ABSTRACT
BACKGROUND: Osteosarcoma (OS) is the most frequent primary malignant bone tumour in children and adolescents with a high propensity for lung metastasis. Chemokines and chemokine receptors have been described to have an important role in many malignancies including OS. The aim of this study was to investigate the expression of CXCR7 receptor in OS tissues and its role in the progression of the disease in the lungs. METHODS: Immunohistochemistry was used to study CXCR7 expression in primary tumours and metastatic tissues from patients with OS. Its contribution to tumour expansion in the lungs has been also assessed using animal models and synthetic-specific CXCR7 ligands. RESULTS: CXCR7 was expressed on human primary bone tumours and on lung metastases. Its expression was predominantly located on tumour-associated blood vessels. Mice challenged with OS cells and systematically treated with synthetic CXCR7 ligands presented a significant reduction of lung nodules compared with untreated mice. CONCLUSION: This study shows that CXCR7 has a critical role in OS progression in the lungs, where are expressed CXCR7 ligands, especially CXCL12. Moreover, we highlight that synthetic CXCR7 ligands could represent a powerful therapeutic tool to impede lung OS progression.
Subject(s)
Bone Neoplasms/metabolism , Lung Neoplasms/metabolism , Lung Neoplasms/secondary , Osteosarcoma/metabolism , Osteosarcoma/secondary , Receptors, CXCR/biosynthesis , Animals , Bone Neoplasms/pathology , Disease Progression , Humans , Immunohistochemistry , Lung Neoplasms/genetics , Lung Neoplasms/pathology , Mice , Osteosarcoma/genetics , Osteosarcoma/pathology , Receptors, CXCR/geneticsABSTRACT
The lung is one target organ to which solid tumors frequently metastasize. Given the systemic adverse effects of currently available treatments, developing effective strategies of drug/gene delivery directly to the lungs is therefore needed. Aerosol delivery is a non-invasive gene transfer approach to target the airways. Here, we sought to evaluate the potential to deliver a fractalkine (FKN)-encoding plasmid formulated with the tetrafunctional amphiphilic block copolymer 704 through aerosolization in two models of pulmonary metastases. FKN is a chemokine recently described as a good candidate to stimulate a strong antitumor immune response in various forms of cancers. Here, we have assessed the effect of single and repeated aerosolizations of FKN-encoding plasmid formulated with 704 on the development of experimental lung metastases of mouse colon carcinoma and osteosarcoma. For this purpose, we have designed FKN-Fc sequences encoding an optimized version of the chemokine. Repeated intratracheal administrations of 704/FKN-Fc markedly inhibited growth of experimental lung metastases of CT-26 and K7M2 cells. Our results showed that tetrafunctional amphiphilic block copolymer 704 is a highly efficient synthetic vector for mediating local and safe gene transfer into the lung. In addition, FKN-Fc gene therapy of pulmonary nodules may provide a promising immunotherapeutic approach.
Subject(s)
Chemokine CX3CL1/genetics , Genetic Therapy/methods , Immunoglobulin Fragments/genetics , Lung Neoplasms/secondary , Lung Neoplasms/therapy , Administration, Inhalation , Animals , Cell Line, Tumor , Drug Delivery Systems , Female , Gene Transfer Techniques , Humans , Immunotherapy , Lung Neoplasms/genetics , Mice , Nanospheres , Neoplasm Metastasis , Plasmids/administration & dosage , Plasmids/genetics , TransfectionABSTRACT
Liver and lung metastases are the predominant cause of colorectal cancer (CRC)-related mortality. Recent research has indicated that CXCR3/chemokines interactions that orchestrate haematopoetic cell movement are implicated in the metastatic process of malignant tumours, including that of CRC cells to lymph nodes. To date, however, the contribution of CXCR3 to liver and lung metastasis in CRC has not been addressed. To determine whether CXCR3 receptors regulate malignancy-related properties of CRC cells, we have used CXCR3-expressing CRC cell lines of human (HT29 cells) and murine (C26 cells) origins that enable the development of liver and lung metastases when injected into immunodeficient and immunocompetent mice, respectively, and assessed the effect of CXCR3 blockade using AMG487, a small molecular weight antagonist. In vitro, activation of CXCR3 on human and mouse CRC cells by its cognate ligands induced migratory and growth responses, both activities being abrogated by AMG487. In vivo, systemic CXCR3 antagonism by preventive or curative treatments with AMG487 markedly inhibited the implantation and the growth of human and mouse CRC cells within lung without affecting that in the liver. In addition, we measured increased levels of CXCR3 and ligands expression within lung nodules compared with liver tumours. Altogether, our findings indicate that activation of CXCR3 receptors by its cognate ligands facilitates the implantation and the progression of CRC cells within lung tissues and that inhibition of this axis decreases pulmonary metastasis of CRC in two murine tumour models.
