CBX7 reprograms metabolic flux to protect against meningioma progression by modulating the USP44/c-MYC/LDHA axis.

Meningioma is one of the most common primary neoplasms in the central nervous system, whereas there is still no specific molecularly targeted therapy that has been approved for the clinical treatment of aggressive meningiomas. There is therefore an urgent demand to decrypt the biological and molecular landscape of malignant meningioma. Here, through the in-silica prescreening and 10-year follow-up of 445 meningioma patients, we uncovered that CBX7 is progressively decreased with malignancy grade and neoplasia stage in meningioma and a high CBX7 expression level predicts a favorable prognosis in meningioma patients. CBX7 restoration significantly induces cell cycle arrest and inhibits meningioma cell proliferation. iTRAQ-based proteomics analysis indicated that CBX7 restoration triggers the metabolic shift from glycolysis to oxidative phosphorylation. The mechanistic study demonstrated that CBX7 promotes the proteasome-dependent degradation of c-MYC proteins by transcriptionally inhibiting the expression of a c-MYC deubiquitinase, USP44, which attenuates c-MYC-mediated transactivation of LDHA transcripts and further inhibits glycolysis and subsequent cellular proliferation. More importantly, the functional role of CBX7 was further confirmed in both subcutaneous and orthotopic meningioma xenografts mouse models and human meningioma patients. Together, our results shed light on the critical role of CBX7 during meningioma malignancy progression and identified the CBX7/USP44/c-MYC/LDHA axis as a promising therapeutic target against meningioma progression.