KÜÇÜK HÜCRELİ OLMAYAN AKCİĞER KANSERİ HÜCRELERİNDE LET-7B-5P’NİN APOPTOTİK GENLER İLE İLİŞKİSİNİN ARAŞTIRILMASI

Amaç: Akciğer kanseri dünya genelinde kansere bağlı gerçekleşen ölümlerde kadınlarda ve erkeklerde ilk sıralarda yer almaktadır. Erken tanı yöntemlerinde ki gelişmeler ve yeni hedeflenen ajanların sayısının artmasına rağmen akciğer kanseri halen erken teşhis edilememekte ve etkin bir şekilde tedavi edilememektedir. Akciğer kanserinin tanısı için doğru ve güvenilir belirteçlere ihtiyaç duyulmaktadır. Ayrıca, akciğer kanserinde let-7b-5p’nin rolü ve terapötik potansiyelini ortaya koyan çalışmaların oldukça yetersiz olduğu gözükmektedir. Bu çalışmada A549 hücrelerinde let-7b-5p’nin ifade seviyesi miRNA mimik uygulaması ile arttırılarak apoptoz ile ilişkili genler ile ilişkisinin araştırılması amaçlanmıştır. Materyal ve Metot: Let-7b-5p’nin hedefi olabilecek apoptoz ile ilişkili genler onlineveri tabanlarından biyoinformatik araçlarla belirlenmiştir. Let-7b-5p’nin ifade seviyesinin A549 hücrelerinde arttırılması amacıyla, let-7b-5p mimiği hücrelereHiPerFect transfeksiyon ajanı ile transfekte edilmiştir. Daha sonra, elde edilen RNA’lardan let-7b-5p ve apoptoz ilişkili genlerin ifade seviyeleri qPCR yöntemi ile belirlenmiştir. Bulgular: Akciğer kanseri hücrelerinde let-7b-5p’nin ifade seviyesinin arttırılmasının ardından BCL2, RB1, XIAP, CASP9, TP53 ve PTEN genlerinin ifade seviyelerinin kontrol gruplarına kıyasla düştüğü bulunmuştur. Bunun aksine BAX geninin ifade seviyesinin arttığı ve CASP3 ve BCL2L1 genlerinin ifade seviyelerinde herhangi bir değişim olmadığı bulunmuştur. In silico analizler sonucunda TP53 geninin 3’ UTR bölgesinde iki farklı pozisyonda let-7b-5p bağlanma alanı olduğu gösterilmiştir. Sonuç: Sonuç olarak elde ettiğimiz bulgular let-7b-5p’nin apoptoz mekanizmasında yer alan genleri hedefleyebileceğini ve bu miRNA’nın akciğer kanserinin tanı ve/veya tedavisine yönelik önemli bir biyobelirteç olabileceğine işaret etmektedir.

INVESTİGATİON OF THE ASSOCİATİON OF LET-7B-5P WİTH APOPTOTİC GENES İN NON-SMALL CELL LUNG CANCER CELLS

Aim: Lung cancer is the leading cause of cancer-related deaths in men and women worldwide. Developments in early diagnostics and the number of new targeted agents have increased, lung cancer still cannot be diagnosed early and treated effectively. Therefore, accurate and reliable markers are needed for the diagnosis of lung cancer. Furthermore, studies showing the role and therapeutic potential of let-7b-5p in lung cancer seem to be quite limited. In this study, the expression level of let-7b-5p was increased by miRNA mimic applications in A549 cells to investigate the relationship between let-7b-5p and apoptosis-related genes. Materials and Methods: The genes involved in the apoptosis and predicted to target let-7b-5p were determined by bioinformatics tools from online databases. In order to increase the expression levels of let-7b-5p in A549 cells, let-7b-5p mimics were transfected into the cells with the HiPerFect transfection reagent. Then, expression levels of let-7b-5p and apoptosis related genes were determined by qPCR method. Results: It was found that the expression levels of BCL2, RB1, XIAP, CASP9, TP53 and PTEN genes decreased after increasing expression levels of let-7b-5p as compared to control groups in lung cancer cells. In contrast, the expression level of the BAX gene increased and no changes were observed in the expression levels of CASP3 and BCL2L1 genes. As a result of the in silico analysis, the TP53 gene was shown to have let-7b-5p binding site at two different positions in the 3’UTR region. Conclusion: In conclusion, our findings suggest that let-7b-5p can target genes involved in apoptosis and this miRNA might be an important biomarker for the diagnosis and/or treatment of lung cancer.

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