Nobuyuki Arima

Shortened microsatellite d(CA)21 sequence down-regulates promoter activity of matrix metalloproteinase 9 gene.

One characteristic elements in the promoter of the matrix metalloproteinase 9 (MMP‐9) gene is the d(CA) repeat. To investigate whether this element regulates the transcription of the MMP‐9 gene and its enzymatic activities, we sequenced the promoter region isolated from esophageal carcinoma cell lines. TE9 cells with low MMP‐9 enzymatic activity had the number of d(CA) repeats shortened from 21 to 14 or 18. TE8, TE10 and TE11 cells with high MMP‐9 activities had 21 or 23 d(CA) repeats. Luciferase assays using MMP‐9 promoter containing 18, 14 or 0 d(CA) repeats showed transcriptional activities which were 50, 50 or 5%, respectively, of the level achieved with promoter containing 21 d(CA) repeats. Sequence analysis of the promoter of 223 Japanese subjects revealed that most had two alleles with 20, 21 or 22 d(CA) repeats, whereas six had one or two alleles with 14, 18 or 19 d(CA) repeats. We postulate that length alteration of the d(CA) repeat causes phenotypic differences among carcinoma cells and that microsatellite instability may contribute to the polymorphism of d(CA) repeat length.

Advanced Glycation End-Products Attenuate Human Mesenchymal Stem Cells and Prevent Cognate Differentiation Into Adipose Tissue, Cartilage, and Bone†‡

The impact of AGEs on human MSCs was studied. AGEs inhibited the proliferation of MSCs, induced apoptosis, and prevented cognate differentiation into adipose tissue, cartilage, and bone, suggesting a deleterious effect of AGEs in the pathogenesis of musculoskeletal disorders in aged and diabetic patients.

Colonic Mucosal Interleukin-6 in Inflammatory Bowel Disease

Interleukin-6, a cytokine produced by various cell types, has a major role in inflammatory and immunological reactions. To define its potential role in inflammatory bowel disease, its concentrations in endoscopic biopsy samples from patients with ulcerative colitis and Crohns disease were measured. The involved colonic mucosa from active disease was found to contain significantly larger amounts of interleukin-6 than that from inactive disease or normal controls. Colonic mucosal interleukin-6 levels correlated well with the grade of macroscopic inflammation, especially in patients with ulcerative colitis. The levels of interleukin-6 decreased in parallel with clinical improvement following the start of therapy in patients with both forms of inflammatory bowel disease. Mucosal interleukin-6 is thus concluded to accurately reflect the degree of colonic inflammation and may be importantly associated with inflammatory and immunological phenomena seen in inflammatory bowel disease.

Is triple negative a prognostic factor in breast cancer

BackgroundBreast cancer is characterized by hormone dependency, and endocrine therapy is a key treatment in breast cancer. Recently, targeted therapies such as Trastuzumab treatment for HER2-positive breast cancer has been important. Triple-negative (TN) breast cancer is characterized by lack of expression of estrogen receptor (ER) and progesterone receptor (PgR), and the absence of HER2 protein overexpression, and so there is no targeted therapy for this subtype. In this study, we examined the biological and prognostic characteristics in TN breast cancer.Patients and methodsBetween January 1998 and September 2006, 1,552 patients with primary breast cancer were investigated retrospectively in this study and ER, PgR and HER2 status were evaluated in all cases. Furthermore, p53 overexpression and Ki67 values were examined immunohistochemically.ResultsPatient distribution according to ER, PgR or HER2 status was as follows: ER and PgR positive: 57.9%, and ER and PgR negative: 25.1%. With regards to the HER2 status, HER2 positive was 23.3%, and triple negative (TN) was 14.0%. TN breast cancer has a high proliferation rate, high nuclear grade and frequent p53 overexpression. Patients with TN tumors had a significantly poorer disease-free survival (DFS) than those with non-TN tumors. After recurrence the overall survival (OS) rate in TN cases was significantly lower than that of the non-TN cases. Multivariate analysis revealed that TN was a significant factor for DFS and OS after recurrence.ConclusionTN breast cancer is a rare subtype with a high proliferation rate and a high nuclear grade, p53 overexpression, and lower DFS/OS. To improve the prognosis of TN breast cancer, a new effective strategy needs to be developed.

Switch of histamine receptor expression from H2 to H1 during differentiation of monocytes into macrophages

It is known that histamine suppresses gene expression and synthesis of tumor necrosis factor alpha (TNF‐α) induced by lipopolysaccharide (LPS) in human peripheral blood mononuclear monocytes (HPM) or alveolar macrophages via histamine H2 receptors. We investigated the effect of histamine and differentiation in macrophages on the expression and secretion of TNF‐α, TNF‐α‐converting enzyme (TACE), and histamine H1 and H2 receptors by use of a leukemia cell line, U937, and HPM. Differentiation of U937 and HPM cells with 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) enhanced the H1 receptor expression and rather suppressed the H2 receptor, resulting in up‐regulation of the histamine‐induced expression and secretion of TNF‐α, modulated via TACE. Therefore, histamine failed to inhibit up‐regulated expression of TNF‐α induced by LPS in macrophages. The switch from H2 to H1 receptors during differentiation in the monocyte/macrophage lineage could participate in the pathogenic processes of atherosclerosis and inflammatory reactions in the arterial wall.

Expression of stem cell factor in human aortic endothelial and smooth muscle cells

It has been confirmed that the receptor protein encoded by the c-kit proto-oncogene is expressed by cells of the hematopoietic, gonadal, pigment, and mast cell lineages and that its ligand, stem cell factor (SCF), is mainly expressed in their microenvironment. In a previous study we investigated the expression of the c-kit gene in human aortic endothelial cells (EC). In the present study we investigated the expression of SCF in human aortic EC and smooth muscle cells (SMC). Reverse transcription (RT)-PCR and Northern blot analyses showed that both human arterial EC and SMC expressed mRNA specific for the SCF gene. In addition, tissue-specific expression of the SCF gene was confirmed by in situ hybridization in the EC and the SMC. Western blot analysis and immunocytochemistry showed evidence of production of SCF protein in both the EC and the SMC. These results indicate the existence of mast cell-SMC interaction and of an autocrine loop of c-kit and its ligand on the surface of EC, suggesting that the interaction between c-kit protein and SCF may play an important role in metabolism of arterial wall and in the pathogenesis of atherosclerosis in the arterial intima.

Changes in the ER, PgR, HER2, p53 and Ki-67 biological markers between primary and recurrent breast cancer: discordance rates and prognosis

BackgroundIn breast cancer, ER/PgR, HER2, and Ki-67 are important biological markers for predicting prognosis and making effective treatment decisions. In addition, changes in markers due to relapse are also clinically experienced; however, the frequency and clinical significance are still not fully understood. Thus, changes in markers and their correlations with prognosis were investigated.Patients and MethodsOut of the patients with relapse from 1997 to March 2011, there were 97 consecutive patients from whom the lesion was resected and evaluated by immunostaining. The biopsy sites were chest wall, lymph node, ipsilateral breast tumor recurrence, lungs, bones, ovaries and brain. The markers sought were ER, PgR, HER2, p53 and Ki-67.ResultsThe hormone receptor positive rate from the primary tumor to recurrence decreased from 63.9% to 57.7% and from 56.7% to 43.3% for ER and PgR, respectively. Changes in the positive/negative evaluation were seen at the rate of 10.3% and 25.8% for ER and PgR, respectively. The Ki-67 index increased significantly from a mean of 29.1% at primary tumor to 36.3% at relapse. When divided into 2 groups (< 50% and ≥50%), changes were seen in 24.7%. On the other hand, the rates of changes in HER2 and p53 positivity were 14.4% and 12.4%. The changes in subtypes were seen in 25%, however, the lowest rate of change was seen in the triple negative cases. Although there was no notable difference in the rate of change between disease-free interval (DFI) and PgR, Ki-67, p53 and HER2, there was a significant difference in the change rates in the ER. A multivariate analysis revealed that the status of distant metastasis and PgR level at relapse, and Ki-67 levels at primary tumor were all significant factors.ConclusionEstrogen receptor and PgR decreased while Ki-67 increased due to relapse; however, the rate of change was high for PgR and Ki-67. Change in the subtypes was seen in 25%. In addition, PgR at relapse and Ki-67 at primary tumor were significant factors for post-relapse prognosis while PgR becoming negative was a poor prognostic factor. These findings are important for making effective treatment decisions.

Increased Expression of a Myc Target Gene Mina53 in Human Colon Cancer

Mina53 is a novel Myc target gene that we previously demonstrated to be involved in cell proliferation. We studied, here, the expression of Mina53 in colon cancer to examine its possible role in carcinogenesis. We generated a specific monoclonal anti-human Mina53 antibody and found that colon tumor cell lines expressed Mina53 highly. We also found that expression of Mina53 was elevated in colon tumor tissues by immunoblotting analysis. Tissue sections of 23 surgical cases of adenocarcinoma and 1 case of adenoma were stained immunohistochemically, and the expression of Mina53 was found to be elevated in all of the adenocarcinomas compared to adjacent nonneoplastic tissues, which showed little staining. Deeply invading tumors as well as tumors that have invaded lymphatic vessels showed strong immunoreactivity against anti-Mina53 antibody. Mina53 was expressed in all pathological grades of cancer as well as in the adenoma. Staining patterns of Ki-67, a biomarker for cell proliferation, were similar to those of Mina53 in most cases, but the percentage of tumor cells stained by anti-Mina53 was higher. Although anti-Ki-67 antibody strongly stained some well-proliferating nonneoplastic cells including cells in the deeper part of the crypts and in lymphoid germinal centers, antibody to Mina53 rarely stained those cells. Suppression of mina53 expression severely suppressed proliferation of colon tumor cells in vitro. Together, our results indicate that the elevated expression of Mina53 is a characteristic feature in colon cancer, one that may have therapeutic applications.

Effects of histamine and interleukin-4 synthesized in arterial intima on phagocytosis by monocytes/macrophages in relation to atherosclerosis

We investigated the localization of histidine decarboxylase (HDC), which is the rate‐limiting enzyme that generates histamine from histidine, in human aorta/coronary artery. RT‐PCR and immunohistochemical staining revealed that the HDC gene was expressed in monocytes/macrophages and T cells in the arterial intima but not in smooth muscle cells in either the arterial intima or the media. A luciferase promoter assay with U937 and Jurkat cells demonstrated that interleukin‐4 (IL‐4) inhibited the expression of the HDC gene. In contrast, among a scavenger receptor family, IL‐4 as well as histamine up‐regulated U937 cells to express the LOX‐1 gene but not the SR‐A gene, which genes encode receptors that scavenge oxidized lipids. These findings suggest that histamine synthesized in the arterial wall participates in the initiation and progression of atherosclerosis and that IL‐4 can act as an important inhibitory and/or stimulatory factor in the function of monocytes/macrophages modulated by histamine in relation to the process of atherosclerosis.

A role for interleukin 4 in production of matrix metalloproteinase 1 by human aortic smooth muscle cells

Effect of interleukin 4 (IL-4) on the production of matrix metalloproteinase 1 (MMP-1) by normal and immortalized human intimal smooth muscle cells (SMC) was investigated. The production of the precursors of MMP-1 by intimal SMC was enhanced in a dose-dependent manner by addition of IL-4 to the culture medium, whereas the cytokine also showed an inhibitory effect on DNA synthesis in the cells. In addition, mRNA of IL-4 was found in the atherosclerotic and nonatherosclerotic areas of the intima. Although the production of MMP-1 and the proliferation of SMC are thought to play an important role in reconstruction of the intima during atherogenesis, our results suggest a possible role of IL-4 induced MMP-1 in inhibiting tissue remodeling caused by a variety of arterial disorders including atherosclerosis.