Current and Future Therapies for Advanced Gastric Cancer

An Integrated Approach Using Network Pharmacology and Experimental Validation to Reveal the Therapeutic Mechanism of Weifuchun in Treating Gastric Cancer

Gastric cancer (GC) is a prevalent malignancy affecting the gastrointestinal tract. Weifuchun (WFC), a Chinese herbal prescription comprising red ginseng, Isodon amethystoides, and Fructus aurantii, is widely used in China for various chronic stomach disorders. However, its therapeutic role and mechanisms in treating GC remain unexplored. In a randomized, controlled, single-blind trial involving postoperative stages II and III GC patients, we compared adjuvant chemotherapy plus WFC (chemo plus WFC group) to adjuvant chemotherapy alone (chemo group) over 6 months. We assessed recurrence and metastasis rates and used systematic pharmacology to predict WFC's active components, screen target genes, and construct network interaction maps, were validated through in vitro experiments. The combined therapy significantly reduced 2-year recurrence and metastasis rates. We identified 67 active ingredients, 211 drug target proteins, 1539 disease targets, 105 shared targets, and 188 signaling pathways associated with WFC. WFC impacted cell apoptosis, proliferation, and the inflammatory response, with top tumor-related signaling pathways involving 5'-adenosine monophosphate-activated protein kinase (AMPK), mitogen-activated protein kinase, nuclear factor kappa-B (NFKB), and apoptosis. In vitro, WFC inhibited proliferation and migration while inducing apoptosis in GC cells, reduced VEGFA, TNFa, and IL6 expressions. Immunocytochemistry showed increased p-AMPK staining, and molecular analysis revealed decreased NFKB and phosphorylation of extracellular-regulated protein kinase 1/2 (ERK1/2) levels, increased p-AMPK and BAX protein levels in WFC-treated cells, effects reversed by Compound C. WFC's antitumor effects involve AMPK-dependent ERK1/2 and NFKB pathways, regulating proliferation, migration, and apoptosis in GC cells.

Advances in targeted therapy for human epidermal growth factor receptor 2 positive in advanced gastric cancer

Emerging therapeutic methods represented by targeted therapy are effective supplements to traditional first-line chemoradiotherapy resistance. Human epidermal growth factor receptor 2 (HER2) is one of the most important targets in targeted therapy for gastric cancer. Trastuzumab combined with chemotherapy has been used as the first-line treatment for advanced gastric cancer. The safety and efficacy of pertuzumab and margetuximab in the treatment of gastric cancer have been verified. However, monoclonal antibodies, due to their large molecular weight, inability to penetrate the blood-brain barrier, and drug resistance, lead to decreased therapeutic efficacy, so it is necessary to explore the efficacy of other HER2-targeting therapies in gastric cancer. Small-molecule tyrosine kinase inhibitors, such as lapatinib and pyrrotinib, have the advantages of small molecular weight, penetrating the blood-brain barrier and high oral bioavailability, and are expected to become the drugs of choice for perioperative treatment and neoadjuvant therapy of gastric cancer after validation by large-scale clinical trials in the future. Antibo-drug conjugate, such as T-DM1 and T-DXd, can overcome the resistance of monoclonal antibodies despite their different mechanisms of tumor killing, and are a supplement for the treatment of patients who have failed the treatment of monoclonal antibodies such as trastuzumab. Therefore, after more detailed stratification of gastric cancer patients, various gastric cancer drugs targeting HER2 are expected to play a more significant role.

Construction of an RNA modification-related gene predictive model associated with prognosis and immunity in gastric cancer

BACKGROUND

Gastric cancer (GC) is one of the most common causes of cancer-related fatalities worldwide, and its progression is associated with RNA modifications. Here, using RNA modification-related genes (RNAMRGs), we aimed to construct a prognostic model for patients with GC.

METHODS

Based on RNAMRGs, RNA modification scores (RNAMSs) were obtained for GC samples from The Cancer Genome Atlas and were divided into high- and low-RNAMS groups. Differential analysis and weighted correlation network analysis were performed for the differential expressed genes (DEGs) to obtain the key genes. Next, univariate Cox regression, least absolute shrinkage and selection operator, and multivariate Cox regression analyses were performed to obtain the model. According to the model risk score, samples were divided into high- and low-risk groups. Enrichment analysis and immunoassays were performed for the DEGs in these groups. Four external datasets from Gene Expression Omnibus data base were used to test the accuracy of the predictive model.

RESULTS

We identified SELP and CST2 as key DEGs, which were used to generate the predictive model. The high-risk group had a worse prognosis compared to the low-risk group (p < 0.05). Enrichment analysis and immunoassays revealed that 144 DEGs related to immune cell infiltration were associated with the Wnt signaling pathway and included hub genes such as ELN. Overall mutation levels, tumor mutation burden, and microsatellite instability were lower, but tumor immune dysfunction and exclusion scores were greater (p < 0.05) in the high-risk group than in the low-risk group. The validation results showed that the prediction model score can accurately predict the prognosis of GC patients. Finally, a nomogram was constructed using the risk score combined with the clinicopathological characteristics of patients with GC.

CONCLUSION

This risk score from the prediction model related to the tumor microenvironment and immunotherapy could accurately predict the overall survival of GC patients.

Discovery of benzochalcone derivative as a potential antigastric cancer agent targeting signal transducer and activator of transcription 3 (STAT3)

Gastric cancer remains a significant health burden worldwide. In continuation of our previous study and development of effective small molecules against gastric cancer, a series of benzochalcone analogues involving heterocyclic molecules were synthesised and biologically evaluated in vitro and in vivo. Among them, the quinolin-6-yl substituted derivative KL-6 inhibited the growth of gastric cancer cells (HGC27, MKN28, AZ521, AGS, and MKN1) with a submicromolar to micromolar range of IC₅₀, being the most potent one in this series. Additionally, KL-6 significantly inhibited the colony formation, migration and invasion, and effectively induced apoptosis of MKN1 cells in a concentration-dependent manner. The mechanistic study revealed that KL-6 could concentration-dependently suppress STAT3 phosphorylation, which may partly contribute to its anticancer activity. Furthermore, in vivo antitumour study on the MKN1 orthotopic tumour model showed that KL-6 effectively inhibited tumour growth (TGI of 78%) and metastasis without obvious toxicity. Collectively, compound KL-6 may support the further development of candidates for gastric cancer treatment.

Interferon gamma expression and mortality in unselected cohorts of urothelial bladder cancer patients

Background

The role of interferon gamma (IFN-γ) expression in long-term survival has not been studied in patients with urinary bladder cancer (UBC). IFN-γ expression was characterized among various UBC patient cohorts to assess if IFN-γ status is associated with overall survival (OS).

Methods

A tumor-based IFN-γ gene signature was evaluated among adult UBC patients newly diagnosed between 2004 and 2017 from two hospital systems in New York. Patient cohorts included metastatic (stage IV or progressing to stage IV [MBC]), muscle-invasive (stages T2a to T4a [MIBC]), and non–muscle-invasive (carcinoma in situ or stages 0a, 0is, and I [NMIBC]) disease. Descriptive analyses were conducted comparing IFN-γ signature in the highest tertile to those in the lowest two tertiles.

Results

234 patients with bladder cancer were evaluated (56 MBC, 38 MIBC, and 140 NMIBC). Median OS was only reached in the MIBC cohort for those with an IFN-γ signature in the lowest two tertiles (15.03 months [95% CI, 8.50–50.60]). Those with an IFN-γ signature in the highest tertile had a decreased risk of mortality in all cohorts indicating better survival, but this was statistically significant in only the MIBC cohort (adjusted HR = 0.09 [95% CI, 0.01–0.73]).

Conclusion

IFN-γ signature status was associated with a decreased mortality risk in all cohorts, particularly MIBC, indicating that it may be a prognostic marker of survival in patients with UBC.

ITGAL as a Prognostic Biomarker Correlated With Immune Infiltrates in Gastric Cancer

Integrin alpha L (ITGAL) is a member of the integrin family in which the abnormal expression is linked with carcinogenesis and immune regulation. However, the relation between ITGAL and the prognosis of gastric cancer (GC) and tumor-infiltrating lymphocytes (TILs) are not well understood. The differential expressions of ITGAL in human tumors and the clinical prognosis in GC were systematically analyzed via multiple databases including Gene Expression Profiling Interaction Analysis (GEPIA), UALCAN, Tumor Immune Estimation Resource (TIMER), and Kaplan–Meier (KM) plotter. TIMER, GEPIA, and TISIDB databases were used to comprehensively investigate the correlation between ITGAL and tumor infiltration immune cells. Also, further results were investigated by immunohistochemistry, qRT-PCR, and Western blot. We found that ITGAL expression in GC samples was considerably increased than in peritumor samples. Sample type, subgroup, cancer stage, lymphatic node stage, and worse survival were strongly related to high ITGAL expression. Moreover, upregulated ITGAL expression was strongly connected with immunomodulators, chemokines, and infiltrating levels of CD8+, CD4+ T cell, B cell, monocyte, neutrophil, macrophage, T-cell regulatory, NK cell, and myeloid dendritic cell in stomach adenocarcinoma (STAD). Specifically, immunohistochemistry and bioinformatic analysis showed that ITGAL expression was shown to have strong relationships with various immunological marker sets including PD1 (T-cell exhaustion marker). In conclusion, ITGAL is a prognostic biomarker for GC patients. It might regulate tumor immune microenvironment leading to poor prognosis. Furthermore, studies are essential to explore therapeutic targeting ITGAL.

Schlafen 11 predicts response to platinum-based chemotherapy in gastric cancers

BACKGROUND

Although unresectable or recurrent gastric cancers (GC) are frequently treated with platinum-based chemotherapy, response to treatment remains unpredictable. Because Schlafen 11 (SLFN11) is recently identified as a critical determinant of platinum sensitivity, we investigated the potential clinical utility of SLFN11 in the treatment of GC.

METHODS

We analysed the correlation between SLFN11 expression and overall survival in 169 GC patients by our established immunohistochemical approach. The impact of SLFN11 expression on the response to platinum and transition of SLFN11 expression upon long-term treatment with platinum were examined using GC cell lines and organoids.

RESULTS

GC patients with high-SLFN11 expression exhibited significantly better survival than those with low-SLFN11 expression, and the significance increased when we selected patients treated with platinum-based chemotherapy. Knockout of SLFN11 and reactivation of SLFN11 in GC cells conferred resistance and sensitivity to platinum, respectively. In GC cells and organoids, long-term treatment with oxaliplatin suppressed SLFN11 expression while imparting drug resistance. The acquired resistance to oxaliplatin was reversed by reactivation of SLFN11 with epigenetic modifying drugs.

CONCLUSIONS

This is the first report revealing definitive clinical implications of SLFN11 in the treatment of GC patients and providing novel strategies for the drug selection based on SLFN11 expression.

Discovery of new [1,2,4] Triazolo[1,5-a]Pyrimidine derivatives that Kill gastric cancer cells via the mitochondria pathway

Mitochondria are known as "powerhouse of cells" and play the role of a bridge in redox balance, cell apoptosis, and autophagy. ROS accumulation can cause mitochondria damage, while the injured mitochondria will further enhance ROS levels reciprocally. Herein, we synthesized a novel series of [1,2,4]triazolo[1,5-a]pyrimidine-based compounds 4a-4v and tested their anti-proliferation efficacy against gastric cancer cell line MGC-803. Among them, compounds 4o and 4p inhibited gastric cancer cells at micromolar level. Compound 4o caused G2/M arrest and induced mitochondria-dependent apoptosis in MGC-803 and SGC-7901. However, inhibiting apoptosis pathway cannot prevent the inhibitory activity of compound 4o against gastric cancer cell. To our surprising, ROS level was increased by compound 4o and elevation of ROS could be rescued by NAC. In accordance with that, NAC absolutely prevented the anti-proliferation efficacy of compound 4o. We further found that autophagy inhibitor CQ rather than 3-MA partially reversed inhibitory activity of compound 4o in MGC-803 cells. Taken together, compound 4o exhibited its anti-proliferative activity via increasing ROS level and inducing autophagy, thus leading to apoptosis of gastric cancer cells. Therefore, compound 4o may support further development of lead compounds for gastric cancer therapy via mitochondria pathway.

Activated HIF1α of tumor cells promotes chemoresistance development via recruiting GDF15-producing tumor-associated macrophages in gastric cancer

Chemotherapy is the preferred treatment for advanced stage gastric cancer (GC) patients, and developing chemoresistance is a tremendous challenge to efficacy of GC treatment. The treatments of anti-tumor chemo-agents recruit more tumor-associated macrophages (TAMs) which are highly implicated in the chemoresistance development, but the underlying molecular mechanism is unclear. Here, we demonstrate that hypoxia-inducible factor 1α (HIF1α) in GC cells is activated upon 5-fluorouracil (5-FU) treatment and results in much more accumulation of M2-type TAMs which protect tumor cells from chemo-agents. Mechanistically, in the GC cells under the 5-FU treatment, reactive oxygen species is accumulated and then induces the activation of HIF1α signaling to drive the expression of high-mobility group box 1, which leads to more macrophage's infiltration into GC tumor. In turn, the recruited TAMs exhibit tumor-protected M2-type phenotype and promote the chemoresistance of GC cells via producing growth differentiation factor 15 (GDF15) to exacerbate the fatty acid β-oxidation in tumor cells. Blocking GDF15 using antibody or inhibiting FAO of tumor cells by etomoxir efficiently gave rise to the tumor cell sensitivity to 5-FU. Therefore, our study demonstrates a novel insight in understanding the cross talking between tumor cells and immune microenvironment and provides new therapeutic targets for clinic treatments of gastric cancer.

CMA1 is potent prognostic marker and associates with immune infiltration in gastric cancer

Background: Chymase 1 (CMA1), a gene known to be expressed in mast cells (MCs), is largely linked to immunity. However, the relationship between CMA1 and prognosis of multiple tumours and tumour-infiltrating lymphocytes (TILs) remains elusive.Methods: The differential expressions of CMA1 in different tumours and their corresponding normal tissues were evaluated via exploring Tumour Immune Estimation Resource (TIMER) and Oncomine database; the correlation within expression level of CMA1 and outcome of cancer patients was evaluated via Kaplan-Meier plotter and Gene Expression Profiling Interactive Analysis (GEPIA) database; the correlation between CMA1 and tumour immune cell infiltration was further investigated by TIMER; additionally, the correlation between CMA1 and gene signature pattern of immune infiltration were checked using TIMER and GEPIA.Results: There were significant differences in CMA1 expression levels between gastric cancer (GC) tissues and adjacent normal tissues. The high expression of CMA1 was closed related to poor overall survival (OS) and progression-free survival (PFS) in patients with GC (OS HR = 1.50, p = .00015; PFS HR = 1.33, p = .016). Especially, in GC patients at N1, N2 and N3 stages, high CMA1 expression was correlated with poor OS and PFS, but not with NO (p = .15, .09). The expression of CMA1 was positively associated with the levels of infiltrated CD4+, CD8+ T cells, neutrophils, macrophages, and dendritic cells (DCs) in GC. Whereas, CMA1 expression was considerably associated with various immune markers.Conclusion: CMA1 is a key gene whose expression level is significantly correlated with GC prognosis and infiltration levels of CD8+, CD4+ T cells, neutrophils, macrophages, and DCs in GC. In addition, the expression of CMA1 may be involved in regulating tumour-associated macrophages (TAMs), dendritic cells, exhausted T cells and regulatory T cells in GC. It suggests that CMA1 could be utilized as a prognostic marker and a sign of immune infiltration in GC.

Investigating the significance of tumor-infiltrating immune cells for the prognosis of lung squamous cell carcinoma

Objective

Increasing evidence has indicated an association between immune cells infiltration in LSCC and clinical outcome. The aim of this research was tantamount to comprehensively investigate the effect of 22 tumor infiltrating immune cells (TIICs) on the prognosis of LSCC patients.

Methods

In our research, the CIBERSORT algorithm was utilized to calculate the proportion of 22 TIICs in 502 cases from the TCGA cohort. Cases with a CIBERSORT P-value of <0.05 were kept for further study. Using the CIBERSORT algorithm, we first investigated the difference of immune infiltration between normal tissue and LSCC in 22 subpopulations of immune cells. Kaplan-Meier analysis was used to analyze the effect of 22 TIICs on the prognosis of LSCC. An immune risk score model was constructed based on TIICs correlated with LSCC-related recurrence. Multivariate cox regression analysis was used to investigate whether the immune risk score was an independent factor for prognosis prediction of LSCC. Nomogram was under construction to comprehensively predict the survival rate of LSCC.

Results

The results of the different analysis showed that except of memory B cells, naive CD4+T cells, T cells and activated NK cells, the remaining immune cells all had differential infiltration in normal tissues and LSCC (p < 0.05). Kaplan-Meier analysis revealed two immune cells statistically related to LSCC-related recurrence, including activated mast cells and follicular helper T cells. Immune risk score model was constructed based on three immune cells including resting memory CD4+T cells, activated mast cells and follicular helper T cells retained by forward stepwise regression analysis. The Kaplan-Meier curve indicated that patients in the high-risk group linked to poor outcome (P = 8.277e−03). ROC curve indicated that the immune risk score model was reliable in predicting recurrence risk (AUC = 0.614). Multivariate cox regression analysis showed that the immune risk score model was just an independent factor for prognosis prediction of LSCC (HR = 2.99, 95% CI [1.65–5.40]; P = 0.0002). The nomogram model combined immune risk score and clinicopathologic parameter score to predict 3-year survival in patients with LSCC.

Conclusions

Collectively, tumor-infiltrating immune cells play a major role in the prognosis of LSCC.

MSC-regulated lncRNA MACC1-AS1 promotes stemness and chemoresistance through fatty acid oxidation in gastric cancer

Chemotherapy is the preferred treatment for advanced stage gastric cancer (GC) patients and chemotherapy resistance is the major obstacle to effective cancer therapy. Increasing evidence suggests that mesenchymal stem cells (MSCs) make important contributions to development of drug resistance. However, the underlying mechanism remains elusive. In this study, we discovered that abundant MSCs in tumor tissues predicted a poor prognosis in GC patients. MSCs promoted stemness and chemoresistance in GC cells through fatty acid oxidation (FAO) in vitro and in vivo. Mechanically, transforming growth factor β1 (TGF-β1) secretion by MSCs activated SMAD2/3 through TGF-β receptors and induced long non-coding RNA (lncRNA) MACC1-AS1 expression in GC cells, which promoted FAO-dependent stemness and chemoresistance through antagonizing miR-145-5p. Moreover, pharmacologic inhibition of FAO with etomoxir (ETX) attenuated MSC-induced FOLFOX regiment resistance in vivo. These results suggest that FAO plays an important role in MSC-mediated stemness and chemotherapy resistance in GC and FAO inhibitors in combination with chemotherapeutic drugs present as a promising strategy to overcome chemoresistance.

miR-577 Regulates TGF-β Induced Cancer Progression through a SDPR-Modulated Positive-Feedback Loop with ERK-NF-κB in Gastric Cancer

Transforming growth factor β (TGF-β) drives epithelial-mesenchymal transition (EMT), playing vital roles in cancer metastasis. The crosstalk between microRNAs (miRNAs) and TGF-β are frequently observed and involved in TGF-β-induced EMT. Here, we determine that miR-577 is significantly upregulated in gastric cancer (GC). miR-577 expression is positively correlated with GC metastasis status and poor patient prognosis. Functional assays demonstrate that miR-577 promotes metastasis and chemoresistance by inducing EMT and stemness-like properties. Moreover, TGF-β promotes the expression of miR-577, and miR-577 participates TGF-β-mediated cancer metastasis. Mechanistically, TGF-β activates miR-577 via NF-κB-mediated transcription, and miR-577 enhances TGF-β signaling by targeting the serum deprivation protein response (SDPR), which directly interacts with ERK to inactivate the ERK-NF-κB pathway, hence forming a feedback loop to drive tumor metastasis. A plausible mechanism of EMT induction by the TGF-β network is elucidated. Our findings suggest that the TGF-β-miR-577-SDPR axis may be a potential prognostic marker and therapeutic target against cancer metastasis in GC.

Does the use of targeted agents in advanced gastroesophageal cancer increase complete response? A meta-analysis of 18 randomized controlled trials

Purpose

We aimed to investigate whether the use of targeted agents (TAs) in advanced gastroesophageal cancer (GEC) increased the complete response (CR) and to assess the surrogate endpoints for survival in the targeted treatment of GEC by using a meta-analysis of randomized controlled trials (RCTs).

Methods

Eligible studies were identified using Medline, PubMed, and meeting abstracts. Searches were last updated on April 30, 2018. We calculated the incidence and Peto odds ratio (Peto OR) of CR events in patients assigned to TAs compared with controls. Simple linear regression models were fitted for median overall survival (OS) and each surrogate [median progression-free survival (PFS), CRs, objective response rate (ORR), and disease control rate (DCR), respectively].

Results

A total of 7,892 GEC patients from 18 RCTs were included for analysis. The incidence of CR in GEC patients treated with TAs was 2.0% (95% CI, 1.3%–3.0%) compared with 1.7% (95% CI, 1.0%–2.7%) in the control arms. The use of TAs in advanced GEC had a tendency to improve the possibility of archiving CR (Peto OR 1.42; 95% CI, 0.98–2.04; P=0.064) compared with controls. Subgroup analysis according to treatment TAs showed that the addition of antiepidermal growth factor receptor (EGFR) agents to chemotherapy in GEC significantly improved the CR rate in comparison with control (Peto OR 1.77; 95% CI, 1.02–3.09; P=0.044), but not for other molecular TAs (P=0.49 for angiogenesis inhibitors, P=0.66 for mesenchymal-epithelial transition inhibitors). We also found that the addition of TAs to first-line therapy (Peto OR 1.41; 95% CI, 0.94–2.11; P=0.098) had a tendency to increase the chance of obtaining a CR, but not for second-line therapy (Peto OR 1.47; 95% CI, 0.60–3.55; P=0.40). In addition, correlation analysis indicates that PFS, ORR, and DCR were strongly correlated with OS for GEC patients receiving TAs (r=0.85 for PFS; r=0.86 for ORR; r=0.81 for DCR). No marked correlation was found between OS and CRs (r=0.43; P=0.18).

Conclusion

Although the CR is a rate event in advanced GEC patients, adding the TAs to therapies, especially for anti-EGFR agents, increases the chance of archiving CR in comparison with the controls. PFS, ORR, and DCR are significantly correlated with OS and could be used as surrogate endpoints in patients with GEC who have received TA therapy, but not for CR.

The combination of apatinib and S-1 for the treatment of advanced gastric cancer in China: A meta-analysis of randomized controlled trials

BACKGROUND

Apatinib-targeted therapy is considered a promising treatment option for malignancies. This study systematically evaluated the efficacy and safety of the combination of apatinib and S-1 for the treatment of patients with advanced gastric cancer (GC).

METHODS

Clinical trials were searched from the PubMed, Cochrane Library, Embase, CNKI, and Wanfang databases. Outcome measures including therapeutic efficacy, quality of life (QoL), and adverse events were extracted and evaluated.

RESULTS

Data from 8 trials including 393 patients with advanced GC were included. The results indicated that, compared with S-1 alone, the combination of apatinib with S-1 significantly improved patient partial response rate (odds ratio [OR] = 1.91, 95% confidence interval [CI] = 1.21-3.02, P = .005), overall response rate (ORR, OR = 2.40, 95% CI = 1.51-3.82, P = .0002), and disease control rate (DCR, OR = 2.78, 95% CI = 1.51-5.10, P = .0010), whereas the rates of complete response (CR, OR = 2.38, 95% CI = 0.93-6.12, P = .07) and stable disease (SD, OR = 0.99, 95% CI = 0.64-1.54, P = .97) and QoL (OR = 1.22, 95% CI = 0.51-2.92, P = .66) did not differ significantly. Moreover, the group receiving the combined therapy had higher rates of hand-foot syndrome (OR = 2.23, 95% CI = 1.19-4.17, P = .01), hypertension (OR = 8.85, 95% CI = 4.07-19.26, P < .00001), albuminuria (OR = 11.25, 95% CI = 3.32-38.06, P = .0001), and hemoglobin reduction (OR = 3.19, 95% CI = 1.32-7.67, P = .010), whereas analysis of other adverse events did not show significant differences (P > .05).

CONCLUSION

The combination of apatinib and S-1 is more effective for GC treatment than S-1 alone. However, this combined treatment could lead to increased hand-foot syndrome, hypertension, albuminuria, and hemoglobin reduction. Therefore, the benefits and risks should be considered before treatment.

Treatment Patterns and Changes in Quality of Life during First-Line Palliative Chemotherapy in Korean Patients with Advanced Gastric Cancer

Purpose

The purpose of this study was to evaluate chemotherapy patterns and changes in quality of life (QOL) during first-line palliative chemotherapy for Korean patients with unresectable or metastatic/recurrent gastric cancer (GC).

Materials and Methods

Thiswas a non-interventional, multi-center, prospective, observational study of 527 patients in Korea. QOL assessments were conducted using the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaires (QLQ)-C30 and QLQ-STO22 every 3 months over a 12-month period during first-line palliative chemotherapy. The specific chemotherapy regimens were selected by individual clinicians.

Results

Most patients (93.2%) received combination chemotherapy (mainly fluoropyrimidine plus platinum) as their first-line palliative chemotherapy. The median progression-free survival and overall survival were 8.2 and 14.8 months, respectively. Overall, “a little” changes (differences of 5-10 points from baseline)were observed in some of the functioning or symptom scales; none of the QOL scales showed either “moderate” or “very much” change (i.e., ≥ 11 point difference from baseline). When examining the best change in each QOL domain from baseline, scales related to some aspects of functioning, global health status/QOL, and most symptoms revealed significant improvements (p < 0.05). Throughout the course of first-line palliative chemotherapy, most patients’ QOL was maintained to a similar degree, regardless of their actual response to chemotherapy.

Conclusion

This observational study provides important information on the chemotherapy patterns and QOL changes in Korean patientswith advanced GC. Overall, first-line palliative chemotherapy was found to maintain QOL, and most parameters showed an improvement compared with the baseline at some point during the course.

Induction of apoptosis and G1 phase cell cycle arrest by Aster incisus in AGS gastric adenocarcinoma cells

In recent decades, various bioactive compounds from plants have been investigated for their potential use in the treatment of diseases in humans. Aster incisus extract (AIE) is the extract of a common plant that is mostly found in Asia. It has traditionally been used for medicinal purposes in South Korea. In this study, we evaluated the potential anticancer effects of a methanolic extract of Aster incisus in a normal human cell line (HaCaT keratinocytes) and in 4 different types of human cancer cell lines (A549, lung cancer; Hep3B, liver cancer; MDA‑MB‑231, breast cancer; and AGS, gastric cancer). The HaCaT, A549, Hep3B, MDA‑MB‑231 and AGS cells were treated with various concentrations of AIE and following treatment, cell survival was evaluated. Additional analyses, such as WST-1 assay, western blot analysis, DAPI staining, flow cytometry, immunofluorescence staining and wound healing assay were performed to elucidate the mechanisms and pathways involved in the cell death induced by AIE. Treatment with AIE induced morphological changes and considerably reduced the viability of the both normal and cancer cell lines. Further analysis of the AGS gastric cancer cells revealed that AIE led to the induction of apoptosis and a high accumulation of cells in the G1 cell phase following treatment with AIE in a dose-dependent manner. The results also revealed that AIE successfully suppressed the migration of the AIE-treated AGS cells. The results of western blot analysis indicated that AIE increased the expression of pro-apoptotic proteins, particularly Bid, Bad, Bak, cytochrome c, apoptosis inducing factor (AIF), cleaved caspase‑3, -8 and -9 and cleaved poly(ADP-ribose) polymerase (PARP). Additionally, AIE decreased the expression of the anti-apoptotic proteins, Bcl-2 and Bcl-xL. On the whole, the findings of this study demonstrate that AIE induces apoptosis through the activation of the caspase‑dependent pathway mediated by the mitochondrial pathway and by arresting the cell cycle in AGS cells.

HER2 inhibition in gastro-oesophageal cancer: A review drawing on lessons learned from breast cancer

Human epidermal growth factor receptor 2 (HER2)-inhibition is an important therapeutic strategy in HER2-amplified gastro-oesophageal cancer (GOC). A significant proportion of GOC patients display HER2 amplification, yet HER2 inhibition in these patients has not displayed the success seen in HER2 amplified breast cancer. Much of the current evidence surrounding HER2 has been obtained from studies in breast cancer, and we are only recently beginning to improve our understanding of HER2-amplified GOC. Whilst there are numerous licensed HER2 inhibitors in breast cancer, trastuzumab remains the only licensed HER2 inhibitor for HER2-amplified GOC. Clinical trials investigating lapatinib, trastuzumab emtansine, pertuzumab and MM-111 in GOC have demonstrated disappointing results and have not yet changed the treatment paradigm. Trastuzumab deruxtecan may hold promise and is currently being investigated in phase II trials. HER2 amplified GOC differs from breast cancer due to inherent differences in the HER2 amino-truncation and mutation rate, loss of HER2 expression, alterations in HER2 signalling pathways and differences in insulin-like growth factor-1 receptor and MET expression. Epigenetic alterations involving different microRNA profiles in GOC as compared to breast cancer and intrinsic differences in the immune environment are likely to play a role. The key to effective treatment of HER2 amplified GOC lies in understanding these mechanisms and tailoring HER2 inhibition for GOC patients in order to improve clinical outcomes.

Multimodality treatment of operable gastric and oesophageal adenocarcinoma: evaluating neoadjuvant, adjuvant and perioperative approaches

INTRODUCTION

Treatment patterns for locally advanced operable gastric and oesophageal adenocarcinoma vary, with the optimal approach an area of debate within oncology. Strategies for treatment include a variety of neo-adjuvant, adjuvant and peri-operative regimens involving differing chemotherapy and radiotherapy combinations. Areas covered: This review will critically appraise the evidence base underpinning the main treatment approaches in operable oesophagogastric adenocarcinoma, highlighting variations in treatment by factors such as geographical area and primary tumor site. Expert commentary: The expert commentary will focus on the optimal evidence-based approaches for clinicians at the present time and explore how increased understanding of the molecular and genetic determinants of the disease may lead to refinements in treatment through the development of both biomarker-driven approaches and the application of novel targeted and immune-modulating agents to early treatment.

lncRNA BG981369 Inhibits Cell Proliferation, Migration, and Invasion, and Promotes Cell Apoptosis by SRY-Related High-Mobility Group Box 4 (SOX4) Signaling Pathway in Human Gastric Cancer

Background

Human gastric cancer (GC) is a leading primary cause of cancer-associated deaths in both males and females worldwide. However, there are few effective diagnostic and therapeutic measures for GC patients due to the complicated underlying mechanisms of GC. Recently, increasing research has indicated that lncRNAs may play a critical role in the progression of GC.

Material/Methods

AI769947, AK054978, DB077273, BG981369, AK054588, and AF131784 expressions were analyzed by qRT-PCR assay in GC tissues and corresponding normal tissues (n=44). BG981369 expression was detected by qRT-PCR assay in GC cells. BG981369 was overexpressed and silenced in AGS and SNU-5 cells. The proliferation ability was detected by MTT and colony formation assays. Cell cycle distribution and cell apoptosis rate were analyzed by flow cytometry. The migration and invasion abilities were measured by Transwell assay. In addition, SOX4 expression was analyzed by qRT-PCR in GC tissues. The correlation between SOX4 and BG981369 was analyzed by Pearson analysis.

Results

The results indicated that lncRNA BG981369 was significantly higher in GC tissues than in normal tissues. Overexpression of BG981369 inhibited the proliferation, migration, and invasion and promoted apoptosis of gastric adenocarcinoma (AGS) cells, and silencing of BG981369 promoted proliferation, migration, and invasion, and inhibited cell apoptosis of SNU-5 cells. Furthermore, we found that SOX4 may act as a downstream mediator of BG981369, suggesting that BG981369 inhibits proliferation, migration, and invasion, and promotes apoptosis by targeting SOX4 in the GC cell lines.

Conclusions

Our results suggest that BG981369 and SOX4 are potentially effective therapeutic targets for GC.

Stromal-Based Signatures for the Classification of Gastric Cancer

Treatment of metastatic gastric cancer typically involves chemotherapy and monoclonal antibodies targeting HER2 (ERBB2) and VEGFR2 (KDR). However, reliable methods to identify patients who would benefit most from a combination of treatment modalities targeting the tumor stroma, including new immunotherapy approaches, are still lacking. Therefore, we integrated a mouse model of stromal activation and gastric cancer genomic information to identify gene expression signatures that may inform treatment strategies. We generated a mouse model in which VEGF-A is expressed via adenovirus, enabling a stromal response marked by immune infiltration and angiogenesis at the injection site, and identified distinct stromal gene expression signatures. With these data, we designed multiplexed IHC assays that were applied to human primary gastric tumors and classified each tumor to a dominant stromal phenotype representative of the vascular and immune diversity found in gastric cancer. We also refined the stromal gene signatures and explored their relation to the dominant patient phenotypes identified by recent large-scale studies of gastric cancer genomics (The Cancer Genome Atlas and Asian Cancer Research Group), revealing four distinct stromal phenotypes. Collectively, these findings suggest that a genomics-based systems approach focused on the tumor stroma can be used to discover putative predictive biomarkers of treatment response, especially to antiangiogenesis agents and immunotherapy, thus offering an opportunity to improve patient stratification. Cancer Res; 76(9); 2573-86. ©2016 AACR.

Expression of ERO1L in gastric cancer and its association with patient prognosis

The present study aimed to assess the expression of endoplasmic reticulum oxidoreductin-1-like (ERO1L) in gastric cancer and determine its association with patient prognosis. A total of 105 patients with gastric cancer undergoing radical gastrectomy were selected for the current study. Gastric cancer tissues (the observation group) and normal gastric tissue adjacent to the carcinoma (the control group) were resected from patients. Levels of ERO1L mRNA and protein in tumor tissues and adjacent tissues were detected using reverse transcription-quantitative polymerase chain reaction, western blotting and immunohistochemistry. Patients were divided into two groups: A positive group and negative group, according to the expression of ERO1. The expression of ERO1L in gastric cancer and its association with patient prognosis was analyzed. Levels of ERO1 mRNA and protein in gastric cancer were significantly higher than those of adjacent tissues (P<0.05). Immunohistochemical analysis demonstrated that there were 22 patients exhibiting negative expression of ERO1L and 83 patients exhibiting positive expression of ERO1L. The cumulative recurrence rates over 3 years in patients with positive expression of ERO1L were significantly higher than in patients with negative expression of ERO1L (P<0.05); the cumulative survival rates over 3 years in patients with positive expression of ERO1L were significantly lower than those of patients with negative expression of ERO1L (P<0.05). Thus, the current study determined that ERO1L was highly expressed in gastric cancer tissue. The high expression of ERO1L was associated with adverse prognoses in patients with gastric cancer. ERO1L may therefore be a therapeutic target for the prevention of gastric cancer.

Quantitative proteomics profiling reveals activation of mTOR pathway in trastuzumab resistance

Trastuzumab is an antibody-based therapy drug targeting HER2-overexpressing tumors. While it has been proven to be very successful initially, most patients eventually develop resistance to trastuzumab. The mechanism of drug resistance is not well understood. Identifying pathways that mediate trastuzumab resistance will improve our understanding of the underlying mechanism and is crucial for the development of therapeutic strategies to overcome resistance.Here we report a quantitative proteomics profiling of a trastuzumab-sensitive (T-S) gastric cancer cell line NCI N87 and a trastuzumab-resistant NCI N87 (T-R) subline generated by low-dose, continuous trastuzumab treatment. By identifying proteins differentially expressed in these two cell lines, we show that multiple pathways including mTOR, Wnt, DNA damage response and metabolic pathways are significantly altered. We further confirm by western blotting that protein levels of multiple components of the mTOR pathway, including mTOR, AKT and RPS6KB1, are increased, whereas AKT1S1 is decreased, suggesting the activation of mTOR pathway. Importantly, treatment of AZD8055, an mTOR inhibitor, leads to the decreased phosphorylation levels of mTOR downstream molecules RPS6KB1 at Thr421/Ser424 and AKT at Ser473. Furthermore, AZD8055 also preferentially reduces viability, and inhibits migration and invasion abilities of the T-R cells. Together, our findings indicate that mTOR pathway is among multiple signaling pathways that mediate trastuzumab resistance in NCI N87 T-R cells, and that mTOR inhibitors may be used to treat trastuzumab resistant, HER2-positive gastric cancer tumors.

Proteomic analysis of cell cycle arrest and differentiation induction caused by ATPR, a derivative of all-trans retinoic acid, in human gastric cancer SGC-7901 cells

PURPOSE

4-amino-2-trifluoromethyl-phenyl retinate (ATPR) was reported to potentially inhibit proliferation and induce differentiation activity in some tumor cells. In this study, a proteomics approach was used to investigate the possible mechanism by screening the differentially expressed protein profiles of SGC-7901 cells before and after ATPR-treatment in vitro.

EXPERIMENTAL DESIGN

Peptides digested from the total cellular proteins were analyzed by reverse phase LC-MS/MS followed by a label-free quantification analysis. The SEQUEST search engine was used to identify proteins and bioinformatics resources were used to investigate the involved pathways for the differentially expressed proteins.

RESULTS

Thirteen down-regulated proteins were identified in the ATPR-treated group. Bioinformatics analysis showed that the effects of ATPR on 14-3-3ε might potentially involve the PI3K-AKT-FOXO pathway and P27Kip1 expression. Western blot and RT-PCR analysis showed that ATPR could inhibit AKT phosphorylation, up-regulate the expression of FOXO1A and P27Kip1 at both the protein and mRNA levels, and down-regulate the cytoplasmic expression of cyclin E and CDK2. ATPR-induced G0/G1 phase arrest and differentiation can be ablated if the P27kip1 gene is silenced with sequence-specific siRNA or in 14-3-3ε overexpression of SGC-7901 cells.

CONCLUSION AND CLINICAL RELEVANCE

ATPR might cause cell cycle arrest and differentiation in SGC-7901 cells by simultaneously inhibiting the phosphorylation of AKT and down-regulating 14-3-3ε. This change would then enhance the inhibition of cyclin E/CDK2 by up-regulating FOXO1A and P27Kip1. Our findings could be of value for finding new drug targets and for developing more effective differentiation inducer.

Surgical treatment of gastric cancer liver metastasis: Focus on controversy

Gastric cancer is the third most common malignancy in China, and the liver is the most common metastasis site which is responsible for poor prognosis in advanced gastric cancer. Gastric cancer liver metastasis (GCLM) has long been regarded as a systemic disease, and chemotherapy is still the main treatment, although the efficacy is unsatisfying. Recently, active surgical resection is reported to be practicable and beneficial in highly selected cases. In addition, either radiofrequency ablation or hepatic arterial infusion can be used for unresectable locally advanced tumors. Management of liver metastasis is the key to significantly improve the prognosis of patients. Further research is needed to establish individualized modalities for these particular patients. We herein discuss the surgical treatment of GCLM.

PFK15, a Small Molecule Inhibitor of PFKFB3, Induces Cell Cycle Arrest, Apoptosis and Inhibits Invasion in Gastric Cancer

PFKFB3 (6-phosphofructo-2-kinase) synthesizes fructose 2,6-bisphosphate (F2,6P₂), which is an allosteric activator of 6-phosphofructo-1-kinase (PFK-1), the rate-limiting enzyme of glycolysis. Overexpression of the PFKFB3 enzyme leads to high glycolytic metabolism, which is required for cancer cells to survive in the harsh tumor microenvironment. The objective of this study was to investigate the antitumor activity of PFK15 (1-(4-pyridinyl)-3-(2-quinolinyl)-2-propen-1-one), a small molecule inhibitor of PFKFB3, against gastric cancer and to explore its potential mechanisms. The effects of PFK15 on proliferation, apoptosis and cell cycle progression in gastric cancer cells were evaluated by cytotoxicity and apoptosis assays, flow cytometry, and western blotting. In addition, the invasion inhibition effects of PFK15 were measured by transwell invasion assay and western blot analysis, and a xenograft tumor model was used to verify the therapeutic effect of PFK15 in vivo. Results showed that PFK15 inhibited the proliferation, caused cell cycle arrest in G0/G1 phase by blocking the Cyclin-CDKs/Rb/E2F signaling pathway, and induced apoptosis through mitochondria in gastric cancer cells. Tumor volume and weight were also significantly reduced upon intraperitoneal injection with PFK15 at 25 mg/kg. In addition, PFK15 inhibited the invasion of gastric cancer cells by downregulating focal adhesion kinase (FAK) expression and upregulating E-cadherin expression. Taken together, our findings indicate that PFK15 is a promising anticancer drug for treating gastric cancer.

Overexpression of suppressor of IKBKE 1 is associated with vincristine resistance in colon cancer cells

In a previous study, the suppressor of IKBKE 1 expression level was confirmed to be higher in vincristine (VCR)-resistant HCT-8 (HCT-8/V) colon cancer cells than in non-VCR-resistant HCT-8 cells. In the current study, IKBKE 1 expression in VCR-resistant colon cancer cells was investigated further. HCT-8 and HCT-8/V human colon cancer cells were used, and polymerase chain reaction (PCR) primers were designed to amplify the IKBKE 1 gene. Fluorescence reverse transcription-quantitative PCR (RT-qPCR) was performed to detect differences in IKBKE 1 expression between sensitive and drug-resistant colon cancer cell lines. Western blotting was performed to further observe IKBKE 1 expression. Based on the RT-qPCR and western blot results, IKBKE 1 expression was observed to be markedly higher in the HCT-8/V cells, and this difference was significant (P<0.05). Thus, IKBKE 1 expression was identified to be associated with the resistance of colon cancer cells to VCR.

Sex Disparity in Gastric Cancer: Female Sex is a Poor Prognostic Factor for Advanced Gastric Cancer

BACKGROUND

The overall incidence of gastric cancer (GC) is higher in males than females. Specifically, signet ring cell carcinoma (SRC) is more frequently observed in younger female patients. However, limited information focused on sex-specific differences in GC has been reported. The aim of our study was to analyze clinicopathological differences between sex groups to reveal sex disparities in GC.

METHODS

We retrospectively analyzed 4722 patients with GC who underwent gastrectomy (females: 1586 (33.6 %); males: 3136 (66.4 %), and analyzed clinicopathological features between these sex groups. The overall survival (OS) rate was investigated between the two sex groups, with special reference to the pathologic World Health Organization GC classifications. Immunohistochemistry staining of sex hormone receptors, including the estrogen receptor (ER)-α, ER-β, progesterone receptor, and androgen receptor, was performed according to sex and pathological classification.

RESULTS

Female patients were significantly associated with a younger age, poorly differentiated adenocarcinoma, and SRC compared with males. Female patients showed a significantly poorer OS than male patients, especially among those with advanced GC (AGC) aged ≤45 years. In females with AGC, those with SRC had a significantly poorer OS than those with other histologies. Moreover, the expression of ER-β was different between females and males with SRC.

CONCLUSIONS

Females with GC were significantly younger and had a different SRC histology compared with males. Furthermore, females had significantly poorer prognostic factors among young patients with SRC. Thus, young female GC patients with SRC are a main target group in which to improve prognosis.

Immunotherapy for oesophagogastric cancer

INTRODUCTION

Gastric and oesophageal cancers are a pressing global health problem with high mortality rates and poor outcomes for advanced disease. The mainstay of treatment in the palliative setting has traditionally been chemotherapy, which accrues only modest survival benefits. As with other cancer types, there is increasing interest in the use of immunotherapy approaches to improve outcomes.

AREAS COVERED

This paper reviews the aetiological and genetic characteristics of oesophagogastric (OG) cancers relevant to the application of immunotherapy and outlines the historical, present-day and potential future applications of immunotherapy in their management.

EXPERT OPINION

The use of agents targeting the PD1 pathway have led to impressive and durable responses in a minority of OG cancer patients and it would be expected that combinatorial approaches with chemotherapy, radiotherapy and other biological agents will improve responses further. Identification of clinically robust biomarkers is crucial in refining such approaches moving forwards. The application of modern sequencing technology to the development of personalized neoantigen-based vaccines represents an exciting amalgamation of genomics and immunotherapy, with potentially important clinical implications in OG cancer.