Matrilysin (MMP-7) degrades VE-cadherin and accelerates accumulation of beta-catenin in the nucleus of human umbilical vein endothelial cells.

Matrilysin, MMP-7, is an important target for anti-metastasis therapy of colorectal cancer because it is a strong proteolytic factor secreted from the cancer cell itself and it induces tumor angiogenesis. In a previous report, we showed that matrilysin accelerated human umbilical vein endothelial cell (HUVEC) proliferation in low serum conditioned medium. In the present study, we show that matrilysin stimulation decreased VE-cadherin expression, induced accumulation of beta-catenin in the nucleus of the HUVEC, and up-regulated matrilysin mRNA expression. These results compel a hypothesis that matrilysin cleaves VE-cadherin and releases beta-catenin from the VE-cadherin/catenin complex; the free beta-catenin can activate T-cell factor (Tcf) DNA binding protein, which accelerates cell proliferation and matrilysin expression.

Pharmacologic preconditioning effects: prostaglandin E1 induces heat-shock proteins immediately after ischemia/reperfusion of the mouse liver.

Prostaglandin E1 (PGE1) has several potential therapeutic effects, including cytoprotection, vasodilation, and inhibition of platelet aggregation. This study investigates the protective action of PGE1 against hepatic ischemia/reperfusion injury in vivo using a complementary DNA microarray. PGE1 or saline was continuously administered intravenously to mice in which the left lobe of the liver was made ischemic for 30 minutes and then reperfused. Livers were harvested 0, 10, and 30 minutes postreperfusion. Messenger RNA was extracted, and the samples were labeled with two different fluorescent dyes and hybridized to the RIKEN set of 18,816 full-length enriched mouse complementary DNA microarrays. Serum alanine aminotransferase and aspartate aminotransferase levels at 180 minutes postreperfusion were significantly lower in the PGE1-treated group than in the saline-treated group. The cDNA microarray analysis revealed that the genes encoding heat-shock protein (HSP) 70, glucose-regulated protein 78, HSP86, and glutathione S-transferase were upregulated at the end of the ischemic period (0 minutes postreperfusion) in the PGE1 group. Our results suggested that PGE1 induces HSPs immediately after ischemia reperfusion. HSPs might therefore play an important role in the protective effects of PGE1 against ischemia/reperfusion injury of the liver.

Telomerase activity and Bcl-2 expression in gallbladders of pancreaticobiliary maljunction patients: a preliminary study.

BACKGROUND: The congenital anomaly pancreaticobiliary maljunction (PBM) is considered to be a precancerous disease. PBM carcinogenesis is believed to be an accumulation of gene abnormalities, but the early events causing PBM carcinogenesis are still unclear. In the present study, telomerase activity and Bcl-2 expression in the gallbladder mucosa of PBM and non-PBM gallbladders were investigated. METHODS: The operative gallbladder materials were from five control cases, two cases of non-PBM gallbladder cancer, three of PBM gallbladder cancer, and three of non-neoplastic PBMs. Multiple sampling was performed from each gallbladder. The studies performed were: (1) immunohistochemistry of p53, Ki-67, and Bcl-2; (2) survey of k-ras point mutations; and (3) measurement of telomerase activity in each sample. RESULTS: In the cases of non-PBM cancer, abnormalities from the above studies were detected only in the cancerous lesions. Normal-appearing mucosa did not show Bcl-2 expression or telomerase activity. However, in the cases of PBM cancer, normal-appearing mucosa showed telomerase activity and Bcl-2 expression, but did not show p53, Ki-67, or k-ras abnormalities. In the non-neoplastic PBM, all samples showed Bcl-2 expression, and many showed telomerase activity. CONCLUSIONS: Bcl-2 expression and activation of telomerase are probably early events causing carcinogenesis of the PBM gallbladder mucosa. They might be important factors causing carcinogenesis associated with chronic inflammation.

Real-time PCR (TaqMan PCR) quantification of carcinoembryonic antigen (CEA) mRNA in the peripheral blood of colorectal cancer patients.

Reverse transcriptase-polymerase chain reaction (RT-PCR) has been utilized to detect living micrometastases of cancer cells in the lymph node, ascites or circulation system. However, the method was so sensitive that false-positives happened frequently. Therefore we have developed a quantification of CEA mRNA using real-time PCR to detect living cancer cells in the circulating blood and examined its usefulness as a predictive marker for liver metastases of colon cancer. In cell spiking experiments, it was possible to detect CEA mRNA in 10(1) cancer cells diluted in 10(7) normal lymphocytes. In the blood samples of cancer patients, the CEA mRNA level was significantly higher in Dukes' D patients than in the other clinical stages of colorectal cancer. This indicates that quantification of CEA mRNA is useful for the evaluation of colorectal cancer progress and that the post-operative increase of CEA mRNA can be a predictive marker for micrometastasis.

Analysis of gene expression involved in brain metastasis from breast cancer using cDNA microarray.

BACKGROUND: Brain metastases occur in 15% to 30% of breast cancer patients, usually as a late event. The patterns of metastases to different organs are determined by the tumor cell phenotype and interactions between the tumor cells and the organ environment. METHODS: We investigated the gene expression profile occurring in brain metastases from a breast cancer cell line. We used cDNA microarrays to compare patterns of gene expression between the mouse breast cancer cell line Jyg MC (A) and a subline that often metastasis to brain, (B). RESULTS: By Microarray analysis about 350 of 21,000 genes were significantly up-regulated in Jyg MC (B). Many candidate genes that may be associated with the establishment of brain metastasis from breast cancer were included. Interestingly, we found that the expression of astrocyte derived cytokine receptors (IL-6 receptor, TGF-beta receptor and IGF receptor) were significantly increased in Jyg MC (B) cells. These results were confirmed by RT-PCR. CONCLUSIONS: These results suggest that cytokines produced by glial cells in vivo may contribute, in a paracrine manner, to the development of brain metastases from breast cancer cells.

Improved functional reserve of hypertrophied contra lateral liver after portal vein ligation in rats.

BACKGROUND/AIMS: We assessed the functional capacity of hypertrophied liver after portal vein ligation (PL) in a test group of rats compared to a control group (without PL) having the same size liver. METHODS: The portal veins of the left and median lobes in the test group were ligated in an initial operation. Four days after the PL, the liver volume of the posterior caudate lobe (5%) increased two-fold, accounting for 10% of the liver. Then a 90% hepatectomy was performed, leaving only the hypertrophied posterior caudate lobe. Rats in a sham group underwent a 90% hepatectomy 4 days after having laparotomy, leaving the normal anterior and posterior caudate lobes (10%). RESULTS: The survival rate for the PL group was significantly higher than for the sham group at 4 days after hepatectomy (56.3 and 26.7%, P<0.05). The regeneration ratio and the proliferating cell nuclear antigen (PCNA) labeling index in the PL group was markedly higher than in the sham group 24h after hepatectomy. CONCLUSIONS: Hypertrophied liver at 4 days after PL still showed liver regeneration. Regenerating liver provided greater tolerance for extended hepatectomy than normal liver. This is because of the induced rapid regeneration of the remaining liver after hepatectomy.

Expression of desmosomal proteins in rat keratinocytes during in vitro differentiation.

The keratinocyte, the major component of the epidermis, expresses several proteins that characterize the keratinization during the differentiation. Proliferation and differentiation of cultured human keratinocytes are known to be regulated by the Ca2+ concentration in the culture medium. However, informations about the rat keratinocyte are relatively limited and their physiology is still an open question. To elucidate the characteristics of the rat keratinocyte, we established rat keratinocyte culture system and examined effects of extracellular calcium concentration on the expression of differentiation-related proteins. Keratinocytes were isolated from the newborn rat skin with 0.25% trypsin, followed by separation with a Percoll density gradient. The separated cells were grown in MCDB 153 medium containing several growth factors and Ca(2+)-free fetal bovine serum, then stimulated with Ca2+. Immunoblotting demonstrated strong expression of beta1 integrin in unstimulated cells, suggesting that the primary culture of rat keratinocytes was successfully established. Expression of desmoglein and transglutaminase was increased by Ca2+ stimulation, whereas beta1 integrin expression was decreased in response to increasing concentrations of Ca2+. These observations indicate that cultured rat keratinocytes maintain the ability to differentiate in vitro, which is similar to that of the basal keratinocytes in the epidermis.

VEGF receptor antisense therapy inhibits angiogenesis and peritoneal dissemination of human gastric cancer in nude mice.

The efficacy of a phosphorothioate antisense oligonucleotide (ASO) for KDR/Flk-1 (KDR/Flk-1-ASO), an endothelial cell-specific vascular endothelial growth factor (VEGF) receptor, was investigated on the peritoneal dissemination and angiogenesis of a human gastric cancer cell line in nude mice. Green fluorescent protein (GFP)-transduced NUGC-4 (NUGC-4-GFP) human gastric cancer cells were implanted into the peritoneal cavity of nude mice. KDR/Flk-1-ASO, -SO, or phosphate-buffered saline was administrated from days 7 to 14, 200 microg/mouse, once a day. The mice were sacrificed on day 28. Disseminated peritoneal tumor nodules expressing GFP were visualized by fluorescence microscopy. KDR/Flk-1-ASO significantly decreased the extent of peritoneal dissemination of the tumors. The number of cells undergoing apoptosis was significantly increased in the KDR/Flk-1-ASO-treated tumors. Microvessel density was significantly reduced in the KDR/Flk-1-ASO-treated tumor nodules. The KDR/Flk-1 antisense strategy, therefore, decreases tumor dissemination apparently by inhibiting angiogenesis.

MMP-7 (matrilysin) accelerated growth of human umbilical vein endothelial cells.

Matrix metalloproteinases (MMP) are considered to play important roles in angiogenesis. In angiogenic processes, endothelial cells secrete MMP-2 or MMP-1 to dissolve the basement membrane or connective tissue around the vessels. MMP-7 (matrilysin) is secreted from the neovasculars induced by cancer and is a metastatic factor of colorectal cancer. The effect of matrilysin on angiogenesis is still unclear, however. We therefore examined the effect of MMP-7 on the proliferation of human umbilical vein endothelial cells (HUVECs) in vitro. Our results showed that recombinant MMP-7 (rMMP-7) accelerated the proliferation of endothelial cells dose-dependently, and did so for endothelial cells cultured not only on type IV collagen, but also on type I collagen. MMP-7 also upregulated MMP-1, -2 secretion, but did not stimulate vascular endothelial growth factor (VEGF) secretion. From this study, we conclude that MMP-7 directly induces angiogenesis, and that therefore MMP-7 would be a good target of cancer therapy.