RESUMO
Successful oncological drug development for bone and soft tissue sarcoma is grossly stagnating. A major obstacle in this process is the lack of appropriate animal models recapitulating the complexity and heterogeneity of musculoskeletal malignancies, resulting in poor efficiency in translating the findings of basic research to clinical applications. In recent years, patient-derived xenograft (PDX) models generated by directly engrafting patient-derived tumor fragments into immunocompromised mice have recaptured the attention of many researchers due to their properties of retaining the principle histopathology, biological behaviors, and molecular and genetic characteristics of the original tumor, showing promising future in both basic and clinical studies of bone and soft tissue sarcoma. Despite several limitations including low take rate and long take time in PDX generation, deficient immune system and heterologous tumor microenvironment of the host, PDXs offer a more advantageous platform for preclinical drug screening, biomarker identification and clinical therapeutic decision guiding. Here, we provide a timely review of the establishment and applications of PDX models for musculoskeletal malignancies and discuss current challenges and future directions of this approach.
Assuntos
Sistema Musculoesquelético/patologia , Neoplasias/patologia , Ensaios Antitumorais Modelo de Xenoenxerto , Tomada de Decisão Clínica , Humanos , Reprodutibilidade dos TestesRESUMO
The F1F0-ATP synthase, an enzyme complex, is mainly located on the mitochondrial inner membrane or sometimes cytomembrane to generate or hydrolyze ATP, play a role in cell proliferation. This study focused on the role of F1F0-ATP synthase in keratinocyte differentiation, and its relationship with intracellular and extracellular ATP (InATP and ExATP). The F1F0-ATP synthase ß subunit (ATP5B) expression in various skin tissues and confluence-dependent HaCaT differentiation models was detected. ATP5B expression increased with keratinocyte and HaCaT cell differentiation in normal skin, some epidermis hyper-proliferative diseases, squamous cell carcinoma, and the HaCaT cell differentiation model. The impact of InATP and ExATP content on HaCaT differentiation was reflected by the expression of the differentiation marker involucrin. Inhibition of F1F0-ATP synthase blocked HaCaT cell differentiation, which was associated with a decrease of InATP content, but not with changes of ExATP. Our results revealed that F1F0-ATP synthase expression is associated with the process of keratinocyte differentiation which may possibly be related to InATP synthesis.
Assuntos
Trifosfato de Adenosina/biossíntese , Dermatite/genética , Queratinócitos/metabolismo , Membranas Mitocondriais/metabolismo , ATPases Mitocondriais Próton-Translocadoras/genética , Psoríase/genética , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Diferenciação Celular , Linhagem Celular Transformada , Dermatite/metabolismo , Dermatite/patologia , Regulação da Expressão Gênica , Humanos , Queratinócitos/citologia , Ceratoacantoma/genética , Ceratoacantoma/metabolismo , Ceratoacantoma/patologia , Ceratose Seborreica/genética , Ceratose Seborreica/metabolismo , Ceratose Seborreica/patologia , Mitocôndrias/metabolismo , ATPases Mitocondriais Próton-Translocadoras/metabolismo , Precursores de Proteínas/genética , Precursores de Proteínas/metabolismo , Prurigo/genética , Prurigo/metabolismo , Prurigo/patologia , Psoríase/metabolismo , Psoríase/patologia , Pele/citologia , Pele/metabolismo , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Verrugas/genética , Verrugas/metabolismo , Verrugas/patologiaRESUMO
Homocysteine (Hcy) is a well-established risk factor for atherosclerosis and may cause dysregulation of gene expression, but the characteristics and the key links involved in its pathogenic mechanisms are still poorly understood. The aim of this study was to explore (i) the effects of Hcy on DNA methylation in vascular smooth muscle cells (VSMCs) and (ii) the underlying mechanism of Hcy-induced changes in DNA methylation patterns in relation to atherosclerosis. We examined the levels of gDNA methylation, namely, the Alu and line-1 element sequences, which can serve as a surrogate marker for gDNA methylation, and also investigated the effects of Hcy on the intracellular S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) concentrations as well as the expressions of SAH hydrolase (SAHH), DNA methyltransferase3a (DNMT3a), DNMT3b, and methyl-CpG-binding domain 2 (MBD2). We found that clinically relevant levels of Hcy (0-500 microM) induced elevation of SAH, declination of SAM and SAM/SAH ratio, and reduction in expression of SAHH and MBD2, but increased the activity of DNMT3a and DNMT3b compared to the control group (p < 0.05). We found also that the genome-wide hypomethylation is a common feature of gDNA in the VSMCs cultured with Hcy. In conclusion, these results suggest that Hcy-induced DNA methylation may be an important potential pathogenic mechanism in the development of atherosclerosis, and may become a therapeutic target for preventing Hcy-induced atherosclerosis.