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We used clinical tissue from lethal metastatic castration-resistant prostate cancer (CRPC) patients obtained at rapid autopsy to evaluate diverse genomic, transcriptomic, and phosphoproteomic datasets for pathway analysis. Using Tied Diffusion through Interacting Events (TieDIE), we integrated differentially expressed master transcriptional regulators, functionally mutated genes, and differentially activated kinases in CRPC tissues to synthesize a robust signaling network consisting of druggable kinase pathways. Using MSigDB hallmark gene sets, six major signaling pathways with phosphorylation of several key residues were significantly enriched in CRPC tumors after incorporation of phosphoproteomic data. Individual autopsy profiles developed using these hallmarks revealed clinically relevant pathway information potentially suitable for patient stratification and targeted therapies in late stage prostate cancer. Here, we describe phosphorylation-based cancer hallmarks using integrated personalized signatures (pCHIPS) that shed light on the diversity of activated signaling pathways in metastatic CRPC while providing an integrative, pathway-based reference for drug prioritization in individual patients.
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Fosfoproteínas/análise , Neoplasias de Próstata Resistentes à Castração/química , Proteoma/análise , Algoritmos , Humanos , Masculino , Medicina de Precisão , Neoplasias de Próstata Resistentes à Castração/metabolismo , Transdução de Sinais , TranscriptomaRESUMO
BACKGROUND: The COVID-19 pandemic has resulted in delays in presentation for other urgent medical conditions, including pediatric appendicitis. Several single-center studies have reported worse outcomes, but no state-level data is available. We aimed to determine the statewide effect of the COVID-19 pandemic on the presentation and management of pediatric appendicitis patients. MATERIALS AND METHODS: Patients < 18 years old with acute appendicitis at four tertiary pediatric hospitals in California between March 19, 2020 to September 19, 2020 (COVID-era) were compared to a pre-COVID cohort (March 19, 2019 to September 19, 2019). The primary outcome was the rate of perforated appendicitis. Secondary outcomes were symptom duration prior to presentation, and rates of non-operative management. RESULTS: Rates of perforated appendicitis were unchanged (40.4% of 592 patients pre-COVID versus 42.1% of 606 patients COVID-era, P = 0.17). The median symptom duration was 2 days in both cohorts (P = 0.90). Computed tomography (CT) use rose from 39.8% pre-COVID to 49.4% during COVID (P = 0.002). Non-operative management increased during the pandemic (8.8% pre-COVID versus 16.2% COVID-era, P < 0.0001). Hospital length of stay (LOS) was longer (2 days pre-COVID versus 3 days during COVID, P < 0.0001). CONCLUSIONS: Pediatric perforated appendicitis rates did not rise during the first six months of the COVID-19 pandemic in California in this multicenter study, and there were no delays in presentation noted. There was a higher rate of CT scans, non-operative management, and longer hospital lengths of stay.
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Apendicite , COVID-19 , Adolescente , Apendicite/epidemiologia , Apendicite/cirurgia , California/epidemiologia , Criança , Humanos , PandemiasRESUMO
BACKGROUND & AIMS: With the rising prevalence of alcoholism, obesity and metabolic syndrome, steatohepatitis will become the leading cause of end-stage liver disease and hepatocellular carcinoma in the United States by 2025. Patients with non-alcoholic steatohepatitis and alcoholic liver disease have similar clinical and histopathological presentations, whether these similarities persist in non-alcoholic steatohepatitis and alcoholic liver disease patients with hepatocellular carcinoma remains unknown. METHODS: A retrospective analysis of the clinical features of adult patients from a large transplant center who underwent liver transplantation for steatohepatitis due to non-alcoholic steatohepatitis and alcoholic causes (alcoholic liver disease) between 1/1/02 and 1/1/12 was performed. Clinical features, explant histopathology, and clinical outcomes were compared. RESULTS: Hepatocellular carcinoma was present in 80 of 317 patients, who underwent liver transplantation for steatohepatitis with equivalent distribution in non-alcoholic steatohepatitis and alcoholic liver disease patients (24% vs 26%; P = 0.8). On multivariate analysis, significant predictors of hepatocellular carcinoma included age, ethnicity (Hispanic), and diabetes, but not BMI, hypertension or smoking. A lower risk of hepatocellular carcinoma was associated with a clinical history of hyperlipidemia. Clinical parameters were similar between patients with alcoholic liver disease - hepatocellular carcinoma and non-alcoholic steatohepatitis-hepatocellular carcinoma, except sex and presence of metabolic syndrome. non-alcoholic steatohepatitis-hepatocellular carcinoma livers retained histopathological features of non-alcoholic steatohepatitis such as ballooning and Mallory bodies, while alcoholic liver disease-hepatocellular carcinoma livers did not. There were no significant differences in hepatocellular carcinoma recurrence rates or post-transplant overall survival. CONCLUSIONS: We report the largest single-center study evaluating clinical, histopathological and outcome measures of patients undergoing liver transplantation for steatohepatitis. Older patients, diabetics, and Hispanics may warrant more frequent cancer screening due to increased risk of hepatocellular carcinoma.
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Carcinoma Hepatocelular/epidemiologia , Diabetes Mellitus Tipo 2/epidemiologia , Fígado Gorduroso Alcoólico/epidemiologia , Hiperlipidemias/epidemiologia , Neoplasias Hepáticas/epidemiologia , Hepatopatia Gordurosa não Alcoólica/epidemiologia , Fatores Etários , Idoso , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/patologia , Diabetes Mellitus Tipo 2/diagnóstico , Fígado Gorduroso Alcoólico/diagnóstico , Fígado Gorduroso Alcoólico/mortalidade , Fígado Gorduroso Alcoólico/cirurgia , Feminino , Hispânico ou Latino , Humanos , Hiperlipidemias/diagnóstico , Hiperlipidemias/mortalidade , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Transplante de Fígado , Masculino , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/diagnóstico , Hepatopatia Gordurosa não Alcoólica/mortalidade , Hepatopatia Gordurosa não Alcoólica/cirurgia , Prevalência , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Resultado do TratamentoRESUMO
Mutationally activated kinases play an important role in the progression and metastasis of many cancers. Despite numerous oncogenic alterations implicated in metastatic prostate cancer, mutations of kinases are rare. Several lines of evidence suggest that nonmutated kinases and their pathways are involved in prostate cancer progression, but few kinases have been mechanistically linked to metastasis. Using a mass spectrometry-based phosphoproteomics dataset in concert with gene expression analysis, we selected over 100 kinases potentially implicated in human metastatic prostate cancer for functional evaluation. A primary in vivo screen based on overexpression of candidate kinases in murine prostate cells identified 20 wild-type kinases that promote metastasis. We queried these 20 kinases in a secondary in vivo screen using human prostate cells. Strikingly, all three RAF family members, MERTK, and NTRK2 drove the formation of bone and visceral metastasis confirmed by positron-emission tomography combined with computed tomography imaging and histology. Immunohistochemistry of tissue microarrays indicated that these kinases are highly expressed in human metastatic castration-resistant prostate cancer tissues. Our functional studies reveal the strong capability of select wild-type protein kinases to drive critical steps of the metastatic cascade, and implicate these kinases in possible therapeutic intervention.
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Neoplasias Ósseas/secundário , Neoplasias da Próstata/patologia , Proteínas Quinases/metabolismo , Vísceras/patologia , Animais , Neoplasias Ósseas/patologia , Osso e Ossos/patologia , Linhagem Celular Tumoral , Perfilação da Expressão Gênica , Humanos , Lentivirus , Pulmão/metabolismo , Masculino , Camundongos , Camundongos SCID , Proteínas de Neoplasias/metabolismo , Fosfoproteínas/metabolismo , Proteômica , Quinases da Família src/metabolismoRESUMO
Metastatic castration-resistant prostate cancer (CRPC) is the primary cause of prostate cancer-specific mortality. Defining new mechanisms that can predict recurrence and drive lethal CRPC is critical. Here, we demonstrate that localized high-risk prostate cancer and metastatic CRPC, but not benign prostate tissues or low/intermediate-risk prostate cancer, express high levels of nuclear Notch homolog 1, translocation-associated (Notch1) receptor intracellular domain. Chronic activation of Notch1 synergizes with multiple oncogenic pathways altered in early disease to promote the development of prostate adenocarcinoma. These tumors display features of epithelial-to-mesenchymal transition, a cellular state associated with increased tumor aggressiveness. Consistent with its activation in clinical CRPC, tumors driven by Notch1 intracellular domain in combination with multiple pathways altered in prostate cancer are metastatic and resistant to androgen deprivation. Our study provides functional evidence that the Notch1 signaling axis synergizes with alternative pathways in promoting metastatic CRPC and may represent a new therapeutic target for advanced prostate cancer.
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Neoplasias de Próstata Resistentes à Castração/metabolismo , Receptor Notch1/metabolismo , Transdução de Sinais , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Animais , Biomarcadores , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Transição Epitelial-Mesenquimal/genética , Expressão Gênica , Perfilação da Expressão Gênica , Xenoenxertos , Humanos , Imuno-Histoquímica , Masculino , Camundongos , Proteínas Quinases Ativadas por Mitógeno , Gradação de Tumores , Metástase Neoplásica , Fenótipo , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/patologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Receptor Notch1/antagonistas & inibidores , Receptor Notch1/genética , Carga Tumoral , Quinases raf/metabolismo , Proteínas ras/metabolismoRESUMO
In prostate cancer, multiple metastases from the same patient share similar copy number, mutational status, erythroblast transformation specific (ETS) rearrangements, and methylation patterns supporting their clonal origins. Whether actionable targets such as tyrosine kinases are also similarly expressed and activated in anatomically distinct metastatic lesions of the same patient is not known. We evaluated active kinases using phosphotyrosine peptide enrichment and quantitative mass spectrometry to identify druggable targets in metastatic castration-resistant prostate cancer obtained at rapid autopsy. We identified distinct phosphopeptide patterns in metastatic tissues compared with treatment-naive primary prostate tissue and prostate cancer cell line-derived xenografts. Evaluation of metastatic castration-resistant prostate cancer samples for tyrosine phosphorylation and upstream kinase targets revealed SRC, epidermal growth factor receptor (EGFR), rearranged during transfection (RET), anaplastic lymphoma kinase (ALK), and MAPK1/3 and other activities while exhibiting intrapatient similarity and interpatient heterogeneity. Phosphoproteomic analyses and identification of kinase activation states in metastatic castration-resistant prostate cancer patients have allowed for the prioritization of kinases for further clinical evaluation.
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Descoberta de Drogas/métodos , Metástase Neoplásica/tratamento farmacológico , Fosfoproteínas/metabolismo , Medicina de Precisão/métodos , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/enzimologia , Proteínas Tirosina Quinases/metabolismo , Western Blotting , Linhagem Celular Tumoral , Ativação Enzimática/efeitos dos fármacos , Receptores ErbB/metabolismo , Humanos , Masculino , Espectrometria de Massas , Fosforilação , Fosfotirosina/metabolismo , Análise de Componente PrincipalRESUMO
Objective: The study objective was to determine what proportion of asymptomatic patients had resectable lung cancer detected through lung cancer screening versus incidentally. Methods: We performed a retrospective study of patients who underwent resection for lung cancer between January 2015 and December 2020. We then assessed whether asymptomatic patients with incidentally found lung cancers were eligible for lung cancer screening using the National Comprehensive Cancer Network, United States Preventive Services Task Force, Centers for Medicare & Medicaid Services, American College of Chest Physicians, American Cancer Society, and American Society of Clinical Oncology guidelines. Results: Of 539 patients who underwent resection for primary lung cancer, 437 (81%) were asymptomatic and 355 (66%) of these patients had lung cancer found discovered incidentally. Of the 355 patients with incidentally detected lung cancer, 10 were excluded for insufficient data. Of the remaining 345 patients, 110 (32%) would have been eligible for screening using National Comprehensive Cancer Network guidelines, 65 (19%) using 2021 United States Preventive Services Task Force guidelines, 53 (15%) using 2013 United States Preventive Services Task Force guidelines, 64 (19%) using 2022 Centers for Medicare & Medicaid Services guidelines, 52 (15%) using 2015 Centers for Medicare & Medicaid Services/American College of Chest Physicians guidelines, and 45 (13%) using American Cancer Society/American Society of Clinical Oncology guidelines. Of the 280 patients who were screen ineligible by 2021 United States Preventive Services Task Force criteria, 143 patients (51%) never smoked, 112 patients (40%) quit smoking more than 15 years ago, 89 patients (32%) did not smoke at least 20 pack-years, and 44 patients (16%) were ineligible due to age. Conclusions: The majority of asymptomatic patients with resectable lung cancers had lung cancer identified incidentally and not through lung cancer screening. Most of these patients were not eligible for screening under current guidelines. This study suggests a need for improved lung cancer screening implementation and further investigation in the identification and assessment of risk factors for lung cancer.
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OBJECTIVE: Gliomas are intrinsic brain tumors with the hallmark of diffuse white matter infiltration, resulting in short- and long-range network dysfunction. Preoperative magnetoencephalography (MEG) can assist in maximizing the extent of resection while minimizing morbidity. While MEG has been validated in motor mapping, its role in speech mapping remains less well studied. The authors assessed how the resection of intraoperative electrical stimulation (IES)-negative, high functional connectivity (HFC) network sites, as identified by MEG, impacts language performance. METHODS: Resting-state, whole-brain MEG recordings were obtained from 26 patients who underwent perioperative language evaluation and glioma resection that was guided by awake language and IES mapping. The functional connectivity of an individual voxel was determined by the imaginary coherence between the index voxel and the rest of the brain, referenced to its contralesional pair. The percentage of resected HFC voxels was correlated with postoperative language outcomes in tasks of increasing complexity: text reading, 4-syllable repetition, picture naming, syntax (SYN), and auditory stimulus naming (AN). RESULTS: Overall, 70% of patients (14/20) in whom any HFC tissue was resected developed an early postoperative language deficit (mean 2.3 days, range 1-8 days), compared to 33% of patients (2/6) in whom no HFC tissue was resected (p = 0.16). When bifurcated by the amount of HFC tissue that was resected, 100% of patients (3/3) with an HFC resection > 25% displayed deficits in AN, compared to 30% of patients (6/20) with an HFC resection < 25% (p = 0.04). Furthermore, there was a linear correlation between the severity of AN and SYN decline with percentage of HFC sites resected (p = 0.02 and p = 0.04, respectively). By 2.2 months postoperatively (range 1-6 months), the correlation between HFC resection and both AN and SYN decline had resolved (p = 0.94 and p = 1.00, respectively) in all patients (9/9) except two who experienced early postoperative tumor progression or stroke involving inferior frontooccipital fasciculus. CONCLUSIONS: Imaginary coherence measures of functional connectivity using MEG are able to identify HFC network sites within and around low- and high-grade gliomas. Removal of IES-negative HFC sites results in early transient postoperative decline in AN and SYN, which resolved by 3 months in all patients without stroke or early tumor progression. Measures of functional connectivity may therefore be a useful means of counseling patients about postoperative risk and assist with preoperative surgical planning.
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Neoplasias Encefálicas/psicologia , Neoplasias Encefálicas/cirurgia , Glioma/psicologia , Glioma/cirurgia , Idioma , Vias Neurais/cirurgia , Procedimentos Neurocirúrgicos/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Mapeamento Encefálico , Neoplasias Encefálicas/diagnóstico por imagem , Estimulação Elétrica , Feminino , Glioma/diagnóstico por imagem , Humanos , Testes de Linguagem , Imageamento por Ressonância Magnética , Magnetoencefalografia , Masculino , Pessoa de Meia-Idade , Vias Neurais/diagnóstico por imagem , Desempenho Psicomotor , Sistema de Registros , Fala , Resultado do Tratamento , Adulto JovemRESUMO
Pituitary adenomas are benign tumors, but still cause significant morbidity and in some cases increases in mortality. Surgical resection is not without risks, and approximately 40% of adenomas are incompletely resected. Medical therapies such as dopamine agonists, somatostatin analogues, and growth hormone antagonists are associated with numerous side effects. Understanding the molecular biology of pituitary adenomas may yield new therapeutic approaches. Additional studies are needed to help determine which genes or pathways are "drivers" of tumorigenesis and should be therapeutic targets. Further studies may also enable pituitary adenoma stratification to tailor treatment approaches.
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Adenoma/genética , Adenoma/metabolismo , Neoplasias Hipofisárias/genética , Neoplasias Hipofisárias/metabolismo , Adenoma Hipofisário Secretor de ACT/genética , Adenoma Hipofisário Secretor de ACT/metabolismo , Animais , Proteínas de Ligação a DNA , Epigênese Genética , Adenoma Hipofisário Secretor de Hormônio do Crescimento/genética , Adenoma Hipofisário Secretor de Hormônio do Crescimento/metabolismo , Humanos , Prolactinoma/genética , Prolactinoma/metabolismo , Transdução de Sinais , Proteínas ViraisRESUMO
[This corrects the article DOI: 10.1371/journal.pone.0223051.].
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INTRODUCTION: Brain tumors are the most common solid malignancy and leading cause of cancer-related deaths in infants. Current epidemiological data is limited by low numbers of reported cases. This study used a population-based approach with analysis of contemporary and historical survival curves to provide up-to-date prognostication. METHODS: Observational cohort analysis was performed using the Surveillance, Epidemiology and End Results (SEER) database. Infants with brain tumors diagnosed from 1973 to 2013 were categorized by the most common tumor types (diffuse astrocytic and oligodendroglioma, choroid plexus, embryonal, ependymal, medulloblastoma and pilocytic astrocytoma). The 1, 5 and 10 year survival was stratified by decade, with trends in management and outcomes analyzed. RESULTS: We identified 2996 affected infants satisfying inclusion criteria. All tumor types, except embryonal and choroid plexus, demonstrated improving survival with time. Infants with embryonal tumors showed a decline in survival from the 1970s to 1990s (p = 0.009), whereas infants with choroid plexus tumors had no change in survival. Infants with ependymal tumors experienced the greatest improvement in survival from 1980s to 1990s and 1990s to 2000s (p = 0.0001, p = 0.01), with 5-year survival probability improving from 28% (95% CI 15-42%) in the 1980s to 77% (95% CI 69-83%) the 2000s. The use of radiation declined from 1970 to 2000 for all tumors; however, radiation treatment for embryonal and ependymal subtypes increased after 2000. CONCLUSIONS: While overall survival for infants with brain tumors has improved from the 1970s onwards, not every tumor type has seen a statistically significant change. Given changes in management and survival, prognostication of infants with brain tumor should be updated.
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Neoplasias Encefálicas/mortalidade , Mortalidade Infantil/tendências , Pré-Escolar , Estudos de Coortes , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Prognóstico , Programa de SEER/estatística & dados numéricos , Análise de Sobrevida , Fatores de Tempo , Estados Unidos/epidemiologiaRESUMO
BACKGROUND: Enhanced recovery pathways (ERPs) have been shown to improve patient outcomes in a variety of contexts. This review summarizes the evidence and defines a protocol for perioperative care of patients with hip fracture and was conducted for the Agency for Healthcare Research and Quality safety program for improving surgical care and recovery. STUDY DESIGN: Perioperative care was divided into components or "bins." For each bin, a semisystematic review of the literature was conducted using MEDLINE with priority given to systematic reviews, meta-analyses, and randomized controlled trials. Observational studies were included when higher levels of evidence were not available. Existing guidelines for perioperative care were also incorporated. For convenience, the components of care that are under the auspices of anesthesia providers will be reported separately. Recommendations for an evidence-based protocol were synthesized based on review of this evidence. RESULTS: Eleven bins were identified. Preoperative risk factor bins included nutrition, diabetes mellitus, tobacco use, and anemia. Perioperative management bins included thromboprophylaxis, timing of surgery, fluid management, drain placement, early mobilization, early alimentation, and discharge criteria/planning. CONCLUSIONS: This review provides the evidence basis for an ERP for perioperative care of patients with hip fracture.
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BACKGROUND: Use of enhanced recovery pathways (ERPs) can improve patient outcomes, yet national implementation of these pathways remains low. The Agency for Healthcare Research and Quality (AHRQ; funder), the American College of Surgeons, and the Johns Hopkins Medicine Armstrong Institute for Patent Safety and Quality have developed the Safety Program for Improving Surgical Care and Recovery-a national effort to catalyze implementation of practices to improve perioperative care and enhance recovery of surgical patients. This review synthesizes evidence that can be used to develop a protocol for elective total knee arthroplasty (TKA) and total hip arthroplasty (THA). STUDY DESIGN: This review focuses on potential components of the protocol relevant to surgeons; anesthesia components are reported separately. Components were identified through review of existing pathways and from consultation with technical experts. For each, a structured review of MEDLINE identified systematic reviews, randomized trials, and observational studies that reported on these components in patients undergoing elective TKA/THA. This primary evidence review was combined with existing clinical guidelines in a narrative format. RESULTS: Sixteen components were reviewed. Of the 10 preoperative components, most were focused on risk factor assessment including anemia, diabetes mellitus, tobacco use, obesity, nutrition, immune-modulating therapy, and opiates. Preoperative education, venous thromboembolism (VTE) prophylaxis, and bathing/Staphylococcus aureus decolonization were also included. The routine use of drains was the only intraoperative component evaluated. The 5 postoperative components included early mobilization, continuous passive motion, extended duration VTE prophylaxis, early oral alimentation, and discharge planning. CONCLUSION: This review synthesizes the evidence supporting potential surgical components of an ERP for elective TKA/THA. The AHRQ Safety Program for Improving Surgical Care and Recovery aims to guide hospitals and surgeons in identifying the best practices to implement in the surgical care of TKA and THA patients.
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Hepatocellular carcinoma (HCC), the second leading cause of cancer deaths worldwide, is difficult to treat and highly lethal. Since HCC is predominantly diagnosed in patients with cirrhosis, treatment planning must consider both the severity of liver disease and tumor burden. To minimize the impact to the patient while treating the tumor, techniques have been developed to target HCC. Anatomical targeting by surgical resection or locoregional therapies is generally reserved for patients with preserved liver function and minimal to moderate tumor burden. Patients with decompensated cirrhosis and small tumors are optimal candidates for liver transplantation, which offers the best chance of long-term survival. Yet, only 20%-30% of patients have disease amenable to anatomical targeting. For the majority of patients with advanced HCC, chemotherapy is used to target the tumor biology. Despite these treatment options, the five-year survival of patients in the United States with HCC is only 16%. In this review we provide a comprehensive overview of current approaches to target HCC. We also discuss emerging diagnostic and prognostic biomarkers, novel therapeutic targets identified by recent genomic profiling studies, and potential applications of immunotherapy in the treatment of HCC.
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As a cell cycle inhibitor and tumor suppressor, p27 is frequently misregulated in human cancers. Increased degradation is the most common mechanism of misregulation, however in some cancers, p27 is mislocalized from its cell cycle inhibitory location in the nucleus, to the cytoplasm. In normal cells cytoplasmic p27 has functions that are distinct from its cell cycle-regulatory nuclear functions. Therefore, an important question is whether localization of p27 to the cytoplasm in tumor cells is primarily a mechanism for cancelling its inhibitory effect on cell proliferation, or whether cytoplasmic p27 has more direct oncogenic actions. To study p27 mislocalization in human cancers we screened a panel of common breast cancer cell lines. We observed that p27 accumulated in the cytoplasm exclusively in cell lines that are Her2+. To address the significance of p27 mislocalization in Her2+ breast cancer cells we interrogated the cellular response to the dual-Her2/EGFR kinase inhibitor, lapatinib. Knockdown of p27 using shRNA sensitized Her2+ cells to lapatinib-induced apoptosis. Moreover, expression of a constitutively cytoplasmic form of p27 (p27ΔNLS) reversed the lapatinib-induced apoptosis, suggesting that cytoplasmic p27 contributed to lapatinib resistance in Her2+ breast cancer cells by suppressing apoptosis. Our results suggest that p27 localization may be useful as a predictive biomarker of therapeutic response in patients with Her2+ breast cancers.
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Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Quinazolinas/farmacologia , Receptor ErbB-2/antagonistas & inibidores , Receptor ErbB-2/metabolismo , Animais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias da Mama/enzimologia , Neoplasias da Mama/patologia , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/fisiologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/fisiologia , Inibidor de Quinase Dependente de Ciclina p27/antagonistas & inibidores , Inibidor de Quinase Dependente de Ciclina p27/genética , Citoplasma/metabolismo , Resistencia a Medicamentos Antineoplásicos , Feminino , Técnicas de Silenciamento de Genes , Humanos , Lapatinib , Camundongos , Terapia de Alvo Molecular , Fosforilação , Inibidores de Proteínas Quinases/farmacologia , RNA Interferente Pequeno/administração & dosagem , RNA Interferente Pequeno/genética , Transdução de SinaisRESUMO
BACKGROUND: Genetic variation is an essential means of evolution and adaptation in many organisms in response to environmental change. Certain DNA alterations can be carried out by site-specific recombinases (SSRs) that fall into two families: the serine and the tyrosine recombinases. SSRs are seldom found in eukaryotes. A gene homologous to a tyrosine site-specific recombinase has been identified in the genome of Plasmodium falciparum. The sequence is highly conserved among five other members of Plasmodia. METHODOLOGY/PRINCIPAL FINDINGS: The predicted open reading frame encodes for a â¼57 kDa protein containing a C-terminal domain including the putative tyrosine recombinase conserved active site residues R-H-R-(H/W)-Y. The N-terminus has the typical alpha-helical bundle and potentially a mixed alpha-beta domain resembling that of λ-Int. Pf-Int mRNA is expressed differentially during the P. falciparum erythrocytic life stages, peaking in the schizont stage. Recombinant Pf-Int and affinity chromatography of DNA from genomic or synthetic origin were used to identify potential DNA targets after sequencing or micro-array hybridization. Interestingly, the sequences captured also included highly variable subtelomeric genes such as var, rif, and stevor sequences. Electrophoretic mobility shift assays with DNA were carried out to verify Pf-Int/DNA binding. Finally, Pf-Int knock-out parasites were created in order to investigate the biological role of Pf-Int. CONCLUSIONS/SIGNIFICANCE: Our data identify for the first time a malaria parasite gene with structural and functional features of recombinases. Pf-Int may bind to and alter DNA, either in a sequence specific or in a non-specific fashion, and may contribute to programmed or random DNA rearrangements. Pf-Int is the first molecular player identified with a potential role in genome plasticity in this pathogen. Finally, Pf-Int knock-out parasite is viable showing no detectable impact on blood stage development, which is compatible with such function.