Ação da proteína amiloide sérica A em melanomas

Concentrações séricas basais da proteína amiloide sérica A (SAA) estão significativamente aumentadas em pacientes com câncer e alguns autores sugerem uma relação causal. Trabalho anterior do grupo mostrou que a SAA induz a proliferação de duas linhagens de glioblastoma humano e afeta os processos de invasividade in vitro, sustentando um papel pró-tumoral para esta proteína. Com base nesse trabalho, investigamos a abrangência dos efeitos de SAA para outro tipo de célula tumoral e para isso escolhemos um painel de linhagens de melanoma humano e uma linhagem primária obtida a partir de aspirado de linfonodo de paciente com melanoma, por nós isolada. Observamos que apesar da célula precursora de melanomas, isto é, melanócito, não produzir SAA, todas as linhagens de melanoma produziram a proteína e expressaram alguns dos seus receptores. Além disso, quando estas células foram estimuladas com SAA houve uma inibição da proliferação em tempos curtos de exposição (48 horas) e efeitos citotóxicos após um tempo maior (7 dias). A SAA também afetou processos de invasividade e a produção das citocinas IL-6, IL-8 e TNF-α. Aos avaliarmos o efeito da SAA na interação das células de melanoma com células do sistema imune, vimos que a SAA ativou uma resposta imune anti-tumoral aumentando a expressão de moléculas co-estumolatórias, como CD69 e HLA-DR, e sua função citotóxica. Ainda, vimos que a produção de TNF-α, IFN-γ, IL-10, IL-1β e IL-8 estimuladas por SAA podem contribuir com os efeitos desta. De forma geral estes resultados nos levam a crer que a SAA tem atividade anti-tumoral em melanomas. Finalizando, com base na importância do desenvolvimento da resistência às terapias atuais para o melanoma, observamos que em células resistentes ao PLX4032, um inibidor de BRAF, os efeitos imunomodulatórios induzidos pela SAA estão abolidos, possivelmente identificando um novo componente da resistência.

Current concepts of tumour metastasis

Background: Tumour metastasis remains the principal cause of treatment failure and poor prognosis in patients with cancer. Recent advances in our understanding of the biology of metastasis are providing novel potential targets for anti-cancer therapies. Aim: This paper reviews the current concepts in tumour metastasis. Methods: A review of Medline publications relating to the molecular biology and therapy of human tumour metastasis was conducted. Results and Discussion: Early metastasis models were based upon the premise of uninterrupted tumour growth, with the inevitable formation of distant metastases and eventual death of the patient. However, current research suggests that metastasis is an inefficient process governed by several rate-limiting steps, and that failure to negotiate these steps can lead to tumour dormancy. Successful metastatic tumour growth depends upon appropriate tumour-host microenvironment interactions and, ultimately, the development of vascularised metastases post-extravasation in the target organ. An understanding of the molecular mechanisms involved in this dynamic process will aid in the identification of therapeutic targets that may allow earlier diagnosis and more specific therapies for patients with metastasis.

Supportive care needs of people with brain tumours and their carers

Goals of work: The diagnosis and treatment of a brain tumour may result in long-term changes in a patient's functional and social abilities and/or in a greatly reduced life span. A qualitative investigation was conducted to examine the supportive care needs of patients with brain tumour and their carers. Materials and methods: Overall, 18 patients and 18 carers participated in focus groups or telephone interviews, following a structured interview guide to elicit supportive care services of importance to these patients and carers. Main results: Six major themes were identified using the framework analysis method, including needs for information and coping with uncertainty, practical support, support to return to pretreatment responsibilities or prepare for long-term care, support to deal with social isolation and organize respite care, support to overcome stigma/discrimination and support to discuss potentially reduced life expectancy. Conclusions: Five recommendations to improve service delivery include: assignment of a dedicated member of the care team or case manager; proactive dissemination of information, education and psychosocial support; access to objective assessment of neuropsychological functioning; facilitating easier access to welfare payments; and services facilitating communication about difficult illness-related topics. Provision of services along these recommendations could improve supportive care of brain tumour patients and their carers.

Cellular uptake and biological activity of synthetic hammerhead ribozymes

Glioblastoma Multiforme (GBM) is a highly malignant form of brain cancer for which there is no effective cure. The over-expression of a number of genes, including the epidermal growth factor receptor (EGFr), has been implicated as a causative factor of tumourigenesis. Ribozymes are a class of ribonucleic acid that possess enzymatic properties. They can inhibit gene-expression in a highly sequence specific manner by catalysing the trans-cleavage of target RNA. The potential use of synthetic hammerhead ribozymes as novel anti-brain tumour agents was investigated in this study. The successful use of synthetic, exogenously administered ribozymes for such applications will require chemical modifications that improve biological stability and a fundamental understanding of cellular uptake mechanisms. Chimeric 2'-O-methylated hammerhead ribozymes proved to be significantly more stable (>4000-fold) in serum than unmodified RNA ribozymes and exhibited high in vitro catalytic activity. The cellular association of an internally [32P]-labelled 2'-O-methylated chimeric ribozyme in U87-MG human glioma cells was temperature-, energy- and pH-dependent and involved an active process that could be competed with a variety of polyanions. Indications are that the predominant mechanism of uptake is by adsorptive and / or receptor mediated endocytosis. Twenty 2'-O-methylated chimeric ribozymes were designed to cleave various sites along the EGFr mRNA. In vitro, 18 ribozymes exhibited high activity in cleaving a complementary short substrate. Using LipofectAMINETM as a delivery agent, the efficacy of these ribozymes was evaluated in the A431 cell line, which expresses amplified levels of EGFr. Studies revealed that although the ribozymes were taken up by the cells and remained stable over a period of 4 days, no significant reduction in either EGFr expression or cell proliferation was evident. The presence of telomerase, a ribonucleoprotein responsible for telomere elongation, has been strongly associated with tumour progression. The biological activity of a 2'-O-methylated ribozyme targeted against the RNA component of telomerase was determined. The ribozyme exhibited specific dose-dependent inhibition of telomerase activity in U87-MG cell lysates with an IC50 of –4μM. When 4μM ribozyme was delivered to intact U87-MG cells, complexed to LipofectAMINETM, telomerase activity was significantly reduced to 74.5±4.17% of the untreated control. Free ribozyme showed no significant inhibitory effect demonstrating the importance of an appropriate delivery system for optimum delivery of exogenously administered ribozymes.

A novel and rational approach towards designing aluminium chelators

Aluminium (Al) is known to be neurotoxic and has been associated with the aetiology of Alzheimer's Disease. To date, only desferrioxamine (DFO), a trihydroxamic acid siderophore has been used in the clinical environment for the removal of Al from the body. However, this drug is expensive, orally inactive and is associated with many side effects. These studies employed a theoretical approach, with the use of quantum mechanics (QM) via semi-empirical molecular orbital (MO) calculations, and a practical approach using U87-MG glioblastoma cells as a model for evaluating the influence of potential chelators on the passage of aluminium into cells. Preliminary studies involving the Cambridge Structural Database (CSD) identified that Al prefers binding to bidentate ligands in a 3:1 manner, whereby oxygen was the exclusive donating atom. Statistically significant differences in M-O bond lengths when compared to other trivalent metal ions such as Fe3+ were established and used as an acceptance criterion for subsequent MO calculations. Of the semi-empirical methods parameterised for Al, the PM3 Hamiltonian was found to give the most reliable final optimised geometries of simple 3:1 Al complexes. Consequently the PM3 Hamiltonian was used for evaluating the Hf of 3:1 complexes with more complicated ligands. No correlation exists between published stability constants and individual parameters calculated via PM3 optimisations, although investigation of the dicarboxylates reveals a correlation of 0.961 showing promise for affinity prediction of closely related ligands. A simple and inexpensive morin spectrofluorescence assay has been developed and optimised producing results comparable to atomic absorption spectroscopy methods for the quantitative analysis of Al. This assay was used in subsequent in vitro models, initially on E. coli, which indicated that Al inhibits the antimicrobial action of ciprofloxacin, a potent quinolone antibiotic. Ensuing studies using the second model, U87-MG cells, investigated the influence of chelators on the transmembrane transport of Al, identifying 1,2-diethylhydroxypyridin-4-one as a ligand showing greatest potential for chelating Al in the clinical situation. In conclusion, these studies have explored semi-empirical MO Hamiltonians and an in-vitro U87-MG cell line, both as possible methods for predicting effective chelators of Al.

DNA chip designed antisense oligodeoxynucleotides targeting EGFR MRNA for brain tumour therapy

Glioblastoma multiforme (GBM) is a malignant brain tumour for which there is currently no effective treatment regime. It is thought to develop due to the overexpression of a number of genes, including the epidermal growth factor receptor (EGFR), which is found in over 40% of GBM. Novel forms of treatment such as antisense therapy may allow for the specific inhibition of aberrant genes and thus they are optimistic therapies for future treatment of GBM. Oligodeoxynucleotides (ODNs) are small pieces of DNA that are often modified to increase their stability to nucleases and can be targeted to the aberrant gene in order to inhibit it and thus prevent its transcription into protein. By specifically binding to mRNA in an antisense manner, they can bring about its degradation by a variety of mechanisms including the activation of RNase H and thus have great potential as therapeutic agents. One of the main drawbacks to the utilisation of this therapy so far is the lack of techniques that can successfully predict accessible regions on the target mRNA that the ODNs can bind to. DNA chip technology has been utilised here to predict target sequences on the EGFR mRNA and these ODNs (AS 1 and AS2) have been tested in vitro for their stability, uptake into cells and their efficacy on cellular growth, EGFR protein and mRNA. Studies showed that phosphorothioate and 2'O-methyl ODNs were significantly more stable than phosphodiester ODNs both in serum and serum-free conditions and that the mechanism of uptake into A431 cells was temperature dependent and more efficient with the use of optimised lipofectin. Efficacy results show that AS 1 and AS2 phosphorothioate antisense ODNs were capable of inhibiting cell proliferation by 69% ±4% and 65% ±4.5% respectively at 500nM in conjunction with a non-toxic dose of lipofectinTM used to enhance cellular delivery. Furthermore, control ODN sequences, 2' O-methyl derivatives and a third ODN sequence, that was found not to be capable of binding efficiently to the EGFR mRNA by DNA chip technology, showed no significant effect on cell proliferation. AS 1 almost completely inhibited EGFR protein levels within 48 hours with two doses of 500nM AS 1 with no effect on other EGFR family member proteins or by control sequences. RNA analysis showed a decrease in mRNA levels of 32.4% ±0.8% but techniques require further optimisation to confirm this. As there are variations found between human glioblastoma in situ and those developed as xenografts, analysis of effect of AS 1 and AS2 was performed on primary tumour cell lines derived from glioma patients. ODN treatment showed a specific knockdown of cell growth compared to any of the controls used. Furthermore, combination therapies were tested on A431 cell growth to determine the advantage of combining different antisense approaches and that of conventional drugs. Results varied between the combination treatments but indicated that with optimisation of treatment regimes and delivery techniques that combination therapies utilising antisense therapies would be plausible.

Cellular delivery of hammerhead ribozymes

Hammerhead ribozymes are potent RNA molecules which have the potential to specifically inhibit gene expression by catalysing the trans-cleavage of mRNAs. However, they are unstable in biological fluids and cellular delivery poses a problem. Site-specific chemical modification of hammerhead ribozymes was evaluated as a means of enhancing biological stability. Chimeric, 2'-O-methylated ribozymes, containing only five unmodified ribonucleotides, were catalytically active in vitro (kcat = 1.46 min-1) and were significantly more stable in serum and lysosomal enzymes than unmodified (all-RNA) counterparts. Furthermore, they remained undegraded in cell-containing media for up to 8 hours. Stability enhancement allowed cellular uptake properties of radiolabelled ribozymes to be assessed following exogenous delivery. Studies in vulval and glial cell lines indicated that chimeric ribozymes became cell-associated via an inefficient process, which was energy and concentration dependant. A considerable proportion of ribozymes remained bound to cell-surface components, however, a small proportion (<1%) were internalised via mechanisms of adsorptive and / or receptor mediated endocytosis. Fluorescent microscopy indicated that ribozymes were localised within endosomal / lysosomal vesicles following cell entry. This was confirmed by immuno-electron microscopy, which allowed the detection of biotin-labelled ribozymes within the cell ultrastructure. Despite the predominant localisation within endocytic vesicles, a small proportion of internalised ribozymes appeared able to exit these compartments and penetrate target sites within the nucleus and cytoplasm. The ribozymes designed in this report were directed against the epidermal growth factor receptor mRNA, which is over-expressed in a malignant brain disease called glioblastoma multiforme. In order to examine the fate of ribozymes in the brain, the distribution of FITC-labelled ribozymes was examined following intra-cerebro ventricular injection to mice. FITC-ribozymes demonstrated high punctate pattern of distribution within the striatum and cortex, which appeared to represent localisation within cell bodies and dendritic processes. This suggested that delivery to glial cells in vivo may be possible. Finally, strategies were investigated to enhance the cellular delivery of ribozymes. Conjugation of ribozymes to anti~transferrin receptor antibodies improved cellular uptake 3-fold as a result of a specific interaction with transferrin receptors. Complexation with cationic liposomes also significantly improved cell association, however, some toxiclty was observed and this could be a limitation to their use. Overall, it would appear that hammerhead ribozymes can be chemically stabilised to allow direct exogenous administration in vivo. However, additional delivery strategies are probably required to improve cellular uptake, and thus, allow ribozymes to achieve their full potential as pharmaceutical agents. KEYWORDS: Catalytic

Evaluation of DNA enzymes targeted against the RNA component of human telomerase

Glioblastoma Multiforme (GBM) is a highly malignant form of brain cancer for which there is currently no effective cure. Consequently, developing new therapies and elucidating effective targets is crucial for this fatal disease. In recent years, DNA enzymes, deoxyribonucleic acid molecules with enzymatic activity, have emerged. In the same manner as ribozymes, DNA enzymes are able to effect cleavage of RNA in a sequence-specific manner, and operate with catalytic efficiency. In this study, two DNA enzymes were designed to target the template region of human telomerase RNA (hTR), utilising the 10-23 and 8-17 catalytic motifs elucidated by Santoro and Joyce (1997). Telomerase is an RNA-dependent DNA polymerase, which stabilises telomere lengths by adding hexameric repeats (TTAGGG in humans) to chromosome termini, thus preventing the telomere shortening that usually occurs during mitotic cell division. Telomerase activity, whilst absent in normal somatic tissues, is present in almost 90% of all tumours. Thus, there is speculation that telomerase may be the much sought universal target for therapeutic intervention in cancer. In vitro cleavage assays showed both DNA enzymes to be catalytically competent. Unmodified phosphodiester (PO) backbone DNA enzymes were rapidly degraded in the presence of serum, with a half-life of 10 minutes. The common approach of introducing phosphorothioate (PS) linkages was used in an effort to overcome this instability. As a result of concurrent activity and stability studies on the DNA enzymes with various numbers of PS linkages, the DNA enzymes with a PO core and PS arms were chosen for use in further cell work. The cleavage activity of both was shown to be specific and affected by temperature, pH, MgCI2 concentration and enzyme concentration. Both DNA enzyme motifs reduced telomerase activity in cell lysates, as assessed by the telomerase repeat amplification protocol (TRAP) with an IC50 of 100nM. DNA enzymes being polyanionic molecules do not readily cross biological barriers. Cellular association of naked DNA enzyme was inefficient at less than 2%. Cellular delivery of the DNA enzymes was effectively improved using commercial cationic lipid formulations. However, the lipid-mediated delivery of DNA enzymes to U87-MG cells over a 4-hour period did not significantly inhibit cell proliferation compared to controls. This is possibly due to an expected lag period between the inhibition of telomere maintenance and cell death. Therefore, biodegradable polymer microspheres were investigated as a potential delivery option for prolonged and sustained delivery. In vitro release profiles showed that after an initial burst, sustained release of DNA enzymes was observed over 35 days. Finally, the efficacy and specificity of the DNA enzymes were demonstrated in a luciferase based reporter assay. Specific inhibition of luciferase expression was displayed at 10nM. Thus DNA enzymes have potential against endogenous cellular targets.

Evaluation of biodegradable polymer microspheres and an anionic dendrimer for the potential delivery of antisense oligonucleotides

Antisense oligonucleotides (AODNs) can selectively inhibit individual gene expression by binding specifically to rnRNA. The over-expression of the epidermal growth factor receptor (EGFR) has been observed in human breast and glioblastoma tumours and therefore AODNs designed to target the EGFR would be a logical approach to treat such tumours. However, poor pharmacokinetic/pharmacodynamic and cellular uptake properties of AODNs have limited their potential to become successful therapeutic agents. Biodegradable polymeric poly (lactide-co-glycolide) (P(LA-GA)) and dendrimer delivery systems may allow us to overcome these problems. The use of combination therapy of AODNs and cytotoxic agents such as 5-fluorouracil (5-FU) in biodegradable polymeric formulations may further improve therapeutic efficacy. AODN and 5-FU were either co-entrapped in a single microsphere formulation or individually entrapped in two separate microsphere formulations (double emulsion method) and release profiles determined in vitro. The release rates (biphasic) of the two agents were significantly slower when co-entrapped as a single microsphere formulation compared to those obtained with the separate formulations. Sustained release over 35 days was observed in both types of formulation. Naked and microsphere-loaded AODN and 5-FU (in separate formulations) were tested on an A431 vulval carcinoma cell line. Combining naked or encapsulated drugs produced a greater reduction in viable cell number as compared with either agent alone. However, controls and Western blotting indicated that non-sequence specific cytotoxic effects were responsible for the differences in viable cell number. The uptake properties of an anionic dendrimer based on a pentaerythritol structure covalently linked to AODNs (targeting the EGFR) have been characterised. The cellular uptake of AODN linked to the dendrimer was up to 3.5-fold higher in A431 cells as compared to naked AODN. Mechanistic studies suggested that receptor-mediated and adsorptive (binding protein-mediated) endocytosis were the predominant uptake mechanisms for the dendrimer-AODN. RNase H cleavage assay suggested that the dendrimer-AODN was able to bind and cleave the target site. A reduction of 20%, 28% and 45% in EGFR expression was observed with 0.05μM, 0.1μM and 0.5μM dendrimer-AODN treatments respectively with a reduction in viable cell number. These results indicated that the dendrimer delivery system may reduce viable cell number by an antisense specific mechanism.

The potential role of environmental exposures and genomic signaling in development of central nervous system tumors

The etiology of central nervous system tumors (CNSTs) is mainly unknown. Aside from extremely rare genetic conditions, such as neurofibromatosis and tuberous sclerosis, the only unequivocally identified risk factor is exposure to ionizing radiation, and this explains only a very small fraction of cases. Using meta-analysis, gene networking and bioinformatics methods, this dissertation explored the hypothesis that environmental exposures produce genetic and epigenetic alterations that may be involved in the etiology of CNSTs. A meta-analysis of epidemiological studies of pesticides and pediatric brain tumors revealed a significantly increased risk of brain tumors among children whose mothers had farm-related exposures during pregnancy. A dose response was recognized when this risk estimate was compared to those for risk of brain tumors from maternal exposure to non-agricultural pesticides during pregnancy, and risk of brain tumors among children exposed to agricultural activities. Through meta-analysis of several microarray studies which compared normal tissue to astrocytomas, we were able to identify a list of 554 genes which were differentially expressed in the majority of astrocytomas. Many of these genes have in fact been implicated in development of astrocytoma, including EGFR, HIF-1α, c-Myc, WNT5A, and IDH3A. Reverse engineering of these 554 genes using Bayesian network analysis produced a gene network for each grade of astrocytoma (Grade I-IV), and ‘key genes’ within each grade were identified. Genes found to be most influential to development of the highest grade of astrocytoma, Glioblastoma multiforme (GBM) were: COL4A1, EGFR, BTF3, MPP2, RAB31, CDK4, CD99, ANXA2, TOP2A, and SERBP1. Lastly, bioinformatics analysis of environmental databases and curated published results on GBM was able to identify numerous potential pathways and geneenvironment interactions that may play key roles in astrocytoma development. Findings from this research have strong potential to advance our understanding of the etiology and susceptibility to CNSTs. Validation of our ‘key genes’ and pathways could potentially lead to useful tools for early detection and novel therapeutic options for these tumors.

Computer assisted synthesis and in-vitro cytotoxic evaluation of new pyrazole-fused isoquinolinoquinones derivatives as PI3K receptor antagonist with promising antitumoral activity

The importance of pyrazole and isoquinoline-5,8-dione scaffolds in medical chemistry is underlined by the high number of drugs currently on trading that contains these active ingredients. Due to their cytotoxic capability, the interest of medicinal chemists in these heterocyclic rings has grown exponentially especially, for cancer therapy. In this project, the first synthesis of pyrazole-fused isoquinoline-5,8-diones has been developed. 1,3-Dipolar cycloaddition followed by oxidative aromatization, established by our research group, has been employed. Screening of reaction conditions and characterization studies about the regioselectivity have been successfully performed. A remote control of regioselectivity, to achieve the two possible regioisomers has been accomplished. Through Molecular Docking studies, Structure-Activity relationship of differently substituted scaffolds containing our central core proved that a family of PI3K inhibitors have been discovered. Finally, in order to verify the promising antitumor activity, a first test of cell viability in vitro on T98G cell line of a solid brain tumor, the Glioblastoma Multiforme, showed cytotoxic inhibition comparable to currently trade anticancer drugs.

The Role of PME-1 in Cancer: Therapeutic Implication

Protein phosphatase 2A (PP2A) plays a major role in maintaining cellular signaling homeostasis in human cells by reversibly affecting the phosphorylation of a variety of proteins. Protein phosphatase methylesterase-1 (PME-1) negatively regulates PP2A activity by reversible demethylation and active site binding. Thus far, it is known that overexpression of PME-1 in human gliomas contributes to ERK pathway signaling, cell proliferation, and malignant progression. Whether PME-1-mediated PP2A inhibition promotes therapy resistance in gliomas is unknown. Specific PP2A targets regulated by PME-1 in cancers also remain elusive. Additionally, whether oncogenic function of PME-1 can be generalized to various human cancers needs to be investigated. This study demonstrated that PME-1 expression promotes kinase inhibitor resistance in glioblastoma (GBM). PME-1 silencing sensitized GBM cells to a group of clinically used indolocarbazole multikinase inhibitors (MKIs). To facilitate the quantitative evaluation of MKIs by cancer-cell specific colony formation assay, Image-J software-plugin ‘ColonyArea’ was developed. PME-1-silencing was found to reactivate specific PP2A complexes and affect PP2A-target histone deacetylase HDAC4 activity. The HDAC4 inhibition induced synthetic lethality with MKIs similar to PME-1 depletion. However, synthetic lethality by both approaches required co-expression of a pro-apoptotic protein BAD. In gliomas, PME-1 and HDAC4 expression was associated with malignant progression. Using tumor PME-1, HDAC4 and BAD expression based stratification signatures this study defined patient subgroups that are likely to respond to MKI alone or in combination with HDAC4 inhibitor therapies. In contrast to the oncogenic role of PME-1 in certain cancer types, this study established that colorectal cancer (CRC) patients with high tumor PME-1 expression display favorable prognosis. Interestingly, PME-1 regulated survival signaling did not operate in CRC cells. Summarily, this study potentiates the candidacy of PME-1 as a therapy target in gliomas, but argues against generalization of these findings to other cancers, especially CRC.

Targeting and treatment of glioblastomas with human mesenchymal stem cells carrying ferrociphenol lipid nanocapsules

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Superparamagnetic Liposomes for MRI Monitoring and External Magnetic Field-Induced Selective Targeting of Malignant Brain Tumors

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Evaluación del perfil transcripcional y potenciales vías de señalización neuronal afectadas tras la inhibición del gen PRR12 por ArNi

Introducción: El sistema nervioso tiene como función el controlar y regular el funcionamiento de los diversos órganos y sistemas de los vertebrados, coordinando su interrelación, así como la relación del organismo con el medio externo, permitiendo su interacción. Este sistema se comienza a desarrollar durante la etapa embrionaria mediante la neurogénesis, en la cual múltiples procesos biológicos trabajan en conjunto para asegurar que los diversos tipos de células nerviosas proliferen, se diferencien, migren y formen sinapsis en el momento y lugar apropiado, siendo un mecanismo finamente regulado, dependiente de la apropiada expresión temporal y espacial, así como del correcto funcionamiento de diferentes productos génicos. Debido a esto, mutaciones que alteren la correcta expresión o función de un gen involucrado en la neurogénesis y/o en el mantenimiento del SNC pueden contribuir a la iniciación y/o progresión de diversos desórdenes neurológicos. En este respecto, nuestro grupo de investigación identificó por primera vez la ruptura del gen PRR12, en una paciente con discapacidad intelectual, alteraciones neuropsiquiátricas y múltiples malformaciones menores. Debido a esto, y a las características de la proteína PRR12, con una función hasta la fecha totalmente desconocida, este es un blanco deseable para el análisis de las vías de señalización en las que participa. Objetivo: Describir los genes que son potencialmente regulados por PRR12 y, a partir de ello, analizar las posibles vías y procesos de comunicación neuronal afectados tras su inhibición. Materiales y Métodos: Se realizó una cuantificación relativa de la expresión de PRR12 en cerebro de rata en diferentes estadios del desarrollo (embrión, neonatal y adulto), mediante Western blot y qPCR. Posteriormente se realizó la inhibición de PRR12 en células C6 de glioblastoma de rata, mediante ARNi, con el fin de determinar los cambios en el perfil de expresión celular, mediante microarreglos de expresión. Resultados: PRR12 se encontró mayormente expresado en cerebro durante la etapa de embrión; además de esto, se encontraron afectados múltiples genes tras su inhibición, entre los que destacan aquellos involucrados en procesos biológicos relacionados a comunicación celular y de las vías de señalización de receptores de membrana acoplados a proteína G. Conclusiones: PRR12 es probablemente un factor de transcripción de remodelación de la cromatina, con posible implicación en el proceso de neurogénesis, especialmente en procesos de comunicación y diferenciación celular.