mycophenolic-acid and Glioma

Diffuse intrinsic pontine glioma (DIPG) is an aggressive incurable brainstem tumor that targets young children. Complete resection is not possible, and chemotherapy and radiotherapy are currently only palliative. This study aimed to identify potential therapeutic agents using a computational pipeline to perform an in silico screen for novel drugs. We then tested the identified drugs against a panel of patient-derived DIPG cell lines. Using a systematic computational approach with publicly available databases of gene signature in DIPG patients and cancer cell lines treated with a library of clinically available drugs, we identified drug hits with the ability to reverse a DIPG gene signature to one that matches normal tissue background. The biological and molecular effects of drug treatment was analyzed by cell viability assay and RNA sequence. In vivo DIPG mouse model survival studies were also conducted. As a result, two of three identified drugs showed potency against the DIPG cell lines Triptolide and mycophenolate mofetil (MMF) demonstrated significant inhibition of cell viability in DIPG cell lines. Guanosine rescued reduced cell viability induced by MMF. In vivo, MMF treatment significantly inhibited tumor growth in subcutaneous xenograft mice models. In conclusion, we identified clinically available drugs with the ability to reverse DIPG gene signatures and anti-DIPG activity in vitro and in vivo. This novel approach can repurpose drugs and significantly decrease the cost and time normally required in drug discovery.

Topics: Animals; Astrocytoma; Brain Stem Neoplasms; Diffuse Intrinsic Pontine Glioma; Gene Expression; Glioma; Guanosine; Humans; Mice; Mycophenolic Acid

Expression of glial fibrillary acidic protein (GFAP) was assayed in 11 glioma-derived cell cultures. Treatment of cells with an inhibitor of guanine nucleotide biosynthesis, mycophenolic acid, enhanced detection of GFAP by indirect immunofluorescence microscopy. Quantitation of GFAP and vimentin demonstrated that enhanced fluorescence occurs without an increase in the level of intermediate filament proteins. Immunoblots provided the most sensitive method for monitoring GFAP expression and showed the limitations of using immunofluorescence detection methods. GFAP was detectable in cultures derived from malignant Grade IV astrocytomas and its expression was stable during the course of the study. While mycophenolic acid has been reported to induce differentiation in leukemia cells at low concentration (D.L. Lucas et al., J. Clin. Invest., 72: 1889-1990, 1983), its effect on glioma cultures at concentrations of 100 microM was consistent with a role as an inhibitor of DNA synthesis, and as an effector of altered intermediate filament organization.

Topics: Animals; Cells, Cultured; DNA; Fluorescent Antibody Technique; Glial Fibrillary Acidic Protein; Glioma; Humans; Mycophenolic Acid; Rats; Vimentin

1. When C6 glioma cells were incubated with mycophenolic acid, a potent and specific inhibitor of IMP:NAD oxidoreductase (EC 1.2.1.14) there was a marked depletion of the cellular content of GTP. The viability of the cells was unaffected. 2. The adenosine 3':5'-monophosphate (cyclic AMP) response of C6 glioma cells to the beta-adrenergic stimulant, (+/-)isoprenaline, was considerably reduced after treatment with mycophenolic acid. The diminished response to (+/-)isoprenaline was prevented by the inclusion of guanine in the culture medium along with mycophenolic acid. 3. The adenylate cyclase response to (+/-)isoprenaline of whole homogenates from C6 cells treated with mycophenolic acid was also depressed; the response was restored to normal by the addition of GTP. 4. The adenylate cyclase response to (+/-)isoprenaline of a membrane fraction prepared from homogenates of C6 cells was almost totally dependent on the presence of added GTP. Membrane fractions from control and mycophenolic-acid-treated C6 cells gave similar adenylate cyclase responses to (+/-)isoprenaline in the presence of GTP. 5. It is concluded that mycophenolic acid may depress the beta-adrenergic sensitivity of C6 cells by depleting the cellular content of GTP.

Topics: Adenosine Triphosphate; Adenylyl Cyclases; Cell Line; Cell Membrane; Cyclic AMP; Enzyme Activation; Glioma; Guanosine Triphosphate; Isoproterenol; Kinetics; Mycophenolic Acid; Time Factors