RESUMEN
This study was designed to identify phytocompounds from the aqueous extract of Solanum torvum unripe fruits using GC-MS analysis against breast cancer. For this, the identified phytocompounds were subjected to perform molecular docking studies to find the effects on breast cancer target protein. Pharmacokinetic properties were also tested for the identified phytocompounds to evaluate the ADMET properties. Molecular docking studies were done using docking software PyRx, and pharmacokinetic properties of phytocompounds were evaluated using SwissADME. From the results, ten best compounds were identified from GC-MS analysis against breast cancer target protein. Of which, three compounds showed very good binding affinity with breast cancer target protein. They are ergost-25-ene-3,6-dione,5,12-dihydroxy-,(5.alpha.,12.beta.) (- 7.3 kcal/mol), aspidospermidin-17-ol,1-acetyl-16-methoxy (- 6.7 kcal/mol) and 2-(3,4-dichlorophenyl)-4-[[2-[1-methyl-2-pyrrolidinyl]ethyl amino]-6-[trichloromethyl]-s-triazine (- 6.7 kcal/mol). Further, docking study was performed for the synthetic drug doxorubicin to compare the efficiency of phytocompounds. The binding affinity of ergost-25-ene-3,6-dione,5,12-dihydroxy-,(5.alpha.,12.beta.) is higher than the synthetic drug doxorubicin (- 7.2 kcal/mol), and the binding affinity of other compounds is also very near to the drug. Hence, the present study concludes that the phytocompounds from the aqueous extract of Solanum torvum unripe fruits have the potential ability to treat breast cancer.
Asunto(s)
Antineoplásicos Fitogénicos , Proteína BRCA1 , Neoplasias de la Mama , Frutas/química , Simulación del Acoplamiento Molecular , Solanum/química , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/farmacocinética , Antineoplásicos Fitogénicos/farmacología , Proteína BRCA1/química , Proteína BRCA1/metabolismo , Neoplasias de la Mama/química , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/metabolismo , Femenino , HumanosRESUMEN
Fibroblast growth factor receptor 2 (FGFR2) is a membrane-spanning tyrosine kinase that mediates FGF signaling. Various FGFR2 alterations are detected in breast cancer, yet it remains unclear if activation of FGFR2 signaling initiates tumor formation. In an attempt to answer this question, a mouse model berrying an activation mutation of FGFR2 (FGFR2-S252W) in the mammary gland is generated. It is found that FGF/FGFR2 signaling drives the development of triple-negative breast cancer accompanied by epithelial-mesenchymal transition that is regulated by FGFR2-STAT3 signaling. It is demonstrated that FGFR2 suppresses BRCA1 via the ERK-YY1 axis and promotes tumor progression. BRCA1 knockout in the mammary gland of the FGFR2-S252W mice significantly accelerated tumorigenesis. It is also shown that FGFR2 positively regulates PD-L1 and that a combination of FGFR2 inhibition and immune checkpoint blockade kills cancer cells. These data suggest that the mouse models mimic human breast cancers and can be used to identify actionable therapeutic targets.
Asunto(s)
Proteína BRCA1/metabolismo , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos/metabolismo , Transducción de Señal/fisiología , Neoplasias de la Mama Triple Negativas/terapia , Animales , Antígeno B7-H1/metabolismo , Proteína BRCA1/antagonistas & inhibidores , Proteína BRCA1/genética , Progresión de la Enfermedad , Transición Epitelial-Mesenquimal , Femenino , Factores de Crecimiento de Fibroblastos/metabolismo , Humanos , Inmunoterapia , Glándulas Mamarias Animales/metabolismo , Ratones , Ratones Transgénicos , Interferencia de ARN , ARN Interferente Pequeño/metabolismo , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos/antagonistas & inhibidores , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos/genética , Factor de Transcripción STAT3/metabolismo , Neoplasias de la Mama Triple Negativas/inmunología , Neoplasias de la Mama Triple Negativas/patología , Factor de Transcripción YY1/metabolismoRESUMEN
The Shieldin complex shields double-strand DNA breaks (DSBs) from nucleolytic resection. Curiously, the penultimate Shieldin component, SHLD1, is one of the least abundant mammalian proteins. Here, we report that the transcription factors THAP1, YY1, and HCF1 bind directly to the SHLD1 promoter, where they cooperatively maintain the low basal expression of SHLD1, thereby ensuring a proper balance between end protection and resection during DSB repair. The loss of THAP1-dependent SHLD1 expression confers cross-resistance to poly (ADP-ribose) polymerase (PARP) inhibitor and cisplatin in BRCA1-deficient cells and shorter progression-free survival in ovarian cancer patients. Moreover, the embryonic lethality and PARPi sensitivity of BRCA1-deficient mice is rescued by ablation of SHLD1. Our study uncovers a transcriptional network that directly controls DSB repair choice and suggests a potential link between DNA damage and pathogenic THAP1 mutations, found in patients with the neurodevelopmental movement disorder adult-onset torsion dystonia type 6.
Asunto(s)
Proteínas de Ciclo Celular/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Animales , Proteína BRCA1/genética , Proteína BRCA1/metabolismo , Proteínas de Ciclo Celular/genética , ADN/metabolismo , Roturas del ADN de Doble Cadena/efectos de los fármacos , Reparación del ADN por Unión de Extremidades/efectos de los fármacos , Reparación del ADN/genética , Distonía/genética , Femenino , Factor C1 de la Célula Huésped/metabolismo , Proteínas Mad2/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Poli(ADP-Ribosa) Polimerasa-1/metabolismo , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología , Reparación del ADN por Recombinación/efectos de los fármacos , Proteínas de Unión a Telómeros/metabolismo , Proteína 1 de Unión al Supresor Tumoral P53/metabolismo , Factor de Transcripción YY1/metabolismoRESUMEN
Singapore is a densely populated small island nation, with a multiethnic and multireligious population. Cancer is the leading cause of death in Singapore. The population is well educated and coupled with greater awareness, there is an increasing demand for genetic testing for hereditary cancer syndromes. In Singapore, the Singapore Cancer Action Network (SCAN) guidelines for referral for genetic testing serves as a guide for clinicians on appropriate referral. We examined the important factors in genetic counselling in such a diverse population, such as acknowledgement of psychosocial impact of BRCA1/2, cultural sensitivity and upskilling of healthcare professionals. Access to genetic services in Singapore is widely available, though the number of patients who undergo testing is lower due to need for out-of-pocket costs and lack of funding from government agencies and insurance companies. The delivery of clinical care and research accrual is performed concurrently in our centre. All patients undergo pre-test counselling before giving informed consent for germline genetic testing and post-test counselling for interpretation of test results. Patients who test positive for BRCA1/2 continue to be on follow up with the cancer genetics clinic for risk-management. Predictive testing is discussed and facilitated for all at-risk relatives. Challenges faced by cancer genetics professionals in Singapore include the high rate of variant of uncertain significance (VUS) and low predictive testing rates. We hold regular support group activities for patients to seek mutual support and to raise overall awareness of BRCA1/2. We believe our comprehensive cancer genetics service serves as a useful model for other Asian countries looking to set up their own unit. We continue to aspire to empower patients, family members and healthcare professionals with cancer genetics knowledge to improve personal and public health.
Asunto(s)
Proteína BRCA1/metabolismo , Proteína BRCA2/metabolismo , Neoplasias de la Mama/genética , Pruebas Genéticas/métodos , Femenino , Predisposición Genética a la Enfermedad , Humanos , SingapurRESUMEN
BACKGROUND: A subgroup of triple-negative breast cancer (TNBC) shows impaired BRCA1 function owing to causes other than mutation, which is called "BRCAness." DNA-damaging agents are known to have more efficacy in BRCA1-mutant tumors than mitotic poisons. We conducted a prospective single-arm clinical trial of neoadjuvant chemotherapy (NAC) using an anthracycline-based regimen without taxanes for BRCAness TNBCs. MATERIALS AND METHODS: BRCAness was examined using the multiplex ligation-dependent probe amplification (MLPA) method in TNBC cases. For BRCAness cases, NAC was performed with anthracycline-based regimens without additional taxanes. RESULTS: A total of 30 patients with TNBC were enrolled. MLPA was successfully performed in 25 patients. Eighteen patients (72%) showed BRCAness. Twenty-three patients received NAC as per the protocol. On analysis, the clinical response rate (complete response plus partial response) was 76.4%, and the pathological complete response rate was 35.3%. CONCLUSIONS: The interim analysis revealed that the pathological complete response rate was lower than estimated. Therefore, BRCAness by MLPA was not sufficient to predict the therapeutic response to anthracycline-based regimens in TNBC.
Asunto(s)
Antraciclinas/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Proteína BRCA1/metabolismo , Terapia Neoadyuvante/métodos , Neoplasias de la Mama Triple Negativas/terapia , Adulto , Anciano , Proteína BRCA1/análisis , Quimioterapia Adyuvante/métodos , Ciclofosfamida/uso terapéutico , Docetaxel/uso terapéutico , Epirrubicina/uso terapéutico , Femenino , Fluorouracilo/uso terapéutico , Humanos , Mastectomía , Persona de Mediana Edad , Proyectos Piloto , Estudios Prospectivos , Resultado del Tratamiento , Neoplasias de la Mama Triple Negativas/patologíaRESUMEN
BACKGROUND: B vitamins [vitamins B-6, B-9 (folate), and B-12] play important roles in nucleotide biosynthesis and biological methylation reactions, aberrancies of which have all been implicated in carcinogenesis. In the general population, evidence has suggested that high circulating folate and folic acid (synthetic form of folate) supplement use may increase breast cancer risk, but the role of folate in BRCA-associated breast cancer is not clear. OBJECTIVE: We prospectively evaluated the relation between plasma folate, pyridoxal 5'-phosphate (PLP; the biologically active form of vitamin B-6), and vitamin B-12 and breast cancer risk in women with a BRCA1/2 mutation. DESIGN: Baseline blood samples and biennial follow-up questionnaires were available for 164 BRCA1/2-mutation carriers with no previous history of cancer other than nonmelanoma skin cancer. Plasma folate, PLP, and vitamin B-12 concentrations were categorized dichotomously as high compared with low based on the upper 25% and the lower 75% of distribution, respectively. Cox proportional hazards were used to estimate the HR and 95% CI for the association between plasma biomarkers of each B vitamin and incident breast cancer. RESULTS: Over a mean follow-up of 6.3 y, 20 incident primary invasive breast cancers were observed. Women with high plasma folate concentrations (>24.4 ng/mL) were associated with significantly increased breast cancer risk (HR: 3.20; 95% CI: 1.03, 9.92; P = 0.04, P-trend across quintiles = 0.07) compared with that of women with low plasma folate concentrations (≤24.4 ng/mL). Plasma PLP and vitamin B-12 concentrations were not associated with breast cancer risk. CONCLUSIONS: Our data suggest that elevated plasma folate concentrations may be associated with increased risk of breast cancer in women with a BRCA1/2 mutation. Additional studies with a larger sample size and longer follow-up periods are warranted to clarify the relation between folate status and breast cancer risk in high-risk women.
Asunto(s)
Proteína BRCA1/genética , Proteína BRCA2/genética , Neoplasias de la Mama/etiología , Suplementos Dietéticos/efectos adversos , Ácido Fólico/efectos adversos , Alimentos Fortificados/efectos adversos , Predisposición Genética a la Enfermedad , Adulto , Proteína BRCA1/metabolismo , Proteína BRCA2/metabolismo , Biomarcadores/sangre , Neoplasias de la Mama/sangre , Neoplasias de la Mama/epidemiología , Neoplasias de la Mama/genética , Estudios de Cohortes , Femenino , Ácido Fólico/sangre , Estudios de Seguimiento , Humanos , Incidencia , Mutación , Ontario/epidemiología , Estudios Prospectivos , Fosfato de Piridoxal/sangre , Riesgo , Vitamina B 12/sangre , Deficiencia de Vitamina B 12/fisiopatología , Deficiencia de Vitamina B 6/fisiopatologíaRESUMEN
Breast and ovarian cancer patients harboring BRCA1/2 germline mutations have clinically benefitted from therapy with PARP inhibitor (PARPi) or platinum compounds, but acquired resistance limits clinical impact. In this study, we investigated the impact of mutations on BRCA1 isoform expression and therapeutic response. Cancer cell lines and tumors harboring mutations in exon 11 of BRCA1 express a BRCA1-Δ11q splice variant lacking the majority of exon 11. The introduction of frameshift mutations to exon 11 resulted in nonsense-mediated mRNA decay of full-length, but not the BRCA1-Δ11q isoform. CRISPR/Cas9 gene editing as well as overexpression experiments revealed that the BRCA1-Δ11q protein was capable of promoting partial PARPi and cisplatin resistance relative to full-length BRCA1, both in vitro and in vivo Furthermore, spliceosome inhibitors reduced BRCA1-Δ11q levels and sensitized cells carrying exon 11 mutations to PARPi treatment. Taken together, our results provided evidence that cancer cells employ a strategy to remove deleterious germline BRCA1 mutations through alternative mRNA splicing, giving rise to isoforms that retain residual activity and contribute to therapeutic resistance. Cancer Res; 76(9); 2778-90. ©2016 AACR.
Asunto(s)
Proteína BRCA1/genética , Neoplasias de la Mama/genética , Resistencia a Antineoplásicos/genética , Neoplasias Ováricas/genética , Empalme Alternativo/genética , Animales , Proteína BRCA1/metabolismo , Western Blotting , Cisplatino/farmacología , Femenino , Técnica del Anticuerpo Fluorescente , Mutación de Línea Germinal , Humanos , Inmunohistoquímica , Ratones , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología , Reacción en Cadena de la Polimerasa , Isoformas de Proteínas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Cancer is as much an epigenetic disease as it is a genetic disease, and epigenetic alterations in cancer often serve as potent surrogates for genetic mutations. Because the epigenetic factors involved in the DNA damage response are regulated by multiple elements, therapies to target specific components of the epigenetic machinery can be inefficient. In contrast, therapies aimed at inhibiting the methionine cycle can indirectly inhibit both DNA and protein methylation, and the wide variety of genes and pathways that are affected by these methylations make this global strategy very attractive. In the present study, we propose an adjuvant therapy that targets the epigenetics of the DNA damage response in breast cancer cells and that results in efficient apoptosis and a reduction in distant metastases in vivo. We observed that a combined therapy designed to uncouple adenosine metabolism using dipyridamole in the presence of a new synthetic antifolate, 3-O-(3,4,5-trimethoxybenzoyl)-(-)-catechin, simultaneously and efficiently blocked both the folic cycle and the methionine cycle in breast cancer cells and sensitized these cells to radiotherapy. The treatment impeded the recruitment of 53BP1 and BRCA1 to the chromatin regions flanking DNA double-strand breaks and thereby avoided the DNA damage responses in breast cancer cells that were exposed to ionizing radiation. In addition, this hypomethylating therapy was also efficient in reducing the self-renewal capability of breast cancer-initiating cells and induced reversion of mesenchymal phenotypes in breast cancer cells.
Asunto(s)
Reparación del ADN , Epigénesis Genética , Animales , Apoptosis/efectos de los fármacos , Apoptosis/efectos de la radiación , Proteína BRCA1/metabolismo , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Neoplasias de la Mama/radioterapia , Puntos de Control del Ciclo Celular/efectos de los fármacos , Puntos de Control del Ciclo Celular/efectos de la radiación , Línea Celular Tumoral , Cromatina/metabolismo , Roturas del ADN de Doble Cadena/efectos de los fármacos , Roturas del ADN de Doble Cadena/efectos de la radiación , Reparación del ADN/efectos de los fármacos , Reparación del ADN/efectos de la radiación , Dipiridamol/metabolismo , Femenino , Antagonistas del Ácido Fólico/farmacología , Histonas/metabolismo , Humanos , Células MCF-7 , Metilación/efectos de los fármacos , Metilación/efectos de la radiación , Ratones , Ratones Endogámicos BALB C , Proteína-Arginina N-Metiltransferasas/antagonistas & inhibidores , Proteína-Arginina N-Metiltransferasas/genética , Proteína-Arginina N-Metiltransferasas/metabolismo , Proteínas Represoras/antagonistas & inhibidores , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Proteína 1 de Unión al Supresor Tumoral P53/metabolismoRESUMEN
The focus of molecular docking is to computationally simulate the molecular recognition process. A binding interaction between a small molecule ligand and protein may result in activation or inhibition of the protein. The docking method using BRCA1 or BRCA2 genes and COX proteins is carefully texted in this chapter to check docking of the best inhibitor molecule.
Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Proteína BRCA1/antagonistas & inhibidores , Proteína BRCA2/antagonistas & inhibidores , Bioprospección/métodos , Inhibidores de la Ciclooxigenasa/farmacología , Descubrimiento de Drogas/métodos , Simulación del Acoplamiento Molecular , Neoplasias/tratamiento farmacológico , Fitoquímicos/farmacología , Extractos Vegetales/farmacología , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/metabolismo , Proteína BRCA1/química , Proteína BRCA1/metabolismo , Proteína BRCA2/química , Proteína BRCA2/metabolismo , Sitios de Unión , Ciclooxigenasa 1/química , Ciclooxigenasa 1/metabolismo , Ciclooxigenasa 2/química , Ciclooxigenasa 2/metabolismo , Inhibidores de la Ciclooxigenasa 2/farmacología , Inhibidores de la Ciclooxigenasa/química , Inhibidores de la Ciclooxigenasa/metabolismo , Bases de Datos de Proteínas , Humanos , Terapia Molecular Dirigida , Neoplasias/enzimología , Fitoquímicos/química , Fitoquímicos/metabolismo , Fitoterapia , Extractos Vegetales/química , Extractos Vegetales/metabolismo , Plantas Medicinales , Unión Proteica , Conformación Proteica , Relación Estructura-ActividadRESUMEN
Dietary supplementation with folic acid (FA) has been shown to induce opposing effects on cancer-related outcomes. The mechanism underlying such heterogeneity is unclear. We hypothesized that FA supplementation induces changes in breast cancer-associated (BRCA) genes 1 and 2 expression and function through altered epigenetic regulation in a cell type-dependent manner. We investigated the effect of treating normal and cancer cells with physiologically relevant FA concentrations on the mRNA and protein expression, capacity for DNA repair, and DNA methylation of BRCA1 and BRCA2. FA treatment induced dose-related increases in BRCA1 mRNA expression in HepG2, Huh-7D12, Hs578T, and JURKAT and in BRCA2 in HepG2, Hs578T, MCF7, and MDA-MB-157 cells. FA did not affect the corresponding normal cells or on any of the ovarian cell lines. Folic acid induced increased BRCA1 protein expression in Hs578T, but not HepG2 cells, whereas BRCA2 protein levels were undetectable. FA treatment did not alter DNA repair in liver-derived cells, whereas there were transient effects on breast-derived cells. There was no effect of FA treatment on BRCA1 or BRCA2 DNA methylation, although there was some variation in the methylation of specific CpG loci between some cell lines. Overall, these findings show that the effects of FA on BRCA-related outcomes differ between cells lines, but the biological consequences of induced changes in BRCA expression appear to be at most limited.
Asunto(s)
Proteína BRCA1/metabolismo , Proteína BRCA2/metabolismo , Metilación de ADN/efectos de los fármacos , Reparación del ADN/efectos de los fármacos , Ácido Fólico/farmacología , Neoplasias/metabolismo , Regiones Promotoras Genéticas/efectos de los fármacos , Línea Celular Tumoral , Islas de CpG , Suplementos Dietéticos , Epigénesis Genética , Humanos , Neoplasias/genética , ARN Mensajero/metabolismo , Complejo Vitamínico B/farmacologíaRESUMEN
Breast cancer is a prominent cause of mortality in women worldwide, with about 2/3(rd) cases linked to hormone mediated malignancy itself. A hormone receptor positive breast cancer represents cells showing rigorous proliferation upon hormonal exposure. BRCA1 is the predominant marker gene responsible for estrogen regulation. However increased exposure to estrogen is not the sole cause for this abnormality as there is no significant alteration reported in breast tissue estrogen levels. Iron metabolism has also been shown to be frequently altered in breast cancer with considerably higher iron in post menstrual women. In fact estrogen and iron have been implicated to exert synergistic effects on cellular proliferation in BRCA1 linked hormone responsive breast cancer. Thus establishing a link between estrogen and iron metabolism has a great prognostic value in predicting clinical outcome in BRCA1 linked hormone responsive breast cancer patients. Since the time immemorial Iron chelators have been implicated in combating iron dysregulation especially in breast cancer. We summarize here in this review the recent advancements in the area of iron chelation therapy delineating the role of iron in hormone receptor positive Breast cancer.
Asunto(s)
Proteína BRCA1/genética , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Estrógenos/metabolismo , Hierro/metabolismo , Animales , Proteína BRCA1/metabolismo , Neoplasias de la Mama/tratamiento farmacológico , Femenino , Humanos , Quelantes del Hierro/uso terapéutico , MutaciónRESUMEN
Bufalin is a key component of a Chinese medicine (Chan Su) and has been proved effective in killing various cancer cells. Its role in inducing DNA damage and the inhibition of the DNA damage response (DDR) has been reported, but none have studied such action in lung cancer in detail. In this study, we demonstrated bufalin-induced DNA damage and condensation in NCI-H460 cells through a comet assay and DAPI staining, respectively. Western blotting indicated that bufalin suppressed the protein levels associated with DNA damage and repair, such as a DNA dependent serine/threonine protein kinase (DNA-PK), DNA repair proteins breast cancer 1, early onset (BRCA1), 14-3-3 σ (an important checkpoint keeper of DDR), mediator of DNA damage checkpoint 1 (MDC1), O6-methylguanine-DNA methyltransferase (MGMT) and p53 (tumor suppressor protein). Bufalin could activate phosphorylated p53 in NCI-H460 cells. DNA damage in NCI-H460 cells after treatment with bufalin up-regulated its ATM and ATR genes, which encode proteins functioning as sensors in DDR, and also up-regulated the gene expression (mRNA) of BRCA1 and DNA-PK. But bufalin suppressed the gene expression (mRNA) of p53 and 14-3-3 σ, however, bufalin did not significantly affect the mRNA of MGMT. In conclusion, bufalin induced DNA damage in NCI-H460 cells and also inhibited its DNA repair and checkpoint function.
Asunto(s)
Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Apoptosis/genética , Bufanólidos/farmacología , Daño del ADN/efectos de los fármacos , Daño del ADN/genética , Reparación del ADN/efectos de los fármacos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Proteínas 14-3-3/metabolismo , Proteínas Adaptadoras Transductoras de Señales , Proteína BRCA1/metabolismo , Biomarcadores de Tumor/metabolismo , Proteínas de Ciclo Celular , Metilasas de Modificación del ADN/metabolismo , Reparación del ADN/genética , Enzimas Reparadoras del ADN/metabolismo , Proteína Quinasa Activada por ADN/metabolismo , Exorribonucleasas/metabolismo , Genes cdc/efectos de los fármacos , Genes cdc/genética , Humanos , Proteínas Nucleares/metabolismo , Transactivadores/metabolismo , Células Tumorales Cultivadas , Proteína p53 Supresora de Tumor/metabolismo , Proteínas Supresoras de Tumor/metabolismoRESUMEN
Laser phototherapy (LPT) is widely used in clinical practice to accelerate healing. Although the use of LPT has advantages, the molecular mechanisms involved in the process of accelerated healing and the safety concerns associated with LPT are still poorly understood. We investigated the physiological effects of LPT irradiation on the production and accumulation of reactive oxygen species (ROS), genomic instability, and deoxyribose nucleic acid (DNA) damage in human epithelial cells. In contrast to a high energy density (20 J/cm²), laser administered at a low energy density (4 J/cm²) resulted in the accumulation of ROS. Interestingly, 4 J/cm² of LPT did not induce DNA damage, genomic instability, or nuclear influx of the BRCA1 DNA damage repair protein, a known genome protective molecule that actively participates in DNA repair. Our results suggest that administration of low energy densities of LPT induces the accumulation of safe levels of ROS, which may explain the accelerated healing results observed in patients. These findings indicate that epithelial cells have an endowed molecular circuitry that responds to LPT by physiologically inducing accumulation of ROS, which triggers accelerated healing. Importantly, our results suggest that low energy densities of LPT can serve as a safe therapy to accelerate epithelial healing.
Asunto(s)
Roturas del ADN de Doble Cadena/efectos de la radiación , Células Epiteliales/efectos de la radiación , Terapia por Luz de Baja Intensidad , Especies Reactivas de Oxígeno/metabolismo , Proteína BRCA1/análisis , Proteína BRCA1/metabolismo , Línea Celular , Reparación del ADN , Células Epiteliales/metabolismo , Histonas/análisis , Histonas/metabolismo , Humanos , Especies Reactivas de Oxígeno/análisis , Especies Reactivas de Oxígeno/efectos de la radiaciónRESUMEN
Aromatase inhibitors (AIs) are the most effective class of drugs in the endocrine treatment of breast cancer, with an approximate 50% treatment response rate. Our objective was to determine whether intratumoral expression levels of estrogen-related genes are predictive of AI responsiveness in postmenopausal women with breast cancer. Primary breast carcinomas were obtained from 112 women who received AI therapy after failing adjuvant tamoxifen therapy and developing recurrent breast cancer. Tumor ERα and PR protein expression were analyzed by immunohistochemistry (IHC). Messenger RNA (mRNA) levels of 5 estrogen-related genes-AKR1C3, aromatase, ERα, and 2 estradiol/ERα target genes, BRCA1 and PR-were measured by real-time PCR. Tumor protein and mRNA levels were compared with breast cancer progression rates to determine predictive accuracy. Responsiveness to AI therapy-defined as the combined complete response, partial response, and stable disease rates for at least 6 months-was 51%; rates were 56% in ERα-IHC-positive and 14% in ERα-IHC-negative tumors. Levels of ERα, PR, or BRCA1 mRNA were independently predictive for responsiveness to AI. In cross-validated analyses, a combined measurement of tumor ERα and PR mRNA levels yielded a more superior specificity (36%) and identical sensitivity (96%) to the current clinical practice (ERα/PR-IHC). In patients with ERα/PR-IHC-negative tumors, analysis of mRNA expression revealed either non-significant trends or statistically significant positive predictive values for AI responsiveness. In conclusion, expression levels of estrogen-related mRNAs are predictive for AI responsiveness in postmenopausal women with breast cancer, and mRNA expression analysis may improve patient selection.
Asunto(s)
Antineoplásicos Hormonales/farmacología , Inhibidores de la Aromatasa/farmacología , Biomarcadores de Tumor/genética , Neoplasias de la Mama/genética , Nitrilos/farmacología , Triazoles/farmacología , 3-Hidroxiesteroide Deshidrogenasas/genética , 3-Hidroxiesteroide Deshidrogenasas/metabolismo , Miembro C3 de la Familia 1 de las Aldo-Ceto Reductasas , Anastrozol , Antineoplásicos Hormonales/uso terapéutico , Aromatasa/genética , Aromatasa/metabolismo , Inhibidores de la Aromatasa/uso terapéutico , Proteína BRCA1/genética , Proteína BRCA1/metabolismo , Biomarcadores de Tumor/metabolismo , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/metabolismo , Quimioterapia Adyuvante , Resistencia a Antineoplásicos , Receptor alfa de Estrógeno/genética , Receptor alfa de Estrógeno/metabolismo , Estrógenos/fisiología , Femenino , Regulación Neoplásica de la Expresión Génica , Marcadores Genéticos , Humanos , Hidroxiprostaglandina Deshidrogenasas/genética , Hidroxiprostaglandina Deshidrogenasas/metabolismo , Letrozol , Persona de Mediana Edad , Nitrilos/uso terapéutico , Curva ROC , Receptores de Progesterona/genética , Receptores de Progesterona/metabolismo , Tamoxifeno/farmacología , Tamoxifeno/uso terapéutico , Resultado del Tratamiento , Triazoles/uso terapéuticoRESUMEN
OBJECTIVE: Alterations in cardiac energy and substrate metabolism play a critical role in the development and clinical course of heart failure. We hypothesized that the cardioprotective role of the breast cancer 1, early onset (BRCA1) gene might be mediated in part by alterations in cardiac bioenergetics. METHODS: We generated cardiomyocyte-specific BRCA1 homozygous and heterozygous knockout mice using the Cre-loxP technology and evaluated the key molecules and pathways involved in glucose metabolism, fatty acid metabolism, and mitochondrial bioenergetics. RESULTS: Cardiomyocyte-specific BRCA1-deficient mice showed reduced cardiac expression of glucose and fatty acid transporters, reduced acetyl-coenzyme A carboxylase 2 and malonyl-coenzyme A decarboxylase (key enzymes that control malonyl coenzyme A, which in turn controls fatty acid oxidation), and reduced carnitine palmitoyltransferase I, a rate-limiting enzyme for mitochondrial fatty acid uptake. Peroxisome proliferator-activated receptor α and γ and carnitine palmitoyltransferase I levels were also downregulated in these hearts. Rates of glucose and fatty acid oxidation were reduced in the hearts of heterozygous cardiomyocyte-restricted BRCA1-deficient mice, resulting in a decrease in the rate of adenosine triphosphate production. This decrease in metabolism and adenosine triphosphate production occurred despite an increase in 5'-adenosine monophosphate-activated protein kinase and AKT activation in the heart. CONCLUSIONS: Cardiomyocyte-specific loss of BRCA1 alters critical pathways of fatty acid and glucose metabolism, leading to an energy starved heart. BRCA1-based cell or gene therapy might serve as a novel target to improve cardiac bioenergetics in patients with heart failure.
Asunto(s)
Proteína BRCA1/metabolismo , Daño del ADN , Reparación del ADN , Metabolismo Energético , Miocitos Cardíacos/metabolismo , Proteínas Quinasas Activadas por AMP/metabolismo , Acetil-CoA Carboxilasa/metabolismo , Adenosina Trifosfato/metabolismo , Animales , Proteína BRCA1/deficiencia , Proteína BRCA1/genética , Carboxiliasas/metabolismo , Ácidos Grasos/metabolismo , Regulación de la Expresión Génica , Glucosa/metabolismo , Heterocigoto , Homocigoto , Ratones , Ratones Noqueados , Mitocondrias Cardíacas/metabolismo , Miocitos Cardíacos/patología , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma , Receptores Activados del Proliferador del Peroxisoma/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Factores de Transcripción/metabolismoRESUMEN
DNA interstrand crosslinks (ICLs) are toxic lesions that block the progression of replication and transcription. CtIP is a conserved DNA repair protein that facilitates DNA end resection in the double-strand break (DSB) repair pathway. Here we show that CtIP plays a critical role during initiation of ICL processing in replicating human cells that is distinct from its role in DSB repair. CtIP depletion sensitizes human cells to ICL inducing agents and significantly impairs the accumulation of DNA damage response proteins RPA, ATR, FANCD2, γH2AX, and phosphorylated ATM at sites of laser generated ICLs. In contrast, the appearance of γH2AX and phosphorylated ATM at sites of laser generated double strand breaks (DSBs) is CtIP-independent. We present a model in which CtIP functions early in ICL repair in a BRCA1- and FANCM-dependent manner prior to generation of DSB repair intermediates.
Asunto(s)
Proteínas Portadoras/genética , Reparación del ADN/genética , Replicación del ADN/genética , Proteínas Nucleares/genética , Proteína BRCA1/genética , Proteína BRCA1/metabolismo , Roturas del ADN de Doble Cadena/efectos de la radiación , Daño del ADN/efectos de la radiación , Endodesoxirribonucleasas , Proteína del Grupo de Complementación D2 de la Anemia de Fanconi/genética , Proteína del Grupo de Complementación D2 de la Anemia de Fanconi/metabolismo , Células HEK293 , Células HeLa , Histonas/genética , Histonas/metabolismo , Humanos , Terapia por Luz de Baja Intensidad , Redes y Vías MetabólicasRESUMEN
S-Equol is a metabolite resulting from the conversion of daidzein, a soya phyto-oestrogen, by the gut microflora. The potential protective effects of equol in breast cancer are still under debate. Consequently, we investigated the effects of equol on DNA methylation of breast cancer susceptibility genes (BRCA1 and BRCA2) and oncosuppressors in breast cancer cell lines (MDA-MB-231 and MCF-7) and in a dystrophic breast cell line (MCF-10a) following exposure to S-equol (2 µm) for 3 weeks. We demonstrated by quantitative analysis of methylated alleles a significant decrease in the methylation of the cytosine phosphate guanine (CpG) islands in the promoters of BRCA1 and BRCA2 after the S-equol treatment in MCF-7 and MDA-MB-231 cells and a trend in MCF-10a cells. We also showed that S-equol increases BRCA1 and BRCA2 protein expression in the nuclei and the cytoplasm in MCF-7, MDA-MB-231 and MCF-10a cell lines by immunohistochemistry. The increase in BRCA1 and BRCA2 proteins was also found after Western blotting in the studied cell lines. In summary, we demonstrated the demethylating effect of S-equol on the CpG islands inside the promoters of BRCA1 and BRCA2 genes, resulting in an increase in the level of expressed oncosuppressors in breast cancer cell lines.
Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Proteína BRCA1/metabolismo , Proteína BRCA2/metabolismo , Neoplasias de la Mama/tratamiento farmacológico , Metilación de ADN/efectos de los fármacos , Equol/farmacología , Fitoestrógenos/farmacología , Alelos , Proteína BRCA1/genética , Proteína BRCA2/genética , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Línea Celular Tumoral , Núcleo Celular/efectos de los fármacos , Núcleo Celular/metabolismo , Islas de CpG/efectos de los fármacos , Citoplasma/efectos de los fármacos , Citoplasma/metabolismo , Epigénesis Genética/efectos de los fármacos , Receptor alfa de Estrógeno/metabolismo , Receptor beta de Estrógeno/metabolismo , Femenino , Humanos , Regiones Promotoras Genéticas/efectos de los fármacos , Transporte de Proteínas/efectos de los fármacos , Regulación hacia Arriba/efectos de los fármacosAsunto(s)
Evaluación Preclínica de Medicamentos , Neoplasias Ováricas/tratamiento farmacológico , Inhibidores de la Angiogénesis/farmacología , Inhibidores de la Angiogénesis/uso terapéutico , Animales , Anticuerpos Monoclonales Humanizados/farmacología , Anticuerpos Monoclonales Humanizados/uso terapéutico , Proteína BRCA1/metabolismo , Proteína BRCA2/metabolismo , Bevacizumab , Modelos Animales de Enfermedad , Femenino , Humanos , Ratones , Mutación , Estadificación de Neoplasias , Neoplasias Ováricas/metabolismo , Microambiente Tumoral/efectos de los fármacos , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
AIM: DNA hypermethylation is an epigenetic mechanism which induces silencing of tumor-suppressor genes in prostate cancer. Many studies have reported that specific components of food plants like soy phytoestrogens may have protective effects against prostate carcinogenesis or progression. Genistein and daidzein, the major phytoestrogens, have been reported to have the ability to reverse DNA hypermethylation in cancer cell lines. The aim of this study was to investigate the potential demethylating effects of these two soy compounds on BRCA1, GSTP1, EPHB2 and BRCA2 promoter genes. METHODS & MATERIALS: Prostate cell lines DU-145 and PC-3 were treated with genistein 40 µM, daidzein 110 µM, budesonide (methylating agent) 2 µM and 5-azacytidine (demethylating agent) 2 µM. In these two human prostate cancer cell lines we performed methylation quantification by using Methyl Profiler DNA methylation analysis. This technique is based on a methylation-specific digestion followed by quantitative PCR. We analyzed the corresponding protein expression by western blotting. RESULTS: Soy phytoestrogens induced a demethylation of all promoter regions studied except for BRCA2, which is not methylated in control cell lines. An increase in their protein expression was also demonstrated by western blot analysis and corroborated the potential demethylating effect of soy phytoestrogens. CONCLUSION: This study showed that the soy phytoestrogens, genistein and daidzein, induce a decrease of methylation of BRCA1, GSTP1 and EPHB2 promoters. Therefore, soy phytoestrogens may have a protective effect on prostate cancer. However, more studies are needed in order to understand the mechanism by which genistein and daidzein have an inhibiting action on DNA methylation.
Asunto(s)
Metilación de ADN/fisiología , Genes Supresores de Tumor/efectos de los fármacos , Glycine max/química , Fitoestrógenos/farmacología , Neoplasias de la Próstata/metabolismo , Proteína BRCA1/metabolismo , Proteína BRCA2/metabolismo , Western Blotting , Línea Celular Tumoral , Metilación de ADN/efectos de los fármacos , Citometría de Flujo , Genisteína/farmacología , Gutatión-S-Transferasa pi/metabolismo , Humanos , Isoflavonas/farmacología , Masculino , Regiones Promotoras Genéticas/efectos de los fármacos , Receptor EphB2/metabolismoRESUMEN
UNLABELLED: The popular vision for the future of oncology includes the rational design of therapies inhibiting specific targets, for which development would be less expensive and the chance of success greater because the agent, the target, and a population predicted to benefit maximally would be known from the outset. In the breast cancer arena, successful targeted therapies have entered clinical practice. Recently, patients with BRCA-associated cancers have been identified as eligible for novel investigational therapies targeting their genetic deficiency. Preclinical data, phase I results, and 2 phase II proof-of-concept studies support the continued development of PARP inhibitors, either as single agents or in combination with specific cytotoxic drugs in this setting. In this article, we provide a brief review of current developments concerning PARP inhibitors in BRCA-associated cancers and express concerns about challenges to further development. SUMMARY: PARP inhibitors may represent a new and promising targeted therapy for patients with BRCA1/2 -associated cancer. In this review we summarize the main challenges in the clinical development of these agents.