Biochemical and breakpoint cluster region-c-ABL oncogene 1 polymorphism study among Iraqi patients with chronic myeloid leukemia

Abstract

BACKGROUND: Chronic myeloid leukemia (CML) has been well recognized as an exemplary instance of a malignant disease characterized by a distinctive molecular occurrence, namely the presence of the breakpoint cluster region (BCR)-c-ABL oncogene 1 (ABL1) oncogene. The Philadelphia chromosome gives rise to an anomalous fusion gene characterized by atypical kinase activity, resulting in the accumulation of reactive oxygen species and genetic instability that holds significance in the advancement of diseases. OBJECTIVE: The objective of this study was to investigate the detection rate of BCR-ABL1 polymorphism and BCR protein level in a group of Iraqi patients with CML. MATERIALS AND METHODS: This study has been carried out on 150 specimens, 120 patients subjected to CML included 20 patients diagnosed as newly diagnosis CML and 100 patients treated with CML. In addition to 30 apparently healthy persons as a control group (normal persons) from the National Center of Hematology/Mustansiryiah University/Baghdad, 65 out of 100 patients on imatinib while 35 nonimatinib (nilotinib and bosutinib). Fresh whole blood and serum were obtained from all patients and controls. We used total DNA genomic extraction extracted from ethylenediaminetetraacetic acid blood for genetic detection of Bcr/Abl Genes Polymorphism by sequencing technique in patients with CML and apparently control groups and used serum for biochemical tests include urea, lactate dehydrogenase (LDH), aspartate transaminase (AST), alanine transaminase (ALT), and creatinine using biochemicals methods (colorimetric and kinetic), respectively, as well as detection BCR protein level using sandwich enzyme-linked immunosorbent assays technique. RESULTS: According to age and sex, the patients' groups were matching with the control group. Regarding the biochemical parameters (urea creatinine, ALT, AST, and LDH) serum level, there are no significant differences among new diagnosis CML, patients respond to treatments and failure group except in serum level of creatinine between new diagnosis CML group and failure group, there are significant differences (P = 0.01). The present results showed that DNA polymorphism distribution was according to C\C; G\C; A\T; and A\A were 32%, 26%, 18%, and 24%, respectively, in patients with CML and 28%; 20%;12%; and 40%, respectively, in the control group. There are significant statistical differences (P < 0.05) between different groups according to the genotyping of BCR\ABL, the results obtained from the sequenced 429 bp fragments, and the detailed positions of the observed variations are described in the NCBI reference sequences (rs766724113). The samples were submitted in NCBI, and the accession number of nucleotide sequences of BCR\ABL as new recording: LC 775148, LC 775149, and LC 775150, while regarding with BCR protein, there are significant differences in level between new diagnosis CML and CML on treatment and control groups, P < 0.001 for each comparison while there are no significant differences between treated group and control group (P = 0.729). CONCLUSION: The present results indicate that BCR-ABL1 polymorphism and BCR protein level in a group of Iraqi patients with CML may play a role in the tumor biology of the examined subset of CML and may contributed to their development.

Keywords

• breakpoint cluster region protein level
• breakpoint cluster region-c-abl oncogene 1 polymorphism
• chronic myeloid leukemia
• polymerase chain reaction
• sequencing