AVALIAÇÃO DA EXPRESSÃO IMUNOISTOQUIMICA DA PROTEÍNA P53 NO ADENOCARCINOMA COLORRETAL - REVISÃO BIBLIOGRÁFICA

RESUMO Introdução: O carcinoma colorretal (CCR) é um tumor que se destaca por suas taxas de incidência e mortalidade no mundo. A maioria dos CRRs se desenvolve a partir de adenomas preexistentes devido a mutações genéticas acumuladas. As mutações no gene TP53 são as mais comuns encontradas nas neoplasias malignas humanas. Sua mutação pode levar ao acúmulo da proteína p53 nuclear, que pode ser vista por métodos de imuno-histoquímica (IHQ). Atualmente, o estadiamento anatomopatológico é principal método utilizado para determinar o prognóstico de pacientes com CCR. Metodologia: Foi realizado um levantamento bibliográfico na base eletrônica PubMed utilizando os descritores: “colorectal cancer” and “p53 protein” and “immunohistochemistry”. Resultados: O CCR é um tumor com altas taxas de incidência e mortalidade no ocidente e oriente. A mutação no gene TP53 parece ser um precursor do CCR e leva ao acúmulo da p53 mutada, que é visível aos métodos de IHQ. A maioria das amostras de CCR apresentaram-se positivas para p53, o que determina um comportamento mais agressivo do tumor e também serve como um fator de prognóstico ruim. Sua superexpressão indica maior chance de metástases e redução da sobrevida. Uma vez que a mutação do TP53 é um evento precoce, a detecção precoce do CCR pode ser feita através da visualização de p53 acumulada sob IHQ. Alterações no gene TP53 são fatores de prognóstico ruim em vários tipos de câncer, incluindo o CCR. Outros marcadores e fenótipos se correlacionam com a p53 no desenvolvimento do CCR, como a vitamina D, o estrogênio e a progesterona. Por fim, em nosso estudo não foi detectado relação entre a expressão da p53, idade, gênero, invasão tumoral, e taxa de regressão. Conclusão: Pode-se inferir que o CCR é um câncer com taxas de incidência, prevalência e mortalidade significantes, e que a IHQ da p53 tem papel importante na detecção precoce e decisão do tratamento. Palavras-chave: Carcinoma colorretal; gene TP53; proteína p53; imuno-histoquímica. ABSTRACT Introduction: Colorectal cancer (CRC) is well known for its incidence and mortality rate. Most of CRCs develops from colonic adenoma, that accumulates genetic mutations. TP53 gene’s mutations are the most common mutations found in human cancers. It’s mutation leads to nuclear p53 accumulation, which can be seen by immunohistochemistry (IHC) methods. Method: A research was done in PubMed using the following words: “colorectal cancer” and “p53 protein” and “immunohistochemistry”. Resulted: The CRC is a tumor with high incidence and mortality rates in the west and in the east. A mutation in TP53 gene seems to be a precursor of the CRC and leads to the accumulation of mutated p53, seen by the IHC methods. Most of CRC samples presents positive p53, and its positivity determinate a more aggressive behavior of the tumor, leading to a poor prognosis. Its overexpression indicates bigger chances of metastasis and survival rate loss. Being an early event, TP53 mutation and the following p53 nuclear accumulation makes the detection of CRC easier by IHC methods. TP53 gene alterations are also poor prognosis factors in various types of cancer, including the CRC. Other marks and phenotypes correlate with p53 in the evolution of CRC, like the vitamin D, estrogen and progesterone. Lastly, it wasn’t detected the relation between age, gender, tumor invasion, neither regression rate. Conclusion: It can be inferred that the CRC is a cancer with significant incidence, prevalence and mortality rates, and that the IHC methods have an important role in the early detection and decision making. Keywords: Colorectal carcinoma; TP53 gene; p53 protein; immunohistochemistry

EXPRESSÃO DAS PROTEÍNAS MUTANTES DO KRAS NO ADENOCARCINOMA COLORRETAL – REVISÃO BIBLIOGRAFICA

Introdução: Os tumores colorretais foram o terceiro tipo de câncer mais diagnosticado em 2018. Na tentativa de aumentar a sobrevida de pacientes com metástases, o teste KRAS é relevante para a escolha da terapia mais apropriada para o carcinoma colorretal (CCR). O gene KRAS (Kirsten Ras Oncogene) acompanhado dos genes BRAF e NRAS é responsável por codificar as proteínas RAS da importante via de sinalização celular RAS/RAF/MEK/ERK. A presença de KRAS mutante no CCR é o principal biomarcador tecidual que indica a resistência do tumor à terapia de primeira linha com anticorpos monoclonais inibidores do EGFR (Cetuximabe e Panitumumabe). Metodologia: Foi realizado um levantamento bibliográfico na base eletrônica Google Scholar utilizando os descritores: “colorectal cancer” and “KRAS gene”. Resultados: A conversão do aminoácido glicina (G) para ácido aspártico (D) no códon 12, também chamada de KRAS G12D, é a mutação mais frequente do KRAS nas neoplasias malignas gastrointestinais. Cerca de 40% dos CCRs têm a mutação no gene KRAS nos códons 12 e 13 do éxon 2. Houve predomínio (57,4%) das mutações no sexo masculino, e todas as amostras de cólon esquerdo, 66% das de cólon direito e 51,8% das de reto apresentaram mutações no KRAS. A sinalização de células com KRAS mutante determina um papel crítico no rompimento inicial da submucosa e, por isso é essencial para a progressão da invasão e metástase do CCR. A eficácia de anti-EGFR é limitada em pacientes que possuem mutação KRAS, entretanto 20% dos pacientes com KRAS selvagem se beneficiam diante da terapia. Atualmente não há droga ou vacina que consiga focalizar efetivamente a proteína KRAS G12D em humanos. Conclusão: Pode-se inferir que o CCR é um câncer de prognostico ainda reservado. A decisão terapêutica apropriada depende do conhecimento do status mutacional do KRAS e as mutações no éxon 2 são claramente preditivas às terapias com anticorpos monoclonais inibidores do EGFR. Palavras-chave: Carcinoma colorretal; gene KRAS; mutação. ABSTRACT Introduction: Colorectal tumors were the third most diagnosed type of cancer in 2018. Trying to improve the overall survival of patients with metastasis, the KRAS test is relevant for choosing a mora appropriate therapy for the colorectal carcinoma (CRC). The KRAS gene (Kirsten Ras Oncogene) along with BRAF and NRAS genes is responsible for encoding RAS proteins from the important RAS / RAF / MEK / ERK cell signaling pathway. The presence of mutant KRAS in the CCR is the major tissue biomarker indicating the patient's resistance to first-line therapy with the monoclonal vaccine EGFR inhibitors (Cetuximabe and Panitumumabe). Methodology: A bibliographic survey was carried out in the database of Google Scholar using the descriptors: "colorectal cancer" and "KRAS gene". Results: The conversion of the amino acid glycine (G) to aspartic acid (D) at codon 12, also called KRAS G12D, is a more frequent mutation of KRAS in gastrointestinal malignancies. About 40% of the RCCs have a mutation in the KRAS gene at codons 12 and 13 of exon 2. There was a predominance (57.4%) of the mutations in the male sex, and all samples from the left colon, 66% of the right colon and 51.8% of the mutational changes in KRAS. Marking of cells with mutant KRAS determines a non-initial critical role of the submucosa and is therefore essential for progression of CCR invasion and metastasis. Anti-EGFR is limited to patients who have KRAS mutation, in addition, 20% of wild-type KRAS patients benefit from the therapy. There is currently no drug or vaccine that can concentrate on a KRAS G12D protein in humans. Conclusion: It can be inferred that the CRC still has a reserved prognosis. The multitude of KRAS and mutations in exon 2 are clearly prescribed in therapies with EGFR inhibitory monoclonal antibodies. Keywords: Colorectal cancer; KRAS gene; mutation

Relato de caso: Linfoma esplênico primário em um homem de 70 anos

Os linfomas esplênicos primários são neoplasias malignas que ocorrem em menos de 1% dos pacientes com linfoma. São raramente diagnosticados porque não causam sintomas até a sua disseminação, fato que obscurece a sua localização primária no baço. No presente relato de caso, ilustramos um exemplo de linfoma primário de baço em um homem de 70 anos completamente assintomático que ao se submeter a um exame de imagem simples foi constatada a presença de um nódulo esplênico inespecífico. Com base nesse relato, foi realizada uma revisão da literatura sobre essa neoplasia e discutido os pontos de maior relevância sobre o assunto.  

Whole genome sequencing of the multidrug-resistant Chryseobacterium indologenes isolated from a patient in Brazil

Chryseobacterium indologenes is a non-glucose-fermenting Gram-negative bacillus. This emerging multidrug resistant opportunistic nosocomial pathogen can cause severe infections in neonates and immunocompromised patients. This study aimed to present the first detailed draft genome sequence of a multidrug-resistant C. indologenes strain isolated from the cerebrospinal fluid of an infant hospitalized at the Neonatal Intensive Care Unit of Brazilian Tertiary Hospital. We first analyzed the susceptibility of C. indologenes strain to different antibiotics using the VITEK 2 system. The strain demonstrated an outstanding resistance to all the antibiotic classes tested, including β-lactams, aminoglycosides, glycylcycline, and polymyxin. Next, C. indologenes was whole-genome-sequenced, annotated using Prokka and Rapid Annotation using Subsystems Technology (RAST), and screened for orthologous groups (EggNOG), gene ontology (GO), resistance genes, virulence genes, and mobile genetic elements using different software tools. The draft genome contained one circular chromosome of 4,836,765 bp with 37.32% GC content. The genomic features of the chromosome present numerous genes related to cellular processes that are essential to bacteria. The MDR C. indologenes revealed the presence of genes that corresponded to the resistance phenotypes, including genes to β-lactamases (blaIND–13, blaCIA–3, blaTEM–116, blaOXA–209, blaVEB–15), quinolone (mcbG), tigecycline (tet(X6)), and genes encoding efflux pumps which confer resistance to aminoglycosides (RanA/RanB), and colistin (HlyD/TolC). Amino acid substitutions related to quinolone resistance were observed in GyrA (S83Y) and GyrB (L425I and K473R). A mutation that may play a role in the development of colistin resistance was detected in lpxA (G68D). Chryseobacterium indologenes isolate harbored 19 virulence factors, most of which were involved in infection pathways. We identified 13 Genomic Islands (GIs) and some elements associated with one integrative and conjugative element (ICEs). Other elements linked to mobile genetic elements (MGEs), such as insertion sequence (ISEIsp1), transposon (Tn5393), and integron (In31), were also present in the C. indologenes genome. Although plasmids were not detected, a ColRNAI replicon type and the most resistance genes detected in singletons were identified in unaligned scaffolds. We provided a wide range of information toward the understanding of the genomic diversity of C. indologenes, which can contribute to controlling the evolution and dissemination of this pathogen in healthcare settings

High Prevalence of Multidrug-Resistant Klebsiella pneumoniae Harboring Several Virulence and β-Lactamase Encoding Genes in a Brazilian Intensive Care Unit

Klebsiella pneumoniae is an important opportunistic pathogen that commonly causes nosocomial infections and contributes to substantial morbidity and mortality. We sought to investigate the antibiotic resistance profile, pathogenic potential and the clonal relationships between K. pneumoniae (n = 25) isolated from patients and sources at a tertiary care hospital’s intensive care units (ICUs) in the northern region of Brazil. Most of K. pneumoniae isolates (n = 21, 84%) were classified as multidrug resistant (MDR) with high-level resistance to β-lactams, aminoglycosides, quinolones, tigecycline, and colistin. All the 25 isolates presented extended-spectrum beta-lactamase-producing (ESBL), including carbapenemase producers, and carried the blaKPC (100%), blaTEM (100%), blaSHV variants (n = 24, 96%), blaOXA-1 group (n = 21, 84%) and blaCTX-M-1 group (n = 18, 72%) genes. The K2 serotype was found in 4% (n = 1) of the isolates, and the K1 was not detected. The virulence-associated genes found among the 25 isolates were mrkD (n = 24, 96%), fimH-1 (n = 22, 88%), entB (100%), iutA (n = 10, 40%), ybtS (n = 15, 60%). The genes related with efflux pumps and outer membrane porins found were AcrAB (100%), tolC (n = 24, 96%), mdtK (n = 22, 88%), OmpK35 (n = 15, 60%), and OmpK36 (n = 7, 28%). ERIC-PCR was employed to determine the clonal relationship between the different isolated strains. The obtained ERIC-PCR patterns revealed that the similarity between isolates was above 70%. To determine the sequence types (STs) a multilocus sequence typing (MLST) assay was used. The results indicated the presence of high-risk international clones among the isolates. In our study, the wide variety of MDR K. pneumoniae harboring β-lactams and virulence genes strongly suggest a necessity for the implementation of effective strategies to prevent and control the spread of antibiotic resistant infections

Congenitally transmitted visceral leishmaniasis: report of two brazilian human cases

Visceral leishmaniasis is a relevant public health problem worldwide. Most of the reported cases in Latin America are from Brazil. Herein we report two human cases of congenitally transmitted visceral leishmaniasis in two patients who developed symptoms during pregnancy. The diagnosis was made by visual examination of Leishmania parasites in bone marrow aspirates of the mothers and by detecting parasite kDNA in bone marrow samples of the newborn children using polymerase chain reaction

Congenitally transmitted visceral leishmaniasis: report of two brazilian human cases

Visceral leishmaniasis is a relevant public health problem worldwide. Most of the reported cases in Latin America are from Brazil. Herein we report two human cases of congenitally transmitted visceral leishmaniasis in two patients who developed symptoms during pregnancy. The diagnosis was made by visual examination of Leishmania parasites in bone marrow aspirates of the mothers and by detecting parasite kDNA in bone marrow samples of the newborn children using polymerase chain reaction