GFP Reporter Cell Line - K562

The researchers used the K562 cell line to study erythroid biology and genetic strategies for erythroid diseases because of its good in vitro erythroid differentiation capacity. Existing methods were insufficient for analyzing globin proteins, so they improved the erythroid differentiation method of K562 cells. In the study, K562 cells were exposed to various agents, such as heme, rapamycin, imatinib, and demethylating agents, and cultured in basal medium or erythropoietin medium. Erythroid differentiation induced by a single agent only showed high glycoprotein A (GPA) expression, but was insufficient to detect globin proteins. The researchers evaluated multiple combinations of agents and developed a method that pretreated with imatinib and then cultured in an erythropoietin medium containing rapamycin and demethylating agents. This method achieved efficient erythroid differentiation, with high levels of GPA expression (>90%) and globin proteins detectable by both hemoglobin electrophoresis and high-performance liquid chromatography. In addition, adult hemoglobin was detectable after β-globin gene transfer. In summary, this study developed an in vitro K562 erythroid differentiation model with high-level globin production, providing a practical evaluation tool for hemoglobin production in human erythroid cells.

Figure 1. The researchers genetically modified K562 cells to express β-globin or GFP genes via lentiviral vectors. After pretreatment with imatinib, these genetically modified K562 cells were subjected to erythroid differentiation under HEMA-based differentiation conditions combined with rapamycin and decitabine. The results showed that the optimized differentiation protocol resulted in high levels of embryonic globin production in K562 cell-derived erythroid cells, allowing the researchers to assess globin protein levels in genetically modified differentiated cells. (Uchida N, et al., 2017)