AlkaPhos: a novel fluorescent probe as a potential point-of-care diagnostic tool to estimate recurrence risk of meningiomas.

Deletion of the short arm of chromosome 1 (1p) increases recurrence rates in meningiomas by up to 33%, regardless of tumor grade, correlating with absence of intracellular alkaline phosphatase enzyme activity. Current screening methods for 1p deletion like fluorescence in situ hybridization (FISH) and loss of heterozygosity (LOH) analysis are resource-intensive. This study evaluated AlkaPhos, a novel fluorescent probe, for detecting alkaline phosphatase in meningioma cells and compared findings with FISH, LOH, and histochemical analysis. AlkaPhos sensitivity in detecting alkaline phosphatase on BEN-MEN-1 cells and primary meningioma cultures was assessed via microscopic fluorescent ratio measurements. FISH and LOH were conducted on the same tumors to detect 1p deletions. Histochemical analysis served as a reference. AlkaPhos results were compared with FISH, LOH, and histochemical analysis. AlkaPhos effectively indicated alkaline phosphatase activity in BEN-MEN-1 cells and correctly identified 1p deletion in 8/14 primary meningioma cultures, matching FISH and LOH findings, respectively. AlkaPhos showed potential superiority over histochemical analysis in identifying tumors with 1p deletion and LOH of 1p. AlkaPhos bears potential as a future diagnostic tool for identifying alkaline phosphatase absence in meningiomas, indicative of 1p deletion. Further evaluation on a larger sample size is necessary for routine clinical application.