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PURPOSE: To assess the diagnostic performance of a panel of standard tumor markers (TMs) in patients hospitalized with significant involuntary weight loss (IWL) and elevated levels of inflammation biomarkers, and a combination of the TM panel and the finding of the computed tomography (CT) scan. METHODS: We conducted a retrospective study in the internal medicine department at Amiens-Picardie University Medical Center (Amiens, France) between January 1st, 2015, and November 1st, 2021. The inclusion criteria were age 18 or over, significant IWL (≥ 5 kg over 6 months), elevated inflammation biomarkers (e.g. C-reactive protein), and assay data on two or more standard TMs (carcinoembryonic antigen (CEA), carbohydrate antigen (CA) 19 - 9, CA 15 - 3, CA 125, neuron-specific enolase (NSE), alpha-fetoprotein (AFP), calcitonin, and prostate-specific antigen (PSA)). The result of each TM assay was interpreted qualitatively (as positive or negative), according to our central laboratory's usual thresholds. RESULTS: Cancer was diagnosed in 50 (37.0%) of the 135 patients included. Positivity for one or more TMs had a positive predictive value (PPV) of 0.55 [0.43-0.66], and a negative predictive value (NPV) of 0.84 [0.75-0.93] for cancer diagnosis. When combined with the presence of suspicious CT findings (e.g. a mass, enlarged lymph nodes and/or effusion), positivity for one or more TMs had a PPV of 0.92 [0.08-0.30]. In the absence of suspicious CT findings, a fully negative TM panel had an NPV of 0.96 [0.89-1.00]. CONCLUSION: A negative TM panel argues against the presence of a cancer, especially in the absence of suspicious CT findings.
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Biomarcadores Tumorais , Neoplasias , Masculino , Humanos , Adolescente , Estudos Retrospectivos , Pacientes Internados , Antígeno Carcinoembrionário , Neoplasias/diagnóstico , Antígeno Ca-125 , Antígeno CA-19-9 , Mucina-1 , Redução de Peso , InflamaçãoRESUMO
PURPOSE OF REVIEW: In the present review, we discuss the possible role of the unfolded protein response (UPR) in the acquisition of tumor cell characteristics and in the prognosis of cancer outcome, which could assist and contribute to the development of more promising therapeutic strategies. RECENT FINDINGS: Accumulating evidence supports the idea that alteration of endoplasmic reticulum proteostasis is a key player in cancer development and aggressiveness. Some UPR components were reported as independent prognostic biomarker. Recent evidence supports a relationship between the UPR activation status and prognosis of tumors. This may represent an interesting avenue for better characterization of carcinogenesis and tumor type. SUMMARY: The contribution of the UPR to the characteristics of malignant tumors is complex and dependent on both intrinsic (e.g. oncogene addiction) and extrinsic (e.g. hypoxia) contexts. Through adaptation to severe microenvironmental conditions, UPR branches are generally a survival strategy for cancer cells, which are able to cope with this challenging context. We address the question of whether the activation status of the UPR is related to tumor properties and discuss the role of the UPR in the clinical context.
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Neoplasias/metabolismo , Neoplasias/patologia , Resposta a Proteínas não Dobradas/fisiologia , Humanos , PrognósticoRESUMO
Cancer is one of the major causes of mortality in organ transplant patients receiving immunosuppressive regimen based on Cyclosporin A (CsA). Organ transplantation and chronic immunosuppression are typically associated with skin cancers (both squamous cell carcinoma and melanoma) and renal cell carcinoma (RCC). Recent studies have shown that in addition to its immunosuppressive effects, accounted for by the inhibition of calcineurin and the modulation of the transcriptional programme of lymphocytes, CsA also directly stimulates the growth and aggressive behaviour of various cancer cells. Using renal carcinogenesis as an example, we discuss the current evidence for a role of cellular proteostasis, i.e. the regulation of the production, maturation and turnover of proteins in eukaryotic cells, in tumorigenesis arising under conditions of chronic immunosuppression. We present the recent studies showing that CsA induces the unfolded protein response (UPR) in normal and transformed kidney cells. We examine how the UPR might be important, considering in particular the genomic analyses showing the existence of a correlation between the levels of expression of the actors of the UPR, the chaperones of the endoplasmic reticulum (ER) and the aggressiveness of renal carcinoma. The UPR may offer a possible explanation for how immunosuppressive regimens based on CsA promote renal carcinogenesis. We discuss the opportunities offered by this biological knowledge in terms of screening, diagnosis and treatment of post-transplant cancers, and propose possible future translational studies examining the role of tumour proteostasis and the UPR in this context.
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Neoplasias/etiologia , Transplante de Órgãos/efeitos adversos , Resposta a Proteínas não Dobradas/fisiologia , Biomarcadores Tumorais/análise , Ciclosporina/efeitos adversos , Ciclosporina/farmacologia , Humanos , Imunossupressores/efeitos adversos , Imunossupressores/farmacologia , Neoplasias/diagnóstico , Neoplasias/fisiopatologia , Resposta a Proteínas não Dobradas/efeitos dos fármacosRESUMO
BACKGROUND: Sorafenib, a kinase inhibitor active against various solid tumours, induces oxidative stress and ferroptosis, a new form of oxidative necrosis, in some cancer cells. Clinically-applicable biomarkers that reflect the impact of sorafenib on the redox metabolism of cancer cells are lacking. METHODS: We used gene expression microarrays, real-time PCR, immunoblot, protein-specific ELISA, and gene reporter constructs encoding the enzyme luciferase to study the response of a panel of cancer cells to sorafenib. Tumour explants prepared from surgical hepatocellular carcinoma (HCC) samples and serum samples obtained from HCC patients receiving sorafenib were also used. RESULTS: We observed that genes of the metallothionein-1 (MT1) family are induced in the HCC cell line Huh7 exposed to sorafenib. Sorafenib increased the expression of MT1G mRNA in a panel of human cancer cells, an effect that was not observed with eight other clinically-approved kinase inhibitors. We identified the minimal region of the MT1G promoter that confers inducibility by sorafenib to a 133 base pair region containing an Anti-oxidant Response Element (ARE) and showed the essential role of the transcription factor NRF2 (Nuclear factor erythroid 2-Related Factor 2). We examined the clinical relevance of our findings by analysing the regulation of MT1G in five tumour explants prepared from surgical HCC samples. Finally, we showed that the protein levels of MT1 increase in the serum of some HCC patients receiving sorafenib, and found an association with reduced overall survival. CONCLUSION: These findings indicate that MT1 constitute a biomarker adapted for exploring the impact of sorafenib on the redox metabolism of cancer cells.
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Antineoplásicos/farmacologia , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Metalotioneína/metabolismo , Niacinamida/análogos & derivados , Oxirredução/efeitos dos fármacos , Compostos de Fenilureia/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Biomarcadores , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/mortalidade , Linhagem Celular Tumoral , Cisteína/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/mortalidade , Metalotioneína/genética , Fator 2 Relacionado a NF-E2/metabolismo , Niacinamida/farmacologia , Estresse Oxidativo , Prognóstico , Regiões Promotoras Genéticas , Sorafenibe , Transcrição GênicaRESUMO
BACKGROUND: Vemurafenib (Zelboraf) is a new tyrosine kinase inhibitor that selectively targets activated BRAF V600E gene and is indicated for the treatment of advanced BRAF mutation-positive melanoma. We developed a simple method for vemurafenib quantification using liquid chromatography-tandem mass spectrometry. A stability study of vemurafenib in human plasma was also performed. METHODS: (13)C(6)-vemurafenib was used as the internal standard. A single-step protein precipitation was used for plasma sample preparation. Chromatography was performed on an Acquity UPLC system (Waters) with chromatographic separation by the use of an Acquity UPLC BEH C18 column (2.1 × 50 mm, 1.7-mm particle size; Waters). Quantification was performed using the monitoring of multiple reactions of following transitions: m/z 488.2 â 381.0 for vemurafenib and m/z 494.2 â 387.0 for internal standard. RESULTS: This method was linear over the range from 1.0 to 100.0 mcg/mL. The lower limit of quantification was 0.1 mcg/mL for vemurafenib in plasma. Vemurafenib remained stable for 1 month at all levels tested, when stored indifferently at room temperature (20 °C), at +4 °C, or at -20 °C. This method was used successfully to perform a plasma pharmacokinetic study of vemurafenib in a patient after oral administration at a steady state. CONCLUSIONS: This liquid chromatography-tandem mass spectrometry method for vemurafenib quantification in human plasma is simple, rapid, specific, sensitive, accurate, precise, and reliable.
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Antineoplásicos/sangue , Antineoplásicos/farmacocinética , Indóis/sangue , Indóis/farmacocinética , Inibidores de Proteínas Quinases/sangue , Inibidores de Proteínas Quinases/farmacologia , Sulfonamidas/sangue , Sulfonamidas/farmacocinética , Calibragem , Cromatografia Líquida de Alta Pressão , Humanos , Indicadores e Reagentes , Controle de Qualidade , Padrões de Referência , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem , VemurafenibRESUMO
Inositol-requiring enzyme 1 (IRE1) is a major mediator of the unfolded protein response (UPR), which is activated upon endoplasmic reticulum (ER) stress. Tumor cells experience ER stress due to adverse microenvironmental cues, a stress overcome by relying on IRE1 signaling as an adaptive mechanism. Herein, we report the discovery of structurally new IRE1 inhibitors identified through the structural exploration of its kinase domain. Characterization in in vitro and in cellular models showed that they inhibit IRE1 signaling and sensitize glioblastoma (GB) cells to the standard chemotherapeutic, temozolomide (TMZ). Finally, we demonstrate that one of these inhibitors, Z4P, permeates the blood-brain barrier (BBB), inhibits GB growth, and prevents relapse in vivo when administered together with TMZ. The hit compound disclosed herein satisfies an unmet need for targeted, non-toxic IRE1 inhibitors and our results support the attractiveness of IRE1 as an adjuvant therapeutic target in GB.
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PURPOSE OF THE STUDY: Atypical serum protein electrophoresis (SPE) profiles may arise in patients who received allogeneic hematopoietic stem cell transplantation (allo-HSCT), but little is known about their clinical significance. Atypical SPE combine either monoclonal and oligoclonal components, suspected on SPE and confirmed by immunofixation. The aim of the study is to analyze the incidence, the etiology and the clinical significance of atypical SPE profiles in patients who received allo-HSCT. PATIENTS AND METHODS: This retrospective study enrolled 117 patients with myeloid malignancies who received an allo-HSCT between 2012 and 2018. We excluded patients with lymphoid malignancies or multiple myeloma, patients presenting atypical electrophoresis prior to transplantation and patients who died within 100 days post-transplant. RESULTS: Atypical SPE occurred in 42.7% of patients. The cumulative incidence of atypical profiles was significantly higher in patients with acute Graft Versus Host Disease (GVHD, p = 0.019) and in patients with Cytomegalovirus (CMV) reactivation (p = 0.0017). We observed for the first time that atypical SPE profiles mostly occurred in patients transplanted from a CMV+ donor (p = 0.031). CMV reactivation preceded the occurrence of atypical SPE in the majority of patients. We show that atypical SPE delay the relapse of the underlying malignant disease (486 vs 189 days, p = 0.006), and significantly improve overall survival (OS; 33.1 months vs 28.3 months, p = 0.049). In both univariate and multivariate analyzes, the presence of an atypical SPE is the only factor that significantly improves OS. CONCLUSIONS: The occurrence of atypical SPE profiles after allo-HSCT may reflect an adapted post-transplant immune response leading to favourable outcomes.
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Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Eletroforese , Doença Enxerto-Hospedeiro/epidemiologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Recidiva Local de Neoplasia , Estudos RetrospectivosRESUMO
BACKGROUND/AIM: Multiple myeloma (MM) is characterized by high production of immunoglobulins resulting in a constant source of endoplasmic reticulum (ER)-stress. Mesencephalic astrocyte-derived neurotrophic factor (MANF) was identified as a possible circulating biomarker that could help in monitoring ER-stress mediated diseases. MATERIALS AND METHODS: To assess the relevance of MANF in MM, we performed in silico and in vitro analysis in malignant cell lines including the myeloma cell line RPMI 8226. Serum MANF concentration was compared between healthy subjects (n=60), patients with MM (n=68), or those with monoclonal gammopathy of undetermined significance (MGUS) (n=73). RESULTS: MANF mRNA expression was upregulated in the RPMI 8226 cell line, and higher secretion of MANF was measured in RPMI 8226 supernatant. Serum MANF levels were not significantly different between MM or MGUS patients and those in age- and sex-matched healthy controls. CONCLUSION: MANF was not validated as a biomarker of interest in MM patients. Its potential implication in myeloma pathogenesis should be investigated.
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Gamopatia Monoclonal de Significância Indeterminada/metabolismo , Mieloma Múltiplo/metabolismo , Fatores de Crescimento Neural/sangue , Fatores de Crescimento Neural/genética , Regulação para Cima , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Linhagem Celular Tumoral , Simulação por Computador , Regulação Neoplásica da Expressão Gênica , Humanos , Pessoa de Meia-Idade , Gamopatia Monoclonal de Significância Indeterminada/sangue , Gamopatia Monoclonal de Significância Indeterminada/genética , Mieloma Múltiplo/sangue , Mieloma Múltiplo/genética , Estudos Retrospectivos , Adulto JovemRESUMO
The survival of patients with head and neck squamous cancer with locoregional recurrence is short if salvage surgery or radiation cannot be performed. Systemic chemotherapy based on platinum salts and cetuximab produces only partial and transient responses. Immune checkpoint inhibitors (i.e., nivolumab) lead to a low complete response rate of only about 10%, but in some cases the effects can be long-lasting. Intratumoral chemotherapy (ITC) has been proposed for patients with local recurrence of head and neck squamous cell carcinoma with an objective response rate of 27-50%. However, it often leads to peritumoral tissue necrosis, and the duration of local control is limited. Here, we present 2 patients with head and neck squamous cell cancer whose local recurrences were refractory to intravenous chemotherapy and nivolumab. ITC using nonnecrotizing molecules, associated with nivolumab, led to complete stable local and distant response. ITC seems to trigger tumor resensitization to previously ineffective immunotherapy. This combination deserves an evaluation in the framework of a prospective trial.
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CD90 is a membrane GPI-anchored protein with one Ig V-type superfamily domain that was initially described in mouse T cells. Besides the specific expression pattern and functions of CD90 that were described in normal tissues, i.e., neurons, fibroblasts and T cells, increasing evidences are currently highlighting the possible involvement of CD90 in cancer. This review first provides a brief overview on CD90 gene, mRNA and protein features and then describes the established links between CD90 and cancer. Finally, we report newly uncovered functional connections between CD90 and endoplasmic reticulum (ER) stress signaling and discuss their potential impact on cancer development.
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Endoplasmic reticulum (ER) proteostasis is often altered in tumor cells due to intrinsic (oncogene expression, aneuploidy) and extrinsic (environmental) challenges. ER stress triggers the activation of an adaptive response named the Unfolded Protein Response (UPR), leading to protein translation repression, and to the improvement of ER protein folding and clearance capacity. The UPR is emerging as a key player in malignant transformation and tumor growth, impacting on most hallmarks of cancer. As such, the UPR can influence cancer cells' migration and invasion properties. In this review, we overview the involvement of the UPR in cancer progression. We discuss its cross-talks with the cell migration and invasion machinery. Specific aspects will be covered including extracellular matrix (ECM) remodeling, modification of cell adhesion, chemo-attraction, epithelial-mesenchymal transition (EMT), modulation of signaling pathways associated with cell mobility, and cytoskeleton remodeling. The therapeutic potential of targeting the UPR to treat cancer will also be considered with specific emphasis in the impact on metastasis and tissue invasion.
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Sorafenib is the standard of care for the treatment of advanced hepatocellular carcinoma (HCC). However, identifying secreted biomarkers that predict sorafenib efficacy in all HCC patients remains challenging. It was recently reported that sorafenib interferes with protein homeostasis and inhibits global translation in tumour cells. A likely consequence of this inhibition would be the interruption of autocrine loops. The aim of the present study was to investigate the effect of sorafenib on two growth factors implicated in autocrine loops and HCC tumour invasion: amphiregulin (AREG) and vascular endothelial growth factor (VEGF). ELISA, quantitative polymerase chain reaction analysis, western blotting and a cytokine array were performed on HCC cell lines and the prognostic role of these two biomarkers in HCC patients was evaluated. Serum AREG and VEGF levels were assayed by ELISA in 55 patients with advanced HCC treated with sorafenib. It was observed that sorafenib decreased AREG, VEGF and cytokine expression at the transcriptional and posttranscriptional levels. All HCC patients in our cohort had detectable concentrations of AREG and VEGF both at baseline and after sorafenib treatment. The decreased serum levels of AREG and VEGF after 15 days of sorafenib treatment were significantly associated with better overall and progressionfree survival. The results of the multivariate analysis demonstrated that a decrease in AREG was an independent prognostic indicator of overall survival (hazard ratio, 0.208; 95% confidence interval, 0.1730.673; P=0.0003). These results suggest that sorafenib inhibits auto-crine loops and that early decrease in serum AREG or VEGF levels predicts sorafenib efficacy in HCC patients.
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Anfirregulina/sangue , Antineoplásicos/uso terapêutico , Biomarcadores Tumorais/sangue , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Sorafenibe/uso terapêutico , Fator A de Crescimento do Endotélio Vascular/sangue , Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/mortalidade , Linhagem Celular Tumoral , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/mortalidade , Masculino , Pessoa de Meia-Idade , Prognóstico , Intervalo Livre de Progressão , Fatores de Tempo , Resultado do TratamentoRESUMO
Uric acid (UA) is the end product of the catabolism of purines, and its serum levels are commonly increased in cancer patients. We aimed to explore the transcriptional regulation of tumour uricogenesis in human tumours, and relate uricogenesis with tumour pathological and pharmacological findings. Using data from The Cancer Genome Atlas (TCGA), we analysed the expression levels of xanthine dehydrogenase (XDH) and adenine phosphoribosyltransferase (APRT), two key enzymes in UA production and the purine salvage pathway, respectively. We found large differences between tumour types and individual tumours in their expression of XDH and APRT Variations in locus-specific DNA methylation and gene copy number correlated with the expression levels of XDH and APRT in human tumours respectively. We explored the consequences of this differential regulation of uricogenesis. Tumours with high levels of XDH mRNA were characterised by higher expression of several genes encoding pro-inflammatory and immune cytokines, and increased levels of tumour infiltration with immune cells. Finally, we studied cancer drug sensitivity using data from the National Cancer Institute-60 (NCI-60) database. A specific correlation was found between the expression levels of APRT and cell sensitivity to the chemotherapeutic agent 5-fluorouracil (5-FU). Our findings underline the existence of great differences in uricogenesis between different types of human tumours. The study of uricogenesis offers promising perspectives for the identification of clinically relevant molecular biomarkers and for tumour stratification in the therapeutic context.
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Adenina Fosforribosiltransferase/genética , Neoplasias/genética , Ácido Úrico/sangue , Xantina Desidrogenase/genética , Adenina Fosforribosiltransferase/metabolismo , Variações do Número de Cópias de DNA/genética , Metilação de DNA/genética , Bases de Dados Factuais , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Fluoruracila/farmacologia , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Masculino , Neoplasias/sangue , Neoplasias/classificação , Xantina Desidrogenase/metabolismoRESUMO
BACKGROUND/AIM: The squamous cell carcinoma antigen (SCCA), encoded by the genes SERPINB3/B4, is a tumour marker produced by head and neck squamous cell carcinoma (HNSCC). We aimed to examine SERPINB3/B4 mRNA levels and its clinical significance in the therapeutic context. MATERIALS AND METHODS: We retrieved mRNA expression levels, clinical, pathological and genomic data for 520 HNSCC from The Cancer Genome Atlas (TCGA). RESULTS: HNSCC tumours express high levels of SERPINB3/B4 mRNA. SERPINB3 expression differs depending on Human papillomavirus (HPV) infection status, primary tumour location, grade and differentiation, extension to lymph nodes and extracapsular spread. Interestingly, we observed an association between SERPINB3/B4 and the presence of tumour immune infiltrate as well as the expression of the immune checkpoint regulators PD-L1/PD-L2 that depended on HPV status. CONCLUSION: Our findings point to potential interest of SERPINB3/B4 for the stratification of HNSCC patients in the therapeutic context.
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Antígenos de Neoplasias/genética , Biomarcadores Tumorais/genética , Carcinoma de Células Escamosas/genética , Neoplasias de Cabeça e Pescoço/genética , Serpinas/genética , Carcinoma de Células Escamosas/classificação , Carcinoma de Células Escamosas/diagnóstico , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Ontologia Genética , Neoplasias de Cabeça e Pescoço/classificação , Neoplasias de Cabeça e Pescoço/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Infecções por Papillomavirus/genética , Infecções por Papillomavirus/virologiaRESUMO
Sorafenib is the first line treatment for advanced hepatocellular carcinoma (HCC). We explored its impact on the proteostasis of cancer cells, i.e. the processes that regulate the synthesis, maturation and turn-over of cellular proteins. We observed that sorafenib inhibits the production of the tumour marker alpha-foetoprotein (AFP) in two different HCC cell lines, an effect that correlated with a radical inhibition of protein biosynthesis. This effect was observed at clinically relevant concentrations of sorafenib and was not related to the effect of sorafenib on the transport of amino acids across the plasma membrane or the induction of the unfolded protein response (UPR). Instead, we observed that sorafenib inhibits translation initiation and the mechanistic target of rapamycin (mTOR) signaling cascade, as shown by the analysis of phosphorylation levels of the protein 4EBP1 (eukaryotic translation initiation factor 4E binding protein 1). We explored the consequences of this inhibition in HCC cells. We observed that overall sorafenib is a weak inducer of the UPR that can paradoxically prevent the UPR induced by tunicamycin. We also found no direct synergistic anticancer effect between sorafenib and various strategies that inhibit the UPR. In agreement with the possibility that translation inhibition might be an adaptive stress response in HCC cells, we noted that it protects cancer cell from ferroptosis, a form of oxidative necrosis. Our findings point to the modulation of protein biosynthesis and mTOR signaling as being important, yet complex determinants of the response of HCC cells to sorafenib.
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BACKGROUND/AIM: Organ transplant patients treated with the immunosuppressive drug cyclosporine A often present malignant kidney tumors. Cyclosporine A can promote oncogenesis in a cell-intrinsic manner by increasing the production of vascular endothelial growth factor (VEGF). MATERIALS AND METHODS: We explored the impact of cyclosporine A and the role of the unfolded protein response (UPR) on three human renal cell carcinoma (RCC) cell lines under normoxic and hypoxic (1% O2) conditions. RESULTS: Cyclosporine A regulated the expression of VEGF at the post-transcriptional level. Cyclosporine A induced the inositol requiring enzyme-1α (IRE1α) arm of the UPR and stabilized neosynthesized proteins in RCC cells. Toyocamycin, an inhibitor of IRE1α, abolished the clonogenic growth of RCC cells and reduced induction of VEGF by cyclosporine A under hypoxia. CONCLUSION: Our findings highlight the impact of cyclosporine A on the proteostasis of RCC cells, and suggest the potential therapeutic interest of targeting the UPR against tumors arising in the context of organ transplantation.
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Carcinoma de Células Renais/metabolismo , Ciclosporina/química , Regulação Neoplásica da Expressão Gênica , Imunossupressores/química , Neoplasias Renais/metabolismo , Resposta a Proteínas não Dobradas , Linhagem Celular Tumoral/efeitos dos fármacos , Endorribonucleases/metabolismo , Regulação da Expressão Gênica , Humanos , Hipóxia , Oxigênio/metabolismo , Reação em Cadeia da Polimerase , Proteínas Serina-Treonina Quinases/metabolismo , Puromicina/química , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Toiocamicina/química , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
The RAS-RAF-MEK-ERK cascade is a key oncogenic signal transduction pathway activated in many types of tumours in humans. Sorafenib, the medical treatment of reference against advanced stages of hepatocellular carcinoma (HCC), inhibits the RAF-MEK-ERK cascade in HCC cells. Based on previous studies suggesting that this cascade is an important target of sorafenib in HCC cells, we explored its regulation using mathematical modelling and ordinary differential equations. We analysed the dynamic regulation of the core components of the RAF-MEK-ERK cascade in three human HCC cell lines (Huh7, Hep3B and PLC/PRF5) with heterogeneous responses to sorafenib. In silico predictions derived from our mathematical model suggested that the disappearance of phosphorylated MEK and ERK proteins catalysed by cellular phosphatases is an essential mechanism underlying the anti-ERK efficacy of sorafenib in HCC cells. This prediction was experimentally validated using specific inhibitors of the phosphatases PP2A (Protein Phosphatase 2A) and DUSP1/6 (Dual-specificity phosphatases 1/6). These findings highlight an unexpected mode of action of sorafenib on the kinome of HCC cells, and open new perspectives regarding the therapeutic targeting of the RAF-MEK-ERK cascade in this context.
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Antineoplásicos/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Neoplasias Hepáticas/tratamento farmacológico , MAP Quinase Quinase Quinases/metabolismo , Modelos Biológicos , Niacinamida/análogos & derivados , Compostos de Fenilureia/farmacologia , Monoéster Fosfórico Hidrolases/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Transdução de Sinais/efeitos dos fármacos , Quinases raf/antagonistas & inibidores , Carcinoma Hepatocelular/enzimologia , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Fosfatase 1 de Especificidade Dupla/metabolismo , Fosfatase 6 de Especificidade Dupla/metabolismo , Humanos , Neoplasias Hepáticas/enzimologia , Neoplasias Hepáticas/patologia , Niacinamida/farmacologia , Monoéster Fosfórico Hidrolases/antagonistas & inibidores , Fosforilação , Proteína Fosfatase 2/metabolismo , Sorafenibe , Fatores de Tempo , Quinases raf/metabolismoRESUMO
Tumour proteostasis and the unfolded protein response (UPR) are emerging drivers of tumour progression and important determinants of clinical efficacy of cancer therapy. Recent findings indicate that they also regulate the production of protein tumour markers. Here, we discuss how this new knowledge opens up new perspectives for cancer therapeutics.
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Biomarcadores/sangue , Neoplasias/sangue , Proteostase , Resposta a Proteínas não Dobradas , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/metabolismoRESUMO
Alpha-foetoprotein (AFP), one of the first protein tumour markers discovered, is widely used today in clinical practice. Its application for the screening and diagnosis of hepatocellular carcinoma (HCC), the most frequent form of primary liver tumour, is a matter of extensive debate. In addition to the studies focused on the role of the AFP in the diagnosis of HCC, in recent years AFP has been used to guide the therapeutic choice in HCC and monitor the treatment. Here, we summarize the latest studies that show the interest of AFP quantification in determining the suitability of liver transplantation or to follow-up on patients receiving the targeted treatment sorafenib. We also highlight the recent studies showing the active role of AFP in tumour progression, and the new modes of regulation of this tumour marker. Among these is the regulation of AFP through tumour proteostasis and the Unfolded Protein Response (UPR). We discuss the implications of this new knowledge in the therapeutic context, in terms of interpreting serum levels of AFP, and the new perspectives offered by AFP for the study of tumour proteostasis.