Heparanase Expression Is Associated With Cancer Stem Cell Features and Radioresistance in Hodgkin's Lymphoma Cells.

Background/aim Heparanase (HPSE) is relevant to therapy resistance in many malignancies yet is largely unstudied in Hodgkin's lymphoma. Here, we investigated links between HPSE, cancer stem cell (CSC) features and radioresistance in KM-H2 and L428 Hodgkin's lymphoma cells. Materials and methods Firstly, HPSE expression in unsorted and sorted CSCs was assessed. Post-irradiation, HPSE and CSC-related gene expression changes were then quantified. Clonogenic ability was investigated with and without artificial changes in HPSE expression pre and post irradiation. Results HPSE was highly expressed in L428 but barely present in KM-H2 cells. HPSE was overexpressed in sorted L428 CSCs. Irradiation induced HPSE and expression of CSC markers. High HPSE-expressing L428 cells showed higher clonogenic ability than low HPSE-expressing KM-H2 cells after irradiation. Down-regulation of HPSE in L428 cells reduced their clonogenic capability post-radiation, whilst overexpression of HPSE in KM-H2 cells increased colony formation. Conclusion HPSE expression is associated with CSC features and contributes to radioresistance in Hodgkin's lymphoma cells.