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Aim of the study In this study, we examined the effect of different fractions and components of Chaga mushroom (Inonotus Obliquus) on viability and apoptosis of colon cancer cells. Among them, one component showed the most effective growth inhibition and was identified as ergosterol peroxide by NMR analysis. We investigated the anti-proliferative and apoptosis mechanisms of ergosterol peroxide associated with its anti-cancer activities in human colorectal cancer (CRC) cell lines and tested its anti-tumor effect on colitis-induced CRC developed by Azoxymethane (AOM)/Dextran sulfate sodium (DSS) in a mouse model. Materials and methods We used MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays, flow cytometry assays, Western blot analysis, colony formation assays, reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry (IHC), and AOM/DSS mouse models to study the molecular mechanism of metastatic activities in CRC cells. Results Ergosterol peroxide inhibited cell proliferation and also suppressed clonogenic colony formation in HCT116, HT-29, SW620 and DLD-1 CRC cell lines. The growth inhibition observed in these CRC cell lines was the result of apoptosis, which was confirmed by FACS analysis and Western blotting. Ergosterol peroxide inhibited the nuclear levels of β-catenin, which ultimately resulted in reduced transcription of c-Myc, cyclin D1, and CDK-8. Ergosterol peroxide administration showed a tendency to suppress tumor growth in the colon of AOM/DSS-treated mice, and quantification of the IHC staining showed a dramatic decrease in the Ki67-positive staining and an increase in the TUNEL staining of colonic epithelial cells in AOM/DSS-treated mice by ergosterol peroxide for both prevention and therapy. Conclusion Our data suggest that ergosterol peroxide suppresses the proliferation of CRC cell lines and effectively inhibits colitis-associated colon cancer in AOM/DSS-treated mice. Ergosterol peroxide down-regulated β-catenin signaling, which exerted anti-proliferative and pro-apoptotic activities in CRC cells. These properties of ergosterol peroxide advocate its use as a supplement in colon cancer chemoprevention. [ABSTRACT FROM AUTHOR]

We demonstrated that 19 out of 20 RNA residues in the guide region of crRNA can be replaced with DNA residues with high GC-contents. The cellular activity of the chimeric crRNAs to disrupt the target gene was comparable to that of the native crRNA. [ABSTRACT FROM AUTHOR]

Abstract: Although many studies which explore on the interaction between stress and antinociception have been conducted, most of them do not divide stress into emotional stress (ES) and physical stress (PS). In the present study, we investigated the differential effects of ES or PS on pain behaviors or on c-Fos immunoreactivity (IR) in the paraventricular nucleus (PVN) or arcuate nucleus (ArcN) using electrical footshock-witness model. In addition, alteration of pain behaviors or c-Fos IR following stress repetition was examined. The electrical foot shock was applied to PS animal group in one chamber, whereas the witness animal group in another chamber without any electrical foot shock was regarded as an ES. In each group, either single (10 stimuli /10 min/1 day) or repeated stress for 5 consecutive days was applied. Our results suggest that ES and PS appear to play differential roles in the regulation of nociception produced by various types of pain stimuli (formalin, substance P, glutamate or pro-inflammatory cytokines) and on c-Fos IR in the PVN or ArcN. Moreover, such antinociceptive effect or c-Fos IR appears to be modified following stress repetition. [Copyright &y& Elsevier]

Abstract: The effect of repeated immobilization stress (RIS) on the expression of interleukin-1β (IL-1β) and types of cells that express IL-1β in hippocampal CA1 region, striatum and paraventricular nucleus (PVN) were investigated in ICR mice. The RIS was induced daily for 2h for 4 consecutive days. In the immunohistochemical study, RIS increased IL-1β immunoreactivities (IR) in the hippocampal CA1 region and striatum and PVN. The RIS also increased glial fibrillary acidic protein (GFAP) IR and complement receptor type 3 (OX-42) IR in the hippocampal CA1 regions and striatum but not PVN. In confocal immunofluorescence study, the IL-1β IR increased by RIS were colocalized with only NeuN, but not GFAP or OX-42 in the hippocampal CA1 region, striatum and PVN. Our results indicate that RIS increases IL-1β IR on neuron, but not astrocyte or microglia in the hippocampal CA1 region, striatum and PVN, suggesting that the IL-1β IR on neuron may play an important role during RIS. In addition, GFAP and OX-42 increased by RIS may be involved indirectly in playing another role in the hippocampal CA1 region and striatum during RIS. [Copyright &y& Elsevier]