NEOPLASTIC TRANSFORMATION IN THE PLANARIAN .2. ULTRASTRUCTURE OF MALIGNANT RETICULOMA
NEOPLASTIC TRANSFORMATION IN THE PLANARIAN .2. ULTRASTRUCTURE OF MALIGNANT RETICULOMA
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DOI：
10.1002/jez.1402400210
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发表时间：
1986-11-01
影响因子：
--
通讯作者：
BEST, JB
中科院分区：
文献类型：
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作者：
HALL, F;MORITA, M;BEST, JB
镉和佛波酯诱导真涡虫 Dugesia dorotocephala 的肿瘤发生，发展为一种致癌过程，涉及肿瘤疾病进展的启动和促进。用亚致死浓度的硫酸镉和 12-O-十四烷酰佛波醇-13-乙酸酯 (TPA) 治疗完整的涡虫，诱导了一种被证明具有潜在致命性的浸润性肿瘤。通过手术将此类肿瘤组织移植到其他健康的涡虫体内，导致相同的组织病理学进展直至致死，这证实了肿瘤的转移性质。电子显微镜研究表明，化学诱导的肿瘤和基于移植的肿瘤都专门涉及异常网状细胞（称为网状细胞瘤细胞）的增殖和分化。网状细胞通常是变形虫状的、吞噬性的，被认为为涡虫提供了免疫监视系统的系统发育前体。在肿瘤区域内观察到相当大的有丝分裂发生率；并阐明了从转化干细胞到成熟但无功能的网状细胞瘤细胞的分化顺序。这种分化概况支持通过干细胞动力学而不是去分化进行细胞衍生的概念。多种超微结构异常被表征：其中一些倾向于证实网状细胞瘤的间变性质，而另一些则更具体地诊断恶性肿瘤。这些发现进一步扩展了涡虫恶性网状细胞瘤作为研究肿瘤干细胞疾病的模型系统的潜在用途。
Cadmium and phorbol ester induced tumorigenesis in the planarian, Dugesia dorotocephala, develops as a cocarcinogenic process involving initiation and promotion in the progression of neoplastic disease. Treatment of intact planarians with sublethal concentrations of cadmium sulfate and 12-O-tetradecanoylphorbol-13-acetate (TPA) induced a type of infiltrating tumor that proved to be potentially lethal. Surgical transplantation of such tumorous tissues into otherwise healthy planarians resulted in the same histopathological progression to lethality, which confirmed the metastatic nature of the neoplasia. Electron microscopic studies revealed that both the chemically-induced and the transplantation-based tumors involved, exclusively, the proliferation and differentiation of abnormal reticular cells, referred to as reticuloma cells. Reticular cells normally are ameboid, phagocytic, and are thought to provide the planarian with a phylogenetic predecessor of an immune surveillance system. A considerable incidence of mitosis was observed within the tumor areas; and the sequence of differentiation, from transformed stem cells to mature but nonfunctional reticuloma cells, was elucidated. This profile of differentiation supports the concept of cellular derivation via stem cell dynamics as opposed to dedifferentiation. A variety of ultrastructural abnormalities were characterized: several of which tend to substantiate the anaplastic quality of the reticuloma, while others are more specifically diagnostic for malignancy. These findings further extend the potential usefulness of the planarian malignant reticuloma as a model system for the study of neoplastic stem cell diseases.