维甲类(Retinoid)是包括自然和合成的与维生素A相关的化合物的总称.维生素A早以被确认对维持生长和分化及支持视力和生殖均至为重要.维生素A代谢为一个醛基一视黄醛和一个酸形式一维甲酸(RA).RA的自然形式是全反式衍生物,全反式维甲酸(Tretinoin,TR).RA有维持生长和分化的能力.作为分化剂,RA能诱导畸胎瘤干细胞、骨髓白血病细胞和成纤维细胞瘤细胞的分化,分化过程伴有基因表达诱导.这些基因的诱导可能是分化过程的基础.作为一种抗肿瘤剂,维甲酸已成功地用于实验动物化学诱导的肺、皮肤、膀胱和乳腺肿瘤.一种维生素A类似物亦显示可抑制放射诱导肿瘤的基因转化.核受体族系 已鉴定出二组受体:维甲酸受体(RAR)α、β、γ和维甲类X受体(RXR)α、β、γ.在人和鼠已克隆出其cDNAs.比较其DNA序列和结构组成,RARs和RXRs同属核受体大家族.包括全 Retinoids are the general term for both natural and synthetic vitamin A-related compounds. Vitamin A has long been identified as essential for maintaining growth and differentiation and supporting vision and reproduction. Vitamin A metabolism is an aldehyde-based one. The natural form of retinaldehyde and an acid form of all-dimensional formic acid (RA).RA is an all-trans derivative, and all-trans-retinoic acid (Tretinoin, TR).RA has the ability to maintain growth and differentiation. As a differentiation agent, RA It can induce the differentiation of teratoma stem cells, myeloid leukemia cells and fibroblasts cells, and the differentiation process is accompanied by gene expression induction. The induction of these genes may be the basis of the differentiation process. As an antitumor agent, retinoic acid has successfully Used for chemically induced lung, skin, bladder, and breast tumors in experimental animals. A vitamin A analog has also been shown to inhibit gene conversion of radiation-induced tumors. Nuclear receptor families have identified two groups of receptors: Retinoic acid receptors. (RAR) alpha, beta, gamma, and retinoid X receptors (RXR) alpha, beta, and gamma. cDNAs have been cloned in humans and mice. Their DNA sequences and structural composition are compared. RARs and RXRs are nuclear receptors. Family. Includes all