Tumorigenicity of chromosomally abnormal human cultured cells in two xenogenic organ culture assays.

Organ cultures of chick and rabbit embryonic skin were used to assess the tumorigenicity of cultured human cell lines. Cell lines were from patients with (1) specific chromosomal abnormalities and an increased risk of cancer (Down's syndrome, Klinefelter's syndrome, Partial D Trisomy, Bloom's syndrome, Franconi's anemia, ataxia telangiectasia and xeroderma pigmentosum); (2) a specific chromosomal abnormality but no increased risk for cancer (Cri du chat), and (3) a biochemical defect (galactosemia). In addition, tumor cell lines and cell lines of normal origin were used as positive and negative standards. Mitotic ability was quantified by dividing the total number of mitoses in the cell inoculum seen in histologic sections by the number of sections examined to give a computed mean number of mitoses per section (MMS). Neoplastic cell lines showed MMS values greater than 1.0 while cell lines of normal origin were less than 0.25. The cell lines derived from patients with chromosomal abnormalities and the patient with a biochemical defect, whether the individuals were at an increased risk for cancer or not, gave the same range of MMS values as obtained for cells of normal origin. These results that chromosomal aberrations per se do not enhance the cell's capability for proliferation on a xenogenic substrate.