Chromatin enrichment of histone marks H4Ac and H3K9me3 in TP53 gene domain in breast cells

In non-cancerous breast cell lines HB2 and MCF10A the TP53 gene is localized inside a relatively small ~ 50 kb loop domain delimited by two S/MARs. Aim. To analyze the chromatin markers H4Ac and H3K9me3 of these two S/MARs and of the TP53 gene P1 promoter in different breast cells lines. Methods. We used chromatin immunoprecipitation (ChIP) to characterize the chromatin status of these S/MARs elements in breast non-cancerous cell lines HB2 and MCF10A and cancerous MCF-7, MDA-MB-231, BT-474 and T47D cell lines, by chromatin enrichment of H4Ac and H3K9me3 epigenetic markers, hallmarks of open and closed chromatin, respectively. Results. We found that these chromatin epigenetic markers are differentially distributed in S/MARs for all analyzed breast cell lines. Conclusions. We found no correlation between S/MARs and chromatin epige- netic status, suggesting that nuclear matrix fixation and chromatin status can be independent. High enrichment of H3K9me3 in the TP53 gene P1 promoter region in MCF-7, could explain lower levels of the TP53 expression, described earlier by our group.У неонкогенних клітинних лініях HB2 і MCF10A ген TP53 локалізований всередині відносно невеликої області (~ 50 тис. пар нуклеотидів) петлі домену, обмеженої двома S/MARs (ділянками, асо- ційованими з матриксом). Мета. Проаналізувати хроматинові маркери H4Ac і H3K9me3 в означених S/MARs і P1 промоторі гена TP53 в різних клітинних лініях молочної залози. Методи. Використано імунопреципітацію хроматину (чип) для характеристики стану хроматину елементів S/MARs у неонкогенних клітинних лініях HB2 і MCF10A та злоякісних клітинних лініях MCF-7, MDA-MB-231, БТ-474 і T47D за допомогою H4Ac і H3K9me3 епігенетичних маркерів за ознаками відкритого і закритого хроматину відповідно. Результати. Виявлено, що зазначені епігенетичні маркери нерівномірно розподілені в S/MARs для всіх проаналізованих клітинних ліній молочної залози. Висновки. Не знайдено кореляції в епігенетичному статусі S/MARs і хроматина, що дозволяє зробити припущення, що фіксація ядерного матриксу і статус хроматину можуть бути незалежними. Суттєве збагачення H3K9me3 P1 промоторної областігена TP53 в клітинній лінії MCF-7 може бути причиною нижчих рівнів експресії TP53, описаних раніше нашою групою.В неонкогенных клеточных линиях HB2 и MCF10A ген TP53 расположен внутри петли домена:относительно небольшой области (~ 50 тыс. пар нуклеотидов), ограниченной двумя S/MARs (участками, ассоциированными с матриксом). Цель. Проанализировать маркеры хроматина H4Ac и H3K9me3 в указанных S/MARs и P1 промотре гена TP53 в различных клеточных линиях молочной железы. Методы. Использовали иммунопреципитацию хроматина (чип) для характеристики состояния хроматина элементов S/MARs в неонкогенных клеточных линиях HB2 и MCF10A и злокачественных клеточных линиях MCF-7, MDA-MB-231, БТ-474 и T47D с помощью H4Ac и H3K9me3 эпигенетических маркеров по признакам открытого и закрытого хроматина соответственно. Результаты. Указанные эпигенетические маркеры неравномерно распределены в исследованных S/MARs для всех анализируемых линий клеток молочной железы. Выводы. Не выявлена корреляция в эпигенетическом статусе S/MARs и хроматина, что позволяет предположить, что фиксация в ядерного матрикса и статус хроматина могут быть независимыми. Существенное обогащение H3K9me3 P1 промоторной области гена TP53 клеточной линии MCF-7 может быть причиной более низких уровней экспрессии TP53, описанных ранее нашей группой

ESTUDOS DE CASO EM TREINO PARENTAL PARA FAMÍLIAS EM DESCUMPRIMENTO DE CONDICIONALIDADES DO PROGRAMA BOLSA FAMÍLIA

O objetivo deste estudo foi implementar e avaliar um programa de habilidades parentais em famílias em descumprimento de condicionalidades junto ao Programa Bolsa Família, por abandono escolar entre filhos adolescentes e alta incidência de conflito familiar. O delineamento utilizado foi o estudo de caso. Participaram duas famílias, avaliadas por meio do Inventário de Estilos Parentais – IEP na condição pré e pós-intervenção e no follow up de três  meses. A intervenção foi realizada no domicílio e consistiu de oito sessões nas quais se discutiu: autocontrole e manejo do estresse; práticas parentais positivas e negativas; análise de contingências; limites e disciplina. Os resultados mostraram que em ambas as famílias houve o acréscimo de repertório comportamental nas mães quanto ao estabelecimento e cumprimento de regras, instalação do diálogo como forma de negociação e resolução de conflitos, do fortalecimento de vínculos através do afeto, das atividades conjuntas e do reforço positivo

Genomic instability at the 13q31 locus and somatic mtDNA mutation in the D-loop site correlate with tumor aggressiveness in sporadic Brazilian breast cancer cases

OBJECTIVE: Genomic instability is a hallmark of malignant tissues. In this work, we aimed to characterize nuclear and mitochondrial instabilities by determining short tandem repeats and somatic mitochondrial mutations, respectively, in a cohort of Brazilian sporadic breast cancer cases. Furthermore, we performed an association analysis of the molecular findings and the clinical pathological data. METHODS: We analyzed 64 matched pairs of breast cancer and adjacent non-cancerous breast samples by genotyping 13 nuclear short tandem repeat loci (namely, D2S123, TPOX, D3S1358, D3S1611, FGA, D7S820, TH01, D13S317, D13S790, D16S539, D17S796, intron 12 BRCA1 and intron 1 TP53) that were amplified with the fluorescent AmpFlSTR Identifiler Genotyping system (Applied Biosystems, USA) and by silver nitrate staining following 6% denaturing polyacrylamide gel electrophoresis. Somatic mtDNA mutations in the D-loop site were assessed with direct sequencing of the hypervariable HVI and HVII mitochondrial regions. RESULTS: Half of the cancer tissues presented some nuclear instability. Interestingly, the D13S790 locus was the most frequently affected (36%), while the D2S123 locus presented no alterations. Forty-two percent of the cases showed somatic mitochondrial mutations, the majority at region 303-315 poly-C. We identified associations between Elston grade III, instabilities at 13q31 region (p = 0.0264) and mtDNA mutations (p = 0.0041). Furthermore, instabilities at 13q31 region were also associated with TP53 mutations in the invasive ductal carcinoma cases (p= 0.0207). CONCLUSION: Instabilities at 13q31 region and the presence of somatic mtDNA mutations in a D-loop site correlated with tumor aggressiveness

Risco de câncer no Brasil: tendências e estudos epidemiológicos mais recentes

O número de casos de câncer tem aumentado de maneira considerável em todo o mundo, principalmente a partir do século passado, configurando-se, na atualidade, como um dos mais importantes problemas de saúde pública mundial. A freqüência de distribuição dos diferentes tipos de câncer apresenta-se variável em função das características de cada região, o que enfatiza a necessidade do estudo das variações geográficas nos padrões desta doença, para seu adequado monitoramento e controle. Por meio de revisão da literatura especializada mais recente, foram descritos alguns dos principais tipos de câncer no Brasil, com enfoque nas pesquisas epidemiológicas que investigaram os fatores associados ao risco de adoecer por estes cânceres em nosso país. Desta forma, os autores deste estudo objetivaram contribuir para a avaliação do risco atual de câncer no Brasil, buscando uma análise das tendências em sua incidência, estratégia de fundamental valor para o desenvolvimento de políticas de saúde adequadas que visem ao controle desta doença em nosso país

Identification of anaerobic threshold using heart rate response during dynamic exercise

The objective of the present study was to characterize the heart rate (HR) patterns of healthy males using the autoregressive integrated moving average (ARIMA) model over a power range assumed to correspond to the anaerobic threshold (AT) during discontinuous dynamic exercise tests (DDET). Nine young (22.3 ± 1.57 years) and 9 middle-aged (MA) volunteers (43.2 ± 3.53 years) performed three DDET on a cycle ergometer. Protocol I: DDET in steps with progressive power increases of 10 W; protocol II: DDET using the same power values as protocol 1, but applied randomly; protocol III: continuous dynamic exercise protocol with ventilatory and metabolic measurements (10 W/min ramp power), for the measurement of ventilatory AT. HR was recorded and stored beat-to-beat during DDET, and analyzed using the ARIMA (protocols I and II). The DDET experiments showed that the median physical exercise workloads at which AT occurred were similar for protocols I and II, i.e., AT occurred between 75 W (116 bpm) and 85 W (116 bpm) for the young group and between 60 W (96 bpm) and 75 W (107 bpm) for group MA in protocols I and II, respectively; in two MA volunteers the ventilatory AT occurred at 90 W (108 bpm) and 95 W (111 bpm). This corresponded to the same power values of the positive trend in HR responses. The change in HR response using ARIMA models at submaximal dynamic exercise powers proved to be a promising approach for detecting AT in normal volunteers

First Record of Xylosandrus Compactus in Seedlings and Plantations of African Mahogany (Khaya Senegalensis) in Northeastern Brazil

Abstract The objective of this study was to report the first record of Xylosandrus compactus in a Khaya senegalensis plantation in the Northeast region of Brazil. The study area comprised 10 hectares of African mahogany (Khaya senegalensis) planted under different silvicultural systems and varying in age (4, 10 and 24 months). From May to July 2019, both larvae and adults of Xylosandrus compactus, attacked the petiole of adult trees in the field, promoting small holes followed by darkening from the hole to the leaf tip. Furthermore, the stem of the seedlings at the nursery had holes in its stem basis and internal galleries in young and adult individuals. It is estimated that 77% of the Khaya senegalensis population in the 24-month trees were attacked. Therefore, the growth of the trees may be compromised, and if there is no proper management, X. compactus can cause economic damage in the K. senegalensis plantation

Spatial configuration of the chicken α-globin gene domain: immature and active chromatin hubs

The spatial configuration of the chicken α-globin gene domain in erythroid and lymphoid cells was studied by using the Chromosome Conformation Capture (3C) approach. Real-time PCR with TaqMan probes was employed to estimate the frequencies of cross-linking of different restriction fragments within the domain. In differentiated cultured erythroblasts and in 10-day chick embryo erythrocytes expressing ‘adult’ αA and αD globin genes the following elements of the domain were found to form an ‘active’ chromatin hub: upstream Major Regulatory Element (MRE), −9 kb upstream DNase I hypersensitive site (DHS), −4 kb upstream CpG island, αD gene promoter and the downstream enhancer. The αA gene promoter was not present in the ‘active’ chromatin hub although the level of αA gene transcription exceeded that of the αD gene. Formation of the ‘active’ chromatin hub was preceded by the assembly of multiple incomplete hubs containing MRE in combination with either −9 kb DHS or other regulatory elements of the domain. These incomplete chromatin hubs were present in proliferating cultured erythroblasts which did not express globin genes. In lymphoid cells only the interaction between the αD promoter and the CpG island was detected

XRCC1 gene polymorphisms in a population sample and in women with a family history of breast cancer from Rio de Janeiro (Brazil)

The X-ray repair cross-complementing Group1 (XRCC1) gene has been defined as essential in the base excision repair (BER) and single-strand break repair processes. This gene is highly polymorphic, and the most extensively studied genetic changes are in exon 6 (Arg194Trp) and in exon 10 (Arg399Gln). These changes, in conserved protein sites, may alter the base excision repair capacity, increasing the susceptibility to adverse health conditions, including cancer. In the present study, we estimated the frequencies of the XRCC1 gene polymorphisms Arg194Trp and Arg399Gln in healthy individuals and also in women at risk of breast cancer due to family history from Rio de Janeiro. The common genotypes in both positions (194 and 399) were the most frequent in this Brazilian sample. Although the 194Trp variant was overrepresented in women reporting familial cases of breast cancer, no statistically significant differences concerning genotype distribution or intragenic interactions were found between this group and the controls. Thus, in the population analyzed by us, variants Arg194Trp and Arg399Gln did not appear to have any impact on breast cancer susceptibility