A report on Lineage switch at relapse of CD19 CAR-T therapy for Philadelphia chromosome-positive B-precursor acute lymphoblastic leukemia

To the Editor:This study reported that a case of Philadelphia chromosome-positive B-acute lymphoblastic leukemia(Ph+B-ALL)underwent a lineage switch to acute myeloid leukemia(AML)following CD19 chimeric antigen receptor(CAR)-modified T(CAR-T)cells therapy.The study was reviewed and approved by the ethics committee of the first affiliated hospital of Nanjing Medical Universit(No.2020-QT-06).A 46-year-old woman with a 1-month history of chest painwas admitted to our hospital on January 24,2014.The results of her laboratory examinations were as follows:(i)White blood cell count 12.01109/L;hemoglobin 92 g/L;platelet count 47109/L;(ii)Bone marrow(BM)smears showed a massive infiltrate(95.2%)of blast cells;(iii)Immunophenotypic analysis by flow cytometry(FCM)revealed that blast cells accounted for 66.3%,which were positive for CD34,CD10,CD19,CD20,CD22,CD38,and human leukocyte antigen DR;(iv)Karyotype analysis showed no mitotic phase;(v)Fluorescence in situ hybridization demonstrated a positive Philadelphia chromosome(BCR-ABL fusion gene);(vi)BM quantitative real-time polymerase chain reaction(qRT-PCR)detected a positive BCR-ABL p190 transcript(BCR-ABL,184.1%).She was thus diagnosed with Ph+B-ALL.

CRISPR-based screening identifies XPO7 as a positive regulatorof senescence

Dear Editor,Cells enter senescence,or irreversible growth arrest,when exposed to stressors such as DNA damage,epigenetic alterations and chronic inflammation(Zhao and Chen,2022).In aging and aging-related diseases,senescent cells are known to accumulate across tissues and organs(Sun et al.,2022;Lopez-Otin et al.,2023).