Expression Of Flt3 In Elderly Acute Myeloid Leukemia

Object:We investigated FLT3 expression level in elderly AML,to evaluate the role of FLT3 in elderly AML and its clinical significance.Methods:We use the semi-quantitative RT-PCR method to investigate FLT3 expression level of 70 samples from marrow aspiration of AML patients.There were 36 samples form elderly AML,include 12 from patients with de novo AML,8 from the patients of complete remission,16 from the patients of the refractory or relapse AML.There were 34 samples from the non-elderly AML,include 19 from patients with de novo AML,7 from the patients of complete remission,8 from the patients of the refractory or relapse AML.We set the normal control group of 11 samples from the patients of benign hemopoietic disease.Results:1.The expression level of FLT3 in 70 samples of AML was 11.8331±0.58104.The expression level of FLT3 in 11 samples of benign hemopoietic disease was 0.1207±0.08552.The expression level of FLT3 was significantly higher in AML patients than in patients of benign hemopoietic disease (p＜0.001).2.The expression level of FLT3 in 36 samples of elderly AML was 12.5692±10.33685.The expression level of FLT3 in 34 samples of non-elderly AML was 11.0537±10.93397.There was no difference between the expression of FLT3 in elderly AML and non-elderly AML(p=0.982).3.We study the expression of FLT3 in elderly AML.The expression level of FLT3 in 12 samples of de novo AML was 11.0518±7.08187.The expression level of FLT3 in 8 samples from the patient of complete remission was 3.0415±1.65646.The expression level of FLT3 in 16 samples from the patient of the refractory or relapse was 18.4710±11.12873. Among three group,the expression level of the refractory or relapse AML was the highest,de novo AML was in the middle and the complete remission AML was the lowest.The difference of FLT3 expression level between three group had statistic significant(p＜0.05).4.We study the expression of FLT3 in non-elderly AML.The expression level of FLT3 in 19 samples of de novo AML was 10.1012±7.12898.The expression level of FLT3 in 7 samples from the patient of complete remission was 1.4527±1.15455. The expression level of FLT3 in 8 samples from the patient of the refractory or relapse was 21.7170±14.39378.Among three group,the expression level of the refractory or relapse AML was the highest,de novo AML was in the middle and the complete remission AML was the lowest.The difference of FLT3 expression level between three group had statistic significant(p＜0.05).5.We study the expression of FLT3 in each of the FAB subtype which was de novo AML.The expression level of FLT3 in 8 samples of M2 was 8.7402±4.26726.The expression level of FLT3 in 6 samples of M3 was 2.2518±0.78154.The expression level of FLT3 in 3 samples of M4 was 12.5073±7.28459.The expression level of FLT3 in 8 samples of M5 was 18.4751±5.40870.The expression level of FLT3 in 4 samples of M6 was 10.1182±1.67600.By the scale of p＜0.05,the M3 was obviously lower than other subtype;the M5 was obviously higher than other subtype and there was no significant difference between M2,M4 and M6(p=0.662).Conclusion:The over expression of FLT3 may play an important role in leukemogenesis.There was no significant difference between the expression of FLT3 of elderly AML and non-elderly AML.The inhibitor specific to the FLT3 may has the therapeutic potential for AML,specially M5.The expression lever of FLT3 is correlated with progression and prognosis of the disease in certain degree, especially with relapse and it was still positive in low degree in the period of complete remission.It has the potential to use as a mark to monitor the MRD (minimal residual disease).