Related Experiment Video
Updated: Jan 8, 2026
Tailoring In Vivo Cytotoxicity Assays to Study Immunodominance in Tumor-specific CD8+ T Cell Responses
Published on: May 6, 2019
Targeting PD-L1 with BMS-202 Enhances Antitumor Cytokine and Cytotoxic T-Lymphocyte Responses in C57BLx/6 Mouse Lung
Mustafa Fahmi Rajab1, Abdullah Abubaker Shareef1, Shukur Wasman Smail1,2
1Department of Biology, College of Science, Salahaddin University-Erbil, Erbil, Kurdistan Region, Iraq.
Purpose:
Lung cancer remains a leading cause of cancer-related mortality, and although immune checkpoint inhibitors have improved outcomes, their use is often limited by immune-related adverse effects and treatment resistance. This study therefore investigates the effects of the small-molecule PD-L1 inhibitor BMS-202 on lung carcinogenesis using a subcutaneous tumor model in C57BL/6 mice. Specifically, we aimed to evaluate its cytotoxic activity, induction of apoptosis, and impact on antitumor immune modulation.
Methods:
In this study, we utilized in vivo mouse models and in vitro CMT167 cancer cells to evaluate the anti-tumor effects of BMS-202. Tumor growth inhibition was assessed through caliper measurements and histological analysis. Apoptosis was analyzed using AO/PI staining, Annexin V-FITC/PI flow cytometry, Caspase-3 activity assays, and Real-Time PCR to evaluate the expression of apoptosis-related genes (Bad, Bax, Apaf1, Bcl2, and Bcl-xl). Additionally, flow cytometry was employed to analyze lymphocyte infiltration in the tumor microenvironment. Finally, enzyme-linked immunosorbent (ELISA) was used for measurement of cytokines.
Results:
Specifically, cell viability decreased from 98.1% to 30.1% at concentrations ranging from 0 μM to 40 μM (P<0.001). Apoptosis assays revealed distinct fluorescence patterns indicating increased apoptosis, with late apoptotic cells becoming prominent at higher concentrations. In vivo, results showed that treatment with BMS-202 significantly reduced tumor weight, with mean weights of 609 ± 41.5 mg and 371.88 ± 47.5 mg at 30 mg/kg and 60 mg/kg, respectively (P<0.001). Flow cytometry analysis indicated a marked increase in CD3+CD8+ cytotoxic T cells, rising from 6.8% to 26.2% (P<0.001), and a reduction in PD-1 expression, suggesting enhanced immune activation. Additionally, BMS-202 treatment significantly elevated levels of pro-inflammatory cytokines, including IFN-γ and TNF-α, indicating a robust immune response (P<0.001).
Conclusion:
These findings suggest that BMS-202 effectively promotes apoptosis and enhances immune responses in lung cancer, underscoring its potential as a therapeutic agent in treating lung carcinogenesis.
Insights
The small-molecule PD-L1 inhibitor BMS-202 effectively reduces lung tumor growth by inducing apoptosis and enhancing anti-tumor immune responses. This study highlights BMS-202
Area of Science:
- Oncology
- Immunology
- Pharmacology
Background:
- Lung cancer is a leading cause of cancer mortality.
- Immune checkpoint inhibitors improve outcomes but face resistance and side effects.
- Novel therapeutic strategies are needed to overcome these limitations.
Purpose of the Study:
- To investigate the anti-tumor effects of the small-molecule PD-L1 inhibitor BMS-202 in lung carcinogenesis.
- To evaluate BMS-202's cytotoxic activity and induction of apoptosis.
- To assess its impact on antitumor immune modulation in a preclinical model.
Main Methods:
- Utilized in vivo mouse models and in vitro cancer cells to assess BMS-202's anti-tumor effects.
- Evaluated tumor growth inhibition via caliper measurements and histological analysis.
- Assessed apoptosis using multiple assays including flow cytometry and caspase activity.
- Analyzed immune cell infiltration and cytokine levels in the tumor microenvironment.
Main Results:
- BMS-202 significantly reduced cancer cell viability and induced apoptosis in a dose-dependent manner.
- In vivo, BMS-202 treatment markedly inhibited tumor growth and reduced tumor weight.
- Enhanced infiltration of cytotoxic T cells (CD3+CD8+) and elevated pro-inflammatory cytokines (IFN-γ, TNF-α) were observed, indicating immune activation.
Conclusions:
- BMS-202 demonstrates significant anti-tumor efficacy by promoting apoptosis and enhancing immune responses.
- These findings suggest BMS-202 holds potential as a therapeutic agent for lung cancer.
- Further investigation into BMS-202 is warranted for its clinical application in lung carcinogenesis.
