Abstract
The present paper deals with the chromosomes of a human gastric carcinoma in the ascites form, with special regard to the analysis of the number and morphology of chromosomes.
It was found that there are present in this tumor at least three populations of tumor cells which are characterized by the chromosome numbers of 42, 45 and 82-84, by particular chromosome patterns and by high frequencies of occurrence. It is highly probable that these tumor cells form at least three stem-cell lineages, the members of which serves as the primary progenitors in the growth of this tumor.
Based on the observations of 201 reliable metaphase plates, it became evident that the stemline ideograms were represented by 17M+21S+4T for the 42-cell, 21M+18S+6T for the 45-cell, and 34M+40 (or 42) S+8T for the 82-(or 84-) cell.
Evidence was obtained that the frequency of these different cell-lines varied in three samplings made at different intervals. In the first sample the 45-cell line appeared at the highest frequency, while in the second and third samples the 42-cell line showed a remarkable increase in frequency with a decrease of the 45-cell line (Table 1). Probably such a variation as above may be regarded as a result of adaptation of stem-cells to certain physiological changes of the host.
The analysis of the chromosomes has revealed that the chromosome complex of the tumor cells having 82-84 chromosomes is a duplication of that of the cells having 42 chromosomes. This sufficiently suggests that the hypotetraploid complex showing 82-84 chromosomes is induced by endoreduplication of the hypodiploid complex showing 42 chromosomes.
