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1.
J Biol Chem ; 299(5): 104644, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36965617

RESUMO

The mechanistic target of rapamycin complex 1 (mTORC1) is a central regulator of mammalian cell growth that is dysregulated in a number of human diseases, including metabolic syndromes, aging, and cancer. Structural, biochemical, and pharmacological studies that have increased our understanding of how mTORC1 executes growth control often relied upon purified mTORC1 protein. However, current immunoaffinity-based purification methods are expensive, inefficient, and do not necessarily isolate endogenous mTORC1, hampering their overall utility in research. Here we present a simple tool to isolate endogenous mTORC1 from various cellular sources. By recombinantly expressing and isolating mTORC1-binding Rag GTPases from Escherichia coli and using them as affinity probes, we demonstrate that mTORC1 can be isolated from mouse, bovine, and human sources. Our results indicate that mTORC1 isolated by this relatively inexpensive method is catalytically active and amenable to scaling. Collectively, this tool may be utilized to isolate mTORC1 from various cellular sources, organs, and disease contexts, aiding mTORC1-related research.


Assuntos
Biotecnologia , Alvo Mecanístico do Complexo 1 de Rapamicina , Proteínas Monoméricas de Ligação ao GTP , Proteínas Recombinantes , Animais , Bovinos , Humanos , Camundongos , Mamíferos/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/química , Alvo Mecanístico do Complexo 1 de Rapamicina/isolamento & purificação , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Proteínas Monoméricas de Ligação ao GTP/química , Proteínas Monoméricas de Ligação ao GTP/genética , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Escherichia coli/genética , Biotecnologia/métodos , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Modelos Moleculares
2.
Genes Dev ; 30(22): 2551-2564, 2016 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-27913603

RESUMO

Noncanonical mechanistic target of rapamycin (mTOR) pathways remain poorly understood. Mutations in the tumor suppressor folliculin (FLCN) cause Birt-Hogg-Dubé syndrome, a hamartomatous disease marked by mitochondria-rich kidney tumors. FLCN functionally interacts with mTOR and is expressed in most tissues, but its role in fat has not been explored. We show here that FLCN regulates adipose tissue browning via mTOR and the transcription factor TFE3. Adipose-specific deletion of FLCN relieves mTOR-dependent cytoplasmic retention of TFE3, leading to direct induction of the PGC-1 transcriptional coactivators, drivers of mitochondrial biogenesis and the browning program. Cytoplasmic retention of TFE3 by mTOR is sensitive to ambient amino acids, is independent of growth factor and tuberous sclerosis complex (TSC) signaling, is driven by RagC/D, and is separable from canonical mTOR signaling to S6K. Codeletion of TFE3 in adipose-specific FLCN knockout animals rescues adipose tissue browning, as does codeletion of PGC-1ß. Conversely, inducible expression of PGC-1ß in white adipose tissue is sufficient to induce beige fat gene expression in vivo. These data thus unveil a novel FLCN-mTOR-TFE3-PGC-1ß pathway-separate from the canonical TSC-mTOR-S6K pathway-that regulates browning of adipose tissue.


Assuntos
Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Animais , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Respiração Celular/genética , Citoplasma/metabolismo , Deleção de Genes , Masculino , Camundongos , Mitocôndrias/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas/genética , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Transdução de Sinais/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/genética
3.
Br J Cancer ; 124(9): 1581-1591, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33723394

RESUMO

BACKGROUND: Eribulin is a microtubule-targeting agent approved for the treatment of advanced or metastatic breast cancer (BC) previously treated with anthracycline- and taxane-based regimens. PIK3CA mutation is associated with worse response to chemotherapy in oestrogen receptor-positive (ER+)/human epidermal growth factor receptor 2-negative (HER2-) metastatic BC. We aimed to evaluate the role of phosphoinositide 3-kinase (PI3K)/AKT pathway mutations in eribulin resistance. METHODS: Resistance to eribulin was evaluated in HER2- BC cell lines and patient-derived tumour xenografts, and correlated with a mutation in the PI3K/AKT pathway. RESULTS: Eleven out of 23 HER2- BC xenografts treated with eribulin exhibited disease progression. No correlation with ER status was detected. Among the resistant models, 64% carried mutations in PIK3CA, PIK3R1 or AKT1, but only 17% among the sensitive xenografts (P = 0.036). We observed that eribulin treatment induced AKT phosphorylation in vitro and in patient tumours. In agreement, the addition of PI3K inhibitors reversed primary and acquired resistance to eribulin in xenograft models, regardless of the genetic alterations in PI3K/AKT pathway or ER status. Mechanistically, PI3K blockade reduced p21 levels likely enabling apoptosis, thus sensitising to eribulin treatment. CONCLUSIONS: PI3K pathway activation induces primary resistance or early adaptation to eribulin, supporting the combination of PI3K inhibitors and eribulin for the treatment of HER2- BC patients.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Classe I de Fosfatidilinositol 3-Quinases/metabolismo , Resistencia a Medicamentos Antineoplásicos , Furanos/farmacologia , Cetonas/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptor ErbB-2/metabolismo , Animais , Apoptose , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/patologia , Ciclo Celular , Proliferação de Células , Classe I de Fosfatidilinositol 3-Quinases/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Fosforilação , Proteínas Proto-Oncogênicas c-akt/genética , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
4.
Mol Syst Biol ; 11(1): 789, 2015 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-25699542

RESUMO

Some mutations in cancer cells can be exploited for therapeutic intervention. However, for many cancer subtypes, including triple-negative breast cancer (TNBC), no frequently recurring aberrations could be identified to make such an approach clinically feasible. Characterized by a highly heterogeneous mutational landscape with few common features, many TNBCs cluster together based on their 'basal-like' transcriptional profiles. We therefore hypothesized that targeting TNBC cells on a systems level by exploiting the transcriptional cell state might be a viable strategy to find novel therapies for this highly aggressive disease. We performed a large-scale chemical genetic screen and identified a group of compounds related to the drug PKC412 (midostaurin). PKC412 induced apoptosis in a subset of TNBC cells enriched for the basal-like subtype and inhibited tumor growth in vivo. We employed a multi-omics approach and computational modeling to address the mechanism of action and identified spleen tyrosine kinase (SYK) as a novel and unexpected target in TNBC. Quantitative phosphoproteomics revealed that SYK inhibition abrogates signaling to STAT3, explaining the selectivity for basal-like breast cancer cells. This non-oncogene addiction suggests that chemical SYK inhibition may be beneficial for a specific subset of TNBC patients and demonstrates that targeting cell states could be a viable strategy to discover novel treatment strategies.


Assuntos
Antineoplásicos/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Terapia de Alvo Molecular , Proteínas Tirosina Quinases/metabolismo , Fator de Transcrição STAT3/metabolismo , Estaurosporina/análogos & derivados , Neoplasias de Mama Triplo Negativas/metabolismo , Animais , Apoptose/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sistemas de Liberação de Medicamentos , Feminino , Perfilação da Expressão Gênica , Humanos , Camundongos , Simulação de Acoplamento Molecular , Domínios e Motivos de Interação entre Proteínas , Proteômica/métodos , Análise de Sequência de RNA , Transdução de Sinais , Estaurosporina/farmacologia , Quinase Syk , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
5.
Proc Natl Acad Sci U S A ; 108(9): 3761-6, 2011 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-21321214

RESUMO

Clinical benefits from trastuzumab and other anti-HER2 therapies in patients with HER2 amplified breast cancer remain limited by primary or acquired resistance. To identify potential mechanisms of resistance, we established trastuzumab-resistant HER2 amplified breast cancer cells by chronic exposure to trastuzumab treatment. Genomewide copy-number variation analyses of the resistant cells compared with parental cells revealed a focal amplification of genomic DNA containing the cyclin E gene. In a cohort of 34 HER2(+) patients treated with trastuzumab-based therapy, we found that cyclin E amplification/overexpression was associated with a worse clinical benefit (33.3% compared with 87.5%, P < 0.02) and a lower progression-free survival (6 mo vs. 14 mo, P < 0.002) compared with nonoverexpressing cyclin E tumors. To dissect the potential role of cyclin E in trastuzumab resistance, we studied the effects of cyclin E overexpression and cyclin E suppression. Cyclin E overexpression resulted in resistance to trastuzumab both in vitro and in vivo. Inhibition of cyclin E activity in cyclin E-amplified trastuzumab resistant clones, either by knockdown of cyclin E expression or treatment with cyclin-dependent kinase 2 (CDK2) inhibitors, led to a dramatic decrease in proliferation and enhanced apoptosis. In vivo, CDK2 inhibition significantly reduced tumor growth of trastuzumab-resistant xenografts. Our findings point to a causative role for cyclin E overexpression and the consequent increase in CDK2 activity in trastuzumab resistance and suggest that treatment with CDK2 inhibitors may be a valid strategy in patients with breast tumors with HER2 and cyclin E coamplification/overexpression.


Assuntos
Anticorpos Monoclonais/farmacologia , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Ciclina E/genética , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Amplificação de Genes/efeitos dos fármacos , Proteínas Oncogênicas/genética , Receptor ErbB-2/metabolismo , Anticorpos Monoclonais Humanizados , Neoplasias da Mama/enzimologia , Linhagem Celular Tumoral , Quinase 2 Dependente de Ciclina/antagonistas & inibidores , Quinase 2 Dependente de Ciclina/metabolismo , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Humanos , Modelos Biológicos , Inibidores de Proteínas Quinases/farmacologia , Trastuzumab
6.
J Pharm Bioallied Sci ; 12(3): 289-294, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33100789

RESUMO

CONTEXT: For several decades, warfarin has been considered the mainstay anticoagulant for patients who require long-term prevention or treatment of thromboembolic disorders in outpatient settings. Hospital and community pharmacists--with adequate knowledge level and counseling skills--can play a significant role in improving warfarin therapy. AIMS: The aim of this study was to assess the hospital and community pharmacists' warfarin therapy knowledge and counseling practices in the eastern province of Saudi Arabia. MATERIALS AND METHODS: A cross-sectional study was conducted for 2 months. A self-administered questionnaire was designed focusing on warfarin mechanism of action, indications, safety profile, management of toxicity, monitoring, drug/food interactions, and patient education. The questionnaire was distributed among a random sample of hospital and community pharmacists in the Eastern Province of Saudi Arabia. RESULTS: One hundred and fifty-three pharmacists participated in the study; ninety-seven of them were hospital-based (63.4%), whereas the remaining were community pharmacists. Participant's mean years' of experience was 5.67. In terms of the percentage of right answers, hospital pharmacists showed significantly better warfarin therapy knowledge than community pharmacists (P = 0.026). The percentages of right answers were 31.3% for drug/food interactions, 49.9% for safety profile/management of toxicity, 53.3% for patient education, and 58.2% for monitoring warfarin safety/efficacy. Neither the participants' educational level nor their duration of experience had a significant correlation with the percentage of right answers (P = 0.22 and 0.61). CONCLUSION: Inadequate knowledge and inappropriate practices were encountered among study participants, especially community pharmacists. Therefore, specialized training of pharmacists about warfarin therapy management is essential to optimize therapeutic outcomes and prevent complications.

7.
Clin Cancer Res ; 26(14): 3720-3731, 2020 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-32220884

RESUMO

PURPOSE: AZD5363/capivasertib is a pan-AKT catalytic inhibitor with promising activity in combination with paclitaxel in triple-negative metastatic breast cancer harboring PI3K/AKT-pathway alterations and in estrogen receptor-positive breast cancer in combination with fulvestrant. Here, we aimed to identify response biomarkers and uncover mechanisms of resistance to AZD5363 and its combination with paclitaxel. EXPERIMENTAL DESIGN: Genetic and proteomic markers were analyzed in 28 HER2-negative patient-derived xenografts (PDXs) and in patient samples, and correlated to AZD5363 sensitivity as single agent and in combination with paclitaxel. RESULTS: Four PDX were derived from patients receiving AZD5363 in the clinic which exhibited concordant treatment response. Mutations in PIK3CA/AKT1 and absence of mTOR complex 1 (mTORC1)-activating alterations, for example, in MTOR or TSC1, were associated with sensitivity to AZD5363 monotherapy. Interestingly, excluding PTEN from the composite biomarker increased its accuracy from 64% to 89%. Moreover, resistant PDXs exhibited low baseline pAKT S473 and residual pS6 S235 upon treatment, suggesting that parallel pathways bypass AKT/S6K1 signaling in these models. We identified two mechanisms of acquired resistance to AZD5363: cyclin D1 overexpression and loss of AKT1 p.E17K. CONCLUSIONS: This study provides insight into putative predictive biomarkers of response and acquired resistance to AZD5363 in HER2-negative metastatic breast cancer.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Biomarcadores Tumorais/genética , Neoplasias da Mama/terapia , Resistencia a Medicamentos Antineoplásicos/genética , Inibidores de Proteínas Quinases/farmacologia , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Mama/patologia , Mama/cirurgia , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Quimioterapia Adjuvante/métodos , Classe I de Fosfatidilinositol 3-Quinases/genética , Análise Mutacional de DNA , Feminino , Humanos , Mastectomia , Camundongos , Mutação , Paclitaxel/farmacologia , Paclitaxel/uso terapêutico , Prognóstico , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas c-akt/genética , Pirimidinas/farmacologia , Pirimidinas/uso terapêutico , Pirróis/farmacologia , Pirróis/uso terapêutico , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/genética , Proteína 1 do Complexo Esclerose Tuberosa/genética , Ensaios Antitumorais Modelo de Xenoenxerto
8.
Mol Cancer Res ; 6(9): 1491-8, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18819936

RESUMO

Progesterone action contributes to the signaling of many growth factor pathways relevant to breast cancer tumor biology, including the insulin-like growth factor (IGF) system. Previous work has shown that insulin receptor substrate-2 (IRS-2) but not IRS-1 levels were regulated by progestin in progesterone receptor-B (PR-B) isoform expressing MCF-7 cells (C4-12 PR-B). Furthermore, type 1 IGF receptor (IGF1R) signaling via IRS-2 correlated with the increased cell migration observed in a number of breast cancer cell lines. Consequently, in this study, we examined whether the elevation of IRS-2 protein induced by progestin was sufficient to promote IGF-I-stimulated cell motility. Treatment of C4-12 PR-B cells with progestin shifted the balance of phosphorylation from IRS-1 to IRS-2 in response to IGF-I. This shift in IRS-2 activation was associated with enhanced migration in C4-12 PR-B cells pretreated with progestin, but had no effect on cell proliferation or survival. Treatment of C4-12 PR-B cells with RU486, an antiprogestin, inhibited IGF-induced cell migration. Attenuation of IRS-2 expression using small interfering RNA resulted in decreased IGF-stimulated motility. In addition, IRS-2 knockdown resulted in an abrogation of PKB/Akt phosphorylation but not mitogen-activated protein kinase. Consequently, LY294002, a phosphoinositide-3-kinase inhibitor, abolished IGF-induced cell motility in progestin-treated C4-12 PR-B cells. These data show a role for the PR in functionally promoting growth factor signaling, showing that levels of IRS proteins can determine IGF-mediated biology, PR-B signaling regulates IRS-2 expression, and that IRS-2 can mediate IGF-induced cell migration via phosphoinositide-3-kinase in breast cancer cells.


Assuntos
Neoplasias da Mama/metabolismo , Movimento Celular/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Fator de Crescimento Insulin-Like I/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Fosfoproteínas/metabolismo , Receptores de Progesterona/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Apoptose/efeitos dos fármacos , Neoplasias da Mama/patologia , Adesão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Feminino , Humanos , Imunoprecipitação , Proteínas Substratos do Receptor de Insulina , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Fosfoproteínas/genética , Fosforilação/efeitos dos fármacos , Progestinas , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Células Tumorais Cultivadas
9.
J Pharm Bioallied Sci ; 11(2): 181-186, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31148896

RESUMO

INTRODUCTION: Cardiovascular diseases (CVDs) are one of the leading causes of morbidity and mortality worldwide. Although genetics could contribute to the incidence of CVD, they are mostly acquired conditions. Management of precipitating factors such as hyperlipidemia can prevent CVD. Therefore, clinical guidelines have been used as a tool to improve patient outcomes and minimize practice variation. OBJECTIVE: The objective of this study was to assess health-care providers' (physicians and clinical pharmacists) awareness about the latest edition of the American College of Cardiology/American Heart Association (ACC/AHA) guidelines of dyslipidemia management. MATERIALS AND METHODS: To meet the study objective, a self-administered questionnaire was designed based on the recommendations of the latest edition of the ACC/AHA guidelines for dyslipidemia management. After validation, the questionnaire was distributed to physicians and clinical pharmacists in Al-Ahsa province of Saudi Arabia. RESULTS: Validation of the questionnaire was carried on 10 participants (Cronbach's alpha = 0.816). Seventy-seven participants completed the questionnaire (acceptance rate = 51.33%). The majority of participants knew about the release of the ACC/AHA 2013 guidelines for dyslipidemia (77% of the physicians and 48% of the clinical pharmacist). Inadequate knowledge of the major changes in the dyslipidemia management was observed in both study groups with no significant difference between them (the median score for physicians and pharmacists was 4 out of 10 with a range of 1-9, Z = -0.15, P = 0.88). CONCLUSION: Inadequate level of knowledge about practice-changing recommendations of the recent ACC/AHA guidelines for dyslipidemia management was observed among the study participants. This level of knowledge could result in clinical malpractice and worsen management outcomes. Thus, efforts should be in place to raise awareness about the evidence-based management of dyslipidemia and monitor compliance to guidelines and their implementation outcomes.

10.
Ann Saudi Med ; 38(5): 319-325, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30284986

RESUMO

BACKGROUND: The problem of substance abuse is one of the top 20 risk factors for poor health worldwide. Though widely prevalent in the Middle East, there are few studies in Saudi Arabia. OBJECTIVE: Record the pattern of substances abuse and the sociodemographic characteristics of abusers attending the local rehabilitation center. DESIGN: Descriptive, retrospective medical record review. SETTING: Patients admitted to psychiatric rehabilitation center. METHODS: The sample included all patients admitted to a rehabilitation center during the period of January 2016-December 2016. Data was collected retrospectively from patient records. MAIN OUTCOME MEASURES: Descriptive epidemiological data and statistical comparisons. SAMPLE SIZE: 612 patients. RESULTS: The majority of patients (73%) were 21-40 years of age. Polysubstance abuse (60%) and amphetamine (24%) abuse were most predominant in the 20-40 year olds (45%) and high school dropouts (41%). The average number of drugs being used by polysubstance abusers was 2.5 (and the maximum was 6). There was no relationship of family history of drug abuse and mental illness. CONCLUSION: There was an increased use of polysubstances and amphetamine with a decreased abuse of prescription drugs when compared to previous studies reported in Saudi Arabia. There was a decreasing prevalence for heroin and alcohol. Substance abusers have certain epidemiological, social and drug patterns and we recommend that authorities and planners integrate their efforts to look for the reasons for substance abuse. LIMITATIONS: Females not included and prevalence of tobacco smoking not studied. CONFLICT OF INTEREST: None.


Assuntos
Centros de Tratamento de Abuso de Substâncias , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Adolescente , Adulto , Fatores Etários , Idoso , Transtornos Relacionados ao Uso de Álcool/epidemiologia , Transtornos Relacionados ao Uso de Anfetaminas/epidemiologia , Criança , Escolaridade , Humanos , Masculino , Abuso de Maconha/epidemiologia , Pessoa de Meia-Idade , Estudos Retrospectivos , Arábia Saudita/epidemiologia , Centros de Tratamento de Abuso de Substâncias/estatística & dados numéricos , Adulto Jovem
11.
EMBO Mol Med ; 10(12)2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30377213

RESUMO

Poly(ADP-ribose) polymerase (PARP) inhibitors (PARPi) are effective in cancers with defective homologous recombination DNA repair (HRR), including BRCA1/2-related cancers. A test to identify additional HRR-deficient tumors will help to extend their use in new indications. We evaluated the activity of the PARPi olaparib in patient-derived tumor xenografts (PDXs) from breast cancer (BC) patients and investigated mechanisms of sensitivity through exome sequencing, BRCA1 promoter methylation analysis, and immunostaining of HRR proteins, including RAD51 nuclear foci. In an independent BC PDX panel, the predictive capacity of the RAD51 score and the homologous recombination deficiency (HRD) score were compared. To examine the clinical feasibility of the RAD51 assay, we scored archival breast tumor samples, including PALB2-related hereditary cancers. The RAD51 score was highly discriminative of PARPi sensitivity versus PARPi resistance in BC PDXs and outperformed the genomic test. In clinical samples, all PALB2-related tumors were classified as HRR-deficient by the RAD51 score. The functional biomarker RAD51 enables the identification of PARPi-sensitive BC and broadens the population who may benefit from this therapy beyond BRCA1/2-related cancers.


Assuntos
Antineoplásicos/administração & dosagem , Neoplasias da Mama/diagnóstico , Resistencia a Medicamentos Antineoplásicos , Xenoenxertos/patologia , Ftalazinas/administração & dosagem , Piperazinas/administração & dosagem , Inibidores de Poli(ADP-Ribose) Polimerases/administração & dosagem , Rad51 Recombinase/análise , Animais , Biomarcadores Tumorais/análise , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Feminino , Recombinação Homóloga , Humanos , Camundongos
12.
Clin Cancer Res ; 11(2 Pt 2): 944s-50s, 2005 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-15701891

RESUMO

Targeting hormonal and growth factor signaling pathways has proven to be useful in the treatment of breast cancer. In vitro, animal, and epidemiologic evidence provide a rationale for the relevance of the insulin-like growth factor (IGF) system to breast cancer biology. The IGF system has been implicated in promoting mitogenic, metastatic, and antiapoptotic phenotypes in breast cancer. As a consequence of the ability of IGF to promote tumorigenesis, pharmacologic interventions targeting the IGF system are being devised. Such strategies include decreasing ligand production, ligand binding, or receptor activation. In this article, directed anti-IGF strategies and the possible clinical impact of using such therapies for treating breast cancer are discussed.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Proteína 1 de Ligação a Fator de Crescimento Semelhante à Insulina/uso terapêutico , Fator de Crescimento Insulin-Like I/antagonistas & inibidores , Neoplasias da Mama/patologia , Transformação Celular Neoplásica/metabolismo , Feminino , Humanos
13.
PLoS One ; 11(3): e0150564, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26991655

RESUMO

Therapies targeting the type I insulin-like growth factor receptor (IGF-1R) have not been developed with predictive biomarkers to identify tumors with receptor activation. We have previously shown that the insulin receptor substrate (IRS) adaptor proteins are necessary for linking IGF1R to downstream signaling pathways and the malignant phenotype in breast cancer cells. The purpose of this study was to identify gene expression profiles downstream of IGF1R and its two adaptor proteins. IRS-null breast cancer cells (T47D-YA) were engineered to express IRS-1 or IRS-2 alone and their ability to mediate IGF ligand-induced proliferation, motility, and gene expression determined. Global gene expression signatures reflecting IRS adaptor specific and primary vs. secondary ligand response were derived (Early IRS-1, Late IRS-1, Early IRS-2 and Late IRS-2) and functional pathway analysis examined. IRS isoforms mediated distinct gene expression profiles, functional pathways, and breast cancer subtype association. For example, IRS-1/2-induced TGFb2 expression and blockade of TGFb2 abrogated IGF-induced cell migration. In addition, the prognostic value of IRS proteins was significant in the luminal B breast tumor subtype. Univariate and multivariate analyses confirmed that IRS adaptor signatures correlated with poor outcome as measured by recurrence-free and overall survival. Thus, IRS adaptor protein expression is required for IGF ligand responses in breast cancer cells. IRS-specific gene signatures represent accurate surrogates of IGF activity and could predict response to anti-IGF therapy in breast cancer.


Assuntos
Neoplasias da Mama/metabolismo , Regulação Neoplásica da Expressão Gênica , Proteínas Substratos do Receptor de Insulina/biossíntese , Proteínas de Neoplasias/biossíntese , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Feminino , Humanos , Prognóstico , Fator de Crescimento Transformador beta2/biossíntese
14.
Nat Commun ; 7: 12595, 2016 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-27553708

RESUMO

Patient stratification has been instrumental for the success of targeted therapies in breast cancer. However, the molecular basis of metastatic breast cancer and its therapeutic vulnerabilities remain poorly understood. Here we show that PML is a novel target in aggressive breast cancer. The acquisition of aggressiveness and metastatic features in breast tumours is accompanied by the elevated PML expression and enhanced sensitivity to its inhibition. Interestingly, we find that STAT3 is responsible, at least in part, for the transcriptional upregulation of PML in breast cancer. Moreover, PML targeting hampers breast cancer initiation and metastatic seeding. Mechanistically, this biological activity relies on the regulation of the stem cell gene SOX9 through interaction of PML with its promoter region. Altogether, we identify a novel pathway sustaining breast cancer aggressiveness that can be therapeutically exploited in combination with PML-based stratification.


Assuntos
Neoplasias da Mama/secundário , Neoplasias da Mama/terapia , Proteína da Leucemia Promielocítica/antagonistas & inibidores , Proteína da Leucemia Promielocítica/metabolismo , Animais , Trióxido de Arsênio , Arsenicais/farmacologia , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Feminino , Técnicas de Silenciamento de Genes , Humanos , Células MCF-7 , Camundongos , Invasividade Neoplásica/genética , Óxidos/farmacologia , Regiões Promotoras Genéticas , Proteína da Leucemia Promielocítica/genética , Fatores de Transcrição SOX9/genética , Fator de Transcrição STAT3/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
15.
Clin Cancer Res ; 21(24): 5499-5510, 2015 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-26272063

RESUMO

PURPOSE: PI3K pathway activation occurs in concomitance with RAS/BRAF mutations in colorectal cancer, limiting the sensitivity to targeted therapies. Several clinical studies are being conducted to test the tolerability and clinical activity of dual MEK and PI3K pathway blockade in solid tumors. EXPERIMENTAL DESIGN: In the present study, we explored the efficacy of dual pathway blockade in colorectal cancer preclinical models harboring concomitant activation of the ERK and PI3K pathways. Moreover, we investigated if TP53 mutation affects the response to this therapy. RESULTS: Dual MEK and mTORC1/2 blockade resulted in synergistic antiproliferative effects in cell lines bearing alterations in KRAS/BRAF and PIK3CA/PTEN. Although the on-treatment cell-cycle effects were not affected by the TP53 status, a marked proapoptotic response to therapy was observed exclusively in wild-type TP53 colorectal cancer models. We further interrogated two independent panels of KRAS/BRAF- and PIK3CA/PTEN-altered cell line- and patient-derived tumor xenografts for the antitumor response toward this combination of agents. A combination response that resulted in substantial antitumor activity was exclusively observed among the wild-type TP53 models (two out of five, 40%), but there was no such response across the eight mutant TP53 models (0%). Interestingly, within a cohort of 14 patients with colorectal cancer treated with these agents for their metastatic disease, two patients with long-lasting responses (32 weeks) had TP53 wild-type tumors. CONCLUSIONS: Our data support that, in wild-type TP53 colorectal cancer cells with ERK and PI3K pathway alterations, MEK blockade results in potent p21 induction, preventing apoptosis to occur. In turn, mTORC1/2 inhibition blocks MEK inhibitor-mediated p21 induction, unleashing apoptosis. Clin Cancer Res; 21(24); 5499-510. ©2015 AACR.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Mutação , Inibidores de Proteínas Quinases/farmacologia , Proteína Supressora de Tumor p53/genética , Animais , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/patologia , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Modelos Animais de Doenças , Sinergismo Farmacológico , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , Feminino , Humanos , Alvo Mecanístico do Complexo 1 de Rapamicina , Alvo Mecanístico do Complexo 2 de Rapamicina , Camundongos , Complexos Multiproteicos/antagonistas & inibidores , Inibidores de Fosfoinositídeo-3 Quinase , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/antagonistas & inibidores , Proteína Supressora de Tumor p53/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto , Proteína X Associada a bcl-2/metabolismo
16.
Sci Transl Med ; 7(283): 283ra51, 2015 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-25877889

RESUMO

Activating mutations of PIK3CA are the most frequent genomic alterations in estrogen receptor (ER)-positive breast tumors, and selective phosphatidylinositol 3-kinase α (PI3Kα) inhibitors are in clinical development. The activity of these agents, however, is not homogeneous, and only a fraction of patients bearing PIK3CA-mutant ER-positive tumors benefit from single-agent administration. Searching for mechanisms of resistance, we observed that suppression of PI3K signaling results in induction of ER-dependent transcriptional activity, as demonstrated by changes in expression of genes containing ER-binding sites and increased occupancy by the ER of promoter regions of up-regulated genes. Furthermore, expression of ESR1 mRNA and ER protein were also increased upon PI3K inhibition. These changes in gene expression were confirmed in vivo in xenografts and patient-derived models and in tumors from patients undergoing treatment with the PI3Kα inhibitor BYL719. The observed effects on transcription were enhanced by the addition of estradiol and suppressed by the anti-ER therapies fulvestrant and tamoxifen. Fulvestrant markedly sensitized ER-positive tumors to PI3Kα inhibition, resulting in major tumor regressions in vivo. We propose that increased ER transcriptional activity may be a reactive mechanism that limits the activity of PI3K inhibitors and that combined PI3K and ER inhibition is a rational approach to target these tumors.


Assuntos
Neoplasias da Mama/metabolismo , Receptor alfa de Estrogênio/metabolismo , Mutação , Fosfatidilinositol 3-Quinases/metabolismo , Animais , Antineoplásicos/química , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Retículo Endoplasmático/metabolismo , Feminino , Humanos , Células MCF-7 , Camundongos , Camundongos Nus , Metástase Neoplásica , Transplante de Neoplasias , Análise de Sequência com Séries de Oligonucleotídeos , Inibidores de Fosfoinositídeo-3 Quinase , Projetos de Pesquisa , Transdução de Sinais , Tiazóis/farmacologia
17.
Growth Horm IGF Res ; 14(4): 261-9, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15231294

RESUMO

Growth factor pathways are fundamental in normal tissue regulation and development. In many tissues, factors that function in normal growth and development also have important regulatory roles in transformed malignant cells. The insulin-like growth factor (IGF) system is implicated in the regulation of the malignant phenotype by its effects on proliferation, differentiation, and apoptosis. IGF-I has also been linked to malignant transformation. The role of the IGF-I in cancer has been recognized in both experimental and clinical settings, suggesting that the enhancement of growth factor pathways potentially could increase the risk for cancer development. In this paper, the role of IGF-I signaling in tumor regulation, and the impact of IGF-I modulation using growth hormone replacement therapy are discussed.


Assuntos
Neoplasias da Mama/metabolismo , Receptor alfa de Estrogênio/metabolismo , Hormônio do Crescimento/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Animais , Estrogênios/metabolismo , Humanos , Neoplasias/metabolismo , Risco , Transdução de Sinais
18.
Artigo | IMSEAR | ID: sea-205697

RESUMO

The national medications safety program founded in 2013 at the Ministry of Health hospitals and primary care centers in the Kingdom of Saudi Arabia. The program focused on adults, pediatrics and neonatal populations. The program was part of the pharmacy strategic plan. The electrolyte replacement therapy preparation and administration for neonates and pediatrics published and distributed as required of the medication safety program. The new initiatives as complementary project was a standardized concentration of electrolyte replacement therapy for neonates and pediatrics implemented at specific hospitals of the Ministry of health. The new project as regular physician’s order form and coveted to computerized physician order entry. The new project prevents neonates and pediatrics medication errors of electrolyte replacement therapy. The project is a new initiative at Ministry of Health hospitals in the Kingdom of Saudi, Gulf and Middle East countries.

19.
Artigo | IMSEAR | ID: sea-205695

RESUMO

The national pediatric pharmacy program was founded in 2014. It is a part of the pharmacy strategic plan. This program has implemented several projects including preparation and administration of intravenous medication to neonates and pediatric patients. The complementary new initiatives program is the neonates and pediatrics standardized concentration of emergency medications with an emphasis on medications used to treat critically ill patients and in emergency department. This new project has physician order form with selected dilutions, concentrations and route of administration. The form may be converted to a computerized order form. The new initiatives of the project may be implemented through project management tools. The project prevents drug-related problem and decrease economic burden on healthcare system for neonates and pediatrics hospitals in the Kingdom of Saudi Arabia.

20.
Artigo | IMSEAR | ID: sea-205696

RESUMO

The electrolyte replacement therapy consternation considered one of the high alert drugs. Most of the medication safety organizations have established preventive guidelines for the prescription of electrolyte therapy. The General Administration of Pharmaceutical Care at the Ministry of Health in the Kingdom of Saudi Arabia also has established guidelines for the preparation and administration of electrolyte replacement for adult patients. This new initiative is regarding the standardized concentration of electrolyte preparation and administration for adult patients. The electrolyte therapy may be prescribed via a physician order form, which may be easily converted as computerized physician order entry. This from is designed to prevent all electrolyte-related errors and improve patient outcomes. This project is a new tool implemented for electrolyte safety at the Ministry of Health hospitals in the Kingdom of Saudi Arabia.

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