Molecular Pathology of Rat Osteosarcoma and Malignant Fibrous Histiocytoma

1)研究了STI 571对大鼠骨肉瘤和MFH细胞系的作用。所有细胞系的细胞生长均受到抑制，且呈时间和剂量依赖性。对MFH细胞系的抑制率较高，约为40%，而对骨肉瘤细胞系的抑制率约为20%。2）检测<INK4a>大鼠骨肉瘤、恶性纤维组织细胞瘤和大鼠肺腺癌细胞系中p16^基因的表达和甲基化状态。PCR-SSCP分析显示，p16基因在肺腺癌组织中无表达，而在骨肉瘤和MFH组织中的表达与正常成纤维细胞相似。骨肉瘤组织中靠近编码区的区域甲基化程度较高，而肺腺癌组织中TATA盒附近区域甲基化程度较高。3）观察HMR 1275（flavopiridol）对大鼠骨肉瘤、MFH细胞株和肺腺癌细胞株的作用。所有细胞系的细胞生长均受到抑制，且呈时间和剂量依赖性。对肺腺癌细胞系的抑制率最高，约为80%，而对骨肉瘤和MFH细胞系的抑制率约为60%。5-氮杂2 '-脱氧胞苷诱导p16基因的表达增强HMR 1275的作用。4）观察2-甲氧基乙烯和组蛋白去乙酰化酶抑制剂对大鼠骨肉瘤和MFH细胞系的作用。两种细胞系的细胞生长均受到2-甲氧基乙烷和组蛋白脱乙酰化酶抑制剂的时间和剂量依赖性抑制。对这些药物作用机制的研究正在进行中，包括缺氧诱导因子、半胱天冬酶等基因表达的研究。

1)The effect of STI571 was investigated on rat osteosarcoma and MFH cell lines. The cell growth of all cell lines was inhibited in a time- and dose-dependent manner. The inhibition rate were greater for MFH cell lines, about 40%, while about 20% for osteosarcoma cell lines. The difference of effectiveness was depend on PDGFRα expression.2)We investigated the expression and methylation status of p16^<INK4a> gene in rat osteosarcoma and malignant fibrous histiocytoma as well as rat lung adenocarcinoma cell lines. The PCR-SSCP analysis showed no expression of p16 gene in lung adenocarcinoma, while similar expression in ostesarcomas and MFHs as normal fibroblasts. The region close to coding region was hypermethylated in osteosarcoma, in contrast, the region nearby TATA box was consistently methylated in lung adenocarcinoma. MFHs and fibroblasts were hypomethylated in both regions.3)The effect of HMR1275 (flavopiridol) was investigated on rat osteosarcoma, MFH cell lines and lung adenocarcinoma cell lines. The cell growth of all cell lines was inhibited in a time- and dose-dependent manner. The inhibition rate were the greatest for lung adenocarcinoma cell lines, about 80%, while about 60% for osteosarcoma and MFH cell lines. The induction of p16 gene by the treatment of 5-aza 2'-deoxycytidine enhances the effects of HMR1275.4)The effects of 2-methoxyestradiol and histone deacethylase inhibitor were investigated on rat osteosarcoma and MFH cell lines. The cell growth of both cell lines was inhibited in a time- and dose-dependent manner by both 2-methoxyestradiol and histone deacethylase inhibitor. The investigation of the effect mechanisms for these drugs is now on-going including the gene expression such as hypoxia inducible factor, caspase etc.