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1.
BMC Cancer ; 21(1): 207, 2021 Mar 01.
Article de Anglais | MEDLINE | ID: mdl-33648461

RÉSUMÉ

BACKGROUND: Colorectal cancer (CRC) is one of the most common cancers worldwide; it is the fourth leading cause of death in the world and the third in Brazil. Mutations in the APC, DCC, KRAS and TP53 genes have been associated with the progression of sporadic CRC, occurring at defined pathological stages of the tumor progression and consequently modulating several genes in the corresponding signaling pathways. Therefore, the identification of gene signatures that occur at each stage during the CRC progression is critical and can present an impact on the diagnosis and prognosis of the patient. In this study, our main goal was to determine these signatures, by evaluating the gene expression of paired colorectal adenoma and adenocarcinoma samples to identify novel genetic markers in association to the adenoma-adenocarcinoma stage transition. METHODS: Ten paired adenoma and adenocarcinoma colorectal samples were subjected to microarray gene expression analysis. In addition, mutations in APC, KRAS and TP53 genes were investigated by DNA sequencing in paired samples of adenoma, adenocarcinoma, normal tissue, and peripheral blood from ten patients. RESULTS: Gene expression analysis revealed a signature of 689 differentially expressed genes (DEG) (fold-change> 2, p< 0.05), between the adenoma and adenocarcinoma paired samples analyzed. Gene pathway analysis using the 689 DEG identified important cancer pathways such as remodeling of the extracellular matrix and epithelial-mesenchymal transition. Among these DEG, the ETV4 stood out as one of the most expressed in the adenocarcinoma samples, further confirmed in the adenocarcinoma set of samples from the TCGA database. Subsequent in vitro siRNA assays against ETV4 resulted in the decrease of cell proliferation, colony formation and cell migration in the HT29 and SW480 colorectal cell lines. DNA sequencing analysis revealed KRAS and TP53 gene pathogenic mutations, exclusively in the adenocarcinomas samples. CONCLUSION: Our study identified a set of genes with high potential to be used as biomarkers in CRC, with a special emphasis on the ETV4 gene, which demonstrated involvement in proliferation and migration.


Sujet(s)
Adénocarcinome/génétique , Adénomes/génétique , Tumeurs colorectales/génétique , Gènes tumoraux , Protéines tumorales/physiologie , Protéines proto-oncogènes c-ets/physiologie , Adénocarcinome/composition chimique , Adénocarcinome/anatomopathologie , Adénomes/composition chimique , Adénomes/anatomopathologie , Sujet âgé , Marqueurs biologiques tumoraux/génétique , Brésil , Division cellulaire/génétique , Lignée cellulaire tumorale , Mouvement cellulaire/génétique , Transformation cellulaire néoplasique/génétique , Tumeurs colorectales/composition chimique , Tumeurs colorectales/anatomopathologie , ADN tumoral/génétique , Évolution de la maladie , Femelle , Régulation de l'expression des gènes tumoraux , Gene Ontology , Humains , Mâle , Adulte d'âge moyen , Protéines tumorales/antagonistes et inhibiteurs , Protéines tumorales/génétique , Protéines proto-oncogènes c-ets/antagonistes et inhibiteurs , Protéines proto-oncogènes c-ets/génétique , Interférence par ARN , Petit ARN interférent/génétique , Petit ARN interférent/pharmacologie , Analyse sur puce à tissus , Transcriptome , Test clonogénique de cellules souches tumorales
2.
Front Oncol ; 9: 1100, 2019.
Article de Anglais | MEDLINE | ID: mdl-31788442

RÉSUMÉ

Head and neck squamous cell carcinoma (HNSCC) is among the most common cancer types. Metastasis, the main cause of death by cancer, can be promoted by an inflammatory microenvironment, which induces epithelial-mesenchymal transition (EMT) through a NF-κB-mediated stabilization of Snail. Here, we aimed to explore how microRNAs (miRs) can affect cell survival and EMT in HNSCC cells under an inflammatory microenvironment. By using a high-content screening (HCS) approach, we evaluated alterations in morphometric parameters, as well as expression/localization of Snail/Slug, in HNSCC cells primed with TNF-α. Based on those quantitation, we established the optimal experimental conditions of EMT induction driven by TNF-α. Those conditions were applied to cells transfected with distinct miRs (N = 31), followed by clusterization of miRs based on alterations related to cell survival and EMT. The signaling pathways enriched with molecular targets from each group of miRs were identified by in silico analyses. Finally, cells were transfected with siRNAs against signaling pathways targeted by miRs with anti-survival/EMT effect and evaluated for alterations in cell survival and EMT. Overall, we observed that TNF-α, at 20 ng/ml, induced EMT-related changes in cell morphology, Snail/Slug expression, and cell migration. Predicted targets of miRs with anti-survival/EMT effect were enriched with targets of NF-κB, PI3K/ATK, and Wnt/beta catenin pathways. Strikingly, individual gene silencing of elements from those pathways, namely RELA (NF-kB), AKT1 (PI3K/AKT), and CTNNB1 (Wnt/beta catenin) reduced cell survival and/or expression of Snail/Slug in cells stimulated with TNF-α. As a whole, our HCS approach allowed for the identification of miRs capable of inhibiting cell survival and EMT considering the presence of an inflammatory microenvironment, also indicating the common signaling pathways and molecular targets most likely to underlie those alterations. These findings may contribute to the development of targeted therapies against HNSCC.

3.
Stem Cell Res Ther ; 10(1): 202, 2019 07 08.
Article de Anglais | MEDLINE | ID: mdl-31287022

RÉSUMÉ

BACKGROUND: By post-transcriptionally regulating multiple target transcripts, microRNAs (miRNAs or miR) play important biological functions. H1 embryonic stem cells (hESCs) and NTera-2 embryonal carcinoma cells (ECCs) are two of the most widely used human pluripotent model cell lines, sharing several characteristics, including the expression of miRNAs associated to the pluripotent state or with differentiation. However, how each of these miRNAs functionally impacts the biological properties of these cells has not been systematically evaluated. METHODS: We investigated the effects of 31 miRNAs on NTera-2 and H1 hESCs, by transfecting miRNA mimics. Following 3-4 days of culture, cells were stained for the pluripotency marker OCT4 and the G2 cell-cycle marker Cyclin B1, and nuclei and cytoplasm were co-stained with Hoechst and Cell Mask Blue, respectively. By using automated quantitative fluorescence microscopy (i.e., high-content screening (HCS)), we obtained several morphological and marker intensity measurements, in both cell compartments, allowing the generation of a multiparametric miR-induced phenotypic profile describing changes related to proliferation, cell cycle, pluripotency, and differentiation. RESULTS: Despite the overall similarities between both cell types, some miRNAs elicited cell-specific effects, while some related miRNAs induced contrasting effects in the same cell. By identifying transcripts predicted to be commonly targeted by miRNAs inducing similar effects (profiles grouped by hierarchical clustering), we were able to uncover potentially modulated signaling pathways and biological processes, likely mediating the effects of the microRNAs on the distinct groups identified. Specifically, we show that miR-363 contributes to pluripotency maintenance, at least in part, by targeting NOTCH1 and PSEN1 and inhibiting Notch-induced differentiation, a mechanism that could be implicated in naïve and primed pluripotent states. CONCLUSIONS: We present the first multiparametric high-content microRNA functional screening in human pluripotent cells. Integration of this type of data with similar data obtained from siRNA screenings (using the same HCS assay) could provide a large-scale functional approach to identify and validate microRNA-mediated regulatory mechanisms controlling pluripotency and differentiation.


Sujet(s)
Différenciation cellulaire/génétique , Tests de criblage à haut débit , microARN/génétique , Cellules souches pluripotentes/métabolisme , Lignée cellulaire , Lignage cellulaire/génétique , Cycline B1/génétique , Régulation de l'expression des gènes au cours du développement/génétique , Humains , Facteur de transcription Oct-3/génétique , Petit ARN interférent/génétique , Transduction du signal/génétique
4.
Oncol Lett ; 14(6): 6485-6496, 2017 Dec.
Article de Anglais | MEDLINE | ID: mdl-29163685

RÉSUMÉ

Despite considerable advances in the understanding of thyroid gland biology, correctly diagnosing thyroid nodules and treating high-grade thyroid carcinoma remains challenging. Cancer/testis (CT) antigens have emerged as potential diagnostic tools as well as targets of potential cancer vaccinations. In the present study, a total of 117 patients who underwent surgical therapy for thyroid disease were available for analysis. The expression levels of melanoma-associated antigen (MAGE) A, MAGE-C1/CT7, cancer/testis antigen 1B (CTAG1B) and G antigen (GAGE) were analyzed by immunohistochemistry. None of the CT antigens were expressed in the normal thyroid or goiter. In papillary and follicular carcinoma, MAGE-A was present in 8.1% of cases, GAGE in 10.8% and CT/7MAGE-C1 and CTAG1B in 2.7% each. In medullary carcinoma, CT antigen expression was as follows: MAGE-A in 42.9% of patients; MAGE-C1/CT7 in 46.5%; GAGE in 92.9%; and CTAG1B in 3.6%. A statistically significant association was observed between the expression of G MAGE-C1/CT7 and patient gender as well as patient clinical stage (P=0.029 and 0.031, respectively). In poorly differentiated and anaplastic carcinoma cases, CT antigen expression was as follows: MAGE-A in 61.8% of cases; MAGE-C1 in 57.1%; GAGE in 66.7%; and CTAG1B in 14.4%. There was a statistically significant association between expression of GAGE and gender (P=0.043). However, there was no association between CT antigen expression and patient survival in any of the tumor entities analyzed. The current study identified a distinct expression pattern of CT antigens in malignant thyroid tumors indicating that CT antigens have the potential to outperform existing thyroid cancer biomarkers. The prevalence of CT antigens in high-grade carcinomas suggests that they serve an important biological role within malignant tumors.

5.
Sci Rep ; 7(1): 3627, 2017 06 15.
Article de Anglais | MEDLINE | ID: mdl-28620241

RÉSUMÉ

Regulatory T cells (Tregs) are essential regulators of immune tolerance. atRA and TGF-ß can inhibit the polarization of naïve T cells into inflammatory Th17 cells, favoring the generation of stable iTregs, however the regulatory mechanisms involved are not fully understood. In this context, the roles of individual microRNAs in Tregs are largely unexplored. Naïve T cells were immunomagnetically isolated from umbilical cord blood and activated with anti-human CD2/CD3/CD28 beads in the presence of IL-2 alone (CD4Med) or with the addition of TGF-ß and atRA (CD4TGF/atRA). As compared to CD4Med, the CD4TGF/atRA condition allowed the generation of highly suppressive CD4+CD25hiCD127-FOXP3hi iTregs. Microarray profiling allowed the identification of a set of microRNAs that are exclusively expressed upon TGF-ß/atRA treatment and that are predicted to target a set of transcripts concordantly downregulated. This set of predicted targets were enriched for central components of IL-6/JAK/STAT and AKT-mTOR signaling, whose inhibition is known to play important roles in the generation and function of regulatory lymphocytes. Finally, we show that mimics of exclusively expressed miRs (namely miR-1299 and miR-30a-5p) can reduce the levels of its target transcripts, IL6R and IL6ST (GP130), and increase the percentage of FoxP3+ cells among CD4+CD25+/hi cells.


Sujet(s)
microARN/génétique , Lymphocytes T régulateurs/immunologie , Lymphocytes T régulateurs/métabolisme , Cellules Th17/immunologie , Cellules Th17/métabolisme , Facteur de croissance transformant bêta/métabolisme , Marqueurs biologiques , Différenciation cellulaire/génétique , Différenciation cellulaire/immunologie , Cytokines/métabolisme , Sang foetal/cytologie , Analyse de profil d'expression de gènes , Humains , Séparation immunomagnétique , Immunophénotypage , Interférence par ARN , Transcription génétique , Transcriptome
6.
In Vitro Cell Dev Biol Anim ; 52(9): 920-934, 2016 Oct.
Article de Anglais | MEDLINE | ID: mdl-27251160

RÉSUMÉ

During the early thymus colonization, Notch signaling activation on hematopoietic progenitor cells (HPCs) drives proliferation and T cell commitment. Although these processes are driven by transcription factors such as HOXB4 and GATA3, there is no evidence that Notch directly regulates their transcription. To evaluate the role of NOTCH and TNF signaling in this process, human CD34+ HPCs were cocultured with OP9-DL1 cells, in the presence or absence of TNF. The use of a Notch signaling inhibitor and a protein synthesis inhibitor allowed us to distinguish primary effects, mediated by direct signaling downstream Notch and TNF, from secondary effects, mediated by de novo synthesized proteins. A low and physiologically relevant concentration of TNF promoted T lymphopoiesis in OP9-DL1 cocultures. TNF positively modulated the expression of both transcripts in a Notch-dependent manner; however, GATA3 induction was mediated by a direct mechanism, while HOXB4 induction was indirect. Induction of both transcripts was repressed by a GSK3ß inhibitor, indicating that activation of canonical Wnt signaling inhibits rather than induces their expression. Our study provides novel evidences of the mechanisms integrating Notch and TNF-alpha signaling in the transcriptional induction of GATA3 and HOXB4. This mechanism has direct implications in the control of self-renewal, proliferation, commitment, and T cell differentiation.


Sujet(s)
Facteur de transcription GATA-3/métabolisme , Protéines à homéodomaine/métabolisme , Lymphopoïèse , Récepteurs Notch/métabolisme , Transduction du signal , Lymphocytes T/métabolisme , Facteurs de transcription/métabolisme , Facteur de nécrose tumorale alpha/métabolisme , Animaux , Facteurs de transcription à motif basique hélice-boucle-hélice/génétique , Facteurs de transcription à motif basique hélice-boucle-hélice/métabolisme , Protéines du cycle cellulaire/génétique , Protéines du cycle cellulaire/métabolisme , Lignée cellulaire , Lignage cellulaire/génétique , Facteur de transcription GATA-3/génétique , Régulation de l'expression des gènes , Protéines à homéodomaine/génétique , Humains , Lymphopoïèse/génétique , Souris , Facteur de transcription NF-kappa B/métabolisme , Sous-unités de protéines/génétique , Sous-unités de protéines/métabolisme , Transduction du signal/génétique , Facteur de transcription HES-1/génétique , Facteur de transcription HES-1/métabolisme , Facteurs de transcription/génétique
7.
Cytotherapy ; 18(7): 846-59, 2016 07.
Article de Anglais | MEDLINE | ID: mdl-27260206

RÉSUMÉ

Multipotent mesenchymal stromal cells (MSC) are imbued with an immunosuppressive phenotype that extends to several immune system cells. In this study, we evaluated how distinct Toll-like receptor (TLR) agonists impact immunosuppressive properties of bone marrow (BM)-MSC and explored the potential mechanisms involved. We show that TLR4 stimulation by lipopolysaccharide (LPS) restricted the ability of MSC to suppress the proliferation of T lymphocytes, increasing the gene expression of interleukin (IL)-1ß and IL-6. In contrast, stimulation of TLR9 by DSP30 induced proliferation and the suppressive potential of BM-MSC, coinciding with reducing tumor necrosis factor (TNF)-α expression, increased expression of transforming growth factor (TGF)-ß1, increased percentages of BM-MSC double positive for the ectonucleotidases CD39+CD73+ and adenosine levels. Importantly, following simultaneous stimulation with LPS and DSP30, BM-MSC's ability to suppress T lymphocyte proliferation was comparable with that of non-stimulated BM-MSC levels. Moreover, stimulation of BM-MSC with LPS reduced significantly the gene expression levels, on co-cultured T lymphocyte, of IL-10 and interferon (IFN)γ, a cytokine with potential to enhance the immunosuppression mediated by MSC and ameliorate the clinical outcome of patients with graft-versus-host disease (GVHD). Altogether, our findings reiterate the harmful effects of LPS on MSC immunosuppression, besides indicating that DSP30 could provide a protective effect against LPS circulating in the blood of GVHD patients who receive BM-MSC infusions, ensuring a more predictable immunosuppressive effect. The novel effects and potential mechanisms following the stimulation of BM-MSC by DSP30 might impact their clinical use, by allowing the derivation of optimal "licensing" protocols for obtaining therapeutically efficient MSC.


Sujet(s)
Adénosine/pharmacologie , Immunosuppresseurs/pharmacologie , Lipopolysaccharides/pharmacologie , Cellules souches mésenchymateuses/cytologie , Antigènes CD/métabolisme , Prolifération cellulaire/effets des médicaments et des substances chimiques , Cellules cultivées , Techniques de coculture , Régulation de l'expression des gènes/effets des médicaments et des substances chimiques , Humains , Immunosuppression thérapeutique , Ligands , Activation des lymphocytes/effets des médicaments et des substances chimiques , Cellules souches mésenchymateuses/effets des médicaments et des substances chimiques , Cellules souches mésenchymateuses/métabolisme , Oligonucléotides/pharmacologie , Lymphocytes T/cytologie , Lymphocytes T/effets des médicaments et des substances chimiques , Lymphocytes T/immunologie , Récepteurs de type Toll/métabolisme
8.
Mem. Inst. Oswaldo Cruz ; 111(2): 101-105, Feb. 2016. tab
Article de Anglais | LILACS | ID: lil-772613

RÉSUMÉ

Natural resistance-associated macrophage protein 1/solute carrier family 11 member 1 gene (Nramp1/Slc11a1) is a gene that controls the susceptibility of inbred mice to intracellular pathogens. Polymorphisms in the human Slc11a1/Nramp1 gene have been associated with host susceptibility to leprosy. This study has evaluated nine polymorphisms of the Slc11a1/Nramp1 gene [(GT)n, 274C/T, 469+14G/C, 577-18G/A, 823C/T, 1029 C/T, 1465-85G/A, 1703G/A, and 1729+55del4] in 86 leprosy patients (67 and 19 patients had the multibacillary and the paucibacillary clinical forms of the disease, respectively), and 239 healthy controls matched by age, gender, and ethnicity. The frequency of allele 2 of the (GT)n polymorphism was higher in leprosy patients [p = 0.04, odds ratio (OR) = 1.49], whereas the frequency of allele 3 was higher in the control group (p = 0.03; OR = 0.66). Patients carrying the 274T allele (p = 0.04; OR = 1.49) and TT homozygosis (p = 0.02; OR = 2.46), such as the 469+14C allele (p = 0.03; OR = 1.53) of the 274C/T and 469+14G/C polymorphisms, respectively, were more frequent in the leprosy group. The leprosy and control groups had similar frequency of the 577-18G/A, 823C/T, 1029C/T, 1465-85G/A, 1703G/A, and 1729+55del4 polymorphisms. The 274C/T polymorphism in exon 3 and the 469+14G/C polymorphism in intron 4 were associated with susceptibility to leprosy, while the allele 2 and 3 of the (GT)n polymorphism in the promoter region were associated with susceptibility and protection to leprosy, respectively.


Sujet(s)
Adulte , Sujet âgé , Femelle , Humains , Mâle , Adulte d'âge moyen , Jeune adulte , Transporteurs de cations/génétique , Prédisposition génétique à une maladie/génétique , Lèpre/génétique , Polymorphisme génétique/génétique , Brésil , Études cas-témoins , Fréquence d'allèle , Modèles logistiques , Lèpre multibacillaire/génétique , Lèpre multibacillaire/microbiologie , Lèpre paucibacillaire/génétique , Lèpre paucibacillaire/microbiologie , Lèpre/microbiologie
9.
Mem Inst Oswaldo Cruz ; 111(2): 101-5, 2016 Feb.
Article de Anglais | MEDLINE | ID: mdl-26814595

RÉSUMÉ

Natural resistance-associated macrophage protein 1/solute carrier family 11 member 1 gene (Nramp1/Slc11a1) is a gene that controls the susceptibility of inbred mice to intracellular pathogens. Polymorphisms in the human Slc11a1/Nramp1 gene have been associated with host susceptibility to leprosy. This study has evaluated nine polymorphisms of the Slc11a1/Nramp1 gene [(GT)n, 274C/T, 469+14G/C, 577-18G/A, 823C/T, 1029 C/T, 1465-85G/A, 1703G/A, and 1729+55del4] in 86 leprosy patients (67 and 19 patients had the multibacillary and the paucibacillary clinical forms of the disease, respectively), and 239 healthy controls matched by age, gender, and ethnicity. The frequency of allele 2 of the (GT)n polymorphism was higher in leprosy patients [p = 0.04, odds ratio (OR) = 1.49], whereas the frequency of allele 3 was higher in the control group (p = 0.03; OR = 0.66). Patients carrying the 274T allele (p = 0.04; OR = 1.49) and TT homozygosis (p = 0.02; OR = 2.46), such as the 469+14C allele (p = 0.03; OR = 1.53) of the 274C/T and 469+14G/C polymorphisms, respectively, were more frequent in the leprosy group. The leprosy and control groups had similar frequency of the 577-18G/A, 823C/T, 1029C/T, 1465-85G/A, 1703G/A, and 1729+55del4 polymorphisms. The 274C/T polymorphism in exon 3 and the 469+14G/C polymorphism in intron 4 were associated with susceptibility to leprosy, while the allele 2 and 3 of the (GT)n polymorphism in the promoter region were associated with susceptibility and protection to leprosy, respectively.


Sujet(s)
Transporteurs de cations/génétique , Prédisposition génétique à une maladie/génétique , Lèpre/génétique , Polymorphisme génétique/génétique , Adulte , Sujet âgé , Brésil , Études cas-témoins , Femelle , Fréquence d'allèle , Humains , Lèpre/microbiologie , Lèpre multibacillaire/génétique , Lèpre multibacillaire/microbiologie , Lèpre paucibacillaire/génétique , Lèpre paucibacillaire/microbiologie , Modèles logistiques , Mâle , Adulte d'âge moyen , Jeune adulte
10.
Oncol Rep ; 33(4): 2017-22, 2015 Apr.
Article de Anglais | MEDLINE | ID: mdl-25633166

RÉSUMÉ

Larynx cancer is the second most common type of cancer among all head and neck cancers. Deregulation of epigenetic effectors, including altered expression of histone methyltransferases from the MLL (mixed lineage leukemia) family, have been reported in many cancer types, yet little is known concerning their involvement in larynx cancer. Our objective was to determine the expression profile of MLL genes in larynx carcinoma and normal adjacent tissues and correlate this profile to tumor characteristics. We analyzed the expression profile of 5 MLL genes in 13 cases of larynx carcinoma and their adjacent non-tumor tissues using quantitative real-time PCR. MLL3 was significantly downregulated in tumor samples compared to their normal counterparts, and all MLL genes showed decreased expression in advanced tumors compared to tumors in the initial stage. Altered expression in a single MLL gene was associated with a similar alteration in the other MLL genes, revealing a strong correlation of expression in each individual patient. In conclusion, MLL genes may have similar transcriptional control, and decreased expression of these genes may contribute to larynx cancer progression.


Sujet(s)
Carcinome épidermoïde/génétique , Régulation de l'expression des gènes tumoraux/génétique , Histone-lysine N-methyltransferase/génétique , Tumeurs du larynx/génétique , Methyltransferases/génétique , Protéine de la leucémie myéloïde-lymphoïde/génétique , Sujet âgé , Sujet âgé de 80 ans ou plus , Régulation négative/génétique , Épigenèse génétique/génétique , Femelle , Humains , Mâle , Adulte d'âge moyen , Transcription génétique/génétique
11.
Stem Cells ; 31(12): 2827-32, 2013 Dec.
Article de Anglais | MEDLINE | ID: mdl-24022994

RÉSUMÉ

Hotair is a member of the recently described class of noncoding RNAs called lincRNA (large intergenic noncoding RNA). Various studies suggest that Hotair acts regulating epigenetic states by recruiting chromatin-modifying complexes to specific target sequences that ultimately leads to suppression of several genes. Although Hotair has been associated with metastasis and poor prognosis in different tumor types, a deep characterization of its functions in cancer is still needed. Here, we investigated the role of Hotair in the scenario of epithelial-to-mesenchymal transition (EMT) and in the arising and maintenance of cancer stem cells (CSCs). We found that treatment with TGF-ß1 resulted in increased Hotair expression and triggered the EMT program. Interestingly, ablation of Hotair expression by siRNA prevented the EMT program stimulated by TGF-ß1, and also the colony-forming capacity of colon and breast cancer cells. Furthermore, we observed that the colon CSC subpopulation (CD133(+)/CD44(+)) presents much higher levels of Hotair when compared with the non-stem cell subpopulation. These results indicate that Hotair acts as a key regulator that controls the multiple signaling mechanisms involved in EMT. Altogether, our data suggest that the role of Hotair in tumorigenesis occurs through EMT triggering and stemness acquisition.


Sujet(s)
Transition épithélio-mésenchymateuse/génétique , Cellules souches tumorales/physiologie , ARN long non codant/génétique , Lignée cellulaire tumorale , Humains , Cellules souches tumorales/anatomopathologie , Transfection
12.
Head Neck ; 34(8): 1123-8, 2012 Aug.
Article de Anglais | MEDLINE | ID: mdl-22083937

RÉSUMÉ

BACKGROUND: Tumor markers are genes or their products expressed exclusively or preferentially in tumor cells and cancer-testis antigens (CTAs) form a group of genes with a typical expression pattern expressed in a variety of malignant neoplasms. CTAs are considered potential targets for cancer vaccines. It is possible that the CTA MAGE-A4 (melanoma antigen) and MAGE-C1 are expressed in carcinoma of the oral cavity and are related with survival. METHODS: This study involved immunohistochemical analysis of 23 patients with oral squamous cell carcinoma (SCC) and was carried out using antibodies for MAGE-A4 and MAGE-C1. Fisher's exact test and log-rank test were used to evaluate the results. RESULTS: The expression of the MAGE-A4 and MAGE-C1 were 56.5% and 47.8% without statistical difference in studied variables and survival. CONCLUSION: The expression of at least 1 CTA was present in 78.3% of the patients, however, without correlation with clinicopathologic variables and survival.


Sujet(s)
Antigènes néoplasiques/génétique , Carcinome épidermoïde/génétique , Tumeurs de la bouche/génétique , Protéines tumorales/génétique , Adulte , Sujet âgé , Consommation d'alcool/épidémiologie , Marqueurs biologiques tumoraux/génétique , Carcinome épidermoïde/immunologie , Carcinome épidermoïde/mortalité , Femelle , Humains , Immunohistochimie , Mâle , Adulte d'âge moyen , Tumeurs de la bouche/immunologie , Tumeurs de la bouche/mortalité , Fumer/épidémiologie
13.
J Orthop Sci ; 16(4): 458-66, 2011 Jul.
Article de Anglais | MEDLINE | ID: mdl-21691740

RÉSUMÉ

BACKGROUND: Osteosarcoma (OS) is the most frequent bone tumor in children and adolescents. Tumor antigens are encoded by genes that are expressed in many types of solid tumors but are silent in normal tissues, with the exception of placenta and male germ-line cells. It has been proposed that antigen tumors are potential tumor markers. OBJECTIVES: The premise of this study is that the identification of novel OS-associated transcripts will lead to a better understanding of the events involved in OS pathogenesis and biology. METHODS: We analyzed the expression of a panel of seven tumor antigens in OS samples to identify possible tumor markers. After selecting the tumor antigen expressed in most samples of the panel, gene expression profiling was used to identify osteosarcoma-associated molecular alterations. A microarray was employed because of its ability to accurately produce comprehensive expression profiles. RESULTS: PRAME was identified as the tumor antigen expressed in most OS samples; it was detected in 68% of the cases. Microarray results showed differences in expression for genes functioning in cell signaling and adhesion as well as extracellular matrix-related genes, implying that such tumors could indeed differ in regard to distinct patterns of tumorigenesis. CONCLUSIONS: The hypothesis inferred in this study was gathered mostly from available data concerning other kinds of tumors. There is circumstantial evidence that PRAME expression might be related to distinct patterns of tumorigenesis. Further investigation is needed to validate the differential expression of genes belonging to tumorigenesis-related pathways in PRAME-positive and PRAME-negative tumors.


Sujet(s)
Antigènes néoplasiques/génétique , Tumeurs osseuses/génétique , Analyse de profil d'expression de gènes , Ostéosarcome/génétique , Adolescent , Adulte , Enfant , Enfant d'âge préscolaire , Femelle , Humains , Mâle , Jeune adulte
14.
Nucleic Acids Res ; 39(14): 6056-68, 2011 Aug.
Article de Anglais | MEDLINE | ID: mdl-21493686

RÉSUMÉ

Although patterns of somatic alterations have been reported for tumor genomes, little is known on how they compare with alterations present in non-tumor genomes. A comparison of the two would be crucial to better characterize the genetic alterations driving tumorigenesis. We sequenced the genomes of a lymphoblastoid (HCC1954BL) and a breast tumor (HCC1954) cell line derived from the same patient and compared the somatic alterations present in both. The lymphoblastoid genome presents a comparable number and similar spectrum of nucleotide substitutions to that found in the tumor genome. However, a significant difference in the ratio of non-synonymous to synonymous substitutions was observed between both genomes (P = 0.031). Protein-protein interaction analysis revealed that mutations in the tumor genome preferentially affect hub-genes (P = 0.0017) and are co-selected to present synergistic functions (P < 0.0001). KEGG analysis showed that in the tumor genome most mutated genes were organized into signaling pathways related to tumorigenesis. No such organization or synergy was observed in the lymphoblastoid genome. Our results indicate that endogenous mutagens and replication errors can generate the overall number of mutations required to drive tumorigenesis and that it is the combination rather than the frequency of mutations that is crucial to complete tumorigenic transformation.


Sujet(s)
Tumeurs du sein/génétique , Variation génétique , Génome humain , Lignée de cellules transformées , Lignée cellulaire tumorale , Aberrations des chromosomes , Femelle , Humains , Lymphocytes , Adulte d'âge moyen , Mutation , Mutation ponctuelle , Cartographie d'interactions entre protéines , Analyse de séquence d'ADN
15.
J Virol Methods ; 173(1): 92-8, 2011 Apr.
Article de Anglais | MEDLINE | ID: mdl-21277903

RÉSUMÉ

Since the discovery of RNAi technology, several functional genomic and disease therapy studies have been conducted using this technique in the field of oncology and virology. RNAi-based antiviral therapies are being studied for the treatment of retroviruses such as HIV-1. These studies include the silencing of regulatory, infectivity and structural genes. The HTLV-1 structural genes are responsible for the synthesis of proteins involved in the entry, assembly and release of particles during viral infection. To examine the possibility of silencing HTLV-1 genes gag and env by RNA interference technology, these genes were cloned into reporter plasmids. These vectors expressed the target mRNAs fused to EGFP reporter genes. Three small interference RNAs (siRNAs) corresponding to gag and three corresponding to env were designed to analyze the effect of silencing by RNAi technology. The plasmids and siRNAs were co-transfected into HEK 293 cells. The results demonstrated that the expression of the HTLV-1 gag and env genes decreased significantly in vitro. Thus, siRNAs can be used to inhibit HTLV-1 structural genes in transformed cells, which could provide a tool for clarifying the roles of HTLV-1 structural genes, as well as a therapy for this infection.


Sujet(s)
Produits du gène env/antagonistes et inhibiteurs , Produits du gène gag/antagonistes et inhibiteurs , Extinction de l'expression des gènes , Virus T-lymphotrope humain de type 1/génétique , Petit ARN interférent/génétique , Fusion artificielle de gènes , Produits du gène env/génétique , Produits du gène gag/génétique , Gènes rapporteurs , Protéines à fluorescence verte/génétique , Protéines à fluorescence verte/métabolisme , Cellules HEK293 , Humains
16.
Head Neck ; 33(10): 1426-32, 2011 Oct.
Article de Anglais | MEDLINE | ID: mdl-21246638

RÉSUMÉ

BACKGROUND: A subset of thyroid tumors characterized by a follicular growth pattern can represent a serious diagnosis. Immunohistochemistry and molecular pathology for genetic profiling have been used in an attempt to resolve some of these issues. METHODS: Tumor tissue samples of thyroid were obtained from 70 patients who underwent surgical therapy. They were divided into 4 groups: 20 adenomatous goiters, 10 follicular adenomas, 24 papillary carcinomas, and 16 follicular carcinomas. Immunohistochemical analysis was carried out using antibodies for MAGE-A4 (melanoma antigen-encoding gene A4) and MAGE-C1 (melanoma antigen-encoding gene C1). RESULTS: Standard histologic analysis and immunohistochemistry analysis of MAGE-A4 and MAGE-C1 expression were performed in all patients. The antigens examined were not expressed in any of the tissues. CONCLUSIONS: The malignant degeneration of normal tissues is a multifactorial process, varying considerably both among tumor types and among individual patients. The present study showed that there was no immunolabeling of the MAGE-A4 and MAGE-C1 antigens.


Sujet(s)
Antigènes néoplasiques/métabolisme , Goitre/métabolisme , Protéines tumorales/immunologie , Tumeurs de la thyroïde/métabolisme , Adénocarcinome folliculaire/métabolisme , Adénocarcinome folliculaire/chirurgie , Adénomes/métabolisme , Adénomes/chirurgie , Adolescent , Adulte , Antigènes néoplasiques/immunologie , Carcinome papillaire/métabolisme , Carcinome papillaire/chirurgie , Femelle , Goitre/chirurgie , Humains , Immunohistochimie , Mâle , Adulte d'âge moyen , Tumeurs de la thyroïde/chirurgie
17.
Anticancer Res ; 30(12): 5023-7, 2010 Dec.
Article de Anglais | MEDLINE | ID: mdl-21187485

RÉSUMÉ

BACKGROUND/AIMS: The expression of cancer/testis antigens (CTAs) on additional normal tissues or stem cells may restrict their use as cancer targets. The objective of the present study was to evaluate the mRNA levels of some CTAs in a variety of tissues. MATERIALS AND METHODS: mRNA of pericytes, fibroblasts and mesenchymal stem cells (MSCs) derived from adult and fetal tissues, human umbilical vein endothelial cells, MSC-derived adipocytes, selected normal tissues and control cancer cell lines (CLs) were extracted and quantitative polymerase chain reaction was performed for MAGED1, PRAME, CTAG1B, MAGEA3 and MAGEA4. RESULTS: MAGED1 was expressed in all normal tissues and cells evaluated. CTAG1B was expressed at levels comparable to control CLs on MSCs derived from arterial, fetal skin, adipose tissue and saphenous vein, heart, brain and skin tissues. MAGEA4 was detected only in fibroblasts and differentiated adipocytes from MSCs, at levels comparable to the control CLs. CONCLUSION: The potential use of CTAs in immunotherapy should take into account the potential off-target effects on MSCs.


Sujet(s)
Antigènes néoplasiques/biosynthèse , Cellules souches mésenchymateuses/immunologie , Fibroblastes/immunologie , Humains , Immunophénotypage , Antigènes spécifiques du mélanome , Protéines membranaires/biosynthèse , Protéines tumorales/biosynthèse , Péricytes/immunologie
18.
Am J Hum Biol ; 22(6): 849-52, 2010.
Article de Anglais | MEDLINE | ID: mdl-20865761

RÉSUMÉ

OBJECTIVES: In this study, we aimed to identify ancestry informative haplotypes and make interethnic admixture estimates using X-chromosome markers. METHODS: A significant sample (461 individuals) of European, African, and Native American populations was analyzed, and four linkage groups were identified. The data obtained were used to describe the ancestral contribution of populations from four different geographical regions of Brazil (745 individuals). RESULTS: The global interethnic admixture estimates of the four mixed populations under investigation were calculated applying all the 24 insertion/deletion (INDEL) markers. In the North region, a larger Native Americans ancestry was observed (42%). The Northeast and Southeast regions had smaller Native American contribution (27% in both of them). In the South region, there was a large European contribution (46%). CONCLUSIONS: The estimates obtained are compatible with expectations for a colonization model with biased admixture between European men (one X chromosome) and Native American and African women (two X chromosomes), so the 24 X-INDEL panel described here can be a useful to make admixture interethnic estimates in Brazilian populations.


Sujet(s)
Chromosomes X humains/génétique , Mutation de type INDEL , 38409 , Brésil/épidémiologie , Femelle , Flux des gènes , Fréquence d'allèle , Marqueurs génétiques , Haplotypes , Humains , Mâle
19.
Leuk Lymphoma ; 51(8): 1543-9, 2010 Aug.
Article de Anglais | MEDLINE | ID: mdl-20528248

RÉSUMÉ

Considering that the importance of cancer/testis (CT) antigens in multiple myeloma (MM) biology is still under investigation, the present study aimed to: (1) identify genes differentially expressed in MM using microarray analysis of plasma cell samples, separated according to the number of expressed CTs; (2) examine possible pathways related to MM pathogenesis; (3) validate the expression of candidate genes by quantitative real-time PCR (RQ-PCR). Three samples predominantly positive (>6 expressed), including the U266 cell line, and three samples predominantly negative (0 or 1 expressed CT for the 13 analyzed CT antigens), were submitted for microarray analysis. Validation by RQ-PCR from 24 MM samples showed that the ITGA5 gene was downregulated in predominantly positive (>6 expressed CTs, p = 0.0030) and in tumor versus normal plasma cells (p = 0.0182). The RhoD gene was overexpressed in tumor plasma cells when compared to normal plasma cells (p = 0.0339). Results of the microarray analysis corroborate the hypothesis that MM could be separated into predominantly positive and predominantly negative expression. The differential expression of ITGA5 and RhoD suggests disruption of the focal adhesion pathway in MM and offers a new target field to be explored in this disease.


Sujet(s)
Antigènes néoplasiques/génétique , Marqueurs biologiques tumoraux/génétique , Contacts focaux/physiologie , Myélome multiple/génétique , Transduction du signal , Testicule/immunologie , Adulte , Sujet âgé , Sujet âgé de 80 ans ou plus , Antigènes néoplasiques/métabolisme , Marqueurs biologiques tumoraux/métabolisme , Femelle , Analyse de profil d'expression de gènes , Humains , Intégrine alpha5/génétique , Intégrine alpha5/métabolisme , Mâle , Adulte d'âge moyen , Myélome multiple/métabolisme , Myélome multiple/thérapie , Séquençage par oligonucléotides en batterie , Plasmocytes/métabolisme , Plasmocytes/anatomopathologie , Pronostic , ARN messager/génétique , RT-PCR , Protéines G rho/génétique , Protéines G rho/métabolisme
20.
J Orthop Res ; 28(9): 1142-8, 2010 Sep.
Article de Anglais | MEDLINE | ID: mdl-20225287

RÉSUMÉ

Bone deposition and bone resorption are ongoing dynamic processes, constituting bone remodeling. Some bone tumors, such as osteosarcoma (OS), stimulate focal bone deposition. OS is the most common primary bone tumor in children and young adults. A complex network of genes regulates bone remodeling and alterations in its expression levels can influence the genesis and progression of bone diseases, including OS. We hypothesized that the expression profiles of bone remodeling regulator genes would be correlated with OS biology and clinical features. We used real-time PCR to evaluate the mRNA levels of the tartrate-resistant acid phosphatase (ACP5), colony stimulating factor-1 (CSF1R), bone morphogenetic protein 7 (BMP7), collagen, type XI, alpha 2 (COL11A2), and protein tyrosine phosphatases zeta 1 (PTPRZ1) genes, in 30 OS tumor samples and correlated with clinical and histological data. All genes analyzed, except CSF1R, were differentially expressed when compared with normal bone expression profiles. In our results, OS patients with high levels of COL11A2 mRNA showed worse overall (p = 0.041) and event free survival (p = 0.037). Also, a trend for better overall survival was observed in patients with samples showing higher expression of BMP7 (p = 0.067). COL11A2 overexpression and BMP7 underexpression could collaborate to OS tumor growth, through its central role in bone remodeling process.


Sujet(s)
Tumeurs osseuses , Résorption osseuse , Calcification physiologique/génétique , Régulation de l'expression des gènes tumoraux , Ostéosarcome , Acid phosphatase/génétique , Adolescent , Biopsie , Protéine morphogénétique osseuse de type 7/génétique , Tumeurs osseuses/génétique , Tumeurs osseuses/mortalité , Tumeurs osseuses/anatomopathologie , Résorption osseuse/génétique , Résorption osseuse/mortalité , Résorption osseuse/anatomopathologie , Enfant , Collagène de type XI/génétique , Évolution de la maladie , Femelle , Humains , Isoenzymes/génétique , Mâle , Ostéosarcome/génétique , Ostéosarcome/mortalité , Ostéosarcome/anatomopathologie , ARN messager/métabolisme , Récepteur du facteur de stimulation des colonies de macrophages/génétique , Receptor-Like Protein Tyrosine Phosphatases, Class 5/génétique , Analyse de survie , Tartrate-resistant acid phosphatase , Jeune adulte
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