Discovery and Protein Modeling Studies of Novel Compound Mutations Causing Resistance to Multiple Tyrosine Kinase Inhibitors in Chronic Myeloid Leukemia

Document Type: Research Articles

Authors

1 Hematology Oncology and Pharmacogenetics Engineering Sciences (HOPES) Group, Health Sciences Research Laboratories, Department of Zoology, University of the Punjab, Lahore, & University of Education, Lahore, Pakistan.

2 Department of Anatomy, College of Medicine and King Khalid University Hospital, King Saud University, Riyadh, Saudi Arabia.

3 Hematology/Oncology Division, Department of Medicine, College of Medicine and King Khalid University Hospital, King Saud University, Riyadh, Saudi Arabia.

4 Foreign Faculty, Asian Medical Institute, Kant City, National Surgical Centre, Bishkek, Kyrgyzstan, and Higher Education Commission Program in “Hematology Oncology and Pharmacogenetics Engineering Sciences (HOPES)”, Kyrgyzstan.

5 Post-Graduate Medical Institute, Hayatabad Medical Complex, Peshawar, Pakistan.

6 Center of Excellence in Genomic Medicine Research & Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia.

7 Blood Bank, Peshawar, Pakistan.

8 Department of Zoology, Division of Science and Technology, University of Education, Township, Lahore, Pakistan.

9 Centre for Advanced Molecular Biology, University of the Punjab, Lahore, Pakistan.

10 Departments of Biotechnology and Genomic Medicine, University of Sialkot, Pakistan.

11 College of Applied Medical Sciences, King Saud Bin Abdulaziz University for Health Sciences (KSAU-HS)/ KAIMRC/SSBMT, National Guards Health Affairs, Al-Ahsa, Kingdom of Saudi Arabia.

12 Jordan University of Science and Technology, Irbid, Jordan.

13 National Guard Health Affairs, King Abdullah International Medical Research Centre (KAIMRC), Al-Ahsa, Saudi Arabia.

14 Allied Hospital, Punjab Medical College & Sahil Hospital, Faisalabad, Pakistan.

Abstract

Objective: BCR-ABL fusion oncogene is the hallmark of chronic myeloid leukemia (CML), causing genomic instability which leads to accumulation of mutations in BCR-ABL as well as other genes. BCR-ABL mutations are the cause of tyrosine kinase inhibitors (TKIs) resistance in CML. Recently, compound BCR-ABL mutations have been reported to resist all FDA approved TKIs. Therefore, finding novel compound BCR-ABL mutations can help and clinically manage CML. Therefore, our objective was to find out novel drug-resistant compound BCR-ABL mutations in CML and carry out their protein modelling studies. Methodology: Peripheral blood samples were collected from ten imatinib resistant CML patients receiving nilotinib treatment. BCR-ABL transcript mutations were investigated by employing capillary sequencing. Patient follow-up was carried out using European LeukemiaNet guidelines. Protein modeling  studies were carried out for new compound mutations using PyMol to see the effects of mutations at structural level. Results: A novel compound mutation (K245N mutation along with G250W mutation) and previously known T351I utation was detected in two of the nilotinib resistance CML patients respectively while in the rest of 8 nilotinib responders, no resistant mutations were detected. Protein modelling studies indicated changes in BCR-ABL mutant protein which may have negatively impacted its binding with nilotinib leading to drug resistance. Conclusion: We report a novel nilotinib resistant BCR-ABL compound mutation (K245N along with G250W mutation) which impacts structural modification in BCR-ABL mutant protein leading to drug resistance. As compound mutations pose a new threat by causing resistance to all FDA approved tyrosine kinase inhibitors in BCR-ABL+ leukemias, our study opens a new direction for in vitro characterization of novel BCR-ABL compound mutations and their resistant to second  generation and third generation TKIs.

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