Kaneko Y, Endo Y, Oda T
Cancer Res. 1978 Dec;38(12):4728-33.
alpha-Fetoprotein (AFP) was shown to be the major secretory protein produced in vitro by normal rat yolk sacs. While not so active, AFP production was also detected in the transplantable tumors derived from normal yolk sacs. The major secretory protein synthesized by the tumor cells had a molecular weight of 40,000 and was reactive with an anti-rat albumin antibody. The functional messenger RNA's coding for these proteins were quantitated by translation in a cell-free system derived from wheat germ followed by specific immunoprecipitation of the newly synthesized peptides. The overall template activity of the RNA prepared from the normal yolk sacs and yolk sac tumor cells was virtually identical. The cytosol RNA prepared from the normal yolk sacs was approximately 12 times more active than that from the tumor cells in directing the synthesis of AFP. The presence of the cytosol RNA prepared from the tumor cells was required for the synthesis of proteins immunoprecipitable with the antialbumin antibody. These results suggest that the changes in AFP and albumin synthesis can be accounted for by a corresponding change in the levels of functional messenger RNA's coding for these proteins.
甲胎蛋白（AFP）被证明是正常大鼠卵黄囊在体外产生的主要分泌蛋白。虽然活性不那么高，但在源自正常卵黄囊的可移植肿瘤中也检测到了AFP的产生。肿瘤细胞合成的主要分泌蛋白分子量为40000，并且与抗大鼠白蛋白抗体发生反应。通过在源自小麦胚芽的无细胞系统中进行翻译，然后对新合成的肽进行特异性免疫沉淀，对编码这些蛋白质的功能性信使RNA进行定量。从正常卵黄囊和卵黄囊肿瘤细胞制备的RNA的总体模板活性实际上是相同的。在指导AFP合成方面，从正常卵黄囊制备的胞质溶胶RNA的活性比从肿瘤细胞制备的胞质溶胶RNA大约高12倍。用抗白蛋白抗体进行免疫沉淀的蛋白质合成需要肿瘤细胞制备的胞质溶胶RNA的存在。这些结果表明，AFP和白蛋白合成的变化可以通过编码这些蛋白质的功能性信使RNA水平的相应变化来解释。
