Phenotypic instability of tumor cell clones: clonal expression of Fc receptors in the human leukemic K562 cell line and its relationship with hemoglobin expression.

Abstract

Membrane expression of Fc receptors (FcR) was studied in clones of human K562 cells during short- and long-term culture. Using a manual cloning method, well-defined clones were generated either from FcR-positive or FcR-negative cells. The fourth day after cloning, the majority of cloned cells manifested shifts in FcR expression without evidence of an orderly pattern. After long-term culture (about 34 passages), most clones expressed FcR values close to those found in the cell line. In addition, the selection of six clones expressing a stable FcR phenotype suggested that the presence of FcR is correlated to a low hemoglobinization of the multipotential K562 cells.