Phospho-ERK5 (Thr219+Tyr221) Antibody - #AF8146

Figure 7 THBS2 induces EMT and tumor progression through activation of the MAPK/ERK5 pathway (A) Volcano plot displaying differentially expressed genes (DEGs) between CAF-THBS2 and CAF-NC. (B) Gene ontology (GO) enrichment analysis of DEGs highlights significant enrichment in ECM remodeling pathways. (C) Ridge plot showing the enriched pathway results from proteomics analysis. (D) Heatmap of phosphoproteomic data involved in the MAPK pathway. (E) Correlation analysis showing a positive association between THBS2 expression and MAPK7 expression (top) and phosphorylation (bottom) in CRC samples from the CPTAC-COAD dataset. (F) Bar plot depicting correlations between THBS2 expression and genes associated with cell proliferation and EMT in the CPTAC-COAD and TCGA-CRC datasets. (G) Gene set variation analysis (GSVA) showing significant positive correlations between THBS2 expression and pathways associated with cell proliferation and EMT. (H) WB analysis of MEK5, CD47, ERK5, p-ERK5, ZEB1, E-cadherin, N-cadherin, Vimentin, and Cyclin D1 in HCT116 and SW480 cells treated with rhTHBS2, si-CD47, or si-MEK5. (I) IHC staining for Ki67, Cyclin D1, E-cadherin, N-cadherin, Vimentin, Snail, and Zeb1 (scale bars, 100 μm). (J) Schematic illustrating the mechanisms involved in this study. Transcription factor CREB3L1 promotes the transformation of NFs into THBS2+ mCAFs. The upregulation of CREB3L1 leads to the increased production of THBS2, FAP, and αSMA in mCAFs. These mCAFs then secrete THBS2, which binds to CD47 receptors on tumor cells. This interaction activates the MEK5-ERK5 signaling pathway within the tumor cells, resulting in the upregulation of transcription factors such as c-JUN, c-FOS, MEF2, and others. These factors promote cell cycle progression (e.g., via Cyclin D1) and drive epithelial-mesenchymal transition (EMT) by inducing EMT-related genes (e.g., SNAIL and ZEB1). This cascade enhances tumor cell proliferation, migration, and invasion, emphasizing the pro-tumorigenic role of THBS2+ mCAFs in CRC.

Fig. 4 MEK5/ERK pathway promotes Nur77 expression, tumorigenesis and mitochondrial function in U2OS cells. A Transfection efficiency measured by immunofluorescence; scale bar = 50 μm. B Western blotting detected MEK5, p-ERK5/ERK5, and Nur77 protein levels in U2OS cells. C Cell migration capability of U2OS cells was detected by Transwell assay; scale bar = 50 μm. D Cell invasive capability of U2OS cells was detected by Transwell assay; scale bar = 50 μm. E Cell viability of U2OS cells was detected by CCK-8 assay. F Mitochondrial membrane potential levels of U2OS cells were detected by JC-1 assay. *P