Browsing by Author "Selli, Cigdem"

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Citation - WoS: 18
Citation - Scopus: 19
Differential Expression of Store-Operated Calcium- and Proliferation-Related Genes in Hepatocellular Carcinoma Cells Following Trpc1 Ion Channel Silencing
(Springer, 2016) Selli, Cigdem; Pearce, Dominic A.; Sims, Andrew H.; Tosun, Metiner
TRPC1 and store-operated Ca2+ (SOC) entry have previously been associated with hepatocellular carcinoma cell proliferation. The aim of the study was to determine genes and processes associated with TRPC1 down-regulation and the resulting increase of SOC entry and decrease in hepatocellular carcinoma cell proliferation. For this purpose, transcriptome analysis was performed to determine differentially expressed genes in TRPC1-silenced Huh7 cells. SOC entry- and proliferation-related genes correlated with TRPC1 down-regulation were also examined. Changes in SOC entry and cell proliferation were monitored in the TRPC1-silenced and parental cells and found to be significantly increased and decreased, respectively, in TRPC1-silenced cells. A total of 71 genes were significantly differentially expressed (40 up- and 31 down-regulated), including four mitogen-activated protein kinase (MAPK) signalling-associated genes. STIM1 levels were significantly up-regulated and negatively correlated with TRPC1 levels. In addition, expression of two cell cycle regulation genes, CDK11A/11B and URGCP, was observed to decrease, whereas ERBB3 and FGFR4, pro-survival genes, increased significantly in TRPC1-silenced cells. In conclusion, these results suggest reciprocal alterations in TRPC1 and STIM1 levels and a role for STIM1 in the regulation of SOC entry in TRPC1-silenced Huh7 cells. In addition to TRPC1, STIM1 may participate in Huh7 cell proliferation by regulating SOC entry. Alterations in MAPK signalling genes may be involved in diminished cell proliferation in TRPC1-silenced Huh7 cells. Similarly, changes in cell cycle regulating genes in TRPC1-silenced cells indicate possible cell cycle arrest along with compensatory up-regulation of ERBB3 growth factor receptor-amongst others-to maintain hepatocellular carcinoma cell proliferation.
Citation - Scopus: 1
Effects of 1-(2 (trim) on Receptor-Independent And-Dependent Contractile Responses in Rat Aorta
(Tubitak Scientific & Technical Research Council Turkey, 2016) Selli, Cigdem; Erac, Yasemin; Tosun, Metiner
Background/aim: This study investigates whether 1-(2-trifluoromethylphenyl)-imidazole (TRIM), originally proposed as a nitric oxide synthase inhibitor and also suggested to be an inhibitor of store-operated calcium entry in mouse anococcygeal muscle, inhibits receptor-independent and -dependent responses in rat thoracic aorta. Materials and methods: Cyclopiazonic acid-and serotonin-induced vascular responses were investigated in aortic segments isolated from male Sprague Dawley rats using isolated tissue experiments. Changes in intracellular calcium levels were also monitored via front surface fluorescence measurements in fura-2-loaded embryonic rat vascular smooth muscle cell line A7r5. Results: TRIM inhibited serotonin-mediated vascular contractions without affecting cyclopiazonic acid-induced responses. In addition, TRIM caused a nonlinear rightward shift in the serotonin concentration-response curve, possibly via serotonin receptor modulation. Conclusion: TRIM may have an impact on investigation of tissue-specific receptor-independent and -dependent vascular responses. It may also be used as a lead compound in the development of selective serotonin receptor modulators.
Citation - WoS: 6
Citation - Scopus: 7
Effects of Cell Seeding Density on Real-Time Monitoring of Anti-Proliferative Effects of Transient Gene Silencing
(Bmc, 2016) Selli, Cigdem; Erac, Yasemin; Tosun, Metiner
Background: Real-time cellular analysis systems enable impedance-based label-free and dynamic monitoring of various cellular events such as proliferation. In this study, we describe the effects of initial cell seeding density on the anti-proliferative effects of transient gene silencing monitored via real-time cellular analysis. We monitored the realtime changes in proliferation of Huh7 hepatocellular carcinoma and A7r5 vascular smooth muscle cells with different initial seeding densities following transient receptor potential canonical 1 (TRPC1) silencing using xCELLigence system. Huh7 and A7r5 cells were seeded on E-plate 96 at 10,000, 5000, 1250 and 5000, 2500 cells well(-1), respectively, following silencing vector transfection. The inhibitory effects of transient silencing on cell proliferation monitored every 30 min for 72 h. Results: TRPC1 silencing did not inhibit the proliferation rates of Huh7 cells at 10,000 cells well(-1) seeding density. However, a significant anti-proliferative effect was observed at 1250 cells well(-1) density at each time point throughout 72 h. Furthermore, significant inhibitory effects on A7r5 proliferation were observed at both 5000 and 2500 cells well(-1) for 72 h. Conclusions: Data suggest that the effects of transient silencing on cell proliferation differ depending on the initial cell seeding density. While high seeding densities mask the significant changes in proliferation, the inhibitory effects of silencing become apparent at lower seeding densities as the entry into log phase is delayed. Using the optimal initial seeding density is crucial when studying the effects of transient gene silencing. In addition, the results suggest that TRPC1 may contribute to proliferation and phenotypic switching of vascular smooth muscle cells.
Citation - WoS: 4
Citation - Scopus: 4
Trpc1 Ion Channel Gene Regulates Store-Operated Calcium Entry and Proliferation in Human Aortic Smooth Muscle Cells
(Tubitak Scientific & Technical Research Council Turkey, 2016) Erac, Yasemin; Selli, Cigdem; Tosun, Metiner
This study investigates whether the reciprocal changes in transient receptor potential canonical (TRPC) 1 and TRPC6 expressions, which have previously been observed in aging rat aorta, are functional in store-operated calcium (SOC) entry and proliferation in human vascular smooth muscle cells. TRPC1 levels were modulated via silencing and overexpression vectors in human primary aortic smooth muscle cells. Following TRPC1 gene modulation, TRPC1 and TRPC6 expression levels were measured using quantitative real-time RT-PCR. In functional analyses, real-time changes in intracellular calcium levels and cell proliferation were determined. Microarray analysis was performed to identify genes associated with functional alterations following TRPC1 silencing. TRPC1 expression was significantly increased in TRPC1-overexpressing cells and inhibited in TRPC1-silenced cells, as expected. TRPC6 expression was significantly decreased in TRPC1-overexpressing cells but not affected by TRPC1 silencing. SOC entry was significantly enhanced in TRPC1-silenced cells but not altered by TRPC1-overexpression. Furthermore, cell proliferation was correlated with changes in TRPC1 expression. Microarray analysis revealed that cell cycle-associated genes were significantly differentially expressed in TRPC1-silenced cells. In addition, STIM1 levels were downregulated significantly following TRPC1 silencing. Data suggest that TRPC1 has a functional role in SOC entry regulation as well as in human aortic smooth muscle cell proliferation.