Indeed, we observed germline microdeletions/duplications of regions encompassing cancer-related genes in 50% of patients undergoing array-CGH: EIF3H duplication in a patient with infantile desmoplastic astrocytoma and low-grade Glioma; SLFN11 deletion, SOX4 duplication, and PARK2 partial deletion in three neuroblastoma patients; a PTPRD partial deletion in a child diagnosed with glioblastoma multiforme.
Specifically, we show that in human GBMs, heterozygous loss of PTPRD is the predominant type of lesion and that loss of PTPRD and the CDKN2A/p16(INK4A) tumor suppressor frequently co-occur.
Sequencing of the PTPRD gene in GBM and other primary human tumors revealed that the gene is mutated in 6% of GBMs, 13% of head and neck squamous cell carcinomas, and in 9% of lung cancers.These mutations were deleterious.
Reconstitution of PTPRD expression in GBM and melanoma cells harboring deletions or mutations led to growth suppression and apoptosis that was alleviated by both the somatic and constitutional mutations.