Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
1.
Langenbecks Arch Surg ; 409(1): 87, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38441707

RESUMO

INTRODUCTION: Appendiceal neoplasms (ANs) are rare, with an estimated incidence of around 1%: neuroendocrine tumours (NETs) and low-grade appendiceal mucinous neoplasms (LAMNs) comprise most cases. Most tumours are cured by appendectomy alone, although some require right hemicolectomy and intra-operative chemotherapy. The aim of the present study is to evaluate our institution's experience in terms of the prevalence of AN, their histological types, treatment and outcomes in adult patients undergoing emergency appendectomy. MATERIAL AND METHODS: Single-centre retrospective cohort analysis of patients treated for acute appendicitis at a large academic medical centre. Patients with a diagnosis of acute appendicitis (AA) where further compared with patients with acute appendicitis and a histologically confirmed diagnosis of appendiceal neoplasm (AN). RESULTS: A diagnosis of acute appendicitis was made in 1200 patients. Of these, 989 patients underwent emergency appendectomy. The overall incidence of appendiceal neoplasm was 9.3% (92 patients). AN rate increased with increasing age. Patients under the age of 30 had a 3.8% (14/367 patients) rate of occult neoplasm, whereas patients between 40 and 89 years and older had a 13.0% rate of neoplasm. No difference was found in clinical presentations and type of approach while we found a lower complicated appendicitis rate in the AN group. CONCLUSION: ANs are less rare with respect to the literature; however, clinically, there are no specific signs of suspicious and simple appendicectomy appears to be curative in most cases. However, age plays an important role; older patients are at higher risk for AN. ANs still challenge the non-operative management concept introduced into the surgical literature.


Assuntos
Neoplasias do Apêndice , Apendicite , Adulto , Humanos , Apendicite/epidemiologia , Apendicite/cirurgia , Neoplasias do Apêndice/epidemiologia , Neoplasias do Apêndice/cirurgia , Apendicectomia , Estudos Retrospectivos , Doença Aguda
2.
Langenbecks Arch Surg ; 408(1): 437, 2023 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-37973620

RESUMO

INTRODUCTION: Gastric cancer with peritoneal metastasis (GCPM) has an unfavourable prognosis. Cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy (CRS + HIPEC) and pressurized intraperitoneal aerosol chemotherapy (PIPAC) are promising treatment options that have been shown to improve survival. The aim of this study was to assess the impact of different treatments such as systemic chemotherapy, systemic chemotherapy + PIPAC, and CRS + HIPEC in patients with GCPM. MATERIAL AND METHODS: This single-centre retrospective study included 82 patients with GCPM treated between January 2016 and June 2021. After first-line chemotherapy, depending on disease response and burden, the patients were divided into three treatment groups: chemotherapy alone, chemotherapy + PIPAC, and CRS + HIPEC. The primary outcome was overall survival (OS) from diagnosis, which was compared among the treatment groups. RESULTS: Thirty-seven (45.1%) patients were administered systemic chemotherapy alone, 25 (30.4%) received chemotherapy + PIPAC, and 20 (24.4%) underwent CRS + HIPEC. The CRS + HIPEC group had better OS (median 24 months) than the PIPAC group (15 months, p = 0.01) and chemotherapy group (5 months, p = 0.0001). Following CRS + HIPEC, the postoperative grade 3-4 complication rate was 25%, and no postoperative in-hospital deaths occurred. The median disease-free survival (DFS) was 12 months. Multivariate analysis identified peritoneal carcinomatosis index (PCI) > 7 as an independent predictor of worse DFS. No independent predictors of OS were identified. CONCLUSION: Among patients with GCPM, we identified a highly selected population with oligometastatic disease. In this group, CRS + HIPEC provided a significant survival advantage with an acceptable major complication rate compared with other available therapies (systemic chemotherapy alone or in combination with PIPAC).


Assuntos
Hipertermia Induzida , Neoplasias Peritoneais , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/patologia , Neoplasias Peritoneais/tratamento farmacológico , Terapia Combinada , Estudos Retrospectivos , Quimioterapia do Câncer por Perfusão Regional , Procedimentos Cirúrgicos de Citorredução , Complicações Pós-Operatórias/terapia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Taxa de Sobrevida
3.
Langenbecks Arch Surg ; 408(1): 375, 2023 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-37743419

RESUMO

PURPOSE: Fluorescence-based imaging has found application in several fields of elective surgery, but there is still a lack of evidence in the literature about its use in emergency setting. The present review critically summarizes currently available applications and limitations of indocyanine green (ICG) fluorescence in abdominal emergencies including acute cholecystitis, mesenteric ischemia, and trauma surgery. METHODS: A systematic review was performed according to the PRISMA statement identifying articles about the use of ICG fluorescence in the management of the most common general surgery emergency. Only studies focusing on the use of ICG fluorescence for the management of acute surgical conditions in adults were included. RESULTS: Thirty-six articles were considered for qualitative analysis. The most frequent disease was occlusive or non-occlusive mesenteric ischemia followed by acute cholecystitis. Benefits from using ICG for acute cholecystitis were reported in 48% of cases (clear identification of biliary structures and a safer surgical procedure). In one hundred and twenty cases that concerned the use of ICG for occlusive or non-occlusive mesenteric ischemia, ICG injection led to a modification of the surgical decision in 44 patients (36.6%). Three studies evaluated the use of ICG in trauma patients to assess the viability of bowel or parenchymatous organs in abdominal trauma, to evaluate the perfusion-related tissue impairment in extremity or craniofacial trauma, and to reassess the efficacy of surgical procedures performed in terms of vascularization. ICG injection led to a modification of the surgical decision in 50 patients (23.9%). CONCLUSION: ICG fluorescence is a safe and feasible tool also in an emergency setting. There is increasing evidence that the use of ICG fluorescence during abdominal surgery could facilitate intra-operative decision-making and improve patient outcomes, even in the field of emergency surgery.


Assuntos
Colecistite Aguda , Isquemia Mesentérica , Cirurgia Assistida por Computador , Adulto , Humanos , Fluorescência , Procedimentos Cirúrgicos Eletivos , Verde de Indocianina
4.
Oncogene ; 41(14): 2122-2136, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35190642

RESUMO

Glioblastomas (GBMs) preferentially generate acetyl-CoA from acetate as a fuel source to promote tumor growth. O-GlcNAcylation has been shown to be elevated by increasing O-GlcNAc transferase (OGT) in many cancers and reduced O-GlcNAcylation can block cancer growth. Here, we identify a novel mechanism whereby OGT regulates acetate-dependent acetyl-CoA and lipid production by regulating phosphorylation of acetyl-CoA synthetase 2 (ACSS2) by cyclin-dependent kinase 5 (CDK5). OGT is required and sufficient for GBM cell growth and regulates acetate conversion to acetyl-CoA and lipids. Elevating O-GlcNAcylation in GBM cells increases phosphorylation of ACSS2 on Ser-267 in a CDK5-dependent manner. Importantly, we show that ACSS2 Ser-267 phosphorylation regulates its stability by reducing polyubiquitination and degradation. ACSS2 Ser-267 is critical for OGT-mediated GBM growth as overexpression of ACSS2 Ser-267 phospho-mimetic rescues growth in vitro and in vivo. Importantly, we show that pharmacologically targeting OGT and CDK5 reduces GBM growth ex vivo. Thus, the OGT/CDK5/ACSS2 pathway may be a way to target altered metabolic dependencies in brain tumors.


Assuntos
Glioblastoma , Acetato-CoA Ligase/metabolismo , Acetatos/metabolismo , Acetatos/farmacologia , Linhagem Celular Tumoral , Humanos , N-Acetilglucosaminiltransferases/metabolismo , Fosforilação
5.
Dis Colon Rectum ; 65(11): 1306-1315, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-35067503

RESUMO

BACKGROUND: In patients with locally advanced extraperitoneal rectal cancer, a multidisciplinary approach represents the standard treatment. However, considering the favorable prognosis in patients with major or complete response, radical surgery might represent overtreatment. OBJECTIVE: This study aimed to evaluate postoperative short-term morbidity, functional outcome, and oncologic long-term outcome in patients with rectal cancer treated with local excision by transanal endoscopic microsurgery or radical surgery and to determine who achieved a complete or major pathological response (ypT0-1) after neoadjuvant treatment. DESIGN: This was a retrospective study. SETTING: The study was conducted at a single center. PATIENTS: Patients who had received neoadjuvant treatment by local excision with a major or complete pathological response at histological examination (transanal endoscopic microsurgery group) were compared to patients treated by radical surgery with the same pathological response (total mesorectal excision group). INTERVENTIONS: The interventions included local excision by transanal endoscopic microsurgery and radical surgery with total mesorectal excision. MAIN OUTCOME MEASURES: Postoperative short-term morbidity, functional outcome 1 year after surgery, and oncologic long-term outcome were measured. RESULTS: Ninety-three patients were included in the study (35 in the transanal endoscopic microsurgery group and 58 in the mesorectal excision group). In the total mesorectal excision group, a sphincter-saving approach was possible in 89.7% (vs 100%; p = 0.049); a protective temporary stoma was necessary in 74.1% of radical procedures (vs 0%; p < 0.001), and 13.8% of these became permanent. Short-term postoperative morbidity was lower after local excision (14.3% vs 46.6%; p = 0.002). One year after surgery, the transanal endoscopic microsurgery group recorded better evacuation and continence function than the total mesorectal excision group. Oncologic outcome was similar between the groups. LIMITATIONS: This study had a retrospective design. CONCLUSION: If a major or complete pathological response occurs after neoadjuvant treatment, an organ-sparing approach by local excision seems to offer the same oncologic results as radical surgery, but it has a better postoperative morbidity rate and better functional results. See Video Abstract at http://links.lww.com/DCR/B901 .Microcirugía endoscópica transanal versus escisión total del mesorrecto en cáncer de recto ypT0-1 después de radioquimioterapia preoperatoria: morbilidad posoperatoria, resultados funcionales y resultado oncológico a largo plazo. ANTECEDENTES: En pacientes con cáncer rectal extraperitoneal localmente avanzado, un abordaje multidisciplinario con radioquimioterapia preoperatoria y cirugía con escisión total del mesorrecto representa el tratamiento estándar. En pacientes que obtienen una respuesta mayor o completa, la cirugía radical puede representar un sobretratamiento, considerando el pronóstico favorable de estos casos. OBJETIVO: Evaluar la morbilidad posoperatoria a corto plazo, el resultado funcional y el resultado oncológico a largo plazo en pacientes con cáncer de recto tratados con escisión local mediante microcirugía endoscópica transanal o mediante cirugía radical y que obtuvieron una respuesta patológica completa o mayor (ypT0-1) después del tratamiento neoadyuvante. DISEO: Este fue un estudio retrospectivo. AJUSTE: El estudio se realizó en un solo centro. ESCENARIO: El estudio se realizó en un solo centro. PACIENTES: Se comparó a los pacientes tratados, tras tratamiento neoadyuvante (1996-2016), mediante escisión local con respuesta patológica mayor o completa al examen histológico (grupo de microcirugía endoscópica transanal), con los pacientes tratados mediante cirugía radical con la misma respuesta patológica (grupo de escisión mesorrectal total). INTERVENCIONES: Extirpación local mediante microcirugía endoscópica transanal y cirugía radical con escisión mesorrectal total. PRINCIPALES MEDIDAS DE RESULTADO: Morbilidad posoperatoria a corto plazo, resultado funcional a un año después de la cirugía (evaluado con una puntuación de evacuación y continencia) y resultado oncológico a largo plazo. LIMITACIONES: Las limitaciones de este estudio incluyen su diseño retrospectivo. CONCLUSIN: Si se produce una respuesta patológica mayor o completa después del tratamiento neoadyuvante, un abordaje con preservación de órganos mediante escisión local parece ofrecer los mismos resultados oncológicos que la cirugía radical, pero tiene una menor tasa de morbilidad postoperatoria y mejores resultados funcionales un año después de la cirugía. Consulte Video Resumen en http://links.lww.com/DCR/B901 . (Traducción-Dr. Felipe Bellolio ).


Assuntos
Neoplasias Retais , Microcirurgia Endoscópica Transanal , Seguimentos , Humanos , Morbidade , Estadiamento de Neoplasias , Neoplasias Retais/diagnóstico , Neoplasias Retais/cirurgia , Estudos Retrospectivos
6.
J Biol Chem ; 297(1): 100848, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34058200

RESUMO

Within the intestinal epithelium, regulation of intracellular protein and vesicular trafficking is of utmost importance for barrier maintenance, immune responses, and tissue polarity. RAB11A is a small GTPase that mediates the anterograde transport of protein cargos to the plasma membrane. Loss of RAB11A-dependent trafficking in mature intestinal epithelial cells results in increased epithelial proliferation and nuclear accumulation of Yes-associated protein (YAP), a key Hippo-signaling transducer that senses cell-cell contacts and regulates tissue growth. However, it is unclear how RAB11A regulates YAP intracellular localizations. In this report, we examined the relationship of RAB11A to epithelial junctional complexes, YAP, and the associated consequences on colonic epithelial tissue repair. We found that RAB11A controls the biochemical associations of YAP with multiple components of adherens and tight junctions, including α-catenin, ß-catenin, and Merlin, a tumor suppressor. In the absence of RAB11A and Merlin, we observed enhanced YAP-ß-catenin complex formation and nuclear translocation. Upon chemical injury to the intestine, mice deficient in RAB11A were found to have reduced epithelial integrity, decreased YAP localization to adherens and tight junctions, and increased nuclear YAP accumulation in the colon epithelium. Thus, RAB11A-regulated trafficking regulates the Hippo-YAP signaling pathway for rapid reparative response after tissue injury.


Assuntos
Proteínas de Ciclo Celular/genética , Colite/genética , Neurofibromina 2/genética , Fatores de Transcrição/genética , beta Catenina/genética , Proteínas rab de Ligação ao GTP/genética , Junções Aderentes/genética , Animais , Células CACO-2 , Proliferação de Células/genética , Colite/induzido quimicamente , Colite/patologia , Colo/crescimento & desenvolvimento , Colo/patologia , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Epitélio/crescimento & desenvolvimento , Epitélio/patologia , Humanos , Camundongos , Junções Íntimas/genética , alfa Catenina/genética
7.
Artigo em Inglês | MEDLINE | ID: mdl-33688466

RESUMO

OBJECTIVES: The aim of the study was to evaluate and check the international literature for Covid-19 prevention and dental education. MATERIALS AND METHODS: A review of the international literature was performed, including articles in English about different aspects of transmission, preventive actions, and educational topics. RESULTS: As a result, it seems that the better way to avoid contagion was represented by the use of personal protective equipment and handwashing in conjunction with social distancing and treatment limitation. CONCLUSIONS: Dental treatment limitation to emergencies, social distancing, and online teaching seemed to be the key to limit the Covid-19 outbreak, although there was no evidence of a universal guideline. This suggests that we have to establish general guidelines to avoid a second rush of contagion and limit the spread of infection in the future.

8.
Sarcoma ; 2020: 8647981, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32300280

RESUMO

Rhabdomyosarcoma (RMS) and rhabdoid tumors (RT) are rare soft-tissue malignancies with the highest incidence in infants, children, and adolescents. Advanced, recurrent, and/or metastatic RMS and RT exhibit poor response to treatment. One of the main mechanisms behind resistance to treatment is believed to be intratumoral heterogeneity. In this study, we investigated the myogenic determination factor 1 (MYOD1) and Noggin (NOG) markers in an embryonal RMS (ERMS) cell line and an RT cell line and the differential response of the MYOD1 and NOG expressing subpopulations to chemotherapy. Importantly, we found that these markers together identify a subpopulation of cells (MYOD1+ NOG+ cells) with primary resistance to Vincristine and Doxorubicin, two commonly used chemotherapies for ERMS and RT. The chemoresistant MYOD1+ NOG+ cells express markers of undifferentiated cells such as myogenin and ID1. Combination of Vincristine with TPA/GSK126, a drug combination shown to induce differentiation of RMS cell lines, is able to partially overcome MYOD1/NOG cells chemoresistance.

9.
Cancer Res ; 79(16): 4099-4112, 2019 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-31239271

RESUMO

The effects of polarized membrane trafficking in mature epithelial tissue on cell growth and cancer progression have not been fully explored in vivo. A majority of colorectal cancers have reduced and mislocalized Rab11, a small GTPase dedicated to trafficking of recycling endosomes. Patients with low Rab11 protein expression have poor survival rates. Using genetic models across species, we show that intact recycling endosome function restrains aberrant epithelial growth elicited by APC or RAS mutations. Loss of Rab11 protein led to epithelial dysplasia in early animal development and synergized with oncogenic pathways to accelerate tumor progression initiated by carcinogen, genetic mutation, or aging. Transcriptomic analysis uncovered an immediate expansion of the intestinal stem cell pool along with cell-autonomous Yki/Yap activation following disruption of Rab11a-mediated recycling endosomes. Intestinal tumors lacking Rab11a traffic exhibited marked elevation of nuclear Yap, upd3/IL6-Stat3, and amphiregulin-MAPK signaling, whereas suppression of Yki/Yap or upd3/IL6 reduced gut epithelial dysplasia and hyperplasia. Examination of Rab11a function in enteroids or cultured cell lines suggested that this endosome unit is required for suppression of the Yap pathway by Hippo kinases. Thus, recycling endosomes in mature epithelia constitute key tumor suppressors, loss of which accelerates carcinogenesis. SIGNIFICANCE: Recycling endosome traffic in mature epithelia constitutes a novel tumor suppressing mechanism.


Assuntos
Neoplasias Colorretais/metabolismo , Endossomos/metabolismo , Células Epiteliais/patologia , Proteínas rab de Ligação ao GTP/metabolismo , Proteína da Polipose Adenomatosa do Colo/genética , Animais , Animais Geneticamente Modificados , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Células Epiteliais/metabolismo , Via de Sinalização Hippo , Humanos , Camundongos Knockout , Proteínas Serina-Treonina Quinases/metabolismo , Células-Tronco/metabolismo , Células-Tronco/patologia , Proteínas rab de Ligação ao GTP/genética
10.
Mech Ageing Dev ; 175: 74-82, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30055190

RESUMO

Developments in medicine have led to a significant increase in the average human lifespan. This increase in aging is most readily apparent in the case of HIV where antiretroviral therapy has shifted infection from a terminal to a chronic but manageable disease. Despite this advance, patients suffer from co-morbidities best described as an accelerated aging phenotype. A potential contributor is cellular senescence, an aging-associated growth arrest, which has already been linked to other HIV co-morbidities such as lipodystrophies and osteoporosis in response to antiretroviral drugs. We have previously demonstrated that astrocytes senescence in response to antiretroviral drugs. As endothelial cells play a critical role regulating the blood brain barrier (BBB) and senescence could severely impact barrier permeability, we investigate the role of a commonly used combination of HIV reverse transcriptase inhibitors on the senescence program of human umbilical vein endothelial cells (HUVECs). Our studies indicate that HUVECs underwent premature senescence associated with inflammation, oxidative stress and altered eNOS activation. Treated cells had detrimental paracrine effects on astrocytes including paracrine senescence, suggesting that senescent HUVECs could influence astrocytes, which line the other side of the BBB. These results may have implications for HIV-associated neurocognitive disorders (HAND), a set of neurological deficits.


Assuntos
Fármacos Anti-HIV/toxicidade , Proliferação de Células/efeitos dos fármacos , Senescência Celular/efeitos dos fármacos , Emtricitabina/toxicidade , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Tenofovir/toxicidade , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Astrócitos/patologia , Células Cultivadas , Células Endoteliais da Veia Umbilical Humana/metabolismo , Células Endoteliais da Veia Umbilical Humana/patologia , Humanos , Mediadores da Inflamação/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Comunicação Parácrina/efeitos dos fármacos
11.
Front Aging Neurosci ; 9: 281, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28900395

RESUMO

With the advent of highly active antiretroviral therapy (HAART) survival rates among patients infected by HIV have increased. However, even though survival has increased HIV-associated neurocognitive disorders (HAND) still persist, suggesting that HAART-drugs may play a role in the neurocognitive impairment observed in HIV-infected patients. Given previous data demonstrating that astrocyte senescence plays a role in neurocognitive disorders such as Alzheimer's disease (AD), we examined the role of HAART on markers of senescence in primary cultures of human astrocytes (HAs). Our results indicate HAART treatment induces cell cycle arrest, senescence-associated beta-galactosidase, and the cell cycle inhibitor p21. Highly active antiretroviral therapy treatment is also associated with the induction of reactive oxygen species and upregulation of mitochondrial oxygen consumption. These changes in mitochondria correlate with increased glycolysis in HAART drug treated astrocytes. Taken together these results indicate that HAART drugs induce the senescence program in HAs, which is associated with oxidative and metabolic changes that could play a role in the development of HAND.

12.
FASEB J ; 31(5): 1828-1846, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28119396

RESUMO

γ-Tubulins are highly conserved members of the tubulin superfamily essential for microtubule nucleation. Humans possess 2 γ-tubulin genes. It is thought that γ-tubulin-1 represents a ubiquitous isotype, whereas γ-tubulin-2 is found predominantly in the brain, where it may be endowed with divergent functions beyond microtubule nucleation. The molecular basis of the purported functional differences between γ-tubulins is unknown. We report discrimination of human γ-tubulins according to their electrophoretic and immunochemical properties. In vitro mutagenesis revealed that the differences in electrophoretic mobility originate in the C-terminal regions of the γ-tubulins. Using epitope mapping, we discovered mouse monoclonal antibodies that can discriminate between human γ-tubulin isotypes. Real time quantitative RT-PCR and 2-dimensional-PAGE showed that γ-tubulin-1 is the dominant isotype in fetal neurons. Although γ-tubulin-2 accumulates in the adult brain, γ-tubulin-1 remains the major isotype in various brain regions. Localization of γ-tubulin-1 in mature neurons was confirmed by immunohistochemistry and immunofluorescence microscopy on clinical samples and tissue microarrays. Differentiation of SH-SY5Y human neuroblastoma cells by all-trans retinoic acid, or oxidative stress induced by mitochondrial inhibitors, resulted in upregulation of γ-tubulin-2, whereas the expression of γ-tubulin-1 was unchanged. Fractionation experiments and immunoelectron microscopy revealed an association of γ-tubulins with mitochondrial membranes. These data indicate that in the face of predominant γ-tubulin-1 expression, the accumulation of γ-tubulin-2 in mature neurons and neuroblastoma cells during oxidative stress may denote a prosurvival role of γ-tubulin-2 in neurons.-Dráberová, E., Sulimenko, V., Vinopal, S., Sulimenko, T., Sládková, V., D'Agostino, L., Sobol, M., Hozák, P., Kren, L., Katsetos, C. D., Dráber, P. Differential expression of human γ-tubulin isotypes during neuronal development and oxidative stress points to γ-tubulin-2 prosurvival function.


Assuntos
Neurogênese/fisiologia , Neurônios/metabolismo , Estresse Oxidativo/fisiologia , Tubulina (Proteína)/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Humanos , Microtúbulos/metabolismo , Neuroblastoma/metabolismo
13.
J Neuropathol Exp Neurol ; 74(7): 723-42, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26079448

RESUMO

The expression, cellular distribution, and subcellular sorting of the microtubule (MT)-nucleating γ-tubulin small complex (γTuSC) proteins, GCP2 and GCP3, were studied in human glioblastoma cell lines and in clinical tissue samples representing all histologic grades of adult diffuse astrocytic gliomas (n = 54). Quantitative real-time polymerase chain reaction revealed a significant increase in the expression of GCP2 and GCP3 transcripts in glioblastoma cells versus normal human astrocytes; these were associated with higher amounts of both γTuSC proteins. GCP2 and GCP3 were concentrated in the centrosomes in interphase glioblastoma cells, but punctate and diffuse localizations were also detected in the cytosol and nuclei/nucleoli. Nucleolar localization was fixation dependent. GCP2 and GCP3 formed complexes with γ-tubulin in the nucleoli as confirmed by reciprocal immunoprecipitation experiments and immunoelectron microscopy. GCP2 and GCP3 depletion caused accumulation of cells in G2/M and mitotic delay but did not affect nucleolar integrity. Overexpression of GCP2 antagonized the inhibitory effect of the CDK5 regulatory subunit-associated tumor suppressor protein 3 (C53) on DNA damage G2/M checkpoint activity. Tumor cell GCP2 and GCP3 immunoreactivity was significantly increased over that in normal brains in glioblastoma samples; it was also associated with microvascular proliferation. These findings suggest that γTuSC protein dysregulation in glioblastomas may be linked to altered transcriptional checkpoint activity or interaction with signaling pathways associated with a malignant phenotype.


Assuntos
Neoplasias Encefálicas/metabolismo , Nucléolo Celular/metabolismo , Regulação Neoplásica da Expressão Gênica/fisiologia , Glioblastoma/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Animais , Anuros , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/ultraestrutura , Ciclo Celular/fisiologia , Linhagem Celular Tumoral , Galinhas , Dano ao DNA/genética , Feminino , Glioblastoma/patologia , Glioblastoma/ultraestrutura , Humanos , Masculino , Camundongos , Proteínas Associadas aos Microtúbulos/genética , Pessoa de Meia-Idade , Transporte Proteico , Tubulina (Proteína)/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Adulto Jovem , Peixe-Zebra
14.
Semin Pediatr Neurol ; 22(1): 49-72, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25976261

RESUMO

Major advances in the genomics and epigenomics of diffuse gliomas and glioblastoma to date have not been translated into effective therapy, necessitating pursuit of alternative treatment approaches for these therapeutically challenging tumors. Current knowledge of microtubules in cancer and the development of new microtubule-based treatment strategies for high-grade gliomas are the topic in this review article. Discussed are cellular, molecular, and pharmacologic aspects of the microtubule cytoskeleton underlying mitosis and interactions with other cellular partners involved in cell cycle progression, directional cell migration, and tumor invasion. Special focus is placed on (1) the aberrant overexpression of ßIII-tubulin, a survival factor associated with hypoxic tumor microenvironment and dynamic instability of microtubules; (2) the ectopic overexpression of γ-tubulin, which in addition to its conventional role as a microtubule-nucleating protein has recently emerged as a transcription factor interacting with oncogenes and kinases; (3) the microtubule-severing ATPase spastin and its emerging role in cell motility of glioblastoma cells; and (4) the modulating role of posttranslational modifications of tubulin in the context of interaction of microtubules with motor proteins. Specific antineoplastic strategies discussed include downregulation of targeted molecules aimed at achieving a sensitization effect on currently used mainstay therapies. The potential role of new classes of tubulin-binding agents and ATPase inhibitors is also examined. Understanding the cellular and molecular mechanisms underpinning the distinct behaviors of microtubules in glioma tumorigenesis and drug resistance is key to the discovery of novel molecular targets that will fundamentally change the prognostic outlook of patients with diffuse high-grade gliomas.


Assuntos
Antineoplásicos/uso terapêutico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioma/tratamento farmacológico , Microtúbulos/efeitos dos fármacos , Microtúbulos/metabolismo , Animais , Antineoplásicos/farmacologia , Carcinogênese/efeitos dos fármacos , Carcinogênese/genética , Carcinogênese/metabolismo , Regulação Neoplásica da Expressão Gênica/genética , Glioma/genética , Glioma/metabolismo , Humanos , Microtúbulos/genética , Redes Neurais de Computação
15.
Aging Clin Exp Res ; 25(6): 711-4, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23934784

RESUMO

The purpose of this study was to investigate whether the documented difficulties of physiological amounts of essential amino acids (EAAs) (7 g) to induce protein synthesis could be reflected in a simple method adaptable to a clinical setting. Sixteen healthy individuals, nine elderly (75.3 ± 3.5 years), and seven young (28 ± 2.5 years) were enrolled in the study. Five minutes before EAA ingestion (baseline) and 20, 40, 60, 90, 120, 180 min after EAA ingestion, venous blood samples were taken from the ante-cubital vein to determine the concentrations of EAAs (µmol/L). The results show that plasma EAA increases were significantly higher in old than in young persons at the considered time points (from p < 0.004 to p < 0.001) (unpaired Student t test). However, the velocity rate of the increasing was slower in old subjects than in young group. The study shows that EAAs ingestion by old subject is associated with reduced muscle EAA uptake.


Assuntos
Envelhecimento/sangue , Aminoácidos Essenciais/sangue , Aminoácidos Essenciais/farmacocinética , Adulto , Fatores Etários , Idoso , Envelhecimento/metabolismo , Velocidade do Fluxo Sanguíneo/fisiologia , Ingestão de Alimentos/fisiologia , Feminino , Humanos , Masculino , Músculo Esquelético/fisiologia
16.
Oncotarget ; 2(12): 1055-74, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22170762

RESUMO

NSP 5a3a is a novel structural protein found to be over-expressed in certain cancer cell lines in-vitro such as Hela, Saos-2, and MCF-7 while barely detectable levels in normal body tissues except for Testis. This particular isoform has been known to interact with cyto- nuclear proteins B23, known to be involved in multi-faceted cellular processes such as cell division, apoptosis, ribosome biogenesis, and rRNA processing, as well as with hnRNP-L, known to be involved with RNA metabolism and rRNA processing. A previous preliminary investigation of NSP 5a3a as a potential target in Head and Neck Carcinoma revealed a novel p73 dependent mechanism through which NSP 5a3a induced apoptosis in Head and Neck cell lines when over-expressed in-vitro. Our present investigation further elucidated a novel dual axis signaling point by which NSP 5a3a induces apoptosis in Head and Neck cell line HN30 through p73-DAXX and TRAF2-TRADD. Interestingly, this novel mechanism appears independent of canonical caspases involved in the intrinsic mitochondrial pathway as well as those in the death receptor pathway thru TRAF2 and TRADD.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Apoptose , Carcinoma de Células Escamosas/metabolismo , Neoplasias de Cabeça e Pescoço/metabolismo , Proteínas Nucleares/metabolismo , Proteína de Domínio de Morte Associada a Receptor de TNF/metabolismo , Proteínas de Ciclo Celular , Divisão Celular , Linhagem Celular Tumoral , Proteínas Correpressoras , Proteínas do Citoesqueleto , Proteínas de Ligação a DNA/metabolismo , Humanos , Chaperonas Moleculares , Nucleofosmina , Transdução de Sinais , Carcinoma de Células Escamosas de Cabeça e Pescoço , Fator 2 Associado a Receptor de TNF/metabolismo , Peptídeos e Proteínas Associados a Receptores de Fatores de Necrose Tumoral/metabolismo , Proteína Tumoral p73 , Proteínas Supressoras de Tumor/metabolismo
17.
Arch Gerontol Geriatr ; 52(3): e123-8, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-20934757

RESUMO

The very high general infection rate (IRI) observed in our Geriatric Intensive Rehabilitation Center (GIRC) led us to investigate whether patient supplementation with essential amino acids (EAAs), modulators of immuno-competence, could reduce IRI. Eighty elderly patients admitted to our GIRC (n=40; age 79.5 ± 7.71; male/female 14/26) or placebo (n=40; age 82.13 ± 6.15; male/female 13/27) were allocated to an 8 g/day oral EAAs group and were surveyed for infections (>48 h from admission) over the first month of their hospital stay. The IRI was 67% for the entire population of patients, 82.5% (33/40 patients) in the placebo group and 52% (21/40 patients) in the EAA group (p<0.02). When patients were divided into infection group (IG) and without-infection group (WIG), independently of post randomization allocation, the WIG had higher levels of serum albumin (p<0.001), blood hemoglobin (Hb) concentration (p=0.01), dietary protein (p=0.008) calorie intakes (p=0.05) but lower serum C-reactive protein (CRP) (p<0.001). The factor of CRP>0.8 mg/dl and Hb ≤ 12 in females, ≤13 in males was associated 4 times and 3.6 times risk of infection, respectively, by sex. EAAs supplementation may lower the risk of infection by 30% in the rehabilitative elderly population. CRP and blood hemoglobin levels can be considered risk markers of future infection.


Assuntos
Aminoácidos Essenciais/administração & dosagem , Infecção Hospitalar/prevenção & controle , Suplementos Nutricionais , Idoso , Idoso de 80 Anos ou mais , Proteína C-Reativa/metabolismo , Proteínas na Dieta/metabolismo , Ingestão de Energia , Feminino , Hemoglobinas/metabolismo , Humanos , Incidência , Assistência de Longa Duração , Masculino , Albumina Sérica/efeitos dos fármacos
18.
Cell Cycle ; 9(6): 1131-42, 2010 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-20237420

RESUMO

NSP 5a3a had been identified along with three other distinct though similar isoforms corresponding to locus HCMOGT-1 on chromosome 17p11.2. ( 1) Secondary structure analysis of the NSP isoforms revealed similarity to Spectrin and Spectrin like proteins containing coiled coil domains. ( 1) These proteins have been implicated and found to be involved in a plethora of cellular activities ranging from intracellular trafficking, cellular and subcellular integrity ( 2, 3) to being involved in protein-protein interactions with other structural proteins as well as involved in protein complex stabilization and scaffolding thus facilitating homo or hetero dimerization of protein complexes. ( 4) The NSP 5a3a isoform had been identified to be highly expressed in-vitro in particular cancer cell lines while very low to null in normal body tissues. ( 1) Subsequent investigation of this isoform revealed its novel interaction with B23 ( 5) , a known nucleolar protein involved in ribosome biogenesis, rRNA transcription, mitosis, cell growth control, and apoptosis. ( 6) We have since then, further elucidated its potential involvement in cellular processes such as ribosome biogenesis and rRNA processing by confirming and establishing NSP 5a3a's novel interaction with B23 and ribonuclear protein hnRNP-L, respectively thus possibly implicating NSP 5a3a in cellular processes such as ribosome biogenesis and rRNA transcription . Finally, an intriguing differential cooperation between these proteins has been observed in both normal and cancer breast cell models and additionally through siRNa silencing, we have found hnRNP-L as a potential novel regulator of NSP 5a3a.


Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Núcleo Celular/metabolismo , Ribonucleoproteínas Nucleares Heterogêneas Grupo L/metabolismo , Proteínas Nucleares/metabolismo , Western Blotting , Proteínas de Ciclo Celular , Extratos Celulares , Linhagem Celular Tumoral , Proteínas do Citoesqueleto , Feminino , Inativação Gênica , Humanos , Imunoprecipitação , Proteínas de Neoplasias/química , Proteínas de Neoplasias/metabolismo , Nucleofosmina , Mapeamento de Peptídeos , Ligação Proteica , Transporte Proteico , Proteômica , RNA Interferente Pequeno/metabolismo , Coloração pela Prata , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Frações Subcelulares/metabolismo
19.
J Cell Biochem ; 110(1): 182-90, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20336668

RESUMO

The formation and progression of mudulloblastoma (MB) is poorly understood. However, somatic inactivation of pRb/p105, in combination with a somatic or a germ-line TP53 inactivation, leads to MB in a mouse model. Presently, there is no specific evidence of pathway/s alterations for the other two members of the retinoblastoma family, pRb2/p130 and/or p107 in MB. JC virus (JCV) is a human polyomavirus. Although there is no firm evidence that this virus plays a causal role in human neoplasia, it has been clearly proven that JCV is highly oncogenic when injected into the brain of experimental animals. The mechanism of JCV-induced tumorigenesis is not entirely clear. However, several studies relate the oncogenic properties of JCV mainly to its early protein large T-antigen (T-Ag), which is able to bind and inactivate both TP53 and Rb family proteins. Here, we compared the protein expression profiles of p53, p73, pRb family proteins, and PCNA, as main regulators of cell proliferation and death, in different cell lines of mouse primitive neuroectodermal tumors (PNET), either T-Ag-positive or -negative, and in human MB cell lines. Our goal was to determine if changes in the relative expression of these regulators could trigger molecular perturbations underlying MB pathogenesis in mouse and human cells. Our results support that the presence of JCV T-Ag may interfere with the expression of pRb family proteins, specific p73 isoforms, and p53. In turn, this "perturbation" may trigger a network of signals strictly connected with survival and apoptosis.


Assuntos
Antígenos Virais de Tumores/imunologia , Proteínas de Ligação a DNA/metabolismo , Vírus JC/imunologia , Meduloblastoma/metabolismo , Proteínas Nucleares/metabolismo , Proteína do Retinoblastoma/metabolismo , Transdução de Sinais , Proteína Supressora de Tumor p53/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Animais , Linhagem Celular Tumoral , Pré-Escolar , Fibroblastos/metabolismo , Perfilação da Expressão Gênica , Humanos , Masculino , Meduloblastoma/virologia , Camundongos , Proteínas de Neoplasias/metabolismo , Antígeno Nuclear de Célula em Proliferação/metabolismo , Proteína Tumoral p73
20.
J Cell Physiol ; 223(2): 519-29, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20162618

RESUMO

In previous studies, we have shown overexpression and ectopic subcellular distribution of gamma-tubulin and betaIII-tubulin in human glioblastomas and glioblastoma cell lines (Katsetos et al., 2006, J Neuropathol Exp Neurol 65:455-467; Katsetos et al., 2007, Neurochem Res 32:1387-1398). Here we determined the expression of gamma-tubulin in surgically excised medulloblastomas (n = 20) and in the human medulloblastoma cell lines D283 Med and DAOY. In clinical tissue samples, the immunohistochemical distribution of gamma-tubulin labeling was pervasive and inversely related to neuritogenesis. Overexpression of gamma-tubulin was widespread in poorly differentiated, proliferating tumor cells but was significantly diminished in quiescent differentiating tumor cells undergoing neuritogenesis, highlighted by betaIII-tubulin immunolabeling. By quantitative real-time PCR, gamma-tubulin transcripts for TUBG1, TUBG2, and TUBB3 genes were detected in both cell lines but expression was less prominent when compared with the human glioblastoma cell lines. Immunoblotting revealed comparable amounts of gamma-tubulin and betaIII-tubulin in different phases of cell cycle; however, a larger amount of gamma-tubulin was detected in D283 Med when compared with DAOY cells. Interphase D283 Med cells exhibited predominantly diffuse cytoplasmic gamma-tubulin localization, in addition to the expected centrosome-associated distribution. Robust betaIII-tubulin immunoreactivity was detected in mitotic spindles of DAOY cells. Our data indicate that overexpression of gamma-tubulin may be linked to phenotypic dedifferentiation (anaplasia) and tumor progression in medulloblastomas and may potentially serve as a promising tumor marker.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias Encefálicas/metabolismo , Meduloblastoma/metabolismo , Tubulina (Proteína)/metabolismo , Biomarcadores Tumorais/análise , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Ciclo Celular/fisiologia , Desdiferenciação Celular/fisiologia , Linhagem Celular Tumoral , Centrossomo/metabolismo , Criança , Pré-Escolar , Citoplasma/metabolismo , Progressão da Doença , Feminino , Regulação Neoplásica da Expressão Gênica/fisiologia , Humanos , Imuno-Histoquímica , Lactente , Masculino , Meduloblastoma/genética , Meduloblastoma/patologia , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Estudos Retrospectivos , Fuso Acromático/metabolismo , Tubulina (Proteína)/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...