Abstract
The mechanisms of NSCLC cells evading the immune system remain poorly understood. For cancer immunotherapy, the signaling pathways of Interleukin-2 family cytokines represent an important target. Acting downstream in IL-2 receptor signaling, Signal Transducer and Activator of Transcription 5 (STAT5) regulates the Treg development and maintenance of Treg function by targeting the promotor of the Treg master regulator FoxP3. In addition, STAT5 supports the development of effector T and natural killer cells and thus could be associated with both a suppressive but also an anti-tumor immunity.
In this study, we wanted to investigate the role of STAT5 and its activation via phosphorylation upon receptor-ligand signaling in the lung of NSCLC patients. Tissue samples from the tumoral area as well as the tumor free control area were obtained by surgery of NSCLC patients. Proteins were extracted and kept frozen for Western blot analysis using antibodies against pSTAT5, STAT5 and T box expressed in T cells (Tbet).
Here we found increased pSTAT5 protein levels in the tumoral region of NSCLC patients at grade 2 of tumor cell differentiation as corrected for both the total protein levels and the total STAT5 expression. In addition, the tumor microenvironment exhibited decreased levels of the anti-tumoral Th1 and Tc1 signature transcription factor T-bet. We recently described the presence of a strong immunosuppressive tumor microenvironment in these NSCLC patients. Thus, understanding the cellular and local distribution of activated STAT5 (pSTAT5) in the lung tumor microenvironment could help to establish more targeted therapeutic settings used against lung cancer.
Footnotes
Cite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 1643.
This abstract was presented at the 2020 ERS International Congress, in session “Respiratory viruses in the "pre COVID-19" era”.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
- Copyright ©the authors 2020