IDH Mutation in the Progression of IDH-mutant Astrocytoma

My project investigated the role of isocitrate dehydrogenase (IDH) mutations in the progression of IDH-mutant astrocytoma, the most common brain malignancies in patients under age 55. Prior studies in murine cell lines suggested that these mutations might be lost sub clonally as tumors progress, raising the possibility that IDH may no longer be a significant driver in later stages. Given that IDH inhibitors are now used in standard care for low-grade astrocytoma, understanding whether IDH is lost in progression is essential to guide the development of effective treatment approaches for high-grade and recurrent astrocytoma. To further investigate this, we used fluorescence immunohistochemistry (FIHC) to examine paired primary and recurrent formalin-fixed paraffin embedded (FFPE) tissue microarrays (TMAs). This methodology allowed us to visualize expression patterns. Images produced from this protocol posed a signal overlap, leading to inconclusive results. This inspired the transition to a confocal microscope due to the possibility of selecting channels absent of crosstalk. Future directions include single-cell RNA sequencing and Light seq. For the single-cell RNA sequencing, we began culturing the Proli 108 murine cell lines with inducible IDH1R132H, p53, and ATRX mutations. In preparation for the final staining, we optimized the FIHC protocol and tested various dyes, buffers, and antibodies. This work will reveal whether tumor subpopulations lose the IDH mutation and its findings will guide to more effective treatment strategies for recurrent and high-grade astrocytomas.