The human central nervous system (CNS) contains a daunting number of cells and tremendous cellular diversity. A fundamental challenge of developmental neurobiology is to address the questions of how so many different types of neurons and glia can be generated at the precise time and place, making precisely the right connections. Resolving this issue involves dissecting the elaborate genetic networks that act within neurons and glia, as well as in the neural progenitor cells that generates them, to specify their identities. My PhD project has involved addressing a number of unresolved issues pertaining to how neural progenitor cells are specified to generate different types of neurons and glial cells in different temporal and spatial domains, and also how these early temporal and spatial cues are integrated to activate late cell fate determinants, which act in post-mitotic neural cells to activate distinct batteries of terminal differentiation genes. Analyzing the development of a specific Drosophila melanogaster (Drosophila) CNS stem cell – the neuroblast 5-6 (NB5-6) – we have identified several novel mechanisms of cell fate specification in the Drosophila CNS. We find that, within this lineage, the differential specification of a group of sequentially generated neurons – the Ap cluster neurons – is critically dependent upon the simultaneous triggering of two opposing feed-forward loops (FFLs) within the neuroblast. The first FFL involves cell fate determinants and progresses within the post-mitotic neurons to establish a highly specific combinatorial code of regulators, which activates a distinct battery of terminal differentiation genes. The second loop, which progresses in the neuroblast, involves temporal and sub-temporal genes that together oppose the progression of the first FFL. This leads to the establishment of an alternative code of regulators in late-born Ap cluster neurons, whereby alternative cell fates are specified. Furthermore, we find that the generation and specification of the Ap cluster neurons is modulated along the neuraxis by two different mechanisms. In abdominal segments, Hox genes of the Bithorax cluster integrates with Pbx/Meis factors to instruct NB5-6 to leave the cell cycle before the Ap cluster neurons are generated. In brain segments, Ap cluster neuron equivalents are generated, but improperly specified due to the absence of the proper Hox and temporal code. Additionally, in thoracic segments we find that the specification of the Ap cluster neurons is critically dependent upon the integration of the Hox, Pbx/Meis, and the temporal genes, in the activation of the critical cell fate determinant FFL. We speculate that the developmental principles of (i) feed-forward combinatorial coding; (ii) simultaneously triggered yet opposing feed-forward loops; and (iii) integration of different Hox, Pbx/Meis, and temporal factors, at different axial levels to control inter-segmental differences in lineage progression and specification; might be used widely throughout the animal kingdom to generate cell type diversity in the CNS.

Following traumatic brain injury, there is an enhanced cell proliferative and neurogenic response in the young adult hippocampus, which may be associated with innate cognitive recovery. However, in the aged brain, an increased level of inflammatory cell responses was observed following injury concomitant to decreased hippocampal neurogenesis and cognitive recovery in the aging population. This suggests that excessive inflammation produced in the injured aging brain has a detrimental effect on neurogenesis and cognitive function. In this study, we examined the effect of anti-inflammatory treatment with minocycline on cell proliferation and generation of new neurons in the dentate gyrus (DG) of the hippocampus in both young and aged rats. Fisher 344 rats aged at 3 months and 20 months were subjected to a moderate lateral fluid percussion injury (LFPI) or cortical impact injury (CCI). Minocycline was administered intraperitoneally starting either at 30 minutes or 4 hours post-injury, thereafter twice daily for 2 days. BrdU was injected at 2 days post-injury to label injury-induced proliferating cells. To examine the effect of minocycline on cell proliferation, generation of new neurons, and inflammatory cell response at the acute stage post-injury, the rats were perfused 3 days post-injury. Brain sections were immunostained for BrdU and early neuronal marker doublecortin (DCX). The results show that short-term anti-inflammatory treatment with minocycline reduces the cell proliferative response, presumably inflammatory cell responses, in young and aged rats following LFPI and CCI injury, and enhances generation of new neurons in the hippocampus in both young and aged rats following LFPI and in aged rats following CCI injury. Therapies that enhance hippocampal neurogenesis may also have potential to improve cognitive recovery following TBI.

Our laboratory is primarily interested in novel pharmacological intervention of cell proliferation and survival pathways expressed in various types of cancer. These cyto-protective pathways can be activated in response to growth factor stimulation, toxic insult and radiation. In our studies, we utilized novel drug combinations with and without radiation to enhance breast & prostate tumor cell death both in vitro and in vivo. Previous studies from our group have shown that UCN-01 and MEK1/2 inhibitors interact to cause tumor cell death in transformed cell lines in vitro. We extended this observation to an in vivo animal model system using the estrogen dependent breast cell carcinoma line MCF-7 and the estrogen independent breast cell carcinoma line MDA-MB-231. This drug combination was shown to profoundly reduce tumor cell proliferation in vivo and also exhibited the ability to significantly reduce ex-vivo tumor cell colony formation 30 days after cessation of the combination drug treatment. In addition, tumor cell death coincided with decreased ERK112 phosphorylation, reduced immunoreactivity of Ki67 and CD31. Overall, these studies demonstrate that UCN-01 and MEK112 inhibitors have the potential to suppress mammary tumor growth in vivo which is independent of p53 status, estrogen dependency, caspase-3 levels or oncogenic K-RAS expression. In our LnCap prostate carcinoma cell studies we demonstrated the impact of hCG and lovastatin in combination with ionizing radiation to radiosensitize and enhance tumor cell lethality. This enhancement was attributed to the hCG-induced activation of ERBB1 via a GPCR, MEK112 and metalloprotease dependent paracrine mechanism which was further enhanced by radiation. This enhanced cell killing effect was shown to involve prolonged activation of PARP1 which could be suppressed by inhibition of ERBB1, MEKl , PI3 kinase or PARP1. Therefore, the combination of hCG, lovastatin and radiation may represent a novel approach to kill prostate cancer cells and potential new therapy.

Este estudo apresenta: (1) uma revisão atualizada sobre o desenvolvimento oocitário em teleósteos, as vias de involução no processo de regressão ovariana e a espécie modelo Astyanax altiparanae; (2) a descrição da morfologia ovariana e das células garminativas de A. altiparanae e a caracterização do seu ciclo reprodutivo; (3) a caracterização dos processos de involução de atresia folicular e complexos pós-ovulatórios de A. altiparanae e a localização de proteínas envolvidas nas vias de apoptose e autofagia ao longo desses processos. Foram apresentados neste estudo novos detalhes da oogênese para espécies de Astyanax, sendo que esses novos dados parecem ter aplicação na piscicultura. Além disso, A. altiparanae apresenta um período de desova longo, com pico reprodutivo de outubro a fevereiro, e desenvolvimento oocitário assíncrono. Por fim, parece haver uma interrelação entre as vias de autofagia e apoptose nos processos de involução ovarianos e as vias regulatórias desses processos parecem ser conservadas entre espécies de teleósteos com fertilização externa. / This study presents: (1) an updated review on oocyte development in teleosts, the involution pathways during the process of ovarian regression, and the model species Astyanax altiparanae; (2) the description of the ovarian and germ cell morphology of A. altiparanae and the characterization of its reproductive cycle; (3) the characterization of the involution processes of follicular atresia and post-ovulatory complexes of A. altiparanae and the localization of proteins involved in the apoptosis and autophagy pathways throughout these processes. New details of the oogenesis for Astyanax species were presented in this study, and these new data seem to be applied in fish culture. In addition, A. altiparanae presents a long spawning period, with reproductive peak from October to February, and asynchronous oocyte development. Finally, there seems to be a crosstalk between autophagy and apoptosis pathways in ovarian involution processes and the regulatory pathways of these processes seem to be conserved among species of teleosts with external fertilization.

O colágeno é a proteína fibrosa predominante da matriz extracelular e é a maior proteína constituinte do tecido conectivo. Alterações nas taxas de colágeno tipo I na derme ocorrem durante o envelhecimento. A introdução de um agente eficaz para a manutenção da pele durante o envelhecimento é importante, possibilitando a redução destes efeitos. Neste projeto foram avaliados os efeitos proliferativos e de biossíntese de colágeno, em fibroblastos humanos de derme normal tratados com colágeno bovino e derivados de diferentes perfis moleculares, colágeno super hidrolisado, colágeno hidrolisado e gelatina, em diferentes experimentos, adesão e viabilidade celular, síntese de colágeno e análises das fases do ciclo celular. Os resultados sugerem que o colágeno bovino e derivados induzem as propriedades adesivas nos fibroblastos, não desencadeiam efeitos citotóxicos e induzem a biossíntese de colágeno pelos fibroblastos. Os resultados de síntese de colágeno indicam que concentrações menores de colágeno super hidrolisado e colágeno hidrolisado podem ser utilizadas em relação à amostra de gelatina. Comparando os resultados após 48 horas de cultura na síntese de colágeno e nas modificações na fase S do ciclo celular, as células tratadas com as amostras de colágeno super hidrolisado e colágeno hidrolisado induziram aumentos significativos. / Collagen is the predominant fibrous protein of the extracellular matrix and it is a major protein constituting connective tissue. Alterations in the rate of collagen type I deposition occur during aging. The introduction of an efficient agent for the maintenance of the skin during the aging process is important as it can reduce those effects. Thus, the proliferative effects and collagen biosynthesis in normal dermis of human fibroblasts were evaluated in this project. The fibroblasts were treated with bovine collagen and its derivates from different molecular mass, as well as super hydrolysate collagen, hydrolysate collagen and gelatine. Different assays were applied as adhesion, cell viability, collagen biosynthesis, and cell cycle phases analysis. The results suggest that the bovine collagen and its derivates can induce to adhesion properties in fibroblasts, they do not produce cytotoxic effects, and they can induce the collagen biosynthesis by fibroblasts. The results also show that super hydrolysate collagen and hydrolysate collagen can be used in lower concentrations than gelatine in collagen biosynthesis analysis. Analyzing the results after 48 hours of culture, the cells treated with the samples of super hydrolysate collagen and hydrolysate collagen had significant improvement in the collagen biosynthesis and in the modifications in the S phase of the cell cycle.

O câncer cervical é o segundo mais comum em mulheres em países em desenvolvimento, sendo causado por infecção persistente por Papilomavírus Humano (HPV). Quando esta persistência ocorre, entre outros fatores, está relacionada a mecanismos de evasão do sistema imune apresentados pelo vírus. A frequência de macrófagos aumenta com a progressão da lesão cervical e há aumento de células mielóides no baço de camundongos com tumor. Este trabalho tem como objetivo observar os efeitos sistêmicos de tumores associados ao HPV sobre a proliferação e recrutamento de células do sistema imune e identificar fatores que tenham papel nesses mecanismos. Utilizando modelos de tumor in vivo, observou-se que tumores associados ao HPV recrutam mais células para o tumor e induzem maior proliferação celular. Também avaliamos o perfil de expressão de citocinas nas linhagens tumorais e o perfil geral de expressão de proteínas através de eletroforese 2D. Com isto, demonstramos que linhagens tumorais positivas para HPV apresentam maior expressão de IL-6, IL-8, CXCL1, sICAM e Serpina E1. / Cervical cancer is the second most common type of cancer in women in developing countries. Its main etiologic factor is persistent infection with high risk human papillomavirus (HPV). This persistence occurs only in some cases and, among other factors, is related to mechanisms of immune evasion displayed by the virus. There is an increase in the frequency of macrophages proportional to cervical intraepithelial lesion grade and an increase of myeloid cells in the spleen of tumor bearing mice. This work aims to observe the systemic effects of HPV associated tumors on the proliferation and recruitment of immune cells, and identify factors that have a role in these mechanisms. Using in vivo tumor models, we found that HPV positive tumors recruit a higher percentage of cells and induce cellular proliferation. We also studied cytokine expression profiles of tumor cell lines, and performed proteomic assay with tumor cells transduced with HPV oncogenes. Our data shows that HPV associated tumor cell lines display higher expression of IL-6, IL-8, CXCL1, sICAM and Serpin E1.

Apesar da ampla aplicação clínica de plasma rico em plaquetas (PRP), a sua eficácia no reparo de defeitos ósseos e na osseointegração de implantes metálicos continua sendo questionada. Em vista disso, objetivo do presente estudo foi avaliar os efeitos de um coquetel contendo os principais fatores de crescimento (GFs) e proteínas de PRP no desenvolvimento do fenótipo osteogênico in vitro sobre titânio (Ti). O coquetel referido continha PDGF-BB, TGF-β1, TGF- β2, albumina, fibronectina e trombospondina. Células da linhagem osteoblástica foram obtidas por digestão enzimática de osso alveolar humano e cultivadas sob condições osteogênicas convencionais até a subconfluência, sendo, em seguida, subcultivadas sobre superfície de Ti. As subculturas foram expostas durante os 7 primeiros dias a meio osteogênico, suplementado com GFs e proteínas, e apenas ao meio osteogênico nos 7 dias subseqüentes. Os grupos controles foram expostos apenas ao meio osteogênico. Nos experimentos dose-resposta foram utilizadas culturas primárias de calvária de ratos, as quais foram expostas ao coquetel de GFs e proteínas e às suas diluições de 1:10 e 1:100. Culturas derivadas de osso alveolar humano expostas ao coquetel de GFs e proteínas apresentaram: aumento significativo do número de células a partir do dia 4 e da proliferação celular em 1 e 4 dias; redução significativa nos níveis de atividade de fosfatase alcalina (ALP) em 4, 7 e 10 dias e ausência de marcação com vermelho de Alizarina em 14 dias. Apesar de as diluições 1:10 e 1:100 restaurarem a atividade proliferativa das culturas aos níveis controles, formações de matriz calcificada foram observadas apenas na diluição 1:100. Os resultados do presente trabalho mostram que o coquetel de GFs e proteínas inibe o desenvolvimento do fenótipo osteogênico de culturas de células osteoblásticas humanas e de ratos crescidas sobre Ti. / Background: Despite wide clinical application, the efficacy of platelet-rich plasma (PRP) for repairing bone defects and enhancing osseointegration of metal implants is still subject of debate. The objective of the present study was to evaluate the effects of a well-defined mixture of growth factors (GFs) and proteins (GFs+proteins) on the development of the osteogenic phenotype on titanium (Ti) in vitro. The composition of the mixture was based on the major components found in PRP preparations. Methods: The PRP-like mixture contained PDGF-BB, TGF-β1, TGF-β2, albumin, fibronectin, and thrombospondin. Osteoblastic cells were obtained by enzymatic digestion of human alveolar bone and cultured under standard osteogenic condition until subconfluence. They were then subcultured on Ti discs up to 14 days. Treated cultures were exposed during the first 7 days to osteogenic medium supplemented with GFs+proteins and to osteogenic medium alone thereafter. Control cultures were exposed to only osteogenic medium throughout the culture interval. Dose-response experiments were carried out using rat primary calvarial cells exposed to GFs+proteins and 1:10 or 1:100 dilutions of the mixture. Results: Treated human-derived cell cultures exhibited a significantly higher number of cells from day 4 on and of cycling cells at days 1 and 4, significantly reduced levels for alkaline phosphatase (ALP) activity, and no Alizarin red stained areas at day 14. Although the 1:10 and 1:100 dilutions restored the proliferative activity of rat calvaria-derived osteogenic cells to control levels, mineralized bone-like nodule formation was only observed with the 1:100 dilution. Conclusions: The present results demonstrated that a PRP-like protein mixture inhibits development of the osteogenic phenotype in both human and rat osteoblastic cell cultures grown on Ti.

MicroRNAs regulam processos celulares e tumorigênese. O carcinoma epidermoide de cabeça e pescoço (CECP) é a sexta neoplasia mais comum no mundo e não existe consenso sobre características moleculares representativas deste tumor. O receptor de fator de crescimento epidemal (EGFR), bem como efetores de sua via de sinalização, podem ser regulados por miRNA-7. Avaliamos a expressão de EGFR e miRNA-7 em amostras tumorais e livres de tumor, observando maior expressão em tumores. O papel do miRNA-7 em CECP foi investigado através de estudo de ganho de função em linhagem celular de carcinoma epidermoide de cabeça e pescoço e em queratinócito oral e por PCR Array direcionado para genes de vias mediadas por EGF. A super-expressão do miRNA-7 alterou a expressão de diversos genes na linhagem celular de carcinoma, resultando na diminuição da proliferação, possivelmente relacionada com a diminuição da expressão gênica e proteica de p70S6K1. Em queratinócitos orais não houve alteração significativa na expressão dos genes avaliados. Concluímos que miRNA-7 interfere na progressão do ciclo celular através da regulação de p70S6K1. A resposta diferente de dois tipos celulares à super-expressão do miRNA-7 mostra a complexidade de suas vias de regulação. / MicroRNAs regulate gene expression. Alterations in microRNA expression are involved in the progression of cancers. MiRNA-7 regulates epidermal growth factor receptor (EGFR) signaling and multiple other genes involved in EGFR-related pathways. Head and neck squamous cell carcinoma (HNSCC) is the six most common cancer in the world, with no consensus on molecular markers for prognosis. We assessed EGFR and miRNA-7 expression levels in HNSCC and tumor-free samples. MiRNA-7 was over-expressed in tumor. Aiming to understand the role of miRNA-7 and EGFR regulation in HNSCC, we over-expressed this molecule in an oral squamous cell carcinoma cell line and in normal oral keratinocytes, and evaluated the expression level of genes of the EGFR signaling pathway using a PCR Array. Most genes were deregulated in the cell line. Cell cycle arrest, possibly due to the down-regulation of p70S6K1, was observed. This deregulation was not detected, in keratinocytes. We conclude that miRNA-7 can interfere in cell cycle progression through targeting p70S6K1 but this action varies according to the molecular background of a given pathology. The understanding of this complexity in gene regulation in critical for therapeutic application of miRNAs.

Gliomas são tumores do sistema nervoso central e o glioblastoma multiforme (GBM) é sua forma mais comum e de pior prognóstico. A proliferação desordenada, migração estão entre os processos biológicos que conferem ao GBM um comportamento altamente agressivo. O objetivo deste estudo foi analisar in vitro o papel de PGE2 na proliferação, migração e apoptose da linhagem de glioma humano T98G através de tratamento com ácido gama-linolênico (GLA), Ibuprofeno (IBU) e adição de prostaglandina E1 (PGE1) e prostaglandina E2 (PGE2) exógeno. Nossos resultados demonstraram através uma diminuição nas taxas de proliferação e de migração e uma indução de apoptose nas células T98G tratadas com GLA ou IBU. Por outro lado, a adição exógeno de PGE1 ou PGE2 resultou num aumentou da proliferação e da migração e numa inibição da apoptose. Esses resultados demonstram a influência de PGE2 na linhagem T98G. / Gliomas are tumors of the central nervous system and glioblastoma multiforme (GBM) is the most common form with the worst prognosis. Uncontrolled cell proliferation, migration are among the biological processes that give GBM a highly aggressive behavior. The aim of this study was to analyze in vitro the role of PGE2 the proliferation, migration and apoptosis of the T98G human glioma cell line through treatment with gamma-linolenic acid (GLA), ibuprofen (IBU) and the addition of exogenous prostaglandin E1 (PGE1) and prostaglandin E2 (PGE2). Our results demonstrated through various tests a decrease in the rates of proliferation and migration and an induction of apoptosis in T98G cells treated with GLA or IBU. On the other hand, the addition of exogenous PGE1 or PGE2 resulted in increased proliferation and migration and inhibition of apoptosis. These results demonstrate the influence of PGE2 in the T98G cell line.

Apesar dos avanços no tratamento dos diferentes subtipos moleculares do câncer de mama, diversos efeitos colaterais e resistência ao tratamento são observados. Nesse contexto, a busca por novos marcadores moleculares ainda é necessária. A família do coativador - 1 do receptor ativado por proliferadores de peroxissoma gama-1 (PGC-1) exerce funções cruciais no metabolismo energético celular e alguns trabalhos na literatura mostram alterações de PGC-1 no desenvolvimento do câncer. Contudo, mecanismos envolvidos na proliferação celular do carcinoma de mama permanecem desconhecidos. O objetivo geral foi determinar os mecanismos pelos quais PGC-1 controla a proliferação de células tumorais de mama, com foco em vias metabólicas e de sinalização redox. Para alcançar os objetivos, foi determinada a expressão de PGC-1alfa e beta em células tumorais de mama dos subtipos moleculares luminal (MCF-7), HER2- superexpresso (SKBR3) e triplo negativo (MDAMB231) em relação a uma linhagem de mama não tumoral (MCF-10A). Foi encontrada maior expressão gênica e proteica de PGC-1beta na superexpressão de HER2, e maior taxa de crescimento para essa linhagem. Para investigar se PGC-1beta pode estar envolvido na proliferação dessas células, utilizamos sequências específicas de RNA de interferência para o knockdown de PGC-1beta nas células SKBR3. Após o tratamento houve diminuição de proliferação celular. Assim, investigamos os prováveis mecanismos pelos quais PGC-1beta diminui a proliferação celular. Nossos resultados mostram que o knockdown de PGC-1beta não influenciou a expressão de ciclinas (B, C, D e E) e não houve diferença na quantidade de DNA mitocondrial, fator de transcrição mitocondrial A (TFAM), fator de respiração nuclear (NRF) 1 e 2. Em seguida, mostramos que o knockdown de PGC-1beta diminuiu a produção de lactato intracelular e aumentou a atividade da enzima citrato sintase, e houve tendência a maior taxa de respiração celular. Detectamos maiores níveis de espécies reativas de oxigênio (EROs) após knockdown de PGC-1beta enquanto que a produção de nitrito e nitrato, não diferiu. Não houve alteração na atividade das enzimas antioxidantes superóxido dismutase, catalase e sistema glutationa. Os resultados revelam presença de despolarização mitocondrial quando PGC-1? é diminuído nas células HER2. Como os receptores relacionados a estrógeno (ERR) possuem conhecido papel na regulação do metabolismo energético, avaliamos se sua expressão é modulada por PGC-1?. A diminuição de PGC-1beta não influenciou a expressão gênica de ERRy e reduziu a expressão gênica de ERRalfa. Por fim, mostramos maior expressão de PGC-1beta proveniente de tumores de pacientes com câncer de mama HER2- superexpresso em relação aos diferentes subtipos moleculares. Conclui-se que a diminuição da sinalização por HER2/ PGC-1beta/ ERRalfa está envolvida com a diminuição da via glicolítica e aumento da via oxidativa com consequente aumento de EROs e perda do potencial de membrana mitocondrial, resultando em diminuição da proliferação celular. Espera-se que os resultados desse estudo ajudem na identificação de vias de sinalização importantes que controlam tanto o metabolismo energético quanto a proliferação de células tumorais, as quais poderão se tornar alvos terapêuticos no futuro / Despite a marked improvement in treatments for all breast cancer subtypes, several side-effects and resistance to therapy are noticed. In this context, the searching for new molecular targets for breast cancer treatment is still a challenge. Peroxisome proliferator-activated receptor- gamma coactivator 1 (PGC-1) is the main regulator of cell energy homeostasis and studies in the literature show alterations regarding PGC-1 in cancer development. However, mechanisms involved in cellular proliferation of breast cancer remain unknown. We aimed to determine the mechanisms by which PGC-1beta controls breast cancer cell proliferation, focusing on metabolic and redox signaling. To reach this goal, we determined PGC-1alfa and beta expression in breast cancer cell lines as luminal (MCF-7), HER2-overexpressed (SKBR3) and triple- negative (MDAMB231) as compared to a non-tumoral breast cell line (MCF-10A). We found increased gene and protein expression of PGC-1beta in HER2- overexpressed cells and increased cellular proliferation. To investigate whether PGC-1beta could be involved in the proliferation of those cells, we used specific sequences of silencing interfering RNA for knockdown of PGC-1beta in SKBR3 cells. After treatment we observed a decrease in cellular proliferation. Thus, we next investigated the probable mechanisms by which PGC-1beta could decrease cellular proliferation. Our results showed that knockdown of PGC-1beta did not influence on cyclin expression (B, C, D and E), mitochondrial DNA number, mitochondrial transcription factor - A (TFAM), nuclear receptor factor (NRF) 1 and 2 expression. We showed that knockdown of PGC-1beta induced a decrease intracellular lactate production, increase in citrate synthase activity and a trend to increase cellular respiration rate. Thereby, we detected greater amounts of reactive oxygen species (ROS) after knockdown of PGC-1beta, and no alterations was found for nitrite and nitrate levels. No alterations regarding antioxidant enzymes activities as superoxide dismutase, catalase, and glutathione system were found. Results revealed loss of mitochondrial membrane potential when PGC-1beta is decreased in HER2- overexpressed cells. As estrogen related receptors (ERR) have a recognized role in the regulation of energetic metabolism, we assessed whether their expression could be modulated by PGC-1beta. The decrease in PGC-1beta expression did not influence on ERRy expression, but it decreased the gene expression of ERRalfa. Finally, we demonstrated increased PGC-1beta expression in HER2- overexpressing tumors from breast cancer patients. Taken together, we conclude that decrease in HER2/ PGC-1beta/ ERRalfa signaling may be related to decrease in glycolytic pathway and increase in oxidative metabolism resulting in increased ROS production and loss of mitochondrial membrane potential, which can lead to decreased cellular proliferation. We hope that the findings may help in the identification of important cellular signaling that may control energetic metabolism regarding tumor cells proliferation, which can became future target therapies