Okada N, Steinberg M L, Defendi V
Exp Cell Res. 1984 Jul;153(1):198-207. doi: 10.1016/0014-4827(84)90461-0.
Infection of human epidermal keratinocytes by the oncogenic virus SV40 leads to progressive inhibition of the normal differentiation process in vitro. Treatment of infected cells with 5-azacytidine (5-aza-CR) over a 24-h period produced a striking enlargement and pronounced flattening of cells within 5-7 days following removal of the agent. This morphological change was accompanied by a several-fold increase in the number of cells staining positively for the cell envelope precursor protein, involucrin, and in the exfoliation of cornified envelope bearing cells from the monolayer. The drug-treated cultures at high passage levels were stained by immunofluorescence using monoclonal antibodies to keratin classes associated with different epidermal layers. These experiments revealed that 5-aza-CR caused the re-expression of two keratin classes (suprabasal and stratum corneum-associated), whose synthesis had been suppressed during the transformation process. 5-Aza-CR also brought about re-expression of 58 and 56 kD keratin markers of epithelial keratinization and stratification, as well as of 40 and 49-52 kD keratin markers of viral transformation. However, the responsiveness to the drug was gradually lost over time following infection.
致癌病毒SV40感染人表皮角质形成细胞会导致体外正常分化过程的逐步抑制。用5-氮杂胞苷（5-aza-CR）处理感染细胞24小时，在去除该试剂后的5-7天内，细胞会显著增大并明显扁平。这种形态变化伴随着细胞包膜前体蛋白内披蛋白阳性染色细胞数量增加数倍，以及含角质化包膜的细胞从单层中脱落。使用针对与不同表皮层相关的角蛋白类别的单克隆抗体，对高传代水平的药物处理培养物进行免疫荧光染色。这些实验表明，5-aza-CR导致两种角蛋白类（与基底上层和角质层相关）重新表达，其合成在转化过程中受到抑制。5-aza-CR还使上皮角质化和分层的58和56 kD角蛋白标记物以及病毒转化的40和49-52 kD角蛋白标记物重新表达。然而，感染后随着时间的推移，对该药物的反应性逐渐丧失。
