Sato K, Satoh K, Sato T, Imai F, Morris H P
Cancer Res. 1976 Feb;36(2 Pt 1):487-95.
Isozyme patterns of glycogen phosphorylase in the Morris and Yoshida hepatomas were compared electrophoretically and immunochemically with those in rat tissues during development. A 3rd phosphorylase isozyme, observed previously in hepatomas and fetal tissues by isoelectric focusing and by immunochemical titration, was also separated by polyacrylamide disc gel electrophoresis. It was observed commonly in various rat hepatomas, together with variable activities of the liver type, depending on the degree of differentiation. This isozyme is nearly the sole type in placenta and early embryo, and in liver and skeletal muscle it is replaced during fetal development with the organ-specific liver and muscle type. In adult rat brain the fetal type is retained at low levels, together with the muscle type. In kidney, spleen, testis, uterus, lung, and stomach, the fetal type is present together with the liver type. This isozyme in hepatomas and adult brain is identical with the fetal-type, as determined by Ouchterlony double diffusion and activity inhibition tests. Thus, it is considered to be a prototype whose appearance in hepatomas is one of many known examples of fetal protein expression in cancer. In some poorly differentiated hepatomas, the liver-type isozyme migrated slightly more slowly in polyacrylamide gel but could not be distinguished from the liver isozyme immunochemically.
对莫里斯肝癌和吉田肝癌中糖原磷酸化酶的同工酶模式，通过电泳和免疫化学方法与大鼠发育过程中各组织的同工酶模式进行了比较。先前通过等电聚焦和免疫化学滴定在肝癌和胎儿组织中观察到的第三种磷酸化酶同工酶，也通过聚丙烯酰胺圆盘凝胶电泳分离出来。在各种大鼠肝癌中普遍观察到这种同工酶，同时存在不同活性的肝型同工酶，这取决于分化程度。这种同工酶在胎盘和早期胚胎中几乎是唯一的类型，在胎儿发育过程中，肝脏和骨骼肌中的这种同工酶会被器官特异性的肝型和肌型所取代。在成年大鼠大脑中，胎儿型同工酶与肌型同工酶一起以低水平保留。在肾脏、脾脏、睾丸、子宫、肺和胃中，胎儿型同工酶与肝型同工酶同时存在。通过奥克特洛尼双向扩散和活性抑制试验确定，肝癌和成年大脑中的这种同工酶与胎儿型相同。因此，它被认为是一种原型，其在肝癌中的出现是癌症中胎儿蛋白表达的众多已知例子之一。在一些低分化肝癌中，肝型同工酶在聚丙烯酰胺凝胶中的迁移速度略慢，但在免疫化学上无法与肝同工酶区分开来。
