Parathyroid Hormone-Related Protein Promotes the Proliferation of Patient-Derived Glioblastoma Stem Cells via Activating cAMP/PKA Signaling Pathway

Background and Objectives: Glioblastoma (GBM) is an aggressive primary brain tumor characterized by its hetero-geneity and high recurrence and lethality rates. Glioblastoma stem cells (GSCs) play a crucial role in therapy resistance and tumor recurrence. Therefore, targeting GSCs is a key objective in developing effective treatments for GBM. The role of Parathyroid hormone-related peptide (PTHrP) in GBM and its impact on GSCs remains unclear. This study aimed to investigate the effect of PTHrP on GSCs and its potential as a therapeutic target for GBM. Methods and Results: Using the Cancer Genome Atlas (TCGA) database, we found higher expression of PTHrP in GBM, which correlated inversely with survival. GSCs were established from three human GBM samples obtained after surgical resection. Exposure to recombinant human PTHrP protein (rPTHrP) at different concentrations significantly enhanced GSCs viability. Knockdown of PTHrP using target-specific siRNA (siPTHrP) inhibited tumorsphere for-mation and reduced the number of BrdU-positive cells. In an orthotopic xenograft mouse model, suppression of PTHrP expression led to significant inhibition of tumor growth. The addition of rPTHrP in the growth medium counteracted the antiproliferative effect of siPTHrP. Further investigation revealed that PTHrP increased cAMP concentration and activated the PKA signaling pathway. Treatment with forskolin, an adenylyl cyclase activator, nullified the anti-proliferative effect of siPTHrP. Conclusions: Our findings demonstrate that PTHrP promotes the proliferation of patient-derived GSCs by activating the cAMP/PKA signaling pathway. These results uncover a novel role for PTHrP and suggest its potential as a ther-apeutic target for GBM treatment.

Automated summary

This study aimed to investigate the effect of Parathyroid hormone-related peptide (PTHrP) on glioblastoma stem cells (GSCs) and its potential as a therapeutic target for glioblastoma (GBM). The results showed that PTHrP promotes the proliferation of GSCs by activating the cAMP/PKA signaling pathway, suggesting its potential as a therapeutic target for GBM treatment.