Fig. 4
CD44 and the transcription factor SP-1 is involved in the inhibitory effect of CBS/H2S axis on CRC cells. A CD44 expression level detected by flow cytometry and quantified through MFI in HT-29 cell line. (*p < 0.05). B Decreased CD44v protein expression after CBS overexpression in HT-29 cell line as well as xenograft samples. C Decreased CD44v mRNA expression after CBS overexpression in HT-29 cell line as well as xenograft samples (***p < 0.001). D Dose-dependent decrease in CD44v protein expression upon GYY4137 supplement. E Elevated CD44v protein expression in HT-29 KO-CBS cell line and Caco-2 sh-CBS cell line. F ChIP assay and following RT-qPCR results showing different level of SP-1 enrichment within the CD44 promoter region in HT-29 control and CBS-overexpressing cells (**p < 0.01). Fold enrichment relative to IgG. G Immunofluorescence assay of SP-1 and DAPI in HT-29 control and CBS-overexpressing cells, depicting SP-1 intracellular distribution. Scale bar, 20 μm. H Analysis of colocalization of SP-1 and DAPI using Pearson's correlation coefficient (**p < 0.01)