The Prediction Of Early Response And The Role Of CFL1 In The Treatment Of Chronic Myeloid Leukemia

Part 1 Outcome was predicted by the transcript level of BCR-ABL at 3 months in patients with chronic myeloid leukemia treated with imatinibPurposeTo assess the significance of BCR-ABL transcript level at 3months after imatinib therapy in different risk groups of CML patients, determine the independent parameter for BCR-ABL level at 3 months.Methods:CML-CP patients diagnosed and treated in our department were enrolled in this retrospective study. Cytogenetic and molecular analysis were performed at diagnosis and monitored at 3,6,12,18months, patients were stratified according to prior interferon-a (IFN-a) treatment, age, and interval time(between diagnosis and imatinib treatment) to investigate the prediction value of BCR-ABL transcript level for overall survival (OS), event-free survival (EFS), progression-free survival (PFS).ResultsAmong the 299 enrolled patients,293 patients received cytogenetic or molecular assessment. Totally,203 patients (67.9%) achieved CCyR, including 167 (55.9%) MMR, and 130 (43.5%) CMR. The BCR-ABL transcript level was assessed in 274 patients. Patients in low risk group or according to transcript level of BCR-ABL≤10% or> 10%. survival of the low risk group(n=146,53.3%) was better as compared with the high risk group (n= 128,46.7%).In the patients with IFN-a his-tory, only better EFS was observed (P= 0.038), PFS(P= 0.229) and OS (P=0.276) were not associated with transcript level. In younger patients (age≤29 years), there was no difference in EFS and OS between two BCR-ABL level groups. In the patients with an IM interval greater than 6 months, no difference in OS was seen between two groups.In patients without IFN-a history, more than 29 years old, or interval time more than 6 months, the cumulative incidence of PCyR, CCR,MMR were better in low risk group but no difference in the other patients.IM start interval time was the independent parameter (OR=9.854, P< 0.001) for BCR-ABL level at 3 months.ConclusionsCML-CP patients who are receiving IM treatment, transcriptional level of BCR-ABL at 3 months could predict outcome, especially for patients who were more than 29-year old, IFN-a naive, and with short IM treatment interval but should be used with caution.Part 2 Investigation of the relationship between CFL1 and early response to imatinibPurposeTo assess the relationship of the expression of CFL1 transcript level and early response to imatinib in CML patients.Methods:CFL1 expression in mononuclear cells from bone marrow in Chronic myeloid leukemia/Acute myelocytic leukemia and PBMC in normal controls were examed by real-time quantitative PCR. Compare the difference between these samples. And the expression of CFL1 also tested in CML patients before and after imatinb therapy. Analysis of the relationship between the expression level of CFL1 and the early response of the patients to imatinib, and the relationship between the gene expression and CML itself.Results:(1) CML and AML Patients with lower level of CFL1 compared with normal control (p<0.05, p<0.05);(2) The expression of CFL1 was improved after imatinib therapy;(3) Lower expression of CFL1 showed better response to therapy at 6months;(4)Lower expression of CFL1 showed better EFS and PFS, but no statistic difference;(5) The expression level of CFL1 was correlated with the peripheral blood white cell and platelet count in patients with CML (p=0.033,p=0.028).ConclusionsThe expression level of CFL1 in patients with CML was related to CML disease state.Patients with low expression of CFL1 can achieve the better response in early stage, and the relationship between the expression level and the prognosis of patients is still need to be further studied.Part 3 The role of cofilin in CML cell lines treated with imatinib and HHTObjective:To investigate the expression and the mechanism of CFL1 influencing CML response to treatment.Method:Use western blot to detect the protein level changes of cofilin after imatinib and HHT treatment. And the changes of F-actin and protein involved in its assemble. Use MTT to detect the inhibition of imatinib and HHT on CML cell proliferation, and the effects of imatinib on K562 and K562/G cells before and after transfection of CFL1-shRNA and overexpression of CFL1/S3A/S3D.Results:(1) The expression of and cofilin and P-cofilin were up-regulated in K562/KCL-22 cell lines after imatinib and HHT treatment;(2) shCFL1 impaired the sensitivity of K562 cells to imatinib; apoptosis and G2/M arrest were decreased;(3) Overexpression of CFL1 and S3 A increased the sensitivity of K562 cells to imatinib,but not in S3D;(4)Overexpression of CFL1 and S3A increased the sensitivity of K562/G cells to imatinib;(5) The migration of K562 cells decreased, and the adhesion of the cells to fibronectin was increased.