Yoshihiro Nosoh

The indications of chemosensitivity tests against various anticancer agents

In order to determine the indications of chemosensitivity tests against various anticancer agents, clinical trials of 4 different assays, namely; nude mouse isotope assay (NMIA), subrenal capsule assay (SRCA), human tumor clonogenic assay (HTCA) and adenosine triphosphate inhibition assay (ATPA), were performed on 391 patients. Analysis of the correlation between assay results and clinical effects presented the possibility of determining the indications as follows; (1) The positive clinical respons of mitomycin C (MMC) should be predicted by ATPA; (2) The clinical tumor resistance against MMC should be predicted by SRCA; (3) Concerning 5-fluorouracil (5-FU) the chemosensitivity test (ATPA) should only be used for the detection of tumor resistance in the assay; (4) The poor results of this study indicated the difficulty of correctly estimating the effects of cyclophosphamide (CPM); (5) The perfect prediction of clinical effects in this trial indicated that cis-DDPlatinum (CDDP) should be estimated by SRCA; (6) The positive clinical tumor response against adriamycin (ADM) should be predicted by SRCA, while the negative one should be predicted by HTCA; and (7) ATPA showed good potential for estimatating not only time dependent drugs such as 5-FU, but also cytotoxic drugs.

Antitumor effects of recombinant human tumor necrosis factor against human tumor xenografts transplanted into nude mice

Antitumor activities of recombinant human tumor necrosis factor (rH-TNF) against human tumor xenografts in nude mice were studied. Thirteen human tumor xenografts serially transplanted into nude mice were used for experiments; five gastric, two breast, two gallbladder, one colon and one esophageal carcinoma, one liposarcoma and one squamous carcinoma of the neck. They were inoculated into the subcutaneous tissue of BALB/c nu/nu nude mice and the treatment was started when the estimated tumor weight reached 100–300 mg. rH-TNF was administered intratumorally at schedule of qd×5 or q3d×5. rH-TNF showed a marked antitumor activity against various human tumors. The hemorrhagic necrosis was observed in all types of the human tumor xenografts (100 per cent), and the complete regression of the tumor was noted in 4 of 11 tumors (36.4 per cent). On the contray, intraperitoneal rH-TNF exhibited little antitumor effect. The additive effect in the combination of TNF and Mitomycin C was observed against two Mitomycin C resistant gastric tumors.

In vitro chemosensitivity tests on human tumor xenografts by clonogenic assay: the combined use of mitomycin C with α-interferon or γ-interferon

Using the human tumor clonogenic assay technique, the effects of Mitomycin C plus either α-interferon or γ-interferon were studied against five human tumor xenografts serially transplanted into nude mice (three gastric and two colon cancers). When the survival fraction found with the drug combination was smaller than the multiplication of survival fractions with either drug alone, the combined effect was defined as synergism. Similarly, antagonistic effect was defined when the survival fraction of drug combination was larger than the larger one observed in either interferon or Mitomycin C alone. Four out of five human tumor xenografts (three gastric and one colon cancers) showed synergistic effects in combination of α-interferon with Mitomycin C. Though two gastric cancer xenografts exhibited synergistic effects in combination of γ-interferon with Mitomycin C, antagonistic effects, which was not found in combination of α-interferon with Mitomycin C, were observed in one gastric cancer and one colon cancer xenografts.

One-stage ante-thoracic reconstruction of the thoracic oesophagus using myocutaneous flaps

An ante-thoracic reconstruction of the thoracic oesophagus was performed by fashioning a skin tube from a skin flap supplied by perforators from the internal mammary vessels. This neo-oesophagus was covered with a trapezius myocutaneous flap and a rectus abdominis myocutaneous flap, in a one stage operation.

Comparative study on nude mice isotope assay (NM-IA) and subrenal capsule assay (SRCA) sensitivity tests of anticancer agents

A comparative study on nude mice isotope assay (NM-IA) and subrenal capsule assay (SRCA) was done to evaluate the usefulness ofin vivo assays for predicting individual tumor sensitivity against anticancer agents. Sixty-one fresh tumor specimens collected at surgery, under sterile conditions, were examined. Mitomycin C (MMC), 5-fluorouracil (5-FU), cyclophosphamide (CPM), adriamycin (ADM) and cis-DDPlatinum (CDDP) were used in both assays. In NM-IA, the tumor sensitivity was determined by the amount of3H-thymidine incorporated into the tumor which had been implanted into subcutaneous spaces of BALB/c nude mice. In the SRCA, the relative increase in weight of the tumor implanted into the subrenal capsular space of ddY mice was determined and measurements made to evaluate the chemosensitivity. Evaluability rates of the trials were 86.9 per cent with both assays and the response rates were 35.8 per cent in NM-IA and 34.0 per cent in SRCA, respectively. Against MMC, 5-FU, CPM, ADM and CDDP, overall consistency rates between the two assays were 77.8 per cent, 88.6 per cent, 72.7 per cent, 81.8 per cent and 68.2 per cent, respectively. In 8 of these 53 evaluated assays, correlations between the results of assays and clinical effects were examined and overall predictive accuracy rates were 87.5 per cent with both assays. Significant differences between these twoin vivo chemosensitivity tests were not evident.

Sensitivity of anticancer agents on human gastric cancers transplanted into nude mice

In the chemotherapy for gastric cancer, the most sensitive anticancer agent against individual tumors should be prescribed. The establishment of a sensitivity test using nude mice as anin vivo model is urgently awaited by clinicians and researchers alike. Seventy-three tumors derived from human gastric cancer were transplanted subcutaneously into nude mice and these mice were then treated intraperitoneally with anticancer agents. Mitomycin C (MMC), 5-fluorouracil (5-FU) and cyclophosphamide (CPM) were used. The doses given were 3 mg/kg of MMC, 75 mg/kg of 5-FU and 200 mg/kg of CPM. In 52 of the 73 cancers, chemosensitivity was evaluated by the microscopic changes in the tumors. The rate of positive sensitivity against gastric cancer was 44.2% in MMC, 34.6% in 5-FU and 30.8% in CPM, respectively. The sensitivity of each agent tested by this method indicated a good correlation with the clinical therapeutic effects. Our results suggest the feasibility of evaluation of the sensitivity of various agents from the microscopic changes on tumors transplanted into nude mice.

Experimental studies on the combined effects of alpha and gamma interferons against human tumor xenografts transplanted into nude mice

The antitumor activities, resulting from the combined treatment of leukocyte interferon (IFN-α), with recombinant human immune interferon (IFN-γ), against human tumor xenografts in nude mice, were studied. Nine human tumor xenografts, (7 from gastric carcinoma, 1 from gallbladder carcinoma and 1 from breast carcinoma), were serially transplanted into nude mice for the purpose of this experiment. Each human tumor xenograft was inoculated subcutaneously into BALB/c nu/nu nude mice and treatment was started after the estimated tumor had reached 100–300 mg. IFN was administered intramuscularly at a schedule of qd×14. Treatment with either IFN-α or IFN-γ alone, did not produce any antitumor effect against the various human tumor xenografts, however the combination of IFN-α with IFN-γ resulted in achieving significant antitumor effects against the various human tumors. Inhibition of tumor growth was observed in 7 of the 9 tumors (77.8 per cent), and regression of the tumor was noted in 5 of the 9 tumors (55.6 per cent).

Antitumor activities of KW-2152, a new isoquinon agent, against human tumor xenografts transplanted into nude mice

The antitumor activities of KW-2152, a new isoquinon derivative, were examined in thirteen human tumor xenografts, transplanted into nude mice. KW-2152 was administered intravenously at a schedule of q4d×3, in daily doses of 7.3 mg/kg and 3.6 mg/kg, and q2d×6 with a daily dosis of 7.3 mg/kg, respectively. KW-2152 displayed significant antitumor activities against the human tumor xenografts in 3 out of 13 strains (23.1 per cent) at the schedule of q4d×3, with a daily dose of 7.3 mg/kg. Depending on the schedule of administration, tumor activity was observed in 8 out of 13 strains (61.5 per cent) at a schedule of q2d×6, with a daily dose of 7.3 mg/kg. SH-2 and SH-9 gastric tumors were sensitive to KW-2152 and growth was completely inhibited with the schedule of q4d×3, and a daily dose of 7.3 mg/kg. Thus, KW-2152 seems to have a wide antitumor spectrum, and the possible antitumor effects for clinical use, warrant attention.

Effects of oxygen tension on tumor colony formations assessed by human tumor clonogenic assay.

To clarify the effects of oxygen tension on colony formation of fresh human tumor cells we examined 25 fresh human tumor samples (sixteen gastric cancers, three colon cancers three breast cancers, one esophageal cancer, one leiomyosarcoma and one malignant lymphoma), using the human tumor clonogenic assay (HTCA) technique. Three different oxygen tensions (2 per cent, 5 per cent, 20 per cent) were tested. At 5 per cent O2, which is considered to be physiological oxygen tension, 19 out of 26 tumors (13/16 in gastric cancer, 2/3 in colon cancer, 1/3 in breast cancer, 1/1 in esophageal cancer, and 1/1 in leiomyosarcoma) showed significant increases of plating efficiencies as compared to those at 20 per cent O2. On the other hand, decreases in plating efficiencies were observed at 2 per cent O2 in seven out of 12 tumors as compared to 20 per cent O2 and eight out of 12 tumors, as compared to 5 per cent O2.

The antiproliferative effects of fluoropyrimidine derivatives against human tumor xenografts in a subrenal capsule assay.

The antiproliferative effects of the fluoropyrimidine derivatives, 5-fluorouracil (5-FU), 1-(2-tetrahydrofuryl)-5-fluorouracil (Tegafur), UFT, 1-hexylcarbamoyl-5-fluorouracil (HCFU), and 5′-deoxy-5-fluorouracil (5′DFUR), were investigated in a 4 day subrenal capsule assay. The antiproliferative effects against two human tumor xenografts established in athymic mice were examined after treatment with three different doses of each anticancer agent, and the adequate dose of each anticancer agent in this experimental system was estimated as: 473 mg/kg for Tegafur, 433 mg/kg for UFT, 50 mg/kg for HCFU and 185 mg/kg for 5′DFUR, respectively. A comparative study of the antiproliferative effects of fluoropyrimidine derivatives was carried out against 7 xenografts. According to our criteria of positive tumor response, the effective rates were: 1 of 7 (14.3 per cent) by 5-FU, 2 of 7 (28.6 per cent) by Tegafur, 2 of 7 (28.6 per cent) by UFT, 1 of 6 (16.7 per cent) by HCFU, and 1 of 4 (25.0 per cent) by 5′DFUR, respectively. Although no statistical differences were demonstrated between the agents, the utility of a chemosensitivity test before clinical use was suggested.