| Objective To investigate the expression of the FLT3 Length Mutations in patients with acute myeloid leukemia(AML), the clinical features of the patients with mutations and the co-expression of FLT3-LM and Multidrug Resistance gene 1(MDR1).Method In addition to the routinely examination of cytogenetics and immunophenotypes, analysis of FLT3-LM and MDR1 gene was performed on bone marrow samples from 54 patients with de novo or relapsed AML by RT-PCR. All PCR products were run by both polyacrylamide gel electrophoresis (PAGE) and agarose gel electrophoresis. Some aberrant PCR products were cloned and then confirmed by sequence analysis.Result The FLT3-LMs, all of which are herterozygous, were present in 9.43% of the patients. The distribution of FLT3-LMs was each one in M1, M3, M5 and two in M4. Although they were irrelevant with sex, age and particular immunophenotypes, the mutations were predominant in patients with normal cytogenetics and associated closely with leukocytosis and a high percentage of bone marrow blast cells. Moreover, the patients with FLT3-LM had a tendency of a low remission rate and low survival rate, which is not relevant with the expression of MDR1.Conclusion FLT3-LM is a frequent mutation in AML. The patients with this mutation had a similar clinical performance and prognosis, which manifests that FLT3-LM is a molecular potentially useful for the stratification of diagnosis and prognosis of AML,especially for those with normal cytogenetics. And it is speculated that the common MDR modulators are useless for the patients with FLT3-LM . |
