Related Experiment Video
Updated: Aug 19, 2025
Radiosensitivity of Cancer Stem Cells in Lung Cancer Cell Lines
Published on: August 21, 2019
Targeting the STAT5A/IDO1 axis overcomes radioresistance and reverses the immunosuppressive tumor microenvironment in
Yang Yang1, Xiaoli Zheng1, Peizan Ni1
1Department of Radiation Oncology, The Affiliated Cancer Hospital of Zhengzhou University and Henan Cancer Hospital, Zhengzhou, Henan 450008, P.R. China.
Abstract:
As a metabolic mediator of antitumor immunity, indoleamine‑2,3‑dioxygenase 1 (IDO1) is upregulated in various types of cancer; however, the regulatory mechanism and clinical significance of IDO1 in non‑small cell lung cancer (NSCLC) radiotherapy (RT) remain unclear. The present study investigated the role of IDO1 in the NSCLC microenvironment. MTT assay, immunofluorescence, apoptosis analysis, cell cycle analysis, and C57BL/6 and BALB/c nude mouse tumor models were utilized to evaluate the roles of the STAT5A/IDO1/kynurenine axis in radioresistance and in the immune microenvironment of NSCLC. Protein expression levels were evaluated by western blotting, immunofluorescence and immunohistochemistry. Flow cytometry was performed to assess the status of CD8+ T lymphocytes, regulatory T cells (Tregs) and immune‑related inflammatory factors in C57BL/6 mice. Notably, IDO1 and STAT5A were positively associated with the immune microenvironment. RT treatment significantly promoted the expression levels of IDO1. IDO1 knockdown markedly enhanced the radiosensitivity of lung tumor cells and the anti‑apoptotic properties of T lymphocytes. It was demonstrated that STAT5A knockdown suppressed T‑cell apoptosis by inhibiting IDO1 enzyme function. Finally, in vivo experiments showed that STAT5A knockdown combined with RT was associated with greater numbers of CD8+ T cells and fewer Tregs. Results from the present study indicated that targeting the STAT5A/IDO1 axis may reshape the immune microenvironment and promote the efficacy of RT in NSCLC treatment. The present study may provide a theoretical foundation for more efficient use of immunotherapy regimens in NSCLC treatment.
Insights
Targeting the STAT5A/IDO1 axis enhances non-small cell lung cancer (NSCLC) radiotherapy by improving tumor immunity. This approach boosts radiosensitivity and reshapes the immune microenvironment for better treatment outcomes.
Area of Science:
- Immunology
- Oncology
- Molecular Biology
Background:
- Indoleamine-2,3-dioxygenase 1 (IDO1) is a metabolic mediator of antitumor immunity, upregulated in many cancers.
- The role and regulation of IDO1 in non-small cell lung cancer (NSCLC) radiotherapy remain unclear.
- Understanding the STAT5A/IDO1/kynurenine axis is crucial for NSCLC treatment efficacy.
Purpose of the Study:
- To investigate the role of IDO1 in the NSCLC microenvironment during radiotherapy.
- To evaluate the STAT5A/IDO1/kynurenine axis's impact on radioresistance and immune response in NSCLC.
- To explore the potential of targeting this axis to enhance radiotherapy efficacy.
Main Methods:
- Utilized MTT assay, immunofluorescence, apoptosis, and cell cycle analysis.
- Employed C57BL/6 and BALB/c nude mouse tumor models for in vivo studies.
- Assessed protein expression via western blotting, immunofluorescence, and immunohistochemistry; analyzed immune cells and factors using flow cytometry.
Main Results:
- IDO1 and STAT5A expression positively correlated with the immune microenvironment.
- Radiotherapy significantly increased IDO1 expression; IDO1 knockdown enhanced radiosensitivity and T-cell anti-apoptotic properties.
- STAT5A knockdown inhibited IDO1, suppressed T-cell apoptosis, and, combined with RT, increased CD8+ T cells while decreasing Tregs in vivo.
Conclusions:
- Targeting the STAT5A/IDO1 axis can reshape the NSCLC immune microenvironment.
- This targeting strategy holds promise for enhancing radiotherapy efficacy in NSCLC.
- Findings provide a foundation for optimizing immunotherapy regimens in NSCLC treatment.
More Related Videos
Related Concept Videos
02:57Targeted Cancer Therapies
There are several types of targeted therapies against...
02:56Treatment Resistant Cancers
01:27Tumor Immunotherapy
02:40Cancer Stem Cells and Tumor Maintenance
Cancer stem cells are thought to originate from tissue-specific normal stem cells or progenitor cells. The normal stem cells usually reside in...
02:49Cancer Therapies
However, cancer treatments can pose several challenges, as therapies used to kill cancer cells are generally also toxic to normal cells. Moreover, cancer cells mutate rapidly and can develop resistance to chemical agents or radiation therapy. Besides, all types of cancer cells may not respond to the same therapy. Some cancer cells respond to one...
02:53Adaptive Mechanisms in Cancer Cells
Some of the advantages that cancer cells have on normal cells include - enhanced ability to divide without terminally differentiating, induce new blood vessel formation,...