Dedifferentiated Liposarcoma : MDM2 Amplification

Comments:
Molecular Pathology: The giant ring and marker chromosomes in dedifferentiated liposarcoma (DLPS) contain amplified sequences from chromosome 12q13-15 which harbors several genes implicated in tumorigenesis, including MDM2, CDK4, GLI, SAS and HMGA2. MDM2, CDK4 and HMGA2 are amplified in 92%, 100%, and 76% of liposarcomas respectively, whereas GLI1 and DDIT3 are overexpressed less frequently.

MDM2 is an E3 ubiquitin protein ligase which promotes degradation of p53 to prevent apoptosis and/or cell-cycle arrest and may also have effects independent of p53.

This FISH image shows MDM2 amplification (red) in a case of DLPS. CEP12-SG (green) is a reference probe for the centromeric region of chromosome 12. Image source: Gambella A et al. FISH Diagnostic Assessment of MDM2 Amplification in Liposarcoma: Potential Pitfalls and Troubleshooting Recommendations. Int. J. Mol. Sci. 2023, 24, 1342.; cropped from originals and used under Creative Common Attribution (CC BY) License 4.0