Nuray VAROL, Ece KONAC, Cenk Y BİLEN, Ilker KİLİCCİOGLU

Proteasome and HDAC Inhibition Changes the Expression Levels of Bcl-2, Bcl-XL, Bim and Bik Proteins in Androgen-Independent PC-3 Cell Line

Amaç: Prostat kanseri, batı ülkelerindeki erkeklerde kanser-ilişkili ölümlerin % 10'unu oluşturduğu tahmin edilen, en sık görülen kanserdir. Androjen-bağımlı formdan metastatik androjenden-bağımsız faza geçiş, kanser hücreleri tarafından terapiye verilen bozulmuş apoptotik yanıtın bir sonucudur. Bcl-2 ailesi üyeleri, apoptotik yanıtın en önemli düzenleyicileridir. Bu çalışmada, proteazom ve Histon Deasetilaz (HDAC) inhibitörlerinin, bazı Bcl-2 ailesi genlerinin ifade değişiklikleri üzerine etkisini protein düzeyinde araştırdık. Yöntem: PC-3 hücrelerine, bortezomib ve TSA'nın tekli ve kombine farklı konsantrasyonları uygulanmadan önce kültüre edildi. Kontrol ve ilaç uygulanmış hücrelerden protein izolasyonu sonrasında, tüm hücre lizatı Bcl-2, Bcl-XL, Bim ve Bik proteinlerini western blot yöntemi ile belirlemek için kullanılmıştır. Bulgular: Hücrelere ilaç uygulamasının ardından pro-apoptotik Bim ve Bik proteinlerinin ekspresyon seviyelerinin arttığını ve anti-apoptotik Bcl-2 ve BclXL proteinlerinin ekspresyon seviyelerinin azaldığı gözlemlenmiştir. Bu ilaçlar arasındaki sinerji, apoptozisin indüksiyonuna yol açmıştır. Sonuç: Bulgularımız, bortezomib ve TSA'nın düşük doz kombinasyonlarının uygulanması, apoptotik yanıtta yeterli olabileceğini göstermiş olup; ileri evre prostat kanseri araştırmaları için önemli olabilir.

Proteazom ve HDAC İnhibisyonunun Androjenden-Bağımsız PC-3 Hücre Hattında Bcl-2, Bcl-XL, Bim ve Bik Proteinlerinin İfadelenme Düzeylerini Değiştirmesi

Objective: Prostate cancer is the most common cancer observed and it is estimated to have caused 10% of all cancer-related deaths in men in western countries. Transition from androgen-dependent form to metastatic androgenindependent phase is a consequence of deranged apoptotic response by the cancer cells to therapy. Bcl-2 family members are important modulators of apoptotic response. In this study, we investigated the effects of proteasome and histone deacetylase (HDAC) inhibitor treatment on the expression changes in some Bcl-2 family genes at protein level. Methods: PC-3 cells were cultured in plate before being exposed to different concentrations of unaccompanied bortezomib and TSA as well as bortezomib - TSA combination. After the protein isolation from control and treated cells, whole cell lysate was used for determining Bcl-2, Bcl-XL, Bim and Bik proteins with western blotting method. Results: We observed that after the drug treatment, the expression levels of pro-apoptotic Bim and Bik proteins have increased and those of anti-apoptotic Bcl-2 and Bcl-XL proteins have decreased. Synergy between bortezomib and TSA induces apoptosis. Conclusion: Our results showed that application of low doses of bortezomib and TSA combination may be sufficient for apoptotic response. Our findings may come in handy for the advanced prostate cancer research.

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