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INTRODUCTION: Pancreatic cancer (PC) surveillance of high-risk individuals (HRI) is becoming more common worldwide, aiming at anticipating PC diagnosis at a preclinical stage. In 2015, the Italian Registry of Families at Risk of Pancreatic Cancer was created. We aimed to assess the prevalence and incidence of pancreatic findings, oncological outcomes, and harms 7 years after the Italian Registry of Families at Risk of Pancreatic Cancer inception, focusing on individuals with at least a 3-year follow-up or developing events before. METHODS: HRI (subjects with a family history or mutation carriers with/without a family history were enrolled in 18 centers). They underwent annual magnetic resonance with cholangiopancreatography or endoscopic ultrasound (NCT04095195). RESULTS: During the study period (June 2015-September 2022), 679 individuals were enrolled. Of these, 524 (77.2%) underwent at least baseline imaging, and 156 (29.8%) with at least a 3-year follow-up or pancreatic malignancy/premalignancy-related events, and represented the study population. The median age was 51 (interquartile range 16) years. Familial PC cases accounted for 81.4% of HRI and individuals with pathogenic variant for 18.6%. Malignant (n = 8) and premalignant (1 PanIN3) lesions were found in 9 individuals. Five of these 8 cases occurred in pathogenic variant carriers, 4 in familial PC cases (2 tested negative at germline testing and 2 others were not tested). Three of the 8 PC were stage I. Five of the 8 PC were resectable, 3 Stage I, all advanced cases being prevalent. The 1-, 2-, and 3-year cumulative hazard of PC was 1.7%, 2.5%, and 3%, respectively. Median overall and disease-free survival of patients with resected PC were 18 and 12 months (95% CI not computable). Considering HRI who underwent baseline imaging, 6 pancreatic neuroendocrine neoplasms (1 resected) and 1 low-yield surgery (low-grade mixed-intraductal papillary mucinous neoplasm) were also reported. DISCUSSION: PC surveillance in a fully public health care system is feasible and safe, and leads to early PC or premalignant lesions diagnoses, mostly at baseline but also over time.
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Carcinoma Ductal Pancreático , Carcinoma , Neoplasias Pancreáticas , Humanos , Adolescente , Estudos Prospectivos , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/epidemiologia , Pâncreas/patologia , Imageamento por Ressonância Magnética , Carcinoma Ductal Pancreático/patologiaRESUMO
BACKGROUND: During the COVID-19 emergency, IRST IRCCS, an Italian cancer research institute and promoter of no profit clinical studies, adapted its activities and procedures as per European and national guidelines to maintain a high standard of clinical trials, uphold participant safety and guarantee the robustness and reliability of the data collected. This study presents the measures adopted by our institute with the aim of providing information that could be useful to other academic centers promoting clinical trials during the pandemic. MAIN TEXT: After an in-depth analysis of European and Italian guidelines and consultation and analysis of publications regarding the actions implemented by international no profit clinical trial promoters during the emergency, we monitored the way in which the institute managed clinical trials, verifying compliance with regulatory guidelines and clinical procedures, and evaluating screening and recruitment trends in studies. During the pandemic, our center activated a new clinical trial for the treatment of patients with COVID-19. A number of procedural changes in clinical trials were also authorized through notified amendments, in accordance with Italian Medicines Agency (AIFA) guidelines. Patient screening and enrolment was not interrupted in any site participating in multicenter interventional clinical trials on drugs. The institute provided clear indications about essential procedures to be followed, identifying those that could be postponed or carried out by telephone/teleconference. All external sites were monitored remotely, avoiding on-site visits. Although home-working was encouraged, the presence of staff in the central office was also guaranteed to ensure the continuity of promoter activities. CONCLUSIONS: Some measures adopted by IRST could also be effective outside of the COVID-19 period, e.g. numerous activities relating to clinical trial management could be performed on a home-working basis, using suitable digital technologies. In the future, electronic medical records and shared guidelines will be essential for the correct identification and management of trial risks, including the protection of the rights and privacy of subjects taking part. Promoter supervision could be increased by implementing centralized monitoring tools to guarantee data quality. Closer collaboration between promoters and local study staff is needed to optimize trial management.
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COVID-19 , Confiabilidade dos Dados , Humanos , Pandemias , Reprodutibilidade dos Testes , SARS-CoV-2RESUMO
BACKGROUND: Neuroendocrine Carcinomas (NECs) prognosis is poor.No standard second-line therapy is currently recognized after failure of platinum-based first-line treatment. FOLFIRI and CAPTEM regimens have shown promising activity in preliminary studies. We aimed to evaluate these regimens in metastatic NEC patients. METHODS: This is an open-label, multicenter, randomized non-comparative phase II trial to evaluate the activity and safety of FOLFIRI or CAPTEM in metastatic NEC patients. Primary endpoints were the 12 weeks-Disease Control Rate (12w-DCR) by investigator assessment per RECIST v1.1 and safety per CTCAE v5.0. Additional endpoints included overall response rate (ORR), progression-free survival (PFS) and overall survival (OS). Patients' serum samples were subject to NGS miRNome profiling in comparison with healthy donors to reveal differentially expressed miRNAs as candidate circulating biomarkers. RESULTS: The study was halted for futility at interim analysis, as the minimum 12w-DCR threshold of 10 out of 25 patients required for the first step was not reached. From 06/03/2017 to 18/01/2021, 53 out of 112 patients were enrolled. Median follow-up was 22.6 months (range: 1.4-60.4). The 12w-DCR was 39.1 % in the FOLFIRI arm and 28.0 % in the CAPTEM arm. In the FOLFIRI subgroup the 12-months OS rate was 28.4 % (95 % CI: 12.7-46.5) while in the CAPTEM subgroup it was 32.4 % (95 % CI: 14.9-51.3). The most common G3-G4 side effects were neutropenia (n = 5, 18.5 %) and anemia (n = 2, 7.4 %) for FOLFIRI and G3-G4 thrombocytopenia (n = 2, 8.0 %), G4 nausea/vomiting (n = 1, 4.0 %) for CAPTEM. Three microRNAs emerged as NEC independent predictors. High expression values were found to be significantly associated with decreased PFS and OS. CONCLUSION: The safety profile of FOLFIRI and CAPTEM was manageable. FOLFIRI and CAPTEM chemotherapy showed comparable activity in the second-line setting after progression on etoposide/platinum. GOV IDENTIFIER: NCT03387592.
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Protocolos de Quimioterapia Combinada Antineoplásica , Camptotecina , Carcinoma Neuroendócrino , Fluoruracila , Leucovorina , Humanos , Masculino , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Feminino , Pessoa de Meia-Idade , Leucovorina/uso terapêutico , Leucovorina/efeitos adversos , Fluoruracila/uso terapêutico , Fluoruracila/efeitos adversos , Idoso , Carcinoma Neuroendócrino/tratamento farmacológico , Carcinoma Neuroendócrino/sangue , Carcinoma Neuroendócrino/patologia , Carcinoma Neuroendócrino/mortalidade , Adulto , Camptotecina/análogos & derivados , Camptotecina/uso terapêutico , Camptotecina/efeitos adversos , Etoposídeo/uso terapêutico , Etoposídeo/efeitos adversos , Etoposídeo/administração & dosagem , Temozolomida/uso terapêutico , Temozolomida/efeitos adversos , Intervalo Livre de ProgressãoRESUMO
HIGHLIGHTS: Although no definitive data exist in literature, adjuvant chemotherapy is usually recommended in patients with radically resected stage III rectal cancer treated with neo-adjuvant chemo-radiotherapy. We performed a systematic review of literature with direct and indirect comparisons to assess the role of adjuvant mono- or poli-chemotherapy in radically resected rectal cancer treated with neoadjuvant chemo-radiotherapy. Neither chemotherapy (mono-or poli-chemotherapy) nor polichemotherapy with oxaliplatin-containing regimens seems to improve Overall Survival and Disease-Free Survival in patients with radically resected rectal cancer treated with neoadjuvant chemo-adiotherapy. Neither the entire population of patients radically resected after neoadjuvant chemotherapy, nor high risk patients seem to benefit from adjuvant chemotherapy. Our data seem to suggest the need of review the actual international guidelines that suggest the need of adjuvant chemotherapy at least in high risk rectal cancer treated with surgery and neoadjuvant chemo-radiotherapy.
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Terapia Neoadjuvante , Neoplasias Retais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Quimiorradioterapia , Quimioterapia Adjuvante , Fluoruracila , Humanos , Estadiamento de Neoplasias , Ensaios Clínicos Controlados Aleatórios como Assunto , Neoplasias Retais/patologia , Neoplasias Retais/terapiaRESUMO
PURPOSE: Cancer clinical trials (CTs) are now more complex than ever before and require dedicated personnel (clinical research coordinators [CRCs]) to perform regulatory and administrative activities and protocol- and patient-related procedures. We developed a simple tool to measure the workload (WL) of CRCs involved in cancer research and to estimate personnel requirements within a Clinical Trial Center. METHODS: A literature review and 2-month period in which CRCs recorded their activities in a diary provided valuable information that led to the Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori Workload Assessment Tool (IWAT) being divided into three sections: Protocol, On-Treatment Patients, and Follow-Up Patients. Twelve full-time senior CRCs from three sites of the Network measured their monthly WL for 30 months to evaluate IWAT reproducibility and accuracy. RESULTS: The IWAT proved to be a user-friendly tool (3-6 minutes required for each CT), with high reproducibility (interobserver reproducibility ranged from 82% to 100% for each IWAT item). In December 2017, the Network had 185 ongoing CTs, with a median of 2.5 active centers for each CT. On the basis of 448 total IWAT measures by CRCs, the majority of trials were academic (57%) or dealt with advanced disease (77%). The median IWAT WL score for each study was 20.98 ± 22.90 (range, 2-188) and 475 ± 229 (range, 150 [junior staff] - 930 [extreme heavy WL]) for each CRC. On the basis of our experience, a monthly WL score of 500-600 was considered an appropriate value for a full-time CRC. CONCLUSION: The IWAT could prove useful in evaluating CT complexity, estimating appropriate CRC WLs, and defining personnel requirements. Independent validation by other CRCs working in different organizational contexts and in different countries is needed.
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Neoplasias , Carga de Trabalho , Emprego , Humanos , Neoplasias/terapia , Reprodutibilidade dos Testes , PesquisadoresRESUMO
AIMS: This study aims to evaluate the safety and efficacy of a new neoadjuvant regimen (FOLFOX4 plus hypofractionated tomotherapy) in patients with locally advanced rectal cancer. METHODS: Patients with stage II-III rectal cancer were treated with the pre-operative chemoradiotherapy regimen comprising FOLFOX4 (two cycles), TomoTherapy (25 Gy in five consecutive fractions, one fraction per day in 5 days on the clinical target volume at the isodose of 95% of the total dose), FOLFOX4 (two cycles), followed by surgery with total mesorectal excision and adjuvant chemotherapy with FOLFOX4 (eight cycles). The primary endpoint was pathological complete response (pCR). RESULTS: Fifty-two patients were enrolled and 50 patients were evaluable. A total of 46 (92%) patients completed chemoradiotherapy according to the study protocol and 49 patients underwent surgery. Overall, 12 patients achieved a pCR (24.5%, 95% CI 12.5-36.5). The most common grade 3 or more adverse events were neutropenia and alteration of the alvus. Adverse reactions due to radiotherapy, mainly grade 1-2 dermatitis, tenesmus, urinary dysfunction and pain, were tolerable and fully reversible. The most important surgical complications included infection, anastomotic leakage and fistula, all resolved with conservative treatment. CONCLUSION: FOLFOX and hypofractionated TomoTherapy is effective and safe in patients with locally advanced rectal cancer. Long-term efficacy needs to be further evaluated. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02000050 (registration date: 26 November 2013) https://clinicaltrials.gov/ct2/show/NCT02000050.
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PURPOSE: After 10 years of clinical practice and research studies, there are still no validated prognostic or predictive factors of response to sorafenib for hepatocellular carcinoma (HCC). On the basis of the results of our two retrospective studies, we designed the multicenter INNOVATE study with the aim to validate the role of nitric oxide synthase 3 (NOS3) and ANGPT2 polymorphisms in patients with HCC treated with sorafenib [NCT02786342]. PATIENTS AND METHODS: This prospective multicenter study was conducted at 10 centers in Italy. All eligible patients received a continuous oral treatment with 400 mg of sorafenib twice daily. Genotyping analysis was performed for NOS3 (rs2070744) and ANGPT2 SNPs (rs55633437). The primary outcome was progression-free survival (PFS), whereas secondary outcomes included overall survival (OS) and disease-control rate. RESULTS: A total of 165 patients were enrolled between March 2016 and June 2018. NOS3 rs2070744 CC/CT genotypes were significantly associated with a higher median PFS (5.9 months vs. 2.4 months; HR = 0.43; P = 0.0007) and OS (15.7 months vs. 8.6 months; HR = 0.38; P < 0.0001) compared with TT genotype. There was no statistically significant association between ANGPT2 rs55633437 TT/GT genotypes and PFS (2.4 months vs. 5.7 months; HR = 1.93; P = 0.0833) and OS (15.1 months vs. 13.0 months; HR = 2.68; P = 0.55) when compared with the other genotype. Following adjustment for clinical covariates, multivariate analysis confirmed NOS3 as an independent prognostic factor for PFS (HR = 0.50; P = 0.0128) and OS (HR = 0.29; P = 0.0041). CONCLUSIONS: The INNOVATE study met the primary endpoint, confirming that patients with advanced HCC with NOS3 rs2070744 CC/CT genotypes had a better prognosis with respect to TT genotype patients.
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Angiopoietina-2/genética , Carcinoma Hepatocelular/genética , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias Hepáticas/genética , Óxido Nítrico Sintase Tipo III/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/mortalidade , Feminino , Humanos , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/mortalidade , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Polimorfismo de Nucleotídeo Único , Prognóstico , Intervalo Livre de Progressão , Estudos Prospectivos , Sorafenibe/farmacologia , Sorafenibe/uso terapêutico , Adulto JovemRESUMO
INTRODUCTION:: Patients' awareness of clinical research and their involvement in clinical trials is of great importance, but it is difficult to estimate the extent of knowledge on the research being undertaken. METHODS:: We evaluated the level of knowledge about clinical research using a self-reporting survey distributed to 967 adult patients with cancer attending the Departments of Medical Oncology and Onco-Haematology Units of IRST IRCCS and 4 hospitals in the region of Emilia-Romagna, Italy. The questionnaire was composed of 10 specific items on research knowledge. Patients responding correctly to at least 8 of the 10 items were considered to have a good understanding of clinical research. RESULTS:: The questionnaire was completed by 769 patients (response rate 79.5%). Only 19% of patients were found to have a good understanding of clinical research. Patients with higher education and those who had previous clinical trial experience showed a significantly better understanding. Fifty-three percent of patients said that they would be willing to participate in a trial studying a new drug and 75% expressed an interest in taking part in informative meetings/events about clinical studies. CONCLUSIONS:: Our results show that patients' understanding of clinical research is limited and highlight an interest in learning more.
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Neoplasias/psicologia , Conscientização , Ensaios Clínicos como Assunto , Hospitais/estatística & dados numéricos , Humanos , Itália , Oncologia/estatística & dados numéricos , Inquéritos e QuestionáriosRESUMO
Preliminary studies suggest that capecitabine may be safe and effective in HCC patients. The aim of this study was to retrospectively evaluate the safety and efficacy of metronomic capecitabine as second-line treatment. This multicentric study retrospectively analyzed data of HCC patients unresponsive or intolerant to sorafenib treatment with metronomic capecitabine or best supportive care (BSC).Median progression free survival was 3.1 months in patients treated with capecitabine (95%CI: 2.7-3.5). Median overall survival was 12.0 months (95% CI: 10.7-15.8) in patients receiving capecitabine, while 9.0 months (95% CI: 6.5-13.9) in patients receiving BSC. The result of univariate unweighted Cox regression model shows a 46% reduction in death risk for patients on capecitabine (95%CI: 0.357-0.829; p =0.005) compared to patients receiving BSC alone. After weighting for potential confounders, death risk remained essentially unaltered (45%; 95%CI: 0.354-0.883; p = 0.013). Metronomic capecitabine seems a safe second-line treatment for HCC patients in terms of management of adverse events, showing a potential anti-tumour activity which needs further evaluation in phase III studies.
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Antimetabólitos Antineoplásicos/uso terapêutico , Capecitabina/uso terapêutico , Carcinoma Hepatocelular/terapia , Neoplasias Hepáticas/terapia , Administração Metronômica , Adulto , Idoso , Idoso de 80 Anos ou mais , Antimetabólitos Antineoplásicos/administração & dosagem , Antimetabólitos Antineoplásicos/efeitos adversos , Capecitabina/administração & dosagem , Capecitabina/efeitos adversos , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/patologia , Terapia Combinada , Feminino , Humanos , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Modelos de Riscos Proporcionais , Retratamento , Estudos Retrospectivos , Resultado do TratamentoRESUMO
AIMS AND BACKGROUND: According to the USA Food and Drug Administration, quality of life (QOL) and/or survival are a priority for new anticancer drug approval. This study was performed to review approaches to QOL in randomized controlled clinical trials (RCCTs) and to survey the use of such measures in trials. MATERIAL AND METHODS: A literature survey was carried out using the Medline/Medscape, Embase, Cochrane Library, and Ovid databases. Included in the survey were all publications in the set period (from 1966 to June 2005) with "quality of life" in the title or in the abstract in the field of "randomized, controlled clinical trials". Each trial was evaluated according to the level of importance of QOL as a measure of outcome (primary, important and secondary) and was analyzed using the quality scoring system reported by Nicolucci et al. with some items regarding QOL. RESULTS: Four hundred and five RCCT articles in the oncology setting were found. Fifty-six of the 405 (13.8%) publications had QOL as primary end point. The overall quality score of these trials ranged from 40% to 100%, with a median overall score of 80%. The overall score was correlated with the year of publication (P = 0.007), the type of journal (P = 0.05), the presence of a biostatistician among the authors (P = 0.001), and the number of participating institutions (P = 0.009). CONCLUSIONS: More attention to QOL in all components of RCCTs (design, choice of instruments, data management and processing) is required from both clinicians and statisticians.
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Neoplasias/terapia , Qualidade de Vida , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Reprodutibilidade dos Testes , Inquéritos e QuestionáriosRESUMO
BACKGROUND: In stage IV colorectal cancer, bevacizumab-based maintenance therapy, complete stop therapy and continuous therapy are considered all possible approaches after first line induction chemotherapy. However, there are no clear data about which approach is preferable. MATERIAL AND METHODS: All randomized phase III trials comparing bevacizumab-based maintenance therapy (MB) with complete stop therapy (ST) or with continuous therapy (CT) were considered eligible and included into the analysis. Primary endpoint was the Time to failure strategies (TFS). Secondary endpoints were Overall Survival (OS) and Progression free survival (PFS). Meta-analysis was performed in line with the PRISMA statement. RESULTS: 1892 patients of five trials were included into the analysis. A significant improvement in TFS (HR 0.79; CI 95% 0.7-0.9 p=0.0005) and PFS (HR 0.56; CI 95% 0.44-0.71 p<0.00001) were observed in favour of MB versus ST. A trend, but not statistically significant, in favour of MB versus ST was also observed for OS (HR 0.88; CI 95% 0.77-1.01, p=0.08). Comparing maintenance therapy versus continuous therapy no statistically differences were observed in the outcomes evaluated (OS 12 months OR 1.1 p=0.62, OS 24 months OR 1 p=1, OS 36 months OR 0.54 p=0.3, TFS 12 months OR 0.76 p=0.65). CONCLUSIONS: Our meta-analysis suggests that use of MB approach increases TFS, PFS compared to ST. Although without observing any statistically advantage, it should be highlighted that MB versus ST showed a trend in favour of MB. We observed no difference between MB and CT. MB should be considered the standard regimen in patients with stage IV colorectal cancer after first line induction therapy.
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Inibidores da Angiogênese/uso terapêutico , Bevacizumab/uso terapêutico , Neoplasias Colorretais/tratamento farmacológico , Ensaios Clínicos Controlados Aleatórios como Assunto , Ensaios Clínicos Fase III como Assunto , Neoplasias Colorretais/diagnóstico , Humanos , Quimioterapia de Indução , Estadiamento de NeoplasiasRESUMO
BACKGROUND: The aim of this study was to assess early serum prostate-specific antigen (PSA) changes in patients treated with abiraterone and to correlate those changes with clinical outcome. PATIENTS AND METHODS: We retrospectively evaluated 103 patients with castrate-resistant prostate cancer (CRPC) treated with compassionate use of abiraterone in Romagna, Italy. In these patients, serum PSA levels were monitored every 4 weeks, and a time course of serum PSA levels was obtained. The PSA flare phenomenon was evaluated. The log-rank test was applied to compare survival between groups of patients according to early PSA level changes. RESULTS: Of 103 patients, 43 (41.7%) had an immediate PSA response, whereas 9 (8.7%) had an initial PSA flare. Of the 9 patients with PSA flare, 5 attained a subsequent PSA response. The temporary PSA flare exceeded baseline values by a median of 19.7% (range, 5%-62.9%). The median PFS of the 9 patients in the PSA-flare group was higher compared with patients without the PSA flare (10.5 vs. 6.4 months; P = .0999) but was similar to the subgroup of patients with immediate PSA response (10.5 vs. 10.7 months; P = .7019). In the multivariate analysis, only the PSA response remained as a predictor of progression-free survival (PFS) (P < .0001) and overall survival (OS) (P = .0003), respectively. CONCLUSION: PSA flare occurs not infrequently in patients with CRPC who respond to abiraterone. Patients should be informed of this possible PSA flare phenomenon.
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Androstenos/uso terapêutico , Antígeno Prostático Específico/sangue , Neoplasias de Próstata Resistentes à Castração/sangue , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Intervalo Livre de Doença , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Estudos Retrospectivos , Análise de Sobrevida , Resultado do TratamentoRESUMO
Sphingolipid derivatives cause diverse effects towards the regulation of intracellular free Ca(2+) concentrations ([Ca(2+)](i)) in a multitude of nonexcitable cells. In the present investigation, the effect of C-8 ceramide-1-(2-cyanoethyl) phosphate (C1CP) on store-operated Ca(2+) (SOC) entry was investigated. C1CP evoked a modest increase in [Ca(2+)](i). The increase was inhibited by the SOC channel antagonist 1-(beta-[3-(4methoxyphenyl)propoxy]-4-methoxyphenethyl)-1H-imidazole (SKF96365) but not by overnight pretreatment of the cells with pertussis toxin. C1CP did not invoke the production of inositol phosphates. When cells were stimulated with both C1CP and thapsigargin, the thapsigargin-invoked increase in [Ca(2+)](i) was enhanced in comparison to control cells. When Ca(2+) was added to cells treated with both C1CP and thapsigargin in a Ca(2+)-free buffer, the increase in [Ca(2+)](i) was enhanced in comparison to control cells. In patch-clamp experiments, C1CP hyperpolarized the membrane potential (E(m)) of the cells and attenuated the thapsigargin-invoked depolarization of the E(m). The effects of C1CP came, in part, as a result of a decreased conductance of the cell membrane towards Cl(-) ions, as C1CP in a Cl(-)-free solution also enhanced Ca(2+) entry. Barium 2-cyanoethylphosphate (Ba2Cy), which also contains the 2-cyanoethyl group, did not modulate thapsigargin-invoked changes in [Ca(2+)](i) nor did it modulate the E(m). In conclusion, C1CP enhances SOC entry, in part, via hyperpolarization of the E(m) and attenuation of the thapsigargin-invoked membrane depolarization, thus increasing the electrochemical gradient for Ca(2+) ions. Hence, C1CP may be a useful reagent for investigating the cellular effects of ceramide derivatives.
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Acrilonitrila/análogos & derivados , Sinalização do Cálcio/efeitos dos fármacos , Ceramidas/química , Ceramidas/farmacologia , Etanol/análogos & derivados , Glândula Tireoide/efeitos dos fármacos , Acrilonitrila/química , Acrilonitrila/farmacologia , Animais , Sinalização do Cálcio/fisiologia , Linhagem Celular , Etanol/química , Etanol/farmacologia , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Ratos , Glândula Tireoide/citologiaRESUMO
Sphingolipid (SP) derivatives have diverse effects on the regulation of intracellular free calcium concentrations ([Ca2+]i) in a multitude of non-excitable cells. In the present investigation, the effect of C2-ceramide 1-phosphate (C1P) on [Ca2+]i was investigated in thyroid FRTL-5 cells. C1P evoked a concentration-dependent increase in [Ca2+]i, both in a calcium-containing and a calcium-free buffer. A substantial part of the C1P-evoked increase in [Ca2+]i was due to calcium entry. The effect of C1P was attenuated by overnight pretreatment of the cells with pertussis toxin. Similar results were obtained with C8-ceramide 1-phosphate, although the magnitude of the responses was smaller than with C1P. The phospholipase C inhibitor U73122 attenuated the effect of C1P. C1P invoked a small, but significant, increase in inositol 1,4,5-trisphosphate (IP3). However, the effect of C1P on [Ca2+]i was inhibited by neither Xestospongin C, 2-aminoethoxydiphenylborate nor neomycin. C1P mobilized calcium from an IP3-sensitive calcium store, as C1P did not increase [Ca2+]i in cells pretreated with thapsigargin. The effect of C1P on [Ca2+]i was potently attenuated by dihydrosphingosine and dimethylsphingosine, two inhibitors of sphingosine kinase, but not by the inactive SP-derivative N -acetyl sphingosine. Stimulating the cells with C1P evoked an increase in the production of intracellular sphingosine 1-phosphate. C1P did not modulate DNA synthesis or the forskolin-evoked production of cAMP. The results indicate that C1P may be an important SP participating in cellular signalling.