The TGFbeta/Smad 3-signaling pathway is involved in butyrate-mediated vitamin D receptor (VDR)-expression.

Previously, we demonstrated the pivotal role of the vitamin D receptor (VDR) in mediating the butyrate-induced differentiation in colon cancer cells. Smad 3, a downstream component of transforming growth factor-beta (TGFbeta) signaling, has been shown to act as a coactivator of VDR and to possibly regulate the vitamin D signaling pathway. In this study, we demonstrate a distinct impact of the TGFbeta/Smad 3-signaling pathway in the butyrate-mediated VDR expression and induction of differentiation.

Upregulation of 25-hydroxyvitamin D(3)-1(alpha)-hydroxylase by butyrate in Caco-2 cells.

Aim: To investigate the possible involvement of 25-hydroxyvitamin D(3)-1(alpha)-hydroxylase [1alpha-25(OH) (2) D(3)] in butyrate-induced differentiation in human intestinal cell line Caco-2 cells.

Methods: Caco-2 cells were incubated either with 3 mmol/L butyrate and 1 micromol/L 25(OH) (2) D(3) or with 1 micromol/L 1alpha-25(OH) (2) D(3) for various time intervals ranging from 0 to 72 h. Additionally, cells were co-incubated with butyrate and either 25(OH) (2) D(3) or 1alpha-25(OH) (2) D(3).

[Enteral nutrition: drug administration via feeding tube].

Enteral nutrition support via a feeding tube is a preferred and broadly applied way of artificial nutrition in patients who cannot take up orally an adequate amount of nutrients. These patients often need simultaneous drug therapy as well. Thus, there is a high risk of drug-nutrient interactions.

p38 MAPK signaling pathway is involved in butyrate-induced vitamin D receptor expression.

Previously, we have demonstrated that the butyrate-induced differentiation in the human colon cancer cell line Caco-2 occurs via upregulation of the vitamin D receptor (VDR). However, the downstream pathways involved are unknown. The mitogen-activated protein kinases (MAPKs) have been shown to play an important role in regulation of cell differentiation, and may therefore be a potential target of butyrate action.

Short-chain fatty acids and colon cancer cells: the vitamin D receptor--butyrate connection.

Butyrate and its prodrug tributyrin, as well as 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3), have important physiological effects on proliferation and differentiation in a variety of malignant cells. The aim of this study was to elucidate the role of the vitamin D receptor (VDR) in butyrate-induced cell differentiation and cell cycle arrest in Caco-2 cells, a human colon cancer cell line. Cell differentiation was evaluated by analyzing the activity of alkaline phosphatase (AP).