STAT3

STAT3 is a signal transducer and activator of transcription protein that functions as a pathway component downstream of cytokine and oncogenic signaling, with activity often tracked by phosphorylation at Tyr705. It is implicated in epithelial–mesenchymal transition (EMT) in pulmonary fibrosis, IL-6-driven hepatic LRG1 induction, exosome-mediated tumor progression via B7-H3, and macrophage polarization, and it is also a therapeutic target for inhibitor discovery. Recent studies highlight that diammonium glycyrrhizinate plus vitamin D3 modulate the STAT3/HSP90AA1–HIF-1α crosstalk in fibrosis, while nanomolar STAT3 inhibitors have been identified through molecular docking and machine learning. In cancer-related contexts, B7-H3 activates STAT3 pathways and tumor-associated inflammation can drive IL-6/STAT3 signaling to induce hepatic LRG1, linking STAT3 to metastasis and immunotherapy resistance. STAT3 Tyr705 phosphorylation was suppressed by pexidartinib in macrophage polarization, underscoring its role as a treatment-responsive signaling node. Overall, the literature positions STAT3 as a central transcriptional signaling hub in fibrosis, inflammation, and tumor microenvironment remodeling, with multiple recent advances focused on pathway modulation and direct inhibition.

Fibrosis

  • A 2026 Journal of Ethnopharmacology study (PMID:41423159) reported that diammonium glycyrrhizinate and vitamin D3 synergistically countered EMT in pulmonary fibrosis by modulating the stat3/HSP90AA1 and HIF-1α pathway. (PMID:41423159)
  • The treatment was described as altering crosstalk involving stat3, consistent with its role as a pathway component affected by therapy. (PMID:41423159)

Cancer / Tumor Microenvironment

  • B7-H3 (CD276) activates stat3 pathways in exosome biogenesis and the tumor microenvironment, linking it to tumor progression. (PMID:41964005)
  • A 2026 Cell Communication and Signaling review (PMID:41964005) highlighted stat3 as part of an exosome-mediated tumor progression axis downstream of B7-H3. (PMID:41964005)
  • Hepatocyte-derived LRG1 primes the liver for metastasis and impairs immunotherapy through IL-6/stat3 signaling. (PMID:41963620)
  • Tumor-associated inflammation induces hepatic LRG1 via IL-6/stat3 signaling, placing stat3 upstream of a metastasis-promoting program. (PMID:41963620)

Immunology / Macrophage Polarization

  • Palbociclib-induced factors drive macrophage polarization through stat3 Tyr705 phosphorylation, identifying a specific activation site. (PMID:41986650)
  • Pexidartinib suppressed stat3 phosphorylation in the same immunomodulatory context, indicating drug-sensitive control of this pathway. (PMID:41986650)
  • The 2026 Oncogene paper (PMID:41986650) connects stat3 signaling to CDK4/6 inhibitor-induced immunosuppression and antitumor immunity. (PMID:41986650)

Drug Discovery / Inhibition

  • A 2026 Chemical Communications study (PMID:41841313) identified nanomolar inhibitors against stat3, supporting its tractability as a drug target. (PMID:41841313)
  • Molecular docking integrated with machine learning was used to discover compounds targeting stat3, emphasizing structure-guided inhibitor development. (PMID:41841313)