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Biomedical subjects

T Etoh

Publications and source records attributed to T Etoh.

At least 19 recordsLinked to original sources
PubMed2001

Differential growth regulation in human melanoma cell lines by TIMP-1 and TIMP-2.

We investigated the role of tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 in the growth regulation. Primary (PM-WK and KHm-4), recurrent primary (RPM-EP and RPM-MC), lymph node metastatic (MM-AN, MM-BP and MM-RU), and a visceral metastatic (MM-LH) melanoma cell lines were used. Reverse transcriptase-coupled polymerase chain reaction and Western blotting revealed that all expressed and produced TIMP-1 and TIMP-2 except for PM-WK, which neither expressed nor produced TIMP-1. TIMP-1 and TIMP-2 secretion levels were measured by enzyme-linked immunosorbent assay in supernatants of cells. We found that the TIMP-1 production level was correlated with the cell migration rate. Moreover, TIMP-1 enhanced the cell migration of PM-WK. The growth of the primary melanoma cell lines was stimulated by TIMP-1 and inhibited by TIMP-2. In contrast, the growth of the visceral metastatic melanoma cell line was stimulated by TIMP-2.

Cell Division↗
PubMed2001

Constitutive activation of Wnt/beta-catenin signaling pathway in migration-active melanoma cells: role of LEF-1 in melanoma with increased metastatic potential.

A constitutive complex of beta-catenin and LEF-1 has been detected in melanoma cell lines expressing either mutant beta-catenin or mutant APC (Rubinfeld et al., Science, 275, 1790-1792, 1997). However, it has been recently reported that beta-catenin mutations are rare in primary malignant melanoma, but its nuclear and/or cytoplasmic localization, a potential indicator of Wnt/beta-catenin pathway activation, is frequently observed in melanoma (Rimm et al., Am. J. Pathol., 154, 325-329, 1999). In human malignant melanoma, the appearance of the tumorigenic phase represents a capacity for metastasis and is the significant phenotypic step in disease progression. Cell motility in invasive melanoma is thought to play a crucial role in metastatic behavior. In this work, we sought to determine which transcription factor of the LEF/TCF family was preferentially involved in human melanoma from different stages of tumor progression. We show that LEF-1 mRNA expression is predominant in highly migrating cells from metastatic melanomas. These actively migrating melanoma cells showed nuclear and cytoplasmic accumulation of beta-catenin and active transcription from a reporter plasmid of the LEF/TCF binding site. These results may provide a new insight into the role of the Wnt/beta-catenin signaling pathway in the tumor progression of malignant melanoma.

Cell Movement↗
PubMed2001

Matrix metalloproteinase inhibition attenuates left ventricular remodeling and dysfunction in a rat model of progressive heart failure.

BACKGROUND: Matrix metalloproteinase (MMP) activation contributes to tissue remodeling in several disease states, and increased MMP activity has been observed in left ventricular (LV) failure. The present study tested the hypothesis that MMP inhibition would influence LV remodeling and function in developing LV failure. METHODS AND RESULTS: LV size and function were measured in 5 groups of rats: (1) obese male spontaneously hypertensive heart failure rats (SHHF) at 9 months (n=10), (2) SHHF at 13 months (n=12), (3) SHHF rats treated with an MMP inhibitor during months 9 to 13 (PD166793 5 mg. kg(-1). d(-1) PO; n=14), (4) normotensive Wistar-Furth rats (WF) at 9 months (n=12), and (5) WF at 13 months (n=12). Plasma concentrations of the MMP inhibitor (116+/-11 micromol/L) reduced in vitro LV myocardial MMP-2 activity by approximately 100%. LV function and geometry were similar in WF rats at 9 and 13 months. LV peak +dP/dt was unchanged at 9 months in SHHF but by 13 months was reduced in the SHHF group compared with WF (3578+/-477 versus 5983+/-109 mm Hg/s, P</=0.05). LV volume measured at an equivalent ex vivo pressure (10 mm Hg) was increased in SHHF at 9 months compared with WF (443+/-12 versus 563+/-33 mL, P</=0.05) and increased further by 13 months (899+/-64 mL, P</=0.05). LV myocardial MMP-2 activity was increased by approximately 2-fold in SHHF at 9 and 13 months. With MMP inhibition, LV peak +dP/dt was similar to WF values and LV volume was reduced compared with untreated SHHF values (678+/-28 mL, P</=0.05). CONCLUSIONS: MMP activity contributes to LV dilation and progression to LV dysfunction in a rodent HF model, and direct MMP inhibition can attenuate this process.

Animals↗
PubMed2001

Angiopoietin-2 is related to tumor angiogenesis in gastric carcinoma: possible in vivo regulation via induction of proteases.

Tumor angiogenesis progresses by a dynamic balance between tumor vascular regression and growth. Angiopoietin (Ang)-2 (the natural antagonist for the angiogenic Tie-2 receptor) and vascular endothelial growth factor (VEGF) are thought to be critical regulators in this process; therefore, these may play a critical role in cancer aggressiveness. The aim of this study was to clarify the clinical and biological significance of the expression of Ang-2 in human gastric cancers and to investigate the relationship between Ang-2 together with VEGF and the induction of proteases such as matrix metalloproteinases (MMPs) in the process of tumor development. Eighty-five individuals with gastric cancer, who had undergone surgery without preoperative treatment, were studied. A stable transfectant of the human MKN-7 gastric cancer cell lines with an Ang-2 expression vector was used for the experimental study. First, we examined the relationship between the mRNA expression of Angs by Northern blot analysis and clinicopathological features. High Ang-2-expression cases showed more frequent vascular involvement and more advanced stages of disease compared with low Ang-2-expression cases (P < 0.05). With regard to prognosis, the survival time for patients in the high-Ang-2 mRNA group was significantly shorter (P < 0.05). When we examined the localization of Ang-2 in human gastric cancers, immunohistochemical analysis revealed that this protein was expressed predominantly in cancer tissues when compared with normal tissues. Interestingly it was expressed not only in endothelia cells (ECs) but also in cancer cells. Second, Ang-2-transfected cells were implanted in vivo into the gastric walls of nude mice. Ang-2-transfectant mice developed highly metastatic tumors with hypervascularity as compared with MKN-7 or control vector-transfectant tumors. There was a significant correlation between Ang-2 mRNA expression and lower grade of vessel maturation. Third, on the basis of the in vivo data, we focused on production of proteases such as MMPs to investigate possible mechanisms in these processes. MMP-1, MMP-9, and urokinase-type plasminogen activator in ECs were strongly up-regulated by Ang-2 in the presence of VEGF in vitro. These data suggest that production of Ang-2 is implicated in tumor development in human gastric cancers. Its production may contribute to tumor angiogenesis by induction of proteases in ECs, which may be enhanced in the presence of VEGF.

Angiopoietin-2↗
PubMed2001

Clinical significance of K-Ras mutations in intraoperative tumor drainage blood from patients with colorectal carcinoma.

BACKGROUND: Recurrent and metastatic carcinoma of the colorectum remains a major problem. This may be ascribed to the presence of micrometastasis at diagnosis. The purpose of this study was to analyze prospectively the clinical value of detecting K-ras mutations in the perioperative circulating blood from patients with colorectal carcinoma. METHODS: Twenty-four patients whose tumor carried mutations in codon 12 of the K-ras gene were studied for the presence of cancer cells in perioperative blood samples, in particular, tumor drainage samples. A detection assay using CD45 immunomagnetic separation plus nested mutant allele specific amplification (MASA) was performed. RESULTS: K-ras mutations in CD45 negative cells in tumor drainage blood were detected in 7 (29.2%) of 24 patients. There was no significant relationship between the presence of a K-ras mutation and clinicopathological features. Four (57.1%) of the seven patients with a positive K-ras mutation in drainage blood had early recurrent disease. Of the 17 patients with no K-ras mutation, none developed metastatic disease. The recurrence rate of the K-ras mutation positive group was higher than that of the K-ras mutation negative group (P < .01). There was a significant difference, regarding prognosis, between K-ras mutation positive and negative groups (P < .01). CONCLUSIONS: This preliminary study demonstrates that the detection of circulating cancer cells in the tumor drainage blood by our new assay system may provide a predictor of recurrence and metastasis of colorectal cancer.

Adenocarcinoma↗
PubMed2001

Randomized phase I study of standard-fractionated or accelerated-hyperfractionated radiotherapy with concurrent cisplatin and vindesine for unresectable non-small cell lung cancer: a report of Japan Clinical Oncology Group Study (JCOG 9601).

BACKGROUND: We attempted dose escalation of standard-fractionated and accelerated-hyperfractionated radiotherapy combined with concurrent cisplatin and vindesine to improve local control and survival in unresectable non-small cell lung cancer. METHODS: Twenty-one patients were enrolled between June 1996 and August 1997. There were 19 males and two females and their median age was 65 years (range 45-74 years). Performance status was 0 in 10 cases and 1 in 11 cases. Disease stage was IIIA in three cases and IIIB in 18 cases. The cases were randomized to a standard-fractionated arm (n = 10) or an accelerated-hyperfractionated radiotherapy arm (n = 11) with two or three cycles of concomitant cisplatin 80 mg/m(2) on day 1 and vindesine 3 mg/m(2) on days 1 and 8 every 4 weeks in both arms. Dose escalation from 60 Gy/30 fractions/6 weeks to 70 Gy/35 fractions/7 weeks was planned in the standard-fractionated radiotherapy group and from 54 Gy/36 fractions/3.6 weeks to 60 Gy/40 fractions/4 weeks and then 66 Gy/44 fractions/4.4 weeks in the accelerated-hyperfractionated radiotherapy group. RESULTS: Grade 3 or 4 hematological toxicities were observed as follows: in the standard-fractionated/accelerated-hyperfractionated radiotherapy group, leukocytopenia 9/10, anemia 2/3 and thrombocytopenia 0/2. Grade 3 non-hematological toxicity consisted of esophagitis 0/3, increased serum total bilirubin 2/0 and hypoxia 0/1. Two patients died of radiation pneumonitis in the standard-fractionated radiotherapy group. Dose-limiting toxicity was observed in four of the 10 and seven of the 11 patients at initial dose level of standard-fractionated radiotherapy, 60 Gy/30 fractions/6 weeks, and of accelerated-hyperfractionated radiotherapy, 54 Gy/36 fractions/3.6 weeks, respectively. Thus, we failed to escalate the dose of radiotherapy in both arms. The overall response rate in the standard-fractionated group and the accelerated-hyperfractionated radiotherapy group was 70 and 73% and the 1-year survival rate was 70 and 64%, respectively. CONCLUSIONS: We concluded that these schedules of radiotherapy with concurrent cisplatin and vindesine were unacceptable for use in patients with unresectable non-small cell lung cancer. Further modifications of the schedule for radiotherapy and evaluation of combination with new chemotherapy are warranted.

Aged↗
PubMed2001

Matrix metalloproteinase expression and activity in isolated myocytes after neurohormonal stimulation.

Changes in myocardial matrix metalloproteinase (MMP) activity and expression have been associated with left ventricular (LV) remodeling. A recent study demonstrated that LV myocytes synthesize and release MMPs, which suggests that LV myocytes may participate in myocardial remodeling. However, extracellular stimuli that may potentially influence LV myocyte MMP production remains to be defined. In the present study MMP activity and expression were measured in porcine LV myocyte preparations (10(5) total cells; n = 6) following incubation (6 h) with endothelin-1 (ET-1;50 pM), angiotensin II (ANG II; 1 microM), or the beta-receptor agonist isoproterenol (Iso; 10 nM). LV myocyte-conditioned media were then subjected to gelatin zymography and an MMP-2 antibody capture assay. MMP zymographic gelatinase activity and MMP-2 content were increased by over 40% in LV myocyte-conditioned media after incubation with ET-1 or ANG II (P < 0.05). Exposure to the phorbol ester phorbol 12-myristate 13-acetate (PMA; 50 ng/ml) resulted in a 30% increase in zymographic gelatinase activity and a 63% increase in MMP-2 content (P < 0.05), suggesting that protein kinase C activation may be an intracellular mechanism for MMP induction. With the use of a confocal microscopy, membrane type-1 MMP (MT1-MMP) was localized to porcine LV myocytes, and immunoblotting for MT1-MMP using LV myocyte extracts revealed that after exposure to Iso, ET-1, ANG II, or PMA (P < 0.05), MT1-MMP abundance increased over 50%. Thus stimulation of specific neurohormonal systems that are relevant to LV remodeling influences LV myocyte MMP synthesis and release.

Angiotensin II↗
PubMed2001

Myocardial and interstitial matrix metalloproteinase activity after acute myocardial infarction in pigs.

A structural event during the evolution of a myocardial infarction (MI) is left ventricular (LV) remodeling. The mechanisms that contribute to early changes in LV myocardial remodeling in the post-MI period remain poorly understood. Matrix metalloproteinases (MMPs) contribute to tissue remodeling in several disease states. Whether and to what degree MMP activation occurs within the myocardial interstitium after acute MI remains to be determined. Adult pigs (n = 15) were instrumented to measure regional myocardial function and interstitial MMP levels within regions served by the circumflex and left anterior descending arteries. Regional function was measured by sonomicrometry, and interstitial MMP levels were determined by selective microdialysis and zymography as well as by MMP interstitial fluorogenic activity. Measurements were performed at baseline and sequentially for up to 3 h after ligation of the obtuse marginals of the circumflex artery. Regional fractional shortening fell by over 50% in the MI region but remained unchanged in the remote region after coronary occlusion. Release of soluble MMPs, as revealed by zymographic activity of myocardial interstitial samples, increased by 2 h post-MI. The increased zymographic activity after MI was consistent with MMP-9. Myocardial interstitial MMP fluorogenic activity became detectable within the ischemic region as early as 10 min after coronary occlusion and significantly increased after 1 h post-MI. MMP fluorogenic activity remained unchanged from baseline values in the remote region. The present study demonstrated that myocardial MMP activation can occur within the MI region in the absence of reperfusion. These unique results suggest that MMP release and activation occurs within the ischemic myocardial interstitium in the early post-MI period.

Animals↗
PubMed2001

The successful treatment of prurigo pigmentosa with macrolide antibiotics.

Recent studies have demonstrated that macrolide antibiotics have anti-inflammatory as well as antibacterial effects. Therefore, macrolide antibiotics have been successfully used to treat patients with various inflammatory diseases. We evaluated the effect of macrolide antibiotics in 4 patients with prurigo pigmentosa who were treated with either 400 mg of clarithromycin or 300 mg of roxythromycin daily. Eruption and pruritus disappeared within a week in all the patients while those symptoms were unresponsive to other drugs. Although the mechanism of this effect remains unclear in patients with prurigo pigmentosa, macrolide antibiotics can be considered as an alternative treatment for prurigo pigmentosa.

Adult↗
PubMed2001

[Effectiveness of high-dose, intermittent 5'-DFUR therapy for advanced gastric cancer].

We report a case of advanced gastric cancer with multiple liver metastases and peritoneal dissemination. The patient was effectively treated with high-dose 5'-DFUR. A 52-year-old patient with advanced gastric cancer and multiple liver metastases, who showed a high serum level of CEA and CA19-9 underwent simple D1 gastrectomy. Thereafter, he received per os 1,200 mg/day of 5'-DFUR intermittently (5 days a week) and TAI every four months postoperatively. The serum levels of both CEA and CA19-9 fell dramatically to within the normal range and were maintained thereafter until the present. The size and number of the liver metastases dramatically decreased, judging from CT and angiography findings.

Adenocarcinoma↗
PubMed2000

A matrix metalloproteinase induction/activation system exists in the human left ventricular myocardium and is upregulated in heart failure.

BACKGROUND: Matrix metalloproteinases (MMPs) contribute to matrix remodeling in disease states such as tumor metastases. Extracellular matrix metalloproteinase inducer (EMMPRIN) has been reported to increase MMP expression, and membrane-type MMP or MT1-MMP has been implicated to activate MMPs. The present study examined whether and to what degree EMMPRIN and MT1-MMP were expressed in human left ventricular (LV) myocardium as well as the association with MMP activity and expression in dilated cardiomyopathy (DCM). METHODS AND RESULTS: LV myocardial zymographic MMP activity increased by >2-fold with both nonischemic DCM (n=21) and ischemic DCM (n=16) compared with normal (n=13). LV myocardial abundance of MMP-9 was increased with both forms of DCM. MMP-2 and MMP-3 were increased with nonischemic DCM. MMP-1 levels were decreased with both forms of DCM. EMMPRIN increased by >250% and MT1-MMP increased by >1000% with both forms of DCM. CONCLUSIONS: Increased LV myocardial MMP activity and selective upregulation of MMPs with nonischemic and ischemic forms of DCM occurred. Moreover, a local MMP induction/activation system was identified in isolated normal human LV myocytes that was upregulated with DCM. The control of MMP activation and expression in the failing human LV myocardium represents a new and potentially significant therapeutic target for this disease process.

Adolescent↗
PubMed2000

Tumor invasion is inhibited by phosphorylated ascorbate via enrichment of intracellular vitamin C and decreasing of oxidative stress.

Tumor metastasis and invasion were shown to be inhibited by the 2-O-phosphorylated form (Asc2P) of L-ascorbic acid (Asc); intact Asc did not inhibit tumor invasion when added once, but appreciably inhibited it upon repeated addition. The anti-metastatic effect is attributable to a marked enrichment of intracellular Asc by Asc2P, subsequently dephosphorylated. Asc2P scavenged most of the intracellular reactive oxygen species (ROSin), and notably inhibited production of matrix metalloproteases and cell motility. ROSin was decreased by Asc2P more markedly than by Asc added once. Thus, involvement of ROSin in tumor invasion and a potent anti-metastatic therapy by ROSin-decreasing agents are suggested.

Animals↗
PubMed2000

Enhanced invasion of Tax-expressing fibroblasts into the basement membrane is repressed by phosphorylated ascorbate with simultaneous decreases in intracellular oxidative stress and NF-kappa B activation.

Invasion of rat fibroblastic cells Rat-1 through Matrigel was shown to be promoted by transfection with tax gene of human T-cell leukemia virus type 1. We found that an oxidation-resistant type of vitamin C (Asc), Asc-2-O-phosphate (Asc2P), inhibited the invasion of the tax-transfected Rat-1 cells (W4 cells). Intracellular Asc (Ascin), after enzymatic dephosphorylation of administered Asc2P, was more abundant in W4 cells than in Rat-1 cells, and the ratio of dehydroascorbic acid versus Asc was increased in W4 cells but scarcely in Rat-1 cells, according to the enhanced level of intracellular reactive oxygen species (ROSin) in W4 cells. Asc2P notably repressed the increases in both ROSin and secretion of matrix metalloproteases (MMPs), but did not affect Tax protein expression in tax-transfectants. NF-kappa B activation, as evidenced by its translocation to the nucleus in W4 cells, was also repressed by Asc2P. Thus, the tax-promoted invasion together with the enhanced production of MMPs occurred with NF-kappa B activation and the increase in ROSin, both of which were effectively reduced by Asc2P. These findings indicate the therapeutic efficacy of Ascin-enriching agents for the prevention against tumor invasion in which ROSin plays a major role.

Animals↗
PubMed2000

Increased expression of collagenase-3 (MMP-13) and MT1-MMP in oesophageal cancer is related to cancer aggressiveness.

BACKGROUND: Collagenase-3 (matrix metalloproteinase-13, MMP-13) is a recently identified human MMP with broad substrate specificity which can be activated by membrane type 1 (MT1) matrix metalloproteinase in vitro. These may play a critical role in cancer aggressiveness. AIMS: To examine the clinical significance of collagenase-3 expression and the cooperative role of MT1-MMP in human oesophageal carcinomas. PATIENTS: Forty five individuals with oesophageal carcinoma who underwent surgery without preoperative treatment. METHODS: The tumour/normal (T/N) ratios of collagenase-3 and MT1-MMP mRNA expression in 45 human oesophageal carcinomas were determined by northern blot analysis. The production and localisation of collagenase-3 and MT1-MMP proteins were investigated by immunohistochemistry, western blot analysis, and zymography. RESULTS: The mean T/N ratio of collagenase-3 mRNA was 3.5 and that of MT1-MMP 2.1. There was a significant correlation between collagenase-3 and MT1-MMP mRNA expression (p<0.001). Twenty two cases with a collagenase-3 T/N ratio >3.5 showed a significantly higher frequency of vascular involvement and lymph node metastasis, and tended to be at a more advanced stage than 23 cases with a T/N ratio < or =3.5 (p<0.05). Western blot analysis and zymography demonstrated production of collagenase-3 protein in tumour tissues but not in normal tissues. Immunohistochemical studies revealed that collagenase-3 was localised predominantly in tumour cells and MT1-MMP was detected in the same collagenase-3 positive cells; there was a significant association between collagenase-3 and MT1-MMP protein expression (p<0.05). With regard to prognosis, the survival time for subjects in the high collagenase-3 group (T/N ratio >3.5) was significantly worse (p<0.05). CONCLUSIONS: These data suggest that production of collagenase-3 together with MT1-MMP is implicated in tumour aggressiveness and prognosis in human oesophageal carcinomas.

Adult↗