The specific expression of hypoxia inducible factor-1alpha in human gastric mucosa induced by nonsteroidal anti-inflammatory drugs

Treatment of gastric ulcer, traditional Chinese medicine may be a better choice

ETHNOPHARMACOLOGICAL RELEVANCE

Gastric ulcer (GU) is the injury of the gastric mucosa caused by the stimulation of various pathogenic factors penetrating the deep mucosal muscle layer. An increasing number of studies have shown that traditional Chinese medicine (TCM) is highly effective in treating GU due to its multitarget, multilevel, and multi-pathway effects.

AIM OF THE STUDY

To review the latest research progress in the treatment of GU by TCM, including clinical and experimental studies, focusing on the target and mechanism of action of drugs and providing a theoretical basis for the treatment of GU by natural herbs.

MATERIALS AND METHODS

Electronic databases (PubMed, Elsevier, Springer, Web of Science, and CNKI) were searched using the keywords "gastric ulcer", "gastric mucosal lesion", "TCM" and or paired with "peptic ulcer" and "natural drugs" for studies published in the last fifteen years until 2023.

RESULTS

TCM, including single components of natural products, Chinese patent medicines (CPM), and TCM decoction, is expected to treat GU by regulating various mechanisms, such as redox balance, inflammatory factors, angiogenesis, gastric mucosal protective factors, intestinal flora, apoptosis, and autophagy.

CONCLUSIONS

We discussed and summarized the mechanism of TCM in the treatment of GU, which provided a sufficient basis for TCM treatment of GU.

Increased expression of hypoxia inducible factor-1 alpha and vascular endothelial growth factor is associated with diabetic gastroparesis

BACKGROUND

Gastroparesis is a recognized complication of diabetes but its pathogenic mechanism incompletely understood. Our aim was to determine whether HIF-1α and VEGF are secreted from gastric tissue is a fundamental factor that drives diabetic gastroparesis.

METHODS

Diabetes was induced in Sprague-Dawley by a single intraperitoneal injection of 65 mg/kg streptozotocin. After 4 and 12 weeks, rats were euthanized for assaying body weight, blood glucose, gastric acid secretion and gastric emptying. Morphologic changes in gastric mucosa were observed by the light microscope. Expression of HIF-1α and VEGF were assessed using immunohistochemistry, RT-PCR and Western blot analyses.

RESULTS

Compared with control group, blood glucose were significantly increased and body weight were markedly decreased in streptozotocin-induced diabetes. Gastric emptying was significantly decreased in diabetic rats compared to the control group at different times. The number of parietal cells was obviously decreased, and vacuolated degeneration in diabetic rats. Gastric acid secretion in diabetic group was significantly decreased, and expression of HIF-1α and VEGF were significantly increased in the diabetic group.

CONCLUSION

These results indicated that overexpression of HIF-1α and VEGF in the gastric mucosa and played a pivotal role in the progression of diabetic gastroparesis.

TFF1 Promotes EMT-Like Changes through an Auto-Induction Mechanism

Trefoil factor 1 (TFF1) is a small secreted protein expressed in the gastrointestinal tract where, together with the other two members of its family, it plays an essential role in mucosal protection and repair against injury. The molecular mechanisms involved in the protective function of all three TFF proteins are not fully elucidated. In this paper, we investigated the role of TFF1 in epithelial to mesenchymal transition (EMT) events. The effects of TFF1 on cellular models in normoxia and/or hypoxia were evaluated by western blot, immunofluorescence, qRT-PCR and trans-well invasion assays. Luciferase reporter assays were used to assess the existence of an auto-regulatory mechanism of TFF1. The methylation status of TFF1 promoter was measured by high-resolution melting (HRM) analysis. We demonstrate a TFF1 auto-induction mechanism with the identification of a specific responsive element located between −583 and −212 bp of its promoter. Our results suggest that TFF1 can regulate its own expression in normoxic, as well as in hypoxic, conditions acting synergistically with the hypoxia-inducible factor 1 (HIF-1α) pathway. Functionally, this auto-induction mechanism seems to promote cell invasion and EMT-like modifications in vitro. Additionally, exogenously added human recombinant TFF1 protein was sufficient to observe similar effects. Together, these findings suggest that the hypoxic conditions, which can be induced by gastric injury, promote TFF1 up-regulation, strengthened by an auto-induction mechanism, and that the trefoil peptide takes part in the epithelial-mesenchymal transition events eventually triggered to repair the damage.

Clinical significance of integrin β6 as a tumor recurrence factor in follicular thyroid carcinoma

BACKGROUND

Overexpression of integrin β6 plays an important role in a variety of malignant tumor invasion and metastasis.

METHODS

The expression levels of integrin β6, matrix metalloproteinase (MMP)-2 and MMP-9 were analyzed by immunohistochemistry with human follicular thyroid carcinomas. Then we investigated their correlation with clinical outcomes parameters, relationship, and the survival time.

RESULTS

The integrin β6 staining was expressed in cellular membrane and cytoplasm of follicular thyroid carcinoma cells. The MMP-2 and MMP-9 expressions were mainly found in cellular cytoplasm. In correlation with the clinical outcome parameters of 60 patients, there were significant statistical differences of integrin β6, MMP-2, and MMP-9 expression levels in different size of tumor. Integrin β6 and MMP-9 expressions have significant statistical differences in T classifications. MMP-2 and MMP-9 expressions have significant statistical differences in different M classification. Other clinical outcome parameters had no significant statistical differences.

CONCLUSION

Integrin β6 expression correlated significantly with MMP-9 expression, and may be a valuable recurrence indicator for follicular thyroid carcinomas.

37-kDa laminin receptor precursor promotes lung adenocarcinoma cell invasion and metastasis by epithelial-to-mesenchymal transition

37-kDa laminin receptor precursor (37LRP) has a crucial role in migration of some human cancers. Epithelial-to-mesenchymal transition (EMT) has received much attention in invasion and metastasis of lung cancer. Nevertheless, the role of 37LRP is not entirely clear in EMT promotion of lung cancer at present. In this study, we firstly examined the possible role of 37LRP in the invasiveness and metastasis process of lung cancer using immunohistochemistry of 80 lung adenocarcinoma cases, western blot and real-time PCR of 12 fresh lung adenocarcinoma tissues. The results showed that 37LRP significantly correlated with clinical stage and were highly expressed in metastatic lung adenocarcinomas compared with nonmetastatic ones. In vitro, we observed that 37LRP significantly increased the adhesive, invasive and metastatic abilities of human lung adenocarcinoma cell lines A549 by 37LRP-lentivirus interference. Furthermore, inoculation of A549 cells transduced with 37LRP-lentivirus in nude mice resulted in multi-metastases including the lung. In addition, western blotting and immunofluorescence were used to detect the significant difference in expression of E-cadherin and fibronectin in A549 by 37LRP-lentivirus interference compared with 37LRP-small interference RNA-lentivirus interference in vitro and vivo. The data indicated that A549 cells of epithelial cell characteristics might be induced to undergo EMT by 37LRP. A549 cells transduced with 37LRP-lentivirus showed marked morphological changes, accompanied by the decrease of epithelial marker E-cadherin and the increase of mesenchymal marker fibronectin. These results indicated that 37LRP may promote lung adenocarcinoma invasion and metastasis via the mechanism of EMT.

Clinical significance of integrin αvβ6 expression effects on gastric carcinoma invasiveness and progression via cancer-associated fibroblasts

Over-expression of integrin αvβ6 and increased numbers of cancer-associated fibroblasts (CAFs) play an important role in the development and progression of cancers. The aim of this study is to investigate the expression level of integrin αvβ6 and CAF numbers, their correlation with clinicopathologic features and their role in the prognosis of human gastric cancers. The expression levels of integrin αvβ6 and α-SMA in CAFs were analyzed by immunohistochemistry. Their correlation with clinicopathologic features, the relationships and the survival time of patients were also analyzed. The integrin αvβ6 expression levels were analyzed mainly in gastric cancers. The α-SMA expression levels were analyzed mainly in gastric cancers and paraneoplastic tissues. Patients with positive integrin β6 and α-SMA expression have a significantly lower overall survival rate than those with negative integrin β6 and α-SMA expression (P < 0.05). A multivariate analysis using a log-rank test indicated that patients with positive integrin β6 and α-SMA expression and/or a diffuse type of gastric cancer had a significantly poorer overall survival rate than did those with negative integrin β6 expression (P < 0.05). Integrin β6 expression correlated significantly with CAF numbers and served as a valuable prognostic indicator for human gastric cancers.

Cytoglobin may be involved in the healing process of gastric mucosal injuries in the late phase without angiogenesis

BACKGROUND AND AIMS

Cytoglobin (Cygb) is the newest globin family and is upregulated during hypoxia to maintain the oxygen status. Herein, we investigated Cygb expression in both acute and chronic gastric mucosal injuries.

METHODS

Acute gastric mucosal injuries in rats were produced by oral administration of indomethacin, followed by sacrifice at 1, 3, 6, 24, and 48 h. Gastric ulcer was produced by acetic acid, followed by sacrifice on days 3, 7, 11, 18, and 25. Each protein expression of Cygb and hypoxia-inducible factor (HIF)-1α was evaluated by western blotting. We measured vascular endothelial growth factor (VEGF) mRNA by RT-PCR and examined localization of Cygb by immunofluorescence.

RESULTS

In indomethacin-induced injury, Cygb protein was significantly increased at 24 h. In ulcerated tissues, HIF-1α protein was significantly increased on days 7 and 11 (1.83 ± 0.11 and 2.12 ± 0.19 folds, respectively, p < 0.05 and 0.01), which corresponded to the early healing phase. In contrast, Cygb protein was significantly increased on days 11 and 18 (1.87 ± 0.13 and 1.60 ± 0.06 folds, respectively, p < 0.05), which demonstrated late phase. Though these proteins peaked on day 11, VEGF mRNA was gradually increased from day 11 to 18. Cygb was expressed in fibroblasts and myofibroblasts in both acute and chronic models. Cygb and HIF-1α were abundantly colocalized at the ulcer margin before angiogenesis development. However, faint localization was observed with angiogenesis.

CONCLUSIONS

Cygb may be involved in the healing process of gastric mucosal injuries in the late phase without angiogenesis.

Lentivirus-delivered ZEB-1 small interfering RNA inhibits lung adenocarcinoma cell growth in vitro and in vivo

PURPOSE

To explore the relationship between the expression of ZEB1 gene and the proliferation ability of lung adenocarcinoma cells.

METHODS

Immunohistochemistry, Western blot and Real-time PCR were used to detect the expression of ZEB1 gene in lung adenocarcinoma tissue and cell lines compared with adjacent noncancerous region and the human lung fibroblast cell HLF cells. The lentivirus RNA interference technique was used to knock down the expression of ZEB1 in lung adenocarcinoma A549 and H1299 cell lines. Cell cycle and cell apoptosis were measured by FCM assay. In vivo, four groups of 4-week-old nude mice were subcutaneously injected with the stably transfected (ZEB-si, scr-si) cells at a single site to investigate the effect of ZEB1-siRNA in the nude mice tumor growth. In situ apoptosis was detection by TUNEL assay.

RESULTS

ZEB-1 was highly expressed in lung adenocarcinoma tissue and cell lines compared with adjacent noncancerous region and the human lung fibroblast cell HLF cells. ZEB1-siRNA could decrease lung adenocarcinoma cell proliferation by delaying S-phase entry and induce cell apoptosis, which led to the inhibition of the tumorigenicity of A549 and H1299 cell lines. Further investigation showed that injecting the ZEB1-siRNA cells into the nude mice could significantly decrease the tumor growth.

CONCLUSION

Knockdown of ZEB-1 expression by lentivirus-delivered siRNA may provide a novel therapeutic target for the treatment of lung cancer.

Nitric oxide induces HIF-1α stabilization and expression of intestinal trefoil factor in the damaged rat jejunum and modulates ulcer healing

BACKGROUND

The induction of intestinal trefoil factor (ITF) has been reported to depend on hypoxia-inducible factor-1 (HIF-1). Nitric oxide modulates HIF-1 activity. The present study aims to analyze the role of nitric oxide in jejunum damage induced by indomethacin and its ability to modulate epithelial function through the expression of ITF.

METHODS

Rats received indomethacin (7.5 mg/kg, s.c., twice), and a time course analysis of damage was performed (24-96 h after the first administration). In these animals, the role of nitric oxide was analyzed by using 1400W, a selective iNOS activity inhibitor (5 mg/kg, i.p./day), on: (1) intestinal damage, (2) ulcer healing, (3) the presence of nitrated proteins in the jejunum and (4) the protein expression of inducible nitric oxide synthase (iNOS), HIF-1α and ITF.

RESULTS

Indomethacin induced damage in the jejunum that was apparent at 24 h and peaked at 48-72 h. An increase in iNOS, HIF-1α, ITF and nitrated proteins was observed in the injured jejunum. Immunoprecipitation of HIF-1α allowed determination of the nitration/nitrosylation of this protein by using nitrotyrosine and nitrocysteine antibodies. Blockade of iNOS activity did not significantly modify damage or iNOS expression, but did significantly impede ITF induction, HIF-1α stabilization and HIF-1α detection with antibodies against nitrated proteins. In parallel to these results, pre-treatment with 1400W delayed the healing of the ulcer provoked by indomethacin.

CONCLUSIONS

These results suggest that iNOS-derived NO is involved in HIF-1α stabilization, probably through S-nitrosylation, and ITF expression in goblet cells of the damaged jejunum of indomethacin-treated rats and mediates ulcer healing.

Expression of hypoxia-inducible factor-1 alpha (HIF-1alpha) in patients with the gallbladder carcinoma

BACKGROUND

Hypoxia-inducible factor-1 (HIF-1) is a transcription factor that plays a central role in biologic processes under hypoxic conditions, especially concerning tumor angiogenesis. Vascular endothelial growth factor (VEGF) is a potent proangiogenic agent and a multifunctional angiogenic cytokine in many malignant tumors.

METHODS

This study was conducted to clarify the role of HIF-1 expression in gallbladder carcinoma. Thirty-one patients with gallbladder carcinoma underwent surgical treatment between 1994 and 2003 at the Department of Surgery, University of Tokushima, Japan. Both HIF-1alpha and VEGF were evaluated by immunohistochemistry, and correlations between the expression of these factors and clinicopathological features including prognosis were analyzed.

RESULTS

Among 31 specimens from patients with gallbladder carcinoma, 22 (70%) and 9 (30%) were positive for HIF-1alpha and VEGF expression, respectively. Expression of HIF-1alpha was significantly correlated with stage, tumor curability, lymph node metastasis, venous invasion, hepatic infiltration, and lymphatic invasion (P < 0.05). The survival rate for patients with HIF-1alpha positive staining was significantly lower than that for patients with HIF-1alpha negative staining. However, VEGF overexpression did not correlate with clinical outcomes. We demonstrated that HIF-1alpha expression was associated with a malignant behavior risk category in gallbladder cancer.

CONCLUSION

Expression of HIF-1alpha was correlated with the poor prognostic indicators, such as lymph node metastasis and venous invasion. Therefore, HIF-1alpha could serve as an auxiliary parameter for predicting malignant behavior for gallbladder carcinomas.

iNOS-derived nitric oxide mediates the increase in TFF2 expression associated with gastric damage: role of HIF-1

Trefoil (TFF) peptides are involved in gastrointestinal mucosal restitution. An hypoxia inducible factor 1 (HIF-1)-dependent induction of TFF genes has been reported in gastric epithelial cells. Nitric oxide (NO) is associated with mucosal damage and modulates HIF-1 activity. The aim of the present study was to analyze the role of iNOS-derived NO in HIF-1alpha stabilization and TFF gene expression in damaged gastric mucosa. Aspirin caused gastric injury that peaked 6 h after dosing and returned to normality at 24 h. iNOS mRNA expression occurs in the corpus in parallel with damage. Blockade of iNOS activity did not modify gastric lesions induced by aspirin but delayed mucosal healing. Aspirin induced HIF-1alpha stabilization and TFF2 mRNA up-regulation in the mucosa, but these effects were diminished when iNOS activity was inhibited. Results obtained using a coculture setup showed that iNOS-derived NO from activated macrophages induced HIF-1alpha stabilization, TFF gene expression, and accelerated wound healing in cultured epithelial cells. Finally, transient silencing of endogenous HIF-1alpha in epithelial cells significantly undermined activated macrophage-induced TFF gene expression. Evidence suggests that the iNOS-derived NO associated with NSAID-induced gastric injury is implicated in mucosal restitution via the HIF-1-mediated induction of TFF genes.

Clopidogrel induced gastrointestinal damage and its prevention

As a new anti-platelet medicine, it has been more than 10 years since clopidogrel was applied to treat cardiovascular and cerebrovascular diseases. Recently, the increasing incidence and mortality of cardiovascular events in preventing clopidogrel associated gastrointestinal damage with PPI have been attracting wide attention of clinicians. This article reviews the present clinical application of clopidogrel, clopidogrel-induced gastrointestinal damage and its prevention strategy.

Integrin alphanvbeta6 acts as a prognostic indicator in gastric carcinoma

AIMS

To investigate the relationships between integrin alphanubeta6 expression and the clinical-pathological features of gastric carcinoma and whether integrin alphanubeta6 can act as a prognostic indicator in gastric carcinoma.

MATERIALS AND METHODS

We generated the microarray of 300 human gastric carcinoma specimens, and used the method of immunohistochemistry to investigate the expression of alphanubeta6 in them and the relationships between the expression of alphanubeta6 and the clinical-pathological features of the tumours. Meanwhile, we retrospectively analysed the relationship between alphanubeta6 expression and the survival times of the patients.

RESULTS

The expression of alphanubeta6 was detected in 36.7% of gastric carcinomas, and the expression was associated with Lauren type, differentiation, N stage and TNM stage of the tumours (the P values were 0.004, 0.035, 0.024 and 0.001, respectively). The Kaplan-Meier plot showed that patients who were alphanubeta6 negative had much longer survival times than those who were alphanubeta6 positive (P<0.0001). The survival estimates showed a striking difference in median survival between the negative and positive alphanubeta6 expression patients, especially in early stage tumours. Univariate analysis indicated that significant factors for prognosis included alphanubeta6 expression, differentiation, TNM stage, T stage, N stage, M stage and R classification (R0: potentially curative resection; R1: had residual microscopic disease after resection; R2: had residual macroscopic disease after resection), whereas in multivariate analysis using the Cox regression model, only alphanubeta6 expression, M stage, TNM stage and R classification retained significance for prognosis.

CONCLUSIONS

Positive alphanubeta6 expression in gastric carcinoma is linked to significantly reduced survival times and, even more important, is that its value as a prognostic marker is significant for early stage tumours.

Hypoxia-inducible factor-1alpha expression in the gastric carcinogenesis sequence and its prognostic role in gastric and gastro-oesophageal adenocarcinomas

Hypoxia-inducible factor-1 (HIF-1)α expression was studied in the gastric carcinogenesis sequence and as a prognostic factor in surgically resected gastric and gastro-oesophageal junction tumours. Protein expression was examined using immunohistochemistry on formalin-fixed biopsies of normal mucosa (n=20), Helicobacter pylori associated gastritis (n=24), intestinal metaplasia (n=24), dysplasia (n=12) and intestinal (n=19) and diffuse (n=21) adenocarcinoma. The relationship between HIF-1α expression and prognosis was assessed in resection specimens from 177 patients with gastric and gastro-oesophageal junction adenocarcinoma. Hypoxia-inducible factor-1α expression was not observed in normal gastric mucosa but increased in density (P<0.01) and intensity (P<0.01) with progression from H. pylori-associated gastritis, intestinal metaplasia, dysplasia to adenocarcinoma. The pattern of staining in the resection specimens was focally positive in 49 (28%) and at the invasive tumour edge in 41 (23%). Invasive edge expression was associated with lymph node metastases (P=0.034), advanced TNM stage (P=0.001) and was an adverse prognostic factor for cancer-specific survival (P=0.019). In univariate analysis and in comparison with tumours not expressing HIF-1α, invasive edge staining was associated with a hazard ratio of 1.6 (95% CI 1.0−2.5) and focally positive staining a hazard ratio of 0.7 (95% CI 0.5−1.2). Hypoxia-inducible factor-1α lost prognostic significance in multivariate analysis. The results suggest HIF-1α is involved in gastric carcinogenesis and disease progression, but is only a weak prognostic factor for survival.

Is the hypoxia-inducible factor pathway important in gastric cancer?

Tumour hypoxia is well recognised in oncology to be a key factor resulting in treatment resistance and poor prognosis. Hypoxia leads to the expression of a number of gene products that are involved in tumour progression, invasion and metastasis formation. The most important of these proteins is thought to be hypoxia-inducible factor-1alpha (HIF-1alpha), which appears to be a master regulator of the cellular response to hypoxia. HIF-1alpha expression is associated with a poor prognosis and treatment response in a number of tumour sites. There is some evidence that the HIF-1alpha pathway might be involved in gastric carcinogenesis. Studies have shown reactive oxygen species from Helicobacter pylori, associated with the development of gastric cancer, stabilise HIF-1alpha. Non-steroidal anti-inflammatory drugs, shown to reduce the risk of gastric cancer, can decrease HIF-1alpha expression. Although a large study correlating HIF-1alpha expression with prognosis is lacking in gastric cancer, the immunohistochemical expression of HIF-1alpha target genes (Glut-1, VEGF, CA9, iNOS) is associated with a poor prognosis. In addition, the targeted inhibition of HIF-1alpha has been shown to inhibit the growth of gastric tumours in animals. Increased understanding of the importance of hypoxia and the HIF-1alpha pathways may therefore hold the key to prevention strategies, improved selection of patients for adjuvant therapy and new treatments for the disease.

Gene expression analysis following hypoxia-reoxygenation in rat gastric epithelial cells using a high-density oligonucleotide array

Recent investigations have demonstrated that the signaling of hypoxia-re-oxygenation is a major contributing pathway leading to gastric mucosal injury induced by stress, non-steroidal anti-inflammatory drugs, and Helicobacter pylori. The aim of the present study was to perform a gene expression analysis on the gastric mucosal cellular response to hypoxia-reoxygenation using a high-density oligonucleotide array. Cells were subjected to hypoxia with 95% N(2) and 5% CO(2) at 37 degrees C for 2 h. Reoxygenation was initiated by placing the cells in an environment of normoxia for 2 h. Total RNA was extracted, and differences in gene expression profiles between the normoxia and hypoxia-reoxygenation groups were investigated using a GeneChip of Rat Toxicology U34 array (Affymetrix). Hypoxia-reoxygenation up-regulated the stress-related genes (heat shock protein-70 [HSP-70], catalase). The enhanced expression of HSP-70 was confirmed by Western blot analysis. In conclusion, these results suggest that up-regulation of the HSP-70 gene after reoxygenation may play a role in maintaining cell survival and supporting cell function as a molecular chaperone.