Browsing by Author "Chesney, Jason A."
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Item 6-phosphofructo-2-kinase/fructose 2,6-bisphosphatase-3 is required for transforming growth factor β1-enhanced invasion of Panc1 cells in vitro(Elsevier, 2017-01-31) Chesney, Jason A.; Yalçın, Abdullah; Solakoğlu, Tuğba H.; Özcan, Selahattin C.; Güzel, Saime; Peker, Sabire; Çelikler, Serap; Balaban, Başak D.; Sevinç, Elif; Gürpınar, Yunus; Uludağ Üniversitesi/Veteriner Fakültesi/Biyokimya Anabilim Dalı.; Uludağ Üniversitesi/Veteriner Fakültesi/Histoloji ve Embriyoloji Anabilim Dalı.; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Biyoloji Bölümü.; 0000-0001-8519-8375; 0000-0003-1733-4288; 0000-0003-0796-5000; 0000-0002-4177-3478; 0000-0002-7698-0872; ABI-4164-2020; AAA-6938-2022; AAH-4275-2021; AAH-2767-2021; 36857831000; 57193156208; 22835997800; 55460886200; 55109615900; 8234554800; 6604052452; 56508326500; 57193160752Transforming growth factor [31 (TGF beta 1) is a well -established inducer of the epithelial-mesenchymal transition (EMT) that is essential for the acquisition of malignant properties, such as invasion, in tumor cells. Although recent studies suggest that the EMT in tumor cells is associated with reprogramming of energy metabolism and TGF beta 1 has been shown to stimulate glycolysis in multiple primary cell lines, little is known about TGF beta l 's effect on glycolysis and glycolytic regulators in transformed cells. Given the known regulatory role of 6-phosphofructo-2-kinase/fructose 2,6-bisphosphatase-3 (PFKFB3) in glycolysis and association of glycolytic activity with malignant features such as invasion, we sought to investigate whether TGF beta 1 regulates PFKFB3 expression and if PFKFB3 is involved in the TGF beta l -mediated increase in the invasive ability of the Panc1 cell cline a well -established model of TGF beta 1 -initiated EMT. Herein we demonstrate that TGF beta 1 induces PFKFB3 expression and stimulates glycolysis in Panci cells. We also show that s1RNA silencing of PFKFB3 prevents the stimulation of glycolysis and in vitro invasive ability of Panci cells by TGF beta 1. Furthermore, PFKFB3 silencing suppresses the TGFfil -mediated induction of the Snail protein, suggesting that PFKFB3 is required for the regulation of Snail expression by TGFfil. Taken together, our study identifies PFKFB3 as a key TGF beta 1 effector protein that mediates TGF beta 1's effect on Snail expression, invasion, and glycolysis.Item A novel small molecule antagonist of choline kinase-alpha that simultaneously suppresses MAPK and PI3K/AKT signaling(Springernature, 2011-07) Clem, Brian F.; Clem, Amy L.; Goswami, Umesh; Arumugam, Sengodagounder; Telang, Sucheta; Trent, John O.; Chesney, Jason A.; Yalçın, Abdullah; Uludağ Üniversitesi/Veterinerlik Fakültesi/Biyokimya Anabilim Dalı.; 0000-0001-8519-8375; ABI-4164-2020; A-5261-2016; 36857831000Choline kinase-alpha expression and activity are increased in multiple human neoplasms as a result of growth factor stimulation and activation of cancer-related signaling pathways. The product of choline kinase-alpha, phosphocholine, serves as an essential metabolic reservoir for the production of phosphatidylcholine, the major phospholipid constituent of membranes and substrate for the production of lipid second messengers. Using in silico screening for small molecules that may interact with the choline kinase-alpha substrate binding domain, we identified a novel competitive inhibitor, N-(3,5-dimethylphenyl)-2-[[5-(4-ethylphenyl)-1H-1,2,4-triazol-3-yl] sulfanyl] acetamide (termed CK37) that inhibited purified recombinant human choline kinase-alpha activity, reduced the steady-state concentration of phosphocholine in transformed cells, and selectively suppressed the growth of neoplastic cells relative to normal epithelial cells. Choline kinase-alpha activity is required for the downstream production of phosphatidic acid, a promoter of several Ras signaling pathways. CK37 suppressed mitogen-activated protein kinase and phosphatidylinositol 3-kinase/AKT signaling, disrupted actin cytoskeletal organization, and reduced plasma membrane ruffling. Finally, administration of CK37 significantly decreased tumor growth in a lung tumor xenograft mouse model, suppressed tumor phosphocholine, and diminished activating phosphorylations of extracellular signal-regulated kinase and AKT in vivo. Together, these results further validate choline kinase-alpha as a molecular target for the development of agents that interrupt Ras signaling pathways, and indicate that receptor-based computational screening should facilitate the identification of new classes of choline kinase-alpha inhibitors.Publication PFKFB2 regulates glycolysis and proliferation in pancreatic cancer cells(Springer, 2020-05-15) Özcan, Selahattin C.; Sarıoğlu, Aybike; Altunok, Tuğba H.; Akkoç, Ahmet; Güzel, Saime; Güler, Sabire; Imbert-Fernandez, Yoannis; Muchut, Robertino J.; Iglesias, Alberto A.; Gürpınar, Yunus; Clem, Amy L.; Chesney, Jason A.; Yalçın, Abdullah; Sarıoğlu, Aybike; Altunok, Tuğba H.; AKKOÇ, AHMET; GÜZEL, SAİME; GÜLER, SABİRE; Gürpınar, Yunus; YALÇIN, ABDULLAH; Bursa Uludağ Üniversitesi/Veteriner Fakültesi/Biyokimya Anabilim Dalı.; Bursa Uludağ Üniversitesi/Veteriner Fakültesi/Patoloji Anabilim Dalı.; Bursa Uludağ Üniversitesi/Veteriner Fakültesi/Histoloji ve Embriyoloji Anabilim Dalı.; 0000-0002-8287-6617; 0000-0003-1263-3799; 0000-0003-0796-5000; 0000-0002-7698-0872; 0000-0001-8519-8375; S-2474-2018; GCY-0775-2022; DTZ-3578-2022; AAH-4275-2021; HNI-3945-2023; ABI-4164-2020Tumor cells increase glucose metabolism through glycolysis and pentose phosphate pathways to meet the bioenergetic and biosynthetic demands of rapid cell proliferation. The family of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatases (PFKFB1-4) are key regulators of glucose metabolism via their synthesis of fructose-2,6-bisphosphate (F2,6BP), a potent activator of glycolysis. Previous studies have reported the co-expression of PFKFB isozymes, as well as the mRNA splice variants of particular PFKFB isozymes, suggesting non-redundant functions. Majority of the evidence demonstrating a requirement for PFKFB activity in increased glycolysis and oncogenic properties in tumor cells comes from studies on PFKFB3 and PFKFB4 isozymes. In this study, we show that the PFKFB2 isozyme is expressed in tumor cell lines of various origin, overexpressed and localizes to the nucleus in pancreatic adenocarcinoma, relative to normal pancreatic tissue. We then demonstrate the differential intracellular localization of two PFKFB2 mRNA splice variants and that, when ectopically expressed, cytoplasmically localized mRNA splice variant causes a greater increase in F2,6BP which coincides with an increased glucose uptake, as compared with the mRNA splice variant localizing to the nucleus. We then show that PFKFB2 expression is required for steady-state F2,6BP levels, glycolytic activity, and proliferation of pancreatic adenocarcinoma cells. In conclusion, this study may provide a rationale for detailed investigation of PFKFB2's requirement for the glycolytic and oncogenic phenotype of pancreatic adenocarcinoma cells.Item PFKFB2: Different roles of distinct splices(Elsevier, 2017-11) Chesney, Jason A.; Özcan, C. C.; Balaban, B. D.; Solakoğlu, T. H.; Güzel, Saime; Abdullah, Yalçın; Uludağ Üniversitesi/Veteriner Fakültesi/Biyokimya Anabilim Dalı.; 0000-0001-8519-8375; 0000-0003-0796-5000; AAA-6938-2022; ABI-4164-2020Item Selective inhibition of choline kinase simultaneously attenuates MAPK and PI3K/AKT signaling(Springernature, 2010-01-07) Clem, Brian F.; Makoni, S.; Clem, Amy L.; Nelson, Kristin K.; Thornburg, Joshua M.; Siow, Deanna L.; Lane, Andrew N.; Brock, Stephanie E.; Goswami, Umesh; Eaton, John W.; Telang, Sucheta; Chesney, Jason A.; Yalçın, Abdullah; Uludağ Üniversitesi/Veterinerlik Fakültesi/Temel Bilimler Bölümü.; 0000-0001-8519-8375; ABI-4164-2020; 36857831000Choline is an essential anabolic substrate for the synthesis of phospholipids. Choline kinase phosphorylates choline to phosphocholine that serves as a precursor for the production of phosphatidylcholine, the major phospholipid constituent of membranes and substrate for the synthesis of lipid signaling molecules. Nuclear magnetic resonance (NMR)-based metabolomic studies of human tumors have identified a marked increase in the intracellular concentration of phosphocholine relative to normal tissues. We postulated that the observed intracellular pooling of phosphocholine may be required to sustain the production of the pleiotropic lipid second messenger, phosphatidic acid. Phosphatidic acid is generated from the cleavage of phosphatidylcholine by phospholipase D2 and is a key activator of the mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K)/AKT survival signaling pathways. In this study we show that the steady-state concentration of phosphocholine is increased by the ectopic expression of oncogenic H-Ras(V12) in immortalized human bronchial epithelial cells. We then find that small interfering RNA (siRNA) silencing of choline kinase expression in transformed HeLa cells completely abrogates the high concentration of phosphocholine, which in turn decreases phosphatidylcholine, phosphatidic acid and signaling through the MAPK and PI3K/AKT pathways. This simultaneous reduction in survival signaling markedly decreases the anchorage-independent survival of HeLa cells in soft agar and in athymic mice. Last, we confirm the relative importance of phosphatidic acid for this pro-survival effect as phosphatidic acid supplementation fully restores MAPK signaling and partially rescues HeLa cells from choline kinase inhibition. Taken together, these data indicate that the pooling of phosphocholine in cancer cells may be required to provide a ready supply of phosphatidic acid necessary for the feed-forward amplification of cancer survival signaling pathways.Item Study of PFKFB2 isoforms in pancreatic duct cells transformed with mutant K-Ras(Wiley, 2016-09) Chesney, Jason A.; Özcan, Selahattin Can; Güzel, Saime; Sevinç, Elif Demirdoğen; Balaban, Başak D.; Yalçın, Abdullah; Uludağ Üniversitesi/Veteriner Fakültesi/Biyokimya Anabilim Dalı.; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Biyoloji Bölümü.; 0000-0003-0796-5000; 0000-0001-8519-8375; HKM-4820-2023; AAH-4275-2021; IOO-2699-2023; IBX-0250-2023; ABI-4164-2020; AAA-6938-2022