RESUMEN
BACKGROUND: Breast cancer (BC) is highly heterogeneous with ~ 60-70% of estrogen receptor positive BC patient's response to anti-hormone therapy. Estrogen receptors (ERs) play an important role in breast cancer progression and treatment. Estrogen related receptors (ERRs) are a group of nuclear receptors which belong to orphan nuclear receptors, which have sequence homology with ERs and share target genes. Here, we investigated the possible role and clinicopathological importance of ERRß in breast cancer. METHODS: Estrogen related receptor ß (ERRß) expression was examined using tissue microarray slides (TMA) of Breast Carcinoma patients with adjacent normal by immunohistochemistry and in breast cancer cell lines. In order to investigate whether ERRß is a direct target of ERα, we investigated the expression of ERRß in short hairpin ribonucleic acid knockdown of ERα breast cancer cells by western blot, qRT-PCR and RT-PCR. We further confirmed the binding of ERα by electrophoretic mobility shift assay (EMSA), chromatin immunoprecipitation (ChIP), Re-ChIP and luciferase assays. Fluorescence-activated cell sorting analysis (FACS) was performed to elucidate the role of ERRß in cell cycle regulation. A Kaplan-Meier Survival analysis of GEO dataset was performed to correlate the expression of ERRß with survival in breast cancer patients. RESULTS: Tissue microarray (TMA) analysis showed that ERRß is significantly down-regulated in breast carcinoma tissue samples compared to adjacent normal. ER + ve breast tumors and cell lines showed a significant expression of ERRß compared to ER-ve tumors and cell lines. Estrogen treatment significantly induced the expression of ERRß and it was ERα dependent. Mechanistic analyses indicate that ERα directly targets ERRß through estrogen response element and ERRß also mediates cell cycle regulation through p18, p21cip and cyclin D1 in breast cancer cells. Our results also showed the up-regulation of ERRß promoter activity in ectopically co-expressed ERα and ERRß breast cancer cell lines. Fluorescence-activated cell sorting analysis (FACS) showed increased G0/G1 phase cell population in ERRß overexpressed MCF7 cells. Furthermore, ERRß expression was inversely correlated with overall survival in breast cancer. Collectively our results suggest cell cycle and tumor suppressor role of ERRß in breast cancer cells which provide a potential avenue to target ERRß signaling pathway in breast cancer. CONCLUSION: Our results indicate that ERRß is a negative regulator of cell cycle and a possible tumor suppressor in breast cancer. ERRß could be therapeutic target for the treatment of breast cancer.
Asunto(s)
Neoplasias de la Mama/patología , Receptor alfa de Estrógeno/metabolismo , Regulación Neoplásica de la Expresión Génica , Receptores de Estrógenos/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Mama/patología , Neoplasias de la Mama/genética , Neoplasias de la Mama/mortalidad , Proliferación Celular/genética , Conjuntos de Datos como Asunto , Receptor alfa de Estrógeno/genética , Femenino , Puntos de Control de la Fase G1 del Ciclo Celular/genética , Técnicas de Silenciamiento del Gen , Humanos , Estimación de Kaplan-Meier , Células MCF-7 , ARN Interferente Pequeño/metabolismo , Transducción de Señal/genética , Análisis de Matrices Tisulares , Regulación hacia ArribaRESUMEN
Acetaminophen (N-acetyl-para-aminophenol (APAP)) toxicity causes acute liver failure by inducing centrilobular hepatic damage as a consequence of mitochondrial oxidative stress. Sterile inflammation, triggered by hepatic damage, facilitates gut bacterial translocation leading to systemic inflammation; TLR4-mediated activation by LPS has been shown to have a critical role in APAP-mediated hepatotoxicity. In this study, we demonstrate significant protection mediated by chitohexaose (Chtx) in mice challenged with a lethal dose of APAP (400 mg/kg b.w.). Decreased mortality by Chtx was associated with reduced hepatic damage, increased peritoneal migration of neutrophils, decreased mRNA expression of IL-1ß as well as inhibition of inflammasome activation in liver. Further, an alternate mouse model of co-administration of a sublethal doses of APAP (200 mg/kg b.w.) and LPS (5 mg/kg b.w.) operating synergistically and mediating complete mortality was developed. Overwhelming inflammation, characterized by increased inflammatory cytokines (TNF-α, IL-1ß and so on) in liver as well as in circulation and mortality was demonstrable in this model. Also, Chtx administration mediated significant reversal of mortality in APAP+LPS co-administered mice, which was associated with reduced IL-1ß in liver and plasma cytokines in this model. In conclusion, Chtx being a small molecular weight linear carbohydrate offers promise for clinical management of liver failure associated with APAP overdose.
Asunto(s)
Acetaminofén/toxicidad , Antiinflamatorios no Esteroideos/farmacología , Enfermedad Hepática Inducida por Sustancias y Drogas/prevención & control , Hepatitis Animal/prevención & control , Hígado/efectos de los fármacos , Oligosacáridos/farmacología , Acetaminofén/antagonistas & inhibidores , Animales , Enfermedad Hepática Inducida por Sustancias y Drogas/genética , Enfermedad Hepática Inducida por Sustancias y Drogas/mortalidad , Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Modelos Animales de Enfermedad , Esquema de Medicación , Regulación de la Expresión Génica , Hepatitis Animal/inducido químicamente , Hepatitis Animal/genética , Hepatitis Animal/mortalidad , Inyecciones Intraperitoneales , Interleucina-1beta/antagonistas & inhibidores , Interleucina-1beta/genética , Interleucina-1beta/inmunología , Lipopolisacáridos/antagonistas & inhibidores , Lipopolisacáridos/toxicidad , Hígado/metabolismo , Hígado/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Infiltración Neutrófila/efectos de los fármacos , Análisis de Supervivencia , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/inmunologíaRESUMEN
Tumor suppressor p53 is a critical player in the fight against cancer as it controls the cell cycle check point, apoptotic pathways and genomic stability. It is known to be the most frequently mutated gene in a wide variety of human cancers. Single-nucleotide polymorphism of p53 at codon72 leading to substitution of proline (Pro) in place of arginine (Arg) has been identified as a risk factor for development of many cancers, including nasopharyngeal carcinoma (NPC). However, the association of this polymorphism with NPC across the published literature has shown conflicting results. We aimed to conduct a case-control study for a possible relation of p53 codon72 Arg>Pro polymorphism with NPC risk in underdeveloped states of India, combine the result with previously available records from different databases and perform a meta-analysis to draw a more definitive conclusion. A total of 70 NPC patients and 70 healthy controls were enrolled from different hospitals of north-eastern India. The p53 codon72 Arg>Pro polymorphism was typed by polymerase chain reaction, which showed an association with NPC risk. In the meta-analysis consisting of 1842 cases and 2330 controls, it was found that individuals carrying the Pro allele and the ProPro genotype were at a significantly higher risk for NPC as compared with those with the Arg allele and the ArgArg genotype, respectively. Individuals with a ProPro genotype and a combined Pro genotype (ProPro+ArgPro) also showed a significantly higher risk for NPC over a wild homozygote ArgArg genotype. Additionally, the strength of each study was tested by power analysis and genotype distribution by Hardy-Weinberg equilibrium. The outcome of the study indicated that both allele frequency and genotype distribution of p53 codon72 Arg>Pro polymorphism were significantly associated with NPC risk. Stratified analyses based on ethnicity and source of samples supported the above result.
