CHROMOSOMES AND CAUSATION OF HUMAN CANCER AND LEUKEMIA .46. CHROMOSOMES AND CELLULAR-ORIGIN OF CHORIOCARCINOMA

  • 1 January 1981
    • journal article
    • research article
    • Vol. 41  (8) , 3137-3143
Abstract
In order to corroborate the cell lineage between hydatidiform moles and choriocarcinoma, the chromosomal constitution and polymorphisms in the latter cells were investigated. Three choriocarcinomas from 3 women with a previous history of hydatidiform moles were examined chromosomally. Cells (213) were analyzed for their chromosome number by conventional Giemsa staining; karyotyping of 33 cells with Q- and C-banding revealed 13 kinds of structural abnormalities unequivocally identified as of clonal origin. Two cases exhibited involvement of the long arm of chromosome 1 in rearrangements. Complete homozygosity and exclusive inheritance of a paternal genome would be expected if the tumor arose from a preceding molar pregnancy. However, the heterozygosity observed in choriocarcinoma cells suggests no common cellular lineage with complete moles; the latter originate through fertilization of an empty egg by a haploid sperm, followed by duplication of the chromosomes. Several possibilities have to be considered for the origin of choriocarcinomas, since it seems unlikely that alterations in the paracentric areas of the marker chromosomes occurred during tumor development. Moles which are characterized by heterozygosity may transform into choriocarcinomas. Alternatively, such tumors may originate from trophoblasts of the conceptuses rather than from moles.