Dexamethasone and lenalidomide have distinct functional effects on erythropoiesis. Homo sapiens

We explored the effects of dexamethasone and lenalidomide, individually and in combination, on the differentiation of primary human bone marrow progenitor cells in vitro. Both agents promote erythropoiesis, increasing the absolute number of erythroid cells produced from normal CD34+ cells and from CD34+ cells with the types of ribosome dysfunction found in DBA and del(5q) MDS. However, the drugs had distinct effects on the production of erythroid progenitor colonies; dexamethasone selectively increased the number burst-forming units-erythroid (BFU-E), while lenalidomide specifically increased colony-forming units-erythroid (CFU-E). Use of the drugs in combination demonstrates that their effects are not redundant. Overall design: Human CD34+ cells were cultured for 48 hours in the erythroid differentiation media described above with the addition of 40 ng/mL of FMS-like tyrosine kinase 3 (flt-3; Miltenyi Biotech) and 15 ng/mL of Granulocyte colony-stimulating factor (G-CSF; Amgen). Cells were cultured in the presence of the drugs of interest for 24 hours. RNA was purified using Trizol (Invitrogen). RNA was amplified and labeled by in vitro transcription and hybridized to the Affymetrix HT Human Genome U133A Array. Three replicates per condition.

本研究探讨了地塞米松（dexamethasone）与来那度胺（lenalidomide）单独给药及联合给药时，对体外培养的原代人骨髓祖细胞分化进程的影响。两类药物均可促进红细胞生成（erythropoiesis），可提升正常CD34+细胞以及携带DBA与del(5q)骨髓增生异常综合征（MDS）相关核糖体功能异常的CD34+细胞所生成的红系细胞绝对数量。然而，两类药物对红系祖细胞集落生成的作用存在显著差异：地塞米松可选择性增加爆式红系集落形成单位（burst-forming units-erythroid, BFU-E）的数量，而来那度胺则特异性提升集落形成单位-红系（colony-forming units-erythroid, CFU-E）的数量。联合给药实验证实，二者的作用并非冗余。

总体实验设计：将人类CD34+细胞置于前述红系分化培养基中培养48小时，同时添加40 ng/mL的FMS样酪氨酸激酶3（FMS-like tyrosine kinase 3, flt-3；Miltenyi Biotech）与15 ng/mL的粒细胞集落刺激因子（Granulocyte colony-stimulating factor, G-CSF；Amgen）。随后将细胞置于目标药物处理体系中培养24小时。采用Trizol试剂（Invitrogen）提取纯化总RNA；通过体外转录完成RNA的扩增与标记，随后将其与Affymetrix HT人类基因组U133A芯片进行杂交。每组实验设置3次生物学重复。