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Biology subjects

Fortin Ensign, S. P.

Publications and source records attributed to Fortin Ensign, S. P..

2 recordsLinked to original sources

Functional genomics identifies therapeutic options, biomarkers, and resistance mechanisms for high-grade gliomas

High-grade gliomas (HGGs) are aggressive tumors with poor outcomes and limited treatment options. Here, we combined genomic and transcriptomic tumor profiling with drug testing in a patient-derived 3-dimensional culture model to identify individualized treatments and predictive biomarkers. Activity of single agents targeting frequently dysregulated glioma pathways was relatively poor ex vivo and generally reflected historical patient data. However, compounds targeting PI3K, epigenetic, and survival/senescence signaling were effective in some cases. Drug sensitivity correlated with transcriptional rather than genomic features and suggested heterogeneity as a resistance mechanism. Bromodomain and extraterminal domain inhibition was particularly effective in tumors enriched in the mesenchymal transcriptional subtype, promoted proneural transition, and was overcome by upregulated PI3K signaling. Notably, combinations were largely effective, with 6 strategies exhibiting stronger efficacy than corresponding single agents in most cases (58-77%). This study identifies HGG vulnerabilities and associated biomarkers, resistance mechanisms, and effective combination strategies that warrant further clinical validation. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=171 SRC="FIGDIR/small/701806v1_ufig1.gif" ALT="Figure 1"> View larger version (31K): org.highwire.dtl.DTLVardef@cdb75corg.highwire.dtl.DTLVardef@1c133e6org.highwire.dtl.DTLVardef@1365153org.highwire.dtl.DTLVardef@11543a4_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

2H MRI-based quantification of leucine uptake in glioblastoma multiforme

Glioblastoma (GBM) brain tumors are among the most lethal of all human cancers, with a median survival time of [~]15 months. Treatment planning requires radiologic demarcation of tumor boundaries with contrast-enhanced magnetic resonance imaging (CE MRI); however, significant tumor burden extends beyond the contrast-enhancing margins of the tumor. GBM tumors have an increased expression of amino acid (AA) transporters, including the Alanine, Serine, Cysteine Transporter 2 (ASCT2) and the L-Type Amino Acid Transporter 1 (LAT1). This upregulation has been leveraged in positron emission tomography (PET) studies to detect tumor burden beyond the contrast-enhancing margins identified by standard-of-care CE MRI. Here we leverage recent approaches in deuterium metabolic magnetic resonance with this known upregulation of AA transporters in GBM to demonstrate that 2H MR can detect glioma based on enhanced branched- chain amino acid (BCAA) uptake. To the best of our knowledge, these data represent the first non- invasive quantification of AA concentrations in brain tumor and raises the potential to (i) detect tumor burden beyond contrast-enhancing margins and (ii) quantify AA metabolism using 2H MR spectroscopy.

cancer biology↗