Classification of Subpopulations of Cells Within Human Primary Brain Tumors by Single Cell Gene Expression Profiling

Abstract

Brain tumors are heterogeneous with respect to genetic and histological properties of cells within the tumor tissue. To study subpopulations of cells, we developed a protocol for obtaining viable single cells from freshly isolated human brain tissue for single cell gene expression profiling. We evaluated this technique for characterization of cell populations within brain tumor and tumor penumbra. Fresh tumor tissue was obtained from one astrocytoma grade IV and one oligodendroglioma grade III tumor as well as the tumor penumbra of the latter tumor. The tissue was dissociated into individual cells and the expression of 36 genes was assessed by reverse transcription quantitative PCR followed by data analysis. We show that tumor cells from both the astrocytoma grade IV and oligodendroglioma grade III tumor constituted cell subpopulations defined by their gene expression profiles. Some cells from the oligodendroglioma grade III tumor proper shared molecular characteristics with the cells from the penumbra of the same tumor suggesting that a subpopulation of cells within the oligodendroglioma grade III tumor consisted of normal brain cells. We conclude that subpopulations of tumor cells can be identified by using single cell gene expression profiling.

Single-cell systems biology: Probing the basic unit of information flow

“…A significant component of non-genetic heterogeneity is due to the discontinuous nature of transcription. Genes are transcribed in “bursts” and this phenomenon has recently been observed in mouse liver tissue with smFISH [29], Drosophila with live-cell imaging [30], mouse embryonic stem cells with scRNA-seq [31], zebrafish embryos with smFISH [32], and human brain tumors [33] and melanoma [34] with single-cell qPCR.…”

Peptide-mediated targeted delivery of SOX9 nanoparticles into astrocytes ameliorates ischemic brain injury

“…5 It has been widely accepted that reactive astrogliosis is neuroprotective because the glial cells can promote cell survival to counteract severe injury or degeneration. 6,7 On the other hand, recent observations suggest that reactive astrogliosis is more nuanced and can have both "neurotoxic" and "neuroprotective" reactivity states. 8,9 Thus, the mechanisms and the function of astrocytes during injury-induced pathogenesis remain unclear.…”