ABSTRACT
The co-occurrence of multiple disease processes can pose diagnostic challenges. We report an unusual case of a patient found to have co-occurrences of an IDH1-mutant high-grade glioma along with cerebral cavernous malformations and pathogenic germline variants in PDCD10 and SMARCA4. Somatic testing was done on the tumor and identified a SMARCA4 and two TP53 variants. Within the literature, little is known about the association of high-grade gliomas with these germline variants. Such findings furthermore not only inform complex diagnoses, but have the potential to play a crucial role in the ongoing care of a patient.
Subject(s)
Brain Neoplasms , Glioma , Humans , Glioma/complications , Glioma/diagnostic imaging , Glioma/genetics , Germ-Line Mutation , Mutation/genetics , Brain Neoplasms/complications , Brain Neoplasms/diagnostic imaging , Brain Neoplasms/genetics , Isocitrate Dehydrogenase/genetics , DNA Helicases/genetics , Nuclear Proteins/genetics , Transcription Factors/genetics , Membrane Proteins/genetics , Proto-Oncogene Proteins/genetics , Apoptosis Regulatory Proteins/geneticsABSTRACT
BACKGROUND: The mitochondrial branched-chain aminotransferase (BCATm) is a recently discovered cancer marker with a poorly defined role in tumour progression. METHODS: To understand how a loss of function of BCATm affects cancer, the global knockout mouse BCATmKO was challenged with EL-4 lymphoma under different diet compositions with varying amounts of branched-chain amino acids (BCAAs). Next, the growth and metabolism of EL-4 cells were studied in the presence of different leucine concentrations in the growth medium. RESULTS: BCATmKO mice experienced delayed tumour growth when fed standard rodent chow or a normal BCAA diet. Tumour suppression correlated with 37.6- and 18.9-fold increases in plasma and tumour BCAAs, 37.5% and 30.4% decreases in tumour glutamine and alanine, and a 3.5-fold increase in the phosphorylation of tumour AMPK in BCATmKO mice on standard rodent chow. Similar results were obtained with a normal but not with a choice BCAA diet. CONCLUSIONS: Global deletion of BCATm caused a dramatic build-up of BCAAs, which could not be utilised for energy or amino acid synthesis, ultimately delaying the growth of lymphoma tumours. Furthermore, physiological, but not high, leucine concentrations promoted the growth of EL-4 cells. BCATm and BCAA metabolism were identified as attractive targets for anti-lymphoma therapy.
