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Öğe Esculetin Inhibits the Survival of Human Prostate Cancer Cells by Inducing Apoptosis and Arresting the Cell Cycle(Korean Soc Cancer Prevention, 2018) Turkekul, Kader; Colpan, R. Dilsu; Baykul, Talha; Ozdemir, Mehmet D.; Erdogan, SuatBackground: Prostate cancer (PCa) is one of the most important causes of death in men and thus new therapeutic approaches are needed. In this study, antiproliferative and anti-migration properties of a coumarin derivative esculetin were evaluated. Methods: Human PCa cell lines PC3, DU145, and LNCaP were treated with various concentrations of esculetin for 24 to 72 hours, and cell viability was determined by the MTT test. Cell cycle and apoptosis were analyzed by using cell-based cytometer. Gene expression levels were assessed by reverse transcription and quantitative real-time PCR, cell migration was determined by the wound healing assay. The protein expression was measured by Western blotting. Results: Esculetin inhibited cell proliferation in a dose- and time-dependent manner. Cell migration was inhibited by esculetin treatment. Administration of esculetin significantly reduced the cells survival, induced apoptosis and caused the G1 phase cell cycle arrest shown by image-based cytometer. The induced expression of cytochrome c, p53, p21 and p27, and down-regulated CDK2 and CDK4 may be the underlying molecular mechanisms of esculetin effect. Esculetin suppressed phosphorylation of Akt and enhanced protein expression of tumor-suppressor phosphatase and tensin homologue. Conclusions: Our findings showed that the coumarin derivative esculetin could be used in the management of PCa. However, further in vivo research is needed.Öğe Esculetin Protects Human Retinal Pigment Epithelial Cells from Lipopolysaccharide-induced Inflammation and Cell Death(Taylor & Francis Inc, 2018) Ozal, S. Altan; Turkekul, Kader; Gurlu, Vuslat; Guclu, Hande; Erdogan, SuatPurpose: Age-related macular degeneration (AMD) is the most common cause of visual loss. The dry AMD is characterized by retinal pigment epithelium (RPE) death and changes in AMD lead to severe loss of vision. Coumarin-derived esculetin has a number of therapeutic and pharmacological effects such as anti-inflammatory and antioxidant with various mechanisms. The purpose of this study was to investigate the effects of esculetin treatment on lipopolysaccharide (LPS)-induced inflammation, oxidative stress, and cell survival.Material and methods: Human RPE cells (ARPE-19) were incubated for 24-72h with 5g/ml LPS to induce inflammation and oxidative stress. Esculetin (5 M) was used to protect the cells from LPS-induced damage. The cell viability was evaluated by quantitative 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide test. Interleukin 6 (IL-6), IL-12, and vascular endothelial growth factor (VEGF) levels were determined by enzyme-linked immunosorbent assay (ELISA). IL-1, tumor necrosis factor receptor (TNFR), TNF-related apoptosis-inducing ligand (TRAIL), catalase, glutathione peroxidase (GPx), superoxide dismutase 1 (CuZnSOD) and SOD2 (MnSOD) mRNA expressions were analyzed by RT-quantitative polymerase chain reaction. Apoptosis was monitored by cell-based cytometer. NF-kappa B (NF-B) p65/RelA levels were determined by ELISA, and NF-B protein expression and extracellular signal-regulated kinase (ERK1/2) phosphorylation were evaluated by Western blot analysis.Results: Esculetin treatment significantly suppressed LPS-induced cell death mediated by apoptosis and necrosis in a concentration-dependent manner. While LPS caused significant inflammation with cytokine increase in cells, esculetin reduced the expression of LPS-induced cytokines, VEGF, TNFR, and TRAIL. Furthermore, exposure to LPS increased the expression of GPx and mitochondrial MnSOD, leading to oxidative stress in the cells. Esculetin treatment attenuated phosphorylation of ERK1/2 and NF-B expression mediated by LPS.Conclusions: These results suggest that esculetin may be an alternative treatment option for endotoxin-induced inflammation and oxidative stress, which therefore may inhibit the development of LPS-mediated AMD.Öğe The flavonoid apigenin reduces prostate cancer CD44+ stem cell survival and migration through PI3K/Akt/NF-?B signaling(Pergamon-Elsevier Science Ltd, 2016) Erdogan, Suat; Doganlar, Oguzhan; Doganlar, Zeynep B.; Serttas, Riza; Turkekul, Kader; Dibirdik, Ilker; Bilir, AyhanAims: Cancer stem cells (CSCs) are involved in drug resistance, metastasis and recurrence of cancers. The efficacy of apigenin on cell survival, apoptosis, migration and stemness properties were analyzed in CSCs. Main methods: Prostate CSCs (CD44(+)) were isolated from human prostate cancer (PCa) PC3 cells using a magnetic-activated cell sorting system. PC3 and CSCs were treated with various concentrations of apigenin, docetaxel and their combinations for 48 h. Key findings: Apigenin dose dependently inhibited CSCs and PC3 cell survival, and this was accompanied with a significant increase of p21 and p27. Apigenin induced apoptosis via an extrinsic caspase-dependent pathway by upregulating the mRNA expressions of caspases-8,-3 and TNF-alpha, but failed to regulate the intrinsic pathway as determined by the Bax, cytochrome c (Cyt-c) and APAF-1 in CSCs. In contrary to CSCs, apigenin induced intrinsic apoptosis pathway as evidenced by the induction of Bax, Cyt-c and caspase-3 while caspase-8, TNF-alpha and Bcl-2 levels remained unchanged in PC3 cells. The flavonoid strongly suppressed the migration rate of CSCs compared to untreated cells. Significant downregulation of matrix metallopeptidases-2,-9, Snail and Slug exhibits the ability of apigenin treatment to suppress invasion. The expressions of NF-kappa B p105/p50, PI3K, Akt and the phosphorylation of pAkt were decreased after apigenin treatment. Moreover, apigenin treatment significantly reduced pluripotency marker Oct3/4 protein expression which might be associated with the down-regulation of PI3K/Akt/NF-kappa B signaling. Significance: Our data indicated that, apigenin could be a useful compound to prevent proliferation and migration of cancer cells as well as CSCs. (C) 2016 Elsevier Inc. All rights reserved.Öğe Inhibition of Midkine Suppresses Prostate Cancer CD133+ Stem Cell Growth and Migration(Elsevier Science Inc, 2017) Erdogan, Suat; Doganlar, Zeynep B.; Doganlar, Oguzhan; Turkekul, Kader; Serttas, RizaBackground: Midkine (MDK) is a tumor-promoting factor that is often overexpressed in various human carcinomas, and the role of MDK has not yet been fully investigated in prostate cancer stem cells. Materials and Methods: Prostate cancer CD133(+) stem cells (PCSCs) were isolated from human castration-resistant PC3 cells. PCSCs were treated with different concentrations of MDK inhibitor, iMDK, for 24-72 hours. The IC50 values were determined by the MTT test. Endogenous MDK messenger RNA expression was knocked down by small interfering RNA. Quantitative reverse transcription polymerase chain reaction, Western blot analyses and image-based cytometry were used to investigate apoptosis and cell cycle progression as well as their underlying molecular mechanisms. Cell migration was evaluated by the wound healing test. Results: iMDK caused dose- and time-dependent inhibition of PCSC survival. Similar growth inhibition was also obtained by small interfering RNA mediated knockdown of endogenous MDK expression. iMDK was shown to preferentially induce cell cycle arrest at the S and G2/M phases. Suppressed PCSC growth was also accompanied by increases in p53 and the cell cycle inhibitor p21 genes. Combinatorial treatment of iMDK with docetaxel significantly inhibited cell proliferation versus either of the agents used alone. Inhibition of MDK expression strongly suppressed the migration of PCSCs compared to untreated and docetaxel-treated cells. iMDK and the knockdown of MDK decreased p-Akt and significantly upregulated the expression of PI3K/phosphatase/tensin homolog. Conclusions: Our data indicate that MDK plays a crucial role in controlling PCSC proliferation and migration. Therefore, suppression of endogenous expression of MDK would, in combination with traditional chemotherapy drugs, be a potential treatment for PCSCs.Öğe Midkine downregulation increases the efficacy of quercetin on prostate cancer stem cell survival and migration through PI3K/AKT and MAPK/ERK pathway(Elsevier France-Editions Scientifiques Medicales Elsevier, 2018) Erdogan, Suat; Turkekul, Kader; Dibirdik, Ilker; Doganlar, Oguzhan; Doganlar, Zeynep B.; Bilir, Ayhan; Oktem, GulperiAims: To examine the functions of growth factor midkine (MK) and a flavonoid quercetin on survival, apoptosis and migration of prostate cancer (PCa) stem cells (CSCs). Main methods: CD44(+)/CD133(+) and CD44(+) stem cells were isolated from PC3 and LNCaP cells, respectively by magnetic-activated cell sorting system. 3D cell culture was used to evaluate the ability of quercetin, MK siRNA, and the combination of both to inhibit spheroid formation, apoptosis and cell cycle arrest. Image-based cytometer, RT-qPCR, Western blotting and transwell migration assays were performed. Key findings: Quercetin treatment for 24-72 h inhibited PC3 and CD44+/CD133+ stem cell proliferation in a time-and dose-dependent manner. Knockdown of endogenous MK expression significantly suppressed proliferation of CD44(+)/CD133(+) and CD44(+) cells as well as their parent cells. Co-administration of MK siRNA and quercetin reduced the cell survival, induced apoptosis and caused G1 phase cell cycle arrest more effectively than the individual therapy. Knockdown of MK significantly enhanced the inhibitory effect of quercetin on CD44(+)/CD133(+) migration and spheroid formation. In addition, the combined therapy inhibited the phosphorylation of PI3K, AKT and ERK1/2, and reduced the protein expression of p38, ABCG2 and NF-kappa B. Significance: Quercetin alone exhibited significant cytotoxic effects on CD44(+)/CD133(+). MK plays an important role in the proliferation of CD44(+)/CD133(+) and CD44(+) cells in particular, and quercetin and MK-silencing therapy may be an important strategy in targeting CSCs that play a role in relapse, migration and drug resistance.Öğe Midkine silencing enhances the anti-prostate cancer stem cell activity of the flavone apigenin: cooperation on signaling pathways regulated by ERK, p38, PTEN, PARP, and NF-?B(Springer, 2020) Erdogan, Suat; Turkekul, Kader; Dibirdik, Ilker; Doganlar, Zeynep B.; Doganlar, Oguzhan; Bilir, AyhanProstate cancer (PCa) is the most common cancer in men worldwide. Midkine (MK) is overexpressed in PCa, as well as in tumor-initiating cells termed cancer stem cells (CSCs). Apigenin is a dietary flavone with considerable anti-tumor activities. In this study, we explored the possible therapeutic use of MK silencing, apigenin treatment, and a combination of both on human PCa and prostate cancer stem cells (PCSCs). CD44(+)CD133(+) PC3 and CD44(+) LNCaP CSCs were isolated from their parent cell lines. Both MK knockdown and apigenin treatment resulted in loss of cell viability in PCSCs, and these effects were significantly elevated when apigenin was applied with MK silencing. Combined treatment of CD44(+)CD133(+) PC3 cells with apigenin and MK siRNA was also more effective in inducing apoptotic and non-apoptotic cell death when compared with individual applications. Treatment of CD44(+) LNCaP cells with apigenin significantly decreased viability, although the combination treatment did not markedly alter the individual therapy. Molecular events underlying cell cycle arrest and inhibition of the survival, proliferation, and migration of CD44(+)CD133(+) PC3 cells were found to be associated with upregulated p21, p27, Bax, Bid, caspase-3, and caspase-8 expression, as well as downregulated p-p38, p-ERK, NF-kappa B, and PARP. In addition, the combination of apigenin treatment and MK silencing showed better outcomes on the anticancer efficacy of docetaxel in CD44(+)CD133(+) PC3 cells. In conclusion, MK-regulated events are different between PCSCs, and when combined with apigenin plus MK silencing, docetaxel treatment may be a valuable approach for the eradication of PCSCs.Öğe Multifaceted impact of adipose conditioned media: Obesity-driven promotion of prostate cancer and cancer stem cell dynamics(Wiley, 2024) Erdogan, Suat; Serttas, Riza; Dibirdik, Ilker; Turkekul, KaderObesity is an established risk factor for the development and progression of prostate cancer (PC). This study used adipose conditioned media (ACM) from differentiated adipocytes to assess its effect on PC development and aggressiveness. Due to limited research on ACM's impact on isolated PC stem cells (PCSCs), we also examined CD44+ PCSCs. ACM notably boosted interleukin-1 beta (IL-1 beta), IL-6, and IL-8 production in normal prostate epithelial cells and LNCaP cells. It also increased IL-6 and IL-8 production in PC3 and CD44+ LNCaP cells, and IL-1 beta and IL-6 production in CD44+ PC3 cells. This indicates that ACM induces the production of inflammatory cytokines in both cancer and prostate epithelial cells. Furthermore, ACM promoted proliferation in androgen receptor (AR)-negative PC3 cells, CD44+ PC3 PCSCs, and nonmalignant RWPE cells, without affecting AR-positive LNCaP cells. In addition, ACM-enhanced invasion and migration potential in both PC3 and CD44+ PC3 cells. Western blot analysis indicated the involvement of NF-kappa B and AKT pathways in ACM-induced proliferation in PC3 cells and NF-kappa B in PCSCs. In ACM-treated PC3 cells, E-cadherin was downregulated, while N-cadherin, Snail, vimentin, fibronectin, and Twist were upregulated, suggesting ACM-induced invasion via classical epithelial-to-mesenchymal transition (EMT) pathways. In response to ACM, PCSCs exhibited increased expression of E-cadherin, Snail, and vimentin, which are partial EMT markers promoting stemness and resistance to apoptosis. In addition, increased expressions of Nanog, Oct3/4, survivin, and Bcl-2 were observed. Although the molecules we studied have diverse effects on cellular regulation, our data emphasize obesity's multifaceted role in promoting and aggressing PC, notably affecting PCSC populations. The link between cancer and obesity has been well-established. Excess adipocyte tissue can promote inflammation and hormone imbalances, all of which contribute to cancer development. This study investigated the effectiveness of adipose tissue secretions on different types of prostate cancer (PC) cells, the proliferation and migration of normal prostate epithelial cells. The findings revealed that adipose tissue contributed to the proliferation, invasion, and migration of PC and cancer stem cells. In addition, it showed a potential relationship between adipose tissue and the proliferation of normal prostate epithelial cells.Öğe Naringin sensitizes human prostate cancer cells to paclitaxel therapy(Elsevier, 2018) Erdogan, Suat; Doganlar, Oguzhan; Doganlar, Zeynep B.; Turkekul, KaderBackground: The aim of the study was to evaluate whether the use of chemotherapy in combination with naringin, a dietary plant polyphenolic flavonoid, could enhance the therapeutic efficacy of paclitaxel treatment in human prostate cancer (PCa) cells. Materials and methods: DU145, PC3, and LNCaP cells were treated with various concentrations of paclitaxel, naringin, and their combinations. Methylthiazolyldiphenyl-tetrazolium bromide (MTT), image-based cytometer, quantitative reverse transcription PCR (RT-qPCR), Western blot, and transwell assay were used to evaluate cell viability, apoptosis and cell cycle, the mRNA expression, protein expression, and cell migration, respectively. Results: Naringin treatment inhibited cell survival in a dose- and time-dependent manner by inducing apoptosis and cell cycle arrest in G1 phase. Among the pathways evaluated, naringin (150 mu M) significantly induced the mRNA expressions of BAX, BID, caspase 3, cytochrome c, p53, p21(Cip1), and p27(Kip1) and down-regulated the expressions of survivin and livin in DU145 cells. The combination of naringin and paclitaxel treatments synergistically increased the cytotoxic effects of paclitaxel in androgen-independent DU145 and PC3 cells, as well as in androgen-sensitive LNCaP cells. The combination of naringin with docetaxel has almost the same inhibitory effect on cell proliferation as the paclitaxel combination in androgen-independent cells, whereas there is no similar effect in LNCaP cells. Naringin exhibits significant inhibitory effects on the cell migration ability. The flavonoid either alone or in combination with paclitaxel therapy resulted in an increase in tumor suppressor PTEN (phosphatase and tensin homolog deleted on chromosome 10) protein expression and decrease in nuclear factor-kB p50 protein level in DU145 cells. Conclusion: In conclusion, naringin acts as a chemosensitizer which synergistically strengths the cytotoxic effect of paclitaxel in PCa cells. Therefore, naringin therapy alone or in combination with paclitaxel may be useful in the treatment of PCa. However, there is a need for more detailed in vivo studies of the mechanism of action. (C) 2017 Asian Pacific Prostate Society, Published by Elsevier Korea LLC.Öğe The natural flavonoid apigenin sensitizes human CD44+ prostate cancer stem cells to cisplatin therapy(Elsevier France-Editions Scientifiques Medicales Elsevier, 2017) Erdogan, Suat; Turkekul, Kader; Serttas, Riza; Erdogan, ZeynepProstate cancer (PCa) is the second most common type of cancer and the fifth leading cause of cancerrelated death among men. Development of chemoresistance, tumor relapse and metastasis remain major barriers to effective treatment and all been identified to be associated with cancer stem cells (CSCs). Natural flavonoids such as apigenin have been shown to have the ability to improve the therapeutic efficacy of common chemotherapy agents through CSCs sensitization. Thus, the aim of this study was to evaluate the combination of apigenin with cisplatin on CD44(+) PCa stem cell growth and migration. Platinum-based anti-neoplastic drugs have been used to treat a number of malignancies including PCa. However, acquired resistance and side effects unfortunately have limited cisplatin's use. A CD44(+) subpopulation was isolated from human androgen-independent PC3 PCa cells by using human CD44-PE antibody. IC50 values were determined by MTT test. RT-qPCR, Western blot analyses and image-based cytometer were used to investigate apoptosis, cell cycle and their underlying molecular mechanisms. Cell migration was evaluated by wound healing test. The combination of the IC50 doses of apigenin (15 mu M) and cisplatin (7.5 mu M) for 48 h significantly enhanced cisplatin's cytotoxic and apoptotic effects through downregulation of Bcl-2, sharpin and survivin; and upregulation of caspase-8, Apaf-1 and p53 mRNA expression. The combined therapy suppressed the phosphorylation of p-PI3K and p-Akt, inhibited the protein expression of NF-kB, and downregulated the cell cycle by upregulating p21, as well as cyclin dependent kinases CDK-2, -4, and -6. Apigenin significantly increased the inhibitory effects of cisplatin on cell migration via downregulation of Snail expression. In conclusion, our study showed the possible therapeutic approach of using apigenin to potentially increase the effects of cisplatin by targeting CSCs subset in prostate cancer. (C) 2017 Elsevier Masson SAS. All rights reserved.Öğe Neferine inhibits epidermal growth factor-induced proliferation and migration of retinal pigment epithelial cells through downregulating p38 MAPK and PI3K/AKT signalling(Taylor & Francis Ltd, 2020) Ozal, Sadik Altan; Gurlu, Vuslat; Turkekul, Kader; Guclu, Hande; Erdogan, SuatPurpose: Proliferative vitreoretinopathy (PVR) occurs in approximately 5-10% of patients after retinal detachment surgery. Neferine is a bis-benzylisoquinoline alkaloid found in the green seed embryos (Nelumbo nucifera) of the lotus flower and has various properties, such as being antithrombotic, antioxidant, neuroprotective, anticancerous, and anti-inflammatory. Although the effects of neferine on the proliferation and migration of cancer cells have been partially shown, their possible role and the mechanism of action on PVR remain unclear. Materials and methods: To mimic a PVR model in vitro, retinal pigment epithelial (RPE) cells were exposed to epidermal growth factor (EGF) and treated with various concentrations of neferine. Cell viability was determined by MTT test. Cell-cycle phase distribution and cell migration were examined by image-based cytometry and wound healing test, respectively. Messenger RNA (mRNA) and protein expression were determined by RT-qPCR and Western blotting, respectively. Results: Stimulation of the cells with EGF significantly increased the rate of proliferation, whilst treatment with low concentrations of neferine-reduced proliferation to a level equal to that seen in untreated cells. Neferine significantly downregulated EGF-increased cell viability, and survivin mRNA expression was depressed to the basal level. In addition, neferine treatment contributed to cell proliferation loss by upregulating p21 and p27 expression leading to cycle arrest at the G1 phase. The treatment significantly inhibited cell migration by upregulating the expression of epithelial markers, such as E-cadherin and occludin, and decreased MMP2, MMP9, alpha-SMA, and vimentin. Neferine treatment markedly reduced phosphotidyl inositol 3-kinase (PI3K), AKT, p-p38 mitogen-activated protein kinase (MAPK), and NF-kappa B (nuclear factor kappa-light-chain-enhancer of activated B cells) protein expression. Conclusion: It can be considered that neferine may be a potential candidate molecule in the treatment of PVR by inhibiting cell proliferation and the migration of EGF-induced RPE cells through the modulation of various transcriptional activities.Öğe Neferine inhibits proliferation and migration of human prostate cancer stem cells through p38 MAPK/JNK activation(Wiley-Hindawi, 2020) Erdogan, Suat; Turkekul, KaderCancer stem cells (CSCs) are one of the significant causes of cancer treatment failure and metastasis, as they have significant chemo-and radio-resistance leading to tumor recurrence. Here we investigated the possible anticancer properties of neferine, a natural alkaloid, on human prostate cancer (PCa) cells and their stem cells. CD44(+) CSCs were isolated from androgen-insensitive PC3 cells by magnetic-activated cell sorting system (MACS). Neferine dose-and time-dependently inhibited the viability of PC3 and CSCs as well as androgen-sensitive LNCaP cells through inducing apoptosis and cell cycle arrest at G1 phase. Neferine was shown to downregulate the expression of Bcl-2 and CDK4, and upregulate caspase 3, clePARP, p21, p27, and p53. The treatment significantly inhibits the migration of CSCs. Neferine induces JNK and p38 MAPK phosphorylation, and downregulates PI3K and NF-& x138;beta signaling. In conclusion, neferine may have a therapeutic effect inhibiting the PCa cell proliferation as well as by eliminating CSCs. Practical applications Neferine is an alkaloid found in the seed embryo of Nelumbo nucifera and has recently been shown to have anticancer effects on various human cancer cells. More than 90% of cancer-related deaths develop after metastasis, and CSCs are considered to be largely responsible for the cell migration and invasion. It has been shown that treatment of neferine kills not only PCa cells but also CSCs, and may contribute to the prevention of progression of PCa and metastasis by inhibiting cell proliferation and migration.Öğe Potent Suppression of Prostate Cancer Cell Growth and Eradication of Cancer Stem Cells by CD44-targeted Nanoliposome-quercetin Nanoparticles(Korean Soc Cancer Prevention, 2023) Turkekul, Kader; Erdogan, SuatThe bioavailability of quercetin, a natural compound, is hindered by low solubility, limited absorption, and restricted systemic availability. Therefore, encapsulating it in biocompatible nanoparticles presents a promising solution. This study aimed to target prostate cancer stem cells (CSCs) overexpressing CD44+ receptors as well as cancer cells, employing quercetin-loaded hyaluronic acid-modified nanoliposomes (LP-Quer-HA). Synthesized via a green ethanol injection method, these nanoliposomes had an average diameter of 134 nm and an impressive loading efficiency of 96.9%. Human prostate cancer cells were treated with either 10 mu M of free quercetin or the same concentration delivered by LP-Quer-HA for 72 hours. Free quercetin reduced androgen-resistant PC3 cell viability by 16%, while LP-Quer-HA significantly increased cell death to 60%. It induced apoptosis, upregulating cytochrome c, Bax, caspases 3 and 8, and downregulating survivin and Bcl-2 expression. Compared to free quercetin, LP-Quer-HA upregulated E-cadherin expression while inhibiting cell migration and reducing the expression of fibronectin, N-cadherin, and MMP9. Treatment of PC3 cell tumor spheroids with LP-Quer-HA decreased the number of CD44 cells and expression of CD44, Oct3/4 and Wnt. Moreover, LP-Quer-HA inhibited p-ERK expression while increasing p38/MAPK and NF-.B protein expression. In androgen-sensitive LNCaP cells, LP-Quer-HA efficacy was notable, reducing cell viability from 10% to 52% compared to free quercetin. Utilizing HA-modified nanoliposomes as a quercetin delivery system enhanced its potency at lower concentrations, reducing the CD44+ cell population and effectively impeding prostate cancer cell proliferation and migration. These findings underscore the potential of quercetin-loaded cationic nanoliposomes as a robust therapeutic approach.Öğe Quercetin Improves Inflammation, Oxidative Stress, and Impaired Wound Healing in Atopic Dermatitis Model of Human Keratinocytes(Mary Ann Liebert, Inc, 2020) Beken, Burcin; Serttas, Riza; Yazicioglu, Mehtap; Turkekul, Kader; Erdogan, SuatBackground: Atopic dermatitis (AD) is a common inflammatory skin disease with complex pathogenesis. Natural flavonoids exhibit strong anti-inflammatory and antioxidant properties in many human diseases. In this study, the potential bioactive effect of quercetin, a polyphenolic plant-derived flavonoid, on the AD model of human keratinocytes was evaluated. Methods: Immortalized human HaCaT keratinocytes were treated with interleukin (IL) -4, -13, and tumor necrosis factor-alpha to mimic AD features in vitro. Then effects of quercetin on inflammation, oxidative stress, and wound healing were assessed. Results: Pretreatment of the cells with 1.5 mu M of quercetin significantly reduced the expression of AD-induced IL-1 beta, IL-6, IL-8, and thymic stromal lymphopoietin, while it strongly enhanced the expression of superoxide dismutase-1 (SOD1), SOD2, catalase, glutathione peroxidase, and IL-10. Quercetin promoted wound healing by inducing epithelial-mesenchymal transition, which was supported by the upregulation of Twist and Snail mRNA expression. Unexpectedly, quercetin pretreatment of AD-induced cells upregulated the mRNA expression of occludin and E-cadherin, while downregulating matrix metalloproteinase 1 (MMP1), MMP2, and MMP9 expression. The pretreatment inhibited AD-induced phosphorylation of extracellular signal-regulated kinase 1/2/mitogen-activated protein kinase (ERK1/2 MAPK) and the expression of nuclear factor-kappa B (NF-kappa B), but it did not alter signal transducer and activator of transcription 6 (STAT6) phosphorylation. Conclusion: Quercetin may serve as a potential bioactive substance for atopic dermatitis-related symptoms through anti-inflammatory and antioxidant activities along with its acceleration of wound healing via ERK1/2 MAPK and NF-kappa B pathways.Öğe The synergistic anticancer effect of salinomycin combined with cabazitaxel in CD44+prostate cancer cells by downregulating wnt, NF-?B and AKT signaling(Springer, 2022) Erdogan, Suat; Serttas, Riza; Turkekul, Kader; Dibirdik, IlkerBackground Tumor-initiating or cancer stem cells (CSCs) reduce the effectiveness of conventional therapy. Thus, it is crucial to eliminate CSCs while killing bulky cancer cells using a combination of conventional chemotherapy and anti-CSC drugs. Salinomycin is a selective inhibitor against CSCs and shows promise in combination applications. The aim of the study was to examine the efficacy of co-administered cabazitaxel and salinomycin on the survival of prostate cancer cells and CSCs. Methods and Results CD44 + stem cells were isolated from human PC3 prostate cancer cells by using magnetic activated cell sorting. The cells were concomitantly exposed to salinomycin and cabazitaxel, and the cell survival was determined by MTT test. Apoptosis was assessed by image-based cytometer, and cell migration was evaluated by wound healing assay. The expression of target mRNA and protein were assessed by RT-qPCR and Western blot, respectively. Combination index (CI) analysis showed that simultaneous administration of salinomycin and cabazitaxel was able to exert strong synergistic effect on CD44 + subpopulation (CI = 0.33), but no synergism was observed in PC3 cells. The combination of the two agents significantly increased Bax, cytochrome c, caspase-3 and - 8 mRNA expression in CD44 + CSCs, causing apoptosis. The applied therapy strategy strongly inhibited the phosphorylation of Akt, protein expression of Akt1, NF-kappa B and Wnt. Conclusions In conclusion, our data suggest that combining salinomycin with cabazitaxel shows promise as a prostate cancer treatment approach that can target CSCs.
