cancer (PCa) frequently relapses after hormone ablation therapy. Unfortunately, once progressed to the castration resistant stage, the disease is regarded as incurable as prostate cancer cells are highly resistant to conventional chemotherapy. METHOD: We recently reported that the two natural compounds polysaccharopeptide (PSP) and Gamma-tocotrienols (γ-T3) possessed potent anti-cancer activities through targeting of CSCs. In the present study, using both prostate cancer cell line and xenograft models, we seek to investigate the therapeutic potential of combining γ-T3 and PSP in the treatment of prostate cancer. RESULT: We showed that in the presence of PSP, γ-T3 treatment induce a drastic activation of AMP-activated protein kinase (AMPK). This was accompanied with inactivation of acetyl-CoA carboxylase (ACC), as evidenced by the increased phosphorylation levels at Ser 79. In addition, PSP treatment also sensitized cancer cells toward γ-T3-induced cytotoxicity. Furthermore, we demonstrated for the first time that combination of PSP and γ-T3 treaments significantly reduced the growth of prostate tumor in vivo. CONCLUSION: Our results indicate that PSP and γ-T3 treaments may have synergistic anti-cancer effect in vitro and in vivo, which warrants further investigation as a potential combination therapy for the treatment of cancer.
Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Antineoplásicos/administración & dosificación , Cromanos/administración & dosificación , Neoplasias de la Próstata/tratamiento farmacológico , Neoplasias de la Próstata/enzimología , Proteoglicanos/administración & dosificación , Vitamina E/análogos & derivados , Proteínas Quinasas Activadas por AMP/genética , Animales , Línea Celular , Sinergismo Farmacológico , Activación Enzimática , Humanos , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Fosforilación/efectos de los fármacos , Neoplasias de la Próstata/genética , Vitamina E/administración & dosificaciónRESUMEN
The phosphatidylinositol-3-kinase (PI3K)/Akt/mTOR pathway is one of the most frequently activated signaling pathways in prostate cancer cells, and loss of the tumor suppressor PTEN and amplification of PIK3CA are the two most commonly detected mechanisms for the activation of these pathways. Aberrant activation of PI3K/Akt/mTOR has been implicated not only in the survival and metastasis of prostate cancer cells but also in the development of drug resistance. As such, selective inactivation of this pathway may provide opportunities to attack prostate cancer from all fronts. However, while preclinical studies examining specific inhibitors of PI3K or mTOR have yielded promising results, the evidence from clinical trials is less convincing. Emerging evidence from the analyses of some solid tumors suggests that a class of dual PI3K/mTOR inhibitors, which bind to and inactivate both PI3K and mTOR, may achieve better anti-cancer outcomes. In this review, we will summarize the mechanisms of action of these inhibitors, their effectiveness when used alone or in combination with other chemotherapeutic compounds, and their potential to serve as the next generation therapies for prostate cancer patients, particularly those who are resistant to the frontline chemotherapeutic drugs.
Asunto(s)
Resistencia a Antineoplásicos , Inhibidores de las Quinasa Fosfoinosítidos-3 , Neoplasias de la Próstata/tratamiento farmacológico , Transducción de Señal/efectos de los fármacos , Serina-Treonina Quinasas TOR/antagonistas & inhibidores , Animales , Humanos , Masculino , Neoplasias de la Próstata/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismoRESUMEN
The development of effective therapeutic strategies against prostate cancer bone metastases has been impeded by the lack of adequate animal models that are able to recapitulate the biology of the disease in humans. Bioengineered approaches allow researchers to create sophisticated experimentally and physiologically relevant in vivo models to study interactions between cancer cells and their microenvironment under reproducible conditions. The aim of this study was to engineer a morphologically and functionally intact humanized organ bone which can serve as a homing site for human prostate cancer cells. Transplantation of biodegradable tubular composite scaffolds seeded with human mesenchymal progenitor cells and loaded with rhBMP-7 resulted in the development of a chimeric bone construct including a large number of human mesenchymal cells which were shown to be metabolically active and capable of producing extracellular matrix components. Micro-CT analysis demonstrated that the newly formed ossicle recapitulated the morphological features of a physiological organ bone with a trabecular network surrounded by a cortex-like outer structure. This microenvironment was supportive of the lodgement and maintenance of murine haematopoietic cell clusters, thus mimicking a functional organ bone. Bioluminescence imaging demonstrated that luciferase-transduced human PC3 cells reproducibly homed to the humanized tissue engineered bone constructs, proliferated, and developed macro-metastases. This model allows the analysis of interactions between human prostate cancer cells and a functional humanized bone organ within an immuno-incompetent murine host. The system can serve as a reproducible platform to study effects of therapeutics against prostate cancer bone metastases within a humanized microenvironment.
Asunto(s)
Neoplasias Óseas/secundario , Neoplasias de la Próstata/complicaciones , Ingeniería de Tejidos , Regulación Neoplásica de la Expresión Génica , Humanos , Inmunohistoquímica , Masculino , Microtomografía por Rayos XRESUMEN
Mitotic progression of mammalian cells is tightly regulated by the E3 ubiquitin ligase anaphase promoting complex (APC)/C. Deregulation of APC/C is frequently observed in cancer cells and is suggested to contribute to chromosome instability and cancer predisposition. In this study, we identified Daxx as a novel APC/C inhibitor frequently overexpressed in prostate cancer. Daxx interacts with the APC/C coactivators Cdc20 and Cdh1 in vivo, with the binding of Cdc20 dependent on the consensus destruction boxes near the N-terminal of the Daxx protein. Ectopic expression of Daxx, but not the D-box deleted mutant (DaxxΔD-box), inhibited the degradation of APC/Cdc20 and APC/Cdh1 substrates, leading to a transient delay in mitotic progression. Daxx is frequently upregulated in prostate cancer tissues; the expression level positively correlated with the Gleason score and disease metastasis (P = 0.027 and 0.032, respectively). Furthermore, ectopic expression of Daxx in a non-malignant prostate epithelial cell line induced polyploidy under mitotic stress. Our data suggest that Daxx may function as a novel APC/C inhibitor, which promotes chromosome instability during prostate cancer development.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteína de la Poliposis Adenomatosa del Colon/antagonistas & inhibidores , Cadherinas/metabolismo , Proteínas de Ciclo Celular/metabolismo , Inestabilidad Cromosómica , Mitosis , Proteínas Nucleares/metabolismo , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Proteína de la Poliposis Adenomatosa del Colon/metabolismo , Antígenos CD , Proteínas Cdc20 , Ciclo Celular , Puntos de Control del Ciclo Celular , Proteínas de Ciclo Celular/genética , Línea Celular Tumoral , Proteínas Co-Represoras , Células HEK293 , Células HeLa , Humanos , Masculino , Chaperonas Moleculares , Mutación , Clasificación del Tumor , Metástasis de la Neoplasia , Proteínas Nucleares/genética , Interferencia de ARN , ARN Interferente PequeñoRESUMEN
The ATM/ATR DNA damage checkpoint functions in the maintenance of genetic stability and some missense variants of the ATM gene have been shown to confer a moderate increased risk of prostate cancer. However, whether inactivation of this checkpoint contributes directly to prostate specific cancer predisposition is still unknown. Here, we show that exposure of non-malignant prostate epithelial cells (HPr-1AR) to androgen led to activation of the ATM/ATR DNA damage response and induction of cellular senescence. Notably, knockdown of the ATM gene expression in HPr-1AR cells can promote androgen-induced TMPRSS2: ERG rearrangement, a prostate-specific chromosome translocation frequently found in prostate cancer cells. Intriguingly, unlike the non-malignant prostate epithelial cells, the ATM/ATR DNA damage checkpoint appears to be defective in prostate cancer cells, since androgen treatment only induced a partial activation of the DNA damage response. This mechanism appears to preserve androgen induced autophosphorylation of ATM and phosphorylation of H2AX, lesion processing and repair pathway yet restrain ATM/CHK1/CHK2 and p53 signaling pathway. Our findings demonstrate that ATM/ATR inactivation is a crucial step in promoting androgen-induced genomic instability and prostate carcinogenesis.
Asunto(s)
Andrógenos/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas de Unión al ADN/metabolismo , Células Epiteliales/citología , Regulación Neoplásica de la Expresión Génica , Próstata/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Proteínas de la Ataxia Telangiectasia Mutada , Línea Celular Tumoral , Aberraciones Cromosómicas , Daño del ADN , Reparación del ADN , Inestabilidad Genómica , Humanos , Masculino , Fosforilación , Neoplasias de la Próstata , Transfección , Translocación Genética , Fosfatasas cdc25/metabolismoRESUMEN
PURPOSE: To study the protective effects and underlying molecular mechanisms of SAMC on carbon tetrachloride (CCl4)-induced acute hepatotoxicity in the mouse model. METHODS: Mice were intraperitoneally injected with CCl4 (50 µl/kg; single dose) to induce acute hepatotoxicity with or without a 2-h pre-treatment of SAMC intraperitoneal injection (200 mg/kg; single dose). After 8 h, the blood serum and liver samples of mice were collected and subjected to measurements of histological and molecular parameters of hepatotoxicity. RESULTS: SAMC reduced CCl4-triggered cellular necrosis and inflammation in the liver under histological analysis. Since co-treatment of SAMC and CCl4 enhanced the expressions of antioxidant enzymes, reduced the nitric oxide (NO)-dependent oxidative stress, and inhibited lipid peroxidation induced by CCl4. SAMC played an essential antioxidative role during CCl4-induced hepatotoxicity. Administration of SAMC also ameliorated hepatic inflammation induced by CCl4 via inhibiting the activity of NF-κB subunits p50 and p65, thus reducing the expressions of pro-inflammatory cytokines, mediators, and chemokines, as well as promoting pro-regenerative factors at both transcriptional and translational levels. CONCLUSIONS: Our results indicate that SAMC mitigates cellular damage, oxidative stress, and inflammation in CCl4-induced acute hepatotoxicity mouse model through regulation of NF-κB. Garlic or garlic derivatives may therefore be a potential food supplement in the prevention of liver damage.
Asunto(s)
Tetracloruro de Carbono/toxicidad , Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Cisteína/análogos & derivados , Inflamación/prevención & control , FN-kappa B/metabolismo , Estrés Oxidativo/efectos de los fármacos , Alanina Transaminasa/sangre , Animales , Antioxidantes/farmacología , Cisteína/farmacología , Femenino , Inflamación/inducido químicamente , Inflamación/patología , Peroxidación de Lípido/efectos de los fármacos , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Malondialdehído/sangre , Ratones , Ratones Endogámicos C57BL , Óxido Nítrico/metabolismoRESUMEN
Recent evidence suggested that prostate cancer stem/progenitor cells (CSC) are responsible for cancer initiation as well as disease progression. Unfortunately, conventional therapies are only effective in targeting the more differentiated cancer cells and spare the CSCs. Here, we report that PSP, an active component extracted from the mushroom Turkey tail (also known as Coriolus versicolor), is effective in targeting prostate CSCs. We found that treatment of the prostate cancer cell line PC-3 with PSP led to the down-regulation of CSC markers (CD133 and CD44) in a time and dose-dependent manner. Meanwhile, PSP treatment not only suppressed the ability of PC-3 cells to form prostaspheres under non-adherent culture conditions, but also inhibited their tumorigenicity in vivo, further proving that PSP can suppress prostate CSC properties. To investigate if the anti-CSC effect of PSP may lead to prostate cancer chemoprevention, transgenic mice (TgMAP) that spontaneously develop prostate tumors were orally fed with PSP for 20 weeks. Whereas 100% of the mice that fed with water only developed prostate tumors at the end of experiment, no tumors could be found in any of the mice fed with PSP, suggesting that PSP treatment can completely inhibit prostate tumor formation. Our results not only demonstrated the intriguing anti-CSC effect of PSP, but also revealed, for the first time, the surprising chemopreventive property of oral PSP consumption against prostate cancer.
Asunto(s)
Quimioprevención/métodos , Sistemas de Liberación de Medicamentos/métodos , Células Madre Neoplásicas/efectos de los fármacos , Neoplasias de la Próstata/tratamiento farmacológico , Neoplasias de la Próstata/prevención & control , Proteoglicanos/farmacología , Animales , Humanos , Masculino , Ratones , Ratones Transgénicos , Neoplasias de la Próstata/patología , Proteoglicanos/uso terapéutico , Resultado del TratamientoRESUMEN
Hepatocellular carcinoma (HCC) is a highly malignant tumor with a poor prognosis. Treatment of HCC is complicated by the fact that the disease is often diagnosed at an advanced stage when it is no longer amenable to curative surgery, and current systemic chemotherapeutics are mostly inefficacious. Sirtuin 1 (SIRT1) is a class III histone deacetylase that is implicated in gene regulations and stress resistance. In this study, we found that SIRT1 is essential for the tumorigenesis of HCC. We showed that although SIRT1 was expressed at very low levels in normal livers, it was overexpressed in HCC cell lines and in a subset of HCC. Tissue microarray analysis of HCC and adjacent nontumoral liver tissues revealed a positive correlation between the expression levels of SIRT1 and advancement in tumor grades. Downregulation of SIRT1 consistently suppressed the proliferation of HCC cells via the induction of cellular senescence or apoptosis. SIRT1 silencing also caused telomere dysfunction-induced foci and nuclear abnormality that were clearly associated with reduced expressions of telomerase reverse transcriptase (TERT), and PTOP, which is a member of the shelter in complex. Ectopic expression of either TERT or PTOP in SIRT1-depleted cells significantly restored cell proliferation. There was also a positive correlation between the level of induction of SIRT1 and TERT [corrected] in human HCC. Finally, SIRT1-silencing sensitized HCC cells to doxorubicin treatment. Together, our findings reveal a novel function for SIRT1 in telomere maintenance of HCC, and they rationalize the clinical exploration of SIRT1 inhibitors for HCC therapy.
Asunto(s)
Carcinoma Hepatocelular/patología , Proliferación Celular , Regulación Neoplásica de la Expresión Génica , Neoplasias Hepáticas/patología , Sirtuina 1/fisiología , Telómero , Apoptosis , Carcinoma Hepatocelular/genética , Línea Celular Tumoral , Senescencia Celular , Doxorrubicina/farmacología , Humanos , Inmunohistoquímica , Neoplasias Hepáticas/genética , Complejo Shelterina , Sirtuina 1/análisis , Telomerasa/análisis , Telomerasa/fisiología , Proteínas de Unión a Telómeros/análisis , Proteínas de Unión a Telómeros/fisiología , Proteína p53 Supresora de Tumor/fisiología , Regulación hacia ArribaRESUMEN
Studies have shown that the expression of inhibitor of differentiation (Id-1) is increased in bladder cancer and is associated with drug resistance. S-allylmercaptocysteine (SAMC), a water-soluble component of garlic, is known to have a potent therapeutic effect on human cancer. The aim of this study was to investigate whether Id-1 expression mediates SAMC-induced cell death in bladder cancer cells. After generating stable Id-1-expressing and si-Id-1 transfectants in various bladder cancer cell lines, cell sensitivity to SAMC was compared by colony formation and MTT assays. The results indicated that Id-1 overexpression reduced the positive effect of SAMC on cell survival, while the inactivation of Id-1 increased cellular susceptibility to SAMC. Using DAPI staining, the apoptosis of bladder cancer cells induced by SAMC was shown to be negatively regulated by Id-1 expression. The expression of apoptosis-related proteins analyzed by Western blotting further supported the negative role of Id-1 in SAMC-induced apoptosis. Furthermore, by wound closure and type I collagen invasion assays, the inhibitory effect of SAMC on the invasion and migration of bladder cancer cells was found to be associated with the down-regulation of Id-1. Our results demonstrated that SAMC-induced apoptosis is associated with the Id-1 pathway, and that the inactivation of Id-1 enhances the ability of SAMC to inhibit the survival, invasion and migration of bladder cancer cells. These findings may lead to the development of novel therapeutic strategies for the treatment of bladder cancer.
Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Cisteína/análogos & derivados , Ajo/química , Proteína 1 Inhibidora de la Diferenciación/metabolismo , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Muerte Celular/efectos de los fármacos , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Cisteína/farmacología , Regulación Neoplásica de la Expresión Génica , Humanos , Proteína 1 Inhibidora de la Diferenciación/genética , Neoplasias de la Vejiga Urinaria/genéticaRESUMEN
Expression of microRNA genes is profoundly altered in cancer but their role in the development of androgen-independent prostate cancer has received limited attention as yet. In this study, we report a functional impact in prostate cancer cells for overexpression of the microRNA miR-616, which occurred consistently in cells that were androgen-independent (AI) versus androgen-dependent (AD). miR-616 overexpression was confirmed in malignant prostate tissues as opposed to benign prostate specimens. Stable miR-616 overexpression in LNCaP cells by a lentiviral-based approach stimulated AI prostate cancer cell proliferation in vitro whereas concomitantly reducing androgen-induced cell growth. More importantly, miR-616 overexpressing LNCaP cells overcame castration resistance as shown by an enhanced ability to proliferate in vivo after bilateral orchiectomy. Conversely, antagonizing miR-616 in AI prostate cancer cells yielded opposite effects. Microarray profiling and bioinformatics analysis identified the tissue factor pathway inhibitor TFPI-2 mRNA as a candidate downstream target of miR-616. In support of this candidacy, we documented interactions between miR-616 and the 3'UTR of TFPI-2 and determined TFPI-2 expression to be inversely correlated to miR-616 in a series of prostate cell lines and clinical specimens. Notably, reexpression of TFPI-2 in LNCaP cells with stable miR-616 overexpression rescued the AD phenotype, as shown by a restoration of androgen dependence and cell growth inhibition. Taken together, our findings define a functional involvement for miR-616 and TFPI-2 in the development and maintenance of androgen-independent prostate cancer.