Acute pro-B-Cell lymphoblastic leukemia transformed from myelodysplastic syndrome with an ASXL1 missense mutation: A case report with literature review.

The development of acute lymphoblastic leukemia (ALL) from myelodysplastic syndrome (MDS) is a very rare event. The current report presents a rare case of a 33-year-old man who was diagnosed with MDS with multiple-lineage dysplasia (MDS-MLD) that transformed into pro-B-ALL. A missense mutation (S1231F) of the additional sex combs like 1, transcriptional regulator gene was identified, which may have a substantial role in the progression, however does not act as an unfavorable prognostic marker. The patient died during induction chemotherapy. The present study further conducted an analysis on 30 patients to determine progression to ALL. Patients were predominantly male (76.7%, 23/30) with a median age of 56 years (3-90 years). The median time to transformation was 5.5 months (2-50 months). The most common type of MDS with ALL transformation comprised of MDS-excess blasts (MDS-EB; 40%, 12/30), MDS with single-lineage dysplasia (MDS-SLD; 30%, 9/30) and MDS with ring sideroblasts (MDS-RS; 16.7%, 5/30). The majority of the patients transformed to B-cell (66.7%, 16/24) followed by T-cell (33.3%, 8/24) ALL. From the 25 cases where data was available, the complete remission rate was 75% (15/20) with ALL-directed chemotherapy and the median remission duration was 15 months (range 4.5 to 51 months). However, the results indicated that ALL following MDS is characterized by a high rate of early death (20%, 5/25).

[Expression of WT1 gene and its isomer ratio changes during phorbol ester induced differentiation of K562 cell line].

OBJECTIVE: To explore the changes in expression of WT1 gene and ration of its isomers during phorbol ester (TPA) induced differentiation of leukemia cell line K562 by fluorescence quantitative RT-PCR and analysis the relationship between different isomers and hematogenic cell differentiation. METHODS: The degree of cellular maturation were verified by NBT reduction test and immunophenotyping. Expression of WT1 gene was determined by fluorescence quantitative RT-PCR during differentiation of K562 cell line. The relative ratio of the four splicing variants WT1 ( + / + ), WT1 ( + / - ), WT1 ( - / + ), WT1 ( - / - ) were calculated. RESULTS: During the differentiation of K562 cell, the NBT reduction rate and the CD9 positive rate both increased significantly (P < 0. 05). The expression of WT1 gene decreased immediately to (1.67 +/- 0.45) x 10(-3) from (4.67 +/- 1.11) x 10(-3), and then increased again to (4.64 +/- 1.53) x 10(-3) at 96 hours. The ratio of WT1 ( + / + ) was decreased gradually, from 0 hour (39.65 +/- 19.46)% to 96 hour (15.25 +/- 7.27)%. While the ratio of WT1( - / - ) was increased, from 0 hour (15.38 +/- 11.34)%, to 96 hour (37.60 +/- 11.90)%. The other two isomers ratios did not change significantly. CONCLUSION: During the TPA induced differentiation of K562 cell, there are two high expression levels of WT1 gene. Before differentiation, the majority is WT1 ( + / + ), and after differentiation, is WT1 ( - / - ). It indicates that WT1 gene may activate or inhibit cell differentiation by regulating the ratio of its four splicing variants.