Start Your Search
Poster Session (ID 8)
- Event: ACLC 2018
- Type: Poster Session
- Presentations: 1
- Coordinates: 11/07/2018, 00:00 - 00:00, Poster Hall
P028 - A Novel Method for Detecting Surface PD-L1 on Circulating Tumor Cells in Peripheral Blood of Patients with SCLC (ID 135)
00:00 - 00:00 | Author(s): Y. Liu
Previous studies have demonstrated that circulating tumor cell (CTC) might work as an alternative to biopsy tissues in the diagnoses of small cell lung cancer (SCLC). Programmed death ligand 1 (PD-L1) is one of the most commonly used biomarkers in immune targeted therapies. However, the expression of PD-L1 in CTC is still unknown. This study aimed to establish an approach to measure PD-L1 in peripheral CTCs from SCLC patients.
Control cells were screened by monoclonal culture and confirmed by immunohistochemistry (IHC) staining and flow cytometry. PD-L1 expression in CTCs and tumor tissue samples from SCLC patients was measured by CellSearch system while the usage of PD-L1 antibody was optimized.
The purity of PD-L1 positive H446 cells had been improved from 70% to 95% by clonal selection, and PD-L1 negative PC3 cells showed lower than 5% purity. In CellSearch system, positive control cells had 98% PD-L1 expression while negative control had less than 3% expression. In two SCLC patients with CTC positive expression, PD-L1 expression was found with 100% (1/1) and 40% (2/5) positive rate.
CellSearch system was used to establish a novel approach for measuring surface PD-L1 expression on CTC, and showed supporting evidences in SCLC patients, thus providing novel insights for automatic assay of PD-L1 in peripheral samples.