ABSTRACT
Bovine lactoferrin (BLF) reportedly lowers blood pressure and induces vasorelaxation, but its effect on nitric oxide (NO) production has not been established. Accordingly, we aimed to determine whether BLF induces NO production in bovine aortic endothelial cells, and the effects of extracellular free magnesium (Mg) ion concentrations on this NO production. BLF induced NO production time-dependently. NO production was markedly inhibited by the NO synthase inhibitor, NG-nitro-L-arginine methyl ester, in an effect abolished by L-arginine, but not D-arginine. NO production was suppressed at low concentrations, and enhanced at high concentrations, of Mg ions in culture medium. These results suggest that BLF has an important role in hypotensive effects. Mg ions may affect BLF-induced NO production.
Subject(s)
Lactoferrin , Nitric Oxide , Animals , Nitric Oxide/metabolism , Lactoferrin/pharmacology , Endothelial Cells/metabolism , Magnesium/pharmacology , Cells, Cultured , IonsABSTRACT
BACKGROUND/AIM: An appropriate animal model is essential to investigate the relationship between inflammation, atherosclerosis, and thrombogenesis, and the development of preventive measures and therapies for atherosclerosis. MATERIALS AND METHODS: Atherosclerosis was induced in Microminipigs (MMPs) using a high-fat diet. We assessed high mobility group box 1 (HMGB1) expression levels and measured thrombus formation using a Total Thrombus Formation Analysis System (T-TAS). MMPs were divided into a normal diet (control) group and four high-fat diet groups, with differing amounts of cholesterol. After 8 weeks, blood was collected for analysis. RESULTS: HMGB1 levels increased with increasing dietary cholesterol, and a negative correlation was found between HMGB1 levels and thrombus formation time. CONCLUSION: T-TAS is useful in the assessment of thrombogenesis in MMPs and HMGB1 is associated with thrombus formation.
Subject(s)
Atherosclerosis , HMGB1 Protein , Hyperlipidemias , Animals , Atherosclerosis/etiology , Cholesterol , Diet, High-Fat/adverse effects , HMGB1 Protein/geneticsABSTRACT
Canine mammary tumor is the most common neoplasm in female dogs, and it has generated considerable attention as a translational model for human breast cancer. Ser/Thr protein phosphatase 2A (PP2A) plays a critical role as a tumor suppressor, and SET/I2PP2A, the endogenous inhibitory protein of PP2A, binds directly to PP2A and suppresses its phosphatase activity. Here, we investigated the role of SET in the tumorigenic growth in canine mammary tumor as well as in the sensitivity of tumors to existing therapeutics. Elevated protein levels of SET were observed in advanced-stage of canine mammary tumor tissues of dogs compared with paired normal tissues. Knockdown of SET expression in a canine mammary tumor cell line CIP-m led to increased PP2A activity and decreased cell proliferation, colony formation, and in vivo tumor growth. We observed suppression of mTOR, ß-catenin, and NFκB signaling by SET knockdown. The sensitivity of CIP-m cells to doxorubicin was decreased by SET knockdown, while SET knockdown in CIP-m cells did not affect sensitivity to 4-OH-tamoxifen, carboplatin, bortezomib, and X-ray radiation. These data suggest that SET plays important roles in the tumor progression of a subset of canine mammary tumor by suppressing PP2A activity and enhancing mTOR, ß-catenin, and NFκB signaling.
Subject(s)
Mammary Neoplasms, Animal/genetics , Mammary Neoplasms, Animal/metabolism , Oncogene Proteins/genetics , Oncogene Proteins/metabolism , Animals , Cell Line, Tumor , Disease Models, Animal , Dogs , Female , Gene Knockdown Techniques , Heterografts , Male , Mammary Neoplasms, Animal/pathology , Mice , Mice, Transgenic , Neoplasm StagingABSTRACT
Death-associated protein kinases (DAPKs) are members of the serine/threonine protein kinase family, which regulate cell death. Although DAPK3 has been implicated as a tumor suppressor, a recent study revealed an oncogenic role of DAPK3. However, the role of DAPK3 in non-small cell lung cancer (NSCLC) remains unclear. Therefore, we examined whether DAPK3 controls the progression of NSCLC using the NSCLC cell line, A549. We generated A549 cells stably expressing small hairpin RNA (shRNA) targeting DAPK3. In the A549 cells, the protein level of DAPK3 was decreased and the cell proliferation was inhibited. DAPK3 knockdown caused G1/G0 cell cycle arrest as assessed by flow cytometric assay and reduced cyclin D1 expression in A549 cells. Phosphorylation of ERK and c-Myc, but not Akt and JNK, was inhibited by DAPK3 knockdown. Cell migration and invasion were also inhibited by DAPK3 knockdown as determined by a Boyden chamber assay and an invasion assay, respectively. Moreover, DAPK3 knockdown inhibited anchorage-independent cell growth as determined by soft-agar colony formation assay. In a mouse xenograft model, tumors derived from DAPK3-knockdown cells exhibited reduced tumor growth. The present results demonstrated for the first time that DAPK3 controls proliferation, migration, invasion, softagar colony formation and tumor growth through activation of ERK/c-Myc signaling in A549 cells. These findings indicate that DAPK3 may be a novel target for the treatment of NSCLC.
