Gene expression changes during differentiation induced by butyrate in Caco2 cells. Caco2 cells were seeded into 60-mm culture dishes at 3 × 105 cells/plate. After 24 hr, cells were cultured in 4 mmol/L sodium butyrate for additional 24 hr, 48 hr, 72 hr. Results are averages of triplicate determinations. A. Total cell lysates with (72 hr point) or without butyrate stimulation were harvested and assayed for AKP activity assessing. Results represent the mean (± SD) of three experiments.*,**p < 0.05. B. Total cell lysates with (72 hr point) or without butyrate stimulation were harvested and assayed for CEA, CDX2 expression Also shown are the corresponding reprobings of these blots with actin as a loading control. This blot is representative of those obtained when the experiment was performed six times. C. Phase-contrast micrographs of cells with (72 hr point) or without butyrate stimulation were photographed. D. IGFBP-rP1 level analyzed by ELISA assay with (72 hr point)or without butyrate stimulation *P < 0.05. E. The relationship between AKP activity and the IGFBP-rP1 level during the sodium butyrate stimulation process. The correlation coefficient (r) = 0.945, P = 0.028. F. rtRT-PCR analysis of the IGFBP-rP1 induced differentially expressed genes (AREG, KRT8, P15, IER5L, IRS1, SOX9, TAGLN) in Caco2 cells with or without butyrate stimulation.