Genetic reprogramming in pathways of colonic cell maturation induced by short chain fatty acids: comparison with trichostatin A, sulindac, and curcumin and implications for chemoprevention of colon cancer.

TLDR

Butyrate, a microbial fermentation product of dietary fiber, regulates colonic epithelial cell maturation through cell cycle arrest, differentiation, and apoptosis. The study aims to use high‑throughput microarray analysis to distinguish the mechanisms of colonic epithelial cell responses to physiological and pharmacological inducers of maturation. The authors performed high‑throughput microarray profiling of 8,063 genes in SW620 colonic epithelial cells treated with butyrate, sulindac, and curcumin, comparing temporal gene‑set recruitment and histone acetylation kinetics. Microarray analysis revealed a time‑dependent cascade of gene‑set recruitment by butyrate, distinct from sulindac’s effects, with overlapping G0‑G1 arrest, β‑catenin‑Tcf activation, and apoptosis but divergent signaling and cell‑cycle pathways, underscoring the potential for chemopreventive agent characterization and synergy assessment.

Abstract

The short-chain fatty acid butyrate, produced by microbial fermentation of dietary fiber in the large intestine, is a physiological regulator of major pathways of colonic epithelial cell maturation: cell cycle arrest, lineage-specific differentiation, and apoptosis. Microarray analysis of 8,063 sequences demonstrated a complex cascade of reprogramming of SW620 colonic epithelial cells upon treatment with butyrate characterized by the progressive recruitment of gene sets as a function of time. Comparison with the effects of trichostatin A, in conjunction with differences in the kinetics of alteration of histone acetylation induced by butyrate and trichostatin A, identified subsets of induced and repressed genes likely coordinately regulated by altered histone acetylation. The butyrate response was also compared in detail with that of sulindac, a nonsteroidal anti-inflammatory drug with significant chemopreventive activity for colon cancer, and curcumin, a component of mustard and curry structurally and functionally related to sulindac that also has chemopreventive activity. Although gene clusters were identified that showed similar responses to butyrate and sulindac, the data were characterized by the extensive differences in the effects of the two agents. This was striking for functional classes of genes involved in signaling pathways and in cell cycle progression, although butyrate and sulindac induce a similar G0-G1 arrest, elevation of beta-catenin-Tcf signaling, and apoptotic cascade. As regards cell cycle arrest, the underlying mechanism in response to butyrate was most similar to that of the Caco-2 cell line that had spontaneously undergone a G0-G1 arrest and least similar to the G2-M arrest stimulated by curcumin. Thus, high-throughput microarray analysis of gene expression profiles can be used to characterize and distinguish the mechanisms of response of colonic epithelial cells to physiological and pharmacological inducers of cell maturation. This has important implications for characterization of chemopreventive agents and recognition of potential toxicity and synergies. The data bases, gene clusters, and analyses are available at http:// sequence.aecom.yu.edu/genome/.