S3核糖体蛋白基因的过表达与K562/DOX细胞耐药性的关系

目的 观察S3核糖体蛋白（S3rp)基因表达的改变对白血病耐药性的影响。通过RT－PCR方法获得含S3rp基因完整开放阅读框架（ORF）的cRNA，并将其克隆到pGEM-T Easy载体里，然后通过亚克隆方法将pGEM-T Easy重组质粒里的S3rp cDNA片段克隆到真核表达载体pcDNA3.1( )中，分别构建正向插入和反向插入的S3rp cDNA重组质粒，进行基因转染。将正义S3rp cDNA真核表达质粒转染K562细胞，使其S3rp基因表达增加，观察其对化疗药物敏感性的改变；将反义S3rp cDNA真核表达质粒转染具有多药耐药（MDR）表型的K562／DOX细胞，阻碍其S3rp基因的表达，观察其对化疗药物耐药性的改变。结果 转染正义S3rp cDNA真核表达质粒后，K562细胞对阿霉素的耐药性比未转染的K562细胞增强5．8倍；转染反义S3rp cDNA真核表达质粒后，K562／DOX细胞对阿霉素的耐药性比未转染的K562／DOX细胞降低69％。结论 S3rp基因过表达在K562／DOX细胞耐药性的形成中起重要作用。

Overexpression of S3 ribosomal protein gene is involved in drug resistance in K562/DOX cells

Objective To investigate the effect of overexpression of S3 ribosomal protein (S3rp) gene on the resistance of leukemia cell to antitumor drugs. Methods Both sense and antisense cDNA recombinants of S3rp gene were constructed with pcDNA3.1 expression vector. Subsequently, the sense S3rp cDNA recombinant was transfected into K562 cells while the antisense one into K562/DOX cells (a multidrug resistant cell line). In addi tion, empty pcDNA3.1 vector was transfected into the corresponding cells as negative controls. The chemosensitivity of cells was evaluated by MTT assay. Results Sense S3rp cDNA transfected K562 cells were 5.8 times more resistant to doxorubicin than control cells did, whereas antisense S3rp cDNA transfected K562/DOX cells were 3.2 times less resistant to doxorubicin than control cells did. Conclusion Overexpression of S3rp gene plays an important role in the development of drug resistance in K562/DOX cells.