Objectives: Pituitary stem cells play a role in the oncogenesis of human adamantinomatous craniopharyngiomas (aCPs). We hypothesized that crosstalk between the Wnt/b-catenin and Sonic Hedgehog (SHH) pathways, both of which are important in normal pituitary development, would contribute to the pathogenesis of aCPs. Design: To explore the mRNA and protein expression of components of the SHH signaling pathway in aCPs and their relationship with the identification of CTNNB1/b-catenin mutations and patients outcomes. Patients and methods: In 18 aCP samples, CTNNB1 was sequenced, and the mRNA expression levels of SHH pathway members (SHH, PTCH1, SMO, GLI1, GLI2, GLI3, and SUFU) and SMO, GLI1, GLI3, SUFU, b-catenin, and Ki67 proteins were evaluated by quantitative real-time PCR and immunohistochemistry respectively. Anterior normal pituitaries were used as controls. Associations between molecular findings and clinical data were analyzed. Results: The aCPs presented higher mRNA expression of SHH (C400-fold change (FC); P!0.01), GLI1 (C102-FC; P!0.001), and GLI3 (C5.1-FC; P!0.01) than normal anterior pituitaries. Longer disease-free survival was associated with low SMO and SUFU mRNA expression (P!0.01 and PZ0.02 respectively). CTNNB1/b-catenin mutations were found in 47% of the samples. aCPs with identified mutations presented with higher mRNA expression of SMO and GLI1 (C4.3-FC; PZ0.02 and C10.2-FC; PZ0.03 respectively). SMO, GLI1, GLI3, and SUFU staining was found in 85, 67, 93, and 64% of the samples respectively. Strong GLI1 and GLI3 staining was detected in palisade cells, which also labeled Ki67, a marker of cell proliferation. Conclusions: The upregulation of SHH signaling occurs in aCPs. Thus, activation of Wnt/b-catenin and SHH pathways, both of which are important in pituitary embryogenesis, appears to contribute to the pathogenesis of aCP.
