Lai S L, Perng R P, Hwang J
Chest Department, Veterans General Hospital-Taipei, Taipei, Taiwan, ROC.
J Biomed Sci. 2000 Jan-Feb;7(1):64-70. doi: 10.1007/BF02255920.
This study examined the effects of p53 gene status on DNA damage-induced cell death and chemosensitivity to various chemotherapeutic agents in non-small cell lung cancer (NSCLC) cells. A mutant p53 gene was introduced into cells carrying the wild-type p53 gene and also vice versa to introduce the wild-type p53 gene into cells carrying the mutant p53 gene. Chemosensitivity and DNA damage-induced apoptosis in these cells were then examined. This study included five cell lines, NCI-H1437, NCI-H727, NCI-H441 and NCI-H1299 which carry a mutant p53 gene and NCI-H460 which carries a wild-type p53 gene. Mutant p53-carrying cells were transfected with the wild-type p53 gene, while mutant p53 genes were introduced into NCI-H460 cells. These p53 genes were individually mutated at amino acid residues 143, 175, 248 and 273. The representative cell line NCI-H1437 cells transfected with wild-type p53 gene (H1437/wtp53) showed a dramatic increase in susceptibility to three anticancer agents (7-fold to cisplatin, 21-fold to etoposide, and 20-fold to camptothecin) compared to untransfected or neotransfected H1437 cells. An increase in chemosensitivity was also observed in wild-type p53 transfectants of H727, H441, H1299 cells. The results of chemosensitivity were consistent with the observations on apoptotic cell death. H1437/wtp53 cells, but not H1437 parental cells, exhibited a characteristic feature of apoptotic cell death that generated oligonucleosomal-sized DNA fragments. In contrast, loss of chemosensitivity and lack of p53-mediated DNA degradation in response to anticancer agents were observed in H460 cells transfected with mutant p53. These observations suggest that the increase in chemosensitivity was attributable to wild-type p53 mediation of the process of apoptosis. In addition, our results also suggest that p53 gene status modulates the extent of chemosensitivity and the induction of apoptosis by different anticancer agents in NSCLC cells.
本研究检测了p53基因状态对非小细胞肺癌（NSCLC）细胞中DNA损伤诱导的细胞死亡及对多种化疗药物的化疗敏感性的影响。将突变型p53基因导入携带野生型p53基因的细胞中，反之亦然，即将野生型p53基因导入携带突变型p53基因的细胞中。然后检测这些细胞的化疗敏感性及DNA损伤诱导的凋亡情况。本研究包括五个细胞系，携带突变型p53基因的NCI-H1437、NCI-H727、NCI-H441和NCI-H1299，以及携带野生型p53基因的NCI-H460。将野生型p53基因转染至携带突变型p53基因的细胞中，同时将突变型p53基因导入NCI-H460细胞中。这些p53基因在氨基酸残基143、175、248和273处分别发生突变。与未转染或新转染的H1437细胞相比，转染野生型p53基因的代表性细胞系NCI-H1437细胞（H1437/wtp53）对三种抗癌药物的敏感性显著增加（对顺铂增加7倍，对依托泊苷增加21倍，对喜树碱增加20倍）。在H727、H441、H1299细胞的野生型p53转染子中也观察到化疗敏感性增加。化疗敏感性结果与凋亡细胞死亡的观察结果一致。H1437/wtp53细胞而非H1437亲本细胞表现出凋亡细胞死亡的特征，即产生寡核小体大小的DNA片段。相反，在转染突变型p53的H460细胞中观察到化疗敏感性丧失以及对抗癌药物缺乏p53介导的DNA降解。这些观察结果表明，化疗敏感性增加归因于野生型p53介导的凋亡过程。此外，我们的结果还表明，p53基因状态调节NSCLC细胞中化疗敏感性的程度以及不同抗癌药物诱导的凋亡。
