ELECTRON MICROSCOPIC OBSERVATIONS ON THE EFFECTS OF ADRENAL GLUCOCORTICOID HORMONE ON HUMAN HEPATOMA CELLS CULTURED IN VITRO
LU YEN-LING AND CHANG SHI-MING (Shanghai Institute of Cell Biology,Academia Sinica)
The effect of synthetic adrenal glu-cocorticoid hormone on a human hepatoma cell line designated as BEL-7402was studied,with particular emphasison electron microscopic observations.Hepatoma cells of the experimentalgroup were treated with dexametha-sone at 7.5×10~(-7)M and 7.5×10~(-6)Mfor 48 or 72 hours,and those cellswithout dexamethasone used as controls. Hepatoma cells which had beencultured at 7.5×10~(-6)M dexamethasone for 48 hours became markedlyenlarged and more epitheloid in charac-ter (Fig.1),as compared with thecontrols (Fig.2).Some significantultrastructural changes have been noted in the various experimental groupswhich can be summarized accordingto the duration of hormone treatment:Hepatoma cells treated with dexamethasone for 48 hours—— (1) Large mitochondrion (Fig.6,A) which seems to be resulted fromthe fusion of several mitochondria canoccassionally be observed at bothdosage levels. (2) A few short microtubules beginto appear in cytoplasm of treatedcells at 7.5×10~(-7)M,but more pro-minent at 7.5×10~(-6)M.Hepatoma cells treated with dexame-thasone for 72 hours—— (1) The cell surface microvilli incells become reduced at two givenhormonal dosages so that they appearwith relatively smooth surfaces andsome bulb like microvilli.Large mi-tochondria (Fig 6,B) and glycogenlakes are also frequently seen. (2) A great number of comparatively long microtubules can often befound in cytoplasm of cells treated at7.5×10~(-6)M (Fig.7). (3) Tonofilaments and bundles ofit located in the vicinity of the nucleus(Fig.5) are more often observed. The significance of these ultrastructural changes as well as the appearance of microtubules in dexamethasone——treated human hepatomacells is briefly discussed.