THE EFFECT OF dbcAMP ON THE MURINE U_(14) ASCITIC TUMOR CELLS SCANNING ELECTRON MICROSCOPIC OBSERVATION AND FLOW MICROCYTOMETRIC ANALYSIS / 解剖学报

ABSTRACT

dbcAMP was injected i. p. into four U_(14) ascitic tumor bearing mice on 3,4,5,6 and 7 days after inoculation of tumor cells. The ascites was aspirated 0.5-1 hour after last injection. For scanning electron microscopy, the tumor cells, washed twice in Hanks solution, were fixed in glutaraldehyde and OsO_4, dehydrated with ethyl alcohol and dried with camphene. For flow microcytometric analysis, the treated tumor cells were fixed in 70% cold ethyl alcohol and stained with propidium iodide. Under SEM, the untreated tumor cells were large, spherical, and uniform in size with numerous long thin microvilli on the cell surface. A few barely visible minute protrusions were present on the microvilli and cell membrane. The great majority of treated tumor cells became smaller and variable in size, with shortened microvilli which reduced in number and even disappeared in some area. Many granular protrusions, larger than that of the control, were clearly observed on the cell membrane and microvilli. The result of flow microcytometric analysis showed that the DNA histogram and cell cycle profile from dbcAMP treated cells have no significant difference from the untreated controls, so it is evident that morphologic changes resulted from dbcAMP were not caused by cell cycle alteration. The morphogenesis of microvilli and cell membrane changes in dbcAMP treated cells is not clear. The relation of these configurations to differentiation of malignant tumor cells is discussed.