Immune microenvironment profiling of gastrointestinal stromal tumors (GIST) shows gene expression patterns associated to immune checkpoint inhibitors response.
Maria A PantaleoGiuseppe TarantinoClaudio AgostinelliMilena UrbiniMargherita NanniniMaristella SaponaraChiara CastelliSilvia StacchiottiElena FumagalliLidia GattoDonatella SantiniAntonio De LeoTeresa MarafiotiAyse AkarcaElena SabattiniAndrea PessionAndrea ArdizzoniValentina IndioAnnalisa AstolfiPublished in: Oncoimmunology (2019)
Few studies were conducted investigating the immunological profiles in gastrointestinal stromal tumors (GIST). Adaptive and innate immune cells are present in the tumor microenvironment, indicating GIST as inflamed tumors. In addition, murine models suggested a potential interaction between immune components and imatinib. In this retrospective study, the GIST immunological profile was investigated through in silico analysis and immunohistochemistry (IHC), exploring the basis for immunotherapy approaches. Gene expression profiles (GEP) from 31 KIT/PDGFRA-mutant GIST were analyzed to evaluate the tumor microenvironment and immunotherapy predictive signatures such as the expanded IFN-γ-induced immune signature (EIIS) and the T-cell-inflamed signature (TIS). GEP and IHC supported the presence of immune infiltrate in GIST, with dominance of CD4+ and CD8+ T cells and M2 macrophages showing a remarkable similarity with melanoma microenvironment. The EIIS genes were expressed in most of GIST samples and positively correlated with PD-L1 abundance (p < .0001). Co-expression was also found between PD-L1 and CD8A (p < .0001) or CD8B (p = .0003). Moreover, the median TIS score for GIST was between the 65th and 70th percentile of the Cancer Genome Atlas dataset, in the same range of tumors responding to anti-PD-1/PD-L1. Analysis of the Gene Expression Omnibus database GIST samples pre- and post-treatment confirmed that imatinib downregulates PD-L1 and IRF1 expression through the inhibition of KIT and PDGFRA, thus contributing to counteract the suppressed adaptive immune response against GIST. The presence of a rich immune infiltrate in GIST along with the presence of TIS and EIIS suggests that GIST may benefit from immunotherapy along with tyrosine kinase inhibitors.
Keyphrases
- gene expression
- immune response
- poor prognosis
- genome wide
- stem cells
- dna methylation
- emergency department
- squamous cell carcinoma
- single cell
- transcription factor
- risk assessment
- long non coding rna
- toll like receptor
- endothelial cells
- oxidative stress
- drug induced
- papillary thyroid
- combination therapy
- human health
- antibiotic resistance genes