耐三苯氧胺大鼠乳腺癌细胞株的分离及其特性

THE,ISOLATION OF TAMOXIFFEN-RESISTANT RAT MAMMARY TUMOR CELL STRAIN AND ITS BDOL OGICAL CHARACTERISATION

应用改良Ｓａｌｍｏｎ－Ｈａｍｂｕｒｇｅｒ双层琼脂培养法，通过对ＳＨＺ－８８细胞进行克隆培养，分离出一株耐三苯氧胺的大鼠乳腺癌细胞株——Ｙ２细胞。该细胞株为单层贴壁生长，具有一般恶性肿瘤细胞的特性；（染色体分析表明）其众数范围为８０～９５条；流式细胞仪检测其增殖指数（ＰＩ）为６１．５％，ＤＮＡ指数（ＤＩ）为１．９５５，系流式ＤＮＡ异倍体，同时只有一个ＤＮＡ干系，说明耐药细胞具有单克隆来源的特性。细胞生长及克隆形成率实验均提示耐药细胞对三苯氧胺的敏感性较原代细胞降低（Ｐ＜０．０１）。本细胞株的建立将有助于阐明对三苯氧胺的耐受机理，并可作为寻找和筛选抗耐药肿瘤药物的模型。

e selected a tamoxifen-resistant rat mamlnary tumor cell strain from SHZ-88 cell line(designated Y2 cell) using improved Salmon-Hamburger、 double-layer soft agar culture,Thiscell strain has about 40 hours doubling time and the malignant phenotype like the parent cell andis an archorage-dependent long diamond epithelium-like cell. Karyotyping analysis showedthat 49%of Y2 cell had 80～95 chromosomes in 100 mitosis metaphase cells. Flow Cytometricstudies demonstrated that Y2 cell had only one DNA stem peak,which is Flow DNA aneuploidywith DNA index of 1.955 and proliferative index of 61.5%.The test of 3H-TdR incorporationand clone-forming efficiancy in soft agar suggested a fair decrease of Y2 cell in sensitivity to ta-moxifen than parent cell.The establishment of Y2 will be helpful to eluciate the mechanism of tamoxifen resistance and provide a practical model for selecting the effective anti-cancer drugs.