Development of colonic neoplasia in p53 deficient mice with experimental colitis induced by dextran sulphate sodium

BACKGROUND

Several animal models for human ulcerative colitis (UC) associated neoplasia have been reported. However, most neoplasias developed in these models have morphological and genetic characteristics different from UC associated neoplasia.

AIMS

To establish a new colitis associated neoplasia model in p53 deficient mice by treatment with dextran sulphate sodium (DSS).

METHODS

DSS colitis was induced in homozygous p53 deficient mice (p53(-/-)-DSS), heterozygous p53 deficient mice (p53(+/-)-DSS) and wild-type mice (p53+/+-DSS) by treatment with 4% DSS. Numbers of developed neoplasias were compared among the experimental groups, and macroscopic and microscopic features of the neoplasias were analysed. Furthermore, K-ras mutation and beta-catenin expression were assessed.

RESULTS

p53(-/-)-DSS mice showed 100% incidence of neoplasias whereas the incidences in p53(+/-)-DSS and p53+/+-DSS mice were 46.2% and 13.3%, respectively. No neoplasias were observed in the control groups. The mean numbers of total neoplasias per mouse were 5.0 (p53(-/-)-DSS), 0.62 (p53(+/-)-DSS), and 0.2 (p53+/+-DSS). The number of neoplasias per mouse in the p53(-/-)-DSS group was significantly higher than that in the other DSS groups. The incidences of superficial type neoplasias were 91.7% in p53(-/-)-DSS mice, 75.0% in p53(+/-)-DSS mice, and 33.3% in p53+/+-DSS mice. The K-ras mutation was not detected in any of the neoplasias tested. Translocation of beta-catenin from the cell membrane to the cytoplasm or nucleus was observed in 19 of 23 (82.6%) neoplasias.

CONCLUSIONS

The p53(-/-)-DSS mice is an excellent animal model of UC associated neoplasia because the morphological features and molecular genetics are similar to those of UC associated neoplasia. Therefore, this model will contribute to the analysis of tumorigenesis related to human UC associated neoplasia and the development of chemopreventive agents.

Manual aspiration thrombectomy with a standard PTCA guiding catheter for treatment of acute massive pulmonary thromboembolism

PURPOSE

To evaluate the efficacy and safety of percutaneous manual aspiration thrombectomy for the treatment of acute massive pulmonary thromboembolism with hemodynamic impairment.

MATERIALS AND METHODS

Over a period of 6 years and 9 months, 15 patients with hemodynamic impairment (4 men, 11 women; aged 27-79 years) were treated by manual clot aspiration with a standard, large-lumen percutaneous transluminal coronary angioplasty (PTCA) guiding catheter.

RESULTS

After treatment, angiography demonstrated improvement of pulmonary perfusion in all patients (mean Miller score: before treatment 18.9, after treatment 12.1; P < 0.01). Mean pulmonary arterial pressure decreased from 29.6 to 22.5 mmHg (P < 0.01). The mean treatment time was 114.2 min. All of the patients survived and their clinical status improved. No patient had any significant complication.

CONCLUSION

Percutaneous manual aspiration thrombectomy with a standard 8 Fr PTCA guiding catheter achieved rapid, safe improvement of the hemodynamic situation in cases of acute massive pulmonary thromboembolism, with low cost both in terms of time and money.

Induction of tumour differentiation and apoptosis and LeY antigen expression in treatment with differentiation-inducing agent, vesnarinone, of a patient with salivary adenoid cystic carcinoma

A patient with locally-advanced submandibular adenoid cystic carcinoma with poorly differentiated solid type, was treated with differentiation-inducing agent, vesnarinone, per os at a dose of 60 mg/day daily for 8 weeks. The vesnarinone administration caused marked regression of the tumour. In addition to conversion into the well-differentiated tubular type from the poorly differentiated solid type, the induction of apoptosis and LeY antigen was observed in the treated tumour. These findings indicate that vesnarinone might be a useful therapeutic agent for treatment of salivary cancer. Since we found the new expression of LeY antigen in the well-differentiated tubular lesion in the salivary adenoid cystic carcinoma treated with vesnarinone, we examined the LeY antigen expression in relation to tumour differentiation in five cases of salivary adenoid cystic carcinoma. Consequently, tissue sections from all of the adenoid cystic carcinoma examined showed no positive LeY staining, except for some areas in the tumour lesion with the tubular pattern including the histologically normal-appearing tissue adjacent to the tumour tissue. These findings suggest that there is the intimate relationship between the LeY antigen expression and tumour differentiation in human salivary adenoid cystic carcinoma.

Dedifferentiation and decreased expression of adhesion molecules, E-cadherin and ZO-1, in colorectal cancer are closely related to liver metastasis

Carcinoma cells with high metastatic potential often show a dedifferentiated phenotype at the primary site. In this study, a total of 48 cases (24 primary tumors of colorectal cancer (Pr-CRC) with liver metastasis, 24 without) were examined for E-cadherin and ZO-1 expression by immunohistochemical staining, and for their dedifferentiated phenotype. The expression levels of E-cadherin and ZO-1 were markedly decreased in the cancer cells of tumors with liver metastasis. Moreover, dedifferentiation of cancer cells, which was evaluated by the modified Gleason score, was also related to liver metastasis. However, none of the conventional clinicopathologic parameters of invasion, except lymph node metastasis, showed any relationship with liver metastasis. These results indicate that dedifferentiation and a decreased expression of E-cadherin and ZO-1 are closely related to liver metastasis.

Transcriptional activation of cyclin-dependent kinase inhibitor, p21waf1 gene by treatment with a differentiation inducing agent, vesnarinone in a human salivary gland cancer cell line

Recently, a new concept for cancer therapy termed "tumor dormancy therapy" has been proposed. The concept of this therapy is to prolong the survival time of cancer patients while maintaining their quality of life. We have been developing a differentiation-inducing therapy, which is included in the tumor dormancy therapy, for salivary gland cancer. In this study, we examined the effect of a differentiation-inducing drug, Vesnarinone on the growth of several cancer cells, and examined the molecular mechanism by which Vesnarinone induces the cyclin dependent kinase inhibitor, p21waf1 in the cancer cells. Vesnarinone significantly suppressed the growth of TYS (salivary gland cancer cells), PC3 (prostate cancer cells), and A431 (squamous cell cancer cells). Furthermore, Vesnarinone dose-dependently enhanced the expression of p21waf1 mRNA in TYS cells. Using the luciferase reporter assay it was found that the enhancement of p21waf1 mRNA expression by Vesnarinone was through direct transcriptional activation of the p21waf1 promoter. Thus, analyzing the molecular mechanisms of differentiation inducing drugs may lead to the development of a new therapeutic strategy for several human malignancies, including salivary gland cancer.

Vesnarinone, a differentiation inducing drug, directly activates p21(waf1) gene promoter via Sp1 sites in a human salivary gland cancer cell line

We previously demonstrated that a differentiation inducing drug, vesnarinone induced the growth arrest and p21(waf1) gene expression in a human salivary gland cancer cell line, TYS. In the present study, we investigated the mechanism of the induction of p21(waf1) gene by vesnarinone in TYS cells. We constructed several reporter plasmids containing the p21(waf1) promoter, and attempted to identify vesnarinone-responsive elements in the p21(waf1) promoter. By the luciferase reporter assay, we identified the minimal vesnarinone-responsive element in the p21(waf1) promoter at -124 to -61 relative to the transcription start site. Moreover, we demonstrated by electrophoretic mobility shift assay that Sp1 and Sp3 transcription factors bound to the vesnarinone-responsive element. Furthermore, we found that vesnarinone induced the histone hyperacetylation in TYS cells. These results suggest that vesnarinone directly activates p21(waf1) promoter via the activation of Sp1 and Sp3 transcription factors and the histone hyperacetylation in TYS cells.

Decreased expression of E-cadherin and Yamamoto-Kohama's mode of invasion highly correlates with lymph node metastasis in esophageal squamous cell carcinoma

OBJECTIVES

A reduction in cell-cell adhesion in cancer cells is an essential step in the progression from localized malignancy to metastatic disease. E-Cadherin is an important component of cell-cell adhesion molecules and may be a crucial determinant of tumor invasion and metastasis. E-Cadherin expression is reported to be correlated with lymph node metastasis in esophageal squamous cell carcinoma (SCC). The objective of this experiment is to examine the factors that are associated with invasion and metastasis of esophageal SCC.

METHODS

Forty-six cases of esophageal SCC were examined by immunohistochemical staining for E-cadherin. The relationship between E-cadherin-staining patterns, conventional clinicopathological parameters and Yamamoto-Kohama's (Y-K's) mode of invasion were examined.

RESULTS

The expression of E-cadherin on the cell membrane was reduced or lost in some of the esophageal SCC. Lymph node metastasis was highly correlated with the expression pattern of E-cadherin (p = 0.0002) and also highly correlated with Y-K's mode of invasion (p = 0.0078). However, lymph node metastasis was not correlated with any conventional clinicopathological parameters for invasion.

CONCLUSIONS

These results indicate that E-cadherin plays a crucial role in invasion and metastasis in esophageal SCC, and that Y-K's mode of invasion highly reflects the invasiveness and metastatic potentials of esophageal SCC cells. Therefore, examination of the expression of E-cadherin and Y-K's mode of invasion would be helpful in predicting lymph node metastasis in esophageal SCC.

Down-regulated p16 expression predicts poor prognosis in patients with extrahepatic biliary tract carcinomas

The prognosis of extrahepatic biliary tract cancer (EBT) patients is generally accepted to be poor. We immunohistochemically evaluated expression of p16, a cyclin-depend kinase inhibitor, in tumor specimens surgically removed from 99 EBT patients. We also examined whether there was any relationship between expression of p16 and biological malignancy of the tumor by comparing its clinicopathological factors. Consequently, we found that there were three types of p16 expression in the tumor cells; diffuse, heterogeneous and negative types, the percentages of which were 19, 41 and 39%, respectively. Heterogeneous and negative types, whose expression of p16 was considered to be down-regulated, showed scirrhous (p=0.022) and infiltrating growth (p=0.002). In addition, we found that the proportion of down-regulated expression of p16 was different, depending on the location of the tumor. We also observed that the down-regulated p16 expression was the highest in a proportion of patients with the extrahepatic bile duct carcinoma. In contrast, the proportion of down-regulated p16 expression was the least among the patients in the region of the ampulla of Vater with better prognosis, and we showed that the prognosis of patients with down-regulated expression of p16 was the poorest in terms of the cancer location where it is limited to the region of ampulla of Vater. These findings suggest that down-regulated p16 expression is evaluated as a factor of poorer prognosis and also that immunohistochemical pattern of p16 expression becomes a marker reflecting the biological malignancy of EBT patients.

Intracytoplasmic localization of cathepsin D reflects the invasive potential of gastric carcinoma

BACKGROUND

The present study was undertaken to investigate the role of cathepsin D in the invasiveness of human gastric cancer.

METHODS

Immunohistochemical cathepsin D staining was performed in samples from 29 early gastric adenocarcinomas (papillary or tubular adenocarcinoma) and 15 gastric adenomas, and their adjacent nonneoplastic gastric mucosa. We classified the patterns of cathepsin D immunostaining into four types; type A, fine granular staining in the apical portion: type B, intense coarse granular staining in the apical portion; type C, fine granular staining in the basal portion; and type D, diffuse granular staining throughout the cytoplasm.

RESULTS

All of the nonneoplastic mucosa showed an apical cytoplasmic distribution pattern (type A or type B). However, 20% (2/10) of low-grade gastric adenomas and 60% (3/5) of high-grade gastric adenomas showed an abnormal staining pattern. i.e., types C and D. Moreover, 82% (9/11) definite intramucosal gastric adenocarcinomas, and the majority of gastric adenocarcinomas with submucosal invasion [83% (15/18) of those in the mucosal part and 100% (14/ 14) of those in the invasive submucosal part] showed an abnormal staining pattern (types C and D). Interestingly, most of the carcinoma cells invading the stroma and lymphatics showed the type D staining pattern.

CONCLUSIONS

These results indicate that an abnormal cytoplasmic staining pattern of cathepsin D may reflect the invasive potential of gastric carcinoma cells.

A new in vivo model for studying invasion and metastasis of esophageal squamous cell carcinoma

The aim of our current study was to establish an orthotopic inoculation model for studying invasion and metastasis of esophageal squamous cell carcinoma (SCC). Male BALB/c nude mice were used for the experiment. A midline incision was made from the upper to middle abdomen. The abdominal esophagus was carefully exposed. Human esophageal T.Tn SCC cells or human cervical HeLa SCC cells, were injected into the submucosa of the lower esophagus. One of the mice injected with T.Tn cells was sacrificed at 5 weeks, and the remaining five sacrificed at 13 weeks after inoculation. The mice injected with HeLa cells were sacrificed at 3-4 weeks after inoculation. T.Tn cells and HeLa cells formed tumors at the esophagus, but did not metastasize to lymph nodes or lungs. HeLa cells produced peritoneal implants, and directly invaded the stomach and the liver. In the present study, we established a novel orthotopic inoculation model of esophageal SCC. This system is an appropriate and a useful model for studying invasion and metastasis of esophageal SCC, and can also be used as a model for developing therapeutic strategies for esophageal cancer in vivo.

Immunoglobulin treatment prevents congestive heart failure in murine encephalomyocarditis viral myocarditis associated with reduction of inflammatory cytokines

We have previously shown that immunoglobulin therapy suppressed murine coxsackievirus B3 myocarditis. In the present study, we examined the effects of immunoglobulin upon murine myocarditis induced by encephalomyocarditis virus, which is not pathogenic to humans. Antiviral activity of immunoglobulin (Venilon) against encephalomyocarditis virus could not be detected in vitro. The production of cytokines was decreased in virus-infected macrophages by the treatment of immunoglobulin in vitro. Immunoglobulin (1 g/kg/day) was administered intraperitoneally to the virus-infected C3H/He mice daily for 2 weeks, beginning simultaneously with virus inoculation in experiment I and on day 14 after virus inoculation in experiment II. In experiment I, survival rate did not differ significantly between immunoglobulin-treated and untreated groups. In experiment II, survival rate was higher in immunoglobulin compared with control groups. Immunoglobulin administration suppressed the development of myocardial necrosis with T-lymphocyte infiltrates in mice not only in the acute viremic but in the chronic aviremic stages concomitantly associated with the reduction of inflammatory cytokines, i.e., tumor necrosis factor-alpha, interferon-gamma, macrophage inflammatory protein-2, and interleukin-6. Taken together, immunoglobulin therapy could have the potential to prevent congestive heart failure.

Dihydropyrimidine dehydrogenase mRNA level correlates with the response to 5-fluorouracil-based chemo-immuno-radiation therapy in human oral squamous cell cancer

The measurement of the intra-tumoral level of thymidylate synthetase (TS), and dihydropyrimidine dehydrogenase (DPD), may be useful in predicting tumor sensitivity to 5-fluorouracil (5-FU). In this study, we examined the mRNA levels of DPD and TS in 28 oral squamous cell carcinomas (SCC), and 22 salivary gland tumors by semi-quantitative reverse transcription polymerase chain reaction. Then we examined the correlation of the responsiveness of the patients with oral SCC to 5-FU with the intra-tumoral levels of DPD and TS mRNA. All specimens were obtained at the biopsy before treatment, and then the patients were treated by oral administration of a 5-FU compound (UFT), the irradiation of cobalt-60 (upto 60 Gy) and injection of an immuno-potentiator (OK-432). Intra-tumoral levels of DPD mRNA in the patients who showed CR (complete response) and PR (partial response) were significantly lower than those in the patients who showed NC (no change). However, intra-tumoral levels of DPD mRNA did not correlate with the local recurrence of the tumor during the observation period after initial treatment with or without surgical resection of the residual tumors. On the other hand, TS mRNA levels in the tumors did not correlate with any clinico-pathological parameters. These observations suggest that intra-tumoral levels of DPD mRNA may predict the tumor response to 5-FU-based chemo-immuno-radiation therapy in the patients with oral SCC.

A randomized clinical trial comparing transjugular intrahepatic portosystemic shunt with endoscopic sclerotherapy in the long-term management of patients with cirrhosis after recent variceal hemorrhage

The aim of this study was to compare the efficacy of transjugular intrahepatic portosystemic shunt (TIPS) with that of endoscopic sclerotherapy (ES) in the long-term management of patients with cirrhosis after variceal bleeding. Seventy-eight consecutive cirrhotic patients with recent variceal bleeding were randomly allocated to either TIPS (n=38) or ES (n=40). All patients were in good condition at randomization. The mean follow-up was 1116+/-92 days in the TIPS group and 1047+/-102 days in the ES group. Differences in rebleeding from any source (18.4% vs. 32.5%) and esophageal variceal rebleeding (15.7% vs. 27.5%) were not significantly different between the two groups (P>0.05). The mortality rates were similar in both treatment groups. Shunt dysfunction was noted in 27 patients (71%) in the TIPS group. There were more numbers of rehospitalization during follow-up in the TIPS group than in the ES group (2.6+/-0.4 vs. 1.1+/-0.2) (P<0.01). TIPS and ES are equally effective in the prevention of variceal rebleeding. However, TIPS is associated with high incidence of shunt dysfunction, which lead to more rehospitalization. Therefore, TIPS may not be a first-line treatment for the prevention of variceal rebleeding in cirrhotic patients who are in stable condition.

Alpha-synuclein has an altered conformation and shows a tight intermolecular interaction with ubiquitin in Lewy bodies

Alpha-synuclein, a protein in which two mutations have been identified that cause autosomal dominant Parkinson's disease, is thought to serve as a nidus for the development of a Lewy body. We hypothesized that alpha-synuclein would display different intra- and intermolecular associations in Lewy bodies than it does in its normal intracellular compartments. Using sensitive fluorescence resonance energy transfer (FRET) techniques, we found evidence that alpha-synuclein is more compact and in closer association with other alpha-synuclein molecules in Lewy bodies than it is in the neuropil. In addition, we found evidence of a close, direct intermolecular interaction between the N terminus of alpha-synuclein and ubiquitin. These observations provide support for the hypothesis that in Lewy bodies alpha-synuclein adopts an altered three-dimensional structure and undergoes N-terminal ubiquitination.

Alpha-synuclein-enhanced green fluorescent protein fusion proteins form proteasome sensitive inclusions in primary neurons

Alpha-synuclein accumulates in the brains of sporadic Parkinson's disease patients as a major component of Lewy bodies, and mutations in alpha-synuclein are associated with familial forms of Parkinson's disease. The pathogenic mechanisms that precede and promote the aggregation of alpha-synuclein into Lewy bodies in neurons remain to be determined. Here, we constructed a series of alpha-synuclein-enhanced green fluorescent protein (alpha-synucleinEGFP, SynEGFP) fusion proteins to address whether the Parkinson's disease-associated mutations alter the subcellular distribution of alpha-synuclein, and to use as a tool for experimental manipulations to induce aggregate formation. When transfected into mouse cultured primary neurons, the 49-kDa alpha-synucleinEGFP fusion proteins are partially truncated to a approximately 27-kDa form. This non-fluorescent carboxy-terminally modified fusion protein spontaneously forms inclusions in the neuronal cytoplasm. A marked increase in the accumulation of inclusions is detected following treatment with each of three proteasome inhibitors, n-acetyl-leu-leu-norleucinal, lactacystin and MG132. Interestingly, Ala30Pro alpha-synucleinEGFP does not form the cytoplasmic inclusions that are characteristic of wild-type and Ala53Thr alpha-synucleinEGFP, supporting the idea that the Ala30Pro alpha-synuclein protein conformation differs from wild-type alpha-synuclein. Similar inclusions are formed if alpha-synuclein carboxy-terminus is modified by the addition of a V5/6xHistidine epitope tag. By contrast, overexpression of unmodified alpha-synuclein does not lead to aggregate formation. Furthermore, synphilin-1, an alpha-synuclein interacting protein also found in Lewy bodies, colocalizes with the carboxy-terminally truncated alpha-synuclein fusion protein in discrete cytoplasmic inclusions.Our finding that manipulations of the carboxy-terminus of alpha-synuclein lead to inclusion formation may provide a model for studies of the pathogenic mechanisms of alpha-synuclein aggregation in Lewy bodies.

Role of HGF/c-met system in invasion and metastasis of oral squamous cell carcinoma cells in vitro and its clinical significance

We examined the role of the hepatocyte growth factor (HGF)/c-met system on invasion and metastasis of oral squamous cell carcinoma (SCC) cells. In monolayer culture, exogenous HGF marginally affected the growth of oral SCC cells (BHY, HN, IH) and human gingival epithelial cells (GE). In type I collagen matrix, however, HGF significantly enhanced the invasive growth of the cancer cells (p < 0.05). We detected the expression of c-met (HGF receptor) mRNA in all of the cancer cells, but not in human gingival fibroblasts (GF). Oral SCC cells did not secret HGF protein into the medium, but GF secreted a large amount of HGF protein (15 ng/ml). Furthermore, HGF markedly enhanced the migration of cancer cells in a Transwell invasion chamber. Then, we examined the serum levels of HGF in oral SCC patients, or HGF concentrations in oral cancer tissues. Serum levels of HGF in the patients were significantly higher than those in healthy volunteers (p < 0.05). After initial treatment, all of the tumor-free survivors showed a marked decline in the serum HGF levels. Furthermore, HGF concentrations in metastatic cancer tissues were significantly higher than those of non-metastatic cancer tissues and normal gingiva (p < 0.01). These results suggest that HGF plays an important role in invasion and metastasis of oral SCC cells as a paracrine factor, and an elevated HGF level in the cancer tissue can be a predictive marker for metastasis formation in patients with oral SCC.

Genetic analysis of a local recurrent tumor after colonic polypectomy

After polypectomy, the cut end of the polyp is usually examined by light microscopy to assess the risk of recurrent cancer. Here, we report a recurrent tumor that appeared in the colon 6 years after polypectomy, although cancer cells were not observed in hematoxylin and eosin-stained sections of the cut end of the primary polyp. Retrospectively, the primary polyp and the recurrent tumor were analyzed for mutations of the p53 gene. We detected p53 mutations in the primary polyp, even in the cut end of the polyp. The same set of two p53 mutations was detected in the recurrent tumor. These observations indicate a common origin of the primary tumor and the recurrent tumor. We conclude that it is important to analyze p53 mutations in colonic polyps, especially when the cut end of the polyp is difficult to evaluate histologically, in order to predict recurrence.

Low-dose retinoic acid enhances in vitro invasiveness of human oral squamous-cell-carcinoma cell lines

Retinoids inhibit the proliferation of several types of tumour cells, and are used for patients with several malignant tumours. In this study, we examined the effect of retinoic acids (RAs) on the invasive potentials of the oral squamous cell carcinoma (SCC) cells, BHY and HNt. BHY cells expressed all of retinoid nuclear receptors (RARalpha, beta, gamma, and RXRalpha) and cytoplasmic retinoic acid binding proteins (CRABP1 and CRABP2). HNt cells lacked the expression of RARbeta, but expressed other nuclear receptors and CRABPs. All-trans retinoic acid (ATRA) and 13-cis retinoic acid (13-cisRA) (10(-6)and 10(-7)M) inhibited the growth of the cells, but low-dose ATRA and 13-cisRA (10(-8)M) marginally affected the growth of the cells. Surprisingly, low-dose RAs enhanced the activity of tissue-type plasminogen activator (tPA), and activated pro-matrix metalloproteinases (proMMP2 and proMMP9). Activation of proMMP2 and proMMP9 was inhibited by aprotinin, a serine-proteinase, tPA inhibitor. Furthermore, low-dose RAs enhanced the in vitro invasiveness of BHY cells. These results indicate that low-dose RAs enhances the in vitro invasiveness of oral SCC cells via an activation of proMMP2 and proMMP9 probably mediated by the induction of tPA.