Vascular Endothelial Growth Factor-D and Its Receptor VEGFR-3: Two Novel Independent Prognostic Markers in Gastric Adenocarcinoma

Monoclonal antibodies for treating gastric cancer: promises and pitfalls

INTRODUCTION

Gastric cancer (GC) presents dismal prognosis when diagnosed at advanced stages, standard chemotherapy having shown little efficacy. Introduction of biotherapies interfering with novel targets and signaling pathways is currently an emerging strategy.

AREAS COVERED

Only two monoclonal antibodies (trastuzumab and ramucirumab) have been approved, mostly in association with cytotoxics. Conversely, testing other promising biotherapies (panitumumab, cetuximab, bevacizumab, rilotumumab) have yielded conflicting results, since encouraging early clinical trials have failed to be confirmed in larger phase-III studies. Empirical and underpowered strategies when designing combinational studies, lack of comprehensive knowledge of pharmacokinetics/pharmacodynamics (PK/PD) relationships, and underestimation of the large inter-patient variability in drug exposure levels with monoclonal antibodies, could explain the failures in developing biotherapies in gastric cancer. This review covers the achievements and limits of monoclonal antibodies in gastric cancer and proposes clues to overcome current failures.

EXPERT OPINION

Trastuzumab efficacy could be improved thanks to its combination with triplet chemotherapy or with another anti-HER2 agents or in continuation during second-line chemotherapy. Concerning ramucirumab, further studies are necessary to prove its interest in first line treatment of advanced GC, to use the optimal dose in each patient-given the large inter-patients variability, and to find predictive biomarkers of efficacy.

TNF-alpha promotes lymphangiogenesis and lymphatic metastasis of gallbladder cancer through the ERK1/2/AP-1/VEGF-D pathway

Background

Tumor necrosis factor-alpha (TNF-α), a key player in cancer-related inflammation, was recently demonstrated to be involved in the lymphatic metastasis of gallbladder cancer (GBC). Vascular endothelial growth factor D (VEGF-D) is a key lymphangiogenic factor that is associated with lymphangiogenesis and lymph node metastasis in GBC. However, whether VEGF-D is involved in TNF-α-induced lymphatic metastasis of GBC remains undetermined.

Methods

The expression of VEGF-D in patient specimens was detected by immunohistochemistry and the relationship between VEGF-D in the tissue and TNF-α in the bile of the matching patients was analyzed. The VEGF-D mRNA and protein levels after treatment with exogenous TNF-α in NOZ, GBC-SD and SGC-996 cell lines were measured by real-time PCR and ELISA. The promoter activity and transcriptional regulation of VEGF-D were analyzed with the relative luciferase reporter assay, mutant constructs, electrophoretic mobility shift assay (EMSA), chromatin immunoprecipitation (ChIP) assay, RNA interference and Western blotting. Inhibitors of JNK, p38 MAPK and ERK1/2 were used to explore the upstream signaling effector of AP-1. We used lentiviral vector expressing a VEGF-D shRNA construct to knockdown VEGF-D gene in NOZ and GBC-SD cells. The role of the TNF-α-VEGF-D axis in the tube formation of human dermal lymphatic endothelial cells (HDLECs) was determined using a three-dimensional coculture system. The role of the TNF-α - VEGF-D axis in lymphangiogenesis and lymph node metastasis was studied via animal experiment.

Results

TNF-α levels in the bile of GBC patients were positively correlated with VEGF-D expression in the clinical specimens. TNF-α can upregulate the protein expression and promoter activity of VEGF-D through the ERK1/2 - AP-1 pathway. Moreover, TNF-α can promote tube formation of HDLECs, lymphangiogenesis and lymph node metastasis of GBC by upregulation of VEGF-D in vitro and in vivo.

Conclusion

Taken together, our data suggest that TNF-α can promote lymphangiogenesis and lymphatic metastasis of GBC through the ERK1/2/AP-1/VEGF-D pathway.

RARα mediates all-trans-retinoic acid-induced VEGF-C, VEGF-D, and VEGFR3 expression in lung cancer cells

The regulation of vascular endothelial growth factors C (VEGF-C) and D (VEGF-D), and their receptor VEGFR3 gene and protein expression by all-trans-retinoic acid (atRA) in A549 lung cancer cells, was investigated. We showed that atRA treatment increased VEGF-C, VEGF-D, and VEGFR3 protein and mRNA contents in dose-dependent manner. atRA-mediated increase of both ligands and receptor expression correlated with the elevated level of retinoic acid receptor α (RARα) expression, while the level of another atRA receptor, peroxisome proliferator-activated receptor β/δ (PPARβ/δ), was decreased. We demonstrated that the classical counterpart of RARα, retinoid X receptor α (RXRα), was down-regulated in both cytoplasm and nucleus of A549 cells upon atRA addition. On the contrary, the nuclear quantity of another possible RARα counterpart, transcription factor Sp1, was increased after atRA treatment.

IL-6 mediates the signal pathway of JAK-STAT3-VEGF-C promoting growth, invasion and lymphangiogenesis in gastric cancer

Gastric cancer shows the highest invasive and metastasis features, especially lymph metastasis, which is closely associated with poor prognosis of gastric cancer. Although there is evidence that interleukin-6 (IL-6) can promote gastric cancer progression, the underlying specific mechanisms and the mechanisms of gastric cancer lymphangiogenesis are largely unknown. In the present study, we explore whether IL-6 could promote the proliferation and invasion activity of gastric cancer cells, and whether IL-6 mediating VEGF-C production affected the lymphangiogenesis in gastric cancer cells. Our results revealed that IL-6 and its receptors (IL-6 and gp130) are broadly expressed in various gastric cancer cell lines including SGC-7901, MGC, MKN-28 and AGS. Exogenous IL-6 increased the ability of gastric cancer cell proliferation and invasion, which could be weakened by AG490. in addition, exogenous IL-6 promoted the VEGF-C production of gastric cancer cells and the lymphangiogenesis of HDLECs. As we expected, AG490 was able to reduce these effects. Western blot analysis showed that IL-6 increased JKA, STAT3, p-STAT3 and VEGF-C protein levels in the gastric cancer cells. However, the JKA, STAT3, p-STAT3 and VEGF-C protein expression levels were inhibited by AG490. Our data suggested that IL-6 mediates the singnal pathway of JAK-STAT3-VEGF-C promoting the growth, invasion and lymphangiogenesis in gastric cancer. Thus, IL-6 and its related signal pathways may be a promising target for treatment of gastric cancer growth and lymphangiogenesis.

Angiogenesis inhibitors in gastric and gastroesophageal junction cancer

Despite significant improvements in systemic chemotherapy during the past two decades, the prognosis of patients with advanced gastric and gastroesophageal junction adenocarcinoma remains poor. Because of molecular heterogeneity, it is essential to classify tumors based on the underlying oncogenic pathways and to develop targeted therapies acting on individual tumors. Unfortunately, although a number of molecular targets have been studied, very few of these agents can be used in a clinical setting. In this review, we summarize the available data on anti-angiogenic agents in advanced/metastatic gastric cancer.

Identification of Serum Biomarkers for Gastric Cancer Diagnosis Using a Human Proteome Microarray

We aimed to globally discover serum biomarkers for diagnosis of gastric cancer (GC). GC serum autoantibodies were discovered and validated using serum samples from independent patient cohorts encompassing 1,401 participants divided into three groups, i.e. healthy, GC patients, and GC-related disease group. To discover biomarkers for GC, the human proteome microarray was first applied to screen specific autoantibodies in a total of 87 serum samples from GC patients and healthy controls. Potential biomarkers were identified via a statistical analysis protocol. Targeted protein microarrays with only the potential biomarkers were constructed and used to validate the candidate biomarkers using 914 samples. To provide further validation, the abundance of autoantibodies specific to the biomarker candidates was analyzed using enzyme-linked immunosorbent assays. Receiver operating characteristic curves were generated to evaluate the diagnostic accuracy of the serum biomarkers. Finally, the efficacy of prognosis efficacy of the final four biomarkers was evaluated by analyzing the clinical records. The final panel of biomarkers consisting of COPS2, CTSF, NT5E, and TERF1 provides high diagnostic power, with 95% sensitivity and 92% specificity to differentiate GC patients from healthy individuals. Prognosis analysis showed that the panel could also serve as independent predictors of the overall GC patient survival. The panel of four serum biomarkers (COPS2, CTSF, NT5E, and TERF1) could serve as a noninvasive diagnostic index for GC, and the combination of them could potentially be used as a predictor of the overall GC survival rate.

Clinical significance of platelet derived growth factor-C and -D in gastric cancer

Platelet-derived growth factor (PDGF)-C and PDGF-D are frequently upregulated in human cancers and play important roles in tumor progression, angiogenesis and metastasis. However, the distribution, frequency and prognostic value of PDGF-C and PDGF-D expression in gastric cancer have not been clarified. The present study evaluated the association between expression of PDGF-C and PDGF-D, clinicopathological factors and outcomes, in patients with gastric cancer. Gastric adenocarcinoma tumor samples were obtained from 204 patients who underwent curative gastrectomy between 2003 and 2007. The expression of PDGF-C and PDGF-D was analyzed by immunohistochemical staining. High expression of PDGF-C and PDGF-D was detected in 114 (56%) and 151 (74%) tumors, respectively. PDGF-D expression was significantly associated with tumor depth (P=0.039), histopathology (P<0.01), tumor stage (P=0.01) and recurrence (P<0.01), whereas PDGF-C expression correlated only with histopathology (P=0.05). High PDGF-D expression was also associated with significantly shorter relapse-free survival (RFS) time (P<0.01), whilst high PDGF-C expression was associated with marginally, but not significantly, shorter RFS (P=0.10). On multivariate analysis, high PDGF-D expression was determined to be an independent prognostic factor (hazard ratio, 3.3; 95% confidence interval, 1.20–9.4; P=0.02). These findings indicate that high PDGF-D expression is strongly associated with tumor progression, recurrence, distant metastasis and poor outcomes in patients with gastric cancer. PDGF-D may therefore be an independent prognostic factor and a novel therapeutic target.

The JAK/STAT signaling cascade in gastric carcinoma (Review)

Gastric carcinoma remains one of the most prevalent forms of cancer worldwide, despite the decline in incidence rates, increased awareness of the disease and advancement in treatment strategies. Helicobacter pylori infection, dietary factors, lifestyle influences and various genetic aberrations have been shown to contribute to the development and progression of gastric cancer. Recent studies on the genomic landscape of gastric adenocarcinoma have identified several key signaling molecules, including epidermal growth factor receptor family (ErbB) members, vascular endothelial growth factor receptor family (VEGFR) members and PI3K/Akt/mTOR pathway components, that have been implicated in the molecular pathogenesis of gastric cancers. However, clinical trials with compounds that target these molecules have failed to show a significant improvement in overall survival rates when supplemented with conventional therapies. Therefore, it is essential to identify effective prognostic and/or diagnostic biomarkers and develop molecular targeted therapies. The JAK/STAT cascade is a principal signal transduction pathway in cytokine and growth factor signaling, regulating various cellular processes such as cell proliferation, differentiation, migration and survival. Numerous in vivo and in vitro studies have shown that dysregulated JAK/STAT signaling is a driving force in the pathogenesis of various solid cancers as well as hematopoietic malignancies. Hence, a large number of preclinical and clinical studies of drugs targeting this pathway are currently underway. Notably, aberrant JAK/STAT signaling has also been implicated in gastric cancers. In this review, we focus on the ongoing research on the JAK/STAT cascade in gastric carcinoma and discuss the therapeutic potential of targeting JAK/STAT signaling for the treatment of gastric cancer.

Advancing pharmacological treatment options for advanced gastric cancer

INTRODUCTION

Gastric cancer is the third most common cause of cancer-related deaths worldwide. Improvement of conventional chemotherapy has been modest in the past decades.

AREAS COVERED

We review recent important studies of metastatic or recurrent gastric cancer. For human epidermal growth factor receptors 2 (HER2) negative cancer, standard treatments are combinations of fluoropyrimidine and platinum with or without epirubicin or docetaxel in first-line therapy. Controversy exists regarding the use of triplet chemotherapies due to their toxicity. For HER2 positive cancer, standard treatments are combinations of fluoropyrimidine and cisplatin with trastuzumab. As second- or third-line treatment, taxanes or irinotecan prolonged survival compared with best supportive care alone, but the extension of overall survival was only 1 - 2 months. A recent study demonstrated that ramucirumab plus paclitaxel improved survival as a second-line therapy.

EXPERT OPINION

Most trials have failed to demonstrate a benefit of targeted agents. It is important to identify predictive biomarkers to enrich an appropriate patient population for targeted agents such as HER2 status for trastuzumab.

Angiogenic inhibitors in gastric cancers and gastroesophageal junction carcinomas: A critical insight

Advanced gastric cancer ranks second as the global leading cause of cancer-related death and improvements in systemic chemotherapy have reached a plateau. Advanced molecular sequencing techniques help identifying patients more likely to respond to targeted agents; nevertheless we are still far from major breakthroughs. Although antiangiogenic drugs have produced notable advances, redundant pathways or mechanisms of resistance may limit their efficacy. Novel compounds have been recently developed to specifically target VEGF receptors, PlGF, FGF, MET, and angiopoietin. Ramucirumab, a monoclonal antibody specifically directed against the VEGFR-2, has emerged as a novel therapeutic opportunity. REGARD and RAINBOW were the first phase III studies to report the value of this strategy in gastric cancer patients, and other ongoing trials are testing novel antiangiogenic compounds. The aim of our review is to present the state-of-the-art of novel antiangiogenic compounds in advanced gastric cancer, underlying the biology, their mechanism of action, and their clinical results.

Disrupted Balance of MMPs/TIMPs in Gastric Carcinogenesis-Paradoxical Low MMP-2 Expression in Tumor and Stromal Compartments as a Potential Marker of Unfavorable Outcome

The aim of the study was to find correlations between MMP/TIMP reactivity and the expression of angiogenic factors, and relationships between these parameters and clinicopathological features of gastric cancer patients. Receiver Operating Characteristic curve analysis was used to find cut-off points that enabled fair decision-making in survival analysis. Low levels of MMP-2 expression in tumor and stromal compartments were significantly associated with poor prognosis-the probability that a patient would die within 60 months of surgery if their MMP-2 was low, and was about 0.8 in both neoplastic and stromal compartments.

Anti-angiogenic therapies for advanced esophago-gastric cancer

Neo-vascularization is a vital process for tumor growth and development which involves the interaction between tumor cells and stromal endothelial cells through several growth factors and membranous receptors which ultimately activate pro-angiogenic intracellular signaling pathways. Inhibition of angiogenesis has become a standard treatment option for several tumor types including colorectal cancer, glioblastoma and ovarian cancer. In gastric cancer, the therapeutic role of anti-angiogenic agents is more controversial. Bevacizumab and ramucirumab, two monoclonal antibodies, which target vascular endothelial growth factor-A and vascular endothelial growth factor receptor-2, respectively, have been demonstrated antitumor activity in patients with tumors of the stomach or esophagogastric junction. However, especially for bevacizumab, this antitumor activity has not consistently translated into a survival advantage over standard treatment in randomized trials. In this article, we provide an overview of the role of angiogenesis in gastric cancer and discuss the results of clinical trials that investigated safety and effectiveness of antiangiogenic therapies in this disease. A review of the literature has been done using PubMed, ClinicalTrials.gov website and the ASCO Annual Meeting Library.

Metastasis-associated in colon cancer-1 upregulates vascular endothelial growth factor-C/D to promote lymphangiogenesis in human gastric cancer

Lymphangiogenesis is actively contributed to lymphatic metastasis in gastric cancer (GC), and vascular endothelial growth factor (VEGF)-C and VEGF-D are key regulators for lymphangiogenesis. Metastasis-associated in colon cancer-1 (MACC1) was reported to be associated with lymph node metastasis in a few clinical studies, while little is known about the role of MACC1 in lymphangiogenesis. Hence, in the present study, we explored the potential role of MACC1 in lymphangiogenesis as well as the underlying mechanisms. By clinical observation, we found a positive relationship between MACC1 and lymphangiogenesis. Besides, similar results were also obtained from in vivo and in vitro studies. With an indirect co-culture system, we got that supernatant from MACC1 overexpressed GC cells accelerated human lymphatic endothelial cells' (HLECs') capacity of tube-like formation through enhancing cell proliferation and migration. Moreover, MACC1 overexpressed xenografts also presented more lymphatic vessels. Furthermore, MACC1 significantly increased the expression of VEGF-C/VEGF-D in GC cells and transplanted tumors, which was subsequently suppressed by c-Met inhibitor. All these data suggested a critical role for MACC1 in lymphatic dissemination of GC, providing evidence that MACC1 upregulated VEGF-C/VEGF-D secretion to promote lymphangiogenesis via c-Met signaling.

Ramucirumab plus paclitaxel versus placebo plus paclitaxel in patients with previously treated advanced gastric or gastro-oesophageal junction adenocarcinoma (RAINBOW): a double-blind, randomised phase 3 trial

BACKGROUND

VEGFR-2 has a role in gastric cancer pathogenesis and progression. We assessed whether ramucirumab, a monoclonal antibody VEGFR-2 antagonist, in combination with paclitaxel would increase overall survival in patients previously treated for advanced gastric cancer compared with placebo plus paclitaxel.

METHODS

This randomised, placebo-controlled, double-blind, phase 3 trial was done at 170 centres in 27 countries in North and South America, Europe, Asia, and Australia. Patients aged 18 years or older with advanced gastric or gastro-oesophageal junction adenocarcinoma and disease progression on or within 4 months after first-line chemotherapy (platinum plus fluoropyrimidine with or without an anthracycline) were randomly assigned with a centralised interactive voice or web-response system in a 1:1 ratio to receive ramucirumab 8 mg/kg or placebo intravenously on days 1 and 15, plus paclitaxel 80 mg/m(2) intravenously on days 1, 8, and 15 of a 28-day cycle. A permuted block randomisation, stratified by geographic region, time to progression on first-line therapy, and disease measurability, was used. The primary endpoint was overall survival. Efficacy analysis was by intention to treat, and safety analysis included all patients who received at least one treatment with study drug. This trial is registered with ClinicalTrials.gov, number NCT01170663, and has been completed; patients who are still receiving treatment are in the extension phase.

FINDINGS

Between Dec 23, 2010, and Sept 23, 2012, 665 patients were randomly assigned to treatment-330 to ramucirumab plus paclitaxel and 335 to placebo plus paclitaxel. Overall survival was significantly longer in the ramucirumab plus paclitaxel group than in the placebo plus paclitaxel group (median 9·6 months [95% CI 8·5-10·8] vs 7·4 months [95% CI 6·3-8·4], hazard ratio 0·807 [95% CI 0·678-0·962]; p=0·017). Grade 3 or higher adverse events that occurred in more than 5% of patients in the ramucirumab plus paclitaxel group versus placebo plus paclitaxel included neutropenia (133 [41%] of 327 vs 62 [19%] of 329), leucopenia (57 [17%] vs 22 [7%]), hypertension (46 [14%] vs eight [2%]), fatigue (39 [12%] vs 18 [5%]), anaemia (30 [9%] vs 34 [10%]), and abdominal pain (20 [6%] vs 11 [3%]). The incidence of grade 3 or higher febrile neutropenia was low in both groups (ten [3%] vs eight [2%]).

INTERPRETATION

The combination of ramucirumab with paclitaxel significantly increases overall survival compared with placebo plus paclitaxel, and could be regarded as a new standard second-line treatment for patients with advanced gastric cancer.

FUNDING

Eli Lilly and Company.

Multicenter phase II study of oxaliplatin and sorafenib in advanced gastric adenocarcinoma after failure of cisplatin and fluoropyrimidine treatment. A GEMCAD study

BACKGROUND

Cisplatin and fluoropyrimidine (CF) are standard first- line treatment in advanced gastric cancer, but no second-line treatment has yet been established. We present a phase II study in which we evaluated the efficacy and toxicity of the combination of Sorafenib (S), and Oxaliplatin as second-line therapy.

METHODS

Patients with progressive gastric adenocarcinoma after CF- first-line, ECOG 0-2, and measurable disease were included. The primary objective was PFS. Treatment doses were Oxaliplatin 130 mg/m²/3 weeks and Sorafenib 800 mg/bid/d.

RESULTS

We included 40 patients. CR was 2.5% and SD was 47.2%. Grade 3-4 toxic effects were neutropenia (9.8%), thrombocytopenia (7.3%), neurotoxicity (4.9%) and diarrhea (4.9%). Median PFS was 3 months (95%CI: 2.3-4.1) and median OS was 6.5 months (95% CI: 5.2-9.6). Time to progression (TTP) to first line therapy was a prognosis factor. Median OS was 9.7 months when time-to-progression during first-line chemotherapy was >6 months and 5.6 m when it was <6 months (p = 0.04).

CONCLUSIONS

Time-to-progression under a CF-based first-line therapy determines subgroups of GC patients with different prognosis. The combination of Oxaliplatin-Sorafenib in advanced GC patients previously treated with CF appears safe, but our results do not support the implementation of a phase III trial.

VEGFR-3 and CXCR4 as predictive markers for treatment with fluorouracil, leucovorin plus either oxaliplatin or cisplatin in patients with advanced esophagogastric cancer: a comparative study of the Arbeitsgemeinschaft Internistische Onkologie (AIO)

BACKGROUND

Combination of fluoropyrimidines and a platinum derivative are currently standards for systemic chemotherapy in advanced adenocarcinoma of the stomach and gastroesophageal junction (GEJ). Nevertheless, individual likelihood for response to these therapeutic regimes remains uncertain. Even more, no predictive markers are available to determine which patients may benefit more from oxaliplatin versus cisplatin or vice versa. The new invasion and stem cell markers VEGFR-3 and CXCR4 have been linked prognostically with more aggressive esophagogastric cancer types. Thus, we aimed to assess correlations of VEGFR-3 and CXCR4 expression levels with clinical outcome in a randomized phase III study of patients with oxaliplatin/leucovorin/5-FU (FLO) versus cisplatin/leucovorin/5-FU (FLP).

METHODS

The patients data examined in this study (n = 72) were from the collective of the FLO vs. FLP phase III AIO trial. Tumour tissues were stained via immunohistochemistry for VEGFR-3 and CXCR4 expression and results were evaluated by two independent, blinded investigators.Outcome parameter: Survival analysis was calculated for patients receiving FLO vs. FLP in relation to VEGFR-3 and CXCR4 expression.

RESULTS

54% and 36% of the examined tumour tissues showed strong positive expression of VEGFR-3 and CXCR4 respectively. No superiority of each regime was detected in terms of overall survival (OS) in the whole population. Patients with strong expression of CXCR4 on their tumour tissues profited more in terms of OS under the treatment of FLP (mOS: 28 vs 15 months, p = 0.05 respectively). Patients with negative VEGFR-3 and CXCR4 expression had a trend to live longer when FLO regime was applied (mOS: 22 vs. 9 months, p = 0.099 and 20 vs. 10 months, p = 0.073 respectively). In an exploratory analysis of patients older than 60 years at diagnosis, we observed a significant benefit in overall survival for VEGFR-3 and CXCR4-positive patients when treated with FLP (p = 0.002, p = 0.021 respectively).

CONCLUSIONS

CXCR4 positive patients profited in terms of OS from FLP, whereas FLO proved to be more effective in CXCR4 and VEGFR-3 negative patients. Our results suggest, despite the limited size of the study, a predictive value of these biomarkers concerning chemotherapy with FLP or FLO in advanced esophagogastric cancer.

Targeted therapy for gastric cancer: molecular pathways and ongoing investigations

Gastric cancer is currently the second leading cause of worldwide cancer mortality. Ongoing collaborative sequencing efforts have highlighted recurrent somatic genomic aberrations in gastric cancer, however, despite advances in characterizing the genomic landscape, there have been few advances in patient outcomes. Prognosis remains poor with a median overall survival of 12 months for advanced disease. The improved survival with trastuzumab, and more recently ramucirumab, underscore the promise of targeted and biologic therapies and the importance of molecular tumor characterization in gastric cancer. Here we review the most frequent actionable alterations in gastric cancer and highlight ongoing clinical investigations attempting to translate biologic understanding into improved clinical outcomes.

Three-dimensional contrast-enhanced sonography in the assessment of breast tumor angiogenesis: correlation with microvessel density and vascular endothelial growth factor expression

OBJECTIVES

The purpose of this study was to differentiate perfusion and vascular characteristics between benign and malignant breast lesions by 3-dimensional contrast-enhanced sonography and evaluate their correlation with microvessel density and vascular endothelial growth factor (VEGF) expression for further clinical exploration.

METHODS

Three-dimensional contrast-enhanced sonography was performed in 183 patients with breast lesions, and sonographic characteristics were carefully observed for further analysis. The mean microvessel density and VEGF expression were measured by immunohistochemical analysis.

RESULTS

Pathologic results showed 35 benign and 148 malignant cases. Malignancy and benignity differed significantly in peripheral vessel characteristics (number, distribution, course, degree of dilatation, and penetrating vessels), rim perfusion and coarseness degree, intratumoral perfusion type, and intratumoral vessel dilatation (P< .05) but not the presence of peripheral and intratumoral vessels and intratumoral perfusion (P > .05). The specificity of penetrating vessels was 88.6% for diagnosing malignancy. The sensitivity, specificity, and accuracy of rim perfusion coarseness were 90.2%, 70.4%, and 85.3% respectively. The sensitivity of the intratumoral perfusion type was 77.8%, whereas the specificity of intratumoral vessel dilatation was 88.9%. Microvessel density and VEGF expression were significantly correlated with perfusion and vascular characteristics (P < .05), except the presence of peripheral vessels, rim perfusion, and intratumoral perfusion (P> .05). The presence of intratumoral vessels was related to VEGF (P< .05) but not microvessel density (P > .05).

CONCLUSIONS

Three-dimensional contrast-enhanced sonographic characteristics were statistically different between benign and malignant breast lesions. Some of them also correlated significantly with microvessel density and VEGF expression and therefore have potential for objective evaluation of tumor angiogenesis.

Transcription of the vascular endothelial growth factor receptor-3 (VEGFR3) gene is regulated by the zinc finger proteins Sp1 and Sp3 and is under epigenetic control: transcription of vascular endothelial growth factor receptor 3

BACKGROUND

In the past, the vascular endothelial growth factor receptor-3 (VEGFR-3) has been linked to the regulation of lymphangiogenesis and the lymphatic spread of solid malignancies. The molecular mechanisms controlling VEGFR3 gene expression have, however, remained poorly understood. Here, we aimed at assessing these mechanisms through VEGFR3 gene promoter analysis and the identification of transcription factors binding to it. In addition, we focussed on epigenetic modifications underlying VEGFR3 transcription regulation.

METHODS

5' Deletion analyses for the identification of functional promoter elements, electrophoretic mobility shift assays, chromatin immunoprecipitations, methylation-specific PCRs, and Trichostatin A (TSA) and 5-Aza desoxycytidine (5-Aza dC) treatments were performed in this study.

RESULTS

Following the isolation of a 2 kb stretch of 5'-flanking DNA of VEGFR3, we identified a novel GC-rich element (GRE) spanning -101/-66 sufficient for VEGFR3 transcription and activated by Sp1 and Sp3, respectively. Histone de-acetylase inhibition by TSA led to the accumulation of acetylated histones H3/H4 at the VEGFR3 gene promoter, up-regulation of its mRNA levels, and transactivation of promoter reporter constructs in endothelial cell lines. Similarly, methylation inhibition by 5-Aza dC triggered up-regulation of VEGFR3 mRNA levels and increased promoter activity. TSA and 5-Aza-dC did not influence Sp1/Sp3 binding, but increased the transactivating capacity of both transcription factors, suggesting epigenetic modification as an underlying mechanism.

CONCLUSIONS

Here we describe the identification of regulatory elements controlling human VEGFR3 gene expression and show that histone acetylation and CpG methylation are important determinants of VEGFR3 transcription regulation. These findings may facilitate the development of intervention strategies aimed at targeting VEGFR3-based tumor lymphangiogenesis and/or lymphatic tumor spread.

ELR-CXC chemokine antagonism and cisplatin co-treatment additively reduce H22 hepatoma tumor progression and ameliorate cisplatin-induced nephrotoxicity

Cisplatin (cis-diamminedichloroplatinum) is one of the most commonly used agents for the chemotherapy of various types of cancers, but its use is limited by its dose-dependent side-effects (e.g., nephrotoxicity). The ELR-CXC chemokines are potent tumor growth, metastatic and angiogenic factors and can foster tumor resistance to chemotherapeutic agents. They are also potent proinflammatory agents. The aim of the present study was to evaluate the added effects of combining cisplatin chemotherapy with ELR-CXC chemokine antagonism in a mouse H22 hepatoma cancer cell model. The mice were injected with tumor cells and were then treated with cisplatin (12.5 or 2 mg/kg doses), either alone or together with the chemokine antagonist CXCL8(3-72)K11R/G31P (G31P) (50 µg/kg). At varying time-points renal function was examined using blood urea nitrogen (BUN) and serum creatinine (SCr) as read-outs for the toxic effects of cisplatin, while tumor growth and metastasis were assessed as endpoints. High-dose cisplatin therapy reduced the tumor burden by 52%, while co-delivery of G31P further augmented the tumor growth-suppressive effects of this dose of cisplatin to 71%; G31P by itself and low-dose cisplatin reduced the tumor burden by 19 and 39%, respectively. G31P also reduced the nephrotoxic effects of high-dose cisplatin to the effects observed in the low-dose cisplatin-treated animals. These data confirm the beneficial effects of combined cisplatin chemotherapy and ELR-CXC chemokine anatagonism in the context of both tumor progression and adverse side-effects.

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.

VEGF targets the tumour cell

The function of vascular endothelial growth factor (VEGF) in cancer is not limited to angiogenesis and vascular permeability. VEGF-mediated signalling occurs in tumour cells, and this signalling contributes to key aspects of tumorigenesis, including the function of cancer stem cells and tumour initiation. In addition to VEGF receptor tyrosine kinases, the neuropilins are crucial for mediating the effects of VEGF on tumour cells, primarily because of their ability to regulate the function and the trafficking of growth factor receptors and integrins. This has important implications for our understanding of tumour biology and for the development of more effective therapeutic approaches.

Anti-angiogenic therapies for metastatic colorectal cancer: Current and future perspectives

Colorectal cancer (CRC) is the fourth most commonly diagnosed cancer and the second leading cause of cancer death in both men and women in the United States, with about 142820 new cases and 50830 deaths expected in 2013. Metastatic disease (mCRC) remains a challenge for oncologists worldwide due to its potential comorbidities. Recently, chemotherapy regimens containing 5-fluorouracil, leucovorin, oxaliplatin and irinotecan combinations are a standard of care in the metastatic disease. Currently, biological therapies involving vascular endothelial growth factor and epidermal growth factor receptor pathways, such as bevacizumab and cetuximab, have emerged as good option for improving mCRC patient survival. Now, aflibercept plus standard chemotherapy has also been approved in second line regimen for mCRC patients. Our review will discuss novel biological drugs and their indications for mCRC patients and will bring future perspectives in this regard.

Expression of VEGF-D in epithelial ovarian cancer and its relationship to lymphatic metastasis

AIM

To investigate the contribution of vascular endothelial growth factor (VEGF)-D to tumor progression, tumor lymphangiogenesis and lymphatic metastasis in epithelial ovarian cancer.

METHODS

The expression profiles of VEGF-D in 18 benign, 14 borderline and 87 malignant epithelial ovarian cancers were examined using immunohistochemical (IHC) staining. Lymphatic vessels were identified using IHC staining on lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1), which is a lymph-specific receptor for hyaluronan in identifying lymphatic vessels. The potential correlation among VEGF-D, lymphatic vessel density (LVD) and clinico-pathological factors of the epithelial ovarian cancer was also analyzed.

RESULTS

Positive IHC staining of VEGF-D was observed in 17% of benign, 21% of borderline and 80% of malignant epithelial ovarian tumors specimens. In the epithelial ovarian cancer specimens, the LVD was 3.41 ± 2.37 in the VEGF-D negative (17 patients), 5.42 ± 3.49 in the weak (26 patients), 7.22 ± 2.36 in the moderate (27 patients) and 7.35 ± 4.06 in the strong (17 patients) groups, respectively. Additionally, the expression of VEGF-D was positively correlated with LVD (r = 0.415, P < 0.001). The expression level of VEGF-D was significantly higher in lymph node-positive epithelial ovarian cancer than in lymph node-negative patients (P = 0.009, P < 0.05). The expression of VEGF-D was significantly correlated with lymph node metastasis, International Federation of Gynecology and Obstetrics stage and tumor histological differentiation, but not with the patients' age or histology type.

CONCLUSION

VEGF-D may play an important role in the process of lymphatic metastasis of epithelial ovarian cancer.

The propeptides of VEGF-D determine heparin binding, receptor heterodimerization, and effects on tumor biology

VEGF-D is an angiogenic and lymphangiogenic glycoprotein that can be proteolytically processed generating various forms differing in subunit composition due to the presence or absence of N- and C-terminal propeptides. These propeptides flank the central VEGF homology domain, that contains the binding sites for VEGF receptors (VEGFRs), but their biological functions were unclear. Characterization of propeptide function will be important to clarify which forms of VEGF-D are biologically active and therefore clinically relevant. Here we use VEGF-D mutants deficient in either propeptide, and in the capacity to process the remaining propeptide, to monitor the functions of these domains. We report for the first time that VEGF-D binds heparin, and that the C-terminal propeptide significantly enhances this interaction (removal of this propeptide from full-length VEGF-D completely prevents heparin binding). We also show that removal of either the N- or C-terminal propeptide is required for VEGF-D to drive formation of VEGFR-2/VEGFR-3 heterodimers which have recently been shown to positively regulate angiogenic sprouting. The mature form of VEGF-D, lacking both propeptides, can also promote formation of these receptor heterodimers. In a mouse tumor model, removal of only the C-terminal propeptide from full-length VEGF-D was sufficient to enhance angiogenesis and tumor growth. In contrast, removal of both propeptides is required for high rates of lymph node metastasis. The findings reported here show that the propeptides profoundly influence molecular interactions of VEGF-D with VEGF receptors, co-receptors, and heparin, and its effects on tumor biology.

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.

High density of peritumoral lymphatic vessels measured by D2-40/podoplanin and LYVE-1 expression in gastric cancer patients: an excellent prognostic indicator or a false friend?

BACKGROUND

One of the most important prognostic indicators in gastric cancer is the presence of metastases in lymph nodes. Even now, little is known about lymphangiogenesis in neoplastic tissue, and little is also known about the transmission of a neoplastic cell from the tumor mass into a lymphatic vessel.

METHODS

This study examined the relationships between the density of lymphatic vessels (LVD) stained immunohistochemically with lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) and D2-40 (podoplanin) antibodies, the expression of vascular endothelial growth factor (VEGF)-C/D, selected clinical and pathomorphological factors, and the 5-year overall survival of gastric cancer patients.

RESULTS

Statistical analysis showed no impact of increased intratumoral or peritumoral LVD on gastric cancer patient survival, irrespective of the protein used to stain lymphatic vessels. Analysis showed that the probability of overall survival was decreased in the cases with enhanced VEGF-D immunoreactivity (P = 0.0045).

CONCLUSION

The study showed that the studied markers cannot be used to determine the required extent of the surgical procedure, as they have no statistically significant correlation with the degree of progression of the cancer, the stage of the disease assessed according to the TNM 5th classification of malignant tumors, clinicopathological features, and patient survival. VEGF-D is the only marker that can be regarded as an unfavorable prognostic indicator for patients with advanced gastric cancer.

Recombinant human endostatin endostar suppresses angiogenesis and lymphangiogenesis of malignant pleural effusion in mice

Background

Malignant pleural effusion (MPE) is a common complication of lung cancer. One widely used treatment for MPE is Endostar, a recombined humanized endostatin based treatment. However, the mechanism of this treatment is still unclear. The aim of this study was to investigate the effects of Endostar in mice with MPE.

Methods and Materials

Lewis lung carcinoma (LLC) cell line expressing enhanced green fluorescent protein (EGFP) was injected into pleural cavity to establish MPE mice model. Mice were randomly divided into four groups. High dose of Endostar (30 mg/kg), low dose of Endostar (8 mg/kg), normal saline, or Bevacizumab (5 mg/kg) was respectively injected into pleural cavity three times with 3-day interval in each group. Transverse computed tomography (CT) was performed to observe pleural fluid formation 14 days after LLC cells injection. Mice were anesthetized and sacrificed 3 days after final administration. The volume of pleural effusion n was measured using 1 ml syringe. Micro blood vessel density (MVD), Lymphatic micro vessel density (LMVD), the expression level of vascular endothelial growth factor A (VEGF-A) and VEGF-C were observed by immunohistochemistry (IHC) staining.

Results

The volume of pleural effusion as well as the number of pleural tumor foci, MVD and the expression of VEGF-A were significantly reduced in high dose of Endostar treat group. More importantly, LMVD and the expression of VEGF-C were markedly lower in treat group than those in the other three control groups.

Conclusion

Our work demonstrated that Endostar played an efficient anti-cancer role in MPE through its suppressive effect on angiogenesis and lymphangiogenesis, which provided a certain theoretical basis for the effectiveness of Endostar on the MPE treatment.

Evaluation of the risk of lymph node metastasis using CRP 1846C>T genetic polymorphism in submucosal thoracic esophageal squamous cell carcinoma

BACKGROUND

More than 40 % of patients with submucosal esophageal squamous cell carcinoma (ESCC) have lymph node metastasis. Furthermore, the potential presence of undetectable metastasis before treatment prompts surgeons to be aggressive with respect to lymph node dissection. Extending the indication for endoscopic resection, a minimally invasive treatment, to superficial ESCCs will require more accurate and individualized evaluation of lymph node metastasis.

METHODS

The study participants were 121 esophageal cancer patients who underwent curative surgery for thoracic submucosal ESCC at three Japanese hospitals. DNA was extracted from blood samples, and the C-reactive protein (CRP) 1846C>T genetic polymorphism (rs1205) was investigated using polymerase chain reaction-restriction fragment length polymorphism. We then evaluated the value of CRP 1846C>T polymorphism for diagnosis of lymph node metastasis.

RESULTS

Forty-nine (40 %) patients had lymph node metastasis. The CRP 1846 C/T genotype was C/C in 19 patients, C/T in 57 patients, and T/T in 45 patients. Fisher's exact analysis of the CRP 1846C>T polymorphism showed a significantly higher frequency of lymph node involvement with the T/T genotype. Univariate and multivariate logistic regression models revealed that patients carrying the 1846 T/T genotype had a significantly greater likelihood of developing lymph node metastasis (odds ratio >2.6). Combining the CRP 1846 C/T genotype with clinical diagnosis, mainly using CT, brought a negative predictive value of 80 % to diagnosing lymph node involvement.

CONCLUSIONS

CRP genetic polymorphism may be a novel predictor of risk of lymph node metastasis in ESCC, which could enable better evaluation of the necessity for lymph node dissection.

Inhibition of lymphatic metastasis in neuroblastoma by a novel neutralizing antibody to vascular endothelial growth factor-D

Lymphatic spread is an important clinical determinant in the prognosis of many human cancers. The lymphangiogenic factor vascular endothelial growth factor-D (VEGF-D) is implicated in the promotion of lymphatic metastasis through the development of lymphatic vessels in some human cancers. In this study, we developed an anti-VEGF-D monoclonal antibody, cVE199, and investigated its in vitro properties, in vivo effects against tumors and possible target indications to evaluate its potential as a therapeutic antibody. The cVE199 molecule was revealed to have a specific binding reactivity against human VEGF-D, as well as a specific inhibitory activity against the binding of human VEGF-D to VEGFR-3. In addition, cVE199 was found to inhibit the biological activity of VEGF-D against lymphatic cells in vitro. Because we determined that a neuroblastoma cell line, SK-N-DZ, abundantly expressed VEGF-D, an in vivo efficacy study was performed using a xenograft model of SK-N-DZ. We found that cVE199 significantly decreased lymphatic metastasis of SK-N-DZ as well as lymphangiogenesis in primary lesions. Finally, we investigated VEGF-D expression in human neuroblastoma, finding that the molecule was expressed in 11 of 29 human neuroblastoma specimens (37.9%). In conclusion, we found that a novel anti-VEGF-D monoclonal antibody, cVE199, with specific reactivity against human VEGF-D, prevents lymphatic metastasis of neuroblastoma through the inhibition of lymphangiogenesis in an animal model. In addition, our results show that VEGF-D is expressed in some cases of human neuroblastomas, which suggests that cVE199 is a potential anti-metastasis therapeutic antibody in neuroblastoma treatment.

Overexpression of MMP-1 and VEGF-C is associated with a less favorable prognosis in esophageal squamous cell carcinoma

BACKGROUND

This study addresses the association of matrix metalloproteinase-1 (MMP-1) and vascular endothelial growth factor-C (VEGF-C) expression in esophageal squamous cell carcinoma (SCC) with clinicopathologic characteristics in the patients.

MATERIAL AND METHODS

We profiled the expression of MMP-1 and VEGF-C by cDNA microarray in 4 cases and by reverse transcription-polymerase chain reaction (RT-PCR) in 14 cases of esophageal SCC. Another 90 cases were reviewed by immunohistochemical examination of paraffin-embedded sections.

RESULTS

Expression of MMP-1 and VEGF-C mRNA in normal esophageal tissue and tumor tissue was compared. Data were fully consistent with the results of RT-PCR. Immunohistochemistry showed that compared to the normal mucosa MMP-1 and VEGF-C protein expression was upregulated in both esophageal atypical hyperplasia (n = 16) and esophageal SCC. Depth of tumor invasion, lymph node metastasis, and clinical stage were directly associated with prognosis in all cases. Furthermore, median overall survival and disease-free survival were significantly shorter in patients with a higher expression of MMP-1 and VEGF-C than in patients with lower expression levels.

CONCLUSION

We demonstrated that the expression of both MMP-1 and VEGF-C mRNA and protein was upregulated in esophageal SCC tissues. Protein expression was associated with progressive tumor stage and poor prognosis in patients with esophageal SCC.

Endo-sulfatase Sulf-1 protein expression is down-regulated in gastric cancer

In our recent report on gene expression in gastric cancer we identified the endo-sulfatase Sulf-1 gene to be up-regulated in gastric tumors relative to apparently normal (AN), and paired normal (PN) gastric tissue samples. In the present report we investigate the protein expression levels of Sulf-1 gene in gastric tumors, AN and PN samples using tissue microarray (TMA) and immunohistochemistry. Expression data was collected from two sets of TMA's containing replicate sections of tissue samples. Scoring data from TMA set-1 revealed a significant difference in Sulf-1 immunoreactivity between tumors and "normals" (PN and AN) (p-value = 0.001928). Also, Sulf-1 expression in tumors was also significantly different from either PN (p-value = 0.019) or AN (p-value = 0.006) samples. Similar results were obtained from analysis of scoring data from the second set of arrays. Comparison of mRNA expression and protein expression in gastric tumor tissues revealed that in 6/20 (30%) tumor samples showed up-regulated protein expression concordant with over-expression of mRNA. However, a discord with mRNA being over-expressed relative to down regulated protein expression was observed in majority 14/20 (70%) of tumor samples. Our study indicates down regulation of Sulf-1 protein expression in gastric tumors relative to PN and AN samples which is discordant with mRNA over-expression seen in tumors.

Immunohistochemical endothelial markers: a review

A relatively large number of new endothelial markers that can assist in the diagnosis and classification of endothelial and vascular neoplasms have become available over the past few years. The expression of these markers, however, differs considerably among the various tumors. A selection of markers that have potential diagnostic utility or are of current interest among pathologists are reviewed and compared with some of the more traditional markers that have been employed in diagnostic pathology.

Expression of vascular endothelial growth factor C in human pterygium

Vascular endothelial growth factor C (VEGF-C) and its receptor VEGFR-3 mediate lymphangiogenesis. In this study, we analyzed the expression of VEGF-C and VEGFR-3 as well as lymphatic vessels in the pterygium and normal conjunctiva of humans. Fifteen primary nasal pterygia and three normal bulbar conjunctivas, surgically removed, were examined in this study. The lymphatic vessel density (LVD) and blood vessel density were determined by the immunolabeling of D2-40 and CD31, markers for lymphatic and blood vessels, respectively. VEGF-C and VEGFR-3 expression in pterygial and conjunctival tissue proteins was detected by Western blotting and were evaluated using immunohistochemistry. The LVD was significantly higher in the pterygium than normal conjunctiva (p < 0.05). Western blot demonstrated high-level expression of VEGF-C and VEGFR-3 in the pterygium compared with normal conjunctiva. VEGF-C immunoreactivity was detected in the cytoplasm of pterygial and normal conjunctival epithelial cells. The number of VEGF-C-immunopositive cells in pterygial epithelial cells was significantly higher than in normal conjunctival cells (p < 0.05). VEGFR-3 immunoreactivity was localized in the D2-40-positive lymphatic endothelial cells. The present findings suggest the potential role of VEGF-C in the pathogenesis and development of a pterygium through lymphangiogenesis and the VEGF-C/VEGFR-3 pathway as a novel therapeutic target for the human pterygium.

The prognostic significance of growth factors and growth factor receptors in gastric adenocarcinoma

We evaluated growth factors/receptors expression in gastric adenocarcinoma. Immunohistochemistry was used to evaluate epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), VEGF-D, VEGF receptor (VEGFR)-2, VEGFR-3, transforming growth factor (TGF)-α, TGF-β1, and TGF-β-RII in tissue microarrays of adenocarcinoma, dysplasia, metaplasia, and gastritis. In adenocarcinoma, the expression rates of EGFR, VEGF, VEGF-D, VEGFR-2, VEGFR-3, TGF-α, TGF-β1, and TGF-β-RII were 2.0%, 0%, 10.7%, 4.4%, 11.2%, 26.3%, 9.4%, and 19.5%, respectively. VEGF-D, TGF-α, TGF-β1, and TGF-β-RII expression rate were higher in adenocarcinoma than in other groups. TGF-β-RII expression was correlated with VEGFR-3, VEGF-D, and TGF-α expression in adenocarcinomas. Tumor location, histologic type, stage, lymphatic invasion, perineural invasion, angioinvasion, VEGF-D, and VEGFR-2 expressions were associated with patient survival in a log rank test and advanced stage and positive expression of VEGF-D were poor prognostic factors using Cox analysis. VEGF-D expression may be of prognostic value in gastric adenocarcinoma, whereas EGFR and TGF family expression may only have a minor influence.

Prognostic significance of vascular endothelial growth factor immunohistochemical expression in gastric cancer: a meta-analysis

Vascular endothelial growth factor (VEGF) is considered as a prime mediator of angiogenesis, and has been implicated in carcinogenesis and metastasis. Various studies examined the relationship between VEGF protein overexpression with the clinical outcome in patients with gastric cancer, but yielded conflicting results. The prognostic significance of VEGF overexpression in gastric cancer remains controversial. Electronic databases updated to July 2011 were searched to find relevant studies. A meta-analysis was conducted with eligible studies which quantitatively evaluated the relationship between VEGF overexpression and survival of patients with gastric cancer. Survival data were aggregated and quantitatively analyzed. We performed a meta-analysis of 30 studies (n = 3,999 patients) that evaluated the correlation between VEGF overexpression detected by immunohistochemistry and survival in patients with gastric cancer. Combined hazard ratios suggested that VEGF-A overexpression had an unfavorable impact on overall survival (OS) (HR [hazard ratio] = 1.49, 95 % CI [confidence interval]: 1.22-1.77) and disease free survival (DFS) (HR = 1.85, 95 % CI: 1.38-2.32) in patients with gastric cancer. However, VEGF-C overexpression did not significantly correlate with OS (HR = 1.24, 95 % CI: 0.92-1.56) or DFS (HR = 1.15, 95 % CI: 0.78-1.52). VEGF-D is an unfavorable indicator of OS (HR = 1.68, 95 % CI: 1.02-2.34) and DFS (HR = 1.88, 95 % CI: 1.07-2.70) in patients with gastric cancer. VEGF-A and VEGF-D overexpression indicated a poor prognosis for patients with gastric cancer. VEGF-C overexpression was not associated with poor prognosis in patients with gastric cancer. The prognostic value of VEGF on survival still needs further larger prospective trials to be confirmed.

Metastatic gastric cancer - focus on targeted therapies

Gastric cancer (GC) is currently the second leading cause of cancer death worldwide; unfortunately, most patients will present with locally advanced or metastatic disease. Despite recent progress in diagnosis, surgery, chemotherapy, and radiotherapy, prognosis remains poor. A better understanding of GC biology and signaling pathways is expected to improve GC therapy, and the integration of targeted therapies has recently become possible and appears to be promising. This article focuses on anti-Her-2 therapy, specifically trastuzumab, as well as other epidermal growth factor receptor antagonists such as cetuximab, panitumub, matuzumab, nimotzumab, gefitinib, and erlotinib. Additionally, drugs that target angiogenesis pathways are also under investigation, particulary bevacizumab, ramucirumab, sorafenib, sunitinib, and cediranib. Other targeted agents in preclinical or early clinical development include mTOR inhibitors, anti c-MET, polo-like kinase 1 inhibitors, anti-insulin-like growth factor, anti-heat shock proteins, and small molecules targeting Hedgehog signaling.

Guggulsterone enhances antitumor activity of gemcitabine in gallbladder cancer cells through suppression of NF-κB

PURPOSE

Patients with gallbladder cancer usually have a poor prognosis, and effective standard chemotherapeutic regimens have not been established. The anticancer activities of guggulsterone have been demonstrated in various cancer cells. The aims of the study were to determine the effect of guggulsterone on gallbladder cancer cells and to investigate whether treatment with guggulsterone influences the antitumor activities of gemcitabine.

METHODS

The Dojindo Cell Counting Kit-8 assay was used to determine the inhibition of proliferation by drugs in TGBC1 and TGBC2 cells. Cell migration and invasion were examined using 24-well inserts and Matrigel™-coated invasion chambers. The activities of NF-κB p65, VEGF-C, and MMP-2 were measured by ELISA.

RESULTS

Guggulsterone inhibited the proliferation and suppressed migration and invasion of gallbladder cancer cells in a dose-dependent manner. Guggulsterone significantly decreased NF-κB p65, VEGF-C, and MMP-2 activities in the gallbladder cancer cells examined. Gallbladder cancer cells treated with a combination of guggulsterone and gemcitabine demonstrated significant inhibition of cell proliferation and invasion when compared to treatment with gemcitabine alone. In addition, NF-κB p65 activation decreased significantly in cells treated with a combination of guggulsterone and gemcitabine when compared to treatment with gemcitabine alone.

CONCLUSIONS

Guggulsterone exhibits anticancer activities and enhances the antitumor activities of gemcitabine through the suppression of NF-κB activation in gallbladder cancer cells. These results suggest that guggulsterone could be a potential therapeutic option for patients with gallbladder cancer.

Tumor-derived VEGF-C, but not VEGF-D, promotes sentinel lymph node lymphangiogenesis prior to metastasis in breast cancer patients

Breast cancer usually initially metastases to the sentinel lymph nodes (SLNs). Recent studies have demonstrated that tumor cells induce SLN lymphangiogenesis before metastasis in several malignancies. In addition, tumor-derived VEGF-C or VEGF-D may induce lymphangiogenesis and promote lymph node metastasis. To explore the mechanisms of lymph node metastasis in breast cancer, we investigated whether primary tumors induce SLN lymphangiogenesis before metastasis and determined the function of tumor-derived VEGF-C and VEGF-D in SLN lymphangiogenesis. Expression of VEGF-C and VEGF-D was examined using immunohistochemistry in 63 primary breast tumors. No significant relationships between VEGF-C and VEGF-D (P=0.420), and VEGF-C or VEGF-D expression and clinical parameters (age, tumor size, grade, hormonal receptor status, her-2 status) were observed (P>0.05). Expression of the lymphatic-specific markers VEGFR-3, Prox-1 and LYVE-1 was measured using quantitative real-time RT-PCR in uninvolved SLNs from 63 patients and compared to control lymph nodes from patients with benign breast disease. Expression of Prox-1 and LYVE-1 mRNA was significantly higher in uninvolved SLNs from breast cancer patients than that in control lymph nodes (P<0.01). Interestingly, expression of VEGFR-3, Prox-1 and LYVE-1 was significantly higher in SLNs from patients with high VEGF-C-expressing tumors than low VEGF-C-expressing tumors (P<0.05), but not VEGF-D-high-expressing tumors (P>0.05). This study demonstrates that primary breast tumors induce SLN lymphangiogenesis before metastasis occurs and that tumor-derived VEGF-C, but not VEGF-D, plays an important role in SLN lymphangiogenesis in breast cancer.

Overexpression of ADP-ribosylation factor 1 in human gastric carcinoma and its clinicopathological significance

Gastric cancer is the sixth leading cause of cancer-related death in Taiwan, and the identification of related factors is essential to increase patient survival. ADP-ribosylation factor 1 (ARF1) was initially identified using 2-D electrophoresis combined with MALDI-time-of-flight mass spectrometry. ADP-ribosylation factor 1 belongs to the Ras superfamily or GTP-binding protein family and has been shown to enhance cell proliferation. In the current study, we evaluated the potential of ARF1 as a biomarker for gastric cancer detection. ADP-ribosylation factor 1 mRNA was upregulated in tumor tissues (compared with adjacent non-tumor tissues, n = 55) in approximately 67.2% of gastric cancer patients. Expression of ARF1 protein was additionally observed using Western blot and immunohistochemistry (IHC) analyses. The clinicopathological correlations of ARF1 were further evaluated. Elevated ARF1 expression was strongly correlated with lymph node metastasis (P = 0.008), serosal invasion (P = 0.046), lymphatic invasion (P = 0.035), and pathological staging (P = 0.010). Moreover, the 5-year survival rate for the lower ARF1 expression group (n = 50; IHC score < 90) was higher than that of the higher expression group (n = 60; IHC score ≥ 90) (P = 0.0228, log-rank test). To establish the specific function of ARF1 in human gastric cancer, isogenic ARF1-overexpressing cell lines were prepared. Our results showed that ARF1-overexpressing clones display enhanced cell proliferation, migration, and invasion. Furthermore, ARF1-overexpression might contribute to poor prognosis of patients. These findings collectively support the utility of ARF1 as a novel prognostic marker for gastric cancer and its role in cell invasion.

Phase I and II clinical trials for gastric cancer

Gastric cancer remains a global public health problem with considerable heterogeneity in pathogenesis and clinical presentation across geographic regions. Improved understanding of the molecular biology of this disease has opened avenues for targeted intervention. An individualized treatment approach is required for optimal management of this cancer. Overcoming resistance to therapy requires combining targeted agents with the traditional options of chemotherapy/radiation therapy, and also targeting more than 1 pathway of carcinogenesis at a time. Encouraging molecular hypothesis and biomarker-driven trials will lead to improved patient outcomes and may eventually enable the therapeutic nihilism associated with gastric cancer to be overcome.

Targeted therapies and predictive markers in epithelial malignancies of the gastrointestinal tract

CONTEXT

In recent years, there has been a tremendous amount of interest in the development of targeted therapies for the treatment of human cancers. Increased understanding of the specific molecular pathways and driver mutations critical to cancer cell growth have allowed the development of these advanced therapeutics. Among these, inhibitors of the epidermal growth factor receptor and HER2/neu pathways now play a major role in the management of gastrointestinal cancers in addition to other solid malignancies. In colorectal and gastric cancers, the use of epidermal growth factor receptor inhibitors and HER2/neu inhibitors has increased the available treatment options for patients with advanced disease.

OBJECTIVE

To focus on the current targeted therapies and predictors of response in malignancies of the gastrointestinal tract.

DATA SOURCES

Medical literature searchable on PubMed (US National Library of Medicine) as well as older studies revealed by the literature review were used as the source of data.

CONCLUSION

Gene testing of critical elements of the pathways targeted by these agents (such as KRAS mutational analysis in colorectal tumors and HER2/neu testing in gastric cancers) allows the ability to predict which patients will respond to these treatments. As the molecular profiling of tumors and our understanding of cancer genomics and epigenetic alterations continues to grow, it is expected that these personalized targeted therapies will form one of the mainstays of gastrointestinal cancer treatment.

Mechanistic role of p38 MAPK in gastric cancer dissemination in a rodent model peritoneal metastasis

Peritoneal dissemination is a highly frequent complication of poorly differentiated gastric cancers for which no effective therapies are available. Constitutive activation of mitogen-activated protein kinases (MAPKs) signaling cascades is recognized as a causative factor in the malignant transformation of several carcinoma cell types. In the present study we provide evidence that p38 MAPK inhibition protects against gastric cancer cells dissemination in a mouse model of peritoneal carcinomatosis. Administering mice with ML3403 and SB203580, potent and selective p38 MAPK inhibitors, attenuate the formation of neoplastic foci induced by intraperitoneal inoculation of gastric cancer cells. By gene array analysis we found that such a protective effect correlates with a robust downregulation in the expression of CXC chemokine receptor-4, Fms-related tyrosine kinase 4 (FLT4), the non-receptor spleen tyrosine kinase (SYK) and the collagen α2(IV) (COL4A2) in neoplasic foci. Inhibition of p38 MAPK in vivo increased the sensitivity of tumor cells to cisplatin and associated with a robust downregulation in the expression of the multidrug resistance (MDR)-1, a well defined marker of resistance to chemotherapy. In summary, p38 MAPK inhibition by a small molecule is beneficial in preventing the peritoneal dissemination of poorly differentiated gastric cancer cells by acting at multiple check-points in the process of attachment and diffusion of tumor cells in the peritoneum.