Prevalence of CCR5-Δ32 and CCR2-V64I polymorphisms in a mixed population from northeastern Brazil.

Chemokines are low-molecular weight proteins that play a key role in inflammatory processes. Genomic variations in chemokine receptors are associated with the susceptibility to various diseases. Polymorphisms in chemokine receptor type 5 (CCR5)-Δ32 and CCR2-V64I are related to human immunodeficiency virus infection resistance, which has led to genetic association studies for several other diseases. Given the heterogeneous distribution of these polymorphisms in different global populations and within Brazilian populations, we analyzed the prevalence of CCR5-Δ32 and CCR2-V64I polymorphisms in a mixed population from northeastern Brazil. The study included 223 individuals from the general population of the city of Parnaíba, Piauí, who had a mean age of 73 years. Of these individuals, 37.2% were men and 62.8% were women. Polymorphisms were analyzed using DNA extracted from peripheral blood leukocytes by using polymerase chain reaction alone (CCR5-Δ32) or accompanied by restriction endonuclease digestion (CCR2-V64I). In both cases, the genotypes were determined using 8% polyacrylamide gel electrophoresis and silver nitrate staining. The population conformed to Hardy-Weinberg equilibrium for both the loci studied. No individuals were homozygous for allele-Δ32, which was present in 1.8% of the population, whereas allele-64I was present in 13.9% of the participants studied; 74.9% were homozygous for the wild-type allele, while 22.4 and 2.7% were heterozygous and homozygous for the mutant allele, respectively. Additional studies are needed to investigate the relationship between these polymorphisms and disease etiopathogenesis in reference populations.

Association of the rs7903146 and rs12255372 polymorphisms in the TCF7L2 gene with type 2 diabetes in a population from northeastern Brazil.

Approximately 200 million people suffer from type 2 diabetes (T2D) worldwide, and the rapid increase in the prevalence of this disease is likely a result of multiple environmental factors, such as increased food intake and decreased physical activity in genetically predisposed individuals. Different population studies have demonstrated a strong association of two polymorphic variations in the TCF7L2 gene, the noncoding single nucleotide polymorphisms (SNPs) rs7903146 (C/T) and rs12255372 (G/T), with T2D. Herein, we analyzed the association of these SNPs with T2D in a population from northeastern Brazil. Our results showed that the genotype and allele frequencies in TCF7L2 rs7903146 and rs12255372 were similar in the patient and control groups (P > 0.05). In addition, the allele frequencies were not significantly associated with T2D risk [rs7903146: odds ratio (OR) = 0.95, 95% confidence interval (CI) = 0.52-1.76, P = 1.00, and rs12255372: OR = 1.38, 95%CI = 0.72-2.62, P = 0.41]. These data suggest that the TCF7L2 SNPs rs7903146 and rs12255372 may not significantly contribute to T2D susceptibility in this population. However, our results may reflect the small number of subjects. Alternatively, these results may be attributable to specific ethnic effects, as most of the previously reported associations were demonstrated with predominantly European populations. To reach a definitive conclusion on the role of such gene variants for T2D in mixed populations, additional efforts are necessary to replicate this study with larger populations from areas with more ethnic heterogeneity.

Prevalence of variants that confer risk for venous thromboembolism in an elderly population of northeastern Brazil.

Venous thromboembolism (VTE) is an important cause of morbidity and mortality stemming from cardiovascular disease. It is a multifactorial disease caused by a combination of acquired risk factors, of which advanced age is the most significant, and genetic factors, including the variants FV G1691A, FII G20210A, and MTHFR C677T. We estimated the prevalence of these genomic variants in an elderly population of northeastern Brazil. The study included 188 elderly persons (65-93 years), of which 68 (36.2%) were men and 120 (63.8%) were women. Variants were detected by polymerase chain reaction-restriction fragment length polymorphism analysis, and subsequent electrophoresis on an 8% polyacrylamide gel stained with silver nitrate. The study population was in Hardy-Weinberg equilibrium for the 3 loci. Of the individuals analyzed, none carried variants of FV or FII (0%), and 24.7% had the MTHFR C677T polymorphism: 59 subjects (31.4%) were heterozygous (CT) and 17 subjects (9%) were homozygous (TT). Based on the analysis of these particular genes, we conclude that the study population does not present an increased risk for the development of VTE. Faced with a growing aging population worldwide, similar studies in other countries will help in the prevention of VTE in older individuals.

Variation in DNA repair gene XRCC3 affects susceptibility to astrocytomas and glioblastomas.

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.

Papillary renal cell neoplasm with reverse polarity: A new subtype of renal tumour with favorable prognosis.

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.

Analysis of the polymorphisms XRCC1Arg194Trp and XRCC1Arg399Gln in gliomas.

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.

Extracorporeal Photopheresis in Pediatric Graft-vs-Host Disease.

BACKGROUND: Extracorporeal photopheresis (ECP) is an immunomodulatory therapy used to treat graft-vs-host disease (GVHD) in adults and children. Few studies have examined its use in children. OBJECTIVE: To describe demographic characteristics, clinical response, adverse effects, and outcomes in a series of pediatric patients with acute or chronic GVHD treated with ECP. MATERIAL AND METHODS: We included all pediatric patients with acute or chronic GVHD treated with ECP by the dermatology department of Hospital Italiano de Buenos Aires between January 2012 and December 2018. We used the UVAR-XTS™ system (2 patients) and the CELLEX system (7 patients). Patients with acute GVHD received 2 sessions a week and were reassessed at 1 month, while those with chronic GVHD received 2 sessions every 2 weeks and were reassessed at 3 months. Treatment duration in both scenarios varied according to response. RESULTS: We evaluated 9 pediatric patients with corticosteroid-refractory, -dependent, and/or -resistant GVHD treated with ECP. Seven responded to treatment and 2 did not. Response was complete in 1 of the 9 patients with skin involvement and partial in 7. Complete response rates for the other sites of involvement were 60% (3/5) for the liver, 50% (1/2) for the gastrointestinal system, and 80% (4/5) for mucous membranes. Two patients died during the study period. CONCLUSION: ECP is a good treatment option for pediatric patients with acute or chronic GVHD.

Extracorporeal Photopheresis in Pediatric Graft-vs-Host Disease. / Fotoféresis extracorpórea en enfermedad injerto contra huésped en una población pediátrica.

BACKGROUND: Extracorporeal photopheresis (ECP) is an immunomodulatory therapy used to treat graft-vs-host disease (GVHD) in adults and children. Few studies have examined its use in children. OBJECTIVE: To describe demographic characteristics, clinical response, adverse effects, and outcomes in a series of pediatric patients with acute or chronic GVHD treated with ECP. MATERIAL AND METHODS: We included all pediatric patients with acute or chronic GVHD treated with ECP by the Dermatology Department of Hospital Italiano de Buenos Aires between January 2012 and December 2018. We used the UVAR-XTS™ system (2 patients) and the CELLEX system (7 patients). Patients with acute GVHD received 2 sessions a week and were reassessed at 1 month, while those with chronic GVHD received 2 sessions every 2 weeks and were reassessed at 3 months. Treatment duration in both scenarios varied according to response. RESULTS: We evaluated 9 pediatric patients with corticosteroid-refractory, -dependent, and/or -resistant GVHD treated with ECP. Seven responded to treatment and 2 did not. Response was complete in 1 of the 9 patients with skin involvement and partial in 7. Complete response rates for the other sites of involvement were 60% (3/5) for the liver, 50% (1/2) for the gastrointestinal system, and 80% (4/5) for mucous membranes. Two patients died during the study period. CONCLUSION: ECP is a good treatment option for pediatric patients with acute or chronic GVHD.

Livedoid vasculopathy and recurrent thrombosis in a patient with lupus: seronegative antiphospholipid syndrome?

Livedoid vasculopathy is a rare condition which predominantly affects young women. It is characterized by intense painful purpuric maculae in the legs, ankles and feet, due to thrombosis of the small and medium-sized dermal vessels, in the absence of vasculitis. Livedoid vasculopathy has been frequently associated with hypercoagulable states and antiphospholipid syndrome. We describe a 34-year-old White woman suffering from systemic lupus erythematosus, livedo reticularis, haemolytic anaemia, severe thrombocytopenia and recurrent venous thrombosis who was admitted to the hospital for extremely painful purpuric lesions in her lower limbs. The clinical and histological findings were diagnostic of livedoid vasculopathy. Once the initial sub-therapeutic international normalized ratio levels were corrected, livedoid vasculopathy did not recur. Tests for antiphospholipid antibodies were repeatedly negative. This case, the first reported of livedoid vasculopathy in a patient with seronegative antiphospholipid syndrome and systemic lupus erythematosus, draws attention to livedoid vasculopathy, a thrombotic dermopathy that may be under-diagnosed in patients with antiphospholipid syndrome.

GSTP1 Ile105Val polymorphism in astrocytomas and glioblastomas.

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.

[Squamous cell carcinoma arising on an epidermal inclusion cyst: a case presentation and review of the literature]. / Carcinoma epidermoide desarrollado sobre quiste de inclusión epidérmica cutáneo. Presentación de un nuevo caso y revisión de la literatura.

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.

Polymorphisms and DNA methylation of gene TP53 associated with extra-axial brain tumors.

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.

Concurrent sequence variation of TP53 and TP73 genes in anaplastic astrocytoma.

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.

Microarray gene expression profiling in meningiomas and schwannomas.

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.

Prognostic value of TP53 Pro47Ser and Arg72Pro single nucleotide polymorphisms and the susceptibility to gliomas in individuals from Southeast Brazil.

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.

Mutational analysis of genes p14ARF, p15INK4b, p16INK4a, and PTEN in human nervous system tumors.

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.

DAPK1 promoter hypermethylaiton in brain metastases and peripheral blood.

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.

Mutation analysis of gene PAX6 in human gliomas.

Gliomas are the most common tumors of the central nervous system. In spite of the marked advances in the characterization of the molecular pathogenesis of gliomas, these tumors remain incurable and, in most of the cases, resistant to treatments, due to their molecular heterogeneity. Gene PAX6, which encodes a transcription factor that plays an important role in the development of the central nervous system, was recently recognized as a tumor suppressor in gliomas. The objective of the present study was to analyze the mutational status of the coding and regulating regions of PAX6 in 94 gliomas: 81 astrocytomas (11 grade I, 23 grade II, 8 grade III, and 39 grade IV glioblastomas), 5 oligodendrogliomas (3 grade II, and 2 grade III), and 8 ependymomas (5 grade II, and 3 grade III). Two regulating regions (SX250 and EIE) and the 11 coding regions (exons 4-13, plus exon 5a resulting from alternative splicing) of gene PAX6 were analyzed and no mutation was found. Therefore, we conclude that the tumor suppressor role of PAX6, reported in previous studies on gliomas, is not due to mutation in its coding and regulating regions, suggesting the involvement of epigenetic mechanisms in the silencing of PAX6 in these tumors.

[Biology molecular of glioblastomas]. / Biología molecular de los glioblastomas.

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.

[Soft tissue metastases by micropapillary bladder carcinoma. Metastatic disease]. / Metástasis en partes blandas por un carcinoma micropapilar de vejiga.

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.