ABL Kinase Domain Mutation
-
Upload
sajjad-ahmad -
Category
Documents
-
view
225 -
download
0
Transcript of ABL Kinase Domain Mutation
-
8/11/2019 ABL Kinase Domain Mutation
1/13
Screening of BCR-ABL Kinase domain Mutations from
Chronic Myeloid Leukemia patients: A preliminary study
Nazneen Islam, Toheed Kausar, Zahra Hasan, Tariq Moatter
Molecular Pathology,Department of Pathology and Microbiology,
Aga Khan University Hospital Karachi.
-
8/11/2019 ABL Kinase Domain Mutation
2/13
Introduction
Chronic myelogenous Leukemia (CML
Chromosomal translocation t(9;22) (q34;q11); yieldsPhiladelphia chromosome.
Fusion gene BCR-ABL encodes constitutively activeprotein tyrosine kinase that promotes;
Cell survival
Cell proliferation
Inhibition of apoptosis.
-
8/11/2019 ABL Kinase Domain Mutation
3/13
Chromosomal translocation t(9;22)
-
8/11/2019 ABL Kinase Domain Mutation
4/13
Mechanism of action of BCR-ABLtyrosine kinase
Mechanism of action of BCR-ABLtyrosine kinase inhibitor (Imatinib)
Imatinib(STI571;Glevic )
Selective inhibitor of Tyrosine kinase
CHR 95% of patients CCyR 76% of patients 3 log in BCR-ABL.. 57% of patients
CMR 4% of patients
-
8/11/2019 ABL Kinase Domain Mutation
5/13
Resistance to Imatinib
50% to 90% of CML patients acquired resistance to Imatinib dueBCR ABL kinase domain point Mutations.
Impair Imatinib Binding
4 region in Kinase domain where mutation can occur
P loop
Activation Loop Binding domain
Catalytic Domain
-
8/11/2019 ABL Kinase Domain Mutation
6/13
Frequency of BCR ABL kinase DomainMutation
100 different mutations have been identified
16 common mutations ---85% of all mutations
Frequency
-
8/11/2019 ABL Kinase Domain Mutation
7/13
Method for Mutation Analysis
RNA ExtractionComplimentaryDNA formation
RT-PCRDNA
Sequencing
-
8/11/2019 ABL Kinase Domain Mutation
8/13
DNA sequencing of ABL kinase Domain
P loopDrug Binding
loop
Catalytic
Domain
Activation
Loop
5TTAGGATCCTAGATTCGGAATCGTTGATCCTTATCACAGTCAGATATACTGGTAATCCATTCGATACGAGTAGATACAGA
TCGTTAGGATCCTTTCGTTGATCCACTGGTAATCCATTCGATTAGATACAGATCCAGTCAGATATACTGGTAATCCAAGTCA
GATATACTGCTGGTAATCCAAACCACAGTCAGATATACTGGTAATCCATTCGCTCACAGTCAGAGGGTACTGGTAATCCAT
TCGATACGAGTAGATACAGATCGTTAGGATCCTTTCGTTGATCCTTCGTTGATCGTTGATCCACTGGTAATCATATGAATA3
716 bp
BCR ABL
M31TE355G
E255KV3791
-
8/11/2019 ABL Kinase Domain Mutation
9/13
Results
S#
Patient Age Sex MutationDetected
Type of Mutation
1 Patient#1 40 M No
2 Patient#2 59 M Yes M351T
3 Patient#3 55 F No
4 Patient#4 30 M No
5 Patient#5 54 M No
6 Patient#6 31 M Yes E355G
7 Patient#7 60 F Yes V379I
8 Patient#8 55 F No
9 Patient#9 21 M No
10 Patient#10 97 F Yes E255K
11 Patient#11 66 M No
-
8/11/2019 ABL Kinase Domain Mutation
10/13
Conclusion
BCR-ABL kinase domain mutations are associated withimatinib Resistance in CML patients.
Timely identification of Imatinib resistance in CMLpatients help to set therapeutic strategies with 2ndgeneration TKIs.
Direct DNA sequencing is a method of Choice indetection of ABL kinase Domain mutation.
-
8/11/2019 ABL Kinase Domain Mutation
11/13
References
Tensuz Tauchi ,Kanzuna OhyasShilei,Molecular mechanism ofresistance of leukemia to Imatinib; Leukemia research28SI(2004)S39-S45.
C.Cameron Yin;Detection and Molecular monitoring of minimalresidual disease in chronic myelogenous leukemia.
Dragana Milojknovic; Mechanism of resistance to imatinib adsecond generation tyrosine kinase in chronic myeloid leukemia;Clin-Cancer-Res 2009;15(24);7519-27.
Micheal J.,mauro;Defining and managing Imatinib resistance;American Society of Hematology.
-
8/11/2019 ABL Kinase Domain Mutation
12/13
Acknowledgment
Faculty Members:Dr. Tariq Moatter
Dr. Zahra Hasan
Lab Fellows:Toheed Kausar
Samina Ghani
Sheeba Parveen
Azra Samreen
-
8/11/2019 ABL Kinase Domain Mutation
13/13