Brg1 promotes both tumor-suppressive and oncogenic activities at distinct stages of pancreatic cancer formation.

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 full-blown 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 context-dependent roles of Brg1 and points to potential therapeutic treatment options based on epigenetic regulation in PDA.

[Evaluation of the Stability and Antibacterial Activity of Burow's and Neo-Burow's Solutions was Prepared Using Different Methods].

Burow's solution is a 13% aluminum acetate solution used for treating chronic suppurative otitis media. However, multiple formulations for Burow's and neo-Burow's solutions are used as in-hospital preparations. Each formulation uses different types and amounts of reagents, and takes a different time to prepare. Thus, the ions, including aluminum ion (Al3+), and other molecules in the prepared Burow's and neo-Burow's solutions are not identical, and the pH also differs. Furthermore, details about the antibacterial activity of these preparations are unknown. This study evaluated the stability and antibacterial activity of four Burow's and two neo-Burow's solutions prepared using different methods. Preparation times ranged from 20 min to 3 d, and the pH ranged from 2.2 to 4, meaning some solutions were more acidic or more basic than the pH 3 devised by Burow. In addition, the Al3+ concentrations ranged from 0.05 to 1.51 mol/L, meaning some solutions were more concentrated or diluted than 13% aluminum acetate (0.64 mol/L). One of the Burow's solutions we prepared produced a white residue after 14 d, making it difficult to ensure stability. In addition, confirming the antibacterial activity of another Burow's solution against the test bacteria was problematic. Despite the differences in pH and Al3+ concentrations between the various Burow's and neo-Burow's solutions, the antibacterial activity was equivalent. It was considered necessary to use the basic data obtained in this study to select a formulation for each hospital. Evaluation of the antibacterial activity of each formulation in clinical settings will be a subject for future study.

[Chemical Stability after Mixing Continuous Infusion Drugs Used to Treat Cardiogenic Shock].

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.

Infertility with defective spermiogenesis in mice lacking AF5q31, the target of chromosomal translocation in human infant leukemia.

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.

Methylamine dichloramine may play a role in the process of colorectal disease through architectural and oxidative changes in crypts in mice.

AIMS: Methylamine dichloramine (CH(3)NCl(2)) produced by neutrophils may promote colon tumors and colitis via architectural and oxidative changes in crypts, which are secretory granulae composed of goblet cells located in the colorectal mucosal layer. We investigated whether CH(3)NCl(2), in comparison with the other reactive oxygen species (ROS) such as H(2)O(2) and HOCl, derived from primed neutrophils in inflammatory sites in the large intestine, is a biogenic factor for the induction of colorectal disease in mice. MAIN METHODS: Male ICR-strain mice were administered each oxidant (0.5-0.7 micromol/mouse) by enema under anesthesia. The colorectal tissues were evaluated by histopathological and immunohistochemical analyses. Hemolysis and hemoglobin oxidation by the methylamine chloramines and HOCl were examined by adding them (50-400 microM) to a sheep erythrocyte suspension (1x10(8) cells/ml) and its lysate at pH 7 and 37 degrees C. KEY FINDINGS: CH(3)NCl(2) oxidized erythrocyte hemoglobin more effectively than HOCl, indicating it has high cell permeability and selective oxidation ability. CH(3)NCl(2) mainly induced atrophy of crypts at 6 h after administration, while the other ROS tested did not. Furthermore, 4-hydroxy-2-nonenal (4-HNE) showed positive immunostains throughout the mucosal layer, including around the basal regions of atrophied crypts, only with CH(3)NCl(2), while positive immunostains were observed for 3-nitrotyrosine (3-NT) in the atrophied crypts and their surrounding lamina propria in the mucosal layer. SIGNIFICANCE: The results suggest that CH(3)NCl(2)derived from primed neutrophils may play the most important role in promoting the development of colon tumor formation and colitis by oxidative stress through its high degree of cell permeability.

Immune suppressor factor confers stromal cell line with enhanced supporting activity for hematopoietic stem cells.

Immune suppressor factor (ISF) is a subunit of the vacuolar ATPase proton pump. We earlier identified a short form of ISF (ShIF) as a stroma-derived factor that supports cytokine-independent growth of mutant Ba/F3 cells. Here, we report that ISF/ShIF supports self-renewal and expansion of primary hematopoietic stem cells (HSCs). Co-culture of murine bone marrow cells with a stromal cell line overexpressing ISF or ShIF (MS10/ISF or MS10/ShIF) not only enhanced their colony-forming activity and the numbers of long-term culture initiating cells, but also maintained the competitive repopulating activity of HSC. This stem cell supporting activity depended on the proton-transfer function of ISF/ShIF. Gene expression analysis of ISF/ShIF-transfected cell lines revealed down-regulation of secreted frizzled-related protein-1 and tissue inhibitor of metalloproteinase-3, and the restoration of their expressions in MS10/ISF cells partially reversed its enhanced LTC-IC supporting activity to a normal level. These results suggest that ISF/ShIF confers stromal cells with enhanced supporting activities for HSCs by modulating Wnt-activity and the extracellular matrix.

Epigenetic marks by DNA methylation specific to stem, germ and somatic cells in mice.

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. RESULTS: We investigated the genome-wide DNA methylation pattern of CpG islands by restriction landmark genomic scanning (RLGS) in mouse stem cells (ES, EG and trophoblast stem) before and after differentiation, and sperm as well as somatic tissues. A total of 247 spots out of 1500 (16%) showed differences in the appearance of their RLGS profiles, indicating that CpG islands having T-DMR were numerous and widespread. The methylation pattern was specific, and varied in a precise manner according to cell lineage, tissue type and during cell differentiation. CONCLUSIONS: Genomic loci with altered methylation status seem to be more common than has hitherto been realized. The formation of DNA methylation patterns at CpG islands is one of the epigenetic events which underlies the production of various cell types in the body. These findings should have implications for the use of embryonic stem cells and cells derived from them therapeutically, and also for the cloning of animals by the transfer of somatic cell nuclei.