EGCG remodels the TGF-β cervical cancer micro-environment towards immune responsiveness

Abstract

Background

Exploring the role of immune modulators alongside TGF-β in cervical cancer (CC) and PBMCs may improve the understanding of targeted treatment strategies.

Methods

We analyzed expression, overall survival (OS), correlation and tumor infiltration of PD-L1, CD55 and CD46, as well as immune cell fractions in CC patients using OncoDB, TIMER 2.0 and TCIA. RT-PCR and western blotting was performed to assess PD-L1, CD55 and CD46 expression. Viability, mitored, apoptosis and MMP-2 were evaluated in CC cells co-cultured with PBMCs. Morphology, crystal violet staining, ROS and MMP-2 were examined in SiHa spheroids.

Results

PD-L1 was upregulated, CD55 was significantly increased and CD46 showed no significant difference in HPV16 positive compared with HPV negative individuals. Elevated PD-L1, CD55 and CD46 were associated with reduced OS in HPV16 positive individuals. PD-L1 and CD55 showed moderate positive and negative correlation with TGF-β, respectively, whereas CD46 correlation was negligible. Immune fractions including M1 macrophages (31 %), M2 macrophages (17 %), CD8 T cells (21 %), NK cells (10 %), were linked to reduced OS. TGF-β, PD-L1 and CD46 infiltration were positively corelated with CD8+ T cells. In CC cells, TGF-β stimulation increased PD-L1, while decreasing CD55 and CD46, reducing viability, metabolic activity and inducing apoptosis in HPV (+) co-cultures. EGCG treatment under TGF-β, reduced PD-L1, CD55 and CD46 expression, decreased viability, metabolic activity and MMP-2 secretion, while inducing apoptosis in SiHa co-culture. In 3D spheroids, EGCG inhibited proliferation and MMP-2 activity while increasing ROS production.

Conclusion

EGCG, by targeting TGF-β and modulating PD-L1 and mCRPs, represents a promising candidate for immunotherapeutic development in CC.