Silibinin-Induced Apoptosis and Downregulation of MicroRNA-21 and MicroRNA-155 in MCF-7 Human Breast Cancer Cells / 한국유방암학회지

PURPOSE: MicroRNAs (miRNAs) have received much attention owing to their aberrant expression in various stages of cancer. In many biological processes, miRNAs negatively regulate gene expression, and may be useful in therapeutic strategies. The present study evaluated the effects of silibinin (silybin), a natural flavonoid, on miRNA expression and attempted to elucidate therapeutic targets in MCF-7 breast cancer cells. METHODS: The rates of cell proliferation and apoptosis were determined in silibinin-treated and untreated MCF-7 cells. Furthermore, the expression levels of miR-21 and miR-155 were measured in MCF-7 cells after incubation with silibinin (100 µg/mL), and the putative targets of the miRNAs within the apoptotic pathways were predicted using bioinformatic approaches. The expression levels of some of these targets were evaluated by quantitative reverse transcription polymerase chain reaction (qRT-PCR). RESULTS: Silibinin induced apoptosis in MCF-7 cells in a dose- and time-dependent manner. qRT-PCR analysis revealed a decrease in miR-21 and miR-155 expression levels in silibinin-treated cells relative to the levels in the untreated cells. Potential miR-21 and miR-155 targets within the apoptotic pathways, such as CASP-9, BID, APAF-1, CASP-3, CASP-8, and PDCD4, were predicted by in silico analysis. qRT-PCR analysis showed upregulation of some of these potential targets including caspase-9 (CASP-9) and BID after silibinin treatment for 48 hours. CONCLUSION: Our results suggest a correlation between the expression of miR-21 and miR-155, and MCF-7 cell proliferation. The antiproliferative activity of silibinin may partly be attributable to the downregulation of miR-21 and miR-155, and the upregulation of their apoptotic targets. Furthermore, the upregulation of CASP-9 and BID indicates that silibinin induces apoptosis through both the extrinsic and intrinsic pathways.

[Investigation of ERG11 gene mutations in fluconazole resistant candida albicans isolated from a number of Rasht hospitals]

Objective: Azole antifungal drugs have been a treatment option for Candida albicans infections. However, azole resistance can occur through different mechanisms such as alterations in ERG11 [lanosterol 14alpha-demethylase]. This study assesses ERG11 gene mutations in Candida albicans strains isolated from patients with Candidia volvovaginitis in a number of Rasht hospitals between 2012-2014 by direct PCR and sequencing

Methods: We identified the yeast strains by standard identification methods, such as germ tubes. Drug sensitivity was determined as MIC 90 values by the macrodilution broth method based on the CLSI protocol. We screened the resistant strains prior to DNA extraction and ERG11 gene mutations were confirmed by PCR sequencing

Results: From 40 strains, 4 showed high levels of resistance to fluconazole. Of these, two species had a MIC 90 of 512microg/ml and the other two species had a MIC 90 of 1024 microg/ml. Three strains had D116E and V456G polymorphisms

Conclusion: The most fluconazole resistant Candida albicans strains worldwide were reported. Our results suggested a correlation between the polymorphism and fluconazole resistance in the Candida albicans strains

[Investigation of free and dendrosomal curcumin effects on apoptosis induction in stem cells and cancer cell lines]

Curcumin, is the active component in turmeric [Curcuma long]. This agent induces apoptosis via inhibiting various signaling pathways. However, its poor aqueous solubility prevents its widespread application. In this study, dendrosomes with water-solubility, nano-sized dimensions and nontoxic properties, was used for curcumin delivery to cells. In the present study, the potential of dendrosomes for use as a drug delivery system was assessed in AGS, HT3, 5637, hBMSC and U87 cell lines. In order to achieve optimal concentration of drug and the most suitable cell line, the effects of different concentrations of free and dendrosomal curcumin was examined on the cell lines. Propidium iodide staining was used for determining apoptosis induction and the expression of Bax gene was investigated by semi-Q RT-PCR. Dendrosomal formulation significantly improved water solubility of highly hydrophobic curcumin in AGS cells. Flow cytometry analysis indicated 48 percent of cells treated with dendrosomal curcumin and 20 percent of cells treated with free curcumin [at the optimal concentration of drug] underwent apoptosis after 18h. Semi-Q RT-PCR results exhibited the increase of expression of Bax pro-apoptotic gene in cells treated with dendrosomal curcumin. Dendrosomal formulation, compared to free curcumin, enhanced curcumin solubility and increased apoptosis induction in treated cells. These data, together with the observation of a 50% increase of Bax gene expression confirmed the apoptotic effects of dendrosomal formulation of curcumin