PAD4-mediated citrullination of IGF2BP2 stabilizes MCM mRNAs to drive intrahepatic cholangiocarcinoma progression

  • J Adv Res. 2026 Jun 5:S2090-1232(26)00460-1. doi: 10.1016/j.jare.2026.06.008.
Geng Tian  1 ,  Lin Zou  1 ,  Minjie Zhang  1 ,  Fangyu Ye  1 ,  Yuting Ye  2 ,  Yuchen Ye  2 ,  Di Pan  3 ,  Jinxuan Li  4 ,  Yabing Guo  2 ,  Yuhan Mao  2 ,  Jia Li  2 ,  Jun Chen  5 ,  Youxiang Ding  6 ,  Li Zhao  7
Affiliations
  • 1. School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing 211198, PR China.
  • 2. Public Experimental Platform, China Pharmaceutical University, Nanjing 211198, PR China.
  • 3. State Key Laboratory of Discovery and Utilization of Functional Components in Traditional Chinese Medicine / High Application of Natural Medicinal Resources Engineering Center of Guizhou Province (Key Laboratory of Novel Anti-Cancer Drug Targets Discovery and Application), School of Pharmaceutical Sciences, Guizhou Medical University, Guiyang 561113, PR China.
  • 4. College of Pharmacy, Xiamen University, Fujian 361005, PR China.
  • 5. Department of Pathology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing 210008, PR China. Electronic address: [email protected].
  • 6. Department of Pathology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing 210008, PR China. Electronic address: [email protected].
  • 7. School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing 211198, PR China; Public Experimental Platform, China Pharmaceutical University, Nanjing 211198, PR China. Electronic address: [email protected].
PMID: 42250722 DOI: 10.1016/j.jare.2026.06.008
Abstract

Introduction: Peptidyl arginine deiminase 4 (PAD4) catalyzes the deamination of arginine residues to citrulline, a post-translational modification known as citrullination, which regulates protein structure, function, and localization. Despite growing evidence connects PAD4 to Cancer progression, its role in intrahepatic cholangiocarcinoma (ICC) remains largely unexplored.

Objectives: This study aimed to elucidate the role and underlying mechanisms of PAD4 in the regulation of intrahepatic cholangiocarcinoma proliferation, as well as to explore its clinical relevance and therapeutic potential.

Methods: Hydrodynamic tail vein injection (HTVI) and subcutaneous xenograft models were used to evaluate the role of PAD4 in vivo. In vitro functional assays were performed to assess the effects of PAD4 on ICC cell proliferation. Putative targets were identified by RNA-seq and Co-IP/MS analyses. Molecular interactions were examined using GST pull-down, surface plasmon resonance (SPR), and RNA immunoprecipitation-PCR. The clinical relevance of PAD4 was evaluated in ICC patient samples using immunohistochemical analysis.

Results: PAD4 was identified as a key promoter of ICC proliferation by enhancing post-transcriptional expression of the MCM complex. Mechanistically, PAD catalytic domain of PAD4 interacted with the KH1 domain of IGF2BP2 and catalyzed its citrullination at R597, which markedly increased the affinity of IGF2BP2 for m6A-modified MCM2-7 transcripts, thereby stabilizing and elevating MCM mRNAs expression. Clinically, high PAD4 expression correlated with poor prognosis in ICC patients, while PAD4 and IGF2BP2 co-expression predicted worse outcomes. In vivo, combined inhibition of PAD4 and IGF2BP2 synergistically suppressed ICC growth.

Conclusion: Our findings identify a tumor-intrinsic PAD4-IGF2BP2 axis that drives ICC progression through citrullination-dependent stabilization of MCM transcripts. Dual targeting of PAD4 and IGF2BP2 represents a promising therapeutic strategy for ICC.

Keywords
Citrullination; DNA replication; Inhibitors; M6A modification; Proliferation.
Products
Inhibitors & Agonists
Other Products