Head and Neck Cancers Are Not Alike When Tarred with the Same Brush: An Epigenetic Perspective from the Cancerization Field to Prognosis.

Head and neck squamous cell carcinomas (HNSCC) are among the ten most frequent types of cancer worldwide and, despite all efforts, are still diagnosed at late stages and show poor overall survival. Furthermore, HNSCC patients often experience relapses and the development of second primary tumors, as a consequence of the field cancerization process. Therefore, a better comprehension of the molecular mechanisms involved in HNSCC development and progression may enable diagnosis anticipation and provide valuable tools for prediction of prognosis and response to therapy. However, the different biological behavior of these tumors depending on the affected anatomical site and risk factor exposure, as well as the high genetic heterogeneity observed in HNSCC are major obstacles in this pursue. In this context, epigenetic alterations have been shown to be common in HNSCC, to discriminate the tumor anatomical subsites, to be responsive to risk factor exposure, and show promising results in biomarker development. Based on this, this review brings together the current knowledge on alterations of DNA methylation and microRNA expression in HNSCC natural history, focusing on how they contribute to each step of the process and on their applicability as biomarkers of exposure, HNSCC development, progression, and response to therapy.

Upper Aerodigestive Tract Squamous Cell Carcinomas Show Distinct Overall DNA Methylation Profiles and Different Molecular Mechanisms behind WNT Signaling Disruption.

Upper aerodigestive tract (UADT) tumors present different biological behavior and prognosis, suggesting specific molecular mechanisms underlying their development. However, they are rarely considered as single entities (particularly head and neck subsites) and share the most common genetic alterations. Therefore, there is a need for a better understanding of the global DNA methylation differences among UADT tumors. We performed a genome-wide DNA methylation analysis of esophageal (ESCC), laryngeal (LSCC), oral (OSCC) and oropharyngeal (OPSCC) squamous cell carcinomas, and their non-tumor counterparts. The unsupervised analysis showed that non-tumor tissues present markedly distinct DNA methylation profiles, while tumors are highly heterogeneous. Hypomethylation was more frequent in LSCC and OPSCC, while ESCC and OSCC presented mostly hypermethylation, with the latter showing a CpG island overrepresentation. Differentially methylated regions affected genes in 127 signaling pathways, with only 3.1% of these being common among different tumor subsites, but with different genes affected. The WNT signaling pathway, known to be dysregulated in different epithelial tumors, is a frequent hit for DNA methylation and gene expression alterations in ESCC and OPSCC, but mostly for genetic alterations in LSCC and OSCC. UADT tumor subsites present differences in genome-wide methylation regarding their profile, intensity, genomic regions and signaling pathways affected.

High infiltration of B cells in tertiary lymphoid structures, TCR oligoclonality, and neoantigens are part of esophageal squamous cell carcinoma microenvironment.

Esophageal squamous cell carcinoma (ESCA) exhibits high intratumoral molecular heterogeneity posing a challenge to cancer therapy. Immune checkpoint blockade therapy has been approved for this disease, but with modest results. RNA-Seq data from paired tumor and surrounding nonmalignant tissue from 14 patients diagnosed with ESCA without previous treatment and from The Cancer Genome Atlas-ESCA cohort were analyzed. Herein, we investigated ESCA immune landscape including mutation-derived neoantigens and immune cell subpopulations. Tumor-associated antigen expression was determined by in silico analyses and confirmed by immunohistochemistry showing that PRAME, CEACAM4, and MAGEA11 proteins are expressed on tumors. Immune checkpoint molecules gene expression was higher in the tumor compared with surrounding nonmalignant tissue, but its expression varies greatly among patients. TCR repertoire and BCR transcripts analysis evidenced low clonal diversity with one TCR clone predicted to be specific for a MAGEA11-derived peptide. A high number of B-cell clones infiltrating the tumors and the abundance of these cells in tertiary lymphoid structures observed in ESCA tumors support B cells as a potential immune modulator in this tumor.

Multi-cancer V-ATPase molecular signatures: A distinctive balance of subunit C isoforms in esophageal carcinoma.

BACKGROUND: V-ATPases are hetero-oligomeric enzymes consisting of 13 subunits and playing key roles in ion homeostasis and signaling. Differential expression of these proton pumps has been implicated in carcinogenesis and metastasis. To elucidate putative molecular signatures underlying these phenomena, we evaluated the expression of V-ATPase genes in esophageal squamous cell carcinoma (ESCC) and extended the analysis to other cancers. METHODS: Expression of all V-ATPase genes were analyzed in ESCC by a microarray data and in different types of tumors available from public databases. Expression of C isoforms was validated by qRT-PCR in paired ESCC samples. FINDINGS: A differential expression pattern of V-ATPase genes was found in different tumors, with combinations in up- and down-regulation leading to an imbalance in the expression ratios of their isoforms. Particularly, a high C1 and low C2 expression pattern accurately discriminated ESCC from normal tissues. Structural modeling of C2a isoform uncovered motifs for oncogenic kinases in an additional peptide stretch, and an actin-biding domain downstream to this sequence. INTERPRETATION: Altogether these data revealed that the expression ratios of subunits/isoforms could form a conformational code that controls the H+ pump regulation and interactions related to tumorigenesis. This study establishes a paradigm change by uncovering multi-cancer molecular signatures present in the V-ATPase structure, from which future studies must address the complexity of the onco-related V-ATPase assemblies as a whole, rather than targeting changes in specific subunit isoforms. FUNDING: This work was supported by grants from CNPq and FAPERJ-Brazil.

Overexpression of HMGA1 Figures as a Potential Prognostic Factor in Endometrioid Endometrial Carcinoma (EEC).

Endometrioid endometrial carcinomas (EEC) are the most common malignant gynecologic tumors. Despite the increase in EEC molecular knowledge, the identification of new biomarkers involved in disease's development and/or progression would represent an improvement in its course. High-mobility group A protein (HMGA) family members are frequently overexpressed in a wide range of malignancies, correlating with a poor prognosis. Thus, the aim of this study was to analyze HMGA1 and HMGA2 expression pattern and their potential role as EEC biomarkers. HMGA1 and HMGA2 expression was initially evaluated in a series of 46 EEC tumors (stages IA to IV), and the findings were then validated in The Cancer Genome Atlas (TCGA) EEC cohort, comprising 381 EEC tumors (stages IA to IV). Our results reveal that HMGA1 and HMGA2 mRNA and protein are overexpressed in ECC, but only HMGA1 expression is associated with increased histological grade and tumor size. Moreover, HMGA1 but not HMGA2 overexpression was identified as a negative prognostic factor to EEC patients. Finally, a positive correlation between expression of HMGA1 pseudogenes-HMGA1-P6 and HMGA1-P7-and HMGA1 itself was detected, suggesting HMGA1 pseudogenes may play a role in HMGA1 expression regulation in EEC. Thus, these results indicate that HMGA1 overexpression possesses a potential role as a prognostic biomarker for EEC.

High-Resolution Melting (HRM) of Hypervariable Mitochondrial DNA Regions for Forensic Science.

Forensic strategies commonly are proceeding by analysis of short tandem repeats (STRs); however, new additional strategies have been proposed for forensic science. Thus, this article standardized the high-resolution melting (HRM) of DNA for forensic analyzes. For HRM, mitochondrial DNA (mtDNA) from eight individuals were extracted from mucosa swabs by DNAzol reagent, samples were amplified by PCR and submitted to HRM analysis to identify differences in hypervariable (HV) regions I and II. To confirm HRM, all PCR products were DNA sequencing. The data suggest that is possible discriminate DNA from different samples by HRM curves. Also, uncommon dual-dissociation was identified in a single PCR product, increasing HRM analyzes by evaluation of melting peaks. Thus, HRM is accurate and useful to screening small differences in HVI and HVII regions from mtDNA and increase the efficiency of laboratory routines based on forensic genetics.

ERM/ETV5 and RUNX1/AML1 expression in endometrioid adenocarcinomas of endometrium and association with neoplastic progression.

The majority of endometrioid endometrial carcinomas (EEC) is diagnosed at stage I. Among these, 30% present myometrial invasion (stage IB), which is associated with tumor spread and relapse after primary treatment. Although an increased expression of RUNX1/AML1 and ERM/ETV5 in EEC have been suggested to be associated with early events of myometrial infiltration, there is no data regarding its expression along the evolution of EEC and possible associations with other clinicopathological parameters. Therefore, ERM/ETV5 and RUNX1/AML1 protein and gene expression profiles were assessed in different EEC stages to evaluate their role in endometrial carcinogenesis. RUNX1/AML1 and ERM/ETV5 proteins were analyzed by immunohistochemistry in 219 formalin fixed paraffin embedded endometrioid tumors and in 12 normal atrophic and proliferative endometrium samples. RUNX1/AML1 and ERM/ETV5 genes expression were analyzed by RT-qPCR. RUNX1/AML1 and ERM/ETV5 expression were decreased with increasing EEC stage, with a positive correlation between protein and gene expression for ERM/ETV5, but not for RUNX1/AML1. Both proteins were present in the nucleus of the tumor cells, whereas RUNX1/AML1, but not ERM/ETV5, was expressed in 7 out of 12 normal endometrial samples, with its expression being restricted to the cytoplasm of the positive cells. We concluded that there is a higher expression of ERM/ETV5 in early stages of EEC, whereas there seems to be a RUNX1/AML1 translocation from cytoplasm to nucleus in EEC neoplastic transformation.

HPV infection in Brazilian patients with esophageal squamous cell carcinoma: interpopulational differences, lack of correlation with surrogate markers and clinicopathological parameters.

The role of HPV in esophageal squamous cell carcinoma (ESCCs) is controversial. Therefore, we determined, through different methodologies, the prevalence of HPV in 264 ESCC samples from Brazil, and correlated it with the presence of surrogate markers and clinicopathological characteristics. HPV is present in 13% of ESCC, and with a 3-fold variation between high and medium incidence areas. Most HPV positive tumors were infected with HPV16, but this was not associated with p16 expression, TP53 mutation status, patient age, amount of tobacco or alcohol consumption, or overall survival. We conclude that HPV infection may not have a role in ESCC.

Alterações genéticas e epigenéticas em carcinoma epidermóide de esôfago / Genetic and epigenetic alterations in esophageal squamous cell carcinoma

O câncer de esôfago encontra-se entre os dez tipos de câncer mais incidentes no mundo, sendo o sexto tipo mais mortal. Fatores genéticos, como mutações no gene TP53, e epigenéticos como, por exemplo, a hipermetilação das ilhotas CpG na região promotora de determinados genes, são eventos importantes no desenvolvimento do câncer e podem causar a inativação de genes supressores de tumor. Neste trabalho, avaliamos o perfil de mutação no gene TP53 em 101 pacientes com carcinoma epidermóide de esôfago (CEE) residentes na região sudeste do Brasil. Destes pacientes, 33,7% apresentaram mutações nos éxons 5, 6, 7 e 8 com prevalência nos códons 248, 179 e 220. A metilação das citosinas das ilhotas CpG resulta da atividade de uma família de enzimas, as DNA metiltransferases (DNMTs). A hipermetilação destas ilhotas leva à formação de um complexo de proteínas incluindo proteínas que têm afinidade por CpG metilado (MBDs e MeCP) impedindo que ocorra a transcrição. Neste trabalho nós investigamos, por RT-PCR semi-quantitativo, a expressão das DNMT1, DNMT3A, DNMT3B, MBD1, MBD3, MDB4 e MeCP2 em mucosa esofágica normal. Em seguida, analisamos a expressão das DNMTs, MBDs esofagina, p14ARF, p16INK4a e E-caderina em 17 amostras pareadas, tecidos normal e tumoral, de pacientes com carcinoma epidermóide de esôfago (CEE). Todas as enzimas foram constitutivamente expressas na mucosa esofágica normal. Nos tumores, foi observado um aumento significativo na expressão da DNMT3B (p=0,0038) e da MBD4 (p=0,0197) em relação à mucosa normal adjacente. A expressão dos genes esofagina, p14ARF e p16INK4a, no tecido tumoral, foi ausente ou reduzida em 64,7%, 52,9% e 58,8% das amostras, respectivamente. Apenas 11,7% das amostras de CEE mostraram níveis reduzidos de E-caderina. Quando a correlação entre a expressão da DNMTs com esofagina, p14ARF, p16INK4a e E-caderina, foi analisada pelo teste de Spearman foi observada uma correlação inversamente proporcional entre a expressão de DNMT3B e esofagina...

Esophageal cancer is one of the ten most common malignancies and it is the sixth cause of cancer-related death in the world. Genetic alterations, such as TP53 mutations and epigenetic modifications, such as the hypermethylation of CpG islands, are important events in cancer development and are a common way of inactivating tumor suppressor genes. in this study, we analyzed the spectrum of TP53 mutations in 101 patients with esophageal squamous cell carcinoma (ESCC) living in Southeastern Brazil. Among those patients, 33.7% showed mutations in exons 5, 6, 7 e 8 and these alterations are prevalent in codons 248, 179 and 220. Cytosine methylation is established and maintained by a family of DNA methiltransferase enzymes (DNMTs). Hypermethylation of CpG dinucleotides initiates the formation of a protein complex, including proteins who bind these methylated residues (MBDs and MeCP2), leading to transcriptional repression. We investigated, by RT-PCR, the expression of human DNMT1, DNMT3A, DNMT3B, MBD1, MBD2, MBD3, MBD4 and MeCP2 in normal esophageal mucosa. Then, we analyzed the mRNA expression of these DNMTs, MBDs, esophagin, p14ARF, p16INK4a and E-cacherin in 17 esophageal squamous cell carcinoma (ESCC) samples as well as their adjacent normal epithelial tissues. The expression of esophagin, p14ARF and p16INK4a was absent of reduced in 64.7%, 52.9% and 58.8% of the ESCC samples, respectively. Only 11.7% of the ESCC samples showed reduced levels of E-cadherin mRNA. When the correlation between mRNA expression of the DNMTs and these genes was analyzed by the Spearman rank test we observed that it was inversely correlated for DNMT3B and esophagin (p=0.0112), p14ARF (p=0.0384) and p16INK4a (p=0.0378). The results suggest that DMNT3B overexpression may be involved in the suppression or in the lower expression of p14ARF and p16INK4a seen in esophageal ESCC. Consequently, we selected DNMY3B, MBD4, p14ARF e p16 INK4a to be analyzed by real time PCR...

Lower expression of p14ARF and p16INK4a correlates with higher DNMT3B expression in human oesophageal squamous cell carcinomas.

Oesophageal squamous cell carcinoma (ESCC) is one of the most common malignancies and is the sixth cause of cancer-related death in the world. Inactivation of cell-cycle regulating genes, such as p14ARF and p16INK4a, and cell adhesion genes, such as E-cadherin, is common in cancer, and results from genetic and/or epigenetic alterations. Therefore, we have analysed the mRNA expression of p14ARF, p16INK4a and E-cadherin in 17 matched ESCC and normal mucosal samples obtained from Brazilian patients by semi-quantitative RT-PCR. The expression of p14ARF and p16INK4a was absent or reduced in several ESCC samples. Hypermethylation of CpG islands, caused by the action of DNA methyltransferases (DNMTs), is a major form of epigenetic inactivation of the p14ARF and p16INK4a genes in tumours. Hence, we also investigated the mRNA expression of the human DNA methyltransferases in normal oesophageal mucosa and in the tumour matched samples. All DNMTs were constitutively expressed in the normal oesophageal mucosa but a significantly higher expression of DNMT3B was observed in the tumours. Data analysis by the Spearman rank test showed that the expression of DNMT3B was inversely correlated with that of p14ARF and p16INK4a. Our results suggest that DNMT3B over-expression may be involved in the suppression or lower expression of p14ARF and p16INK4a observed in ESCC.

Mutações no gene TP53 em tumores malignos de mama: associação com fatores de risco e característica clínico-patológicas, inclusive risco de óbito, em pacientes residentes no Rio de Janeiro / TP53 mutation in malignant breast tumors: association with risk factors and clinical-pathological characteristics, including risk of death, in patients from Rio de Janeiro

No Brasil o câncer de mama é a primeira causa de óbito por câncer entre mulheres, sendo o Rio de Janeiro o Estado que apresenta o maior coeficiente de mortalidade do país. Estudos que avaliam a sobrevida por câncer de mama têm indicado que vários fatores de ordem genética e molecular podem influenciar a evolução dos casos. O objetivo deste trabalho foi descrever mutações no gene TP53 em 120 pacientes com diagnóstico de carcinoma invasivo de mama, recrutadas no Instituto Nacional de Câncer (INCA), Rio de Janeiro, entre 1995 a 1997, e analisar as possíveis associações entre fatores de risco e presença de mutação e entre características do tumor, incluindo estas mutações e o risco de óbito. A análise molecular detectou 24 mutações no gene TP53 em 22 casos (18,3 por cento), sendo que 2 casos apresentaram 2 mutações cada e, em um caso observamos o polimorfismo no éxon 6. As mutações encontradas eram: 14 com troca de sentido; 2 sem sentido; 2 silenciosas; 2 deleções; 1 inserção e 3 localizadas em íntron. Em relação aos fatores de risco estudados em associação à presença de mutação, observou-se que apenas o consumo de tabaco mostrou associação negativa (OR ajustado = 0,24 (0,06-0,88)). A análise multivariada utilizada para avaliar as características tumorais associadas ao risco de óbito mostrou que apenas a agressividade do tumor apresentou OR indicativo de risco (3,98, IC 95 por cento 1,25-12,72). Estes resultados corroboram outros estudos que mostram que a mutação no gene TP53 pode ser um indicador de tumores de mama biologicamente mais agressivos, apesar de não ser o único parâmetro a ser considerado.