Single-Cell Profiling and Proteomics-Based Insights Into mTORC1-Mediated Angio+TAMs Polarization in Recurrent IDH-Mutant Gliomas.

BACKGROUND

IDH mutant gliomas often exhibit recurrence and progression, with the mTORC1 pathway and tumor-associated macrophages potentially contributing to these processes. However, the precise mechanisms are not fully understood. This study seeks to investigate these relationships using proteomic, phosphoproteomic, and multi-dimensional transcriptomic approaches.

METHODS

This study established a matched transcriptomic, proteomic, and phosphoproteomic cohort of IDH-mutant gliomas with recurrence and progression, incorporating multiple glioma-related datasets. We first identified the genomic landscape of recurrent IDH-mutant gliomas through multi-dimensional differential enrichment, GSVA, and deconvolution analyses. Next, we explored tumor-associated macrophage subpopulations using single-cell sequencing in mouse models of IDH-mutant and wild-type gliomas, analyzing transcriptional changes via AddmodelScore and pseudotime analysis. We then identified these subpopulations in matched primary and recurrent IDH-mutant datasets, investigating their interactions with the tumor microenvironment and performing deconvolution to explore their contribution to glioma progression. Finally, spatial transcriptomics was used to map these subpopulations to glioma tissue sections, revealing spatial co-localization with mTORC1 and angiogenesis-related pathways.

RESULTS

Multi-dimensional differential enrichment, GSVA, and deconvolution analyses indicated that the mTORC1 pathway and the proportion of M2 macrophages are upregulated during the recurrence and progression of IDH-mutant gliomas. CGGA database analysis showed that mTORC1 activity is significantly higher in recurrent IDH-mutant gliomas compared to IDH-wildtype, with a correlation to M2 macrophage infiltration. KSEA revealed that AURKA is enriched during progression, and its inhibition reduces mTORC1 pathway activity. Single-cell sequencing in mouse models identified a distinct glioma subpopulation with upregulated mTORC1, exhibiting both M2 macrophage and angiogenesis transcriptional features, which increased after implantation of IDH-mutant tumor cells. Similarly, human glioma single-cell data revealed the same subpopulation, with cell-cell communication analysis showing active VEGF signaling. Finally, spatial transcriptomics deconvolution confirmed the co-localization of this subpopulation with mTORC1 and VEGFA in high-grade IDH-mutant gliomas.

CONCLUSIONS

Our findings suggest mTORC1 activation and Angio-TAMs play key roles in the recurrence and progression of IDH-mutant gliomas.