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Omics · study · 2026

RNF43 p.G659fs Leads to Natural Killer Cell Dysfunction in MSI-high Colorectal Cancer Through PI3K/AKT/mTOR Signaling and HLA-E Upregulation

Listed in NCBI GEO

The RNF43 p.G659fs (RNF43659mut) mutation occurs in 8% of colorectal cancers (CRCs) and is enriched in microsatellite instability-high (MSI-H) tumors.

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While RNF43659mut promotes tumor growth through PI3K/AKT/mTOR activation independent of WNT signaling, its immunologic effects are poorly defined. We show that RNF43659mut shapes an immunosuppressive NK cell landscape in MSI-H CRC.

Single-cell RNA sequencing and multiplex immunohistochemistry revealed increased NK cell infiltration in RNF43659mut tumors, yet these cells displayed inhibitory phenotypes. Bulk RNA-seq and flow cytometry of NK cells co-cultured with RNF43659mut isogenic lines and MSI-H patient-derived organoids demonstrated reduced functional NK subsets, decreased activation markers, increased inhibitory receptors, and impaired cytotoxicity.

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Mechanistically, RNF43659mut-mediated PI3K/AKT activation induced HLA-E expression, suppressing NK cell function. Pharmacological or siRNA-mediated PI3K/AKT inhibition restored NK cell activity and enhanced tumor cell killing. Spatial analysis of MSI-H patient tumors revealed close proximity between NKG2A⁺NK cells and HLA-E⁺ tumor cells, which were themselves adjacent to PI3K/AKT-activated tumor cells, highlighting a localized immunosuppressive niche.

These findings uncover an immune evasion mechanism in MSI-H CRC, implicating the PI3K/AKT-HLA-E/NKG2A axis as a promising therapeutic target to overcome immunotherapy resistance.

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Life Sciences
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Cancer 75% · RNA sequencing 75% · Sequencing 75% · Single-cell RNA sequencing 75%
Provenance · 1 source records, 11 field assertions
SourceKeyLast seenRaw
NCBI GEOGSE34268415 d agoJSON v1
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concepts[disease].local:disease:cancerenrichment · NCBI GEOkeyword-concept-rules@1.0.0title+description (75%)
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concepts[method].geo_series_type:expression-profiling-by-high-throughput-sequencingsource · NCBI GEOconnector:ncbi_geo@1.0.0/gdstype
concepts[modality].local:modality:rna-seqenrichment · NCBI GEOkeyword-concept-rules@1.0.0title+description (75%)
concepts[modality].local:modality:sequencingenrichment · NCBI GEOkeyword-concept-rules@1.0.0title+description (75%)
concepts[modality].local:modality:single-cell-rna-seqenrichment · NCBI GEOkeyword-concept-rules@1.0.0title+description (75%)
concepts[organism].NCBITaxon:9606source · NCBI GEOconnector:ncbi_geo@1.0.0/taxon
descriptionsource · NCBI GEOconnector:ncbi_geo@1.0.0/summary
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titlesource · NCBI GEOconnector:ncbi_geo@1.0.0/title