245P - The role of TGF-β in the formation of the protumor phenotype of circulating neutrophils at different stages of renal cancer

Background

Currently, the ambiguous role of neutrophils (Nph) in renal cancer (RC), which is determined by their phenotype, is of considerable interest. TGF-β is able to change the expression of pro-inflammatory cytokines of Nph and their receptors, as well as stimulate the production of chemokines that attract Nph to the site of inflammation, thus forming a pro-tumor phenotype (N2). TGF-β in the tumor microenvironment induces the migration of the CD11b+ Nph population. CD11b provides adhesion, migration, degranulation of Nph. Therefore, the study was aimed at assessing the expression of the TGF-β gene, as well as CD11b receptors, by circulating Nph at different stages of RC.

Methods

The study included patients with stage I-II (n=20), stage III-IV (n=20) clear cell RC (Med 62 years) and 20 - control group (CG) (Med 60 years). The study was approved by the Ethics Committee of the IME&PС of UlSU (prot. No. 1, 01/15/2020). RNA was isolated from the fraction of peripheral blood Nph on SileksMagNA magnetic particles (Sileks, Russia). After isolation, a reverse transcription reaction was performed. Expression of the TGF-β gene was determined by quantitative reverse transcription PCR using primers (Evrogen, Russia). Immunophenotyping was performed using monoclonal antibodies to the surface antigen CD11b (Sorbent, Russia). The results were expressed as Med (Q1-Q3). Statistical processing was performed using the Statistica 13, using the Mann–Whitney U-test and the Spearman correlation coefficient (p<0.05).

Results

A significant increase in the expression of the TGF-β gene in Nph was found in patients with RC compared with the CG (0.07 (0.12-2.21) vs 0.05 (0.04-0.13), p=0, 008), and also depending on the stage: at I-II stages of RC 0.43 (0.09-1.21), at III-IV 1.91 (0.87-3.18) (p=0.05). A significant increase in the expression of CD11b on the surface of Nph was found in patients with RC 73.3±5.1% vs the CG 19.0±9.3% (p=0.001), while no relationship with the stage was found. A direct correlation was found between TGF-β and CD11b gene expression in Nph (r=0.48, p=0.01).

Conclusions

In RC, the affinity of circulating neutrophils to the tumor microenvironment increases. At the same time, the level of expression of the growth factor TGF-β increases in Nph.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.