Introduction: Triple Negative Breast Cancer (TNBC) is an aggressive form of breast cancer that is difficult to treat because it does not display usual breast cancer biomarkers. This study aims to explore checkpoint inhibitors PD1 and LAG-3 as potential targets for TNBC therapy. It is believed that the inhibition of these checkpoint inhibitors can promote TNBC cell death.
Methods: CD8+ T-cells and MD-MB-231 breast cancer cells interactions were observed in a single cell fashion using a microfluidic device over a 24-hour period. CD8+ T-cells were incubated with either PD1 and LAG-3 inhibitors, or none as a control. Data on contact time, cancer cell death, and T cell death was recorded subjectively as a collaboration between all three researchers.
Results: Percent of cancer cell death was significantly higher in the control group versus the anti-PD1 and anti-LAG3 exposed group. Over time, the non-exposed group had consistently higher cancer cell death percentage than the exposed group. The anti-PD1 and anti-LAG3 exposed group did have non-significant increased contact time between cancer and T-cells, however, this did not reflect a higher rate of cancer cell killing. T-cell viability was similar amongst the two groups.
Conclusions: This study found a significant decrease in cancer cell killing when using checkpoint inhibitors anti-PD1 and anti-LAG3. Contact time between cancer and T-cells was found to be non-significantly increased in the presence of checkpoint inhibitors, but this did not correlate with increased cancer cell killing.