Acquired STAT4 deficiency as a consequence of cancer chemotherapy

Ivan P. Lupov, Larry Voiles, Ling Han, Allysia Schwartz, Manuel De La Rosa, Kinnari Oza, David Pelloso, Ravi P. Sahu, Jeffrey B. Travers, Michael J. Robertson, Hua Chen Chang

Research output: Contribution to journalArticlepeer-review

17 Scopus citations


Signal Transducer and Activator of Transcription 4 (STAT4) is a transcription factor that is activated by IL-12 signaling and promotes Th1-cell differentiation and IFN-γ production. Defective IFN-γ production because of STAT4 mRNA and protein deficiency occurs after autologous stem cell transplantation for lymphoma. In the present study, we investigated the mechanisms of STAT4 deficiency in lymphoma patients. The tumor-bearing state is not responsible, because STAT4 levels were not significantly different in PBMCs obtained from healthy control subjects compared with those from lymphoma patients before treatment. STAT4 protein levels were significantly decreased in PBMCs and T cells obtained from lymphoma patients after standard-dose chemotherapy. Furthermore, treatment of control PBMC cultures or a natural killer cell line with chemotherapy drugs in vitro also resulted in reduced STAT4 protein and diminished, IL-12-induced IFN-γ production. Translation of STAT4 protein was not impaired in chemotherapy-treated cells, whereas the STAT4 protein half-life was significantly reduced. Chemotherapy drugs promoted the ubiquitination and proteasomal degradation of STAT4. Treatment with the proteasome inhibitor bortezomib reversed chemotherapy-induced STAT4 deficiency and defective IFN-γ production. We conclude that acquired STAT4 deficiency in lymphoma patients is a consequence of treatment with chemotherapy, results that have important implications for the design of optimal immunotherapy for lymphoma.

Original languageEnglish (US)
Pages (from-to)6097-6106
Number of pages10
Issue number23
StatePublished - Dec 1 2011

ASJC Scopus subject areas

  • Biochemistry
  • Immunology
  • Hematology
  • Cell Biology

Fingerprint Dive into the research topics of 'Acquired STAT4 deficiency as a consequence of cancer chemotherapy'. Together they form a unique fingerprint.

Cite this