Molecular targeted agents for gastric cancer: a step forward towards personalized therapy

Nucleobindin 2 inhibits senescence in gastric carcinoma

Here, we focused on the role of Nucleobindin 2 (NUCB2), a multifunctional protein, in gastric carcinoma (GC) progression. NUCB2 expression was investigated in 150 GC cases (20 non-invasive (pT1) and 130 invasive (pT2/pT3/pT4) tumors) by immunohistochemistry (IHC), and in situ hybridization for detection of the mRNA in 21 cases. Using GC cell lines, we determined whether NUCB2 expression was associated with specific cellular phenotypes. In GC clinical samples, NUCB2 was transcriptionally upregulated when compared to normal tissues. High NUCB2 expression was associated with clinicopathological factors including deep tumor invasion, lymphovascular invasion, lymph node metastasis, and advanced clinical stages, and was a significant independent predictor of unfavorable progression-free survival in 150 non-invasive and invasive GC patients. Similar findings were also evident in 72 invasive GC cases in which patients received post-operative chemotherapy, but not in 58 invasive tumors from patients who did not receive the chemotherapy. In cell lines, NUCB2 knockout inhibited proliferation, susceptibility to apoptosis, and migration capability by inducting cellular senescence; this was consistent with higher proliferation and apoptotic indices in the NUCB2 IHC-high compared to NUCB2 IHC-low GC cases. NUCB2-dependent inhibition of senescence in GC engenders aggressive tumor behavior by modulating proliferation, apoptosis, and migration.

Clinical progress of anti-angiogenic targeted therapy and combination therapy for gastric cancer

The incidence of gastric cancer is increasing year by year. Most gastric cancers are already in the advanced stage with poor prognosis when diagnosed, which means the current treatment is not satisfactory. Angiogenesis is an important link in the occurrence and development of tumors, and there are multiple anti-angiogenesis targeted therapies. To comprehensively evaluate the efficacy and safety of anti-angiogenic targeted drugs alone and in combination against gastric cancer, we systematically searched and sorted out relevant literature. In this review, we summarized the efficacy and safety of Ramucirumab, Bevacizumab, Apatinib, Fruquintinib, Sorafenib, Sunitinib, Pazopanib on gastric cancer when used alone or in combination based on prospective clinical trials reported in the literature, and sorted response biomarkers. We also summarized the challenges faced by anti-angiogenesis therapy for gastric cancer and available solutions. Finally, the characteristics of the current clinical research are summarized and suggestions and prospects are raised. This review will serve as a good reference for the clinical research of anti-angiogenic targeted drugs in the treatment of gastric cancer.

SPI1 Mediates N-Myristoyltransferase 1 to Advance Gastric Cancer Progression via PI3K/AKT/mTOR Pathway

Gastric cancer (GC) is a common digestive tract malignancy worldwide. N-myristoyltransferase 1 (NMT1) has been implicated in many cancers, but its association with gastric cancer remains to be clarified. Thus, this paper elucidated the role of NMT1 in GC. The NMT1 expression level in GC and normal tissue samples as well as the relationship between NMT1 high or low expression and overall survival in GC was analyzed via GEPIA. GC cells were transfected with NMT1 or SPI1 overexpression plasmid and short hairpin RNA against NMT1 (shNMT1) or shSPI1. NMT1, SPI1, p-PI3K, PI3K, p-AKT, AKT, p-mTOR, and mTOR levels were detected through qRT-PCR and western blot. MTT, wound healing, and transwell assays were applied to test cell viability, migration, and invasion. The binding relationship of SPI1 and NMT1 was determined through a dual-luciferase reporter assay and chromatin immunoprecipitation. NMT1 was upregulated in GC, the high level of which connected with a poor prognosis. Overexpressed NMT1 elevated viability, migration rate, and invasion rate of GC cells, whereas NMT1 knockdown leads to the opposite results. Besides, SPI1 could bind to NMT1. Overexpressed NMT1 reversed the effects of shSPI1 on decreasing viability, migration, invasion, p-PI3K/PI3K, p-AKT/AKT, and p-mTOR/mTOR in GC cells, and NMT1 knockdown reversed the effects of SPI1 overexpression on increasing viability, migration, invasion, p-PI3K/PI3K, p-AKT/AKT, and p-mTOR/mTOR. SPI1 upregulated NMT1 to facilitate the malignant behaviors of GC cells through the PI3K/AKT/mTOR pathway.

Network Pharmacology and Molecular Docking Study of Zhishi-Baizhu Herb Pair in the Treatment of Gastric Cancer

Objective

This study aimed to investigate the possible mechanism of the Zhishi and Baizhu herb pair in the treatment of gastric cancer by means of network pharmacology and molecular docking and to provide a theoretical basis for experiments and clinical application of traditional Chinese medicine for treating gastric cancer.

Methods

The main active chemical components of Zhishi and Baizhu were screened through Traditional Chinese Medicine Systems Pharmacology (TCMSP) database and selected by using the thresholds of oral bioavailability ≥30% and drug-likeness ≥18%. The targets of Zhishi and Baizhu were obtained from TCMSP, Therapeutic Targets Database (TTD), and the DrugBank database. The corresponding genes of the targets were retrieved from the UniProt database, and the gastric cancer targets were obtained from the GeneCards database and TTD. Subsequently, the networks were built between the main drug components, drug targets, and gastric cancer targets. Then, the enrichment analyses of GO and KEGG were applied to predict the potential roles of gastric cancer pathogenesis via the R package clusterProfiler. Finally, molecular docking was used to determine the affinity between the targets and components.

Results

Twenty-seven main active components were predicted from the Zhishi-Baizhu herb pair, and a total of 120 intersection genes were screened from 303 potential medicine genes and 1,839 disease genes. The enrichment included the PI3K-Akt and IL-17 signaling pathways, and the network analysis showed that the Zhishi-Baizhu herb pair acted on seven key targets, namely, AKT1, MMP9, IL-6, CCND1, BCL2, MTOR, and MDM2 (where they played a role in treating gastric cancer). Molecular docking showed that luteolin and naringenin could stably bind to the targets.

Conclusion

The possible mechanisms of the components of the Zhishi-Baizhu herb pair in treating gastric cancer might be related to luteolin and naringenin, which intervened with the targets AKT1, MMP9, IL-6, CCND1, BCL2, MTOR, and MDM2, and are linked with the PI3K-Akt and IL-17 signaling pathways. This knowledge will lay a solid foundation for further experimental and clinical studies.

An Anti-HER2 Monoclonal Antibody H2Mab-41 Exerts Antitumor Activities in Mouse Xenograft Model Using Dog HER2-Overexpressed Cells

Overexpression of human epidermal growth factor receptor 2 (HER2) has been reported in a variety of cancer types, including breast, lung, gastric, pancreatic, and colorectal cancers. Trastuzumab, a humanized anti-HER2 monoclonal antibody (mAb), has been shown to provide significant survival benefits in HER2-overexpressing breast cancer and gastric cancer patients. Previously, an anti-HER2 mAb, H₂Mab-41 (IgG_2b, kappa), was developed in our laboratory and its antitumor activity was demonstrated in mouse xenograft models of human colon cancer. The present study aimed to investigate the ability of H₂Mab-41 to induce antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) in dog HER2 (dHER2)-overexpressed cell lines, and thus exert its antitumor activity against dHER2-overexpressed tumors in vivo. Flow cytometry results demonstrated the cross-reactivity of H₂Mab-41 with dHER2. Further evaluation of interaction between H₂Mab-41 and dHER2-overexpressed CHO-K1 (CHO/dHER2) cells indicated moderate binding affinity of H₂Mab-41 toward dHER2, with a dissociation constant (K_D) of 2.6 × 10^-8 M. In vitro analysis revealed that the administration of H₂Mab-41 induced high levels of ADCC and CDC in CHO/dHER2 cells. Furthermore, intraperitoneal administration of H₂Mab-41 in mouse xenograft models of CHO/dHER2 resulted in significant inhibition of tumor development compared to the control mouse IgG. Thus, the findings of the present study demonstrated the in vivo safety and efficacy of H₂Mab-41, highlighting its suitability to be included as a part of a therapeutic regimen for dHER2-expressing canine cancers.

Predictive significance of STK17A in patients with gastric cancer and association with gastric cancer cell proliferation and migration

Gastric cancer (GC) is one of the most frequently diagnosed types of cancer worldwide, and exploring its potential therapeutic targets is particularly important for improving the prognosis of patients with GC. The aim of the present study was to investigate the association between serine/threonine kinase 17a (STK17A) expression and GC prognosis. STK17A expression was measured by quantitative real-time PCR, western blotting and immunohistochemical staining. Standard stable transfection technology was also used to construct overexpression and knockdown cell lines. Wound healing, Transwell, Cell Counting Kit-8 and colony formation assays, as well as other methods, were used to explore the function and underlying molecular mechanism of STK17A in GC. The results indicated that STK17A overexpression significantly promoted the proliferation and migration of GC cells. The clinical significance of STK17A in a cohort of 102 cases of GC was assessed by clinical correlation and Kaplan-Meier analyses. Overexpression of STK17A was demonstrated to be associated with tumor invasion depth (P<0.001), lymph node metastasis (P<0.001) and poor prognosis in terms of 5-year survival (P<0.001). In addition, Cox multivariate analysis revealed that STK17A expression was an independent risk factor for overall and progress-free survival (P<0.001). Therefore, STK17A may be a valuable biomarker for the prognosis of patients with GC.

Silencing of LncRNA Metastasis-Associated Lung Adenocarcinoma Transcript 1 Inhibits the Proliferation and Promotes the Apoptosis of Gastric Cancer Cells Through Regulating microRNA-22-3p-Mediated ErbB3

Purpose

This study aimed to investigate the regulatory effects and mechanisms of long non-coding RNA (LncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) on gastric cancer (GC) cells.

Methods

The expression of MALAT1 was detected in GC tissues and two GC cell lines (SGC-7901 and BGC-823). MALAT1 was overexpressed and silenced in GC cells by the transfection of pcDNA-MALAT1 and siRNA-MALAT1, respectively. The proliferation and apoptosis of transfected cells, as well as the tumor volume and weight in mice injected with transfected cells were determined. After identifying the interaction between microRNA-22-3p (miR-22-3p) and MALAT1/epidermal growth factor receptor 3 (ErbB3), the effects of miR-22-3p/ErbB3 silencing on the proliferation and apoptosis of GC cells were evaluated.

Results

MALAT1 was significantly upregulated in GC tissues and cells and negatively associated with the survival of GC patients. Overexpression of MALAT1 significantly promoted the proliferation and inhibited the apoptosis of SGC-7901 cells, while silencing of MALAT1 exerts contrary effects on BGC-823 cells. Silencing of MALAT1 also significantly inhibited the tumor growth in mice. In addition, MALAT1 negatively regulated its target miR-22-3p. Silencing of miR-22-3p reversed the anti-tumor effects of MALAT1 silencing on GC cells. MiR-22-3p negatively regulated its target ErbB3. Silencing of ErbB3 reversed the tumor-promoting effects of miR-22-3p silencing on GC cells.

Conclusion

Silencing of MALAT1 inhibited the proliferation and promoted the apoptosis of GC cells through upregulating miR-22-3p and downregulating ErbB3.

Evaluation of PAX8 expression promotes the proliferation of stomach Cancer cells

Background

PAX8 was not only a mitotic factor, but identified as a transcription factor involved in the prognosis of human tumor patients. Elucidating the function of PAX8 on the pathology of stomach cancer was meaningful.

Results

PAX8 was found to be upregulated in primary stomach cancer tissue and the TCGA stomach cancer dataset. Interestingly, SOX13 and PAX8 showed consistent expression patterns, and the combined high PAX8 and SOX18 expression induced a worse prognosis of stomach cancer patients. SOX13 was further identified as a transcription factor of PAX8, and further affect Aurora B and Cyclin B1 expression, two cell cycle related factors of the downstream of PAX8, including. Furthermore, PAX8 depletion inducted G1-phase arrest and the decrease of EdU incorporation, cell viability and colony formation can be rescued by SOX13 overexpression.

Conclusions

SOX13 participated in the elevated expression of PAX8, which promote the proliferation of stomach cancer cells. Therefore, SOX13 mediated PAX8 expression was recognized as a tumor-promoting role in stomach cancer.

SOX13 dependent PAX8 expression promotes the proliferation of gastric carcinoma cells

PAX8 is identified as a regulator in the pathogenesis of human tumours and an indicator of the prognosis for patients. However, the role of PAX8 on proliferation in gastric cancer have not been studied. This study was aimed to explore the expression pattern of PAX8 in gastric cancer, and investigate the effect of PAX8 on the proliferation of gastric cancer cells. PAX8 and SOX13 were identified to be synchronously up-regulated in primary gastric cancer in human gastric cancer tissues and the gastric cancer datasets of TCGA, and gastric cancer patients of combined high PAX8 and SOX13 expression showed poor prognosis. Furthermore, SOX13 can mediate PAX8 and its targeted genes, Aurora B and Cyclin B1, expression in AGS and MGC803 cell lines. Flow cytometry and EdU incorporation assays showed that silencing PAX8 can block the cell cycle of gastric cancer cell in G1 phase and SOX13 expression can rescue the arrested proliferative process induced by PAX8 silenced in CCK8 and colony formation assays. Thus, combined SOX13 and PAX8 expression regulate the proliferation of gastric cancer cells, and both SOX13 and PAX8 play an oncogene function in gastric cancer.

High expression of MRE11 correlates with poor prognosis in gastric carcinoma

Background

MRE11, a protein known to play a vital role in DNA double-strand break repair, is associated with the prognosis of a variety of tumours, but there are few studies regarding the role of MRE11 in gastric carcinoma (GC). The present study aimed to explore the clinicopathological significance and prognostic value of MRE11 expression in GC.

Methods

Data from the TCGA, GEO and Oncomine databases were analysed to assess MRE11 mRNA levels in GC. The prognostic role of the level of MRE11 mRNA was examined via the Kaplan-Meier plotter. MRE11 protein expression in tumour tissues from 155 GC patients was analysed by immunohistochemistry. Relationships between MRE11 expression and clinicopathological characteristics, overall survival (OS) and recurrence-free survival (RFS) were evaluated by Cox proportional hazards regression models and Kaplan-Meier survival curves.

Results

The results of bioinformatics analysis showed that MRE11 mRNA levels in GC tissues were higher than those in normal tissues (P < 0.01). Tissue microarray analysis showed that MRE11 protein expression was increased in GC tissues (P < 0.001), and MRE11 overexpression in GC tissues was significantly related to lymph node metastasis (P < 0.05), distant metastasis (P < 0.05) and tumour-node-metastasis stage (P < 0.05). Kaplan-Meier analyses showed that patients with GC who exhibited MRE11 overexpression had worse OS and RFS. According to Cox proportional hazards analyses, MRE11 overexpression was an independent prognostic factor for OS and RFS in these GC patients.

Conclusions

MRE11 overexpression is significantly associated with poor prognosis, and MRE11 may serve as a prognostic biomarker in GC patients.

NADPH oxidase 4 is correlated with gastric cancer progression and predicts a poor prognosis

NADPH oxidase 4 (NOX4) is one of the main sources of reactive oxygen species, and plays a crucial role in the occurrence and development of tumors. However, there is currently little evidence demonstrating that NOX4 expression is associated with gastric cancer. To establish whether NOX4 plays a role in gastric cancer progression and prognosis, we performed immunohistochemistry on gastric cancer tissues and paired adjacent normal tissues from 90 gastric cancer patients to detect and compare NOX4 expression. Next, we analyzed the association between NOX4 expression and clinicopathological characteristics. Survival analysis was performed to explore the association between NOX4 expression and the prognosis of gastric cancer patients. Furtherly, we investigated the effect of NOX4-knockdown using siRNA on gastric cancer progression in vitro and in vivo. Our results revealed that NOX4 expression in gastric cancer tissues is higher than in paired adjacent normal tissues (P = 0.0009). NOX4 expression is significantly correlated with tumor size (P = 0.0321), lymphatic metastasis (P = 0.0125) and vascular invasion (P = 0.0017) and a poor prognosis (P = 0.0000) in gastric cancer patients. NOX4 depletion could significantly inhibit the invasion, proliferation, EMT and MMP7 expression of gastric cancer cells and suppress the progression of gastric cancer in vivo. In conclusion, NOX4 is related to gastric cancer development and predicts a poor prognosis. NOX4 may play an essential role in the progression of gastric cancer, and is a promising target for the prevention and treatment of gastric cancer.

Clinical Stratification of High-Grade Ovarian Serous Carcinoma Using a Panel of Six Biomarkers

Molecular stratification of high-grade serous ovarian carcinoma (HGSC) for targeted therapy is a pertinent approach in improving prognosis of this highly heterogeneous disease. Enabling the same necessitates identification of class-specific biomarkers and their robust detection in the clinic. We have earlier resolved three discrete molecular HGSC classes associated with distinct functional behavior based on their gene expression patterns, biological networks, and pathways. An important difference revealed was that Class 1 is likely to exhibit cooperative cell migration (CCM), Class 2 undergoes epithelial to mesenchymal transition (EMT), while Class 3 is possibly capable of both modes of migration. In the present study, we define clinical stratification of HGSC tumors through the establishment of standard operating procedures for immunohistochemistry and histochemistry based detection of a panel of biomarkers including TCF21, E-cadherin, PARP1, Slug, AnnexinA2, and hyaluronan. Further development and application of scoring guidelines based on expression of this panel in cell line-derived xenografts, commercial tissue microarrays, and patient tumors led to definitive stratification of samples. Biomarker expression was observed to vary significantly between primary and metastatic tumors suggesting class switching during disease progression. Another interesting feature in the study was of enhanced CCM-marker expression in tumors following disease progression and chemotherapy. These stratification principles and the new information thus generated is the first step towards class-specific personalized therapies in the disease.

miR-384 targets metadherin gene to suppress growth, migration, and invasion of gastric cancer cells

Objective

MicroRNA-384 (miR-384) has been reported to function as a tumor suppressor in multiple cancers; however, its role in gastric cancer (GC) remains unclear.

Methods

We measured expression levels of miR-384 in GC cell lines and in a normal gastric cell line (GES-1). The association between miR-384 and the metadherin gene (MTDH) was assessed by luciferase reporter assay and western blot. The effects of the miR-384/MTDH axis on GC cell behaviors were measured by CCK-8, wound-healing, and transwell invasion assays.

Results

miR-384 was significantly downregulated in GC cell lines compared with normal gastric cells. MTDH was identified as a direct target of miR-384 by bioinformatics analysis, luciferase assay, and western blot. Functional assays demonstrated that miR-384 inhibited GC cell proliferation, migration, and invasion through targeting MTDH.

Conclusion

These results reveal that miR-384 acts as a tumor suppressor in GC and suggest that the miR-384/MTDH axis may be a potential therapeutic target for GC.

An anti-ASCT2 monoclonal antibody suppresses gastric cancer growth by inducing oxidative stress and antibody dependent cellular toxicity in preclinical models

Glutamine is a major nutrient for cancer cells during rapid proliferation. Alanine-serine-cysteine (ASC) transporter 2 (ASCT2; SLC1A5) mediates glutamine uptake in a variety of cancer cells. We previously reported that KM8094, a novel anti-ASCT2 humanized monoclonal antibody, possesses anti-tumor efficacy in gastric cancer patient-derived xenografts. The aim of this study was to investigate the molecular mechanism underlying the effect of KM8094 and to further substantiate the preclinical feasibility of using KM8094 as a potential therapeutic agent against gastric cancer. First, ASCT2 was found to be highly expressed in cancer tissues derived from gastric cancer patients by an immunohistochemical analysis. Next, we performed in vitro studies using multiple gastric cancer cell lines and observed that several gastric cancer cells expressing ASCT2 showed glutamine-dependent cell growth, which was repressed by KM8094. We found that KM8094 inhibited the glutamine uptake, leading to the reduction of glutathione (GSH) level and the elevation of oxidative stress. KM8094 suppressed the cell cycle progression and increased the apoptosis. Furthermore, KM8094 exerted antibody dependent cellular cytotoxicity (ADCC) against human gastric cancer cells in vitro. Finally, in vivo studies revealed that KM8094 suppressed tumor growth in several gastric cancer xenografts. This effect was enhanced by docetaxel, one of the agents commonly used in gastric cancer therapy. Thus, our findings suggest that KM8094 is a potential new therapeutic agent for gastric cancer expressing ASCT2, which blocks the cellular glutamine metabolism and possesses ADCC activity.

Knockdown of long noncoding RNA GHET1 inhibits cell‑cycle progression and invasion of gastric cancer cells

GHET1 is an oncogenic long noncoding RNA (lncRNA) that promotes the proliferation and invasion of many malignant cell types. However, the function and underlying mechanisms of lncRNA GHET1 in gastric cancer are not fully understood. In this study, the expression of GHET1 was investigated in gastric cancer and it was determined whether GHET1 may potentially be used as a biomarker for the disease. The gastric cancer cell lines MGC‑803 and AGS were transfected with GHET1‑directed small interfering RNA (siRNA) and the changes in phenotype and cell‑cycle‑related molecules were assessed. The downregulation of GHET1 induced G0/G1‑phase arrest in gastric cancer cells and inhibited their proliferation, migration, and invasion. DNA synthesis and the expression of proliferating cell nuclear antigen (PCNA) decreased, which was consistent with the results of the CCK‑8 assay. The levels of specific cell‑cycle regulators were determined and the expression and activities of positive cell‑cycle regulators (cyclin D, CDK4, CDK6, cyclin E, CDK2) were reduced, whereas those of a negative regulator (P21) were increased in GHET1‑knockdown cells. Taken together, the present findings show that the downregulation of GHET1 not only inhibits the migration and invasion of gastric cancer cells, but also inhibits their proliferation, at least in part by upregulating P21 expression and downregulating cyclin and CDK expression to inhibit the G0/G1 to S phase transition. The present findings may provide a potential therapeutic target for gastric cancer.

MFAP2 promotes epithelial-mesenchymal transition in gastric cancer cells by activating TGF-β/SMAD2/3 signaling pathway

Introduction

Microfibril-associated protein 2 (MFAP2) is an extracellular matrix protein that interacts with fibrillin to modulate the function of microfibrils. MFAP2 has been reported to play a significant role in obesity, diabetes, and osteopenia, and has been shown to be upregulated in head and neck squamous cell carcinoma. However, the molecular function and prognostic value of MFAP2 have never been reported in gastric cancer (GC) or any other tumors.

Methods

The current study investigated the expression patterns, prognostic significance, functional role, and possible mechanisms of MFAP2 in GC.

Results

We demonstrated that MFAP2 was overexpressed in GC tissues, and its overexpression was significantly correlated with poor overall and disease-free survival in patients with GC. Moreover, we found that MFAP2 promoted the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) phenotype in GC cells. MFAP2 might modulate EMT of GC cells by activating the TGF-β/SMAD2/3 signaling pathway.

Conclusion

These findings provide novel evidence that MFAP2 plays a crucial role in the progression of GC. Therefore, MFAP2 may be a promising prognostic marker and a potent anticancer agent.

SSH1 expression is associated with gastric cancer progression and predicts a poor prognosis

Background

Slingshot homolog-1 (SSH1) plays an important role in pathological processes, including in the occurrence and development of tumours. The purpose of this study was to determine whether SSH1 is a key biomarker with prognostic value for survival in patients with gastric cancer.

Methods

We performed immunohistochemistry (IHC) on tissue microarrays containing 100 gastric cancer specimens to evaluate SSH1 protein expression. The association of pathological characteristics with cumulative survival was determined by Kaplan-Meier analysis. A Cox proportional hazards model was generated in the multi-factorial survival analysis to identify univariate prognostic factors of GC.

Results

SSH1 expression level in gastric cancer tissues was significantly associated with lymph node metastasis (P = 0.032). Additionally, multivariate regression analysis clearly indicated that SSH1 expression was significantly correlated with poor clinical outcomes of patients with gastric cancer (P = 0.016). Multivariate analyses showed that SSH1 was the best predictor of poor prognosis in patients with gastric cancer (P = 0.030).

Conclusions

SSH1 expression is associated with gastric cancer progression and predicts a poor prognosis. SSH1 may play an important role in the development of gastric cancer, and it is a promising target for prevention and/or treatment of gastric cancer.

High expression of nucleobindin 2 is associated with poor prognosis in gastric cancer

Nucleobindin 2 has been reported that its high expression is associated with poor outcome and promotes cell migration and lymph node metastasis in breast cancer, colon cancer, and prostate cancer. However, we aimed to investigate the nucleobindin 2 expression in gastric cancer tissues and adjacent non-tumor tissues and its potential relevance to clinicopathological factors and prognosis using immunohistochemical analysis. In our study, nucleobindin 2 level in gastric cancer tissues was higher than in non-tumor tissues. A high expression of nucleobindin 2 is significantly associated with tumor depth, lymph node metastasis, lymphatic invasion, venous invasion, and clinical stage. Furthermore, the expression level of nucleobindin 2 protein was independent predictor of progression-free survival. In summary, nucleobindin 2 might play a crucial role in gastric cancer development and could serve as an independent predictor of prognosis of gastric cancer patients.

Clinical significance of expression of proliferating cell nuclear antigen and E-cadherin in gastric carcinoma

AIM

to investigate the expression of proliferating cell nuclear antigen (PCNA) and E-cadherin in gastric carcinoma and to analyze their clinical significance.

METHODS

A total of 146 patients were selected for this study, including 38 patients with intestinal metaplasia, 42 with dysplasia, and 66 with primary gastric cancer. In addition, 40 patients with normal gastric tissues were selected as controls. The expression of PCNA and E-cadherin was detected by immunohistochemistry. Differences in PCNA and the E-cadherin labeling indexes among normal gastric mucosa, intestinal metaplasia, dysplasia, and gastric carcinoma were compared. Subjects with normal gastric tissues were assigned to a normal group, while gastric cancer patients were assigned to a gastric cancer group. The difference in PCNA and E-cadherin expression between these two groups was compared. The relationship between expression of PCNA and E-cadherin and clinicopathological features was also explored in gastric cancer patients. Furthermore, prognosis-related factors, as well as the expression of PCNA and E-cadherin, were analyzed in patients with gastric cancer to determine the 3-year survival of these patients.

RESULTS

The difference in PCNA and the E-cadherin labeling indexes among normal gastric mucosa, intestinal metaplasia, dysplasia, and gastric carcinoma was statistically significant (P < 0.05). During the transition of normal gastric mucosa to gastric cancer, the PCNA labeling index gradually increased, while the E-cadherin labeling index gradually decreased (P < 0.05). The PCNA labeling index was significantly higher and the E-cadherin labeling index was significantly lower in gastric cancer than in dysplasia (P < 0.05). The expression of PCNA was significantly higher in the gastric cancer group than in the normal group, but E-cadherin was weaker (P < 0.05). There was a negative correlation between the expression of PCNA and E-cadherin in gastric carcinoma (r = -0.741, P = 0.000). PCNA expression differed significantly between gastric cancer patients with and without lymph node metastasis and between patients at different T stages. E-cadherin expression also differed significantly between gastric cancer patients with and without lymph node metastasis (P < 0.05). High T stage and positive PCNA expression were risk factors for the prognosis of patients with gastric cancer (RR > 1), while the positive expression of E-cadherin was a protective factor (RR < 1). The sensitivity, specificity, and accuracy of PCNA positivity in predicting the 3-year survival of patients with gastric cancer were 93.33%, 38.89%, and 0.64, respectively; while these values for E-cadherin negativity were 80.0%, 41.67%, and 0.59, respectively. When PCNA positivity and E-cadherin negativity were combined, the sensitivity, specificity, and accuracy were 66.67%, 66.67%, and 0.67, respectively.

CONCLUSION

Combined detection of PCNA and E-cadherin can improve the accuracy of assessing the prognosis of patients with gastric cancer.

Predictive biomarkers along gastric cancer pathogenetic pathways

INTRODUCTION

Gastric cancer is the second leading cause of cancer all over the world. Unfortunately, several gastric cancers are diagnosed in an advanced stage and chemotherapy and/or target therapies remain the only options to treat patients. Areas covered: Herein we evaluate the new molecular proposal of gastric cancer classification, offering the possibility to recognize different pathogenetic mechanisms and molecular biomarkers potentially useful for target therapies. Expert commentary: The possibility of introducing new specific tests for identification of molecular biomarkers critical for targeted therapies response represents the new frontier in the selection of gastric cancer patients to improve their survival. Besides HER2, already used in clinical settings as a target biomarker for biological therapy in gastric cancer patients with tissue cancer cells overexpressing HER2, other promising target biomarkers which are deregulated in gastric cancer, such as MET and FGFR, could be identified in tissue and then used for therapeutic purposes. In addition immunotherapy represents the most promising possibility of advanced gastric cancer treatment. In particular, as in other solid tumors, PD-1/PDL1 pathway has emerged in several clinical trials as an interesting therapeutic target.

Development of novel HER2 inhibitors against gastric cancer derived from flavonoid source of Syzygium alternifolium through molecular dynamics and pharmacophore-based screening

Continuous usage of synthetic chemotherapeutic drugs causes adverse effects, which prompted for the development of alternative therapeutics for gastric cancer from natural source. This study was carried out with a specific aim to screen gastroprotective compounds from the fruits of Syzygium alternifolium (Myrtaceae). Three flavonoids, namely, 1) 5-hydroxy-7,4′-dimethoxy-6,8-di-C-methylflavone, 2) kaempferol-3-O-β-d-glucopyranoside, and 3) kaempferol-3-O-α-l-rhamnopyranoside were isolated from the above medicinal plant by employing silica gel column chromatography and are characterized by NMR techniques. Antigastric cancer activity of these flavonoids was examined on AGS cell lines followed by cell cycle progression assay. In addition, pharmacophore-based screening and molecular dynamics of protein–ligand complex were carried out to identify potent scaffolds. The results showed that compounds 2 and 3 exhibited significant cytotoxic effect, whereas compound 1 showed moderate effect on AGS cells by inhibiting G2/M phase of cell cycle. Molecular docking analysis revealed that compound 2 has higher binding energies on human growth factor receptor-2 (HER2). The constructed pharmacophore models reveal that the compounds have more number of H-bond Acc/Don features which contribute to the inhibition of HER2 activity. By selecting these features, 34 hits were retrieved using the query compound 2. Molecular dynamic simulations (MDS) of protein–ligand complexes demonstrated conspicuous inhibition of HER2 as evidenced by dynamic trajectory analysis. Based on these results, the compound ZINC67903192 was identified as promising HER2 inhibitor against gastric cancer. The present work provides a basis for the discovery a new class of scaffolds from natural products for gastric carcinoma.

Sunitinib added to FOLFIRI versus FOLFIRI in patients with chemorefractory advanced adenocarcinoma of the stomach or lower esophagus: a randomized, placebo-controlled phase II AIO trial with serum biomarker program

BACKGROUND

As a multi-targeted anti-angiogenic receptor tyrosine kinase (RTK) inhibitor sunitinib (SUN) has been established for renal cancer and gastrointestinal stromal tumors. In advanced refractory esophagogastric cancer patients, monotherapy with SUN was associated with good tolerability but limited tumor response.

METHODS

This double-blind, placebo-controlled, multicenter, phase II clinical trial was conducted to evaluate the efficacy, safety and tolerability of SUN as an adjunct to second and third-line FOLFIRI (NCT01020630). Patients were randomized to receive 6-week cycles including FOLFIRI plus sodium folinate (Na-FOLFIRI) once every two weeks and SUN or placebo (PL) continuously for four weeks followed by a 2-week rest period. The primary study endpoint was progression-free survival (PFS). Preplanned serum analyses of VEGF-A, VEGF-D, VEGFR2 and SDF-1α were performed retrospectively.

RESULTS

Overall, 91 patients were randomized, 45 in each group (one patient withdrew). The main grade ≥3 AEs were neutropenia and leucopenia, observed in 56 %/20 % and 27 %/16 % for FOLFIRI + SUN/FOLFIRI + PL, respectively. Median PFS was similar, 3.5 vs. 3.3 months (hazard ratio (HR) 1.11, 95 % CI 0.70-1.74, P = 0.66) for FOLFIRI + SUN vs. FOLFIRI + PL, respectively. For FOLFIRI + SUN, a trend towards longer median overall survival (OS) compared with placebo was observed (10.4 vs. 8.9 months, HR 0.82, 95 % CI 0.50-1.34, one-sided P = 0.21). In subgroup serum analyses, significant changes in VEGF-A (P = 0.017), VEGFR2 (P = 0.012) and VEGF-D (P < 0.001) serum levels were observed.

CONCLUSIONS

Although sunitinib combined with FOLFIRI did not improve PFS and response in chemotherapy-resistant gastric cancer, a trend towards better OS was observed. Further biomarker-driven studies with other anti-angiogenic RTK inhibitors are warranted.

TRIAL REGISTRATION

This study was registered prospectively in the NCT Clinical Trials Registry (ClinicalTrials.gov) under NCT01020630 on November 23, 2009 after approval by the leading ethics committee of the Medical Association of Rhineland-Palatinate, Mainz, in coordination with the participating ethics committees (see Additional file 2) on September 16, 2009.

MiR-455-5p acts as a novel tumor suppressor in gastric cancer by down-regulating RAB18

AIM

To detect the potential regulation pathway of microRNA-455-5p (miR-455-5p) and RAB18, member RAS oncogene family (RAB18) in gastric cancer (GC) cells and tissues and discuss the clinical significance of miR-455-5p in GC genesis and progression.

METHODS

Real-time PCR was used to measure mRNA level of miR-455-5p in GC, TargetScan and dual luciferase assay were used to predict and demonstrate the candidate target gene of miR-455-5p, Western blot were utilized to detect the protein level of RAB18. Cell function assays were also performed to determine the function of miR-455-5p in GC.

RESULTS

miR-455-5p was reduced significantly in gastric cancer cells and tissues compared with the corresponding normal control, the lower expression of miR-455-5p was related to advanced clinical stage in gastric cancer, re-expression of miR-455-5p could inhibit human GC cell proliferation and invasion, overexpression of miR-455-5p could also promote GC cell apoptosis. Furthermore, we found that RAB18 was a candidate target of miR-455-5p. Re-expression of miR-455-5p could inhibit the protein level of RAB18.

CONCLUSION

MiR-455-5p might serve as a novel biomarker in gastric cancer by targeting RAB18.

Emerging molecular classifications and therapeutic implications for gastric cancer

Gastric cancer (GC) is a highly aggressive and life-threatening malignancy. Even with radical surgical removal and front-line chemotherapy, more than half of GCs locally relapse and metastasize at a distant site. The dismal outcomes reflect the ineffectiveness of a one-size-fits-all approach for a highly heterogeneous disease with diverse etiological causes and complex molecular underpinnings. The recent comprehensive genomic and molecular profiling has led to our deepened understanding of GC. The emerging molecular classification schemes based on the genetic, epigenetic, and molecular signatures are providing great promise for the development of more effective therapeutic strategies in a more personalized and precise manner. To this end, the Cancer Genome Atlas (TCGA) research network conducted a comprehensive molecular evaluation of primary GCs and proposed a new molecular classification dividing GCs into four subtypes: Epstein-Barr virus-associated tumors, microsatellite unstable tumors, genomically stable tumors, and tumors with chromosomal instability. This review primarily focuses on the TCGA molecular classification of GCs and discusses the implications on novel targeted therapy strategies. We believe that these fundamental findings will support the future application of targeted therapies and will guide our efforts to develop more efficacious drugs to treat human GCs.

Tissue microRNAs as predictive markers for gastric cancer patients undergoing palliative chemotherapy

MicroRNAs have the potential to become valuable predictive markers for gastric cancer. Samples of biopsy tissue, routinely taken from gastric cancer patients undergoing palliative chemotherapy, constitute suitable material for microRNA profiling with the aim of predicting the effect of chemotherapy. Our study group consisted of 54 patients, all of whom underwent palliative chemotherapy based on 5-fluorouracil (5-FU) or 5-FU in combination with platinum derivatives between 2000 and 2013. The expression of 29 selected microRNAs and genes BRCA1, ERCC1, RRM1 and TS, in gastric cancer tissue macrodissected from FFPE tissue samples, was measured by quantitative RT-PCR. The relationship between gene expression levels and time to progression (TTP) and overall survival (OS) was analysed. From the set of the 29 microRNAs of interest, we found high expression of miR-150, miR-342-3p, miR-181b, miR-221, miR-224 and low levels of miR-520h relate to shorter TTP. High levels of miR-150, miR-192, miR-224, miR-375 and miR-342-3p related to shorter OS. In routinely available FFPE tissue samples, we found 6 miRNAs with a relation to TTP, which may serve as predictors of the effectiveness of palliative treatment in gastric cancer patients. These miRNAs could also help in deciding whether to indicate palliative chemotherapy.

Overexpression of fatty acid synthase predicts a poor prognosis for human gastric cancer

Fatty acid synthase (FASN), a lipogenic multi-enzyme complex, is reported to be overexpressed in various types of of tumor tissues and serves an important role in tumor development and progression. However, the expression of FASN and its possible role in gastric cancer (GC) remains to be defined. In the present study, FASN expression in a group sample of 167 GC tissues was detected by immunohistochemistry and its correlation with clinicopathological features was analyzed. By clinical analysis, it was identified that FASN overexpression was positively correlated with the overall survival [P=0.008; hazard ratio (HR), 4.412; 95% confidence interval (CI), 1.463‑13.305] and recurrence rate (P=0.014; HR, 1.705; 95% CI, 1.116‑2.606) in patients with GC. In addition, expression of the FASN protein in GC tissues was correlated with age (P=0.032), clinical stage (P<0.001), gastric wall invasion (P=0.014), lymph node metastasis (P<0.001) and distant metastasis (P<0.001), however not with gender (P>0.05). In addition, FASN was observed to be overexpressed in GC tissues at an mRNA and protein level, compared with the adjacent non-cancerous tissues (P<0.05). Taken together, it was suggested that FASN was closely associated with GC metastasis and survival, which further provided evidence that FASN may be a promising prognostic biomarker for patients with GC.

Targeted therapies in gastric cancer treatment: where we are and where we are going

Gastric cancer (GC) is one of the most common malignancies and a major cause of cancer-related deaths worldwide. Its incidence has significantly declined over the last few decades, probably due to the identification of specific etiologic agents such as Helicobacter pylori and other dietary and environmental risk factors. Nevertheless, most of the cases are unfortunately diagnosed at an advanced stage justifying median overall survival rates frequently not exceeding one year. Palliative combination chemotherapy usually represented by a platinum-based doublet is the mainstay of treatment in the metastatic setting. Adding a third drug such as an anthracycline or a taxane has been shown to improve response rate and provide limited survival benefits in fit selected patients. Unlike other tumors, the introduction of molecularly targeted drugs in the medical armamentarium for GC is relatively recent with trastuzumab and ultimately ramucirumab constituting the only agents approved to date. Recent advances in the understanding of GC biology have led to the development of novel targeted therapies holding the promise to further improve treatment outcomes. The aim of this paper is to review the main available data coming from clinical trials of targeted drugs and to describe some of the most interesting molecules in clinical development in GC. These include drugs targeting EGFR, angiogenesis, c-MET, FGFR2, mTOR and immune checkpoints.

Co-infection of Epstein-Barr virus and human papillomavirus in human tumorigenesis

Viral infections contribute to approximately 12% of cancers worldwide, with the vast majority occurring in developing countries and areas. Two DNA viruses, Epstein-Barr virus (EBV) and human papillomavirus (HPV), are associated with 38% of all virus-associated cancers. The probability of one patient infected with these two distinct types of viruses is increasing. Here, we summarize the co-infection of EBV and HPV in human malignancies and address the possible mechanisms for the co-infection of EBV and HPV during tumorigenesis.

DCT015, a new sorafenib derivate, inhibits tumor growth and angiogenesis in gastric cancer models

The objective of this study is to investigate antiproliferative activities against gastric cancer and anti-angiogenesis of DCT015, a novel sorafenib derivate, and potential mechanisms. The effects of DCT015 on proliferation and apoptosis in gastric cancer cells were evaluated by cytotoxicity assays, apoptosis analysis, flow cytometry analysis, and Western blotting assays. The in vivo antitumor effects were carried out in nude mice bearing gastric cancer. On the other hand, the anti-angiogenesis effects of DCT015 were measured by human umbilical vein endothelial cell (HUVEC) proliferation, migration, tube formation, and Western blotting analysis. The results showed that DCT015 inhibited the proliferation, induced the morphological changes of apoptosis, and increased the apoptosis percentage, as well as increased the "sub-G1" population in gastric cancer cells. DCT015 also significantly decreased the tumor volumes and tumor weights in vivo by oral administration. Immunohistochemistry assay demonstrated that DCT015 inhibited tumor growth and neovascularization. In vitro studies found that DCT015 inhibited both MEK/ERK and PI3K/Akt signaling pathways by Western blotting assays. Moreover, DCT015 significantly inhibited VEGF-induced migration and tube formation in HUVECs. Western blotting analysis showed that DCT015 downregulated VEGF-induced VEGFR2 phosphorylation with the decreased phosphorylation of the downstream key proteins. Taken together, our findings highlight that DCT015 is a promising orally anticancer drug for treating gastric cancer.

Gene copy number gain of EGFR is a poor prognostic biomarker in gastric cancer: evaluation of 855 patients with bright-field dual in situ hybridization (DISH) method

BACKGROUND

EGFR overexpression is a prognostic biomarker and is expected to be a predictive biomarker for anti-EGFR therapies in gastric cancer. However, few studies have reported the clinical impact of EGFR gene copy number (GCN) and its correlation with EGFR overexpression.

METHODS

We used dual in situ hybridization (DISH) to detect EGFR GCN and chromosome 7 centromere (CEN7) in a set of tissue microarrays representing 855 patients with gastric cancer. These data were compared with those of immunohistochemical (IHC) analysis of EGFR expression to evaluate prognostic value.

RESULTS

EGFR GCN gain (≥ 2.5 EGFR signals per cell) was detected in 194 patients (22.7%) and indicated poor prognosis. Among 194 patients, EGFR amplification (EGFR/CEN7 ≥ 2.0) was observed in 29 patients (14.9%), which was almost identical to the IHC 3+ subgroup and worst prognostic subgroup. Patients with EGFR GCN gain but not amplification, including those exhibiting polysomy, also exhibited poorer prognosis than GCN non-gain patients and were distributed between IHC 0/1+ and 2+ subgroups. GCN gain was frequently observed in patients with more advanced disease, but served as an independent prognostic factor regardless of the pathological stage.

CONCLUSIONS

EGFR GCN gain is a more accurate prognostic biomarker than EGFR overexpression in patients with gastric cancer.

Targeted therapy for advanced gastric cancer: A review of current status and future prospects

In the West in particular, the vast majority of gastric cancer (GC) patients present with advanced-stage disease. Although combination chemotherapy is still the most important component of treatment for these patients, it confers a modest survival advantage. Recently, increased knowledge of the key molecular signaling pathways involved in gastric carcinogenesis has led to the discovery of specific molecular-targeted therapeutic agents. Some of these agents such as trastuzumab and ramucirumab have changed the treatment paradigm for this disease. In this paper, we will summarize the current clinical status of targeted drug therapy in the management of GC.

Nanobodies for targeted treatment of gastric cancer

With the development and application of monoclonal antibody-based targeted therapy drugs in recent years, some achievements have been made in the treatment of gastric cancer; however, because their preparation is relatively complex and expensive, their application is limited. Nanobodies have some advantages over conventional molecular targeted drugs, such as small molecular weight and unique structural features, and provide a new treatment strategy for targeted therapy of gastric cancer. In this paper, we review the nanobodies that have the potential for targeted treatment of gastric cancer.

MicroRNA-638 inhibits cell proliferation by targeting phospholipase D1 in human gastric carcinoma

MicroRNAs (miRNAs) are a type of small non-coding RNAs that are often play important roles in carcinogenesis, but the carcinogenic mechanism of miRNAs is still unclear. This study will investigate the function and the mechanism of miR-638 in carcinoma (GC). The expression of miR-638 in GC and the DNA copy number of miR-638 were detected by real-time PCR. The effect of miR-638 on cell proliferation was measured by counting kit-8 assay. Different assays, including bioinformatics algorithms (TargetScan and miRanda), luciferase report assay and Western blotting, were used to identify the target gene of miR-638 in GC. The expression of miR-638 target gene in clinical CRC tissues was also validated by immunohistochemical assay. From this research, we found that miR-638 was downregulated in GC tissues compared with corresponding noncancerous tissues (NCTs), and the DNA copy number of miR-638 was lower in GC than NCTs, which may induce the corresponding downregulation of miR-638 in GC. Ectopic expression of miR-638 inhibited GC cell growth in vitro. Subsequently, we identified that PLD1 is the target gene of miR-638 in GC, and silencing PLD1 expression phenocopied the inhibitory effect of miR-638 on GC cell proliferation. Furthermore, we observed that PLD1 was overexpressed in GC tissues, and high expression of PLD1 in GC predicted poor overall survival. In summary, we revealed that miR-638 functions as a tumor suppressor in GC through inhibiting PLD1.

A systematic review and meta-analysis of randomized trials on the role of targeted therapy in the management of advanced gastric cancer: Evidence does not translate?

It is still uncertain if targeted therapy-based regimens in advanced gastric cancer actually produce survival benefit. To shed light on this important question, we performed a systematic review and meta-analyses on each relevant targeted-pathway. By searching literature databases and proceedings of major cancer meetings in the time-frame 2005-2014, 22 randomized clinical trials exploring targeted therapy for a total of 7022 advanced gastric cancer patients were selected and included in the final analysis. Benefit was demonstrated for antiangiogenic agents in terms of overall survival (HR 0.759; 95%CI 0.655-0.880; p < 0.001). Conversely no benefit was found for EGFR pathway (HR 1.077; 95%CI 0.847-1.370; p = 0.543). Meta-analysis of HER-2 pathway confirmed improvement in terms of survival outcome, already known for this class of drugs (HR 0.823; 95%CI 0.722-0.939; p = 0.004). Pooled analysis demonstrated a significant survival benefit (OS: HR 0.823; PFS: HR 0.762) with acceptable tolerability profile for targeted-based therapies as compared to conventional treatments. This finding conflicts with the outcome of most individual studies, probably due to poor trial design or patients selection. In conclusion, our findings demonstrate a significant survival benefit for targeted therapy in its whole, which can be ascribed to anti-angiogenic and anti-HER2 agents.

Emerging kinase inhibitors of the treatment of gastric cancer

INTRODUCTION

Gastric cancer (GC) is the fifth most common malignancy in the world. In the last years, for the first time in literature, the addition of a targeted therapy to standard chemotherapy has proved to prolong median overall survival. In this scenario, kinase inhibitors (KIs), smaller intracellular agents, could be an interesting and novel type of targeted treatment of metastatic GC both in first and further lines of therapy.

AREAS COVERED

Several KI have been evaluated in the preclinical setting. This review will underline the most relevant targeted pathways involved in GC tumorigenesis and disease progression including EGFR, VEGFR, c-MET, mTOR, fibroblast growth factor receptor, Src and Aurora kinases.

EXPERT OPINION

Despite the good results of TOGA, RAINBOW and REGARD trials about the addition of monoclonal antibodies to standard of care in GC, the addition of KI seems not to achieve comparable interesting results in management of GC. However, an improved patient selection before and during treatment according to molecular characteristics, as well as combination studies evaluating the synergistic effect of combination schedules of different KIs and standard chemotherapy, or KI plus KI or KI plus antibodies-based therapy may reveal interesting results and lead to understand mechanisms of multi-drug resistance.

Clinical management of advanced gastric cancer: the role of new molecular drugs

Gastric cancer is the fourth most common malignant neoplasm and the second leading cause of death for cancer in Western countries with more than 20000 new cases yearly diagnosed in the United States. Surgery represents the main approach for this disease but, notwithstanding the advances in surgical techniques, we observed a minimal improvement in terms of overall survival with a significant increasing of relapsing disease rates. Despite the development of new drugs has significantly improved the effectiveness of chemotherapy, the prognosis of patients with unresectable or metastatic gastric adenocarcinoma remains poor. Recently, several molecular target agents have been investigated; in particular, trastuzumab represents the first target molecule showing improvements in overall survival in human epithelial growth factor 2-positive gastric cancer patients. New molecules targeting vascular epithelial growth factor, mammalian target of rapamycin, and anti hepatocyte growth factor-c-Met pathway are also under investigation, with interesting results. Anyway, it seems necessary to select more accurately the population to treat with new agents by the identification of new biomarkers in order to optimize the results. In this paper we review the actual "scenario" of targeted treatments, also focusing on the new agents in development for gastric cancer and gastro-esophageal carcinoma, discussing their efficacy and potential applications in clinical practice.

Molecular genetics of gastric adenocarcinoma in clinical practice

The molecular genetics of gastric carcinoma (GC) dictates their biology and clinical behavior. The two morphologically distinct types of gastric carcinoma by Lauren classification, i.e., intestinal and diffuse cell types, have a significant difference in clinical outcome. These two types of GC have different molecular pathogenetic pathways with unique genetic alterations. In addition to environmental and other etiologies, intestinal type GC is associated with Helicobacter pylori (H. pylori) infection and involves a multistep molecular pathway driving the normal epithelium to intestinal metaplasia, dysplasia, and malignant transformation by chromosomal and/or microsatellite instability (MSI), mutation of tumor suppressor genes, and loss of heterozygosity among others. Diffuse type shows no clear causal relationship with H. pylori infection, but is commonly associated with deficiency of cell-cell adhesion due to mutation of the E-cadherin gene (CDH1), and a manifestation of the hereditary gastric cancer syndrome. Thus, detection of CDH1 mutation or loss of expression of E-cadherin may aid in early diagnosis or screening of diffuse type GC. Detection of certain genetic markers, for example, MSI and matrix metalloproteinases, may provide prognostic information, particularly for intestinal type. The common genetic alterations may offer therapeutic targets for treatment of GC. Polymorphisms in Thymidylate synthase to metabolize 5-fluorouracil, glutathione S-transferase for degradation of Cisplatin, and amplification/overexpression of human epidermal growth factor receptor 2 targeted by monoclonal antibody Trastuzumab, are a few examples. P13K/Akt/mTOR pathway, c-Met pathways, epidermal growth factor receptor, insulin-like growth factor receptor, vascular endothelial growth factor receptor fibroblast growth factor receptor, and micro RNAs are several potential therapeutic biomarkers for GC under investigation.

Silencing of HIF-1α enhances the radiation sensitivity of human glioma growth in vitro and in vivo

Gliomas are the leading cause of cancer-related mortality worldwide, and the incidence is increasing. Because gliomas often become resistant to radiation treatment, it is urgent to develop novel therapeutic methods that are more effective and less toxic than current therapies so as to enhance patient survival and quality of life. Effective enhancement of radiation therapy for gliomas in vivo and in vitro was observed upon silencing of hypoxia-inducible factor 1α (HIF-1α) with RNA interference; this enhancement was related to changes in the cell cycle and apoptosis that were accompanied by modulation of Cdc2, cyclin B1, and Bcl-2 expression. Our data suggest that HIF-1α silencing combined with radiation therapy will increase the therapeutic efficacy of glioma treatment via regulation of cell cycle and apoptosis-related signaling pathways.

Gastric Cancer: New Drugs - New Strategies

BACKGROUND

Gastric cancer is the second most common cause of cancer-related deaths worldwide. There are large geographic variations in the incidence of these tumors, with 60% occurring in East Asia. For patients with resectable disease, surgery and perioperative treatment can be effective. For patients with advanced gastric cancer, chemotherapy regimens result in a median survival of 9-11 months. In general, the prognosis for advanced disease is poor and 5-year overall survival rates are around 15%. Combination therapies yield better survival rates, albeit with increased toxicity. Therefore, more effective and less toxic treatment regimens are needed.

SUMMARY

The molecular aberrations that characterize the different subgroups of gastric cancer have been used as therapeutic targets. However, the heterogeneity and complexity of gastric cancers is a major challenge for the development of effective targeted therapies. This review examines the main molecular targets in the treatment of gastric cancer, namely the vascular endothelial growth factor (VEGF), human epidermal growth factor receptor 2 (HER2), hepatocyte growth factor (HGF)/c-Met, epidermal growth factor receptor (EGFR) and phosphoinositide 3-kinase (PI3K)/Akt pathways.

KEY MESSAGE

The molecular aberrations characteristic of gastric cancer are being explored for the development of targeted therapies, including the VEGF, HER2, HGF/c-Met, EGFR and PI3K/Akt signaling pathways.

PRACTICAL IMPLICATIONS

Trastuzumab, an antibody which targets HER2, is the first approved targeted therapy for the treatment of gastric cancer. However, trastuzumab is only effective in HER2-positive tumors (about 10-20% of all gastric cancers). Ramucirumab, which targets the VEGF receptor 2, has yielded benefits with respect to overall survival in a phase III trial and is an effective treatment for advanced gastric cancer with approval in second-line treatment. Apatinib and rilotumumab are another two promising new agents currently under development.

Clinicopathologic significance of nuclear factor-κB and vascular endothelial growth factor expression in advanced gastric cancer patients

BACKGROUND

Nuclear factor-κB (NF-κB) and vascular endothelial growth factor (VEGF) are involved in cell proliferation, invasion, angiogenesis, and metastasis. The principal objective of this study was to assess the prognostic significance of NF-κB and VEGF expression in gastric cancer.

METHODS

Tumor tissues of 154 patients with gastric cancer, all of whom underwent potentially curative resection, were immunohistochemically evaluated using monoclonal antibodies against NF-κB and VEGF.

RESULTS

The positivity rates of NF-κB and VEGF staining were 44.2% and 39.6%, respectively. NF-κB expression in tumor tissues was significantly correlated with VEGF expression (p < 0.001). VEGF expression was related to Lauren's classification (p = 0.002), differentiation (p = 0.043), depth of invasion (p = 0.005), carcinoembryonic antigen expression (p = 0.032), and stage (p = 0.026). Univariate analysis demonstrated that NF-κB expression was significantly related to both the 5-year disease-free survival (65.2% vs. 46.4%, p = 0.007) and the 5-year overall survival (60.0% vs. 42.5%, p = 0.014). Multivariate analysis verified that NF-κB was independently associated with disease-free survival (hazard ratio: 2.082, p = 0.005) and overall survival (hazard ratio: 1.841, p = 0.008).

CONCLUSION

NF-κB expression in tumor tissue is associated with poor survival in gastric cancer patients.