Tumor Suppressive Role of miR-342-5p in Human Chondrosarcoma Cells and 3D Organoids.

Clément Veys,Jérôme E Lafont,Romain Contentin,Christophe Denoyelle,Laurent Poulain,Magali Demoor,Amandine Duchemin,Yannick Saintigny,Philippe Galéra,Abderrahim Benmoussa,Emilie Brotin,Florence Legendre

doi:10.3390/ijms22115590

Abstract

Chondrosarcomas are malignant bone tumors. Their abundant cartilage-like extracellular matrix and their hypoxic microenvironment contribute to their resistance to chemotherapy and radiotherapy, and no effective therapy is currently available. MicroRNAs (miRNAs) may be an interesting alternative in the development of therapeutic options. Here, for the first time in chondrosarcoma cells, we carried out high-throughput functional screening using impedancemetry, and identified five miRNAs with potential antiproliferative or chemosensitive effects on SW1353 chondrosarcoma cells. The cytotoxic effects of miR-342-5p and miR-491-5p were confirmed on three chondrosarcoma cell lines, using functional validation under normoxia and hypoxia. Both miRNAs induced apoptosis and miR-342-5p also induced autophagy. Western blots and luciferase reporter assays identified for the first time Bcl-2 as a direct target of miR-342-5p, and also Bcl-xL as a direct target of both miR-342-5p and miR-491-5p in chondrosarcoma cells. MiR-491-5p also inhibited EGFR expression. Finally, only miR-342-5p induced cell death on a relevant 3D chondrosarcoma organoid model under hypoxia that mimics the in vivo microenvironment. Altogether, our results revealed the tumor suppressive activity of miR-342-5p, and to a lesser extent of miR-491-5p, on chondrosarcoma lines. Through this study, we also confirmed the potential of Bcl-2 family members as therapeutic targets in chondrosarcomas.

Highlights

Chondrosarcomas are the second-most common primary malignant bone tumors after osteosarcomas [1,2]
Our study unambiguously demonstrated the antiproliferative, antimetabolic and cytotoxic effects of MicroRNA or miRNA (miR)-491-5p and miR-342-5p on the SW1353 chondrosarcoma cell line
Neither miRNA was able to induce chemosensitivity to Cis-diaminedichloroplatinum or cisplatin (CDDP) in our experimental conditions, but the tumor suppressive effects of these miRNAs were validated in three out of four chondrosarcoma cell lines cultured under normoxia and hypoxia

Summary

Introduction

Chondrosarcomas are the second-most common primary malignant bone tumors after osteosarcomas [1,2]. They mainly affect adults between 30 and 70 years old. Chondrosarcomas are an heterogeneous group of tumors characterized by the production of an extracellular matrix with cartilaginous characteristics [3]. They are classified into different histological grades, from low to high, related to their metastatic potential and associated survival rates. Several mechanisms are involved in their resistance [4] They are poorly vascularized, produce an abundant cartilaginous extracellular matrix and are composed of a limited number of proliferating cells which, as whole, hinder drug efficacy. There is an urgent need for new therapeutic strategies to treat chondrosarcomas and/or overcome their resistance to conventional therapies

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Discussion

Conclusion