Efficacy of the MMP inhibitor MMI270 against lung metastasis following removal of orthotopically transplanted human colon cancer in rat

We have investigated the antitumor effects of synthetic MMP inhibitor MMI270 against postoperative lung metastasis from colon cancer in nude rat. The KM12SM human colon cancer cells were injected into the cecal wall, and at 5 weeks after the injection, the cecum was removed including the tumor. Then, 30 mg/kg of MMI270 was administered perorally twice per day for 2 or 4 weeks, either immediately after removal or after week 2 after the removal. At week 7 after the removal, lung metastasis was significantly inhibited by the early administration of MMI270 immediately after the tumor removal but not by the late administration. The survival rates were significantly higher in the rats treated by early administration of MMI270 compared to the survival rate in untreated rats. Moreover, no lung metastasis was detected in some rats with 24-weeks' survival treated by early administration. Lower microvessel density, lower PCNA Index and higher Apoptotic Index in the lung metastases of the rats treated with MMI270 were found compared to those in untreated rats. A beneficial effect of by early administration of MMI270 against postoperative lung metastases may be expected through inhibiting neovascularization of metastases in nude rat.     

A derivative of aminopeptidase inhibitor (BE15) has a dual inhibitory effect of invasion and motility on tumor and endothelial cells

Bestatin is an inhibitor of aminopeptidase N (APN)/CD13 and aminopeptidase B. In our previous report, bestatin inhibited the tumor cell invasion and the angiogenesis induced by the inoculation of B16-BL6 melanoma cells into mice and capillary formation on human umbilical vein endothelial cells (HUVECs) in vitro. The results show that the enzymatic activity of APN is deeply involved in tumor invasion and angiogenesis. We investigated the effect of three bestatin derivatives on A375 human melanoma cells and in vitro. All the derivatives inhibited the activity of APN, but BE15 was most effective and controlled the migration of A375 cells and HUVECs and capillary formation of HUVECs. Furthermore, the bestatin derivatives had an inhibitory effect not only on aminopeptidase activity but also on cell motility. Compared with bestatin and the other derivatives, BE15 had a marked inhibitory effect on the formation of capillary structure by HUVECs in vitro. These results suggest that new anti-metastatic and anti-angiogenic agents, which have a dual inhibitory effect on the degradation of the extra cellular matrix and cell motility, may be developed from bestatin.     

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.     

Clinical effects and plasma concentration levels of aprindine hydrochloride in patients with tachyarrhythmias

Aprindine hydrochloride (aprindine) was administered orally in 17 Japanese patients with supraventricular or ventricular tachyarrhythmias, and the clinical effects and plasma concentration levels were evaluated. The antiarrhythmic effects were defined using Holter ECG recordings. Aprindine was administered orally with a daily dose of 40 mg for 2 weeks in all cases, and aprindine, 60 mg daily, was administered for the next 2 weeks in patients who did not show sufficient antiarrhythmic effects with 40 mg of the drug. Aprindine was effective in 9 of 17 patients, and the mean plasma concentration level reached 0.6 micrograms/ml 2 weeks after the administration was started. Effective results were seen in 2 of the 4 patients receiving a daily dose of 60 mg, and the mean plasma concentration level reached 1.0 microgram/ml 2 weeks after the administration was started. Transient mild elevations of liver transaminases were observed in one patient and mild transient anemia was observed in another. These abnormal data disappeared although the drug administration was continued. In conclusion, the administration of a relatively small dose of aprindine and, consequently, low plasma concentration levels, are effective for cardiac tachyarrhythmias in Japanese patients.