CD44/JAK2/STAT3 signaling pathway

Overview

The CD44/JAK2/STAT3 signaling pathway is a cell-signaling axis centered on the transmembrane adhesion receptor CD44 and the intracellular kinases/transcription factors JAK2 and STAT3. In biomedical research, this pathway is commonly discussed as a regulator of cell survival, proliferation, inflammatory signaling, stem-like phenotypes, immune-cell polarization, and tumor progression. CD44 is frequently implicated in hyaluronan-dependent cell interactions and tumor microenvironment signaling, while JAK2-mediated phosphorylation of STAT3 can drive transcriptional programs associated with inflammation and malignancy.

In recent literature, this pathway has been studied in cancer and inflammatory disease contexts, including thyroid cancer, pancreatic cancer, glioblastoma, acute myeloid leukemia, acute lymphoblastic leukemia, psoriasis, cutaneous T-cell lymphoma, and acute lung injury. It also appears in mechanistic studies of natural products and combination therapies that modulate IL-6/JAK2/STAT3, JAK2/STAT3, or CD44-linked signaling, often alongside related pathways such as PI3K/Akt signaling pathway, PI3K/AKT/mTOR pathway, TGFB1, interleukin-6, KRAS, and STAT5A.

Focus of Latest Publications

Recent studies have established JAK2/STAT3 signaling as a critical and therapeutically tractable node across malignancies and inflammatory disease. In non-small cell lung cancer, novel butein derivatives achieved dual targeting of EGFR kinase and downstream JAK2/STAT3 signaling, inducing G2/M cell cycle arrest and apoptosis in A549 cells and successfully suppressing oncogenic activation in gefitinib-resistant models. In pancreatic ductal adenocarcinoma, combination therapy simultaneously inhibiting STAT3 alongside Kras and EGFR achieved complete and durable tumor regression in orthotopic models and patient-derived xenografts with no evidence of therapeutic resistance sustained over 200 days posttreatment. In gastric cancer, ginkgetin suppressed STAT3 phosphorylation to induce immunogenic cell death in malignant cells while reversing the immunosuppressive tumor microenvironment and activating anti-tumor immunity.

CD44-enriched cancers have emerged as particularly susceptible to JAK2/STAT3-targeted approaches. Pancreatic cancer cells overexpressing CD44 were therapeutically targeted both via CD44-functionalized nanoparticles and through direct JAK2/STAT3 inhibition, and mechanistic studies identified CD44 as a chondroitin sulfate proteoglycan core protein that masks HER2 and functions as a glycan-mediated therapeutic resistance mechanism. These findings suggest that CD44-expressing cancer stem cells may be uniquely dependent on STAT3 signaling for maintenance of stemness and chemoresistance.

JAK2/STAT3 pathway suppression has proven efficacious in inflammatory and immune dysregulation contexts. In sepsis, combined moxibustion and anti-PD-1 antibody therapy synergistically suppressed STAT3 expression and nuclear translocation, reversing immunosuppression through the PD-1/PD-L1/STAT3 axis and restoring T cell proportions and function. Traditional herbal formulas suppressed JAK2/STAT3 signaling in blood deficiency syndrome via IL-6 pathway inhibition and in psoriasis by rebalancing Th17/Treg responses. In sepsis-associated acute kidney injury, a CD44-targeted nanozyme modulating the SIRT3/RORγt/STAT3 pathway simultaneously suppressed Th17-driven inflammation and restored mitochondrial homeostasis. Mechanistically, the fungal metabolite IM502 redirected STAT3 signaling from pro-inflammatory STAT3/6 to pro-antiviral STAT1/2 pathways, thereby reprogramming tumor-associated macrophage phenotype and enhancing NK and CD8+ T cell function. Collectively, these studies establish JAK2/STAT3 and CD44-expressing cellular populations as conserved therapeutic nodes in both oncologic and inflammatory pathologies.

Key Publications

• NEWJun Novel patient-derived tongue squamous cell carcinoma cell lines from non-smokers: 3D and in vivo models for drug response studies. (Medical oncology (Northwood, London, England), 2026, PMID 42371352): "Interestingly, CD44 and c-Myc expression were observed only in fibroblast-enriched cultures, but not in the epithelial LMSCC03 and LMSCC16 cells."
• NEWJun Moxibustion combined with anti-PD-1 antibodies improves immunosuppression in septic mice potentially through the PD-1/PD-L1 pathway. (Immunologic research, 2026, PMID 42307810): "Combination therapy suppressed PD-1, PD-L1, and STAT3 expression in the spleen while reducing STAT3 nuclear translocation."
• Jun A targeted combination therapy achieves effective pancreatic cancer regression and prevents tumor resistance. (Proceedings of the National Academy of Sciences of the United States of America, 2026, PMID 42224594): "genetic ablation of three independent nodes involved in downstream (RAF1), upstream (EGFR), and orthogonal (STAT3) KRAS signaling pathways leads to complete and permanent regression of orthotopic PDACs induced by Kras/Tp53 mutations."
• Jun Pacritinib Impact on QT Interval: Results of a Thorough QT Study and Post Hoc Analysis of Prospective Clinical Trial Data. (Clinical pharmacology in drug development, 2026, PMID 42213484): "Pacritinib, an inhibitor of JAK2/IRAK1/ACVR1 that is devoid of JAK1 activity, approved for treating myelofibrosis in patients with severe thrombocytopenia, carries a label warning for QT interval prolongation."
• Jun Fungal metabolite-based immunotherapy overcomes tumor-associated macrophage immunosuppression. (Cell reports. Medicine, 2026, PMID 42173096): "Mechanistically, IM502 primarily inhibits PI3Kγ and redirects STAT signaling from STAT3/6 to STAT1/2 dominance, thereby reversing TAM-mediated immunosuppression, substantially enhancing the abundance and functional quality of natural killer (NK) and T cells."
• May Targeted dermal delivery of phloretin via thermoresponsive nanoparticles potently suppresses STAT3/NF-κB-driven psoriatic inflammation. (Phytomedicine : international journal of phytotherapy and phytopharmacology, 2026, PMID 42134228): "Targeted dermal delivery of phloretin via thermoresponsive nanoparticles potently suppresses STAT3/NF-κB-driven psoriatic inflammation."
• Jun A mechanistic study on the SIRT3/RORγt/STAT3-regulated Th17-targeted bionic black phosphorus quantum dot cluster nanozyme for improving sepsis-associated acute kidney injury. (Biomaterials science, 2026, PMID 42093466): "Mechanistically, the nanozyme's overexpression of SIRT3 inhibited RORγt/STAT3 signaling, resulting in reduced Th17 differentiation and inflammatory cytokine release."
• Jun Preparation of CPD12C15 hyaluronic acid nanoparticles, a novel glycolytic inhibitor and preliminary pharmacologic study on anti-pancreatic cancer. (International journal of pharmaceutics, 2026, PMID 42055152): "Nanoparticles with excellent release properties, modified with hyaluronic acid (HA) targeting CD44, which is highly expressed on pancreatic cells, can evade the removal of natural defense system and enhance tumor-targeting ability."
• Apr 3-Deoxy-4-sulfonamido-butein derivatives promote cell cycle arrest and apoptosis by inhibiting EGFR/JAK2/STAT3 signaling in A549 lung cancer cells. (Bioorganic & medicinal chemistry, 2026, PMID 42044554): "these lead candidates operated through a convergent dual-targeting mechanism by directly inhibiting epidermal growth factor receptor (EGFR) tyrosine kinase activity while concurrently suppressing the downstream JAK2/STAT3 signaling axis."
• Jun Superior In Vivo Efficacy of Fermented Over Aqueous Astragalus membranaceus in Diabetic Nephropathy: A Systematic Pharmacological Evaluation and Mechanistic Study. (Biomedical chromatography : BMC, 2026, PMID 42009593): "Chemical profiling identified 14 FA bioactive components; network pharmacology revealed core targets (STAT3, IL6, and TGFB1) and key pathways (AGE-RAGE, HIF-1, and FoxO)."