Increasing Breast Cancer Cells’ Sensitivity in Response to Quercetin via Declining DFF45/ICADExpression Level

Nowadays RNA interference (RNAi) technology is used as a new methodology in cancertherapy. RNAi can probably decrease the expression of genes by sending a double-strandedRNA- in which - sequence of a strand that complements the sequence of a specific gene,make the target mRNA to be cleaved. In recent years, Flavonoids like Quercetin are knownas an anti-cancer agent. The Quercetin Effectiveness mechanism has been reported to bethrough Cell cycle arrest, inhibition of proliferation and induction of apoptosis. The purpose ofthis study is to decrease Quercetin’s side effects by increasing breast cancer cells’sensitivity to prepare an environment for displaying Quercetin cytotoxicity in lowerconcentrations. The drug cytotoxicity on MCF-7 cell line, assessed by MTT test with 48 hoursof Quercetin treatment. Total RNAs were extracted from cells incubated with Quercetin andQuercetin+DFF45 siRNA. The gene expression levels were detected by Real time PCR.According to the cell viability diagrams, the LC50 value for Quercetin was determined 220ÂμM. Real time PCR results indicate that the simultaneous treatment of Quercetin andDFF45 siRNA decreases the expression of DFF45 and increases the expression of DFF40.Analysis of Apoptotic (caspase3, p53, bax, bcl-2 and aif) and autophagic (lc3, atg5, beclinand dram) genes along with survival genes (akt and mtor) reveals that Quercetin+DFF45siRNA completely blocked the apoptosis and down regulate survival genes but triggerautophagy pathway. One of the regulating pathway of Apoptosis is forcing the inhibitory effectof DFF45/ICAD on DFF40/CAD nuclease. Down regulation of DFF45/ICAD or DFF40/CADoverexpression, when applied with Quercetin, leads to induction of Apoptosis, may offer anovel therapeutic strategy for treatment of breast cancer.

کلیدواژه ها:

Quercetin ، DFF45 ، siRNA ، MCF-7 ، Breast Cancer