Chang K S, Hsu M L, Josephs S F
Graduate Institute of Clinical Medicine, Chang Gung Medical College, Taoyuan-Hsien, Taiwan, China.
Cancer Lett. 1993 Oct 15;74(1-2):75-83. doi: 10.1016/0304-3835(93)90047-d.
The regulation of trans-activating activities of two human hepatocellular carcinoma cell (HCC) lines, HEP-G2 and SK-HEP-1, was investigated. These cells were transfected with the wild-type and a nested series of its 5'-deletion mutants of the long terminal (LTR) repeat derived from HIV-1, which were ligated with the chloramphenicol acetyl transferase gene. These two HCC cell lines exhibited different biological characteristics, reflecting their status of differentiation. Both cell lines showed moderate degrees of constitutive (basal) trans-activating activities. While HEP-G2 cells, which are well differentiated, showed marked degrees of enhancement of trans-activation after treatment with 12-O-tetradecanoylphorbol-13-acetate, SK-HEP-1 cells, which are poorly differentiated, showed only moderate or low degrees of enhancement. These two cell lines up-regulated their trans-activating activities in response to the deletion of some regions of positive and negative regulatory elements, suggesting that they produce trans-acting factors that are quantitatively different from each other, and often employ different sets of positive and negative regulatory elements for trans-activation.
研究了两种人肝癌细胞系（HCC），即HEP-G2和SK-HEP-1的反式激活活性调控。用源自HIV-1的长末端重复序列（LTR）的野生型及其一系列5'端缺失突变体转染这些细胞，这些突变体与氯霉素乙酰转移酶基因连接。这两种肝癌细胞系表现出不同的生物学特性，反映了它们的分化状态。两种细胞系均表现出中等程度的组成型（基础）反式激活活性。虽然分化良好的HEP-G2细胞在用12-O-十四酰佛波醇-13-乙酸酯处理后反式激活显著增强，但分化差的SK-HEP-1细胞仅表现出中等或低程度的增强。这两种细胞系对正负调控元件某些区域的缺失作出反应，上调其反式激活活性，表明它们产生的反式作用因子在数量上彼此不同，并且在反式激活中经常使用不同的正负调控元件组合。
