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Fueling Immunotherapy Resistance: SSBP4 Links Tumor Cholesterol Biosynthesis to Immune Evasion

James Gow1,2,3, Yibin Kang1,2,4

  • 1Department of Molecular Biology, Princeton University, Princeton, New Jersey.

Cancer Immunology Research
|June 29, 2026
PubMed

Insights

Researchers found that single-stranded DNA binding protein 4 (SSBP4) drives resistance to cancer therapies like immune checkpoint inhibitors (ICI). Targeting SSBP4 may enhance the effectiveness of these crucial treatments.

Area of Science:

  • Cancer immunology
  • Molecular oncology
  • Metabolic pathways in cancer

Background:

  • Immune checkpoint inhibitors (ICIs) have revolutionized cancer therapy, but response rates remain limited.
  • Identifying mechanisms of resistance to ICIs is critical for improving patient outcomes.
  • Intratumoral metabolic dysregulation is increasingly recognized as a factor in immune evasion.

Purpose of the Study:

  • To identify novel molecular drivers of resistance to immune checkpoint inhibitors (ICIs).
  • To investigate the role of single-stranded DNA binding protein 4 (SSBP4) in mediating immune evasion.
  • To explore SSBP4 as a potential therapeutic target for enhancing antitumor immunity.

Main Methods:

  • Analysis of SSBP4 expression in tumor samples.
  • Investigating the impact of SSBP4 on cholesterol biosynthesis pathways.
  • Assessing the effects of SSBP4 on immune cell infiltration (lymphocytes) within the tumor microenvironment.
  • Evaluating the potential of targeting SSBP4 to improve responses to ICIs in preclinical models.

Main Results:

  • Single-stranded DNA binding protein 4 (SSBP4) was identified as a key factor promoting resistance to ICIs.
  • SSBP4 promotes intratumoral cholesterol biosynthesis, which suppresses the recruitment of lymphocytes to the tumor.
  • Elevated SSBP4 levels correlate with immune evasion and reduced efficacy of ICI therapy.

Conclusions:

  • SSBP4 is a novel driver of resistance in cancers treated with immune checkpoint inhibitors.
  • The mechanism involves SSBP4-mediated enhancement of cholesterol biosynthesis, leading to immune suppression.
  • Targeting SSBP4 represents a promising strategy to overcome ICI resistance and enhance antitumor immunity.

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