中等纤维在几种人体上皮细胞有丝分裂过程中的行为

本文用间接免疫荧光法和电镜术观察了分别来自人表皮(PcaSE-1)、复层上皮(CNE)和单层上皮(SPC-A-1)的3个上皮细胞系的细胞在有丝分裂过程中中等纤维的行为。结果表明,CNE细胞和SPC-A-1细胞表达两种不同类型的中等纤维系统:角蛋白纤维和波形纤维,而PcaSE-1细胞仅表达角蛋白纤维。当细胞进入有丝分裂时,PcaSE-1细胞的角蛋白纤维维持完整的形态且将有丝分裂纺锤体围绕在细胞中央。相反,在CNE细胞和SPC-A-1细胞中,在细胞有丝分裂时,角蛋白纤维解聚成无定形的胞质小体,然而它们的波形纤维始终保持完整的形态。我们认为(1)在分裂上皮细胞中,角蛋白纤维的解聚与细胞的恶性程度有关,而与间期上皮细胞中是否含有丰富的角蛋白纤维无明显关系。(2)在上皮细胞有丝分裂时,中等纤维可能参于纺锤体的定位和趋中。(3)在分裂CNE细胞中,波形纤维的可能功能是染色体的定位和定向。

BEHAVIOR OF INTERMEDIATE FILAMENTS IN HUMAN EPITHELIAL CELLS DURING MITOSIS

By indirect immunofluorescence microscopy and electron microscopy, we studied the behavior of intermediate filaments during mitosis in three human epithelial cell lines, derived from normal epidermis (PcaSE-1, from a cancer patient), stratified epithelium (CNE, from nasopharyngeal carcinoma) and simple epithelium (SPC-A-1 from lung adenocarcinoma) respectively. CNE cells and SPC-A-1 cells express two different intermediate filament systems; keratin filaments and vimentin filaments, but PcaSE-1 cells only express keratin filaments. The keratin filament system in PcaSE-1 cells remained intact and encircled the developing mitotic spindle as the cells entered mitosis. In contrast, in CNE cells and SPC-A-1 cells, keratin filaments appeared to disassemble into amorphous cytoplasmic bodies during mitosis. However, their vimentin filaments remained morphologically intact throughout mitosis. We propose; (1) The disassembly of keratin filaments in mitotic epithelial cells is more or less associated with the degree of their cell malignance rather than with the abundance of keratin filaments in interphase. (2) Intermediate filaments may be involved in the positioning and/or centering of the spindle during mitosis. (3) The possible function of vimentin filament system in CNE cells is positioning and orientation of chromosomes.