Figure 3. HFD and gliomagenesis inhibit H2S production.
(A) Schematic detailing the generation of H2S as a byproduct of cysteine metabolism associated with MPST activity and the transsulfuration pathway. (B) H2S production analysis indicates that HFD consumption results in decreased H2S synthesis in the tumors of HFD-fed mice compared with tumors isolated from mice fed a control diet. Each well contains tumor tissue homogenate from separate and distinct experimental animals. P values determined by unpaired t test. (C and D) Human patient data curated by The Cancer Genome Atlas Low-Grade Glioma and GBM data set indicate that patients with GBM present with the lowest average expression of the H2S-generating enzymes CBS and MPST. (E) While the mRNA expression of CGL remained stable across glioma subtype, previously published biochemical analysis confirmed that this enzyme is nonfunctional in the context of GBM.