Background : DNA methylation is involved in many gene functions such as gene-silencing, X-inactivation, imprinting and stability of the gene. We recently found that some CpG islands had a tissue-dependent and differentially methylated region (T-DMR) in normal tissues, raising the possibility that there may be more CpG islands capable of differential methylation.

Pancreatic ductal adenocarcinoma (PDA) develops predominantly through pancreatic intraepithelial neoplasia (PanIN) and intraductal papillary mucinous neoplasm (IPMN) precursor lesions. Pancreatic acinar cells are reprogrammed to a "ductal-like" state during PanIN-PDA formation. Here, we demonstrate a parallel mechanism operative in mature duct cells during which functional cells undergo "ductal retrogression" to form IPMN-PDA. We further identify critical antagonistic roles for Brahma-related gene 1 (Brg1), a catalytic subunit of the SWI/SNF complexes, during IPMN-PDA development. In mature duct cells, Brg1 inhibits the dedifferentiation that precedes neoplastic transformation, thus attenuating tumor initiation. In contrast, Brg1 promotes tumorigenesis in fullblown PDA by supporting a mesenchymal-like transcriptional landscape. We further show that JQ1, a drug that is currently being tested in clinical trials for hematological malignancies, impairs PDA tumorigenesis by both mimicking some and inhibiting other Brg1-mediated functions. In summary, our study demonstrates the contextdependent roles of Brg1 and points to potential therapeutic treatment options based on epigenetic regulation in PDA.

AF5q31 (also called MCEF) was identified by its involvement in chromosomal translocation with the gene MLL (mixed lineage leukemia), which is associated with infant acute lymphoblastic leukemia. Several potential roles have been proposed for AF5q31 and other family genes, but the specific requirements of AF5q31 during development remain unclear. Here, we show that AF5q31 is essential for spermatogenesis. Although most AF5q31-deficient mice died in utero and neonatally with impaired embryonic development and shrunken alveoli, respectively, 13% of AF5q31-deficient mice thrived as wild-type mice did. However, the male mice were sterile with azoospermia. Histological examinations revealed the arrest of germ cell development at the stage of spermiogenesis, and virtually no spermatozoa were seen in the epididymis. AF5q31 was found to be preferentially expressed in Sertoli cells. Furthermore, mutant mice displayed severely impaired expression of protamine 1, protamine 2, and transition protein 2, which are indispensable to compact the haploid genome within the sperm head, and an increase of apoptotic cells in seminiferous tubules. Thus, AF5q31 seems to function as a transcriptional regulator in testicular somatic cells and is essential for male germ cell differentiation and survival. These results may have clinical implications in the understanding of human male infertility.Chromosomal translocation is one of the common pathogenic mechanisms in various human malignancies, particularly in leukemias and lymphomas, and genes located at the breakpoints are involved in disease pathogenesis (21,59,60). The mixed lineage leukemia gene MLL (also called HRX, HTRX, and ALL-1) is frequently targeted by chromosomal rearrangements and is associated with clinically aggressive lymphoid and myeloid leukemias which are particularly prevalent in infant leukemias and treatment-related secondary leukemias (2,18,24,64). MLL located on 11q23 is a human homologue of Drosophila trithorax, has a SET domain that normally functions as histone methyltransferase, and is assembled into a supermultiprotein complex with additional chromatin-remodeling components (45,50,70). Importantly, most of the leukemic variants of MLL lack the SET domain (7). In Drosophila, genetic evidence suggests that Trithorax controls the expression of homeobox (Hox) genes and regulates embryogenesis (39,44,47). In MLL-deficient mice, Hox gene expression initiates normally but is not maintained after 9.5 days postcoitus (dpc), demonstrating the importance of MLL in the maintenance of Hox gene expression (72,73). Hox genes also play an important role in hematopoietic differentiation, and their expression levels are upregulated in the human leukemias carrying MLL rearrangements (1). An unusual feature of MLL fusion proteins is the large number and diversity of heterologous proteins that fuse with MLL. To date, the MLL locus has been found to be translocated to approximately 40 different genetic loci and at least 30 of the partner genes have been characterized (13,31). The fun...

Photo-initiated crosslinking of epoxides is very interesting from the viewpoint of application to organic coatings and photoresists. Although alkyl amines are known to be useful as crosslinking reagents for epoxides, the photochemical formation of alkyl amines which are convenient as crosslinking reagents is not known. Sakuragi et al? reported that in the photolysis of 0-acetyl benzophenone oxime (l), N-methyl benzophenone imine (2) was formed in 23% yield. The photoreaction was thought to proceed as shown in eq. (1).

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During the treatment of cardiogenic shock, various continuous infusion drugs are used simultaneously. However, administration from the same route may result in stability changes due to mixing of drugs. In addition, stability tests after mixing more than three types of drugs have hardly been conducted. In this study, noradrenaline, milrinone, dobutamine hydrochloride, and landiolol hydrochloride were used to evaluate the chemical stability of the mixture. Chemical stability was evaluated by measuring the change in each drug concentration over time and calculating the content. The concentration of each drug was measured using an optimized gradient elution method by HPLC. In a four-drug mixed sample, noradrenaline, milrinone, dobutamine hydrochloride, and landiolol hydrochloride had retention times of 2.1 min, 5.2 min, 9.3 min, and 11.9 min, respectively. The concentration immediately after mixing each drug was almost the same as the theoretical concentration at the time of mixing each drug. Furthermore, noradrenaline, milrinone, and dobutamine hydrochloride concentrations were maintained up to 99％ in each drug mixture until 24 h after mixing all the samples. However, the content of landiolol hydrochloride was 90％ or less 24 h after mixing, except for two types of mixed solutions with dobutamine hydrochloride. This result suggested that landiolol hydrochloride was being degraded owing to acidic conditions. The results of this study suggest that noradrenaline, milrinone, and dobutamine hydrochloride can be administered from one route, while it is recommended that landiolol hydrochloride be administered from another route.

Ceramide is a bioactive lipid signaling molecule that regulates multiple cellular processes influencing pancreatic tumor progression and drug response. The pleiotropic role of ceramide signaling in cancer includes modulation of exosome biogenesis and secretion. Smpd3 encodes an enzyme that generates ceramide through hydrolysis of sphingomyelin. Employing the KPC mouse model of pancreatic cancer, we demonstrated that Smpd3 regulates exosome biogenesis in pancreatic ductal adenocarcinoma (PDA) cells and is pro-tumorigenic during PDA progression. Ablation of Smdp3 in KPC mice significantly extends survival by 19% when compared to KPC; Smpd3wt/wt controls. KPC; Smpd3f/f mice display significantly less PanIN and tumor burden compared to KPC; Smpd3wt/wt controls. Lipidomics analysis of epithelial cell lines generated from end-stage pancreatic tumors of KPC; Smpd3f/f and KPC; Smpd3wt/wt mice demonstrated an alteration in hundreds of lipid species including ceramides, triacylglycerides, sphingomyelins, and phosphatidylcholines. Analysis of RNA-seq data of these epithelial cell lines showed a switching of primary tumors from the predominant more aggressive basal-like subtype seen in KPC; Smpd3wt/wt mice to classical in KPC; Smpd3f/f mice. Pathways analysis of our RNA-seq dataset showed an enrichment for genes involved in cellular mechanics and regulation of the tumor microenvironment. To query if Smpd3-generated exosomes have a direct effect on pancreatic tumor progression, we injected KPC; Smpd3wt/wt and KPC; Smpd3f/f mice with exosomes isolated from KPC; Smpd3f/f and KPC; Smpd3wt/wt PDA cell lines. Injection of exosomes derived from KPC; Smpd3f/f mice significantly extended survival of both Smpd3wt/wt and KPC; Smpd3f/f mice when compared to injection of exosomes isolated from KPC; Smpd3wt/wt mice, suggesting an anti-tumorigenic effect of exosomes isolated from Smpd3-deficient PDA cell lines. We observed a decrease in extracellular matrix collagen abundance and fewer activated stellate cells and fibroblasts in KPC; Smpd3f/f compared to control KPC; Smpd3wt/wt pancreata. Abrogation of Smpd3 expression also affected immune cell infiltration, as demonstrated by a significant increase in iNOS+ F4/80+ double positive macrophages in KPC; Smpd3f/f pancreata when compared to KPC; Smpd3wt/wt pancreata. Loss of Smpd3 resulted in a significant reduction in CD31+ endothelial cells in pancreatic tumors of KPC; Smpd3f/f mice when compared to KPC; Smpd3wt/wt mice, which may influence the ability of chemotherapeutics to enter pancreatic tumors. Our patient data demonstrate that high SMPD3 expression in surgically resected, treatment naive PDA significantly correlated with longer patient survival when patients received adjuvant chemotherapy, more than 95% of which was gemcitabine. Collectively, our data show that ceramide-dependent exosomes promote tumorigenesis, specifically activation of stellate cells and fibroblasts – which may in turn induce a stiff, fibrotic, proinflammatory tumor microenvironment that also impedes vasculature formation. Citation Format: Audrey M. Hendley, Atsushi Urano, Xianlu L. Peng, Sudipta Ashe, Natanya R. Kerper, Tuan A. Phu, Martin Ng, Simone Giacometti, David I. Berrios, Gun H. Jang, Jen J. Yeh, Steven Gallinger, David K. Chang, Andrew V. Biankin, Valerie M. Weaver, Grace E. Kim, David W. Dawson, Robert L. Raffai, Matthias Hebrok. Ceramide signaling regulates PDA aggression through exosome reprogramming of the stroma [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr C051.