RESUMEN
BACKGROUND: Castration-resistant prostate cancer (PCa) represents a serious health challenge. Based on mechanistically-supported rationale we explored new therapeutic options based on clinically available drugs with anticancer effects, including inhibitors of PARP1 enzyme (PARPi), and histone deacetylases (vorinostat), respectively, and disulfiram (DSF, known as alcohol-abuse drug Antabuse) and its copper-chelating metabolite CuET that inhibit protein turnover. METHODS: Drugs and their combination with ionizing radiation (IR) were tested in various cytotoxicity assays in three human PCa cell lines including radio-resistant stem-cell like derived cells. Mechanistically, DNA damage repair, heat shock and unfolded protein response (UPR) pathways were assessed by immunofluorescence and immunoblotting. RESULTS: We observed enhanced sensitivity to PARPi/IR in PC3 cells consistent with lower homologous recombination (HR) repair. Vorinostat sensitized DU145 cells to PARPi/IR and decreased mutant p53. Vorinostat also impaired HR-mediated DNA repair, as determined by Rad51 foci formation and downregulation of TOPBP1 protein, and overcame radio-resistance of stem-cell like DU145-derived cells. All PCa models responded well to CuET or DSF combined with copper. We demonstrated that DSF interacts with copper in the culture media and forms adequate levels of CuET indicating that DSF/copper and CuET may be considered as comparable treatments. Both DSF/copper and CuET evoked hallmarks of UPR in PCa cells, documented by upregulation of ATF4, CHOP and phospho-eIF2α, with ensuing heat shock response encompassing activation of HSF1 and HSP70. Further enhancing the cytotoxicity of CuET, combination with an inhibitor of the anti-apoptotic protein survivin (YM155, currently undergoing clinical trials) promoted the UPR-induced toxicity, yielding synergistic effects of CuET and YM155. CONCLUSIONS: We propose that targeting genotoxic and proteotoxic stress responses by combinations of available drugs could inspire innovative strategies to treat castration-resistant PCa.
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Disulfiram/uso terapéutico , Inhibidores de Poli(ADP-Ribosa) Polimerasas/uso terapéutico , Neoplasias de la Próstata/tratamiento farmacológico , Vorinostat/uso terapéutico , Línea Celular Tumoral , Reparación del ADN/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Masculino , Terapia Molecular Dirigida/métodos , Células PC-3 , Fosfohidrolasa PTEN/genética , Tolerancia a Radiación , Reparación del ADN por Recombinación/efectos de los fármacos , Estrés Fisiológico/efectos de los fármacos , Estrés Fisiológico/genética , Proteína p53 Supresora de Tumor/genéticaAsunto(s)
Proteínas de la Ataxia Telangiectasia Mutada/metabolismo , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/metabolismo , Daño del ADN , Regulación hacia Abajo , Leucemia Linfocítica Crónica de Células B/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Adulto , Anciano , Proteínas de la Ataxia Telangiectasia Mutada/genética , Western Blotting , Ciclo Celular/genética , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/genética , Citometría de Flujo , Humanos , Leucemia Linfocítica Crónica de Células B/genética , Mutación , Transducción de Señal/genética , Proteína p53 Supresora de Tumor/genéticaRESUMEN
BACKGROUND: Small leucine rich proteoglycans (SLRPs), major non-collagen components of the extracellular matrix (ECM), have multiple biological roles with diverse effects. Asporin, a member of the SLRPs class I, competes with other molecules in binding to collagen and affects its mineralization. Its role in cancer is only now being elucidated. METHODS: The PubMed online database was used to search relevant reviews and original articles. Furthermore, altered asporin expression was analysed in publicly available genome-wide expression data at the Gene Expression Omnibus database. RESULTS: Polymorphisms in the N-terminal polyaspartate domain, which binds calcium, are associated with osteoarthritis and prostate cancer. Asporin also promotes the progression of scirrhous gastric cancer where it is required for coordinated invasion by cancer associated fibroblasts and cancer cells. Besides the enhanced expression of asporin observed in multiple cancer types, such as breast, prostate, gastric, pancreas and colon cancer, tumour suppressive effects of asporin were described in triple-negative breast cancer. We also discuss a number of factors modulating asporin expression in different cell types relevant for alterations toing the tumour microenvironment. CONCLUSION: The apparent contradicting tumour promoting and suppressive effects of asporin require further investigation. Deciphering the role of asporin and other SLRPs in tumour-stroma interactions is needed for a better understanding of cancer progression and potentially also for novel tumour microenvironment based therapies.
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Proteínas de la Matriz Extracelular/fisiología , Neoplasias/etiología , Microambiente Tumoral/fisiología , Tejido Adiposo/fisiología , Progresión de la Enfermedad , Proteínas de la Matriz Extracelular/genética , Proteínas de la Matriz Extracelular/metabolismo , Femenino , Humanos , Masculino , MicroARNs/fisiología , Neoplasias/genética , Polimorfismo Genético/genética , Microambiente Tumoral/genéticaRESUMEN
Asporin has been reported as a tumor suppressor in breast cancer, while asporin-activated invasion has been described in gastric cancer. According to our in silico search, high asporin expresion associates with significantly better relapse free survival (RFS) in patients with low-grade tumors but RFS is significantly worse in patients with grade 3 tumors. In line with other studies, we have confirmed asporin expression by RNA scope in situ hybridization in cancer associated fibroblasts. We have also found asporin expression in the Hs578T breast cancer cell line which we confirmed by quantitative RT-PCR and western blotting. From multiple testing, we found that asporin can be downregulated by bone morphogenetic protein 4 while upregulation may be facilited by serum-free cultivation or by three dimensional growth in stiff Alvetex scaffold. Downregulation by shRNA inhibited invasion of Hs578T as well as of CAFs and T47D cells. Invasion of asporin-negative MDA-MB-231 and BT549 breast cancer cells through collagen type I was enhanced by recombinant asporin. Besides other investigations, large scale analysis of aspartic acid repeat polymorphism will be needed for clarification of the asporin dual role in progression of breast cancer.
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Neoplasias de la Mama/patología , Proteínas de la Matriz Extracelular/metabolismo , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/mortalidad , Supervivencia sin Enfermedad , Femenino , Fibroblastos/metabolismo , Fibroblastos/patología , Humanos , Estimación de Kaplan-Meier , Pronóstico , Microambiente Tumoral/fisiologíaRESUMEN
Tumors are not merely masses of neoplastic cells but complex tissues composed of cellular and noncellular elements. This review provides recent data on the main components of a dynamic system, such as carcinoma associated fibroblasts that change the extracellular matrix (ECM) topology, induce stemness and promote metastasis-initiating cells. Altered production and characteristics of collagen, hyaluronan and other ECM proteins induce increased matrix stiffness. Stiffness along with tumor growth-induced solid stress and increased interstitial fluid pressure contribute to tumor progression and therapy resistance. Second, the role of immune cells, cytokines and chemokines is outlined. We discuss other noncellular characteristics of the tumor microenvironment such as hypoxia and extracellular pH in relation to neoangiogenesis. Overall, full understanding of the events driving the interactions between tumor cells and their environment is of crucial importance in overcoming treatment resistance and improving patient outcome.
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Impaired DNA damage response pathways may create vulnerabilities of cancer cells that can be exploited therapeutically. One such selective vulnerability is the sensitivity of BRCA1- or BRCA2-defective tumors (hence defective in DNA repair by homologous recombination, HR) to inhibitors of the poly(ADP-ribose) polymerase-1 (PARP-1), an enzyme critical for repair pathways alternative to HR. While promising, treatment with PARP-1 inhibitors (PARP-1i) faces some hurdles, including (1) acquired resistance, (2) search for other sensitizing, non-BRCA1/2 cancer defects and (3) lack of biomarkers to predict response to PARP-1i. Here we addressed these issues using PARP-1i on 20 human cell lines from carcinomas of the breast, prostate, colon, pancreas and ovary. Aberrations of the Mre11-Rad50-Nbs1 (MRN) complex sensitized cancer cells to PARP-1i, while p53 status was less predictive, even in response to PARP-1i combinations with camptothecin or ionizing radiation. Furthermore, monitoring PARsylation and Rad51 foci formation as surrogate markers for PARP activity and HR, respectively, supported their candidacy for biomarkers of PARP-1i responses. As to resistance mechanisms, we confirmed the role of the multidrug resistance efflux transporters and its reversibility. More importantly, we demonstrated that shRNA lentivirus-mediated depletion of 53BP1 in human BRCA1-mutant breast cancer cells increased their resistance to PARP-1i. Given the preferential loss of 53BP1 in BRCA-defective and triple-negative breast carcinomas, our findings warrant assessment of 53BP1 among candidate predictive biomarkers of response to PARPi. Overall, this study helps characterize genetic and functional determinants of cellular responses to PARP-1i and contributes to the search for biomarkers to exploit PARP inhibitors in cancer therapy.
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Biomarcadores de Tumor/genética , Carcinoma/tratamiento farmacológico , Resistencia a Antineoplásicos/genética , Regulación Neoplásica de la Expresión Génica , Péptidos y Proteínas de Señalización Intracelular/genética , Neoplasias/tratamiento farmacológico , Poli(ADP-Ribosa) Polimerasas/genética , Ácido Anhídrido Hidrolasas , Antineoplásicos/farmacología , Proteína BRCA1/genética , Proteína BRCA1/metabolismo , Proteína BRCA2/genética , Proteína BRCA2/metabolismo , Biomarcadores de Tumor/metabolismo , Camptotecina/farmacología , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Línea Celular Tumoral , Daño del ADN , Enzimas Reparadoras del ADN/genética , Enzimas Reparadoras del ADN/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Inhibidores Enzimáticos/farmacología , Femenino , Rayos gamma/uso terapéutico , Genes MDR , Humanos , Péptidos y Proteínas de Señalización Intracelular/antagonistas & inhibidores , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteína Homóloga de MRE11 , Masculino , Neoplasias/genética , Neoplasias/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Poli(ADP-Ribosa) Polimerasa-1 , Inhibidores de Poli(ADP-Ribosa) Polimerasas , Poli(ADP-Ribosa) Polimerasas/metabolismo , Reparación del ADN por Recombinación/efectos de los fármacos , Reparación del ADN por Recombinación/efectos de la radiación , Proteína 1 de Unión al Supresor Tumoral P53RESUMEN
BACKGROUND: The Wnt signaling pathway is crucial for cell fate decisions, stem cell renewal, regulation of cell proliferation and differentiation. Deregulated Wnt signaling is also implicated in a number of hereditary and degenerative diseases and cancer. METHODS AND RESULTS: This review highlights the role of the Wnt pathway in the regulation of stem/progenitor cell renewal and prostate gland development and how this signaling is altered in prostate cancer. Recent evidence suggests that Wnt signaling regulates androgen activity in prostate cancer cells, enhances androgen receptor expression and promotes the growth of prostate cancer even after androgen ablation therapy. There is also strong evidence that Wnt signaling is enhanced in androgen-ablation resistant tumors and bone metastases. CONCLUSIONS: Further study of the modulators of this pathway will be of therapeutic relevance as inhibition of Wnt signaling may have the potential to reduce the self-renewal and aggressive behaviour of prostate cancer while Wnt signaling activation might enhance stem cell activity when tissue regeneration is required.