Retinoids, effects

Adapalene, a derivative of naphthoic acid, is a synthetic retinoid-like compound that is available in solution, cream, and gel formulations for topical use. In addition to displaying typical retinoid effects, it also has antiinflammatory properties. Adapalene has similar efficacy to tretinoin, but unlike tretinoin, it is stable in sunlight and tends to be less irritating in nature. 

Lotan,R and Clifford, J L.( 1990) Nuclear receptors for retinoids mediators of retinoid effects on normal and malignant cells. Biomed. Pharmacother 45,145-156. 

Retinoid Effects on Glycoconjugate Synthesis in Vivo and in Vitro... 

Further direct proof that retinoid-effected inhibition of tumor growth and lower incidence of tumors is due to stimulation of the immune system rather than by toxic effects of retinoid directly on the tumor was provided by the experiments of Patek et al. (1979). Animals were thymectomized, lethally irradiated, and reconstituted with fetal liver (ATxFL) in order to compromise their humoral and cell-mediated immune system by the elimination of T cells. Under these conditions it was demonstrated that ATxFL mice are not able to suppress the growth of S91 or L33 tumor growth when treated with retinoid. Therefore, for these two tumor models, it seems highly likely that the retinoid effect requires the participation of immunocompetent cells, in particular, T cells. 

Kochhar DM, Penner JD, Tellone C (1984) Comparative teratogenic activities of two retinoids Effects on palate and limb development. Teratogen Carcinogen Mutagen 4 377-387... 

Because of the tight control of the experimental variables possible in studies conducted in cultured cells and because of the homogeneity of cell lines, many studies can be carried out which would be impossible in whole animal systems. This review will focus primarily on retinoid effects on the transformation of normal cells. 

Mordan LJ, Mariner JE, Bertram JS (1983) Quantitative Neoplastic Transformation of C3H/10T1/2 Fibroblasts Dependence upon the Size of the Initiated Cell Colony at Confluence. Cancer Res 43 4062-4067 Loewenstein Rose B (1992) The cell-cell channel in the control of growth. Semin Cell Biol 3 59-79 Mordan LJ, Bertram JS (1983) Retinoid effects on cell-cell interactions and growth characteristics of normal and carcinogen-treated C3H/10T1/2 cells. Cancer Res 43 567-571... 

The demonstrated auxiliary role exerted by retinoid x receptors (RXRs) [39] in mediating the retinoid effect on breast cancer cell fines is not of great relevance when we analyze RA activity because of the low binding and transactivating activity of this retinoid for this class of receptors. These observations are important only when considering reversal of RA resistance through the use of RXR-selective compounds [40]. 

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