Using a machine learning approach to identify key prognostic molecules for esophageal squamous cell carcinoma.

BACKGROUND: A plethora of prognostic biomarkers for esophageal squamous cell carcinoma (ESCC) that have hitherto been reported are challenged with low reproducibility due to high molecular heterogeneity of ESCC. The purpose of this study was to identify the optimal biomarkers for ESCC using machine learning algorithms. METHODS: Biomarkers related to clinical survival, recurrence or therapeutic response of patients with ESCC were determined through literature database searching. Forty-eight biomarkers linked to recurrence or prognosis of ESCC were used to construct a molecular interaction network based on NetBox and then to identify the functional modules. Publicably available mRNA transcriptome data of ESCC downloaded from Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) datasets included GSE53625 and TCGA-ESCC. Five machine learning algorithms, including logical regression (LR), support vector machine (SVM), artificial neural network (ANN), random forest (RF) and XGBoost, were used to develop classifiers for prognostic classification for feature selection. The area under ROC curve (AUC) was used to evaluate the performance of the prognostic classifiers. The importances of identified molecules were ranked by their occurrence frequencies in the prognostic classifiers. Kaplan-Meier survival analysis and log-rank test were performed to determine the statistical significance of overall survival. RESULTS: A total of 48 clinically proven molecules associated with ESCC progression were used to construct a molecular interaction network with 3 functional modules comprising 17 component molecules. The 131,071 prognostic classifiers using these 17 molecules were built for each machine learning algorithm. Using the occurrence frequencies in the prognostic classifiers with AUCs greater than the mean value of all 131,071 AUCs to rank importances of these 17 molecules, stratifin encoded by SFN was identified as the optimal prognostic biomarker for ESCC, whose performance was further validated in another 2 independent cohorts. CONCLUSION: The occurrence frequencies across various feature selection approaches reflect the degree of clinical importance and stratifin is an optimal prognostic biomarker for ESCC.

Porphyromonas gingivalis promotes progression of esophageal squamous cell cancer via TGFß-dependent Smad/YAP/TAZ signaling.

Microbial dysbiosis in the upper digestive tract is linked to an increased risk of esophageal squamous cell carcinoma (ESCC). Overabundance of Porphyromonas gingivalis is associated with shorter survival of ESCC patients. We investigated the molecular mechanisms driving aggressive progression of ESCC by P. gingivalis. Intracellular invasion of P. gingivalis potentiated proliferation, migration, invasion, and metastasis abilities of ESCC cells via transforming growth factor-ß (TGFß)-dependent Drosophila mothers against decapentaplegic homologs (Smads)/Yes-associated protein (YAP)/Transcriptional coactivator with PDZ-binding motif (TAZ) activation. Smads/YAP/TAZ/TEA domain transcription factor1 (TEAD1) complex formation was essential to initiate downstream target gene expression, inducing an epithelial-mesenchymal transition (EMT) and stemness features. Furthermore, P. gingivalis augmented secretion and bioactivity of TGFß through glycoprotein A repetitions predominant (GARP) up-regulation. Accordingly, disruption of either the GARP/TGFß axis or its activated Smads/YAP/TAZ complex abrogated the tumor-promoting role of P. gingivalis. P. gingivalis signature genes based on its activated effector molecules can efficiently distinguish ESCC patients into low- and high-risk groups. Targeting P. gingivalis or its activated effectors may provide novel insights into clinical management of ESCC.

NEAT1_2-SFPQ axis mediates cisplatin resistance in liver cancer cells in vitro.

BACKGROUND: Liver cancer is a type of malignant tumor with high morbidity and mortality in People's Republic of China. Its occurrence and development involve the variation and expression changes of multiple genes, and the pathogenesis and related regulatory networks are complex. PURPOSE: In the present research, we investigate the involvement of NEAT1_2 and SFPQ in cisplatin resistance in liver cancer. The effects of LncRNA NEAT1 and SFPQ expression on the chemotherapeutic resistance of liver cancer cells were analyzed. METHODS: The expression level of NEAT1_2 and SFPQ mRNA in tissue specimens or cell lines were examined by RT-qPCR and western blotting. CCK-8 assay was performed to evaluate cell viability. Cell proliferation was performed using the EdU cell proliferation assay. RESULTS: Our data showed that increase NEAT1_2 and SFPQ expressions in liver cancer specimens were associated with the development of cisplatin resistance; high SFPQ expression level impaired patients' survival from liver cancer. Gain-and loss-of function assay using NEAT1_2 knock-in and knock-out cells constructed using CRISPER/Cas9 system revealed that NEAT1_2 is essential for liver cancer cell survival and mediates cisplatin resistance in liver cancer cells at least partially through SFPQ. Artificial change in NEAT1_2 expression level didn't significantly influence SFPQ transcription or translation level. CONCLUSION: Our data revealed NEAT1_2-SFPQ axis as a novel cisplatin resistance mechanism in liver cancer cells in vitro.

Preoperative serum immunoglobulin G and A antibodies to Porphyromonas gingivalis are potential serum biomarkers for the diagnosis and prognosis of esophageal squamous cell carcinoma.

BACKGROUND: The key-stone-pathogen, Porphyromonas gingivalis associates not only with periodontal diseases but with a variety of other chronic diseases such as cancer. We previously reported an association between the presence of Porphyromonas gingivalis in esophageal squamous cell carcinoma (ESCC) and its progression. We now report the diagnostic and prognostic potential of serum immunoglobulin G and A antibodies (IgG/A) against Porphyromonas gingivalis for ESCC. METHODS: An enzyme-linked immunosorbent assay (ELISA) was used to determine the serum levels of Porphyromonas gingivalis IgG and IgA in 96 cases with ESCC, 50 cases with esophagitis and 80 healthy controls. RESULTS: The median serum levels of IgG and IgA for P. gingivalis were significantly higher in ESCC patients than non-ESCC controls. P. gingivalis IgG and IgA in serum demonstrated sensitivities/specificities of 29.17%/96.90% and 52.10%/70.81%, respectively, and combination of IgG and IgA produced a sensitivity/specificity of 68.75%/68.46%. The diagnostic performance of serum P. gingivalis IgA for early ESCC was superior to that of IgG (54.54% vs. 20.45%). Furthermore, high serum levels of P. gingivalis IgG or IgA were associated with worse prognosis of ESCC patients, in particular for patients with stage 0-IIor negative lymphnode metastasis, and ESCC patients with high levels of both IgG and IgA had the worst prognosis. Multivariate analysis revealed that lymph node status, IgG and IgA were independent prognostic factors. CONCLUSIONS: The IgG and IgA for P. gingivalis are potential serum biomarkers for ESCC and combination of IgG and IgA improves the diagnostic and prognostic performance. Furthermore, serum P. gingivalis IgG and IgA can detect early stage ESCC.

CyclinD1 and p57kip2 as biomarkers in differentiation, metastasis and prognosis of gastric cardia adenocarcinoma.

OBJECTIVE: This study aims to investigate the expression and significance of p57kip2 and cyclinD1 in gastric cardia adenocarcinoma (GCA). p57kip2 is a negative regulator in the cell cycle. On the contrary, cyclinD1 is a positive regulator of cell cycle progression. METHODS: Thirty-two cases of GCA tissues and adjacent non-cancerous tissues were collected for this study. Immunohistochemistry and fluorescence qualitative PCR was used to determine the level of p57kip2 and cyclinD1 in GCA and its adjacent non-cancerous tissues. Furthermore, the correlation between the mRNA/protein and GCA clinical pathologic parameters were analyzed, and the relationship of p57kip2 and cyclinD1 in GCA were also evaluated. RESULTS: The expression of p57kip2 significantly lower in GCA (P = 0.036), and there was a significant correlation in the different degrees of differentiation (P < 0.05). Furthermore, median survival time was 41 months for patients with high mRNA expression of p57kip2. This was longer compared to patients with low mRNA expression of P57kip2 (37 months, X2 = 4.788, P = 0.029).The expression of cyclinD1 was significantly higher in GCA(P = 0.002), and was significant correlated to clinical stage(P<0.05). Median survival time was 34 months in patients with high mRNA expression of cyclinD1, which was shorter than in patients with low expression of cyclinD1 mRNA (41 months, X2 = 4.071, P = 0.044). The protein expression of p57kip2 was not correlated to the protein expression of cyclinD1 (P = 0.55). CONCLUSION: The expression of p57kip2 and cyclinD1 are likely to suppress or promote the tumorigenesis and progression of GCA.

E-cadherin expression phenotypes associated with molecular subtypes in invasive non-lobular breast cancer: evidence from a retrospective study and meta-analysis.

BACKGROUND: This retrospective study and meta-analysis was designed to explore the relationship between E-cadherin (E-cad) expression and the molecular subtypes of invasive non-lobular breast cancer, especially in early-stage invasive ductal carcinoma (IDC). METHODS: A total of 156 post-operative cases of early-stage IDCs were retrospectively collected for the immunohistochemistry (IHC) detection of E-cad expression. The association of E-cad expression with molecular subtypes of early-stage IDCs was analyzed. A literature search was conducted in March 2016 to retrieve publications on E-cad expression in association with molecular subtypes of invasive non-lobular breast cancer, and a meta-analysis was performed to estimate the relational statistics. RESULTS: E-cad was expressed in 82.7% (129/156) of early-stage IDCs. E-cad expression was closely associated with the molecular types of early-stage IDCs (P < 0.050); moreover, the molecular subtypes were an independent factor influencing E-cad expression in early-stage IDCs. A total of 12 observational studies (including our study) were included in the meta-analysis. The meta-analytical results show a significantly greater risk of E-cad expression loss in triple-negative breast cancer (TNBC) than in other molecular subtypes (TNBC vs. luminal A: RR = 3.45, 95% CI = 2.79-4.26; TNBC vs. luminal B: RR = 2.41, 95% CI = 1.49-3.90; TNBC vs. HER2-enriched: RR = 1.95, 95% CI = 1.24-3.07). CONCLUSIONS: Early-stage IDCs or invasive non-lobular breast cancers with the TNBC molecular phenotype have a higher risk for the loss of E-cad expression than do tumors with non-TNBC molecular phenotypes, suggesting that E-cad expression phenotypes were closely related to molecular subtypes and further studies are needed to clarify the underlying mechanism.

Prognostic significance of PD-L1 expression in patients with gastric cancer in East Asia: a meta-analysis.

The overexpression of programmed cell death-ligand 1(PD-L1) has been observed in gastric cancer (GC). However, whether the expression of PD-L1 in tumor cells or blood serum is associated with the prognosis of patients with GC remains unclear. Therefore, we performed a meta-analysis to evaluate the prognostic significance of PD-L1 expression in GC. Electronic databases were searched systematically. Studies that met the inclusion criteria were included in the meta-analysis. Data concerning the hazard ratio (HR) for overall survival and disease-free survival with a 95% confidence interval (CI) according to the expression status of PD-L1 evaluated by immunohistochemistry or enzyme-linked immunosorbent assay were extracted. The data were analyzed using a random effects model. Subgroup analyses were proposed. Our results showed that eight studies with 950 patients met the inclusion criteria and were included in the meta-analysis. The pooled HR for overall survival indicated that patients with PD-L1-positive expression had significantly shorter survival time compared with the PD-L1-negative group (HR 1.60, 95% CI 1.09-2.36, P=0.012). The pooled HR for disease-free survival demonstrated that the difference between the two groups was not statistically significant (HR 1.02, 95% CI 0.32-3.20, P=0.98). In conclusion, our results indicate that the evaluation of PD-L1 overexpression in GC tissue or blood serum may be useful in the future as a novel prognostic factor.

Integrative topological analysis of mass spectrometry data reveals molecular features with clinical relevance in esophageal squamous cell carcinoma.

Combining MS-based proteomic data with network and topological features of such network would identify more clinically relevant molecules and meaningfully expand the repertoire of proteins derived from MS analysis. The integrative topological indexes representing 95.96% information of seven individual topological measures of node proteins were calculated within a protein-protein interaction (PPI) network, built using 244 differentially expressed proteins (DEPs) identified by iTRAQ 2D-LC-MS/MS. Compared with DEPs, differentially expressed genes (DEGs) and comprehensive features (CFs), structurally dominant nodes (SDNs) based on integrative topological index distribution produced comparable classification performance in three different clinical settings using five independent gene expression data sets. The signature molecules of SDN-based classifier for distinction of early from late clinical TNM stages were enriched in biological traits of protein synthesis, intracellular localization and ribosome biogenesis, which suggests that ribosome biogenesis represents a promising therapeutic target for treating ESCC. In addition, ITGB1 expression selected exclusively by integrative topological measures correlated with clinical stages and prognosis, which was further validated with two independent cohorts of ESCC samples. Thus the integrative topological analysis of PPI networks proposed in this study provides an alternative approach to identify potential biomarkers and therapeutic targets from MS/MS data with functional insights in ESCC.

Mandible ameloblastoma with lung metastasis: a rare case report.

BACKGROUND: The ameloblastoma is the most common odontogenic epithelial tumor, which belong to benign neoplasms that present a painless course, and usually occur in the oromaxillo-facial region. Although the histopathological manifestation of ameloblastoma is benign, it has unique biological behavior, for example local invasion and recurrence repeatedly. A few case of ameloblastoma was locally aggressive growth, and rarely metastasis to other tissue, for example the lungs, lymph nodes, and spine. CASE REPORT: A 64-year-old Chinese man, diagnosed with metastatic ameloblastoma, was treated with palliative chemotherapy consisting of cyclophosphamide, doxorubicin, and cisplatin for six cycles, and radiotherapy for 50 Gy after the last cycle chemotherapy. During the surveillance CT scan after the therapy, the tissues of the tumor were nearly complete response. CONCLUSION: The purpose of this study was to report a case of a patient with a right mandible ameloblastoma that recurred repeatedly and metastasized into bilateral lung. After the chemotherapy and radiotherapy, the tissues of the tumor were nearly complete response. This case is interesting because it investigated the diagnosis and treatment of the malignancy ameloblastoma, as this may help diagnose and treatment for clinician to the metastatic ameloblastoma.

Recombinant Human Granulocyte Colony-Stimulating Factor Promotes Preinvasive and Invasive Estrogen Receptor-Positive Tumor Development in MMTV-erbB2 Mice.

PURPOSE: We investigated whether recombinant human granulocyte colony-stimulating factor (rhG-CSF) could promote the development of preinvasive and invasive breast cancer in mouse mammary tumor virus (MMTV-erbB2) mice with estrogen receptor-positive tumors. METHODS: MMTV-erbB2 mice were randomly divided into three experimental groups with 20 mice in each group. MMTV-erbB2 mice were treated with daily subcutaneous injections of vehicle or rhG-CSF (low-rhG-CSF group, rhG-CSF 0.125 µg; vehicle-rhG-CSF group, normal saline 0.25 µg; and high-rhG-CSF group, rhG-CSF 0.25 µg) at 3 months of age. Cellular and molecular mechanisms of G-CSF action in mammary glands were investigated via immunohistochemistry and reverse transcription polymerase chain reaction. RESULTS: Low, but not high, rhG-CSF doses significantly accelerated mammary tumorigenesis in MMTV-erbB2 mice. Short-term treatment with rhG-CSF could significantly promote the development of preinvasive mammary lesions. The cancer prevention effect was associated with reduced expression of proliferating cell nuclear antigen, cluster of differentiation 34, and signal transducers and activators of transcription 3 in mammary glands by >80%. CONCLUSION: We found that G-CSF was regulated by rhG-CSF both in vitro and in vivo. Identification of G-CSF genes helped us further understand the mechanism by which G-CSF promotes cancer. Low doses of rhG-CSF could significantly increase tumor latency and increase tumor multiplicity and burden. Moreover, rhG-CSF effectively promotes development of both malignant and premalignant mammary lesions in MMTV-erbB2 mice.

Risk factors for the Long-Term Efficacy, Recurrence, and Metastasis in Small Hepatocellular Carcinomas.

We tried to determine the risk factors for the long-term efficacy, recurrence, and metastasis of small hepatocellular carcinoma (HCC, diameter <5 cm). One hundred sixty-eight small liver cancer patients received percutaneous cryoablation therapy by argon-helium superconducting surgery system under the ultrasound guidance. Clinical parameter and the efficacy were analyzed after follow-up. After cryoablation treatment, the median follow-up time for the 168 patients was 36 (7-41) months. Liver functions were impaired as indicated by increased alanine aminotransferase, total bilirubin, total protein, albumin, and prothrombin activity. The difference of VEGF expression in liver cancer and the surrounding tissue is significant. 1-, 2-, and 3-year overall survival were 92.9, 83.9, and 65.5 %, respectively. Relapse-free survival was 76.8, 53.0, and 41.1 %. Less tumor number, higher tumor differentiation, and low VEGF expression predict higher metastasis-free and relapse-free survival rate. Lower Child-Pugh classification is correlated with the higher overall survival after cryoablation. There was no statistical significance in in situ intrahepatic recurrence patients, but VEGF changes were statistically significant for metastasis in other parts of liver or extrahepatic metastasis. Tumor number, differentiation, VEGF expression, large vessel invasion, lymph node, and extrahepatic metastasis all affect the overall and relapse-free survival. VEGF expression can be a predictable factor for liver cancer recurrence and metastasis.

Down-regulation of C/EBP homologous protein (CHOP) expression in gastric cardia adenocarcinoma: Their relationship with clinicopathological parameters and prognostic significance.

OBJECTIVE: C/EBP homologous protein (CHOP) is a multi-functional protein involved in the apoptosis pathway of endoplasmic reticulum stress (ERS) and is related to cancer progression. The purpose of this study was to assess CHOP expression as a prognostic biomarker in gastric cardia adenocarcinoma (GCA). METHODS: The levels of CHOP mRNA and protein in GCA and matched adjacent non-cancerous tissues were evaluated by quantitative real-time-polymerase chain reaction (qRT-PCR) and western blot. Furthermore, the CHOP protein expression and localization were examined by immunohistochemistry in GCA and corresponding adjacent non-cancerous tissues, gastritis and normal cardiac tissues. The association of CHOP expression with clinical pathological parameters and prognosis of GCA patients was statistically analyzed. RESULTS: Compared with adjacent non-cancerous tissues, the CHOP was down-regulated at mRNA and protein levels in GCA (P<0.01). In addition, immunohistochemistry analysis showed that CHOP positivity was lower in GCA than that in paired adjacent non-cancerous tissues, gastritis and normal tissues (P<0.01). CHOP expression rate gradually decreased with an increase in clinical stage, tumor differentiation and lymph node metastasis of GCA (P<0.05). Kaplan-Meier survival analysis revealed that low expression of CHOP correlated with poor prognosis of GCA patients. Moreover, univariate and multivariate analyses showed that CHOP was an independent prognostic marker for overall survival of GCA patients. CONCLUSIONS: Our results suggest that low CHOP expression predicts poor prognosis of GCA patients, and CHOP may be potentially a prognostic biomarker for GCA.

Serum CA242, CA199, CA125, CEA, and TSGF are Biomarkers for the Efficacy and Prognosis of Cryoablation in Pancreatic Cancer Patients.

This study aimed to compare the changes and determine the clinical significance of carbohydrate antigens CA242, CA199, CA125, carcinoembryonic antigen (CEA), and tumor-specific growth factor (TSGF) before and after cryoablation by Cryocare system. Thirty-one pancreatic cancer patients were selected to receive cryoablation by Cryocare system. The serum expression levels of CA242, CA199, CA125, CEA, and TSGF before and 1 month after treatment were determined. Meanwhile, the serum level of these factors was also determined in 31 healthy volunteers. The parameter changes were analyzed with the clinical pathological data. The serum levels of CA242, CA199, CA125, CEA, and TSGF in the pancreatic cancer group were significantly higher than those of the control group both before and after the cryoablation treatment (P < 0.05). The serum CA199, CEA, and TSGF dramatically decreased 1 month after the treatment, which were statistically different (P < 0.05). The positive rates of serum CA242, CA199, CA125, and CEA in the pancreatic cancer group were much higher than those in the control group both before and after treatment (P < 0.05), and the positive rate of TSGF was significantly higher than that of the control group before the treatment (P < 0.05). The positive rate of CA199, CEA, and TSGF after the treatment was significantly lower than that before the treatment (P < 0.05). Serum level of CA242 was correlated with the tumor diameter, clinical staging, tumor differentiation, lymph node, and liver metastasis (P < 0.05). Except gender, CA199 was correlated with all the other clinical pathological parameters (P < 0.05). The serum levels of CA125 and CEA were correlated with all the other clinical pathological parameters (P < 0.05). The serum level of TSGF was only correlated with tumor differentiation (P < 0.05). Cryoablation treatment by Cryocare system can decrease the serum levels of CA199, CEA, TSGF, and the positive rate. Serum CA199, CEA, and TSGF can be important index for pancreatic cancer treatment assessment. Serum levels of CA242, CA199, CA125, and CEA are of great clinical value for metastasis assessment and prognosis in pancreatic cancer patients.

Forkhead factor FOXQ1 promotes TGF-ß1 expression and induces epithelial-mesenchymal transition.

Epithelial-mesenchymal transition (EMT) promotes tumor invasion and metastasis, but the coordination and integration mechanisms of these processes are still not fully understood. In this study, we used a cross-species expression profiling strategy of Hela cells to determine an important genetic program transfers. In particular, we have discovered a new transfer function, which is not previously known about transcription factor forkhead box Q1 (FOXQ1). The shRNA anti-FOXQ1 gene was synthesized and transfected into the Hela and EpRas cells. RT-PCR assay was performed to detect the mRNA levels in cells. Cell adhesion and separation assay were used to examine the cell-cell adhesion and separation among cells. Wound healing assay was utilized to examine cell migration and invasion ability. Chromatin immunoprecipitation assay was used to investigate the interaction between E-cadherin and N-cadherin and FOXQ1 promoter region. The results indicated that ectopic expression of FOXQ1 increased cell migration and invasion in vitro, enhanced mammary epithelial cells in vivo lung metastasis, and triggered significant EMT. In contrast, the opposite effects in vitro and in vivo of FOXQ1 knockdown phenotypes were caused by these mechanisms. Notably, FOXQ1 repressed core EMT regulation of the expression of TGF-ß1. FOXQ1 protein directly interacts with E-cadherin and N-cadherin promoter region. And surveys show that FOXQ1 expression regulation by TGF-ß1 and blockade induced EMT both morphological and molecular levels. Our findings emphasize the feasibility of cross-species expression profiles, as a strategy to identify metastasis-related genes. The induction of EMT by FOXQ1 defines a new transfer function in promoting cancer behind possible mechanisms.

Joint analysis of three genome-wide association studies of esophageal squamous cell carcinoma in Chinese populations.

We conducted a joint (pooled) analysis of three genome-wide association studies (GWAS) of esophageal squamous cell carcinoma (ESCC) in individuals of Chinese ancestry (5,337 ESCC cases and 5,787 controls) with 9,654 ESCC cases and 10,058 controls for follow-up. In a logistic regression model adjusted for age, sex, study and two eigenvectors, two new loci achieved genome-wide significance, marked by rs7447927 at 5q31.2 (per-allele odds ratio (OR) = 0.85, 95% confidence interval (CI) = 0.82-0.88; P = 7.72 × 10(-20)) and rs1642764 at 17p13.1 (per-allele OR = 0.88, 95% CI = 0.85-0.91; P = 3.10 × 10(-13)). rs7447927 is a synonymous SNP in TMEM173, and rs1642764 is an intronic SNP in ATP1B2, near TP53. Furthermore, a locus in the HLA class II region at 6p21.32 (rs35597309) achieved genome-wide significance in the two populations at highest risk for ESSC (OR = 1.33, 95% CI = 1.22-1.46; P = 1.99 × 10(-10)). Our joint analysis identifies new ESCC susceptibility loci overall as well as a new locus unique to the population in the Taihang Mountain region at high risk of ESCC.

Midkine and syndecan­1 levels correlate with the progression of malignant gastric cardiac adenocarcinoma.

The present study aimed to determine whether the expression levels of midkine (MK) and syndecan­1 correlate with the malignant progression and poor prognosis of gastric cardiac adenocarcinoma (GCA). GCA tissue samples (n=72) were obtained from the Department of Pathology of the First Affiliated Hospital of Henan University of Science and Technology (Luoyang, China). The paraffin­embedded samples had been surgically resected and pathologically diagnosed between 2007 and 2009. Normal gastric cardiac biopsy specimens (n=40) were also collected as the control. The expression levels of MK and syndecan­1 were assessed by immunohistochemistry using the high­sensitivity streptavidin­peroxidase method. Statistical analysis was performed on the data obtained using the SPSS 17.0 statistics package. MK expression was detected in 76.4% of GCA samples and 5% of normal gastric cardiac mucosa specimens. A significant positive correlation was observed between the expression levels of MK and the infiltrative depth of the tumor, the presence of lymph node metastasis and the prognosis of the patients (P<0.05). Syndecan­1 expression was detected in 38.9% of GCA samples and 100% of normal gastric cardiac mucosa samples. The expression levels of syndecan­1 were negatively correlated with the grade of differentiation, serosal membrane invasion, lymph node metastasis and the patient's prognosis (P<0.05). Notably, the expression levels of MK and syndecan­1 were inversely correlated (r=­0.352, P<0.01) in the GCA tissue samples. These results suggest that high expression levels of MK in GCA tissues may indicate a differentiation stage that is characteristic of malignancy, a late clinical stage and a poor prognosis, whereas increased syndecan­1 levels may indicate a high degree of differentiation, an early clinical stage and a favorable prognosis. MK and syndecan­1 may serve as important biomarkers for monitoring the development and progression of GCA.

Reduced expression of circulating microRNA-218 in gastric cancer and correlation with tumor invasion and prognosis.

AIM: To investigate the expression of microRNA-218 (miR-218) in serum from gastric cancer patients and its relationship with clinicopathological characteristics. METHODS: A total of 68 patients with pathologically diagnosed gastric cancer and 56 healthy individuals were recruited to this study. The expression of miR-218 was detected in the serum of gastric cancer patients and healthy individuals by quantitative real-time polymerase chain reaction. The clinical data were collected and analyzed by statistical software. RESULTS: miR-218 was reduced significantly in the serum of gastric cancer patients compared to healthy individuals (1.15 ± 0.08 vs 0.37 ± 0.023; P = 0.026). In the gastric cancer group, serum expression of miR-218 was lower in patients with metastasis and poorly differentiated cancer compared with non-metastatic and well-differentiated cancer (0.19 ± 0.011 vs 0.45 ± 0.021, P = 0.031 and 0.21 ± 0.019 vs 0.49 ± 0.021, P = 0.025). Serum miR-218 was found to be significantly associated with gastric cancer metastasis (P = 0.003), tumor T stage (P = 0.018) and tumor grade (P = 0.012). Low serum expression of miR-218 was related to an increase in the stage of gastric cancer. The expression level of miR-218 in the serum was correlated with the 3-year survival. Ninety-seven percent of patients with a high level of miR-218 expression survived for 3 years, while only 54% of those with low miR-218 expression survived. CONCLUSION: miR-218 is deregulated in gastric cancer patients and is strongly correlated with tumor stage, grade and metastasis. Serum expression of miR-218 may be a prognostic marker.

Prevalence and age, gender and geographical area distribution of esophageal squamous cell carcinomas in North China from 1985 to 2006.

OBJECTIVE: To establish the prevalence and distribution profile of esophageal squamous cell carcinomas (ESCCs) over a 22-yr period in North China. METHODS: Using endoscopy for primary diagnosis and histological analysis for the further confirmation, a total of 74,854 ESCC patients aged 20-89 between January 1985 and December 2006 were investigated to analyze the epidemiological profile including prevalence rates, distribution of age-of-onset, gender and geographical area of ESCC in Luoyang, the highest incidence area of North China. RESULTS: A total of 4092 cases of ESCC were finally diagnosed among 74,854 patients who had their first endoscopies. The prevalence among males was higher than that among females (p<0.01), resulting in an overall male:female OR of 1.2 (95%CI, 1.2-1.3). The prevalence in rural areas was higher than in urban areas (p<0.01), resulting in an overall rural:urban OR of 2.6 (95%CI, 2.4-2.9). The rural:urban ORs and the 95% CI increased continuously from 2.6, 2.3-3.0 to 2.7, 2.2-3.3, respectively, for 4 consecutive periods during the 22-yr study period. Moreover, the median age of onset among females was higher than that among males (p<0.01). For both sexes and in both areas, the prevalence rates declined and the median age of onset rose for 4 consecutive periods in the 22-yrs time frame (p<0.01). CONCLUSIONS: [corrected] These data reveal the epidemiological profile of ESCC in the area of North China, and suggest that urban areas and rural people account for a growing proportion of the ESCC patients although the prevalence of ESCC significantly declined and the median age-of-onset postponed over the 22-yrs period. Moreover, the prevalence status of ESCC in rural areas also underlines the need for public health initiatives aimed at reducing risk factors of this fatal disease.

Midkine promotes perineural invasion in human pancreatic cancer.

AIM: To investigate midkine (MK) and syndecan-3 protein expression in pancreatic cancer by immunohistochemistry, and to analyze their correlation with clinicopathological features, perineural invasion, and prognosis. METHODS: Pancreatic cancer tissues (including adequately sized tumor tissue samples and tissue samples taken from areas less than 2.0 cm around the tumor) were taken from 42 patients who were undergoing a partial duodenopancreatectomy. MK and syndecan-3 proteins were detected by immunohistochemistry using a standardized streptavidin-peroxidase method, and analyzed for their correlation with clinicopathological features, perineural invasion, and prognosis. Associations of neural invasion with aggressive characteristics of pancreatic cancer and the presence of perineural invasion were assessed by two independent observers blinded to the patient status. RESULTS: MK and syndecan-3 were found in 26 (61.9%) and 24 (57.1%) specimens, respectively. MK and syndecan-3 expression was associated with perineural invasion (P = 0.018 and 0.031, respectively). High MK expression was closely associated with advanced tumor, node and metastasis stage (P = 0.008), lymph node metastasis (P = 0.042), and decreased postoperative survival at 3 years (51.0% vs 21.8%, P = 0.001). Syndecan-3 levels were correlated with tumor size (P = 0.028). Patients who were syndecan-3 negative had a higher cumulative survival rate than those who were positive, but the difference was not significant (44.0% vs 23.0%, P > 0.05). CONCLUSION: MK and syndecan-3 are frequently expressed in pancreatic cancer and associated with perineural invasion. High expression of MK and syndecan-3 may contribute to the highly perineural invasion and poor prognosis of human pancreatic cancer.

Recombinant lentivirus targeting the pleotrophin gene reduces pleotrophin protein expression in pancreatic cancer cells and inhibits neurite outgrowth of dorsal root ganglion neurons.

The objectives of the present study were to construct the recombinant primate lentivirus­short hairpin RNA-pleiotrophin (pLV-shRNA-PTN) vector, to investigate the silencing effect of pLV-shRNA-PTN on PTN expression in MIA PaCa-2 cells and to observe the inhibition efficiency of pLV-shRNA­PTN on neurite outgrowth from dorsal root ganglion (DRG) neurons in vitro. The construction procedure for recombinant lentivirus pLV-shRNA-PTN has been described previously. In the present study, pLV-shRNA­PTN was used to infect MIA PaCa-2 pancreatic cancer cells and the efficiency of the knockdown of the PTN gene on day 7 following infection was analyzed using western blotting. The morphological changes in the cultured DRG neurons were observed by monoculture of DRG neurons and co-culture with MIA PaCa-2 cells in vitro. The recombinant lentivirus pLV-shRNA­PTN was successfully constructed. The western blot analysis showed that the inhibition rates of PTN expression were 46, 80, 20 and 21%, respectively, following pLV-shRNA­PTN-A, B, C and D infection. pLV-shRNA-PTN­B showed the highest knockdown efficiency. DRG neurons co-cultured with infected MIA PaCa-2 cells were decreased in size when compared with the control, and there was a significant decrease in the number and length of neurites. The results suggest that efficient and specific knockdown of PTN in MIA PaCa-2 pancreatic cancer cells and the subsequent reduction in PTN expression results in the inhibition of neurite outgrowth from DRG neurons.