Expression of thymidine phosphorylase in human gastric carcinoma

The activity of thymidine phosphorylase (dThdPase) has been reported to increase in several types of malignant tumors. Experimental evidence has shown that dThdPase is identical to platelet-derived endothelial cell growth factor, and that dThdPase has angiogenic activity. We examined the expression of dThdPase to investigate whether the expression of dThdPase correlates with angiogenesis, clinicopathologic features and the prognosis of patients with human gastric carcinomas. Microvessels were assessed by immunostaining endothelial cells for factor VIII. We counted microvessels in the tumors of 158 patients whose tumors were completely removed surgically. Microvessels were counted in a x400 field in the most active areas of neovascularization. We purified a monoclonal antibody (TMA-1) against dThdPase and studied the expression of dThdPase using TMA-1 in the same serial sections as those used for the detection of factor VIII. The correlation between angiogenesis and dThdPase, and the clinicopathological significance of dThdPase, in patients with gastric carcinoma were examined. The positive expression of dThdPase was more frequent (P < 0.001) in gastric carcinomas (67/158, 43.4%) than that in normal tissues (12/158, 7.6%). The average microvessel count in dThdPase-positive gastric carcinomas was higher (P < 0.001) than that in dThdPase-negative carcinomas. The percentage of gastric carcinoma cells expressing dThdPase was significantly correlated with the microvessel count (P < 0.001). Further, the average size of dThdPase-positive carcinomas was significantly larger (P < 0.001) than that of negative carcinomas and the mean microvessel count in dThdPase-positive gastric carcinomas was also significantly higher (P < 0.001) than that in dThdPase-negative carcinomas. There was a significant correlation between the positive expression of dThdPase and microvessel count (P < 0.001) or lymph node metastasis (P = 0.013) by multivariate logistic analysis. Further, patients with dThdPase-positive carcinoma showed a significantly worse prognosis than those with dThdPase-negative carcinoma overall and in stage III. These findings indicate that the expression of dThdPase in gastric carcinomas is related to progression and metastasis, and this enzyme affects the prognosis of some patients with the disease.

High-performance liquid chromatography of long chain aliphatic aldehydes with peroxyoxalate chemiluminescence detection utilizing a fluorogenic reagent, 4-(N,N-dimethylaminosulphonyl)-7-hydrazino-2,1,3-benzoxadiazole

A peroxyoxalate chemiluminescence detection in high-performance liquid chromatography was examined for determination of long chain aliphatic aldehydes using 4-(N,N-dimethylaminosulphonyl)-7-hydrazino-2,1,3-benzoxadiazole (DBD-H) as a fluorogenic labelling reagent. A mixture of 0.6 mM bis(2,4,6-trichlorophenyl)oxalate and 100 mM H2O2 in acetonitrile was used as a post-column chemiluminescent reagent. DBD-hydrazones of five long chain aliphatic aldehydes (C11-C18:1) were eluted and well separated within 16 min with a mobile phase of 5 mM imidazole in acetonitrile. The detection limits were 14-18 fmol at a signal-to-noise ratio (S/N) of 2. DBD-hydrazones of four aliphatic aldehydes (C6-C11) were also eluted and well separated within 30 min with a mobile phase of 5mM imidazole buffer (pH 7.5)-acetonitrile (20/80, v/v). The detection limits were 86-152 fmol (S/N = 2).

Expression of MRP and mdr1 in human gastrointestinal cancer cell lines: a correlation with resistance against doxorubicin

The mRNA expression of mdr1 and MRP, each of which codes for a transport protein belonging to ATP-binding cassette superfamily and are reported to be responsible for multidrug resistance phenotype, were semi-quantified by RT-PCR in a panel of gastrointestinal cancer cell lines. Although the expression of MRP was predominant in esophageal cancer cell lines, expression of either or both of the genes was detected in all the cell lines tested. Expression of these two genes added together correlated significantly with chemosensitivity against doxorubicin, implicating that expression of both genes should be evaluated in the future analysis of multidrug resistance phenotype. The ID50 values for pirarubicin, although generally lower than the values for doxorubicin, correlated well with the latter, suggesting that the similar phenotype as that for doxorubicin might be responsible for drug resistance against this semisynthetic anthracycline glycoside.

Loss of H19 imprinting in esophageal cancer

Recent articles have reported that loss of imprinting (LOI) of the endogenous gene H19 was frequently found in lung cancer and chorio-carcinoma, common adulthood cancers. Consequently, we examined the status of genomic imprinting of H19 in 29 esophageal and 48 colorectal cancer specimens, and studied its relation to the expression of H19. Of 12 esophageal cancer specimens heterozygous for the RsaI polymorphism, 6 (50%) exhibited LOI of H19, but none of the 18 colorectal cancer specimens heterozygous for the RsaI polymorphism exhibited LOI of H19. The present study suggests that LOI of H19 may play an important role in the pathogenesis of esophageal cancer. Moreover, H19 expression was frequently abundant in both cancers, and all six esophageal cancers carried LOI with overexpressed H19. Therefore, this overexpression of H19 seems to be an important phenomenon for the development of esophageal and colorectal cancer cells.

Tumor necrosis factor and interferon-gamma augment anticolon antibody- dependent cellular cytotoxicity in ulcerative colitis

The effect of tumor necrosis factor (TNF) and interferon (IFN)-gamma on antibody-dependent cellular cytotoxicity (ADCC) in patients with ulcerative colitis (UC) was investigated. ADCC activity was measured by the 51Cr release assay, using peripheral blood mononuclear cells of healthy subjects as effector cells and RPMI 4788 cells derived from human colon cancer as target cells. ADCC activity under sera from healty subjects remained low whether or not the effector cells were pretreated with TNF (100 U/ml, 16h). Under sera from UC patients, ADCC activity of 13.9%, compared to 9.6% when pretreatment was deleted. The effect of IFN pretreatment (100 U/ml, 16h) was also examined under sera from UC patients; in that experiment activity rose to 26.8%, in comparison to a 10.7% when IFN-gamma pretreatment was deleted. Finally, when the effector cells were pretreated with both TNF and IFN-gamma (100 U/ml of each, 16h) the ADCC activity under sera from UC patients was higher than when either TNF or IFN-gamma were used alone. These results suggest that TNF and IFN-gamma, by increasing ADCC activity in UC lesions, are involved in cell injury in the colonic epithelium. IFN-gamma appears to increase ADCC activity by increasing the number of high affinity monocyte Fc gamma RI receptors, while TNF increases ADCC activity by a different mechanism.

Efficient adenovirus-mediated gene transfer into human cancer cell lines derived from digestive tract

The efficiency of gene transfer into human cancer cells from digestive tract was evaluated using a replication-deficient recombinant adenovirus (Ad) vector harboring a lacZ gene of E. coli as a reporter gene (AxCALacZ). Average percent X-gal staining of esophageal cancer cell lines was 46%, that of gastric cancer cell lines 82% and that of colon cancer cell lines 70% at 3 days after Ad vector infection. X-gal staining in vitro continued 2 months after infection. By the direct injection of adenovirus vector to the tumors in nude mice, a certain percentage of tumor cells was stained by the X-gal. Colon26 cell line infected with AxCALacZ was implanted in BALB/c mice immunized with AxCALacZ, and tumor growth was suppressed. We presume this was due to anti-adenoviral immunity.

Use of 3-(1,8-naphthalimido)propyl-modified silyl silica gel as a stationary phase for the high-performance liquid chromatographic separation of purine derivatives

The use of a packing material, 3-(1,8-naphthalimido)propyl-modified silyl silica gel (NAIP), as a stationary phase for high-performance liquid chromatography, has been studied. NAIP behaved like a reversed-phase stationary phase with some pi-pi interaction. Purine derivatives, i.e., xanthine, hypoxanthine, uric acid, theobromine, theophylline and caffeine, were separated by a column packed with NAIP using an eluent of borate solution (pH 6.4)-MeOH (50:50, v/v). Of these, caffeine was selected as the target of the subsequent investigation and its determination was examined in commercially available medicinal drinks and pharmaceutical preparations. The average recoveries of caffeine were 98.0-107.4% for five drinks and 99.6-107.8% for five tablets and one powder. Subsequently, determination of caffeine and its metabolites in human plasma was examined. In twelve normal human plasma, caffeine levels ranged from 0.24 to 4.26 micrograms/ml. Time curves of plasma caffeine concentrations and those of its demethylated metabolite, 1,7-dimethylxanthine (1,7-DMX), after an oral ingestion of caffeine (200 mg) were measured by the proposed method and it was found that the maximum concentrations of caffeine and 1,7-DMX were obtained at 1-1.5 h and 3-6 h after ingestion, respectively.

Feasibility study on protracted infusional 5-fluorouracil and consecutive low-dose cisplatin for advanced gastric cancer

In this phase II trial 31 patients with advanced gastric cancer (21 with metastatic cancer and 10 with locally advanced cancer) were treated with a continuous 24-hour infusion of 5-fluorouracil (5-FU) 330 mg/m2/day plus low-dose cisplatin (CDDP) 6 mg/m2/day by bolus infusion on days 1-5. The regimen with a combination of 5-FU and low-dose CDDP (FLDP) was repeated weekly for two to four courses according to response and tolerance. In 24 (77%) of the 31 patients, four courses of this regimen were administered. The overall response rate was in 14/31 (45%) patients with measurable disease, including one complete response and 13 partial responses. An especially high response rate of 60% was seen in 10 patients with liver metastasis. Median survival time was 11 months (range 6-27+) in the 10 cases of locally advanced cancer and 11 months (range 6-24+) in the 21 cases of metastatic cancer. Toxicity was primarily hematologic. Leukopenia and thrombocytopenia of World Health Organization (WHO) grade 3 or 4 occurred in 4/31 (13%) and 4/31 (13%) of patients, respectively. Renal dysfunction, which is a major toxicity associated with CDDP, was not observed without hydration. The patients were able to eat during therapy and preserved a good quality of life. A randomized trial including the FLDP regimen is needed to compare it with other active regimens, particularly the use of high-dose CDDP.

Development of an efficient amino acid sequencing method using fluorescent Edman reagent 7-[(N,N-dimethylamino)sulfonyl]-2,1,3-benzoxadiazol-4-yl isothiocyanate

In this paper, a new method is described for N-terminal amino acid sequencing of peptides using the fluorescent reagent 7-[(N,N-dimethylamino)sulfonyl]-2,1,3-benzoxadiazol-4-yl isothiocyanate (DBD-NCS). Sequence determination is carried out by identifying thiazolinone (TZ) amino acids, which are generally unstable and difficult to detect. The employed system can easily and quickly derive TZ amino acids using the Edman reaction with DBD-NCS; these amino acids are also stable enough to be efficiently detected by high-performance liquid chromatography. Resultant detection limits for DBD-TZ amino acids range from 50 fmol to a sub-picomole level (S/N = 3). This system successfully analyzed sequences of Leu5-enkephalin (25 pmol) and angiotensin I (100 pmol) using fluorometric detection at 524 nm with excitation at 387 nm.

Early gastric carcinoma after gastrojejunostomy: clinical and pathological aspects

Two rare cases of early gastric carcinoma that followed gastrojejunostomy without gastrectomy are reported. The time intervals between the initial gastrojejunostomy and resection of the distal stomach with the formation of a gastrojejunal stoma were 30 yr and 33 yr, respectively. The Japanese classification confirmed both lesions as type IIc type mucosal early gastric cancer. In these two cases, with coexisting gastric ulcers, atrophic gastritis and diffuse intestinal metaplasia were observed in the lesions of the carcinomas. The potential correlation between the exposure of tissue to duodenal juice and the subsequent development of a gastric carcinoma is discussed. Literature regarding gastric carcinoma after gastrojejunostomy is reviewed.

Preoperative intra-aortic ultrasonography to determine resectability in advanced oesophageal cancer

This study was designed to evaluate the effectiveness of intra-aortic ultrasonography in the preoperative diagnosis of aortic wall invasion by oesophageal cancer. Twenty-four patients with advanced oesophageal cancer underwent the procedure, and aortic invasion was found in seven. In three of these seven patients, the invasion was diagnosed to be limited to the aortic adventitia, enabling preoperative prediction of the resectability of the tumour. The contact angle of the tumour in relation to the descending aorta was more than 90 degrees in six patients, and aortic invasion to all layers was visualized in four by intra-aortic ultrasonography. On the other hand, aortic invasion to the adventitia was found in three of 14 patients in whom the contact angle was less than 90 degrees. Intra-aortic ultrasonography provides important information to help determine the resectability of advanced oesophageal cancer.

Use of the double-stapling technique in esophageal surgery

This study was conducted to examine the effectiveness of the double-stapling technique (DST) for performing esophageal anastomoses. A total of 17 patients, 10 with esophageal cancer and 7 with gastric cancer, underwent esophageal anastomosis employing this technique. Of the ten patients who underwent esophageal operations, eight received esophageal-gastric tube anastomosis, one esophageal-colon and colon-residual stomach anastomosis, and one pharyngeal-gastric tube anastomosis, while all seven of the patients who underwent operations for gastric cancer received esophagojejunostomy. Thus, a total of 18 anastomoses were performed. No problems were encountered during the anastomoses, and no leakage occurred in any of the patients. Thus, we conclude that DST is a safe and easy technique for performing esophageal anastomosis, especially intrathoracic or intramediastinal anastomoses.

Preferential expression of the multidrug-resistance-associated protein (MRP) in adenocarcinoma of the lung

The expression of multidrug-resistance-associated protein (MRP) was assessed in various types of untreated lung cancer using an immunohistochemical technique. MRP was abundantly expressed in 28 of 59 adenocarcinoma specimens (47%) and its expression was associated with the degree of glandular differentiation of the tumor. MRP expression in well-differentiated adenocarcinomas (56%) was higher than in poorly differentiated adenocarcinomas (22%) (p < 0.01). lower--20% in squamous-cell carcinomas, 20% in large-cell carcinomas and 0% in small-cell carcinomas and carcinoids. RT-PCR showed that the MRP-positive adenocarcinomas and squamous-cell carcinomas expressed mrp mRNA significantly. Immunoelectron microscopically, MRP was localized in the plasma membrane and rough endoplasmic reticulum. It is thus important to take MRP into account when considering chemotherapy for lung cancers because levels of mdr I gene product, another multidrug-resistance gene family, are low in untreated lung cancers.

[A synchronous double cancer of esophagus and stomach treated with 5-fluorouracil and consecutive low-dose cisplatin]

We report a case of double cancer of esophagus and stomach treated with 5-fluorouracil and consecutive low-dose cisplatin. The patient was a 58-year-old man with liver cirrhosis. Using upper gastrointestinal fiberscopy, a superficial depressed lesion (O-IIc) in the middle thoracic part of the esophagus and Borrmann 2 type lesion in the fundus of the stomach were also detected. Microscopic examination of the biopsy specimen revealed moderately differentiated squamous cell carcinoma and adenocarcinoma. But laparotomy could not be done due to impaired liver function (KICG 0.051, ICGR15 45.2%). The patient was treated for 28 days with continuous 24 hour infusion 5-FU, 250 mg/body/day plus low dose CD-DP, 10 mg/body daily by bolus infusion d1-5, 8-12, 15-19, 22-26. One month after the chemotherapy, both the gastric cancer and the esophageal cancer were remarkably reduced (diagnosis: PR), and showed no malignancy in the histology. There was no change in the histological findings of the esophageal lesion at 31 months after the chemotherapy. This therapy is effective for patients with gastric cancer and esophageal cancer.

High-performance liquid chromatography with fluorescence detection of ebiratide using 4-(N,N-dimethylamino-sulphonyl)-7-fluoro-2,1,3-benzoxadiazole as a fluorogenic reagent

A sensitive high-performance liquid chromatography (HPLC) method with fluorescence detection has been developed and applied to the determination of ACTH4-9 analogue (ebiratide). 4-(N,N-Dimethylamino-sulphonyl)-7-fluoro-2,1,3-benzoxadiazole (DBD-F) was used as a fluorogenic labelling reagent. Ebiratide in 0.1 M borate buffer (pH 9.0) was reacted with DBD-F in acetonitrile solution at 50 degrees C for 30 min. After cooling, the mixture was separated by a reversed-phase HPLC. Then DBD-ebiratide was monitored at 580 nm with the excitation at 440 nm. The calibration curve was linear up to 10 pmol on column (r = 0.999) with the detection limit of 0.25 pmol (signal-to-noise = 3).

[Treatment of solid tumor by a small amount of direct current]

Solid tumor treatment was given in our animal laboratory to determine the mechanism of tumor disappearance by direct electric current, and clinical trials were done on 9 far advanced recurrent rectal cancers. Solid tumors of Yoshida sarcoma in Donryu rat were treated by 1 mA of constant direct current for 1 hour a day, for 4 days. The tumors disappeared in 13/16 within 21 days. Positive results of DNA Nick-end labeling and ladder patterns in the gel electrophoresis of DNA were observed in the regressing tumor specimen. It is considered that apoptosis is the one of the mechanisms of a disappearing tumor. As for the clinical trial concern, in 9 cases of rectal cancer, one CR and 5 PR were seen.

The correlation of thymidine phosphorylase activity with the expression of interleukin 1 alpha, interferon alpha and interferon gamma in human colorectal carcinoma

Thymidine phosphorylase (dThdPase) is an angiogenic enzyme and seems to be related to an angiogenesis in human colorectal carcinoma. The incidence of dThdPase-positive cells was significantly correlated with microvessel count in 21 human colorectal carcinomas. Interleukin 1 alpha (IL-1 alpha), tumor necrosis factor alpha (TNF-alpha), interferon alpha (IFN-alpha) interferon gamma (IFN-gamma) induce dThdPase activity in human cancer cell lines. To study whether this phenomenon occurs in the human colorectal carcinomas, we examined the correlation between dThdPase activity and the expression levels of IL-1 alpha, TNF-alpha, IFN-alpha and IFN-gamma in colorectal carcinoma tissues. dThdPase activity was assayed by the methods of Friedkin and Robert, and the expression level of IL-1 alpha, TNF-alpha, IFN-alpha and IFN-gamma was determined by ELISA. dThdPase activity was significantly correlated with the amount of IL-1 alpha (n = 19, r = 0.347, P = 0.0001), INF-alpha (n = 18, r = 0.717, P = 0.008), and IFN-gamma (n = 4, r = 0.9777, P = 0.0234) in human colorectal carcinomas. However, the dThdPase activity was not correlated with the amount of TNF-alpha (n = 21, r = 0.235, P = 0.2682). These results suggested that the expression levels of IL-1 alpha, IFN-alpha and IFN-gamma are correlated with dThdPase activity in human colorectal carcinomas and that these cytokines may cause angiogenesis by inducing the expression of dThdPase.

Expression of multidrug resistance-associated protein (MRP) in thyroid cancers

It was found that the mechanism of anti-cancer drug resistance in anaplastic carcinoma of the thyroid was not explicable only in terms of expression of mdr1 and its gene product, P-glycoprotein. The multidrug resistance-associated protein (MRP), another member of the mdr gene family, may be involved in anti-cancer drug resistance of this carcinoma. The MRP expression was examined immunohistochemically in 8 cell lines and 73 thyroid cancer tissues; its frequency in anaplastic carcinoma (52%) was significantly higher than that in other thyroid cancer types.

Pathogenesis of adenocarcinoma induced by gastrojejunostomy in Wistar rats: role of duodenogastric reflux

The pathogenetic effect of duodenogastric reflux of the development of gastric stump carcinoma was studied experimentally. In this animal model, 95 male Wistar rats were subjected to a specially designed gastrojejunostomy to divert the duodenal contents into the resected stomach through the afferent and efferent loop. The rats were fed normally without any carcinogen administration. The incidence of adenocarcinomas around the anastomosis of afferent loop was 0% at 10 weeks, 18.8% at 20 weeks and 34.4% at 40 weeks, so the incidence was apt to rise in parallel with passing of the weeks. At 40 weeks, the rats had a significantly higher incidence of adenocarcinoma in the gastric mucosa around the afferent loop than around the efferent loop (P < 0.05). Of particular interest is that invasive growth of the cancerous tissue into the liver was observed in one animal. Polypoid lesions called 'atypical hyperplasia' in the present study were similar to gastritis cystica polyposa of humans. The development of adenocarcinoma was found to be intimately connected with atypical hyperplasia, which might be promoted by repeated destruction and regeneration by duodenogastric reflux. These results suggest that the direct contact of the duodenal juice with the gastric mucosa induces carcinoma in the anastomotic lesion. From the clinical perspective, our findings suggest that a surgical technique that minimizes the duodenogastric reflux should be chosen.

Structural characterization of thymidine phosphorylase purified from human placenta

Human thymidine phosphorylase (dThdPase) is thought to be identical to an angiogenesis factor, platelet-derived endothelial cell growth factor (PD-ECGF). However, the whole amino acid sequence of dThdPase is still unknown. N-terminal amino acid sequencing of dThdPase isolated from human placenta gave the sequence Ac-AALMTPGTGAPPAPG. Comparison with the sequence predicted from the PD-ECGF cDNA reveals that residues 2-16 of dThdPase are identical to that of PD-ECGF. If dThdPase and PD-ECGF are derived from the same gene, the primary translational product of dThdPase would be processed one amino acid from the translation-initiating methionine residue and Ala-2 acetylated. Since placental and platelet PD-ECGF is reported to be processed at Thr-6 and Ala-11, respectively, and the N-terminal end is not blocked, further study is needed to clarify the reason for this discrepancy and whether the difference in N-terminal sequence affects the physiological function of these molecules.

Establishment and characterization of human gastric and colonic xenograft lines resistant to CPT-11 (a new derivative of camptothecin)

CPT-11-resistant human gastric and colonic xenograft lines were established by direct intratumoral injection of CPT-11 into subcutaneous SC-1-NU and CC-2-NU tumors in nude mice once a week for 10 months. The resistance of these xenograft lines to CPT-11 was confirmed by growth inhibition rate, to be 36.3% and 45.4%, respectively, compared to each parent cell line. DNA topoisomerase I activity of the nuclear extracts of SC-1-NU/CPT-11 and CC-2-NU/CPT-11, as assayed by relaxation of supercoiled DNA Col-E1, was significantly less than those of the parent lines. The cellular levels of topoisomerase I in those resistant lines measured by Western blot analysis were 0.57- and 0.79-fold lower than those of the parental lines, respectively. However, the activity of DNA topoisomerase II of those resistant cell lines assayed by decatenation of kinetoplast DNA was higher than that of the parental lines and the cellular levels of topoisomerase II in the resistant lines measured by Western blot analysis were 10.8- and 8.1-fold higher than those of the parent lines. Intracellular accumulation of CPT-11 in CPT-11-resistant tumors was not changed as compared to that of the parental lines, but hydrolysis of CPT-11 to more active SN-38 was reduced in the resistant tumors.

International perceptions and approval of gene therapy

Gene therapy is in clinical trials in a number of countries, raising the question of whether different ethical standards can be justified in different countries. One key issue is how divergent are the perceptions and bioethical reasoning of peoples around the world. An International Bioethics Survey with 150 questions, including 35 open ones, was developed to look at how people think about diseases, life, nature, and selected issues of science and technology, biotechnology, genetic engineering, genetic screening, and gene therapy. The mail response survey was conducted in 1993 among the public in Australia, India, Israel, Japan, New Zealand, Russia, and Thailand, and the same written survey was conducted among university students in Australia, Hong Kong, India, Japan, New Zealand, The Philippines, Russia, Singapore, and Thailand. Similar questions were included in an international high school education bioethics survey among high school teachers in Australia, Japan, and New Zealand. Further international comparisons to the United States and Europe are made. About three-quarters of all samples supported personal use of gene therapy, with higher support for children's use of gene therapy. The diversity of views was generally similar within each country. The major reasons given were to save life and increase the quality of life. About 5-7% rejected gene therapy, considering it to be playing God, or unnatural. There was very little concern about eugenics (0.5-2%), and more respondents gave supportive reasons like "improving genes," especially in Thailand and India. Support for specific applications was significantly less for "improving physical characters," "improving intelligence," or "making people more ethical" than for curing diseases like cancer or diabetes, but there was little difference between inheritable or noninheritable gene therapy.