Cytotoxic effects of allyl trisulfide (Alt, a synthetic chemical identical with one of the main active principles of garlic), 5 FU, MMC and DDP on SGC 7901 ( a moderately differentiated human gastric adenocarcinoma cell line) and MGC 803 (a poorly differentiated human gastric mucoadenocarcinoma cell line) had been reported before. In this paper, effects of repeated two doses of each drug and the combination of two drugs on these two cell lines were studied using relative clone-survival test. The inhibitory effects of Alt, MMC alone or combined on MGC tumor in nude mice were observed. No drug resistance was found when any one of the four agents at the same concentration were repeated twice separately at 60 hour interval in vitro. The cytotoxic effect of the repeated two doses was approximately equal to that of the single dose at double concentration. The in vitro test of combinations of two drugs showed that Alt plus MMC or 5 FU plus DDP had markedly synergistic effect on MGC cells; 5 FU plus DDP had markedly synergistic effect on SGC cells. The inhibition test on the growth of MGC tumor in nude mice indicated that the inhibition rates of Alt, MMC alone or combined were 58.3%, 86.3% and 84.3%. The systemic toxic effect of MMC alone was severe, whereas Alt alone or MMC plus Alt showed mild toxicity. For this reason, Alt plus MMC is recommended for clinical trials on poorly differentiated gastric cancer. In addition, for the comparison of in vitro test dose and clinical dose of each drug, the principle of clinical adult dose range (CADR) is proposed.

This paper reports an observation on kinetics of induction and resolution of the thermotolerance expressed by Tca8113 in vitro in form of colony-forming rate, synchronization and laser flow cytometry after the cells being exposed to continuous and fractionized heat treatment of 41.5-45.5 degrees C for 4 hours. The process of thermotolerance kinetics could be divided into three phases: triggering, development and decay. The triggering phase lasted about 8 hours. The duration of development and decay phases was related to the temperature of initial heating. The higher the temperature, the shorter the duration. Generally, thermotolerance gradually disappeared 96 hours after the initial heating treatment. The thermotolerance of the synchronized cells in various phases was G1 greater than G2 greater than M greater than S. Hyperthermia simultaneously combined with pingyangmycin both produces a greater synergetic cytotoxic effect and reduces the degree of thermotolerance.

Cheek pouches of Syrian golden hamsters and transparent access chambers of BALB/C mice were implanted with SP2/0 and HeLa tumor cells separately. Observation was done by continual photo and video from D 1 through the D 10 after implantation. It was found by the development of angiogenesis and the density of microvessels that both kinds of tumor cells could induce angiogenesis. On D 2 after implantation, there appeared leakage and hemorrhage from the microvessels near the tumor cells. On D 3 and D 4, there was an increased density of new capillaries which formed a very fine, tortuous and basketlike vascular plexus of irregular diameter. Most of the new microvessels came from the venules on the edge of the implant mass and they grew toward the tumor cells to penetrate the tumor tissue on D 4 to D 5. On D 7, the density of new microvessels reached the maximum and they began to extend outside the tumor which was surrounded by dense new capillaries. Compound 36 has been proved an effective substance against some tumors in clinical applications in this country. Also proved by our experiments, a drug effective in inhibition of angiogenesis induced by SP2/0 tumor cells.