Hazuka M B, Edwards-Prasad J, Newman F, Kinzie J J, Prasad K N
Division of Radiation Oncology, University of Colorado Health Science Center, Denver 80262.
J Am Coll Nutr. 1990 Apr;9(2):143-9. doi: 10.1080/07315724.1990.10720363.
Several studies suggest that beta-carotene reduces the risk of some cancers. Except for its function as an antioxidant, the effect of this vitamin on mammalian cells remains poorly defined. This study was performed to show whether beta-carotene treatment of murine B-16 melanoma cells in culture induces differentiation and alters the adenylate cyclase (AC) system. The AC system mediates the action of agents which regulate cell differentiation and transformation. Results showed that beta-carotene treatment for a period of 24 hours or more caused morphological differentiation without changing the level of melanin, and reduced basal and melanocyte-stimulated hormone (MSH)-, sodium fluoride (NaF)-, and forskolin-stimulated AC activity in vitro. Retinol, a metabolite of beta-carotene, inhibited growth without morphological differentiation and reduced basal and MSH- and NaF-stimulated AC activity. However, butylated hydroxyanisole, a lipid-soluble antioxidant, also reduced growth without morphological differentiation, but it failed to alter basal or MSH-stimulated AC activity. The present and previous studies show that the AC system represents a common site where some antitumor-promoting vitamins (beta-carotene, retinol, retinoic acid, and alpha-tocopheryl succinate) act.
多项研究表明，β-胡萝卜素可降低某些癌症的风险。除了具有抗氧化功能外，这种维生素对哺乳动物细胞的作用仍不太明确。本研究旨在表明，在培养中用β-胡萝卜素处理小鼠B-16黑色素瘤细胞是否会诱导分化并改变腺苷酸环化酶（AC）系统。AC系统介导调节细胞分化和转化的因子的作用。结果表明，β-胡萝卜素处理24小时或更长时间会导致形态分化，而不会改变黑色素水平，并在体外降低基础和促黑素细胞激素（MSH）、氟化钠（NaF）和福斯可林刺激的AC活性。视黄醇是β-胡萝卜素的一种代谢产物，可抑制生长但无形态分化，并降低基础和MSH及NaF刺激的AC活性。然而，丁基羟基茴香醚是一种脂溶性抗氧化剂，也可降低生长但无形态分化，但它未能改变基础或MSH刺激的AC活性。目前和以前的研究表明，AC系统是一些抗肿瘤促进维生素（β-胡萝卜素、视黄醇、视黄酸和α-生育酚琥珀酸酯）作用的共同位点。
