Related Experiment Video
Updated: Oct 8, 2025
MR Molecular Imaging of Prostate Cancer with a Small Molecular CLT1 Peptide Targeted Contrast Agent
Published on: September 3, 2013
STAT3 as a target for sensitizing prostate cancer cells to irradiation
Qu Zhang1, Xiao-Mei Zhou1, Shao-Zhong Wei2
1Department of Radiotherapy Center, Hubei Cancer Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Abstract:
Radioresistance of prostate cancer (PCa) is a major factor leading to local failure of radiotherapy. STAT3 is an oncogenic protein that was recently found to be activated in PCa tumors. This study aimed to investigate the radiosensitization effect of targeting STAT3 in PCa tumors. Here, the radiosensitization effect of STAT3 blockade was investigated by clonogenic assay, flow cytometry and western blot analysis in human PCa cells in vitro and in vivo. We demonstrated that STAT3 blockade with a STAT3 inhibitor or siRNA increased the radiosensitivity of PCa cells and that radiation together with STAT3 blockade induced more apoptosis and double-strand breaks (DSBs) than radiation alone in LNCaP cells. In addition, radiation induced STAT3 activation and survivin expression in PCa cells, which was inhibited by STAT3 blockade. Transfection with survivin cDNA attenuated the radiosensitization effect of STAT3 blockade. These effects were further confirmed by in vivo studies, which showed that the STAT3 inhibitor enhanced the treatment efficacy of radiation on LNCaP xenografts with decreased STAT3 activation and survivin expression. These findings suggest that STAT3 blockade radiosensitizes PCa cells through regulation of survivin. Thus, our study has revealed STAT3 as a potential sensitizer for irradiation in PCa cells. Its clinical application as an adjuvant in radiotherapy of PCa should be explored in the future.
Insights
Targeting STAT3 (Signal Transducer and Activator of Transcription 3) can overcome radioresistance in prostate cancer (PCa). Blocking STAT3 enhances radiation therapy
Area of Science:
- Oncology
- Molecular Biology
- Radiotherapy Research
Background:
- Prostate cancer (PCa) radioresistance limits radiotherapy effectiveness.
- Signal Transducer and Activator of Transcription 3 (STAT3) is an oncogenic protein activated in PCa.
- Targeting STAT3 may enhance prostate cancer treatment outcomes.
Purpose of the Study:
- To investigate the radiosensitizing effect of blocking STAT3 in prostate cancer.
- To elucidate the molecular mechanisms underlying STAT3-mediated radiosensitization.
Main Methods:
- In vitro studies using clonogenic assays, flow cytometry, and Western blot on human PCa cells.
- In vivo studies using LNCaP xenografts in mouse models.
- Investigated STAT3 inhibition using a STAT3 inhibitor and siRNA.
- Assessed apoptosis, DNA double-strand breaks (DSBs), and survivin expression.
Main Results:
- STAT3 blockade significantly increased PCa cell radiosensitivity.
- Combined radiation and STAT3 blockade induced greater apoptosis and DSBs than radiation alone.
- Radiation-induced STAT3 activation and survivin expression were suppressed by STAT3 blockade.
- Survivin overexpression counteracted the radiosensitizing effect of STAT3 blockade.
- In vivo studies confirmed enhanced radiotherapy efficacy with STAT3 inhibition.
Conclusions:
- STAT3 blockade acts as a radiosensitizer in prostate cancer by regulating survivin expression.
- STAT3 is a promising therapeutic target to improve radiotherapy outcomes in PCa.
- Clinical investigation of STAT3 blockade as an adjuvant to radiotherapy for PCa is warranted.
