The CD44s Isoform is a Potential Biomarker for Predicting Craniopharyngioma Recurrence in Children

Adamantinomatous craniopharyngioma (ACP) is an intracranial tumor considered partly malignant due to its ability to infiltrate surrounding structures and tendency to relapse despite radical resection. CD44 is a known stem cell marker in ACP and is upregulated in cell clusters of invasive ACP protrusions; however, the functions of its alternative splicing isoform variants, CD44s and CD44v1-10, have not yet been studied in terms of ACP recurrence, despite their confirmed roles in cancer development and progression. In this study, we first confirmed the difference in total CD44 expression between samples from patients who experienced relapse and those from patients who did not. Moreover, our findings showed that, in recurrent samples, the predominant isoform expressed was CD44s, which might indicate its significance in predicting ACP recurrence. The association between increased CD44 expression and recurrence may lead to the development of prognostic markers of ACP aggressiveness and relapse potential; however, further studies are needed to clarify the exact mechanism of CD44 expression.