STAT3 Inhibition Enhances the Therapeutic Efficacy of Immunogenic Chemotherapy by Stimulating Type 1 Interferon Production by Cancer Cells.

Abstract

STAT3 is an oncogenic transcription factor with potent immunosuppressive functions. We found that pharmacologic inhibition of STAT3 or its selective knockout in cancer cells improved the tumor growth-inhibitory efficacy of anthracycline-based chemotherapies. This combined effect of STAT3 inhibition/depletion and anthracyclines was only found in tumors growing on immunocompetent (not in immunodeficient) mice. As compared with Stat3-sufficient control tumors, Stat3(-/-) cancer cells exhibited an increased infiltration by dendritic cells and cytotoxic T lymphocytes after chemotherapy. Anthracyclines are known to induce several stress pathways that enhance the immunogenicity of dying and dead cancer cells, thereby stimulating a dendritic cell-dependent and T lymphocyte-mediated anticancer immune response. Among these therapy-relevant stress pathways, Stat3(-/-) cancer cells manifested one significant improvement, namely an increase in the expression of multiple type-1 interferon-responsive genes, including that of the chemokines Cxcl9 and Cxcl10. This enhanced type-1 interferon response could be suppressed by reintroducing wild-type Stat3 (but not a transactivation-deficient mutant Stat3(Y705F)) into the tumor cells. This maneuver also abolished the improved chemotherapeutic response of Stat3(-/-) cancers. Finally, the neutralization of the common type-1 interferon receptor or that of the chemokine receptor CXCR3 (which binds CXCL9 and CXCL10) abolished the difference in the chemotherapeutic response between Stat3(-/-) and control tumors. Altogether, these results suggest that STAT3 inhibitors may improve the outcome of chemotherapy by enhancing the type-1 interferon response of cancer cells.

• Authors: Heng Yang, Takahiro Yamazaki, Federico Pietrocola, Heng Zhou, Laurence Zitvogel, Yuting Ma, Guido Kroemer
• Journal: Cancer research (Cancer Res) Vol. 75 Issue 18 Pg. 3812-22 (Sep 15 2015) ISSN: 1538-7445 [Electronic] United States
• PMID: 26208907 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: ©2015 American Association for Cancer Research.

Chemical References

• Antibiotics, Antineoplastic
• Chemokine CXCL10
• Chemokine CXCL9
• Cxcl10 protein, mouse
• Cxcl9 protein, mouse
• Cxcr3 protein, mouse
• Cyclic S-Oxides
• Ifnar1 protein, mouse
• Interferon Type I
• Neoplasm Proteins
• Receptors, CXCR3
• STAT3 Transcription Factor
• Stat3 protein, mouse
• stattic
• Receptor, Interferon alpha-beta
• Doxorubicin

Topics

• Animals
• Antibiotics, Antineoplastic (administration & dosage, pharmacology, therapeutic use)
• Cell Line, Tumor
• Chemokine CXCL10 (biosynthesis, genetics)
• Chemokine CXCL9 (biosynthesis, genetics)
• Colorectal Neoplasms (drug therapy, immunology, therapy)
• Combined Modality Therapy
• Cyclic S-Oxides (administration & dosage, pharmacology, therapeutic use)
• Dendritic Cells (immunology)
• Doxorubicin (administration & dosage, pharmacology, therapeutic use)
• Drug Synergism
• Female
• Fibrosarcoma (drug therapy, immunology, therapy)
• Gene Expression Regulation, Neoplastic (drug effects)
• Immunocompetence
• Interferon Type I (biosynthesis, genetics)
• Lymphocytes, Tumor-Infiltrating (immunology)
• Mice
• Mice, Inbred BALB C
• Mice, Inbred C57BL
• Mice, Nude
• Neoplasm Proteins (antagonists & inhibitors, biosynthesis, genetics, physiology)
• Receptor, Interferon alpha-beta (antagonists & inhibitors)
• Receptors, CXCR3 (antagonists & inhibitors, physiology)
• STAT3 Transcription Factor (antagonists & inhibitors, genetics, physiology)
• Signal Transduction (drug effects)
• T-Lymphocytes, Cytotoxic (immunology)
• Transcriptional Activation