Browsing by Author "Gencer Akçok, Emel Başak"

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Inhibition of PI3K-AKT-mTOR pathway and modulation of histone deacetylase enzymes reduce the growth of acute myeloid leukemia cells
(HUMANA PRESS INC, 2023) Şansaçar, Merve; Sağır, Helin; Gencer Akçok, Emel Başak; 0000-0002-6559-9144; 0000-0002-1731-5215; AGÜ, Yaşam ve Doğa Bilimleri Fakültesi, Biyomühendislik Bölümü; Şansaçar, Merve; Sağır, Helin; Gencer Akçok, Emel Başak
One of the most widespread forms of blood cancer is known as acute myeloid leukemia (AML) which has an incidence of 80% with poor prognosis. Although there are different treatment methods for AML in clinic, the heterogeneity and complexity of the disease show that new treatments are needed. The aim of this study is to investigate the anticancer effects of inhibition of PI3K and HDAC enzymes on CMK and MOLM-13 AML cells lines. We demonstrated that the combination of LY294002 with SAHA and Tubastatin A significantly decreased the cell viability of both cell lines. In contrast, the LY294002 and PCI-34051 combination did not show a significant difference compared to the single LY294002 administration. The combination treatment of LY294002 and HDAC inhibitors did not induce apoptosis significantly. However, LY294002 + SAHA and LY294002 + PCI-34051 resulted in G0/G1 and G2/M cell cycle arrest in CMK cells, respectively. On the other hand, compared to control cells, LY294002 + SAHA and LY294002 + PCI-34051 led to G0/G1 phase arrest in MOLM-13. Furthermore, the LY294002 + PCI-34051 combination elevated the expression rate of LC3BII/I, an autophagy marker, in CMK cells by 2.5-fold. Our study revealed that the combinations of PI3K inhibitor and HDAC inhibitors showed a synergistic effect and caused a reduction in cell viability and increased cell cycle arrest on MOLM-13 and CMK cell lines. In addition, the expression of LC3BII was elevated in the CMK cell line. In conclusion, although more mechanistic studies are required, a combinational inhibition of PI3K and HDAC could be a promising approach for AML.
Pi3k-Akt-Mtor Yolağı Ve Histon Deasetilaz Enzimlerinin Hedeflenmesinin Akut Myeloid Lösemi Hücreleri Üzerine Antitümör Etkisinin Incelenmesi
(TÜBİTAK, 2022) Gencer Akçok, Emel Başak; Şansaçar, Merve; Karaca, Münevver; Okur, Tuğba; 0000-0002-6559-9144; AGÜ, Yaşam ve Doğa Bilimleri Fakültesi, Moleküler Biyoloji ve Genetik Bölümü; Gencer Akçok, Emel Başak
Akut Miyeloid Lösemi (AML), periferik kan, kemik iliği, dalak ve karaciğerde blast adı verilen olgunlaşmamış miyeloid hücrelerin birikmesiyle karakterize edilen ve sonunda hematopoietik maligniteye yol açan bir hastalıktır. Genetik anormalliklerin yanı sıra PI3K/AKT/mTOR, Wnt, Notch, STAT3, Hedgehog gibi önemli hücresel yolakların AML patogenezinde rol oynadığı bildirilmiştir. Histon deasetilaz (HDAC) inhibitörleri, AML için umut verici antikanser aktiviteye sahiptir. Çalışmada, PI3K/AKT/mTOR yolunun inhibisyonunun ve HDAC inhibisyonunun farklı AML alt gruplarının hücre hatları olan MOLM-13 ve CMK hücre hatları kullanılarak bu hastalığın altında yatan moleküler mekanizma üzerindeki etkisinin araştırılması amaçlamıştır. Bu amaçla PI3K inhibitörü LY294002 ve HDAC inhibitörleri (SAHA, PCI-3501 ve Tubastatin A) ve bunların kombinasyonlarının etkisi incelenmiştir. Hücre proliferasyonu MTT hücre sitotoksisite testi ile apoptoz oranları ise Annexin-V/PI çift boyama yöntemi ile belirlenmiş, ilaçların hücre döngüsüne olan etkileri de PI boyaması ile belirlenmiştir. Otofaji belirteci olan LC3B protein seviyesi moleküler düzeyde western blot ile doğrulanmıştır. Kullanılan inhibitörler her iki hücre hattı üzerinde düşük mikromolar konsantrasyonda hücre canlılığını azaltmıştır. Sonuçlar LY294002+SAHA kombinasyon tedavisinin MOLM-13 hücrelerinde hücre proliferasyonunu %50, CMK hücrelerinde ise %25 azalma gösterdiği belirlenmiştir. LY294002+Tubastatin A tedavisi, MOLM-13 ve CMK hücrelerinde hücre proliferasyonunu sırasıyla %65 ve %40 oranında azalttığını göstermiştir. Sonuçlarımız, LY294002 ve HDAC inhibitör kombinasyonlarının kontrol hücrelerine kıyasla MOLM-13 hücrelerinde G1 fazı tutuklanmasıyla sonuçlandığını gösterdi. Öte yandan, LY294002+SAHA, LY294002+PCI-3501 ve LY294002+Tubastatin A kombinasyonları ile tedavi edilen CMK hücreleri, sırasıyla G2/M, G2/M ve G1 fazında tutuklanmıştır. Kombinasyonların apoptotik hücre ölümü üzerine etkisine bakılmış, LC3BII/I protein ifade düzeyi kombinasyon tedavisi sonucunda incelenmiştir. HDAC enzimlerinin hem AML hem de farklı kanserler üzerindeki etkileri düşünüldüğünde, HDAC inhibisyonu AML için önemli ve yüksek potansiyelli bir hedeftir. Bu nedenle PI3K/AKT/mTOR yolağı ve HDAC'lerin farklı alt gruplarda inhibisyonunun araştırılması, AML'nin patogenezine yol açan mekanizmalar hakkında fikir verebilir. Sonuç olarak, PI3K/AKT/mTOR ve HDAC'nin bu inhibisyonunun, AML'nin ortadan kaldırılmasıyla sonuçlanan daha spesifik bir kombinasyon hedefli tedaviye yol açacağı umulmaktadır.
The therapeutic potential of targeting HDAC6 with Tubastatin A in TFK-1 and EGI-1 cholangiocarcinoma cells
(SİVAS CUMHURİYET ÜNİVERSİTESİ: Sivas Cumhuriyet University, 2021) Yenigül, Münevver; Gencer Akçok, Emel Başak; 0000-0003-0468-721X; 0000-0002-6559-9144; AGÜ, Fen Bilimleri Enstitüsü, Biyomühendislik Ana Bilim Dalı; Yenigül, Münevver; Gencer Akçok, Emel Başak
Cholangiocarcinoma (CCA) is a highly aggressive and invasive malignancy with a poor diagnosis because of the resistance, relapse and limited therapy. Histone deacetylases (HDAC) are a class of enzyme that have important roles in epigenetic modulations. These enzymes are intensely studied and HDAC inhibitors are considered as potent anticancer agents in both solid tumors and hematological malignancies. HDAC inhibitors can affect and induce different mechanisms such as cell cycle arrest, differentiation, and cell death. In this study, we aim to investigate the cytotoxic effect of Tubastatin A, which is a selective HDAC6 inhibitor, on cholangiocarcinoma cell lines, TFK-1 and EGI-1, by MTT assay. Besides, it was aimed to examine the impact on colony formation potential of the cells. The effect of the inhibitor on cell cycle distribution was also examined by using flow cytometry. Tubastatin A has significantly decreased the colony formation and changed cell cycle progression. Taken together, our results suggest that Tubastatin A could be a potent inhibitor against cholangiocarcinoma. On the basis of these results, further mechanistic studies are required to elucidate the antineoplastic activity of Tubastatin A.
Tomatidine, a Steroidal Alkaloid, Synergizes with Cisplatin to Inhibit Cell Viability and Induce Cell Death Selectively on FLT3-ITD+ Acute Myeloid Leukemia Cells
(SPRINGER NATURE Link, 2024) Ayvaz, Havva Berre; Yenigül, Münevver; Gencer Akçok, Emel Başak; 0000-0002-5873-7879; 0000-0003-0468-721X; 0000-0002-6559-9144; AGÜ, Yaşam ve Doğa Bilimleri Fakültesi, Moleküler Biyoloji ve Genetik Bölümü; Ayvaz, Havva Berre; Yenigül, Münevver; Gencer Akçok, Emel Başak
Background: Acute Myeloid Leukemia (AML) is a hematological cancer that frequently presents with a range of side effects and drug resistance during anticancer drug treatment. The current study aims to achieve increased efficacy by combining lower doses of cisplatin with increasing concentrations of tomatidine in AML cells to increase efficacy. Methods: Anti-proliferative effects of single and combination of cisplatin and tomatidine were assessed via MTT cell viability assay. The Annexin V/Propidium Iodide Double Staining method was used to measure the apoptotic effects of combined tomatidine and cisplatin treatment. Then, Western Blot analysis was performed to measure Poly (ADP-ribose) polymerase (PARP) and Caspase-3 protein expression levels. Results: Cisplatin treatment with lower concentrations displayed high cytotoxic effects on AML cells, compared with tomatidine. The combination of the Inhibitory Concentration (IC) 20 value of cisplatin and increasing doses of tomatidine exhibited a significant decrease in cell viability relative to single treatments. The combination index analysis revealed a mild synergistic effect of cisplatin IC20 and varying tomatidine doses. The apoptosis induced when cisplatin was combined with 500 µM tomatidine by almost 20%, while the percentage of apoptosis in combination with 1 mM tomatidine was measured by 50% for both cell lines. The upregulation of proapoptotic cleaved-PARP (3.2 and 1.08-fold for THP-1 and MOLM-13, respectively) and downregulation in Caspase-3 (0.23 and 0.13-fold for THP-1 and MOLM-13, respectively) was detected. Conclusions: Together, the study indicated that when tomatidine combined with cisplatin on AML cell lines, a combinatorial anti-proliferative and apoptotic effect is observed. The combination of cisplatin with tomatidine may be a promising approach.