环六亚甲基双乙酰胺诱导人肝癌SMMC-7721细胞分化过程中核基质-中间纤维系统的构型变化

Configurational changes of the nuclear matrix-intermediate filament(NM-IF) system during the differentiation of human hepatocarcinoma SMMC-7721 cells after being induced by hexcamethylamine bisacetamide(HMBA)

目的:研究环六亚甲基双乙酰胺(HMBA)诱导人肝癌SMMC-7721细胞分化过程中细胞核基质-中间纤维系统的构型变化。方法:应用选择性抽提整装光镜与电镜技术观察SMMC-7721细胞诱导前后其核基质-中间纤维系统的构型特征。结果:对照组SMMC-7721细胞中,核基质纤维与中间纤维具有数量较少、单丝纤维较少、分布不均匀、排列无序、核纤层较厚、与两类纤维联系不紧密等特点,其核区域内可见一至数个由少量纤维维系着的残余核仁;而在经HMBA诱导处理后的分化细胞中,两类纤维不仅数量增多、层次丰富、分布更为均匀、单丝成份增多,而且核纤层更加致密,呈现薄层均一结构并与两类纤维发生更为紧密的联系,形成较为规则的纤维网架体系,其残余核仁由更加丰富且呈放射状排列的纤维所维系。结论:HMBA诱导体外培养人肝癌SMMC-7721细胞分化过程中的核基质-中间纤维系统的构型发生了明显的变化,这种变化是癌细胞恶性表型逆转的重要形态和功能表现。

Objective ：To explore the configurational changes of nuclear matrix-intermediate filament （NM-IF） system during differentiation of human hepatocarcinoma SMMC-7721 cells in vitro after being induced by hexcamethylamine bisacetamide（HMBA）. Methods： SMMC-7721 cells treated with or without HMBA were cultured and then treated by selective extraction method and prepared for whole mount electron microscopy observation. The samples were examined under light and transmission electron microscope respectively. Results： It can be seen that the nuclear matrix-intermediate filament（NM- IF） in SMMC-7721 cells were relatively few and arranged irregularly. The nuclear lamina was nonuniform, and the two kinds of filaments connected were relaxed and not tightly. One or more residual nucleoli which maintained by a small quantity of fibres cccurred in the nucleus. After being induced by HMBA, the NM-IF filaments were dense and distributed uniformly. The heterogeneous population of filaments, included highly branched ultrathin filaments were also appeared in the regular meshwork. The connection between the two kinds of filaments and the relatively thin, condensed and sharply demarcated lamina composed of intermediate-sized filaments was relatively fastened. And the residual nucleoli were connected with relatively abundant filament bundles. Conclusion： It is implied that the NM-IF system in SMMC-7721 cells had been undergone a restorational change similar to that of normal cells after HMBA treatment, and this alternation is an important morphological and functional indication of the reversion of cancer cell.