MUC16: clinical targets with great potential.

Mucin 16 (MUC16) is a membrane-bound mucin that is abnormally expressed or mutated in a variety of diseases, especially tumors, while being expressed in normal body epithelium. MUC16 and its extracellular components are often important cancer-related biomarkers. Abnormal expression of MUC16 promotes tumor progression through mesenchymal protein, PI3K/AKT pathway, JAK2/STAT3 pathway, ERK/FBW7/c-Myc, and other mechanisms, and plays an important role in the occurrence and development of tumors. In addition, MUC16 also helps tumor immune escape by inhibiting T cells and NK cells. Many drugs and trials targeting MUC16 have been developed, and MUC16 may be a new direction for future treatments. In this paper, the mechanism of action of MUC16 in the development of cancer, especially in the immune escape of tumor, is introduced in detail, indicating the potential of MUC16 in clinical treatment.

Systematic pan-cancer analyses of the potential function of the Golgi scaffold protein PAQR3.

Progesterone and AdipoQ Receptor 3 (PAQR3) is a member of the AdipoQ receptor. Our previous studies have found that PAQR3 plays a role as a candidate inhibitor in cardiac adenocarcinoma, breast cancer, gastric cancer and colorectal cancer, but the systematic analysis of PAQR3 in tumors is currently lacking. The objective of this study was to investigate the prognostic and therapeutic value of PAQR3 in 31 tumors. Through the analysis of TCGA, UALCAN, GEO, GEPIA2, TIMER, Kaplan-Meier plotter, TISIDB and other databases, it was found that the expression level of PAQR3 changed significantly in different tumor types, and the expression level of Neuroblastoma was very high. And the level of Prostate adenocarcinoma is low. In addition, the expression level of PAQR3 in Cholangiocarcinoma, Esophageal carcinoma, Head and neck squamous carcinoma, Liver Hepatocellular Carcinoma, Lung Adenocarcinoma and Lung squamous cell carcinoma was significantly higher than that in normal tissues. However, the expression level of PAQR3 in Breast Cancer, Kidney Renal Clear Cell Carcinoma, Kidney renal papillary cell carcinoma, Prostate Adenocarcinoma, Rectum Adenocarcinoma, Thyroid Cancer and Uterine Corpus Endometrial Carcinoma was lower than that in normal tissues. Subsequently, we explored the value of PAQR3 as a prognostic indicator of cancer. In Acute Myeloid Leukemia, Lower-grade Glioma and Glioblastoma, Pediatric Low-grade Gliomas, Kidney Chromophobe, and Thyroid Cancer, PAQR3 expression was positively correlated with OS and DSS, while in Rectum Adenocarcinoma, PAQR3 expression was negatively correlated with OS. PAQR3 high expression group Lower-grade Glioma and Glioblastoma, Pediatric Low-grade Gliomas, Uveal Melanoma, Kidney Chromophobe and DFI were positively correlated. PAQR3 can be used as a risk factor for the prognosis of multiple tumors. Then, we discussed the correlation between PAQR3 and immunology, and found that PAQR3 has a wide range of mutations in various tumor types, the most common mutation type is missense mutation, and common mutation types also include amplification, depth deletion, splicing, truncation and structural variation. Among the tumor samples with PAQR3 alterations, mutation occurred in all tumor samples except prostate adenocarcinoma and adrenal cortical carcinoma, head and neck squamous cell carcinoma, brain low-grade glioma, and kidney clear cell carcinoma, while esophageal adenocarcinoma had the highest total alteration frequency. PAQR3 was strongly associated with CNV in 18 tumors, particularly in Ovarian cancer, Lung squamous cell carcinoma, and Adenoid cystic carcinoma. On the other hand, PAQR3 has a higher SNV frequency in Uterine Corpus Endometrial Carcinoma, Skin Cutaneous Melanoma and Lung Adenocarcinoma, among which Uterine Corpus Endometrial Carcinoma has the highest SNV frequency. These results showed that PAQR3 expression levels were significantly correlated with tumor mutation load, microsatellite instability, neoantigens, and purity. In summary, PAQR3 can affect the tumor microenvironment and has potential for chemotherapy. Finally, we investigated the role of PAQR3 in tumor resistance and found that the expression of PAQR3 affects the efficacy of multiple chemotherapy drugs. Based on these studies, we found that PAQR3 plays an important role in cancer and has potential in tumor diagnosis and prognosis.

Methyltransferase-like proteins in cancer biology and potential therapeutic targeting.

RNA modification has recently become a significant process of gene regulation, and the methyltransferase-like (METTL) family of proteins plays a critical role in RNA modification, methylating various types of RNAs, including mRNA, tRNA, microRNA, rRNA, and mitochondrial RNAs. METTL proteins consist of a unique seven-beta-strand domain, which binds to the methyl donor SAM to catalyze methyl transfer. The most typical family member METTL3/METTL14 forms a methyltransferase complex involved in N6-methyladenosine (m6A) modification of RNA, regulating tumor proliferation, metastasis and invasion, immunotherapy resistance, and metabolic reprogramming of tumor cells. METTL1, METTL4, METTL5, and METTL16 have also been recently identified to have some regulatory ability in tumorigenesis, and the rest of the METTL family members rely on their methyltransferase activity for methylation of different nucleotides, proteins, and small molecules, which regulate translation and affect processes such as cell differentiation and development. Herein, we summarize the literature on METTLs in the last three years to elucidate their roles in human cancers and provide a theoretical basis for their future use as potential therapeutic targets.

Oncofetal protein IGF2BPs in human cancer: functions, mechanisms and therapeutic potential.

N6-methyladenosine (m6A) is the most prevalent and well-characterized internal chemical modification in eukaryotic RNA, influencing gene expression and phenotypic changes by controlling RNA fate. Insulin-like growth factor-2 mRNA-binding proteins (IGF2BPs) preferentially function as m6A effector proteins, promoting stability and translation of m6A-modified RNAs. IGF2BPs, particularly IGF2BP1 and IGF2BP3, are widely recognized as oncofetal proteins predominantly expressed in cancer rather than normal tissues, playing a critical role in tumor initiation and progression. Consequently, IGF2BPs hold potential for clinical applications and serve as a good choice for targeted treatment strategies. In this review, we discuss the functions and mechanisms of IGF2BPs as m6A readers and explore the therapeutic potential of targeting IGF2BPs in human cancer.

Potential role of intratumor bacteria outside the gastrointestinal tract: More than passengers.

INTRODUCTION: Tumor-associated bacteria and gut microbiota have gained significant attention in recent years due to their potential role in cancer development and therapeutic response. This review aims to discuss the contributions of intratumor bacteria outside the gastrointestinal tract, in addition to exploring the mechanisms, functions, and implications of these bacteria in cancer therapy. METHODS: We reviewed current literature on intratumor bacteria and their impact on tumorigenesis, progression, metastasis, drug resistance, and anti-tumor immune modulation. Additionally, we examined techniques used to detect intratumor bacteria, precautions necessary when handling low microbial biomass tumor samples, and the recent progress in bacterial manipulation for tumor treatment. RESULTS: Research indicates that each type of cancer uniquely interacts with its microbiome, and bacteria can be detected even in non-gastrointestinal tumors with low bacterial abundance. Intracellular bacteria have the potential to regulate tumor cells' biological behavior and contribute to critical aspects of tumor development. Furthermore, bacterial-based anti-tumor therapies have shown promising results in cancer treatment. CONCLUSIONS: Understanding the complex interactions between intratumor bacteria and tumor cells could lead to the development of more precise cancer treatment strategies. Further research into non-gastrointestinal tumor-associated bacteria is needed to identify new therapeutic approaches and expand our knowledge of the microbiota's role in cancer biology.

Comprehensive transcriptomic profiling and mutational landscape of primary gastric linitis plastica.

BACKGROUND: Primary gastric linitis plastica (GLP) is a distinct phenotype of gastric cancer with poor survival. Comprehensive molecular profiles and putative therapeutic targets of GLP remain undetermined. METHODS: We subjected 10 tumor-normal tissue pairs to whole exome sequencing (WES) and whole transcriptome sequencing (WTS). 10 tumor samples were all GLP which involves 100% of the gastric wall macroscopically. TCGA data were compared to generate the top mutated genes and the overexpressed genes in GLP. RESULTS: Our results reveal that GLP has distinctive genomic and transcriptomic features, dysfunction in the Hippo pathway is likely to be a key step during GLP development. 6 genes were identified as significantly highly mutated genes in GLP, including AOX1, ANKRD36C, CPXM1, PTPN14, RPAP1, and DCDC1). MUC6, as a previously identified gastric cancer driver gene, has a high mutation rate (20%) in GLP. 20% of patients in our GLP cohort had CDH1 mutations, while none had RHOA mutations. GLP exhibits high immunodeficiency and low AMPK pathway activity. Our WTS results showed that 3 PI3K-AKT pathway-related genes (PIK3R2, AKT3, and IGF1) were significantly up-regulated in GLP. Two genes were identified using immunohistochemistry (IHC), IGF2BP3 and MUC16, which specifically expressed in diffuse-type-related gastric cancer cell lines, and its knockdown inhibits PI3K-AKT pathway activity. CONCLUSIONS: We provide the first integrative genomic and transcriptomic profiles of GLP, which may facilitate its diagnosis, prognosis, and treatment.

Golgi scaffold protein PAQR3 as a candidate suppressor of gastric cardia adenocarcinoma via regulating TGF-ß/Smad pathway.

OBJECTIVES: To investigate the function of PAQR3 in gastric cardia adenocarcinoma (GCA) and understand the possible mechanism of PAQR3 in regulating epithelial-mesenchymal transition (EMT). METHODS: We detected PAQR3 protein in 146 GCA tissues and paired normal adjacent tissues (PNTs) specimens using immunohistochemical analysis, and explored its clinical significance. The expression levels of PAQR3 protein in 20 GCA tissues, their paired PNTs, HGC27, SGC7901, and GES-1 cells were analyzed by Western blot. Wild-type PAQR3 was overexpressed in HGC27 cells. The effects of PAQR3 overexpression on the function of HGC27 cells and its underlying mechanisms were then analyzed through a series of cell and molecular biology experiments. RESULTS: PAQR3 was significantly down-regulated in GCA tissues when compared with paired PNTs (p < 0.0001). The expression level of PAQR3 in GCA tissues was significantly negatively correlated with Helicobacter pylori infection (p = 0.000), venous invasion (p = 0.000), invasion depth (p = 0.000), lymph node metastasis (p = 0.022), tumor stage (p = 0.000), and patient survival (p = 0.009). Downregulation of PAQR3 was highly correlated with increased EMT signature and activated TGF-ß/Smad pathway in GCA tissues. Overexpression of PAQR3 in HGC27 cells negatively regulates its cellular functions, such as cell proliferation and migration, and suppresses EMT. Mechanistically, overexpression of PAQR3 significantly down-regulates the protein expression levels of TGF-1, p-Smad2, and p-Smad3 in HGC27 cells. CONCLUSION: PAQR3 was significantly down-regulated in GCA tissues, HGC27, and SGC7901 cells. PAQR3 significantly inhibits the proliferation, migration, and invasion of HGC27 cells. Mechanistically, PAQR3 can inhibit the EMT process in HGC27 cells by regulating TGF-ß/Smad signaling pathway.

Circulating methylated THBS1 DNAs as a novel marker for predicting peritoneal dissemination in gastric cancer.

OBJECTIVES: Thrombospondin 1 (THBS1) is known to play a key role in tumor metastasis, and aberrant DNA methylation is one of the mechanisms regulating THBS1. The present study investigated whether methylated THBS1 in circulating cell-free DNA from preoperative peritoneal lavage fluid (PPLF) and peripheral blood could be used as a potential biomarker for predicting peritoneal dissemination in gastric cancer (GC) patients. METHODS: The status of THBS1 methylation was detected by quantitative methylation-specific PCR (MSP) in tumor tissues, paired PPLF, and serum from 92 GC patients. The correlation between methylated THBS1 levels and peritoneal dissemination of GC was studied, and its diagnostic value for predicting peritoneal dissemination was clarified by the receiver operating characteristic (ROC) curve. RESULTS: Aberrant THBS1 methylation in tumor tissues was significantly higher than that in paracancerous normal tissues (p < 0.0001). No THBS1 methylation was found in 40 healthy controls, and partial methylation was detected in 3 of 48 patients with chronic non-atrophic gastritis. The frequency of THBS1 methylation in pairing PPLF and serum from 92 GC patients was 52.2% (48/92) and 58.7% (54/92), respectively. The results of methylated THBS1 in pairing PPLF and serum were similar to those of tumor tissues. Aberrant THBS1 methylation in tumor tissues and pairing PPLF or serum was closely related to peritoneal dissemination, tumor progression, and poor prognosis (all p < 0.0001). CONCLUSION: Circulating methylated THBS1 DNAs in PPLF/serum may predict peritoneal dissemination, a potential poor prognostic factor for GC patients.

A Potential Oncogenic Role for PFKFB3 Overexpression in Gastric Cancer Progression.

OBJECTIVES: PFKFB3 regulates glycolysis in tumor cells, might function as an oncogene, and is associated with cancer metastasis. However, its role in gastric cancer (GC) remains largely unknown. METHODS: PFKFB3 expression was assessed by immunohistochemistry (IHC) in GC tissues and paired paracancerous histological normal tissues (PCHNTs). The associations of PFKFB3 expression with clinical features and HIF-1α, Ki-67, E-cadherin, Snail, and Vimentin expression levels were assessed. A series of in vivo and in vitro experiments were performed to investigate the effects of PFKFB3 on the growth, migration, and invasion of GC cells. RESULTS: We found that PFKFB3 expression was significantly higher in GC tissues compared with PCHNTs (P = 0.000). PFKFB3 expression was positively correlated with tumor size (P = 0.000), differentiation (P = 0.025), venous invasion (P = 0.084), nerve invasion (P = 0.014), lymphatic invasion (P = 0.000), local invasion (P = 0.000), invasive depth (P = 0.000), nodal metastasis (P = 0.000), tumor-node-metastasis stage (P = 0.000), and patient survival (P = 0.000). Notably, PFKFB3 upregulation was highly correlated with increased epithelial-mesenchymal transition (EMT) in GC samples. PFKFB3 overexpression positively modulated cell proliferation, migration, and EMT in GC cells in vitro, with concomitant activation of NF-κB signaling. Administration of an NF-κB inhibitor attenuated PFKFB3-induced EMT in GC cells. PFKFB3 overexpression promoted tumor development and EMT in nude mice, which were attenuated by PFK-15, a PFKFB3 inhibitor. DISCUSSION: PFKFB3 could potentiate malignancy in GC cells through NF-κB pathway-mediated EMT, suggesting PFKFB3 represents a potential target for GC therapy.

Oxidative stress-mediated AMPK inactivation determines the high susceptibility of LKB1-mutant NSCLC cells to glucose starvation.

The liver kinase B1 (LKB1) is an important tumor suppressor and its loss-of-function mutations are observed in around 16% of non-small cell lung cancer (NSCLC) cases. One of the main functions of LKB1 is to activate AMP-activated protein kinase (AMPK) via direct phosphorylation. Under metabolic or energy stress conditions, the LKB1-AMPK axis inhibits the anabolic pathways and activates the catabolic pathways to maintain metabolic homeostasis for cell survival. In this study, we found that LKB1-mutant NSCLC cells are particularly susceptible to cell death induced by glucose starvation, but not by other forms of starvation such as amino acid starvation or serum starvation. Reconstitution of LKB1 in LKB1-mutant cells or LKB1 knockout in LKB1-wild type cells highlighted the importance of the LKB1-AMPK axis for cell survival under glucose starvation. Mechanistically, in LKB1-mutant cells, glucose starvation elicits oxidative stress, which causes AMPK protein oxidation and inactivation, and eventually cell death. Importantly, this process could be effectively reversed and rescued by 2DG (a glucose analog capable of producing NADPH, a key antioxidant), A769662 (an allosteric AMPK activator), and N-acetyl cysteine (NAC) (a ROS scavenger), indicating the presence of a vicious circle between AMPK inactivation and ROS in LKB1-mutant NSCLC cells under glucose starvation. Our study thus elucidates the critical role of redox balance in determining the susceptibility to cell death under glucose starvation in LKB1-mutant NSCLC cells. The findings from this study reveal important clues in search of novel therapeutic strategies for LKB1-mutant NSCLC by targeting glucose metabolism and redox balance.

Characterization of the Golgi scaffold protein PAQR3, and its role in tumor suppression and metabolic pathway compartmentalization.

The Golgi apparatus is critical in the compartmentalization of signaling cascades originating from the cytoplasmic membrane and various organelles. Scaffold proteins, such as progestin and adipoQ receptor (PAQR)3, specifically regulate this process, and have recently been identified in the Golgi apparatus. PAQR3 belongs to the PAQR family, and was recently described as a tumor suppressor. Accumulating evidence demonstrates PAQR3 is downregulated in different cancers to suppress its inhibitory effects on malignant potential. PAQR3 functions biologically through the pathological regulation of altered signaling pathways. Significant cell proliferation networks, including Ras proto-oncogene (Ras)/mitogen-activated protein kinase (MAPK), phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt), insulin, and vascular endothelial growth factor, are closely controlled by PAQR3 for physiologically relevant effects. Meanwhile, genetic/epigenetic susceptibility and environmental factors, may have functions in the downregulation of PAQR3 in human cancers. This study aimed to assess the subcellular localization of PAQR3 and determine its topological features and functional domains, summarizing its effects on cell signaling compartmentalization. The pathophysiological functions of PAQR3 in cancer pathogenesis, metabolic diseases, and developmental ailments were also highlighted.

Polyamine synthesis enzyme AMD1 is closely associated with tumorigenesis and prognosis of human gastric cancers.

Adenosylmethionine decarboxylase 1 (AMD1) is a key enzyme involved in biosynthesis of polyamines including spermidine and spermine. The potential function of AMD1 in human gastric cancers is unknown. We analyzed AMD1 expression level in 319 human gastric cancer samples together with the adjacent normal tissues. The protein expression level of AMD1 was significantly increased in human gastric cancer samples compared with their corresponding para-cancerous histological normal tissues (P < 0.0001). The expression level of AMD1 was positively associated with Helicobactor pylori 16sRNA (P < 0.0001), tumor size (P < 0.0001), tumor differentiation (P < 0.05), tumor venous invasion (P < 0.0001), tumor lymphatic invasion (P < 0.0001), blood vessel invasion (P < 0.0001), and tumor lymph node metastasis (TNM) stage (P < 0.0001). Patients with high expression of AMD1 had a much shorter overall survival than those with normal/low expression of AMD1. Knockdown of AMD1 in human gastric cancer cells suppressed cell proliferation, colony formation and cell migration. In a tumor xenograft model, knockdown of AMD1 suppressed the tumor growth in vivo. Inhibition of AMD1 by an inhibitor SAM486A in human gastric cancer cells arrested cell cycle progression during G1-to-S transition. Collectively, our studies at the cellular, animal and human levels indicate that AMD1 has a tumorigenic effect on human gastric cancers and affect the prognosis of the patients.

Deregulation of CSMD1 targeted by microRNA-10b drives gastric cancer progression through the NF-κB pathway.

Aim: This study aimed to investigate the oncogenic activity of microRNA-10b by targeting CUB and sushi multiple domains protein 1 (CSMD1) in human gastric cancer (GC) and the underlying mechanisms. Methods: The expression of CSMD1 in human GC tissues was evaluated by real-time reverse transcription polymerase chain reaction (RT-PCR), immunoblotting, and immunohistochemical analysis. The expressive abundance of microRNA-10b was detected by stem-loop RT-PCR. Molecular and cellular techniques, including lentiviral vector-mediated knockdown or overexpression, were used to elucidate the effect of microRNA-10b on the expression of CSMD1. Results: CSMD1 was targeted and downregulated by microRNA-10b in human GC tissues and cells, and the down-regulated expression of CSMD1 contributed to poor survival. The knockdown of microRNA-10b expression inhibited cell proliferation in GC cells in vitro and tumor growth in vivo. The inhibition of microRNA-10b expression repressed invasion and migration of HGC27 cells and retarded GC cells metastasis to the liver in Balb/c nude mice. The up-regulated expression of microRNA-10b promoted the proliferation and metastasis of MKN74 cell in vitro. Intratumoral injection of microRNA-10b mimic also promoted the growth and metastasis of tumor xenografts in Balb/c nude mice. Mechanistically, microRNA-10b promoted the invasion and metastasis of human GC cells through inhibiting the expression of CSMD1, leading to the activation of the nuclear factor-κB (NF-κB) pathway that links inflammation to carcinogenesis, subsequently resulting in the upregulation of c-Myc, cyclin D1 (CCND1), and epithelial-mesenchymal transition (EMT) markers. Conclusions: The findings established that microRNA-10b is an oncomiR that drives metastasis. Moreover, a set of critical tumor suppressor mechanisms was defined that microRNA-10b overcame to drive human GC progression.

Validation study of susceptibility loci for esophageal squamous cell carcinoma identified by GWAS in a Han Chinese subgroup from Eastern China.

Esophageal squamous cell carcinoma (ESCC) occurs at a relatively high frequency in China and is one of the most prevalent cancers in the world. Genome-wide association studies (GWAS) have identified 24 single-nucleotide polymorphisms (SNPs) that could be associated with ESCC in Chinese patients. This retrospective study aimed to validate the association between these 24 SNPs and ESCC in a Han Chinese subgroup from East China. A total of 2280 and 1900 patients with ESCC (case group) and non-esophageal cancer (control group) were included from a single center. Genotyping of the 24 polymorphisms was performed using the Sequenom MassARRAY system. Unconditional logistic regression analyses were conducted for every polymorphism. It was found that rs12188136 (P=0.027, OR=1.158, 95% CI=1.016-1.319 for AG/AA) was associated with ESCC. Binary logistic regression analyses revealed a significant negative association of rs875339 in RORA (P=0.014, OR=0.762, 95% CI=0.613-0.947 for TT/CC). Under the dominant model, rs6854472 was slightly associated with ESCC risk (P=0.048, OR=1.192, 95% CI=1.002-1.418). Under the recessive model, a significant negative association was observed for rs875339 (P=0.010, OR=0.758, 95% CI=0.615-0.935). In a word, this large-scale replication study validated that rs12188136 and rs6854472 are associated with ESCC in a Han Chinese subgroup from Eastern China, and that rs875339 is negative associated with ESCC.

Potential role of NDRG2 in reprogramming cancer metabolism and epithelial-to-mesenchymal transition.

Epithelial-to-mesenchymal transition (EMT) allows a cell with epithelial characteristics to transdifferentiate into a cell with mesenchymal characteristics, which is recognized as a key priming event for the initiation and evolvement of cancer metastasis. Accumulating data have shown that aberrant cancer metabolism contributes to the execution of EMT and cancer metastasis through multiple pathological pathways. Recently, the N-MYC downstream-regulated gene 2 (NDRG2), as a tumor suppressor and metabolism-related gene in various cancers, has been widely noted. NDGR2 is associated with energy metabolism, especially glycose metabolism. Hence, we propose a hypothesis that EMT is repressed by NDRG2 via cancer metabolic reprogramming, and summarize the pathological processes and molecular pathways related to the regulation of NDRG2.

miR-21 regulates tumor progression through the miR-21-PDCD4-Stat3 pathway in human salivary adenoid cystic carcinoma.

miR-21, which is a putative tumor onco-miR and frequently overexpressed microRNA in various tumors, has been linked to tumor progression through targeting of tumor-suppressor genes. In this study, we sought to determine whether miR-21 has any role on tumor progression of salivary adenoid cystic carcinoma (SACC) and the possible mechanisms. We found that the level of miR-21 expression was significantly higher in SACC than that in normal salivary tissues, and it is also higher in tumors with metastasis than that without metastasis. Using an anti-miR-21 inhibitor in an in vitro model, downregulation of miR-21 significantly decreased the capacity of invasion and migration of SACC cells, whereas a pre-miR-21 increased the capacity of invasion and migration of SACC cells. To explore the potential mechanisms by which miR-21 regulate invasion and migration, we identified one direct miR-21 target gene, programmed cell death 4 (PDCD4), which has been implicated in invasion and metastasis. The suppression of miR-21 in metastatic SACC-LM cells significantly increased the report activity of PDCD4 promoter and the expression of PDCD4 protein. This subsequently resulted in downregulation of the p-STAT3 protein. The level of miR-21 expression positively related to the expression of PDCD4 protein and negatively related to the expression of p-STAT3 protein in SACC specimens, respectively, indicating the potential role of the STAT3-miR-21-PDCD4 pathway in these tumors. Dysregulation of miR-21 has an important role in tumor growth and invasion by targeting PDCD4. Therefore, suppression of miR-21 may provide a potential approach for the treatment of advanced SACC patients.

Ndrg2 promoter hypermethylation triggered by helicobacter pylori infection correlates with poor patients survival in human gastric carcinoma.

N-myc downstream regulated gene 2 (Ndrg2) is a candidate suppressor of cancer metastasis. We found that Ndrg2 promoter was frequently hypermethylated in gastric cancer cell lines and in 292 gastric tumor tissues. This resulted in down-regulation of Ndrg2 mRNA and protein. Ndrg2 promoter methylation was associated with H. pylori infection and worse prognosis of gastric cancer patients, which is an independent prognostic factor for the disease-free survival (DFS). We found that H. pylori silenced Ndrg2 by activating the NF-κB pathway and up-regulating DNMT3b, promoting gastric cancer progression. These findings uncover a previously unrecognized role for H. pylori infection in gastric cancer.

Methylated TIMP-3 DNA in body fluids is an independent prognostic factor for gastric cancer.

CONTEXT: Fluid methylated DNA may be a suitable biomarker for cancer patients. OBJECTIVE: To investigate whether circulating methylated tissue inhibitor of metalloproteinase 3 (TIMP-3) DNA in body fluids is a useful prognostic biomarker in gastric cancer (GC). DESIGN: TIMP-3 methylation was detected by real-time methylation-specific polymerase chain reaction in tumor tissues, paired preoperative peritoneal washes (PPWs), and paired serum samples from 92 GC patients. RESULTS: The frequency of TIMP-3 methylation was significantly elevated in GC tissues (63.04%; 58 of 92) compared with that in paired adjacent normal tissue (4.3%; 4 of 92) (P < .001). TIMP-3 methylation correlated closely with peritoneal metastasis and TNM stage (all P < .001). The frequency of TIMP-3 methylation in preoperative peritoneal washes and serum samples was 53.3% (49 of 92) and 58.7% (54 of 92), respectively. The Aζ values of the receiver operator characteristic curve for methylated TIMP-3 were 0.966 and 0.922 for serum and preoperative peritoneal washes, respectively, compared with those in GC tissues. The patients with elevated methylated TIMP-3 levels in body fluids had poorer disease-free survival rates than those without (all P < .001). Cox regression analysis showed that detection of methylated TIMP-3 DNA in body fluids was an independent risk factor for GC patients, with a remarkable decrease in disease-free survival 30 months after surgical resection of the gastric tumor. CONCLUSION: Presence of methylated TIMP-3 DNA in body fluids is a useful biomarker for predicting the progression and prognosis of GC patients.