Journal: Frontiers in Immunology

Article Title: STAT6 inhibition of M2 macrophages suppresses tumor growth by modulating the tumor microenvironment in colon cancer model

doi: 10.3389/fimmu.2026.1733991

Figure Lengend Snippet: TAMpep-IP reduces phosphorylation of STAT6 in M2 macrophages. (A) Schematic structure of TAMpep-IP composed of an M2 macrophage-homing peptide (TAMpep), a cleavable linker, and a STAT6-inhibitory peptide (IP). (B) THP-1 cells were differentiated into M0, M1, or M2 macrophages and stained for phosphorylated STAT6 (p-STAT6; red). Nuclear staining was performed with DAPI (blue). Immunofluorescence microscopy revealed elevated nuclear p-STAT6 in M2 macrophages compared to M0 and M1. Representative confocal images were acquired using a 40× objective lens. Scale bars, 20 μm. (C) M0 and M2 macrophages were treated with TAMpep, IP, or TAMpep-IP (0.5 μM, 72 h). Flow cytometry was used to measure p-STAT6 expression levels (mean fluorescence intensity), showing that TAMpep-IP significantly reduced p-STAT6 in M2 macrophages. (D) Western blot analysis was performed to detect p-STAT6 and total STAT6 levels in M2 macrophages after administration with TAMpep, IP, or TAMpep-IP (0.5 μM, 72 h). TAMpep-IP effectively reduced p-STAT6. The experiment was performed in triplicate. All data are presented as mean ± SEM. *p<0.05, **p<0.01, ***p < 0.001 and ****p < 0.0001..

Article Snippet: The human monocytic leukemia cell line THP-1 (KCLB; Korean Cell Line Bank, Seoul, Korea) was cultured in RPMI 1640 medium (Welgene, Gyeongsangbuk, Korea) supplemented with 10% heat-inactivated fetal bovine serum (FBS) and 1% penicillin–streptomycin (Hyclone, Logan, UT, USA).

Techniques: Phospho-proteomics, Staining, Immunofluorescence, Microscopy, Flow Cytometry, Expressing, Fluorescence, Western Blot

Journal: Frontiers in Immunology

Article Title: STAT6 inhibition of M2 macrophages suppresses tumor growth by modulating the tumor microenvironment in colon cancer model

doi: 10.3389/fimmu.2026.1733991

Figure Lengend Snippet: TAMpep-IP inhibits polarization of M2 macrophages. (A) THP-1 monocytes were differentiated into M0 and M2 macrophages, and M2 cells were treated with TAMpep-IP (0.5 μM, 72 h). Quantitative RT-PCR analysis showed that TAMpep-IP significantly reduced the mRNA expression of TGF-β and Arg-1, two markers associated with M2 polarization. (B) ELISA was performed to measure the levels of secreted TGF-β and IL-13 in the culture supernatant of M0, M2, and TAMpep-IP–treated M2 macrophages (72 h). TAMpep-IP markedly decreased secretion of both cytokines. (C) Flow cytometric analysis was used to assess CD206 surface expression in M0, M2, and TAMpep-IP–treated M2 macrophages (72 h). CD206 expression was significantly decreased in the TAMpep-IP group compared to untreated M2 macrophages. All data are presented as mean ± SEM. *p<0.05, **p<0.01, ***p<0.001, ****p < 0.0001. (D) The expression of IL-1β mRNA was analyzed by quantitative RT-PCR in M0, M1, and M2 macrophages after TAMpep-IP. TAMpep-IP significantly upregulated IL-1β expression in M2 macrophages, to levels comparable with M1-polarized cells.

Article Snippet: The human monocytic leukemia cell line THP-1 (KCLB; Korean Cell Line Bank, Seoul, Korea) was cultured in RPMI 1640 medium (Welgene, Gyeongsangbuk, Korea) supplemented with 10% heat-inactivated fetal bovine serum (FBS) and 1% penicillin–streptomycin (Hyclone, Logan, UT, USA).

Techniques: Quantitative RT-PCR, Expressing, Enzyme-linked Immunosorbent Assay