Nnav1.5 Sodyum Kanalı ve Noç-4 Reseptör Sinyalinin Baskılanmasının İnsan Meme Kanseri Hücrelerinde Çoğalma ve Metastatik Potansiye Üzerine Etkisinin İncelenmesi

Abstract

The incidence of breast cancer is rapidly increasing and it is one of the major causes of death. The molecular changes leading to malignant transformation and metastasis of mammary cells is studied intensively. The expression of neonatal form of sodium channel nNav1.5 and overexpression of Notch-4 receptor is one these molecular changes. The aim of this thesis is to investigate the effect of the inhibition of these two molecules on the proliferation and metastatic behaviour of higly metastatic MDA-MB-231 human breast cancer cell as well as the interaction between these molecular systems. For this purpose, sodium ion channel was inhibited phenytoin by an anticonvulsive agent and the Notch-4 receptor was inhibited N-[N-(3,5-Difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT) by gamma secretase inhibitor. The dose dependent effects of these inhibitors were detected by real time polimerase chain reaction (RT-PCR). Metastatic properties were analysed by gelatin zymography and wound healing methods. Furthermore, another metastatic property, MMP-9/TIMP-1 ratio was followed by RT-PCR. Resulted in inhibition of Notch receptor signalling and sodium ion channel, cell motility, MMP-9 protein expression and MMP-9/TIMP-1 proportion decreased significantly. On the other hand, DAPT inhibits both molecules and when used in combination with phenytoin decreases MMP-9/TIMP-1 ratio significantly reducing the metastatic power of cancer cells. Thus, an interaction exists between nNav1.5 and Notch-4 receptor and both of these molecules may be considered as targets for anti-metastatic therapy.