Effect of retinoic acid on the changes of nuclear matrix-intermediate filament system in gastric carcinoma cells

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 malignantphenotypic reversion of cancer cells.METHODS The human gastric adenocarcinomacell line MGc80-3 cells were induced with 10-6mol/ L retinoic acid and subouItured at cover slipstrip and gold grids. The cells were treated byselective extraction methOd and prepared for whole mount electron microscopy observation.The samples were examined respectively withscanning and transmission electron microscope.RESULTS The nuclear matrix filaments andintermediate filaments in MGC80-3 cells wererelatively few and scattered, not welldistributed and arranged irregularly. The nuclear lamina was ununiformly thick and compact,connected to the nuclear matrix filaments and intermediate filaments relaxedly. However, thetwo kinds of filaments were abundant and welldistributed, 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 intermediate filaments were connected closely by the thin and compact fiber-Iike lamina, and interlaced into a regularnetwork throughout the whole cell region.CONCLUSION The NM-IF system in MGc80-3cells had undergone a restorational changesimilar to those of normaI cells after RAinducement. This alternation is an importantmorpholOgical and functional expression to themalignant phenotypic reversion of cancer cells.