Tomika Harada

Membrane-type matrix metalloproteinase-1(MT1-MMP) gene is overexpressed in highly invasive hepatocellular carcinomas

Abstract Background/Aims: The matrix metalloproteinase (MMP) family play important roles in the invasion of cancer cells by degrading the extracellular matrices. The current study was designed to determine the expression pattern of membrane-type matrix metalloproteinase-1 (MT1-MMP) in hepatocellular carcinomas and its participation in invasion potential. Methods: MT1-MMP mRNA expression was examined in 25 human hepatocellular carcinoma specimens using Northern blot, and the correlation to clinico-pathological features was evaluated. In situ hybridization and immunohistochemistry were performed to study the localization and the cells responsible for the production. Results: Northern blot analysis revealed high levels of MT1-MMP mRNA, expression in tumorous portions in all cases, whereas in non-tumorous portions moderate or faint expression was evident in 22/25 cases. In 21/25 cases, the expression levels in tumorous portion were higher than those in non-tumorous portion. In particular, hepatocellular carcinoma with capsule infiltration demonstrated significantly higher expression than those without ( p In situ hybridization and immunohistochemical study revealed MT1-MMP transcripts and proteins in cancer cells and stromal cells, respectively. MT1-MMP positive cells were preferentially observed in the invading border of tumor nests. The MMP-2 transcript showed a similar pattern to that of MT1-MMP by in situ hybridization. Conclusion: The present study showed that the MT1-MMP gene is strongly expressed in hepatocellular carcinoma cells and is involved in the invasion potential of hepatocellular carcinoma, and also that MT1-MMP may be one of the key molecules responsible for the invasion potential of hepatocellular carcinoma. Furthermore, the evidence suggests that MT1-MMP and MMP-2 cooperate in the process of cancer invasion.

Expression of membrane-type matrix metalloproteinase-1 in human pancreatic adenocarcinomas

Abstract The expression of a new type of matrix metalloproteinase, membrane-type matrix metalloproteinase-1 (MT-MMP-1), was examined in 24 cases of primary pancreatic adenocarcinomas and 9 cases of secondary liver tumors derived from pancreatic adenocarcinomas, using a non-radioactive in situ hybridization and immunohistochemical methods. Out of 24 cases of primary pancreatic adenocarcinomas, 18 showed positive expression of MT-MMP-1 transcripts in cancer cells and 20 of 24 showed positive expression in the tumor stromal cells. The immunoreactivity of the gene products for MT-MMP-1 was demonstrated to be almost the same, as shown by in situ hybridization in these 24 cases. In particular, both the staining intensity for MT-MMP-1 transcripts and the immunoreactivity of the gene products in the tumor stromal cells of mucinous cystadenocarcinomas were significantly weaker than those of common-type ductal adenocarcinomas among the 24 cases. All of the 9 cases of secondary liver tumors derived from pancreatic adenocarcinomas showed positive expression for MT-MMP-1 transcripts but less immunoreactivity for the gene products. These results suggest that MT-MMP-1 is transcribed and translated in both cancer cells and the tumor stromal cells in human pancreatic adenocarcinomas. Furthermore, considering that common-type ductal adenocarcinoma of the pancreas usually shows a strong desmoplastic reaction, while mucinous cystadenocarcinoma typically does not, MT-MMP-1 expressed in the tumor stromal cells of common-type adenocarcinomas may be involved in processes leading to the desmoplastic reaction.

Decreased expression and rare somatic mutation of the CIP1/WAF1 gene in human hepatocellular carcinoma

CIP1/WAF1, a critical downstream effector of tumor suppressor p53, encodes a cyclin-dependent kinase inhibitor. By Northern blot analysis, the CIP1/WAF1 mRNA level in the tumor was significantly lower than that in the corresponding normal liver from 19 Japanese patients with hepatocellular carcinoma (P < 0.05). In the tumor from only one out of 19 patients (5%), somatic mutations of the CIP1/WAF1 as well as that of p53 gene were identified by RT-PCR/SSCP analysis. These results suggest that the decreased CIP1/WAF1 expression is involved in the carcinogenesis or the progression of hepatocellular carcinoma.

Involvement of thromboxane A2-thromboxane A2 receptor system of the hepatic sinusoid in pathogenesis of cold preservation/reperfusion injury in the rat liver graft.

This study was designed to investigate the possible involvement of the thromboxane A2 (TXA2)-TXA2 receptor (TXA2R) system of the hepatic sinusoid in cold preservation/reperfusion injury in liver grafts. Rat livers were preserved in cold University of Wisconsin solution for either 6 or 24 hr. The number of TXA2Rs in sinusoidal endothelial cells isolated from 0-, 6-, and 24-hr preserved liver specimens was 22.50 +/- 1.80 x 10(3)/cell, 12.66 +/- 1.00 x 10(3)/cell, and 4.17 +/- 0.65 x 10(3)/cell, respectively. Kd and Bmax at 0 hr, 6 hr, and 24 hr of preservation were 8.54 +/- 1.26 nM and 37.34 +/- 3.01 fmol/10(6) cells, 7.08 +/- 1.14 nM and 12.66 +/- 1.00 fmol/10(6) cells, and 1.91 +/- 0.10 nM and 3.88 +/- 0.59 fmol/10(6) cells, respectively. The administration of OKY-046 (inhibitor of TXA2 synthesis) to the University of Wisconsin solution suppressed this reduction in TXA2R number. Furthermore, the concentration of TXA2 in hepatic sinusoid was decreased by OKY-046. In a reperfusion experiment, liver tissue preserved for 24 hr exhibited a higher reperfusion pressure, and effluent levels of both aspartate aminotransferase and lactate dehydrogenase were markedly elevated. The addition of OKY-046 to the preservation solution, however, prevented the rise in reperfusion pressure almost completely and the increase in effluent enzyme levels. This study showed that the TXA2Rs in sinusoidal endothelial cells were internalized through binding with TXA2 during cold preservation, causing activation of the TXA2-TXA2R system. This activation apparently induces an increase in reperfusion pressure, possibly due to sinusoidal contraction, resulting in microcirculatory disturbances.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibition of tumor growth and microvascular angiogenesis by the potent angiogenesis inhibitor, TNP-470, in rats

The antiangiogenic effects of TNP-470 on the neovascularization of tumors were studied by examining ultrastructural alterations in the vasculature and interstitial fluid pressure (IFP) of tumors. Wistar rats were first inoculated subcutaneously (s.c.) with the Walker 256 carcinosarcoma cell line, then either vehicle medium or TNP-470, 30 mg/kg, was injected s.c. on day 1. A tumor growth assay, the necrotic area, and the IFP in the tumor were all measured on day 12. The antiangiogenic effects of TNP-470 were studied by scanning electron microscopic images of tumor vascular casts. TNP-470 was observed to inhibit tumor growth and increase the necrotic area significantly. In the TNP-470-treated group, the IFP in the superficial layer, defined as 2–3 mm from the tumor capsule, and in the deep layer, defined as 8–10 mm from the tumor capsule, were significantly higher than the corresponding values in the control. Moreover, vascular casts showed a significant reduction in the budding of sprouts in the superficial layer, and a decrease in the maximum diameter of the tumor vessels in the deep layer. It is possible that the higher IFP in the TNP-470-treated tumors might have prevented tumor vessel dilation. The findings of this study demonstrated that TNP-470 inhibited the budding of tumor vessel sprouts, and increased the IFP. These processes seem to act synergistically to suppress tumor angiogenesis.

Membrane-type matrix metalloproteinase-1 (MT1-MMP) gene is overexpressed in highly invasive hepatocellular carcinomas

BACKGROUND/AIMS The matrix metalloproteinase (MMP) family play important roles in the invasion of cancer cells by degrading the extracellular matrices. The current study was designed to determine the expression pattern of membrane-type matrix metalloproteinase-1 (MT1-MMP) in hepatocellular carcinomas and its participation in invasion potential. METHODS MT1-MMP mRNA expression was examined in 25 human hepatocellular carcinoma specimens using Northern blot, and the correlation to clinicopathological features was evaluated. In situ hybridization and immunohistochemistry were performed to study the localization and the cells responsible for the production. RESULTS Northern blot analysis revealed high levels of MT1-MMP mRNA expression in tumorous portions in all cases, whereas in non-tumorous portions moderate or faint expression was evident in 22/25 cases. In 21/25 cases, the expression levels in tumorous portion were higher than those in non-tumorous portion. In particular, hepatocellular carcinoma with capsule infiltration demonstrated significantly higher expression than those without (p<0.05). In situ hybridization and immunohistochemical study revealed MT1-MMP transcripts and proteins in cancer cells and stromal cells, respectively. MT1-MMP positive cells were preferentially observed in the invading border of tumor nests. The MMP-2 transcript showed a similar pattern to that of MT1-MMP by in situ hybridization. CONCLUSION The present study showed that the MT1-MMP gene is strongly expressed in hepatocellular carcinoma cells and is involved in the invasion potential of hepatocellular carcinoma, and also that MT1-MMP may be one of the key molecules responsible for the invasion potential of hepatocellular carcinoma. Furthermore, the evidence suggests that MT1-MMP and MMP-2 cooperate in the process of cancer invasion.