Sürdürülebilir Kalkınma Amaçları

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• MakaleAçık Erişim2025Scopus SJRQ1/r/kostu/10661
  Prognostic Significance of mTOR Expression in Recurrence Following Hepatic Metastasectomy in Colorectal Cancer

  Aksoy, Fuat; Ak-Aksoy, Secil; Karamustafaoglu, Ahmet; Tekin, Cagla; Ercelik, Melis; Tunca, Berrin; Duman, Busra Oncel; Isik, Ozgen; Ugras, Nesrin; Kaya, Ekrem

  Surgery is one of the most effective treatment methods for liver metastases developing from primary colorectal cancer (CRC). Despite the widespread application of surgical approaches, recurrence rates remain substantial. Although chemotherapy is frequently employed, the supporting evidence for its efficacy in this context remains inconclusive. In the present study, we aimed to identify potential predictors of post-metastasectomy recurrence by analyzing clinical, pathological, and molecular features of both primary colorectal tumors and their corresponding hepatic metastases. Specifically, we evaluated the expression of epithelial–mesenchymal transition (EMT) markers, cancer stem cell (CSC) markers, and selected oncogenic mRNAs (RAS, mTOR, and CMYC) in tissue samples from 84 patients. RAS and CMYC are well-known proto-oncogenes involved in cell proliferation and survival, while mTOR functions as a central regulator of cell growth and metabolism. Following liver metastasectomy, intra-hepatic recurrence was observed in 40.5% of the cases. Among the molecular markers analyzed, the EMT transcription factor SNAIL—which plays a critical role in cancer cell invasion and metastasis—and mTOR exhibited significantly elevated expression in metastatic lesions from patients who experienced recurrence. While SNAIL expression did not show a clear association with the time to recurrence, increased mTOR expression in metastatic liver tissue was significantly associated with both shorter recurrence-free survival and diminished overall survival (p < 0.001). Results showed that mTOR expression levels could be a clinically relevant predictive indicator of remnant liver recurrence. In patients with liver metastases, the use of mTOR inhibitors may be considered after hepatic metastasectomy.

  İncele
• MakaleAçık Erişim2024Scopus SJRQ2/r/kostu/10500
  Production of alginate macrocapsule device for long-term normoglycaemia in the treatment of type 1 diabetes mellitus with pancreatic cell sheet engineering

  Duman, Büşra Öncel; Yazir, Yusufhan; Halbutoğullari, Zehra Seda; Mert, Serap; Öztürk, Ahmet; Gacar, Gülçin; Duruksu, Gökhan

  Type 1 diabetes-mellitus (T1DM) is characterized by damage of beta cells in pancreatic islets. Cell-sheet engineering, one of the newest therapeutic approaches, has also been used to create functional islet systems by creating islet/beta cell-sheets and transferring these systems to areas that require minimally invasive intervention, such as extrahepatic areas. Since islets, beta cells, and pancreas transplants are allogeneic, immune problems such as tissue rejection occur after treatment, and patients become insulin dependent again. In this study, we aimed to design the most suitable cell-sheet treatment method and macrocapsule-device that could provide long-term normoglycemia in rats. Firstly, mesenchymal stem cells (MSCs) and beta cells were co-cultured in a temperature-responsive culture dish to obtain a cell-sheet and then the cell-sheets macroencapsulated using different concentrations of alginate. The mechanical properties and pore sizes of the macrocapsule-device were characterized. The viability and activity of cell-sheets in the macrocapsule were evaluated in vitro and in vivo. Fasting blood glucose levels, body weight, and serum insulin & C-peptide levels were evaluated after transplantation in diabetic-rats. After the transplantation, the blood glucose level at 225 mg dl-1 on the 10th day dropped to 168 mg dl-1 on the 15th day, and remained at the normoglycemic level for 210 days. In this study, an alginate macrocapsule-device was successfully developed to protect cell-sheets from immune attacks after transplantation. The results of our study provide the basis for future animal and human studies in which this method can be used to provide long-term cellular therapy in T1DM patients.

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  AtıfScopus7·WoS7·OpenAlex7

  İncele
• MakaleYalnız künye2022Scopus SJRQ2/r/kostu/10578
  Bio-engineering of 3-D cell sheets for diabetic rats: Interaction between mesenchymal stem cells and beta cells in functional islet regeneration system

  Duman, Busra Oncel; Sariboyaci, Ayla Eker; Karaoz, Erdal

  Type 1 diabetes is an autoimmune disease that emerges with the destruction of beta cells of pancreatic Langerhans islets. Three different therapeutical approaches have been developed so far; pancreas transplantation, islet transplantation, and cell-based therapies. Bioengineering cell sheets for tissue generating is one of the latest approaches that have been used to construct cell-sheets instead of single cells so that it mimics the in vivo environments more. In this study, extra-hepatic functional islet tissue was constructed by transferring the 3-D beta cells and GFP labelled MSCs MSC sheets to the subcutaneous site of rats with STZ-induced diabetes. rBM-MSCs and beta cells were cultured on the 6-well PIPAAm culture dishes. Obtained rBM-MSCs as two-cell sheets and beta cells cultured in droplets with matrigel has transplanted into the dorsal subcutaneous area of diabetic rats. Fasting blood glucose levels and body weights were evaluated for 30 days after transplantation. Immunocytochemistry analysis for the anti-apoptotic, anti-inflammatory, and angiogenetic effects of MSCs on the 30th day of subcutaneous cell transplantation. All recipient rats transplanted with beta-cells with MSCs returned toward normoglycemia by day 5 and remained at this level for 30 days. Immunocytochemical analyses supported that the MSCs and beta cells preserved their viability and function. MSCs secrete cytokines and growth factors TGF-β and IL-6; MSCs of the important features of the anti-apoptotic and anti-inflammatory properties, thanks to apoptosis of beta cells preserve graft explained by inhibition. In transplantation of MSCs induced angiogenesis and neovascularization, PECAM-1 and GFP positive simultaneously determining endothelial cells was observed indicating. Subcutaneous 3D beta-cell transplantation would be possible with the MSC-sheets as a feeder layer of beta cells. The beta-cell line is glucose-sensitive and has a high insulin release potential, and can be used as an alternative to islets in in vivo transplant studies.

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  AtıfScopus7·WoS6·OpenAlex6

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