ANAPLASTIC THYROID CANCER CELL-SECRETED TGFΒ1 CONTRIBUTES TO THE ACTIVATION OF MACROPHAGES THROUGH MODULATION OF SNAIL AND SLUG EXPRESSION

JAROSZEWSKI, A; GEYSELS, RC; PELLIZAS, CG; MOTRAN, CC; STEMPIN, CC; NICOLA, JP; CHENG, S; FOZZATTI, L

San Luis

Congreso; LXXI Reunión Científica Anual de la Sociedad Argentina de Inmunología.; 2023

Sociedad Argentina de Inmunología

Introduction: Anaplastic thyroid cancer (ATC) is a clinically aggressive form ofundifferentiated thyroid cancer with limited treatment options. Tumor-associatedmacrophages (TAMs) constitute over 50% of ATC-infiltrating cells, and theirpresence is associated with a poor prognosis. The mechanisms of how TAMspromote ATC progression are not clear. We have previously shown that solublefactors secreted by ATC cells induced pro-tumor M2-like polarization of THP-1cells. However, it remains to be identified which ATC cell-derived soluble factorsdrive macrophage activation. It has been previously reported that transforminggrowth factor β (TGFβ) induces M2-like macrophage phenotype. Therefore, weinvestigated the involvement of TGFβ1, its main member, on the phenotype ofmacrophage activation induced by ATC cell-derived conditioned media (CM).Methods: THP-1 cells (human monocytes) were treated with human ATC cell lines8505C or C643-derived CM (ATC-CM) or recombinant human TGFβ1 protein.THP-1 cells exposed to ATC cell-derived CM, were also treated with a TGFβreceptor inhibitor (SB- 431542) 20μM. THP-1 cell proliferation and polarizationwere assessed by flow cytometry, RT-qPCR and Western blot analysis. TGFβ1levels in ATC-CM were quantified by ELISA. Gene expression profiles wereobtained from the NCBI Gene Expression Omnibus database and analyzed usingbioinformatics analysis.Results: Similar to our previous studies using ATC-CM, recombinant humanTGFβ1 treatment significantly influenced the phenotype of THP-1 cells. Thechanges involved increased expression of Dectin1 and CD163, which are classicM2 phenotype markers of TAMs. In contrast, the levels of CCL13, another M2marker, were decreased. In addition, TGFβ1 treatment decreased theproliferation of THP-1 cells. Moreover, we showed that TGFβ1 induced mRNAand protein levels of the transcription factors SNAIL and SLUG. Accordingly,TGFβ1 was detected in ATC-CM (DMEM, 10.42±5.4pg/mL; 8505C cell- derivedCM, 3251±162.5pg/mL; C643 cell-derived CM, 2752±213.1pg/mL). SB-431542significantly decreased the Dectin1, CD163, SNAIL and SLUG expressionpromoted by ATC-CM, whereas increased CCL13 expression in THP-1 cells. Wevalidated the clinical significance of the expression of TGFβ ligands, its receptorsas well as SNAIL and SLUG in human ATC by analyzing public microarraydatasets, and found that the expression of the main TGFβ ligands, TGFβ1,TGFβ2 and TGFβ3, as well as their receptors were significantly higher in humanATC tissue samples than in normal thyroid tissues.