The emergence and establishment of a clonal subline with partial duplication of chromosome 1q from a tumorigenic human chronic lymphocytic leukemic B-cell line.

Sequential analysis was performed on a tumorigenic human B-cell chronic lymphocytic leukemia cell line in which the initial population consisted of two abnormal clones, one with trisomy 12 (47%), the other with duplication of 1q; that is, 46,XY,dup(1)(q11----q32) (10%), and rest of the population had a normal karyotype. The clone with 1q+ marker expanded steadily and after 11 weeks became the only proliferating cell population in vitro and remained so till the end of an observation period of 75 weeks. All tumors recovered from nude mice that were inoculated with this newly established subline had retained the 1q+ marker. All the secondary clones also carried this aberration.