Abstract
A series of experiments were designed in order to estimate the validity of cultivation methods for evaluating the effectiveness of anti-cancer drugs aginst human malignant tumor diseases involving the leukemias.
In this experiment, Yoshi da Sarcoma (YS) cells inoculated on the chorio-allantoic membrane (CAM) were examined for cultivation influence, especially as to growth rate by using the radio-autographic method.
Results:
1) Macr oscopical tumors were obtained in all cases when 7.5x 105 or more cells had been inoculated in each 10 days old egg. The mean weight of the tumors was 1224.5±269.3mg.
2) Up to the third generation of the serial passage, no remarkable differences were recognized in tumor histology, growth rate, reaction to anti-cancer drugs, or the rate of successful reinoculation to rats; but after the fifth generation, the reinoculation rate was slightly depressed.
3) The labeling index by tritium thymidine (3H-TdR) of YS cells cultivated 48 hours on the CAM of the embryonated chicken eggs was 45.0%, which was similar to that of YS cells cultivated in the peritoneal cavity of rats.
4) The average silver grain number of YS cells labeled with 3H-TdR after cultivation on the CAM of embryonated eggs decreased in 48 hours at almost the same rate as that of YS cells cultivated in the peritoneal cavity of rats.
5) In conclusion: Since the properties of tumor cells cultivated on the CAM hardly undergo any change for at least three generations, the worth of in ovo cultivation merits recognition in the evaluation of anti-cancer drugs.
