All-Trans Retinoic Acid Reverses Phorbol Ester Resistance

All-trans retinoic acid reverses phorbol ester resistance in a human myeloid leukemia cell line.

Treatment of human HL-60 leukemic cells with 12-O-tetradecanoylphorbol-13-acetate (TPA) is associated with activation of protein kinase C (PKC) and induction of monocytic differentiation. An HL-60 variant cell line, termed HL-525, derived from long-term exposure to TPA (Homma et al, Proc Natl Acad Sci USA 83: 7316, 1986) is resistant to TPA-induced differentiation and displays decreased PKC bet...

All-trans Retinoic Acid Regulates the Balance of Treg-Th17 Cells through ERK and P38 Signaling Pathway

Regulation of involucrin gene expression by retinoic acid and glucocorticoids.

Involucrin is a major component of the cornified envelope and a marker for terminal differentiation in keratinocytes. We examined hormone regulation of involucrin mRNA expression and transcriptional modulation of the involucrin gene in human keratinocyte cell lines. Dexamethasone enhanced, and retinoic acid decreased, endogenous involucrin mRNA expression in cells treated with these ligands. Fu...

Phosphorylation in the U937 Human Monoblastoid Cell Differentiation and Protein Kinase C-dependent Effect of Retinoic Acid on Phorbol Ester-stimulated

Phorbol esters stimulate differentiation of certain human leukemic cell lines. Although activation of protein kinase C may mediate certain effects of phorbol esters, controversy exists as to the role of protein kinase C activation in phorbol ester-induced differentiation. Retinole acid modu lates responses to phorbol esters in several cell types. Retinoic acid has also been found to alter prote...

The effect of bilateral intrahippocampal injection of all–trans retinoic acid on spatial learning in adult male rats.

Introduction: Previous studies have shown that vitamin A and its derivatives such as retinoid and all-trans retinoic acid have a crucial role in memory, learning and synaptic plasticity. The receptors of vitamin A are seen in different parts of the brain such as hippocampus, where vitamin A has an important role in learning. In this study, the effect of intrahippocampal (CA1) injection of al...