Basic amd clinical study on differentiation induction of solid tumors with frequent metastasis

本研究的最终目的是通过生理活性物质诱导骨肉瘤等恶性实体瘤的分化。但在兽医中，特别是在JAPN，肿瘤患者的临床方面，如取决于治疗的存活率，并没有得到充分的调查。我们在东京大学医院看到了各种癌症患者，因此我们开始调查这些肿瘤患者的预后。在研究期间，我们报道了关于犬口鼻肿瘤、肥大细胞肿瘤、猫乳腺大肿瘤预后的综述和一些原创文献。实验结果与国外报道的结果基本一致，但可作为我们进一步研究的参考数据。在此期间，我们已经建立了另外两种犬骨肉瘤细胞，即恶性瘤细胞和犬猫乳腺肿瘤细胞。以克隆犬骨肉瘤细胞为实验材料，以维生素D、转铁蛋白-β和重组人骨形态发生蛋白-2(rh BMP-2)为生理物质，对其诱导分化进行了研究。通过在培养基中加入这些物质，碱性磷酸酶的活性。作为成骨细胞表型特征的碱性磷酸酶染色强度、骨钙素浓度和I型胶原浓度增加。这一结果提示，骨肉瘤细胞必须被这些物质诱导分化到更高的阶段。维生素D和重组人骨形态发生蛋白-2的诱导力高于转化生长因子-β。在其他犬骨肉瘤细胞中加入维甲酸和维生素D衍生物也能观察到分化，尽管结果仍是初步的。还需要进一步的研究，包括体内和临床研究。

Final purpose of this study is to induce differentiation of malignant solid tumor like osteosarvoma by physiologically active substances. But in veterinary medicine especially in Japn, the clinical aspects to tumor patients such as survival rates depending on the treatments are not fully investigated. We have seen various cancer patients in our hospital of Univerdity of Tokyo, therefore we have statted to investigate the prognosis of these tumor patients.During the research period, we reported a review and some original papers on the prognosis of canine oral and nasal tumors, mast cell tumors, feline mammary grand tumors. The results were almost the same as described in foreign countries before, but can be used as reference data for our further reseaches.Establishment of tumor cell lines from spontaneous animal tumors were also tried. During this period, we have establishe two other canine osteosarcoma cells, malanoma cells and canine and feline mamary gland tumor cells. These cells could be quite valuable ones for the further reseaches of induction of differentiation of malignant tumors.Differentiation induction was investigated using cloned canine osteosarcoma cells and vitamine D,TFG-beta, and recombinant human bone morphogenetic protein-2 (rhBMP-2) as physiologic substance. By addition of these substances into the culture media, ALP activity. ALp staining strength, osteocalcin concentrations, and type I collagen concentrations, as the phenotypic characteristics of osteoblasts, increased. This result suggests that osteosarcoma cells must be induced higher differentiation stages by these substances. The potency of induction was higher in vitamine D and rhBMP-2 than in TGF-beta.Differentiation was also observed by addition of retinoic acids and vitamine D derivatives in other canine osteosarcoma cells, though the results were still preliminary. Further researches including in vivo and clinical studies must be needed.