Ca2+-dependent neutral protease (Calpain) activity in breast cancer tissue and estrogen receptor status

Cancer invasion and metastasis require action of tumor-associated proteases, which degrade the extracellular matrix. It has been reported that calpain, a calcium-activated neutral protease and a thiol protease regulated by Ca²+;, proteolyzes estrogen recepor (ER) and that calpain may play an important role in the regulation of ER function. In the present study, the activities of calpain were measured in human normal breast tissues and breast cancer tissues stratified by estrogen receptor levels. There were no correlations between calpain activity and tumor size or lymph node involvement. Activities of calpain were significantly higher in breast cancer tissues compared with those of normal breast tissues, and were higher in the ER-positive tumors than in ER-negative ones. These results indicate that calpain is related to mammary malignant transformation and is involved in the regulation of the ER function in breast cancer tissues.     

Cleavage of cytoskeletal proteins by two forms of Ca2+ activated neutral proteases in human platelets

Two forms of calcium activated neutral proteases (CANPs) with different affinity to Ca²⁺ were partially purified from the soluble fraction of human platelets; one (μ-CANP¹) required 6 μM Ca²⁺ and the other (m-CANP¹) did 900 μM Ca²⁺ for the respective half maximal activity. Human platelets were found to contain μ-CANP predominantly in contrast to our previous study on bovine platelets, in which μ- and m-CANP were equally distributed. Among platelet protein preparations examined for possible endogenous substrates of platelet CANPs, actin binding protein (ABP) and 230 K protein were proteolysed completely by μ- or m-CANP in the presence of the respective optimal concentration of Ca²⁺. As far as μ-CANP is concerned, this is the first demonstration of proteolysis of endogenous substrates, which implies possible involvement of μ-CANP in stimulus-linked platelet reaction coupled with an increase in intracellular Ca²⁺ to micromolar concentration. Furthermore, microtubules associated proteins (MAPs) of bovine brain was proteolysed by μ- or m-CANP of human platelet in the similar manner, indicating functional ubiquity of CANPs.     

Mechanism of the cytoprotective effect of prostaglandin I2 and its analogue in human platelets

The responsiveness of washed human platelets to thrombin was well preserved up to 72 and 96 hours, when they were stored at 4 degrees C with prostaglandin I2 (PGI2) and its stable analogue OP-41483, respectively, while the washed platelets stored with sodium citrate completely lost their responsiveness to thrombin at 48 hours. The effect of PGI2 or the analogue on the resting level of intraplatelet Ca2+ concentration ([Ca2+]i) was investigated, utilizing fluorescent Ca2+ indicator quin 2. PGI2 lowered the resting [Ca2+]i in a dose related manner in the presence or absence of the extracellular Ca2+. The similar results were obtained when OP-41483 was added to the quin 2 loaded platelets. From these results, it was concluded that the lowering of the resting [Ca2+]i may be the prerequisite for the cytoprotective effect of PGI2 or OP-41483.     

Expression of valosin-containing protein in colorectal carcinomas as a predictor for disease recurrence and prognosis.

PURPOSE: Valosin-containing protein (VCP or p97) is associated with antiapoptotic function and metastasis via activation of the nuclear factor-kappaB signaling pathway. The present study was designed to investigate the prognostic significance of VCP expression in colorectal adenocarcinoma. EXPERIMENTAL DESIGN: We analyzed VCP expression immunohistochemically in 129 patients with colorectal carcinoma ages 35-84 years. The staining intensity of tumor cells was categorized as either weaker-to-equal (low VCP expression) or stronger (high expression) than that in noncancerous colonic mucosa. We also analyzed 8 colorectal adenomas and 10 metastatic foci. RESULTS: Low VCP expression was noted in 41 (31.8%) cases and high expression in 88 (68.2%) cases. A low level of VCP expression was noted in all adenomas, whereas a high level was seen in all metastatic tumors. A significant difference was observed in depth of invasion (T(1-2) versus T(3-4), P < 0.05), presence or absence of venous invasion (P < 0.05), and tumor stage (I and II versus III and IV; P < 0.05) between adenocarcinomas with low and high VCP expression. Patients with high VCP-expressing tumors had a higher recurrence rate (P < 0.001) and poorer disease-free and overall survival (P < 0.01 and P < 0.05, respectively) compared with the low expression group. Multivariate analysis revealed VCP expression level to be an independent prognosticator for both disease-free and overall survival. VCP level was an indicator of disease-free survival in both stage II and III (pathological Tumor-Node-Metastasis classification, P < 0.05 and <0.01, respectively). CONCLUSIONS: A high expression level of VCP in tumors is a poor prognostic marker in patients with colorectal carcinomas.     

Evaluation of Regional Liver Function by Gadolinium-EOB-DTPA-Enhanced MR Imaging

We evaluated the role of magnetic resonance (MR)imaging withgadolinium-ethoxybenzyl-diethylenetriamine-pentaaceticacid (Gd-EOB-DTPA), in estimating regional liverfunction in a rat ischemia-reperfusion model. Ischemic liver damage was induced in theright lobe by vascular clamping for 0 (sham), 30 (I-30),60 (I-60), and 90 min (I-90 group). The ischemic lobesin the I-60 and I-90 groups was clearly visualized as a high intensity area in the T1 images atlate phase of Gd-EOB-DTPA enhancement, Moreover, the T1/2 of signal intensity in ischemic lobes significantlycorrelated with the duration of vascular clamping. We also observed significant correlationbetween T 1/2 and ATP concentration in the liver tissue(r = –0.719, P = 0.04). Our results indicate thatMR imaging with Gd-EOB-DTPA is useful for evaluation of regional liver function in rats.     

Overexpression of MT3-MMP in hepatocellular carcinoma correlates with capsular invasion

BACKGROUND/AIMS: Extracellular matrix-degrading matrix metalloproteinases (MMPs) are invariably up-regulated in epithelial cancers and are key agonists of angiogenesis, invasion and metastasis. Recent studies have shown high levels of various MMPs, including MT1-MMP, MMP-1, MMP-2 and MMP-9, and their involvement in tumor progression in human hepatocellular carcinoma (HCC). However, the expression and role of MT3-MMP in HCC remains unclear. METHODOLOGY: We examined the immunohistochemical expression of MT3-MMP in surgically resected HCCs (n=58), hepatitis C virus (HCV) and hepatitis B virus (HBV)-related chronic hepatitis (n=34) and cirrhosis (n=24). RESULTS: MT3-MMP expression was observed in all non-cancerous liver tissues. In HCCs, 52% (30/58) of patients showed high MT3-MMP expression while the remaining 48% (28/58) of patients showed low expression. A clinicopathological survey demonstrated a significant correlation between high MT3-MMP expression and capsular invasion of carcinoma (p = 0.034) although there was no correlation between high MT3-MMP expression in HCC and overall survival or disease-free survival. CONCLUSIONS: MT3-MMP was expressed not only in chronic hepatitis and liver cirrhosis, but also in HCC, and high MT3-MMP expression correlated significantly with capsular invasion of carcinoma.     

Corynebacterium jeikeium-induced infective endocarditis and perivalvular abscess diagnosed by 16S ribosomal RNA sequence analysis: A case report

IntroductionCorynebacterium jeikeium normally presents on human skin, and it is often judged as contamination when it is cultured from blood. C. jeikeium can cause infective endocarditis, especially, that associated with cardiac surgery and prosthetic valvular endocarditis.Case reportA 66-year-old Japanese male patient was diagnosed with C. jeikeium-induced infective endocarditis (IE) and perivalvular abscess after a coronary artery bypass grafting and aortic valve replacement with bioprosthesis; pyogenic spondylodiscitis was also observed. Patch repair for aortic valve annulus and re-Bentall procedure with bioprosthesis was performed for IE and perivalvular abscess. The causative bacterium was confirmed as C. jeikeium on 16S ribosomal RNA sequencing of surgical sample and positive blood culture. The patient underwent six weeks of intravenous antibacterial treatment with vancomycin and an additional two weeks of oral treatment with linezolid, following which, his condition improved. Corynebacterium jeikeium can cause infective endocarditis and perivalvular abscess, which is a more severe condition than IE.Conclusion16S ribosomal RNA sequencing is useful in diagnosing bacterial species that can cause contamination, such as Corynebacterium spp.     

Cognitive function in Japanese elderly with type 2 diabetes mellitus

The current study was conducted to investigate the cognitive function in Japanese elderly with type 2 diabetes mellitus (DM). Participants included 69 diabetic and 27 nondiabetic subjects (60 to 85 years old). The cognitive functional tests conducted were the Mini-Mental State Examination (MMSE), Word Lists Recall (immediate, delayed), Digit Symbol Test (Wechsler Adult Intelligence Scale-Revised [WAIS-R]), and the Stroop Color Word Test. Hemoglobin A1c (HbA1c) was measured as the index of glycemic control, and information about recent hypoglycemic episodes was gathered by using questionnaires. Student's t test showed that DM subjects had significantly lower scores in the MMSE (P<.01) and Digit Symbol Test (P<.05) than non-DM subjects. The scores of the Digit Symbol Test in diabetes subjects had a significant negative relationship with HbA1c (r=-.433; P<.001), and insulin-use had a significant relationship with the scores of the MMSE and Digit Symbol Test. Subjects in the DM group were further divided by insulin use. Comparison of insulin-treated DM subjects, non-insulin-treated DM subjects, and nondiabetic subjects by analysis of variance followed by Bonferroni's post hoc test showed that insulin-treated DM subjects had significantly lower scores in the MMSE and Digit Symbol Tests than both non-insulin-treated DM subjects (P<.05) and nondiabetic subjects (P<.01). Our study suggests that Japanese elderly DM subjects, especially those with insulin treatment, have poor cognitive function.