AUTHOR=Dai Hai-Ping , Yin Jia , Li Zheng , Yang Chun-Xiao , Cao Tin , Chen Ping , Zong Yun-Hui , Zhu Ming-Qing , Zhu Xia-Ming , Xiao Sheng , Wu De-Pei , Tang Xiao-Wen 

TITLE=Rapid Molecular Response to Dasatinib in a Pediatric Relapsed Acute Lymphoblastic Leukemia With NCOR1-LYN Fusion

JOURNAL=Frontiers in Oncology

VOLUME=10

YEAR=2020

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2020.00359

DOI=10.3389/fonc.2020.00359

ISSN=2234-943X

ABSTRACT=<p><bold>Background:</bold> Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL) is associated with high rates of treatment failure and poor outcome. Activation of ABL/Src family kinases is found in ~10% of Ph-like ALL, which can be therapeutically targeted by tyrosine kinase inhibitors. LYN is a member of the ABL/Src-tyrosine kinase family. Somatic <italic>LYN</italic> rearrangements are found in 5 cases of hematopoietic malignancies so far, although none of them were treated with tyrosine kinase inhibitors.</p><p><bold>Case presentation:</bold> A 6-year-old boy with relapsed B-ALL had no response to reinduction chemotherapy. He was then treated with the <italic>ABL1</italic> tyrosine kinase inhibitor dasatinib and achieved complete remission within 2 weeks. Haploidentical allogenic stem cell transplantation (allo-HSCT) was subsequently performed and maintenance therapy with dasatinib initiated 8 weeks post-transplantation. He has been in minimal residual disease negative remission for 10 months after allo-HSCT.</p><p><bold>Result:</bold> His bone marrow karyotype showed a balanced translocation between chromosomes 8 and 17, leading to a <italic>NCOR1-LYN</italic> fusion gene confirmed with sequencing.</p><p><bold>Conclusion:</bold> Although <italic>LYN</italic> overexpression is described in many AML and B-ALL patients, intragenic <italic>LYN</italic> rearrangement is a rare event. For the first time, we present evidence that dasatinib is effective in treating a pediatric B-ALL with <italic>NCOR-LYN</italic> fusion.</p>