Overexpression of CDC7 in malignant salivary gland tumors correlates with tumor differentiation / Superexpressão de CDC7 em tumores malignos de glândulas salivares correlaciona-se com a diferenciação dos tumores

Abstract Introduction: Cell division cycle-7 protein is a serine/threonine kinase that has a basic role in cell cycle regulation and is a potential prognostic or therapeutic target in some human cancers. Objectives: This study investigated the expression of cell division cycle-7 protein in benign and malignant salivary gland tumors and also its correlation with clinicopathologic factors. Methods: Immunohistochemical expression of cell division cycle-7 was evaluated in 46 cases, including 15 adenoid cystic carcinoma, 12 mucoepidermoid carcinoma, 14 pleomorphic adenoma, and 5 normal salivary glands. Cell division cycle-7 expression rate and intensity were compared statistically. Results: The protein was expressed in almost all tumors. The intensity and mean of cell division cycle-7 expression were higher in malignant tumors in comparison with pleomorphic adenomas (p = 0.000). The protein expression was correlated with tumor grades (p = 0.000). Conclusions: The present study demonstrated cell division cycle-7 overexpression in malignant salivary gland tumors in comparison with pleomorphic adenomas, and also a correlation with tumor differentiation. Therefore, this protein might be a potential prognostic and therapeutic target for salivary gland tumors.

Resumo Introdução: A cell division cycle-7 é uma serina/treonina quinase que tem um papel básico na regulação do ciclo celular e é um potencial marcador prognóstico ou terapêutico em alguns tipos de câncer humano. Objetivos: Este estudo investigou a expressão de cell division cycle-7 em tumores de glândulas salivares benignos e malignos e também sua correlação com fatores clínico-patológicos. Método: A expressão imuno-histoquímica de cell division cycle-7 foi avaliada em 46 casos, incluindo 15 carcinomas adenoide císticos, 12 carcinomas mucoepidermoides, 14 adenomas pleomórficos e 5 glândulas salivares normais. A taxa de expressão e a intensidade da proteína cell division cycle-7 foram comparadas estatisticamente. Resultados: A proteína foi expressa em quase todos os tumores. A intensidade e a média da expressão de cell division cycle-7 foram maiores em tumores malignos em comparação com adenoma pleomórfico (p = 0,000). A expressão da proteína foi correlacionada com os graus do tumor (p = 0,000). Conclusões: O presente estudo demonstrou a superexpressão de cell division cycle-7 em tumores malignos de glândulas salivares quando comparada com o adenoma pleomórfico, além de uma correlação com a diferenciação de tumores. Portanto, essa proteína pode ser um potencial marcador prognóstico e terapêutico para tumores de glândulas salivares.

Remodelamento da matriz extracelular da medula óssea em desnutrição protéica: possível relação da via de AKT com a expressão de fibronectina e metaloproteinases de matriz / Extracellular matriz remodeling of the bone marrow in protein malnutrition: possible relationship of AKT pathway with expression of fibronectin and matriz metalloproteínases

A desnutrição proteica (DP) pode ocasionar alterações na matriz extracelular (MEC) de diferentes órgãos e tecidos, inclusive o hematopoético, com comprometimento funcional. Estudos do nosso laboratório demonstraram, em modelo murino de DP, aumento da expressão proteica de fibronectina (FN) no estroma medular ósseo in vivo, principalmente na região subendosteal (local de fixação da célula tronco progenitora hemopoética). Já in vitro, no estroma medular ósseo, observou-se tanto o aumento quanto a diminuição de FN e a presença de suas isoformas. Essas alterações de FN parecem estar envolvidas com a hipoplasia da medula óssea (MO) em camundongos desnutridos. As modificações quantitativas de FN podem ser devidas: (i) à ação das metaloproteinases de matriz (MMP) responsáveis pela degradação das proteínas da MEC; (ii) aos inibidores de metaloproteinases (TIMP) que regulam a degradação da MEC; (iii) às alterações transcricionais, reguladas pela via de AKT/mTOR, que controla os splicing alternativos na FN, resultando em isoformas dessa proteína; (iv) a processos pós-transcricionais modulados por LC3, que aumenta a tradução do RNAm de FN. Assim, o objetivo deste estudo foi elucidar os mecanismos que alteram o turnover de FN no estroma medular ósseo em modelo murino de DP. Utilizamos camundongos, C57BL/6J machos, adultos, separados em dois grupos: controle e desnutrido, alimentados, ad libitum, com ração contendo 12% e 2% de proteína, respectivamente. Após cinco semanas de indução à desnutrição os camundongos foram eutanasiados, e coletado o material biológico. Avaliamos: o estado nutricional, o hematológico, a histologia da MO femoral bem como a determinação imunohistoquímica da FN, MMP-2 e MMP-9, determinação da expressão de FN e suas isoformas em células totais da MO, o estabelecimento do estroma medular ósseo in vitro, por 28 e 35 dias de cultivo. A partir das culturas foram avaliadas a expressão de RNAm de FN e suas isoformas, MMP-2, MMP-9, TIMP-1, TIMP-2, AKT, mTOR e LC3α e ß, quantificação de MMP-2, MMP-9, TIMP-1, TIMP-2,TNFα, TGFß e IL-1ß e determinação de LC3ß e proteínas da via de AKT/mTOR. Não observamos alterações na expressão do RNAm de FN e suas isoformas ex vivo e in vitro, mas um aumento da deposição de FN na MO.Também não observamos modificações na imunolocalização de MMP-2 e MMP-9 na MO e na atividade dessas proteínas no sobrenadante de culturas de células estromais in vitro, mas houve aumento da expressão do RNAm de MMP-9 em 28 dias de cultivo. Não detectamos alterações na expressão de RNAm e na concentração de TIMP-1 e TIMP-2 no sobrenadante das culturas. Houve redução significativa de TNFα e TGFß no sobrenadante das culturas de 28 dias. Observamos aumento da expressão do RNAm de mTOR em culturas de 28 dias e LC3α e LC3ß em 35 dias de células estromais. Encontramos menor fosforilação de PI3K, AKT, PTEN, mTOR e mTOR total e aumento de LC3ß em culturas de 28 dias, mas redução de LC3ß em 35 dias. Em função dos dados inferimos que a DP conduz a alterações da FN que não estão relacionadas à ação de MMPs e TIMPs e sim a modificações de LC3ß e da via de AKT/mTOR

Protein malnutrition (PM) can lead changes in extracellular matrix (ECM) from several organs and tissues, including hematopoietic, with functional impairments. Research from our laboratory demonstrated, in a murine model of protein malnutrition, increase in proteic expression of fibronectin (FN) in vivo bone marrow stroma, principally in subendosteal region (attachment site of hematopoietic stem/progenitor cell - HSPC). It was observed as both an increase and a decrease in the presence of FN and its isoforms in vitro bone marrow stroma. These FN changes seem to be related to bone marrow (BM) hypoplasia in malnourished mice. Quantitative FN changes may be due to: (i) action of matrix metalloproteinases (MMP) responsible for ECM proteins degradation; (ii) tissue inhibitors of metalloproteinases (TIMP) that regulate ECM degradation; (iii) transicional changes regulated by AKT/mTOR pathway, which controls alternative splicing in FN, resulting in isoforms from this protein; (iv) post-transcriptional processes modulated by LC3 that increases FN mRNA translation. Therefore, the aim of this study was to elucidade the mechanisms that changes the FN turnover in bone marrow stroma in a murine model of PM. C57BL/6J, adult and male mice were used and divided into two groups: control and malnourished, fed ad libitum with ration containing 12% and 2% of protein, respectively. After five weeks of induction malnutrition, mice were euthanized and the biological material was collected. We evaluated: nutritional and hematologic status, the femoral BM histology, immunohistochemistry determination of FN, MMP-2 and MMP-9, the FN and its isoforms expression determination in total BM cells, establishment of in vitro bone marrow stroma for 28 and 35 days of culture. From the cultures were evaluated FN mRNA expressions and its isoforms, MMP-2, MMP-9, TIMP-1, TIMP-2, AKT, mTOR, LC3α and ß, quantification of MMP-2, MMP-9, TIMP-1, TIMP-2,TNFα, TGFß and IL-1ß and determination of LC3ß and AKT/mTOR proteins. No changes were observed, ex vivo and in vitro, in the expression of FN mRNA and its isoforms, but there was a FN deposition increase in BM. We did not observe modifications in MMP-2 e MMP-9 immunolocalization in BM and in these proteins activity in the supernatant of in vitro stromal cell culture, but there was an increase in MMP-9 mRNA expression after 28 days of culture. We did not detect changes in mRNA and in TIMP-1 and TIMP-2 expressions in the supernatant of cultures. There was significant reduction of TNFα and TGFß in the cultures supernatant of 28 days. We observed an increase of mTOR RNAm in 28 days cultures and also LC3α and LC3ß in stromal cells with 35 days. We found lower phosphorylation of PI3K, AKT, PTEN, mTOR e total mTOR and an LC3ß increase in 28 days cultures, yet an LC3ß reduction in 35 days. According to the data we conclude that PM leads to FN changes that are not related to MMPs and TIMPs actions, but the LC3ß and AKT/mTOR pathway modifications

Duodenal jejunal bypass attenuates non-alcoholic fatty liver disease in western diet-obese rats

PURPOSE: To evaluate the effects of duodenal-jejunal bypass (DJB) on serum and hepatic profiles of obese rats fed on a western diet (WD). METHODS: Twenty eight male Wistar rats were fed a standard rodent chow diet (CTL group) or WD ad libitum. After 10 weeks, WD rats were submitted to sham (WD SHAM) or duodenal-jejunal bypass (WD DJB). Body weight, fat pad depots, glycemia, insulinemia, HOMA-IR, TyG, lipids profile and hepatic analyses were evaluated two months after surgery. RESULTS: The WD SHAM group presented greater obesity, hyperglycemia, hyperinsulinemia, insulin resistance, hypertriglyceridemia and hepatic steatosis than the CTL group. WD DJB rats presented decreased serum glucose and insulin resistance, when compared to WD SHAM animals, without changes in insulinemia. In addition, DJB surgery normalized serum TG and attenuated TG accumulation and steatosis in the liver of the WD DJB group. Hepatic ACC and FAS protein expressions were similar in all groups. CONCLUSION: Duodenal-jejunal bypass attenuates hepatic parameters of non-alcoholic fatty liver disease in obese rats fed on a western diet. .

FGF-2, TGFâ-1, PDGF-A and respective receptors expression in pleomorphic adenoma myoepithelial cells: an in vivo and in vitro study

Myoepithelial cells have an important role in salivary gland tumor development, contributing to a low grade of aggressiveness of these tumors. Normal myoepithelial cells are known by their suppressor function presenting increased expression of extracellular matrix genes and protease inhibitors. The importance of stromal cells and growth factors during tumor initiation and progression has been highlighted by recent literature. Many tumors result from the alteration of paracrine growth factors pathways. Growth factors mediate a wide variety of biological processes such as development, tissue repair and tumorigenesis, and also contribute to cellular proliferation and transformation in neoplastic cells. OBJECTIVES: This study evaluated the expression of fibroblast growth factor-2 (FGF-2), transforming growth factor â-1 (TGFâ-1), platelet-derived growth factor-A (PDGF-A) and their respective receptors (FGFR-1, FGFR-2, TGFâR-II and PDGFR-á) in myoepithelial cells from pleomorphic adenomas (PA) by in vivo and in vitro experiments. MATERIAL AND METHODS: Serial sections were obtained from paraffin-embedded PA samples obtained from the school's files. Myoepithelial cells were obtained from explants of PA tumors provided by surgery from different donors. Immunohistochemistry, cell culture and immunofluorescence assays were used to evaluate growth factor expression. RESULTS: The present findings demonstrated that myoepithelial cells from PA were mainly positive to FGF-2 and FGFR-1 by immunohistochemistry and immunofluorescence. PDGF-A and PDGFR-á had moderate expression by immunohistochemistry and presented punctated deposits throughout cytoplasm of myoepithelial cells. FGFR-2, TGFâ-1 and TGFâR-II were negative in all samples. CONCLUSIONS: These data suggested that FGF-2 compared to the other studied growth factors has an important role in PA benign myoepithelial cells, probably contributing to proliferation of ...

Molecular assembly of mitogen-activated protein kinase module in ras-transformed NIH3T3 cell line

The ras, is a G-like protein that controls the mitogen-activated protein kinase (MAPK) pathway involved in control and differentiation of cell growth. MAPK is a key component of its signaling pathway and the aberrant activation may play an important role in the transformation process. To better understand roles of ras in the activation of MAPKs, we have established ras transformed NIH3T3 fibroblast cell line, and analyzed the MAPK module. The ras transformed cells formed numerous spikes at the edges of cells and showed loss of contact inhibition. The levels of ERK1/2 MAPKs as revealed by Western blot analysis were not significantly different between ras transformed and non-transformed cells. However, phosphorylation of ERK MAPKs and the level of MEK were significantly increased although the heavily expressed level of Raf-1, an upstream component of MAPK pathway was unchanged in ras transformed NIH3T3 cells. The sedimentation profile of the MAPK module kinases in a glycerol gradient showed the presence of a rather homogeneous species of multimeric forms of ERK1/2 and MEK as indicated by the narrow distribution peak areas. The broad sedimentation profile of the Raf-1 in a glycerol gradient may suggest possible heterologous protein complexes but the identification of interacting molecules still remains to be identified in order to understand the organization of the MAPK signal transduction pathway.