Discovery of potent small molecule inhibitors of histone lysine methyltransferase NSDs.

Nuclear receptor binding SET domain (NSD) proteins are a class of histone lysine methyltransferases and implicated in multiple cancer types with aberrant expression and involvement of cancer related signaling pathways. In this study, a series of small-molecule compounds including compound 2 and 3 are identified against the SET domain of NSDs through structure-based virtual screening. Our lead compound 3 exhibits potent inhibitory activities in vitro towards the NSD2-SET and NSD3-SET with an IC50 of 0.81 µM and 0.84 µM, respectively, and efficiently inhibits histone H3 lysine 36 dimethylation and decreases the expression of NSDs-targeted genes in non-small cell lung cancer cells at 100 nM. Compound 3 suppresses cell proliferation and reduces the clonogenicity in H460 and H1299 non-small cell lung cancer cells, and induces s-phase cell cycle arrest and apoptosis. These data establish our compounds as a valuable tool-kit for the study of the biological roles of NSDs in cancer.

LncRNA-CCAT5-mediated crosstalk between Wnt/ß-Catenin and STAT3 signaling suggests novel therapeutic approaches for metastatic gastric cancer with high Wnt activity.

BACKGROUND: Although the constitutively activated Wnt/ß-catenin signaling pathway plays vital roles in gastric cancer (GC) progression, few Wnt inhibitors are approved for clinical use. Additionally, the clinical significance of long non-coding RNAs (lncRNAs) in GC intraperitoneal dissemination (IPD) remains elusive. Here, we investigated the function and therapeutic potential of Wnt-transactivated lncRNA, colon cancer-associated transcript 5 (CCAT5), in GC metastasis. METHODS: LncRNA-sequencing assay was performed to document abundance changes of lncRNAs induced by Wnt family member 3A (Wnt3a) and degradation-resistant ß-catenin (S33Y mutated) in ascites-derived GC cells with low Wnt activity. Luciferase reporter, Chromatin immunoprecipitation (ChIP)-re-ChIP assays were performed to determine how CCAT5 was transcribed. The clinical significance of CCAT5 was examined in 2 cohorts of GC patients. The biological function of CCAT5 was investigated through gain- and loss-of-function studies. The molecular mechanism was explored through RNA-sequencing, mass spectrometry, and CRISPR/Cas9-knocknout system. The therapeutic potential of CCAT5 was examined through RNAi-based cell xenograft model and patient-derived xenograft (PDX) model of IPD. RESULTS: We identified a novel Wnt-regulated lncRNA, CCAT5, which was transactivated by the ß-catenin/transcription factor 3 (TCF3) complex. CCAT5 was significantly upregulated in GC and predicted poor prognosis. Functional studies confirmed the promotive role of CCAT5 in GC growth and metastasis. Mechanistically, CCAT5 bound to the C-end domain of signal transducer and activator of transcription 3 (STAT3) and blocks Src homology 2 domain-containing protein tyrosine phosphatase 1 (SHP-1)-mediated STAT3Y705 dephosphorylation, leading to STAT3 nuclear entry and transactivation, thus accelerating GC progression. Furthermore, we demonstrated that both Wnt3a and ß-catenin acted as activator of STAT3 signaling pathway, and the interplay between CCAT5 and STAT3 was functionally essential for Wnt-drived STAT3 signaling and tumor evolution. Finally, we revealed in vivo si-CCAT5 selectively attenuated growth and metastasis of Wnthigh GC, but not Wntlow GC. The combination of si-CCAT5 and oxaliplatin displayed obvious synergistic therapeutic effects on Wnthigh PDX mice. CONCLUSIONS: We identified a novel Wnt-transactivated lncRNA, CCAT5. Our study revealed a mechanism of STAT3 signaling regulation via canonical Wnt signaling and the functional significance of CCAT5 as critical mediator. We provided conceptual advance that lncRNAs serve as therapeutic targets reversing GC progression.

Palladium and Iron Cocatalyzed Aerobic Alkene Aminoboration.

Aminoboration of simple alkenes with nitrogen nucleophiles remains an unsolved problem in synthetic chemistry; this transformation can be catalyzed by palladium via aminopalladation followed by transmetalation with a diboron reagent. However, this catalytic process faces inherent challenges with instability of the alkylpalladium(II) intermediate toward ß-hydride elimination. Herein, we report a palladium/iron cocatalyzed aminoboration, which enables this transformation. We demonstrate these conditions on a variety of alkenes and norbornenes with an array of common nitrogen nucleophiles. In the developed strategy, the iron cocatalyst is crucial to achieving the desired reactivity by serving as a halophilic Lewis acid to release the transmetalation-active cationic alkylpalladium intermediate. Furthermore, it serves as a redox shuttle in the regeneration of the Pd(II) catalyst by reactivation of nanoparticulate palladium.

Periostin secreted from podoplanin-positive cancer-associated fibroblasts promotes metastasis of gastric cancer by regulating cancer stem cells via AKT and YAP signaling pathway.

Cancer-associated fibroblasts (CAFs) are heterogeneous stromal cells present in the tumor microenvironment (TME), which play a critical role in gastric cancer (GC) progression. Here, we examined a subset of CAFs with high podoplanin (PDPN) expression, which is correlated with tumor metastasis and poor survival in GC patients. Animal models of gastric cancer liver metastasis monitored by micro-PET/CT confirmed that periostin (POSTN) derived from PDPN(+) CAFs regulated CAFs' pro-migratory ability. Mechanistically, PDPN(+) CAFs secreted POSTN to modulate cancer stem cells (CSCs) through FAK/AKT phosphorylation. Furthermore, POSTN could also activate FAK/YAP signaling in GC cells to produce increased amounts of IL-6, which in turn induced phosphorylation of PI3K/AKT in PDPN(+) CAFs. Prolonged PI3K/AKT pathway activation in PDPN(+) CAFs maintains the production of POSTN and the effect on CSC enrichment and GC cell migration. In conclusion, our study demonstrated a positive feedback loop between PDPN(+) CAFs and CSCs during GC progression and suggested a selective target for GC treatment.

Clinical value and application of a novel nomogram containing inflammatory, nutritional and clinical markers in predicting overall survival of stage II/III gastric cancer patients after radical resection: a bi-centered retrospective study of 2,443 patients.

OBJECTIVES: We aimed to identify nutritional, inflammatory and clinical indicators associated with stage II/III gastric cancer in patients, and construct a nomogram model for accurate prediction of prognosis of patients. METHODS: We retrospectively recruited stage II/III gastric cancer (GC) patients who underwent radical gastrectomy at Fudan University Shanghai Cancer Center, from 2012 to 2019. The patients were randomly divided into training and internal validation sets, and then the Maximum log-rank statistic method was used to determine the optimal cut-off value. Next, we performed univariate and multivariate Cox regression analyses to identify independent risk factors associated with overall survival (OS). These were subsequently used to develop a nomogram model. We validated this model in patients with stage II/III gastric cancer (from 2010 to 2019) at Guangxi Medical University Affiliated Tumor Hospital. RESULTS: A total of 2,443 patients met our inclusion criteria and were therefore included in our study. Patients from Fudan University Shanghai Cancer Center were randomly divided into training (n=1725) and internal validation (n=430) sets, while those from Guangxi Medical University Affiliated Tumor Hospital were used as the external validation set (n=288). Results from univariate and multivariate Cox regression analyses revealed that age (adjusted HR, 1.23; 95% CI, 1.05-1.44; P=0.012), TNM stage (adjusted HR, 3.62; 95% CI, 2.79-4.68; P<0.001), CEA (adjusted HR, 1.40; 95% CI, 1.14-1.71; P<0.001), CA199 (adjusted HR, 1.47; 95% CI, 1.21-1.79; P<0.001), and Prognostic Nutritional Index (PNI, adjusted HR, 0.81; 95% CI, 0.67-0.98; P=0.026) were independent prognostic factors for OS in the training set. The established nomogram model, with a C-index of 0.67, had 3- and 5-year Area under Curve (AUC) values of 0.719 and 0.714, respectively. Notably, the model effectively distinguished patients' OS in both the internal (P<0.001) and external (P<0.001) datasets. CONCLUSIONS: PNI is an independent prognostic factor for stage II/III GC patients after radical resection. The established novel nomogram model, based on nutritional, inflammatory and clinical indicators, can accurately and efficiently predict prognosis of stage II/III GC patients.

Palladium-Catalyzed Oxidative Amination of α-Olefins with Indoles.

Herein we report the use of indoles, one of the most common nitrogen-containing heterocycles in FDA-approved drugs, as nucleophiles in the Pd-catalyzed aza-Wacker reaction. This N-functionalization of indoles is a Markovnikov selective olefin functionalization of simple alkenes using catalytic Pd(NPhth)2(PhCN)2 and O2 as the terminal oxidant in the presence of catalytic Bu4NBr. Various substituted indoles and alkenes are found to participate; 21 examples are presented with yields ranging from 41 to 97% isolated yield. Additionally, lactams and oxazolidinones are shown to participate under the reaction conditions. Mechanistic investigations suggest that the phthalimide ligand and Bu4NBr additive slow undesired side reactions: indole decomposition and olefin isomerization, respectively.

A study protocol of a randomized phase II trial of perioperative chemoimmunotherapy verses perioperative chemoimmunotherapy plus preoperative chemoradiation for locally advanced gastric (G) or gastroesophageal junction (GEJ) adenocarcinoma: the NeoRacing study.

BACKGROUND: Perioperative chemotherapy (ChT) and preoperative chemoradiation (CRT) are both the standard treatments for locally advanced gastric cancer (LAGC). CRT can achieve a higher pathological complete regression (pCR) rate, but whether this higher pCR rate can be transformed into a long-term survival benefit remains inconclusive. Therefore, relevant studies are in progress. On the other hand, immunotherapy has been established for the first-line treatment of advanced gastric cancer (AGC) and has been widely explored in the perioperative setting. The combination of chemotherapy/radiotherapy and immunotherapy may have a synergistic effect, which will lead to a better antitumor effect. The preliminary reports of ongoing studies show promising results, including a further improved pCR rate. However, the preferred treatment combination for LAGC is still not established. To solve this problem, we are carrying out this randomized phase II trial, which aims to evaluate the efficacy and safety of perioperative chemotherapy plus the use of PD-1 antibody with or without preoperative chemoradiation for LAGC. METHODS: Eligible patients with LAGC or gastroesophageal junction (GEJ) adenocarcinoma were randomized to receive perioperative ChT, PD-1 antibody, surgery with (Arm A) or without preoperative CRT (Arm B), and PD-1 antibody maintenance until one year after surgery. The primary endpoint of this study is that the pCR rate of Arm A will be significantly higher than that of Arm B. The secondary endpoints include the pathological partial regression (pPR) rate, R0 resection rate, objective response rate (ORR), event-free survival (EFS), overall survival (OS), safety and surgical complications. Moreover, several explorative endpoints will be evaluated to find and validate the predictive biomarkers of immunotherapy. DISCUSSION: The results of the NeoRacing study will provide important information concerning the application of PD-1 antibody in LAGC patients during the perioperative setting. Meanwhile, the two treatment protocols will be compared in terms of efficacy and safety. TRIAL REGISTRATION: ClinicalTrials.gov , NCT05161572 . Registered 17 December 2021 - Retrospectively registered.

Crocetin suppresses angiogenesis and metastasis through inhibiting sonic hedgehog signaling pathway in gastric cancer.

Gastric cancer (GC) is one of the major causes of cancer-related deaths and chemoresistance is a key obstacle to the treatment of GC, particularly in advanced GC. As an active component of saffron stigma, crocetin has important therapeutic effects on various diseases including tumors. However, the therapeutic potential of crocetin targeting GC is still unclear and the underlying mechanisms are remained to be further explored. In this study, crocetin significantly inhibited angiogenesis in GC, including tubes of HUVECs and vasculogenic mimicry (VM) formation of GC cells. Crocetin also suppressed cell proliferation, migration and invasion. To explore which signaling pathway involving in crocetin, HIF-1α, Notch1, Sonic hedgehog (SHH) and VEGF were examined with crocetin treatment and we found that SHH significantly decreased. Crocetin suppressed SHH signaling with SHH, PTCH2, Sufu and Gli1 protein level decreased in western blot assay. In addition, crocetin suppressed SHH secretion in GC and HUVEC cells. The promoted effects on cell migration induced by secreted SHH were also inhibited by crocetin in GC and HUVEC cell co-culture system. Furthermore, recombinant SHH promoted angiogenesis as well as cell migration and proliferation. However, these promoted effects were reversed by crocetin treatment. These results revealed that crocetin suppressed GC angiogenesis and metastasis through SHH signaling pathway, indicating that crocetin may function as an effective therapeutic drug against GC.

Development of a Quantitative Diagnostic Criterion for Gastric Linitis Plastica: Findings From a Large Single-Institutional Study.

Gastric linitis plastica (GLP) is a descriptive term but lacks a quantitative definition. Several relatively quantitative criteria had been proposed, such as tumor involving a limit of one-third or two-thirds of the gastric surface. However, these criteria needed doctors to subjectively judge tumor infiltration area, which made diagnosis difficult to be objective and reproducible. This study aimed to propose a quantitative diagnostic criterion for distinguishing GLP. We performed a retrospective cohort study of 2,907 patients with Borrmann III and IV gastric cancer (GC) who underwent gastrectomy between 2011 and 2018 in our center. The Kaplan-Meier curves showed that patients with an observed tumor size more than 8 cm had obviously lower overall survival (OS) and disease-free survival (DFS) rates than those with a size less than 8 cm(p < 0.001; p < 0.001). However, there was no significantly different prognosis of patients with tumor sizes between more than 8 cm and more than 10 cm (p = 0.248; p = 0.534). Moreover, patients with tumor sizes greater than 8 cm more presented with advanced stage and had extremely poor 3-year OS and DFS (31.4%; 29.3%), with a stronger propensity toward peritoneal metastasis. Therefore, we considered patients' observed tumor size more than 8 cm as a critical value for distinguishing the prognosis of Borrmann III and IV GC. Furthermore, we proposed an observed tumor size more than 8 cm as a quantitative diagnostic criterion for GLP on the premise of satisfying the originally descriptive and pathological definition regardless of Borrmann type.

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.

Copper-Catalyzed Three-Component Alkene Carbofunctionalization: C-N, C-O, and C-C Bond Formation from a Single Reaction Platform.

A general system achieving three-component intermolecular carbofunctionalization of alkenes is presented, including carboetherification, carboesterification, carboarylation, and carboamination. The scope of the reaction is presented with respect to the carbon electrophile, the olefin, and the nucleophile. Furthermore, the synthesis of γ-lactams via a carboamination reaction is demonstrated in a telescoped three-step protocol.

NTF4 stimulates the progression of gastric cancer via regulating FOXL1.

PURPOSE: To elucidate the diagnostic and prognostic potentials of NTF4 in gastric cancer (GC), as well as its regulatory effects on biological functions of GC cells. METHODS: Fifty-two GC patients treated by surgical resection were retrospectively analyzed and their cancer and adjacent tissues were collected. NTF4 levels in GC tissues were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The relationship between NTF4 and clinical features of GC was analyzed. After knockdown of NTF4, the proliferative and migratory abilities of MKN45 and BGC-823 cells, and growth rate of GC in nude mice were examined. In addition, the target gene of NTF4, FOXL1 was confirmed by dual-luciferase reporter assay, and co-regulation on GC process was determined by rescue experiments. RESULTS: NTF4 was upregulated in GC tissues than in normal ones. High level of NTF4 predicted malignant progression, poor overall survival and progression-free survival in GC patients. Knockdown of NTF4 attenuated the in vitro proliferative and migratory abilities of GC cells, as well as in vivo tumorigenicity of GC in nude mice. FOXL1 was the target gene of NTF4, which was lowly expressed in GC. Knockdown of FOXL1 was able to reverse the influence of silenced NTF4 on the biological functions of GC cells. CONCLUSIONS: NTF4 is an effectively diagnostic biomarker for early-stage GC, and it stimulates the proliferative and migratory potentials in GC by negatively regulating FOXL1.

Genetic risk, incident gastric cancer, and healthy lifestyle: a meta-analysis of genome-wide association studies and prospective cohort study.

BACKGROUND: Genetic variants and lifestyle factors have been associated with gastric cancer risk, but the extent to which an increased genetic risk can be offset by a healthy lifestyle remains unknown. We aimed to establish a genetic risk model for gastric cancer and assess the benefits of adhering to a healthy lifestyle in individuals with a high genetic risk. METHODS: In this meta-analysis and prospective cohort study, we first did a fixed-effects meta-analysis of the association between genetic variants and gastric cancer in six independent genome-wide association studies (GWAS) with a case-control study design. These GWAS comprised 21 168 Han Chinese individuals, of whom 10 254 had gastric cancer and 10 914 geographically matched controls did not. Using summary statistics from the meta-analysis, we constructed five polygenic risk scores in a range of thresholds (p=5 × 10-4 p=5 × 10-5 p=5 × 10-6 p=5 × 10-7, and p=5 × 10-8) for gastric cancer. We then applied these scores to an independent, prospective, nationwide cohort of 100 220 individuals from the China Kadoorie Biobank (CKB), with more than 10 years of follow-up. The relative and absolute risk of incident gastric cancer associated with healthy lifestyle factors (defined as not smoking, never consuming alcohol, the low consumption of preserved foods, and the frequent intake of fresh fruits and vegetables), was assessed and stratified by genetic risk (low [quintile 1 of the polygenic risk score], intermediate [quintile 2-4 of the polygenic risk score], and high [quintile 5 of the polygenic risk score]). Individuals with a favourable lifestyle were considered as those who adopted all four healthy lifestyle factors, those with an intermediate lifestyle adopted two or three factors, and those with an unfavourable lifestyle adopted none or one factor. FINDINGS: The polygenic risk score derived from 112 single-nucleotide polymorphisms (p<5 × 10-5) showed the strongest association with gastric cancer risk (p=7·56 × 10-10). When this polygenic risk score was applied to the CKB cohort, we found that there was a significant increase in the relative risk of incident gastric cancer across the quintiles of the polygenic risk score (ptrend<0·0001). Compared with individuals who had a low genetic risk, those with an intermediate genetic risk (hazard ratio [HR] 1·54 [95% CI 1·22-1·94], p=2·67 × 10-4) and a high genetic risk (2·08 [1·61-2·69], p<0·0001) had a greater risk of gastric cancer. A similar increase in the relative risk of incident gastric cancer was observed across the lifestyle categories (ptrend<0·0001), with a higher risk of gastric cancer in those with an unfavourable lifestyle than those with a favourable lifestyle (2·03 [1·46-2·83], p<0·0001). Participants with a high genetic risk and a favourable lifestyle had a lower risk of gastric cancer than those with a high genetic risk and an unfavourable lifestyle (0·53 [0·29-0·99], p=0·048), with an absolute risk reduction of 1·12% (95% CI 0·62-1·56). INTERPRETATION: Chinese individuals at an increased risk of incident gastric cancer could be identified by use of our newly developed polygenic risk score. Compared with individuals at a high genetic risk who adopt an unhealthy lifestyle, those who adopt a healthy lifestyle could substantially reduce their risk of incident gastric cancer. FUNDING: National Key R&D Program of China, National Natural Science Foundation of China, 333 High-Level Talents Cultivation Project of Jiangsu Province, and China Postdoctoral Science Foundation.

Stereoselective access to [5.5.0] and [4.4.1] bicyclic compounds through Pd-catalysed divergent higher-order cycloadditions.

Medium-sized rings, including those embedded in bridged and fused bicyclic scaffolds, are common core structures of myriad bioactive molecules. Among various synthetic strategies towards their synthesis, intermolecular higher-order cycloaddition provides great potential to build complex medium-sized rings from simple building blocks. Unfortunately, such transformations are often plagued with competitive reaction pathways and low levels of site- and stereoselectivity. Herein, we report catalyst-controlled divergent access to three classes of medium-sized bicyclic compounds in high efficiency and stereoselectivity, by palladium-catalysed cycloadditions of tropones with γ-methylidene-δ-valerolactones. Mechanistic studies and density functional theory calculations disclosed that the divergent reactions stem from the different reaction profiles of the diastereomeric intermediates. While one undergoes either O- or C-allylation to provide [5.5.0] or [4.4.1] bicyclic compounds, the unique conformation of the other diastereomer allows an unconventional alkene isomerization to deliver bridgehead alkene-containing bicyclo[4.4.1] compounds. The conversion of these products to diverse complex polycyclic scaffolds has also been demonstrated.

Analysis of lymph node metastasis in early gastric cancer: a single institutional experience from China.

BACKGROUND: Lymph node metastasis (LNM) has a strong influence on the prognosis of patients with early gastric cancer (EGC). The aim of this study was to reveal the incidence of LNM and evaluate risk factors for LNM to determine the appropriate treatment for EGC in a Chinese population. METHODS: Patients who underwent radical gastrectomy with lymph node dissection for EGC between 2012 and 2017 were retrospectively analyzed. Univariate and multivariate analyses were conducted to identify clinicopathological features that were risk factors for LNM. RESULTS: A total of 1033 patients with EGC were enrolled. Of these patients, 668 (64.7%) were men, and 365 (35.3%) were women, ranging in age from 19 to 82 years (mean 56.9 ± 10.9 years). LNM was detected in 173(16.7%) patients with EGC. Among 508 patients with mucosal cancer, 44 (8.7%) patients had LNM. In 525 patients with submucosal cancer, the incidence of LNM was 24.6% (129/525). The age, gender, tumor size, type of differentiation, Lauren classification, and lymphovascular and perineural invasion showed a significant correlation with the rate of LNM in EGC by univariate and multivariate analyses. Patients with submucosal gastric cancer had an older age, a higher proportion of proximal lesion, larger tumor size, more frequent lymphovascular invasion, perineural invasion, and more LNM than patients with mucosal gastric cancer. CONCLUSIONS: Our study revealed a relatively high incidence of LNM in EGC, compared with Japanese and Korean cohorts. Female sex, large tumor size, undifferentiated-type, and lymphovascular invasion were independent risk factors for LNM in EGC. Radical gastrectomy with lymphadenectomy should be performed in EGC patients with a high risk of LNM.

Meta-analysis of genome-wide association studies and functional assays decipher susceptibility genes for gastric cancer in Chinese populations.

OBJECTIVE: Although a subset of genetic loci have been associated with gastric cancer (GC) risk, the underlying mechanisms are largely unknown. We aimed to identify new susceptibility genes and elucidate their mechanisms in GC development. DESIGN: We conducted a meta-analysis of four genome-wide association studies (GWASs) encompassing 3771 cases and 5426 controls. After targeted sequencing and functional annotation, we performed in vitro and in vivo experiments to confirm the functions of genetic variants and candidate genes. Moreover, we selected 33 promising variants for two-stage replication in 7035 cases and 8323 controls from other five studies. RESULTS: The meta-analysis of GWASs identified three loci at 1q22, 5p13.1 and 10q23.33 associated with GC risk at p<5×10-8 and replicated seven known loci at p<0.05. At 5p13.1, the risk rs59133000[C] allele enhanced the binding affinity of NF-κB1 (nuclear factor kappa B subunit 1) to the promoter of PRKAA1, resulting in a reduced promoter activity and lower expression. The knockout of PRKAA1 promoted both GC cell proliferation and xenograft tumour growth in nude mice. At 10q23.33, the rs3781266[C] and rs3740365[T] risk alleles in complete linkage disequilibrium disrupted and created, respectively, the binding motifs of POU2F1 and PAX3, resulting in an increased enhancer activity and expression of NOC3L, while the NOC3L knockdown suppressed GC cell growth. Moreover, two new loci at 3q11.2 (OR=1.21, p=4.56×10-9) and 4q28.1 (OR=1.14, p=3.33×10-11) were associated with GC risk. CONCLUSION: We identified 12 loci to be associated with GC risk in Chinese populations and deciphered the mechanisms of PRKAA1 at 5p13.1 and NOC3L at 10q23.33 in gastric tumourigenesis.

In-Hospital Mortality Risk Model of Gastric Cancer Surgery: Analysis of a Nationwide Institutional-Level Database With 94,277 Chinese Patients.

Background: The objective of this study is to identify independent risks and protective factors and to construct a mortality prediction model for gastrectomy in the Chinese population. Study design: This is a population-based prospective cohort at an institutional level. Seventy-two participating hospitals reported their annual gastrectomy data between 2014 and 2016, while 44 variables covering the institution and surgical information were included in the analysis. We used R software to encode and complete data pre-processing. The first difference model was applied to build the risk model. Data from 2014 and 2015 were assigned to risk model development, while data from 2016 was used for validation. Results: In the included centers with 94,277 gastric cancer cases, the in-hospital mortality rate was 0.32%. The regression model revealed that provinces with low-middle GDP, hospitals with annual gastrectomy volume between 100 and 500, greater volume of urgent surgeries performed, larger proportion of males, and a higher proportion of liver metastasis were independent risk factors for mortality following gastric surgeries, while higher laparoscopic resection volume, greater volume of distal gastrectomy with B2 reconstruction, and larger proportion of palliative surgery were independent protective factors (p < 0.05, respectively). In the prediction test, the mean square error of the training set was 0.948, while that of the test set was 0.728, demonstrating the effectiveness of this model. Conclusions: We constructed the first mortality risk prediction model for gastric cancer surgery in the Chinese population. The identified risk factors will help with the therapy selection, while further informing Chinese medical policy decision-makers.

Long non-coding RNA SNHG3 promotes progression of gastric cancer by regulating neighboring MED18 gene methylation.

To understand the mechanistic involvement of long non-coding RNA (lncRNA) SNHG3 in gastric cancer (GC), the relative abundance of SNHG3 was determined by real-time PCR. Overall and metastasis-free survival was analyzed by Kaplan-Meier's plot. The potential impact of SNHG3 on tumor progression was evaluated both in vitro and in vivo. The in vivo metastasis was monitored in the tail vein-injected mice. Our data suggested that high SNHG3 associated with unfavorable prognosis in respect to overall and metastasis-free survival. SNHG3-deficiency significantly suppressed cell proliferation and cell viability in vitro and xenograft progression in vivo. In addition, ectopic overexpression of SNHG3 promoted cell migration and invasion in vitro and lung metastasis in vivo. Mechanistically, we uncovered SNHG3 associated with EZH2 and negatively regulated MED18 expression through methylation modulation. Transient knockdown of MED18 in SNHG3-deficient cells completely rescued the tumor suppressive phenotypes in GC cells. Our data unraveled the oncogenic properties of high SNHG3 in GC, which predominantly depended on epigenetically regulated MED18.

Identification and external validation of a novel miRNA signature for lymph node metastasis prediction in submucosal-invasive gastric cancer patients.

Endoscopic resection (ER) has been increasingly performed in the treatment of early gastric cancer (GC). However, lymph node metastasis (LNM) can cause treatment failure with ER, especially in T1b patients. Here, we attempted to develop a miRNA-based classifier to detect LNM in T1b patients. Based on high-throughput data from The Cancer Genome Atlas, we identified 20 miRNAs whose expression significantly changed in T1-2 GC with LNM vs T1-2 GC without LNM. We then developed a miRNA signature to predict LNM of T1b GC using the LASSO model and backward step wise elimination approach in a training cohort. Furthermore, the predictive accuracy of this classifier was validated in both an internal testing group of 63 patients and an external independent group of 114 patients. This systematic and comprehensive in silico study identified a 7-miRNA signature with an area under the receiver operating characteristic curve (AUROC) value of 0.843 in T1-2 GC and 0.911 in T1 EGC. The backward elimination was further used to develop a 4-miRNA (miR-153-3p, miR-708, miR-940 and miR-375) risk-stratification model in the training cohort with an AUROC value of 0.898 in cohort 2. When pathologic results were used as a reference, the risk model yielded AUROC values of 0.829 and 0.792 in two cohorts of endoscopic biopsy specimens. This novel miRNA-LNM classifier works better than the currently used pathologic criteria of ER in T1b EGC. This classifier could individualize the management of T1b patients and facilitate treatment decisions.