Melek Yaman

TSH-induced gene expression involves regulation of self-renewal and differentiation-related genes in human bone marrow-derived mesenchymal stem cells

Bone marrow-derived mesenchymal stem cells are pluripotent cells that are capable of differentiating into a variety of cell types including neuronal cells, osteoblasts, chondrocytes, myocytes, and adipocytes. Despite recent advances in stem cell biology, neuroendocrine relations, particularly TSH interactions remain elusive. In this study, we investigated expression and biological consequence of TSH receptor (TSHR) interactions in mesenchymal stem cells of cultured human bone marrow. To the best of our knowledge, we demonstrated for the first time that human bone marrow-derived mesenchymal stem cells expressed a functional thyrotropin receptor that was capable of transducing signals through cAMP. We extended this study to explore possible pathways that could be associated directly or indirectly with the TSHR function in mesenchymal stem cells. Expression of 80 genes was studied by real-time PCR array profiles. Our investigation indicated involvements of interactions between TSH and its receptor in novel regulatory pathways, which could be the important mediators of self-renewal, maintenance, development, and differentiation in bone marrow-derived mesenchymal stem cells. TSH enhanced differentiation to the chondrogenic cell lineage; however, further work is required to determine whether osteoblastic differentiation is also promoted. Our results presented in this study have opened an era of regulatory events associated with novel neuroendocrine interactions of hypothalamic-pituitary axis in mesenchymal stem cell biology and differentiation.

Establishment of a primary pleomorphic xanthoastrocytoma cell line: in vitro responsiveness to some chemotherapeutics.

BACKGROUND Anaplastic pleomorphic xanthoastrocytoma is an aggressively growing, malignant, and eventually fatal tumor of the central nervous system. Testing chemotherapeutic drug sensitivity under in vitro conditions would be a useful strategy to determine sensitive or resistant drugs for fatal brain cancers. OBJECTIVE To establish primary cell cultures of excised tumor tissue from pleomorphic xanthoastrocytoma–bearing patients and to test their sensitivity against various anticancer chemotherapy drugs. METHODS Prepared suspensions of the excised tumor tissue from a patient who had a recurrent grade 3 pleomorphic xanthoastrocytoma was cultured in culture dishes until cells began to grow. Immunofluorescent and immunohistochemical visualizations were performed using confocal and light microscopy. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay in comparison with 3H-thymidine incorporation assay was used to test cellular toxicity of several anticancer drugs. RESULTS We established vigorously growing primary cells of the tumor. Drug sensitivity testing was conducted successfully. CONCLUSION Primary cell cultures of surgically removed tumor tissues may be useful in studies of cancer biology and chemotherapeutic drug sensitivity for recurrent malignant brain tumors, particularly for anaplastic pleomorphic xanthoastrocytoma.

Prognostic importance of markers for inflammation, angiogenesis and apoptosis in high grade glial tumors during temozolomide and radiotherapy

INTRODUCTION Angiogenesis, inflammation and apoptosis have an important place in the carcinogenesis of high-grade gliomas (HGG). We evaluated the postoperative levels and the prognostic importance of tumor necrosis factor-alpha (TNFα), interleukin 6 (IL6), endoglin (CD105), vascular endothelial growth factor (VEGF), M65 and M30 as markers of inflammation, angiogenesis and apoptosis in patients with HGG. METHODS AND RESULTS Postoperative pretreatment sera were collected from 44 newly diagnosed patients with HGG. The control group was also consisted of 44 healthy people. The median age of all patients with HGG was 59 (range: 30-80). Temozolomide concurrent with radiotherapy was given to 37 patients. Thereafter 24 patients received consolidation temozolomide monotherapy. Mean chemotherapy cycle was 4.2. Progression free survival and overall survival were 6 (95% CI; 5.16-6.83) and 16 months (95% CI; 13.07-18.93) respectively in patients treated with concurrent chemoradiotherapy and consolidation chemotherapy. Relative to the control cohort endoglin (p = 0.000) and TNFα (p = 0.000) levels were significantly lower; however VEGF (p = 0.030) levels were higher in the patient group. In contrast, there were no significant change in IL-6 levels and the plasma apoptotic markers M65 (p = 0.085) and M30 (p = 0.292). In separate log rank tests, these biological markers did not correlate with survival. DISCUSSION AND CONCLUSION In HGG, a significant decrease in endoglin and TNFα levels was observed, while VEGF levels were significantly increased postoperatively. However, with the power from this patient population, no correlation with survival was observed.

Attitudes of International Students towards Turkish Foods

Abstract The aim of the paper is to determine the attitudes of international students towards Turkish foods. The present research was carried out on students educated in Turkish in Gazi University, Turkish Learning Application and Research Center (TOMER) in Ankara. Since the number of international students is limited, the research is performed on all the students. Out of the total 212 students, 50 students from the Turkish Republics, 68 students from the Middle East, 38 students from the Balkan countries, 26 students from Africa and 30 students from East Asia participated in the research on voluntary basis. During the research it was noticed that among students who prepare their own food at home or dorms, female students from Turkey preferred preparing food more than male students from same place (p<.05). The reason that female students’ attitudes are more positive than male students’ attitudes on the “inquisitiveness about new food” subscale is that females are typically more curious and interested in foods of different countries (p<.05).