ESTABLISHMENT OF A HUMAN RECTAL CANCER CELL LINE PRODUCING CARCINOEMBRYONIC ANTIGEN

: A permanent cell line (S-7512) was established by cell culture from the subcutaneous metastatic tumor of a human rectal cancer and has been maintained for 18 months. Cultured cells grew as isolated and piled-up colonies of epithelial cells, each with a scanty cytoplasm and a large nucleus containing several nucleoli. The average doubling time of this cell line was 57 hr and plating efficiency was 30.1 approximately 45.2% in a liquid medium. The modal chromosome number was 115 but a marker chromosome was not evident. Electron microscopic examination revealed many microvilli, free ribosomes, and abundant glycogen granules. Heterotransplantation of the cultured cells produced a large tumor and its microscopic examination showed the same histological appearance as the original tumor (carcinoma simplex). Carcinoembryonic antigen level of the spent medium of the confluent culture was 235.50 ng/3.2 X 10(6) cells.