Abstract 3178
Background
To date little is known about receptor tyrosine kinases (RTK) expression on peripheral blood mononuclear cells (PBMC) and tumor infiltrating lymphocytes (TIL) in cancer patients. The aim of this study was to evaluate expression levels of major RTK: VEGFR1, VEGFR2, PDGFRα, PDGFRβ, FGFR2 in CD45+ population of PBMC and TIL isolated from patients with clear cell renal cell carcinoma (RCC).
Methods
Tumor and blood samples were obtained from 20 patients with RCC immediately after surgical resection of primary tumor. Tumors were harvested into sterile antibiotic-containing RPMI 1640 medium (Gibco). TIL isolation was performed under modified protocol [Baldan et al., 2015]. Isolated TIL and PBMC were prepared for flow cytometry. Cells were double stained with anti-CD45 FITC-conjugated mouse antibody, and with PE-conjugated mouse antibodies to VEGFR1, VEGFR2, PDGFRa, PDGFRb, FGFR2 (all Sony Biotech) and were analyzed on NovoCyte 2000R flow cytometer (ACEA Biosciences). Expression of RTK was evaluated with NovoExpress Software.
Results
Among PBMC 72.1±21.3% cells were CD45-positive. Isolated TIL contain 19.2±5.6% CD45-positive cells. PBMC and TIL express RTK. Expression levels of RTK are summarized in the table.Table:
59P
| Expression of RTK | PBMC | TIL | P |
|---|---|---|---|
| VEGFR1 | 25.6±11.4% | 31.0±27.2% | 0,699 |
| VEGFR2 | 23.8±11.1% | 53.2±29.3% | 0,096 |
| PDGFRa | 48.0±18.9% | 45.4±16.7% | 0,833 |
| PDGFRb | 63.3±28.7% | 66.7±26.1% | 0,843 |
| FGFR2 | 41.2±27.8% | 23.6±12.3% | 0,168 |
Conclusions
To our knowledge, this is first study that showed significant RTK expression on peripheral and RCC-infiltrating lymphocytes in RCC patients. PBMC and TIL have similar RTK expression levels.
Clinical trial identification
Legal entity responsible for the study
Ethical committee, KCRB
Funding
Kidney Cancer Research Bureau
Disclosure
All authors have declared no conflicts of interest.