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1.
Actas Urol Esp (Engl Ed) ; 46(10): 600-605, 2022 12.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-36216763

RESUMO

INTRODUCTION: Papillary renal cell neoplasm with reverse polarity (PRNRP) has recently been recognized as an entity separate from the traditional classification of papillary renal cell carcinomas, due to its specific histopathological, immunophenotypic and molecular characteristics, as well as its indolent behavior. MATERIAL AND METHODS: We provide 6 new cases and a review of the literature published until the present time, which comprises a total number of 104 cases. RESULTS: Our PRNRP cases correspond to 5 men and one woman aged between 47 and 91 years. In 5 of the 6 cases, the PRNRP was an incidental finding in nephrectomy specimens. Nephrectomy had been indicated due to the presence of another renal tumor, except for one case, in which surgical intervention was indicated due to PRNRP. Our cases present mass sizes between 2 and 13 mm, as well as papillary histology with a monolayered lining of eosinophilic cells with low-grade nuclei in apical location. Immunohistochemically, they show a constant positivity for GATA3 and negativity for vimentin. KRAS mutations were identified in 50% of our cases. After a follow-up ranging between one and 60 months, 5 of the cases were still alive without recurrences or metastases, and one died from urothelial carcinoma. CONCLUSIONS: Our cases agree with the clinical and pathological characteristics described in the PRNRP cases published to date. With the present study, we provide the first series of national cases corroborating the existence of well-defined and constant diagnostic criteria that allow PRNRP to be considered as a distinctive entity.


Assuntos
Carcinoma de Células de Transição , Neoplasias Renais , Neoplasias da Bexiga Urinária , Humanos , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais
2.
Actas Urol Esp ; 41(9): 577-583, 2017 Nov.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-28461097

RESUMO

OBJECTIVES: The incidental presence of seminal vesicle epithelium in prostate needle biopsies is generally recognisable through routine microscopy. However, the biopsy can sometimes be erroneously interpreted as malignant due to its architectural and cytological characteristics, and immunohistochemistry can be useful for correctly identifying the biopsy. Our objective was to analyse the potential usefulness of GATA-3 as a marker of seminal epithelium. MATERIAL AND METHODS: Through immunohistochemistry with a monoclonal anti-GATA-3 antibody (clone L50-823), we studied seminal vesicle sections from 20 prostatectomy specimens, 12 prostate needle biopsies that contained seminal vesicle tissue and 68 prostate biopsies without seminal vesicle epithelium, 36 of which showed adenocarcinoma. RESULTS: Staining for GATA-3 was intense in the 20 seminal vesicles of the prostatectomy specimens and in the 12 prostate needle biopsies that contained seminal epithelium. In the 60 biopsies without a seminal vesicle, GATA-3 was positive in the prostate basal cells and even in the secretory cells (57 cases), although with less intensity in 55 of the cases. One of the 36 prostatic adenocarcinomas tested positive for GATA-3. CONCLUSIONS: The intense immunohistochemical expression of GATA-3 in the seminal vesicle epithelium can help identify the epithelium in prostate biopsies. This marker is also positive in the basal cells of healthy prostates and, with less intensity, in the secretory cells. Positivity, weak or moderate, is observed on rare occasions in prostatic adenocarcinomas.


Assuntos
Biomarcadores Tumorais/análise , Fator de Transcrição GATA3/análise , Próstata/patologia , Glândulas Seminais/química , Glândulas Seminais/patologia , Biópsia por Agulha , Epitélio/química , Epitélio/patologia , Humanos , Imuno-Histoquímica , Masculino
3.
Actas Urol Esp ; 37(6): 338-41, 2013 Jun.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-23058995

RESUMO

OBJECTIVES: To evaluate interobserver reproducibility of a grading system proposed by Paner et al. for chromophobe renal cell carcinoma. MATERIAL AND METHODS: After selecting 23 cases of chromophobe renal cell carcinoma from the Xeral-Cíes Hospital, Meixoeiro Hospital and POVISA Hospital from the last 15 years, an informative meeting on the Paner et al. grading system criteria was held. After, the participating pathologists applied the system to each case, evaluating one slide selected. Kappa index for interobserver reproducibility was calculated, and it was classified according to the Landis and Koch scale. RESULTS: The grading distribution was similar for most of the 6 participating observers, with grade 1 predominance. The remaining 2 observers considered a relatively higher proportion of grade 2. Kappa index values ranged from 0.136 to 0.674, with a discrete-moderate reproducibility index predominance (0.21-0.60). Highest Kappa value (0.674) was obtained between the most novel and the most expert interobservers. The lowest Kappa value was obtained among the most veteran pathologists (0.136). CONCLUSIONS: Interobserver reproducibility for chromophobe renal cell carcinoma is discrete-moderate in our institutions when the novel grade proposed by Paner et al. is used. Labeling of grades 1 and 2 is not homogeneous among 6 participating observers. While awaiting a grading consensus on a new classification by the scientific societies, we consider that the routine use of a grading system for chromophobe renal cell carcinoma should not be used.


Assuntos
Carcinoma de Células Renais/patologia , Neoplasias Renais/patologia , Gradação de Tumores/métodos , Variações Dependentes do Observador , Carcinoma de Células Renais/classificação , Carcinoma de Células Renais/ultraestrutura , Nucléolo Celular/ultraestrutura , Núcleo Celular/ultraestrutura , Cromatina/ultraestrutura , Humanos , Neoplasias Renais/classificação , Neoplasias Renais/ultraestrutura , Reprodutibilidade dos Testes , Estudos Retrospectivos , Coloração e Rotulagem
4.
Genet Mol Res ; 11(1): 332-9, 2012 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-22370935

RESUMO

The gene XRCC3 (X-ray cross complementing group 3) has the task of repairing damage that occurs when there is recombination between homologous chromosomes. Repair of recombination between homologous chromosomes plays an important role in maintaining genome integrity, although it is known that double-strand breaks are the main inducers of chromosomal aberrations. Changes in the XRCC3 protein lead to an increase in errors in chromosome segregation due to defects in centrosomes, resulting in aneuploidy and other chromosomal aberrations, such as small increases in telomeres. We examined XRCC3 Thr241Met polymorphism using PCR-RFLP in 80 astrocytoma and glioblastoma samples. The individuals of the control group (N = 100) were selected from the general population of the São Paulo State. Odds ratio and 95%CI were calculated using a logistic regression model. Patients who had the allele Met of the XRCC3 Thr241Met polymorphism had a significantly increased risk of tumor development (odds ratio = 3.13; 95% confidence interval = 1.50-6.50). There were no significant differences in overall survival of patients. We suggest that XRCC3 Thr241Met polymorphism is involved in susceptibility for developing astrocytomas and glioblastomas.


Assuntos
Astrocitoma/genética , Proteínas de Ligação a DNA/genética , Glioblastoma/genética , Adolescente , Adulto , Idoso , Alelos , Centrossomo/patologia , Criança , Pré-Escolar , Aberrações Cromossômicas , Segregação de Cromossomos/genética , Reparo do DNA , Feminino , Predisposição Genética para Doença , Variação Genética , Genótipo , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Adulto Jovem
5.
Genet Mol Res ; 10(2): 1120-9, 2011 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-21710464

RESUMO

XRCC genes (X-ray cross-complementing group) were discovered mainly for their roles in protecting mammalian cells against damage caused by ionizing radiation. Studies determined that these genes are important in the genetic stability of DNA. Although the loss of some of these genes does not necessarily confer high levels of sensitivity to radiation, they have been found to represent important components of various pathways of DNA repair. To ensure the integrity of the genome, a complex system of DNA repair was developed. Base excision repair is the first defense mechanism of cells against DNA damage and a major event in preventing mutagenesis. Repair genes may play an important role in maintaining genomic stability through different pathways that are mediated by base excision. In the present study, we examined XRCC1Arg194Trp and XRCC1Arg399Gln polymorphism using PCR-RFLP in 80 astrocytoma and glioblastoma samples. Patients who had the allele Trp of the XRCC1Arg194Trp polymorphism had an increased risk of tumor development (OR = 8.80; confidence interval at 95% (95%CI) = 4.37-17.70; P < 0.001), as did the allele Gln of XRCC1Arg399Gln (OR = 1.01; 95%CI = 0.53-1.93; P = 0.971). Comparison of overall survival of patients did not show significant differences. We suggest that XRCC1Arg194Trp and XRCC1Arg399Gln polymorphisms are involved in susceptibility for developing astrocytomas and glioblastomas.


Assuntos
Neoplasias Encefálicas/genética , Proteínas de Ligação a DNA/genética , Glioma/genética , Arginina/química , Primers do DNA , Proteínas de Ligação a DNA/química , Glicina/química , Humanos , Reação em Cadeia da Polimerase , Polimorfismo de Nucleotídeo Único , Triptofano/química , Proteína 1 Complementadora Cruzada de Reparo de Raio-X
6.
Genet Mol Res ; 9(4): 2328-34, 2010 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-21128213

RESUMO

Glutathione S-transferases (GSTs) constitute a superfamily of ubiquitous multifunctional enzymes that are involved in the cellular detoxification of a large number of endogenous and exogenous chemical agents that have electrophilic functional groups. People who have deficiencies in this family of genes are at increased risk of developing some types of tumors. We examined GSTP1 Ile105Val polymorphism using PCR-RFLP in 80 astrocytoma and glioblastoma samples. Patients who had the Val allele of the GSTP1 Ile105Val polymorphism had an increased risk of tumor development (odds ratio = 8.60; 95% confidence interval = 4.74-17.87; P < 0.001). Overall survival of patients did not differ significantly. We suggest that GSTP1 Ile105Val polymorphisms are involved in susceptibility to developing astrocytomas and glioblastomas.


Assuntos
Astrocitoma/genética , Neoplasias Encefálicas/genética , Glioblastoma/genética , Glutationa Transferase/genética , Isoleucina/genética , Polimorfismo de Nucleotídeo Único , Valina/genética , Adolescente , Adulto , Idoso , Astrocitoma/enzimologia , Sequência de Bases , Neoplasias Encefálicas/enzimologia , Estudos de Casos e Controles , Primers do DNA , Feminino , Glioblastoma/enzimologia , Glutationa Transferase/química , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Adulto Jovem
7.
Actas Dermosifiliogr ; 101(4): 349-53, 2010 May.
Artigo em Espanhol | MEDLINE | ID: mdl-20487691

RESUMO

Epidermal inclusion cysts are very common lesions that very rarely undergo malignant transformation-in the English-language literature we have only found 18 adequately documented cases. We present the case of a man with a 2-month history of a retroauricular skin lesion in which histological study revealed squamous cell carcinoma arising on an epidermal inclusion cyst. Cysts that grow rapidly, reach a large size, ulcerate, develop a fistula, or that do not respond to medical treatment, and those that recur should be excised completely and histological study performed of the whole lesion.


Assuntos
Carcinoma de Células Escamosas/patologia , Cisto Epidérmico/patologia , Lesões Pré-Cancerosas , Dermatopatias/patologia , Neoplasias Cutâneas/patologia , Idoso , Humanos , Masculino
8.
Genet Mol Res ; 8(4): 1257-63, 2009 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-19876867

RESUMO

Disruption or loss of tumor suppressor gene TP53 is implicated in the development or progression of almost all different types of human malignancies. Other members of the p53 family have been identified. One member, p73, not only shares a high degree of similarity with p53 in its primary sequence, but also has similar functions. Like p53, p73 can bind to DNA and activate transcription. Using PCR-SSCP and gene sequencing, we analyzed the TP53 and TP73 genes in a case of a grade III anaplastic astrocytoma that progressed to glioblastoma. We found a deletion of AAG at position 595-597 of TP53 (exon 6), resulting in the deletion of Glu 199 in the protein and a genomic polymorphism of TP73, identified as an A-to-G change, at position E8/+15 at intron 8 (IVS8-15A>G). The mutation found at exon 6 of the gene TP53 could be associated with the rapid tumoral progression found in this case, since the mutated p53 may inactivate the wild-type p53 and the p73alpha protein, which was conserved here, leading to an increase in cellular instability.


Assuntos
Astrocitoma/genética , Neoplasias Encefálicas/genética , Proteínas de Ligação a DNA/genética , Proteínas Nucleares/genética , Proteína Supressora de Tumor p53/genética , Proteínas Supressoras de Tumor/genética , Adulto , Sequência de Bases , Primers do DNA , Humanos , Masculino , Reação em Cadeia da Polimerase , Polimorfismo Conformacional de Fita Simples , Proteína Tumoral p73
9.
Genet Mol Res ; 8(1): 8-18, 2009 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-19224462

RESUMO

The p53 tumor suppressor gene is the most frequently mutated gene in human cancer; this gene is mutated in up to 50% of human tumors. It has a critical role in the cell cycle, apoptosis and cell senescence, and it participates in many crucial physiological and pathological processes. Polymorphisms of p53 have been suggested to be associated with genetically determined susceptibility in various types of cancer. Another process involved with the development and progression of tumors is DNA hypermethylation. Aberrant methylation of the promoter is an alternative epigenetic change in genetic mechanisms, leading to tumor suppressor gene inactivation. In the present study, we examined the TP53 Arg72Pro and Pro47Ser polymorphisms using PCR-RFLP and the pattern of methylation of the p53 gene by methylation-specific PCR in 90 extra-axial brain tumor samples. Patients who had the allele Pro of the TP53 Arg72Pro polymorphism had an increased risk of tumor development (odds ratio, OR = 3.23; confidence interval at 95%, 95%CI = 1.71-6.08; P = 0.003), as did the allele Ser of TP53 Pro47Ser polymorphism (OR = 1.28; 95%CI = 0.03-2.10; P = 0.01). Comparison of overall survival of patients did not show significant differences. In the analysis of DNA methylation, we observed that 37.5% of meningiomas, 30% of schwannomas and 52.6% of metastases were hypermethylated, suggesting that methylation is important for tumor progression. We suggest that TP53 Pro47Ser and Arg72Pro polymorphisms and DNA hypermethylation are involved in susceptibility for developing extra-axial brain tumors.


Assuntos
Neoplasias Encefálicas/genética , Metilação de DNA/genética , Genes p53/genética , Meningioma/genética , Estudos de Casos e Controles , Códon , Predisposição Genética para Doença , Humanos , Neurilemoma/genética , Reação em Cadeia da Polimerase , Polimorfismo Genético
10.
Biocell ; 32(3): 237-243, Dec. 2008. ilus, tab
Artigo em Inglês | LILACS | ID: lil-541105

RESUMO

Gastric cancer is one of the most common malignancies. DNA methylation is implicated in DNA mismatch repair genes deficiency. In the present study, we evaluated the methylation status of MLH1, MSH2, MSH6 and PMS2 in 20 diffuse- and 26 intestinal-type gastric cancer samples and 20 normal gastric mucosal of gastric cancer patients from Northern Brazil. We found that none of the nonneoplastic samples showed methylation of any gene promoter and 50% of gastric cancer samples showed at least one methylated gene promoter. Methylation frequencies of MLH1, MSH2, MSH6 and PMS2 promoter were 21.74%, 17.39%, 0% and 28.26% respectively in gastric cancer samples. MLH1 and PMS2 methylation were associated with neoplastic samples compared to nonneoplastic ones. PMS2 methylation was associated with diffuse- and intestinal-type cancer compared with normal controls. Intestinal-type cancer showed significant association with MLH1 methylation. Diffuse-type cancer was significantly associated with MSH2 methylation. Our findings show differential gene methylation in tumoral tissue, which allows us to conclude that methylation is associated with gastric carcinogenesis. Methylation of mismatch repair genes was associated with gastric carcinogenesis and may be a helpful tool for diagnosis, prognosis and therapies. However, MSH6 does not seem to be regulated by methylation in our samples.


Assuntos
Humanos , Masculino , Adulto , Feminino , Pessoa de Meia-Idade , Metilação de DNA , Neoplasias Gástricas/genética , Reparo de Erro de Pareamento de DNA , Análise de Sequência de DNA , Brasil , Enzimas Reparadoras do DNA/genética , Regiões Promotoras Genéticas
11.
Braz J Med Biol Res ; 41(6): 539-43, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18622497

RESUMO

Gastric cancer is the forth most frequent malignancy and the second most common cause of cancer death worldwide. DNA methylation is the most studied epigenetic alteration, occurring through a methyl radical addition to the cytosine base adjacent to guanine. Many tumor genes are inactivated by DNA methylation in gastric cancer. We evaluated the DNA methylation status of ANAPC1, CDKN2A and TP53 by methylation-specific PCR in 20 diffuse- and 26 intestinal-type gastric cancer samples and 20 normal gastric mucosa in individuals from Northern Brazil. All gastric cancer samples were advanced stage adenocarcinomas. Gastric samples were surgically obtained at the João de Barros Barreto University Hospital, State of Pará, and were stored at -80 degrees C before DNA extraction. Patients had never been submitted to chemotherapy or radiotherapy, nor did they have any other diagnosed cancer. None of the gastric cancer samples presented methylated DNA sequences for ANAPC1 and TP53. CDKN2A methylation was not detected in any normal gastric mucosa; however, the CDKN2A promoter was methylated in 30.4% of gastric cancer samples, with 35% methylation in diffuse-type and 26.9% in intestinal-type cancers. CDKN2A methylation was associated with the carcinogenesis process for ~30% diffuse-type and intestinal-type compared to non-neoplastic samples. Thus, ANAPC1 and TP53 methylation was probably not implicated in gastric carcinogenesis in our samples. CDKN2A can be implicated in the carcinogenesis process of only a subset of gastric neoplasias.


Assuntos
Adenocarcinoma/genética , Metilação de DNA/genética , Genes p16 , Genes p53 , Neoplasias Gástricas/genética , Complexos Ubiquitina-Proteína Ligase/metabolismo , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Adulto , Idoso , Ciclossomo-Complexo Promotor de Anáfase , Subunidade Apc1 do Ciclossomo-Complexo Promotor de Anáfase , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Regiões Promotoras Genéticas/genética , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia
12.
Genet Mol Res ; 7(2): 451-9, 2008 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-18551412

RESUMO

Cancer is one of the most common and severe problems in clinical medicine, and nervous system tumors represent about 2% of the types of cancer. The central role of the nervous system in the maintenance of vital activities and the functional consequences of the loss of neurons can explain how severe brain cancers are. The cell cycle is a highly complex process, with a wide number of regulatory proteins involved, and such proteins can suffer alterations that transform normal cells into malignant ones. The INK4 family members (CDK inhibitors) are the cell cycle regulators that block the progression of the cycle through the R point, causing an arrest in G1 stage. The p14ARF (alternative reading frame) gene is a tumor suppressor that inhibits p53 degradation during the progression of the cell cycle. The PTEN gene is related to the induction of growth suppression through cell cycle arrest, to apoptosis and to the inhibition of cell adhesion and migration. The purpose of the present study was to assess the mutational state of the genes p14ARF, p15INK4b, p16INK4a, and PTEN in 64 human nervous system tumor samples. Homozygous deletions were found in exon 2 of the p15INK4b gene and exon 3 of the p16INK4a gene in two schwannomas. Three samples showed a guanine deletion (63 codon) which led to a loss of heterozygosity in the p15 gene, and no alterations could be seen in the PTEN gene. Although the group of patients was heterogeneous, our results are in accordance with other different studies that indicate that homozygous deletion and loss of heterozygosity in the INK4 family members are frequently observed in nervous system tumors.


Assuntos
Inibidor de Quinase Dependente de Ciclina p15/genética , Inibidor p16 de Quinase Dependente de Ciclina/genética , Neoplasias do Sistema Nervoso/genética , PTEN Fosfo-Hidrolase/genética , Proteína Supressora de Tumor p14ARF/genética , Análise Mutacional de DNA/métodos , Deleção de Genes , Homozigoto , Humanos , Perda de Heterozigosidade , Neoplasias do Sistema Nervoso/patologia , Reação em Cadeia da Polimerase
13.
Braz. j. med. biol. res ; 41(6): 539-543, June 2008. ilus, tab
Artigo em Inglês | LILACS | ID: lil-485848

RESUMO

Gastric cancer is the forth most frequent malignancy and the second most common cause of cancer death worldwide. DNA methylation is the most studied epigenetic alteration, occurring through a methyl radical addition to the cytosine base adjacent to guanine. Many tumor genes are inactivated by DNA methylation in gastric cancer. We evaluated the DNA methylation status of ANAPC1, CDKN2A and TP53 by methylation-specific PCR in 20 diffuse- and 26 intestinal-type gastric cancer samples and 20 normal gastric mucosa in individuals from Northern Brazil. All gastric cancer samples were advanced stage adenocarcinomas. Gastric samples were surgically obtained at the João de Barros Barreto University Hospital, State of Pará, and were stored at -80°C before DNA extraction. Patients had never been submitted to chemotherapy or radiotherapy, nor did they have any other diagnosed cancer. None of the gastric cancer samples presented methylated DNA sequences for ANAPC1 and TP53. CDKN2A methylation was not detected in any normal gastric mucosa; however, the CDKN2A promoter was methylated in 30.4 percent of gastric cancer samples, with 35 percent methylation in diffuse-type and 26.9 percent in intestinal-type cancers. CDKN2A methylation was associated with the carcinogenesis process for ~30 percent diffuse-type and intestinal-type compared to non-neoplastic samples. Thus, ANAPC1 and TP53 methylation was probably not implicated in gastric carcinogenesis in our samples. CDKN2A can be implicated in the carcinogenesis process of only a subset of gastric neoplasias.


Assuntos
Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adenocarcinoma/genética , Metilação de DNA/genética , Neoplasias Gástricas/genética , Complexos Ubiquitina-Proteína Ligase/metabolismo , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Estudos de Casos e Controles , Reação em Cadeia da Polimerase , Regiões Promotoras Genéticas/genética , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia
14.
Genet Mol Res ; 7(1): 207-16, 2008 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-18393224

RESUMO

The TP53 tumor suppressor gene codifies a protein responsible for preventing cells with genetic damage from growing and dividing by blocking cell growth or apoptosis pathways. A common single nucleotide polymorphism (SNP) in TP53 codon 72 (Arg72Pro) induces a 15-fold decrease of apoptosis-inducing ability and has been associated with susceptibility to human cancers. Recently, another TP53 SNP at codon 47 (Pro47Ser) was reported to have a low apoptosis-inducing ability; however, there are no association studies between this SNP and cancer. Aiming to study the role of TP53 Pro47Ser and Arg72Pro on glioma susceptibility and oncologic prognosis of patients, we investigated the genotype distribution of these SNPs in 94 gliomas (81 astrocytomas, 8 ependymomas and 5 oligodendrogliomas) and in 100 healthy subjects by the polymerase chain reaction-restriction fragment length polymorphism approach. Chi-square and Fisher exact test comparisons for genotype distributions and allele frequencies did not reveal any significant difference between patients and control groups. Overall and disease-free survivals were calculated by the Kaplan-Meier method, and the log-rank test was used for comparisons, but no significant statistical difference was observed between the two groups. Our data suggest that TP53 Pro47Ser and Arg72Pro SNPs are not involved either in susceptibility to developing gliomas or in patient survival, at least in the Brazilian population.


Assuntos
Glioma/genética , Polimorfismo de Nucleotídeo Único , Proteína Supressora de Tumor p53/genética , Adolescente , Adulto , Idoso , Apoptose/genética , Brasil , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Frequência do Gene , Genes p53 , Predisposição Genética para Doença , Genótipo , Glioma/etiologia , Glioma/mortalidade , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Prognóstico , Análise de Sobrevida
15.
Curr Med Chem ; 15(8): 826-33, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18393851

RESUMO

Microarray gene expression profiling is a high throughput system recently used in basic and applied research. It provides a large amount of data -at molecular level- that once acquired, must be functionally integrated in order to find common patterns within a defined group of biological samples. In addition to identification of differentially expressed genes and the establishment of gene regulation patterns, microarrays may also allow us to discover new tumor markers that could have a great impact on the improvement of clinical practice and therapeutics for cancer. The classification method used for cancer is currently based on the morphological characteristics of the biological samples. The information obtained with this method is limited, omitting many important tumor characteristics like the proliferation rate, the capacity of invasion and metastases, as well as the possible development of mechanisms of cellular resistance to treatment. Microarrays can be used in combination with conventional diagnostics as a helpful complement. In this review we focus on how this technology has contributed to our knowledge of the molecular pathogenesis of meningiomas and schwannomas, its potential role as a useful tool for tumor classification and its application in clinical practice.


Assuntos
Perfilação da Expressão Gênica , Meningioma/genética , Neurilemoma/genética , Análise de Sequência com Séries de Oligonucleotídeos , Animais , Humanos , Meningioma/classificação , Meningioma/patologia , Neurilemoma/classificação , Neurilemoma/patologia
16.
Genet. mol. res. (Online) ; 7(1): 207-216, Jan. 2008. ilus, tab
Artigo em Inglês | LILACS | ID: lil-553787

RESUMO

The TP53 tumor suppressor gene codifies a protein responsible for preventing cells with genetic damage from growing and dividing by blocking cell growth or apoptosis pathways. A common single nucleotide polymorphism (SNP) in TP53 codon 72 (Arg72Pro) induces a 15-fold decrease of apoptosis-inducing ability and has been associated with susceptibility to human cancers. Recently, another TP53 SNP at codon 47 (Pro47Ser) was reported to have a low apoptosis-inducing ability; however, there are no association studies between this SNP and cancer. Aiming to study the role of TP53 Pro47Ser and Arg72Pro on glioma susceptibility and oncologic prognosis of patients, we investigated the genotype distribution of these SNPs in 94 gliomas (81 astrocytomas, 8 ependymomas and 5 oligodendrogliomas) and in 100 healthy subjects by the polymerase chain reaction-restriction fragment length polymorphism approach. Chi-square and Fisher exact test comparisons for genotype distributions and allele frequencies did not reveal any significant difference between patients and control groups. Overall and disease-free survivals were calculated by the Kaplan-Meier method, and the log-rank test was used for comparisons, but no significant statistical difference was observed between the two groups. Our data suggest that TP53 Pro47Ser and Arg72Pro SNPs are not involved either in susceptibility to developing gliomas or in patient survival, at least in the Brazilian population.


Assuntos
Humanos , Masculino , Feminino , Pré-Escolar , Criança , Adolescente , Adulto , Pessoa de Meia-Idade , Glioma/genética , Polimorfismo de Nucleotídeo Único , /genética , Apoptose/genética , Brasil , Estudos de Casos e Controles , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Glioma/etiologia , Glioma/mortalidade , Prognóstico , Análise de Sobrevida
17.
Genet. mol. res. (Online) ; 7(2): 451-459, 2008. tab, ilus
Artigo em Inglês | LILACS | ID: lil-640993

RESUMO

The cancer is one of the most common and severe problems in clinical medicine, and nervous system tumors represent about 2% of the types of cancer. The central role of the nervous system in the maintenance of vital activities and the functional consequences of the loss of neurons can explain how severe brain cancers are. The cell cycle is a highly complex process, with a wide number of regulatory proteins involved, and such proteins can suffer alterations that transform normal cells into malignant ones. The INK4 family members (CDK inhibitors) are the cell cycle regulators that block the progression of the cycle through the R point, causing an arrest in G1 stage. The p14ARF (alternative reading frame) gene is a tumor suppressor that inhibits p53 degradation during the progression of the cell cycle. The PTEN gene is related to the induction of growth suppression through cell cycle arrest, to apoptosis and to the inhibition of cell adhesion and migration. The purpose of the present study was to assess the mutational state of the genes p14ARF, p15INK4b, p16INK4a, and PTEN in 64 human nervous system tumor samples. Homozygous deletions were found in exon 2 of the p15INK4b gene and exon 3 of the p16INK4a gene in two schwannomas. Three samples showed a guanine deletion (63 codon) which led to a loss of heterozygosity in the p15 gene, and no alterations could be seen in the PTEN gene. Although the group of patients was heterogeneous, our results are in accordance with other different studies that indicate that homozygous deletion and loss of heterozygosity in the INK4 family members are frequently observed in nervous system tumors.


Assuntos
Humanos , /genética , /genética , Neoplasias do Sistema Nervoso/genética , /genética , Análise Mutacional de DNA/métodos , Deleção de Genes , Homozigoto , Perda de Heterozigosidade , Neoplasias do Sistema Nervoso/patologia , Reação em Cadeia da Polimerase , PTEN Fosfo-Hidrolase
18.
Neurocirugia (Astur) ; 18(5): 373-82, 2007 Oct.
Artigo em Espanhol | MEDLINE | ID: mdl-18008011

RESUMO

Glioblastomas, the most frequent and malignant human brain tumors, may develop de novo (primary glioblastoma) or by progression from low-grade or anapalsic astrocytoma (secondary glioblastoma). The molecular alteration most frequent in these tumor-like types is the loss of heterozygosity on chromosome 10, in which several genes have been identified as tumors suppressor. The TP53/MDM2/P14arf and CDK4/RB1/ P16ink4 genetic pathways involved in cycle control are deregulated in the majority of gliomas as well as genes that promote the cellular division, EGFR. Finally the increase of growth and angiogenics factors is also involved in the development of glioblastomas. One of the objectives of molecular biology in tumors of glial ancestry is to try to find the genetic alterations that allow to approach better the classification of glioblastomas, its evolution prediction and treatment. The new pathmolecular classification of gliomas should improve the old one, especially being concerned about the oncogenesis and heterogeneity of these tumors. It is desirable that this classification had clinical applicability and integrates new molecular findings with some known histological features with pronostic value. In this paper we review the most frequent molecular mechanisms involved in the patogenesis of glioblastomas.


Assuntos
Neoplasias Encefálicas/genética , Glioblastoma/genética , Proteínas de Neoplasias/genética , Proteínas Angiogênicas/genética , Proteínas de Ciclo Celular/genética , Cromossomos Humanos Par 10/genética , Receptores ErbB/genética , Genes Supressores de Tumor , Glioblastoma/classificação , Glioma/classificação , Glioma/patologia , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Perda de Heterozigosidade
19.
Actas Urol Esp ; 31(7): 788-91, 2007.
Artigo em Espanhol | MEDLINE | ID: mdl-17902477

RESUMO

Micropapillary transitional cell carcinoma is a rare (incidence of 0.7%) and highly aggressive variant of bladder carcinoma. Morphologically, it is characterized by small tight clusters of neoplastic cell floating in clear spaces resembling lymphatic channels. Its usual presentation is like a high grade and stage carcinoma and most often is associated with a variable component of conventional carcinoma or other variants. The usual sites of bladder cancer metastases are the lymph nodes, lungs, bone and liver. Soft tissues metastases from transitional cell carcinoma of the bladder occur infrequently. We report the cases of a 77-year-old man presenting with an abdominal soft tissue mass a six years after local excision of a micropapillary bladder carcinoma.


Assuntos
Parede Abdominal , Carcinoma de Células de Transição/secundário , Neoplasias de Tecidos Moles/secundário , Neoplasias da Bexiga Urinária/patologia , Idoso , Humanos , Masculino
20.
Neoplasma ; 54(2): 123-6, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17319784

RESUMO

The DAPK1 gene works as a regulator of apoptosis and is frequently inactivated in cancer by aberrant promoter hypermethylation. Loss of DAPK1 expression is associated with a selective advantage for tumor cells to resist apoptotic stimuli, allowing them to separate from the original tumor; from this point of view, DAPK1 could be considered a tumor metastases inhibitor gene. To verify the participation of DAPK1 silencing in cerebral invasion, we analyzed its promoter methylation status in a series of 28 samples from cerebral metastases using MSP and sequencing of the MSP-product. We have found hypermethylation in 53.6% (15/28) metastatic tumor samples as well as in 27.8% (5/18) of its peripheral blood samples. Our data suggest an important role of DAPK1 for silencing through promoter CpG island hypermethylation in the development of brain metastases from solid tumors. The detection of aberrant hypermethylation on DAPK1 promoter from peripheral blood samples has potential clinical implications as a tumor prognosis marker.


Assuntos
Proteínas Reguladoras de Apoptose/sangue , Proteínas Reguladoras de Apoptose/genética , Neoplasias Encefálicas/genética , Proteínas Quinases Dependentes de Cálcio-Calmodulina/sangue , Proteínas Quinases Dependentes de Cálcio-Calmodulina/genética , Metilação de DNA , Regiões Promotoras Genéticas , Antimetabólitos Antineoplásicos/farmacologia , Azacitidina/farmacologia , Biomarcadores Tumorais/metabolismo , Neoplasias Encefálicas/sangue , Neoplasias Encefálicas/secundário , Ilhas de CpG , DNA de Neoplasias/genética , Proteínas Quinases Associadas com Morte Celular , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Humanos
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