Full text
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| Author(s): |
Cintia do Couto Mascarenhas
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Faculdade de Ciências Médicas |
| Defense date: | 2009-07-17 |
| Examining board members: |
Carmino Antonio de Souza;
Israel Bendit;
Afonso Celso Vigorito
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| Advisor: | Katia Borgia Barbosa Pagnano; Carmino Antonio de Souza |
| Abstract | |
The development of chronic myeloid leukemia (CML) is the formation of the characteristic Philadelphia chromosome involving breach of the BCR gene generating a molecular rearrangement called BCR-ABL, whose final product is a cytoplasmic fusion protein that determines the pathogenesis of the disease. This is a protein tyrosine kinase (TK) that has self-ativaçãoe to inactivate this protein have developed the inhibitors of tyrosine kinase (ITK), which has ability to connect on the same site of binding of molecule of ATP. This connection prevents the transfer of phosphate groups to substrates subsequent, blocking the cascade of signal transduction and preventing the activation of mitogenic pathways dependent kinase BCR-ABL and anti leading to apoptotic death phenotype of BCR-ABL.One major mechanisms of resistance to treatment with ITK are mutations off, and the T315I focus of more detailed studies by making mutant protein highly insensitive to all drugs Inhibit TK protein currently available was used in this work to D-HPLC technique to screening for mutations in patients with CML with sub-optimal response or failure of treatment according to the criteria Leukemia Net For the screening of exon 6 were selected 93 CML patients: 5 were intolerant, 67 resistant and 21 with answer sub-optimal. The negative control we used the peripheral blood donors Blood from the blood of UNICAMP. For the screening of mutations throughout the BCR-ABL gene were studied 37 patients with CML and control negative, we used the HL60 cell line that does not have the translocation BCR-ABL. In the screening of exon 6, 23 samples (25%) showed a profile of the D-HPLC elution abnormal in the control, which suggested the presence of mutation. The overall survival (OS) for whole group was 80% in a median time of observation of 30 months. OS for patients with mutations was 87% and for patients with mutations was 56% in the median observation time of 37 and 10 months respectively (p <0.0001, RR = 68). In screening the entire gene BCR-ABL 17 (46%) had chromatographic profile different from the control we were setting the standardization of methods, procedures with the sequencing of all samples and the results were compared with the sequence deposited in the GenBank database (U07563). Of the 17 samples with change the chromatographic profile, we observed the presence of mutation in 13 samples. We believe that this is due to sensitivity of the method of D-HPLC is able to identify the mutations both polymorphisms with greater efficiency to the sequencing. In summary, the D-HPLC has proved a sensitive and practical method for monitoring the appearance of mutations in the kinase domain in the clinical routine. Mutations studied in this region are clinically relevant and may confer worse prognosis. Early detection can be a tool important to optimize therapy in CML. (AU) | |