High-molecular-weight tropomyosins localize to the contractile rings of dividing CNS cells but are absent from malignant pediatric and adult CNS tumors
High-molecular-weight tropomyosins localize to the contractile rings of dividing CNS cells but are absent from malignant pediatric and adult CNS tumors
复制标题
DOI：
10.1002/glia.10174
复制
发表时间：
2003-04-01
期刊：
影响因子：
6.2
通讯作者：
Weinberger, RP
中科院分区：
文献类型：
--
作者：
Hughes, JAI;Cooke-Yarborough, CM;Weinberger, RP
原肌球蛋白参与细胞迁移、形态发生和胞质分裂过程中肌动蛋白丝动力学的控制。为了深入了解原肌球蛋白在细胞分裂中的作用，我们研究了它们在发育和肿瘤脑组织中的表达。我们发现高分子量原肌球蛋白在出生时下调，这与胶质细胞分化和大多数细胞退出细胞周期有关。这些亚型的表达仅限于胚胎脑中的增殖区域，并且在成人中不存在，其中大多数细胞是静止的。然而，它们是在神经胶质细胞响应损伤而增殖的条件下诱导的。在胞质分裂过程中，这些原肌球蛋白亚型与收缩环相关。我们还研究了原肌球蛋白在肿瘤性CNS组织中的表达。低级别星形细胞肿瘤表达高分子量原肌球蛋白，而不同来源的高度恶性CNS肿瘤则不表达（P <或等于0.001）。此外，高分子量的原肌球蛋白缺乏高度恶性星形细胞瘤细胞的收缩环。我们的研究结果表明高分子量原肌球蛋白在星形胶质细胞胞质分裂中的作用，尽管高度恶性的中枢神经系统肿瘤在它们不存在的情况下仍然能够进行细胞分裂。此外，高分子量原肌球蛋白表达和肿瘤分级之间的相关性表明，原肌球蛋白是潜在的有用的指标中枢神经系统肿瘤分级。(C)2003 Wiley-Liss，Inc.
Tropomyosin has been implicated in the control of actin filament dynamics during cell migration, morphogenesis, and cytokinesis. In order to gain insight into the role of tropomyosins in cell division, we examined their expression in developing and neoplastic brain tissue. We found that the high-molecular-weight tropomyosins are downregulated at birth, which correlates with glial cell differentiation and withdrawal of most cells from the cell cycle. Expression of these isoforms was restricted to proliferative areas in the embryonic brain and was absent from the adult, where the majority of cells are quiescent. However, they were induced under conditions where glial cells became proliferative in response to injury. During cytokinesis, these tropomyosin isoforms were associated with the contractile ring. We also investigated tropomyosin expression in neoplastic CNS tissues. Low-grade astrocytic tumors expressed high-molecular-weight tropomyosins, while highly malignant CNS tumors of diverse origin did not (P less than or equal to 0.001). Furthermore, high-molecular-weight tropomyosins were absent from the contractile ring in highly malignant astrocytoma cells. Our findings suggest a role for high-molecular-weight tropomyosins in astrocyte cytokinesis, although highly malignant CNS tumors are still able to undergo cell division in their absence. Additionally, the correlation between high-molecular-weight tropomyosin expression and tumor grade suggests that tropomyosins are potentially useful as indicators of CNS tumor grade. (C) 2003 Wiley-Liss, Inc.