It is now well established that the type la of serine/threonine protein phosphatases (PP1α) may be implicated in malignant phenotype. Although the PP1α mRNA level increased in livers at preneoplastic stages of hepatocarinogenesis and all of examined rat ascites hepatomas, unexpectedly, dramatically decreased in some of primary hepatomas. In order to elucidate the low level of PP1α mRNA in some ...

RNA taken up into the cells. The 4 types of RNA used included whole cellular 4 5, 18 5, and 28 S RNA from NHAC and the very GC-rich B3 fragment enzymatically cleaved from 28 S RNA of NHAC (1 7, 37, 37). The B3 fragment, composed of approximately 550 nucleotides, was chosen because it is highly hydrogen bonded and is less susceptible to degradation by RNase. The present results show that the cel...

The effects of inhibitors of polyamine synthesis on the invasive capacity of rat ascites hepatoma (LC-AH) cells were examined by in vitro assay of penetration of the LC-AH cells through a monolayer of calf pulmonary arterial endothelial (CPAE) cells. Pretreatment of LC-AH cells with alpha-difluoromethylornithine (DFMO), an inhibitor of ornithine decarboxylase, before seeding them onto a CPAE ce...

Cells from methylcholanthrene-induced tumor (MC-tumor), Ehrlich ascites cancer or mouse ascites hepatoma (MH-134) were subcutaneously implanted in dorsal area of mice to examine the specific cell mediated immunity following implantation. The migration index (MI) of lymphocytes was determined at various time periods after cell transplantation. The MI-activity increased under all three implantati...

A fine structural analysis of ascites tumor cells in the original sensitive strain and in the subline resistant to antitumor agents was performed with the Yoshida ascites sarcoma; its subline resistant to methylbis03-chloroethyl)amine N-oxide (MBAO); ascites hepatoma AH 13; and its sublines resistant to MBAO, mitomycin C, and 6mercaptopurine (6-MP), respectively. In the sublines resistant to MB...

In vitro and in vivo invasive capacities of rat ascites hepatoma cells (AH 130) that had been cultured on the feeder layers of rat macrophages were examined. The in vitro invasive capacity of the tumor cells was measured by their ability to form tumor cell colonies underneath cultured mesothelial cell monolayers; in vivo invasive capacity was examined by the implantation of the tumor cells into...