Tıp Fakültesi / Faculty of Medicine

Permanent URI for this collectionhttps://hdl.handle.net/11727/1403

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    Small Cell Lung Cancer Stem Cells Display Mesenchymal Properties And Exploit Immune Checkpoint Pathways In Activated Cytotoxic T Lymphocytes
    (2021) Kursunel, M. Alper; Taskiran, Ekim Z.; Tavukcuoglu, Ece; Yanik, Hamdullah; Demirag, Funda; Karaosmanoglu, Beren; Ozbay, Feyza Gul; Uner, Aysegul; Esendagli, Dorina; 0000-0002-6619-2952; 34228218; ABF-9398-2020
    Small cell lung cancer (SCLC) is an aggressive tumor type with early dissemination and distant metastasis capacity. Even though optimal chemotherapy responses are observed initially in many patients, therapy resistance is almost inevitable. Accordingly, SCLC has been regarded as an archetype for cancer stem cell (CSC) dynamics. To determine the immune-modulatory influence of CSC in SCLC, this study focused on the characterization of CD44(+)CD90(+) CSC-like subpopulations in SCLC. These cells displayed mesenchymal properties, differentiated into different lineages and further contributed to CD8(+) cytotoxic T lymphocytes (CTL) responses. The interaction between CD44(+)CD90(+) CSC-like cells and T cells led to the upregulation of checkpoint molecules PD-1, CTLA-4, TIM-3, and LAG3. In the patient-derived lymph nodes, CD44(+) SCLC metastases were also observed with T cells expressing PD-1, TIM-3, or LAG3. Proliferation and IFN-gamma expression capacity of TIM-3 and LAG3 co-expressing CTLs are adversely affected over long-time co-culture with CD44(+)CD90(+) CSC-like cells. Moreover, especially through IFN-gamma secreted by the T cells, the CSC-like SCLC cells highly expressed PD-L1 and PD-L2. Upon a second encounter with immune-experienced, IFN-gamma-stimulated CSC-like SCLC cells, both cytotoxic and proliferation capacities of T cells were hampered. In conclusion, our data provide evidence for the superior potential of the SCLC cells with stem-like and mesenchymal properties to gain immune regulatory capacities and cope with cytotoxic T cell responses. With their high metastatic and immune-modulatory assets, the CSC subpopulation in SCLC may serve as a preferential target for checkpoint blockade immunotherapy .
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    Response to first-line chemotherapy regimen is associated with efficacy of immune checkpoint blockade therapies in patients with metastatic urothelial carcinoma
    (2021) Sumbul, Ahmet Taner; 34762201
    Background Atezolizumab (ATZ) has demonstrated antitumor activity in previous studies in patients with metastatic platinum-resistant urothelial carcinoma. However, the response rate of ATZ was modest. Therefore, finding biologic or clinical biomarkers that could help to select patients who respond to the immune checkpoint blockade remains important. Patients and methods In this study, we present the retrospective analysis of 105 patients with urothelial cancer treated with ATZ after progression on first-line chemotherapy. Data of patients were obtained from patient files and hospital records. The association between response to first-line chemotherapy and ATZ was using Fisher's exact test. Median follow-up was calculated using the reverse Kaplan-Meier method. OS was estimated by using the Kaplan-Meier method. Results The median follow-up time was 23.5 months. Forty (74.1%) of patients who experienced clinical benefit after firs-line chemotherapy also had clinical benefit after atezolizumab, while only 14 (25.9%) of patients with initial PD after first-line chemotherapy subsequently experienced clinical benefit with ATZ (p = 0.001). The median OS on ATZ of 14.8 and 3.4 months for patients with clinical benefit and progressive disease in response to first-line chemotherapy, respectively (p = 0.001). Three of the adverse prognostic factors according to the Bellmunt criteria were independent factors of short survival: liver metastases {Hazard ratio [HR] = 1.9; p = 0.04}, ECOG PS >= 1 (HR = 2.7; p = 0.001), and Hemoglobin level below 10 mg/dl (HR = 2.8; p < 0.001). In addition, patients with clinical benefit from first-line chemotherapy (HR = 0.39; p < 0.001) maintained a significant association with OS in multivariate analysis. Conclusions Our study demonstrated that clinical benefit from first-line chemotherapy was independent prognostic factors on OS in patients' use of ATZ as second-line treatment in metastatic bladder cancer. Furthermore, these findings are important for stratification factors for future immunotherapy study design in patients with bladder cancer who have progressed after first-line chemotherapy.
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    Real-World Treatment Patterns and Clinical Outcomes in Patients With Stage III NSCLC: Results of KINDLE, a Multicountry Observational Study
    (2021) Jazieh, Abdul Rahman; Onal, Huseyin Cem; Tan, Daniel Shao Weng; Soo, Ross A.; Prabhash, Kumar; Kumar, Amit; Huggenberger, Reto; Robb, Stephen; Cho, Byoung-Chul; 34051381
    Introduction: Stage III NSCLC is a heterogeneous disease requiring a multimodal management approach. We conducted a real-world, global study to characterize patients, treatment patterns, and their associated clinical outcomes for stage III NSCLC. Methods: KINDLE was a retrospective study in patients with stage III NSCLC (American Joint Committee on Cancer, seventh edition) diagnosed between January 2013 and December 2017, with at least 9 months of documented follow-up since index diagnosis. In addition to descriptive statistics, Kaplan-Meier methodology evaluated survival estimates; two-sided 95% confidence interval was computed. Cox proportional hazards model was used for univariate and multivariate analyses. Results: A total of 3151 patients from more than 100 centers across 19 countries from Asia, Middle East, Africa, and Latin America were enrolled. Median age was 63.0 years (range: 21.0-92.0); 76.5% were males, 69.2% had a smoking history, 53.7% had adenocarcinoma, and 21.4% underwent curative resection. Of greater than 25 treatment regimens, concurrent chemoradiotherapy was the most common (29.4%). The overall median progression-free survival (95% confidence interval) and median overall survival (mOS) were 12.5 months (12.06-13.14) and 34.9 months (32.00-38.01), respectively. Significant associations (p < 0.05) were observed for median progression-free survival and mOS with respect to sex, region, smoking status, stage, histology, and Eastern Cooperative Oncology Group status. In univariate and multivariate analyses, younger age, stage IIIA, better Eastern Cooperative Oncology Group status, concurrent chemoradiotherapy, and surgery as initial therapy predicted better mOS. Conclusions: KINDLE reveals the diversity in treatment practices and outcomes in stage III NSCLC in a real-world setting in the preimmuno-oncology era. There is a high unmet medical need, necessitating novel approaches to optimize outcomes. (C) 2021 International Association for the Study of Lung Cancer. Published by Elsevier Inc.
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    Systematic identification of cancer-specific MHC-binding peptides with RAVEN
    (2018) Ozen, Ozlem; Baldauf, Michaela C.; Gerke, Julia S.; Kirschner, Andreas; Blaeschke, Franziska; Effenberger, Manuel; Schober, Kilian; Rubio, Rebeca Alba; Kanaseki, Takayuki; Kiran, Merve M.; Dallmayer, Marlene; Musa, Julian; Akpolat, Nurset; Akatli, Ayse N.; Rosman, Fernando C.; Sugita, Shintaro; Hasegawa, Tadashi; Sugimura, Haruhiko; Baumhoer, Daniel; Knott, Maximilian M. L.; Sannino, Giuseppina; Marchetto, Aruna; Li, Jing; Busch, Dirk H.; Feuchtinger, Tobias; Ohmura, Shunya; Orth, Martin F.; Thiel, Uwe; Kirchner, Thomas; Gruenewald, Thomas G. P.; 30228952
    Immunotherapy can revolutionize anti-cancer therapy if specific targets are available. Immunogenic peptides encoded by cancer-specific genes (CSGs) may enable targeted immunotherapy, even of oligo-mutated cancers, which lack neo-antigens generated by protein-coding missense mutations. Here, we describe an algorithm and user-friendly software named RAVEN (Rich Analysis of Variable gene Expressions in Numerous tissues) that automatizes the systematic and fast identification of CSG-encoded peptides highly affine to Major Histocompatibility Complexes (MHC) starting from transcriptome data. We applied RAVEN to a dataset assembled from 2,678 simultaneously normalized gene expression microarrays comprising 50 tumor entities, with a focus on oligo-mutated pediatric cancers, and 71 normal tissue types. RAVEN performed a transcriptome-wide scan in each cancer entity for gender-specific CSGs, and identified several established CSGs, but also many novel candidates potentially suitable for targeting multiple cancer types. The specific expression of the most promising CSGs was validated in cancer cell lines and in a comprehensive tissue-microarray. Subsequently, RAVEN identified likely immunogenic CSG-encoded peptides by predicting their affinity to MHCs and excluded sequence identity to abundantly expressed proteins by interrogating the UniProt protein-database. The predicted affinity of selected peptides was validated in T2-cell peptide-binding assays in which many showed binding-kinetics like a very immunogenic influenza control peptide. Collectively, we provide an exquisitely curated catalogue of cancer-specific and highly MHC-affine peptides across 50 cancer types, and a freely available software (https://github.com/JSGerke/RAVENsoftware) to easily apply our algorithm to any gene expression dataset. We anticipate that our peptide libraries and software constitute a rich resource to advance anti-cancer immunotherapy.