Su Z Z, Zhang P Q, Fisher P B
Department of Neurological Surgery, Columbia University College of Physicians and Surgeons, New York, New York 10032.
Mol Carcinog. 1990;3(5):309-18. doi: 10.1002/mc.2940030512.
We have analyzed the effect of the poly(ADP-ribose) synthesis inhibitor 3 aminobenzamide (3AB) on de novo and methyl methanesulfonate (MMS) and gamma irradiation enhancement of viral transformation of a cloned rat embryo fibroblast cell line, CREF, by a cold-sensitive host-range mutant of type 5 adenovirus, H5hr1. Additionally, we have evaluated the effect of 3AB on the transformation of CREF cells following transfection with a gene conferring resistance to hygromycin (hygr) or the neomycin analogue G418 (neor) in combination with a cloned type 5 adenovirus E1A transforming gene (Ad5 E1A) or the Ha-ras (T24) oncogene. 3AB induced a dose- and time-dependent increase in the level of de novo MMS-enhanced and gamma irradiation-enhanced transformation of CREF cells by H5hr1, whereas it did not induce morphological transformation in uninfected control, MMS-pretreated, or gamma irradiation-pretreated CREF cells. Temporal kinetic studies indicated that 3AB was most effective in enhancing de novo and MMS-enhanced and gamma irradiation-enhanced viral transformation when applied early after viral and carcinogen plus viral infection and when present for extended time periods (4-5 wk). 3AB also increased the frequency of resistant colonies following transfection with several cloned genes, including hygr, neor, and protein kinase C (which also contained a neor gene), and the frequency of morphological transformation of CREF cells following cotransfection with a hygr gene and an Ad5 E1A or an activated Ha-ras (T24) gene. In contrast, 3AB exerted the opposite effect, i.e., an inhibitory effect, when applied to NIH 3T3 cells transfected with a hygr or neor gene, alone or in combination with a T24 gene. The ability of 3AB to enhance the frequency of transformation of CREF cells was not associated with a selective effect on the growth of H5hr1-transformed CREF cells in monolayer or agar culture. Similarly, 3AB did not alter the percentage of MMS- or gamma irradiated-pretreated H5hr1-infected cells retaining free Ad5 DNA or the random pattern or quantity of viral DNA integration in control or carcinogen-treated H5hr1-transformed cells. These results suggest that cellular processes regulated by the nuclear enzyme ADPRT, or additional processes modified by 3AB, may be important mediators of stable transformation induced by transfected DNA and both de novo and carcinogen-enhanced viral transformation of specific target cells.
我们分析了聚（ADP - 核糖）合成抑制剂3 - 氨基苯甲酰胺（3AB）对5型腺病毒冷敏感宿主范围突变体H5hr1介导的克隆大鼠胚胎成纤维细胞系CREF的从头转化以及甲基磺酸甲酯（MMS）和γ射线增强的病毒转化的影响。此外，我们评估了3AB对用赋予潮霉素（hygr）或新霉素类似物G418（neor）抗性的基因与克隆的5型腺病毒E1A转化基因（Ad5 E1A）或Ha - ras（T24）癌基因共转染后CREF细胞转化的影响。3AB诱导H5hr1介导的CREF细胞从头转化、MMS增强的转化和γ射线增强的转化水平呈剂量和时间依赖性增加，而在未感染的对照、MMS预处理或γ射线预处理的CREF细胞中未诱导形态转化。时间动力学研究表明，3AB在病毒和致癌物加病毒感染后早期应用且存在较长时间（4 - 5周）时，在增强从头转化、MMS增强的转化和γ射线增强的病毒转化方面最有效。3AB还增加了用包括hygr、neor和蛋白激酶C（其也含有neor基因）在内的几个克隆基因转染后抗性集落的频率，以及用hygr基因与Ad5 E1A或活化的Ha - ras（T24）基因共转染后CREF细胞的形态转化频率。相反，当应用于单独或与T24基因一起用hygr或neor基因转染的NIH 3T3细胞时，3AB产生相反的效果，即抑制作用。3AB增强CREF细胞转化频率的能力与对单层或琼脂培养中H5hr1转化的CREF细胞生长的选择性作用无关。同样，3AB没有改变MMS或γ射线预处理的H5hr1感染细胞中保留游离Ad5 DNA的百分比，也没有改变对照或致癌物处理的H5hr1转化细胞中病毒DNA整合的随机模式或数量。这些结果表明，由核酶ADPRT调节的细胞过程，或由3AB修饰的其他过程，可能是转染DNA诱导的稳定转化以及特定靶细胞的从头转化和致癌物增强的病毒转化的重要介导因子。
