人乳腺癌细胞株WAF1/CIP1/p21基因的表达及其与细胞生物学特性的关系

WAF1/CIP1/p21 gene in wild type p53 and mutant p53 human breast cancer cell lines in relation to its cytobiological features

目的研究人乳腺癌细胞株ＷＡＦ１／ＣＩＰ１基因的ＤＮＡ状况、ｍＲＮＡ和蛋白的表达水平及其意义。方法应用细胞培养、分子生物学Ｓｏｕｔｈｅｒｎｂｌｏｔ和Ｎｏｒｔｈｅｒｎｂｌｏｔ杂交以及免疫组化染色等技术，检测人乳腺癌表达野生型ｐ５３（ｗｔｐ５３）的ＭＣＦ７细胞和表达突变型ｐ５３（ｍｔｐ５３）的ＭＤＡＭＢ２３１细胞中ＷＡＦ１／ＣＩＰ１基因ＤＮＡ状况、ｍＲＮＡ和蛋白质的表达水平，研究其与ｍｄｍ２、ｐ５３蛋白的表达和细胞生物学特性的关系。结果比较ＭＣＦ７细胞与ＭＤＡＭＢ２３１细胞：（１）两者ＷＡＦ１／ＣＩＰ１基因ＤＮＡ状况无明显差异，前者ｍＲＮＡ和蛋白质的表达水平明显高于后者（Ｐ＜０．０５）；（２）两者ｐ５３蛋白的性质和分布不同，前者ｍｄｍ２蛋白的表达水平明显高于后者（Ｐ＜０．０５）；（３）前者生物学特性好于后者。结论人乳腺癌细胞株ＷＡＦ１／ＣＩＰ１基因ｍＲＮＡ和蛋白质的表达水平与ｐ５３基因表型和细胞生物学特性有关。

Objective To study the WAF1/CIP1 gene DNA status, mRNA and protein expressions in human breast cancer cell line and its significance. Methods Using cell culture, molecular biological techniques such as Southern blot, Northern blot and immunocytochemical methods, the WAF1/CIP1 gene DNA status, mRNA and protein expression levels in MCF 7 expressing wild type p53(wtp53) and MDA MB 231 expressing mutant p53 (mtp53) human breast cancer cell lines were detected respectively. The p53 and mdm 2 protein expression levels and cytobiological features of the 2 cell lines were compared and correlated to their WAF1/CIP1 gene expression levels. Results (1)There was no difference in WAF1/CIP1 gene DNA status in the two breast cancer cell lines. Neither of them showed gene amplificatian or deletion. However, the WAF1/CIP1 mRNA and p21 WAF1/CIP1 protein expression levels of MCF 7 cells were higer than those of MDA MB 231 cells ( P <0.05). (2)The character and cellular distribution of p53 protein in the two cell lines were clearly different. The expression level of mdm 2 proteion was significantly higher in MCE 7 than in MDA MB 231 cells ( P <0.05). (3)Compered to the other breast cancer cell line, MCF 7 cells were better differentiated, grew more slowly and adhered more closely with each other. Conclusion The WAF1/CIP1 gene expression at mRNA and protein levels is associated with p53 phenotype and some cytobiological features of human breast cancer.