Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 152
Filtrar
1.
HPB (Oxford) ; 22(8): 1206-1215, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-31959487

RESUMO

BACKGROUND: Two Cochrane reviews compared overall survival following liver resection (LR) or radiofrequency ablation (RFA) for patients with hepatocellular carcinoma. The first from 2013, found moderate evidence for a survival advantage for LR over RFA when limiting the analysis to trials at low risk of bias. The second (2017), found no evidence for a difference in all-cause mortality for LR versus RFA. Aim was to assess the validity of the randomized controlled trials included in both Cochrane reviews and to investigate their impact on current guidelines. METHODS: The validity of the studies was analyzed using the CONSORT checklist. Two meta-analyses were then performed with all eligible studies from both meta-analyses. Finally, the impact of the result of the original meta-analyses on eight international guidelines was assessed. RESULTS: The four randomized controlled trials showed several inconsistencies (unclear or inadequate randomization, absence of sample-size calculation, missing blinded setup and/or conflicts of interest). All guidelines used recommendations based on the results of the meta-analyses or on studies included in the meta-analyses. CONCLUSION: The analyzed studies showed a substantial lack of overall validity. However the results of these studies and subsequent meta-analyses are used as the evidence base for the majority of current guidelines.


Assuntos
Carcinoma Hepatocelular , Ablação por Cateter , Neoplasias Hepáticas , Ablação por Radiofrequência , Carcinoma Hepatocelular/cirurgia , Ablação por Cateter/efeitos adversos , Hepatectomia/efeitos adversos , Humanos , Neoplasias Hepáticas/cirurgia , Ablação por Radiofrequência/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como Assunto
2.
Biosci Biotechnol Biochem ; 83(9): 1663-1675, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31094292

RESUMO

Members of the casein kinase 1 (CK1) family are key regulators in numerous cellular signal transduction pathways and in order to prevent the development of certain diseases, CK1 kinase activity needs to be tightly regulated. Modulation of kinase activity by site-specific phosphorylation within the C-terminal regulatory domain of CK1δ has already been shown for several cellular kinases. By using biochemical methods, we now identified residues T161, T174, T176, and S181 within the kinase domain of CK1δ as target sites for checkpoint kinase 1 (Chk1). At least residues T176 and S181 show full conservation among CK1δ orthologues from different eukaryotic species. Enzyme kinetic analysis furthermore led to the hypothesis that site-specific phosphorylation within the kinase domain finally contributes to fine-tuning of CK1δ kinase activity. These data provide a basis for the extension of our knowledge about the role of site-specific phosphorylation for regulation of CK1δ and associated signal transduction pathways.


Assuntos
Quinase 1 do Ponto de Checagem/química , Quinase 1 do Ponto de Checagem/metabolismo , Humanos , Fosforilação , Transdução de Sinais
3.
Int J Mol Sci ; 20(24)2019 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-31817920

RESUMO

Protein kinases of the CK1 family can be involved in numerous physiological and pathophysiological processes. Dysregulated expression and/or activity as well as mutation of CK1 isoforms have previously been linked to tumorigenesis. Among all neoplastic diseases, colon and rectal cancer (CRC) represent the fourth leading cause of cancer related deaths. Since mutations in CK1δ previously found in CRC patients exhibited increased oncogenic features, inhibition of CK1δ is supposed to have promising therapeutic potential for tumors, which present overexpression or mutations of this CK1 isoform. Therefore, it is important to develop new small molecule inhibitors exhibiting higher affinity toward CK1δ mutants. In the present study, we first characterized the kinetic properties of CK1δ mutants, which were detected in different tumor entities. Subsequently, we characterized the ability of several newly developed IWP-based inhibitors to inhibit wild type and CK1δ mutants and we furthermore analyzed their effects on growth inhibition of various cultured colon cancer cell lines. Our results indicate, that these compounds represent a promising base for the development of novel CRC therapy concepts.


Assuntos
Caseína Quinase Idelta/antagonistas & inibidores , Neoplasias do Colo/tratamento farmacológico , Desenvolvimento de Medicamentos , Proteínas Mutantes/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Bibliotecas de Moléculas Pequenas/farmacologia , Caseína Quinase Idelta/genética , Caseína Quinase Idelta/metabolismo , Neoplasias do Colo/enzimologia , Neoplasias do Colo/patologia , Humanos , Modelos Moleculares , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Mutação , Fosforilação , Células Tumorais Cultivadas
4.
BMC Cancer ; 18(1): 140, 2018 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-29409464

RESUMO

BACKGROUND: Colorectal cancer (CRC) is the fourth leading cause of cancer related deaths worldwide and prognosis in advanced tumor stage still remains poor. Since CK1 isoforms have been reported to be deregulated in several tumor entities CK1 has emerged as a novel drug target in cancer therapy. In this study we set out to investigate whether CK1α might have the potential to serve as prognostic marker. METHODS: CK1α RNA and protein expression levels in healthy and tumor tissue of CRC patients were analyzed using quantitative real-time PCR and Western Blot analysis, respectively. Prognostic relevance was investigated by correlating obtained CK1α expression levels with patients' survival rate generating Kaplan-Meier survival plots. RESULTS: It could be shown that CK1α is overexpressed in colorectal tumor tissue compared to normal tissue and CK1α overexpression in tumor tissue correlates with poor survival in CRC patients. Results become more significant when only considering patients with high-grade tumors, as well as patients assigned to UICC II and UICC III stage. Furthermore, Cox regression analysis revealed that CK1α is an independent prognostic factor. In addition, tumors expressing decreased levels of the kinase reveal positive effects on overall survival when localized in the right colon compared to those in the left side. CONCLUSION: In summary, this study provides evidence for the first time that CK1α RNA levels might serve as prognostic marker for CRC.


Assuntos
Biomarcadores Tumorais/genética , Caseína Quinase Ialfa/genética , Neoplasias Colorretais/genética , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/metabolismo , Caseína Quinase Ialfa/metabolismo , Neoplasias Colorretais/enzimologia , Neoplasias Colorretais/patologia , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico
5.
Langenbecks Arch Surg ; 403(5): 655-662, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29909530

RESUMO

PURPOSE: Alveolar echinococcosis (AE) is a life-threatening helminthic disease. In humans, AE mostly affects the liver; the regional hepatic lymph nodes may be involved, indicating dissemination of AE from the liver. To achieve complete removal of the disease, enlarged hepatic lymph nodes may be resected during surgical treatment. We evaluated the frequency of affected lymph nodes by conventional microscopic and immunohistochemical analyses including detection of small particles of Echinococcus multilocularis (spem). Furthermore, we analyzed the association of resection of enlarged and affected lymph nodes with long-term outcome after surgical therapy of patients who underwent surgery with curative intent. MATERIALS AND METHODS: We identified 43 patients who underwent hepatic surgery with curative intent with lymph node resection for AE. We analyzed the cohort for the manifestation of the parasite in the resected lymph nodes by conventional histology and by immunohistochemistry and compared these data with the further course of AE. RESULTS: Microscopically infected lymph nodes (laminar layer visible) were found in 7 out of these 43 patients (16%). In more than three quarters (25/32) of all specimens investigated, lymph nodes showed spems when stained with antibody against Em2G11, a monoclonal antibody specific for the Em2 antigen of the Echinococcus multilocularis metacestode. Most frequently, lymph nodes were resected due to enlargement. The median size of microscopically affected lymph nodes was 2 cm (range, 1.2 to 2.5 cm), the median size of immunohistochemically and non-affected lymph nodes was 1.3 cm each (range, "small" to 2.3 or 2.5 cm, respectively). Median follow-up was 8 years for all patients, 5 years for patients with lymph node resection, and 4 years for patients with infested lymph nodes. Overall, recurrent disease was seen in ten patients (10/109; 9%) after a median period of 1.5 years (range, 4 months to 4 years). None of the seven patients with conventionally microscopically affected lymph nodes suffered from recurrent disease. One patient with negative resected nodes and one patient with spems showed recurrent disease after 4 and 35 months, respectively. CONCLUSIONS: Lymph node involvement in AE is frequent, particularly when evaluated by immunohistochemical examination of lymph nodes with the monoclonal antibody Em2G11. Affected lymph nodes tend to be larger in size. Lymph node involvement is not associated with recurrent disease and therefore warrants further analysis of the biological significance of lymph node involvement.


Assuntos
Equinococose/patologia , Equinococose/cirurgia , Linfonodos/parasitologia , Adolescente , Adulto , Idoso , Feminino , Humanos , Imuno-Histoquímica , Excisão de Linfonodo , Linfonodos/patologia , Linfonodos/cirurgia , Masculino , Pessoa de Meia-Idade , Recidiva , Adulto Jovem
6.
Ultraschall Med ; 39(6): 690-696, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30340247

RESUMO

PURPOSE: The diagnosis of an inguinal hernia is usually made clinically. Precise imaging appears to be necessary when the clinical examination is inconclusive. The aim of this study was to determine the diagnostic value of ultrasonography for inguinal hernias and whether it influences the decision for or against surgery. MATERIALS AND METHODS: This study was a single-center retrospective study carried out from January 2012 to December 2016. All 326 patients had undergone ultrasound scanning of the groin as part of the diagnostic workup. Besides surgical findings being the gold standard, follow-up data and alternative ultrasound diagnoses were considered as references, allowing us to assess the accuracy of negative ultrasound findings as well. RESULTS: The findings on ultrasonography were positive in 248 patients and negative in 78 patients. In addition to 201 operated patients, we were able to validate a further 40 patients by means of a questionnaire and the alternative ultrasound diagnoses. The correlation with all three references resulted in a sensitivity of 97 %, a specificity of 77 %, a positive predictive value of 95 %, and a negative predictive value of 87 %. CONCLUSION: Ultrasonography is an accurate method for evaluating inguinal hernias. High sensitivity makes it particularly suitable for ruling out an inguinal hernia when the findings are negative. An ultrasound scan carried out in addition to clinical examination can therefore help to determine the right indication for surgical intervention.


Assuntos
Hérnia Inguinal , Ultrassonografia , Virilha , Hérnia Inguinal/diagnóstico por imagem , Humanos , Estudos Retrospectivos , Sensibilidade e Especificidade
7.
Int J Mol Sci ; 19(10)2018 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-30340359

RESUMO

The family of cyclin-dependent kinases (CDKs) has critical functions in cell cycle regulation and controlling of transcriptional elongation. Moreover, dysregulated CDKs have been linked to cancer initiation and progression. Pharmacological CDK inhibition has recently emerged as a novel and promising approach in cancer therapy. This idea is of particular interest to combat pancreatic ductal adenocarcinoma (PDAC), a cancer entity with a dismal prognosis which is owed mainly to PDAC's resistance to conventional therapies. Here, we review the current knowledge of CDK biology, its role in cancer and the therapeutic potential to target CDKs as a novel treatment strategy for PDAC.


Assuntos
Carcinoma Ductal Pancreático/etiologia , Carcinoma Ductal Pancreático/metabolismo , Quinases Ciclina-Dependentes/genética , Quinases Ciclina-Dependentes/metabolismo , Neoplasias Pancreáticas/etiologia , Neoplasias Pancreáticas/metabolismo , Animais , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/patologia , Ciclo Celular/genética , Ensaios Clínicos como Assunto , Quinases Ciclina-Dependentes/antagonistas & inibidores , Regulação Neoplásica da Expressão Gênica , Humanos , Terapia de Alvo Molecular , Família Multigênica , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Transdução de Sinais , Transcrição Gênica , Neoplasias Pancreáticas
8.
Artigo em Inglês | MEDLINE | ID: mdl-27795367

RESUMO

Ertapenem provides broad-spectrum activity against many pathogens, and its use is relevant for the prophylaxis and treatment of infections in morbidly obese patients undergoing surgery. However, its pharmacokinetics and tissue penetration in these patients are not well defined. We assessed the population pharmacokinetics and target attainment for ertapenem in the plasma, subcutaneous tissue, and peritoneal fluid of morbidly obese patients. Six female patients (body mass index, 43.7 to 55.9 kg/m2) received 1,000 mg ertapenem as 15-min infusions at 0 and 26 h. On day 2, the unbound ertapenem concentrations in plasma, subcutaneous tissue, and peritoneal fluid were measured by microdialysis; total plasma concentrations were additionally quantified. The probability of attaining a target of an unbound ertapenem concentration above the MIC for at least 40% of the dosing interval was predicted via Monte Carlo simulations. The population pharmacokinetic model contained two disposition compartments and simultaneously described all concentrations. For unbound ertapenem, total clearance was 12.3 liters/h (coefficient of variation, 21.6% for between-patient variability) and the volume of distribution at steady state was 57.8 liters in patients with a 53-kg fat-free mass. The area under the concentration-time curve (AUC) for ertapenem was 49% lower in subcutaneous tissue and 25% lower in peritoneal fluid than the unbound AUC in plasma. Tissue penetration was rapid (equilibration half-life, <15 min) and was variable in subcutaneous tissue. Short-term ertapenem infusions (1,000 mg every 24 h) achieved robust (>90%) target attainment probabilities for MICs of up to 1 mg/liter in plasma, 0.25 to 0.5 mg/liter in subcutaneous tissue, and 0.5 mg/liter in peritoneal fluid. Ertapenem presents an attractive choice for many pathogens relevant to morbidly obese patients undergoing surgery. (This study has been registered at ClinicalTrials.gov under identifier NCT01407965.).


Assuntos
Obesidade Mórbida/sangue , beta-Lactamas/farmacocinética , beta-Lactamas/uso terapêutico , Adulto , Antibacterianos/farmacocinética , Antibacterianos/uso terapêutico , Ertapenem , Feminino , Humanos , Laparoscopia , Testes de Sensibilidade Microbiana , Microdiálise , Pessoa de Meia-Idade , Método de Monte Carlo , Obesidade Mórbida/terapia
9.
Tumour Biol ; 39(2): 1010428317694304, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28231737

RESUMO

Despite recent advances in diagnosis and therapy, prognosis of pancreatic cancer still remains very poor. Besides valid prognostic markers, novel therapeutic approaches are urgently needed. The family of cyclin-dependent kinases comprises 20 kinases which contribute to malignancy by promoting proliferation, migration, invasion, and apoptotic resistance of cancer cells. In this work, we investigated the role of CDK9 in pancreatic cancer. Immunohistochemical analysis of CDK9 expression in tumor and normal tissue of pancreatic cancer patients revealed an overexpression of CDK9 in pancreatic cancer tissue. In addition, high CDK9 expression in tumor tissue is associated with significantly shortened survival, especially in well-differentiated tumors. Moreover, the therapeutic potential of selective CDK9 inhibition on pancreatic cancer cells was evaluated by analysis of cell viability, long-term survival, and induction of apoptosis and characterized by western blotting and flow cytometry. Pharmacological CDK9 inhibition by SNS-032 drastically reduced cell viability in pancreatic cancer cells and potently suppressed long-term survival. Analyzing the mechanism of action revealed that CDK9 inhibition induced apoptosis and cell cycle arrest in a time-dependent manner by suppression of anti-apoptotic proteins. Furthermore, CDK9 inhibition potently enhances the therapeutic effect of chemotherapeutics in pancreatic cancer cells. In conclusion, we identified CDK9 as a negative prognostic marker in pancreatic cancer. Furthermore, pharmacological CDK9 inhibition is a novel and promising therapeutic approach for pancreatic cancer.


Assuntos
Biomarcadores Tumorais/biossíntese , Carcinoma Ductal Pancreático/enzimologia , Quinase 9 Dependente de Ciclina/biossíntese , Neoplasias Pancreáticas/enzimologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/patologia
10.
World J Surg ; 41(4): 1012-1018, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27822723

RESUMO

INTRODUCTION: In humans, alveolar echinococcosis (AE) is a serious helminthic disease. Additionally to a long-term medical treatment, in all suitable cases a complete surgical resection with a 20-mm safe distance (minimal distance of larval tissue to resection margin) is recommended. We analyzed the influence of the safe distance and the effect of the postoperative anthelmintic prophylaxis on the long-term outcome of patients who underwent surgery with curative intent. OBJECTIVE: Ninety-two operated patients were evaluated regarding the safe distance, the duration of medical therapy with benzimidazole derivates, and the further course of AE. RESULTS: Median follow-up after surgical procedure was 8.3 years. Twelve patients had a safe distance of 20 mm or more, 16 patients between 10 and 19 mm, 21 patients between 1 and 10 mm, and 10 patients 1 mm. In a further 33 patients, the affected liver was resected without any safe distance. Recurrence of AE was seen in 15 patients between 4 months and 24 years after initial operation. Safe distances of patients with recurrent disease were: 13 ×  no safe distance, one patient with 1-mm and one patient with 13-mm safe distance. In all patients except one with recurrent AE, postoperative therapy with benzimidazole derivates was stopped. CONCLUSION: A safe distance of at least 1 mm in combination with medical anthelmintic treatment continuing for two years might offer a good chance of being disease-free long term, but the exact period of medical treatment needed is not defined. The therapy regime should be determined through an interdisciplinary approach in specialized centers.


Assuntos
Equinococose Hepática/cirurgia , Hepatectomia/métodos , Adolescente , Adulto , Idoso , Anti-Helmínticos/uso terapêutico , Criança , Equinococose , Equinococose Hepática/tratamento farmacológico , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Cuidados Pós-Operatórios , Recidiva , Adulto Jovem
11.
BMC Surg ; 17(1): 115, 2017 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-29183351

RESUMO

BACKGROUND: Thyroid hemorrhage is considered to be an uncommon complication following blunt trauma to the neck. This condition is potentially life-threatening due to airway compression and may therefore require emergency airway management and surgical intervention in some cases. CASE PRESENTATION: We present the case of a 52-year-old woman who experienced a traumatic thyroid gland rupture (right lobe) with subsequent active arterial bleeding from branches of the inferior thyroid artery. On the same day, the patient presented to our emergency department with a painful swelling of the neck with an inspiratory stridor and hoarseness a few hours after a cycling accident. A right hemithyroidectomy was performed. The postoperative course was uneventful. We identified 33 additional cases published in English literature within the last 30 years, reporting blunt trauma to the neck with hemorrhagic complication of the thyroid gland. We provide a systematic review and particularly consider the aspects of endocrine surgery. CONCLUSION: The treatment approach for patients with blunt thyroid trauma should be dependent on the extent of the thyroid injury. Patients with tracheal compression, active bleeding and increasing hoarseness/shortness of breath require emergency airway control and often surgical exploration for hemorrhage control followed by resection of the ruptured thyroid. Importantly, in contrast to routine thyroid surgery, no electromyographic endotracheal tube is used during emergency intubation. Exchange of an endotracheal tube should be carefully evaluated due to difficult airway management in this setting. For protection against double-sided recurrent nerve palsy and postoperative hypoparathyroidism, a unilateral approach is preferable whenever possible.


Assuntos
Hemorragia/etiologia , Doenças da Glândula Tireoide/etiologia , Ferimentos não Penetrantes/complicações , Feminino , Humanos , Pessoa de Meia-Idade , Ruptura , Doenças da Glândula Tireoide/cirurgia , Tireoidectomia/métodos , Ferimentos não Penetrantes/cirurgia
12.
Int J Mol Sci ; 18(4)2017 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-28350325

RESUMO

Exogenous interleukin-4 (IL-4) has been demonstrated to affect the growth of different human malignancies including pancreatic cancer cells. The aim of our study was to determine the role of endogenously expressed IL-4-receptor-α-chain (IL-4Rα) in pancreatic cancer cells. IL-4Rα-suppression was achieved by generating Capan-1 cells stably expressing shRNA targeting IL-4Rα. The malignant phenotype was characterized by assessing growth properties, directional and non-directional cell movement in vitro and tumor growth in vivo. Signaling pathways were analyzed upon IL-4 and IL-13 stimulation of wildtype (WT) and control-transfected cells compared to IL-4Rα-knockdown cells. Silencing of IL-4Rα resulted in reduced anchorage-dependent cell growth (p < 0.05) and reduced anchorage-independent colony size (p < 0.001) in vitro. Moreover, cell movement and migration was inhibited. IL-4 and IL-13 stimulation of Capan-1-WT cells induced activation of similar pathways like stimulation with Insulin-like growth factor (IGF)-I. This activation was reduced after IL-4Rα downregulation while IGF-I signaling seemed to be enhanced in knockdown-clones. Importantly, IL-4Rα silencing also significantly suppressed tumor growth in vivo. The present study indicates that endogenously expressed IL-4 and IL-4Rα contribute to the malignant phenotype of pancreatic cancer cells by activating diverse pro-oncogenic signaling pathways. Addressing these pathways may contribute to the treatment of the disease.


Assuntos
Subunidade alfa de Receptor de Interleucina-4/genética , Interleucina-4/metabolismo , Neoplasias Pancreáticas/patologia , RNA Interferente Pequeno/farmacologia , Animais , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Predisposição Genética para Doença , Humanos , Técnicas In Vitro , Interleucina-3/metabolismo , Subunidade alfa de Receptor de Interleucina-4/antagonistas & inibidores , Camundongos , Transplante de Neoplasias , Neoplasias Pancreáticas/genética , Transdução de Sinais
13.
Tumour Biol ; 37(7): 8731-9, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26738869

RESUMO

Cancers arising from the large intestine or rectum are called colorectal cancer (CRC) and represent the fourth leading cause of cancer-related death worldwide. Since casein kinase 1 (CK1) isoforms are involved in many cellular processes and have been reported to be deregulated in various tumor entities, CK1 has become an interesting drug target. In this study, we examined the potential of CK1δ expression levels in tumor tissue of CRC patients as a prognostic biomarker. We show by quantitative RNA expression analyses that decreased CK1δ expression levels in tumor tissue predict prolonged survival rates. Random sampling of CK1δ stained tumor tissue indicates that CK1δ gene expression corresponds with CK1δ protein expression. Especially in low grade (grade 1, grade 2) and in UICC II/III classified tumors decreased CK1δ RNA levels correlate with significantly improved survival rates when the tumor was located in the right colon. We furthermore found gender-specific differences within these subgroups, revealing most significant increase in overall survival rates in male patients with tumors in right colon expressing low levels of CK1δ RNA. Results become even clearer, when only male patients over 50 years were considered. Together, these findings support the assumption that CK1δ might be a prognostic biomarker for CRC thereby providing an interesting drug target for the development of new therapy concepts.


Assuntos
Caseína Quinase Idelta/genética , Neoplasias Colorretais/genética , Neoplasias Colorretais/mortalidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/genética , Colo/patologia , Neoplasias Colorretais/patologia , Feminino , Expressão Gênica/genética , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , RNA/genética , Taxa de Sobrevida
14.
Amino Acids ; 48(5): 1185-97, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26803658

RESUMO

Cellular signal transduction components are usually regulated not only on transcriptional or translational level, but also by posttranslational modifications. Among these, reversible phosphorylation represents the most abundant modification. In general, phosphorylation events are essential for regulating the activity of central signal transduction proteins, also including kinases itself. Members of the CK1 family can be found as central signal transduction proteins in numerous cellular pathways. Due to its wide variety of cellular functions the activity of CK1 family members has to be tightly regulated. We previously reported that PKA and Chk1 are able to phosphorylate CK1δ within its C-terminal regulatory domain, consequently resulting in altered CK1 kinase activity. In the present study, we show by several methods that protein kinase C α (PKCα) as well is able to phosphorylate CK1δ at its C-terminally located residues S328, T329, and S370. Furthermore, we analyze the functional consequences of PKCα-mediated phosphorylation on CK1δ kinase activity. Mutation of S328, T329, or S370 to alanine dramatically alters the kinetic parameters of CK1δ. By using the PKCα-specific inhibitor Go-6983 in a selected cell culture model, we finally show that the in vitro detected regulatory connection between PKCα and CK1δ is also relevant in the cellular context. Taken together, these data contribute to a deeper understanding of cellular signal transduction networks thereby helping to form a basis for the development of future therapeutic concepts.


Assuntos
Caseína Quinase Idelta/química , Caseína Quinase Idelta/metabolismo , Proteína Quinase C-alfa/metabolismo , Motivos de Aminoácidos , Caseína Quinase Idelta/genética , Humanos , Mutagênese Sítio-Dirigida , Mutação , Fosforilação , Domínios Proteicos
15.
Amino Acids ; 48(2): 579-92, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26464264

RESUMO

CK1 protein kinases form a family of serine/threonine kinases which are highly conserved through different species and ubiquitously expressed. CK1 family members can phosphorylate numerous substrates thereby regulating different biological processes including membrane trafficking, cell cycle regulation, circadian rhythm, apoptosis, and signal transduction. Deregulation of CK1 activity and/or expression contributes to the development of neurological diseases and cancer. Therefore, CK1 became an interesting target for drug development and it is relevant to further understand the mechanisms of its regulation. In the present study, Cyclin-dependent kinase 2/Cyclin E (CDK2/E) and Cyclin-dependent kinase 5/p35 (CDK5/p35) were identified as cellular kinases able to modulate CK1δ activity through site-specific phosphorylation of its C-terminal domain. Furthermore, pre-incubation of CK1δ with CDK2/E or CDK5/p35 reduces CK1δ activity in vitro, indicating a functional impact of the interaction between CK1δ and CDK/cyclin complexes. Interestingly, inhibition of Cyclin-dependent kinases by Dinaciclib increases CK1δ activity in pancreatic cancer cells. In summary, these results suggest that CK1δ activity can be modulated by the interplay between CK1δ and CDK2/E or CDK5/p35. These findings extend our knowledge about CK1δ regulation and may be of use for future development of CK1-related therapeutic strategies in the treatment of neurological diseases or cancer.


Assuntos
Caseína Quinase Idelta/metabolismo , Quinase 2 Dependente de Ciclina/metabolismo , Quinase 5 Dependente de Ciclina/metabolismo , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Linhagem Celular Tumoral , Óxidos N-Cíclicos , Quinase 2 Dependente de Ciclina/antagonistas & inibidores , Quinase 5 Dependente de Ciclina/antagonistas & inibidores , Humanos , Indolizinas , Fosforilação , Compostos de Piridínio/farmacologia , Transdução de Sinais
16.
Int J Cancer ; 136(12): 2799-810, 2015 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-25404202

RESUMO

Colorectal cancer (CRC) is the fourth leading cause of cancer related death worldwide due to high apoptotic resistance and metastatic potential. Because mutations as well as deregulation of CK1 isoforms contribute to tumor development and tumor progression, CK1 has become an interesting drug target. In this study we show that CK1 isoforms are differently expressed in colon tumor cell lines and that growth of these cell lines can be inhibited by CK1-specific inhibitors. Furthermore, expression of CK1δ and ɛ is changed in colorectal tumors compared to normal bowel epithelium, and high CK1ɛ expression levels significantly correlate with prolonged patients' survival. In addition to changes in CK1δ and ɛ expression, mutations within exon 3 of CK1δ were detected in colorectal tumors. These mutations influence ATP binding resulting in changes in kinetic parameters of CK1δ. Overexpression of these mutants in HT29 cells alters their ability to grow anchorage independently. Consistent with these results, these CK1δ mutants lead to differences in proliferation rate and tumor size in xenografts due to changes in gene expression, especially in genes involved in regulation of cell proliferation, cell cycle, and apoptosis. In summary, our results provide evidence that changes in the expression levels of CK1 isoforms in colorectal tumors correlate with patients' survival. Furthermore, CK1 mutants affect growth and proliferation of tumor cells and induce tumor growth in xenografts, leading to the assumption that CK1 isoforms provide interesting targets for the development of novel effective therapeutic concepts to treat colorectal cancer.


Assuntos
Caseína Quinase 1 épsilon/genética , Caseína Quinase Idelta/genética , Neoplasias Colorretais/genética , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Idoso , Animais , Western Blotting , Caseína Quinase 1 épsilon/metabolismo , Caseína Quinase Idelta/metabolismo , Adesão Celular/genética , Linhagem Celular Tumoral , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Feminino , Perfilação da Expressão Gênica , Células HT29 , Humanos , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Pessoa de Meia-Idade , Mutação , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transplante Heterólogo , Carga Tumoral/genética
17.
Antimicrob Agents Chemother ; 59(10): 6241-7, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26248353

RESUMO

Meropenem serves as a clinically important, broad-spectrum antibiotic. While meropenem is commonly used in obese patients, its pharmacokinetics in this patient group is not well known. Our aim was to characterize the population pharmacokinetics and target attainment in plasma, subcutaneous tissue, and peritoneal fluid for meropenem in morbidly obese patients. Four doses of 1g meropenem were given as 15-min infusions every 8 h to five morbidly obese patients (body mass index [BMI], 47.6 to 62.3 kg/m(2)). After the fourth dose, serial meropenem concentrations were determined in plasma and, via microdialysis, in subcutaneous tissue and peritoneal fluid. All concentrations were analyzed simultaneously via population modeling, and target attainment probabilities predicted via Monte Carlo simulations using the target of unbound meropenem concentrations above the MIC for at least 40% of the dosing interval. For patients with 53 kg fat-free mass, total clearance was 18.7 liters/h and volume of distribution at steady state was 27.6 liters. The concentrations in subcutaneous tissue and peritoneal fluid largely paralleled those in plasma (equilibration half-life, <30 min). The area under the curve (AUC) in subcutaneous tissue divided by the plasma AUC had a mean of 0.721. For peritoneal fluid, this AUC ratio had a mean of 0.943. Target attainment probabilities were >90% after 1 g meropenem every 8 h as a 15-min infusion for MICs of up to 2 mg/liter in plasma and peritoneal fluid and 0.5 mg/liter in subcutaneous tissue. Meropenem pharmacokinetics in plasma and peritoneal fluid of obese patients was predictable, but subcutaneous tissue penetration varied greatly. (This study has been registered at ClinicalTrials.gov under registration no. NCT01407965.).


Assuntos
Antibacterianos/farmacocinética , Laparoscopia , Obesidade Mórbida/tratamento farmacológico , Obesidade Mórbida/metabolismo , Tienamicinas/farmacocinética , Adulto , Antibacterianos/sangue , Antibacterianos/farmacologia , Área Sob a Curva , Líquido Ascítico/química , Líquido Ascítico/metabolismo , Disponibilidade Biológica , Feminino , Meia-Vida , Humanos , Injeções Intravenosas , Masculino , Meropeném , Testes de Sensibilidade Microbiana , Microdiálise , Pessoa de Meia-Idade , Método de Monte Carlo , Obesidade Mórbida/microbiologia , Obesidade Mórbida/cirurgia , Cavidade Peritoneal/microbiologia , Cavidade Peritoneal/cirurgia , Estudos Prospectivos , Tela Subcutânea/química , Tela Subcutânea/metabolismo , Tienamicinas/sangue , Tienamicinas/farmacologia
18.
BMC Cancer ; 15: 57, 2015 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-25886494

RESUMO

BACKGROUND: Risk classification and prediction of prognosis in GIST is still a matter of debate. Data on the impact of age and gender as potential confounding factors are limited. Therefore we comprehensively investigated age and gender as independent risk factors for GIST. METHODS: Two independent patient cohorts (cohort I, n = 87 [<50 years]; cohort II, n = 125 [≥50 years]) were extracted from the multicentre Ulmer GIST registry including a total of 659 GIST patients retrospectively collected in 18 collaborative German oncological centers. Based on demographic and clinicopathological parameters and a median follow-up time of 4.3 years (range 0.56; 21.33) disease-specific-survival (DSS), disease-free-survival (DFS) and overall survival (OS) were calculated. RESULTS: GIST patients older than fifty years showed significantly worse DSS compared to younger patients (p = 0.021; HR = 0.307, 95% CI [0.113; 0.834]). DSS was significantly more favorable in younger female GIST patients compared with elderly females (p = 0.008). Female gender resulted again in better prognosis in younger patients (p = 0.033). CONCLUSIONS: Patient age (<50 years) and female gender were significantly associated with a more favourable prognosis in GIST. Extended studies are warranted to confirm our clinical results and to elucidate underlying pathophysiological mechanisms.


Assuntos
Neoplasias Gastrointestinais/patologia , Tumores do Estroma Gastrointestinal/patologia , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Neoplasias Gastrointestinais/mortalidade , Tumores do Estroma Gastrointestinal/mortalidade , Alemanha , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Sistema de Registros , Estudos Retrospectivos , Fatores Sexuais , Análise de Sobrevida , Adulto Jovem
20.
Int J Mol Sci ; 15(9): 16816-30, 2014 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-25247579

RESUMO

About 10% of all cancer patients will develop brain metastases during advanced disease progression. Interestingly, the vast majority of brain metastases occur in only three types of cancer: Melanoma, lung and breast cancer. In this review, we focus on summarizing the prognosis and impact of surgical resection of brain metastases originating from gastrointestinal cancers such as esophageal, gastric, pancreatic and colorectal cancer. The incidence of brain metastases is <1% in pancreatic and gastric cancer and <4% in esophageal and colorectal cancer. Overall, prognosis of these patients is very poor with a median survival in the range of only months. Interestingly, a substantial number of patients who had received surgical resection of brain metastases showed prolonged survival. However, it should be taken into account that all these studies were not randomized and it is likely that patients selected for surgical treatment presented with other important prognostic factors such as solitary brain metastases and exclusion of extra-cranial disease. Nevertheless, other reports have demonstrated long-term survival of patients upon resection of brain metastases originating from gastrointestinal cancers. Thus, it appears to be justified to consider aggressive surgical approaches for these patients.


Assuntos
Neoplasias Encefálicas/secundário , Carcinoma/secundário , Neoplasias Esofágicas/patologia , Neoplasias Gastrointestinais/patologia , Procedimentos Neurocirúrgicos , Neoplasias Pancreáticas/patologia , Neoplasias Encefálicas/epidemiologia , Neoplasias Encefálicas/cirurgia , Carcinoma/epidemiologia , Carcinoma/cirurgia , Craniotomia , Intervalo Livre de Doença , Neoplasias Esofágicas/epidemiologia , Neoplasias Gastrointestinais/epidemiologia , Humanos , Incidência , Cuidados Paliativos , Neoplasias Pancreáticas/epidemiologia , Seleção de Pacientes , Prognóstico , Qualidade de Vida , Resultado do Tratamento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA