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ALTUN, SEYHAN

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ALTUN

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SEYHAN

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Now showing 1 - 4 of 4
  • PublicationOpen Access
    Riluzole: Anti-Invasive Effects on Rat Prostate Cancer Cells Under Normoxic and Hypoxic Conditions
    (Blackwell Publishing Ltd., 2020) Rizaner, Nahit; Uzun, Sercan; Fraser, Scott P.; Djamgoz, Mustafa B. A.; ALTUN, SEYHAN
    Anti-invasive effects of riluzole and ranolazine, a neuro-protectant and an anti-anginal drug, respectively, on Mat-LyLu rat prostate cancer (PCa) cells were tested in vitro (a) at non-toxic doses and (b) under both normoxic and hypoxic conditions, the latter common to growing tumours. Tetrodotoxin (TTX) was used as a positive control. Hypoxia had no effect on cell viability but reduced growth at 48 hours. Riluzole (5 μmol/L) or ranolazine (20 μmol/L) had no effect on cell viability or growth under normoxia or hypoxia over 24 hours. Matrigel invasion was not affected by hypoxia but inhibited by TTX, ranolazine and riluzole under a range of conditions. The expression of Nav1.7 mRNA, the prevailing, pro-invasive voltage-gated sodium channel α-subunit (VGSCα), was up-regulated by hypoxia. Riluzole had no effect on Nav1.7 mRNA expression in normoxia but significantly reduced it in hypoxia. VGSCα protein expression in plasma membrane was reduced in hypoxia; riluzole increased it but only under hypoxia. It was concluded (a) that riluzole and ranolazine have anti-invasive effects on rat PCa cells and (b) that Nav1.7 mRNA and protein expression can be modulated by riluzole under hypoxia. Overall, therefore, riluzole and ranolazine may ultimately be "repurposed" as anti-metastatic drugs against PCa.
  • PublicationRestricted
    Lidocaine Inhibits Rat Prostate Cancer Cell Invasiveness and Voltage-Gated Sodium Channel Expression in Plasma Membrane
    (Springer, 2024) Rizaner, Nahit; Fraser, Scott P.; Gül, İlknur Bugan; Purut, Esma; Djamgoz, Mustafa B. A.; ALTUN, SEYHAN
    There is increasing evidence, mostly from breast cancer, that use of local anaesthetics during surgery can inhibit disease recurrence by suppressing the motility of the cancer cells dependent on inherent voltage-gated sodium channels (VGSCs). Here, the possibility that lidocaine could affect cellular behaviours associated with metastasis was tested using the Dunning cell model of rat prostate cancer. Mostly, the strongly metastatic (VGSC-expressing) Mat-LyLu cells were used under both normoxic and hypoxic conditions. The weakly metastatic AT-2 cells served for comparison in some experiments. Lidocaine (1-500 mu M) had no effect on cell viability or growth but suppressed Matrigel invasion dose dependently in both normoxia and hypoxia. Used as a control, tetrodotoxin produced similar effects. Exposure to hypoxia increased Nav1.7 mRNA expression but VGSC alpha protein level in plasma membrane was reduced. Lidocaine under both normoxia and hypoxia had no effect on Nav1.7 mRNA expression. VGSC alpha protein expression was suppressed by lidocaine under normoxia but no effect was seen in hypoxia. It is concluded that lidocaine can suppress prostate cancer invasiveness without effecting cellular growth or viability. Extended to the clinic, the results would suggest that use of lidocaine, and possibly other local anaesthetics, during surgery can suppress any tendency for post-operative progression of prostate cancer.
  • Publication
    Anti-metastatic effect of ranolazine in an in vivo rat model of prostate cancer, and expression of voltage-gated sodium channel protein in human prostate
    (2019-03-20) Bugan, İlknur; Küçük, Selma; Karagöz, Zeynep; Fraser, SP; Kaya, Handan; Dodson; Foster, Cs; Djamgoz, Mba; ALTUN, SEYHAN; 4995
    Background Voltage-gated Na+ channels (VGSCs) are functionally upregulated in rat and human prostate cancer (PCa) where channel activity promotes cellular invasiveness in vitro and metastasis in vivo. Ranolazine is a clinically used VGSC inhibitor/anti-anginal drug, which has been shown previously to inhibit breast cancer metastasis in vivo. Methods Using the Dunning model of rat PCa, the effect of ranolazine applied systemically (by gavage) was tested on the development of primary tumours and metastases following subcutaneous inoculation of Mat-LyLu cells into Copenhagen rats. In addition, human prostate tissue microarrays were used to determine VGSC protein expression in cancerous versus non-cancerous tissue. Several public databases were searched to compare Nav1.7/ SCN9A expression levels in ‘normal’ vs. PCa tissues. Results Ranolazine (2.5 and 5 µM) decreased the number of lung metastases by up to 63%. In contrast, primary tumourigenesis was not affected. Ranolazine also reduced the percentage of cells in the metastases expressing Nav1.7, the main VGSC subtype expressed in PCa, but the expression level was higher. In prostate tissue microarrays, VGSC protein expression was significantly higher in cancerous versus non-cancerous tissue. There was no correlation between the VGSC expression and either prostate-specific antigen or Gleason score. In public databases, little information could be found on Nav1.7 protein expression in PCa. In addition, the database information on Nav1.7 mRNA (SCN9A) expression levels did not correlate with previously reported upregulation in PCa cells and tissues. Conclusions The main conclusions were (i) ranolazine inhibited metastasis and (ii) it was a subpopulation of cells with particularly high levels of Nav1.7 protein that reached the metastatic sites. These data extend earlier studies and suggest that Nav1.7 expression could serve as a functional biomarker of metastatic PCa and that VGSC blockers may be useful as antimetastatic agents.
  • PublicationRestricted
    The Protective Effect of Metformin Against Testicular Damage in Diabetes and Prostate Cancer Model
    (Wiley, 2022) Aydın, Pınar Köroğlu; Karabulut-Bulan, Ömür; Bugan, İlknur; Türkyılmaz, İsmet Burcu; ALTUN, SEYHAN; Yanardağ, Refiye
    Individuals with diabetes have an increased risk of breast, colorectal, pancreatic and prostate cancer. Metformin, an oral biguanide used to treat diabetes, has anti-hyperglycaemic, anti-hyperinsulinemic and antioxidant activities. The effects of metformin on testicular tissue damage in cancer and diabetic + cancer rat models were evaluated histologically, immunohistochemically and biochemically. The diabetic model was produced in Copenhagen rats using a single dose of streptozotocin (65 mg/kg), while prostate cancer was induced through subcutaneous inoculation of 2 x 10(4) Mat-LyLu cells into the animals. At the end of the experimental period, testicular tissues with a close functional relationship to the prostate were collected. Histological evaluation found moderate to severe damage to testes following the diabetes and cancer process. Histopathological and biochemical impairments were observed in the early stage of prostate cancer, which were increased in the diabetic animals. Metformin administration reversed these injuries and provided substantial protection of the testes. In particular, metformin had protective effects on tissue damage, apoptosis, oxidative stress and antioxidant capacity. This suggests that metformin should be further investigated as a targeted protective drug against prostate cancer-related damage to the testes.