Toxicicty of ruxolitinib in normal mice

Background and methods: Ruxolitinib (RUX), a Jak1/2 inhibitor, has been reported to attenuate murine bone marrow failure recently. Its potential toxocicty of anemia and thrombocytopenia in human remains a concern. We tested the toxicity of ruxolitinib on hematopoiesis in normal mice by feeding the mice with RUX chow for 3 months. Bone marrow Lin-CD117+ cells were sorted from treated or untreated mice. RNA-Seq and analysis was performed using SMART-Seq mRNA LP Kit (Takara) and the Illumina Novaseq6000, according to the Institute's protocols. Results: Ruxolitinib reduced RBC and lymphocytes, but did not affect NEU and PLT in normal mice. RNA sequencing demonstrated that HSPCs from RUX-treated and untreated mice had overlapped transcriptome distribution in multiple dimentional scalling plot, indicating overall similarity at molecular level. Conclusion: Our results demonstrate that ruxolitinib has minimal toxicity on hematopoiesis in normal mice. Overall design: We compared transcriptomes of HSPCs from the mice treated with and without ruxolitinib, and described differentially expressed genes of these cells. Lin-CD117+ cells were FACS-sorted from bone marrow of ruxolitinib-treated and untreated mice. To get enough cells for RNA extraction, Lin-CD117+ cells from every 2-3 mice in the same group were pooled together, we obtained 3 pools/group.