Study of Tumor Progression in vivo and in vitro using

从荷尔蒙依赖性小鼠乳腺肿瘤TPDMT-4(T4)经不同条件传代，建立了5个自主亚系：T4-OI320(329)、T4-OI320CY(320CY)、T4-OI165(165)、T4-OI145(145)和T4-OI96(96)。这些自主肿瘤的特征是在DDD处女鼠中生长迅速，而亲本T4在它们中不生长。因此，将10^5320、210^4320CY、2×10^3165、2*10^3145和10^396细胞与5×10^5T4细胞共注射到处女鼠体内，以确定激素依赖性肿瘤细胞是否影响自主肿瘤细胞的生长。T4细胞对320和320CY的生长有抑制作用，对165、145和96的生长有促进作用。照射后的T4细胞可刺激除320外的所有细胞亚系的生长。在三维胶原凝胶培养中，320和320CY细胞形成与正常乳腺相似的分枝或星状结构，而165、145和96细胞则生长为圆形团块，形态完全不同。165、145和96细胞均有肺定植能力，其余细胞均无定植能力。在胶原凝胶培养体系中，抗生素蛋白酶抑制剂对转移性肿瘤的生长抑制作用强于对亲本和非转移性肿瘤的生长抑制作用。因此，自主性亚系肿瘤细胞对壁激素依赖肿瘤细胞的生长抑制调节的敏感性与胶原凝胶内的生长形态和转移特性密切相关。结果表明，转移能力强的肿瘤细胞变异体一旦出现，可能在激素依赖型乳腺肿瘤中具有生长优势。这一体外系统在人类乳腺癌中的应用正在进行中。

Five autonomous sublines, T4-OI320 (329), T4-OI320CY (320CY), T4-OI165 (165), T4-OI145 (145), and T4-OI96 (96), were established from the transpalantable hormone-dependent mouse mammary tumor, TPDMT-4 (T4), by passaging under different conditions. These autonomous tumors were characterized by rapid growth in DDD virgin mice and the parental T4 by no growth in them. Thus, 10^5320,210^4320CY,2*10^3165,2*10^3145 and 10^396 cells were co-injected with 5*10^5T4 cells into virgin mice to determine whether hormone-dependent tumor cells influence the growth of autonomous tumor cells or not. T4 cells retarded the growth of 320 and 320CY tumors but accelerated that of 165,145 and 96. Irradiated T4 cells stimulated the growth of all the sublines but 320. In three-dimensional collagen gel culture, 320 and 320CY cells formed branched or stellate structures similar to normal mammary glands as did T4, but 165,145 and 96 cells grew as rounded masses with knobs and showed completely different morphology. 165,145 and 96 cells but not the others had lung-colonizing capability. In the collagen gel culture system, an antibiotic protease inhibitor exerted a stronger growth-inhibiting effect on the metastatic than on the parent and non-metastatic tumors. Thus, the susceptibility of autonomous subline tumor cells to the growth-inhibitory regulation from the parenetal hormone-dependent tumor cells was well correlated with growth morphology within collagen gels and metastatic property. The results suggest that metastatically-competent tumor cell variants, once they appear, may have a growth advantage in hormone-dependent mammary tumors. Application of this in vitro sytem to human breast cancer is in progress.