Purpose Medulloblastoma (MB) is the most common malignant paediatric brain tumour. Current treatment modalities are not completely effective and can lead to severe neurological and cognitive adverse effects. In addition to urgently needing better treatment approaches, new diagnostic and prognostic biomarkers are required to improve the therapy outcomes of MB patients. The RNA binding proteins, LIN28A and LIN28B, are known to regulate invasive phenotypes in many different cancer types. However, the expression and function of these proteins in MB had not been studied to date.
Methods This study identified the expression of LIN28A and LIN28B in MB patient samples and cell lines and assessed the effect of LIN28 inhibition on MB cell growth, metabolism and stemness.
Results LIN28B expression was significantly upregulated in MB tissues compared to normal brain tissues. This upregulation, which was not observed in other brain tumours, was specific for the aggressive MB subgroups and correlated with patient survival and metastasis rates. Functionally, pharmacological inhibition of LIN28 activity concentration dependently reduced LIN28B expression, as well as the growth of D283 MB cells. While, LIN28 inhibition did not affect the levels of intracellular ATP, it reduced the expression of the stemness marker CD133 in D283 cells, and sphere formation of CHLA-01R cells. LIN28B, which is highly expressed in human cerebellum during the first few months after birth, subsequently decreased with age.
Conclusion The results of this study highlight the potential of LIN28B as a diagnostic and prognostic marker for MB and opens the possibility to utilise LIN28 as a pharmacological target to suppress MB cell growth and stemness.