cdk2反义RNA对乳腺癌细胞增殖及致瘤性的抑制作用

为了研究cdk2对乳腺癌细胞生长及cyclinA，cyclinB1和ckdl（cdc2)mRNA表达水平的影响，利用直接表达载体p XJ41-neo构建了表达cdk2反义RNA的重组载体，并用此载体转染了人乳腺癌细胞系Bcap37，获得了ckd2受到抑制的细胞模型Bcap37-CDK2AS，然后将Bcap37-CDK2AS细胞的生长能力及cyclinA,cyclinB1和cdk1 mRNA折水平与转入空载体的对照细胞进行了对比分析，结果显示，cdk2表达受到抑制时，细胞生长速率下降，根据测定出的细胞生长曲线，细胞培养至第7天时，细胞生长抑制率为64％，在流式细胞术的分析结果中，G1期细胞中的百分比从39％增加到47％，S期细胞由51％下降到39％，裸鼠接种的实验表明，Bcap37－CDK2AS的致瘤性明显减弱，在对cyclinA,cyclinB1和cdk1mRNA折分析中发现，Bcap37－CDK2AS中这3种基因的mRAN水平均有不同程度的下降，依据这些结果可以推测，ckd2反义RNA可使乳腺癌细胞生长及致瘤性受到抑制，并且cdk2表达的抑制将cyclinA,cyclinB和cdk14的表达水平。

INHIBITION OF BREAST CANCER CELL PROLIFERATION AND TUMORIGENECITY BY cdk2 ANTISENSE RNA

Recombinant eukarytic expression plasmid expressing cdk2 antisense RNA was constructed using pXJ41-neo. Breast cancer cells (Bcap37) were transfected with the recombinant plasmid and cell clones in which the expression of cdk2 is inhibited by cdk2 antisense RNA were selected (Bcap37-CDK2AS). Proliferation, tumorigenecity in nude mice and mRNA level of cyclinA, cuclinB1 and cdk1 of Bcap37-CDK2AS cells were compared with control cells. Due to the inhibition of cdk2 expression, the ratio of cell proliferation decreases. The ratio of growth inhibition is about 64% after 7 days acording to growth curve test. The proportion of cells increases from 39% to 47% in G1 phase and decreases from 51% to 39% in S phase in flow cytometry analysis. The tumorigenecity of Bcap37-SDK2SA is weakened in test of nude mice inoculation. Northern blot analysis shows that the mRNA level of cyclinA, cyuclinB1 and cdk1 decreases with the inhibition of cdk2 expression. It is indicated that the inhibition of cdk2 affects the cell proliferation, tumorigenecity and the expression of cyclinA, cyclinB1 as well as cdk1.