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1.
RNA Biol ; 19(1): 1305-1315, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-36469564

RESUMO

The microRNA-200 family has wide-ranging regulatory functions in cancer development and progression. Above all, it is strongly associated with the epithelial-to-mesenchymal transition (EMT), a process during which cells change their epithelial to a mesenchymal phenotype and acquire invasive characteristics. More recently, miR-200 family members have also been reported to impact the immune evasion of cancer cells by regulating the expression of immunoinhibitory immune checkpoints (ICs) like PD-L1. Therefore, we aimed to comprehensively characterize this miR-200 family as a regulatory interface between EMT and immune evasion mechanisms in biliary tract cancer. Initial correlation analyses and transient overexpression experiments using miRNA mimics suggested miR-200c-3p as a putative regulator of ICs including PD-L1, LGALS9, and IDO1. However, these effects could not be confirmed in stable miR-200c-3p overexpression cell lines, nor in cells transiently transfected with miR-200c-3p mimic from an independent manufacturer. By shifting our efforts towards dissecting the mechanisms leading to these disparate effects, we observed that the initially used miR-200c-3p mimic triggered a double-stranded (ds)RNA-dependent antiviral response. Besides upregulating the ICs, this had substantial cellular consequences including an induction of interferon type I and type III expression, increased levels of intracellular dsRNA sensors, and a significantly altered cellular growth and apoptotic activity.Our study highlights the capability of miRNA mimics to non-specifically induce a dsRNA-mediated antiviral interferon response. Consequently, phenotypic alterations crucially distort physiological miRNA functions and might result in a major misinterpretation of previous and future miRNA studies, especially in the context of IC regulation.


Assuntos
MicroRNAs , MicroRNAs/metabolismo , Interferons/genética , Interferons/metabolismo , Antígeno B7-H1/genética , Antígeno B7-H1/metabolismo , Transição Epitelial-Mesenquimal/genética , Proliferação de Células , Antivirais/farmacologia , Regulação Neoplásica da Expressão Gênica , Linhagem Celular Tumoral
2.
Int J Mol Sci ; 21(7)2020 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-32252259

RESUMO

Fibroblast growth factor receptor 2 (FGFR2) gene fusions are bona fide oncogenic drivers in 10-15% of intrahepatic cholangiocarcinoma (CCA), yet currently there are no cell lines publically available to study endogenous FGFR2 gene fusions. The ability of clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 to generate large yet precise chromosomal rearrangements has presented the possibility of engineering endogenous gene fusions for downstream studies. In this technical report, we describe the generation of an endogenous FGFR2-Bicaudal family RNA binding protein 1 (BICC1) fusion in multiple independent cholangiocarcinoma and immortalized liver cell lines using CRISPR. BICC1 is the most common FGFR2 fusion partner in CCA, and the fusion arises as a consequence of a 58-megabase-sized inversion on chromosome 10. We replicated this inversion to generate a fusion product that is identical to that seen in many human CCA. Our results demonstrate the feasibility of generating large megabase-scale inversions that faithfully reproduce human cancer aberrations.


Assuntos
Sistemas CRISPR-Cas , Inversão Cromossômica , Edição de Genes , Fusão Gênica , Proteínas de Ligação a RNA/genética , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/genética , Linhagem Celular , Pontos de Quebra do Cromossomo , Marcação de Genes , Loci Gênicos , Humanos , RNA Guia de Cinetoplastídeos
3.
Eur Surg Res ; 60(1-2): 1-12, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30650425

RESUMO

BACKGROUND: Biliary tract cancers (BTCs) have a poor prognosis. BTCs are characterized by a prominent desmoplastic reaction which possibly contributes to the aggressive phenotype of this tumor. The desmoplastic reaction includes excessive production and deposition of extracellular matrix proteins such as periostin, secreted protein acidic and rich in cysteine (SPARC), thrombospondin-1, as well as accumulation of α-smooth muscle actin-positive cancer-associated fibroblasts and immune cells, secreting growth factors and cytokines including transforming growth factor (TGF)-ß. In the present study, we investigated the expression of SPARC in BTC as well as its possible regulation by TGF-ß. METHODS: Expression levels of Sparc, TGF-ß1 and its receptor ALK5 were evaluated by quantitative real-time PCR in 6 biliary tract cell lines as well as 1 immortalized cholangiocyte cell line (MMNK-1). RNAs from tumor samples of 7 biliary tract cancer patients were analyzed for expression of Sparc, TGF-ß type II receptor (TbRII) as well as Twist and ZO-1. MMNK-1 cells were stimulated with TGF-ß for 24 h, and Sparc, ZO-1 and E-Cadherin expressions were determined. The presence of SPARC protein was analyzed by immunohistochemistry in tumor specimens from 10 patients. RESULTS: When comparing basal Sparc transcript levels in diverse BTC cell lines to MMNK-1 cells, we found that it was strongly downregulated in all cancer cell lines. The remaining expression levels were higher in highly differentiated cell lines (CCSW1, MZChA1, MZChA2 and TFK-1) than in less differentiated and undifferentiated ones (BDC, SKChA1). Expression of Sparc in BTC patient samples showed a significant positive correlation with expression of the epithelial marker ZO-1. In contrast, the mesenchymal marker Twist and the TbRII showed a trend of negative correlation with expression of Sparc in these samples. TGF-ß exposure significantly downregulated Sparc expression in MMNK-1 cholangiocytes in vitro in parallel to downregulation of epithelial markers (E-Cadherin and ZO-1). Finally, SPARC immunostaining was performed in 10 patient samples, and the correlation between absence of SPARC and survival times was analyzed. CONCLUSIONS: These data imply that a decrease in SPARC expression is correlated with dedifferentiation of BTC cells resulting in enhanced EMT being possibly mediated by TGF-ß. Thereby SPARC levels might be a marker for individual prognosis of a patient, and strategies aiming at inhibition of SPARC downregulation might have potential for new future therapies.


Assuntos
Neoplasias do Sistema Biliar/patologia , Transição Epitelial-Mesenquimal , Osteonectina/fisiologia , Diferenciação Celular , Linhagem Celular Tumoral , Regulação para Baixo , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Humanos , Osteonectina/análise , Osteonectina/genética , RNA Mensageiro/análise , Fator de Crescimento Transformador beta/farmacologia , Proteína da Zônula de Oclusão-1/análise
4.
Int J Mol Sci ; 20(21)2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31652839

RESUMO

The liver is the central metabolic organ of mammals. In humans, most diseases of the liver are primarily caused by an unhealthy lifestyle-high fat diet, drug and alcohol consumption- or due to infections and exposure to toxic substances like aflatoxin or other environmental factors. All these noxae cause changes in the metabolism of functional cells in the liver. In this literature review we focus on the changes at the miRNA level, the formation and impact of reactive oxygen species and the crosstalk between those factors. Both, miRNAs and oxidative stress are involved in the multifactorial development and progression of acute and chronic liver diseases, as well as in viral hepatitis and carcinogenesis, by influencing numerous signaling and metabolic pathways. Furthermore, expression patterns of miRNAs and antioxidants can be used for biomonitoring the course of disease and show potential to serve as possible therapeutic targets.


Assuntos
Hepatopatias/etiologia , Fígado/metabolismo , MicroRNAs/genética , Estresse Oxidativo , Carcinogênese/metabolismo , Humanos , Hepatopatias/patologia , MicroRNAs/metabolismo
5.
Cell Physiol Biochem ; 50(4): 1460-1473, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30359963

RESUMO

BACKGROUND/AIMS: The neutral, non-essential amino acid glycine has manifold functions and effects under physiological and pathophysiological conditions. Besides its function as a neurotransmitter in the central nervous system, glycine also exerts immunomodulatory effects and as an osmolyte it participates in cell volume regulation. During phagocytosis, glycine contributes to (local) cell volume-dependent processes like lamellipodium formation. Similar to the expansion of the lamellipodium we assume that glycine also affects the migration of microglial cells in a cell volume-dependent manner. METHODS: Mean cell volume (MCV) and cell migration were determined using flow cytometry and trans-well migration assays, respectively. Electrophysiological recordings of the cell membrane potential (Vmem) and swelling-dependent chloride (Cl-) currents (IClswell, VSOR, VRAC) were performed using the whole-cell patch clamp technique. RESULTS: In the murine microglial cell line BV-2, flow cytometry analysis revealed that glycine (5 mM) increases the MCV by ∼9%. The glycine-dependent increase in MCV was suppressed by the partial sodium-dependent neutral amino acid transporter (SNAT) antagonist MeAIB and augmented by the Cl- current blocker DCPIB. Electrophysiological recordings showed that addition of glycine activates a Cl- current under isotonic conditions resembling features of the swelling-activated Cl- current (IClswell). The cell membrane potential (Vmem) displayed a distinctive time course after glycine application; initially, glycine evoked a rapid depolarization mediated by Na+-coupled glycine uptake via SNAT, followed by a further gradual depolarization, which was fully suppressed by DCPIB. Interestingly, glycine significantly increased migration of BV-2 cells, which was suppressed by MeAIB, suggesting that SNAT is involved in the migration process of microglial cells. CONCLUSION: We conclude that glycine acts as a chemoattractant for microglial cells presumably by a cell volume-dependent mechanism involving SNAT-mediated cell swelling.


Assuntos
Sistema A de Transporte de Aminoácidos/metabolismo , Tamanho Celular/efeitos dos fármacos , Glicina/farmacologia , Sistema A de Transporte de Aminoácidos/antagonistas & inibidores , Animais , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Cloretos/metabolismo , Ciclopentanos/farmacologia , Soluções Hipotônicas/farmacologia , Indanos/farmacologia , Potenciais da Membrana/efeitos dos fármacos , Camundongos , Microglia/citologia , Microglia/metabolismo , Nitrobenzoatos/farmacologia , Técnicas de Patch-Clamp
6.
Strahlenther Onkol ; 194(11): 991-1006, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30069738

RESUMO

PURPOSE: This study was conducted to investigate the potential predictive value of tumor budding for neoadjuvant chemoradiotherapy response in locally advanced rectal cancer. PATIENTS AND METHODS: Surgical specimens of 128 ypUICC (Union for International Cancer Control) stage 0-III mid-to-low rectal cancer patients were identified from a prospectively maintained colorectal cancer database and classified into two groups using the 10 high-power field average method: none/mild tumor budding (BD-0) and moderate/severe tumor budding (BD-1). Overall survival, relapse-free survival (RFS), and recurrence estimates were calculated using the Kaplan-Meier method and compared with the log-rank test. For RFS, a multivariable Cox's proportional hazards regression analysis was performed. RESULTS: No (n = 20) or mild (n = 27) tumor budding (BD-0) was identified in 47 (37%) and moderate (n = 52) or severe (n = 29) tumor budding (BD-1) in 81 (63%) surgical specimens. Positive tumor budding (BD-1) was associated with significantly reduced T­level downstaging (P < 0.001) and tumor regression (P < 0.001). After a median follow-up time of 7 years (range 2.9-146.7 months), BD-0 patients had more favorable 5­year RFS (90 vs. 71%, P = 0.02) and distant recurrence (2 vs. 12%, P = 0.03) estimates. Multivariable analyses confirmed BD-1 as a negative predictive parameter for RFS (hazard ratio = 3.44, 95% confidence interval 1.23-9.63, P = 0.018). CONCLUSIONS: Our data confirm tumor budding as a strong prognostic factor and its potential predictive value for neoadjuvant chemoradiotherapy response in locally advanced rectal cancer patients. This provides the opportunity to modify and individualize neoadjuvant therapy regimens for non-responders.


Assuntos
Transformação Celular Neoplásica/patologia , Quimiorradioterapia , Terapia Neoadjuvante , Recidiva Local de Neoplasia/patologia , Neoplasias Retais/patologia , Neoplasias Retais/terapia , Microambiente Tumoral/fisiologia , Idoso , Terapia Combinada , Transição Epitelial-Mesenquimal/fisiologia , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/mortalidade , Recidiva Local de Neoplasia/terapia , Estadiamento de Neoplasias , Modelos de Riscos Proporcionais , Estudos Prospectivos , Neoplasias Retais/mortalidade
7.
Thorac Cardiovasc Surg ; 66(4): 287-293, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-28259111

RESUMO

BACKGROUND: evidence-based medicine (EBM) approaches have reached broad acceptance, both in conservative and surgical disciplines. The aim of this study is to clarify the role of EBM in a rare condition of aortic regurgitation (AR) with surgical indication. METHODS: A purpose-built Internet-based questionnaire was sent to 607 cardiovascular surgeons in Germany, Austria, and Switzerland. A virtual 64-year-old patient's medical history was presented, including two ultrasound images and one computed tomography scan, showing a 58-mm aortic root aneurysm and a severe trileaflet regurgitant aortic valve. Participants had to choose their preferred therapeutic strategy from a list. Additionally, demographics including nationality, the center size, and the frequency of similar types of patients referred to their departments were collected. RESULTS: Of 607 questionnaires, 100 were returned (16%). One participant was excluded due to conflicting answers. Most surgeons (n = 84; 84%) chose a valve-sparing root replacement (VSRR). A Bentall procedure was preferred by 13 surgeons (13%). Two surgeons voted for aortic valve replacement combined with partial root resection. The decision-making process was not significantly influenced by center size, nationality, or frequency of patients. CONCLUSION: Applying the current guidelines to our virtual study patient, 84% of participants acted accordingly choosing VSRR. Remarkably, 14% of these surgeons see less than 10 and 43% see not more than 20 comparable patients per year. Since the guidelines reserve VSRR for competent centers, those numbers as well as the guidelines themselves should be further discussed.


Assuntos
Aneurisma Aórtico/cirurgia , Insuficiência da Valva Aórtica/cirurgia , Valva Aórtica/cirurgia , Implante de Prótese Vascular/tendências , Medicina Baseada em Evidências/tendências , Implante de Prótese de Valva Cardíaca/tendências , Padrões de Prática Médica/tendências , Cirurgiões/tendências , Aneurisma Aórtico/diagnóstico por imagem , Aneurisma Aórtico/fisiopatologia , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/fisiopatologia , Insuficiência da Valva Aórtica/diagnóstico por imagem , Insuficiência da Valva Aórtica/fisiopatologia , Aortografia/tendências , Tomada de Decisão Clínica , Angiografia por Tomografia Computadorizada/tendências , Ecocardiografia Doppler em Cores/tendências , Europa (Continente) , Pesquisas sobre Atenção à Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Carga de Trabalho
8.
Z Gastroenterol ; 56(5): 495-498, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29734448

RESUMO

Anal intraepithelial neoplasia (AIN) is a precursor of anal carcinoma. Conventional therapy is based on topical and local ablative approaches. However, the recurrence rates are very high, leading to repetitive treatment sessions and need for long-term surveillance. Endoscopic submucosal dissection (ESD) is an established treatment for malignant early neoplasias of the gastrointestinal tract, especially in the esophagus, stomach, and colorectum. Japanese centers have reported few cases of ESD for early anal carcinoma. We report a case of high-grade AIN diagnosed with magnifying narrow-band imaging and chromoendoscopy that was resected R0 with ESD en bloc.


Assuntos
Neoplasias do Ânus/cirurgia , Carcinoma in Situ/cirurgia , Ressecção Endoscópica de Mucosa/métodos , Canal Anal , Neoplasias do Ânus/patologia , Carcinoma in Situ/patologia , Dissecação/métodos , Endoscopia Gastrointestinal/métodos , Humanos , Recidiva Local de Neoplasia , Resultado do Tratamento
9.
Dig Endosc ; 30(3): 354-363, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29218732

RESUMO

BACKGROUND AND AIM: Colorectal endoscopic submucosal dissection (ESD) shows higher R0 resection and lower local recurrence rates than endoscopic mucosal resection (EMR) in Japan. In Europe, independent learning of ESD in the colorectum is feasible, but yet to be analyzed for curative resection and recurrence rates. METHODS: After experimental training under supervision by Japanese experts (T.O., N.Y.), three endoscopists independently carried out 83 ESD procedures intention-to-treat for lesions in the entire colorectum of 67 patients in a prospective registry (November 2009 to June 2016). RESULTS: ESD was feasible in 80 (96%) colorectal neoplasias (mean diameter 33.6 [± 1.8] mm), and three more required conversion to piecemeal EMR. The lesions were adenomas in 66% with low-grade intraepithelial neoplasia (LGIN), 29% with high-grade intraepithelial neoplasia, and 5% with carcinomas (G2, pT1). ESD had to be facilitated by the final use of snaring (hybrid-ESD, n = 45), especially in the initial learning period. En-bloc resection rate was 85%. Complications were microperforations (7%, conducive to one hemicolectomy), and delayed bleeding (1%) without mortality or long-term morbidity. Residual adenomas with LGIN (5%) after hybrid-ESD did not recur after endoscopic ablation. All malignant neoplasias (34%) were curatively resected without recurrence after a mean follow up of 19.5 (± 3.2) months. CONCLUSIONS: During independent ESD learning in the colorectum, ESD intention-to-treat showed a low recurrence rate after appropriate training, and hybrid-ESD showed acceptable complication and recurrence rates, justifying hybrid-ESD as a strategy for self-completion and rescue.


Assuntos
Adenoma/cirurgia , Carcinoma/cirurgia , Neoplasias Colorretais/cirurgia , Ressecção Endoscópica de Mucosa , Recidiva Local de Neoplasia/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Humanos , Análise de Intenção de Tratamento , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
10.
Int J Mol Sci ; 19(3)2018 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-29510509

RESUMO

The clonogenic assay is a widely used method to study the ability of cells to 'infinitely' produce progeny and is, therefore, used as a tool in tumor biology to measure tumor-initiating capacity and stem cell status. However, the standard protocol of using 6-well plates has several disadvantages. By miniaturizing the assay to a 96-well microplate format, as well as by utilizing the confluence detection function of a multimode reader, we here describe a new and modified protocol that allows comprehensive experimental setups and a non-endpoint, label-free semi-automatic analysis. Comparison of bright field images with confluence images demonstrated robust and reproducible detection of clones by the confluence detection function. Moreover, time-resolved non-endpoint confluence measurement of the same well showed that semi-automatic analysis was suitable for determining the mean size and colony number. By treating cells with an inhibitor of clonogenic growth (PTC-209), we show that our modified protocol is suitable for comprehensive (broad concentration range, addition of technical replicates) concentration- and time-resolved analysis of the effect of substances or treatments on clonogenic growth. In summary, this protocol represents a time- and cost-effective alternative to the commonly used 6-well protocol (with endpoint staining) and also provides additional information about the kinetics of clonogenic growth.


Assuntos
Miniaturização/métodos , Ensaio Tumoral de Célula-Tronco/métodos , Linhagem Celular Tumoral , Citostáticos/toxicidade , Compostos Heterocíclicos com 2 Anéis/toxicidade , Humanos , Tiazóis/toxicidade
11.
Int J Mol Sci ; 19(9)2018 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-30223590

RESUMO

Epigenetic factors are essentially involved in carcinogenesis, tumor promotion, and chemoresistance. Two epigenetic key players are miRNAs and histone deacetylases (HDACs). As previously shown by own theoretical databank analysis, the crosstalk between miRNAs and HDACs is relevant in different human chronic diseases and cancerogenic pathways. We aimed to investigate a potential connection between the expression of a well-defined subset of "proliferation-associated" miRNAs and the expression of HDACs as well as clinical parameters in pancreatic neuroendocrine tumors (pNETs). MATERIALS AND METHODS: Expression levels of miRNA132-3p, miRNA145-5p, miRNA183-5p, miRNA34a-5p, and miRNA449a in 57 pNETs resected between 1997 and 2015 were measured and linked to the immunohistochemical expression pattern of members of the four HDAC classes on human tissue microarrays. All pNET cases were clinically and pathologically characterized according to published guidelines. Correlation analysis revealed a significant association between expression of specific miRNAs and two members of the HDAC family (HDAC3 and HDAC4). Additionally, a linkage between miRNA expression and clinico-pathological parameters like grading, TNM-staging, and hormone activity was found. Moreover, overall and disease-free survival is statistically correlated with the expression of the investigated miRNAs. Overall, we demonstrated that specific miRNAs could be linked to HDAC expression in pNETs. Especially miRNA449a (associated with HDAC3/4) seems to play an important role in pNET proliferation and could be a potential prognostic factor for poor survival. These first data could help, to improve our knowledge of the complex interactions of the epigenetic drivers in pNETs for further therapeutic approaches.


Assuntos
Carcinoma Neuroendócrino/genética , Carcinoma Neuroendócrino/metabolismo , Regulação Neoplásica da Expressão Gênica , Histona Desacetilases/metabolismo , MicroRNAs/genética , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Idoso , Biomarcadores Tumorais , Carcinoma Neuroendócrino/diagnóstico , Carcinoma Neuroendócrino/mortalidade , Linhagem Celular Tumoral , Proliferação de Células , Epigênese Genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/mortalidade , Prognóstico
12.
Int J Mol Sci ; 19(10)2018 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-30321986

RESUMO

Histone deacetylases (HDACs) play a key role in epigenetic mechanisms in health and disease and their dysfunction is implied in several cancer entities. Analysis of expression patterns in pancreatic neuroendocrine tumors (pNETs) indicated HDAC5 to be a potential target for future therapies. As a first step towards a possible treatment, the aim of this study was to evaluate the in vitro cellular and molecular effects of HDAC5 inhibition in pNET cells. Two pNET cell lines, BON-1 and QGP-1, were incubated with different concentrations of the selective class IIA HDAC inhibitor, LMK-235. Effects on cell viability were determined using the resazurin-assay, the caspase-assay, and Annexin-V staining. Western Blot and immunofluorescence microscopy were performed to assess the effects on HDAC5 functionality. LMK-235 lowered overall cell viability by inducing apoptosis in a dose- and time-dependent manner. Furthermore, acetylation of histone-H3 increased with higher LMK-235 concentrations, indicating functional inhibition of HDAC4/5. Immunocytochemical analysis showed that proliferative activity (phosphohistone H3 and Ki-67) decreased at highest concentrations of LMK-235 while chromogranin and somatostatin receptor 2 (SSTR2) expression increased in a dose-dependent manner. HDAC5 expression was found to be largely unaffected by LMK-235. These findings indicate LMK-235 to be a potential therapeutic approach for the development of an effective and selective pNET treatment.


Assuntos
Inibidores de Histona Desacetilases/farmacologia , Histona Desacetilases/metabolismo , Tumores Neuroendócrinos/metabolismo , Neoplasias Pancreáticas/metabolismo , Acetilação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Histonas/metabolismo , Humanos , Tumores Neuroendócrinos/tratamento farmacológico , Neoplasias Pancreáticas/tratamento farmacológico , Proteínas Repressoras/metabolismo
13.
Cell Physiol Biochem ; 41(3): 1011-1019, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28291963

RESUMO

BACKGROUND/AIMS: For in vitro cytotoxicity testing, discrimination of apoptosis and necrosis represents valuable information. Viability analysis performed at two different time points post treatment could serve such a purpose because the dynamics of metabolic activity of apoptotic and necrotic cells is different, i.e. a more rapid decline of cellular metabolism during necrosis whereas cellular metabolism is maintained during the entire execution phase of apoptosis. This study describes a straightforward approach to distinguish apoptosis and necrosis. METHODS: A431 human epidermoid carcinoma cells were treated with different concentrations/doses of actinomycin D (Act-D), 4,5,6,7-tetrabromo-2-azabenzimidazole (TBB), Ro 31-8220, H2O2 and photodynamic treatment (PDT). The resazurin viability signal was recorded at 2 and 24 hrs post treatment. Apoptosis and necrosis were verified by measuring caspase 3/7 and membrane integrity. RESULTS: Calculation of the difference curve between the 2 and 24 hrs resazurin signals yields the following information: a positive difference signal indicates apoptosis (i.e. high metabolic activity at early time points and low signal at 24 hrs post treatment) while an early reduction of the viability signal indicates necrosis. For all treatments, this dose-dependent sequence of cellular responses could be confirmed by independent assays. CONCLUSION: Simple and cost-effective viability analysis provides reliable information about the dose ranges of a cytotoxic agent where apoptosis or necrosis occurs. This may serve as a starting point for further in-depth characterisation of cytotoxic treatments.


Assuntos
Apoptose/efeitos dos fármacos , Bioensaio , Indicadores e Reagentes/química , Necrose/induzido quimicamente , Oxazinas/química , Xantenos/química , Biomarcadores/metabolismo , Caspase 3/genética , Caspase 3/metabolismo , Caspase 7/genética , Caspase 7/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Dactinomicina/farmacologia , Relação Dose-Resposta a Droga , Epiderme , Expressão Gênica , Humanos , Peróxido de Hidrogênio/farmacologia , Indóis/farmacologia , Luz , Necrose/metabolismo , Necrose/patologia , Triazóis/farmacologia
14.
Cell Physiol Biochem ; 43(3): 1037-1051, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28968600

RESUMO

BACKGROUND/AIMS: Glucose-stimulated insulin secretion (GSIS) of pancreatic ß-cells involves glucose uptake and metabolism, closure of KATP channels and depolarization of the cell membrane potential (Vmem), activation of voltage-activated Ca2+ currents (ICav) and influx of Ca2+, which eventually triggers hormone exocytosis. Beside this classical pathway, KATP-independent mechanisms such as changes in intracellular pH (pHi) or cell volume, which also affect ß-cell viability, can elicit or modify insulin release. In ß-cells the regulation of pHi is mainly accomplished by Na+/H+ exchangers (NHEs). To investigate if other proton extrusion mechanisms than NHEs are involved in pH regulation, we tested for the presence of the non-gastric H+/K+ ATPase in rat insulinoma cells and assessed effects of the H+/K+ ATPase inhibitor SCH-28080 on insulin secretion, cell viability and apoptosis. METHODS: In INS-1E cell cultures, H+/K+ ATPase gene and protein expression was analyzed by reverse transcription PCR and Western blotting. Intracellular pH (pHi) recovery after acute acidic load was measured by NH4Cl prepulsing using BCECF. Insulin secretion was determined by ELISA from the cell culture supernatant. Vmem, K+ and Ca2+ currents were recorded using patch clamp. Overall cell responses were determined using resazurin (viability) and cytotoxicity assays. The mean cell volume (MCV), cell granularity (side-scatter; SSC), phosphatidylserine (PS) exposure, cell membrane integrity, caspase activity and the mitochondrial membrane potential (ΔΨm) were measured by flow cytometry. RESULTS: We found that the α-subunit of the non-gastric H+/K+ ATPase (HKα2) is expressed on mRNA and protein level. However, compared to rat colon tissue, in INS-1E cells mRNA abundance was very low. In NH4Cl prepulsing experiments no K+-dependent pHi recovery was observed under Na+-free extracellular conditions. Nonetheless within 1 h, 20 µM SCH-28080 inhibited GSIS by ∼50%, while basal release was unaffected. The L-type ICav blocker nifedipine caused a full inhibition of GSIS at 10 and 20 µM. At 20 µM, SCH-28080 inhibited ICav comparable to 20 µM nifedipine and in addition augmented IKATP recorded at -60 mV and hyperpolarized Vmem by ∼15 mV. Cell viability 2 and 24 h post treatment with SCH-28080 was dose-dependently inhibited with IC50 values of 22.9 µM and 15.3 µM, respectively. At 20 µM the percentages of Annexin-V+, caspase+ and propidium iodide+ cells were significantly increased after 24 and 48 h. Concurrently, the MCV was significantly decreased (apoptotic volume decrease, AVD) and the SSC signal was increased. At concentrations >40-50 µM, SCH-28080 became progressively cytotoxic causing a steep increase in necrotic cells already 2 h post treatment and a breakdown of ΔΨm within 4 h under 50 and 100 µM while 10 and 20 µM had no effect on ΔΨm within 24 h. CONCLUSION: We demonstrate expression of HKα2 in rat INS-1E cells. However, the pump is apparently non-functional under the given conditions. Nonetheless the H+/K+ ATPase blocker SCH-28080 inhibits insulin secretion and induces cell death. Importantly, we show that SCH-28080 inhibits ICav - and activates KATP channels identifying them as novel "off-targets" of the inhibitor, causing hyperpolarization of Vmem and inhibition of insulin secretion.


Assuntos
Apoptose/efeitos dos fármacos , ATPase Trocadora de Hidrogênio-Potássio/metabolismo , Imidazóis/toxicidade , Insulina/análise , Inibidores da Bomba de Prótons/toxicidade , Animais , Cálcio/metabolismo , Linhagem Celular Tumoral , Tamanho Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Colo/metabolismo , Ensaio de Imunoadsorção Enzimática , Glucose/farmacologia , ATPase Trocadora de Hidrogênio-Potássio/química , ATPase Trocadora de Hidrogênio-Potássio/genética , Concentração de Íons de Hidrogênio , Insulina/metabolismo , Secreção de Insulina , Insulinoma/metabolismo , Insulinoma/patologia , Canais KATP/metabolismo , Potenciais da Membrana/efeitos dos fármacos , Nifedipino/toxicidade , Técnicas de Patch-Clamp , Fosfatidilserinas/farmacologia , RNA Mensageiro/metabolismo , Ratos
15.
J Clin Ultrasound ; 45(7): 400-407, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28251661

RESUMO

BACKGROUND: We aimed to analyze the benefits of adding ultrasound (US) guidance to the standard fluoroscopically assisted percutaneous transhepatic biliary drainage (F-PTBD). We also performed a systematic literature review of success and complication rates of US-PTBD in a wide field of indications. METHODS: We evaluated a total of 81 US-PTBDs carried out in our institution, 74% of which were part of the management of malignancy. In addition, we compared our results with those of a total of 5,272 procedures (3,779 F-PTBD and 1,493 US-PTBD) reported in the literature. RESULTS: US-PTBD was technically successful in 94% of attempts with a mean of 2.2 needle passes. Procedural success was achieved in 86% of cases. There were no procedure-related deaths or severe complications. Minor complications were catheter dislodgement (15%) as well as one case each of a porto-biliary fistula, hematoma, and biloma. A systematic review of the literature also showed that US-PTBD has a similar technical success rate to F-PTBD but lower median rates of severe early complications (0% versus 8%) and procedural death (0% versus 1%). CONCLUSIONS: Given our results and our review of the literature, US-PTBD is as effective as F-PTBD and has significantly lower complication rates. US-PTBD should be preferred to F-PTBD. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 45:400-407, 2017.


Assuntos
Doenças dos Ductos Biliares/diagnóstico por imagem , Doenças dos Ductos Biliares/terapia , Drenagem/métodos , Ultrassonografia de Intervenção/métodos , Idoso , Ductos Biliares/diagnóstico por imagem , Feminino , Fluoroscopia , Humanos , Masculino , Estudos Retrospectivos
16.
Hepatology ; 62(5): 1456-65, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25990106

RESUMO

UNLABELLED: Photodynamic therapy using porfimer (P-PDT) improves palliation and survival in nonresectable hilar bile duct cancer. Tumoricidal penetration depth of temoporfin-PDT (T-PDT) is twice that of P-PDT. In a single-arm phase II study we investigated the safety, efficacy, survival time, and adverse events of T-PDT compared with previous data on P-PDT. Twenty-nine patients (median 71 [range 47-88] years) with nonresectable hilar bile duct cancer were treated with T-PDT (median 1 [range 1-4] sessions) plus stenting and followed up every 3 months. The PDT was well tolerated. In patients with occluded segments at baseline (n=28) a reopening of a median of 3 (range 1-7) segments could be achieved: n=16 local response and n=11 stable local disease, one progressive disease. Cholestasis and performance significantly improved when impaired at baseline. Time to local tumor progression was a median of 6.5 (2.7-41.0) months. Overall survival time was a median of 15.4 (range 4.4-62.4) months. Patients died from tumor progression (55%), cholangitis (18%), pneumonia (7%), hemobilia (7%), esophagus variceal hemorrhage (3%), and vascular diseases (10%). Adverse events were cholangitis (n=4), liver abscess (n=2), cholecystitis (n=2), phototoxic skin (n=5), and injection site reactions (n=7). Compared to previous P-PDT, T-PDT shows prolonged time to local tumor progression (median 6.5 versus 4.3 months, P<0.01), fewer PDT treatments needed (median 1 versus 3, P<0.01), a higher 6-month survival rate (83% versus 70%, P<0.01), and a trend for longer overall median survival (15.4 versus 9.3 months, P=0.72) yet not significantly different. The risk of adverse events is not increased except for (avoidable) subcutaneous phototoxicity at the injection site. CONCLUSION: Temoporfin-PDT can safely be delivered to hilar bile duct cancer patients and results in prolonged patency of hilar bile ducts, a trend for longer survival time, and similar palliation as with P-PDT.


Assuntos
Neoplasias do Sistema Biliar/tratamento farmacológico , Mesoporfirinas/uso terapêutico , Fotoquimioterapia , Idoso , Idoso de 80 Anos ou mais , Neoplasias do Sistema Biliar/sangue , Neoplasias do Sistema Biliar/mortalidade , Bilirrubina/sangue , Causas de Morte , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fotoquimioterapia/efeitos adversos
17.
Int J Mol Sci ; 17(4): 573, 2016 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-27092491

RESUMO

Renal cell carcinoma (RCC) represents a deadly disease with rising mortality despite intensive therapeutic efforts. It comprises several subtypes in terms of distinct histopathological features and different clinical presentations. Long non-coding RNAs (lncRNAs) are non-protein-coding transcripts in the genome which vary in expression levels and length and perform diverse functions. They are involved in the inititation, evolution and progression of primary cancer, as well as in the development and spread of metastases. Recently, several lncRNAs were described in RCC. This review emphasises the rising importance of lncRNAs in RCC. Moreover, it provides an outlook on their therapeutic potential in the future.


Assuntos
Carcinoma de Células Renais/genética , Neoplasias Renais/genética , Rim/patologia , RNA Longo não Codificante/genética , Animais , Carcinoma de Células Renais/patologia , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Renais/patologia , Metástase Neoplásica/genética , Metástase Neoplásica/patologia
18.
Int J Mol Sci ; 17(12)2016 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-27916938

RESUMO

MicroRNAs (miRNAs) are master regulators of drug resistance and have been previously proposed as potential biomarkers for the prediction of therapeutic response in colorectal cancer (CRC). Sorafenib, a multi-kinase inhibitor which has been approved for the treatment of liver, renal and thyroid cancer, is currently being studied as a monotherapy in selected molecular subtypes or in combination with other drugs in metastatic CRC. In this study, we explored sorafenib-induced cellular effects in Kirsten rat sarcoma viral oncogene homolog olog (KRAS) wild-type and KRAS-mutated CRC cell lines (Caco-2 and HRT-18), and finally profiled expression changes of specific miRNAs within the miRNome (>1000 human miRNAs) after exposure to sorafenib. Overall, sorafenib induced a time- and dose-dependent growth-inhibitory effect through S-phase cell cycle arrest in KRAS wild-type and KRAS-mutated CRC cells. In HRT-18 cells, two human miRNAs (hsa-miR-597 and hsa-miR-720) and two small RNAs (SNORD 13 and hsa-miR-3182) were identified as specifically sorafenib-induced. In Caco-2 cells, nine human miRNAs (hsa-miR-3142, hsa-miR-20a, hsa-miR-4301, hsa-miR-1290, hsa-miR-4286, hsa-miR-3182, hsa-miR-3142, hsa-miR-1246 and hsa-miR-720) were identified to be differentially regulated post sorafenib treatment. In conclusion, we confirmed sorafenib as a potential anti-neoplastic treatment strategy for CRC cells by demonstrating a growth-inhibitory and cell cycle-arresting effect of this drug. Changes in the miRNome indicate that some specific miRNAs might be relevant as indicators for sorafenib response, drug resistance and potential targets for combinatorial miRNA-based drug strategies.


Assuntos
Neoplasias Colorretais/tratamento farmacológico , MicroRNAs/biossíntese , Niacinamida/análogos & derivados , Compostos de Fenilureia/administração & dosagem , Animais , Células CACO-2 , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica , Humanos , MicroRNAs/genética , Mutação , Niacinamida/administração & dosagem , Proteínas Proto-Oncogênicas p21(ras)/genética , Sorafenibe
19.
Int J Mol Sci ; 17(12)2016 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-27941621

RESUMO

Extensive stromal interaction is one reason for the dismal outcome of biliary tract cancer (BTC) patients. Epithelial to mesenchymal transition (EMT) is involved in tumor invasion and metastasis and is partly regulated by microRNAs (miRs). This study explores the expression of anti-EMT miR200 family (miR141, -200a/b/c, -429) and miR205 as well as the EMT-related proteins E-cadherin and vimentin in a panel of BTC cell lines and clinical specimens by quantitative real-time polymerase chain reaction, Western blot and immunohistochemistry, respectively. MicroRNA expression was correlated to (i) the expression patterns of E-cadherin and vimentin; (ii) clinicopathological characteristics; and (iii) survival data. MicroRNA-200 family and miR205 were expressed in all BTC cells and clinical specimens. E-cadherin and vimentin showed a mutually exclusive expression pattern in both, in vitro and in vivo. Expression of miR200 family members positively correlated with E-cadherin and negatively with vimentin expression in BTC cells and specimens. High expression of miR200 family members (but not miR205) and E-cadherin was associated with longer survival, while low miR200 family and high vimentin expression was a predictor of unfavorable survival. Overall, the current study demonstrates the relevance of the miR200 family in EMT of BTC tumors and suggests these miRs as predictors for positive outcome.


Assuntos
Neoplasias do Sistema Biliar/genética , Neoplasias do Sistema Biliar/patologia , Transição Epitelial-Mesenquimal/genética , MicroRNAs/genética , Linhagem Celular Tumoral , Transição Epitelial-Mesenquimal/fisiologia , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Regulação Neoplásica da Expressão Gênica/fisiologia , Humanos , RNA Mensageiro/genética
20.
Mol Carcinog ; 54(11): 1442-50, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25256312

RESUMO

Expression of miR-96-5p is frequently altered in various types of cancer and the KRAS oncogene has been identified as one of its potential targets. However, the biological role of miR-96-5p expression in colorectal cancer (CRC) and its ability to predict the clinical course of patients have not been investigated yet. In this study, we explored miR-96-5p expression in 80 CRC patients and evaluated the impact on clinical outcome by Kaplan-Meier curves and multivariate Cox proportional models. In vitro miR-96-5p inhibition and overexpression were performed in CRC cells and the effects on cellular growth, anchorage-independent growth, apoptosis, and epithelial-mesenchymal transition (EMT)-related gene expression were explored. Low miR-96-5p expression levels in tumor tissue were associated with distant metastasis (P = 0.025) and multivariate Cox regression analysis identified low levels of miR-96-5p as an independent prognostic factor with respect to cancer-specific survival (hazard ratio = 1.78, 95%CI = 1.03-3.03, P < 0.038). In vitro overexpression of miR-96-5p led to a reduced cellular growth rate (P < 0.05), reduced colonies in soft agar (P < 0.05), corroborated by a decreased cyclin D1 and increased p27-CDKN1A expression (P < 0.05). Forced expression of miR-96-5p in CRC cells entailed no effects on apoptosis or EMT-related genes but decreased the expression levels of the KRAS oncogene (P < 0.05). Despite regulating KRAS expression, there was no significant association in miR-96-5p expression levels and response rates to EGFR-targeting agents. In conclusion, our data suggest that miR-96-5p influences cellular growth of CRC cells and low expression of miR-96-5p seems to be associated with poor clinical outcome in CRC patients.


Assuntos
Proliferação de Células/genética , Neoplasias Colorretais/genética , Neoplasias Colorretais/mortalidade , MicroRNAs/genética , Apoptose/genética , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p27/genética , Transição Epitelial-Mesenquimal/genética , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Genes ras/genética , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Modelos de Riscos Proporcionais
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