In a novel MedERβ-null knockout model developed by crossing Esr2(-/-) mice with cerebellar granule cell precursor specific Ptch1 conditional knockout mice, the tumor growth rate was significantly decreased in males and females.
Similar to previous studies in normal cerebellar granule cell precursors, these studies demonstrate that the physiological actions of estrogens in MD are mediated by ERbeta.
In conclusion, inhibition of ERβ considered as a supplemental anticancer therapy, has been found to interfere with cisplatin-induced cytotoxicity in human medulloblastoma cell lines.
These findings demonstrate that E2 and environmental estrogens decrease sensitivity of MB to cytotoxic chemotherapeutics, and that ERβ selective and non-selective inhibition of estrogen receptor activity blocks these cytoprotective actions.