A Novel Risk Score Model of Lactate Metabolism for Predicting over Survival and Immune Signature in Lung Adenocarcinoma.

BACKGROUND: The role of lactate acid in tumor progression was well proved. Recently, it was found that lactate acid accumulation induced an immunosuppressive microenvironment. However, these results were based on a single gene and it was unclear that lactate acid genes were associated with immunotherapy and able to predict overall survival. METHODS: Genes and survival data were acquired from TCGA, GEO and GENECARDS. PCA and TSNE were used to distinguish sample types according to lactate metabolism-associated gene expression. A Wilcox-test examined the expression differences between normal and tumor samples. The distribution in chromatin and mutant levels were displayed by Circo and MAfTools. The lactate metabolism-associated gene were divided into categories by consistent clustering and visualized by Cytoscape. Immune cell infiltration was evaluated by CIBERSORT and LM22 matrix. Enrichment analysis was performed by GSVA. We used the ConsensusClusterPlus package for consistent cluster analysis. A prognostic model was constructed by Univariate Cox regression and Lasso regression analysis. Clinical specimens were detected their expression of genes in model by IHC. RESULTS: Most lactate metabolism-associated gene were significantly differently expressed between normal and tumor samples. There was a strong correlation between the expression of lactate metabolism-associated gene and the abundance of immune cells. We divided them into two clusters (lactate.cluster A,B) with significantly different survival. The two clusters showed a difference in signal, immune cells, immune signatures, chemokines, and clinical features. We identified 162 differential genes from the two clusters, by which the samples were divided into three categories (gene.cluster A,B,C). They also showed a difference in OS and immune infiltration. Finally, a risk score model that was composed of six genes was constructed. There was significant difference in the survival between the high and low risk groups. ROC curves of 1, 3, 5, and 10 years verified the model had good predictive efficiency. Gene expression were correlated with ORR and PFS in patients who received anti-PD-1/L1. CONCLUSION: The lactate metabolism-associated genes in LUAD were significantly associated with OS and immune signatures. The risk scoring model that was constructed by us was able to well identify and predict OS and were related with anti-PD-1/L1 therapy outcome.

Neutrophil Extracellular Traps Facilitate A549 Cell Invasion and Migration in a Macrophage-Maintained Inflammatory Microenvironment.

INTRODUCTION: The biological functions of neutrophil extracellular traps (NETs) in tumorigenesis have drawn an increasing amount of attention. This study explored the relationship between NETs and the inflammatory microenvironment in lung cancer cell invasion and metastasis. METHODS: NETs were quantified using myeloperoxidase (MPO-DNA) and immunofluorescence staining. Cytokine levels were measured using ELISA kits. THP-1 and A549 cells were used for in vitro experiments. Transwell and Matrigel assays were used to assess the invasion and migration abilities of the cells. RESULTS: Neutrophil infiltration and NET formation were observed in the lung cancer tissues. Compared with healthy controls, the level of MPO-DNA complexes in lung cancer patients increased remarkably and was positively correlated with peripheral blood neutrophil counts, smoking status, and poor prognosis. Increased circulating NET levels were also positively correlated with the levels of inflammatory cytokines, including IL-1ß, IL-6, IL-18, and TNF-α. Neutrophils isolated from patients with lung cancer are more prone to NET release. NETs can promote the invasion and migration ability of THP-1 and A549 cell in coculture systems, while pretreatment with NET inhibitors can effectively reduce NET-induced invasion and metastasis. The ability of NETs to promote invasion and metastasis is partly dependent on macrophages. CONCLUSION: Taken together, our study demonstrated that NETs facilitate A549 cell invasion and migration in a macrophage-maintained inflammatory microenvironment.

Development and Validation of a Prognostic N6-Methyladenosine-Related Immune Gene Signature for Lung Adenocarcinoma.

PURPOSE: The prognostic value of an N6-methyladenosine (m6A) methylation-related immune gene signature for lung adenocarcinoma (LUAD) was investigated. PATIENTS AND METHODS: Gene expression and clinical phenotype data of LUAD patients were downloaded from The Cancer Genome Atlas database. A list of immune-related genes was retrieved from the InnateDB database. Correlation analysis, survival analysis, and univariate and multivariate Cox regression analyses were performed. After allocating patients into a high-risk or a low-risk group, the corresponding survival rates, immune microenvironment, expression of immune checkpoint genes, and modulation of Kyoto Encyclopedia of Genes and Genomes pathways were examined. Finally, the expression levels of prognostic biomarkers were assessed in the GSE126044 dataset. RESULTS: Seven m6A-related immune prognostic genes were identified. High expression of PSMD10P1, DIDO1, ABCA5, and CIITA was associated with high survival rates, while that of PRC1, ZWILCH, and ANLN was associated with low survival rates. The high- and low-risk groups showed significant differences in terms of the abundance of six tumor-infiltrating immune cell types and expression of 12 immune checkpoint genes. The risk group acted as an independent prognostic factor (hazard ratio = 0.398, 95% confidence interval = 0.217-0.729, P = 0.003). Finally, the developed nomogram could predict most efficiently the 1-, 2-, and 3-year survival probability of LUAD patients with a C-index of 0.833. CONCLUSION: A seven-gene risk signature, associated with the immune microenvironment in LUAD, showed independent prognostic value.

Efficacy and Safety of Afatinib in the Treatment of Advanced Non-Small-Cell Lung Cancer with EGFR Mutations: A Meta-Analysis of Real-World Evidence.

INTRODUCTION: The purpose of this study was to explore the efficacy and safety of afatinib in advanced non-small-cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutations based on real-world evidence. MATERIALS AND METHODS: Eligible real-world studies were identified from PubMed, Cochrane Library, and Embase. Cochrane guidelines were used to assess the quality of included studies. Cochran's Q test and I2 statistics were used for the heterogeneity analysis. RESULTS: Twenty-five studies were included in this meta-analysis; nine studies were included in the qualitative descriptive analysis. The summarized disease control rate (DCR) was 87.6% (81.5%, 92.7%), and the overall response rate (ORR) was 58.9% (48.8%, 68.7%). The pooled median progression-free survival (PFS) was 12.4 (10.3, 14.5) months, mean time to failure (TTF) was 15.4 (13.6, 17.2) months, and median overall survival (OS) was 31.6 (26.7, 36.5) months. The total incidences of adverse events (AEs) for skin rashes, diarrhea, paronychia, and mucositis were 71.4% (64.4%, 77.9%), 70.4% (60.1%, 79.8%), 52.1% (41.9, 62.3%), and 36.5% (29.5%, 43.8%), respectively. The incidences of severe adverse events (SAEs, Grade ≥3) for diarrhea, skin rashes, paronychia, and mucositis were 9.7% (6.8%, 13.1%), 5.8% (4.5%, 7.2%), 3.8% (2.0%, 6.2%), and 2.1% (1.0%, 3.6%), respectively. Differences in PFS and OS between the afatinib non-full-dose (<40 mg) and full-dose (>40 mg) groups were not significant (P > 0.05). However, the ORR in the full-dose group was 78.5% (66.7%, 88.4%), which was significantly higher than that in the non-full-dose group (67.8% [56.8%, 77.9%]). CONCLUSION: The efficacy and safety of afatinib has been confirmed by real-world evidence in advanced NSCLC with EGFR mutation, consistent with randomized controlled trial results. In real-world setting, tolerability-guided dose adjustment might not affect the afatinib efficacy.

Depression accelerates gastric cancer invasion and metastasis by inducing a neuroendocrine phenotype via the catecholamine/ß2 -AR/MACC1 axis.

BACKGROUND: Depression is a common, easily ignored, accompanied disease of gastric cancer (GC) patients and is often observed with elevated plasma catecholamine levels. Depression frequently promotes GC progression and leads to poor clinical outcomes; however, the molecular mechanisms underlying depression-induced GC progression remain poorly understood. We aimed to study the effects of depression on GC progression and explore possible mechanisms mediating the action of depression-associated catecholamines on GC. METHODS: Depression states of GC patients were graded using the Patient Health Questionnaire-9, and plasma catecholamine levels were examined by high performance liquid chromatography coupled with tandem mass spectrometry. Migrative and invasive GC cells were examined using transwell assays, and metastatic GC niches were imaged using bioluminescence technology in a depression mouse model established with chronic unpredictable mild stress. Mouse depression-like behaviors were assessed through sucrose preference, forced swimming, and tail suspension tests. Characteristics of the neuroendocrine phenotype were observed via RT-PCR, Western blotting, flow cytometry, and transmission electron microscopy. RESULTS: Fifty-one GC patients (age: 53.61 ± 1.79 years; cancer duration: 3.71 ± 0.33 months; depression duration: 2.37 ± 0.38 months; male-to-female ratio: 1.55:1) were enrolled in the study. Depression grade was significantly higher in GC patients showing higher plasma levels of catecholamines (epinephrine: P = 0.018; noradrenaline: P = 0.009), higher oncogene metastasis-associated in colon cancer-1 (MACC1) level (P = 0.018), and metastasis (P < 0.001). Further, depression-associated catecholamine specifically bound to the beta-2 adrenergic receptor (ß2 -AR) and upregulated MACC1 expression, and thus promoting neuroendocrine phenotypic transformation through direct binding between MACC1 and synaptophysin. Eventually, the neuroendocrine phenotypic transformation accelerated GC invasion in vitro and metastasis in vivo. However, ß2 -AR antagonist ICI-118,551 or MACC1 silencing effectively blocked the catecholamine-induced neuroendocrine phenotypic transformation and eliminated depression-enhanced GC migration and invasion. Moreover, ß2 -AR blocking or MACC1 silencing prevented GC metastasis attributed to a neuroendocrine phenotype in a depression mouse model. CONCLUSIONS: Catecholamine-induced neuroendocrine phenotypes of GC cells led to depression-accelerated GC invasion and metastasis via the ß2 -AR/MACC1 axis, while ß2 -AR antagonist or MACC1 silencing could reverse it, showing promising potential therapeutic strategies for improving the outcome of GC patients with comorbid depression.

Multiple microarray analyses identify key genes associated with the development of Non-Small Cell Lung Cancer from Chronic Obstructive Pulmonary Disease.

Introduction: Chronic obstructive pulmonary disease (COPD) is an independent risk factor of non-small cell lung cancer (NSCLC). This study aimed to analyze the key genes and potential molecular mechanisms that are involved in the development from COPD to NSCLC. Methods: Expression profiles of COPD and NSCLC in GSE106899, GSE12472, and GSE12428 were downloaded from the Gene Expression Omnibus (GEO) database, followed by identification of the differentially expressed genes (DEGs) between COPD and NSCLC. Based on the identified DEGs, functional pathway enrichment and lung carcinogenesis-related networks analyses were performed and further visualized with Cytoscape software. Then, principal component analysis (PCA), cluster analysis, and support vector machines (SVM) verified the ability of the top modular genes to distinguish COPD from NSCLC. Additionally, the corrections between these key genes and clinical staging of NSCLC were studied using the UALCAN and HPA websites. Finally, a prognostic risk model was constructed based on multivariate Cox regression analysis. Kaplan-Meier survival curves of the top modular genes on the training and verification sets were generated. Results: A total of 2350, 1914, and 1850 DEGs were obtained from GSE106899, GSE12472, and GSE12428 datasets, respectively. Following analysis of protein-protein interaction networks, the identified modular gene signatures containing H2AFX, MCM2, MCM3, MCM7, POLD1, and RPA1 were identified as markers for discrimination between COPD and NSCLC. The modular gene signatures were mainly enriched in the processes of DNA replication, cell cycle, mismatch repair, and others. Besides, the expression levels of these genes were significantly higher in NSCLC than in COPD, which was further verified by the immunohistochemistry. In addition, the high expression levels of H2AFX, MCM2, MCM7, and POLD1 correlate with poor prognosis of lung adenocarcinoma (LUAD). The Cox regression prognostic risk model showed the similar results and the predictive ability of this model is independent of other clinical variables. Conclusions: This study revealed several key modules that closely relate to NSCLC with underlying disease COPD, which provide a deeper understanding of the potential mechanisms underlying the malignant development from COPD to NSCLC. This study provides valuable prognostic factors in high-risk lung cancer patients with COPD.

Identification of the key genes and characterizations of Tumor Immune Microenvironment in Lung Adenocarcinoma (LUAD) and Lung Squamous Cell Carcinoma (LUSC).

This study aimed to investigate the key genes and immune microenvironment involved in different TNM stages of lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC). The gene expression and clinical characteristics data were downloaded from the genomic data commons (GDC) database. After initial data processing, the characteristics of the immune microenvironment were analyzed. The differentially expressed genes (DEGs) in tumor vs. normal, and in early vs. advanced stages were screened, followed by Spearman correlation test for tumor infiltrating immune cells (TIICs) to identify immune-related genes. Finally, functional enrichment, protein-protein interaction, and survival analyses were performed. In LUAD, early stage was with higher immune scores, greater number of memory B cells and M0 macrophages compared to advanced stage. M0 and M2 macrophages, and resting memory CD4+ T cells accounted for a large proportion of TIICs in LUAD. The abundance of M0 macrophage infiltration was significantly correlated with the TNM stage and survival. In LUSC, early stage was with higher cytolytic activity and neoantigen burden compared to advanced stage. M0 and M2 macrophages, and plasma cells accounted for a large proportion of TIICs in LUSC. The abundance of resting and activated mast cells was significantly correlated with TNM stage, while resting dendritic cells, eosinophils, activated memory CD4 T cells, and mast cells were significantly correlated with prognosis. Tumor mutation burden analysis revealed that the median of variants per sample decreased from stage I to IV in LUAD, while it increased in LUSC. Further, 83 and 9 immune-related DEGs were identified in LUAD and LUSC, respectively, of which 23 genes in LUAD and 2 genes in LUSC correlated with survival. In conclusion, we identified the key genes, and characterized the tumor immune microenvironment in LUAD and LUSC which may provide therapeutic targets for the treatment of NSCLC.

Identification of Differentially Expressed Genes and miRNAs Associated with Esophageal Squamous Cell Carcinoma by Integrated Analysis of Microarray Data.

To identify candidate key genes and miRNAs associated with esophageal squamous cell carcinoma (ESCC) development and prognosis, the gene expression profiles and miRNA microarray data including GSE20347, GSE38129, GSE23400, and GSE55856 were downloaded from the Gene Expression Omnibus (GEO) database. Clinical and survival data were retrieved from The Cancer Genome Atlas (TCGA). Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of differentially expressed genes (DEGs) was analyzed via DAVID, while the DEG-associated protein-protein interaction network (PPI) was constructed using the STRING database. Additionally, the miRNA target gene regulatory network and miRNA coregulatory network were constructed, using the Cytoscape software. Survival analysis and prognostic model construction were performed via the survival (version 2.42-6) and rbsurv R packages, respectively. The results showed a total of 2575, 2111, and 1205 DEGs, and 226 differentially expressed miRNAs (DEMs) were identified. Pathway enrichment analyses revealed that DEGs were mainly enriched in 36 pathways, such as the proteasome, p53, and beta-alanine metabolism pathways. Furthermore, 448 nodes and 1144 interactions were identified in the PPI network, with MYC having the highest random walk score. In addition, 7 DEMs in the microarray data, including miR-196a, miR-21, miR-205, miR-194, miR-103, miR-223, and miR-375, were found in the regulatory network. Moreover, several reported disease-related miRNAs, including miR-198a, miR-103, miR-223, miR-21, miR-194, and miR-375, were found to have common target genes with other DEMs. Survival analysis revealed that 85 DEMs were related to prognosis, among which hsa-miR-1248, hsa-miR-1291, hsa-miR-421, and hsa-miR-7-5p were used for a prognostic survival model. Taken together, this study revealed the important roles of DEGs and DEMs in ESCC development, as well as DEMs in the prognosis of ESCC. This will provide potential therapeutic targets and prognostic predictors for ESCC.

Gastric cancer cells escape metabolic stress via the DLC3/MACC1 axis.

Metabolic stress usually occurs in rapidly growing gastric cancer (GC) when the energy demand exceeds the supply. Interestingly, cancer cells can somehow escape this stress. Some small Rho GTPases regulating cell migration can be activated by metabolic stress. DLC3 is a RhoA-specific GTPase-activating protein of unclear function in cancer. We hypothesized that it participated in metabolic stress escape. Methods: Metabolic stress in GC cells was induced by glucose deprivation, and DLC3 expression was detected. Based on the prognostic value, cell viability, motility and glycolysis were detected in DLC3 differently expressed GC cells in vitro and in vivo. DLC3 downstream targets were screened and verified. Chemotactic ability was evaluated to study DLC3 and its downstream signaling on metabolic stress escape. In addition, therapeutic strategies targeting DLC3 were explored. Results: DLC3 expression was lowered by metabolic stress in GC cells. DLC3 downregulation indicated poor cancer prognosis, and silencing DLC3 promoted GC cell proliferation and invasion. MACC1, an oncogene promoting GC growth and metastasis, was proved to be the downstream target of DLC3. Low DLC3 expression and high MACC1 expression indicated high recurrence rate after GC resection. DLC3 transcriptionally inhibited MACC1 expression via RhoA/JNK/AP-1 signaling, and subsequently suppressed GC cell glycolysis and survival under metabolic stress. The DLC3/MACC1 axis modulated the chemotaxis of GC cells from energy deficient area to glucose abundant area. Finally, lovastatin was found to be a promising therapeutic drug targeting the DLC3/MACC1 axis. Conclusions: The DLC3/MACC1 axis modulates GC glycolysis and chemotaxis to escape glucose deprivation. Lovastatin may inhibit GC by targeting the DLC3/MACC1 axis.

ATXN2L upregulated by epidermal growth factor promotes gastric cancer cell invasiveness and oxaliplatin resistance.

For gastric cancer (GC) control, metastasis and chemoresistance are the major challenges, accompanied with various stresses. Ataxin-2-like (ATXN2L) was discovered as a novel regulator of stress granules, yet its function in cancers remained unknown. Hence, we wanted to explore the functions of ATXN2L to see whether it participates in stress-related cancer malignant activities. Clinical follow-up was performed to see the impact of ATXN2L on GC patient survival. As a result, ATXN2L expression was upregulated in GC tissue and indicated adverse prognosis for overall survival and recurrence. In GC cells, ATXN2L expression was knocked down and functional experiments were performed. ATXN2L promoted GC cell migration and invasion via epithelial to mesenchymal transition, yet no influence on proliferation was detected by ATXN2L interference. When adding the chemotherapeutic agent oxaliplatin to induce stress, silencing ATXN2L sensitized GC cells to oxaliplatin. Interestingly, oxaliplatin was found to in turn promote ATXN2L expression and stress granule assembly. Then, two acquired oxaliplatin-resistant strains were generated by long-term oxaliplatin induction. The oxaliplatin-resistant strains presented with elevated ATXN2L levels, while silencing ATXN2L in the strains reversed the oxaliplatin resistance by increasing reactive oxygen species production and apoptosis. These results suggested that ATXN2L was responsible for not only intrinsic but also acquired oxaliplatin chemoresistance. Finally, ATXN2L-related signaling was screened using bioinformatic methods, and epidermal growth factor (EGF) was verified to promote ATXN2L expression via PI3K/Akt signaling activation. Blocking EGFR/ATXN2L signaling reversed GC cell oxaliplatin resistance and inhibited migration. In conclusion, ATXN2L promotes cell invasiveness and oxaliplatin resistance and can be upregulated by EGF via PI3K/Akt signaling. ATXN2L may be an indicator and therapeutic target in GC, especially for oxaliplatin-based chemotherapy.

Combined neutrophil/platelet/lymphocyte/differentiation score predicts chemosensitivity in advanced gastric cancer.

BACKGROUND: Gastric cancer is common in developing regions, and we hope to find out an economical but practical prognostic indicator. It was reported that pre-treatment peripheral neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR), as well as differentiation status, were associated with cancer progression. Hence, we introduced a novel combined Neutrophil/platelet/lymphocyte/differentiation Score (cNPLDS) to improve the prediction value of palliative chemotherapeutic response in advanced gastric cancer. METHODS: According to statistical sample size estimation, 136 primary diagnosed unresectable advanced ptaients were included for a retrospective study. The follow-up end-point was progression free survival (PFS) during the first-line palliative chemotherapy. Differentiation stratified patients into well, medium and poor groups by score 1 to 3, while patients with neither elevated NLR and PLR, only one elevated, or both elevated were of the combined NLR-PLR score (cNPS) 1 to 3, respectively. The cNPLDS was calculated by multiplying the tumor differentiation score and cNPS. RESULTS: Determined by the receiver operating characteristic (ROC) curve, the optimal cut-off points for NLR and PLR were 3.04 and 223. Through univariate analysis and survival analysis, poor differentiation, high NLR, high PLR, high cNPS, and high cNPLDS respectively indicated inferior PFS during the first-line palliative chemotherapy. Patients were furhter classified into low to high risk groups by cNPLDS. Groups of elevated NLR, PLR, cNPS, and cNPLDS showed lower disease control rate. Compared to other parameters, cNPLDS significantly improved the accuracy in predicing the first-progression. CONCLUSIONS: This study indicates that the novel parameter cNPLDS is superior to NLR or PLR alone, or even cNPS, in predicting the first-line chemosensitivity in advanced gastric cancer.

Theranostic pH-sensitive nanoparticles for highly efficient targeted delivery of doxorubicin for breast tumor treatment.

A multifunctional theranostic nanoplatform integrated with environmental responses has been developed rapidly over the past few years as a novel treatment strategy for several solid tumors. We synthesized pH-sensitive poly(ß-thiopropionate) nanoparticles with a supermagnetic core and folic acid (FA) conjugation (FA-doxorubicin-iron oxide nanoparticles [FA-DOX@ IONPs]) to deliver an antineoplastic drug, DOX, for the treatment of folate receptor (FR)-overexpressed breast cancer. In addition to an imaging function, the nanoparticles can release their payloads in response to an environment of pH 5, such as the acidic environment found in tumors. After chemical (1H nuclear magnetic resonance) and physical (morphology and super-magnetic) characterization, FA-DOX@IONPs were shown to demonstrate pH-dependent drug release profiles. Western blotting analysis revealed the expression of FRs in three breast cancer cell lines, MCF-7, BT549, and MD-MBA-231. The cell counting kit-8 assay and transmission electron microscopy showed that FA-DOX@IONPs had the strongest cytotoxicity against breast cancer cells, compared with free DOX and non-FR targeted nanoparticles (DOX@IONPs), and caused cellular apoptosis. The FA-DOX@IONP-mediated cellular uptake and intracellular internalization were clarified by fluorescence microscopy. FA-DOX@IONPs plus magnetic field treatment suppressed in vivo tumor growth in mice to a greater extent than either treatment alone; furthermore, the nanoparticles exerted no toxicity against healthy organs. Magnetic resonance imaging was successfully applied to monitor the nanoparticle accumulation. Our results suggest that theranostic pH-sensitive nanoparticles with dual targeting could enhance the available therapies for cancer.

TOP1MT deficiency promotes GC invasion and migration via the enhancements of LDHA expression and aerobic glycolysis.

Aerobic glycolysis plays an important role in cancer progression. New target genes regulating cancer aerobic glycolysis must be explored to improve patient prognosis. Mitochondrial topoisomerase I (TOP1MT) deficiency suppresses glucose oxidative metabolism but enhances glycolysis in normal cells. Here, we examined the role of TOP1MT in gastric cancer (GC) and attempted to determine the underlying mechanism. Using in vitro and in vivo experiments and analyzing the clinicopathological characteristics of patients with GC, we found that TOP1MT expression was lower in GC samples than in adjacent nonmalignant tissues. TOP1MT knockdown significantly promoted GC migration and invasion in vitro and in vivo Importantly, TOP1MT silencing increased glucose consumption, lactate production, glucose transporter 1 expression and the epithelial-mesenchymal transition (EMT) in GC. Additionally, regulation of glucose metabolism induced by TOP1MT was significantly associated with lactate dehydrogenase A (LDHA) expression. A retrospective analysis of clinical data from 295 patients with GC demonstrated that low TOP1MT expression was associated with lymph node metastasis, recurrence and high mortality rates. TOP1MT deficiency enhanced glucose aerobic glycolysis by stimulating LDHA to promote GC progression.

Bapx1 mediates transforming growth factor-ß- induced epithelial-mesenchymal transition and promotes a malignancy phenotype of gastric cancer cells.

The homeoprotein Bapx1 is an important regulator of gastroduodenal tract morphogenesis. Here, we investigated how Bapx1 influences gastric cancer (GC) prognosis and elucidated the underlying mechanisms. Bapx1 expression was greater in GC tissues compared to adjacent non-tumor tissues and expression was positively correlated with mortality, lymph node and distance metastasis. Silencing Bapx1 diminished cell invasion/migration and decreased mesenchymal phenotypes. Transforming growth factor-ß (TGF-ß) induced Bapx1 expression and epithelial-mesenchymal transition (EMT) in GC cells. However, down-regulated Bapx1 reversed TGF-ß induced invasion, migration, morphological changes, and EMT. In summary, Bapx1 indicates poor prognosis for GC by promoting tumor migration and invasion via TGF-ß-induced EMT.

IGF1/IGF1R/STAT3 signaling-inducible IFITM2 promotes gastric cancer growth and metastasis.

Interferon-induced transmembrane proteins (IFITMs) are expressed in some types of cancer. However, their precise roles in tumor progression remain unclear. The present study investigated the function of IFITM2 in gastric cancer (GC) progression. A retrospective analysis of a public database and 167 GC patients revealed that IFITM2 expression was upregulated in gastric tumor samples, which was positively correlated with disease progression, more frequent postoperative recurrence, and higher mortality rate. IFITM2 knockdown decreased GC cell proliferation, migration, invasion, and epithelial-to-mesenchymal transition in vitro. We also found that IFITM2 expression was in part induced by insulin-like growth factor (IGF) 1 via IGF1 receptor/signal transducer and activator of transcription 3 signaling. Furthermore, IFITM2 regulated interleukin-6 expression and secretion, which in turn increased IFITM2 expression. Silencing of IFITM2 expression suppressed tumor growth and lung metastasis in vivo. These results suggest that IFITM2 is a novel prognostic biomarker and regulator of GC progression.

A new mechanism of trastuzumab resistance in gastric cancer: MACC1 promotes the Warburg effect via activation of the PI3K/AKT signaling pathway.

BACKGROUND: Trastuzumab, a humanized antibody targeting HER2, exhibits remarkable therapeutic efficacy against HER2-positive gastric cancer. However, recurrent therapeutic resistance presents revolutionary claims. Warburg effect and AKT signaling pathway was involved in the resistance to trastuzumab. Our previous studies have demonstrated that overexpression of metastasis associated with the colon cancer 1 (MACC1) predicted poor prognosis of GC and promoted tumor cells proliferation and invasion. In this study, we found that MACC1 was significantly upregulated in trastuzumab-resistant cell lines. Besides, downregulation of MACC1 reversed this resistance. METHODS: The effect of trastuzumab and glycolysis inhibitor combination on cell viability, apoptosis, and cell metabolism was investigated in vitro using established trastuzumab-resistant GC cell lines. We assessed the impact of trastuzumab combined with oxamate on tumor growth and metabolism in an established xenograft model of HER2-positive GC cell lines. RESULTS: Here, we found that MACC1 was significantly upregulated in trastuzumab-resistant cell lines. Besides, downregulation of MACC1 in trastuzumab-resistant cells reversed this resistance. Overexpression of MACC1-induced trastuzumab resistance, enhanced the Warburg effect, and activated the PI3K/AKT signaling pathway, while downregulation of MACC1 presented the opposite effects. Moreover, when the PI3K/AKT signaling pathway was inhibited, the effects of MACC1 on resistance and glycolysis were diminished. Our findings indicated that MACC1 promoted the Warburg effect mainly through the PI3K/AKT signaling pathway, which further enhanced GC cells trastuzumab resistance. CONCLUSIONS: Our results indicate that co-targeting of HER2 and the Warburg effect reversed trastuzumab resistance in vitro and in vivo, suggesting that the combination might overcome trastuzumab resistance in MACC1-overexpressed, HER2-positive GC patients.

Golgi phosphoprotein3 overexpression is associated with poor survival in patients with solid tumors: a meta-analysis.

Golgi phosphoprotein3 (GOLPH3) is known as an oncoprotein and may be a prognostic biomarker in various tumors. Here we performed a meta-analysis on the association of GOLPH3 expression and survival in solid tumors. All eligible studies were identified in Embase, PubMed and Web of Science Databases up to November 2014. Data about overall survival (OS), and disease-free survival (DFS) were extracted and pooled hazard ratios (HRs) of GOLPH3 for survival were calculated by using a random-effect model. Heterogeneity and publication bias were also assessed. A total of 15 eligible studies which comprised of 2529 cases were included in this global analysis: 14 were dealing with overall survival (OS) and 6 were with disease-free survival (DFS). We found that GOLPH3 overexpression was associated with shorter OS (HR 2.487, 95% CI 1.897-3.258, P < 0.001) and DFS (HR 1.911, 95% CI 1.245-2.932, P = 0.003) in general carcinomas. Importantly, subgroup analysis suggested that overexpression of GOLPH3 correlated with shorter OS in urogenital system cancers (HR 4.258, 95% CI 1.81-4.91, P < 0.001). Moreover, publication bias was not significant (P > 0.05). In conclusion, the present meta-analysis showed that overexpression of GOLPH3 predicts poor prognosis in solid tumors.

Low expression of DLC1 is predictive of poor therapeutic efficiency of fluoropyrimidine and oxaliplatin as adjuvant chemotherapy in gastric cancer.

The Rho­GTPase­activating protein, deleted in liver cancer­1 (DLC1), has been reported to be a tumor suppressor. However, the prognostic value of DLC1 in gastric cancer (GC) remains to be fully elucidated. Fluoropyrimidine­oxaliplatin (FP­LOHP) combination therapy has been widely used for the adjuvant chemotherapy of GC, however, no reliable marker has been identified to determine its efficiency. Thus, the present study performed a retrospective investigation involving 251 patients with stage IB­III GC, who received adjuvant chemotherapy following radical resection and 37 patients with stage IV GC, who underwent palliative resection. The expression of DLC1 was found to be reduced in the majority of GC samples (212/288 pairs of samples), compared with normal mucosa, in immunohistochemical analyses. Lower expression levels of DLC1 indicated a more advanced tumor­node­metastasis stage, increased lymph node metastasis, deeper tumor invasion, increased tumor size and a higher rate of distant metastasis. By contrast, relatively increased expression levels of DLC1 indicated a longer time to recurrence (TTR) [hazard ratio (HR), 2.232; P=0.004] and overall survival (OS) rate (HR, 2.910; P=0.001). Patients receiving FP­LOHP adjuvant chemotherapy were significantly less likely to suffer GC recurrence (P=0.001) and succumb to mortality (P=0.004), compared with those who received alternative chemotherapies. However, only the patients with DLC1­positive GC receiving FP­LOHP [DLC1 (+)/FP­LOHP (+)] exhibited a more favorable TTR and OS, compared with the patients with DLC1 (+)/FP­LOHP (­) (TTR, P=0.001; OS, P=0.020). No significant improvement in clinical outcome was observed in GC patients with low DLC1 receiving FP­LOHP treatment (TTR, P=0.270; OS, P=0.197). In conclusion, low expression of DLC1 correlated with GC progression and is predictive of higher rates of recurrence and mortality. Only patients with DLC1­positive GC may have an improved treatment outcome from the use of FP­LOHP as adjuvant chemotherapy.

Flotillin-2 promotes nasopharyngeal carcinoma metastasis and is necessary for the epithelial-mesenchymal transition induced by transforming growth factor-ß.

Transforming growth factor-ß (TGF-ß) promotes cancer metastasis via the epithelial-mesenchymal transition (EMT) but the underlying mechanisms in nasopharyngeal carcinoma (NPC) remain unclear. Flotillin-2 (Flot2), a specialized lipid raft domain in cellular membrane, was reported to promote cancer metastasis. Recently, in neuropathy, it was also suggested that Flot2 was involved in Src activation, which is known as the downstream signal of TGF-ß. Therefore, we intended to find out the relationship between Flot2 and TGF-ß in the process of nasopharyngeal carcinoma (NPC) metastasis. In this study, we found that Flot2 expression level positively correlated with the cancer stage in NPC tissues. Elevated Flot2 in tumor tissue was an independent prognostic marker, and higher Flot2 expression level showed shorter overall survival time in 181 NPC patients. In NPC cells, silencing Flot2 reversed the metastatic effect induced by TGF-ß. Moreover, TGF-ß-induced Src phosphorylation was significantly inhibited by Flot2 knocking down. As the consequence of Flot2 inhibition, the expression of the epithelial biomarker E-cadherin was upregulated, while the mesenchymal marker vimentin and signaling transducer ß-catenin was suppressed. In conclusions, Flot2 is an indispensable member for TGF-ß signaling, which is essential for the EMT process in NPC metastasis. Suppressing Flot2 may be a novel way against TGF-ß-induced EMT.