The progress of targeted therapy in advanced gastric cancer

Comprehensive Insights into Biological Roles of Rosmarinic Acid: Implications in Diabetes, Cancer and Neurodegenerative Diseases

Phytochemicals are abundantly occurring natural compounds extracted from plant sources. Rosmarinic acid (RA) is an abundant phytochemical of Lamiaceae species with various therapeutic implications for human health. In recent years, natural compounds have gained significant attention as adjuvant and complementary therapies to existing medications for various diseases. RA has gained popularity due to its anti-inflammatory and antioxidant properties and its roles in various life-threatening conditions, such as cancer, neurodegeneration, diabetes, etc. The present review aims to offer a comprehensive insight into the multifaceted therapeutic properties of RA, including its potential as an anticancer agent, neuroprotective effects, and antidiabetic potential. Based on the available evidences, RA could be considered a potential dietary component for treating various diseases, including cancer, diabetes and neurodegenerative disorders.

Discovery of tertiary amide derivatives incorporating benzothiazole moiety as anti-gastric cancer agents in vitro via inhibiting tubulin polymerization and activating the Hippo signaling pathway

On the basis and continuation of our previous studies on anti-tubulin and anti-gastric cancer agents, novel tertiary amide derivatives incorporating benzothiazole moiety were synthesized and the antiproliferative activity was studied in vitro. Preliminary structure activity relationships (SARs) were explored according to the in vitro antiproliferative activity results. Some of compounds could significantly inhibit the proliferation of three cancer cells (HCT-116, MGC-803 and PC-3 cells) and compound F10 exhibited excellent antiproliferative activity against HCT-116 cells (IC₅₀ = 0.182 μM), MGC-803 cells (IC₅₀ = 0.035 μM), PC-3 cells(IC₅₀ = 2.11 μM) and SGC-7901 cells (IC₅₀ = 0.049 μM). Compound F10 effectively inhibited tubulin polymerization (IC₅₀ = 1.9 μM) and bound to colchicine binding site of tubulin. Molecular docking results suggested compound F10 could bind tightly into the colchicine binding site of β-tubulin. Moreover, compound F10 could regulate the Hippo/YAP signaling pathway. Compound F10 activated Hippo signaling pathway from its very beginning MST1/2, as the result of Hippo cascade activation YAP were inhibited. And then it led to a decrease of c-Myc and Bcl-2 expression. Further molecular experiments showed that compound F10 arrested at G2/M phase, inhibited cell colony formatting and induced extrinsic and intrinsic apoptosis in MGC-803 and SGC-7901 cells. Collectively, compound F10 was the first to be reported as a new anticancer agent in vitro via inhibiting tubulin polymerization and activating the Hippo signaling pathway.

2-Pyrazine-PPD, a novel dammarane derivative, showed anticancer activity by reactive oxygen species-mediate apoptosis and endoplasmic reticulum stress in gastric cancer cells

20 (R)-Dammarane-3β, 12β, 20, 25-tetrol (25-OH-PPD), a ginsenoside, was derived from Panax ginseng (C. A. Meyer) and inhibited growth of several cancer cell lines. To improve the anti-cancer activity, we introduced the pyrazine ring to 25-OH-PPD and obtained the compound 20(R)-[2,3-β]-Pyrazine-dammarane-12β,20,25-triol (2-Pyrazine-PPD). we evaluated the anti-cancer activity of 2-Pyrazine-PPD and investigated the main anti-cancer mechanisms of 2-Pyrazine-PPD in gastric cancer cells. We found that 2-Pyrazine-PPD remarkably suppressed the proliferation of gastric cancer cells in a concentration-dependent, and showed little toxicity to the normal cell (human gastric epithelial cell line-GES-1). Further study indicated that 2-Pyrazine-PPD induced apoptosis by mitochondria pathway in BGC-803 cancer cells, and activated unfolded protein response and the protein kinase RNA-activated (PKR)-like ER kinase (PERK)/Eukaryotic translation initiation factor-2α (eIF-2α)/Activating transcription factor 4 (ATF4) axis, the expression level of the protein C/EBP homologous protein (CHOP), the marker of endoplasmic reticulum stress, and the apoptosis inducing by 2-Pyrazine-PPD can partly be inhibited by siRNA-mediated knockdown of CHOP. Moreover, the production of reactive oxygen species was remarkably up-regulated in BGC-803 cancer cells treated with 2-Pyrazine-PPD. N-acetylcysteine (NAC, a reactive oxygen species scavenger) can attenuate 2-Pyrazine-PPD-induced apoptosis and endoplasmic reticulum stress. Taken together, we suggested that 2-Pyrazine-PPD exhibited remarkable anti-cancer activity by reactive oxygen species-mediate cell apoptosis and endoplasmic reticulum stress in gastric cancer cells. Our results uncovered the mechanism of 2-Pyrazine-PPD as a promising anti-tumor candidate for gastric cancer therapy.

Novel tertiary sulfonamide derivatives containing benzimidazole moiety as potent anti-gastric cancer agents: Design, synthesis and SAR studies

With the expectation to find out new anti-gastric cancer agents with high efficacy and selectivity, a series of novel tertiary sulfonamide derivatives were synthesized and the anti-cancer activity was studied in three selected cancer cell lines (MGC-803, PC-3, MCF-7) in vitro. Some of the synthesized compounds could significantly inhibit the proliferation of these tested cancer cells and were more potent than the positive control (5-Fu). The structure-activity relationship of tertiary sulfonamide derivatives was explored in this report. Among the tested compounds, compound 13g containing benzimidazole moiety showed the best anti-proliferation activities against MGC-803 cells (IC₅₀ = 1.02 μM), HGC-27 cells (IC₅₀ = 1.61 μM), SGC-7901 (IC₅₀ = 2.30 μM) cells as well as the good selectivity between the cancer and normal cells. Cellular mechanism studies elucidated compound 13g inhibited the colony formation of gastric cancer cell lines. Meanwhile, compound 13g arrested cell cycle at G2/M phase and induced cell apoptosis. Mechanistically, compound 13g markedly decreased p-Akt and p-c-Raf expression, which revealed that compound 13g targeted gastric cancer cell lines via interfering with AKT/mTOR and RAS/Raf/MEK/ERK pathways. All the findings suggest that compound 13g might be a valuable lead compound for the anti-gastric cancer agents.

4-XL-PPD, a novel ginsenoside derivative, as potential therapeutic agents for gastric cancer shows anti-cancer activity via inducing cell apoptosis medicated generation of reactive oxygen species and inhibiting migratory and invasive

(20R)-Dammarane-3β, 12β, 20, 25-tetrol (25-OH-PPD) is a ginsenoside isolated from Panax ginseng (C. A. Meyer). Previous research shows that the compound exhibits anti-cancer activities on many human cancer cell lines. In an attempt to enhance 25-OH-PPD activity, some derivatives were synthesized. Through screening of the derivative compounds for anti-cancer activity against gastric carcinoma cells, 12β-O-(L-Chloracetyl)-dammar-20(22)-ene-3β, 25-diol (4-XL-PPD) was selected as a strong anti-cancer agent. In this study, the anti-cancer mechanisms of 4-XL-PPD were investigated. The results showed that compound 4-XL-PPD resulted in a concentration-dependent inhibition of cells viability in gastric cancer cells, without affecting the viability of normal cell (human gastric epithelial cell line-GES-1). In BGC-803 cancer cells, 4-XL-PPD triggered apoptosis, and stimulated reactive oxygen species production. Apoptosis can be attenuated by the reactive oxygen species scavenger N-acetylcysteine. Meantime, 4-XL-PPD effectively suppressed the migratory and invasive capabilities of BGC-803 cancer cell and inhibited the expression levels of proteins associated with migratory and invasive capabilities (MMP-2, MMP-9, E-cadherin and CD34). All the results suggest that 4-XL-PPD exhibited remarkable anticancer activity base on inducing apoptosis via generating reactive oxygen species and inhibiting migratory and invasive, which support development of 4-XL-PPD as a potential agent for cancer therapy.

Elevated HOXA13 expression promotes the proliferation and metastasis of gastric cancer partly via activating Erk1/2

Purpose

HOXA13 is a transcription factor of the Homeobox (HOX) gene family, which is highly evolutionarily conserved. HOXA13 is upregulated and associated with oncogenic properties in some cancers. Here, we studied the potential mechanism of HOXA13-mediated proliferation and metastasis in gastric cancer (GC).

Methods

Quantitative real-time PCR, Western blot, and immunohistochemistry were used to detect HOXA13 expression levels in GC. In vitro and in vivo assays were performed to investigate the function of HOXA13 in GC cell proliferation, migration, and invasion. RNA-Seq transcriptome analysis was performed to study the underlying mechanism of HOXA13-mediated aggressiveness in GC.

Results

HOXA13 mRNA and protein expression levels were upregulated in GC tissues. According to Cell Counting Kit-8 and colony formation assays, we found that HOXA13 over-expression promoted proliferation. Flow cytometry analysis showed that HOXA13 overexpression or knockdown led to G1-S phase transition or G1 phase arrest, respectively. Western blot analysis results showed that HOXA13 overexpression increased cyclin D1 expression, while knockdown decreased its expression. Wound healing and transwell assay results demonstrated that HOXA13 overexpression promoted the migration and invasion of GC cells. Western blot analysis results also showed that HOXA13 overexpression upregulated N-cadherin and vimentin and downregulated E-cadherin, while HOXA13 knockdown led to the opposite results, indicating that HOXA13 might participate in epithelial to mesenchymal transition. These results were verified in vivo by tumor xenograft and metastasis assays. Mechanistically, using RNA-Seq transcriptome analysis, we found that Erk1/2 activation played an important role in HOXA13-induced GC progression.

Conclusion

Our results show that HOXA13 plays an important role in GC development. HOXA13 overexpression promotes proliferation and metastasis partly via activation of Erk1/2 in GC. Thus, HOXA13, together with Erk1/2, may be promising targets for novel anticancer strategies.

A novel tetravalent bispecific antibody targeting programmed death 1 and tyrosine-protein kinase Met for treatment of gastric cancer

Background Redirecting T cells to tumor cells using bispecific antibodies (BsAbs) is emerging as a potent cancer therapy. The main concept of this strategy is to cross-link tumor cells and T cells by simultaneously binding to cell surface tumor-associated antigen (TAA) and the CD3ƹ chain. However, immune checkpoint programmed cell death ligand-1 (PD-L1) on tumor cells or other myeloid cells upreglulated remarkablely after the treatment of CD3-binding BsAbs, leads to the generation of suppressed microenvironment for immune evasion and tumor progression. Although this resistance could be partially reversed by anti-PD-L1 treatment, targeting two pathways through one antibody-based molecule may provide a strategic advantage over the combination of BsAbs and immune checkpoint inhibitors. Methods We developed two novel BsAbs PD-1/c-Met DVD-Ig and IgG-scFv both targeting PD-1 to restore the immune effector function of T cells and engaging them to tumor cells via binding to cellular-mesenchymal to epithelial transition factor (c-Met). Binding activities, T cell activation and proliferation were analyzed by flow cytometry. Cell Cytotoxicity and cytokine release were measured using LDH release assay and ELISA, respectively. Anti-tumor response in vivo was evaluated by generate xenograft models in NOD-SCID mice. Results These bispecific antibodies exhibited effective antitumor activity against high- and low- c-Met-expressing gastric cancer cell lines in vitro and mediated strong tumor growth inhibition in human gastric cancer xenograft models. Conclusion The engagement of the PD-1/PD-L1 blockade to c-Met-overexpressing cancer cells is a promising strategy for the treatment of gastric cancer and potentially other malignancies.

C1QTNF6 is overexpressed in gastric carcinoma and contributes to the proliferation and migration of gastric carcinoma cells

In the present study, proteins differentially expressed between gastric cancer tissue and para‑tumoral normal gastric tissues were screened, and the function of the highly expressed protein C1QTNF6 in gastric carcinoma was investigated. The differential expression of mRNAs extracted from the tumor and adjacent tissues was analyzed using GeneChip assay. An AGS si‑C1QTNF6 cell line was constructed using shRNA‑C1QTNF6 lentivirus. The cell invasion and migration ability of C1QTNF6‑knockdown cells were determined by Transwell chamber migration and wound healing assays, respectively. The effects of C1QTNF6 on AGS cell cycle distribution and apoptosis were detected using a FACScan flow cytometer. The results demonstrated that the expression of 109 genes was increased and the expression of 129 was decreased in tumor tissues. Among these genes, the C1QTNF6 gene was highly expressed in tumor tissues and the AGS7901 cell line. C1QTNF6‑knockdown decreased the cell growth, and the proliferative and migration ability, as well as increasing the apoptosis of gastric carcinoma cells. In addition, the number of AGS cells in the G2/M phase was significantly increased after 5 days of C1QTNF6‑shRNA lentivirus infection. The results of the present study indicated that C1QTNF6 serves an important role in the development of gastric carcinoma. C1QTNF6 is involved in promoting the proliferation and migration, and in reducing the apoptosis of gastric carcinoma cells. These results provided a potential therapeutic target for the treatment of gastric carcinoma.

Rosmarinic acid influences collagen, MMPs, TIMPs, glycosylation and MUC1 in CRL-1739 gastric cancer cell line

Rosmarinic acid (RA) is a natural phenylpropanoid with numerous pharmacological activities. Because of limited studies of the effects of RA action in gastric cancer cells we examined how 100 and 200 μM acid influences MMPs, TIMPs, collagen, MUC1 and specific sugar antigens in gastric adenocarcinoma CRL-1739 cells. We revealed inhibitory effect of RA on MMP-9 activity what was correlated with increased collagen type I expression, main ECM substrate degraded by MMPs. Tissue inhibitor of MMPs, TIMP-1 but not TIMP-2 was significantly decreased on the protein level and increased on mRNA level by RA action what can suggest TIMP-1 independent inhibitory action of an acid on MMP-9 activity. Glycosylation of gastric cancer proteins was also effected by RA. ELISA tests revealed inhibitory effect of an acid on Tn antigen in cell lysates and culture supernatant and on T antigen in cell lysates. RA inhibited also sialylated Tn antigen in protein of culture supernatant and sialyl T in cell lysates. Extracellular domain of MUC1 mucin, main carrier of Tn and T antigens was significantly inhibited by higher dose of RA. The data suggest potential usefulness of RA as a complementary agent supporting chemotherapy in cancer treatment.

Is concomitant splenectomy necessary in radical gastric cancer surgery? A systematic review and meta-analysis

PURPOSE

This study is a systematic review and meta-analysis compare the short- and long-term outcomes of splenectomy (SP) versus splenic preservation (NSP) in radical gastric cancer surgery.

METHODS

A comprehensive search of PubMed, Embase, Cochrane Library and Web of Knowledge was performed. Evaluation of short- and long-term outcomes was collected and analyzed by a fixed or random effects model, according to the heterogeneity using RevMan 5.2 software.

RESULTS

A total of 5431 gastric cancer patients who underwent radical surgery (1706 with SP and 3725 with NSP) were reviewed in 11 studies included in this study. Compared with NSP, SP was significantly associated with higher rate of overall postoperative complication and increased incidence of pulmonary complications, abdominal abscess and pancreas complications. No statistical difference was observed regarding mortality, wound infection, anastomotic leakage and postoperative 5-year overall survival.

CONCLUSION

There was no difference in long-term oncological outcome but remarkably poorer short-term outcomes in SP group than NSP group. Therefore, SP seems unnecessary in radical gastric cancer surgery. However, well-designed, multicenter, prospective, randomized controlled trials are warranted for further validation.

Frequency and clinicopathological features of metastasis to liver, lung, bone, and brain from gastric cancer: A SEER-based study

The hematogenous metastatic pattern of gastric cancer (GC) was not fully explored. Here we analyzed the frequency and clinicopathological features of metastasis to liver, lung, bone, and brain from GC patients. Data queried for this analysis included GC patients from the Surveillance, Epidemiology, and End Results Program database from 2010 to 2014. All of statistical analyses were performed using the Intercooled Stata 13.0 (Stata Corporation, College Station, TX). All statistical tests were two‐sided. Totally, there were 19 022 eligible patients for analysis. At the time of diagnosis, there were 7792 patients at stage IV, including 3218 (41.30%) patients with liver metastasis, 1126 (14.45%) with lung metastasis, 966 (12.40%) with bone metastasis and 151 (1.94%) with brain metastasis. GC patients with lung or liver metastasis have a higher risk of bone and brain metastasis than those without lung nor liver metastasis. Intestinal subtype had significantly higher rate of liver and lung metastasis, while diffuse type was more likely to have bone metastasis. Proximal stomach had significantly higher risk to develop metastasis than distal stomach. African‐Americans had the highest risk of liver metastasis and Caucasian had the highest prone to develop lung and brain metastasis. The median survival for patients with liver, lung, bone, and brain metastasis was 4 months, 3 months, 4 months and 3 months, respectively. It is important to evaluate the status of bone and brain metastasis in GC patients with lung or liver metastasis. Knowledge of metastatic patterns is helpful for clinicians to design personalized pretreatment imaging evaluation for GC patients.

Hyperbaric oxygen treatment sensitizes gastric cancer cells to melatonin-induced apoptosis through multiple pathways

Although extensive efforts have been made in recent decades to treat advanced gastric cancer with comprehensive therapy based on chemotherapy, effective anti-gastric cancer therapeutics are still lacking in the clinics. Therefore, potent novel anti-gastric cancer ways are greatly needed. Here, we explored hyperbaric oxygen treatment as a novel and effective adjuvant treatment method which has anti-gastric cancer effects when used together with melatonin. When performed together with MLT, HBO effectively inhibited tumorigenicity of gastric cancer through selectively inducing a robust tumor suppressive apoptosis response. Mechanistic studies revealed that the sensitizing effect of hyperbaric oxygen is due to decreased ratio of Bcl-2/Bax, increased level of p53, cleaved Caspase3, GRP78, CHOP, and LC3. These results give a vivid picture that classic apoptosis pathways including mitochondrial pathway, tumor suppressive endoplasmic reticulum stress (ERS), and autophagy are all involved in the process. From the preliminary results got from the current study, we identified that HBO sensitizes human gastric cancer cells to MLT-induced apoptosis through a variety of complicated molecular mechanisms. HBO may provide a novel candidate supplemental treatment method for further development of potential anti-gastric cancer therapeutics. The combination of HBO and MLT could be a promising treatment for advanced gastric cancer.

The bile acid receptor GPBAR1 (TGR5) is expressed in human gastric cancers and promotes epithelial-mesenchymal transition in gastric cancer cell lines

GPBAR1 (also known as TGR5) is a bile acid activated receptor expressed in several adenocarcinomas and its activation by secondary bile acids increases intestinal cell proliferation. Here, we have examined the expression of GPBAR1 in human gastric adenocarcinomas and investigated whether its activation promotes the acquisition of a pro-metastatic phenotype. By immunohistochemistry and RT-PCR analysis we found that expression of GPBAR1 associates with advanced gastric cancers (Stage III-IV). GPBAR1 expression in tumors correlates with the expression of N-cadherin, a markers of epithelial-mesenchymal transition (EMT) (r=0.52; P<0.01). Expression of GPBAR1, mRNA and protein, was detected in cancer cell lines, with MKN 45 having the higher expression. Exposure of MKN45 cells to GPBAR1 ligands, TLCA, oleanolic acid or 6-ECDCA (a dual FXR and GPBAR1 ligand) increased the expression of genes associated with EMT including KDKN2A, HRAS, IGB3, MMP10 and MMP13 and downregulated the expression of CD44 and FAT1 (P<0.01 versus control cells). GPBAR1 activation in MKN45 cells associated with EGF-R and ERK1 phosphorylation. These effects were inhibited by DFN406, a GPBAR1 antagonist, and cetuximab. GPBAR1 ligands increase MKN45 migration, adhesion to peritoneum and wound healing. Pretreating MKN45 cells with TLCA increased propensity toward peritoneal dissemination in vivo. These effects were abrogated by cetuximab. In summary, we report that GPBAR1 is expressed in advanced gastric cancers and its expression correlates with markers of EMT. GPBAR1 activation in MKN45 cells promotes EMT. These data suggest that GPBAR1 antagonist might have utility in the treatment of gastric cancers.

PCDHGA9 acts as a tumor suppressor to induce tumor cell apoptosis and autophagy and inhibit the EMT process in human gastric cancer

The results of a cDNA  array revealed that protocadherin gamma subfamily A, 9 (PCDHGA9) was significantly decreased in SGC-7901 gastric cancer (GC) cells compared with GES-1 normal gastric cells and was strongly associated with the Wnt/β-catenin and transforming growth factor-β (TGF-β)/Smad2/3 signaling pathway. As a member of the cadherin family, PCDHGA9 functions in both cell-cell adhesion and nuclear signaling. However, its role in tumorigenicity or metastasis has not been reported. In the present study, we found that PCDHGA9 was decreased in GC tissues compared with corresponding normal mucosae and its expression was correlated with the GC TNM stage, the UICC stage, differentiation, relapse, and metastasis (p < 0.01). Multivariate Cox analysis revealed that PCDHGA9 was an independent prognostic indicator for overall survival (OS) and disease-free survival (DFS) (p < 0.01). The effects of PCDHGA9 on GC tumor growth and metastasis were examined both in vivo and in vitro. PCDHGA9 knockdown promoted GC cell proliferation, migration, and invasion, whereas PCDHGA9 overexpression inhibited GC tumor growth and metastasis but induced apoptosis, autophagy, and G1 cell cycle arrest. Furthermore, PCDHGA9 suppressed epithelial-mesenchymal transition (EMT) induced by TGF-β, decreased the phosphorylation of Smad2/3, and inhibited the nuclear translocation of pSmad2/3. Our results suggest that PCDHGA9 might interact with β-catenin to prevent β-catenin from dissociating in the cytoplasm and translocating to the nucleus. Moreover, PCDHGA9 overexpression restrained cell proliferation and reduced the nuclear β-catenin, an indicator of Wnt/β-catenin pathway activation, suggesting that PCDHGA9 negatively regulates Wnt signaling. Together, these data indicate that PCDHGA9 acts as a tumor suppressor with anti-proliferative activity and anti-invasive ability, and the reduction of PCDHGA9 could serve as an independent prognostic biomarker in GC.

FcγRIIA and IIIA polymorphisms predict clinical outcome of trastuzumab-treated metastatic gastric cancer

Trastuzumab has substantial antitumor activity in metastatic gastric cancer. One such mechanism by which it exerts its antitumor activity is antibody-dependent cell-mediated cytotoxicity, which has been reported to be influenced by FcγRIIA and IIIA polymorphisms. This study is the first to assess their impact on trastuzumab efficacy in patients with metastatic gastric cancer. We retrospectively examined 42 Her-2-positive patients receiving fluorouracil and platinum-based chemotherapy and trastuzumab, and 68 Her-2-negative patients receiving fluorouracil and platinum-based chemotherapy only as the first-line treatment. FcγRIIA and IIIA polymorphisms were assessed, and their associations with efficacy in both settings were analyzed. In patients treated with trastuzumab, the FcγRIIA H/H genotype was associated with significantly superior progression-free survival (PFS) (hazard ratio [HR] [95% CI]: 0.36 [0.16–0.82], adjusted HR [95% CI]: 0.18 [0.07–0.48], P=0.001). When combining FcγRIIA and IIIA polymorphisms, the FcγRIIA H/H or FcγRIIIA V/V genotype was associated with a significantly improved disease control rate (P=0.04) and PFS (HR [95% CI]: 0.29 [0.13–0.67], adjusted HR [95% CI]: 0.17 [0.07–0.45], P<0.001). As expected, no association of FcγRIIA and IIIA polymorphisms with efficacy was found in patients receiving chemotherapy only. We concluded that FcγRIIA and IIIA polymorphisms might predict disease control rate and PFS in metastatic gastric cancer patients receiving trastuzumab treatment.

GRIK3: A novel oncogenic protein related to tumor TNM stage, lymph node metastasis, and poor prognosis of GC

Glutamate receptor, ionotropic, kainate 3 (GRIK3), as a member of the glutamate kainate receptor family, mainly participated in neuroactive ligand receptor interaction pathway. Other members of GRIK family were previously reported to regulate cellular migration, transformation, and proliferation in tumor. However, the mechanism of GRIK3 in tumor is still unclear. Therefore, the purpose of our study was to reveal the expression and clinical significance of GRIK3 in gastric cancer (GC). First, we performed the expression analysis and survival analysis of GRIK3 using The Cancer Genome Atlas (TCGA) database, and the results showed that the GRIK3 expressed differentially between gastric cancer tissues and the adjacent normal tissues and that higher expression of GRIK3 was associated with poor survival outcomes. And the gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis suggested that GRIK3 mainly took part in cancer-related process. Subsequently, the validated immunohistochemistry showed that GRIK3 expressed higher in the GC tissues than in the matched normal tissues and the patients with overexpressed GRIK3 had worse survival outcomes. The univariate and multivariate analyses suggested that the expression of GRIK3 was an independent prognostic factor to predict GC prognosis. Furthermore, additional experiment showed that the lymph node metastasis tissues had higher GRIK3 expression than their matched primary GC tissues. These findings suggested that elevated GRIK3 expression could serve as an independent prognostic biomarker and a novel potential treatment target for patients with GC.

Anti-metastatic activity of fangchinoline in human gastric cancer AGS cells

Fangchinoline (FCL) is an active component isolated from the traditional medicinal plant Stephania tetrandra S. Moore, and has been reported to possess anti-cancer functions in several types of cancers; however, the effect of FCL on gastric cancer metastasis and its underlying molecular mechanisms remain unknown. The current study aimed to investigate the effect of FCL on the cell migration and invasion of human metastatic gastric cancer AGS cells and its mechanisms. Our study demonstrates that FCL dosage dependently suppressed the adhesion, migration and invasion capacities of human gastric cancer AGS cells without obvious cytotoxic effects. Reverse transcription-polymerase chain reaction and western blot assays demonstrated that FCL greatly inhibited the expression of matrix metalloproteinase (MMP)-2 and MMP-9 at both the mRNA and protein levels, while it significantly increased the expression of tissue inhibitor of metalloproteinase (TIMP) 1 and TIMP2 messenger RNAs. Our results also indicated that FCL repressed the phosphorylation of AKT in gastric cancer AGS cells. In summary, FCL may exert its anti-metastatic property in human gastric cancer cells in vitro by suppression of MMP-2 and MMP-9, increase of TIMP1 and TIMP2 genes, and inhibition of AKT phosphorylation. FCL may be a drug candidate for the treatment of gastric cancer metastasis.

The efficiency and safety of trastuzumab for advanced gastric and gastroesophageal cancer: a meta-analysis of five randomized controlled trials

A meta-analysis was performed to examine the efficiency and safety of trastuzumab in patients with advanced gastric and gastroesophageal cancer (AGC). By searching multiple databases from 1990 to March 2016, all randomized controlled trials (RCTs) which compared the effect of trastuzumab-combined chemotherapy (TC) versus chemotherapy alone (CT) in gastric cancer would be included. Five RCTs with a total of 875 patients were included. Trastuzumab can improve the overall survival (OS) rate, progression-free survival (PFS), one-year survival rate, two-year survival rate and overall response rate (ORR) of patients with AGC. There were no difference between the two arms in terms of grade 3/4 adverse effects, such as vomiting, nausea, neutropenia, thrombocytopaenia and anemia. Diarrhea increased in TC group. Trastuzumab can significantly improve the survival rate, PFS, ORR of patients with AGC. It is safe and feasible and can be tolerated. It needs further prospective multinational multicenter RCTs with large samples to define the clinical benefits of trastuzumab.

Short-term and long-term efficacy of 7 targeted therapies for the treatment of advanced hepatocellular carcinoma: a network meta-analysis: Efficacy of 7 targeted therapies for AHCC

BACKGROUND

A variety of targeted drug therapies in clinical trials have been proven to be effective for the treatment of hepatocellular carcinoma (HCC). Our study aims to compare the short-term and long-term efficacies of different targeted drugs in advanced hepatocellular carcinoma (AHCC) treatment using a network meta-analysis approach.

METHODS

PubMed, Embase, Ovid, EBSCO, and Cochrane central register of controlled trials were searched for randomized controlled trials (RCTs) of different targeted therapies implemented to patients with AHCC. And the retrieval resulted in 7 targeted drugs, namely, sorafenib, ramucirumab, everolimus, brivanib, tivantinib, sunitinib, and sorafenib+erlotinib. Direct and indirect evidence were combined to evaluate stable disease (SD), progressive disease (PD), complete response (CR), partial response (PR), disease control rate (DCR), overall response ratio (ORR), overall survival (OS), and surface under the cumulative ranking curve (SUCRA) of patients with AHCC.

RESULTS

A total of 11 RCTs were incorporated into our analysis, including 6594 patients with AHCC, among which 1619 patients received placebo treatment and 4975 cases had targeted therapies. The results revealed that in comparison with placebo, sorafenib, and ramucirumab displayed better short-term efficacy in terms of PR and ORR, and brivanib was better in ORR. Regarding long-term efficacy, sorafenib and sorafenib+erlotinib treatments exhibited longer OS. The data of cluster analysis showed that ramucirumab or sorafenib+erlotinib presented relatively better short-term efficacy for the treatment of AHCC.

CONCLUSION

This network meta-analysis shows that ramucirumab and sorafenib+erlotinib may be the better targeted drugs for AHCC patients, and sorafenib+erlotinib achieved a better long-term efficacy.

A new brominated chalcone derivative suppresses the growth of gastric cancer cells in vitro and in vivo involving ROS mediated up-regulation of DR5 and 4 expression and apoptosis

A new series of 20 brominated chalcone derivatives were designed, synthesized, and investigated for their effects against the growth of four cancer cell lines (EC109, SKNSH, HepG2, MGC803). Among them, compound 19 which given chemical name of H72, was the most potent one on gastric cancer cell lines (i.e. MGC803, HGC27, SGC7901) with IC50s ranged from 3.57 to 5.61μM. H72 exhibited less cytotoxicity to non-malignant gastric epithelial cells GES-1. H72 treatment of MGC803 and HGC27 induced generation of reactive oxygen species (ROS) leading to activation of caspase 9/3 cascade and mitochondria mediated apoptosis. H72 also up-regulated the expression of DR5, DR4 and BimEL, and down-regulated the expression of Bid, Bcl-xL, and XIAP. N-acetyl cysteine (NAC), a ROS scavenger completely blocked these effects of H72 in MGC803 cells. Intraperitoneal administration of H72 significantly inhibited the growth of MGC803 cells in vivo in a xenograft mouse model without observed toxicity. These results indicated that H72 is a lead brominated chalcone derivate and deserves further investigation for prevention and treatment of gastric cancer.

Importance of the type I insulin-like growth factor receptor in HER2, FGFR2 and MET-unamplified gastric cancer with and without Ras pathway activation

Amplification of seven oncogenes: HER2, EGFR, FGFR1, FGFR2, MET, KRAS and IGF1R has been identified in gastric cancer. The first five are targeted therapeutically in patients with HER2-positivity, FGFR2- or MET-amplification but the majority of patients are triple-negative and require alternative strategies. Our aim was to evaluate the importance of the IGF1R tyrosine kinase in triple-negative gastric cancer with and without oncogenic KRAS, BRAF or PI3K3CA mutations. Cell lines and metastatic tumor cells isolated from patients expressed IGF1R, and insulin-like growth factor-1 (IGF-1) activated the PI3-kinase/Akt and Ras/Raf/MAP-kinase pathways. IGF-1 protected triple-negative cells from caspase-dependent apoptosis and anoikis. Protection was mediated via the PI3-kinase/Akt pathway. Remarkably, IGF-1-dependent cell survival was greater in patient samples. IGF-1 stimulated triple-negative gastric cancer cell growth was prevented by IGF1R knockdown and Ras/Raf/MAP-kinase pathway inhibition. The importance of the receptor in cell line and metastatic tumor cell growth in serum-containing medium was demonstrated by knockdown and pharmacological inhibition with figitumumab. The proportions of cells in S-phase and mitotic-phase, and Ras/Raf/MAP-kinase pathway activity, were reduced concomitantly. KRAS-addicted and BRAF-impaired gastric cancer cells were particularly susceptible. In conclusion, IGF1R and the IGF signal transduction pathway merit consideration as potential therapeutic targets in patients with triple-negative gastric cancer.

Impact of marital status on survival of gastric adenocarcinoma patients: Results from the Surveillance Epidemiology and End Results (SEER) Database

Marital status was found to be an independent prognostic factor for survival in various cancer types. In this study, we used the Surveillance, Epidemiology and End Results database to analyze the survival difference among different marital status in the United States. Gastric adenocarcinoma patients from 2004-2012 were enrolled for study. The 5-year cause specific survival (CSS) was our primary endpoint. Totally 29,074 eligible patients were identified. We found that more male patients were married than female. Asian patients had the highest percentages of married than the other races. More married patients were covered by the insurance. Married patients had better 5-year CSS than unmarried, 30.6% vs 25.7%, P < 0.001. The median overall CSS was 17.87 and 13.61 months for the married and unmarried patients, hazard ratio: 1.09 (95% confidence interval: 1.01-1.17), P = 0.027. The survival difference was significant in the insured but not in the uninsured patients. Widowed patients had the worst prognosis compared with other groups even though they had more stage I disease and more well / moderate differentiated tumors. These results indicated that unmarried gastric adenocarcinoma patients were at greater risk of cancer specific mortality. We recommend every patient should have access to best available gastric cancer therapy.

Dehydroeffusol inhibits gastric cancer cell growth and tumorigenicity by selectively inducing tumor-suppressive endoplasmic reticulum stress and a moderate apoptosis

Gastric cancer is ranked as the third leading cause of cancer-related death in the world. Although extensive efforts have been made in recent decades to treat gastric cancer with various anticancer drugs, effective anti-gastric cancer therapeutics to cure the disease are still lacking in the clinics. Therefore, potent novel anti-gastric cancer drugs are greatly needed. In this study, we explored a novel anti-gastric cancer agent from a medicinal herb named Juncus effusus and found that the active component dehydroeffusol (DHE), a small molecular phenanthrene, effectively inhibited gastric cancer cell proliferation and tumorigenesis by inducing tumor suppressive endoplasmic reticulum (ER) stress and by triggering moderate apoptosis. Mechanistic studies revealed that DHE selectively activated the intracellular tumor suppressive stress response by promoting the overexpression of the key ER stress marker DNA damage-inducible transcript 3 (DDIT3), through upregulation of activating transcription factor 4 (ATF4). Concurrently, DHE suppressed the expression of the cell survival and ER stress marker glucose regulated protein of molecular mass 78 (GRP78) via downregulation of the transcription factor ATF6. In addition, DHE markedly activated the stress response signaling pathway MEKK4-MKK3/6-p38-DDIT3, but significantly inhibited ERK signaling. Our data suggest that DHE inhibits gastric cancer cell growth and tumorigenicity through selectively inducing a robust tumor suppressive ER stress response and a moderate apoptosis response. Therefore, DHE may provide a novel drug candidate for further development of potential anti-gastric cancer therapeutics.

Anti-epidermal growth factor receptor-targeted therapy in upper gastrointestinal tract cancers: a meta-analysis

This meta-analysis evaluated the efficacy and safety of anti-epidermal growth factor receptor (EGFR) treatment of patients with upper gastrointestinal (GI) tract cancers. A systematic search of multiple databases identified seven randomized controlled trials. Anti-EGFR combination therapy improved disease control rate (DCR) in all patients and progression-free survival (PFS) in patients receiving the same dose of standard therapy as patients receiving standard therapy alone. Combinations of anti-EGFR with non-capecitabine chemotherapy further improved DCR, whereas combinations with capecitabine masked the benefits of DCR and worsened PFS. Overall survival was apparently lower in patients without metastasis, and PFS was apparently improved in patients with squamous cell carcinoma of the esophagus and esophagogastric junction. Anti-EGFR treatment was associated with higher rates of cardiac events, hand-foot syndrome, rash, hypomagnesemia, diarrhea and mucositis and lower rates of neutropenia. Combinations of anti-EGFR agents with non-capecitabine chemotherapy or better supportive care may benefit patients with upper GI tract cancers.

Arsenic sulfide, the main component of realgar, a traditional Chinese medicine, induces apoptosis of gastric cancer cells in vitro and in vivo

Background

Arsenic sulfide (As₄S₄), the main component of realgar, a traditional Chinese medicine, has shown antitumor efficacy in several tumor types, especially for acute promyelocytic leukemia. In this study, we aimed to explore the efficacy and mechanism of As₄S₄ in gastric cancer.

Methods

The effect of As₄S₄ on cell proliferation and apoptosis of gastric cancer cells was investigated by MTT assay, 4′,6-diamidino-2-phenylindole (DAPI) staining, and annexin V–fluorescein isothiocyanate/propidium iodide staining using gastric cancer cell lines AGS (harboring wild-type p53) and MGC803 (harboring mutant p53) in vitro. The expression of apoptosis-related proteins was measured by Western blotting, real-time polymerase chain reaction, and immunohistochemistry analysis. Mouse xenograft models were established by inoculation with MGC803 cells, and the morphology and the proportion of apoptotic cells in tumor tissues were detected by hematoxylin and eosin staining and TdT-mediated dUTP nick end labeling (TUNEL) assay, respectively.

Results

As₄S₄ inhibited the proliferation and induced apoptosis of AGS and MGC803 cells in a time- and dose-dependent manner. As₄S₄ upregulated the expression of Bax and MDM2 while downregulated the expression of Bcl-2. The expression of p53 increased significantly in the AGS cells but did not readily increase in the MGC803 cells, which harbored mutant p53. Pifithrin-α, a p53 inhibitor, blocked the modulation of As₄S₄ on AGS cells, but not on MGC803 cells. Using xenograft as a model, we showed that As₄S₄ suppressed tumor growth and induced apoptosis in vivo and that the expression of p53 increased accordingly.

Conclusion

As₄S₄ is a potent cytotoxic agent for gastric cancer cells, as it induced apoptosis both in vitro and in vivo through a p53-dependent pathway. Our data indicate that As₄S₄ may have therapeutic potential in gastric cancer.

Ramucirumab: first global approval

Ramucirumab (Cyramza™ [US]), a fully human immunoglobulin G1 (IgG1) monoclonal antibody that inhibits vascular endothelial growth factor receptor-2 (VEGFR-2), has been developed by Eli Lilly (formerly ImClone Systems) for the treatment of cancer. Ramucirumab has received its first global approval in the US for use as monotherapy in the treatment of advanced or metastatic gastric cancer or gastro-oesophageal junction adenocarcinoma in patients who experience disease progression on or after fluoropyrimidine- or platinum-containing chemotherapy. Ramucirumab is the first treatment to be approved by the US FDA for this setting. This article summarizes the milestones in the development of ramucirumab leading to this first approval for the treatment of gastric cancer and gastro-oesophageal junction adenocarcinoma.

Gastric cancer stem cells in gastric carcinogenesis, progression, prevention and treatment

In recent decades, the study of the mechanism of tumorigenesis has brought much progress to cancer treatment. However, cancer stem cell (CSC) theory has changed previous views of tumors, and has provided a new method for treatment of cancer. The discovery of CSCs and their characteristics have contributed to understanding the molecular mechanism of tumor genesis and development, resulting in a new effective strategy for cancer treatment. Gastric CSCs (GCSCs) are the basis for the onset of gastric cancer. They may be derived from gastric stem cells in gastric tissues, or bone marrow mesenchymal stem cells. As with other stem cells, GCSCs highly express drug-resistance genes such as aldehyde dehydrogenase and multidrug resistance, which are resistant to chemotherapy and thus form the basis of drug resistance. Many specific molecular markers such as CD44 and CD133 have been used for identification and isolation of GCSCs, diagnosis and grading of gastric cancer, and research on GCSC-targeted therapy for gastric cancer. Therefore, discussion of the recent development and advancements in GCSCs will be helpful for providing novel insight into gastric cancer treatment.