Chemoprevention by retinoids of the progression of carci nomas induced in rats by azaserine was evaluated. Wistar/ Lewis rats were given 15 weekly injections of azaserine, 10 mg/kg, while fed a chow diet; after the completion of carcino gen treatment, they were fed a chow diet supplemented with four different retinoids at the level of 0.5 to 2 mmol/kg diet for 1 year. The incidence of neoplasms...

Vitamin A (retinol) and its active derivatives (the retinoids) are essential for growth and development of the mammalian fetus. Maternally-derived retinol has to pass through the placenta to reach the developing fetus. Despite its apparent importance, little is known about placental metabolism of retinol, and particularly placental production and/or secretion of active retinoids. It has been pr...

Cutaneous T-cell lymphomas (CTCL) are characterized by an infiltration of the skin with malignant T cells. Curative treatments for aggressive entities such as Sézary syndrome have not been identified yet. Arsenic trioxide (AsO3) is used for the treatment of acute promyelocytic leukemia in combination with retinoids. As the latter are established treatment options in CTCL, we sought to evaluate ...

Retinoids have shown clinical efficacy in cancer chemoprevention and therapy presumably by modulating the growth, differentiation, and apoptosis of normal, premalignant, and malignant cells. To better understand the mechanisms by which retinoids exert their effects, we used a high-throughput Western blotting method (Becton-Dickinson PowerBlot) to evaluate changes in the levels of cellular signa...

Evidence from a randomized clinical trial showed that, in spite of the many surgical procedures effective in ameliorating the clinical appearance of photoaged skin, the only medical therapy with proven benefits in photoaged skin are topical retinoids, in particular tretinoin, isotretinoin, and tazarotene. The application of retinoids might not only clinically and biochemically repair photoaged ...

Retinoids inhibit rat vascular smooth muscle cell (VSMC) proliferation in vitro and intimal hyperplasia in vivo. We examined the mechanism of the antiproliferative effect of retinoids on human coronary artery smooth muscle cells (human CASMCs). The RAR ligands all-trans-retinoic acid (atRA) and ethyl-p-[(E)-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl)-l-propenyl]-benzoic acid (TTNPB); ...

Carotenoids and retinoids are groups of nutritionally-relevant compounds present in many foods of plant origin (carotenoids) and animal origin (mainly retinoids). Their levels in human subjects vary depending on the diversity and amount of the individual's nutrient intake. Some carotenoids and retinoids have been investigated for their effects on the immune system both in vitro and in vivo. It ...

Actinic keratosis is a common cause of dermatological consultations and it presents a strong association with squamous cell carcinoma. Many substances are used for treatment and prevention, such as retinoids. Nevertheless, many studies on retinoids emphasize their application in treating and preventing non melanoma skin cancers. In this article, we reviewed studies about systemic and topical re...

S91 melanoma cells, which are sensitive to retinoic acid and contain a cellular retinoic acid-binding protein (RABP), were used in an investigation of the possible correlation between the capacities of various retinoids to inhibit cell proliferation and to bind to the RABP. Each of 27 different retinoids was evaluated for growth-inhibitory activity by exposing S91 melanoma cells to various reti...