GLI1 amplification and fusion in MDM2 -amplified low-grade osteosarcoma

Le résumé fourni par la source

Aims Glioma-associated oncogene homologue 1 ( GLI1 ) was recently shown to be coamplified with mouse double minute 2 ( MDM2 ), cyclin-dependent kinase 4 ( CDK4 ) and some other adjacent genes in a significant subset of GLI1 -altered mesenchymal tumours and well-differentiated/dedifferentiated liposarcomas, which are characterised by MDM2 amplification. Given that MDM2 is also amplified in low-grade osteosarcoma (LGOS), we investigated the prevalence of GLI1 amplifications/fusions in a series of 15 cases of MDM2 -amplified LGOS, an area that has not been previously explored. Methods This study conducted a retrospective analysis and examined GLI1 amplifications/fusions in 15 cases of MDM2 -amplified LGOS and 46 cases of other bone tumours and tumour-like lesions using fluorescence in situ hybridisation with a GLI1 amplification probe and a GLI1 break-apart probe. Six cases of LGOS were also tested by next-generation sequencing. Results Fluorescence in situ hybridisation analysis revealed that 13 of 15 (87%) LGOS cases exhibited GLI1 amplification; no fusion gene was found. Next-generation sequencing revealed that all six tested cases showed GLI1 amplification and one case had both GLI1 amplification and GLI1 gene fusion ( PPM1H::GLI1 ). All 46 cases of other bone tumours and tumour-like lesions were negative for GLI1 amplification and GLI1 fusion. Conclusion These results indicate that GLI1 amplification is common in LGOS, and GLI1 fusion could occur in LGOS.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.