OBJECTIVETo explore the effects of TBLR1-RARα on the differentiation induction of leukemia cell line K562 cells into erythroid lineage and to investigate its related mechanisms.

METHODSTet-Off inducible system was used to construct the conditional expression vector of TBLR1-RARα fusion gene by cloning the TBLR1-RARα fragment into lentivirus vector pLVX-Tight-Puro, the expression of TBLR1-RARα fusion gene was induced by doxycycline (Dox). Then, K562 cells were transfected with lentivirus pLVX-Tight-Puro-TBLR1-RARα-flag, and the expression of fusion proteins was verified by Western blot. After treatment of K562 with all-trans retinoid acid (ATRA), real time RT-PCR was performed to test the expression of erythroid differentiation-related CD71 and α, ε, γ-globins gene. Flow cytometry was used also to analyze the expression of erythroid differentiation markers CD71 and CD235a. Benzidine staining was used to detect the production of hemoglobin in K562 cells.

RESULTSqRT-RCR showed that ATRA could increase the expression level of CD71 and α, ε, γ-globin genes when TBLR1-RARα was expressed. After treatment of ATRA, the proportion of CD71(+) cells detected by the flow cytometry also increased. Benzidine staining showed that ATRA could induce hemoglobin production in K562 cells with TBLR1-RARα fusion gene expression.

CONCLUSIONThe expression of TBLR1-RARα fusion gene contribute to ATRA-inducing differentiation of K562 cells into erythroid lineage.