RESUMO
Emerging evidence suggests that the tumour microenvironment plays a critical role in osteosarcoma (OS) development. Thus, cytokine immunotherapy could be a novel strategy for OS treatment. In this study, we explored the role of macrophage migration inhibitory factor (MIF), an important cytokine in OS progression, and investigated the anti-tumour effects of targeting MIF in OS. The results showed that MIF significantly increased in the tissue and serum samples of OS patients and was associated with tumour size, pulmonary metastasis and the survival rate of OS patients. We verified a positive correlation between MIF and p-ERK1/2 in OS patients. The in vitro results indicated that MIF could activate the RAS/MAPK pathway in a time- and dose-dependent manner, thereby promoting cell proliferation and migration. Furthermore, shRNA targeting MIF significantly inhibited tumour growth and lung metastasis in a mouse xenograft model and orthotopic model of OS. Additionally, inhibition of MIF significantly enhanced the sensitivity of OS cells to cisplatin and doxorubicin. Our findings suggest that immunotherapy targeting MIF to block the RAS/MAPK kinase cascade may represent a feasible and promising approach for OS treatment.
Assuntos
Neoplasias Ósseas/enzimologia , Movimento Celular , Proliferação de Células , Oxirredutases Intramoleculares/metabolismo , Neoplasias Pulmonares/enzimologia , Fatores Inibidores da Migração de Macrófagos/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Osteossarcoma/enzimologia , Transdução de Sinais , Proteínas ras/metabolismo , Adolescente , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Cisplatino/farmacologia , Relação Dose-Resposta a Droga , Doxorrubicina/farmacologia , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Oxirredutases Intramoleculares/genética , Oxirredutases Intramoleculares/farmacologia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/prevenção & controle , Neoplasias Pulmonares/secundário , Fatores Inibidores da Migração de Macrófagos/genética , Fatores Inibidores da Migração de Macrófagos/farmacologia , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Osteossarcoma/tratamento farmacológico , Osteossarcoma/genética , Osteossarcoma/secundário , Interferência de RNA , Transdução de Sinais/efeitos dos fármacos , Análise de Sobrevida , Fatores de Tempo , Transfecção , Carga Tumoral , Microambiente Tumoral , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Osteosarcoma (OS) is the most common primary bone malignancy and remains a leading cause of cancer-related deaths in adolescents. Emerging evidence indicates that microRNAs (miRNAs) are correlated with clinical and biological characteristics of OS. However, the involvement of miR-199a-5p in OS development remains unclear. In this study, we examined the function of miR-199a-5p in vitro and in vivo. The results showed that miR-199a-5p was significantly up-regulated in OS patient tissues and cells. The inhibition of miR-199a-5p led to a significant decrease in cell proliferation and tumour growth. We further demonstrated that miR-199a-5p could directly bind to the 3'UTRs of the mRNA of both PIAS3 and p27 and mediate a decrease in the protein levels of PIAS3 and p27, thereby stimulating STAT3 activation and cell cycle progression in OS cells. Rescue experiments of PIAS3 and p27 further revealed that PIAS3 and p27 were functional targets of miR-199a-5p. Moreover, enhancing the expressions of both PIAS3 and p27 using miR-199a-5p-targeted inhibitors in an OS xenograft model was shown to be a promising approach for OS clinical therapy. Our findings indicate that the pathway of miR-199a-5p targeting both PIAS3 and p27 is a possible mechanism that contributes to tumour growth in OS.
