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Background: Despite advances in the treatment of cancer, pancreatic ductal adenocarcinoma (PDAC) remains highly lethal due to the lack of effective therapies. Our previous study showed that Luteolin (Lut), a flavonoid, suppressed pancreatocarcinogenesis and reduced the expression of dihydropyrimidine dehydrogenase (DPYD), an enzyme that degrades pyrimidines such as 5‐fluorouracil (5‐FU), in PDACs. In this study, we investigated the role of DPYD and evaluated the therapeutic potential of combining 5‐FU with Lut in PDACs. Methods and Results: PDAC cells overexpressing DPYD showed increased proliferation, and invasiveness, adding to the resistance to 5‐FU. The xenograft tumors of DPYD‐overexpressing PDAC cells also exhibit enhanced growth and invasion compared to the control xenograft tumors. RNA‐seq analysis of the DPYD‐overexpressing PDAC xenograft tumors revealed an upregulation of genes associated with metallopeptidase activity—MMP9 and MEP1A. Furthermore, the overexpression of MEP1A in PDAC was associated with invasion. Next, we investigated the combined effects of Lut, a DPYD suppressor, and 5‐FU on DPYD‐overexpressing xenograft tumors and PDAC of Pdx1‐Cre; LSL‐KrasG12D/+; Trp53flox/flox(KPPC) mice. Neither single administration of 5‐FU nor Lut showed significant inhibitory effects; however, the combined administration of 5‐FU and Lut exhibited a significant tumor‐suppressive effect in both the xenograft tumors and KPPC models. Conclusion: We have elucidated that DPYD expression contributes to proliferation, invasiveness, and 5‐FU resistance, in PDACs. The combination therapy of Lut and 5‐FU holds the potential for enhanced efficacy against PDACs. [ABSTRACT FROM AUTHOR]

Cholangiocarcinoma (CCA) is a cancer with a poor prognosis due to difficulties in diagnosis and limited treatment options, highlighting the urgent need for new targeted therapies. In a clinical setting, we found that leukotriene levels in bile were higher than in serum. Immunohistochemical analysis of surgically resected samples also revealed that CysLT receptor 1 (CysLTR1) was more highly expressed in CCA than in normal bile duct tissue, prompting us to investigate leukotriene as a potential therapeutic target in CCA. In vitro studies using CCA cell lines expressing CysLTR1 showed that leukotriene D4, a major ligand of CysLTR1, promoted cell proliferation, with increased phosphorylation of AKT and extracellular signal-regulated kinase 1/2 (ERK1/2). Additionally, treatment with two clinically available anti-allergic drugs—zileuton, an inhibitor of CysLT formation, and montelukast, a CysLTR1 inhibitor—had inhibitory effects on cell proliferation and migratory capacity, accompanied by the reduced phosphorylation of AKT and ERK1/2. Furthermore, the simultaneous administration of both drugs synergistically enhanced the inhibitory effect on cell proliferation. Our study suggests that use of these drugs may represent a novel approach to treat CCA through drug repositioning. [ABSTRACT FROM AUTHOR]

More than 100 different herpes simplex virus 1 (HSV‐1) genes belong to three major classes, and their expression is coordinately regulated and sequentially ordered in a cascade. This complex HSV‐1 gene expression is thought to be regulated by various viral and host cellular proteins. A host cellular protein, Myb‐binding protein 1A (MYBBP1A), has been reported to be associated with HSV‐1 viral genomes in conjunction with viral and cellular proteins critical for DNA replication, repair, and transcription within infected cells. However, the role(s) of MYBBP1A in HSV‐1 infections remains unclear. In this study, we examined the effects of MYBBP1A depletion on HSV‐1 infection and found that MYBBP1A depletion significantly reduced HSV‐1 replication, as well as the accumulation of several viral proteins. These results suggest that MYBBP1A is an important host cellular factor that contributes to HSV‐1 replication, plausibly by promoting viral gene expression. [ABSTRACT FROM AUTHOR]

Herpes simplex virus-1 (HSV-1) is the most common cause of sporadic viral encephalitis, which can be lethal or result in severe neurological defects even with antiviral therapy. While HSV-1 causes encephalitis in spite of HSV-1-specific humoral and cellular immunity, the mechanism by which HSV-1 evades the immune system in the central nervous system (CNS) remains unknown. Here we describe a strategy by which HSV-1 avoids immune targeting in the CNS. The HSV-1 UL13 kinase promotes evasion of HSV-1-specific [CD8.sup.+] T cell accumulation in infection sites by downregulating expression of the [CD8.sup.+] T cell attractant chemokine CXCL9 in the CNS of infected mice, leading to increased HSV-1 mortality due to encephalitis. Direct injection of CXCL9 into the CNS infection site enhanced HSV-1-specific [CD8.sup.+] T cell accumulation, leading to marked improvements in the survival of infected mice. This previously uncharacterized strategy for HSV-1 evasion of [CD8.sup.+] T cell accumulation in the CNS has important implications for understanding the pathogenesis and clinical treatment of HSV-1 encephalitis., Introduction HSV-1 is generally associated with various mucocutaneous diseases, such as herpes labialis, genital herpes, herpetic whitlow, and keratitis (1). Also, HSV-1 is the most common cause of sporadic viral [...]