Surgical tumor specimens from 67 urological malignancy patients were subjected to a human tumor clonogenic assay (HTCA) developed by Hamberger and Salmon. Appreciable growth of colonies was obtained in 20 of the 33 renal cancers, 20 of the 30 urothelial cancers and 1 of the 4 testicular cancers examined. Using HTCA, a plating efficiency ranging from 0.01 to 0.5% was obtained in these urologic malignancies. However, colonial growth adequate for chemosensitivity was obtained in 30 of these 67 patients. According to Von Hoff's definition, more than a 70% decrease in the plating efficiency after anticancer drug exposure was defined as susceptible. Susceptibility to vinblastine (VBL) was seen in 4 of the 11 patients with renal cancer. Susceptibility to cis-dichlorodiamine platinum (CDDP) was seen in 4 of the 15 patients with urothelial cancer, 1 of the 4 patients with renal cancer, and that to adriamycin (ADM) was seen in 3 of the 15 patients with urothelial cancer, 2 of the 10 patients with renal cancer and 1 patient with testicular cancer. For comparison, the ratio of IC90 to the peak plasma concentration of the drug tested was used as the "in vivo-in vitro therapeutic index (TI)". According to TI, susceptibility to VBL was seen in 3 of the 7 patients with renal cancer, and that to CDDP was seen in 2 of the 12 patients with urothelial cancer, and 1 of the 2 patients with renal cancer. Susceptibility to ADM was seen in 3 of the 15 patients with urothelial cancer, and 1 of the 6 patients with renal cancer.(ABSTRACT TRUNCATED AT 250 WORDS)

We carried out fundamental subrenal capsule assay methodology, using tumor specimens of human cancer xenografts (breast cancer and colon cancer) serially transplanted into nude mice. With regard to sequential changes in the tumor grafts implanted under the renal space of immunocompetent mice, tumor size was largest macroscopically around day 6 after inoculation, and later involuted gradually. Histological findings showed that implanted tumor tissues were preserved to a moderate extent until day 4 after inoculation, but leukocyte infiltration by host reaction had begun by day 4, and tumor tissues were almost replaced by host reactive tissues on day 6. Labeling index scoring did not indicate growth of implanted tumor cells. We found that macroscopic tumor size was largest around day 6 because we measured tumor size with involved leukocyte infiltration, and the macroscopic tumor did not represent the true extent of the tumor tissue.

A study on the effect of anti-tumor agents combined with caffeine on sarcoma cells was carried out by clonogenic assay. The materials used were an established line of human osteosarcoma cells (OST strain) and twelve surgically resected or biopsied specimens. Caffeine showed a marked synergistic effect on sarcoma cells with the DNA-damaging agents, ADR, CDDP, CPM and MMC in terms of colony inhibition. In particular, 0.2 micrograms/ml CDDP with 2 mM caffeine showed a considerable synergistic effect on human sarcoma cells. Among the 12 cases, more than 50% colony inhibition was observed in 7 cases which were treated with this combination of CDDP with caffeine. Furthermore, a combination of 0.02 micrograms/ml CDDP (1/100 of peak plasma concentration) with 2 mM caffeine also showed more than 50% colony inhibition. Therefore, we assumed that caffeine was able to reduce the necessary dose of anti-tumor agent in some way. We stress that caffeine seems to be a very useful synergistic drug for causing lethality in sarcoma cells in combination with various DNA-damaging agents which are not effective on sarcoma cells.

Cultured murine erythroleukemia (MEL) cells can be induced to differentiate into erythrocytes. During this induced differentiation, a certain type of sequentially programmed gene expression and repression appears to occur in addition to the induction of globin mRNA. This system provides a commitment model for erythrodifferentiation and decancerization. By transfection of a beta-globin/TK chimeric gene into a B8/3 cell line, we examined the regulatory factors controlling beta-globin gene expression. Our results suggested that the timing of the appearance of inducible, positive trans-acting factor (s) and activation of chromatin conformation occur during induction. We demonstrated that a novel MEL cell line, TSA 8, could be induced to be committed to CFU-E, an erythropoietin-mediated progenitor cell, with the addition of DMSO. In the commitment process, we observed an asymmetric cell division, which could explain the self-renewal and the commitment of multipotential hemopoietic stem cells. For this commitment, the receptor for erythropoietin is required, but is insufficient and the other factor (s) are induced in the earlier phase of induction. Finally, we found that erythropoietin induced two signals for proliferation and differentiation of the progenitor cells and that these two signals are not coupled.

Human tumor clonogenic assay(HTCA) not only offers potential advantages for prediction of the sensitivity of individual patients, to anticancer drugs, but also for the development and preclinical testing of prospective new antineoplastic agents. However, HTCA has several theoretical and technical problems, such as a low success rate, the requirement of large numbers of tumor cells and the long time period necessary for evaluation. In order to solve these problems, the MINI-hybrid assay has been developed. We reviewed our experiences to date with chemosensitivity testing by MINI-hybrid assay. Twenty-two of 23 tumors gave evaluable chemosensitivity results (95.6%), and the range of thymidine incorporation for evaluable assays was 7 X 10(2)-1.2 X 10(5)cpm. In addition, the results of drug sensitivity testing of cultured cell lines by MINI-hybrid assay were well correlated with those obtained by HTCA. With its high evaluability rates, the need for fewer cells, the short duration (5 days) required and ease of quantitation, the MINI-hybrid assay is widely applicable to the chemosensitivity testing of human tumors.

The influences of T cell subsets on erythropoiesis were studied in ten SLE patients with anemia of unknown etiology. In these SLE patients CFU-E growth from bone marrow mononuclear cells was significantly decreased compared with normal controls. However, an increase in CFU-E growth was resulted by the depletion of T cells or cytotoxic/suppressor T cells from bone marrow mononuclear cells with treatment of OKT3 or OKT8 monoclonal antibody in three out of the ten patients. Autologous peripheral blood mononuclear cells inhibited CFU-E growth by co-culture methods in three out of the ten patients. The inhibition of CFU-E growth was diminished by the depletion of OKT8+ T cells from peripheral blood mononuclear cells in one out of the three patients. After the corticosteroid therapy, in two patients, the suppression of CFU-E growth by peripheral blood mononuclear cells was significantly reduced in accord with recovery of anemia. It is assumed that T cells with inhibitory action to CFU-E growth belonging to OKT8+ subsets are present in some SLE patients with anemia and may play a pathogenetic role in the development of anemia.