Targeted and novel therapy in advanced gastric cancer

Mapping the landscape of gastric cancer immunotherapy: Bibliometric insights into advances and hotspots

BACKGROUND

Immunotherapy has surfaced as a promising therapeutic modality for gastric cancer (GC). A comprehensive review of advancements, current status, and research trends in GC immunotherapy is essential to inform future investigative efforts.

AIM

To delineate the trends, advancements, and focal points in immunotherapy for GC.

METHODS

We performed a bibliometric analysis of 2906 articles in English concerning GC immunotherapy published from 2000 to December 20, 2023, indexed in the Web of Science Core Collection. Data analysis and visualization were facilitated by CiteSpace (6.1.6R), VOSviewer v.1.6.17, and GraphPad Prism v8.0.2.

RESULTS

There has been an increase in the annual publication rate of GC immunotherapy research. China leads in publication volume, while the United States demonstrates the highest citation impact. Fudan University is notable for its citation frequency and publication output. Co-citation analysis and keyword frequency revealed and highlighted a focus on GC prognosis, the tumor microenvironment (TME), and integrative immunotherapy with targeted therapy. Emerging research areas include gastroesophageal junction cancer, adoptive immunotherapy, and the role of Treg cell in immunotherapy.

CONCLUSION

GC immunotherapy research is an expanding field attracting considerable scientific interest. With the clinical adoption of immunotherapy in GC, the primary goals are to enhance treatment efficacy and patient outcomes. Unlike hematological malignancies, GC's solid TME presents distinct immunological challenges that may attenuate the cytotoxic effects of immune cells on cancer cells. For instance, although CAR-T therapy is effective in hematological malignancies, it has underperformed in GC settings. Current research is centered on overcoming immunosuppression within the TME, with a focus on combinations of targeted therapy, adoptive immunotherapy, Treg cell dynamics, and precise prognosis prediction in immunotherapy. Additionally, immunotherapy's role in treating gastroesophageal junction cancer has become a novel research focus.

Downregulation of LncRNA CCAT1 Enhances Chemosensitivity in Cisplatin-Resistant Gastric Cancer Cells

Chemotherapy is an effective treatment for gastric cancer. However, many patients develop resistance to chemotherapeutic agents during clinical treatment. LncRNA CCAT1 has recently been shown to influence cellular resistance to specific chemotherapeutic drugs, but its role in gastric cancer remains underexplored. This study aims to investigate the role of LncRNA CCAT1 in cisplatin resistance in gastric cancer cells and its potential underlying mechanisms. Gastric cancer cell lines with acquired resistance were established. The expression of CCAT1 was assessed in both cisplatin-sensitive and cisplatin-resistant AGS cell lines. CCAT1 expression was knocked down in AGS/DDP cells, and the changes in IC50 values were measured using the Cell Counting Kit-8 (CCK-8) assay. Apoptosis in gastric cancer cells was evaluated by flow cytometry. Additionally, Western blotting was employed to measure the expression levels of PI3K/AKT/mTOR signaling pathway proteins and apoptosis-related proteins in both interference and control groups. RT-qPCR results indicated that CCAT1 expression was significantly elevated in cisplatin-resistant gastric cancer cells compared to non-resistant cells. Similarly, CCK-8 assay results demonstrated that knocking down CCAT1 in resistant cells increased their sensitivity to cisplatin treatment. Flow cytometry and Western blot results further confirmed that silencing CCAT1 promoted apoptosis in these cells. Additionally, the expression of PI3K/AKT/mTOR signaling pathway proteins was higher in resistant cells compared to their sensitive counterparts, and silencing CCAT1 in AGS/DDP cells resulted in reduced expression of these proteins. In conclusion, the above studies demonstrated that LncRNA CCAT1 induced cisplatin resistance in gastric cancer cells.

Clinical significance of Talin-1 and HER-2 status in different types of gastric carcinoma

BACKGROUND

Talin-1 (TLN1) is crucial in cell migration, metastasis, and cancer development. This study evaluated Talin-1 expression and its clinical significance in gastric cancer (GC), along with human epidermal growth factor receptor-2 (HER-2) expression and its correlation with Talin-1.

METHODS

Bioinformatics analysis assessed the potential prognostic value of Talin-1 and HER-2 in GC patients. The study included 223 GC patients (Signet Ring Cells and Intestinal subtypes) and 29 non-malignant tissue samples. Immunohistochemistry (IHC) on tissue microarray slides evaluated Talin-1 and HER-2 expression and clinical significance. Receiver operating characteristic (ROC) curves assessed their diagnostic value.

RESULTS

Bioinformatics identified Talin-1 as a potential prognostic factor and HER-2 as an oncogene in GC. Talin-1 and HER-2 expression increased in SRC-type GC samples compared to non-malignant tissues. High cytoplasmic Talin-1 expression inversely correlated with tumor expansion and invasion in SRC-type GC. Increased HER-2 expression positively correlated with metastasis. ROC curves showed significant diagnostic values for both proteins.

CONCLUSIONS

Higher cytoplasmic Talin-1 expression is associated with less invasive tumor behavior, while increased membranous HER-2 expression is associated with metastasis in SRC-type GC. These findings suggest potential use in assessing diagnosis and screening high-risk cancer patients, particularly those with SRC-type GC.

Lectin-modified drug delivery systems - Recent applications in the oncology field

Chemotherapy with cytotoxic drugs remains the core treatment for cancer but, due to the difficulty to find general and usable biochemical differences between cancer cells and normal cells, many of these drugs are associated with lack of specificity, resulting in side effects and collateral cytotoxicity that impair patients' adherence to therapy. Novel cancer treatments in which the cytotoxic effect is maximized while adverse effects are reduced can be implemented by developing targeted therapies that exploit the specific features of cancer cells, such as the typical expression of aberrant glycans. Modification of drug delivery systems with lectins is one of the strategies to implement targeted chemotherapies, as lectins are able to specifically recognize and bind to cancer-associated glycans expressed at the surface of cancer cells, guiding the drug treatment towards these cells and not affecting healthy ones. In this paper, recent advances on the development of lectin-modified drug delivery systems for targeted cancer treatments are thoroughly reviewed, with a focus on their properties and performance in diverse applications, as well as their main advantages and limitations. The synthesis and analytical characterization of the cited lectin-modified drug delivery systems is also briefly described. A comparison with free-drug treatments and with antibody-modified drug delivery systems is presented, emphasizing the advantages of lectin-modified drug delivery systems. Main constraints and potential challenges of lectin-modified drug delivery systems, including key difficulties for clinical translation of these systems, and the required developments in this area, are also signalled.

Clinical implications of CT-detected ascites in gastric cancer: association with peritoneal metastasis and systemic inflammatory response

OBJECTIVES

This study aimed to evaluate the diagnostic significance of computed tomography (CT) detected ascites in gastric cancer (GC) with peritoneal metastasis (PM) and investigate its association with systemic inflammatory response.

METHODS

This retrospective study included 111 GCs with ascites (PM: n = 51; No PM: n = 60). Systemic inflammatory indexes, tumor markers, and the CT-assessed characteristics of ascites were collected. The differences in parameters between the two groups were analyzed. Diagnostic performance was obtained by receiver operating characteristic curve analysis. The association between the volume of ascites and clinical characteristics was evaluated with correlation analysis.

RESULTS

In this study, over half of GCs with ascites were not involved with PM. The systemic immune-inflammation index (SII), neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), five tumor markers, and the characteristics of ascites showed significant differences between the two groups (all p < 0.05). Among them, SII, NLR, PLR, and the volume of ascites achieved the areas under the curve of 0.700, 0.698, 0.704, and 0.903, respectively. Moreover, the volumes of ascites showed positive correlations with SII, NLR, and PLR in GCs with PM, and the volumes of ascites detected in the upper abdomen were more strongly correlated with CA125 level (all p < 0.05).

CONCLUSION

Many GCs with CT-detected ascites did not occur with synchronous PM. The presence of upper abdominal ascites had certain clinical significance for diagnosing PM in GCs. Systemic inflammatory indexes were elevated and positively correlated with the volume of ascites in GCs with PM, which might suggest the enhanced systemic inflammatory response.

CRITICAL RELEVANCE STATEMENT

CT-detected ascites in the upper abdomen played an indicative role in identifying synchronous PM in GCs, and the systemic inflammatory response was enhanced in GCs with PM, which might be helpful for clinical evaluation.

KEY POINTS

Many GCs with CT-detected ascites did not occur with synchronous PM. CT-detected ascites in the upper abdomen help in identifying PM in GCs. GCs with PM showed elevated systemic inflammatory indexes and enhanced systemic inflammatory response.

Activity-based protein profiling and global proteome analysis reveal MASTL as a potential therapeutic target in gastric cancer

BACKGROUND

Gastric cancer (GC) is a prevalent malignancy with limited therapeutic options for advanced stages. This study aimed to identify novel therapeutic targets for GC by profiling HSP90 client kinases.

METHODS

We used mass spectrometry-based activity-based protein profiling (ABPP) with a desthiobiotin-ATP probe, combined with sensitivity analysis of HSP90 inhibitors, to profile kinases in a panel of GC cell lines. We identified kinases regulated by HSP90 in inhibitor-sensitive cells and investigated the impact of MASTL knockdown on GC cell behavior. Global proteomic analysis following MASTL knockdown was performed, and bioinformatics tools were used to analyze the resulting data.

RESULTS

Four kinases-MASTL, STK11, CHEK1, and MET-were identified as HSP90-regulated in HSP90 inhibitor-sensitive cells. Among these, microtubule-associated serine/threonine kinase-like (MASTL) was upregulated in GC and associated with poor prognosis. MASTL knockdown decreased migration, invasion, and proliferation of GC cells. Global proteomic profiling following MASTL knockdown revealed NEDD4-1 as a potential downstream mediator of MASTL in GC progression. NEDD4-1 was also upregulated in GC and associated with poor prognosis. Similar to MASTL inhibition, NEDD4-1 knockdown suppressed migration, invasion, and proliferation of GC cells.

CONCLUSIONS

Our multi-proteomic analyses suggest that targeting MASTL could be a promising therapy for advanced gastric cancer, potentially through the reduction of tumor-promoting proteins including NEDD4-1. This study enhances our understanding of kinase signaling pathways in GC and provides new insights for potential treatment strategies.

Prognostic Influence of Galectin-1 in Gastric Adenocarcinoma

Galectin-1 (Gal-1), a member of the human lectin family, has garnered attention for its association with aggressive behavior in human tumors, prompting research into the development of targeted drugs. This study aims to assess the staining pattern and prognostic significance of Gal-1 immunohistochemical expression in a homogeneous cohort of Western patients with gastric cancer (GC). A total of 149 cases were included and tissue microarrays were constructed. Stromal Gal-1 expression was observed to some extent in most tumors, displaying a cytoplasmic pattern. Cases with stromal Gal-1 overexpression showed significantly more necrosis, lymphovascular invasion, advanced pTNM stages, recurrences, and cancer-related deaths. Epithelial Gal-1 expression was present in 63.8% of the cases, primarily exhibiting a cytoplasmic pattern, and its overexpression was significantly associated with lymphovascular invasion, peritumoral lymphocytic infiltration, and tumor-related death. Kaplan/Meier curves for cancer-specific survival (CSS) revealed a significantly worse prognosis for patients with tumors exhibiting stromal or epithelial Gal-1 overexpression. Furthermore, stromal Gal-1 expression stratified stage III patients into distinct prognostic subgroups. In a multivariable analysis, increased stromal Gal-1 expression emerged as an independent prognostic factor for CSS. These findings underscore the prognostic relevance of Gal-1 and suggest its potential as a target for drug development in Western patients with GC.

Curcumin Induces Autophagy-mediated Ferroptosis by Targeting the PI3K/AKT/mTOR Signaling Pathway in Gastric Cancer

As a very common malignancy of the digestive system, the incidence and mortality rates of gastric cancer (GC) are increasing year by year. The critical role of ferroptosis in cancer development has been well-documented. The polyphenol compound curcumin shows prominent anti-tumor effects in multiple cancer types, including GC. However, whether curcumin participates in GC tumorigenesis by regulating ferroptosis remains unknown. Gastric cancer cells AGS and HGC-27 were treated with curcumin (0, 10, and 20 μM). Cell viability and death were evaluated through CCK-8 and LDH release assays. LC3B expression in cells was estimated through immunofluorescence staining. Intracellular ferrous iron (Fe2+), GSH, MDA, and lipid ROS levels were assessed by corresponding assay kits. The cellular levels of autophagy markers (ATG5, ATG7, Beclin 1, and LC3B), ferroptosis markers (ACSL4, SLC7A11, and GPX4), and phosphorylated (p)-PI3K, p-AKT, and p-mTOR were determined through western blotting. Curcumin attenuated cell viability but stimulated cell death in GC cells. Curcumin enhanced autophagy in GC cells, as demonstrated by the increased levels of ATG5, ATG7, Beclin 1, and LC3B. Besides, curcumin upregulated iron, MDA, GSH, and ACSL4 levels while downregulated lipid ROS, SLC7A11, and GPX4 levels, suggesting its stimulation on ferroptosis in GC cells. Curcumin decreased p-PI3K, p-AKT, and p-mTOR levels in cells. Importantly, the ferroptosis inhibitor ferrostatin-1 overturned the impacts of curcumin on GC cell viability, death, and ferroptosis. Curcumin suppresses GC development by inducing autophagy-mediated ferroptosis by inactivating the PI3K/AKT/mTOR signaling.

Potential role of lncRNA LOXL1-AS1 in human cancer development: a narrative review

Background and Objective

Long non-coding RNAs (lncRNAs) are a group of non-coding RNAs consisting of more than 200 nucleotides that are widely involved in various physiological and pathobiological processes in the body. LncRNA plays a crucial role in tumorigenesis and development with its unique functions, such as playing a role in a variety of biological processes of malignant tumors as a cancer-promoting factor or a cancer-suppressor factor. Lysyl oxidase-like protein 1-antisense RNA1 (LOXL1-AS1) is a novel functional lncRNA recently reported. This article reviews the current findings on the role of LOXL1-AS1 in cancer, and discusses the potential clinical significance and application prospects, in order to provide a theoretical basis and reference for the clinical diagnosis, treatment and screening of prognostic markers for malignant tumors.

Methods

The PubMed and Embase databases were searched using the keywords "cancer" or "tumor" or "neoplasm" and "LOXL1-AS1" for publications from 2018 to the present. The English literature was searched, with a focus on relevant articles. These articles validated the role and mechanism of LOXL1-AS1 in different cancers.

Key Content and Findings

LOXL1-AS1 is a recently reported novel lncRNA, which is abnormally expressed and upregulated in more than ten cancers, and is positively correlated with adverse clinical features and poor prognosis in cancer patients. LOXL1-AS1 competently binds to a variety of microRNAs to regulate the expression of downstream target genes and regulate related signaling pathways, including proliferation, migration, invasion and inhibition of malignant biological behaviors such as apoptosis.

Conclusions

LOXL1-AS1 is expected to become a novel biomarker for cancer diagnosis and treatment, with great potential as an independent prognostic indicator.

E-cadherin loss drives diffuse-type gastric tumorigenesis via EZH2-mediated reprogramming

Diffuse-type gastric adenocarcinoma (DGAC) is a deadly cancer often diagnosed late and resistant to treatment. While hereditary DGAC is linked to CDH1 mutations, the role of CDH1/E-cadherin inactivation in sporadic DGAC tumorigenesis remains elusive. We discovered CDH1 inactivation in a subset of DGAC patient tumors. Analyzing single-cell transcriptomes in malignant ascites, we identified two DGAC subtypes: DGAC1 (CDH1 loss) and DGAC2 (lacking immune response). DGAC1 displayed distinct molecular signatures, activated DGAC-related pathways, and an abundance of exhausted T cells in ascites. Genetically engineered murine gastric organoids showed that Cdh1 knock-out (KO), KrasG12D, Trp53 KO (EKP) accelerates tumorigenesis with immune evasion compared with KrasG12D, Trp53 KO (KP). We also identified EZH2 as a key mediator promoting CDH1 loss-associated DGAC tumorigenesis. These findings highlight DGAC's molecular diversity and potential for personalized treatment in CDH1-inactivated patients.

Overview of tumor immunotherapy based on approved drugs

Tumor immunotherapy has become a new hotspot for cancer treatment. Various immunotherapies, such as immune checkpoint inhibitors, oncolytic viruses (OVs), cytokines, and cancer vaccines, have been used to treat tumors. They operate through different mechanisms, along with certain toxicities and side effects. Understanding the mechanisms by which immunotherapy modulates the immune system is essential for improving the efficacy and managing these adverse effects. This article discusses various currently approved cancer immunotherapy mechanisms and related agents approved by the Food and Drug Administration, the European Medicines Agency, and the Medicines and Medical Devices Agency. We also review the latest progress in immune drugs approved by the National Medical Products Administration, including monoclonal antibodies, cytokines, OVs, and chimeric antigen receptor-T cell therapy, to help understand the clinical application of tumor immunotherapy.

A Review on Anaplastic Lymphoma Kinase (ALK) Rearrangements and Mutations: Implications for Gastric Carcinogenesis and Target Therapy

Gastric adenocarcinoma is a complex disease with diverse genetic modifications, including Anaplastic Lymphoma Kinase (ALK) gene changes. The ALK gene is located on chromosome 2p23 and encodes a receptor tyrosine kinase that plays a crucial role in embryonic development and cellular differentiation. ALK alterations can result from gene fusion, mutation, amplification, or overexpression in gastric adenocarcinoma. Fusion occurs when the ALK gene fuses with another gene, resulting in a chimeric protein with constitutive kinase activity and promoting oncogenesis. ALK mutations are less common but can also result in the activation of ALK signaling pathways. Targeted therapies for ALK variations in gastric adenocarcinoma have been developed, including ALK inhibitors that have shown promising results in pre-clinical studies. Future studies are needed to elucidate the ALK role in gastric cancer and to identify predictive biomarkers to improve patient selection for targeted therapy. Overall, ALK alterations are a relevant biomarker for gastric adenocarcinoma treatment and targeted therapies for ALK may improve patients' overall survival.

Novel HER2-targeted therapy to overcome trastuzumab resistance in HER2-amplified gastric cancer

Trastuzumab is used to treat HER2-amplified metastatic gastric cancer; however, most patients become trastuzumab-resistant within a year. Knowledge of the mechanisms underlying trastuzumab resistance is required to overcome this limitation. Here, we aimed to elucidate this resistance mechanism using four trastuzumab-resistant (TR) cell lines and investigate the efficacy of HER2-targeted therapies to overcome treatment resistance. Each TR cell line had different phenotypic characteristics. Interestingly, HER2 expression remained as high as the parental cell lines in TR cell lines, suggesting that HER2-targeted agents were still useful. As expected, three tyrosine kinase inhibitors (lapatinib, neratinib, and tucatinib) and one antibody-drug conjugate (trastuzumab deruxtecan: T-DXd) exhibited good antitumor effects against TR cell lines. We further investigated the potential biological mechanism of T-DXd. When treated with trastuzumab or T-DXd, HER2 or its downstream signals were disrupted in parental cell lines, but not in TR cell lines. Moreover, T-DXd induced the expression of pH2A.X and cPARP and caused cell cycle arrest in the S or G2-M phase in TR cell lines. T-DXd showed promising antitumor activity in both parental and TR cell lines, suggesting that it is a potential candidate for overcoming trastuzumab resistance.

ONC201/TIC10 plus TLY012 anti-cancer effects via apoptosis inhibitor downregulation, stimulation of integrated stress response and death receptor DR5 in gastric adenocarcinoma

Gastric adenocarcinoma typically presents with advanced stage when inoperable. Chemotherapy options include non-targeted and toxic agents, leading to poor 5-year patient survival outcomes. Small molecule ONC201/TIC10 (TRAIL-Inducing Compound #10) induces cancer cell death via ClpP-dependent activation of the integrated stress response (ISR) and up-regulation of the TRAIL pathway. We previously found in breast cancer, pancreatic cancer and endometrial cancer that ONC201 primes tumor cells for TRAIL-mediated cell death through ISR-dependent upregulation of ATF4, CHOP and TRAIL death receptor DR5. We investigated the ability of ONC201 to induce apoptosis in gastric adenocarcinoma cells in combination with recombinant human TRAIL (rhTRAIL) or PEGylated trimeric TRAIL (TLY012). AGS (caspase 8-, KRAS-, PIK3CA-mutant, HER2-amplified), SNU-1 (KRAS-, MLH1-mutant, microsatellite unstable), SNU-5 (p53-mutant) and SNU-16 (p53-mutant) gastric adenocarcinoma cells were treated with ONC201 and TRAIL both in cell culture and in vivo. Gastric cancer cells showed synergy following dual therapy with ONC201 and rhTRAIL/TLY012 (combination indices < 0.6 at doses that were non-toxic towards normal fibroblasts). Synergy was observed with increased cells in the sub-G1 phase of the cell cycle with dual ONC201 plus TRAIL therapy. Increased PARP, caspase 8 and caspase 3 cleavage after ONC201 plus TRAIL further documented apoptosis. Increased cell surface expression of DR5 with ONC201 therapy was observed by flow cytometry, and immunoblotting revealed ONC201 upregulation of the ISR, ATF4, and CHOP. We observed downregulation of anti-apoptotic cIAP-1 and XIAP in all cells except AGS, and cFLIP in all cells except SNU-16. We tested the regimen in an organoid model of human gastric cancer, and in murine sub-cutaneous xenografts using AGS and SNU-1 cells. Our results suggest that ONC201 in combination with TRAIL may be an effective and non-toxic option for the treatment of gastric adenocarcinoma by inducing apoptosis via activation of the ISR, increased cell surface expression of DR5 and down-regulation of inhibitors of apoptosis. Our results demonstrate in vivo anti-tumor effects of ONC201 plus TLY012 against gastric cancer that could be further investigated in clinical trials.

CDH1 loss promotes diffuse-type gastric cancer tumorigenesis via epigenetic reprogramming and immune evasion

Diffuse-type gastric adenocarcinoma (DGAC) is a deadly cancer often diagnosed late and resistant to treatment. While hereditary DGAC is linked to CDH1 gene mutations, causing E-Cadherin loss, its role in sporadic DGAC is unclear. We discovered CDH1 inactivation in a subset of DGAC patient tumors. Analyzing single-cell transcriptomes in malignant ascites, we identified two DGAC subtypes: DGAC1 (CDH1 loss) and DGAC2 (lacking immune response). DGAC1 displayed distinct molecular signatures, activated DGAC-related pathways, and an abundance of exhausted T cells in ascites. Genetically engineered murine gastric organoids showed that Cdh1 knock-out (KO), KrasG12D, Trp53 KO (EKP) accelerates tumorigenesis with immune evasion compared to KrasG12D, Trp53 KO (KP). We also identified EZH2 as a key mediator promoting CDH1 loss-associated DGAC tumorigenesis. These findings highlight DGAC's molecular diversity and potential for personalized treatment in CDH1-inactivated patients.

The E3 ubiquitin ligase TRIM17 promotes gastric cancer survival and progression via controlling BAX stability and antagonizing apoptosis

Tripartite motif 17 (TRIM17) belongs to a subfamily of the RING-type E3 ubiquitin ligases, and regulates several cellular processes and pathological conditions including cancer. However, its potential function in gastric cancer (GC) remains obscure. Here, we have found TRIM17 mRNA and protein levels are both upregulated in human GC compared with normal specimens, and TRIM17 upregulation indicates poor survival for GC patients. Functionally, TRIM17 was found to act as an oncogene by promoting the proliferation and survival of GC cell lines AGS and HGC-27. Mechanistically, TRIM17 acts to interact with BAX and promote its ubiquitination and proteasomal degradation, leading to a deficiency in BAX-dependent apoptosis in GC cells in the absence and presence of apoptosis stimuli. Moreover, TRIM17 and BAX expression levels are inversely correlated in human GC specimens. Our data thus suggest TRIM17 contributes to gastric cancer survival through regulating BAX protein stability and antagonizing apoptosis, which provides a promising therapeutic target for GC treatment and a biomarker for prognosis.

Predictive biomarkers and new developments of immunotherapy in gastric cancer: a 2023 update

Gastric cancer is an extremely common digestive tract tumor. The promotion and application of standardized therapy, treatment scheme optimization, and development of new targeted drugs and immunotherapies have improved gastric cancer survival somewhat. However, gastric cancer prognosis generally remains non-optimistic. Immune checkpoint inhibitors (ICI) have gradually become a new choice for gastric cancer treatment and can prolong the survival of some patients. Among them, high-microsatellite instability, Epstein-Barr virus-positive status, or high-tumor mutational burden patients with gastric cancer may be the potential population to benefit from immunotherapy. Nevertheless, there remains a lack of unified and effective predictive markers. Accordingly, this review mainly focused on the possible predictive biomarkers of anti-PD-1/PD-L1 in gastric cancer treatment. Furthermore, the application of anti-PD-1/PD-L1 therapy-related clinical trials on gastric cancer is discussed. The current findings suggest that immunotherapy is a promising application in gastric cancer treatment. Therefore, combining immunotherapy and other therapies may be the trend in the future. Nevertheless, exploring biomarkers to predict ICI response remains a major challenge.

Clinical efficacy and safety of bispecific antibodies for the treatment of solid tumors: a systematic review and meta-analysis

INTRODUCTION

Immunotherapy is a promising and progressing treatment approach for cancer. Bispecific antibodies (BsAbs) are antibody constructs that can bind to two different epitopes. The dual-specificity of BsAbs improves their efficacy compared to monoclonal antibodies.

AREAS COVERED

Although BsAbs have achieved excellent therapeutic effects in hematologic cancers, no systematic review with meta-analysis evaluated their efficacy in solid tumors. In the present systematic review and meta-analysis, we aimed to establish the clinical efficacy and safety of BsAbs in solid tumors.

EXPERT OPINION

BsAbs are not associated with significantly better safety or efficacy outcomes than conventional therapies. BsAb was not associated with improvement in overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and disease control rate (DCR). However, BsAb increased the rate of stable disease (SD) significantly. Also, BsAb substantially increased the OS and PFS and resulted in a higher frequency of DCR for uveal melanoma. Furthermore, the safety analysis showed no obvious difference in the rate of any adverse events (AEs), grade ≥3 AEs, serious AEs, and AEs leading to treatment discontinuation in the intervention group compared to controls. Further high-quality randomized controlled trials on BsAbs in solid tumors are highly recommended.

Molecular mechanism of XB130 adaptor protein mediates trastuzumab resistance in gastric cancer

BACKGROUND

Recent studies have shown that the activation of PI3K/AKT signaling pathway is an essential molecular mechanism participating in trastuzumab resistance in HER2 + GC (gastric cancer). However, how can we effectively inhibit AKT activity associated with drug resistance during trastuzumab treatment? Screening inhibitors against the upstream receptors of PI3K/AKT signaling pathway or interacting proteins of members has become an important way.

METHODS

In this study, western blot, qRT-PCR, CCK8, Co-IP and other techniques were used to explore possible mechanisms participating in trastuzumab resistance in vitro. Besides, the xenograft mouse model and GC tissue samples from patients were used to further validate the in-vitro results.

RESULTS

The expression of XB130 adaptor protein was remarkably increased in GC cell lines resistant to trastuzumab, and knockdown of XB130 could reverse the resistance via downregulating p-AKT. In addition, p-SRC (Tyr416) was increased in resistant cells, which could facilitate the binding of XB130 to PI3K p85α. It was also discovered that XB130 could negatively regulate PTEN gene transcription, and thus a positive feedback loop was formed between SRC-XB130-PTEN.

CONCLUSIONS

In HER2 + GC, XB130 contributes to trastuzumab resistance by stimulating the PI3K/AKT signaling pathway through binding to PI3K p85α under the mediation of SRC kinase and regulating PTEN gene transcription, and in turn forming a positive feedback loop between SRC-XB130-PTEN.

Global retrospective analysis of clinician- and patient-reported clinical characteristics and humanistic burden of patients with gastroesophageal cancers on first-line treatment

BACKGROUND

Gastric cancer (GC), gastroesophageal junction cancer (GEJC), and esophageal adenocarcinoma (EAC), together, are leading causes of cancer deaths worldwide. Patient health-related quality of life (HRQoL) and well-being has become increasingly important alongside traditional oncologic outcomes for both patients and clinicians and may aid treatment decisions. We conducted a survey to examine the clinical characteristics, humanistic burden, and the effects of first-line (1L) treatment in patients with GC/GEJC/EAC, across different geographic regions, to address the paucity of real-world data.

METHODS

Clinicians treating patients with unresectable advanced or metastatic GC/GEJC/EAC in China, France, Germany, Japan, the United Kingdom, and the United States, during April-October 2019, were invited to provide data on their patients' demographics, clinical characteristics, treatment, and HRQoL via medical chart reviews, clinician surveys, and patient questionnaires. Data were analyzed using descriptive statistics, regression analyses comparing active treatment and best supportive care. Patients were also stratified into subgroups that were identified either as human epidermal growth factor receptor 2 (HER2) positive, HER2 negative (which has a higher prevalence but for whom there are limited treatment options), or unknown HER2 status.

RESULTS

Survey data were analyzed for 995 patients, 87% of whom were on active treatment, most commonly dual or triple chemotherapy. Demographics and clinical characteristics were similar across countries with most patients having GC and the lowest incidence of GEJC and EAC in China. Overall, most patients had de novo disease with good response to 1L treatment, while their HRQoL and well-being was significantly worse than the general population. In 682 patients on active treatment with HER2 negative or unknown status, HRQoL also appeared to be worse in those with recurrent disease. Regression analysis identified several drivers of treatment decisions and factors impacting patients' HRQoL, including stage of disease and comorbidities.

CONCLUSIONS

In patients with advanced GC/GEJC/EAC, screening and assessment of HER2 status as well as patient-reported HRQoL outcomes are invaluable in aiding treatment decisions. The introduction of appropriate therapy soon after diagnosis has the prospect of achieving improved HRQoL and survival in these patients.

ARID1A deficiency is targetable by AKT inhibitors in HER2-negative gastric cancer

BACKGROUND

The PI3K/AKT signaling pathway is frequently activated in gastric cancer (GC); however, AKT inhibitors are not effective in unselected GC patients in clinical trials. Mutations in AT-rich interactive domain 1A (ARID1A), which are found in approximately 30% of GC patients, activate PI3K/AKT signaling, suggesting that targeting the ARID1A deficiency-activated PI3K/AKT pathway is a therapeutic candidate for ARID1A-deficient GC.

METHODS

The effect of AKT inhibitors was evaluated using cell viability and colony formation assays in ARID1A-deficient and ARID1A knockdown ARID1A-WT GC cells as well as in HER2-positive and HER2-negative GC. The Cancer Genome Atlas cBioPortal and Gene Expression Omnibus microarray databases were accessed to determine the extent of dependence of GC cell growth on the PI3K/AKT signaling pathway.

RESULTS

AKT inhibitors decreased the viability of ARID1A-deficient cells and the inhibitory effect was greater in ARID1A-deficient/HER2-negative GC cells. Bioinformatics data suggested that PI3K/AKT signaling plays a greater role in proliferation and survival in ARID1A-deficient/HER2-negative GC cells than in ARID1A-deficient/HER2-positive cells, supporting the higher therapeutic efficacy of AKT inhibitors.

CONCLUSIONS

The effect of AKT inhibitors on cell proliferation and survival is affected by HER2 status, providing a rationale for exploring targeted therapy using AKT inhibitors in ARID1A-deficient/HER2-negative GC.

Pharmacokinetics of biologics in gastric cancer

Gastric cancer (GC) remains one of the leading causes of cancer death worldwide despite improvements in therapeutic options. Several biologics have been investigated in patients with GC, including those approved in other solid tumors; however, the success rate of the pivotal trials that investigated these biologic molecules in GC remains low. Elevation in total clearance and a decrease in systemic pharmacokinetic (PK) exposure in GC compared with other indications have been observed in these biologics across different pathways. Achieving optimal exposure for patients with GC is an important factor in balancing risk and optimizing therapeutic benefit and thus maximizing chance of positive outcomes for pivotal trials. Therefore, in this review, we summarize the PK disposition of several molecules (e.g., anti-HER2, anti-VEGF, and anti-PD1) evaluated in GC and showed a consistent trend of lower drug exposure as compared to other solid tumors. We hypothesize that two possible mechanisms: (1) hyper-catabolism of endogenous and exogenous proteins due to cancer cachexia; and (2) gastric protein leakage due to local inflammation at the gastrointestinal tract may explain or partially explain the increase of clearance in patients with GC. Last, the potential implications of such findings on dose selection to optimize the benefit: risk profile for biologics in GC are also discussed.

Clinical Management of Gastric Cancer Treatment Regimens

Gastric cancer is the fifth most common cancer and the fourth leading cause of cancer-associated death in the world. Endoscopic resection can be the treatment in selected cases of very early gastric cancer. Surgery is recommended for tumors that do not meet the criteria for endoscopic resection or for tumors with lymph node invasion but without distant metastases. Gastrectomy should include D2 lymphadenectomy without splenectomy. Perioperative or adjuvant chemotherapy improves survival and is recommended in locally advanced gastric cancer (>T1 and/or with lymph nodes positive). In locally advanced cancer with microsatellite instability (MSI), immunotherapy should be considered. Advanced unresectable or metastatic gastric cancer has a poor prognosis. The basis of the treatment is cytotoxic chemotherapy, with platinum and fluoropyrimidine doublet in the first line. Targeted therapies can be combined with chemotherapy. Trastuzumab (anti-HER2) is recommended in the first line in HER2-positive cancer. Ramucirumab (anti-VEGFR2) is recommended in the second line, in addition to paclitaxel chemotherapy. Zolbetuximab (anti-Claudine 18.2) should also be considered in the first line in Claudine 18.2-positive cancer. Immunotherapy can also be associated with chemotherapy in the first line of PD-L1-positive cancer. In HER2-positive and PD-L1-positive cancer, adjunction of trastuzumab and immunotherapy should be considered. In advanced and metastatic cancer with microsatellite instability (MSI), immunotherapy should be the first choice depending on its availability. Important progress has been made in recent years in the treatment of gastric cancer, especially due to a better understanding of molecular characteristics and heterogeneity of this disease. New targets and therapeutic approaches are being developed, which will very likely lead to changes in the management of gastric cancer.

Recent Trends and Advancements in the Diagnosis and Management of Gastric Cancer

Gastric cancer is an enigmatic malignancy that has recently been shown to be increasing in incidence globally. There has been recent progress in emerging technologies for the diagnosis and treatment of the disease. Improvements in non-invasive diagnostic techniques with serological tests and biomarkers have led to decreased use of invasive procedures such as endoscopy. A multidisciplinary approach is used to treat gastric cancer, with recent significant advancements in systemic therapies used in combination with cytotoxic chemotherapies. New therapeutic targets have been identified and clinical trials are taking place to assess their efficacy and safety. In this review, we provide an overview of the current and emerging treatment strategies and diagnostic techniques for gastric cancer.

Construction and validation of a glycolysis-related lncRNA signature for prognosis prediction in Stomach Adenocarcinoma

Background: Glycolysis is closely related to the occurrence and progression of gastric cancer (GC). Currently, there is no systematic study on using the glycolysis-related long non-coding RNA (lncRNA) as a model for predicting the survival time in patients with GC. Therefore, it was essential to develop a signature for predicting the survival based on glycolysis-related lncRNA in patients with GC. Materials and methods: LncRNA expression profiles, containing 375 stomach adenocarcinoma (STAD) samples, were obtained from The Cancer Genome Atlas (TCGA) database. The co-expression network of lncRNA and glycolysis-related genes was used to identify the glycolysis-related lncRNAs. The Kaplan-Meier survival analysis and univariate Cox regression analysis were used to detect the glycolysis-related lncRNA with prognostic significance. Then, Bayesian Lasso-logistic and multivariate Cox regression analyses were performed to screen the glycolysis-related lncRNA with independent prognostic significance and to develop the risk model. Patients were assigned into the low- and high-risk cohorts according to their risk scores. A nomogram model was constructed based on clinical information and risk scores. Gene Set Enrichment Analysis (GSEA) was performed to visualize the functional and pathway enrichment analyses of the glycolysis-related lncRNA. Finally, the robustness of the results obtained was verified in an internal validation data set. Results: Seven glycolysis-related lncRNAs (AL353804.1, AC010719.1, TNFRSF10A-AS1, AC005586.1, AL355574.1, AC009948.1, and AL161785.1) were obtained to construct a risk model for prognosis prediction in the STAD patients using Lasso regression and multivariate Cox regression analyses. The risk score was identified as an independent prognostic factor for the patients with STAD [HR = 1.315, 95% CI (1.056-1.130), p < 0.001] via multivariate Cox regression analysis. Receiver operating characteristic (ROC) curves were drawn and the area under curve (AUC) values of 1-, 3-, and 5-year overall survival (OS) were calculated to be 0.691, 0.717, and 0.723 respectively. Similar results were obtained in the validation data set. In addition, seven glycolysis-related lncRNAs were significantly enriched in the classical tumor processes and pathways including cell adhesion, positive regulation of vascular endothelial growth factor, leukocyte transendothelial migration, and JAK_STAT signaling pathway. Conclusion: The prognostic prediction model constructed using seven glycolysis-related lncRNA could be used to predict the prognosis in patients with STAD, which might help clinicians in the clinical treatment for STAD.

Advances in CAR T-cell therapy in bile duct, pancreatic, and gastric cancers

Bile duct, pancreatic, and gastric cancers are deadly digestive system tumors with high malignancy and poor patient prognosis. The efficiencies of conventional surgical treatment, radiation therapy, and chemotherapy are limited. In contrast, chimeric antigen receptor (CAR) T-cell therapy represents a landmark therapeutic approach to antitumor immunity with great efficacy in treating several hematological malignancies. CAR T-cell therapy involves genetically engineering the expression of specific antibodies based on the patient's T-cell surface and amplifying these antibodies to identify and target tumor-associated antigens. CAR T-cell therapy can effectively inhibit disease progression and improve the survival of patients with bile duct, pancreatic, and gastric cancers. The effectiveness of CAR T cells in tumor therapy can be validated using xenograft models, providing a scientific testing platform. In this study, we have reviewed the progress in CAR T-cell production and its development, focusing on the current status and optimization strategies for engineered CAR T cells in the bile duct, pancreatic, and gastric cancers.

Gastric Cancer Subtypes in Tumour and Nontumour Tissues by Immunologic and Hallmark Gene Sets

A previous research study on differentiating gastric cancer (GC) into distinct subtypes or prognostic models was mostly based on GC tissues, which neglected the role of nontumour tissues in GC subtypes. The purpose of the research was to identify GC subtypes on the basis of tumour and adjacent nontumour tissues to assess the prognosis of GC patients. We characterized three GC subtypes on the basis of the immunologic and hallmark gene sets in GC and adjacent nontumour tissues: among them, the GC patients with subtype I had the longest survival time compared to patients with other subtypes. The classification was closely associated with T stage and pathological stage of GC patients. A prognostic model containing two gene sets was constructed by LASSO analysis. Kaplan–Meier analysis showed that patients in the high-risk group survived longer than those in the low-risk group and the two prognostic genes sets in the model were strongly correlated with survival status. Then, GO and KEGG analyses and PPI network show that nontumour and tumour tissues are influencing the prognosis of GC patients in separate manners. In summary, we emphasized the prognostic value of nontumour tissue in GC patients and proposed a novel insight that both changes in tumour and nontumour tissues should be taken into account when selecting a treatment strategy for GC.

Evolution of predictive and prognostic biomarkers in the treatment of advanced gastric cancer

Despite new therapeutic options, advanced gastric cancer remains associated with a poor prognosis compared with other cancers. Recent gains in the treatment of gastric cancer were accompanied by the identification of novel biomarkers associated with various cellular pathways and corresponding diagnostic technologies. It is expected that the standardization of clinical workflow and technological refinements in biomarker assessment will support greater personalization and further improve treatment outcomes. In this article, we review the current state of prognostic and predictive biomarkers in gastric cancer.

Novel Drug Delivery Systems as an Emerging Platform for Stomach Cancer Therapy

Cancer has long been regarded as one of the world's most fatal diseases, claiming the lives of countless individuals each year. Stomach cancer is a prevalent cancer that has recently reached a high number of fatalities. It continues to be one of the most fatal cancer forms, requiring immediate attention due to its low overall survival rate. Early detection and appropriate therapy are, perhaps, of the most difficult challenges in the fight against stomach cancer. We focused on positive tactics for stomach cancer therapy in this paper, and we went over the most current advancements and progressions of nanotechnology-based systems in modern drug delivery and therapies in great detail. Recent therapeutic tactics used in nanotechnology-based delivery of drugs aim to improve cellular absorption, pharmacokinetics, and anticancer drug efficacy, allowing for more precise targeting of specific agents for effective stomach cancer treatment. The current review also provides information on ongoing research aimed at improving the curative effectiveness of existing anti-stomach cancer medicines. All these crucial matters discussed under one overarching title will be extremely useful to readers who are working on developing multi-functional nano-constructs for improved diagnosis and treatment of stomach cancer.

Augmenting Experimental Gastric Cancer Activity of Irinotecan through Liposomal Formulation and Antiangiogenic Combination Therapy

Gastric adenocarcinoma (GAC) is the third most common cause of cancer-related deaths worldwide. Combination chemotherapy remains the standard treatment for advanced GAC. Liposomal irinotecan (nal-IRI) has improved pharmacokinetics (PK) and drug biodistribution compared with irinotecan (IRI, CPT-11). Angiogenesis plays a crucial role in the progression and metastasis of GAC. We evaluated the antitumor efficacy of nal-IRI in combination with novel antiangiogenic agents in GAC mouse models. Animal survival studies were performed in peritoneal dissemination xenografts. Tumor growth and PK studies were performed in subcutaneous xenografts. Compared with controls, extension in animal survival by nal-IRI and IRI was >156% and >94%, respectively. The addition of nintedanib or DC101 extended nal-IRI response by 13% and 15%, and IRI response by 37% and 31% (MKN-45 xenografts); nal-IRI response by 11% and 3%, and IRI response by 16% and 40% (KATO-III xenografts). Retardation of tumor growth was greater with nal-IRI (92%) than IRI (71%). Nintedanib and DC101 addition tend to augment nal-IRI or IRI response in this model. The addition of antiangiogenic agents enhanced tumor cell proliferation inhibition effects of nal-IRI or IRI. The tumor vasculature was decreased by nintedanib (65%) and DC101 (58%), while nal-IRI and IRI alone showed no effect. PK characterization in GAC xenografts demonstrated that compared with IRI, nal-IRI treatment groups had higher retention, circulation time, and tumor levels of CPT-11 and its active metabolite SN-38. These findings indicate that nal-IRI, alone and in combination with antiangiogenic agents, has the potential for improving clinical GAC therapy.

Wnt/beta-catenin signaling confers ferroptosis resistance by targeting GPX4 in gastric cancer

The development of chemotherapy resistance is the most vital obstacle to clinical efficacy in gastric cancer (GC). The dysregulation of the Wnt/beta-catenin signaling pathway is critically associated with GC development and chemotherapy resistance. Ferroptosis is a form of regulated cell death, induced by an iron-dependent accumulation of lipid peroxides during chemotherapy. However, whether the Wnt/beta-catenin signaling directly controls resistance to cell death, remains unclear. Here, we show that the activation of the Wnt/beta-catenin signaling attenuates cellular lipid ROS production and subsequently inhibits ferroptosis in GC cells. The beta-catenin/TCF4 transcription complex directly binds to the promoter region of GPX4 and induces its expression, resulting in the suppression of ferroptotic cell death. Concordantly, TCF4 deficiency promotes cisplatin-induced ferroptosis in vitro and in vivo. Thus, we demonstrate that the aberrant activation of the Wnt/beta-catenin signaling confers ferroptosis resistance and suggests a potential therapeutic strategy to enhance chemo-sensitivity for advanced GC patients.

Docetaxel and 5-FU enhanced the inhibitory effects of apatinib and ramucirumab on growth and migration of gastric cancer

BACKGROUND

Gastric cancer (GC) is one of the most common malignant tumors in the world. The clinical benefit of anti-angiogenic strategy as a single drug is limited. Some studies showed that the combination of anti-angiogenic therapy and chemotherapy exhibited synergistic effect and reduced the side effects of chemotherapy drugs. We investigated the combined effects of these two types of drugs in gastric cancer cells in vitro and in vivo.

METHODS

cell viability, migration, invasion, and apoptosis were evaluated by CCK-8, wound-healing, transwell, and Annexin V-FITC/PI assay, respectively. In vivo anti-cancer efficacy was tested for the cell proliferation and metastasis in cell line derived tumor xenograft (CDX) model and patient derived tumor xenografted (PDX) model based on Tg (fli-1: EGFP) zebrafish embryos; RESULTS: In the cell experiments, the combination of the two types of drugs could inhibit the proliferation and metastasis of gastric cancer cells and promote apoptosis through VEGFR-2/AKT/ERK1/2 signal. In the zebrafish CDX (zCDX) model and zebrafish PDX (zPDX) model, the combination of the two treatment also showed a synergistic effect in inhibiting gastric cancer cell metastasis and cell proliferation.

CONCLUSIONS

Apatinib/ramucirumab targeted therapy combined with docetaxel or 5-fluorouracil (5-FU) may serve as an effective treatment strategy for patients with advanced gastric cancer.

Trends and Projections in National United States Health Care Spending for Gastrointestinal Malignancies (1996-2030)

BACKGROUND & AIMS

The management of gastrointestinal (GI) cancers is associated with high health care spending. We estimated trends in United States (US) health care spending for patients with GI cancers between 1996 and 2016 and developed projections to 2030.

METHODS

We used economic data, adjusted for inflation, developed by the Institute for Health Metrics and Evaluations for the Disease Expenditure Project. Corresponding US age-adjusted prevalence of GI cancers was estimated from the Global Burden of Diseases Study. Prevalence-adjusted temporal trends in the US health care spending in patients with GI cancers, stratified by cancer site, age, and setting of care, were estimated using joinpoint regression, expressed as annual percentage change (APC) with 95% confidence intervals (CIs). Autoregressive integrated moving average models were used to project spending to 2030.

RESULTS

In 2016, total spending for GI cancers was primarily attributable to colorectal ($10.50 billion; 95% CI, $9.35-$11.70 billion) and pancreatic cancer ($2.55 billion; 95% CI, $2.23-$2.82 billion), and primarily for inpatient care (64.5%). Despite increased total spending, more recent per-patient spending for pancreatic (APC 2008-2016, -1.4%; 95% CI, -2.2% to -0.7%), gallbladder/biliary tract (APC 2010-2016, -4.3%; 95% CI, -4.8% to -3.8%), and gastric cancer (APC 2011-2016, -4.4%; 95% CI, -5.8% to -2.9%) decreased. Increasing price and intensity of care provision was the largest driver of higher expenditures. By 2030, it is projected more than $21 billion annually will be spent on GI cancer management.

CONCLUSIONS

Total spending for GI cancers in the US is substantial and projected to increase. Expenditures are primarily driven by inpatient care for colorectal cancer, although per-capita spending trends differ by GI cancer type.

FDA-Approved Small Molecule Compounds as Drugs for Solid Cancers from Early 2011 to the End of 2021

Solid cancers are the most common types of cancers diagnosed globally and comprise a large number of deaths each year. The main challenge currently in drug development for tumors raised from solid organs is to find more selective compounds, which exploit specific molecular targets. In this work, the small molecule drugs registered by the Food and Drug Administration (FDA) for solid cancers treatment between 2011 and 2022 were identified and analyzed by investigating a type of therapy they are used for, as well as their structures and mechanisms of action. On average, 4 new small molecule agents were introduced each year, with a few exceptions, for a total of 62 new drug approvals. A total of 50 of all FDA-approved drugs have also been authorized for use in the European Union by the European Medicines Agency (EMA). Our analysis indicates that many more anticancer molecules show a selective mode of action, i.e., 49 targeted agents, 5 hormone therapies and 3 radiopharmaceuticals, compared to less specific cytostatic action, i.e., 5 chemotherapeutic agents. It should be emphasized that new medications are indicated for use mainly for monotherapy and less for a combination or adjuvant therapies. The comprehensive data presented in this review can serve for further design and development of more specific targeted agents in clinical usage for solid tumors.

Ferroptosis-related gene SLC1A5 is a novel prognostic biomarker and correlates with immune infiltrates in stomach adenocarcinoma

BACKGROUND

Stomach adenocarcinoma (STAD) is associated with high morbidity and mortality rates. Ferroptosis is an iron-dependent form of cell death, which plays an important role in the development of many cancers. Tumor-associated competing endogenous RNAs (ceRNAs) regulate tumorigenesis and development. Our study aimed to construct ceRNA networks and explore the relationship between ferroptosis-related genes in the ceRNA network and immune infiltration in STAD.

METHODS

Based on the interactions among long noncoding RNAs (lncRNAs), microRNAs (miRNAs), and messenger RNAs (mRNAs), a ceRNA network was constructed to illustrate the relationships among lncRNAs, miRNAs, and mRNAs. Subsequently, gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) functional enrichment analyses were carried out to explore the functions and interactions of the differentially expressed (DE) mRNAs related to the ceRNA network. Differential expression and prognostic analysis of ferroptosis-related genes in the ceRNA network were performed using the R package "limma" and "survminer." The correlation between ferroptosis-related genes and tumor-infiltrating immune cells was analyzed using Spearman correlation analysis and CIBERSORT. Quantitative real-time PCR (qRT-PCR) was used to validate the expression of ferroptosis-related genes in STAD cells lines.

RESULTS

A ceRNA network consisting of 29 DElncRNAs, 31 DEmiRNAs, and 182 DEmRNAs was constructed. These DEmRNAs were significantly enriched in pathways related to the occurrence and development of STAD. The ferroptosis-related gene SLC1A5 was upregulated in STAD (P < 0.001) and was associated with better prognosis (P = 0.049). The CIBERSORT database and Spearman correlation analysis indicated that SLC1A5 was correlated with eight types of tumor-infiltrating immune cells and immune checkpoints, including PD-L1(CD-274) and PD-1(PDCD1). The SLC1A5 mRNA was found to be highly expressed in STAD cells lines.

CONCLUSIONS

Our study provides insights into the function of ceRNAs in STAD and identifies biomarkers for the development of therapies for STAD. The ferroptosis-related gene SLC1A5 in the ceRNA network was associated with both tumor-infiltrating immune cells and immune checkpoints in the tumor microenvironment, suggesting that SLC1A5 may be a novel prognostic marker and a potential target for STAD immunotherapy in the future.

Human Epidermal Growth Factor Receptor 2 (HER2) Expression in Colorectal Carcinoma: A Potential Area of Focus for Future Diagnostics

Objective In this study, we aimed to explore the potential diagnostic utility of human epidermal growth factor receptor 2 (HER2) expression in colorectal carcinoma. We investigated the association of HER2 expression with the type and grade of the tumor along with the pattern, staining intensity, and the percentage of cells stained. Methods This was an observational study involving 50 cases of colorectal carcinoma that underwent immunohistochemistry to analyze the HER2 expression. Results The positive expression of HER2 was seen in 16 (32%) cases. The majority of the study population was between the fifth-seventh decades of life. The most commonly diagnosed tumor was conventional adenocarcinoma with grade II, cytoplasmic pattern, +2 positivity, and moderate intensity. The maximum positivity for HER2 was seen in tumors of the rectum in eight (16%) cases. Conclusion A substantial rate of HER2 overexpression paves the way for it to become a potential future target in cancer therapeutics.

Identification of a new RNA-binding proteins-based signature for prognostic prediction in gastric cancer

Gastric cancer (GC) is one of the most common cancers with high incidence and mortality worldwide. Recently, RNA-binding proteins (RBPs) have drawn more and more attention for its role in cancer pathophysiology. However, the function and clinical implication of RBPs in GC have not been fully elucidated. RNA sequencing data along with the corresponding clinical information of GC patients were downloaded from The Cancer Genome Atlas (TCGA) database. Differentially expressed RNA-binding proteins (DERBPs) between tumor and normal tissues were identified by "limma" package. Functional enrichment analysis and the protein-protein interaction (PPI) network were harnessed to explore the function and interaction of DERBPs. Next, univariate and multiple Cox regression were applied to screen prognosis-related hub RBPs and to construct a signature for GC. Meanwhile, a nomogram was built on the basis of the independent factors. A total of 296 DERBPs were found, and most of them mainly related to post-transcriptional regulation of RNA and ribonucleoprotein. A PPI network of DERBPs was constructed, consisting of 262 nodes and 2567 edges. A prognostic signature was built depending on 7 prognosis-related hub RBPs that could divide GC patients into high-risk and low-risk groups. Survival analysis showed that high-risk group had a worse prognosis compared with the low-risk group and the time-dependent receiver operating characteristic (ROC) curves suggested that signature existed moderate predictive capacities of survival for GC patients. Similar results were obtained from another independent set GSE62254, confirming the robustness of signature. Besides, the genetic variation and immune heterogeneity differences were identified between the high-risk and low-risk groups by bioinformatics methods. These findings would provide evidence of the effect of RBPs and offer a novel potential biomarker in prognostic prediction and clinical decision for GC.

CircPVT1: a pivotal circular node intersecting Long Non-Coding-PVT1 and c-MYC oncogenic signals

The role of circular RNAs in oncogenesis has begun to be widely studied in recent years, due to the significant impact that these molecules have in disease pathogenesis, as well as their potential for the future of innovative therapies. Moreover, due to their characteristically circular shape, circular RNAs are very resistant molecules to RNA degradation whose levels are easily assessed in body fluids. Accordingly, they represent an opportunity for the discovery of new diagnostic and prognostic markers in a wide range of diseases. Among circular RNAs, circPVT1 is a rather peculiar one that originates from the circularization of the exon 2 of the PVT1 gene that encodes a pro-tumorigenic long non-coding RNA named lncPVT1. There are a few examples of circular RNAs that derive from a locus producing another non-coding RNA. Despite their apparent transcriptional independence, which occurs using two different promoters, a possible synergistic effect in tumorigenesis cannot be excluded considering that both have been reported to correlate with the oncogenic phenotype. This complex mechanism of regulation appears to also be controlled by c-MYC. Indeed, the PVT1 locus is located only 53 Kb downstream c-MYC gene, a well-known oncogene that regulates the expression levels of about 15% of all genes. Here, we review circPVT1 origin and biogenesis highlighting the most important mechanisms through which it plays a fundamental role in oncogenesis, such as the well-known sponge activity on microRNAs, as well as its paradigmatic interactome link with lncPVT1 and c-MYC expression.

Patient and caregiver socioeconomic burden of first-line systemic therapy for advanced gastroesophageal adenocarcinoma

Aim: This study assessed the work productivity and financial impact of advanced gastroesophageal adenocarcinomas, comprising gastric, esophageal and gastroesophageal junction cancers, on patients of working age and their caregivers. Patients & methods: A multicenter medical chart review and surveys of patients with advanced gastroesophageal adenocarcinoma and their caregivers was conducted in France, Germany, the UK, China, Japan and the USA. Results: Across differing regions, the study highlighted the impact of cancer on patients' ability to work, to function normally and on their wellbeing, as well as the economic burden placed on patients and their caregivers. Conclusion: Advanced gastroesophageal adenocarcinomas have a significant impact on patients' and caregivers' well-being and are associated with reduced work productivity, and income loss.

Mono-PEGylated thermostable Bacillus caldovelox arginase mutant (BCA-M-PEG20) induces apoptosis, autophagy, cell cycle arrest and growth inhibition in gastric cancer cells

Gastric cancer is one of the most common malignant solid tumors in the world, especially in Asia with high mortality due to a lack of effective treatment. The potential usage of the newly constructed arginine-depleting enzyme-mono-PEGylated Bacillus caldovelox arginase mutant (BCA-M-PEG20), an effective drug against multiple cancer cell lines such as cervical and lung cancers, for the treatment of gastric cancer was demonstrated. Our results indicated that BCA-M-PEG20 significantly inhibited argininosuccinate synthetase (ASS)-positive gastric cancer cells, MKN-45 and BGC-823, while another arginine-depleting enzyme, arginine deiminase (ADI, currently under Phase III clinical trial), failed to suppress the growth of gastric cancer cells. In vitro studies demonstrated that BCA-M-PEG20 inhibited MKN-45 cells by inducing autophagy and cell cycle arrest at the S phase under 0.58 U/mL (IC₅₀ values). Significant caspase-dependent apoptosis was induced in MKN-45 after the treatment with 2.32 U/mL of BCA-M-PEG20. In vivo studies showed that administrations of BCA-M-PEG20 at 250 U/mouse twice per week significantly suppressed about 50% of tumor growth in the MKN-45 gastric cancer xenograft model. Taken together, BCA-M-PEG20 demonstrated a superior potential to be an anti-gastric cancer drug.

Clinical effects of Apatinib combined with DOS neoadjuvant chemotherapy regimen in neoadjuvant chemotherapy for LAGC

Objective

To evaluate the clinical effects of apatinib combined with DOS regimen in the neoadjuvant chemotherapy for locally advanced gastric cancer (LAGC).

Methods

Eighty patients with LAGC admitted to Baoding first Central Hospital from January 2018 to October 2020 were randomly divided into two groups (n=40, respectively). The control group received DOS chemotherapy regimen alone. The experiment group additionally orally took apatinib mesylate tablets. The changes in CEA, CA19-9 and other tumor markers, RO resection rate, incidence of operative complications, adverse reactions, and other indicators were compared between the two groups.

Results

The overall response rate (ORR) of the experimental group was 72.5%, which was significantly better than that of the control group (50%) (p=0.03). After the treatment, the CEA and CA19-9 in the experiment group were significantly lower than those in the control group (p=0.00). The Ro resection rate was 77.5% in the experiment group and 57.5% in the control group (p=0.03). The operation time was shortened and amount of bleeding decreased in the experiment group, and the differences were statistically significant (p=0.00). The incidence of surgical complications in the experimental group was 17.5%, significantly lower than that in the control group (37.5%) (p=0.04).

Conclusion

Apatinib combined with DOS regimen is effective for patients with LAGC without significantly increasing adverse reactions. Meanwhile, tumor markers are reduced significantly. Besides, the Ro resection rate and the incidence of operative complications are obviously superior to the DOS neoadjuvant chemotherapy regimen alone.

Histological and mutational profile of diffuse gastric cancer: current knowledge and future challenges

Gastric cancer (GC) pathogenesis is complex and heterogeneous, reflecting morphological, molecular and genetic diversity. Diffuse gastric cancer (DGC) and intestinal gastric cancer (IGC) are the major histological types. GC may be sporadic or hereditary; sporadic GC is related to environmental and genetic low-risk factors and hereditary GC is caused by inherited high-risk mutations, so far identified only for the diffuse histotype. DGC phenotypic heterogeneity challenges the current understanding of molecular mechanisms underlying carcinogenesis. The definition of a DGC-specific mutational profile remains controversial, possibly reflecting the heterogeneity of DGC-related histological subtypes [signet-ring cell carcinoma (SRCC) and poorly cohesive carcinoma not otherwise specified (PCC-NOS)]. Indeed, DGC and DGC-related subtypes may present specific mutational profiles underlying the particularly aggressive behaviour and dismal prognosis of DGC vs IGC and PCC-NOS vs SRCC. In this systematic review, we revised the histological presentations, molecular classifications and approved therapies for gastric cancer, with a focus on DGC. We then analysed results from the most relevant studies, reporting mutational analysis data specifying mutational frequencies, and their relationship with DGC and IGC histological types, and with specific DGC subtypes (SRCC and PCC-NOS). We aimed at identifying histology-associated mutational profiles with an emphasis in DGC and its subtypes (DGC vs IGC; sporadic vs hereditary DGC; and SRCC vs PCC-NOS). We further used these mutational profiles to identify the most commonly affected molecular pathways and biological functions, and explored the clinical trials directed specifically to patients with DGC. This systematic analysis is expected to expose a DGC-specific molecular profile and shed light into potential targets for therapeutic intervention, which are currently missing.

Reducing tumor invasiveness by ramucirumab and TGF-β receptor kinase inhibitor in a diffuse-type gastric cancer patient-derived cell model

BACKGROUND

Diffuse-type gastric cancer (GC) is known to be more aggressive and relatively resistant to conventional chemotherapy. Hence, more optimized treatment strategy is urgently needed in diffuse-type GC.

METHODS

Using a panel of 10 GC cell lines and 3 GC patient-derived cells (PDCs), we identified cell lines with high EMTness which is a distinct feature for diffuse-type GC. We treated GC cells with high EMTness with ramucirumab alone, TGF-β receptor kinase inhibitor (TEW-7197) alone, or in combination to investigate the drug's effects on invasiveness, spheroid formation, EMT marker expression, and tumor-induced angiogenesis using a spheroid-on-a-chip model.

RESULTS

Both TEW-7197 and ramucirumab treatments profoundly decreased invasiveness of EMT-high cell lines and PDCs. With a 3D tumor spheroid-on-a-chip, we identified versatile influence of co-treatment on cancer cell-induced blood vessel formation as well as on EMT progression in tumor spheroids. The 3D tumor spheroid-on-a-chip demonstrated that TEW-7197 + ramucirumab combination significantly decreased PDC-induced vessel formation.

CONCLUSIONS

In this study, we showed TEW-7197 and ramucirumab considerably decreased invasiveness, thus EMTness in a panel of diffuse-type GC cell lines including GC PDCs. Taken together, we confirmed that combination of TEW-7197 and ramucirumab reduced tumor spheroid and GC PDC-induced blood vessel formation concomitantly in the spheroid-on-a-chip model.

Preliminary Study on the In Vitro Antitumor Effects of Nidus Vespae on Gastric Cancer

Objective

The aim of this study was to investigate the in vitro antitumor effects of Nidus Vespae on gastric cancer and its ability to promote immune function.

Methods

Cell viability was detected by the Cell Counting Kit-8 (CCK-8) assay. Cell cycle distribution and apoptosis were detected using flow cytometry. The THP-1 human monocytic cell line was used as a source of monocytic effector cells for analyzing proliferation and dendritic cell (DC) induction. Enzyme-linked immunosorbent assay was used to detect cytokine production, and multicolor flow cytometry was used to study the phenotype and functionality of THP-1 DCs.

Results

A high concentration (>10 mg/mL) of Nidus Vespae decoction (NVD) inhibited SGC-7901 gastric cancer cell growth by inducing G2/M cell cycle arrest and apoptosis. However, a low concentration (≤10 mg/mL) of NVD significantly increased the proliferative ability of THP-1 in serum-containing medium and caused an increase in dendritic protrusions with the typical morphology of DCs compared to the negative control in serum-free medium. The THP-1 DCs had significantly increased expression of cluster of differentiation 11c (CD11c), CD40, CD80, CD83, and CD86, as well as secretion of tumor necrosis factor-alpha. Furthermore, the supernatant of THP-1 DCs significantly inhibited the proliferation of gastric cancer cells by inducing apoptosis and G1/S cell cycle arrest.

Conclusions

Our findings suggest that NVD not only directly inhibits the growth of gastric cancer cells but also exerts indirect antitumor effects by enhancing immune function. These results provide an important theoretical basis for the clinical application of Nidus Vespae in gastric cancer treatment.

Differences in Somatic Mutation Profiles between Korean Gastric Cancer and Gastric Adenoma Patients

BACKGROUND

We aimed to investigate molecular factors potentially related to the progression of gastric adenoma (GA) to gastric cancer (GC) and compare the mutation characteristics between GC and GA.

METHODS

We conducted custom gene panel sequencing for 135 GC-related genes and estimated the difference in somatic mutation profiles between 20 GC and 20 GA cases.

RESULTS

A total of 31 somatic mutations, including 22 missense, 3 nonsense, and 6 frameshift mutations, were detected in 17 samples. We estimated an average of 1.8 mutations per sample (range, 1 to 3 mutations), with 12 in GC and 5 in GA. GC tended to have one or more mutated genes (p = 0.0217), as well as higher allele frequencies of mutated genes (p = 0.0003), compared to GA. Likewise, known driver mutations associated with GC tumorigenesis (TP53, ERBB2, PIK3CA, and RNF43) were identified in half of the GC cases (50%, 10/20; p = 0.0002). Only the mutant burden, regardless of gene type, was retained, with an odds ratio of 1.8392 (95% confidence interval (CI), 1.0071 to 3.3588; p = 0.0474).

CONCLUSION

Our study demonstrates that the accumulation of mutant burden contributes to tumorigenesis progression from GA to GC in Korean patients, regardless of the kind of genes. These findings may elucidate the molecular pathogenesis of gastric carcinogenesis and malignant progression.

Co-expression of VEGF-B and FLT-1 correlates with malignancy and prognosis of gastric cancer

Background: This study aims to investigate the correlation of VEGF-B and FLT-1 co-expression with the prognosis of gastric cancer (GC). Materials & methods: Primary GC samples and adjacent tissues were obtained from 96 patients. Results: Both VEGF-B and FLT-1 were testified to be upregulated in the human GC compared with adjacent tissues. Spearman's rank correlation analysis indicated that VEGF-B and FLT-1 expression were correlated (r = 0.321, p = 0.0015). High VEGF-B and FLT-1 co-expression patients showed poor prognosis when compared with low VEGF-B and FLT-1 co-expression patients (p = 0.0169). Conclusion: The high co-expression of VEGF-B and FLT-1 in GC shows a poor prognosis of overall survival, and targeted therapy against the interaction between VEGF-B and FLT-1 is worth further detailed analysis.

Computational Drug Repositioning and Experimental Validation of Ivermectin in Treatment of Gastric Cancer

Objective: The aim of the present study was repositioning of ivermectin in treatment of gastric cancer (GC) by computational prediction based on gene expression profiles of human and mouse model of GC and validations with in silico, in vitro and in vivo approaches.

Methods: Computational drug repositioning was performed using connectivity map (cMap) and data/pathway mining with the Ingenuity Knowledge Base. Tissue samples of GC were collected from 16 patients and 57 mice for gene expression profiling. Additional seven independent datasets of gene expression of human GC from the TCGA database were used for validation. In silico testing was performed by constructing interaction networks of ivermectin and the downstream effects in targeted signaling pathways. In vitro testing was carried out in human GC cell lines (MKN74 and KATO-III). In vivo testing was performed in a transgenic mouse model of GC (INS-GAS mice).

Results: GC gene expression “signature” and data/pathway mining but not cMAP revealed nine molecular targets of ivermectin in both human and mouse GC associated with WNT/β-catenin signaling as well as cell proliferation pathways. In silico inhibition of the targets of ivermectin and concomitant activation of ivermectin led to the inhibition of WNT/β-catenin signaling pathway in “dose-depended” manner. In vitro, ivermectin inhibited cell proliferation in time- and concentration-depended manners, and cells were arrested in the G₁ phase at IC₅₀ and shifted to S phase arrest at >IC₅₀. In vivo, ivermectin reduced the tumor size which was associated with inactivation of WNT/β-catenin signaling and cell proliferation pathways and activation of cell death signaling pathways.

Conclusion: Ivermectin could be recognized as a repositioning candidate in treatment of gastric cancer.

MiRNA-mediated EMT and CSCs in cancer chemoresistance

Cancer stem cells (CSCs) are a small group of cancer cells, which contribute to tumorigenesis and cancer progression. Cancer cells undergoing epithelial-to-mesenchymal transition (EMT) acquire the chemoresistant ability, which is regarded as an important feature of CSCs. Thus, there emerges an opinion that the generation of CSCs is considered to be driven by EMT. In this complex process, microRNAs (miRNAs) are found to play a key role. In order to overcome the drug resistance, inhibiting EMT as well as CSCs phenotype seem feasible. Thereinto, regulating the EMT- or CSCs-associated miRNAs is a crucial approach. Herein, we conduct this review to elaborate on the complicated interplay between EMT and CSCs in cancer chemoresistance, which is modulated by miRNAs. In addition, we elucidate the therapeutic strategy to overcome drug resistance through targeting EMT and CSCs.