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Hereditary breast and ovarian cancer are mainly linked to mutations in BRCA1 and BRCA2 genes which confer a similar cumulative risk of developing breast cancer. Importantly, while BRCA2 mutation carriers generally have a lower cumulative risk for ovarian cancer, mutations clustered in the central portion of BRCA2 are associated with a higher proportion of ovarian compared with breast cancer cases. The boundaries of this ovarian cancer cluster region (OCCR) have been tentatively defined within a 3.3 kb region of BRCA2 exon 11, and herein, we reassessed these boundaries using our series of Italian breast/ovarian cancer families. We used direct sequencing to investigate BRCA mutations in 367 breast/ovarian cancer families. We also studied the association between the location of the mutations and the ovarian cancer phenotype in our cohort of BRCA2-mutated families. We observed the novel c.7309_7309delA frameshift mutation and the c.7007G>A deleterious mutation in BRCA2 exons 14 and 13, respectively, in five independent Italian families characterized by a high proportion of ovarian cancer cases. Of note, a significantly higher proportion of ovarian versus breast cancer cases was associated not only with mutations in the previously defined OCCR (OR = 5.91; p = 0.004), but also with the exon 13-14 region (OR = 7.37; p = 0.001) in our BRCA2-mutated families. Our data provide initial evidence for a novel putative OCCR in BRCA2 exons 13-14.
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Proteína BRCA2/genética , Neoplasias de la Mama Masculina/genética , Neoplasias Ováricas/genética , Adulto , Anciano , Neoplasias de la Mama/epidemiología , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Neoplasias de la Mama Masculina/epidemiología , Exones , Femenino , Mutación de Línea Germinal , Humanos , Italia , Masculino , Persona de Mediana Edad , Mutación , Neoplasias Ováricas/epidemiología , Neoplasias Ováricas/patología , LinajeRESUMEN
Introduction: Compared with breast cancer (BC) in women, BC in men is a rare disease with genetic and molecular peculiarities. Therapeutic approaches for male BC (MBC) are currently extrapolated from the clinical management of female BC, although the disease does not exactly overlap in males and females. Data on specific molecular biomarkers in MBC are lacking, cutting out male patients from more appropriate therapeutic strategies. Growing evidence indicates that Next Generation Sequencing (NGS) multigene panel testing can be used for the detection of predictive molecular biomarkers, including Tumor Mutational Burden (TMB) and Microsatellite Instability (MSI). Methods: In this study, NGS multigene gene panel sequencing, targeting 1.94 Mb of the genome at 523 cancer-relevant genes (TruSight Oncology 500, Illumina), was used to identify and characterize somatic variants, Copy Number Variations (CNVs), TMB and MSI, in 15 Formalin-Fixed Paraffin-Embedded (FFPE) male breast cancer samples. Results and discussion: A total of 40 pathogenic variants were detected in 24 genes. All MBC cases harbored at least one pathogenic variant. PIK3CA was the most frequently mutated gene, with six (40.0%) MBCs harboring targetable PIK3CA alterations. CNVs analysis showed copy number gains in 22 genes. No copy number losses were found. Specifically, 13 (86.7%) MBCs showed gene copy number gains. MYC was the most frequently amplified gene with eight (53.3%) MBCs showing a median fold-changes value of 1.9 (range 1.8-3.8). A median TMB value of 4.3 (range 0.8-12.3) mut/Mb was observed, with two (13%) MBCs showing high-TMB. The median percentage of MSI was 2.4% (range 0-17.6%), with two (13%) MBCs showing high-MSI. Overall, these results indicate that NGS multigene panel sequencing can provide a comprehensive molecular tumor profiling in MBC. The identification of targetable molecular alterations in more than 70% of MBCs suggests that the NGS approach may allow for the selection of MBC patients eligible for precision/targeted therapy.
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Pediatric high-grade gliomas represent a heterogeneous group of tumors with a wide variety of molecular features. We performed whole exome sequencing and methylation profiling on matched primary and recurrent tumors from four pediatric patients with hemispheric high-grade gliomas. Genetic analysis showed the presence of some variants shared between primary and recurrent tumors, along with other variants exclusive of primary or recurrent tumors. NSD1 variants, all novel and not previously reported, were present at high frequency in our series (100%) and were all shared between the samples, independently of primary or recurrence. For every variant, in silico prediction tools estimated a high probability of altering protein function. The novel NSD1 variant (c.5924T > A; p.Leu1975His) was present in one in four cases at recurrence, and in two in four cases at primary. The novel NSD1 variant (c.5993T > A; p.Met1998Lys) was present in one in four cases both at primary and recurrence, and in one in four cases only at primary. The presence of NSD1 mutations only at recurrence may suggest that they can be sub-clonal, while the presence in both primary and recurrence implies that they can also represent early and stable events. Furthermore, their presence only in primary, but not in recurrent tumors, suggest that NSD1 mutations may also be influenced by treatment.
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BACKGROUND: BRCA1/2 VUSs represent an important clinical issue in risk assessment for the breast/ovarian cancer families (HBOC) families. Among them, some occurring within the intron-exon boundary may lead to aberrant splicing process by altering or creating de novo splicing regulatory elements or unmasking cryptic splice site. Defining the impact of these potential splice variants at functional level is important to establish their pathogenic role. METHODS: Genomic DNA was extracted from peripheral blood sample of a young woman affected with breast cancer belonging to a HBOC family and the entire coding regions of the BRCA1 and BRCA2 genes were amplified using the Ion AmpliSeq BRCA1 and BRCA2 Panel. The BRCA2 c.682-2delA variant has been characterized by RT-PCR analysis performed on mRNA extracted from blood and lymphoblastoid cell line. RESULTS: We demonstrated that a novel BRCA2 c.682-2delA variant at the highly conserved splice consensus site in intron 8 disrupts the canonical splice acceptor site generating a truncated protein as predicted by several bioinformatics tools. Segregations analysis in the family and LOH performed on proband breast cancer tissue further confirmed its classification as pathogenic variant. CONCLUSION: Combining different methodologies, we characterized this new BRCA2 variant and provided findings of clinical utility for its classification as pathogenic variant.
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Proteína BRCA2/genética , Eliminación de Gen , Síndrome de Cáncer de Mama y Ovario Hereditario/genética , Sitios de Empalme de ARN , Adulto , Secuencia Conservada , Síndrome de Cáncer de Mama y Ovario Hereditario/patología , Humanos , Pérdida de HeterocigocidadRESUMEN
We performed next generation sequencing of DNA extracted from the neoplastic tissues obtained from a patient who underwent surgery for a large right ovarian carcinoma (OC) of endometrioid type associated with endometrial cancer (EC). This was done in order to ascertain whether the tumors were synchronous endometrial/ovarian cancers or an advanced metastatic stage from either the ovary or the uterus. Pathologic criteria favoured synchronous EC/OC. We identified a PTEN c.959 T > G (p.L320X) truncating mutation occurring with similar allele frequency in both neoplastic tissues (ovary: 88 %, endometrium 89 %) and a CTNNB1 c.100C > G (p.S37C) activating mutation, with a comparable allelic frequency in both tumor tissues (ovary 51 %, endometrium 52 %). The shared genetic mutations, and the presence of PTEN c.959 T > G (p.L320X) truncating mutation, albeit at low allelic frequency (6 %), in the healthy peritumoral endometrial tissue, appear to confirm the recent literature on a primary endometrial origin for synchronous EC/OC. A third mutation was CTNNB1 c.92 T > C (p.L31 P), a missense mutation occurring with a low allele frequency (3.7 %) only in the ovarian cancer tissue. This mutation is only occasionally described in hepatocellular carcinomas.
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Carcinoma Endometrioide/genética , Mutación Missense , Neoplasias Primarias Múltiples/genética , Neoplasias Ováricas/genética , Neoplasias Uterinas/genética , beta Catenina/genética , Adulto , Carcinoma Endometrioide/patología , Carcinoma Endometrioide/cirugía , Análisis Mutacional de ADN , Femenino , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Neoplasias Primarias Múltiples/patología , Neoplasias Primarias Múltiples/cirugía , Neoplasias Ováricas/patología , Neoplasias Ováricas/cirugía , Neoplasias Uterinas/patología , Neoplasias Uterinas/cirugíaRESUMEN
Extensive molecular characterization of human colorectal cancer (CRC) via Next Generation Sequencing (NGS) indicated that genetic or epigenetic dysregulation of a relevant, but limited, number of molecular pathways typically occurs in this tumor. The molecular picture of the disease is significantly complicated by the frequent occurrence of individually rare genetic aberrations, which expand tumor heterogeneity. Inter- and intratumor molecular heterogeneity is very likely responsible for the remarkable individual variability in the response to conventional and target-driven first-line therapies, in metastatic CRC (mCRC) patients, whose median overall survival remains unsatisfactory. Implementation of an extensive molecular characterization of mCRC in the clinical routine does not yet appear feasible on a large scale, while multigene panel sequencing of most commonly mutated oncogene/oncosuppressor hotspots is more easily achievable. Here, we report that clinical multigene panel sequencing performed for anti-EGFR therapy predictive purposes in 639 formalin-fixed paraffin-embedded (FFPE) mCRC specimens revealed previously unknown pairwise mutation associations and a high proportion of cases carrying actionable gene mutations. Most importantly, a simple principal component analysis directed the delineation of a new molecular stratification of mCRC patients in eight groups characterized by non-random, specific mutational association patterns (MAPs), aggregating samples with similar biology. These data were validated on a The Cancer Genome Atlas (TCGA) CRC dataset. The proposed stratification may provide great opportunities to direct more informed therapeutic decisions in the majority of mCRC cases.
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BACKGROUND: Conventional methods used to identify BRCA1 and BRCA2 germline mutations in hereditary cancers, such as Sanger sequencing/multiplex ligation-dependent probe amplification (MLPA), are time-consuming and expensive, due to the large size of the genes. The recent introduction of next-generation sequencing (NGS) benchtop platforms offered a powerful alternative for mutation detection, dramatically improving the speed and the efficiency of DNA testing. Here we tested the performance of the Ion Torrent PGM platform with the Ion AmpliSeq BRCA1 and BRCA2 Panel in our clinical routine of breast/ovarian hereditary cancer syndrome assessment. METHODS: We first tested the NGS approach in a cohort of 11 patients (training set) who had previously undergone genetic diagnosis in our laboratory by conventional methods. Then, we applied the optimized pipeline to the consecutive cohort of 136 uncharacterized probands (validation set). RESULTS: By minimal adjustments in the analytical pipeline of Torrent Suite Software we obtained a 100% concordance with Sanger results regarding the identification of single nucleotide alterations, insertions, and deletions with the exception of three large genomic rearrangements (LGRs) contained in the training set. The optimized pipeline applied to the validation set (VS), identified pathogenic and polymorphic variants, including a novel BRCA2 pathogenic variant at exon 3, 100% of which were confirmed by Sanger in their correct zygosity status. To identify LGRs, all negative samples of the VS were subjected to MLPA analysis. DISCUSSION: Our experience strongly supports that the Ion Torrent PGM technology in BRCA1 and BRCA2 germline variant identification, combined with MLPA analysis, is highly sensitive, easy to use, faster, and cheaper than traditional (Sanger sequencing/MLPA) approaches.
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BACKGROUND: Genetic testing for BRCA1/2 germline mutations in hereditary breast/ovarian cancer patients requires screening for single nucleotide variants, small insertions/deletions and large genomic rearrangements (LGRs). These studies have long been run by Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA). The recent introduction of next-generation sequencing (NGS) platforms dramatically improved the speed and the efficiency of DNA testing for nucleotide variants, while the possibility to correctly detect LGRs by this mean is still debated. The purpose of this study was to establish whether and to which extent the development of an analytical algorithm could help us translating NGS sequencing via an Ion Torrent PGM platform into a tool suitable to identify LGRs in hereditary breast-ovarian cancer patients. METHODS: We first used NGS data of a group of three patients (training set), previously screened in our laboratory by conventional methods, to develop an algorithm for the calculation of the dosage quotient (DQ) to be compared with the Ion Reporter (IR) analysis. Then, we tested the optimized pipeline with a consecutive cohort of 85 uncharacterized probands (validation set) also subjected to MLPA analysis. Characterization of the breakpoints of three novel BRCA1 LGRs was obtained via long-range PCR and direct sequencing of the DNA products. RESULTS: In our cohort, the newly defined DQ-based algorithm detected 3/3 BRCA1 LGRs, demonstrating 100% sensitivity and 100% negative predictive value (NPV) (95% CI [87.6-99.9]) compared to 2/3 cases detected by IR (66.7% sensitivity and 98.2% NPV (95% CI [85.6-99.9])). Interestingly, DQ and IR shared 12 positive results, but exons deletion calls matched only in five cases, two of which confirmed by MLPA. The breakpoints of the 3 novel BRCA1 deletions, involving exons 16-17, 21-22 and 20, have been characterized. CONCLUSIONS: Our study defined a DQ-based algorithm to identify BRCA1 LGRs using NGS data. Whether confirmed on larger data sets, this tool could guide the selection of samples to be subjected to MLPA analysis, leading to significant savings in time and money.
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The response of metastatic colorectal cancer (mCRC) to the first-line conventional combination therapy is highly variable, reflecting the elevated heterogeneity of the disease. The genetic alterations underlying this heterogeneity have been thoroughly characterized through omic approaches requiring elevated efforts and costs. In order to translate the knowledge of CRC molecular heterogeneity into a practical clinical approach, we utilized a simplified Next Generation Sequencing (NGS) based platform to screen a cohort of 77 patients treated with first-line conventional therapy. Samples were sequenced using a panel of hotspots and targeted regions of 22 genes commonly involved in CRC. This revealed 51 patients carrying actionable gene mutations, 22 of which carried druggable alterations. These mutations were frequently associated with additional genetic alterations. To take into account this molecular complexity and assisted by an unbiased bioinformatic analysis, we defined three subgroups of patients carrying distinct molecular patterns. We demonstrated these three molecular subgroups are associated with a different response to first-line conventional combination therapies. The best outcome was achieved in patients exclusively carrying mutations on TP53 and/or RAS genes. By contrast, in patients carrying mutations in any of the other genes, alone or associated with mutations of TP53/RAS, the expected response is much worse compared to patients with exclusive TP53/RAS mutations. Additionally, our data indicate that the standard approach has limited efficacy in patients without any mutations in the genes included in the panel. In conclusion, we identified a reliable and easy-to-use approach for a simplified molecular-based stratification of mCRC patients that predicts the efficacy of the first-line conventional combination therapy.
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The introduction of multigene panel testing for hereditary breast/ovarian cancer screening has greatly improved efficiency, speed, and costs. However, its clinical utility is still debated, mostly due to the lack of conclusive evidences on the impact of newly discovered genetic variants on cancer risk and lack of evidence-based guidelines for the clinical management of their carriers. In this pilot study, we aimed to test whether a systematic and multiparametric characterization of newly discovered mutations could enhance the clinical utility of multigene panel sequencing. Out of a pool of 367 breast/ovarian cancer families Sanger-sequenced for BRCA1 and BRCA2 gene mutations, we selected a cohort of 20 BRCA1/2-negative families to be subjected to the BROCA-Cancer Risk Panel massive parallel sequencing. As a strategy for the systematic characterization of newly discovered genetic variants, we collected blood and cancer tissue samples and established lymphoblastoid cell lines from all available individuals in these families, to perform segregation analysis, loss-of-heterozygosity and further molecular studies. We identified loss-of-function mutations in 6 out 20 high-risk families, 5 of which occurred on BRCA1, CHEK2 and ATM and are esteemed to be risk-relevant. In contrast, a novel RAD50 truncating mutation is most likely unrelated to breast cancer. Our data suggest that integrating multigene panel testing with a pre-organized, multiparametric characterization of newly discovered genetic variants improves the identification of risk-relevant alleles impacting on the clinical management of their carriers.
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Predisposición Genética a la Enfermedad , Pruebas Genéticas/métodos , Síndrome de Cáncer de Mama y Ovario Hereditario/genética , Ácido Anhídrido Hidrolasas , Adulto , Proteínas de la Ataxia Telangiectasia Mutada/genética , Proteína BRCA1/genética , Proteína BRCA2/genética , Quinasa de Punto de Control 2/genética , Estudios de Cohortes , Análisis Mutacional de ADN/métodos , Enzimas Reparadoras del ADN/genética , Proteínas de Unión al ADN/genética , Femenino , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Humanos , Mutación con Pérdida de Función , Persona de Mediana Edad , Proyectos PilotoRESUMEN
Peroxiredoxins (PRDXs) are a ubiquitously expressed family of small (22-27 kDa) non-seleno peroxidases that catalyze the peroxide reduction of H2O2, organic hydroperoxides and peroxynitrite. They are highly involved in the control of various physiological functions, including cell growth, differentiation, apoptosis, embryonic development, lipid metabolism, the immune response, as well as cellular homeostasis. Although the protective role of PRDXs in cardiovascular and neurological diseases is well established, their role in cancer remains controversial. Increasing evidence suggests the involvement of PRDXs in carcinogenesis and in the development of drug resistance. Numerous types of cancer cells, in fact, are characterized by an increase in reactive oxygen species (ROS) production, and often exhibit an altered redox environment compared with normal cells. The present review focuses on the complex association between oxidant balance and cancer, and it provides a brief account of the involvement of PRDXs in tumorigenesis and in the development of chemoresistance.
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Transforming Growth Factor-beta1 (TGF -beta1) is a multifunctional cytokine that regulates a number of cellular processes such as cell growth, differentiation, plasticity, cell motility, adhesiveness, embryogenesis, development and apoptosis through binding to TGF-beta receptors. We have previously demonstrated that K-ras-transformed rat thyroid cells, K10, are resistant to the growth inhibitory action of TGF-beta1, because they show a decreased expression of type II receptor (TbetaRII). Clones obtained transfecting TbetaRII, partially revert their malignant phenotype, showing a reduction in the anchorage-dependent and -independent cell growth and a statistically significant decrease in tumourigenicity with respect to the highly malignant parental cells, both in spontaneous and artificial metastases, when transplanted in athymic nude mice. The purpose of the present work is to elucidate the molecular events involved in the modulation of the tumourigenic potential of K-ras-transformed rat thyroid cells overexpressing TbetaRII. Our data demonstrate that the TbetaRII overexpressed in K-ras-transformed thyroid cell clones is a functional receptor and is essential to restore in these cells behaviour similar to that of control cells. The TbetaRII overexpression is responsible for a strong reduction of adhesive and migratory behaviour of highly malignant K-ras-transformed thyroid cells. These results suggest that the restore of a functional TGF-beta receptor in these cells may be useful for the limitation of tumour spread and dissemination.
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Adhesión Celular/fisiología , Movimiento Celular/fisiología , Genes ras , Invasividad Neoplásica/fisiopatología , Receptores de Factores de Crecimiento Transformadores beta/fisiología , Glándula Tiroides/citología , Animales , Línea Celular Transformada/efectos de los fármacos , Línea Celular Transformada/patología , Transformación Celular Viral , Células Clonales , Evaluación Preclínica de Medicamentos , Fibronectinas , Humanos , Laminina , Proteínas Serina-Treonina Quinasas , Transporte de Proteínas , Ratas , Receptor Tipo II de Factor de Crecimiento Transformador beta , Receptores de Factores de Crecimiento Transformadores beta/genética , Proteínas Recombinantes de Fusión/fisiología , Transducción de Señal , Proteína Smad2/metabolismo , Proteína smad3/metabolismo , Proteína Smad4/metabolismo , Factor de Crecimiento Transformador beta1/metabolismoRESUMEN
BACKGROUND: Variant ATM heterozygotes have an increased risk of developing cancer, cardiovascular diseases, and diabetes. Costs and time of sequencing and ATM variant complexity make large-scale, general population screenings not cost-effective yet. Recently, we developed a straightforward, rapid, and inexpensive test based on p53 mitotic centrosomal localization (p53-MCL) in peripheral blood mononuclear cells (PBMCs) that diagnoses mutant ATM zygosity and recognizes tumor-associated ATM polymorphisms. METHODS: Fresh PBMCs from 496 cancer patients were analyzed by p53-MCL: 90 cases with familial BRCA1/2-positive and -negative breast and/or ovarian cancer, 337 with sporadic cancers (ovarian, lung, colon, and post-menopausal breast cancers), and 69 with breast/thyroid cancer. Variants were confirmed by ATM sequencing. RESULTS: A total of seven individuals with ATM variants were identified, 5/65 (7.7 %) in breast cancer cases of familial breast and/or ovarian cancer and 2/69 (2.9 %) in breast/thyroid cancer. No variant ATM carriers were found among the other cancer cases. Excluding a single case in which both BRCA1 and ATM were mutated, no p53-MCL alterations were observed in BRCA1/2-positive cases. CONCLUSIONS: These data validate p53-MCL as reliable and specific test for germline ATM variants, confirm ATM as breast cancer susceptibility gene, and highlight a possible association with breast/thyroid cancers.
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Proteínas de la Ataxia Telangiectasia Mutada/genética , Neoplasias de la Mama/genética , Centrosoma/metabolismo , Mutación de Línea Germinal , Proteína p53 Supresora de Tumor/genética , Adulto , Edad de Inicio , Anciano , Anciano de 80 o más Años , Proteína BRCA1/genética , Proteína BRCA2/genética , Femenino , Predisposición Genética a la Enfermedad , Pruebas Genéticas/métodos , Humanos , Persona de Mediana Edad , MitosisRESUMEN
OBJECTIVES: Treatment individualization based on specific molecular biomarkers is becoming increasingly important in oncology. In colorectal cancer (CRC), the molecular characterization of RAS and BRAF mutation status for prognostic and predictive purposes is commonly performed by different validated methods. However, as the number of clinically relevant mutations to be analyzed increases, the definition of new approaches for more sensitive, rapid and economic patient selection urges. To this aim, we evaluated the Ion Semiconductor sequencing using the Ion Torrent Personal Genome Machine (IT-PGM) in our routine molecular diagnostics for CRC in comparison with the gold standard direct Sanger sequencing. DESIGN AND METHODS: Formalin-fixed and paraffin-embedded tumor tissues obtained by surgery or biopsy of 66 CRCs were collected. DNA was extracted and sequenced by IT-PGM and Sanger method. RESULTS: The proposed IT-PGM sequencing strategy exceeded the 500 reads of coverage for all clinically relevant RAS/BRAF amplicons in most samples and thus guaranteed optimal determination. Indeed, the frequencies and the mutational spectrum of RAS and BRAF mutations were in agreement with literature data and revealed 100% concordance between the IT-PGM and routine Sanger sequencing approaches. Turnaround time and cost evaluation indicate that the IT-PGM sequencing permits the characterization of the clinically relevant mutational spots at lower cost and turnaround time compared to Sanger sequencing and allows inclusion of additional amplicons whose characterization may acquire significance in the very next future. CONCLUSION: The IT-PGM is a valid, flexible, sensitive and economical method alternative to the Sanger sequencing in routine diagnostics to select patients for anti-epidermal growth factor receptor therapy for metastatic CRC.
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Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/genética , Genoma Humano , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Patología Molecular/métodos , Humanos , Mutación/genética , Reproducibilidad de los Resultados , Proteínas ras/genéticaRESUMEN
TGF-beta1 is a potent inhibitor of growth and DNA synthesis in thyroid cells. It has also been shown that TGF-beta1 inhibits thyrocyte function. The functional inhibition is represented by a downregulation of thyroid specific genes, such as Na(+)/I(-) symporter (NIS), thyroglobulin (TG) and thyroperoxidase (TPO). The transcriptional control of these genes is mediated by thyroid-specific transcription factors: thyroid transcription factor-1 (TTF-1) and PAX-8. It has been shown that Smad proteins play a pivotal role in the intracellular signal transduction of the TGF-beta family members. In this paper, the functional relevance of Smad4, in the control of thyroid differentiation genes and thyroid-specific transcription factors, has been investigated. The data obtained provides, for the first time, evidence that D.N. Smad4-100T is capable of blocking TGF-beta1 action in the regulation of thyroid-specific genes expression. Such action is possible by blocking nuclear translocation of Smad4 and Smad2.
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Diferenciación Celular/efectos de los fármacos , Glándula Tiroides/efectos de los fármacos , Factor de Crecimiento Transformador beta/farmacología , Animales , Autoantígenos/genética , Autoantígenos/fisiología , Northern Blotting , Western Blotting , Línea Celular , Células Clonales , Cisteína Endopeptidasas/genética , Cisteína Endopeptidasas/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Proteínas de Unión al ADN/fisiología , Regulación hacia Abajo , Regulación de la Expresión Génica/efectos de los fármacos , Vectores Genéticos/genética , Inmunohistoquímica , Yoduro Peroxidasa/genética , Yoduro Peroxidasa/fisiología , Proteínas de Unión a Hierro/genética , Proteínas de Unión a Hierro/fisiología , Luciferasas/genética , Luciferasas/metabolismo , Mutación/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Factor de Transcripción PAX8 , Factores de Transcripción Paired Box , Fosforilación , Ratas , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Transducción de Señal/fisiología , Proteína Smad2 , Proteína Smad4 , Simportadores/genética , Simportadores/fisiología , Glándula Tiroides/citología , Factor Nuclear Tiroideo 1 , Tirotropina/farmacología , Transactivadores/genética , Transactivadores/metabolismo , Transactivadores/fisiología , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Transfección , Factor de Crecimiento Transformador beta/fisiología , Factor de Crecimiento Transformador beta1RESUMEN
Many clinical studies highlight the dichotomous role of PRDXs in human cancers, where they can exhibit strong tumor-suppressive or tumor-promoting functions. Recent evidence suggests that lower expression of PRDXs correlates with cancer progression in colorectal cancer (CRC) or in esophageal squamous carcinoma. In the thyroid, increased levels of PRDX1 has been described in follicular adenomas and carcinomas, as well as in thyroiditis, while reduced levels of PRDX6 has been found in follicular adenomas. We studied the expression of PRDX1 and PRDX6, in a series of thyroid tissue samples, covering different thyroid diseases, including 13 papillary thyroid carcinomas (PTCs). Our results show that PRDX1 and PRDX6 are significantly reduced in all PTCs compared to normal tissues, to non-neoplastic tissue (MNG) or follicular neoplasms. This reduction is strongly evident in PTCs harboring BRAF V600E (31% of our cases). Using TPC-1 and BCPAP and FRTL-5 cell lines, we demonstrate for the first time that the presence of BRAF V600E is responsible of the hypoexpression of PRDX1 and PRDX6 both at mRNA and protein levels. Finally, independently of BRAF status, we observe an interesting correlation between the tumor size, the presence of lymph node metastasis and the lowest PRDX1 and PRDX6 levels. Therefore, these data indicate that PRDX1 and PRDX6 expression not only may play a key role in papillary thyroid carcinogenesis via a BRAF V600E-dependent mechanism, but their determination could be considered as potential tumor marker for indicating tumor progression in PTCs, independently of BRAF status.
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Adenoma/metabolismo , Carcinoma Papilar/metabolismo , Mutación/genética , Peroxiredoxina VI/metabolismo , Peroxirredoxinas/metabolismo , Proteínas Proto-Oncogénicas B-raf/genética , Neoplasias de la Tiroides/metabolismo , Adenoma/genética , Adenoma/patología , Adulto , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Western Blotting , Carcinoma Papilar/genética , Carcinoma Papilar/secundario , Femenino , Humanos , Técnicas para Inmunoenzimas , Metástasis Linfática , Masculino , Persona de Mediana Edad , Peroxiredoxina VI/genética , Peroxirredoxinas/genética , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Glándula Tiroides/metabolismo , Glándula Tiroides/patología , Neoplasias de la Tiroides/genética , Neoplasias de la Tiroides/patología , Células Tumorales CultivadasRESUMEN
Circadian rhythms are highly conserved time tracking systems regulating important biological processes at both systemic and cellular levels. The present study was aimed to identify proteins and biological functions circadian regulated in human keratinocytes. HaCaT keratinocytes were entrained by temperature cycles, and a proteomic study was performed on cell fractions isolated under free running conditions at constant temperature. Bioinformatics analysis revealed that molecular clock entrainment was associated with changes in molecular components regulating cell proliferation, energy metabolism, transcription, translation and redox balance. Nuclear levels of the antioxidant enzyme Peroxiredoxin 2 (PRDX2) were found to oscillate rhythmically over two entire 24h long cycles. Donwregulation of PRDX2 resulted in upregulation of the mitochondrion-specific Peroxiredoxin 3 (PRDX3), all other members of the Peroxiredoxin family remained unaltered. Furthermore, PRDX2 knockdown increased intracellular levels of reactive oxygen species (ROS) and impaired cell cycle progression and proliferation. HaCaT cells transduced with a scramble shRNA were used as control. Our work is the first to show that nuclear levels of PRDX2 display circadian oscillation participating in the regulation of human keratinocytes redox balance.
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Puntos de Control del Ciclo Celular/genética , Proliferación Celular/genética , Relojes Circadianos/genética , Peroxirredoxinas/genética , Metabolismo Energético/genética , Regulación de la Expresión Génica , Humanos , Queratinocitos/metabolismo , Proteínas Nucleares/biosíntesis , Peroxirredoxinas/biosíntesis , Proteómica , Especies Reactivas de OxígenoRESUMEN
Smad4 is a key mediator of the transforming growth factor-ß (TGF-ß) superfamily that is involved in the control of cell proliferation and differentiation. We recently demonstrated that a Smad4 mutation, Smad4 C324Y, isolated from nodal metastases of papillary thyroid carcinoma, causes an increase of TGF-ß signaling, responsible for the acquisition of transformed phenotype and invasive behaviour in thyroid cells stably expressing this mutation. In this paper, we demonstrate that the stable expression of Smad4 C324Y mutation in FRTL-5 cells is responsible for TSH-independent growth ability. Our data show that the Smad4 C324Y mutation interacts with P-Smad3 more strongly than Smad4 wt, already in basal condition; this interaction is responsible for TGF-ß signaling and PKA activation that, in turn, determines an increased phosphorylation of CREB, necessary for the mitogenic actions of TSH. The expression of cyclin D1 also increases in all cells overexpressing the Smad4 C324Y mutation. All together, these data demonstrate that Smad4 C324Y mutation, interacting with the PKA pathway, gives cells the ability to proliferate independently from TSH.
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Carcinoma/genética , Mutación , Proteína Smad4/genética , Glándula Tiroides/citología , Neoplasias de la Tiroides/genética , Tirotropina/metabolismo , Carcinoma Papilar , Diferenciación Celular/genética , Línea Celular , Proliferación Celular , Transformación Celular Neoplásica/genética , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Ciclina D1/genética , Ciclina D1/metabolismo , Humanos , Fosforilación , Proteína smad3/genética , Proteína smad3/metabolismo , Proteína Smad4/metabolismo , Tiroglobulina/genética , Tiroglobulina/metabolismo , Cáncer Papilar Tiroideo , Glándula Tiroides/metabolismo , Factor de Crecimiento Transformador beta/metabolismoRESUMEN
Smad proteins are the key effectors of the transforming growth factor ß (TGFß) signaling pathway in mammalian cells. Smad4 plays an important role in human physiology, and its mutations were found with high frequency in wide range of human cancer. In this study, we have functionally characterized Smad4 C324Y mutation, isolated from a nodal metastasis of papillary thyroid carcinoma. We demonstrated that the stable expression of Smad4 C324Y in FRTL-5 cells caused a significant activation of TGFß signaling, responsible for the acquisition of transformed phenotype and invasive behavior. The coexpression of Smad4 C324Y with Smad4 wild-type determined an increase of homo-oligomerization of Smad4 with receptor-regulated Smads and a lengthening of nuclear localization. FRTL-5 clones overexpressing Smad4 C324Y showed a strong reduction of response to antiproliferative action of TGFß1, acquired the ability to grow in anchorage-independent conditions, showed a fibroblast-like appearance and a strong reduction of the level of E-cadherin, one crucial event of the epithelial-mesenchymal transition process. The acquisition of a mesenchymal phenotype gave the characteristics of increased cellular motility and a significant reduction in adhesion to substrates such as fibronectin and laminin. Overall, our results demonstrate that the Smad4 C324Y mutation plays an important role in thyroid carcinogenesis and can be considered as a new prognostic and therapeutic target for thyroid cancer.
Asunto(s)
Carcinoma/genética , Proteína Smad4/genética , Neoplasias de la Tiroides/genética , Factor de Crecimiento Transformador beta1/metabolismo , Carcinoma/metabolismo , Carcinoma/patología , Carcinoma Papilar , Adhesión Celular , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Progresión de la Enfermedad , Humanos , Mutación , Invasividad Neoplásica , Proteína Smad4/metabolismo , Cáncer Papilar Tiroideo , Neoplasias de la Tiroides/metabolismo , Neoplasias de la Tiroides/patologíaRESUMEN
Phosphoinositide-3-OH kinase (PI3K) signalling regulates various cellular processes, including cell survival, growth, proliferation and motility, and is among the most frequently mutated pathways in cancer. Although the involvement of p85αPI3K SH2 domain in signal transduction has been extensively studied, the function of the SH3 domain at the N-terminus remains elusive. A serine (at codon 83) adjacent to the N-terminal SH3 domain in the PI3K regulatory subunit p85αPI3K that is phosphorylated by protein kinase A (PKA) in vivo and in vitro has been identified. Virtually all receptors binding p85αPI3K can cooperate with cAMP-PKA signals via phosphorylation of p85αPI3KSer83. To analyse the role of p85αPI3KSer83 in retinoic acid (RA) and cAMP signalling, in MCF7 cells, we used p85αPI3K mutated forms, in which Ser83 has been substituted with alanine (p85A) to prevent phosphorylation or with aspartic acid (p85D) to mimic the phosphorylated residue. We demonstrated that p85αPI3KSer83 is crucial for the synergistic enhancement of RARα/p85αPI3K binding induced by cAMP/RA co-treatment in MCF7 cells. Growth curves, colorimetric MTT assay and cell cycle analysis demonstrated that phosphorylation of p85αPI3KSer83 plays an important role in the control of MCF7 cell proliferation and in RA-induced inhibition of proliferation. Wound healing and transwell experiments demonstrated that p85αPI3KSer83 was also essential both for the control of migratory behaviour and for the reduction of motility induced by RA. This study points to p85αPI3KSer83 as the physical link between different pathways (cAMP-PKA, RA and FAK), and as an important regulator of MCF7 cell proliferation and migration.