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.

Healing potential of mesenchymal stem cells cultured on a collagen-based scaffold for skin regeneration

Wound healing of burned skin remains a major goal in public health. Previous reports showed that the bone marrow stem cells were potent in keratinization and vascularization of full thickness skin wounds. In this study, mesenchymal stem cells were derived from rat adipose tissues and characterized by flowcytometry. Staining methods were used to evaluate their differentiation ability. A collagen-chitosan scaffold was prepared by freeze-drying method and crosslinked by carbodiimide-based crosslinker. The results of immunecytochemistry and PCR experiments confirmed the adipose-derived stem cells [ASC] in differentiation to the keratinocytes under the treatment of keratinocyte growth factor. The isolated ASC were seeded on the scaffolds and implanted at the prepared wounds. The scaffolds without cells were considered as a control and implanted on the other side of the rat. Histopathological analyses confirmed the formation of new tissue on the scaffold-cell side after 14 days with the formation of dermis and epidermis. These results indicated the capacity of ASC in differentiation to keratinocytes and also wound healing in vivo

MICB gene expression on peripheral blood mononuclear cells and susceptibility to multiple sclerosis in north of Iran

Multiple sclerosis [MS] is an autoimmune multifactorial degenerative disease with detrimental affliction on central nervous system. MHC class I chain- related geneA,B [MICA and MICB] are nonclassical human leukocyte antigens that can affect on some diseases and also on transplantation. The purpose of this study was to evaluate the MICA and MICB MRNA expression in multiple sclerosis patients. In this study, we evaluated MICA and MICB MRNA expression in the peripheral blood mononuclear cells by reverse transcryptase-polymerase chain reaction [RT-PCR] in MS patients and normal controls. The results of this study showed that 32.6% of patients with progressive clinical outcome over expressed MICB genes in comparison with controls [p=0.002]. It is concluded that the high expression of MICB gene in MS patients is an important criterion of MS disease that it may be due to the interaction between MICB and its receptor on CD8+T or NK cells

[ prevalence of dental fluorosis and its relationship with level of waters fluoride in 12-15 years old guidance school students in center part of Iran]

This study investigates the prevalence of dental fluorosis and its relationship with level of fluoride in drinking water among children aged 12-15 years old throughout a community in center part of Iran. The study was cross-sectional and cluster random sampling and performed on 300 students [150 female and 150 male] in the Aghda and its saburb, which belongs to city of Ardakan, [one of Yazd provinces city]. The study shows that the high level of waters fluoride amount for prevalence and severity of dental fluorosis over there. For instance, the rate of waters fluoride in Mazrae No village [1.57 PPM] that compare to Aghda village [0.44 PPM] show more pervalance of dental fluorosis in Mazrae No than Aghda. Considering to statistical result, there are no clear relationship between age, upper jaw and lower jaw with fluorosis. Considering the average level of fluorid in water [1.05 PPM] and averge local temperature [26.1?C] whit the community fluorosis index [CFI] for this area [0.86], we conclude that the rate of waters fluoride in drinking water for this area is well above the W.H.O recommendation.Finally, we suggest that the rate of fluorid should be reduced in local drinking water