No description available.

No description available.

Genetically engineered oncolytic viruses (OVs) have been proven to be effective anti-cancer agents. However, the heterogeneity of tumours and obligate attenuation of OVs to achieve safety can limit their efficacy. Our lab has previously shown that diverse small molecules, which we have termed “Viral Sensitizers”, used in combination with OVs can potentiate the infection of cancer cells by OVs over 1000-fold in some cases, resulting in cancer-specific killing in both in vitro and in vivo tumour models. We observed that a subset of viral sensitizer compounds ultimately acts by reducing the expression of IFNb, thereby inhibiting antiviral signaling. Here, we aimed to further refine the mechanism of action of this class of compounds. Our results suggest that VSe1 and more stable analogs such as VSe1-28 inhibit nuclear accumulation of NF-kB p65 and expression of various antiviral cytokines including, TNFa, IL-6, IFITM1, and MX2 in multiple oncolytic VSV-resistant cancer cell lines but not in normal cells. This was also observed in vivo in CT26wt immune-competent mouse tumour models, where our group has already demonstrated the therapeutic benefit of combining VSe1-28 with oncolytic VSV. Using various biochemical methods, we have determined that VSe1 and its analog VSe1-28 lead to these effects at least in part through covalent modification of NF-kB p65. In sum, this study provides a new understanding of how these novel viral sensitizers work at the molecular level. This new understanding will not only aid in the discovery and development of improved molecules but also their clinical translation in combination with oncolytic viruses.

No description available.

Indiana University-Purdue University Indianapolis (IUPUI) / The overexpression of protein arginine methyltransferase 5 (PRMT5) is strongly correlated to poor clinical outcomes for colorectal cancer (CRC) patients. Previously, we demonstrated that PRMT5 overexpression could substantially augment activation of NF-κB via methylation of arginine 30 (R30) on its p65 subunit, while knockdown of PRMT5 showed the opposite effect on the transcriptional competence of p65. However, the precise mechanisms governing this PRMT5/NF-κB axis are still largely unknown. We report a novel finding that PRMT5 is phosphorylated on serine 15 (S15) in response to interleukin-1β (IL-1β) stimulation. Overexpression of the serine-to-alanine mutant of PRMT5 (S15A-PRMT5), in either HEK293 cells or HT29, DLD1 and HCT116 CRC cells attenuated NF-κB activation compared to wild type (WT)-PRMT5, confirming that S15 phosphorylation is critical for the activation of NF-κB by PRMT5. Furthermore, we found that overexpression of S15A-PRMT5 mutant attenuated the expression of a subset of NF-κB target genes through decreased p65 occupancy at their respective promoters. Importantly, the S15A-PRMT5 mutant also reduced IL-1β-induced methyltransferase activity of PRMT5 as well as its ability to form a complex with p65. Finally, we observed that the S15A-PRMT5 mutant diminished the growth, migratory and colony-forming abilities of CRC cells compared to the WT-PRMT5. Collectively, our findings provide strong evidence that novel phosphorylation of PRMT5 at S15 is critical to its regulation of NF-κB and plays an essential role in promoting the cancer-associated functions exerted by the PRMT5/NF-κB axis. Therefore, development of inhibitors to block phosphorylation of PRMT5 at S15 could become a potential novel therapeutic approach to treat CRC. / 2020-10-15

京都大学 / 0048 / 新制・課程博士 / 博士(薬学) / 甲第18549号 / 薬博第811号 / 新制||薬||238(附属図書館) / 31449 / 京都大学大学院薬学研究科医療薬科学専攻 / (主査)教授 橋田 充, 教授 髙倉 喜信, 教授 佐治 英郎 / 学位規則第4条第1項該当 / Doctor of Pharmaceutical Sciences / Kyoto University / DFAM

Sodium methyldithiocarbamate (SMD) is commonly reported to cause health risks in humans. Previous reports indicate SMD causes oxidative stress, which can contribute to the activation of NF-êB and cause other characteristics of inflammatory responses to be altered. Almost all pro-inflammatory cytokines require NF-êB activation for full expression and development of an innate immune or inflammatory response. This study evaluated NF-êB activation, providing new information regarding reactive oxygen in macrophages from SMD-treated mice. Studies were conducted in which NF-êB reporter mice were treated with lipopolysaccharide (LPS), SMD, buthionine sulfoximine (BSO), and N-acetyl cysteine (NAC). BSO depletes glutathione (GSH) and increases oxidative stress, whereas NAC spares GSH by acting as a precursor for rapid synthesis to replace oxidized GSH. The work here indicates that NF-êB is not affected directly by increased or decreased reactive oxygen species (ROS), and oxidative stress is not the major mechanism by which SMD inhibits inflammatory responses.

京都大学 / 新制・課程博士 / 博士(医学) / 甲第24796号 / 医博第4988号 / 新制||医||1066(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 竹内 理, 教授 上野 英樹, 教授 椛島 健治 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

No description available.