Relationship between the expression of iNOS, VEGF, tumor angiogenesis and gastric cancer

Effect of metabolic reprogramming on the immune microenvironment in gastric cancer

Gastric cancer (GC) is a malignant tumor of the gastrointestinal tract with a high mortality rate worldwide, a low early detection rate and a poor prognosis. The rise of metabolomics has facilitated the early detection and treatment of GC. Metabolism in the GC tumor microenvironment (TME) mainly includes glucose metabolism, lipid metabolism and amino acid metabolism, which provide energy and nutrients for GC cell proliferation and migration. Abnormal tumor metabolism can influence tumor progression by regulating the functions of immune cells and immune molecules in the TME, thereby contributing to tumor immune escape. Thus, in this review, we summarize the impact of metabolism on the TME during GC progression. We also propose novel strategies to modulate antitumor immune responses by targeting metabolism.

Pharmacological modulation of Sonic Hedgehog signaling pathways in Angiogenesis: A mechanistic perspective

The Sonic hedgehog (SHh) signaling pathway is an imperative operating network that helps in regulates the critical events during the development processes like multicellular embryo growth and patterning. Disruptions in SHh pathway regulation can have severe consequences, including congenital disabilities, stem cell renewal, tissue regeneration, and cancer/tumor growth. Activation of the SHh signal occurs when SHh binds to the receptor complex of Patch (Ptc)-mediated Smoothened (Smo) (Ptc-smo), initiating downstream signaling. This review explores how pharmacological modulation of the SHh pathway affects angiogenesis through canonical and non-canonical pathways. The canonical pathway for angiogenesis involves the activation of angiogenic cytokines such as fibroblast growth factor (FGF), vascular endothelial growth factor (VEGF), placental growth factor (PGF), hepatocyte growth factor (HGF), platelet-derived growth factor (PDGF), stromal cell-derived factor 1α, transforming growth factor-β1 (TGF-β1), and angiopoietins (Ang-1 and Ang-2), which facilitate the process of angiogenesis. The Non-canonical pathway includes indirect activation of certain pathways like iNOS/Netrin-1/PKC, RhoA/Rock, ERK/MAPK, PI3K/Akt, Wnt/β-catenin, Notch signaling pathway, and so on. This review will provide a better grasp of the mechanistic approach of SHh in mediating angiogenesis, which can aid in the suppression of certain cancer and tumor growths.

Insights on the functional dualism of nitric oxide in the hallmarks of cancer

Nitric oxide (NO), a gaseous radical, governs a variety of physiological and pathological processes, including cancer, pro-inflammatory signalling, and vasodilation. The family of nitric oxide synthases (NOS), which comprises the constitutive forms, nNOS and eNOS, and the inducible form, iNOS, produces NO enzymatically. Additionally, NO can be generated non-enzymatically from the nitrate-nitrite-NO pathway. The anti- and pro-oxidant properties of NO and its functional dualism in cancer is due to its highly reactive nature. Numerous malignancies have NOS expression, which interferes with the tumour microenvironment to modulate the tumour's growth in both favourable and unfavourable ways. NO regulates a number of mechanisms in the tumour microenvironment, including metabolism, cell cycle, DNA repair, angiogenesis, and apoptosis/necrosis, depending on its concentration and spatiotemporal profile. This review focuses on the bi-modal impact of nitric oxide on the alteration of a few cancer hallmarks.

Ethanolic extract of Origanum syriacum L. leaves exhibits potent anti-breast cancer potential and robust antioxidant properties

Background: Breast cancer (BC) is the second most common cancer overall. In women, BC is the most prevalent cancer and the leading cause of cancer-related mortality. Triple-negative BC (TNBC) is the most aggressive BC, being resistant to hormonal and targeted therapies. Hypothesis/Purpose: The medicinal plant Origanum syriacum L. is a shrubby plant rich in bioactive compounds and widely used in traditional medicine to treat various diseases. However, its therapeutic potential against BC remains poorly investigated. In the present study, we screened the phytochemical content of an ethanolic extract of O. syriacum (OSEE) and investigated its anticancer effects and possible underlying mechanisms of action against the aggressive and highly metastatic human TNBC cell line MDA-MB-231. Methods: MTT, trans-well migration, and scratch assays were used to assess cell viability, invasion, or migration, respectively. Antioxidant potential was evaluated in vitro using the DPPH radical-scavenging assay and levels of reactive oxygen species (ROS) were assessed in cells in culture using DHE staining. Aggregation assays were used to determine cell-cell adhesion. Flow cytometry was used to analyze cell cycle progression. Protein levels of markers of apoptosis (BCL-2, pro-Caspase3, p53), proliferation (p21, Ki67), cell migration, invasion, or adhesion (FAK, E-cadherin), angiogenesis (iNOS), and cell signaling (STAT3, p38) were determined by immunoblotting. A chorioallantoic Membrane (CAM) assay evaluated in ovo angiogenesis. Results: We demonstrated that OSEE had potent radical scavenging activity in vitro and induced the generation of ROS in MDA-MB-231 cells, especially at higher OSEE concentrations. Non-cytotoxic concentrations of OSEE attenuated cell proliferation and induced G₀/G₁ cell cycle arrest, which was associated with phosphorylation of p38 MAPK, an increase in the levels of tumor suppressor protein p21, and a decrease of proliferation marker protein Ki67. Additionally, only higher concentrations of OSEE were able to attenuate inhibition of proliferation induced by the ROS scavenger N-acetyl cysteine (NAC), indicating that the anti-proliferative effects of OSEE could be ROS-dependent. OSEE stimulated apoptosis and its effector Caspase-3 in MDA-MB-231 cells, in correlation with activation of the STAT3/p53 pathway. Furthermore, the extract reduced the migration and invasive properties of MDA-MB-231 cells through the deactivation of focal adhesion kinase (FAK). OSEE also reduced the production of inducible nitric oxide synthase (iNOS) and inhibited in ovo angiogenesis. Conclusion: Our findings reveal that OSEE is a rich source of phytochemicals and has robust anti-breast cancer properties that significantly attenuate the malignant phenotype of MD-MB-231 cells, suggesting that O. syriacum may not only act as a rich source of potential TNBC therapeutics but may also provide new avenues for the design of novel TNBC drugs.

A Network Pharmacology Approach for Uncovering the Antitumor Effects and Potential Mechanisms of the Sijunzi Decoction for the Treatment of Gastric Cancer

Background

Sijunzi decoction (SJZD), a classic Chinese formula, has been clinically used for the treatment of gastrointestinal disorders. However, few studies have uncovered its antitumor effects and its potential mechanisms against gastric cancer (GC). Therefore, this work aimed to identify the active compounds and putative targets of the SJZD and to further explore the potential mechanisms involved in the treatment of GC.

Materials and Methods

The active compounds and potential targets of the SJZD and related genes for GC treatment were collected from a public database. Traditional Chinese medicine (TCM)-compound-target-disease networks, Venn diagrams, protein–protein interactions (PPIs), gene ontology (GO), and the Kyoto Encyclopedia of Genes and Genomes (KEGG) were used to obtain the bioactive compounds, key targets, and potential pathways. Next, the human gastric adenocarcinoma cell line NUGC-4 was inoculated subcutaneously into the right flank of NCG mice to build a tumor-bearing mouse model to further verify the findings.

Results

There were 117 compounds in the SJZD in total. The SJZD and GC had 161 and 3288 potential targets, respectively, among which 123 targets overlapped. The network analysis showed that quercetin, kaempferol formononetin, ginsenoside, atractylenolide III, etc., were bioactive molecules. The tumor necrosis factor (TNF), interleukin-6 (IL-6), cellular tumor antigen p53 (TP53), transcription factor AP-1 (JUN), and vascular endothelial growth factor A (VEGFA) were potential targets. A KEGG pathway enrichment analysis revealed 110 pathways involved in the pathways for cancer, including the PI3K-AKT signaling pathway. Validation experiments showed that the SJZD inhibited tumor growth and induced apoptosis in tumor cells. In addition, the SJZD downregulated expressions of VEGFA, iNOS, COX-2, and Bax/Bcl2 and inhibited the expressions of p-PI3K and p-AKT.

Conclusion

The SJZD treats GC by inhibiting blood vessel hyperplasia and inducing cell apoptosis by regulating the PI3K/AKT pathway.

The role of extracellular matrix in tumour angiogenesis: the throne has NOx servants

The extracellular matrix (ECM) dynamics in tumour tissue are deregulated compared to the ECM in healthy tissue along with disorganized architecture and irregular behaviour of the residing cells. Nitric oxide (NO) as a pleiotropic molecule exerts different effects on the components of the ECM driving or inhibiting augmented angiogenesis and tumour progression and tumour cell proliferation and metastasis. These effects rely on the concentration of NO within the tumour tissue, the nature of the surrounding microenvironment and the sensitivity of resident cells to NO. In this review article, we summarize the recent findings on the correlation between the levels of NO and the ECM components towards the modulation of tumour angiogenesis in different types of cancers. These are discussed principally in the context of how NO modulates the expression of ECM proteins resulting in either the promotion or inhibition of tumour growth via tumour angiogenesis. Furthermore, the regulatory effects of individual ECM components on the expression of the NO synthase enzymes and NO production were reviewed. These findings support the current efforts for developing effective therapeutics for cancers.

Arterial instillation of rapamycin in treatment of rabbit hepatic xenograft tumors and its effects on VEGF, iNOS, HIF-1α, Bcl-2, Bax expression and microvessel density

Hepatocellular carcinoma is one of the leading causes of malignant tumor related death word wide with poor prognosis. Chemotherapy and TACE are main treatment methods for advanced stage cases. Rapamycin, a macrolide compound that initially used to coat coronary stents, can inhibit the growth of a variety of cancer cells especially hepatocellular carcinoma. Twenty-four healthy adult New Zealand white rabbits underwent CT-guided puncture to prepare a model of VX2 liver xenograft tumor. The rabbits were randomly divided into four groups with six in each group and received the following treatments: APR-TACE1: arterial perfusion of high-dose rapamycin combined with TACE; APR-TACE2: arterial perfusion of low-dose rapamycin combined with TACE; TACE: TACE alone; and IVR-TACE: intravenous injection of rapamycin combined with TACE. Two weeks after TACE treatment, the rabbits received CT scan and DSA angiography examination, and then killed by air embolism. The non-necrotic region and surrounding tissues were obtained from the peripheral tumor for iNOS, HIF-1α, VEGF, Bcl-2, and Bax protein expression analysis. Protein expression of iNOS, HIF-1α, VEGF, and Bcl-2 in APR-TACE1 were significantly lower than those in groups APR-TACE2, TACE, and IVR-TACE (p < 0.05). iNOS, HIF-1α, and VEGF in APR-TACE2 were lower than those in TACE (p < 0.05). iNOS and VEGF in APR-TACE2 were significantly lower than those in IVR-TACE (p < 0.05). iNOS in IVR-TACE was significantly lower than that in TACE (p < 0.05). The expression levels of Bcl-2 and Bax were statistically significant between APR-TACE2 and TACE (p < 0.05). The MVD of the tumor tissue in APR-TACE1 was lower than that of groups APR-TACE2, TACE, IVR-TACE with statistical difference (p < 0.05). However, MVD of APR-TACE2 was lower than that of groups TACE, IVR-TACE with significant statistical difference (p < 0.05). Arterial instillation of rapamycin+TACE in treatment of rabbit hepatic xenograft tumors can reduce tumor neovascularization and inhibit iNOS, HIF-1α, VEGF, Bcl-2, and Bax protein expression.

Association between Inflammation and Function of Cell Adhesion Molecules Influence on Gastrointestinal Cancer Development

Gastrointestinal cancer is highly associated with inflammatory processes inducing the release of cytokines from cancer or immune cells, including interferons, interleukins, chemokines, colony-stimulating factors, and growth factors, which promote or suppress tumor progression. Inflammatory cytokines within the tumor microenvironment promote immune cell infiltration. Infiltrating immune, and tumor-surrounding stromal cells support tumor growth, angiogenesis, metastasis, and immunosuppression through communication with inflammatory cytokines and cell adhesion molecules. Notably, infiltrating immune and tumor cells present immunosuppressive molecules, such as programmed death-ligand 1 (PD-L1) and CD80/CD86. Suppression of cytotoxic T cells promotes tumor avoidance of immune surveillance and greater malignancy. Moreover, glycosylation and sialylation of proteins hyperexpressed on the cancer cell surface have been shown to enhance immune escape and metastasis. Cytokine treatments and immune checkpoint inhibitors are widely used in clinical practice. However, the tumor microenvironment is a rapidly changing milieu involving several factors. In this review, we have provided a summary of the interactions of inflammation and cell adhesion molecules between cancer and other cell types, to improve understanding of the tumor microenvironment.

Integrative Bioinformatics Analysis of iNOS/NOS2 in gastric and colorectal cancer

Objective The aim of the present work was to investigate the expression of nitric oxide synthase 2 (iNOS/ NOS2) in colorectal and gastric cancers and evaluate its association with patient’s prognosis by integrated bioinformatics analysis.

Methods The data for present study was obtained from the TCGA, GTEx, and STRING database. iNOS/NOS2 mRNA expression in normal tissue and colorectal, and gastric cancer tissuea were investigated through the GTEx and TCGA database. iNOS/NOS2 gene mutations and frequency were analyzed in the TCGA database using the cBioPortal online data analysis tool. The protein-protein interaction (PPI) network of iNOS/NOS2 was constructed by STRING database. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway of iNOS/NOS2 and relevant proteins involved in the PPI network were enriched and demonstrated by the bubble plot. Comparison of the overall survival(OS) and disease free survival(DFS) between samples expressing high and low levels of iNOS/NOS2 was analysis based on the TCGA databases through the GEPIA online data analysis tool.

Results For colon adenocarcinoma (COAD) and rectal adenocarcinoma(READ) iNOS/NOS2 mRNA expression levels in tumor tissue were significant higher than those of corresponding normal colorectal tissue (p<0.05). iNOS/NOS2 mutations were identified in both colorectal cancer and gastric cancer. Missense substitutions and synonymous substitution were the top two mutation types for colorectal and gastric cancer. The top positive and negative co-expressed genes correlated with iNOS/ NOS2 were TRIM40 (rpearson=0.56, p<0.05) and GDPD5 (rpearson=-0.41, p<0.05) in colorectal cancer respectively andCASP5 (rpearson=0.63,p<0.05) and PIAS3 (rpearson=-0.43,p<0.05) in gastric cancer. Twenty one proteins were included in the PPI network with 51 nodes and 345 edges which indicated the PPI enrichment wassignificant (p=1.0e-16). The KEGG of the included genes were mainly enriched in metabolic pathway and Jak-STAT signaling pathway. There was a significant difference indisease free survival (DFS) between samples expressing high and low iNOS/NOS2 (HR=0.37, p=0.044) in rectal cancer. The difference was not statistical between iNOS/NOS2 high and low expressing groups for overall survival(OS) or DFS in the colon cancer or gastric cancer(p>0.05).

Conclusions iNOS/NOS2 mRNA isup-regulated in tumor tissue compared to corresponding normal tissue in colorectal and gastric cancer which implement it in the development of colorectal and gastric cancers.

Imatinib exhibit synergistic pleiotropy in the prevention of colorectal cancer by suppressing proinflammatory, cell survival and angiogenic signaling

Recent global incidences and mortality rates have placed colorectal cancer (CRC) at third and second positions, respectively, among both sexes of all ages. Resistance during chemotherapy is a big problem in the treatment and disease-free survival of CRC patients. Discovery of new anticancer drug(s) is a time taking process and therefore, invites studies for repurposing the known therapeutics. The present study was conceived to analyze the anticancer role of Imatinib in experimental CRC at early stages. Different experimental procedures e.g. tumor incidences or histoarchitectural changes, gene and protein expression analysis, estimations of intracellular calcium, ROS, mitochondrial membrane potential, apoptotic index and molecular docking was performed to support the hypothesis. It was observed that Imatinib could function as an immunomodulator by breaking the feed-back loop between the proinflammatory cytokines (IL-1β and TNF-α) and transcription factors (NF-κB, Jak3/Stat3) knowingly involved in increased cell proliferation during tumorigenesis via activating different intracellular signaling. Also, Imatinib could independently deregulate the other cell survival and proliferation signaling e.g. PI3-K/Akt/mTOR, Wnt/β-catenin and MAPK. Proinflammatory cytokines orchestrated intracellular signaling also involve angiogenic factors to be upregulated during CRC which were also seemed to be independently suppressed by Imatinib. Restoration of physiological apoptosis by increasing the release of intracellular calcium to generate ROS thereby reducing the mitochondrial membrane potential for the release of cytochrome c and activation of caspase-3 was also reported with Imatinib administration. Thus, it may be suggested that Imatinib show synergistic pleiotropy in suppressing the interlinked tumorigenic signaling pathways independently.

Bioinformatics analysis of the expression of inducible nitric oxide synthases (iNOS/NOS2) in human glioma and its correlation with patients’ prognoses

Objective To evaluate the expression of inducible nitric oxide synthases (iNOS/NOS2) in human glioma and its correlation with patients’ prognoses.

Methods IiNOS/NOS2 expression in tumor and corresponding normal tissues of glioma patients was analyzed using the TCGA database and the online analysis tool GEPIA. The mutation statuses of iNOS/NOS2 genes were also explored in the TCGA database using cBioPortal. Co-expressed genes relevant to iNOS/NOS2 were screened by LinkedOmics. Gene ontology (GO) and KEGG pathway enrichment for iNOS/NOS2 and co-expressed genes was performed using LinkedOmics. Overall survival (OS) and disease-free survival (DFS) outcomes between iNOS/NOS2 mRNA high and low expression groups were compared using a log-rank test. Twenty-two glioma patients who underwent operation were included in the present work. A real-time PCR assay was used to detect iNOS/NOS2 mRNA expression in tumor tissue and normal brain tissue.

Results There was no statistical difference in iNOS/NOS2 mRNA expression levelss between tumor and normal tissues of glioma. A real-time PCR assay indicated that iNOS/NOS2 mRNA expression in tumor tissue and normal brain tissues were not statistical difference (p>0.05). A mutation rate of 0.8% for the iNOS/NOS2 gene was found using 1044 glioma patients from two datasets. The mutation types include deep deletion (0.4%), truncating (0.2%) and missense (0.2%). The top positive and negative co-expressed gene with iNOS/NOS2 were COL25A1 (rpearson=0.4734, p<0.05) and ALCAM (rpearson=0.4734, p<0.05), respectively. For KEGG pathway analysis, iNOS/NOS2 was mainly enriched in calcium signaling pathway, Wnt signaling pathway, GnRH signaling pathway, HIF-1 signaling pathway and pathways in cancer. The overall survival (HR=2.0, p<0.05) and disease-free survival (HR=1.6, p<0.05) values were significantly different between iNOS/NOS2 high and low expression groups.

Conclusion OS and DFS were significantly decreased in high iNOS/NOS2 mRNA expression groups. iNOS/NOS2 can be used as a poor prognostic biomarker for glioma.

Drug-Mimicking Nanofibrous Peptide Hydrogel for Inhibition of Inducible Nitric Oxide Synthase

In this work, we develop a drug-mimicking nanofibrous peptide hydrogel that shows long-term bioactivity comparable to a small-molecule inhibitor of inducible nitric oxide synthase (iNOS). The iNOS inhibitor, N ⁶-(1-iminoethyl)-l-lysine (l-NIL), is a positively charged amino acid whose structure could be readily integrated into the framework of a positively charged multidomain peptide (MDP) through the modification of lysine side chains. This new l-NIL-MDP maintains the self-assembling properties of the base peptide, forming β-sheet nanofibers, which entangle into a thixotropic hydrogel. The l-NIL-MDP hydrogel supports cell growth in vitro and allows syringe-directed delivery that persists in a targeted location in vivo for several weeks. Multiple characterization assays demonstrate the bioactivity of the l-NIL-MDP hydrogel to be comparable to the l-NIL small molecule. This includes iNOS inhibition of macrophages in vitro, reduced nitrotyrosine immunostaining in murine subcutaneous histology, and reduced serum levels of vascular endothelial growth factor in vivo. This study expands the toolbox of available peptide hydrogel scaffold designs that can modify biological activity without the need for any additional small-molecule drugs, proteins, or cells.

Imatinib modulates pro-inflammatory microenvironment with angiostatic effects in experimental lung carcinogenesis

Lung cancer has second highest rate of incidence and mortality around the world. Smoking cigarettes is the main stream cause of lung carcinogenesis along with other factors such as spontaneous mutations, inactivation of tumor suppressor genes. The present study was aimed to identify the mechanistic role of Imatinib in the chemoprevention of experimental lung carcinogenesis in rat model. Gross morphological observations for tumor formation, histological examinations, RT-PCR, Western blotting, fluorescence spectroscopy and molecular docking studies were performed to elucidate the chemopreventive effects of Imatinib and support our hypothesis by various experiments. It is evident that immuno-compromised microenvironment inside solid tumors is responsible for tumor progression and drug resistance. Therefore, it is inevitable to modulate the pro-inflammatory signaling inside solid tumors to restrict neoangiogenesis. In the present study, we observed that Imatinib could downregulate the inflammatory signaling and also attributed angiostatic effects. Moreover, Imatinib also altered the biophysical properties of BAL cells such as plasma membrane potential, fluidity and microviscosity to restrict their infiltration and thereby accumulation to mount immuno-compromised environment inside the solid tumors during angiogenesis. Our molecular docking studies suggest that immunomodulatory and angiostatic properties of Imatinib could be either independent of each other or just a case of synergistic pleiotropy. Imatinib was observed to activate the intrinsic or mitochondrial pathway of apoptosis to achieve desired effects in cancer cell killings. Interestingly, binding of Imatinib inside the catalytic domain of PARP-1 also suggests that it has caspase-independent properties in promoting cancer cell deaths.

Knitted Silk-Collagen Scaffold Incorporated with Ligament Stem/Progenitor Cells Sheet for Anterior Cruciate Ligament Reconstruction and Osteoarthritis Prevention

Current surgical management of anterior cruciate ligament (ACL) rupture still remains an intractable challenge in ACL regeneration due to the weak self-healing capability of ACL. Inadequate cell numbers and vascularization within the articular cavity contribute mainly to the poor prognosis. This time, we fabricated a new tissue engineering scaffold by adding ligament stem/progenitor cell (LSPC) sheets to our previous knitted silk-collagen sponge scaffold, which overcame these limitations by providing sufficient numbers of seed cells and a natural extracellular matrix to facilitate regeneration. LSPCs display excellent proliferation and multilineage differentiation capacity. Upon ectopic implantation, the knitted silk-collagen sponge scaffold incorporated with an LSPC sheet exhibited less immune cells but more fibroblast-like cells, deposited ECM and neovascularization, and better tissue ingrowth. In a rabbit model, we excised the ACL and performed a reconstructive surgery with our scaffold. Increased expression of ligament-specific genes and better collagen fibril formation could be observed after orthotopic transplantation. After 6 months, the LSPC sheet group showed better results on ligament regeneration and ligament-bone healing. Furthermore, no obvious cartilage and meniscus degeneration were observed at 6 months postoperation. In conclusion, these results indicated that the new tissue engineering scaffold can promote ACL regeneration and slow down the progression of osteoarthritis, thus suggesting its high clinical potential as an ideal graft in ACL reconstruction.

Gene expression patterns of COX-1, COX-2 and iNOS in H. Pylori infected histopathological conditions

BACKGROUND

Research indicates that Helicobacter pylori can inflict severe histological damage through the modulation of host-related genes. The current study investigated the effect of H. pylori genotypes in the outcome of disease, and the expression of anti-apoptotic related genes, COX-1, COX-2, and iNOS genes in benign, pre-malignant, and malignant lesions of gastric carcinogenesis.

MATERIALS AND METHODS

Tissue samples from H. pylori positive patients were graded based on the genotype of the infected H. pylori strain. Expression of COX-1, COX-2 and iNOS was assessed using a combination of real-time PCR and immunohistochemistry.

RESULTS

Gene expression studies confirmed that COX-2 and iNOS expression was highly and selectively induced in epithelium with premalignant changes such as atrophic conditions, metaplasia and dysplasia, suggesting an important role of these genes in the sequence to gastric carcinoma of the intestinal type. Furthermore, the expression of COX-2 and iNOS was also dependent on the genotype of H. pylori and subjects with genotype-1 exhibited significantly higher expressions of COX-2 and iNOS compared to other genotypes. Comparison of the expression levels among infected and uninfected individuals demonstrated significant difference in the expression pattern of COX-2 gene whereas iNOS expression was found only in subjects infected H. pylori (p < 0.001). Immunohistochemical staining showed 1.5619 folds higher propensity of COX-2 and 3.2941 folds higher intensity of iNOS expression in subjects infected with H. pylori genotype 1.

CONCLUSION

The up-regulation of COX-2 and iNOS was associated with the genotype of the H. pylori strain and the presence of certain genotype may greatly affect early events during carcinogenesis.

Ramucirumab with cisplatin and fluoropyrimidine as first-line therapy in patients with metastatic gastric or junctional adenocarcinoma (RAINFALL): a double-blind, randomised, placebo-controlled, phase 3 trial

BACKGROUND

VEGF and VEGF receptor 2 (VEGFR-2)-mediated signalling and angiogenesis can contribute to the pathogenesis and progression of gastric cancer. We aimed to assess whether the addition of ramucirumab, a VEGFR-2 antagonist monoclonal antibody, to first-line chemotherapy improves outcomes in patients with metastatic gastric or gastro-oesophageal junction adenocarcinoma.

METHODS

For this double-blind, randomised, placebo-controlled, phase 3 trial done at 126 centres in 20 countries, we recruited patients aged 18 years or older with metastatic, HER2-negative gastric or gastro-oesophageal junction adenocarcinoma, an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, and adequate organ function. Eligible patients were randomly assigned (1:1) with an interactive web response system to receive cisplatin (80 mg/m2, on the first day) plus capecitabine (1000 mg/m2, twice daily for 14 days), every 21 days, and either ramucirumab (8 mg/kg) or placebo on days 1 and 8, every 21 days. 5-Fluorouracil (800 mg/m2 intravenous infusion on days 1-5) was permitted in patients unable to take capecitabine. The primary endpoint was investigator-assessed progression-free survival, analysed by intention to treat in the first 508 patients. We did a sensitivity analysis of the primary endpoint, including a central review of CT scans. Overall survival was a key secondary endpoint. This study is registered with ClinicalTrials.gov, number NCT02314117.

FINDINGS

Between Jan 28, 2015, and Sept 16, 2016, 645 patients were randomly assigned to receive ramucirumab plus fluoropyrimidine and cisplatin (n=326) or placebo plus fluoropyrimidine and cisplatin (n=319). Investigator-assessed progression-free survival was significantly longer in the ramucirumab group than the placebo group (hazard ratio [HR] 0·753, 95% CI 0·607-0·935, p=0·0106; median progression-free survival 5·7 months [5·5-6·5] vs 5·4 months [4·5-5·7]). A sensitivity analysis based on central independent review of the radiological images did not corroborate the investigator-assessed difference in progression-free survival (HR 0·961, 95% CI 0·768-1·203, p=0·74). There was no difference in overall survival between groups (0·962, 0·801-1·156, p=0·6757; median overall survival 11·2 months [9·9-11·9] in the ramucirumab group vs 10·7 months [9·5-11·9] in the placebo group). The most common grade 3-4 adverse events were neutropenia (85 [26%] of 323 patients in the ramucirumab group vs 85 [27%] of 315 in the placebo group), anaemia (39 [12%] vs 44 [14%]), and hypertension (32 [10%] vs 5 [2%]). The incidence of any-grade serious adverse events was 160 (50%) of 323 patients in the ramucirumab group and 149 (47%) of 315 patients in the placebo group. The most common serious adverse events were vomiting (14 [4%] in the ramucirumab group vs 21 [7%] in the placebo group) and diarrhoea (11 [3%] vs 19 [6%]). There were seven deaths in each group, either during study treatment or within 30 days of discontinuing study treatment, which were the result of treatment-related adverse events. In the ramucirumab group, these adverse events were acute kidney injury, cardiac arrest, gastric haemorrhage, peritonitis, pneumothorax, septic shock, and sudden death (n=1 of each). In the placebo group, these adverse events were cerebrovascular accident (n=1), multiple organ dysfunction syndrome (n=2), pulmonary embolism (n=2), sepsis (n=1), and small intestine perforation (n=1).

INTERPRETATION

Although the primary analysis for progression-free survival was statistically significant, this outcome was not confirmed in a sensitivity analysis of progression-free survival by central independent review, and did not improve overall survival. Therefore, the addition of ramucirumab to cisplatin plus fluoropyrimidine chemotherapy is not recommended as first-line treatment for this patient population.

FUNDING

Eli Lilly and Company.

Evolving Treatment Strategies and Outcomes in Advanced Gastric Cancer with Peritoneal Metastasis

Gastric cancer (GC) has a predilection to metastasize to the peritoneum, denoting a poor prognosis. Treatment strategies available for advanced GC have significantly evolved over time and can be categorized into systemic, regional, and surgical. Although systemic therapies have been the mainstay for the treatment of advanced GC, their ability in achieving long-term survival in patients with peritoneal involvement is modest at best. This article describes advances in combined modality treatment of peritoneal metastases, specifically with an emphasis on peritoneal-directed therapies.

Ethanol Enhances Estrogen Mediated Angiogenesis in Breast Cancer

Angiogenesis, a highly regulated process, is exploited by tumors like breast cancer to ensure a constant supply of oxygen and nutrients and is key for tumor survival and progression. Estrogen and alcohol independently have been observed to contribute to angiogenesis in breast cancer but their combinatorial effects have never been evaluated. The exact mechanism by which estrogen and alcohol contribute to breast cancer angiogenesis remains to be elucidated. In this study, we defined the in vitro effects of the combination of estrogen and alcohol in breast cancer angiogenesis using the tubulogenesis and scratch wound assays. Conditioned media, generated by culturing the murine mammary cancer cell line, TG1-1, in estrogen and ethanol, enhanced tubule formation and migration as well as modulated the MAP Kinase pathway in the murine endothelial cell line, SVEC4-10. Additionally, estrogen and ethanol in combination enhanced the expression of the pro-angiogenic factors VEGF, MMP-9, and eNOS, and modulated Akt activation. These observations suggest that TG1-1 cells secrete pro-angiogenic molecules in response to the combination of estrogen and ethanol that modulate the morphological and migratory properties of endothelial cells. The data presented in this study, is the first in attempting to link the cooperative activity between estrogen and ethanol in breast cancer progression, underscoring correlations first made by epidemiological observations linking the two.

pH-Responsive Cross-Linked Low Molecular Weight Polyethylenimine as an Efficient Gene Vector for Delivery of Plasmid DNA Encoding Anti-VEGF-shRNA for Tumor Treatment

RNA interference (RNAi) is a biological process through which gene expression can be inhibited by RNA molecules with high selectivity and specificity, providing a promising tool for tumor treatment. Two types of molecules are often applied to inactivate target gene expression: synthetic double stranded small interfering RNA (siRNA) and plasmid DNA encoding short hairpin RNA (shRNA). Vectors with high transfection efficiency and low toxicity are essential for the delivery of siRNA and shRNA. In this study, TDAPEI, the synthetic derivative of low-molecular-weight polyethylenimine (PEI), was cross-linked with imine bonds by the conjugation of branched PEI (1.8 kDa) and 2,5-thiophenedicarboxaldehyde (TDA). This biodegradable cationic polymer was utilized as the vector for the delivery of plasmid DNA expressing anti-VEGF-shRNA. Compared to PEI (25 kDa), TDAPEI had a better performance since experimental results suggest its higher transfection efficiency as well as lower toxicity both in cell and animal studies. TDAPEI did not stimulate innate immune response, which is a significant factor that should be considered in vector design for gene delivery. All the results suggested that TDAPEI delivering anti-VEGF-shRNA may provide a promising method for tumor treatment.

Current Targeted Therapies in HER2-Positive Gastric Adenocarcinoma

Gastric cancer is one of the most common types of cancer in the world, usually diagnosed at an advanced stage. Despite the advances in specific anticancer agents' development, the survival rates remain modest, even in early stages. In 15%-20% of cases, the human epidermal growth factor receptor 2 (HER2) overexpression was identified. We conducted a general review to summarize the progress that has been made in the targeted treatment of HER2-positive esogastric junction or gastric adenocarcinoma. According to our findings, trastuzumab is the only validated anti-HER2 agent in locally advanced or metastatic disease and its adjuvant effectiveness is assessed in a RTOG phase III study. In a previously treated advanced disease, the maytansine derivate TDM 1 failed to be approved as a second-line regimen, and the tyrosine kinase inhibitor, lapatinib, shows modest results. The antiangiogenics have not been analyzed in specific populations and targeting the mesenchymal-epithelial transition factor (MET) receptor, overexpressed in up to 46% of the advanced disease, seems encouraging. Regarding the checkpoint inhibitors, based on KEYNOTE 059 multilevel ongoing trial, stratified according to the HER2 and programmed death-ligand (PD-L) 1 status, pembrolizumab was approved for third-line treatment of gastric or gastroesophageal junction adenocarcinoma.

The genetic association between iNOS and eNOS polymorphisms and gastric cancer risk: a meta-analysis

Objective

There are a number of susceptible factors for an increased risk of gastric cancer. Nitric oxide (NO) is considered to be associated with the development of a range of cancers. In particular, inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) are known to play a central role in the production of NO. Published studies relating to the association between eNOS rs1799983, rs2070744, and iNOS rs2297518 polymorphisms and the risk of gastric cancer risk are conflicting and inconclusive and require further analysis.

Materials and methods

This study involved a meta-analysis of case–control studies relating to eNOS rs1799983, rs2070744, and iNOS rs2297518 polymorphisms published prior to January 2018. Literature searches were carried out in PubMed, Embase, Web of Science, the Cochrane Library databases, and the Chinese National Knowledge Infrastructure. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the strength of association based on genotype data.

Results

A total of 1,356 cases and 1,791 controls were included from nine case–control studies involving eNOS rs1799983 (G894T), rs2070744 (T-786C), and iNOS rs2297518 (C150T) polymorphisms. Data analysis indicated that iNOS rs2297518 was a risk factor for Helicobacter pylorus-positive gastric cancer when compared with H. pylorus-negative gastric cancer (p=0.003, OR [95% CI] =2.19 [1.31–3.66]). In addition, the allelic, dominant, and recessive models of eNOS rs2070744 were significantly associated with a risk of gastric cancer (allelic model: p<0.00001, OR [95% CI] =0.23 [0.16–0.34]; dominant model: p<0.00001, OR [95% CI] =0.25 [0.15–0.42]; recessive model: p<0.00001, OR [95% CI] =0.16 [0.08–0.30]). No association was identified between eNOS rs1799983 and the risk of gastric cancer (p>0.05).

Conclusion

iNOS rs2297518 and eNOS rs2070744 polymorphisms may represent susceptible factors for gastric cancer.

Neuroendocrine factors: The missing link in non‑melanoma skin cancer (Review)

Non‑melanoma skin cancer (NMSC) is the most common form of cancer worldwide, comprising 95% of all cutaneous malignancies and approximately 40% of all cancers. In spite of intensive efforts aimed towards awareness campaigns and sun‑protective measures, epidemiological data indicate an increase in the incidence of NMSC. This category of skin cancers has many common environmental triggers. Arising primarily on sun‑exposed skin, it has been shown that ultraviolet radiation is, in the majority of cases, the main trigger involved in the pathogenesis of NMSC. Aside from the well‑known etiopathogenic factors, studies have indicated that several neuroactive factors are involved in the carcinogenesis of two of the most common types of NMSC, namely basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), with the exception of penile SCC, for which a paucity of specific data on their pathogenic role exists. The complex interaction between the peripheral nervous system and target cells in the skin appears to be mediated by locally released neuroendocrine factors, such as catecholamines, substance P, calcitonin gene‑related peptide and somatostatin, as well as neurohormones, such as proopiomelanocortin and its derived peptides, α‑melanocyte‑stimulating hormone and adrenocorticotropin. All these factors have been, at least at some point, a subject of debate regarding their precise role in the pathogenesis of NMSC. There is also a significant body of evidence indicating that psychological stress is a crucial impact factor influencing the course of skin cancers, including SCC and BCC. Numerous studies have suggested that neuroendocrine factor dysregulation, as observed in stress reactions, may be involved in tumorigenesis, accelerating the development and progression, and suppressing the regression of NMSC. Further studies are required in order to elucidate the exact mechanisms through which neuroactive molecules promote or inhibit cutaneous carcinogenesis, as this could lead to the development of more sophisticated and tailored treatment protocols, as well as open new perspectives in skin cancer research.

A new key player in VEGF-dependent angiogenesis in human hepatocellular carcinoma: dimethylarginine dimethylaminohydrolase 1

BACKGROUND

Anti-angiogenic therapies, targeting VEGF, are a promising treatment for hepatocellular carcinoma (HCC). To enhance this potential therapy, identification of novel targets in this pathway is of major interest. Nitric oxide (NO) plays a crucial role in VEGF-dependent angiogenesis. NO production depends on arginine as substrate and asymmetric dimethylarginine (ADMA) as inhibitor. Dimethylarginine dimethylaminohydrolase 1 (DDAH-1) catabolizes ADMA and therefore regulates NO and VEGF expression. This study unravels additional mechanisms to improve VEGF targeting therapies.

METHODS

The expression of DDAH-1 was examined in HCC specimen and non-tumorous background liver of 20 patients undergoing liver resection. Subsequently, arginine/ADMA balance, NO production, and VEGF expression were analyzed. The influence of hypoxia on DDAH-1 and angiogenesis promoting factors was evaluated in HepG2 cells and primary human hepatocytes.

RESULTS

DDAH-1 expression was significantly induced in primary HCC tumors compared to non-tumorous background liver. This was associated with an increased arginine/ADMA ratio, higher NO formation, and higher VEGF expression in human HCC compared to non-tumorous liver. Hypoxia induced DDAH-1, iNOS, and VEGF expression in a time-dependent manner in HepG2 cells.

CONCLUSIONS

Our results indicate that DDAH-1 expression is increased in human HCC, which is associated with an increase in the arginine/ADMA ratio and enhanced NO formation. Hypoxia may be an initiating factor for the increase in DDAH-1 expression. DDAH-1 expression is associated with promotion of angiogenesis stimulating factor VEGF. Together, our findings for the first time identified DDAH-1 as a key player in the regulation of angiogenesis in human HCC, and by understanding this mechanism, future therapeutic strategies targeting VEGF can be improved.

Inducible Nitric Oxide Synthase in the Carcinogenesis of Gastrointestinal Cancers

SIGNIFICANCE

Gastrointestinal (GI) cancer taken together constitutes one of the most common cancers worldwide with a broad range of etiological mechanisms. In this review, we have examined the impact of nitric oxide (NO) on the etiology of colon, colorectal, gastric, esophageal, and liver cancers. Recent Advances: Despite differences in etiology, initiation, and progression, chronic inflammation has been shown to be a common element within these cancers showing interactions of numerous pathways. NO generated at the inflammatory site contributes to the initiation and progression of disease. The amount of NO generated, time, and site vary and are an important determinant of the biological effects initiated. Among the nitric oxide synthase enzymes, the inducible isoform has the most diverse range, participating in numerous carcinogenic processes. There is emerging evidence showing that inducible nitric oxide synthase (NOS2) plays a central role in the process of tumor initiation and/or development.

CRITICAL ISSUES

Redox inflammation through NOS2 and cyclooxygenase-2 participates in driving the mechanisms of initiation and progression in GI cancers.

FUTURE DIRECTIONS

Understanding the underlying mechanism involved in NOS2 activation can provide new insights into important prevention and treatment strategies. Antioxid. Redox Signal. 26, 1059-1077.

Mucosal Inducible NO Synthase-Producing IgA+ Plasma Cells in Helicobacter pylori-Infected Patients

The mucosal immune system is relevant for homeostasis, immunity, and also pathological conditions in the gastrointestinal tract. Inducible NO synthase (iNOS)-dependent production of NO is one of the factors linked to both antimicrobial immunity and pathological conditions. Upregulation of iNOS has been observed in human Helicobacter pylori infection, but the cellular sources of iNOS are ill defined. Key differences in regulation of iNOS expression impair the translation from mouse models to human medicine. To characterize mucosal iNOS-producing leukocytes, biopsy specimens from H. pylori-infected patients, controls, and participants of a vaccination trial were analyzed by immunohistochemistry, along with flow cytometric analyses of lymphocytes for iNOS expression and activity. We newly identified mucosal IgA-producing plasma cells (PCs) as one major iNOS(+) cell population in H. pylori-infected patients and confirmed intracellular NO production. Because we did not detect iNOS(+) PCs in three distinct infectious diseases, this is not a general feature of mucosal PCs under conditions of infection. Furthermore, numbers of mucosal iNOS(+) PCs were elevated in individuals who had cleared experimental H. pylori infection compared with those who had not. Thus, IgA(+) PCs expressing iNOS are described for the first time, to our knowledge, in humans. iNOS(+) PCs are induced in the course of human H. pylori infection, and their abundance seems to correlate with the clinical course of the infection.

Evaluation of microvessel density and p53 expression in pancreatic adenocarcinoma

OBJECTIVE

To evaluate the prognostic significance of microvessel density and p53 expression in pancreatic cancer.

METHODS

Between 2008 and 2012, 49 patients with pancreatic adenocarcinoma underwent resection with curative intention. The resected specimens were immunohistochemically stained with anti-p53 and anti-CD34 antibodies. Microvessel density was assessed by counting vessels within ten areas of each tumoral section a highpower microscope.

RESULTS

The microvessel density ranged from 21.2 to 54.2 vessels/mm2. Positive nuclear staining for p53 was found in 20 patients (40.6%). The overall median survival rate after resection was 24.1 months and there were no differences in survival rates related to microvessel density or p53 positivity. Microvessel density was associated with tumor diameter greater than 3.0 cm and with R0 resection failure.

CONCLUSIONS

Microvessel density was associated with R1 resection and with larger tumors. p53 expression was not correlated with intratumoral microvessel density in pancreatic adenocarcinoma.

Scabraside D Derived from Sea Cucumber Induces Apoptosis and Inhibits Metastasis via iNOS and STAT-3 Expression in Human Cholangiocarcinoma Xenografts

Scabraside D, a sulfated triterpene glycoside, was extracted from the sea cucumber Holothuria scabra. It shows anti-proliferation in many of cancer cell lines, but the function and mechanisms of action of scabraside D in human cholangiocarcinoma (HuCCA) have not previously determined. In this study, we investigated the activity of scabraside D on HuCCA cell apoptosis, lymphangiogenesis and metastasis in a nude mouse model. Scabraside D induced signs of apoptosis, such as cell shrinkage, nuclear condensation, nuclear fragmentation and DNA fragmentation on TUNEL assays, while effectively decreasing expression of BCl-2 but increasing caspase-3 gene level expression. Immunohistochemistry revealed that scabraside D significantly reduced lymphatic vessel density (LVD). Moreover, scabraside D treatment significantly decreased VEGF-C, MMP-9 and uPA gene expression, which play important roles in the lymphangiogenesis and invasion of cancer cells in metastasis processes. Quantitative real-time PCR showed that scabraside D significantly decreased iNOS and STAT-3 gene expression. This study demonstrated that scabraside D plays a role in activation of HuCCA tumor apoptosis and inhibition of lymphangiogenesis, invasion and metastasis through decreasing BCl-2, MMP-9, uPA and VEGF-C and increasing caspase-3 expression by suppression of iNOS and STAT-3 expression. Therefore, scabraside D could be a promising candidate for cholangiocarcinoma treatment.

Radiation enhances the therapeutic effect of Banoxantrone in hypoxic tumour cells with elevated levels of nitric oxide synthase

Banoxantrone (AQ4N) is a prototype hypoxia selective cytotoxin that is activated by haem containing reductases such as inducible nitric oxide synthase (iNOS). In the present study, we evaluate whether elevated levels of iNOS in human tumour cells will improve their sensitivity to AQ4N. Further, we examine the potential of radiation to increase cellular toxicity of AQ4N under normoxic (aerobic) and hypoxic conditions. We employed an expression vector containing the cDNA for human iNOS to transfect human fibrosarcoma HT1080 tumour cells. Alternatively, parental cells were exposed to a cytokine cocktail to induce iNOS gene expression and enzymatic activity. The cells were then treated with AQ4N alone and in combination with radiation in the presence or absence of the iNOS inhibitor N-methyl-L‑arginine. In parental cells, AQ4N showed little difference in toxicity under hypoxic verses normoxic conditions. Notably, cells with upregulated iNOS activity showed a significant increase in sensitivity to AQ4N, but only under conditions of reduced oxygenation. When these cells were exposed to the combination of AQ4N and radiation, there was much greater cell killing than that observed with either modality alone. In the clinical development of hypoxia selective cytotoxins it is likely they will be used in combination with radiotherapy. In the present study, we demonstrated that AQ4N can selectively kill hypoxic cells via an iNOS-dependent mechanism. This hypoxia-selective effect can be augmented by combining AQ4N with radiation without increasing cytotoxicity to well‑oxygenated tissues. Collectively, these results suggest that targeting hypoxic tumours with high levels of iNOS with a combination of AQ4N and radiotherapy could be a useful clinical therapeutic strategy.

Novel targets in the treatment of advanced gastric cancer: a perspective review

Gastric cancer is responsible for a high burden of disease globally. Although more extensive use of chemotherapy together with the recent introduction of the two targeted agents trastuzumab and ramucirumab have contributed to marginal outcome prolongation, overall survival for patients with advanced stage disease remains poor. Over the last decade, a number of novel agents have been examined in clinical trials with largely disappointing results. Potential explanations for this are the absence of molecularly selected trial populations or weak predictive biomarkers within the context of a highly heterogeneous disease. In the recently published gastric cancer The Cancer Genome Atlas (TCGA) project a new classification of four different tumour subtypes according to different molecular characteristics has been proposed. With some overlap, several relatively distinct and potentially targetable pathways have been identified for each subtype. In this perspective review we match recent trial results with the subtypes described in the gastric cancer TCGA aiming to highlight data regarding novel agents under evaluation and to discuss whether this publication might provide a framework for future drug development.

Advanced gastric cancer: Current treatment landscape and future perspectives

Gastric cancer currently ranks fourth in cancer-related mortality worldwide. In the western world, it is most often diagnosed at an advanced stage, after becoming metastatic at distant sites. Patients with advanced disease (locally advanced or metastatic) have a somber prognosis, with a median overall survival of 10-12 mo, and palliative chemotherapy is the mainstay of treatment. In recent years, novel approaches using inhibition of human epidermal growth factor receptor 2 (HER2) have demonstrated significant improvements in progression-free and overall survival, compared with chemotherapy alone, in first-line treatment of patients with overexpression of HER2. In addition, both second-line chemotherapy and treatment with the vascular endothelial growth factor receptor-inhibitor ramucirumab demonstrated significant benefits in terms of overall survival, compared with best supportive care, in randomized studies. Moreover, ramucirumab in combination with chemotherapy demonstrated further significant benefits in terms of progression-free and overall survival, compared with chemotherapy alone, in second-line treatment for patients with metastatic gastric cancer. A recently published molecular classification of gastric cancer is expected to improve patient stratification and selection for clinical trials and provide a roadmap for future drug development. Nevertheless, despite these developments the prognosis of patients with advanced gastric cancer remains poor. In this review we discuss current standards of care and outline major topics of drug development in gastric cancer.

Evaluation of estrogen receptor expression and its relationship with clinicopathologic findings in gastric cancer

Background:

The presence of estrogen receptor alpha has been reported in the cell and tissue levels in gastric cancer; however, its impact on patients’ survival remains unclear. The aim of this study was to investigate the expression of estrogen receptor in gastric carcinoma as well as its relationship with the clinicopathologic findings of the patients.

Materials and Methods:

The study was performed on 100 endoscopic biopsies of gastric adenocarcinoma for estrogen receptor expression using an immunohistochemical method, and their relationship with the clinicopathologic findings of the patients, such as age, gender, tumor site, size, grade, depth of tumor invasion (T), and lymphatic status (N), were analyzed using independent sample t-test and Pearson Chi-square test. A P < 0.05 was considered significant in all analyses.

Results:

Using an immunohistochemical method on endoscopic biopsies of 74 males and 26 females with the mean age of 63 years, estrogen receptor was found to be positive in 41% of patients. No significant difference was found between estrogen receptor expression and other clinicopathologic findings (P = 0.75). There was a significant difference between estrogen receptor (+) and estrogen receptor (−) groups in nodal involvement (P = 0.001). The estrogen receptor (+) patients had more number of lymph nodes involved.

Conclusion:

This study showed that lymph node involvement has a significant relationship with estrogen receptor expression. However, no significant relationship was found between estrogen receptor expression and other clinicopathologic findings such as age, gender, tumor site in stomach, tumor size, tumor grade, and T-stage.

Inhibitory effect of withaferin A on Helicobacter pylori‑induced IL‑8 production and NF‑κB activation in gastric epithelial cells

Withaferin A (WA), a withanolide purified from Withania somnifera, has been known to exert anti-inflammatory effects. The present study sought to determine the effects of WA on Helicobacter (H.) pylori-mediated inflammation in the AGS gastric epithelial cell line. Cellular production of interleukin (IL)-8 and vascular endothelial growth factor (VEGF) was measured by ELISA. Western blot analysis was performed to determine the activation of nuclear factor (NF)-κB and mitogen-activated protein kinases (MAPKs) as well as hypoxia-inducible factor 1α stabilization. Bacterial growth was also examined by measuring the optical density. Pre-treatment or co-treatment with WA efficiently reduced IL-8 production by AGS cells in response to H. pylori infection. H. pylori-induced activation of NF-κB, but not MAPKs, was also inhibited by pre-treatment of WA in the cells. However, WA did not affect VEGF production and HIF-1α stabilization induced by H. pylori in AGS cells. In addition, WA did not influence the growth of H. pylori, suggesting that the anti-inflammatory effect of WA was not due to any bactericidal effect. These findings indicate that WA is a potential preventive or therapeutic agent for H. pylori-mediated gastric inflammation.

Anatomical specificity of vascular endothelial growth factor expression in glioblastomas: a voxel-based mapping analysis

INTRODUCTION

The expression of vascular endothelial growth factor (VEGF) is a common genetic alteration in malignant gliomas and contributes to the angiogenesis of tumors. This study aimed to investigate the anatomical specificity of VEGF expression levels in glioblastomas using voxel-based neuroimaging analysis.

METHODS

Clinical information, MR scans, and immunohistochemistry stains of 209 patients with glioblastomas were reviewed. All tumor lesions were segmented manually and subsequently registered to standard brain space. Voxel-based regression analysis was performed to correlate the brain regions of tumor involvement with the level of VEGF expression. Brain regions identified as significantly associated with high or low VEGF expression were preserved following permutation correction.

RESULTS

High VEGF expression was detected in 123 (58.9 %) of the 209 patients. Voxel-based statistical analysis demonstrated that high VEGF expression was more likely in tumors located in the left frontal lobe and the right caudate and low VEGF expression was more likely in tumors that occurred in the posterior region of the right lateral ventricle.

CONCLUSION

Voxel-based neuroimaging analysis revealed the anatomic specificity of VEGF expression in glioblastoma, which may further our understanding of genetic heterogeneity during tumor origination. This finding provides primary theoretical support for potential future application of customized antiangiogenic therapy.

Environmental immune disruptors, inflammation and cancer risk

An emerging area in environmental toxicology is the role that chemicals and chemical mixtures have on the cells of the human immune system. This is an important area of research that has been most widely pursued in relation to autoimmune diseases and allergy/asthma as opposed to cancer causation. This is despite the well-recognized role that innate and adaptive immunity play as essential factors in tumorigenesis. Here, we review the role that the innate immune cells of inflammatory responses play in tumorigenesis. Focus is placed on the molecules and pathways that have been mechanistically linked with tumor-associated inflammation. Within the context of chemically induced disturbances in immune function as co-factors in carcinogenesis, the evidence linking environmental toxicant exposures with perturbation in the balance between pro- and anti-inflammatory responses is reviewed. Reported effects of bisphenol A, atrazine, phthalates and other common toxicants on molecular and cellular targets involved in tumor-associated inflammation (e.g. cyclooxygenase/prostaglandin E2, nuclear factor kappa B, nitric oxide synthesis, cytokines and chemokines) are presented as example chemically mediated target molecule perturbations relevant to cancer. Commentary on areas of additional research including the need for innovation and integration of systems biology approaches to the study of environmental exposures and cancer causation are presented.

Bevacizumab plus capecitabine and cisplatin in Chinese patients with inoperable locally advanced or metastatic gastric or gastroesophageal junction cancer: randomized, double-blind, phase III study (AVATAR study)

BACKGROUND

In the AVAGAST study, fluoropyrimidine and cisplatin plus bevacizumab did not significantly improve overall survival (OS) versus fluoropyrimidine and cisplatin plus placebo in patients with advanced gastric cancer. Geographic differences in efficacy were observed in AVAGAST, but the study only included 12 Chinese patients. AVATAR, a study similar in design to AVAGAST, was a randomized, double-blind, phase III study conducted in Chinese patients with advanced gastric cancer.

METHODS

Patients more than 18 years of age with gastric adenocarcinoma were randomized 1:1 to capecitabine-cisplatin plus either bevacizumab or placebo. The primary endpoint was OS; secondary endpoints included progression-free survival (PFS) and safety.

RESULTS

In total, 202 patients were included (placebo n = 102; bevacizumab n = 100). Baseline characteristics were well balanced. The primary analysis result did not show a difference in OS for the bevacizumab arm compared to the placebo arm [hazard ratio, 1.11 (95% CI, 0.79-1.56); P = 0.5567]. Median PFS was also similar in both arms. Bevacizumab plus capecitabine-cisplatin was well tolerated. Grade 3-5 adverse events (AEs) occurred in 60% of bevacizumab-treated and 68% of placebo-treated patients, respectively. Grade 3-5 AEs of special interest with bevacizumab occurred in 8% of bevacizumab-treated patients and 15% of placebo-treated patients, mainly grade 3-5 hemorrhage (bevacizumab 4%, placebo 12%).

CONCLUSIONS

Addition of bevacizumab to capecitabine-cisplatin in Chinese patients with advanced gastric cancer did not improve outcomes in AVATAR. There was no difference in OS between the two arms and PFS was similar in both arms. Safety findings were as previously experienced with bevacizumab, including AVAGAST; no new safety signals were reported.

Helicobacter pylori induces vascular endothelial growth factor production in gastric epithelial cells through hypoxia-inducible factor-1α-dependent pathway

BACKGROUND

Although Helicobacter pylori have been known to induce vascular endothelial growth factor (VEGF) production in gastric epithelial cells, the precise mechanism for cellular signaling is incompletely understood. In this study, we investigated the role of bacterial virulence factor and host cellular signaling in VEGF production of H. pylori-infected gastric epithelial cells.

MATERIALS AND METHODS

We evaluated production of VEGF, activation of nuclear factor nuclear factor-kappaB (NF-κB) and mitogen-activated protein kinases (MAPKs) and hypoxia-inducible factor-1α (HIF-1α) stabilization in gastric epithelial cells infected with H. pylori WT or isogenic mutants deficient in type IV secretion system (T4SS).

RESULTS

H. pylori induced VEGF production in gastric epithelial cells via both T4SS-dependent and T4SS-independent pathways, although T4SS-independent pathway seems to be the dominant signaling. The inhibitor assay implicated that activation of NF-κB and MAPKs is dispensable for H. pylori-induced VEGF production in gastric epithelial cells. H. pylori led to HIF-1α stabilization in gastric epithelial cells independently of T4SS, NF-κB, and MAPKs, which was essential for VEGF production in these cells. N-acetyl-cysteine (NAC), a reactive oxygen species (ROS) inhibitor, treatment impaired H. pylori-induced HIF-1α stabilization and VEGF production in gastric epithelial cells.

CONCLUSION

We defined the important role of ROS-HIF-1α axis in VEGF production of H. pylori-infected gastric epithelial cells, and bacterial T4SS has a minor role in H. pylori-induced VEGF production of gastric epithelial cells.

Connection between expression of inducible nitric oxide synthase (iNOS) in skull base chordoma and lower urinary tract symptoms

OBJECTIVE

To provide first insights into the potential role of iNOS expressed by skull base chordoma, which causes brainstem compression in and around Barrington's nucleus, and its effect on the micturition center.

METHODS

Urodynamic testing of 22 symptomatic patients was performed. All women and men with skull base chordoma treated in two hospitals in Germany between 1986 and 2007 were studied. Lower urinary tract symptoms (LUTS) were documented in patients with acute brainstem compression due to local chordoma growth positive for iNOS expression. Brain magnetic resonance (MRI) images of the lesions of the symptomatic patients were performed.

RESULTS

Of 74 treated patients, 22 (7 women, 15 men) with a median age of 37 years were evaluated with voiding diaries and computer urodynamic investigation. Urodynamic testing of 22 symptomatic patients with positive iNOS expression of skull base chordoma revealed detrusor overactivity in 55 %, low-compliance bladder in 14 %, detrusor sphincter dyssynergia in 45 % and uninhibited sphincter relaxation in 27 %. There was a significant correlation between strong iNOS expression (score 3-6) in skull base chordoma and severe urinary symptoms (p = 0.003, Spearman ρ = 0.526).

CONCLUSIONS

The expression of iNOS in skull base chordoma compressing the dorsolateral pons, in and around Barrington's nucleus, may influence the pontine micturition center (PMC) and be responsible for lower urinary tract symptoms. Nitric oxide may possibly act as a neurotransmitter. We assume that the high infiltration of chordoma with monocyte/macrophages enhances the release of nitric oxide, as monocyte/macrophages are the main source of iNOS.

Ramucirumab monotherapy for previously treated advanced gastric or gastro-oesophageal junction adenocarcinoma (REGARD): an international, randomised, multicentre, placebo-controlled, phase 3 trial

BACKGROUND

Vascular endothelial growth factor (VEGF) and VEGF receptor-2 (VEGFR-2)-mediated signalling and angiogenesis can contribute to the pathogenesis and progression of gastric cancer. We aimed to assess whether ramucirumab, a monoclonal antibody VEGFR-2 antagonist, prolonged survival in patients with advanced gastric cancer.

METHODS

We did an international, randomised, double-blind, placebo-controlled, phase 3 trial between Oct 6, 2009, and Jan 26, 2012, at 119 centres in 29 countries in North America, Central and South America, Europe, Asia, Australia, and Africa. Patients aged 24-87 years with advanced gastric or gastro-oesophageal junction adenocarcinoma and disease progression after first-line platinum-containing or fluoropyrimidine-containing chemotherapy were randomly assigned (2:1), via a central interactive voice-response system, to receive best supportive care plus either ramucirumab 8 mg/kg or placebo, intravenously once every 2 weeks. The study sponsor, participants, and investigators were masked to treatment assignment. The primary endpoint was overall survival. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00917384.

FINDINGS

355 patients were assigned to receive ramucirumab (n=238) or placebo (n=117). Median overall survival was 5·2 months (IQR 2·3-9·9) in patients in the ramucirumab group and 3·8 months (1·7-7·1) in those in the placebo group (hazard ratio [HR] 0·776, 95% CI 0·603-0·998; p=0·047). The survival benefit with ramucirumab remained unchanged after multivariable adjustment for other prognostic factors (multivariable HR 0·774, 0·605-0·991; p=0·042). Rates of hypertension were higher in the ramucirumab group than in the placebo group (38 [16%] vs nine [8%]), whereas rates of other adverse events were mostly similar between groups (223 [94%] vs 101 [88%]). Five (2%) deaths in the ramucirumab group and two (2%) in the placebo group were considered to be related to study drug.

INTERPRETATION

Ramucirumab is the first biological treatment given as a single drug that has survival benefits in patients with advanced gastric or gastro-oesophageal junction adenocarcinoma progressing after first-line chemotherapy. Our findings validate VEGFR-2 signalling as an important therapeutic target in advanced gastric cancer.

FUNDING

ImClone Systems.

Ramucirumab: targeting angiogenesis in the treatment of gastric cancer

Gastroesophageal cancer is responsible for over 1 million deaths annually worldwide; for patients with advanced disease treatment options are limited. Angiogenesis is an attractive therapeutic target that has been successfully exploited in other cancers. Ramucirumab, a fully humanized monoclonal antibody targeting VEGFR-2 has demonstrated efficacy as a single agent and in combination with paclitaxel in two large randomized trials (REGARD and RAINBOW) for the treatment of advanced previously treated gastroesophageal cancer. In combination with paclitaxel chemotherapy ramucirumab treated patients demonstrated increased rates of neutropenia, and ramucirumab is also associated with hypertension consistent with other antiangiogenic agents. Ramucirumab has been US FDA approved for patients with advanced gastroesophageal cancer who have progressed during or after treatment with fluoropyrimidine- or platinum-containing chemotherapy.

The progress of targeted therapy in advanced gastric cancer

Although palliative chemotherapy has been shown to prolong survival and improve quality of life, the survival of advanced gastric cancer (AGC) patients remains poor. With the advent of targeted therapy, many molecular targeted agents have been evaluated in clinical studies. Trastuzumab, an anti-HER2 monoclonal antibody, has shown activity against HER2-positive AGC and becomes the first targeted agent approved in AGC. Drugs that target epidermal growth factor receptor, including monoclonal antibody and tyrosine kinase inhibitor, do not bring survival benefit to patients with AGC. Additionally, vascular endothelial growth factor inhibitors are also under investigation. Ramucirumab has shown promising result. Other targeted agents are in preclinical or early clinical development, such as mammalian target of rapamycinm inhibitors and c-MET inhibitors.

Angiostatic properties of sulindac and celecoxib in the experimentally induced inflammatory colorectal cancer

Initiation of various cancers has been observed to be regulated via a prolonged inflammatory state in the tissues. However, molecular role of such a localized inflammation is not clear in the advanced stages of colorectal cancer. In this study, we have elaborated the role of various pro- and anti-inflammatory cytokines, transcription, and angiogenic factors in the progression of the 1,2-dimethylhydrazine dihydrochloride (DMH)-induced late phage colorectal cancer and also observed the chemopreventive role of the two non-steroidal anti-inflammatory drugs (NSAIDs), viz., Sulindac and Celecoxib. Carcinogenic changes were observed with morphological and histopathological studies, whereas mRNA and protein regulations of various biomolecules were identified via RT- or qRT-PCR, western blot and immunofluorescence analysis, respectively. Activity of inducible nitric oxide (NO) and cyclooxygenase-2 enzymes were analyzed using standard NO assay and prostaglandin E2 immunoassay, whereas activities of matrix metalloproteinases (MMP-2 and-9) were identified by gelatin zymography. Flowcytometry was performed for the relative quantification of the apoptotic events. Molecular docking studies of Sulindac and Celecoxib were also performed with different target proteins to observe their putative mechanisms of action. As a result, we found that DMH-treated animals were having over-expression of various pro-inflammatory cytokines (IL-1β, IL-2, and IFNγ), aberrant nuclear localization of activated cell survival transcription factors (NF-κB and Stat3) along with the increased incidence of activated angiogenic factors (MMP-2 and MMP-9) suggesting a marked role of inflammation in the tumor progression. However, NSAIDs co-administration has significantly reduced the angiogenic potential of the growing neoplasm.

Vascular endothelial growth factor and survivin immunostaining in gastric adenocarcinoma

Two molecules - vascular endothelial growth factor involved in new vessels formation and survivin - antiapoptotic protein, reported to be associated with worse prognosis in various malignancies have been chosen for the study. Both are potential target for novel therapies.

THE AIM OF THE STUDY

Was to determine the immunostaining of VEGF and survivin in gastric carcinoma and to analyse their relationship to the selected clinicopathological features and survival.

MATERIAL AND METHODS

Formalin-fixed, paraffin-embedded sections from 41 gastric adenocarcinomas were used for immunohistochemical reaction with monoclonal antibodies against vascular endothelial growth factor and survivin. The results were compared with selected clinicopathological features and survival.

RESULTS

Positive immunohistochemical reaction for vascular endothelial growth factor and survivin was revealed in 24 (58,53%) and 30 (73,17%), gastric carcinomas respectively. Vascular endothelial growth factor-negative gastric carcinomas were significantly more common in cases without metastases to regional lymph nodes and distant organs and in less advanced cases. Similar, distant metastases were also statistically less common in survivin-negative carcinomas. The differences in immunohistochemical reactions for survivin between less and more advanced cases almost reach statistical significance. The only factors significantly influenced 1, 2 and 3-year survival were vascular endothelial growth factor and survivin status. Statistically significant higher percentage of survival was noted in patients with vascular endothelial growth factor- and survivin-negative tumors.

CONCLUSIONS

It seems that vascular endothelial growth factor and survivin play role in local invasion and spread of gastric adenocarcinoma and negatively influences survival. However, further studies are required to assess their true usefulness in the clinical practice.

Correlation of vascular endothelial growth factor expression with tumor recurrence and poor prognosis in patients with pN0 gastric cancer

BACKGROUND

Vascular endothelial growth factor (VEGF) and matrix metalloproteinase (MMP)-9 play important roles in tumor angiogenesis, development, and progression. This study investigates the expression of VEGF combined with MMP-9, their correlation with clinical characteristics, and their effect on the prognosis for patients with pN0 gastric cancer after curative surgery.

METHODS

A total of 55 patients were enrolled in the study. They were analyzed by immunohistochemistry, and their correlation with clinical characteristics was then investigated. Their relations and the survival time of patients were retrospectively analyzed.

RESULTS

VEGF and MMP-9 were positively expressed in 24 (43.6%) and 16 (29.1%) patients, respectively, and had a positive correlation (r = 0.324, p = 0.016) in the Spearman rank correlation analysis. Univariate analysis showed that VEGF, MMP-9 expression, vascular invasion, T stage, and tumor size were associated with tumor recurrence as well as the disease-specific (DSS) and overall (OS) survival rates. Patients with positive VEGF expression showed significantly higher recurrence and poorer DSS and OS rates compared with those with negative VEGF expression. Multivariate analysis showed that VEGF expression, vascular invasion, T stage (serosal invasion), and tumor size were significant independent prognostic factors for tumor recurrence, DSS, and OS in patients with pN0 gastric cancer with the exception that T stage was not for DSS.

CONCLUSIONS

VEGF expression, vascular invasion, T stage (serosal invasion), and tumor size can be used as valuable prognosticators in predicting tumor recurrence and prognosis for patients with pN0 gastric cancer after curative surgery. VEGF may have a synergistic effect with MMP-9 during tumor angiogenesis, development, and progression.

Novel targeted agents for gastric cancer

Contemporary advancements have had little impact on the treatment of gastric cancer (GC), the world’s second highest cause of cancer death. Agents targeting human epidermal growth factor receptor mediated pathways have been a common topic of contemporary cancer research, including monoclonal antibodies (mAbs) and receptor tyrosine kinase inhibitors (TKIs). Trastuzumab is the first target agent evidencing improvements in overall survival in HER2-positive (human epidermal growth factor receptor 2) gastric cancer patients. Agents targeting vascular epithelial growth factor (VEGF), mammalian target of rapamycin (mTOR), and other biological pathways are also undergoing clinical trials, with some marginally positive results. Effective targeted therapy requires patient selection based on predictive molecular biomarkers. Most phase III clinical trials are carried out without patient selection; therefore, it is hard to achieve personalized treatment and to monitor patient outcome individually. The trend for future clinical trials requires patient selection methods based on current understanding of GC biology with the application of biomarkers.

Role of Sulindac and Celecoxib in the regulation of angiogenesis during the early neoplasm of colon: exploring PI3-K/PTEN/Akt pathway to the canonical Wnt/β-catenin signaling

Angiogenesis refers to the generation of new blood vasculature from the nearby pre-existing one and is regulated by a balance between the pro- and anti-angiogenic factors. During carcinogenesis, pro-angiogenic factors dominate and initialize the growth of new blood capillaries to provide nutrition, growth factors and overcome hypoxia inside the tumor microenvironment. In the present study, we have observed the role of Phosphatidylinositol-3-kinase (PI3-K)/Phophatase and tensin homolog deleted on chromosome ten (PTEN)/Akt (Protein kinase B) pathway and canonical Wnt/β-catenin downstream signaling in the regulation of various pro-angiogenic molecules including the vascular endocrine growth factor-A (VEGF-A), matix metalloproteinases (MMPs), inducible nitric oxide synthase (iNOS) and chemokines for the progression of experimental colorectal cancer with 1,2-dimethylhydrazine dihydrochloride (DMH) and anti-angiogenic effects of two non-steroidal anti-inflammatory drugs (NSAIDs) viz. Sulindac and Celecoxib. Morphological and histopathological studies were performed to analyze the tumorigenic modifications while flow cytometry for the relative quantification of apoptotic events. Transcriptional and translational modifications of biomolecules were analyzed via Reverse Transcriptase-and quantitative Real Time PCR, Western immoblotting and immunoflurescence, respectively. In vitro phosphorylation, gelatin zymography and nitric oxide (NO) assay were performed to observe the activation states of Akt, MMPs and iNOS enzyme, respectively. Dysregultion in Akt activation, and thereby, aberrant signaling of β-catenin along with the production of NO could positively regulate tumor angiogenesis. NSAIDs can overcome these carcinogenic effects by controlling various key check points including higher PTEN and glycogen synthase kinase-3β (GSK-3β) expression and repressing Akt, MMPs and iNOS activation while inducing apoptosis among the cancer cells.

Expression of NOS and VEGF in feline mammary tumours and their correlation with angiogenesis

In order to define the role of nitric oxide (NO) in feline mammary tumours, the expression of endothelial or inducible nitric oxide synthase (e/iNOS) and vascular endothelial growth factor (VEGF), and their relationship with angiogenesis, was investigated in 23 feline mammary tumours (two hyperplastic, 19 adenocarcinoma, one osteosarcoma and one squamous cell carcinoma) by immunohistochemistry. Tumour angiogenesis was assessed by CD31 immunostaining and was expressed as microvessel density (MVD). In general, iNOS immunoreactivity was localised in tumour cells and occasionally in stromal myofibroblasts, whereas eNOS and VEGF were localised in the cytoplasm of tumour epithelial cells and endothelium. In malignancy, expression of iNOS increased from well- to less-differentiated phenotypes (Grades 1-3) and was significantly higher in G3 and G2 when compared with G1 cases. However, increasing eNOS expression was limited only in hyperplastic lesions and showed no significant changes among the grades. In addition, expression of iNOS was positively correlated with VEGF and MVD in feline mammary tumours and both measures were significantly greater in less differentiated phenotypes (P<0.05). In conclusion, the expression of NOS isoforms in feline mammary tumours depended on tumour grade, and the positive correlations between iNOS and angiogenic markers suggests that iNOS synthesised by tumour cells promotes tumour growth. Thus, iNOS can be used as an important immunohistochemical marker to determine the degree of malignancy and prognosis of feline mammary carcinoma.

Bevacizumab in Combination With Chemotherapy As First-Line Therapy in Advanced Gastric Cancer: A Randomized, Double-Blind, Placebo-Controlled Phase III Study

Purpose

The Avastin in Gastric Cancer (AVAGAST) trial was a multinational, randomized, placebo-controlled trial designed to evaluate the efficacy of adding bevacizumab to capecitabine-cisplatin in the first-line treatment of advanced gastric cancer.

Patients and Methods

Patients received bevacizumab 7.5 mg/kg or placebo followed by cisplatin 80 mg/m2 on day 1 plus capecitabine 1,000 mg/m2 twice daily for 14 days every 3 weeks. Fluorouracil was permitted in patients unable to take oral medications. Cisplatin was given for six cycles; capecitabine and bevacizumab were administered until disease progression or unacceptable toxicity. The primary end point was overall survival (OS). Log-rank test was used to test the OS difference.

Results

In all, 774 patients were enrolled; 387 were assigned to each treatment group (intention-to-treat population), and 517 deaths were observed. Median OS was 12.1 months with bevacizumab plus fluoropyrimidine-cisplatin and 10.1 months with placebo plus fluoropyrimidine-cisplatin (hazard ratio 0.87; 95% CI, 0.73 to 1.03; P = .1002). Both median progression-free survival (6.7 v 5.3 months; hazard ratio, 0.80; 95% CI, 0.68 to 0.93; P = .0037) and overall response rate (46.0% v 37.4%; P = .0315) were significantly improved with bevacizumab versus placebo. Preplanned subgroup analyses revealed regional differences in efficacy outcomes. The most common grade 3 to 5 adverse events were neutropenia (35%, bevacizumab plus fluoropyrimidine-cisplatin; 37%, placebo plus fluoropyrimidine-cisplatin), anemia (10% v 14%), and decreased appetite (8% v 11%). No new bevacizumab-related safety signals were identified.

Conclusion

Although AVAGAST did not reach its primary objective, adding bevacizumab to chemotherapy was associated with significant increases in progression-free survival and overall response rate in the first-line treatment of advanced gastric cancer.