IGSF3 binds to TNFR2 on Treg to facilitate immunosuppression in cervical cancer

Cancer Lett. 2026 Apr 28:644:218307. doi: 10.1016/j.canlet.2026.218307. Epub 2026 Feb 12.

Abstract

The clinical success of immune checkpoint blockades has revolutionized oncology; however, their efficacy in cervical cancer remains limited, primarily due to intricate tumor immune evasion mechanisms. Here, we identify elevated IGSF3 expression on tumor cells as a key driver enhancing regulatory T cell (Treg) infiltration and function. Crucially, we reveal a previously unrecognized ligand-receptor pair: IGSF3 on cervical cancer cells binds to TNFR2 on Tregs, activating NF-κB pathway and thereby amplifying Treg-mediated immunosuppression. Through structure-based virtual screening and rigorous multi-level validation, we developed purpurogallin, a conventionally recognized antioxidant compound, as a novel IGSF3 inhibitor, which effectively disrupts the IGSF3-TNFR2 interaction, reduces Treg abundance, suppresses tumor growth, and synergizes with anti-PD-1/anti-CTLA-4 antibodies. Notably, pretreatment with purpurogallin followed by PD-1 blockade yields prominent therapeutic efficacy. This study establishes IGSF3 as a pivotal regulator of the immunosuppressive microenvironment and unveils a promising sequential immunotherapy strategy for cervical cancer.

Keywords: Cervical cancer; IGSF3; Purpurogallin; TNFR2; Treg.

MeSH terms

  • Animals
  • Cell Line, Tumor
  • Female
  • Humans
  • Immunoglobulins* / genetics
  • Immunoglobulins* / metabolism
  • Membrane Proteins* / antagonists & inhibitors
  • Membrane Proteins* / genetics
  • Membrane Proteins* / metabolism
  • Mice
  • Receptors, Tumor Necrosis Factor, Type II* / metabolism
  • T-Lymphocytes, Regulatory* / drug effects
  • T-Lymphocytes, Regulatory* / immunology
  • T-Lymphocytes, Regulatory* / metabolism
  • Tumor Microenvironment / drug effects
  • Tumor Microenvironment / immunology
  • Uterine Cervical Neoplasms* / drug therapy
  • Uterine Cervical Neoplasms* / immunology
  • Uterine Cervical Neoplasms* / metabolism
  • Uterine Cervical Neoplasms* / pathology

Substances

  • Receptors, Tumor Necrosis Factor, Type II
  • Membrane Proteins
  • Immunoglobulins