Browsing by Author "Gursoy, P"

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    Paclitaxel in combination with AT-101 induces apoptosis via supressing Bcl-2, bcl-XL, mcl-1 proteins in human breast cancer cells.
    Cakar, B; Gursoy, P; Atmaca, H; Kisim, A; Bozkurt, E; Uzunoglu, S; Sezgin, C; Sanli, UA; Karabulut, B; Uslu, R; Karaca, B
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    Systemic Immune Inflammation Index as a Key Marker of Survival and Immune-related Adverse Events in Immune Checkpoint Inhibitor Therapy
    Ekinci, F; Balcik, OY; Demir, B; Gursoy, P; Ozveren, A; Erdogan, AP
    Objective: To evaluate the prognostic significance of the new index designed by formulating neutrophil, lymphocyte, and platelet counts in patients with metastatic disease receiving immune checkpoint inhibitors (ICI) and its effect on the immune -re-lated adverse events (irAEs). Study Design: Cohort study. Place and Duration of Study: Department of Medical Oncology, University of Manisa Celal Bayar, University of Aydin Adnan Menderes, and University of Ege, and Izmir Kent Hospital, Turkey, from January 2016 to April 2020. Methodology: Patients with metastatic disease receiving ICI sufficient follow-up data were included. Patients, who had received treatment for a minimum of 3 months, were evaluated for the response. Systemic immune-inflammation index (SII) was calcu-lated as neutrophil (/L) x (lymphocyte (/L) / platelet (/L). The cut-off value was determined by examining the area under the receiver operating characteristic (ROC) curve for the SII value. The endpoints of this study included overall survival (OS) and progression-free survival (PFS). Results: A total of 168, patients who received ICI in the metastatic stage, were evaluated. The OS of the patients with low SII scores was 110.8 months (95% CI, 88.2-133.5), while patients with high SII scores were 36.0 months (95% CI, 28.4-43.6) and reached statistical significance (p <0.001). The results of univariate (HR=3.376, 95% CI, 1.986-5.739, p<0.001 and multivariate (HR=2.792, 95% CI, 1.495-5.215, p=0.011) analyses were statistically significant as well. Conclusion: The SII score in patients with metastatic disease receiving ICI was closely related to the prognosis. Patients with a high SII score are associated with a worse prognosis, these patients develop fewer irAEs.
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    Combination of zoledronic acid and serine/threonine phosphatase inhibitors induces synergistic cytotoxicity and apoptosis in human breast cancer cells via inhibition of PI3K/Akt pathway
    Surmeli, Z; Gursoy, P; Erdogan, AP; Bozkurt, E; Atmaca, H; Uzunoglu, S; Sezgin, C; Sanli, UA; Uslu, R; Karaca, B
    The aim of this study was to investigate the cytotoxic and apoptotic effects of zoledronic acid (ZA) in combination with serine/threonine protein phosphatase inhibitors, calyculin-A (CA) and okadaic acid (OA), in human MCF-7 and MDA-MB-231 breast cancer cells. XTT cell viability assay was used to evaluate cytotoxicity. DNA fragmentation and caspase-3/7 activity assays were performed to evaluate apoptosis. Activities of phosphatase 1 (PP1) and phosphatase 2A (PP2A) were measured by serine/threonine phosphatase ELISA kit. Expression levels of PI3K, p-PI3K, Akt, p-Akt, Bcl-2, p-Bcl-2, Bad, and p-Bad proteins were evaluated by Western blot analysis. Combination of ZA with either CA or OA showed synergistic cytotoxicity and apoptosis as compared to any agent alone in both MCF-7 and MDA-MB-231 breast cancer cells. Combination treatment also resulted in inhibition of both PP1 and PP2A activities. Both agents used alone or in combination did not induce significant changes in total PI3K, Akt, Bcl-2, and Bad expressions, while p-PI3K, p-Akt, p-Bcl-2, and p-Bad levels were reduced by the combination treatment as compared to agents alone. Moreover, apoptotic effect of combination treatment was significantly inhibited in the presence of LY294002, a specific PI3K inhibitor, in both breast cancer cell lines. In conclusion, synergistic apoptotic effect of the combination treatment is correlated with the block of the PI3K/Akt signal pathway in breast cancer cells.
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    Real-life comparison of afatinib and erlotinib in non-small cell lung cancer with rare EGFR exon 18 and exon 20 mutations: a Turkish Oncology Group (TOG) study
    Gursoy, P; Tatli, AM; Erdem, D; Goker, E; Celik, E; Demirci, NS; Sakin, A; Atci, MM; Bayram, E; Telli, TA; Bilgin, B; Bilici, A; Akangunduz, B; Balli, S; Demirkazik, A; Selçukbiricik, F; Menekse, S; Cavdar, E; Ozturk, A; Bekmez, ET; Turhal, S; Kilickap, S; Yildirim, HC; Oyan, B; Aksoy, A; Turkoz, FP; Kut, E; Katgi, N; Sakalar, T; Akyol, M; Ellez, HI; Topcu, A; Erdogan, AP; Pilanci, KN; Hedem, E; Arak, H; Akdeniz, N; Alan, Ö; Yapar, B; Nart, D; Yumuk, PF
    Objectives To compare the survival of first- and second-generation tyrosine kinase inhibitors (TKIs) in patients with rare EGFR exon 18 and exon 20 mutation-positive non-small cell lung cancer (NSCLC). Materials and methods We retrospectively evaluated survival characteristics of 125 patients with EGFR exon 18 and exon 20 mutated NSCLC who received erlotinib or afatinib as first line treatment between 2012 and 2021 from 34 oncology centres. Since exon 20 insertion is associated with TKI resistance, these 18 patients were excluded from the study. Results EGFR exon 18 mutations were seen in 60%, exon 20 mutations in 16%, and complex mutations in 24% of the patients with NSCLC who were evaluated for the study. There were 75 patients in erlotinib treated arm and 50 patients in afatinib arm. Patients treated with erlotinib had progression-free survival time (PFS) of 8.0 months and PFS was 7.0 months in the afatinib arm (p = 0.869), while overall survival time (OS) was 20.0 vs 24.8 months, respectively (p = 0.190). PFS of exon 18 mutated arm was 7.0 months, exon 20 mutated arm was 4.3 months, and complex mutation positive group was 17.3 months, and this was statistically significant (p = 0.036). The longest OS was 32.5 months, seen in the complex mutations group, which was not statistically different than exon 18 and in exon 20 mutated groups (21.0 and 21.2 months, respectively) (p = 0.323). Conclusion In this patient group, especially patients with complex mutations are as sensitive to EGFR TKI treatment similar to classical mutations, and in patients with rare exon 18 and exon 20 EGFR mutation both first- and second-generation EGFR-TKIs should be considered, especially as first- and second-line options.