Evans Blue leakage and IgG detection in the brain tissue suggested a negative correlation between PTH1R expression levels and blood-brain barrier function. Further, a risk model based on differentially expressed genes in PTH1R+ pericytes had predictive value for GBM, as validated using independent and in-house cohorts.
Conversely, overexpression of PTHrP in 4T1 cells increased migration towards MC3T3-E1 osteoblasts and this was not inhibited by PTH. In conclusion, PTH1R expression is crucial in both osteoblasts and breast cancer cells for PTH to reduce bone metastases and in breast cancer cells this may be mediated in part by suppression of PTHrP.