CDKN2A somatic copy number amplification in normal tissues surrounding gastric carcinoma reduces cancer metastasis risk in droplet digital PCR analysis.

BACKGROUND: The CDKN2A gene is frequently affected by somatic copy number variations (SCNVs, including deletions and amplifications [SCNdel and SCNamp]) in the cancer genome. Using surgical gastric margin tissue samples (SMs) as the diploid reference in SCNV analysis via CDKN2A/P16-specific real-time PCR (P16-Light), we previously reported that the CDKN2A SCNdel was associated with a high risk of metastasis of gastric carcinoma (GC). However, the status of CDKN2A SCNVs in SMs and their clinical significance have not been reported. METHODS: Peripheral white blood cell (WBC) and frozen GC and SM tissue samples were collected from patients (n = 80). Droplet digital PCR (ddPCR) was used to determine the copy number (CN) of the CDKN2A gene in tissue samples using paired WBCs as the diploid reference. RESULTS: A novel P16-ddPCR system was initially established with a minimal proportion (or limit, 10%) of the detection of CDKN2A CN alterations. While CDKN2A SCNamp events were detected in both SMs and GCs, fewer CDKN2A SCNdel events were detected in SMs than in GCs (15.0% vs. 41.3%, P = 4.77E-04). Notably, significantly more SCNamp and fewer SCNdel of the CDKN2A gene were detected in SMs from GC patients without metastasis than in those from patients with lymph node metastasis by P16-ddPCR (P = 0.023). The status of CDKN2A SCNVs in SM samples was significantly associated with overall survival (P = 0.032). No cancer deaths were observed among the 11 patients with CDKN2A SCNamp. CONCLUSION: CDKN2A SCNVs in SMs identified by P16-ddPCR are prevalent and significantly associated with GC metastasis and overall survival.

Targeting SALL4 by Entinostat Inhibits the Malignant Phenotype of Gastric Cancer Cells by Reducing EMT Signaling.

BACKGROUND/AIM: Spalt-like transcription factor 4 (SALL4), as a proto-oncogene, is expressed in various tumors and correlates with poor prognosis of patients. Entinostat, a histone deacetylase (HDAC) inhibitor, has emerged as a potentially promising anti-cancer drug. This study aims to explore the biological role and underlying mechanism of SALL4 targeting by entinostat in gastric cancer. MATERIALS AND METHODS: Online databases were used to exam the link between SALL4 and prognosis. We tested the biological roles of SALL4 in gastric cancer cells. Cell viability and growth were analyzed using the Cell Counting Kit-8 (CCK-8) assay and clone formation assay. Cell migration was assessed using the wound healing assay. The effects of entinostat on gastric cancer cell lines were measured by the CCK-8 assay, clone formation assay, wound healing assay and transwell assay. Epithelial-mesenchymal transition (EMT) signaling pathways were detected by western blot. RESULTS: SALL4 expression was upregulated in gastric cancer tissues and positively correlated with tumor stage and prognosis of patients by TCGA dataset analysis. Knockdown of SALL4 by siRNA inhibited the proliferation and migration of gastric cancer cells. In contrast, SALL4 overexpression by stably transfecting a SALL4-expressing plasmid promoted the proliferation and invasiveness of gastric cancer cells in vitro through alteration of EMT-related genes. In addition, entinostat, a HDAC inhibitor targeting SALL4, could suppress the proliferation, migration, and invasion of gastric cancer cells via regulating expression of EMT-associated proteins. CONCLUSION: SALL4 may be a new therapeutic target for the treatment of gastric cancer, and entinostat is a potential novel agent for the treatment of gastric cancer partially by targeting SALL4.

High-throughput proteomics profiling-derived signature associated with chemotherapy response and survival for stage II/III colorectal cancer.

Adjuvant chemotherapy (ACT) is usually used to reduce the risk of disease relapse and improve survival for stage II/III colorectal cancer (CRC). However, only a subset of patients could benefit from ACT. Thus, there is an urgent need to identify improved biomarkers to predict survival and stratify patients to refine the selection of ACT. We used high-throughput proteomics to analyze tumor and adjacent normal tissues of stage II/III CRC patients with /without relapse to identify potential markers for predicting prognosis and benefit from ACT. The machine learning approach was applied to identify relapse-specific markers. Then the artificial intelligence (AI)-assisted multiplex IHC was performed to validate the prognostic value of the relapse-specific markers and construct a proteomic-derived classifier for stage II/III CRC using 3 markers, including FHL3, GGA1, TGFBI. The proteomics profiling-derived signature for stage II/III CRC (PS) not only shows good accuracy to classify patients into high and low risk of relapse and mortality in all three cohorts, but also works independently of clinicopathologic features. ACT was associated with improved disease-free survival (DFS) and overall survival (OS) in stage II (pN0) patients with high PS and pN2 patients with high PS. This study demonstrated the clinical significance of proteomic features, which serve as a valuable source for potential biomarkers. The PS classifier provides prognostic value for identifying patients at high risk of relapse and mortality and optimizes individualized treatment strategy by detecting patients who may benefit from ACT for survival.

The N6-methyladenine DNA demethylase ALKBH1 promotes gastric carcinogenesis by disrupting NRF1 binding capacity.

DNA N6-methyladenine (6mA) is an epigenetic modification that regulates various biological processes. Here, we show that gastric cancer (GC) cells and tumors display a marked reduction in 6mA levels compared with normal gastric tissues and cells. 6mA is abundant in the surrounding transcription start sites and occurs at consensus motifs. Among the 6mA regulators, ALKBH1, a demethylase, is significantly overexpressed in GC tissues compared with adjacent normal tissues. Moreover, high ALKBH1 expression is associated with poor survival of patients with GC. ALKBH1 knockout in mice impairs chemically induced gastric carcinogenesis. Mechanistically, ALKBH1 mediates DNA 6mA demethylation to repress gene expression. In particular, the 6mA sites are enriched in NRF1 binding sequences and targeted for demethylation by ALKBH1. ALKBH1-induced 6mA demethylation inhibits NRF1-driven transcription of downstream targets, including multiple genes involved in the AMP-activated protein kinase (AMPK) signaling pathway. Accordingly, ALKBH1 suppresses AMPK signaling, causing a metabolic shift toward the Warburg effect, which facilitates tumorigenesis.

MicroRNA-143-3p Inhibits Wilms' Tumor Cell Growth By Targeting the Ras/Raf/MEK/ERK Pathway.

Background: A previous study found that microRNA-143-3p (miR-143-3p) is a tumor suppressor in various types of human cancer. However, the roles and molecular mechanisms of miR-143-3p in the progression of Wilms' tumor (WT) remain to be clarified. The aim of the present study was to determine the expression and biological functions of miR-143-3p in WT. Material and Methods: The expression levels of miR-143-3p in primary WT tissues and adjacent tissues were determined using quantitative-reverse transcription polymerase chain reaction (qRT-PCR), and the association of the miR-143-3p expression level with various clinicopathological features of WT was investigated. Western blotting was used to evaluate the protein expression of the related signaling pathway. Results: The expression of miR-143-3p was significantly downregulated in WT tissues and its expression levels were closely associated with tumor stage and lymph node metastasis. Overexpression of miR-143-3p in SK-NEP-1 and G401 cell lines inhibited cell proliferation by G0/G1 cell cycle phase arrest and induction of apoptosis. Moreover, k-Ras, a unique oncogene, was confirmed as a direct target of miR-143-3p, and k-Ras messenger RNA (mRNA) expression was increased in WT tissues and inversely correlated with miR-143-3p. Knockdown of k-Ras by si-k-Ras could inhibit, whereas overexpression of k-Ras could promote. cell proliferation in WT cells. Meanwhile, overexpression of k-Ras reversed the inhibitory effects on WT cells induced by miR-143-3p mimics. Conclusion: Our findings indicate that miR-143-3p may be a potential novel prognostic biomarker and therapeutic target for WT.

DUSP5P1 promotes gastric cancer metastasis and platinum drug resistance.

We elucidated the functional significance and molecular mechanisms of DUSP5P1 lncRNA (dual specificity phosphatase 5 pseudogene 1) in gastric carcinogenesis. We demonstrated that gastric cancer (GC) patients with high DUSP5P1 expression had shortened survival in two independent cohorts. DUSP5P1 promoted GC cell migration and invasion in vitro and metastasis in vivo. Mechanistically, DUSP5P1 activated ARHGAP5 transcription by directly binding to the promoter of ARHGAP5 with a binding motif of TATGTG. RNA-seq revealed that ARHGAP5 activated focal adhesion and MAPK signaling pathways to promote GC metastasis. DUSP5P1 also dysregulated platinum drug resistance pathway. Consistently, DUSP5P1 overexpression in GC cells antagonized cytotoxic effect of Oxaliplatin, and shDUSP5P1 plus Oxaliplatin exerted synergistic effect on inhibiting GC metastasis in vitro and in vivo. DUSP5P1 depletion also suppressed the growth of platinum drug-resistant PDO models. In conclusion, DUSP5P1 promoted GC metastasis by directly modulating ARHGAP5 expression to activate focal adhesion and MAPK pathways, serves as therapeutic target for platinum drug resistant GC, and is an independent prognostic factor in GC.

Gamma-glutamyltransferase 7 suppresses gastric cancer by cooperating with RAB7 to induce mitophagy.

We identified gamma-glutamyltransferase 7 (GGT7) to be frequently downregulated in gastric cancer, but its role remains unknown. Here we elucidated the clinical significance, functional roles, and molecular mechanism of GGT7 in gastric cancer. GGT7 was downregulated by promoter methylation and restored by demethylation treatment in gastric cancer cells. GGT7 methylation inversely correlated with mRNA expression in gastric tumors (n = 221; r = -0.686, P < 0.0001). High-expression of GGT7 in adjacent non-tumor tissues was significantly associated with favorable survival in gastric cancer patients (n = 138; P = 0.009), and was an independent prognostic factor by multivariate Cox regression (HR = 0.381, P < 0.05). GGT7 significantly inhibited gastric cancer cell growth, G1-S transition, and migration and invasion abilities. GGT7 also significantly attenuated the growth of subcutaneous xenograft tumors and reduced metastasis to the lung in nude mice. The mitophagy regulator RAB7 was identified as a direct downstream co-player of GGT7 by co-immunoprecipitation followed by mass spectrometry. Growth suppression effect of GGT7 was at least partly dependent on RAB7 by rescue experiments. GGT7 induced autophagy as shown by electron microscopy and confirmed by the increased LC3B and decreased p62. GGT7 recruited RAB7 by direct binding and drove RAB7 to translocate from nucleus to cytoplasm, subsequently mediating mitophagy by increasing mitophagy mediators/inducers. GGT7 inhibited intracellular ROS, which was associated with increased mitophagy, and subsequently suppressed MAPK signaling. Collectively, GGT7 plays a pivotal tumor-suppressing role in gastric cancer by directly binding with RAB7 to induce mitophagy and inhibit ROS and MAPK cascades. GGT7 is an independent prognostic factor for gastric cancer patients.

Prognostic and predictive value of mismatch repair deficiency in gastric and gastroesophageal junction adenocarcinoma patients receiving neoadjuvant or adjuvant chemotherapy.

BACKGROUND AND OBJECTIVES: Evidence is inconclusive regarding the prognostic significance of deficient DNA mismatch repair (dMMR) in gastric and gastroesophageal junction (GEJ) adenocarcinoma patients receiving chemotherapy. We aim to explore such associations with a large cohort. METHODS: We retrospectively identified a consecutive cohort of patients who had histology proven gastric or GEJ adenocarcinoma and received neoadjuvant chemotherapy plus surgery or upfront surgery plus adjuvant chemotherapy. MMR status was assessed by immunohistochemistry staining on surgical specimen. The association of MMR status with tumor regression grade (TRG), overall survival (OS), and disease-free survival (DFS) were analyzed. RESULTS: In total, 1568 patients received neoadjuvant or adjuvant chemotherapy, of which 128 (8.2%) had dMMR tumors. No significant difference was found in the frequencies of TRG categories between proficient MMR (pMMR) and dMMR tumors (p = .62). Among patients receiving neoadjuvant chemotherapy, dMMR status was associated with better OS (log-rank p = .044) and DFS (log-rank p = .022) in the univariate analysis; this association became nonsignificant after adjusting for pathologic stages and other prognostic factors. Similar results were found for patients receiving adjuvant chemotherapy. CONCLUSIONS: dMMR status was not significantly associated with OS and DFS among gastric and GEJ adenocarcinoma patients with neoadjuvant and adjuvant platinum and fluorouracil-based chemotherapy.

Perioperative or postoperative adjuvant oxaliplatin with S-1 versus adjuvant oxaliplatin with capecitabine in patients with locally advanced gastric or gastro-oesophageal junction adenocarcinoma undergoing D2 gastrectomy (RESOLVE): an open-label, superiority and non-inferiority, phase 3 randomised controlled trial.

BACKGROUND: The optimal perioperative chemotherapeutic regimen for locally advanced gastric cancer remains undefined. We evaluated the efficacy and safety of perioperative and postoperative S-1 and oxaliplatin (SOX) compared with postoperative capecitabine and oxaliplatin (CapOx) in patients with locally advanced gastric cancer undergoing D2 gastrectomy. METHODS: We did this open-label, phase 3, superiority and non-inferiority, randomised trial at 27 hospitals in China. We recruited antitumour treatment-naive patients aged 18 years or older with historically confirmed cT4a N+ M0 or cT4b Nany M0 gastric or gastro-oesophageal junction adenocarcinoma, with Karnofsky performance score of 70 or more. Patients undergoing D2 gastrectomy were randomly assigned (1:1:1) via an interactive web response system, stratified by participating centres and Lauren classification, to receive adjuvant CapOx (eight postoperative cycles of intravenous oxaliplatin 130 mg/m2 on day one of each 21 day cycle plus oral capecitabine 1000 mg/m2 twice a day), adjuvant SOX (eight postoperative cycles of intravenous oxaliplatin 130 mg/m2 on day one of each 21 day cycle plus oral S-1 40-60 mg twice a day), or perioperative SOX (intravenous oxaliplatin 130 mg/m2 on day one of each 21 day plus oral S-1 40-60 mg twice a day for three cycles preoperatively and five cycles postoperatively followed by three cycles of S-1 monotherapy). The primary endpoint, assessed in the modified intention-to-treat population, 3-year disease-free survival to assess the superiority of perioperative-SOX compared with adjuvant-SOX and the non-inferiority (hazard ratio non-inferiority margin of 1·33) of adjuvant-SOX compared with adjuvant-CapOx. Safety analysis were done in patients who received at least one dose of the assigned treatment. This study is registered with ClinicalTrials.gov, NCT01534546. FINDINGS: Between Aug 15, 2012, and Feb 28, 2017, 1094 patients were screened and 1022 (93%) were included in the modified intention-to-treat population, of whom 345 (34%) patients were assigned to the adjuvant-CapOx, 340 (33%) patients to the adjuvant-SOX group, and 337 (33%) patients to the perioperative-SOX group. 3-year disease-free survival was 51·1% (95% CI 45·5-56·3) in the adjuvant-CapOx group, 56·5% (51·0-61·7) in the adjuvant-SOX group, and 59·4% (53·8-64·6) in the perioperative-SOX group. The hazard ratio (HR) was 0·77 (95% CI 0·61-0·97; Wald p=0·028) for the perioperative-SOX group compared with the adjuvant-CapOx group and 0·86 (0·68-1·07; Wald p=0·17) for the adjuvant-SOX group compared with the adjuvant-CapOx group. The most common grade 3-4 adverse events was neutropenia (32 [12%] of 258 patients in the adjuvant-CapOx group, 21 [8%] of 249 patients in the adjuvant-SOX group, and 30 [10%] of 310 patients in the perioperative-SOX group). Serious adverse events were reported in seven (3%) of 258 patients in adjuvant-CapOx group, two of which were related to treatment; eight (3%) of 249 patients in adjuvant-SOX group, two of which were related to treatment; and seven (2%) of 310 patients in perioperative-SOX group, four of which were related to treatment. No treatment-related deaths were reported. INTERPRETATION: Perioperative-SOX showed a clinically meaningful improvement compared with adjuvant-CapOx in patients with locally advanced gastric cancer who had D2 gastrectomy; adjuvant-SOX was non-inferior to adjuvant-CapOx in these patients. Perioperative-SOX could be considered a new treatment option for patients with locally advanced gastric cancer. FUNDING: National Key Research and Development Program of China, Beijing Scholars Program 2018-2024, Peking University Clinical Scientist Program, Taiho, Sanofi-Aventis, and Hengrui Pharmaceutical. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.

Spatial state distribution and phase transition of non-uniform water in soils: Implications for engineering and environmental sciences.

The physical behaviors of water in the interface are the fundamental to discovering the engineering properties and environmental effects of aqueous porous media (e.g., soils). The pore water pressure (PWP) is a key parameter to characterize the pore water state (PWS) and its phase transition in the micro interface. Traditionally, the water in the interface is frequently believed to be uniform, negative in pressure and tensile based on macroscopic tests and Gibbs interface model. However, the water in the interface is a non-uniform and compressible fluid (part of tensile and part of compressed), forming a spatial profile of density and PWP depending on its distance from the substrate interface. Herein, we introduced the static and dynamic theory methods of non-uniform water based on diffuse interface model to analyze non-uniform water state dynamics and water density and PWP. Based on the theory of non-uniform water, we gave a clear stress analysis on soil water and developed the concepts of PWS, PWP and matric potential in classical soil mechanics. In addition, the phase transition theory of non-uniform water is also examined. In nature, the generalized Clausius-Clapeyron equation (GCCE) is consistent with Clapeyron equation. Therefore, a unified interpretation is proposed to justify the use of GCCE to represent frozen soil water dynamics. Furthermore, the PWP description of non-uniform water can be well verified by some experiments focusing on property variations in the interface area, including the spatial water density profile and unfrozen water content variations with decreasing temperature and other factors. In turn, PWP spatial distribution of non-uniform water and its states can well explain some key phenomena on phase transition during ice or hydrate formation, including the discrepancies of phase transition under a wide range of conditions.

Construction and Validation of a Risk-Scoring Model that Preoperatively Predicts Lymph Node Metastasis in Early Gastric Cancer Patients.

OBJECTIVE: The aim of this study was to create a risk-scoring model to preoperatively predict the incidence of lymph node metastasis (LNM) in early gastric cancer (EGC) patients to guide treatment. METHODS: To construct the risk-scoring model, we retrospectively analyzed a primary cohort of 548 EGC patients. Univariate analysis and logistic regression were performed. A risk-scoring model for predicting LNM in EGC patients was developed based on preoperative factors, and another cohort of 73 patients was then analyzed to validate the model. RESULTS: In the primary cohort, LNM was pathologically confirmed in 72 (13.1%) patients. In the multivariate analysis, the presence of ulceration and tumor size on gastroscopy, undifferentiated histological type, and presence of enlarged lymph nodes on computed tomography or endoscopic ultrasonography were independent risk factors for LNM. A 17-point risk-scoring model was developed to predict LNM risk. The cut-off score of the model was 8, and the area under the receiver operating characteristic curve (AUC) of the model was 0.835 [95% confidence interval (CI) 0.784-0.886]. In the validation cohort, the AUC of the model was 0.829 (95% CI 0.699-0.959). CONCLUSIONS: We developed and validated an effective 17-point risk-scoring model that could preoperatively predict LNM for EGC patients.

Up-Regulation of SALL4 Is Associated With Survival and Progression via Putative WNT Pathway in Gastric Cancer.

SALL4, a transcriptional factor involved in embryonic stem cell self-renewal and pluripotency, is overexpressed in gastric cancer (GC). However, the association of SALL4 with the survival of GC patients is not well-understood, and the role of SALL4 in cancer progression is still unknown. In the present study, a total of 1,815 GC patients who underwent radical resection at Peking Cancer Hospital were included consecutively from 2015 to 2018, confirming the prognostic value of SALL4 and validating by data from TCGA and GEO. The protein and mRNA expression levels of SALL4 were evaluated by immunohistochemistry and qPCR, respectively. Besides, GSEA and WGCNA were applied to explore the SALL4-related cancer-promoting signaling pathways and gene modules. Our results showed that overexpression of SALL4 was observed in 16.7% of GC patients. SALL4 positivity was associated with male, older age, mixed-type histology, late stages, lymphatic metastasis, vascular invasion, non-cardia location, high AFP level, and no EBV infection background. SALL4 could be served as a marker for prognostic prediction in GC, and SALL4-positive GC was significantly associated with shortened survival. Further, the bioinformatic analysis indicated that the Wnt/ß-catenin signaling pathway was activated in SALL4-high cases compared with SALL4-low cases. Expression of SALL4 was also positively correlated with the expression of multiple co-expressed genes, such as TRIB3, which plays an important role in activating the Wnt/ß-catenin pathway. Our findings indicate that SALL4 is associated with clinicopathological features related to cancer progression in GC and its function in the Wnt/ß-catenin pathway.

CDKN2A Deletion Leading to Hematogenous Metastasis of Human Gastric Carcinoma.

INTRODUCTION: Somatic copy number deletion (SCND) of CDKN2A gene is the most frequent event in cancer genomes. Whether CDKN2A SCND drives human cancer metastasis is far from clear. Hematogenous metastasis is the main reason of human gastric carcinoma (GC) death. Thus, prediction GC metastasis is eagerly awaited. METHOD: GC patients (n=408) enrolled in both a cross-sectional and a prospective cohorts were analysed. CDKN2A SCND was detected with a quantitative PCR assay (P16-Light). Association of CDKN2A SCND and GC metastasis was evaluated. Effect of CDKN2A SCND by CRISPR/Cas9 on biological behaviors of cancer cells was also studied. RESULTS: CDKN2A SCND was detected in 38.9% of GCs from patients (n=234) enrolled in the cross-sectional cohort. Association analysis showed that more CDKN2A SCND was recognized in GCs with hematogenous metastasis than those without (66.7% vs. 35.7%, p=0.014). CDKN2A SCND was detected in 36.8% of baseline pN0M0 GCs from patients (n=174) enrolled in the prospective study, the relationship between CDKN2A SCND and hematogenous metastasis throughout the follow-up period (62.7 months in median) was also significant (66.7% vs. 34.6%, p=0.016). Using CDKN2A SCND as a biomarker for predicting hematogenous metastasis of GCs, the prediction sensitivity and specificity were 66.7% and 65.4%. The results of functional experiments indicated that CDKN2A SCND could obviously downregulate P53 expression that consequently inhibited the apoptosis of MGC803 GC and HEK293T cells. This may account for hematogenous metastasis of GCs by CDKN2A SCND. CONCLUSION: CDKN2A SCND may drive GC metastasis and could be used as a predictor for hematogenous metastasis of GCs.

Molecular characteristics of synchronous multiple gastric cancer.

Rationale: Multiple gastric cancer (MGC) is characterized by the presence of more than two different tumors in the stomach. However, the clonal relationship and carcinogenesis of MGC remain unclear. We investigated the clonal relationship and role of germline mutations in the carcinogenesis of MGC. Methods: We gathered 16 multiple gastric cancer patients. Thirty-three tumor samples and sixteen normal gastric tissue or blood samples were obtained from January 2016 to December 2017. We also conducted analyses for 208 gastric cancer and 49 esophagogastric junction cancer (GC-EGJ) tumors from TCGA. DNA extraction from our samples was conducted for whole-exome sequencing (WES). Results: Tumor mutation burden (TMB) was not statistically significant within database and our data in the GC-EGJ (P=0.0591) and GC groups (P=0.3113). The mutation spectrum and signatures also showed uniform distributions in GC and GC-EGJ groups within our data and TCGA database. Among sixteen patients, four were identified as monoclonal, in which 11, 10, 26 and 6 somatic mutations were shared within different tumors of P7, P8, P9 and P16, respectively. However, no common mutation between different tumors of the same patient was found among the other 12 patients. After identifying predisposing genes, we found that germline MSH2 and NCOR2 mutations were significantly dominant in 8/12 and 10/12 of genetic MGC patients. Additionally, all patients were identified with MSH2 mutations in cancer samples of those genetic MGC patients. Taking genetic MGCs as a whole, we identified that TP53 were significantly mutated in 14 of 25 tumor samples. Main conclusions: WES analyses are suggestive of monoclonal and polyclonal origin of MGC, which may promote the classification of MGC into genetic and metastatic MGC. For patients with genetic MGC, germline MSH2 X314_splice variants may contribute to carcinogenesis, thus prompting the consideration of more radical surgery and/or anti-PD-1/PD-L1 therapy.

TUG1 Promoted Tumor Progression by Sponging miR-335-5p and Regulating CXCR4-Mediated Infiltration of Pro-Tumor Immunocytes in CTNNB1-Mutated Hepatoblastoma.

INTRODUCTION: HB presents with the highest frequency of CTNNB1 mutations, resulting in activation of Wnt signaling pathway. A number of studies have demonstrated CTNNB1 mutation contributed to the development of HB. However, limited research explored the function of lncRNAs in HB with CTNNB1 mutation. METHODS: We screened lncRNA expression profiles in CTNNB1-mutated HB samples and identified lncRNAs associated with malignant phenotype in HB. The association between lncRNA and immune microenvironment was investigated. The biological function of lncRNA was further explored using in vitro experiments. RESULTS: TUG1 was identified as onco-lncRNA in CTNNB1-mutated HB. TUG1 was shown to be associated with the infiltration of pro-tumor immunocytes via regulating the expression of CXCR4, a chemokine receptor playing a critical role in regulation of immune microenvironment. Inhibiting TUG1 could increase endogenous levels of miR-335-5p and consequently downregulating CXCR4, a direct target of miR-335-5p. CONCLUSION: Our findings provide evidence for TUG1 mediating infiltration of pro-tumor immunocytes in HB patients carrying CTNNB1 mutation. TUG1-miR-335-5p-CXCR4 axis might be a promising immunological target for the treatment of HB patients.

Multi-omics characterization of molecular features of gastric cancer correlated with response to neoadjuvant chemotherapy.

Neoadjuvant chemotherapy is a common treatment for patients with gastric cancer. Although its benefits have been demonstrated, neoadjuvant chemotherapy is underutilized in gastric cancer management, because of the lack of biomarkers for patient selection and a limited understanding of resistance mechanisms. Here, we performed whole-genome, whole-exome, and RNA sequencing on 84 clinical samples (including matched pre- and posttreatment tumors) from 35 patients whose responses to neoadjuvant chemotherapy were rigorously defined. We observed increased microsatellite instability and mutation burden in nonresponse tumors. Through comparisons of response versus nonresponse tumors and pre- versus posttreatment samples, we found that C10orf71 mutations were associated with treatment resistance, which was supported by drug response data and potentially through inhibition of cell cycle, and that MYC amplification correlated with treatment sensitivity, whereas MDM2 amplification showed the opposite pattern. Neoadjuvant chemotherapy also reshapes tumor-immune signaling and microenvironment. Our study provides a critical basis for developing precision neoadjuvant regimens.

The clinical value and usage of inflammatory and nutritional markers in survival prediction for gastric cancer patients with neoadjuvant chemotherapy and D2 lymphadenectomy.

BACKGROUND: The clinical values of inflammatory and nutritional markers remained unclear for gastric cancer with neoadjuvant chemotherapy (NACT). METHODS: The inflammatory, nutritional markers and their changes were analyzed for locally advanced gastric cancer with NACT. The predictive value was evaluated by the Cox proportional hazards regressions under three hypothesized scenarios. The nomograms including independent prognostic factors were plotted for survival prediction. RESULTS: A total of 225 patients were included in the study. The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio, lymphocyte-to-monocyte ratio (LMR), systemic immune-inflammation index, and hemoglobin (Hgb) were significantly reduced, and the body mass index was significantly increased after NACT (all P < 0.05). The pre-NACT NLR [hazard ratio (HR) = 1.176, P = 0.059] showed a trend to correlate with the overall survival (OS) when only pre-NACT markers available; The post-NACT Hgb (HR = 0.982, P = 0.015) was the independent prognostic factor when only post-NACT markers available; The post-NACT Hgb (HR = 0.984, P = 0.025) and the change value of LMR (HR = 1.183, P = 0.036) were the independent prognostic factors when both pre- and post-NACT markers available. The nomogram had a similar Harrell's C-statistic compared to ypTNM stage (0.719 vs. 0.706). CONCLUSION: For locally advanced gastric cancer, the NACT could significantly decrease some inflammatory markers. The pre-NACT NLR, the post-NACT Hgb and the change value of LMR had some values in survival prediction combined with age, sex, tumor location and the clinical stages under different clinical scenarios. The elevated initial NLR, the preoperative anemia and the greater change value of LMR implied a poor prognosis.

The phosphatase PAC1 acts as a T cell suppressor and attenuates host antitumor immunity.

Cancer cells subvert immune surveillance through inhibition of T cell effector function. Elucidation of the mechanism of T cell dysfunction is therefore central to cancer immunotherapy. Here, we report that dual specificity phosphatase 2 (DUSP2; also known as phosphatase of activated cells 1, PAC1) acts as an immune checkpoint in T cell antitumor immunity. PAC1 is selectively upregulated in exhausted tumor-infiltrating lymphocytes and is associated with poor prognosis of patients with cancer. PAC1hi effector T cells lose their proliferative and effector capacities and convert into exhausted T cells. Deletion of PAC1 enhances immune responses and reduces cancer susceptibility in mice. Through activation of EGR1, excessive reactive oxygen species in the tumor microenvironment induce expression of PAC1, which recruits the Mi-2ß nucleosome-remodeling and histone-deacetylase complex, eventually leading to chromatin remodeling of effector T cells. Our study demonstrates that PAC1 is an epigenetic immune regulator and highlights the importance of targeting PAC1 in cancer immunotherapy.

A panel of DNA methylated markers predicts metastasis of pN0M0 gastric carcinoma: a prospective cohort study.

BACKGROUND: The aim of this prospective study was to evaluate the feasibility of predicting GC metastasis using CDH1, GFRA1, P16 and ZNF382 DNA methylation as biomarkers. METHODS: 198 GC patients without metastasis at the time of surgery resection were recruited into the double-blind cohort (NCT02159339). Gene methylation was analysed using MethyLight assays. GC metastasis and survival data were obtained from 178 patients with 94.7% compliance during follow-up. RESULTS: Twenty six cases of metastasis and 5 cases of recurrence were observed in 178 cases (17.4%) during the follow-up (median, 62.7 months). The GC metastasis rate for GFRA1 methylation-positive patients was significantly reduced compared with GFRA1 methylation-negative patients (odds ratio [OR]: 0.23, 95% confidence interval [CI] 0.08-0.66). Similar results were also observed using ZNF382 methylation as a predictor (OR: 0.17, 95% CI 0.06-0.47). A risk score including methylation of GFRA1 and ZNF382 was generated. The metastasis rate was significantly increased in high-risk GC patients (OR: 4.71, 95% CI: 1.85-12.00). GC patients with high risk had a shorter overall survival, especially for patients with stage I GC (P = 0.024). CONCLUSIONS: The combination of GFRA1 and ZNF382 methylation is a biomarker panel for the prediction of GC metastasis.

Impact of postoperative major complications on long-term survival after radical resection of gastric cancer.

BACKGROUND: This study was designed to evaluate the impact of postoperative major complications on long-term survival following curative gastrectomy. METHODS: This retrospective study included 239 patients with gastric cancer undergoing gastrectomy at the Beijing Cancer Hospital from February 2012 to January 2013. Survival curves were compared between patients with major complications (mC group) and those without major complications (NmC group). Multivariate analysis was conducted to identify independent prognostic factors. RESULTS: Postoperative complication and mortality rates were 24.7 and 0.8%, respectively. The severity of complications was graded in accordance with the Clavien-Dindo classification. The incidence of minor complications (grades I-II) and major complications (grades III-V) was 9.2 and 15.5%, respectively. The 3-year overall survival (OS) and disease-free survival (DFS) rates were better in the NmC group than in the mC group (p = 0.014, p = 0.013). Multivariate analysis identified major complications as an independent prognostic factor for OS and DFS. After stratification by pathological stage, this trend was also observed in stage II patients. CONCLUSIONS: Postoperative major complications adversely affect OS and DFS. The prevention and early diagnosis of complications are essential to minimize the negative effects of complications on surgical safety and long-term patient survival.