Effect of retinoic acid on the changes of nuclear matrix in termediate filament system in gastric carcinoma cells.

Abstract

AIM:To explore the relationship between the configuration changes of the nuclear matrix intermediate filament system in cancer cell induced by retinoic acid and the malignant phenotypic reversion of cancer cells.METHODS:The human gastric adenocarcinoma cell line MGc80-3 cells were induced with 10(-6) mol/L retinoic acid and subcultured at cover slip strip and gold grids. The cells were treated by selective extraction method and prepared for whole mount electron microscopy observation. The samples were examined respectively with scanning and transmission electron microscope.RESULTS:The nuclear matrix filaments and intermediate filaments in MGc80-3 cells were relatively few and scattered, not well-distributed and arranged irregularly. The nuclear lamina was ununiformly thick and compact, connected to the nuclear matrix filaments and intermediate filaments relaxedly. However, the two kinds of filaments were abundant and well-distributed, different in slender and thick form and interweaved into a regular network in the cells induced by 10(-6)mol/L RA. The nuclear matrix filaments and inter-mediate filaments were connected closely by the thin and compact fiber-like lamina, and interlaced into a regular network throughout the whole cell region.CONCLUSION:The NM-IF system in MGc80-3 cells had undergone a restorational change similar to those of normal cells after RA inducement. This alternation is an important mor-phological and functional expression to the malignant phenotypic reversion of cancer cells.