Are gastroprotective drugs useful for gastric ulcer healing: re-evaluation using current ICH E9 guidelines

Most of the gastroprotective drugs which had been marketed in Japan were considered to have insufficient rationale for use as ulcer treatments. Such drugs may have a crucial role in maintaining mucosal integrity by the mechanisms other than inhibition of acid secretion. We re-evaluated the effect of gastroprotective drugs on gastric ulcer healing using current ICH E9 guidelines. We collected reports of pivotal trials on healing rate of gastric ulcer with 9 kinds of gastroprotective drugs submitted in New Drug Applications. In the comparative trial of cetraxate vs. placebo, the healing rate of gastric ulcer at 8-week endoscopy in the cetraxate was significantly higher than that in the placebo groups (88.6% and 62.2%, p = 0.0062). Non-inferiority to cetraxate was confirmed for 8 kinds of gastroprotective drugs. In conclusion, the superiority of cetraxate over placebo and non-inferiority to cetraxate for 7 drugs was established in the respect of effect on ulcer healing.

Lafutidine can improve the quality of gastric ulcer healing in humans: a randomized, controlled, multicenter trial

Improving the quality of ulcer healing (QOUH) is one of the valid methods of prevention of relapse of gastric ulcers. We investigated the effect of lafutidine on the QOUH of gastric ulcer compared with famotidine in a randomized, multi-centre controlled trial. Consecutive 80 patients with a gastric ulcer were randomly assigned to receive twice daily either lafutidine (10 mg) or famotidine (20 mg) for 12 weeks. Esophagogastroduodenoscopy was performed to examine the ulcer healing rate and rate of flat type ulcer scars using dye-contrast. The gastric ulcer healing rate was 92.1% in the lafutidine group (35/38) and 94.7% in the famotidine group (36/38). The rate of flat-type ulcer scars was significantly higher in the lafutidine group (68.4%, 26/38) than in the famotidine group (42.1%, 16/38) (P = 0.021). In conclusion, the present study demonstrated that lafutidine, as compared to famotidine, yields a significantly superior QOUH in patients with gastric ulcers in the clinical setting.

Expansion of the indications for endoscopic mucosal resection in patients with superficial esophageal carcinoma

BACKGROUND AND STUDY AIMS

Endoscopic mucosal resection (EMR) is a minimally invasive local treatment for superficial esophageal carcinoma (SEC). The use of EMR in patients with m3 or sm1 SEC remains controversial, however. The aim of this retrospective study was to evaluate the histopathological risk factors for lymph-node metastasis and recurrence in patients with m3 or sm1 SEC.

PATIENTS AND METHODS

The study subjects were 43 patients with m3 or sm1 esophageal squamous-cell carcinomas: 23 patients were treated surgically (the surgery group), and 20 were treated by EMR (the EMR group). We assessed the following variables of the specimens resected by surgery or EMR: tumor depth, maximal surface diameter of the tumor (superficial size), maximum diameter of tumor invasion at the lamina muscularis mucosae (LMM invasion width), and lymphatic invasion. The relationships of these variables to lymph-node metastasis and recurrence were examined.

RESULTS

In the surgery group, lymph-node metastasis was found in four patients, all of whom had tumors with lymphatic invasion, a superficial size of at least 25 mm, and an LMM invasion width of at least 2500 microm. In the EMR group, no patient met all three of these criteria, and there was no evidence of lymph-node metastasis or distant metastasis on follow-up after EMR (median follow-up 39 months).

CONCLUSIONS

In patients with m3 or sm1 SEC, tumors that have lymphatic invasion, larger superficial size, and wider LMM invasion are associated with a high risk for lymph-node metastasis. EMR might be indicated for the treatment of patients with m3 or sm1 SECs without these characteristics.

Efficient correction of Fabry mice and patient cells mediated by lentiviral transduction of hematopoietic stem/progenitor cells

A deficiency in alpha-galactosidase A (alpha-gal A) activity causes Fabry disease. Virus-based delivery of genes can correct cells and establish a sustained supply of therapeutic proteins. Recombinant lentiviral vectors (LVs) show promise in this context. We first demonstrate LV-mediated marking of peripheral blood (PB) cells by transduction/transplantation of hematopoietic stem/progenitor cells. Stable enGFP expression was observed in PB for 37 weeks. Next, we transplanted Fabry mice with bone marrow mononuclear cells (BMMNCs) transduced a single time with a LV encoding the human alpha-gal A cDNA. Sustained expression of functional alpha-gal A in Fabry mice was observed over 24 weeks. Plasma alpha-gal A activity from treated Fabry mice was two-fold higher than wild-type controls. Increased alpha-gal A activity, often to supra-normal levels, and reduction of globotriaosylceramide, a glycolipid that accumulates in Fabry disease, was observed in all organs assessed. In secondary bone marrow transplantations, Fabry mice showed multilineage marking of PB, splenocytes and BMMNCs, along with therapeutic levels of alpha-gal A activity in plasma and organs over 20 weeks. Lastly, we transduced mobilized PB CD34(+) cells from a Fabry patient and observed corresponding enzymatic increases. Thus a single LV-mediated transduction of primitive hematopoietic cells can result in sustained correction for Fabry disease.

Automated diagnosis of heart disease in patients with heart murmurs: application of a neural network technique

This study was conducted to test a three-layered artificial neural network analysis of phonocardiogram recordings to diagnose, automatically and objectively, the condition of the heart in patients with heart murmurs. The data were recorded simultaneously in each of 49 patients with a heart murmur through eight microphones attached to the skin surface with adhesive tape, and were analysed by computer. The diagnosis was automated using a three-layered neural network technique. The neural network generated correct answers in over 70% of cases. Furthermore, about 80% of cases of two concurrent diseases were identified correctly. However, ventricular septal defects were incorrectly classified as aortic stenosis or aortic regurgitation, and patent ductus arteriosus was not diagnosed correctly. Accurate diagnoses can frequently be obtained using a neural network, but accuracy can be improved with further data accumulation.

FK506 Induces the Atrophy of Enteric Ganglia in Small Bowel Transplantation, Which Can Be Prevented by the Neuropeptide Bombesin

PURPOSE

FK506, which is widely used for immunosuppression, is reported to have neurotoxicity. However, its neurotoxicity for transplanted graft enteric ganglia (TGEG) has never been reported. The aim of this study was to investigate whether FK506 has a neurotoxic effect on TGEG, and whether bombesin (BBS) prevents such atrophy.

METHODS

Eighteen rats that underwent syngertic heterotopic small bowel transplantation (SBTx) using a cuff method were divided into three groups of six rats each; A: SBTx alone, B: SBTx with FK506, C: SBTx with FK506/BBS. Either BBS (10 mg/kg/d) or normal saline was infused continuously from day 14 to 28. Rats in groups B and C were administered FK506 (0.32 mg/kg/day, intramuscularly) daily. Analysis of TGEG was performed using immunohistochemistry with protein gene product (PGP) 9.5. The ganglionic number was obtained by counting PGP9.5-positive ganglia in each graft.

RESULTS

The number of TGEG were reduced significantly in group B (51.5 +/- 7.7 ganglia per cross section (G/CS)) compared with group A (69.7 +/- 6.0 G/CS), but were well preserved in group C (84.8 +/- 10.2 G/CS). There were significant differences between groups B and C (P < .001) and also between groups A and C (P < .001).

CONCLUSION

FK506 showed severe neurotoxicity on transplanted grafts, and bombesin could rescue TGEG against FK506 neurotoxicity.

Prevention of Warm Ischemic Injury by Neuropeptide Bombesin in Small Bowel Transplantation

PURPOSE

This study investigated whether preoperative administration of neuropeptide bombesin (BBS) had a protective effect against IR/I and subsequent acute rejection.

METHODS

Allogeneic SBTx was performed heterotopically in rats (n = 18). That were administered FK506 (0.32 kg/d) daily. The rats were divided into three groups of six rats each: group 1, BBS(-)5: warm ischemic time (WIT); 5 minutes without BBS; group 2, BBS(-)15: WIT; 15 minutes without BBS; group 3, BBS(+)15: WIT; 15 minutes with BBS. The specimens were obtained from the stoma site at 1 hour after reperfusion and on postoperative days (PODs) 1 and 7. The graft mucosal state and degree of acute rejection were evaluated by H and E staining. The apoptotic cells in the crypt lesion were evaluated using TUNEL immunohistochemistry. An apoptotic index (AI) was calculated for quantitative analysis.

RESULTS

H and E staining revealed that on POD 1 the mucosal villi were shortened in the BBS(-)15 group compared with the other two groups. One hour after reperfusion, the AI in BBS(-)15 group was 125.0 per thousand +/- 37.2 per thousand, which was significantly higher (P < .05) than that in the BBS(-)5 group (32.6 per thousand +/- 5.0 per thousand) or the BBS(+)15 group (32.0 per thousand +/- 3.0 per thousand). On POD 7, the AI in the BBS(-)15 group was 63.7 per thousand +/- 5.03 per thousand, which was significantly higher (P < .05) than in the BBS(-)5 (17.3 per thousand +/- 4.6 per thousand) or the BBS(+)15 group (12.3 per thousand +/- 3.06 per thousand).

CONCLUSIONS

Even a short WIT of 15 minutes induced considerable allograft mucosal damage, which also heightened the possibility of acute rejection. Exogenous BBS prevented mucosal damage by IR/I and was also beneficial to prevent acute rejection.

Neuroendocrine-Immune Modulation May Be Useful for Allograft-Specific Immunosuppression in Small Bowel Transplantation

PURPOSE

The authors have previously demonstrated that the neuropeptide bombesin (BBS) prevented allograft mucosal atrophy under tacrolimus (TRL) immunosuppression for rats small bowel transplantation (SBT). The present study investigated whether BBS had immunosuppressive effects on small bowel allografts.

METHODS

Allogeneic SBT was performed heterotopically in rats (n = 12) that received daily administration of 0.1 mg/kg/d TRL from postoperative day 0 to day 14. Rats divided into two groups of six rats each were administered BBS or normal saline as a control. Biopsy of the allograft was performed from the stomal site on postoperative days 6, 10, and 14. The state of the graft mucosal villi was evaluated by H & E staining and TUNEL immunohistochemistry.

RESULTS

By postoperative day 14, extensive mucosal destruction accompanied by heavy transmural cellular infiltration had developed in the control group. Lymphocytes and plasma cells infiltrated the lamina propria of the allograft without the distorting villous architecture in the BBS group. The TUNEL index of graft mucosa in the control group was 1.26% +/- 0.37% (mean +/- SD) and that in the BBS group, 0.59% +/- 0.20%, respectively (p < .001).

CONCLUSION

This study demonstrated an immunosuppressive effect of bombesin on transplanted allografts, which might dramatically reduce the dose of TRL required for postoperative immunosuppression.

Roles of cyclooxygenase 2 and microsomal prostaglandin E synthase 1 in rat acid reflux oesophagitis

BACKGROUND

Although prostaglandin E2 (PGE2), cyclooxygenase 2 (COX-2), and microsomal prostaglandin E synthase 1 (mPGES-1) are known to play a role in various inflammatory events, their roles in the pathogenesis of gastro-oesophageal reflux disease are not known.

AIMS

We examined the dynamics of COX-1, COX-2, mPGES-1, mPGES-2, cytosolic PGES (cPGES), and PGE2 synthetic activity in rat acid reflux oesophagitis and the effects of COX-2 inhibitors on the severity of oesophagitis.

METHODS

Acid reflux oesophagitis was induced by ligating the transitional region between the forestomach and the glandular portion and wrapping the duodenum near the pylorus. Rats were killed on day 3 (acute phase) or day 21 (chronic phase) after induction of oesophagitis.

RESULTS

Expression of COX-2 and mPGES-1 was markedly increased in oesophagitis while modest changes in COX-1, cPGES, and mPGES-2 expression were observed. COX-2 and mPGES-1 were colocalised in epithelial cells of the basal layer, as well as inflammatory and mesenchymal cells in the lamina propria and submucosa. COX-2 inhibitors significantly reduced the severity of chronic oesophagitis but did not affect acute oesophageal lesions. COX-2 inhibitors significantly inhibited the increase in PGE2 synthesis in oesophageal lesions on both days 3 and 21. Epithelial proliferation was significantly increased in the basal layer on day 21. Inflammatory cells and epithelial cells of the basal layer exhibited reactions for EP4 in oesophagitis.

CONCLUSION

PGE2 derived from COX-2 and mPGES-1 plays a significant role in the pathogenesis of chronic acid reflux oesophagitis, and possibly in basal hyperplasia and persistent inflammatory cell infiltration.

Graft insertion technique for distal anastomosis in cases of ascending aortic aneurysm

We describe a simple and reliable technique of making a secure graft for aorta anastomosis, involving sandwiching the friable aortic wall between the graft and a Teflon strip. This technique makes possible a secure anastomosis with the distal friable tissue and prevents bleeding from the junction.

Laceration of gastric mucosa associated with dialysis-related amyloidosis

We report a 72-year-old female on long-term hemodialysis, who was admitted to the hospital because of hematemesis. On emergency laparotomy, pylorogastrectomy was performed. The resected specimen showed a giant hematoma and traversing fissure along the lesser curvature of the body of the stomach. Histologically, the specimen showed wide hematoma formation and amyloid deposits in the submucosal layer, especially in the wall of blood vessels. These deposits reacted positively to antihuman beta2-microglobulin antibody. The post-operative course was favorable, and the patient was discharged on the 35th hospital day. In this case, the laceration site on the gastric mucosa was almost intact and did not demonstrate ischemic change, suggesting that the giant hematoma was caused by submucosal vessel rupture, which led to the gastric mucosa laceration. To our knowledge, this is the first case of gastric mucosa laceration associated with dialysis-related amyloidosis.

Augmented expression of secondary lymphoid tissue chemokine and EBI1 ligand chemokine in Crohn's disease

BACKGROUND

A dominant T helper type 1 (Th1) immune response is thought to be involved in Crohn's disease (CD). SLC/CCL21 and ELC/CCL19, chemokines that regulate T cell homing and promote recirculating T and dendritic cell (DC) interactions, help control antigen specific T cell responses.

AIMS

To investigate the Th1 response and SLC and ELC in CD pathogenesis.

METHODS

Surgically resected intestine and mesenteric lymph nodes (MLNs) from controls and patients with CD and ulcerative colitis (UC) were investigated. CD3, CD83, HECA452, VEGFR3, SLC, ELC, and CCR7 expression was studied immunohistochemically. CCR7 mRNA was quantified using real time RT-PCR.

RESULTS

ELC was almost undetectable in intestinal samples. SLC was found sporadically in lymphoid follicles, lymphoid aggregate venules, and lymphatic vessels. In MLNs, SLC was highly expressed in high endothelial venules (HEVs), lymphatic vessels, and stromal DCs, predominantly in T cell areas. ELC was highly expressed in mature DCs. There were significantly more SLC positive HEVs and ELC positive mature DCs, important components of T cell areas, in CD. SLC, ELC, and CCR7 mRNA was significantly higher in CD MLNs compared with UC. CD MLNs had increased expression of SLC and ELC, mainly in HEVs, mature DCs, and lymphatic vessels, inducing T cell hyperplasia. CCR7 mRNA was increased in T cell areas.

CONCLUSION

The dominant Th1 immune response is facilitated by interaction of SLC positive HEVs/lymphatic vessels, ELC positive mature DCs, and CCR7 positive T cells in hyperplastic T cell areas. In CD, memory T cells and mature DCs may home to MLN.

Famotidine vs. omeprazole: a prospective randomized multicentre trial to determine efficacy in non-erosive gastro-oesophageal reflux disease

BACKGROUND

Several studies in Western countries showed that proton-pump inhibitors are superior to histamine2-receptor antagonists or placebo in the treatment of non-erosive gastro-oesophageal reflux disease. The efficacy of acid-suppressive drugs for non-erosive gastro-oesophageal reflux disease in Japan, in which the prevalence of Helicobacter pylori infection is higher compared with Western countries, is unknown.

AIM

To compare the efficacy of famotidine and omeprazole in Japanese patients with non-erosive gastro-oesophageal reflux disease by a prospective randomized multicentre trial.

METHODS

A total of 98 patients received either famotidine 20 mg b.d. (n = 48) or omeprazole once daily (n = 50). Frequency of gastro-oesophageal reflux disease symptoms and health-related quality of life were evaluated at baseline and after 4 weeks of treatment. Complete relief was defined as no gastro-oesophageal reflux disease symptoms during the 7-day interval in week 4.

RESULTS

Complete relief was achieved in 23 (48%) of patients receiving famotidine and 28 (56%) of patients treated with omeprazole. In the famotidine group, complete relief rate in H. pylori-negative patients was significantly lower than H. pylori-positive patients (35% vs. 64%). Both famotidine and omeprazole improved most scales of health-related quality of life. Omeprazole significantly improved reflux score irrespective of H. pylori infection while famotidine significantly improved reflux score in H. pylori-positive patients but not in H. pylori-negative patients.

CONCLUSIONS

Omeprazole is more effective than famotidine for the control of gastro-oesophageal reflux disease symptoms in H. pylori-negative patients, while similar efficacy is observed in H. pylori-positive patients with non-erosive gastro-oesophageal reflux disease.

A novel murine model of aging, Senescence-Accelerated Mouse (SAM)

Senescence-Accelerated Mouse (SAM) has been under development by our research team at Kyoto University since 1970, based on the AKR/J strain donated by the Jackson Laboratory in 1968. The SAM mouse has an accelerated senescence and age-associated pathologies such as senile amyloidosis, senile osteoporosis, degenerative joint disease, cataract, deficits in learning and memory, brain atrophy, hyperinflation of lungs, hearing impairment and so on. SAM research is advancing world-wide and attempts are being made to clarify fundamental mechanisms involved in primary aging processes, pathogenesis of age-associated pathologies and effective methods to modulate or ameliorate the advance of senescence and disease processes involved in age-associated pathologies.

TGF-beta signaling pathway: its role in gastrointestinal pathophysiology and modulation of ulcer healing

Gastrointestinal ulcer healing is a complex process, involving cell migration, proliferation, angiogenesis and extracellular matrix deposition, all ultimately leading to reconstruction of tissue architecture within the ulcer scar. These processes are controlled by growth factors, cytokines and hormones. Transforming growth factor-beta (TGF-beta), one of the multifunctional peptide growth factors, has been reported to positively regulate gastrointestinal ulcer healing. Although TGF-beta inhibits cell proliferation in a variety of cells, it induces cell migration, angiogenesis, and enhances extracellular matrix production necessary for gastrointestinal ulcer healing. TGF-beta exerts its action by binding to its transmembrane serine/threonine kinase receptors, which in turn triggers activation of various intracellular signaling pathways. Smads are intermediate effector proteins that play key roles in biological activities of TGF-beta by transmitting the signals from the cell surface directly into the nucleus and initiating transcription. New insight into the mechanisms underlying TGF-beta-Smad modulation of gastrointestinal ulcer healing will likely enhance our understanding of the mechanisms controlling the healing processes of gastrointestinal ulcers.

Effects of ranitidine on quality of gastric ulcer healing compared with famotidine: a randomized, controlled, multicenter trial

Ranitidine has been found to have anti-inflammatory action as well as antisecretory action in experimental models. However, there are no reports in human gastric ulcer. The aim of this study was to investigate the effects of ranitidine compared with those of famotidine on the quality of gastric ulcer healing. We randomly assigned 69 consecutive patients with gastric ulcers to ranitidine (n = 34) or famotidine (n = 35) for 12 weeks, with endoscopic assessment of the quality of gastric ulcer healing and histological assessment of gastric mucosa 12 weeks after treatment started. Ulcer healing rates of over 95% were very similar in the two groups. The rates of ulcer scars with a flat pattern (good-quality healing) were significantly higher in the ranitidine group than in the famotidine group (per protocol, 63.0% and 34.5%, p = 0.033). The neutrophil infiltration score in the body mucosa treated with famotidine, but not ranitidine, significantly increased after treatment. In contrast, the mononuclear cell infiltration score in the antral mucosa treated with ranitidine, but not in that treated with famotidine, had significantly decreased. In conclusion, initial therapy with ranitidine significantly improved the quality of gastric ulcer healing and the histological scores of gastric mucosa compared with famotidine.

Bacillus thuringiensis serovar shandongiensis strain 89-T-34-22 produces multiple cytotoxic proteins with similar molecular masses against human cancer cells

AIMS

To prove that Bacillus thuringiensis serovar shandongiensis strain 89-T-34-22 produces several novel cytotoxic proteins against human leukaemic T cells.

METHODS AND RESULTS

Parasporal inclusion protein was solubilized and processed by proteinase K and was separated by anion-exchange chromatography. Cytopathic effects of each fraction against MOLT-4 and Jurkat cells were monitored.

CONCLUSIONS

Existence of at least two novel cytotoxic proteins was suggested and N-terminal sequences of the newly identified proteins were determined to be QSTTDVIREY and X (Y or I) (P or I) NLANELA (X indicates uncertain amino acids). Molecular masses of the two proteins were approx. 27-28 kDa.

SIGNIFICANCE AND IMPACT OF THE STUDY

In this study, we demonstrated that the strain 89-T-34-22 produces at least two novel cytotoxic proteins with similar molecular masses against human cancer cells. This is the first strain of B. thuringiensis which produces multiple cytotoxic proteins against human cancer cells.

Correlation of MAP kinases with COX-2 induction differs between MKN45 and HT29 cells

BACKGROUND

Mitogen-activated protein (MAP) kinases, including extracellular signal-regulated kinases (ERK),c-Jun NH2-terminal kinases (JNK) and p38 MAP kinase (p38 MAPK) are important intermediates of the signal-transduction pathway from the cell surface to the nucleus. Expression of cyclooxygenase (COX)-2, associated with proliferation, apoptosis or both of gastrointestinal cancer cells, is mediated through MAP kinase families. However, the correlation between respective MAP kinase signals and COX-2 in the proliferation of gastric and colon cancer cells has not been well elucidated.

AIM

We examined the effect of selective inhibitors of MAP kinases and COX-2 on serum-induced proliferation of gastric (MKN45) and colon (HT29) cancer cells.

METHODS

After 24-h serum starvation, cancer cells were stimulated with 2% serum and COX-2 inhibitors (NS398 10 micromol/L, or etodolac 100 micromol/L) or 1 h after preincubation with inhibitors for ERK (PD98059 20 micromol/L) or p38 MAPK (SB203580 10 micromol/L). Phosphorylated MAP kinases and COX-2 protein were evaluated by Western blotting, and the proliferation of cancer cells was estimated by 3H-thymidine incorporation. Transcription factors nuclear factor-kappaB and CREB were assayed by an electorophoretic mobility shift assay.

RESULTS

Serum increased the proliferation of MKN45 and HT29 cells by 280% and 200%, respectively, compared with the control levels (100%). In both cancer cells, phosphorylated MAP kinases were increased within 30 min after stimulation. PD98059 and SB203580 inhibited the serum-induced proliferation of MKN45 by 21% and 51% and of HT29 by 81% and 69%, respectively. NS398 and etodolac inhibited the proliferation of HT29 by 21% and 41%, respectively, but not that of MKN45. PD98059 and SB203580 also suppressed serum-induced expression of COX-2 protein in HT29 cells. In addition to the activation of MAP kinases and COX-2, activities of nuclear factor-kappaB and CREB were also increased during HT29 cell proliferation.

CONCLUSIONS

These results suggest that the correlation of MAP kinases with COX-2 induction for cell proliferation differs between MKN45 and HT29 cells.

Prevalence of symptomatic gastro-oesophageal reflux disease in Japanese patients with peptic ulcer disease after eradication of Helicobacter pylori infection

BACKGROUND

The association between cure of Helicobacter pylori infection and the development of gastro-oesophageal reflux disease is controversial.

AIM

To examine the prevalence of symptomatic GERD (sGERD) in Japanese patients with peptic ulcer disease after successful eradication and identify associated factors affecting sGERD development.

METHODS

We retrospectively examined 72 patients (40 gastric ulcer and 32 duodenal ulcer) with successful eradication. Associated factors such as age, gender, drinking and smoking habits, body mass index, presence of gastric atrophy and hiatal hernia were analysed.

RESULTS

Seven (9.7%) of 72 peptic ulcer patients newly developed sGERD. There were no differences in mean age, gender, smoking habit, drinking habit, body mass index, or presence of gastric atrophy and hiatal hernia between the sGERD and non-sGERD groups, while the proportion of subjects aged over 70 was significantly higher in the sGERD than the non-sGERD group. Six of 40 patients with gastric ulcer newly developed sGERD while only one of 32 patients with duodenal ulcer developed it.

CONCLUSION

Approximately 10% of Japanese patients with peptic ulcer disease newly developed sGERD after cure of H. pylori infection. Age > 70 years was associated with development of sGERD. Eradication in patients in this age group should be carefully determined.

Dominant-negative mutant of c-Jun gene transfer: a novel therapeutic strategy for colorectal cancer

Activator protein-1 (AP-1), a transcription factor, is activated through many oncogenic signals. However, its biological role in colorectal cancer has not been fully elucidated. To investigate the role of AP-1 in colorectal cancer, we constructed an adenovirus-expressing TAM67, a dominant-negative mutant of c-Jun lacking the transactivation domain of wild c-Jun (DN-c-Jun), to inhibit endogenous AP-1. AP-1 DNA-binding activity was increased in colon cancer cells (HT-29 cells) by serum stimulation, followed by an increase in both [(3)H]thymidine incorporation and cell number. Transfection of Ad-DN-c-Jun to HT-29 cells significantly inhibited serum-induced cell proliferation in vitro. As shown by flow cytometric analysis, DN-c-Jun significantly inhibited entrance into S phase after serum stimulation, thereby leading to G(1) arrest. In vivo transfection of Ad-DN-c-Jun into xenografted HT-29 cell tumors in nude mice significantly decreased tumor volume on day 21 after treatment. A change was associated with decrease in Ki-67 labeling index. These observations together showed that AP-1 is a critical modulator for proliferation and cell cycle of HT-29 cells. We obtained the first evidence that DN-c-Jun gene transfer exerted a significant antitumor effect on colon cancer both in vitro and in vivo. DN-c-Jun gene transfer may be a new candidate for treatment of colorectal cancer.

Indomethacin, but not Helicobacter pylori, inhibits adaptive relaxation in isolated guinea-pig stomach

Nonsteroidal anti-inflammatory drugs (NSAIDs) and Helicobacter pylori (H. pylori) are major factors in gastritis and peptic ulcer However, the role of NSAIDs and H. pylori infection in dyspepsia remains unclear. Gastric adaptive relaxation may be related to the pathogenesis of functional dyspepsia because the response is often disturbed in dyspeptic patients. In this study, we investigated the effects of indomethacin or H. pylori water extracts on gastric adaptive relaxation. This experiment was performed using the modified method of Desai et al. Isolated guinea-pig stomach in an organ bath was monitored for intragastric pressure and volume. Adaptive relaxation was induced by gastric luminal distention. The effects of indomethacin and H. pylori on gastric relaxation were tested in this system. Indomethacin (> 1 x 10(-5) M) significantly inhibited adaptive relaxation. Indomethacin (> 3 x 10(-6) M) induced gastric relaxation in a dose-dependent fashion. However, aspirin at a concentration sufficient for cyclooxygenase (COX)-1 inhibition did not induce gastric relaxation. Preincubation with N-nitro-L-arginine methyl ester, a nitric oxide (NO)-synthase inhibitor, inhibited indomethacin-induced gastric relaxation. Adaptive relaxation was not affected by H. pylori water extracts. In conclusion, indomethacin inhibited adaptive relaxation via prior gastric relaxation. NO production, but not COX-1 inhibition, may be involved in this effect of indomethacin. H. pylori water extracts may not have direct effects on adaptive relaxation. Inhibition of adaptive relaxation may be one of the major mechanisms underlying NSAID-induced dyspepsia.