RESUMEN
Bladder cancer (BC) is the fifth most common cancer in the world, being the non-muscle invasive tumors (NMIBC) the most frequent. NMIBC shows a very high frequency of recurrence and, in certain cases, tumor progression. The phosphatidylinositol 3-kinase (PI3K) pathway, which controls cell growth, tumorigenesis, cell invasion and drug response, is frequently activated in numerous human cancers, including BC, in part through alterations of PIK3CA gene. However, the significance of PIK3CA gene alterations with respect to clinicopathological characteristics, and in particular tumor recurrence and progression, remains elusive. Here, we analyzed the presence of mutations in FGFR3 and PIK3CA genes and copy number alterations of PIK3CA gene in bladder tumor and their correspondent paired normal samples from 87 patients. We observed an extremely high frequency of PIK3CA gene alterations (mutations, copy gains, or both) in tumor samples, affecting primarily T1 and T2 tumors. A significant number of normal tissues also showed mutations and copy gains, being coincident with those found in the corresponding tumor sample. In low-grade tumors PIK3CA mutations associated with FGFR3 mutations. Alterations in PIK3CA gene resulted in increased Akt activity in tumors. Interestingly, the presence of PIK3CA gene alterations, and in particular gene mutations, is significantly associated with reduced recurrence of NMIBC patients. Importantly, the presence of FGFR3 mutations may influence the clinical outcome of patients bearing alterations in PIK3CA gene, and increased recurrence was associated to FGFR3 mutated, PIK3CA wt tumors. These findings may have high relevance in terms of using PI3K-targeted therapies for BC treatment.
Asunto(s)
Mutación , Recurrencia Local de Neoplasia/genética , Fosfatidilinositol 3-Quinasas/genética , Receptor Tipo 3 de Factor de Crecimiento de Fibroblastos/genética , Neoplasias de la Vejiga Urinaria/genética , Vejiga Urinaria/patología , Anciano , Anciano de 80 o más Años , Fosfatidilinositol 3-Quinasa Clase I , Femenino , Dosificación de Gen , Humanos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/metabolismo , Recurrencia Local de Neoplasia/patología , Fosforilación , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal , Vejiga Urinaria/metabolismo , Neoplasias de la Vejiga Urinaria/metabolismo , Neoplasias de la Vejiga Urinaria/patologíaRESUMEN
Bladder Cancer (BC) represents a current clinical and social challenge. The recent studies aimed to describe the genomic landscape of BC have underscored the relevance of epigenetic alterations in the pathogenesis of these tumors. Among the epigenetic alterations, histone modifications occupied a central role not only in cancer, but also in normal organism homeostasis and development. EZH2 (Enhancer of Zeste Homolog 2) belongs to the Polycomb repressive complex 2 as its catalytic subunit, which through the trimethylation of H3 (Histone 3) on K27 (Lysine 27), produces gene silencing. EZH2 is frequently overexpressed in multiple tumor types, including BC, and plays multiple roles besides the well-recognized histone mark generation. In this review, we summarize the present knowledge on the oncogenic roles of EZH2 and its potential use as a therapeutic target, with special emphasis on BC pathogenesis and management.
Asunto(s)
Complejo Represivo Polycomb 2/genética , Complejo Represivo Polycomb 2/metabolismo , Neoplasias de la Vejiga Urinaria/genética , Neoplasias de la Vejiga Urinaria/metabolismo , Animales , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Metilación de ADN , Proteína Potenciadora del Homólogo Zeste 2 , Epigénesis Genética , Regulación Neoplásica de la Expresión Génica , Silenciador del Gen , Histonas/metabolismo , Humanos , MicroARNs/genética , MicroARNs/metabolismo , Terapia Molecular Dirigida , Complejo Represivo Polycomb 2/antagonistas & inhibidores , Unión Proteica , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Neoplasias de la Vejiga Urinaria/tratamiento farmacológicoRESUMEN
In previous studies we described a decreased alpha-L-fucosidase activity in colorectal tumors, appearing as a prognostic factor of tumoral recurrence. The aim of this work was to extend the knowledge about tissue alpha-L-fucosidase in colorectal cancer by quantifying the expression of its encoding gene FUCA1 in tumors and healthy mucosa. FUCA1 mRNA levels were measured by RT-qPCR in paired tumor and normal mucosa tissues from 31 patients. For the accuracy of the RT-qPCR results, five candidate reference genes were validated in those samples. In addition, activity and expression of alpha-L-fucosidase in selected matched tumor and healthy mucosa samples were analyzed. According to geNorm and NormFinder algorithms, RPLP0 and HPRT1 were the best reference genes in colorectal tissues. These genes were used for normalization of FUCA1 expression levels. A significant decrease of more than 60% in normalized FUCA1 expression was detected in tumors compared to normal mucosa (p = 0.002). Moreover, a gradual decrease in FUCA1 expression was observed with progression of disease from earlier to advanced stages. These findings were confirmed by Western blot analysis of alpha-L-fucosidase expression. Our results demonstrated diminished FUCA1 mRNA levels in tumors, suggesting that expression of tissue alpha-L-fucosidase could be regulated at transcriptional level in colorectal cancer.
Asunto(s)
Adenocarcinoma/enzimología , Neoplasias Colorrectales/enzimología , alfa-L-Fucosidasa/metabolismo , Adenocarcinoma/genética , Anciano , Anciano de 80 o más Años , Neoplasias Colorrectales/genética , Cartilla de ADN/genética , Cartilla de ADN/normas , Represión Enzimática , Femenino , Expresión Génica , Regulación Neoplásica de la Expresión Génica , Humanos , Mucosa Intestinal/enzimología , Masculino , Persona de Mediana Edad , Reacción en Cadena en Tiempo Real de la Polimerasa , Estándares de Referencia , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/normas , alfa-L-Fucosidasa/genéticaRESUMEN
BACKGROUND: We explore the utility of TruSight Tumor 170 panel (TST170) for detecting somatic mutations in tumor and cfDNA from locoregional recurrent and/or metastatic head and neck squamous cell carcinoma (HNSCC). METHODS: Targeted NGS of tumor DNA and plasma cfDNA was performed using TST170 panel. In addition, a set of somatic mutations previously described in HNSCC were selected for validating in tumor, plasma, and saliva by digital droplet PCR. RESULTS: The TST170 panel identified 13 non-synonymous somatic mutations, of which five were detected in tumoral tissue, other five in plasma cfDNA, and three in both tissue and plasma cfDNA. Of the eight somatic mutations identified in tissue, three were also identified in plasma cfDNA, showing an overall concordance rate of 37.5%. CONCLUSIONS: This preliminary study shows the possibility to detect somatic mutations in tumor and plasma of HNSCC patients using a single assay that would facilitate the clinical implementation of personalized medicine in the clinic.
Asunto(s)
Ácidos Nucleicos Libres de Células , Neoplasias de Cabeza y Cuello , Humanos , Carcinoma de Células Escamosas de Cabeza y Cuello/genética , Neoplasias de Cabeza y Cuello/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Mutación , Biomarcadores de Tumor/genéticaRESUMEN
The study of the proteome (proteomics), which includes the dynamics of protein expression, regulation, interactions and its function, has played a less prominent role in evolutionary and ecological investigations in comparison with the study of the genome and transcriptome. There are, however, a number of arguments suggesting that this situation should change. First, the proteome is closer to the phenotype than the genome or the transcriptome, and as such may be more directly responsive to natural selection, and thus closely linked to adaptation. Second, there is evidence of a low correlation between protein and transcript expression levels across genes in many different organisms. Finally, there have been some recent important technological improvements in proteomics methods that make them feasible, practical and useful to address a wide range of evolutionary questions even in nonmodel organisms. The different proteomic methods, their limitations and problems when interpreting empirical data are described and discussed. In addition, the proteomic literature pertaining to evolutionary ecology is reviewed with examples, and potential applications of proteomics in a variety of evolutionary contexts are outlined. New proteomic research trends such as the study of posttranslational modifications and protein-protein interactions, as well as the combined use of the different -omics approaches, are discussed in relation to the development of a more functional and integrated perspective, needed for achieving a more comprehensive knowledge of evolutionary change.
Asunto(s)
Evolución Biológica , Ecología/métodos , Genotipo , Fenotipo , Proteómica/métodos , Proteoma/análisisRESUMEN
Immunotherapy with Immune Checkpoint Inhibitors (ICIs) has demonstrated a profitable performance for Non-Small Cell Lung Cancer (NSCLC) cancer treatment in some patients; however, there is still a percentage of patients in whom immunotherapy does not provide the desired results regarding beneficial outcomes. Therefore, obtaining predictive biomarkers for ICI response will improve the treatment management in clinical practice. In this sense, liquid biopsy appears as a promising method to obtain samples in a minimally invasive and non-biased way. In spite of its evident potential, the use of these circulating biomarkers is still very limited in the real clinical practice, mainly due to the huge heterogeneity among the techniques, the lack of consensus, and the limited number of patients included in these previous studies. In this work, we review the pros and cons of the different proposed biomarkers, such as soluble PD-L1, circulating non-coding RNA, circulating immune cells, peripheral blood cytokines, and ctDNA, obtained from liquid biopsy to predict response to ICI treatment at baseline and to monitor changes in tumor and tumor microenvironment during the course of the treatment in NSCLC patients.
RESUMEN
CTCs have extensively been used for the monitoring and characterization of metastatic prostate cancer, but their application in the clinic is still very scarce. Besides, the resistance mechanisms linked to prostate cancer treatment remain unclear. Liquid biopsies represent the most promising alternative due to the complexity of biopsying bone metastasis and the duration of the disease. We performed a prospective longitudinal study in CTCs from 20 castration-resistant prostate cancer patients treated with docetaxel. For that, we used CellSearch® technology and a custom gene expression panel with qRT-PCR using a CTCs negative enrichment approach. We found that CTCs showed a hybrid phenotype during the disease, where epithelial features were associated with the presence of ≥ 5 CTCs/7.5 mL of blood, while high relative expression of the gene MYCL was observed preferentially in the set of samples with < 5 CTCs/7.5 mL of blood. At baseline, patients whose CTCs had stem or hybrid features showed a later progression. After 1 cycle of docetaxel, high relative expression of ZEB1 indicated worse outcome, while KRT19 and KLK3 high expression could predisposed the patients to a worse prognosis at clinical progression. In the present work we describe biomarkers with clinical relevance for the prediction of early response or resistance in castration-resistant prostate cancer patients. Besides, we question the utility of targeted isolated CTCs and the use of a limited number of markers to define the CTCs population.
Asunto(s)
Docetaxel/uso terapéutico , Células Neoplásicas Circulantes/metabolismo , Neoplasias de la Próstata Resistentes a la Castración/patología , Transcriptoma , Anciano , Anciano de 80 o más Años , Recuento de Células , Transición Epitelial-Mesenquimal , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Neoplasias de la Próstata Resistentes a la Castración/tratamiento farmacológico , Proteínas Proto-Oncogénicas c-myc/genética , Homeobox 1 de Unión a la E-Box con Dedos de Zinc/genéticaRESUMEN
Most cancers are characterized by the somatic acquisition of genomic rearrangements during tumour evolution that eventually drive the oncogenesis. Here, using multiplatform sequencing technologies, we identify and characterize a remarkable mutational mechanism in human hepatocellular carcinoma caused by Hepatitis B virus, by which DNA molecules from the virus are inserted into the tumour genome causing dramatic changes in its configuration, including non-homologous chromosomal fusions, dicentric chromosomes and megabase-size telomeric deletions. This aberrant mutational mechanism, present in at least 8% of all HCC tumours, can provide the driver rearrangements that a cancer clone requires to survive and grow, including loss of relevant tumour suppressor genes. Most of these events are clonal and occur early during liver cancer evolution. Real-time timing estimation reveals some HBV-mediated rearrangements occur as early as two decades before cancer diagnosis. Overall, these data underscore the importance of characterising liver cancer genomes for patterns of HBV integration.
Asunto(s)
Carcinoma Hepatocelular/genética , ADN Viral , Genoma Humano , Virus de la Hepatitis B/genética , Neoplasias Hepáticas/genética , Carcinoma Hepatocelular/virología , Regulación Neoplásica de la Expresión Génica , Humanos , Integración Viral , Secuenciación Completa del GenomaRESUMEN
BACKGROUND: In the past 40 years, there has been increasing acceptance that variation in levels of gene expression represents a major source of evolutionary novelty. Gene expression divergence is therefore likely to be involved in the emergence of incipient species, namely, in a context of adaptive radiation. In this study, a genome-wide expression profiling approach (cDNA-AFLP), validated by quantitative real-time polymerase chain reaction (qPCR) were used to get insights into the role of differential gene expression on the ecological adaptation of the marine snail Littorina saxatilis. This gastropod displays two sympatric ecotypes (RB and SU) which are becoming one of the best studied systems for ecological speciation. RESULTS: Among the 99 transcripts shared between ecotypes, 12.12% showed significant differential expression. At least 4% of these transcripts still displayed significant differences after correction for multiple tests, highlighting that gene expression can differ considerably between subpopulations adapted to alternative habitats in the face of gene flow. One of the transcripts identified was Cytochrome c Oxidase subunit I (COI). In addition, 6 possible reference genes were validated to normalize and confirm this result using qPCR. α-Tubulin and histone H3.3 showed the more stable expression levels, being therefore chosen as the best option for normalization. The qPCR analysis confirmed a higher COI expression in SU individuals. CONCLUSIONS: At least 4% of the transcriptome studied is being differentially expressed between ecotypes living in alternative habitats, even when gene flow is still substantial between ecotypes. We could identify a candidate transcript of such ecotype differentiation: Cytochrome c Oxidase Subunit I (COI), a mitochondrial gene involved in energy metabolism. Quantitative PCR was used to confirm the differences found in COI and its over-expression in the SU ecotype. Interestingly, COI is involved in the oxidative phosphorylation, suggesting an enhanced mitochondrial gene expression (or increased number of mitochondria) to improve energy supply in the ecotype subjected to the strongest wave action.
Asunto(s)
Adaptación Fisiológica/genética , Perfilación de la Expresión Génica , Especiación Genética , Caracoles/genética , Análisis del Polimorfismo de Longitud de Fragmentos Amplificados , Animales , ADN Complementario/genética , ADN Mitocondrial/genética , Ecología , Complejo IV de Transporte de Electrones/genética , Femenino , Flujo Génico , Masculino , Análisis de Secuencia de ADNRESUMEN
BACKGROUND: The role of phenotypic plasticity is increasingly being recognized in the field of evolutionary studies. In this paper we look at the role of genetic determination versus plastic response by comparing the protein expression profiles between two sympatric ecotypes adapted to different shore levels and habitats using two-dimensional protein maps. RESULTS: We compared qualitative and quantitative differences in protein expression between pools of both ecotypes from different environments (field and laboratory conditions). The results suggested that ecotype differences may affect about 7% of the proteome in agreement with previous studies, and moreover these differences are basically insensitive to environmental changes. Thus, observed differences between wild ecotypes can be mainly attributed to genetic factors rather than phenotypic plasticity. CONCLUSIONS: These results confirm the mechanism of adaptation already proposed in this species and a minor role of phenotypic plasticity in this ecological speciation process. In addition, this study provides a number of interesting protein spots potentially involved in adaptation, and therefore candidates for a future identification.
Asunto(s)
Proteoma/análisis , Caracoles/química , Caracoles/genética , Animales , Análisis por Conglomerados , Ecosistema , Electroforesis en Gel Bidimensional , FenotipoRESUMEN
Bladder cancer is the most common malignancy of the urinary tract, having one of the highest recurrence rates and progression from non-muscle to muscle invasive bladder cancer that commonly leads to metastasis. Cystoscopy and urine cytology are the standard procedures for its detection but have limited clinical sensitivity and specificity. Herein, a microfluidic device, the UriChip, was developed for the enrichment of urothelial exfoliated cells from fresh and frozen urine, based on deformability and size, and the cancer-associated glycan Sialyl-Tn explored as a putative bladder cancer urinary biomarker. Spiking experiments with bladder cancer cell lines showed an isolation efficiency of 53%, while clinical sample analyses revealed retention of cells with various morphologies and sizes. in situ immunoassays demonstrated significantly higher number of Sialyl-Tn-positive cells in fresh and frozen voided urine from bladder cancer patients, compared to healthy individuals. Of note, urothelial exfoliated cells from cryopreserved urine sediments were also successfully isolated by the UriChip, and found to express significantly high levels of Sialyl-Tn. Remarkably, Sialyl-Tn expression is correlated with tumor stage and grade. Overall, our findings demonstrate the potential of UriChip and Sialyl-Tn to detect urothelial bladder cancer cells in follow-up and long-term retrospective studies.
RESUMEN
Non-muscle invasive bladder cancer (NMIBC) represents a crucial problem for the national health care systems due to its high rates of recurrence and the consequent need of frequent follow-ups. Here, gene expression analyses in patients diagnosed as NMIBC were performed to determine those molecular pathways involved in tumor initiation, finding that both MYC and E2F are up regulated and helps to tumor initiation and progression. Our results also support an important involvement of alternative splicing events, modifying key pathways to favour bladder tumor evolution. Finally, since MDM2 showed differential exon usage, mutations in TP53 and its protein expression have been also studied in the same patients. Our data support that recurrence is epigenetically mediated and favoured by an increase protein expression of TP53, which appears more frequently mutated in advanced stages and grades, being associated to a worse prognosis. Therefore, TP53 mutational status could be used as a potential biomarker in the first stages of NMIBC to predict recurrence and prognosis.
Asunto(s)
Empalme Alternativo , Carcinoma de Células Transicionales/genética , Regulación Neoplásica de la Expresión Génica , Genes p53 , Papiloma/genética , Neoplasias de la Vejiga Urinaria/genética , Carcinoma de Células Transicionales/patología , Supervivencia sin Enfermedad , Factores de Transcripción E2F/genética , Exones/genética , Ontología de Genes , Genes myc , Humanos , Estimación de Kaplan-Meier , Mutación Missense , Invasividad Neoplásica , Proteínas de Neoplasias/biosíntesis , Proteínas de Neoplasias/genética , Papiloma/patología , Pronóstico , Proteínas Proto-Oncogénicas c-mdm2/genética , Proteínas Proto-Oncogénicas c-myc/genética , Recurrencia , Análisis de Matrices Tisulares , Neoplasias de la Vejiga Urinaria/patología , Secuenciación del ExomaRESUMEN
Bladder cancer (BC) is the most common neoplasia of the urothelial tract. Due to its high incidence, prevalence, recurrence and mortality, it remains an unsolved clinical and social problem. The treatment of BC is challenging and, although immunotherapies have revealed potential benefit in a percentage of patients, it remains mostly an incurable disease at its advanced state. Epigenetic alterations, including aberrant DNA methylation, altered chromatin remodeling and deregulated expression of non-coding RNAs are common events in BC and can be driver events in BC pathogenesis. Accordingly, these epigenetic alterations are now being used as potential biomarkers for these disorders and are being envisioned as potential therapeutic targets for the future management of BC. In this review, we summarize the recent findings in these emerging and exciting new aspects paving the way for future clinical treatment of this disease.
RESUMEN
The study of circulating tumor cells (CTCs) has a huge clinical interest in advance and metastatic breast cancer patients. However, many approaches are biased by the use of epithelial markers, which underestimate non-epithelial CTCs phenotypes. CTCs enumeration provides valuable prognostic information; however, molecular characterization could be the best option to monitor patients throughout the disease since it may provide more relevant clinical information to the physicians. In this work, we aimed at enumerating and performing a molecular characterization of CTCs from a cohort of 20 patients with metastatic breast cancer (MBC), monitoring the disease at different time points of the therapy, and at progression when it occurred. To this end, we used a CTC negative enrichment protocol that allowed us to recover a higher variety of CTCs phenotypes. With this strategy, we were able to obtain gene expression data from CTCs from all the patients. In addition, we found that high expression levels of PALB2 and MYC were associated with a worse outcome. Interestingly, we identified that CTCs with an EpCAMhighVIMlowALDH1A1high signature showed both shorter overall survival (OS) and progression-free survival (PFS), suggesting that CTCs with epithelial-stem features had the most aggressive phenotype.
RESUMEN
PURPOSE: Bladder cancer is a clinical and social problem due to its high incidence and recurrence rates. It frequently appears in elderly patients showing other medical comorbidities that hamper the use of standard chemotherapy. We evaluated the activity of CDK4/6 inhibitor as a new therapy for patients unfit for cisplatin (CDDP). EXPERIMENTAL DESIGN: Bladder cancer cell lines were tested for in vitro sensitivity to CDK4/6 inhibition. A novel metastatic bladder cancer mouse model was developed and used to test its in vivo activity. RESULTS: Cell lines tested were sensitive to CDK4/6 inhibition, independent on RB1 gene status. Transcriptome analyses and knockdown experiments revealed a major role for FOXM1 in this response. CDK4/6 inhibition resulted in reduced FOXM1 phosphorylation in vitro and in vivo and showed synergy with CDDP, allowing a significant tumor regression. FOXM1 exerted important oncogenic roles in bladder cancer. CONCLUSIONS: CDK4/6 inhibitors, alone or in combination, are a novel therapeutic strategy for patients with advanced bladder cancer previously classified as unfit for current treatment options.
Asunto(s)
Quinasa 4 Dependiente de la Ciclina/genética , Quinasa 6 Dependiente de la Ciclina/genética , Proteína Forkhead Box M1/genética , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Anciano , Animales , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Cisplatino/farmacología , Quinasa 4 Dependiente de la Ciclina/antagonistas & inhibidores , Quinasa 6 Dependiente de la Ciclina/antagonistas & inhibidores , Femenino , Xenoinjertos , Humanos , Masculino , Ratones , Recurrencia Local de Neoplasia/tratamiento farmacológico , Recurrencia Local de Neoplasia/genética , Recurrencia Local de Neoplasia/patología , Fosforilación/efectos de los fármacos , Supervivencia sin Progresión , Inhibidores de Proteínas Quinasas/farmacología , Proteínas de Unión a Retinoblastoma/genética , Ubiquitina-Proteína Ligasas/genética , Neoplasias de la Vejiga Urinaria/genética , Neoplasias de la Vejiga Urinaria/patologíaRESUMEN
Bladder cancer is lethal in its advanced, muscle-invasive phase with very limited therapeutic advances1,2. Recent molecular characterization has defined new (epi)genetic drivers and potential targets for bladder cancer3,4. The immune checkpoint inhibitors have shown remarkable efficacy but only in a limited fraction of bladder cancer patients5-8. Here, we show that high G9a (EHMT2) expression is associated with poor clinical outcome in bladder cancer and that targeting G9a/DNMT methyltransferase activity with a novel inhibitor (CM-272) induces apoptosis and immunogenic cell death. Using an immunocompetent quadruple-knockout (PtenloxP/loxP; Trp53loxP/loxP; Rb1loxP/loxP; Rbl1-/-) transgenic mouse model of aggressive metastatic, muscle-invasive bladder cancer, we demonstrate that CM-272 + cisplatin treatment results in statistically significant regression of established tumors and metastases. The antitumor effect is significantly improved when CM-272 is combined with anti-programmed cell death ligand 1, even in the absence of cisplatin. These effects are associated with an endogenous antitumor immune response and immunogenic cell death with the conversion of a cold immune tumor into a hot tumor. Finally, increased G9a expression was associated with resistance to programmed cell death protein 1 inhibition in a cohort of patients with bladder cancer. In summary, these findings support new and promising opportunities for the treatment of bladder cancer using a combination of epigenetic inhibitors and immune checkpoint blockade.
Asunto(s)
N-Metiltransferasa de Histona-Lisina/antagonistas & inhibidores , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Animales , Línea Celular Tumoral , Cisplatino/uso terapéutico , Proteína Potenciadora del Homólogo Zeste 2/fisiología , Femenino , Antígenos de Histocompatibilidad , Humanos , Ratones , Neoplasias de la Vejiga Urinaria/inmunología , Neoplasias de la Vejiga Urinaria/patologíaRESUMEN
BACKGROUND: MicroRNAs (miRNAs) play a unique role in posttranscriptional regulation of gene expression and control different aspects of skin development, homeostasis, and disease. Although it is generally accepted that thyroid hormone signaling is important in skin pathophysiology, the role of their nuclear receptors (TRs) in cutaneous miRNA expression has yet to be explored. METHODS: RNAseq was used to compare the skin miRnome of wild-type mice and genetically modified mice lacking both TRα1 and TRß, the main thyroid hormone binding isoforms. Changes in miRNAs with a crucial role in skin physiopathology were confirmed by stem-loop quantitative polymerase chain reaction in both total skin and isolated keratinocytes, and the levels of their target mRNAs were evaluated by real-time polymerase chain reaction. RESULTS: The skin of TRα1/TRß knockout mice displays altered levels of >50 miRNAs. Among the downregulated species are several miRNAs, including miR-21, miR-31, miR-34, and miR-203, with crucial roles in skin homeostasis. TRα1 appears to be the main isoform responsible for their regulation. Increased levels of gene transcripts previously shown to be bona fide targets of these miRNAs are also found in the skin and keratinocytes of TR-deficient mice. This suggests that multiple miRNAs that are downregulated in the absence of TRs cooperate to regulate gene expression in the skin. CONCLUSIONS: The miRNAs reduced in TRα1/TRß knockout mice are known to play crucial roles in epidermal proliferation, hair cycling, wound healing, stem-cell function, and tumor development, all processes altered in the absence of TRs. These results suggest that their regulation could contribute to the skin defects found in these mice and to the skin disorders associated with altered thyroid status in humans.
Asunto(s)
MicroARNs/metabolismo , Receptores de Hormona Tiroidea/metabolismo , Piel/metabolismo , Animales , Proliferación Celular , Regulación de la Expresión Génica , Homeostasis/fisiología , Ratones , Ratones Noqueados , MicroARNs/genética , Receptores de Hormona Tiroidea/genética , Transducción de Señal , Cicatrización de Heridas/fisiologíaRESUMEN
Although Ras genes are frequently mutated in human tumors, these mutations are uncommon in breast cancer. However, many breast tumors show evidences of Ras pathway activation. In this manuscript, we have analyzed and characterized mouse mammary tumors generated by random Sleeping Beauty transposon mutagenesis and identify ERAS -a member of the RAS family silenced in adult tissues- as a new gene involved in progression and malignancy of breast cancer. Forced expression of ERAS in human non-transformed mammary gland cells induces a process of epithelial-to-mesenchymal transition and an increase in stem cells markers; these changes are mediated by miR-200c downregulation. ERAS expression in human tumorigenic mammary cells leads to the generation of larger and less differentiated tumors in xenotransplant experiments. Immunohistochemical, RT-qPCR and bioinformatics analysis of human samples show that ERAS is aberrantly expressed in 8-10% of breast tumors and this expression is associated with distant metastasis and reduced metastasis-free survival. In summary, our results reveal that inappropriate activation of ERAS may be important in the development of a subset of breast tumors. These findings open the possibility of new specific treatments for this subset of ERAS-expressing tumors.
Asunto(s)
Neoplasias de la Mama/fisiopatología , Proteína Oncogénica p21(ras)/metabolismo , Animales , Neoplasias de la Mama/patología , Carcinogénesis , Diferenciación Celular , Células Cultivadas , Células Epiteliales/fisiología , Transición Epitelial-Mesenquimal , Humanos , Ratones , Trasplante de Neoplasias , Neoplasias Experimentales/patología , Neoplasias Experimentales/fisiopatología , Proteína Oncogénica p21(ras)/genética , Trasplante HeterólogoRESUMEN
The high rates of tumor recurrence and progression represent a major clinical problem in non-muscle invasive bladder cancer. Previous data showed that EZH2-dependent signaling mediates these processes, whereas the frequent alterations of PIK3CA gene (copy gains and mutations) are predictive of reduced recurrence. Here we show, using clinical samples and bladder cancer cell lines, a functional interaction between EZH2- and PIK3CA-dependent signaling pathways. PIK3CA alterations mediated, on the one hand, the increased expression of two miRNAs, miR-101 and miR-138, which posttranscriptionally downregulate EZH2 expression. On the other hand, PIK3CA alterations facilitate the activation of Akt which phosphorylates EZH2 on Ser21, precluding the trimethylation of histone H3 in K27. Remarkably the increased expression of miR101 or miR138 and the expression of Ser21-phosphorylated EZH2 are good prognostic factors regarding non-muscle invasive bladder cancer recurrence and progression. Collectively, this study provides molecular evidences indicating that the gene expression rewiring occurring in primary bladder tumors, associated with increased EZH2 expression and activity and mediating the increased recurrence and progression risk, are prevented by PIK3CA-dependent signaling. This molecular process may have deep implications in the management of bladder cancer patients and in the design of novel molecularly targeted therapeutic approaches.