IRF1

Overview

IRF1, or interferon regulatory factor 1, is a transcription factor that plays a central role in immune and inflammatory gene regulation. It is best known for mediating interferon-responsive transcriptional programs and for integrating signals from pathways such as JAK2/STAT3 signaling, MAPK signaling, and mechanistic target of rapamycin kinase-related networks. In cancer and inflammatory biology, IRF1 is often studied as a context-dependent regulator of cell-state transitions, cytokine responses, and immune checkpoint-related pathways.

Recent studies have highlighted IRF1 as a biologically important node linking pathway inhibition to downstream transcriptional reprogramming. Depending on the cellular context, IRF1 can promote proinflammatory responses, regulate genes involved in immune evasion or antitumor immunity, and participate in transcriptional complexes that influence tumor progression and therapy response. Its relevance spans endothelial inflammation, cholangiocarcinoma, non-small cell lung cancer, and KRAS-MAPK-driven adaptive signaling.

Role in Recent Research

Recent publications have examined IRF1 as a transcriptional regulator that is induced or functionally engaged after therapeutic pathway inhibition, with consequences for inflammation, immune signaling, and tumor vulnerability.

In a study of prolonged KRAS-MAPK inhibition in cancer cells, IRF1 was implicated in interferon signaling that emerged after relief of ERK-mediated transcriptional repression. The report specifically noted that TRIM22 expression was driven by IRF1 and IRF9 during pathway inhibition, linking IRF1 to a broader interferon-regulated transcriptional state associated with cell-state transition and therapeutic vulnerability. This places IRF1 downstream of MAPK pathway suppression and suggests that it contributes to adaptive transcriptional remodeling under targeted therapy.

In endothelial biology, IRF1 was identified as a proinflammatory transcription factor induced by mTOR inhibition. The study connected IRF1 to cytoskeletal contraction and inflammatory responses in endothelial cells, with a mechanism converging on myosin light chain phosphorylation-dependent cytoskeletal dynamics. This work tied IRF1 to endothelial hyperpermeability and pulmonary inflammation caused by mTOR inhibition, and it is mechanistically relevant to mTORC1 complex and mTORC2 complex signaling, as well as regulators such as Rictor and RPTOR gene-associated pathways. Related pharmacologic contexts included sirolimus and torin 1, both of which are used to probe mTOR-dependent biology.

In cholangiocarcinoma research, IRF1 was described as part of a transcriptional complex with OGT that supports MUC16 expression. The study reported that OSMI-1 suppresses MUC16 expression by disrupting the transcriptional complex formed between OGT and IRF1. This indicates that IRF1 can participate in oncogenic transcriptional regulation and that interfering with its protein complex formation may reduce malignant progression and chemoresistance in large-duct type intrahepatic cholangiocarcinoma. The work also involved patient-derived organoids, primary iCCA cell lines, xenograft models, and gemcitabine-based therapeutic contexts.

In immunotherapy-related research, IRF1 was linked to AMPK-IRF1 signaling in the regulation of PD-L1. One study reported that SLC5A11-dependent activation of AMPK led to subsequent JAK2-STAT1-IRF1 downregulation, which enhanced cancer immunotherapy by suppressing PD-L1. This connects IRF1 to anti-PD1 therapy and anti-programmed cell death protein 1 strategies, emphasizing its role in immune checkpoint regulation and tumor immune responsiveness.

Another study focused on the IRF1-TRIM21 axis in non-small cell lung cancer and showed that IRF1 regulates TRIM21 transcription. This axis was proposed to enhance antitumor immunity by promoting ubiquitin-mediated degradation of FGL1, a factor implicated in immune suppression. The findings support a model in which IRF1 contributes to immune activation by controlling transcription of genes that shape the tumor microenvironment and immune escape.

Finally, a multi-omics and machine-learning study of lung adenocarcinoma PANoptosis identified IRF1 among six core genes, alongside CASP1, NLRP3, TIMP1, S100A8, and TLR4. This places IRF1 within a broader inflammatory cell-death and tumor microenvironment framework, consistent with its known role in interferon and cytokine-associated signaling. Related entities such as proinflammatory cytokine, TLR4, and tumour cells were part of the same research context, reinforcing IRF1’s association with inflammatory tumor biology.

Key Publications

NEWJul Prolonged KRAS-MAPK Inhibition Induces Interferon Signaling That Promotes Cell State Transition and Confers Therapeutic Vulnerabilities. (Cancer research, 2026, PMID 42008116): "TRIM22 expression was driven by IRF1 and IRF9 following relief of ERK-mediated transcriptional repression during pathway inhibition."
Jun IRF-1 Links Cytoskeletal Contraction With Inflammatory Response in mTOR-Inhibited Endothelial Cells. (FASEB journal : official publication of the Federation of American Societies for Experimental Biology, 2026, PMID 42273992): "Recent studies independently revealed the upregulation of the proinflammatory transcription factor interferon regulatory factor-1 (IRF-1) by mTOR inhibition (mTORi) of endothelial cells (EC) and further highlighted a mechanism converging on myosin light chain (MLC) phosphorylation-dependent cytoskeletal dynamics in promoting the endothelial hyperpermeability and pulmonary inflammation caused by mTORi."
May Targeting MUC16 suppresses malignant progression and chemoresistance in large-duct type intrahepatic cholangiocarcinoma. (Cancer letters, 2026, PMID 41839437): "Mechanistically, OSMI-1 suppresses MUC16 expression by disrupting the transcriptional complex formed between OGT and IRF1."
Apr SLC5A11 mediates metformin-induced PD-L1 suppression to enhance cancer immunotherapy through AMPK-IRF1 signaling. (Cancer letters, 2026, PMID 41690450): "SLC5A11-dependent activation of AMPK and subsequent JAK2-STAT1-IRF1 downregulation."
Apr Targeting IRF1-TRIM21 axis enhances anti-tumor immunity by promoting ubiquitin-mediated degradation of FGL1 in non-small cell lung cancer. (Communications biology, 2026, PMID 42020516): "We further show that interferon regulatory factor 1 (IRF1) regulates TRIM21 transcription."
Apr Integration of multi-omics and machine learning to identify core genes in PANoptosisof lung adenocarcinoma and their mechanisms in the tumor microenvironment and therapeutic potential. (Naunyn-Schmiedeberg's archives of pharmacology, 2026, PMID 41935997): "Six core genes of LUAD PANoptosis, including IRF1, NLRP3, CASP1, TIMP1, S100A8, and TLR4, were identified in the study."