Fig. 6

GLCC1 co-ordinates the localization of c-Myc genome-wide. a Venn diagram shows the gene promoters occupied by c-Myc in control but not in lncGLCC1 siRNA-transfected cells (Distance <20,000 bp, 779 genes), downregulated after knockdown of lncGLCC1 (p < 0.001, Fold change < 0.5, 568 genes), and are target genes of c-Myc (124 genes). b Real-time PCR of target genes were performed in DLD-1 cells after transfection of GLCC1 siRNA1/2. c Cell supernatant was harvested for lactic acid level detection in DLD-1 cells cotransfected with GLCC1 overexpression plasmid LDHA, EIF4G2, or control siRNA. d The OD value at 450 nm was detected in DLD-1 cells cotransfected with GLCC1 overexpression plasmid LDHA, EIF4G2, or control siRNA. e LDHA DNA was detected in the chromatin sample immunoprecipitated from DLD-1 cells using an antibody against c-Myc; f Real-time PCR of the ChIP samples shows the binding efficiency of c-Myc to the LDHA gene promoter. g, h Luciferase reporter vectors were generated by inserting the promoter region (–1500 to 0 bp) of the LDHA gene. The reporter vectors were then cotransfected into DLD-1 (g) and HT29 (h) cells with either GLCC1 siRNA or control siRNA. Cells were harvested for luciferase activity assay. i, j Western blot of proteins from control or GLCC1 siRNA transfection group were performed in DLD-1 (i) and HT29 (j). Data in b–h are presented as the mean ± SE. p-values were calculated by one-way ANOVA followed by SNK multiple comparison test. *p < 0.05. k The representative images of ISH of GLCC1 and immunohistochemical staining of c-Myc and LDHA in cohort 2. Scale bar indicates 100 μm. l Statistical analysis of colorectal cancer tissues under different staining conditions in cohort 2. m Schematic representation for the mechanism of GLCC1/HSP90/LDHA axis as a switch that regulates glucose metabolism in human colorectal cancer progression by stabilizing and specifying the transcription modification pattern of c-Myc