Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/395
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Article Citation - WoS: 653Citation - Scopus: 739Flow Cytometry: Basic Principles and Applications(Taylor & Francis Ltd, 2016-01-14) Adan, Aysun; Alizada, Gunel; Kiraz, Yagmur; Baran, Yusuf; Nalbant, AytenFlow cytometry is a sophisticated instrument measuring multiple physical characteristics of a single cell such as size and granularity simultaneously as the cell flows in suspension through a measuring device. Its working depends on the light scattering features of the cells under investigation, which may be derived from dyes or monoclonal antibodies targeting either extracellular molecules located on the surface or intracellular molecules inside the cell. This approach makes flow cytometry a powerful tool for detailed analysis of complex populations in a short period of time. This review covers the general principles and selected applications of flow cytometry such as immunophenotyping of peripheral blood cells, analysis of apoptosis and detection of cytokines. Additionally, this report provides a basic understanding of flow cytometry technology essential for all users as well as the methods used to analyze and interpret the data. Moreover, recent progresses in flow cytometry have been discussed in order to give an opinion about the future importance of this technology.Article Citation - WoS: 1Citation - Scopus: 1Concurrent Inhibition of FLT3 and Sphingosine Kinase-1 Triggers Synergistic Cytotoxicity in Midostaurin Resistant FLT3-ITD Positive Acute Myeloid Leukemia Cells via Blocking FLT3/TAT5A Signaling to Induce Apoptosis(Taylor & Francis Ltd, 2025-03-21) Tecik, Melisa; Adan, AysunThe FMS-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD) is one of the most frequent mutations observed in acute myeloid leukemia (AML) which contributes to disease progression and unfavorable prognosis. Midostaurin, a small FLT3 inhibitor (FLT3I), is clinically approved. However, patients generally possess acquired resistance when midostaurin used alone. Shifting the balance in the sphingolipid rheostat toward anti-apoptotic sphingosine kinase-1 (SK-1) or glucosylceramide synthase (GCS) is related to therapy resistance in cancer, however, their role in midostaurin resistant FLT3-ITD positive AML has not been previously investigated. We generated midostaurin resistant MV4-11 and MOLM-13 cell lines which showed increased IC50 values compared to their sensitive partner cells. SK-1 is overexpressed in resistant cells while GCS remains unchanged. Subsequent pharmacological targeting of SK-1 in resistant cells decreased SK-1 protein level, inhibited cell proliferation and showed additive or synergistic effect on cell growth, as confirmed by the Chou-Talalay combination index, and induced G0/G1 arrest (PI staining by flow cytometry). Cotreatment (SKI-II plus midostaurin) triggered apoptosis via phosphatidylserine exposure (annexin V/PI double staining). Mechanistically, induction of the intrinsic pathway of apoptosis was confirmed as increased activating cleavages of caspase-3 and PARP and increased Bax/Bcl-2 ratios. Activating phosphorylations of FLT3 (at tyrosine residue 591) and STAT5A (at tyrosine residue 694) dramatically inhibited in resistant cells treated with the combination. In conclusion, midostaurin resistance could be reversed by dual SK-1 and FLT3 inhibition in midostaurin resistant AML cell lines, providing the first evidence of a novel treatment approach to re-sensitize FLT3-ITD positive AML.