INVESTIGATION OF R882H MUTATION IN THE GENE CODING DNA METHYL TRANSFERASE 3A (DNMT3A) IN CHRONIC MYELOID LEUKEMIA (CML) PATIENTS

Öz

Objective: Chronic Myeloid Leukemia (CML) is a clonal myeloproliferative disease of hematopoietic stem cell (HKH) origin. Along with the Bcr-Abl chimeric gene in KML, other additional mutations and epigenetic modifications are necessary for the disease to progress to the blastic phase. DNA methyltransferases (DNMTs) are key proteins for genome methylation, which play an important role in the expression and suppression of epigenetically regulated genes. Mutations in DNMT3A and other DNA methylation regulators have been identified in hematological malignancies. R882H mutation is the most common mutation in DNMT3a. The aim of this study is to investigate the incidence of DNMT3A R882H mutation in CML patients. Materials and Methods: AciI restriction enzyme cutting was used to screen the DNMT3A R882H mutation in cDNA samples obtained from bone marrow samples of CML patients sent for Bcr/Abl chimeric gene analysis. DNA sequence analysis was performed for DNMT3A after random selection from Bcr/Abl + and Bcr/Abl- samples after cutting. Analyzes of the data obtained were evaluated statistically. Results: It was observed that 35 Bcr/Abl + and 60 Bcr/Abl- samples did not carry this mutation after AciI restriction enzyme cutting. It was confirmed that there was no R882H mutation in the samples evaluated randomly by DNA sequence analysis from these samples. Conclusion: According to our results, it was founded that DNMT3A-R882H mutation was not observed in CML patients and there was no difference in the rate of mutation among Bcr/Abl + and Bcr/Abl- individuals. It has been demonstrated that the DNMT3A R882H mutation, which is known to play a role in increasing the proliferation potential of hematopoietic cells, is not effective for CML progression.

Anahtar Kelimeler

• Chronic Myeloid Leukemia
• Bcr/Abl
• DNMT3A
• R882H mutation

Kronik Miyeloid Lösemi (KML) hastalarında DNA Metil Transferaz 3A (DNMT3A) kodlayan gende R882H mutasyon varlığının araştırılması

Öz

Amaç: Kronik Miyeloid Lösemi (KML), hematopoetik kök hücre (HKH) orijinli klonal miyeloproliferatif bir hastalıktır. KML’deki Bcr-Abl kimerik geni ile birlikte diğer ek mutasyonlar ve epigenetik modifikasyonlar hastalığın blastik faza doğru ilerleyişi için gereklidir. DNA metiltransferazlar (DNMTler), epigenetik olarak düzenlenmiş genlerin ifade edilmesinde ve baskılanmasında önemli rol oynayan genom metilasyonu için anahtar proteinlerdir. Hematolojik malignitelerde DNMT3A ve diğer DNA metilasyon düzenleyicilerinde mutasyonlar tanımlanmıştır. R882H mutasyonu DNMT3a’da en sık gözlenen mutasyondur. Bu çalışmanın amacı DNMT3A R882H mutasyonunun KML hastalarındaki görülme oranını araştırmaktır. Gereç ve Yöntem: Bcr/Abl kimerik gen analizi amacıyla gönderilmiş KML hastalarının kemik iliklerinden elde edilmiş olan cDNA örneklerinde, DNMT3A R882H mutasyonunu taramak için, AciI restriksiyon enzim kesimi kullanıldı. Kesim sonrası Bcr/Abl+ ve Bcr/Abl- örneklerden random seçilerek DNMT3A için DNA dizi analizi yapıldı. Elde edilen verilerin analizleri istatistiksel olarak değerlendirildi. Bulgular: 35 Bcr/Abl+ ve 60 Bcr/Abl- örneğin AciI restriksiyon enzim kesimi sonrası bu mutasyonu taşımadıkları gözlendi. Bu örneklerden random seçilerek DNA dizi analizi ile değerlendirilen örneklerde de R882H mutasyonunun olmadığı doğrulandı. Sonuç: Elde edilen sonuçlarımıza göre DNMT3A-R882H mutasyonunun KML hastalarında gözlenmediği, Bcr/Abl+ ve Bcr/Abl- bireyler arasında mutasyon görülme oranı açısından herhangi bir farklılık olmadığı gözlenmiştir. Hematopoetik hücrelerin proliferasyon potansiyelini artırmakta rol oynadığı bilinen DNMT3A R882H mutasyonunun KML progresyonu açısından etkili olmadığı ortaya konmuştur.

Anahtar Kelimeler

• Kronik Myeloid Lösemi
• Bcr/Abl
• DNMT3A
• R882H mutasyonu

Kaynakça

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