Histologically defined intratumoral sequencing uncovers evolutionary cues into conserved molecular events driving gliomagenesis

ABSTRACT

BACKGROUND:

Glioblastoma represents an archetypal example of a heterogeneous malignancy. To understand the diverse molecular consequences of this complex tumor ecology, we analyzed RNA-seq data generated from commonly identified intra-tumoral structures in glioblastoma enriched using laser capture microdissection.

METHODS:

Raw gene-level fragments per kilobase of transcript per million reads mapped (FPKM) values and the associated clinical data were acquired from the publically available Ivy GAP database and analyzed using MetaboAnalyst (v.3.0). The database includes gene expression data generated from multiple structural features commonly identified in glioblastoma enriched by laser capture microdissection.

RESULTS:

We uncovered a relationship between subtype heterogeneity in glioblastoma and its unique tumor microenvironment, with infiltrating cells harboring a proneural signature while the mesenchymal subtype was enriched in perinecrotic regions. When evaluating the tumors’ transcriptional profiles in the context of their derived structural regions, there was a relative small amount of inter-tumoral heterogeneity in glioblastoma, with individual regions from different tumors clustering tightly together. Analyzing the transcriptional profiles in the context of evolutionary progression identified unique cellular programs associated with specific phases of gliomagenesis. Mediators of cell signaling and cell cycle progression appear to be critical events driving proliferation in the tumor core, while in addition to a multiplex strategy for promoting angiogenesis and/or an immune tolerant environment, transformation to perinecrotic zones involved global metabolic alterations.

CONCLUSION:

These findings suggest intra-tumoral heterogeneity in glioblastoma is a conserved, predictable consequence to its complex microenvironment and combinatorial approaches designed to target these unequivocally present tumor biomes may lead to therapeutic gains.

from #ORL-AlexandrosSfakianakis via ola Kala on Inoreader http://ift.tt/2rXyPcr
via IFTTT