IgG-secretion was induced in a human B blastoid cell line, CESS, by the addition of partially purified T cell-derived helper factor(s) (TRF), which had been obtained from PHA-stimulated human T cells. The number of IgG-producing cells in CESS cells reached its maximal level (10% of total cells) within 48 hr after the addition of TRF. TRF did not affect the proliferation of CESS cells and the block of cell proliferation with hydroxyurea did not inhibit the increase of IgG-producing cells, showing that TRF induced IgG-production in CESS cells without any requirement of cell division. TRF activity was completely removed by CESS cells but TCGF-activity in the same preparation was not absorbed with CESS cells. On the other hand, TCGF-dependent human killer cells absorbed TCGF activity but not TRF activity in the same preparation. The binding of 125I-labeled factor(s) on CESS cells was also demonstrated. These results showed the presence of acceptors for TRF on the surface of CESS cells and this cell line will provide useful means for the chemical characterization of acceptors and for the study of the mechanisms of the signal transmission through acceptors.

Absorption↗

PubMed1981

[Application of flow cytometric analysis to brain tumor chemotherapy. Report 1: Changes of cell kinetics induced by anticancer drugs (author's transl)].

It has been reported that flow cytometric analysis offers good indicators to select drugs for chemotherapy of malignant neoplasms, however, there are still few reports to try to apply these data to clinical treatment. For this purpose perturbation of cell cycle traverse which induced by several anticancer drugs was studied to determined the fundamental factors to indicate the sensitivity of each drugs. Results were: 1) Drugs showed high efficiency of accumulation of cells in SG2M phase even in low concentration; MMC, AD, CQ. 2) Drugs showed high efficiency of accumulation of cells in SG2M from low concentration high concentration; Vincristine. 3) Drugs which showed accumulation of SG2M in high concentration; ACNU, BCNU. 9L rat glioma cells treated with BCNU showed high efficiency of accumulation of cells in SG2M phase. In this cell line cytocidal effect was high. However, C6 cells which showed low accumulation in SG2M even by treatment with high concentration of BCNU revealed quite resistant to anticancer drugs from nitrosourea derivatives (ACNU, BCNU). Cytocidal effect of MMC and ACNU on C6 glioma cells was studied by colony forming efficiency assay using multicell spheroids treated with these drugs and it was discussed the correlation between percent of accumulated cells and cytocidal effect of each drug.

Animals↗

PubMed1981