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1.
Artigo em Inglês | MEDLINE | ID: mdl-38626354

RESUMO

RATIONALE: Immune checkpoint inhibitor-related pneumonitis is a serious autoimmune event affecting up to 20% of patients with non-small cell lung cancer, yet the factors underpinning its development in some patients and not others are poorly understood. OBJECTIVES: To investigate the role of autoantibodies and autoreactive T cells against surfactant-related proteins in the development of pneumonitis. METHODS: The study cohort consisted of non-small cell lung cancer patients who gave blood samples before and during immune checkpoint inhibitor treatment. Serum was used for proteomics analyses and to detect autoantibodies present during pneumonitis. T cell stimulation assays and single-cell RNA sequencing were performed to investigate the specificity and functionality of peripheral autoreactive T cells. The findings were confirmed in a validation cohort comprising patients with non-small cell lung cancer and patients with melanoma. MEASUREMENTS AND MAIN RESULTS: Across both cohorts, patients who developed pneumonitis had higher pre-treatment levels of immunoglobulin G autoantibodies targeting surfactant protein-B. At the onset of pneumonitis, these patients also exhibited higher frequencies of CD4+ interferon-gamma-positive surfactant protein B-specific T cells, and expanding T cell clonotypes recognizing this protein, accompanied by a pro-inflammatory serum proteomic profile. CONCLUSIONS: Our data suggest that the co-occurrence of surfactant protein-B-specific immunoglobulin G autoantibodies and CD4+ T cells is associated with the development of pneumonitis during ICI therapy. Pre-treatment levels of these antibodies may represent a potential biomarker for elevated risk of developing pneumonitis and on-treatment levels may provide a diagnostic aid. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).

2.
J Dtsch Dermatol Ges ; 22(2): 210-221, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38243888

RESUMO

BACKGROUND AND OBJECTIVES: Due to frailty, dermatosurgery in the elderly is preferably performed under tumescent local anesthesia, but data is limited. The aim was to evaluate tumescent local anesthesia for skin cancer surgery in the elderly with focus on clinical benefits (treatment processes, pain management) and local postoperative complication risk. PATIENTS AND METHODS: Investigation of patients ≥ 75 years with inpatient head and neck skin cancer surgery under tumescent local anesthesia. RESULTS: 2,940 procedures in 782 patients (mean age 83.3 years) were performed with the aim of complete tumor resection during the inpatient stay. 3.8 (range: 1-20) interventions were done over an average of 4.9 days (range: 1-28). 43.2% did not require any postoperative analgesia. 53.5% received NSAIDs, 3.3% opioids. Infection (13.6%) was the most common local postoperative complication. Surgical intervention due to bleeding was required in 2.8%. None was hemoglobin relevant or life-threatening. Suture dehiscence and necrosis were rare (0.6%). CONCLUSIONS: Tumescent local anesthesia is an effective method for skin cancer surgery in the elderly. By avoiding general anesthesia, treatment processes can be optimized and anesthesiologic risks minimized. Local postoperative complications are still low and well treatable. The long-lasting analgesia results in a reduced need for analgesics and drug interactions.


Assuntos
Neoplasias de Cabeça e Pescoço , Neoplasias Cutâneas , Humanos , Idoso , Idoso de 80 Anos ou mais , Anestesia Local/métodos , Estudos Retrospectivos , Neoplasias Cutâneas/cirurgia , Complicações Pós-Operatórias , Manejo da Dor , Neoplasias de Cabeça e Pescoço/cirurgia , Anestésicos Locais/uso terapêutico
3.
J Eur Acad Dermatol Venereol ; 38(1): 84-92, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37611257

RESUMO

BACKGROUND: Lentigo maligna melanoma is mainly localized in the head and neck region in elderly patients. Due to its slow horizontal growth, it has a good prognosis compared to other melanoma subtypes, but specific data are rare. OBJECTIVES: The aim of this study was to investigate sentinel lymph node biopsy in lentigo maligna melanoma under local anaesthesia and to discuss the benefit. METHODS: Investigation of patients with lentigo maligna melanoma and tumour thickness ≥1 mm treated at the Department of Dermatology, University Medical Centre Tuebingen, between January 2008 and October 2019. RESULTS: In total, 204 patients (126 SLNB, 78 non-SLNB) with a median age of 75.7 years (SLNB: 73.3 years, non-SLNB: 79.7 years) could be included. Sixteen of 126 (12.7%) sentinel lymph nodes were positive. Five-year overall survival was 87.9% (88.5% SLNB; 87.4% non-SLNB) and 5-year distant metastasis-free survival was 85.8% (85.4% SLNB; 86.7% non-SLNB). There was no significant difference for distant metastasis-free survival (p = 0.861) and overall survival (p = 0.247) between patients with and without sentinel lymph node biopsy. CONCLUSIONS: Sentinel lymph node biopsy in lentigo maligna melanoma under local anaesthesia is a safe and simple method, even in very old patients. However, LMM has a very good 5-year overall survival. In high-risk patients with high tumour thickness and/or ulceration, adjuvant immunotherapy can now be offered without the need to perform this procedure.


Assuntos
Sarda Melanótica de Hutchinson , Melanoma , Linfonodo Sentinela , Neoplasias Cutâneas , Humanos , Idoso , Biópsia de Linfonodo Sentinela , Melanoma/patologia , Neoplasias Cutâneas/patologia , Sarda Melanótica de Hutchinson/cirurgia , Sarda Melanótica de Hutchinson/patologia , Anestesia Local , Metástase Linfática , Prognóstico , Linfonodo Sentinela/patologia , Estudos Retrospectivos
4.
J Autoimmun ; 140: 103118, 2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37826919

RESUMO

BACKGROUND: The role of autoreactive T cells on the course of Coronavirus disease-19 (COVID-19) remains elusive. Type II pneumocytes represent the main target cells of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Autoimmune responses against antigens highly expressed in type II pneumocytes may influence the severity of COVID-19 disease. OBJECTIVE: The aim of this study was to investigate autoreactive T cell responses against self-antigens highly expressed in type II pneumocytes in the blood of COVID-19 patients with severe and non-severe disease. METHODS: We collected blood samples of COVID-19 patients with varying degrees of disease severity and of pre-pandemic controls. T cell stimulation assays with peptide pools of type II pneumocyte antigens were performed in two independent cohorts to analyze the autoimmune T cell responses in patients with non-severe and severe COVID-19 disease. Target cell lysis assays were performed with lung cancer cell lines to determine the extent of cell killing by type II PAA-specific T cells. RESULTS: We identified autoreactive T cell responses against four recently described self-antigens highly expressed in type II pneumocytes, known as surfactant protein A, surfactant protein B, surfactant protein C and napsin A, in the blood of COVID-19 patients. These antigens were termed type II pneumocyte-associated antigens (type II PAAs). We found that patients with non-severe COVID-19 disease showed a significantly higher frequency of type II PAA-specific autoreactive T cells in the blood when compared to severely ill patients. The presence of high frequencies of type II PAA-specific T cells in the blood of non-severe COVID-19 patients was independent of their age. We also found that napsin A-specific T cells from convalescent COVID-19 patients could kill lung cancer cells, demonstrating the functional and cytotoxic role of these T cells. CONCLUSIONS: Our data suggest that autoreactive type II PAA-specific T cells have a protective role in SARS-CoV-2 infections and the presence of high frequencies of these autoreactive T cells indicates effective viral control in COVID-19 patients. Type II-PAA-specific T cells may therefore promote the killing of infected type II pneumocytes and viral clearance.

5.
J Eur Acad Dermatol Venereol ; 37(1): 65-74, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36152007

RESUMO

BACKGROUND: Due to demographic change and increased UV exposure, the number of dermatosurgical procedures in the elderly is increasing. Data on the occurrence of systemic side effects during and after treatment with tumescent local anaesthesia are limited and do not refer to details such as volume and composition of local anaesthetics or epinephrine additive. OBJECTIVES: The aim of this study was to investigate the risk of systemic side effects in elderly patients undergoing skin tumour surgery with tumescent local anaesthesia. METHODS: Investigation of systemic complications in patients (≥75 years) who underwent head and neck skin tumour surgery under tumescent local anaesthesia at the Department of Dermatology, University Medical Centre Tübingen, between October 2018 and March 2020. RESULTS: In total 782 patients (479 males, 303 females) with a mean age of 83.3 years (range: 75.1-102.2 years) could be included. A total of 2940 procedures were performed. Patients were assigned to two groups. The old-old group (≥75-84 years) included 491 patients and the oldest-old group (≥85 years) included 291 patients. The total inpatient stay and thus mean follow-up period was 4.9 days (range 1-28 days). 92.0% (719/782) suffered from pre-existing comorbidities. Systemic complications occurred in 10.2% (80/782; old-olds: 8.6%, oldest-olds: 13.1%). Hypertensive crisis (>180/120 mmHg) requiring intervention (6.7%) that occurred intraoperatively or during the inpatient stay was the most frequent systemic complication. Cardiac arrhythmias occurred postoperatively in 0.8% of cases. No life-threatening complications directly related to tumescent local anaesthesia were found. CONCLUSIONS: Skin tumour surgery in tumescent local anaesthesia for the elderly is safe, and complications caused by general anaesthesia can be avoided. Systemic complications can occur, but are usually mild, are caused by pre-existing diseases and perioperative excitement, and can be rapidly detected and well treated by monitoring. There is no direct correlation of complications to high-tumescent concentrations or volume quantities.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Neoplasias Cutâneas , Masculino , Feminino , Humanos , Idoso , Idoso de 80 Anos ou mais , Anestesia Local/efeitos adversos , Anestesia Local/métodos , Anestésicos Locais , Epinefrina , Neoplasias Cutâneas/cirurgia , Medição de Risco
6.
Sci Immunol ; 7(75): eabn9644, 2022 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-36054337

RESUMO

Cancer treatment with immune checkpoint blockade (ICB) often induces immune-related adverse events (irAEs). We hypothesized that proteins coexpressed in tumors and normal cells could be antigenic targets in irAEs and herein described DITAS (discovery of tumor-associated self-antigens) for their identification. DITAS computed transcriptional similarity between lung tumors and healthy lung tissue based on single-sample gene set enrichment analysis. This identified 10 lung tissue-specific genes highly expressed in the lung tumors. Computational analysis was combined with functional T cell assays and single-cell RNA sequencing of the antigen-specific T cells to validate the lung tumor self-antigens. In patients with non-small cell lung cancer (NSCLC) treated with ICB, napsin A was a self-antigen that elicited strong CD8+ T cell responses, with ICB responders harboring higher frequencies of these CD8+ T cells compared with nonresponders. Human leukocyte antigen (HLA) class I ligands derived from napsin A were present in human lung tumors and in nontumor lung tissues, and napsin A tetramers confirmed the presence of napsin A-specific CD8+ T cells in blood and tumors of patients with NSCLC. Napsin A-specific T cell clonotypes were enriched in lung tumors and ICB-induced inflammatory lung lesions and could kill immortalized HLA-matched NSCLC cells ex vivo. Single-cell RNA sequencing revealed that these T cell clonotypes expressed proinflammatory cytokines and cytotoxic markers. Thus, DITAS successfully identified self-antigens, including napsin A, that likely mediate effective antitumor T cell responses in NSCLC and may simultaneously underpin lung irAEs.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Antígenos de Neoplasias , Autoantígenos , Linfócitos T CD8-Positivos , Carcinoma Pulmonar de Células não Pequenas/genética , Antígenos de Histocompatibilidade Classe I , Humanos , Inibidores de Checkpoint Imunológico , Pulmão , Neoplasias Pulmonares/genética
7.
Eur J Cancer ; 174: 121-130, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35994792

RESUMO

INTRODUCTION: Sentinel node biopsy is a key procedure to predict prognosis in melanoma. In a prospective study we compare reporting on melanoma cell densities in cytospin preparations with semiquantitative histopathology for predicting outcome. PATIENTS AND METHODS: Sentinel nodes from 900 melanoma patients were bisected. One half of each node was disaggregated mechanically. The melanoma cell density (number of HMB45 positive cells per million lymphocytes with at least one cell showing morphological features of a melanoma cell) was recorded after examining two cytospins. For the second half the maximum diameter of metastasis was determined after haematoxylin and eosin (H&E) and immunohistological staining of three slides. RESULTS: Cytospins were positive for melanoma in 218 of 900 patients (24%). Routine pathology was positive in 111 of 900 (12%) patients. A more extensive pathological workup in cytospin-only positive patients led to a revised diagnosis (from negative to positive) in 23 of 101 patients (22.7%). We found a moderate but significant correlation between melanoma cell densities (determined in cytospins) and the maximum diameter of metastasis (determined by pathology) (rho = 0.6284, p < 0.001). At a median follow-up of 37 months (IQR 25-53 months) melanoma cell density (cytospins) (p < 0.001), thickness of melanoma (p = 0.008) and ulceration status (p = 0.026) were significant predictors for melanoma specific survival by multivariable testing and were all confirmed as key predictive factors by the random forest model. Maximum diameter of metastases, age and sex were not significant by multivariable testing (all p > 0.05). CONCLUSION: Recording melanoma cell densities by examining two cytospins accurately predicts melanoma outcome and outperforms semiquantitative histopathology.


Assuntos
Linfadenopatia , Melanoma , Neoplasias Cutâneas , Contagem de Células , Amarelo de Eosina-(YS) , Humanos , Linfonodos/patologia , Metástase Linfática/patologia , Melanoma/patologia , Prognóstico , Estudos Prospectivos , Biópsia de Linfonodo Sentinela/métodos , Neoplasias Cutâneas/patologia
8.
Eur J Cancer ; 154: 128-137, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34265505

RESUMO

PURPOSE: Presence of disseminated tumour cells (DTCs) in the bone marrow (BM) has been described as a surrogate of residual disease in patients with early breast cancer (EBC). PADDY (Pooled Analysis of DTC Detection in Early Breast Cancer) is a large international analysis of pooled data that aimed to assess the prognostic impact of DTCs in patients with EBC. EXPERIMENTAL DESIGN: Individual patient data were collected from 11 centres. Patients with EBC and available follow-up data in whom BM sampling was performed at the time of primary diagnosis before receiving any anticancer treatment were eligible. DTCs were identified by antibody staining against epithelial cytokeratins. Multivariate Cox regression was used to compare the survival of DTC-positive versus DTC-negative patients. RESULTS: In total, 10,307 patients were included. Of these, 2814 (27.3%) were DTC-positive. DTC detection was associated with higher tumour grade, larger tumour size, nodal positivity, oestrogen receptor and progesterone receptor negativity, and HER2 positivity (all p < 0.001). Multivariate analyses showed that DTC detection was an independent prognostic marker for overall survival, disease-free survival and distant disease-free survival with hazard ratios (HR) and 95% confidence intervals (CI) of 1.23 (95% CI: 1.06-1.43, p = 0.006), 1.30 (95% CI: 1.12-1.52, p < 0.001) and 1.30 (95% CI: 1.08-1.56, p = 0.006), respectively. There was no association between locoregional relapse-free survival and DTC detection (HR 1.21; 95% CI 0.68-2.16; p = 0.512). CONCLUSIONS: DTCs in the BM represent an independent prognostic marker in patients with EBC. The heterogeneous metastasis-initiating potential of DTCs is consistent with the concept of cancer dormancy.


Assuntos
Medula Óssea/patologia , Neoplasias da Mama/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/mortalidade , Feminino , Humanos , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Receptor ErbB-2/análise , Adulto Jovem
9.
Breast Cancer Res Treat ; 183(1): 137-144, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32613540

RESUMO

BACKGROUND: The estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) statuses are frequently discordant between the primary tumor and metastatic lesions in metastatic breast cancer. This can have important therapeutic implications. PATIENTS AND METHODS: In all, 541 patients with available receptor statuses from both primary tumor and metastatic lesion treated at Heidelberg and Tuebingen University Hospitals between 1982 and 2018 were included. RESULTS: Statistically significant discordance rates of 14% and 32% were found for ER and PR. HER2 status was statistically insignificantly discordant in 15% of patients. Gain in HER2 positivity was associated with an improved overall survival, whereas loss of HR positivity was associated with worse overall survival. Antiendocrine treatment differed in 20% of cases before and after biopsy and HER2-directed treatment in 14% of cases. CONCLUSIONS: Receptor statuses are discordant between primary tumor and metastasis in a considerable fraction of patients with metastatic breast cancer. Next to a highly presumed predictive value with respect to efficacy of endocrine and HER2-targeted therapy, discordance seems to provide prognostically relevant information. Where feasible, metastatic lesions should be biopsied in accordance with current guidelines.


Assuntos
Neoplasias da Mama/química , Estrogênios , Proteínas de Neoplasias/análise , Neoplasias Hormônio-Dependentes/química , Progesterona , Receptor ErbB-2/análise , Receptores de Estrogênio/análise , Receptores de Progesterona/análise , Adolescente , Adulto , Idoso , Antineoplásicos Hormonais/uso terapêutico , Biomarcadores Tumorais , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Feminino , Seguimentos , Alemanha , Humanos , Estimativa de Kaplan-Meier , Pessoa de Meia-Idade , Terapia de Alvo Molecular , Metástase Neoplásica , Proteínas de Neoplasias/antagonistas & inibidores , Neoplasias Hormônio-Dependentes/tratamento farmacológico , Neoplasias Hormônio-Dependentes/patologia , Inibidores de Proteínas Quinases/uso terapêutico , Receptor ErbB-2/antagonistas & inibidores , Estudos Retrospectivos , Adulto Jovem
10.
Geburtshilfe Frauenheilkd ; 80(6): 619-627, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32565552

RESUMO

Background Multigene assays are being used increasingly to aid in decision-making about chemotherapy in breast cancer. Here, we present the 21-gene recurrence score (RS) of patients tested in routine clinical practice in Germany. Patients and Methods In a retrospective analysis, 4695 patients with hormone receptor-positive and HER2-negative early breast cancer (pT1 - 3, pN0 - 1, M0) were included in whom RS testing was conducted in Germany between November 2015 and July 2018. RS groups as defined in the TAILORx trial (RS result 0 - 10; 11 - 25; 26 - 100) were used. Results Of these patients, 21% were assigned to the low RS group, 63% to the midrange RS group, and 15% to the high RS group. 1772 (81%) of 2175 node-negative patients over 50 years of age were grouped either into the low RS group or the midrange RS group. The portion of patients with a low or midrange RS was 90% among node-positive patients (1284 of 1432 patients), 79% among patients with Ki-67-high (≥ 20%) tumors (1829 of 2310 patients), 86% vs. 70% among patients with G2 and G3 tumors (3244 of 3762 patients and 368 of 522 patients), respectively, 88% among patients with a tumor size of > 5 cm (140 of 159 patients), and 82% among node-negative patients at high clinical risk (1110 of 1352). Conclusions The distribution of the 21-gene RS in German patients that were tested in routine clinical practice indicates that, according to the results of the TAILORx trial, chemotherapy may not be beneficial in most of these.

11.
Arch Gynecol Obstet ; 297(3): 785-790, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29380106

RESUMO

PURPOSE: Pathological complete response (pCR) is a common endpoint in neoadjuvant chemotherapy (NACT) of primary breast cancer patients (PBC), but does not address the systemic prevalence of minimal residual disease. In this study, we compared pCR with the detection of circulating (CTC) and disseminated tumor cells (DTC) following NACT, as well as their impact on survival. METHODS: Patients with PBC receiving NACT and consecutive surgery were eligible for this study. CTCs were detected using the CellSearch® system and DTCs were determined using immunocytochemistry (cytokeratin staining with the A45-B/B3 antibody). pCR was defined as ypT0/ypTis and ypN0. RESULTS: 58 patients were included in the analysis with a median follow-up of 30 months. Of these, 5 (9%) presented with CTCs and 36 (62%) with DTCs. 16 patients (28%) achieved a pCR. No significant correlation between CTCs, DTCs and pCR and no statistically significant impact on disease free (DFS) or overall survival (OS) was apparent. CONCLUSIONS: Both CTCs and DTCs are detectable after NACT. As we could not show a significant relationship between CTC detection, DTC detection and pCR, all three methods may provide independent information regarding treatment response. Since we were unable to show a significant impact on survival, larger prospective studies that include CTCs and DTCs are needed. These trials should include the molecular characterization of primary tumor tissue, CTCs and DTCs to determine whether these cells are independent subpopulations of malignant cell clones.


Assuntos
Neoplasias da Mama/sangue , Neoplasias da Mama/patologia , Terapia Neoadjuvante , Células Neoplásicas Circulantes/patologia , Neoplasias da Mama/tratamento farmacológico , Feminino , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Metástase Neoplásica , Neoplasia Residual , Prognóstico , Estudos Prospectivos , Reação em Cadeia da Polimerase Via Transcriptase Reversa
12.
Breast Cancer Res Treat ; 169(2): 305-309, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29374853

RESUMO

PURPOSE: The 70-gene signature (70-GS) is a prognostic tool, grouping patients in risk groups to assess their need for adjuvant chemotherapy. Tumor cell dissemination to the bone marrow is a marker of minimal residual disease and associated with impaired survival. In this study, we aimed to evaluate whether 70-GS is associated with the presence of disseminated tumor cells (DTCs) in the bone marrow of patients with early breast cancer. METHODS: In patients with hormone receptor-positive HER2-negative early breast cancer, the 70-GS was obtained and the presence of DTCs was immunohistochemically evaluated using cytokeratin staining with the A45-B/B3 antibody. RESULTS: 149 patients were included into the analysis. 40 (27%) had a high-risk 70-GS and 35 (23%) had detectable DTCs in their bone marrow. 9 (22%) of the 40 patients with high-risk 70-GS and 26 (24%) of the 109 patients with a low-risk 70-GS were positive for DTCs (p = 0.863). CONCLUSIONS: As both 70-GS and DTC detection are known prognostic factors but do not seem to correlate, a follow-up on a larger cohort is warranted to evaluate if a combination of the two is able to better stratify the relapse risk in early breast cancer patients.


Assuntos
Neoplasias da Mama/diagnóstico , Recidiva Local de Neoplasia/genética , Neoplasia Residual/diagnóstico , Prognóstico , Adulto , Idoso , Medula Óssea/patologia , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Quimioterapia Adjuvante , Feminino , Humanos , Queratinas/genética , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Neoplasia Residual/genética , Neoplasia Residual/patologia , Células Neoplásicas Circulantes/patologia , Transcriptoma/genética
13.
Am J Pathol ; 174(6): 2324-36, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19435792

RESUMO

The calcium-binding protein calretinin has emerged as a useful marker for the identification of mesotheliomas of the epithelioid and mixed types, but its putative role in tumor development has not been addressed previously. Although exposure to asbestos fibers is considered the main cause of mesothelioma, undoubtedly, not all mesothelioma patients have a history of asbestos exposure. The question as to whether the SV40 virus is involved as a possible co-factor is still highly debated. Here we show that increased expression of SV40 early gene products in the mesothelial cell line MeT-5A induces the expression of calretinin and that elevated calretinin levels strongly correlate with increased resistance to asbestos cytotoxicity. Calretinin alone mediates a significant part of this protective effect because cells stably transfected with calretinin cDNA were clearly more resistant to the toxic effects of crocidolite than mock-transfected control cells. Down-regulation of calretinin by antisense methods restored the sensitivity to asbestos toxicity to a large degree. The protective effect observed in clones with higher calretinin expression levels could be eliminated by phosphatidylinositol 3-kinase (PI3K) inhibitors, implying an important role for the PI3K/AKT signaling (survival) pathway in mediating the protective effect. Up-regulation of calretinin, resulting from either asbestos exposure or SV40 oncoproteins, may be a common denominator that leads to increased resistance to asbestos cytotoxicity and thereby contributes to mesothelioma carcinogenesis.


Assuntos
Asbesto Crocidolita/efeitos adversos , Transformação Celular Neoplásica/metabolismo , Mesotelioma/induzido quimicamente , Mesotelioma/virologia , Infecções por Polyomavirus/metabolismo , Proteína G de Ligação ao Cálcio S100/metabolismo , Antígenos Transformantes de Poliomavirus , Western Blotting , Calbindina 2 , Linhagem Celular Tumoral , Transformação Celular Neoplásica/induzido quimicamente , Expressão Gênica , Humanos , Imuno-Histoquímica , Fosfatidilinositol 3-Quinases/metabolismo , Infecções por Polyomavirus/complicações , Proteínas Proto-Oncogênicas c-akt/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/fisiologia , Vírus 40 dos Símios , Transfecção , Infecções Tumorais por Vírus/complicações , Infecções Tumorais por Vírus/metabolismo , Regulação para Cima
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