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BACKGROUND: The cut-off of < 1% positive cells to define estrogen receptor (ER) negativity by immunohistochemistry (IHC) in breast cancer (BC) is debated. We explored the tumor immune microenvironment and gene-expression profile of patients with early-stage HER2-negative ER-low (ER 1-9%) BC, comparing them to ER-negative (ER < 1%) and ER-intermediate (ER 10-50%) tumors. PATIENTS AND METHODS: Among 921 patients with early-stage I-III, ER ≤ 50%, HER2-negative BCs, tumors were classified as ER-negative (n = 712), ER-low (n = 128), or ER-intermediate (n = 81). Tumor-infiltrating lymphocytes (TILs) were evaluated. CD8+, FOXP3+ cells, and PD-L1 status were assessed by IHC and quantified by digital pathology. We analyzed 776 BC-related genes in 116 samples. All tests were 2-sided at < 0.05 significance level. RESULTS: ER-low and ER-negative tumors exhibited similar median TILs, significantly higher than ER-intermediate tumors. CD8/FOXP3 ratio and PD-L1 positivity rates were comparable between ER-low and ER-negative groups. These groups showed similar enrichment in Basal-like intrinsic subtypes and comparable expression of immune-related genes. ER-low and ER-intermediate tumors showed significant transcriptomic differences. High TILs (≥30%) were associated with improved relapse-free survival (RFS) in ER-low (5-year RFS 78.6% vs 66.2%, log-rank p = .033, hazard ratio (HR) 0.37 [95% CI 0.15-0.96]) and ER-negative patients (5-year RFS 85.2% vs 69.8%, log-rank p < .001, HR 0.41 [95% CI 0.27-0.60]). CONCLUSIONS: ER-low and ER-negative tumors are similar biological and molecular entities, supporting their comparable clinical outcomes and treatment responses, including to immunotherapy. Our findings contribute to the growing evidence calling for a reevaluation of ER-positive BC classification and management, aligning ER-low and ER-negative tumors more closely.
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OBJECTIVES: Non-celiac wheat sensitivity (NCWS) is an emerging clinical condition characterized by gastrointestinal and extraintestinal symptoms following the ingestion of gluten-containing foods in patients without celiac disease (CD) or wheat allergy. Despite the great interest for NCWS, the genetic risk factors still need to be fully clarified. In this study, we first assessed the possible contribution of KIR genes and KIR haplotypes on the genetic predisposition to NCWS. METHODS: Fifty patients with NCWS, 50 patients with CD, and 50 healthy controls (HC) were included in this study. KIR genes and KIR genotyping were investigated in all subjects by polymerase chain reaction with the sequence oligonucleotide probe (PCR-SSOP) method using Luminex technology. RESULTS: We found a statistically different distribution of some KIR genes among NCWS, CD, and HC. Specifically, NCWS showed a decreased frequency of KIR2DL1, -2DL3, -2DL5, -2DS2, -2DS3, -2DS4, -2DS5, and -3DS1 genes, and an increased frequency of -3DL1 gene respect to both CD and HC. No difference was detected in the KIR haplotype expression. At the multivariate analysis, KIR2DL5, -2DS4, and -2DS5 were independent predictors of NCWS. CONCLUSIONS: Our findings suggest a role of KIR genes in NCWS susceptibility, with KIR2DL5, -2DS4, and -2DS5 having a protective effect. Further large-scale multicentric studies are required to validate these preliminary findings.
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Predisposición Genética a la Enfermedad , Haplotipos , Receptores KIR , Hipersensibilidad al Trigo , Humanos , Receptores KIR/genética , Femenino , Masculino , Adulto , Hipersensibilidad al Trigo/genética , Persona de Mediana Edad , Enfermedad Celíaca/genética , Estudios de Casos y Controles , Triticum/genética , Genotipo , Adulto JovenRESUMEN
INTRODUCTION: Immune-related adverse events (irAEs) constitute a challenge in the clinical management of solid tumors. This study aims to collect real-world data on the occurrence of immune-mediated diarrhea and colitis (IMDC) in advanced non-small cell lung cancer (aNSCLC) treated with immune checkpoint inhibitors (ICIs) and to assess the clinical impact of a multidisciplinary approach (MDA) on IMDC management. METHODS: We retrospectively collected data on patients with aNSCLC consecutively treated with ICIs, either as single agent or in combination with chemotherapy, between September 2013 and July 2022. Among patients developing IMDC, we conducted blinded revision of colonic biopsies and evaluated the clinical impact of the introduction of MDA through predefined indicators. RESULTS: Among the 607 patients included, 84 (13.8%) experienced IMDC. Pathological review highlighted a high prevalence of microscopic colitis (28%), with a collagenous pattern linked to longer symptoms duration (Pâ =â .01). IMDC occurred more frequently in females (Pâ =â .05) and PD-L1 expressors (Pâ =â .014) and was correlated with longer progression-free survival (17.0 vs 5.8, Pâ <â .001) and overall survival (28.3 vs 9.5, Pâ <â .001). The introduction of MDA was associated with increased employment of diagnostical tools such as fecal calprotectin test (Pâ <â .001), colonoscopy (Pâ <â .001), and gastroenterological evaluation (Pâ =â .017) and a significant decrease in both grade 3 conversion rate (Pâ =â .046) and recurrence after rechallenge (Pâ =â .016). Hospitalization rate dropped from 17.2% to 3.8% (P: ns). CONCLUSION: These findings highlight the clinical relevance of IMDC and support the incorporation of a MDA to optimize the clinical management of this irAE to improve patient care. Prospective validation has been planned.
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Carcinoma de Pulmón de Células no Pequeñas , Colitis , Neoplasias Pulmonares , Femenino , Humanos , Carcinoma de Pulmón de Células no Pequeñas/complicaciones , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Estudios Retrospectivos , Neoplasias Pulmonares/complicaciones , Neoplasias Pulmonares/tratamiento farmacológico , Colitis/inducido químicamente , Colitis/diagnóstico , Colitis/tratamiento farmacológico , Diarrea/etiologíaRESUMEN
PURPOSE: We aim to evaluate the prognostic significance of tumor-infiltrating lymphocyte on residual disease (RD-TIL) in HER2+ patients with breast cancer who failed to achieve pathologic complete response (pCR) after anti-HER2+ chemotherapy (CT)-based neoadjuvant treatment (NAT). We assessed the feasibility of combining the prognostic information provided by residual cancer burden (RCB) and RD-TILs into a composite score (RCB+TIL). EXPERIMENTAL DESIGN: HER2+ patients with breast cancer treated with CT+anti-HER2-based NAT at three institutions were retrospectively included. RCB and TIL levels were evaluated on hematoxylin and eosin-stained slides from surgical samples according to available recommendations. Overall survival (OS) was used as an outcome measure. RESULTS: A total of 295 patients were included, of whom 195 had RD. RCB was significantly associated with OS. Higher RD-TILs were significantly associated with poorer OS as compared with lower RD-TILs (15% cutoff). In multivariate analysis, both RCB and RD-TIL maintained their independent prognostic value. A combined score, RCB+TIL, was calculated from the estimated coefficient of RD-TILs and the RCB index in a bivariate logistic model for OS. The RCB+TIL score was significantly associated with OS. The C-index for OS of the RCB+TIL score was numerically higher than that of RCB and significantly higher than that of RD-TILs. CONCLUSIONS: We have reported an independent prognostic impact of RD-TILs after anti-HER2+CT NAT, which might underlie an imbalance of the RD microenvironment towards immunosuppressive features. We provided a new composite prognostic score based on RCB+TIL, which was significantly associated with OS and proved to be more informative than the isolated evaluation of RCB and RD-TILs.
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Neoplasias de la Mama , Humanos , Femenino , Neoplasias de la Mama/patología , Pronóstico , Linfocitos Infiltrantes de Tumor , Neoplasia Residual/patología , Terapia Neoadyuvante , Estudios Retrospectivos , Receptor ErbB-2/genética , Receptor ErbB-2/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Microambiente TumoralRESUMEN
INTRODUCTION: Patients with triple-negative breast cancer (TNBC) achieving a pathological complete response (pCR) after neoadjuvant chemotherapy have a better event-free survival. The role of gut microbiome in early TNBC is underexplored. METHODS: Microbiome was analyzed by 16SrRNA sequencing. RESULTS: Twenty-five patients with TNBC treated with neoadjuvant anthracycline/taxane-based chemotherapy were included. Fifty-six percent achieved a pCR. Fecal samples were collected before (t0), at 1 (t1), and 8 weeks (t2) from chemotherapy. Overall, 68/75 samples (90.7%) were suitable for microbiome analysis. At t0, pCR group showed a significantly higher α-diversity as compared with no-pCR, (P = .049). The PERMANOVA test on ß-diversity highlighted a significant difference in terms of BMI (P = 0.039). Among patients with available matched samples at t0 and t1, no significant variation in microbiome composition was reported over time. CONCLUSIONS: Fecal microbiome analysis in early TNBC is feasible and deserves further investigation in order to unravel its complex correlation with immunity and cancer.
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Microbioma Gastrointestinal , Neoplasias de la Mama Triple Negativas , Humanos , Neoplasias de la Mama Triple Negativas/patología , Terapia Neoadyuvante , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Antraciclinas/efectos adversosRESUMEN
BACKGROUND: The generation of data capturing the risk-benefit ratio of incorporating carboplatin (Cb) to neoadjuvant chemotherapy (NACT) for triple-negative breast cancer (TNBC) in a clinical practice setting is urgently needed. Tumour-infiltrating lymphocytes (TILs) have an established role in TNBC receiving NACT, however, the role of TIL dynamics under NACT exposure in patients receiving the current standard of care is largely uncharted. METHODS: Consecutive TNBC patients receiving anthracycline-taxane [A-T] +/- Cb NACT at three Institutions were enrolled. Stromal-TILs were evaluated on pre-NACT and residual disease (RD) specimens. In the clinical cohort, propensity-score-matching was used to control selection bias. RESULTS: In total, 247 patients were included (A-T = 40.5%, A-TCb = 59.5%). After propensity-score-matching, pCR was significantly higher for A-TCb vs A-T (51.9% vs 34.2%, multivariate: OR = 2.40, P = 0.01). No differences in grade ≥3 haematological toxicities were observed. TILs increased from baseline to RD in the overall population and across A-T/A-TCb subgroups. TIL increase from baseline to RD was positively and independently associated with distant disease-free survival (multivariate: HR = 0.43, P = 0.05). CONCLUSIONS: We confirmed in a clinical practice setting of TNBC patients receiving A-T NACT that the incorporation of weekly Cb significantly improved pCR. In addition, A-T +/- Cb enhanced immune infiltration from baseline to RD. Finally, we reported a positive independent prognostic role of TIL increase after NACT exposure.
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Neoplasias de la Mama Triple Negativas , Humanos , Carboplatino/efectos adversos , Neoplasias de la Mama Triple Negativas/metabolismo , Paclitaxel/efectos adversos , Terapia Neoadyuvante , Antraciclinas/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Linfocitos Infiltrantes de Tumor/metabolismoRESUMEN
The serology surveillance of SARS-CoV-2 antibodies represents a useful tool for monitoring protective immunity in the population. We compared the performance of three SARS-CoV-2 antibody serological immunoassays in 600 vaccinated subjects after the BNT162b2 mRNA COVID-19 vaccine. All serum samples were evaluated by three different immunoassays for detecting anti-SARS-COV-2 antibodies. All SARS-CoV-2 antibody serological immunoassays could detect, when present, a post-vaccine humoral immune response. Median (interquartile range, IQR) anti-S-RBD IgG, Access SARS-CoV-2 IgG (1st IS) and Access SARS-CoV-2 IgG II levels of the subjects investigated were, respectively, 687 BAU/mL (131-2325), 419 IU/mL (58-1091) and 104 AU/mL (14-274). By studying a cohort of unvaccinated subjects, without previous COVID-19 infection, we found a high specificity for all methods. A high correlation was found between IgG titres. Considering the kinetics of subjects with multiple doses, we observed that percentage decreasing gradients were comparable across methods. Our results suggest that all the SARS-CoV-2 antibody serological immunoassays evaluated in this study are suitable for monitoring IgG titers over time. This study contributes to a better understanding of antibody response in vaccinated subjects using some currently available assays.
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Vacuna BNT162 , COVID-19 , Humanos , COVID-19/diagnóstico , Vacunas contra la COVID-19 , Luminiscencia , SARS-CoV-2 , Anticuerpos Antivirales , Inmunoglobulina GRESUMEN
Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of many solid tumors. In breast cancer (BC), immunotherapy is currently approved in combination with chemotherapy, albeit only in triple-negative breast cancer. Unfortunately, most patients only derive limited benefit from ICIs, progressing either upfront or after an initial response. Therapeutics must engage with a heterogeneous network of complex stromal-cancer interactions that can fail at imposing cancer immune control in multiple domains, such as in the genomic, epigenomic, transcriptomic, proteomic, and metabolomic domains. To overcome these types of heterogeneous resistance phenotypes, several combinatorial strategies are underway. Still, they can be predicted to be effective only in the subgroups of patients in which those specific resistance mechanisms are effectively in place. As single biomarker predictive performances are necessarily suboptimal at capturing the complexity of this articulate network, precision immune-oncology calls for multi-omics tumor microenvironment profiling in order to identify unique predictive patterns and to proactively tailor combinatorial treatments. Multiplexed single-cell spatially resolved tissue analysis, through precise epitope colocalization, allows one to infer cellular functional states in view of their spatial organization. In this review, we discuss-through the lens of the cancer-immunity cycle-selected, established, and emerging markers that may be evaluated in multiplexed spatial protein panels to help identify prognostic and predictive patterns in BC.
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BACKGROUND: Walking difficulties, which are widespread among people with MS (pwMS), represent one of the major factors contributing to physical disability and, as such, may greatly affect an individual's independence and quality of life. In this context, the study of lower limb kinematics may provide an important contribution to unveiling the underlying mechanisms of walking dysfunctions in MS. However, limited information about the inter-joint coordination during gait-the functional relationship between joint pairs during the whole gait cycle-is available. METHODS: We retrospectively analyzed the gait patterns of 104 pwMS (56 women, 48 men, mean age 46.3, average Expanded Disability Status Scale score 3.5) and 84 unaffected individuals age-and-sex-matched, who underwent 3D computerized gait analysis carried out using an optical motion capture system. PwMS were also stratified into two groups according to their level of disability. Those with EDSS ≤ 3.5 (n = 62) formed the "low-mild disability" group, while those with EDSS > 3.5 (n = 42) were assigned to the "moderate-severe disability" group. The raw data were processed to calculate the main spatio-temporal parameters and the kinematics in the sagittal plane at the hip, knee, and ankle joints. At each point of the gait cycle, the angular values were employed to build angle-angle diagrams (cyclograms) for the hip-knee and the knee-ankle joint couples. Inter-joint coordination was quantified using geometric features of the cyclograms (i.e., area, perimeter, and dimensionless ratio) and compared between groups. For pwMS only, we also explored possible relationships between cyclograms parameters, disability level, and spatio-temporal parameters of gait. RESULTS: PwMS exhibit a well-known gait pattern characterized by reduced speed, stride length, increased step width, and double support phase duration. Their inter-joint coordination was found altered at both hip-knee and knee-ankle joint couples, as indicated by the significantly reduced cyclogram area and perimeter with respect to unaffected individuals. However, the detailed analysis of the angle-angle diagram trajectories showed some differences associated with the level of disability. In particular, pwMS with mild-low disability exhibit cyclograms partly superposed with those of unaffected individuals in the first half of the stance phase (hip-knee couple) and the second half of the swing phase (knee-ankle couple), while in those with a moderate-severe disability, the differences are substantially extended to the whole gait cycle. Significant moderate to large correlations were also observed between cyclogram area and perimeter, EDSS score, and spatio-temporal parameters of gait. CONCLUSION: The study of inter-joint coordination during gait in pwMS represents a useful source of information about the way lower limb joints interact, thus potentially expanding the knowledge of the mechanisms underlying walking dysfunctions associated with the disease. From a clinical perspective, the availability of reference data for the co-variation of hip-knee and knee-ankle joint angles during gait can effectively support both the characterization of the progression of the disease and the assessment of the effectiveness of rehabilitative treatments.
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Esclerosis Múltiple , Fenómenos Biomecánicos , Femenino , Marcha , Humanos , Masculino , Persona de Mediana Edad , Esclerosis Múltiple/complicaciones , Calidad de Vida , Estudios Retrospectivos , CaminataRESUMEN
BACKGROUND: Tumour infiltrating lymphocytes (TILs) are an established prognostic biomarker for triple-negative breast cancer (TNBC). We evaluated the role of programmed cell-death ligand-1 (PD-L1), CD8 and FOXP3 expression in refining a prognostic model for non-metastatic TNBC beyond classic factors and TILs. METHODS: Primary tumour samples from 244 early patients with TNBC, all treated with surgery and chemotherapy, were collected. Stromal TILs were evaluated on haematoxylin-eosin slides according to guidelines. PD-L1, CD8 and FOXP3 were assessed by immunohistochemistry and evaluated by digital pathology. RESULTS: TILs, PD-L1, CD8 and FOXP3 were positively correlated with each other (P < 0.001). TILs were confirmed as an independent prognostic factor. When PD-L1, CD8 and FOXP3 were added to multivariable models including classic factors (age, stage, histologic grade) and TILs, PD-L1 provided the largest amount of additional prognostic information: likelihood ratio χ2 4.60, P = 0.032 (in a model including classic factors and TILs 10% increments) and likelihood ratio χ2 6.50, P = 0.011 (in a model including classic factors and TILs >30% versus <30%). In the subset of patients treated with neoadjuvant chemotherapy, FOXP3 provided further prognostic information beyond classic factors, TILs and pathological complete response (pCR) (likelihood ratio χ2 5.01, P = 0.025). For patients who did not achieve a pCR, the expression of CD8 and PD-L1 was significantly increased from baseline to residual disease. CONCLUSIONS: Beyond clinicopathological factors and TILs, other immune biomarkers may add prognostic information for early TNBC. The increased PD-L1 expression on residual disease after neoadjuvant chemotherapy strengthens the rationale of testing immune checkpoint inhibitors in the post-neoadjuvant setting.
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Antígeno B7-H1/metabolismo , Linfocitos T CD8-positivos/metabolismo , Factores de Transcripción Forkhead/metabolismo , Linfocitos Infiltrantes de Tumor/metabolismo , Neoplasias de la Mama Triple Negativas/diagnóstico , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/inmunología , Biomarcadores de Tumor/metabolismo , Antígenos CD8/análisis , Antígenos CD8/metabolismo , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/patología , Estudios de Cohortes , Femenino , Factores de Transcripción Forkhead/análisis , Humanos , Inmunohistoquímica/métodos , Linfocitos Infiltrantes de Tumor/inmunología , Linfocitos Infiltrantes de Tumor/patología , Persona de Mediana Edad , Terapia Neoadyuvante , Estadificación de Neoplasias , Neoplasia Residual , Valor Predictivo de las Pruebas , Pronóstico , Medición de Riesgo/métodos , Factores de Riesgo , Nivel de Atención , Resultado del Tratamiento , Neoplasias de la Mama Triple Negativas/metabolismo , Neoplasias de la Mama Triple Negativas/patología , Neoplasias de la Mama Triple Negativas/terapiaRESUMEN
Animal cells use pattern-recognition receptors (PRRs) to detect specific pathogens. Pathogen detection mounts an appropriate immune response, including interferon and cytokine induction. The intracellular PRR-signaling pathways that detect DNA viruses have been characterized, particularly in myeloid cells. In these pathways, cGMP-AMP synthase (cGAS) and the pyrin and HIN domain family member (PYHIN) protein interferon-γ-inducible protein 16 (IFI16) detect DNA and signal via stimulator of interferon genes protein (STING). However, although airway epithelial cells are frontline sentinels in detecting pathogens, information on how they respond to DNA viruses is limited, and the roles of PYHIN proteins in these cells are unknown. Here, we examined expression and activities of cGAS, STING, and PYHINs in human lung epithelial cells. A549 epithelial cells, commonly used for RNA-sensing studies, failed to respond to DNA because they lacked STING expression, and ectopic STING expression restored a cGAS-dependent DNA response in these cells. In contrast, NuLi-1 immortalized human bronchial epithelial cells did express STING, which was activated after DNA stimulation and mediated DNA-dependent gene induction. PYHIN1, which like IFI16 has been proposed to be a viral DNA sensor, was the only PYHIN protein expressed in both airway epithelial cell types. However, rather than having a role in DNA sensing, PYHIN1 induced proinflammatory cytokines in response to interleukin-1 (IL-1) or tumor necrosis factor α (TNFα) stimulation. Of note, PYHIN1, via its HIN domain, directly induced IL-6 and TNFα transcription, revealing that PYHIN proteins play a role in proinflammatory gene induction in airway epithelial cells.
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Citocinas/metabolismo , ADN Viral/metabolismo , Inmunidad Innata , Proteínas Nucleares/metabolismo , Línea Celular , Células Epiteliales/citología , Células Epiteliales/inmunología , Células Epiteliales/metabolismo , Herpesvirus Humano 1/genética , Herpesvirus Humano 1/fisiología , Humanos , Interleucina-1/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Proteínas Nucleares/antagonistas & inhibidores , Proteínas Nucleares/genética , Nucleotidiltransferasas/antagonistas & inhibidores , Nucleotidiltransferasas/genética , Nucleotidiltransferasas/metabolismo , Fosfoproteínas/metabolismo , Regiones Promotoras Genéticas , Interferencia de ARN , ARN Interferente Pequeño/metabolismo , Virus Sendai/genética , Virus Sendai/fisiología , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
OBJECTIVE: Ovarian cancer is the deadliest gynaecological cancer. A major contributor to the poor survival rate is the development of chemoresistance to platinum-based therapies such as cisplatin and carboplatin. Here we aimed to test the role of miRNAs in the acquisition of drug resistance in ovarian cancer. METHODS: We used microarrays to measure miRNA levels in the ovarian cancer cell line A2780 and its cisplatin-resistant derivative CP70. The role of miRNAs and the mRNA targets were tested using transfected miRNA mimics and siRNAs, respectively. Potential in vivo significance was investigated by analysing RNA levels in cohorts of ovarian cancer patients. RESULTS: We identified several miRNAs that are increased in cisplatin-resistant cells. We show that most of these do not directly contribute to cisplatin resistance. Interestingly, miR-21-3p, the passenger strand of the known oncomiR, directed increased resistance to cisplatin in a range of ovarian cell lines. This effect was specific to the star strand, as miR-21-5p had the opposite effect and actually increased sensitivity of A2780 cells to cisplatin. We identify NAV3 as a potential target of miR-21-3p and show that knockdown of NAV3 increases resistance. Exosomes released by CP70 cells were also capable of increasing resistance in A2780 cells, although this was independent of miR-21-3p. Finally, we use publically available transcriptomic data to demonstrate that miR-21-3p is raised, while NAV3 is reduced, in ovarian tumours that are resistant to platinum treatment. CONCLUSION: Our data suggest that miR-21-3p can induce cisplatin resistance in ovarian tumours, potentially by targeting the NAV3 gene.
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Cisplatino/farmacología , MicroARNs/genética , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/genética , Antineoplásicos/farmacología , Línea Celular Tumoral , Resistencia a Antineoplásicos/genética , Femenino , Técnicas de Silenciamiento del Gen , Humanos , Proteínas de la Membrana/antagonistas & inhibidores , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , MicroARNs/metabolismo , Proteínas del Tejido Nervioso/antagonistas & inhibidores , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismoRESUMEN
Organisms are often exposed to environmental pressures that affect homeostasis, so it is important to understand the biological basis of stress-response. Various biological mechanisms have evolved to help cells cope with potentially cytotoxic changes in their environment. miRNAs are small non-coding RNAs which are able to regulate mRNA stability. It has been suggested that miRNAs may tip the balance between continued cytorepair and induction of apoptosis in response to stress. There is a wealth of data in the literature showing the effect of environmental stress on miRNAs, but it is scattered in a large number of disparate publications. Meta-analyses of this data would produce added insight into the molecular mechanisms of stress-response. To facilitate this we created and manually curated the miRStress database, which describes the changes in miRNA levels following an array of stress types in eukaryotic cells. Here we describe this database and validate the miRStress tool for analysing miRNAs that are regulated by stress. To validate the database we performed a cross-species analysis to identify miRNAs that respond to radiation. The analysis tool confirms miR-21 and miR-34a as frequently deregulated in response to radiation, but also identifies novel candidates as potentially important players in this stress response, including miR-15b, miR-19b, and miR-106a. Similarly, we used the miRStress tool to analyse hypoxia-responsive miRNAs. The most frequently deregulated miRNAs were miR-210 and miR-21, as expected. Several other miRNAs were also found to be associated with hypoxia, including miR-181b, miR-26a/b, miR-106a, miR-213 and miR-192. Therefore the miRStress tool has identified miRNAs with hitherto unknown or under-appreciated roles in the response to specific stress types. The miRStress tool, which can be used to uncover new insight into the biological roles of miRNAs, and also has the potential to unearth potential biomarkers for therapeutic response, is freely available at http://mudshark.brookes.ac.uk/MirStress.