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Resistance to inactive state-selective RASG12C inhibitors frequently entails accumulation of RASGTP, rendering effective inhibition of active RAS potentially desirable. Here, we evaluated the anti-tumor activity of the RAS(ON) multi-selective tri-complex inhibitor RMC-7977 and dissected mechanisms of response and tolerance in KRASG12C-mutant NSCLC. Broad-spectrum, reversible RASGTP inhibition with or without concurrent covalent targeting of active RASG12C yielded superior and differentiated antitumor activity across diverse co-mutational KRASG12C-mutant NSCLC mouse models of primary or acquired RASG12C(ON) or (OFF) inhibitor resistance. Interrogation of time-resolved single cell transcriptional responses established an in vivo atlas of multi-modal acute and chronic RAS pathway inhibition in the NSCLC ecosystem and uncovered a regenerative mucinous transcriptional program that supports long-term tumor cell persistence. In patients with advanced KRASG12C-mutant NSCLC, the presence of mucinous histological features portended poor response to sotorasib or adagrasib. Our results have potential implications for personalized medicine and the development of rational RAS inhibitor-anchored therapeutic strategies.
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The regulatory T cell master transcription factor, Forkhead box P3 (Foxp3), has been detected in cancer cells; however, its role in breast tumor pathogenesis remains controversial. Here we assessed Foxp3 tumor intrinsic effects in experimental breast cancer using a Foxp3 binder peptide (P60) that impairs Foxp3 nuclear translocation. Cisplatin upregulated Foxp3 expression in HER2+ and triple-negative breast cancer (TNBC) cells. Foxp3 inhibition with P60 enhanced chemosensitivity and reduced cell survival and migration in human and murine breast tumor cells. We also developed an adenoviral vector encoding P60 (Ad.P60) that efficiently transduced breast tumor cells, reduced cell viability and migration, and improved the cytotoxic response to cisplatin. Conditioned medium from transduced breast tumor cells contained lower levels of IL-10 and improved the activation of splenic lymphocytes. Intratumoral administration of Ad.P60 in breast-tumor-bearing mice significantly reduced tumor infiltration of Tregs, delayed tumor growth, and inhibited the development of spontaneous lung metastases. Our results suggest that Foxp3 exerts protumoral intrinsic effects in breast cancer cells and that gene-therapy-mediated blockade of Foxp3 could constitute a therapeutic strategy to improve the response of these tumors to standard treatment.
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Neoplasias da Mama , Neoplasias de Mama Triplo Negativas , Humanos , Animais , Camundongos , Feminino , Neoplasias da Mama/genética , Neoplasias da Mama/terapia , Cisplatino/farmacologia , Linfócitos T Reguladores , Peptídeos/farmacologia , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismoRESUMO
Infiltration of regulatory T (Treg) cells, an immunosuppressive population of CD4+ T cells, into solid cancers represents a barrier to cancer immunotherapy. Chemokine receptors are critical for Treg cell recruitment and cell-cell interactions in inflamed tissues, including cancer, and thus are an ideal therapeutic target. Here, we show in multiple cancer models that CXCR3+ Treg cells were increased in tumors compared with lymphoid tissues, exhibited an activated phenotype, and interacted preferentially with CXCL9-producing BATF3+ dendritic cells (DCs). Genetic ablation of CXCR3 in Treg cells disrupted DC1-Treg cell interactions and concomitantly increased DC-CD8+ T cell interactions. Mechanistically, CXCR3 ablation in Treg cells increased tumor antigen-specific cross-presentation by DC1s, increasing CD8+ T cell priming and reactivation in tumors. This ultimately impaired tumor progression, especially in combination with anti-PD-1 checkpoint blockade immunotherapy. Overall, CXCR3 is shown to be a critical chemokine receptor for Treg cell accumulation and immune suppression in tumors.
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Neoplasias , Linfócitos T Reguladores , Humanos , Neoplasias/metabolismo , Linfócitos T CD8-Positivos , Imunoterapia , Células Dendríticas/metabolismo , Receptores CXCR3/genética , Receptores CXCR3/metabolismoRESUMO
Humanin (HN) is a mitochondrial-derived peptide with cytoprotective effect in many tissues. Administration of HN analogs has been proposed as therapeutic approach for degenerative diseases. Although HN has been shown to protect normal tissues from chemotherapy, its role in tumor pathogenesis is poorly understood. Here, we evaluated the effect of HN on the progression of experimental triple negative breast cancer (TNBC). The meta-analysis of transcriptomic data from The Cancer Genome Atlas indicated that HN and its receptors are expressed in breast cancer specimens. By immunohistochemistry we observed up-regulation of HN in TNBC biopsies when compared to mammary gland sections from healthy donors. Addition of exogenous HN protected TNBC cells from apoptotic stimuli whereas shRNA-mediated HN silencing reduced their viability and enhanced their chemo-sensitivity. Systemic administration of HN in TNBC-bearing mice reduced tumor apoptotic rate, impaired the antitumor and anti-metastatic effect of chemotherapy and stimulated tumor progression, accelerating tumor growth and development of spontaneous lung metastases. These findings suggest that HN may exert pro-tumoral effects and thus, caution should be taken when using exogenous HN to treat degenerative diseases. In addition, our study suggests that HN blockade could constitute a therapeutic strategy to improve the efficacy of chemotherapy in breast cancer.
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Biomarcadores Tumorais/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Neoplasias Pulmonares/secundário , Neoplasias de Mama Triplo Negativas/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Apoptose , Biomarcadores Tumorais/genética , Proliferação de Células , Progressão da Doença , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/cirurgia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Pessoa de Meia-Idade , Prognóstico , Taxa de Sobrevida , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/cirurgia , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto , Adulto JovemRESUMO
Resumen La humanina es un péptido derivado de la mitocondria con efectos protectores robustos contra una gran variedad de estímulos citotóxicos en diversos tipos celulares. Esto la convierte en un blanco terapéutico interesante para muchas enfermedades, como el cáncer y enfermedades neurodegenerativas, entre otras. Además, este péptido podría utilizarse como un biomarcador en estas enfermedades. Durante la última década, han sido desarrollados análogos y péptido-miméticos de la humanina que muestran resultados prometedores en modelos preclínicos. A su vez, también se está explorando el potencial terapéutico de vectores de terapia génica que puedan sobreexpresar o silenciar la humanina endógena. Varios puntos importantes a considerar antes de trasladar estas estrategias terapéuticas a la clínica son su posible papel en la progresión del cáncer y la eventual generación de quimiorresistencia. Todos estos temas serán abordados en este artículo de revisión.
Abstract Humanin is a mitochondrial-derived peptide which shows robust protective effects against large series of cytotoxic stimuli in many cell types. This makes it an interesting therapeutic target for many diseases, including cancer and neurodegenerative diseases, among others. Furthermore, this peptide could be used as a biomarker for such diseases. Over the last decade, humanin analogs and peptide mimetics have been developed, which exert highly promising results in preclinical models. Besides, the therapeutic potential of gene therapy vectors that overexpress or silence endogenous humanin is under evaluation. Nonetheless, its possible role in cancer progression and chemoresistance are critical issues to be addressed before translating these therapeutic approaches to the clinic. All these matters will be covered in this review.
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Doenças Neurodegenerativas , Volição , Doença , NeoplasiasRESUMO
Overcoming the immunosuppressive tumour microenvironment is the major challenge impeding cancer immunotherapy today. Regulatory T-cells (Tregs) are prevalent in nearly all cancers and, as immunosuppressive regulators of immune responses, they are the principal opponents of cancer immunotherapy. However, disabling Tregs systemically causes severe autoimmune toxicity, hastening the need for more selective methods to target intratumoural Tregs. In this review, we discuss a burgeoning new modality to specifically target tumour-infiltrating Tregs (TI-Tregs) by reprogramming their functionality from immunosuppressive to immune stimulatory within tumours. As the basis for therapeutic selectivity of TI-Tregs, we will focus on the defining features of Tregs within cancer: their highly activated state controlled by the engagement of key surface receptors, their distinct metabolic programme, and their unique transcriptional programme. By identifying proteins and pathways that distinguish TI-Tregs from other Tregs in the body, as well as from the beneficial antitumour effector T-cells within tumours, we highlight mechanisms to selectively reprogramme TI-Tregs for the treatment of cancer.
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Imunoterapia , Linfócitos do Interstício Tumoral/imunologia , Neoplasias/terapia , Linfócitos T Reguladores/imunologia , Evasão Tumoral , Diferenciação Celular , Metabolismo Energético , Humanos , Ativação Linfocitária , Linfócitos do Interstício Tumoral/metabolismo , Neoplasias/imunologia , Neoplasias/metabolismo , Neoplasias/patologia , Fenótipo , Transdução de Sinais , Linfócitos T Reguladores/metabolismo , Microambiente TumoralRESUMO
In recent years a non-neuronal cholinergic system has been described in immune cells, which is often usually activated during the course of inflammatory processes. To date, it is known that Acetylcholine (ACh), a neurotransmitter extensively expressed in the airways, not only induces bronchoconstriction, but also promotes a set of changes usually associated with the induction of allergic/Th2 responses. We have previously demonstrated that ACh polarizes human dendritic cells (DC) toward a Th2-promoting profile through the activation of muscarinic acetylcholine receptors (mAChR). Here, we showed that ACh promotes the acquisition of an inflammatory profile by murine DC, with the increased MHC II IAd expression and production of two cytokines strongly associated with inflammatory infiltrate and tissue damage, namely TNF-α and MCP-1, which was prevented by blocking mAChR. Moreover, we showed that ACh induces the up-regulation of M3 mAChR expression and the blocking of this receptor with tiotropium bromide prevents the increase of MHC II IAd expression and TNF-α production induced by ACh on DC, suggesting that M3 is the main receptor involved in ACh-induced activation of DC. Then, using a short-term experimental murine model of ovalbumin-induced lung inflammation, we revealed that the intranasal administration of ACh-treated DC, at early stages of the inflammatory response, might be able to exacerbate the recruitment of inflammatory mononuclear cells, promoting profound structural changes in the lung parenchyma characteristic of chronic inflammation and evidenced by elevated systemic levels of inflammatory marker, TNF-α. These results suggest a potential role for ACh in the modulation of immune mechanisms underlying pulmonary inflammatory processes.
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Acetilcolina/metabolismo , Células Dendríticas/imunologia , Lesão Pulmonar/imunologia , Animais , Células Cultivadas , Células Dendríticas/metabolismo , Células Dendríticas/transplante , Modelos Animais de Doenças , Progressão da Doença , Feminino , Antígenos de Histocompatibilidade Classe II/metabolismo , Humanos , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Pulmão/citologia , Pulmão/imunologia , Pulmão/patologia , Lesão Pulmonar/sangue , Lesão Pulmonar/diagnóstico , Camundongos , Ovalbumina/imunologia , Cultura Primária de Células , Índice de Gravidade de Doença , Fator de Necrose Tumoral alfa/sangue , Fator de Necrose Tumoral alfa/imunologiaRESUMO
INTRODUCTION: Mitochondrial-derived peptides (MDPs) are encoded within the mitochondrial genome. They signal within the cell or are released to act as autocrine/paracrine/endocrine cytoprotective factors playing a key role in the cellular stress response. The first reported and better characterized MDP is humanin (HN), which exerts robust protective effects against a myriad of cytotoxic stimuli in many cell types. These effects have led to the evaluation of HN and its analogs as therapeutic targets for several chronic diseases. Areas covered: We describe the latest findings on the mechanism of action of HN and discuss the role of HN as therapeutic target for neurodegenerative and cardiovascular diseases, diabetes, male infertility, and cancer. Since HN can be detected in circulation, we also depict its value as a biomarker for these diseases. Expert opinion: HN analogs and peptide mimetics have been developed over the last decade and show promising results in preclinical models of degenerative diseases. Local administration of gene therapy vectors that overexpress or silence endogenous HN could also hold therapeutic potential. Controversy on the role of HN in cancer progression and chemoresistance should be addressed before the translation of these therapeutic approaches.
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Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Terapia de Alvo Molecular , Neoplasias/terapia , Animais , Doenças Cardiovasculares/fisiopatologia , Doenças Cardiovasculares/terapia , Modelos Animais de Doenças , Terapia Genética/métodos , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Mitocôndrias/metabolismo , Neoplasias/patologia , Doenças Neurodegenerativas/fisiopatologia , Doenças Neurodegenerativas/terapiaRESUMO
PURPOSE: Regulatory T cells (Tregs) impair the clinical benefit of cancer immunotherapy. To optimize the antitumor efficacy of therapeutic dendritic cell (DC) vaccines, we aimed to inhibit Foxp3, a transcription factor required for Treg function. METHODS: Mice bearing established syngeneic LM3 and 4T1 breast tumors were treated with antitumor DC vaccines and a synthetic peptide (P60) that has been shown to inhibit Foxp3. RESULTS: Treatment with P60 improved the therapeutic efficacy of DC vaccines in these experimental models. In addition, monotherapy with P60 inhibited tumor growth in immunocompetent as well as in immuno-compromised animals bearing established tumors. We found expression of Foxp3 in human and murine breast tumor cells. P60 inhibited IL-10 secretion in breast cancer cells that expressed Foxp3. CONCLUSIONS: Our results suggest that Foxp3 blockade improves the therapeutic efficacy of DC vaccines by inhibition of Tregs and through a direct antitumor effect. This strategy could prove useful to neutralize the immunosuppressive microenvironment and to boost antitumor immunity in breast cancer.
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Neoplasias da Mama/terapia , Peptídeos Penetradores de Células/administração & dosagem , Células Dendríticas/transplante , Fatores de Transcrição Forkhead/antagonistas & inibidores , Linfócitos T Reguladores/efeitos dos fármacos , Animais , Neoplasias da Mama/imunologia , Neoplasias da Mama/metabolismo , Vacinas Anticâncer/administração & dosagem , Vacinas Anticâncer/farmacologia , Linhagem Celular Tumoral , Peptídeos Penetradores de Células/farmacologia , Células Dendríticas/imunologia , Feminino , Humanos , Imunoterapia , Camundongos , Linfócitos T Reguladores/imunologia , Resultado do Tratamento , Microambiente Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
INTRODUCTION: Breast cancer is the most common cancer in women all over the world. Furthermore, up to one third of breast tumors develop metastases that are resistant to standard therapies. Gene therapeutic strategies have been developed in order to specifically target cancer cells either directly or through the stimulation of antitumor immunity. Areas covered: This review describes the therapeutic strategies that are currently under development to treat this disease using engineered viral vectors including: adenovirus, adeno-associated virus, lentivirus, poxvirus, reovirus, baculovirus, herpesvirus and oncolytic viruses. Advantages and disadvantages of these multiple gene therapy platforms are discussed in detail. Expert opinion: Metastatic breast cancer is a perfect candidate for gene therapy approaches due to the presence of several tumor antigens and the aberrant expression of many molecular pathways. Oncolytic vectors are able to attack tumor cells while sparing normal cells and their activity is often enhanced by the administration of chemotherapy. However, more efforts are needed in order to reduce toxicity and to achieve better transduction efficiency. Improved preclinical models and a more critical patient selection for clinical trials, along with advances in gene therapy regulations, will surely facilitate the evolution of gene therapy for the treatment of metastatic breast cancer.
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Neoplasias da Mama/terapia , Terapia Viral Oncolítica , Adenoviridae/genética , Feminino , Vetores Genéticos/genética , Vetores Genéticos/metabolismo , Humanos , Lentivirus/genética , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/virologia , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/virologia , Vírus Oncolíticos/genética , Poxviridae/genéticaRESUMO
Humanin (HN) and Rattin (HNr), its homologous in the rat, are peptides with cytoprotective action in several cell types such as neurons, lymphocytes and testicular germ cells. Previously, we have shown that HNr is expressed in pituitary cells and that HN inhibited the apoptotic effect of TNF-α in both normal and tumor pituitary cells. The aim of the present study was to identify signaling pathways that mediate the antiapoptotic effect of HN in anterior pituitary cells from ovariectomized rats and in GH3 cells, a somatolactotrope cell line. We assessed the role of STAT3, JNK, Akt and MAPKs as well as proteins of the Bcl-2 family, previously implicated in the antiapoptotic effect of HN. We also evaluated the participation of NF-κB in the antiapoptotic action of HN. STAT3 inhibition reversed the inhibitory effect of HN on TNF-α-induced apoptosis in normal and pituitary tumor cells, indicating that STAT3 signaling pathway mediates the antiapoptotic effect of HN on pituitary cells. Inhibition of NF-κB pathway did not affect action of HN on normal anterior pituitary cells but blocked the cytoprotective effect of HN on TNF-α-induced apoptosis of GH3 cells, suggesting that the NF-κB pathway is involved in HN action in tumor pituitary cells. HN also induced NF-κB-p65 nuclear translocation in these cells. In pituitary tumor cells, JNK and MEK inhibitors also impaired HN cytoprotective action. In addition, HN increased Bcl-2 expression and decreased Bax mitochondrial translocation. Since HN expression in GH3 cells is higher than in normal pituitary cells, we may suggest that through multiple pathways HN could be involved in pituitary tumorigenesis.
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INTRODUCTION: Breast cancer is the most common cancer as well as the first cause of death by cancer in women worldwide. Although routine treatment improves the outcome of early stage breast cancer patients, there is no effective therapy for the disseminated disease. Immunotherapy has emerged as a powerful therapeutic strategy for the treatment of many cancers. Although traditionally conceived as a non-immunogenic tumor, breast cancer is now considered a potential target for immunotherapy. Areas covered: In this review, the authors discuss different immunotherapeutic strategies that are currently being tested for the treatment of breast cancer: These strategies include: (i) blockade of immunological checkpoints, (ii) antitumor vaccines, (iii) regulatory T cell blockade, (iv) adoptive T cell transfer therapy, (iv) adoptive immunotherapy with monoclonal antibodies, and (v) combination of immunotherapy with chemotherapy. Expert opinion: A growing body of evidence indicates that immunotherapeutic strategies can benefit a larger cohort of breast cancer patients than hitherto anticipated. Since breast tumors entail multiple mechanisms to impair antitumor immunity, the immunological characterization of individual tumors and the selection of suitable combinations of chemotherapeutic and immunotherapeutic approaches are required to achieve significant clinical benefit in these patients.
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Neoplasias da Mama/terapia , Imunoterapia , Anticorpos Monoclonais/uso terapêutico , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Antígeno CTLA-4/imunologia , Antígeno CTLA-4/metabolismo , Vacinas Anticâncer/imunologia , Vacinas Anticâncer/uso terapêutico , Terapia Combinada , Feminino , Humanos , Receptor de Morte Celular Programada 1/imunologia , Receptor de Morte Celular Programada 1/metabolismo , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismoRESUMO
PURPOSE: Since combination of Toll-like receptor (TLR) ligands could boost antitumor immunity, we evaluated the efficacy of dendritic cell (DC) vaccines upon dual activation of TLR9 and TLR7 in breast cancer models. METHODS: DCs were generated from mouse bone marrow or peripheral blood from healthy human donors and stimulated with CpG1826 (mouse TLR9 agonist), CpG2006 or IMT504 (human TLR9 agonists) and R848 (TLR7 agonist). Efficacy of antitumor vaccines was evaluated in BALB/c mice bearing metastatic mammary adenocarcinomas. RESULTS: CpG-DCs improved the survival of tumor-bearing mice, reduced the development of lung metastases and generated immunological memory. However, dual activation of TLRs impaired the efficacy of DC vaccines. In vitro, we found that R848 inhibited CpG-mediated maturation of murine DCs. A positive feedback loop in TLR9 mRNA expression was observed upon CpG stimulation that was inhibited in the presence of R848. Impaired activation of NF-κB was detected when TLR9 and TLR7 were simultaneously activated. Blockade of nitric oxide synthase (NOS) and indoleamine-pyrrole-2,3-dioxygenase (IDO) improved the activation of CpG-DCs. When we evaluated the effect of combined activation of TLR9 and TLR7 in human DCs, we found that R848 induced robust DC activation that was inhibited by TLR9 agonists. CONCLUSIONS: These observations provide insight in the biology of TLR9 and TLR7 crosstalk and suggest caution in the selection of agonists for multiple TLR stimulation. Blockade of NOS and IDO could improve the maturation of antitumor DC vaccines. R848 could prove a useful adjuvant for DC vaccines in human patients.
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Adenocarcinoma/terapia , Neoplasias da Mama/terapia , Vacinas Anticâncer/imunologia , Receptor 7 Toll-Like/agonistas , Receptor Toll-Like 9/agonistas , Adjuvantes Imunológicos/farmacologia , Animais , Vacinas Anticâncer/farmacologia , Células Dendríticas/imunologia , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BLRESUMO
Survival of glioma (GBM) patients treated with the current standard of care remains dismal. Immunotherapeutic approaches that harness the cytotoxic and memory potential of the host immune system have shown great benefit in other cancers. GBMs have developed multiple strategies, including the accumulation of myeloid-derived suppressor cells (MDSCs) to induce immunosuppression. It is therefore imperative to develop multipronged approaches when aiming to generate a robust anti-tumor immune response. Herein, we tested whether combining MDSC depletion or checkpoint blockade would augment the efficacy of immune-stimulatory herpes simplex type-I thymidine kinase (TK) plus Fms-like tyrosine kinase ligand (Flt3L)-mediated immune stimulatory gene therapy. Our results show that MDSCs constitute >40% of the tumor-infiltrating immune cells. These cells express IL-4Rα, inducible nitric oxide synthase (iNOS), arginase, programmed death ligand 1 (PDL1), and CD80, molecules that are critically involved in antigen-specific T cell suppression. Depletion of MDSCs strongly enhanced the TK/Flt3L gene therapy-induced tumor-specific CD8 T cell response, which lead to increased median survival and percentage of long-term survivors. Also, combining PDL1 or CTLA-4 immune checkpoint blockade greatly improved the efficacy of TK/Flt3L gene therapy. Our results, therefore, indicate that blocking MDSC-mediated immunosuppression holds great promise for increasing the efficacy of gene therapy-mediated immunotherapies for GBM.
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Terapia Genética , Glioma/genética , Glioma/imunologia , Células Supressoras Mieloides/imunologia , Células Supressoras Mieloides/metabolismo , Microambiente Tumoral/genética , Microambiente Tumoral/imunologia , Animais , Antígeno B7-H1/metabolismo , Biomarcadores , Células da Medula Óssea/imunologia , Células da Medula Óssea/metabolismo , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/imunologia , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/terapia , Antígeno CTLA-4/metabolismo , Células Cultivadas , Citotoxicidade Imunológica/genética , Citotoxicidade Imunológica/imunologia , Feminino , Expressão Gênica , Terapia Genética/métodos , Glioma/patologia , Glioma/terapia , Humanos , Imunofenotipagem , Terapia de Imunossupressão , Imunoterapia , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Timidina Quinase/genética , Timidina Quinase/metabolismo , TransgenesRESUMO
Humanin (HN) is a 24-amino acid peptide with cytoprotective action in several cell types such as neurons and testicular germ cells. Rattin (HNr), a homologous peptide of HN expressed in several adult rat tissues, also has antiapoptotic action. In the present work, we demonstrated by immunocytochemical analysis and flow cytometry the expression of HNr in the anterior pituitary of female and male adult rats as well as in pituitary tumor GH3 cells. HNr was localized in lactotropes and somatotropes. The expression of HNr was lower in females than in males, and was inhibited by estrogens in pituitary cells from both ovariectomized female and orquidectomized male rats. However, the expression of HNr in pituitary tumor cells was not regulated by estrogens. We also evaluated HN action on the proapoptotic effect of TNF-α in anterior pituitary cells assessed by the TUNEL method. HN (0.5 µM) per se did not modify basal apoptosis of anterior pituitary cells but completely blocked the proapoptotic effect of TNF-α in total anterior pituitary cells, lactotropes and somatotropes from both female and male rats [corrected]. Also, HN inhibited the apoptotic effect of TNF-α on pituitary tumor cells. In summary, our results demonstrate that HNr is present in the anterior pituitary gland, its expression showing sexual dimorphism, which suggests that gonadal steroids may be involved in the regulation of HNr expression in this gland. Antiapoptotic action of HN in anterior pituitary cells suggests that this peptide could be involved in the homeostasis of this gland. HNr is present and functional in GH3 cells, but it lacks regulation by estrogens, suggesting that HN could participate in the pathogenesis of pituitary tumors.
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Apoptose/efeitos dos fármacos , Citoproteção/efeitos dos fármacos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Hipófise/metabolismo , Neoplasias Hipofisárias/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Animais , Linhagem Celular Tumoral , Estradiol/farmacologia , Estrogênios/farmacologia , Feminino , Masculino , Orquiectomia , Ovariectomia , Hipófise/efeitos dos fármacos , Hipófise/patologia , Adeno-Hipófise/efeitos dos fármacos , Adeno-Hipófise/metabolismo , Adeno-Hipófise/patologia , Neoplasias Hipofisárias/patologia , Proteínas/metabolismo , Ratos WistarRESUMO
INTRODUCTION: Glioblastoma multiforme (GBM) is the most common primary brain tumor in adults and it carries a dismal prognosis. Adenoviral vector (Ad)-mediated gene transfer is being developed as a promising therapeutic strategy for GBM. Preclinical studies have demonstrated safety and efficacy of adenovirus administration into the brain and tumor mass in rodents and into the non-human primates' brain. Importantly, Ads have been safely administered within the tumor resection cavity in humans. AREAS COVERED: This review gives background on GBM and Ads; we describe gene therapy strategies for GBM and discuss the value of combination approaches. Finally, we discuss the results of the human clinical trials for GBM that have used Ads. EXPERT OPINION: The transduction characteristics of Ads, and their safety profile, added to their capacity to achieve high levels of transgene expression have made them powerful vectors for the treatment of GBM. Recent gene therapy successes in the treatment of retinal diseases and systemic brain metabolic diseases encourage the development of gene therapy for malignant glioma. Exciting clinical trials are currently recruiting patients; although, it is the large randomized Phase III controlled clinical trials that will provide the final decision on the success of gene therapy for the treatment of GBM.