ARMS-PCR combined with capillary electrophoresis can be a sensitive and quantitative method for detection of MYD88-L265P mutation in lymphoma / 中国实验血液学杂志

OBJECTIVE@#To investigate the feasibility of sensitive and quantitative detection of MYD88 gene L265P mutation in lymphoma patients by using ARMS-PCR combined with capillary electrophoresis.@*METHODS@#ARMS-PCR amplified MYD88 gene was analyzed by capillary electrophoresis in ABI 3730 sequencer; Exon 5 of the same gene was sequenced bi-directionally as reported.@*RESULTS@#The sensitivity of detection L265P mutations by the ARMS-PCR combined with capillary electrophoresis and direct sequencing was 0.2% and 5%, respectively, according to the detection of the gradient-diluted plasmid standards. The detection rate of 184 patients was 13.59% and 8.28%, respectively (p<0.001). Moreover, the former method can successfully detect the mutation ratio(R=0.979), and the repeatabilities (CV=2.86%, 1.94%, 5.49%) are acceptable.@*CONCLUSION@#ARMS-PCR combined with capillary electrophoresis can quantitatively detect the MYD88 gene L265P mutation, and the detection sensitivity is significantly higher than sanger sequencing. As a supplement to the latter, it can effectively lead to the earlier diagnose and monitoring of minimal residual disease.

Frequently ABL kinase domain G:C→A:T mutation and uracil DNA glycosylase abnormal expression in TKI-resistant acute lymphoblastic leukemia of Chinese population / 中国实验血液学杂志

Most Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph(+) ALL) patients often show rapid recurrence and development of ABL kinase domain (KD) mutation after tyrosine kinase inhibitor (TKI) treatment. To further investigate the mechanism of Ph(+) ALL fast relapse after TKI treatment, ABL KD mutation in 35 Chinese Ph(+) ALL with TKI resistance was detected by direct sequencing. The results showed that 77.1% (27/35) Ph(+) ALL patients with TKI resistance had ABL KD mutation and 55.6% (15/27) Ph(+) ALL patients with ABL KD mutation had T315I. Interestingly, 77.8% (21/27) Ph(+)ALL showed ABL mutation G: C→A:T, including T315I, E255K and E459K. Furthermore, all the Ph(+) ALL patients with two or more ABL KD mutations collaborated with complex chromosome abnormality and all the TKI-resistant Ph(+) ALL patients, whose karyotype progressed from simple t (9;22) into complex, developed ABL KD mutation. Moreover, the expression level of uracil-DNA glycosylase UNG2, which inhibits G:C→A:T transition in genomic DNA, decreased in Ph(+) ALL with TKI-resistance compared to that in newly diagnosis Ph(+) ALL. It is concluded that there is a high frequent ABL KD G:C→A:T mutation and a high genomic instability in Chinese TKI-resistant Ph(+) ALL. In addition, the decreased UNG2 expression in TKI-resistant Ph(+) ALL probably contributes to their high rate of ABL KD G:C→A:T mutation.