Exploring Adenosine Analogues for Chondrosarcoma Therapy: In Vitro and In Vivo Insights

Abstract

Chondrosarcoma (CS) is described as resistant to conventional chemotherapy and radiotherapy. The development of new therapeutic approaches is necessary. The aim of the present study is to validate the use of adenosine analogues as a new therapeutic strategy in the treatment of CS. Five adenosine analogues (aristeromycin, cladribine, clofarabine, formycin, and pentostatin) were evaluated in vitro on several chondrosarcoma cell lines using both 2D cultures and 3D alginate bead models. Cell viability was assessed using Acridine Orange and DAPI staining, or ATP assay. Apoptosis was measured via Annexin V and Propidium Iodide staining, while cell cycle progression was analyzed with DAPI staining. The most promising compounds were further tested in vivo using a xenograft chondrosarcoma model in nude mice. Results showed that four analogues (aristeromycin, formycin, cladribine, and clofarabine) significantly reduced cell viability in 2D cell cultures. Of these, cladribine and clofarabine demonstrated potent efficacy in both 2D and 3D models by inducing apoptosis. Cladribine was further found to induce cell cycle arrest, leading to apoptosis-mediated cell death. In vivo, both cladribine and clofarabine exhibited substantial antitumor effects in a xenograft model. In conclusion, cladribine and clofarabine, which are already approved for clinical use in leukemia and multiple sclerosis, show promise as potential candidates for chondrosarcoma treatment. Their efficacy in preclinical models suggests these molecules could be repurposed for Phase II clinical trials in CS patients.