Characterization of two metastatic subpopulations originating from a single human colon carcinoma.

Two separate cell lines originating from distinct metastatic deposits in a patient with a primary colonic carcinoma have been established both in vivo and in vitro. One metastasis, OM-1, was found in the omentum, and the other, HOT-3, was located on the ovary. These two metastases differ in several significant characteristics, including growth kinetics and the production of carcinoembryonic antigen by the cultured cells. OM-1 xenograft tumors contain about 8-fold more colonic mucin antigen than do HOT-3 heterografts. Similarities also exist. Both cell lines contain extra chromosomes in the A group, and both are missing chromosomes in Pair 14 of the D group and in Pair 18 of the E group. Xenograft tumors from these two metastases contain equivalent amounts of carcinoembryonic antigen and nonspecific cross-reacting antigen. These metastases developed through a process of progression and natural selection that occurred during the course of the patient's disease. Thus, the cell lines established from them provide material which may be used to study functional intraneoplastic diversity.