Upon cultivation of various human ovarian cancer, a successful establish ment was made on a long term continuous culture of the papillary serous cystadenocarcinoma. This new cell line was named human ovarian cancer twenty-one (HOC-21).
The material obtained from an ovarian cancer on the left side of a 56 year-old woman, was placed into culture on September 22, 1971. A favorable growth has been recognized from the time of culture till now, for a period of 2 years and 4 months, and presents no signs of declining. Doubling time was 28 hours at the 26th generation.
The cultured cells were commonly polygonal and epithelial in shape and the nuclei revealed pleomorphism and proved clearly to be atypical under exfoliative cytology. A jigsaw puzzle like cellular arrangement, wheeled pat tern and piling-up tendency in the growing process were characteristics of the cells. And sometimes a vesicle formation was shown.
The PAS staining in the cultured cell was negative; alkaline phosphatase was negative and acid phosphatase positive.
Chromosomes, manifesting near-diploid, possessed a large telocentric marker chromosome.
When HOC-21 was transplanted into a hamster cheek pouch, it demon strated a definite tumor formation whose histologic picture revealed papillary adenocarcinoma. The original characteristics of ovarian adenocarcinoma have been precisely maintained in vitro culture system.