A liquid biopsy signature of circulating exosome-derived mRNAs, miRNAs and lncRNAs predict therapeutic efficacy to neoadjuvant chemotherapy in patients with advanced gastric cancer.

At present, there is no validated marker to identify the subpopulation of patients with advanced gastric cancer (AGC) who might benefit from neoadjuvant chemotherapy (NACT). In view of this clinical challenge, the identification of non-invasive biomarkers for efficacy prediction of NACT in patients with AGC is imperative. Herein, we aimed to develop a non-invasive, liquid-biopsy-based assay by using an exosome-derived RNAs model based on multi-omics characteristics of RNAs. We firstly used a multi-omics strategy to characterize the mRNAs, microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) profiles of circulating exosome enriched fractions in responders to NACT paired with non-responders, using RNA sequencing. Finally, numerous miRNAs, mRNAs and lncRNAs were identified to be associated with the response to NACT in patients with AGC, and it was validated in an independent cohort with promising AUC values. Furthermore, we established a 6-exosome-RNA panel that could robustly identified responders from non-responders treated with fluorouracil-based neoadjuvant chemotherapy.

A Novel Classification and Scoring Method Based on Immune-Related Transcription Factor Regulation Patterns in Gastric Cancer.

Background: Transcription factors (TFs) play a crucial role in tumorigenesis and anti-tumor immunity. However, the potential role of large-scale transcription factor regulation patterns in the progression in gastric cancer (GC) is unknown. Methods: We comprehensively assessed the relevance of immune-related TF (IRTF) regulation patterns in anti-tumor immunity and immunotherapy in 1,136 gastric cancer (GC) patients, and evaluated the IRTF score based on IRTF regulation patterns using random forests. Results: Two distinct IRTF regulation patterns were identified, which demonstrating the distinct characteristics in clinical phenotypes, tumor immune microenvironment (TIME), immunogenicity and prognosis in GC. Subsequently, the IRTF score was established to quantify the IRTF regulation pattern for each GC patient. Analysis of large conventional therapy cohorts showed low IRTF score was associated with a better prognosis. In addition, analysis of multiple immunotherapy cohorts showed low IRTF score was also linked to enhanced response to immunotherapy. Conclusion: TF regulation patterns were found to play an important role in the complex immune regulatory relationships in GC. Evaluation of the IRTF regulation patterns in patients will enhance our understanding of immune specificities, and thus, provide effective strategies for personalized therapy.

Exosome-derived noncoding RNAs in gastric cancer: functions and clinical applications.

Exosomes are a subpopulation of the tumour microenvironment (TME) that transmit various biological molecules to promote intercellular communication. Exosomes are derived from nearly all types of cells and exist in all body fluids. Noncoding RNAs (ncRNAs) are among the most abundant contents in exosomes, and some ncRNAs with biological functions are specifically packaged into exosomes. Recent studies have revealed that exosome-derived ncRNAs play crucial roles in the tumorigenesis, progression and drug resistance of gastric cancer (GC). In addition, regulating the expression levels of exosomal ncRNAs can promote or suppress GC progression. Moreover, the membrane structures of exosomes protect ncRNAs from degradation by enzymes and other chemical substances, significantly increasing the stability of exosomal ncRNAs. Specific hallmarks within exosomes that can be used for exosome identification, and specific contents can be used to determine their origin. Therefore, exosomal ncRNAs are suitable for use as diagnostic and prognostic biomarkers or therapeutic targets. Regulating the biogenesis of exosomes and the expression levels of exosomal ncRNAs may represent a new way to block or eradicate GC. In this review, we summarized the origins and characteristics of exosomes and analysed the association between exosomal ncRNAs and GC development.

Circular RNA CircCDYL Regulates Proliferation and Apoptosis in Non-Small Cell Lung Cancer Cells by Sponging miR-185-5p and Upregulating TNRC6A.

AIM: A series of research reveal that circular RNA (circRNA) plays a vital role in regulating the development of tumor cells. In this research, we would explore the role and mechanism of circCDYL in non-small cell lung cancer (NSCLC). METHODS: RT-PCR was performed to detect the expression of circCDYL in NSCLC tissues, plasma, and cell lines. The tumor cell proliferation ability was evaluated by clone formation assay, and cell cycle determination. Flow cytometry was used to detect apoptosis in NSCLC cell lines. Western blot and RT-PCR were used to assess the expression of proteins and genes. Luciferase assay was performed to confirm the relationship of circRNA-miRNA-mRNA. RESULTS: The decreased level of circCDYL was observed in NSCLC patients' tissues and plasma, which was also downregulated in NSCLC cell lines. Forced expression of circCDYL inhibited cell viability, proliferation and induced apoptosis in A549 cells. Luciferase assay verified that circCDYL could bind with miR-185-5p and confirmed that TNRC6A was a downstream target of miR-185-5p. Overexpression of miR-185-5p or silencing of TNRC6A could inhibit the anti-tumor effect of circCDYL in A549 cells via regulating the ERK1/2 signal. CONCLUSION: Here, we revealed that circCDYL inhibited proliferation and induced apoptosis in NSCLC cell lines via regulating ERK1/2 signal, and the mechanism of this progression may target miR-185-5p/TNRC6A, which provided a theoretical basis for clinical therapy.

Insulin gene enhancer protein 1 mediates glycolysis and tumorigenesis of gastric cancer through regulating glucose transporter 4.

BACKGROUND: Insulin gene enhancer protein 1, (ISL1), a LIM-homeodomain transcription factor, is involved in multiple tumors and is associated with insulin secretion and metabolic phenotypes. However, the role of ISL1 in stimulating glycolysis to promote tumorigenesis in gastric cancer (GC) is unclear. In this study, we aimed to characterize the expression pattern of ISL1 in GC patients and explore its molecular biological mechanism in glycolysis and tumorigenesis. METHODS: We analyzed the expression and clinical significance of ISL1 in GC using immunohistochemistry and real-time polymerase chain reaction (PCR). Flow cytometry and IncuCyte assays were used to measure cell proliferation after ISL1 knockdown. RNA-sequencing was performed to identify differentially expressed genes, followed by Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis and Gene Set Enrichment Analysis (GSEA) to reveal key signaling pathways likely regulated by ISL1 in GC. Alteration of the glycolytic ability of GC cells with ISL1 knockdown was validated by measuring the extracellular acidification rate (ECAR) and oxygen consumption rate (OCR) and by detecting glucose consumption and lactate production. The expression of glucose transporter 4 (GLUT4) and ISL1 was assessed by Western blotting, immunohistochemistry, and immunofluorescent microscopy. The luciferase reporter activity and chromatin immunoprecipitation assays were performed to determine the transcriptional regulation of ISL1 on GLUT4. RESULTS: High levels of ISL1 and GLUT4 expression was associated with short survival of GC patients. ISL1 knockdown inhibited cell proliferation both in vitro and in vivo. KEGG analysis and GSEA for RNA-sequencing data indicated impairment of the glycolysis pathway in GC cells with ISL1 knockdown, which was validated by reduced glucose uptake and lactate production, decreased ECAR, and increased OCR. Mechanistic investigation indicated that ISL1 transcriptionally regulated GLUT4 through binding to its promoter. CONCLUSION: ISL1 facilitates glycolysis and tumorigenesis in GC via the transcriptional regulation of GLUT4.

ISL1 predicts poor outcomes for patients with gastric cancer and drives tumor progression through binding to the ZEB1 promoter together with SETD7.

ISL1, a LIM-homeodomain transcription factor, serves as a biomarker of metastasis in multiple tumors. However, the function and underlying mechanisms of ISL1 in gastric cancer (GC) have not been fully elucidated. Here we found that ISL1 was frequently overexpressed in GC FFPE samples (104/196, 53.06%), and associated with worse clinical outcomes. Furthermore, the overexpression of ISL1 and loss-of-function of ISL1 influenced cell proliferation, invasion and migration in vitro and in vivo, including GC patient-derived xenograft models. We used ChIP-seq and RNA-seq to identify that ISL1 influenced the regulation of H3K4 methylation and bound to ZEB1, a key regulator of the epithelial-mesenchymal transition (EMT). Meanwhile, we validated ISL1 as activating ZEB1 promoter through influencing H3K4me3. We confirmed that a complex between ISL1 and SETD7 (a histone H3K4-specific methyltransferase) can directly bind to the ZEB1 promoter to activate its expression in GC cells by immunoprecipitation, mass spectrometry, and ChIP-re-ChIP. Moreover, ZEB1 expression was significantly positively correlated with ISL1 and was positively associated with a worse outcome in primary GC specimens. Our paper uncovers a molecular mechanism of ISL1 promoting metastasis of GC through binding to the ZEB1 promoter together with co-factor SETD7. ISL1 might be a potential prognostic biomarker of GC.

Higher autocrine motility factor/glucose-6-phosphate isomerase expression is associated with tumorigenesis and poorer prognosis in gastric cancer.

BACKGROUND: Glucose-6-phosphate isomerase (GPI) is a glycolytic-related enzyme that inter-converts glucose-6-phosphate and fructose-6-phosphate in the cytoplasm. This protein is also secreted into the extracellular matrix by cancer cells and is, therefore, also called autocrine motility factor (AMF). METHODS: To clarify the roles of AMF/GPI in gastric cancer (GC), we collected 335 GC tissues and the corresponding adjacent noncancerous tissues, performed immunohistochemical studies, and analyzed the relationship between AMF/GPI expression and the patients' clinicopathologic features. RESULTS: AMF/GPI expression was found to be significantly higher in the GC group than in the corresponding noncancerous tissue group (P<0.001). Additionally, AMF/GPI expression positively associated with a higher TNM stage and poorer prognosis in patients. Through Kaplan-Meier analysis and according to the Oncomine database, we found that AMF/GPI was overexpressed in GC tissues compared to normal mucosa, and the patients with higher AMF/GPI expression had poorer outcomes. We used AMF/GPI-silenced GC cell lines to observe how changes in AMP/GPI affect cellular phenotypes. AMF/GPI knockdown suppressed proliferation, migration, invasion, and glycolysis, and induced apoptosis in GC cells. CONCLUSION: These findings suggest that AMF/GPI overexpression is involved in carcinogenesis and promotes the aggressive phenotypes of GC cells.

MicroRNA-1 acts as a tumor suppressor microRNA by inhibiting angiogenesis-related growth factors in human gastric cancer.

BACKGROUND: We recently reported that miR-1 was one of the most significantly downregulated microRNAs in gastric cancer (GC) patients from The Cancer Genome Atlas microRNA sequencing data. Here we aim to elucidate the role of miR-1 in gastric carcinogenesis. METHODS: We measured miR-1 expression in human GC cell lines and 90 paired primary GC samples, and analyzed the association of its status with clinicopathological features. The effect of miR-1 on GC cells was evaluated by proliferation and migration assay. To identify the target genes of miR-1, bioinformatic analysis and protein array analysis were performed. Moreover, the regulation mechanism of miR-1 with regard to these predicted targets was investigated by quantitative PCR (qPCR), Western blot, ELISA, and endothelial cell tube formation. The putative binding site of miR-1 on target genes was assessed by a reporter assay. RESULTS: Expression of miR-1 was obviously decreased in GC cell lines and primary tissues. Patients with low miR-1 expression had significantly shorter overall survival compared with those with high miR-1 expression (P = 0.0027). Overexpression of miR-1 in GC cells inhibited proliferation, migration, and tube formation of endothelial cells by suppressing expression of vascular endothelial growth factor A (VEGF-A) and endothelin 1 (EDN1). Conversely, inhibition of miR-1 with use of antago-miR-1 caused an increase in expression of VEGF-A and EDN1 in nonmalignant GC cells or low-malignancy GC cells. CONCLUSIONS: MiR-1 acts as a tumor suppressor by inhibiting angiogenesis-related growth factors in human gastric cancer. Downregulated miR-1 not only promotes cellular proliferation and migration of GC cells, but may activates proangiogenesis signaling and stimulates the proliferation and migration of endothelial cells, indicating the possibility of new strategies for GC therapy.

Increased expression of S100A6 promotes cell proliferation in gastric cancer cells.

S100A6 is involved in regulating the progression of cancer. S100A6 can regulate the dynamics of cytoskeletal constituents, cell growth and differentiation by interacting with binding or target proteins. The present study investigated whether S100A6 affects cell proliferation in gastric cancer cells by stimulating several downstream factors. Firstly, the expression and localization of S100A6 were investigated using immunohistochemical staining, an immunoelectron microscopy and laser confocal scanning. A ChIP-Chip assay was performed to determine the downstream factors of S100A6 using promoter Chip analysis, including approximately the -800 to +200 regions around the transcription starting point. Polymerase chain reaction analysis was performed to confirm this. It was found that the intensity of S100A6 staining was markedly higher in the cytoplasm and nucleus, and its expression level correlated with that of the Ki67 protein. The overexpression of S100A6 also promoted cell proliferation in AGS and BGC823 cell lines, detected using a Cell Counting-Kit 8 assay. In cells overexpressing S100A6, the expression levels of interleukin (IL)-8, cyclin-dependent kinase (CDK)5, CDK4, minichromosome maintenance complex component 7 (MCM7) and B-cell lymphoma 2 (Bcl2) were noticeably increased. In conclusion, the increased expression of S100A6 promoted cell proliferation by regulating the expression levels of IL-8, CDK5, CDK4, MCM7 and Bcl2 in gastric cancer cells.

Paclitaxel enhances tumoricidal potential of TRAIL via inhibition of MAPK in resistant gastric cancer cells.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) holds promise for cancer therapy due to its unique capacity to selectively trigger apoptosis in cancer cells. However, TRAIL therapy is greatly hampered by its resistance. A preclinical successful strategy is to identify combination treatments that sensitize resistant cancers to TRAIL. In the present study, we fully assessed TRAIL sensitivity in 9 gastric cancer cell lines. We found combined administration of paclitaxel (PTX) markedly enhanced TRAIL-induced apoptosis in resistant cancer cells both in vitro and in vivo. The sensitization to TRAIL was accompanied by activation of mitochondrial apoptotic pathway, upregulation of TRAIL receptors and downregulation of anti-apoptotic proteins including C-IAP1, C-IAP2, Livin and Mcl-1. Noticeably, we found PTX could suppress the activation of mitogen-activated protein kinases (MAPKs). Inhibition of MAPKs using specific inhibitors (ERK inhibitor U0126, JNK inhibitor SP600125 and P38 inhibitor SB202190) facilitated TRAIL-mediated apoptosis and cytotoxicity. Additionally, SP600125 upregulated TRAL receptors as well as downregulated C-IAP2 and Mcl-1 suggesting the anti-apoptotic role of JNK. Thus, PTX-induced suppression of MAPKs may contribute to restoring TRAIL senstitivity. Collectively, our comprehensive analyses gave new insight into the role of PTX on enhancing TRAIL sensitivity, and provided theoretical references on the development of combination treatment in TRAIL-resistant gastric cancer.

Trichostatin A potentiates TRAIL-induced antitumor effects via inhibition of ERK/FOXM1 pathway in gastric cancer.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is an ideal apoptosis inducer and believed to have promise in cancer therapy, yet part of cancer cells exhibit resistance to TRAIL-mediated apoptosis. This necessitates the exploration of agents that resensitizes cancer cells to TRAIL. In our study, we found that Trichostatin A (TSA), an histone deacetylase (HDAC) inhibitor, augmented TRAIL-induced apoptosis in gastric cancer cells in a caspase-dependent manner. Besides, upregulation of DR5 and downregulation of anti-apoptotic proteins including XIAP, Mcl-1, Bcl-2 and Survivin also contributed to this synergism. Noticeably, TSA treatment inhibited Forkhead boxM1 (FOXM1), which expression level showed negative correlation with TRAIL sensitivity. Similarly, silencing of FOXM1 by small interfering RNA (siRNA) resensitized cancer cells to TRAIL and strengthened the TRAIL-augmenting effect of TSA. In addition, we demonstrated the depletion of FOXM1 was a consequence of the inactivation of ERK mediated by TSA. Collectively, it was first shown that TSA potentiated TRAIL sensitivity via ERK/FOXM1 pathway in gastric cancer cells. FOXM1 might serve as a biomarker for predicting sensitivity to TRAIL.

Maternal embryonic leucine zipper kinase serves as a poor prognosis marker and therapeutic target in gastric cancer.

Maternal embryonic leucine zipper kinase (MELK) is upregulated in a variety of human tumors, and is considered an attractive molecular target for cancer treatment. We characterized the expression of MELK in gastric cancer (GC) and measured the effects of reducing MELK mRNA levels and protein activity on GC growth. MELK was frequently overexpressed in primary GCs, and higher MELK levels correlated with worse clinical outcomes. Reducing MELK expression or inhibiting kinase activity resulted in growth inhibition, G2/M arrest, apoptosis and suppression of invasive capability of GC cells in vitro and in vivo. MELK knockdown led to alteration of epithelial mesenchymal transition (EMT)-associated proteins. Furthermore, targeting treatment with OTSSP167 in GC patient-derived xenograft (PDX) models had anticancer effects. Thus, MELK promotes cell growth and invasiveness by inhibiting apoptosis and promoting G2/M transition and EMT in GC. These results suggest that MELK may be a promising target for GC treatment.

High-level SAE2 promotes malignant phenotype and predicts outcome in gastric cancer.

BACKGROUND: The SUMO pathway has been shown to play an important role in tumorigenesis. This report analyzed the involvement of the sole SUMO-Activating Enzyme Subunit 2 (SAE2) in human gastric cancer (GC) progression and prognosis. METHODS: Expression of SAE2 was examined by Quantigene Plex, western blotting and immunohistochemistry. The expression of SAE2 and c-MYC were detected in parallel in 276 cases. The molecular mechanisms of SAE2 expression and its effects on cell growth, colony formation, migration and invasion were also explored by CCK8 assay, colony formation experiment, transwell chamber assay with or without matrigel, immunoprecipitation and in vivo tumorigenesis and tumor metastasis. RESULTS: SAE2 was markedly overexpressed in GC cell lines and primary tumor samples of GC, and significantly correlated with deeper tumor depth, distant metastasis, higher pathological stage and stratified survival in human GC. SAE2 positivity was independently associated with a worse outcome in multivariate analysis. Knockdown of SAE2 expression inhibited the proliferation, migration, and invasion of SAE2-overexpressing GC cells. Consistent with the in vitro results, down-regulation of SAE2 in human GC BGC823 cells significantly reduced the tumorigenic and metastatic potential of the cells in vivo. SAE2 protein was significantly associated with the higher expression of c-MYC in primary GC tissues. Moreover, FoxM1 was SUMOylated in GC and that inhibition of SAE2 resulted in a decrease in SUMO1-FoxM1 levels compared with those in the controls. CONCLUSIONS: These findings suggest that SAE2 has a pivotal role in the aggressiveness of GC, and highlight its usefulness as a prognostic factor in GC.

High-level SAE2 promotes malignant phenotype and predicts outcome in gastric cancer.

BACKGROUND: The SUMO pathway has been shown to play an important role in tumorigenesis. This report analyzed the involvement of the sole SUMO-Activating Enzyme Subunit 2 (SAE2) in human gastric cancer (GC) progression and prognosis. METHODS: Expression of SAE2 was examined by Quantigene Plex, western blotting and immunohistochemistry. The expression of SAE2 and c-MYC were detected in parallel in 276 cases. The molecular mechanisms of SAE2 expression and its effects on cell growth, colony formation, migration and invasion were also explored by CCK8 assay, colony formation experiment, transwell chamber assay with or without matrigel, immunoprecipitation and in vivo tumorigenesis and tumor metastasis. RESULTS: SAE2 was markedly overexpressed in GC cell lines and primary tumor samples of GC, and significantly correlated with deeper tumor depth, distant metastasis, higher pathological stage and stratified survival in human GC. SAE2 positivity was independently associated with a worse outcome in multivariate analysis. Knockdown of SAE2 expression inhibited the proliferation, migration, and invasion of SAE2-overexpressing GC cells. Consistent with the in vitro results, down-regulation of SAE2 in human GC BGC823 cells significantly reduced the tumorigenic and metastatic potential of the cells in vivo. SAE2 protein was significantly associated with the higher expression of c-MYC in primary GC tissues. Moreover, FoxM1 was SUMOylated in GC and that inhibition of SAE2 resulted in a decrease in SUMO1-FoxM1 levels compared with those in the controls. CONCLUSIONS: These findings suggest that SAE2 has a pivotal role in the aggressiveness of GC, and highlight its usefulness as a prognostic factor in GC.

[Expression of CCAAT/enhancer binding protein beta in human gastric carcinoma and its clinical significance].

OBJECTIVE: To explore the expression of CCAAT/enhancer binding protein beta (CEBPB) in gastric carcinoma tissues and its association with clinicopathological features and prognosis. METHODS: CEBPB protein expression level was detected by immunohistochemistry method in resected gastric carcinomas and adjacent gastric mucosa tissues (n=81), and its association with clinicopathological features and prognosis was analyzed. RESULTS: The immunohistochemical staining of CEBPB was predominantly in the nucleus with some cytoplasmic staining. As a result, 16% (13/81) of the gastric carcinomas were stained positively, whereas there was hardly positive expression in adjacent gastric mucosa tissues. There was a significant association between the expression of CEBPB and distant metastasis on univariate analysis (P<0.05). The median survival time in patients with positive CEBPB expression was significantly lower than those with negative CEBPB expression (19.4 months vs. 45.2 months, P=0.024). Multivariable analysis showed that CEBPB was independently associated with prognosis (HR=2.544, 95%CI:1.154-5.610, P=0.021). CONCLUSION: Up-regulation of CEBPB suggests poor prognosis in patients with gastric cancer.

Intestinal stem cell marker LGR5 expression during gastric carcinogenesis.

AIM: To investigate the differential expression of leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5) in gastric cancer tissues and its significance related to tumor growth and spread. METHODS: Formalin-fixed biopsy specimens of intestinal metaplasia (n = 90), dysplasia (n = 53), gastric adenocarcinoma (n = 180), metastases in lymph nodes and the liver (n = 15), and lesion-adjacent normal gastric mucosa (controls; n = 145) were obtained for analysis from the Peking University Cancer Hospital's Department of Pathology and Gastrointestinal Surgery tissue archives (January 2003 to December 2011). The biopsied patients' demographic and clinicopathologic data were retrieved from the hospital's medical records database. Each specimen was subjected to histopathological typing to classify the tumor node metastasis (TNM) stage and to immunohistochemistry staining to detect the expression of the cancer stem cell marker LGR5. The intergroup differences in LGR5 expression were assessed by Spearman's rank correlation analysis, and the relationship between LGR5 expression level and the patients' clinicopathological characteristics was evaluated by the χ(2) test or Fisher's exact test. RESULTS: Significantly more gastric cancer tissues showed LGR5(+) staining than normal control tissues (all P < 0.01), with immunoreactivity detected in 72.2% (65/90) and 50.9% (27/53) of intestinal metaplasia and dysplasia specimens, respectively, 52.8% (95/180) of gastric adenocarcinoma specimens, and 73.3%% (11/15) of metastasis specimens, but 26.9% (39/145) of lesion-adjacent normal gastric mucosa specimens. Comparison of the intensity of LGR5(+) staining showed an increasing trend that generally followed increasing dedifferentiation and tumor spread (normal tissue < dysplasia, < gastric adenocarcinoma

Presence of S100A9-positive inflammatory cells in cancer tissues correlates with an early stage cancer and a better prognosis in patients with gastric cancer.

BACKGROUND: S100A9 was originally discovered as a factor secreted by inflammatory cells. Recently, S100A9 was found to be associated with several human malignancies. The purpose of this study is to investigate S100A9 expression in gastric cancer and explore its role in cancer progression. METHODS: S100A9 expression in gastric tissue samples from 177 gastric cancer patients was assessed by immunohistochemistry. The expression of its dimerization partner S100A8 and the S100A8/A9 heterodimer were also assessed by the same method. The effect of exogenous S100A9 on motility of gastric cancer cells AGS and BGC-823 was then investigated. RESULTS: S100A9 was specifically expressed by inflammatory cells such as macrophages and neutrophils in human gastric cancer and gastritis tissues. Statistical analysis showed that a high S100A9 cell count (> = 200) per 200x magnification microscopic field in cancer tissues was predictive of early stage gastric cancer. High S100A9-positive cell count was negatively correlated with lymph node metastasis (P = 0.009) and tumor invasion (P = 0.011). S100A9 was identified as an independent prognostic predictor of overall survival of patients with gastric cancer (P = 0.04). Patients with high S100A9 cell count were with favorable prognosis (P = 0.021). Further investigation found that S100A8 distribution in human gastric cancer tissues was similar to S100A9. However, the number of S100A8-positive cells did not positively correlate with patient survival. The inflammatory cells infiltrating cancer were S100A8/A9 negative, while those in gastritis were positive. Furthermore, exogenous S100A9 protein inhibited migration and invasion of gastric cancer cells. CONCLUSIONS: Our results suggested S100A9-positive inflammatory cells in gastric cancer tissues are associated with early stage of gastric cancer and good prognosis.

PTK7 as a novel marker for favorable gastric cancer patient survival.

BACKGROUND AND OBJECTIVES: Protein tyrosine kinase 7 (PTK7) plays important functions in several cancer types but its expression in gastric cancer remains unknown. This study was designed to investigate PTK7 expression in gastric cancer. METHODS: PTK7 expression was assessed by immunohistochemistry in 201 gastric cancer patients. The relationship between PTK7 expression and clinicopathological features and patients prognosis were statistically analyzed. RESULTS: PTK7 expression was detected in 56.72% (114 of 201) of gastric cancer patients. The immunostaining was predominantly localized in the cytoplasm. The statistical analyses showed that PTK7 expression was more frequently detected in patients with well-differentiated tumors (P = 0.001). Furthermore, PTK7 expression was significantly related to the favorable overall survival (OS; P = 0.012) and disease-free survival (DFS; P = 0.009). Multivariate Cox regression analyses revealed that PTK7 expression was an independent prognostic factor for both favorable OS (P = 0.028) and DFS (P = 0.012). CONCLUSION: Our findings demonstrate that PTK7 can serve as a novel prognostic biomarker for gastric cancer patients.

[Clinical value of serum CEA, CA19-9, CA72-4 and CA242 in the diagnosis and prognosis of gastric cancer].

OBJECTIVE: To investigate the clinical value of tumor markers CEA, CA19-9, CA72-4 and CA242 in the diagnosis and prognosis of patients with gastric cancer. METHODS: One hundred and sixty gastric cancer patients who had received treatment from 2002 to 2007 at the Beijing Cancer Hospital were retrospectively analyzed. Blood samples were taken from patients upon admission to the hospital, and CEA, CA19-9, CA72-4, CA242 levels were detected. Statistical analysis was performed to identify the clinical value of these tumor markers in diagnosis and prognosis. RESULTS: On initial diagnosis, the positive rates of CEA, CA19-9, CA72-4 and CA242 were 37.7%, 26.7%, 37.6% and 21.3%, respectively, and the positive rate of combined detection was 62.9%. CEA was more frequently positive in patients with lymph node metastasis (P=0.029); CA72-4 was more frequently positive in patients with vascular involvement and advanced stage (P=0.039, P=0.011). Multivaraite analysis showed that CA72-4 was an independent prognostic factor (P=0.012). Patients with positive CA72-4 carried a 2.147-fold increased risk of death than those with negative CA72-4. Kaplan-Meier analysis showed that patients with positive CA19-9 or positive CA72-4 had worse survival than those with negative CA19-9 or CA72-4 (P=0.006, P=0.002). CONCLUSIONS: Tumor markers including CEA, CA19-9, CA72-4 and CA242 have clinical significance and prognostic value in patients with gastric cancer. Combined detection of four tumor markers can increase the positive rate. CA72-4 is an independent prognostic factor. CA19-9 and CA72-4 are associated with the prognosis of patients with gastric cancer.

HIWI expression profile in cancer cells and its prognostic value for patients with colorectal cancer.

BACKGROUND: HIWI is a member of PIWI gene family and its expression is found in various tumors, indicating that it may play a pivotal role in tumor development. This study was designated to examine HIWI protein expression profile in several cancer cell lines and its prognostic value for patients with colorectal cancer. METHODS: Totally 270 patients who underwent surgical resection of primary colorectal cancer between January 1999 and December 2002 with a median follow-up time of 33 months were registered in the study. Formalin-fixed and paraffin-embedded specimens from these patients and 236 matched adjacent non-cancerous normal colorectal tissues were collected. Anti-HIWI monoclonal antibodies were generated and used for evaluating HIWI protein expression. χ(2) tests were conducted to determine the association between HIWI expression and the other variables. Survival curves were estimated using the Kaplan-Meier method and compared by the log-rank test. Multivariate analysis was performed by using the Cox regression model. RESULTS: By generating antibodies specific for HIWI, we examined HIWI protein expression in several cancer cell lines and demonstrated positive expression of HIWI in 69 out of 270 (25.6%) colorectal cancer tissues; 15 of 236 (6.4%) matched adjacent non-cancerous tissues were also positive for HIWI. Patients with positive HIWI expression in adjacent non-cancerous tissue had statistically lower overall survival (OS) and disease free survival (DFS) compared with negative patients (OS: 10.4% vs. 55.5%, P = 0.009; DFS: 10.4% vs. 55.1%, P = 0.015). For early stage group (stages I and II), patients with positive HIWI expression had significantly lower OS and DFS (OS: 57.4% vs. 79.5%, P = 0.014; DFS: 56.7% vs. 80.5%, P = 0.010). In lymph node negative group, patients with positive HIWI expression had statistically lower OS and DFS (OS: 53.0% vs. 73.5%, P = 0.037; DFS: 52.2% vs. 74.6%, P = 0.025). Multivariate analysis revealed that HIWI over-expression was a significant prognostic factor for OS (95%CI: 1.132 - 2.479, P = 0.010). CONCLUSION: HIWI could be a potential prognostic biomarker for the patients with colorectal cancer, especially for those at early stages or without lymph node metastasis.