Year: 2021
Type: article
Abstract: Gastrointestinal stromal tumor (GIST) is commonly driven by oncogenic KIT mutations that are effectively targeted by imatinib (IM), a tyrosine kinase inhibitor (TKI). However, IM does not cure GIST, and adjuvant therapy only delays recurrence in high-risk tumors. We hypothesized that GIST contains cells with primary IM resistance that may represent a reservoir for disease persistence. Here, we report a subpopulation of CD34+KITlow human GIST cells that have intrinsic IM resistance. These cells possess cancer stem cell-like expression profiles and behavior, including self-renewal and differentiation into CD34+KIThigh progeny that are sensitive to IM treatment. We also found that TKI treatment of GIST cell lines led to induction of stem cell–associated transcription factors (OCT4 and NANOG) and concomitant enrichment of the CD34+KITlow cell population. Using a data-driven approach, we constructed a transcriptomic-oncogenic map (Onco-GPS) based on the gene expression of 134 GIST samples to define pathway activation during GIST tumorigenesis. Tumors with low KIT expression had overexpression of cancer stem cell gene signatures consistent with our in vitro findings. Additionally, these tumors had activation of the Gas6/AXL pathway and NF-κB signaling gene signatures. We evaluated these targets in vitro and found that primary IM-resistant GIST cells were effectively targeted with either single-agent bemcentinib (AXL inhibitor) or bardoxolone (NF-κB inhibitor), as well as with either agent in combination with IM. Collectively, these findings suggest that CD34+KITlow cells represent a distinct, but targetable, subpopulation in human GIST that may represent a novel mechanism of primary TKI resistance, as well as a target for overcoming disease persistence following TKI therapy.
Source: Molecular Cancer Therapeutics
Language: English
Subfield: Gastroenterology
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
Awards: G1443061497, G2217456570, G2524457625, G2595615132, G2666609578, G2986972424, G3549828030, G3803015799, G403864660, Research Center for Cancer Systems Biology: Cancer Cell Map Initiative, Targeting Drug-Resistant Cancer Stem Cell Niches of Gastrointestinal Stromal Tumor, G5520316217, Specialized Cancer Center Support Grant, Novel Allosteric Kinase Inhibitors Target Imatinib-Resistant GIST, G7907473461, GenePattern and GenePattern Notebook: Integrative 'Omic Analysis for Cancer Research, Next-generation Functional Genetic Screening of Un-screenable Traits, G9000018132, G9000019377, G9000021148, G9000030157, G9000066880, G9000158433, G9000207135, G9000317936, G900966905
OpenAlex ID: W3193151996