DeBortoli M E, Abou-Issa H, Haley B E, Cho-Chung Y S
Biochem Biophys Res Commun. 1985 Mar 15;127(2):699-706. doi: 10.1016/s0006-291x(85)80218-7.
Western blotting analysis was utilized to determine the amount of a ras oncogene product, p21 present in mammary carcinomas of humans and rats. The levels of p21 in hormone-dependent rat tumors was about 7-fold that of hormone-independent tumors. The majority of human breast carcinomas examined had high p21 levels, about 10-fold that of the normal breast tissue; 70% of these tumors were estrogen and progesterone receptor positive. p21 levels in the remaining tumors were 3-fold that of the normal breast tissue, regardless of the receptor status. Fibroadenomas and fibrocystic disease showed p21 levels similar to that of the normal mammary glands. Moreover, the high p21 levels in the mammary carcinomas correlated directly with high GTPase activity, as revealed by the photo-incorporation of 8-N3-[gamma-32P]GTP into the tumor lysates. The results suggest that hormone-dependency of mammary carcinomas may correlate with quantitative change in 'normal' p21 protein.
采用蛋白质免疫印迹分析来测定人类和大鼠乳腺癌中癌基因ras的产物p21的含量。激素依赖型大鼠肿瘤中p21的水平约为激素非依赖型肿瘤的7倍。大多数检测的人类乳腺癌p21水平较高，约为正常乳腺组织的10倍；其中70%的肿瘤雌激素和孕激素受体呈阳性。其余肿瘤的p21水平是正常乳腺组织的3倍，与受体状态无关。纤维腺瘤和纤维囊性疾病的p21水平与正常乳腺相似。此外，如通过8-N3-[γ-32P]GTP光掺入肿瘤裂解物所显示的，乳腺癌中较高的p21水平与较高的GTP酶活性直接相关。结果表明，乳腺癌的激素依赖性可能与“正常”p21蛋白的定量变化有关。
