Karyotypic differences between primary cultures and cell lines from tumors with the human T-cell leukemia virus

Chromosome abnormalities were studied in primary cultures and in established T-cell lines from patients with human T-cell leukemia virus (HTLV)-positive leukemia or lymphoma. The present findings, and data from other laboratories, indicated that primary cultures of the HTLV-positive neoplastic cells nearly always showed a chromosomally abnormal clone, whereas most established cell lines had an apparently normal karyotype. These differences included circumstances in which the same blood specimen was used for both types of culture or in which separate specimens were obtained within a short time span. These observations indicated that many cell lines from HTLV-positive leukemia or lymphoma may be derived from nonneoplastic T-cells that were transformed in vitro by the leukemia virus; human T-cells newly infected with HTLV were suggested to have an in vitro growth advantage over the HTLV-infected tumor cells.