Upregulated expression of C-X-C chemokine receptor 4 is an independent prognostic predictor for patients with gastric cancer

Application progress of liquid biopsy in gastric cancer

Gastric cancer (GC) is one of the most common malignant tumors globally. Guiding the individualized treatment of GC is the focus of research. Obtaining representative biological samples to study the biological characteristics of GC is the focus of diagnosis and treatment of GC. Liquid biopsy technology can use high-throughput sequencing technology to detect biological genetic information in blood. Compared with traditional tissue biopsy, liquid biopsy can determine the dynamic changes of tumor. As a noninvasive auxiliary diagnostic method, liquid biopsy can provide diagnostic and prognostic information concerning the progression of the disease. Liquid biopsy includes circulating tumor cells, circulating tumor DNA, circulating tumor RNA, tumor educated platelets, exosomes, and cytokines. This article describes the classification of liquid biopsy and its application value in the occurrence, development, and therapeutic efficacy of GC.

The Expression and Prognostic Significance of VEGF and CXCR4 in Gastric Cancer: Correlation with Angiogenesis, Lymphangiogenesis and Progression

The cellular response to hypoxia includes the expression of hypoxia-inducible factor-1 (HIF-1) and its target genes: vascular endothelial growth factor (VEGF) and CXC chemokine receptor 4 (CXCR4). The aim of this study was to investigate the expression and prognostic significance of VEGF and CXCR4, which are responsible for angiogenesis and progression in gastric cancer. Twenty-eight gastric cancer patients were analyzed. The mRNA expression was examined in primary tumors and corresponding normal gastric mucosa by RT-PCR. The protein level was examined by immunohistochemistry staining. The high expression of VEGF and CXCR4 was found in 71.0 and 64.0% of tumors, respectively. The mean levels of VEGF and CXCR4 were upregulated in primary tumors compared to normal mucosa (p = 0.0007, p = 0.0052). A correlation between VEGF expression and tumor invasion (p = 0.0216) and stage (p = 0.0181) was found. CXCR4 expression correlated with lymph node metastases (p = 0.0237) and stage (p = 0.0054). The VEGF expression correlated with microvessel density (MVD) (p = 0.0491). The overall 3-year survival rate was 46.4% and correlated negatively with high CXCR4 mRNA expression (p = 0.0089). VEGF and CXCR4 play an important role in tumor progression. Their overexpression correlates with a bad prognosis and may improve high-risk patient selection, and these patients may obtain additional survival benefits if treated more aggressively.

CXCR4 is a Novel Biomarker Correlated With Malignant Transformation and Immune Infiltrates in Gastric Precancerous Lesions

Background: As early gastric cancer (EGC) has a far better prognosis than advanced gastric cancer (GC), early diagnosis and treatment are essential. However, understanding the mechanism of the process from gastric precancerous lesion (GPL) becoming EGC has made little advances. Besides, biomarkers that can monitor the progression of GPL-to-GC are still much insufficient. Methods: Key gene modules associated with GPL progression to EGC were identified by integrating two GPL-related data sets, GSE55696 and GSE130823, using the WGCNA method. Combining with the TCGA-STAD cohort, hub genes were identified. Immunofluorescence was conducted to validate the expression. To explore the implication of hub genes in GPL malignant transformation, a correlation test was conducted to identify their co-expression genes, co-expression cytokines, and co-expression immune cells. Least absolute shrinkage and selection operator (LASSO) Cox regression was applied to shrink CXCR4-related predictors and construct a prognostic model. Functional enrichment was applied for exploring the potential mechanism. Results: The green module in GSE55696 and the yellow module in GSE130823 were regarded as key gene modules associated with GPL progression to EGC, and 219 intersection genes from them were mainly enriched in critical immune biological processes. Combining with the TCGA-STAD cohort, CXCR4 was identified as a novel biomarker correlated with the malignant transformation of GPL, the positive rate of which was increased with GPL progression according to immunofluorescence. CXCR4 co-expression genes were found mainly involved in regulation of actin. CXCR4 co-expression cytokines were enriched in regulation of chemotaxis, cell chemotaxis, mononuclear cell migration, leukocyte chemotaxis, etc. As for co-expression immune cells, the expression level of CXCR4 was positively correlated with the abundance of macrophages but negatively correlated with that of effector memory T cells and NKT cells during GPL malignant transformation. In addition, the CXCR4-related prognostic model was able to predict the prognosis of GC and serve as an independent predictor for overall survival (OS). Conclusions: CXCR4 was a novel biomarker correlated with malignant transformation of GPL and played a vital role in the control of tumor immunity. CXCR4 is possible to serve as a therapeutic target for malignant transformation of GPL.

Role of CC Chemokines Subfamily in the Platinum Drugs Resistance Promotion in Cancer

Cancer is a significant medical issue, being one of the main causes of mortality around the world. The therapies for this pathology depend on the stage in which the cancer is found, but it is usually diagnosed at an advanced stage in which the treatment is chemotherapy. Platinum drugs are among the most commonly used in therapy, unfortunately, one of the main obstacles to this treatment is the development of chemoresistance, which is the ability of cancer cells to evade the effects of drugs. Although some molecular mechanisms involved in resistance to platinum drugs are described, elucidation is still required of others. Secretion of inflammatory mediators such as cytokines and chemokines, by tumor microenvironment components or tumor cells, show direct influence on proliferation, metastasis and progression of cancer and are related to chemoresistance and poor prognosis. In this review, the general mechanisms associated with resistance to platinum drugs, inflammation on cancer development and chemoresistance in various types of cancer will be approached with special emphasis on the current history of CC chemokines subfamily-mediated chemoresistance.

lncRNA HOTAIR promotes gastric cancer proliferation and metastasis via targeting miR-126 to active CXCR4 and RhoA signaling pathway

HOTAIR, a well-known long noncoding RNAs (lncRNA), has been recognized to contribute to the tumor metastasis in several tumors. But its role in gastric cancer remains elusive. Here, we reported an increase in HOTAIR promoted proliferation and metastasis of gastric cancer cell lines. The HOTAIR and miR-126 level was determined in 15 paired primary gastric cancer tissues and their adjacent noncancerous gastric tissues. Over-expression or downregulation HOTAIR was conducted in AGS or BGC-823 cells to investigate the impact of HOTAIR in proliferation and metastasis. Then dual luciferase reporter assay was utilized to study the interaction between CXCR4 and miR-126. Cells transfected with shHOTAIR or miR-126 mimic were subjected to western blot to investigate the role of SDF-1/CXCR4 signaling in HOTAIR mediated proliferation and metastasis. HOTAIR was highly expressed in gastric cancer tissues and several gastric cancer cell lines. Overexpressed HOTAIR facilitated proliferation and metastasis in vitro while HOTAIR knockdown inhibit proliferation and metastasis. A negative correlation was observed between miR-126 and HOTAIR. And, we also confirmed the decrease in miR-126 in clinic specimen. Furthermore, HOTAIR and miR-126 negatively regulated each other and then increase or decrease CXCR4 expression and downstream pathway, respectively. CXCR4 was confirmed as a direct target of miR-126. Our study demonstrated that high HOTAIR expression promote proliferation and metastasis in gastric cancer via miR-126/CXCR4 axis and downstream signaling pathways.

CXCR4 as a prognostic biomarker in gastrointestinal cancer: a meta-analysis

Background: CXCR4 is a member of the C-X-C chemokine receptor family, which is associated with multiple types of cancer. Although it has been widely reported, the prognostic value of CXCR4 expression in gastrointestinal (GI) cancer remains controversial. Methods: A meta-analysis was conducted to investigate the relationship between CXCR4 and prognosis of patients with GI cancer. Subgroup analysis was also performed according to tumour subtypes and heterogeneity test. Results: A total of 24 studies including 3637 cases suggested that overexpression of CXCR4 is significantly associated with overall survival (OS) for patients with GI cancer (HR = 1.71, 95% CI = 1.45-2.03, p = 0.000). Subgroup analysis also indicated that high CXCR4 expression in oesophagus, gastric and colorectal cancer all predicted a worse prognosis (HR = 1.52, 95% CI = 1.26-1.84, p = 0.001 for oesophagus cancer; HR = 1.59, 95% CI = 1.10-2.30, p = 0.015 for gastric cancer; HR = 2.21, 95% CI = 1.56-3.14, p = 0.000 for colorectal cancer). Conclusions: CXCR4 may serve as a prognostic indicator in GI cancer patients.

Prognostic and Predictive Value of p21-activated Kinase 6 Associated Support Vector Machine Classifier in Gastric Cancer Treated by 5-fluorouracil/Oxaliplatin Chemotherapy

To determine whether p21-activated Kinase (PAK) 6 is a prognostic and predictive marker in gastric cancer (GC) and to construct a classifier that can identify a subset of patients who are highly sensitive to 5-fluorouracil/oxaliplatin chemotherapy. We retrospectively analyzed the expression levels of PAK6, cyclooxygenase 2, p21^WAF1, Ki-67, excision repair cross-complementing gene 1, and thymidylate synthase in 242 paraffin-embedded GC specimens of the training cohort by immunohistochemistry. Then, we used support vector machine (SVM)–based methods to develop a predictive classifier for chemotherapy (chemotherapy score – CS-SVM classifier). Further validation was performed in an independent cohort of 279 patients. High PAK6 expression was associated with poor prognosis and increased chemoresistance to 5-FU/oxaliplatin chemotherapy. The CS-SVM classifier distinguished patients with stage II and III GC into low- and high-CS-SVM groups, with significant differences in the 5-year disease-free survival (DFS) and overall survival (OS) in chemotherapy patients. Moreover, chemotherapy significantly prolonged the DFS and OS of the high CS-SVM patients in the training and validation cohorts. In conclusion, PAK6 was an independent prognostic factor and increased chemoresistance. The CS-SVM classifier distinguished a subgroup of stage II and III patients who would highly benefit from chemotherapy, thus facilitating patient counseling and individualizing the management.

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p21-activated Kinase 6 was a predictive biomarker and increased chemoresistance to 5-FU/oxaliplatin chemotherapy.

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The CS-SVM classifier distinguished a subgroup of stage II and III patients who would highly benefit from chemotherapy.

PAK6 was an independent prognostic factor and increased chemoresistance. The chemotherapy score – support vector machine classifier distinguished a subgroup of stage II and III patients who would highly benefit from chemotherapy. The model maybe useful for patient counseling and individualized treatment decision-making.

Inhibition of CXCL12/CXCR4 axis as a potential targeted therapy of advanced gastric carcinoma

The whole outcome for patients with gastric carcinoma (GC) is very poor because most of them remain metastatic disease during survival even at diagnosis or after surgery. Despite many improvements in multiple strategies of chemotherapy, immunotherapy, and targeted therapy, exploration of novel alternative therapeutic targets is still warranted. Chemokine receptor 4 (CXCR4) and its chemokine ligand 12 (CXCL12) have been identified with significantly elevated levels in various malignancies including GC, which correlates with the survival, proliferation, angiogenesis, and metastasis of tumor cells. Increasing experimental evidence suggests an implication of inhibition of CXCL12/CXCR4 axis as a promising targeted therapy, although there are rare trials focused on the therapeutic efficacy of CXCR4 inhibitors in GC until recently. Therefore, it is reasonable to infer that specific antagonists or antibodies targeting CXCL12/CXCR4 axis alone or combined with chemotherapy will be effective and worthy of further translational studies as a potential treatment strategy in advanced GC.

Regorafenib inhibited gastric cancer cells growth and invasion via CXCR4 activated Wnt pathway

AIM

Regorafenib is an oral small-molecule multi kinase inhibitor. Recently, several clinical trials have revealed that regorafenib has an anti-tumor activity in gastric cancer. However, only part of patients benefit from regorafenib, and the mechanisms of regorafenib's anti-tumor effect need further demonstrating. In this study, we would assess the potential anti-tumor effects and the underlying mechanisms of regorafenib in gastric cancer cells, and explore novel biomarkers for patients selecting of regorafenib.

METHODS

The anti-tumor effects of regorafenib on gastric cancer cells were analyzed via cell proliferation and invasion. The underlying mechanisms were demonstrated using molecular biology techniques.

RESULTS

We found that regorafenib inhibited cell proliferation and invasion at the concentration of 20μmol/L and in a dose dependent manner. The anti-tumor effects of regorafenib related to the decreased expression of CXCR4, and elevated expression and activation of CXCR4 could reverse the inhibition effect of regorafenib on gastric cancer cells. Further studies revealed that regorafenib reduced the transcriptional activity of Wnt/β-Catenin pathway and led to decreased expression of Wnt pathway target genes, while overexpression and activation of CXCR4 could attenuate the inhibition effect of regorafenib on Wnt/β-Catenin pathway.

CONCLUSIONS

Our findings demonstrated that regorafenib effectively inhibited cell proliferation and invasion of gastric cancer cells via decreasing the expression of CXCR4 and further reducing the transcriptional activity of Wnt/β-Catenin pathway.

CXCR7/CXCL12 axis is involved in lymph node and liver metastasis of gastric carcinoma

AIM

To investigate the role of CXC chemokine receptor (CXCR)-7 and CXCL12 in lymph node and liver metastasis of gastric carcinoma.

METHODS

In 160 cases of gastric cancer, the expression of CXCR7 and CXCL12 in tumor and matched tumor-adjacent non-cancer tissues, in the lymph nodes around the stomach and in the liver was detected using immunohistochemistry to analyze the relationship between CXCR7/CXCL12 expression and clinicopathological features and to determine whether CXCR7 and CXCL12 constitute a biological axis to promote lymph node and liver metastasis of gastric cancer. Furthermore, the CXCR7 gene was silenced and overexpressed in human gastric cancer SGC-7901 cells, and cell proliferation, migration and invasiveness were measured by the MTT, wound healing and Transwell assays, respectively.

RESULTS

CXCR7 expression was up-regulated in gastric cancer tissues (P = 0.011). CXCR7/CXCL12 expression was significantly related to high tumor stage and lymph node (r = 0.338, P = 0.000) and liver metastasis (r = 0.629, P = 0.000). The expression of CXCL12 in lymph node and liver metastasis was higher than that in primary gastric cancer tissues (χ2 = 6.669, P = 0.010; χ2 = 25379, P = 0.000), and the expression of CXCL12 in lymph node and liver metastasis of gastric cancer was consistent with the positive expression of CXCR7 in primary gastric cancer (r = 0.338, P = 0.000; r = 0.629, P = 0.000). Overexpression of the CXCR7 gene promoted cell proliferation, migration and invasion. Silencing of the CXCR7 gene suppressed SGC-7901 cell proliferation, migration and invasion. Human gastric cancer cell lines expressed CXCR7 and showed vigorous proliferation and migratory responses to CXCL12.

CONCLUSION

The CXCR7/CXCL12 axis is involved in lymph node and liver metastasis of gastric cancer. CXCR7 is considered a potential therapeutic target for the treatment of gastric cancer.

Prolonged inflammatory microenvironment is crucial for pro-neoplastic growth and genome instability: a detailed review

INTRODUCTION

Chronic inflammation can affect the normal cell homeostasis and metabolism by rendering the cells susceptible to genomic instability that may lead to uncontrolled cellular growth and proliferation ensuing tumorigenesis. The causal agents for inflammation may be pathogenic infections like microbial agents ranging from viruses to bacteria. These infections lead to DNA damage or disruption of normal cell metabolism and alter the genome integrity.

FINDINGS

In this review, we have highlighted the role of recurrent infections in tumor microenvironment can lead to recruitment of pro-inflammatory cells, cytokines and growth factors to the site of inflammation. This makes the environment rich in cytokines, chemokines, DNA-damaging agents (ROS, RNS) and growth factors which activate DNA damage response pathway and help in sustained proliferation of the tumor cells. In any inflammatory response, the production of cytokines and related signaling molecules is self-regulating and limiting. But in case of neoplastic risk, deregulation of these factors may lead to abnormalities and related pathogenesis.

CONCLUSION

The scope of the present review is to explore the probable mechanistic link and factors responsible for chronic inflammation. The relation between chronic inflammation and DNA damage response was further elucidated to understand the mechanism by which it makes the cells susceptible to carcinogenesis.

Differential expression and prognostic value of the chemokine receptor CXCR4 in bronchopulmonary neuroendocrine neoplasms

Introduction

For many tumors, the overexpression of the chemokine receptor CXCR4 is associated with increased malignancy and poor patient outcomes. However, comprehensive data for neuroendocrine neoplasms of the lung are still lacking.

Methods

CXCR4 expression was evaluated in a panel of bronchopulmonary neuroendocrine neoplasms (BP-NEN) comprising typical carcinoids (n = 26), atypical carcinoids (n = 30), and small cell lung cancers (SCLC, n = 34). Samples were analyzed by immunohistochemistry using the novel monoclonal rabbit anti-human CXCR4 antibody UMB-2 and by qRT-PCR. The expression was correlated with clinical data and overall patient survival.

Results

CXCR4 was predominantly localized at the plasma membrane of the tumor cells. CXCR4 was expressed with a high intensity in almost all of the 30 SCLC samples. In contrast, it was detected infrequently and with low intensity in the typical carcinoid and atypical carcinoid samples. There was a significant correlation between the immunohistochemistry and qRT-PCR data. Additionally, there was a significant negative relationship between CXCR4 expression and overall survival.

Conclusions

With increasing malignancy, BP-NEN clearly differ in the extent of CXCR4 expression. As in other tumor entities, CXCR4 overexpression significantly correlates with negative patient outcome. Due to its particular high expression rate in SCLC, CXCR4 may serve as a promising new target for diagnostic and pharmacological intervention as well as for peptide receptor-based radionuclide therapy.

CXCR4 over-expression and survival in cancer: a system review and meta-analysis

C-X-C chemokine receptor 4 (CXCR4) is frequently over-expressed in various types of cancer; many agents against CXCR4 are in clinical development currently despite variable data for the prognostic impact of CXCR4 expression. Here eighty-five studies with a total of 11,032 subjects were included to explore the association between CXCR4 and progression-free survival (PFS) or overall survival (OS) in subjects with cancer. Pooled analysis shows that CXCR4 over-expression is significantly associated with poorer PFS (HR 2.04; 95% CI, 1.72-2.42) and OS (HR=1.94; 95% CI, 1.71-2.20) irrespective of cancer types. Subgroup analysis indicates significant association between CXCR4 and shorter PFS in hematological malignancy, breast cancer, colorectal cancer, esophageal cancer, renal cancer, gynecologic cancer, pancreatic cancer and liver cancer; the prognostic effects remained consistent across age, risk of bias, levels of adjustment, median follow-up period, geographical area, detection methods, publication year and size of studies. CXCR4 over-expression predicts unfavorable OS in hematological malignancy, breast cancer, colorectal cancer, esophageal cancer, head and neck cancer, renal cancer, lung cancer, gynecologic cancer, liver cancer, prostate cancer and gallbladder cancer; these effects were independence of age, levels of adjustment, publication year, detection methods and follow-up period. In conclusion, CXCR4 over-expression is associated with poor prognosis in cancer.

Prognostic significance of EZH2 expression in patients with oesophageal cancer: a meta-analysis

Enhancer of zeste 2 (EZH2), a key component of polycomb repressive complex 2 (PRC2), was of great importance in human cancer pathogenesis. Various studies examined the relationship between EZH2 overexpression with the clinical outcome in patients with digestive cancers, but yielded conflicting results. Electronic databases updated to January 2015 were searched to find relevant studies. A meta‐analysis was conducted with eligible studies which quantitatively evaluated the relationship between EZH2 overexpression and survival of patients with digestive cancers. Survival data were aggregated and quantitatively analysed. We performed a meta‐analysis of 10 studies (n = 1461 patients) that evaluated the correlation between EZH2 overexpression and survival in patients with digestive cancers. Combined hazard ratios suggested that EZH2 overexpression was associated with poor prognosis of overall survival (HR = 1.54, 95% CI: 1.27–1.81) in patients with oesophageal cancer. In the stratified analysis, no significant risks were found among gastric cancer (HR = 0.66, 95% CI: 0.16–1.15) and colorectal cancer (HR = 0.91, 0.63–1.19), indicating that EZH2 was not an indicator of poor prognosis in gastric cancer or colorectal cancer. Enhancer of zeste 2 overexpression indicates a poor prognosis for patients with oesophageal cancer, but not among gastric cancer or colorectal cancer.

CXCL12/CXCR4 activation by cancer-associated fibroblasts promotes integrin β1 clustering and invasiveness in gastric cancer

Cancer-associated fibroblasts (CAFs) are reportedly involved in invasion and metastasis in several types of cancer, including gastric cancer (GC), through the stimulation of CXCL12/CXCR4 signaling. However, the mechanisms underlying these tumor-promoting effects are not well understood, which limits the potential to develop therapeutic targets against CAF-mediated CXCL12/CXCR4 signaling. CXCL12 expression was analyzed in resected GC tissues from 110 patients by immunohistochemistry (IHC). We established primary cultures of normal fibroblasts (NFs) and CAFs from the GC tissues and examined the functional differences between these primary fibroblasts using co-culture assays with GC cell lines. We evaluated the efficacy of a CXCR4 antagonist (AMD3100) and a FAK inhibitor (PF-573,228) on the invasive ability of GC cells. High CXCL12 expression levels were significantly associated with larger tumor size, increased tumor depth, lymphatic invasion and poor prognosis in GC. CXCL12/CXCR4 activation by CAFs mediated integrin β1 clustering at the cell surface and promoted the invasive ability of GC cells. Notably, AMD3100 was more efficient than PF-573,228 at inhibiting GC cell invasion through the suppression of integrin β1/FAK signaling. These results suggest that CXCL12 derived from CAFs promotes GC cell invasion by enhancing the clustering of integrin β1 in GC cells, resulting in GC progression. Taken together, the inhibition of CXCL12/CXCR4 signaling in GC cells may be a promising therapeutic strategy against GC cell invasion.

Infiltration of diametrically polarized macrophages predicts overall survival of patients with gastric cancer after surgical resection

BACKGROUND

Tumor-associated macrophages (TAMs), the most predominant tumor-infiltrating immune cells, are emerging prognostic factors and therapeutic targets for personalized therapy against malignant neoplasms. We aimed to evaluate the prognostic significance of diametrically polarized TAMs in gastric cancer and generate a predictive nomogram to refine a risk stratification system.

METHODS

We evaluated polarized functional status of infiltrated TAMs by immunohistochemical staining of CD68, CD11c, and CD206 in 180 consecutive gastric cancer patients from Zhongshan Hospital, Shanghai, China. Prognostic values were assessed in these patients. We created a predictive nomogram by integrating polarized TAMs with the TNM staging system for overall survival of gastric cancer patients.

RESULTS

CD68(+) TAMs display polarized programs comprising CD11c(+) proinflammatory macrophages (M1) and CD206(+) immunosuppressive macrophages (M2) that configure versatile infiltration files in gastric cancer. CD11c(+) TAMs negatively correlated with lymph node metastasis (p = 0.012), whereas CD206(+) TAMs correlated with the Lauren classification (p = 0.031). No prognostic difference was observed for overall survival for CD68 density (high vs low, p = 0.1031), whereas high versus low CD11c density (p < 0.0001) and low vs high CD206 density (p = 0.0105) indicate better overall survival. Multivariate Cox regression analysis identified CD11c and CD206 as independent prognostic factors (p < 0.001 and p = 0.030, respectively), which could be integrated with the TNM staging system to generate a predictive nomogram for patient outcomes.

CONCLUSION

Infiltration of polarized TAMs, a novel identified independent prognostic factor, could be combined with the TNM stage to refine a risk stratification system and better stratify patients with different prognosis. Tipping TAMs to an antitumoral phenotype might be a promising therapeutic target for postoperative treatment.

Prognostic significance of EZH2 expression in patients with digestive cancers: a meta-analysis

BACKGROUND

Enhancer of zeste 2 (EZH2), a key component of polycomb repressive complex 2 (PRC2), was of great importance in human cancer pathogenesis. Various studies examined the relationship between EZH2 overexpression with the clinical outcome in patients with digestive cancers, but yielded inconsistent results.

METHODS

Electronic databases updated to January 2015 were searched to find relevant studies. A meta-analysis was conducted with eligible studies which quantitatively evaluated the relationship between EZH2 overexpression and survival of patients with digestive cancers. Survival data were aggregated and quantitatively analyzed.

RESULTS

We performed a meta-analysis of 10 studies (n = 1,461 patients) that evaluated the correlation between EZH2 overexpression and survival in patients with digestive cancers. Combined hazard ratios suggested that EZH2 overexpression was associated with poor prognosis of overall survival (HR = 1.54, 95% CI: 1.27-1.81) in patients with esophageal cancer. In the stratified analysis, no significantly risks were found among gastric cancer (HR = 0.66, 95% CI: 0.16-1.15) and colorectal cancer (HR = 0.91, 0.63-1.19), indicating EZH2 was not an indicator of poor prognosis in gastric cancer or colorectal cancer.

CONCLUSIONS

EZH2 overexpression indicates a poor prognosis for patients with esophageal cancer, but not among gastric cancer or colorectal cancer.

CXCL12 and CXCR4 as predictive biomarkers of glioma recurrence pattern after total resection

PURPOSE OF THE STUDY

Previous studies have shown that the pattern of recurrence for glioma is related to the direction of glioma cell invasion. Recent studies demonstrated that the CXCL12/CXCR4 signaling pathway mediates cellular invasion in glioma. Therefore, in this study, we investigated the possible relationship between CXCL12/CXCR4 expression and recurrence pattern in glioma.

PATIENTS AND METHODS

Immunohistochemical techniques were used to assess CXCL12/CXCR4 expression in 42 glioma tissues following total resection. According to magnetic resonance imaging (MRI) of gliomas, the recurrence pattern was classified as close or distant pattern. The relationship between recurrence pattern and CXCL12/CXCR4 expression were initially examined by Chi-squared analysis. The prognostic significance of CXCL12 and CXCR4 was determined by log-rank tests and COX proportional hazards model.

RESULTS

CXCL12 was expressed mainly in vascular endothelial cells and CXCR4 was expressed mainly in tumor cells. The recurrence pattern was significantly related to the expression level of CXCL12 in vascular endothelial cells (P=0.002) and CXCR4 in tumor cells (P=0.004). However, CXCL12 and CXCR4 were not independent prognostic factors for progression-free survival or overall survival in glioma patients.

CONCLUSION

The glioma recurrence pattern is related to CXCL12 expression levels in vascular endothelial cells and CXCR4 expression levels in tumor cells; thus, implicating the CXCL12/CXCR4 signaling pathway as a potential target for glioma therapy.

Prognostic value of long noncoding RNA HOTAIR in digestive system malignancies

BACKGROUND AND AIM

HOX transcript antisense intergenic RNA (HOTAIR), a well-known long noncoding RNA, has been found to play significant roles in several tumors. However, the clinical application value of HOTAIR in digestive system malignancies remains to be clarified. We aimed to explore comprehensively the potential role of HOTAIR as a prognostic indicator in digestive system malignancies.

METHODS

Systematic search was performed in Pubmed, Embase, Cochrane Library, and Web of Science until July 5, 2014. A quantitative meta-analysis was conducted with standard statistical methods for eligible papers on the prognostic value of HOTAIR in digestive system cancers.

RESULTS

A total of 1059 patients from 13 studies were included in the meta-analysis. A significant association was found between HOTAIR abundance and poor overall survival (OS) of patients with digestive system malignancies, with pooled hazard ratio (HR) of 2.587 (95% confidence interval [CI]: 2.054-3.259, P < 0.001). By combining HRs from Cox multivariate analyses, we found HOTAIR was an independent prognostic factor for OS without obvious heterogeneity (HR: 2.405, 95% CI: 1.883-3.0722, P < 0.001). Subgroup analysis showed that tumor type, histology type, region, publication year, sample size, and quality score did not alter the predictive value of HOTAIR as an independent factor for survival. Meta-regression and sensitivity analysis both suggested the reliability of our findings. A slight publication bias was observed. After adjustment by nonparametric "trim-and-fill" method, the corrected HRs had no significant change.

CONCLUSION

HOTAIR could be exploited as a novel prognostic biomarker for patients with digestive system malignancies.

Aberrant CCR4 expression is involved in tumor invasion of lymph node-negative human gastric cancer

Cellular chemotaxis is the best-known function of chemokine receptors which are closely linked with tumor metastasis. In fact, positive expression of chemokine receptors could also be identified even in some patients without metastatic tumors, while the clinical relevance of this data has not been fully established. Our studies were designed to clarify the CCR4 expression profiles and to explore its potential role in histologically node-negative (pN0) gastric cancer (GC). Immunohistochemistry (IHC) or immunohistofluorescence (IHF) analysis was performed on specimens obtained from 108 patients with pN0 GC. We found that CCR4 was aberrantly over-expressed inpN0 GC tissues, with different expression patterns on tumor cells and being associated with T-stage (P = 0.002). The matrigel in vitro invasion assay revealed that over-expression of CCR4 in GC cell lines significantly enhanced the invasive capacity of these cells. Results from real-time RT-PCR and gelatinzymography showed a significant increase in matrix metalloproteinase (MMP)-9 production induced by the forced expression of CCR4 in GC cell lines. Our data suggest that the aberrant CCR4 expression is involved in tumor invasion of pN0 GC and, conceivably, antagonists of CCR4 might be useful candidates for controlling early events in tumor progression.

Screening for candidate genes related to breast cancer with cDNA microarray analysis

Objective

The aim of this study was to reveal the exact changes during the occurrence of breast cancer to explore significant new and promising genes or factors related to this disease.

Methods

We compared the gene expression profiles of breast cancer tissues with its uninvolved normal breast tissues as controls using the cDNA microarray analysis in seven breast cancer patients. Further, one representative gene, named IFI30, was quantitatively analyzed by real-time PCR to confirm the result of the cDNA microarray analysis.

Results

A total of 427 genes were identified with significantly differential expression, 221 genes were up-regulated and 206 genes were down-regulated. And the result of cDNA microarray analysis was validated by detection of IFI30 mRNA level changes by real-time PCR. Genes for cell proliferation, cell cycle, cell division, mitosis, apoptosis, and immune response were enriched in the up-regulated genes, while genes for cell adhesion, proteolysis, and transport were significantly enriched in the down-regulated genes in breast cancer tissues compared with normal breast tissues by a gene ontology analysis.

Conclusion

Our present study revealed a range of differentially expressed genes between breast cancer tissues and normal breast tissues, and provide candidate genes for further study focusing on the pathogenesis and new biomarkers for breast cancer.

Prognostic value of stromal cell-derived factor 1 expression in patients with gastric cancer after surgical resection

Aberrant chemokine stromal cell-derived factor 1 (SDF-1) expression has been shown to be involved in the development and progression of various malignancies. Our present study aims to investigate the clinical and prognostic value of SDF-1 expression and improve risk stratification in patients with gastric cancer. Peritumoral and intratumoral SDF-1 levels were assessed in 220 retrospectively enrolled gastric cancer patients, and their relations with clinicopathological features and clinical outcomes were evaluated. A predictive nomogram was created to refine risk stratification for overall survival of gastric cancer patients. Compared with peritumor tissues, tumor tissues showed decreased SDF-1 expression levels according to TNM stage progression in gastric cancer specimens. Peritumoral SDF-1 expression correlated positively with tumor invasion depth and lymph node metastasis, whereas intratumoral SDF-1 expression associated negatively with tumor size, tumor differentiation, tumor invasion depth, lymph node metastasis, and clinical TNM stage. Moreover, both low peritumoral SDF-1 expression and high intratumoral SDF-1 expression indicated favorable overall survival, and SDF-1 risk derived from the peritumoral/intratumoral SDF-1 expression signature could stratify prognosis of patients with gastric cancer. After backward elimination, SDF-1 risk was identified as an independent prognostic factor for survival. Finally, a predictive nomogram was generated with identified independent prognosticators to assess patient survival at 3 and 5 years following surgery. Conclusively, SDF-1 risk, an identified independent prognostic factor, could be developed into a nomogram with tumor invasion depth, lymph node involvement, and distant metastasis to refine predictive accuracy for survival in patients with gastric cancer after surgical resection.

Inflammation-related factors predicting prognosis of gastric cancer

Gastric cancer (GC), which is mainly induced by Helicobacter pylori (H. pylori) infection, is one of the leading causes of cancer-related death in the developing world. Active inflammation initiated by H. pylori infection and maintained by inherent immune disorders promotes carcinogenesis and postoperative recurrence. However, the presence with H. pylori in tumors has been linked to a better prognosis, possibly due to the induction of antitumor immunity. Tumor infiltrations of tumor-associated macrophages, myeloid-derived suppressor cells, neutrophils, Foxp3⁺ regulatory T cells are correlated with poor prognosis. Tumor infiltrating CD8⁺ cytotoxic T lymphocytes, dendritic cells, and CD45RO T cells are generally associated with good prognosis of GC, although some subsets of these immune cells have inverse prognosis prediction values. High ratios of Foxp3⁺/CD4⁺ and Foxp3⁺/CD8⁺ in tumors are associated with a poor prognosis; whereas high Th1/Th2 ratio in tumors predicts a good prognosis. High levels of interleukin (IL)-6, IL-10, IL-32, and chemokine C-C motif ligands (CCL)7 and CCL21 in circulation, high expression of CXC chemokine receptor 4, chemokine C-C motif receptor (CCR)3, CCR4, CCR5, CCR7, hypoxia-inducible factor-1α, signal transducer activator of transcription-3, cyclooxygenase-2, and orphan nuclear receptor 4A2 in tumors are associated with an unfavorable prognosis. Increased serum levels of matrix metalloproteinases (MMP)-3, MMP-7, and MMP-11 and increased levels of MMP-9, MMP-12, and MMP-21 in tumors are consistently associated with poor survival of GC. Further emphasis should be put on the integration of these biomarkers and validation in large cohorts for personalized prediction of GC postoperative prognosis.

Clinical significance of polypeptide N-acetylgalactosaminyl transferase-5 (GalNAc-T5) expression in patients with gastric cancer

BACKGROUND

The family of polypeptide N-acetylgalactosaminyl transferases is responsible for the altered O-linked glycosylation occurring during the development of various cancers and their progression via altering O-glycan biosynthesis. Our studies were designed to investigate the expression and prognostic values of GalNAc-T5 and improve the risk stratification in patients with gastric cancer.

METHODS

Tissue samples from a training set and a validation set of patients with gastric adenocarcinoma from China were used for analyses. GalNAc-T5 expression was retrospectively analysed by immunohistochemistry. Results were assessed for association with clinicopathological parameters and overall survival by using Kaplan-Meier analysis. Prognostic values of GalNAc-T5 expression and clinical outcomes were evaluated by Cox regression analysis. A molecular prognostic stratification scheme incorporating GalNAc-T5 expression was determined by using receiver operating characteristic analysis.

RESULTS

GalNAc-T5 expression was markedly reduced in gastric cancer tissues compared with non-malignant gastric mucosa. Low intratumoral GalNAc-T5 density, which was associated with tumour cell differentiation, T classification, N classification, and TNM stage in the two independent sets, was an independent prognosticator for poor prognosis of gastric cancer patients. Applying the prognostic value of intratumoral GalNAc-T5 density to the conventional clinicopathologic TNM stage system showed a better prognostic value in patients with gastric cancer.

CONCLUSIONS

Intratumoral GalNAc-T5 expression was recognised as an independent prognostic marker for the overall survival of gastric cancer patients. Detection of GalNAc-T5 expression in gastric cancer tissues might add some prognostic information for patients with this disease and lead to a more accurate classification under the TNM stage system.

CXC chemokines and chemokine receptors in gastric cancer: From basic findings towards therapeutic targeting

Gastric cancer is the fourth most common cancer, and the second-highest cause of cancer-related deaths worldwide. Despite extensive research to identify novel diagnostic and therapeutic agents, patients with advanced gastric cancer suffer from a poor quality of life and poor prognosis, and treatment is dependent mainly on conventional cytotoxic chemotherapy. To improve the quality of life and survival of gastric cancer patients, a better understanding of the underlying molecular pathologies, and their application towards the development of novel targeted therapies, is urgently needed. Chemokines are a group of small proteins associated with cytoskeletal rearrangements, the directional migration of several cell types during development and physiology, and the host immune response via interactions with G-protein coupled receptors. There is also growing evidence to suggest that chemokines not only play a role in the immune system, but are also involved in the development and progression of tumors. In gastric cancer, CXC chemokines and chemokine receptors regulate the trafficking of cells in and out of the tumor microenvironment. CXC chemokines and their receptors can also directly influence tumorigenesis by modulating tumor transformation, survival, growth, invasion and metastasis, as well as indirectly by regulating angiogenesis, and tumor-leukocyte interactions. In this review, we will focus on the roles of CXC chemokines and their receptors in the development, progression, and metastasis of gastric tumors, and discuss their therapeutic potential for gastric cancer.

Expression of CXCR4 and breast cancer prognosis: a systematic review and meta-analysis

Background

The chemokine receptor CXCR4 plays a significant role in biological processes, as well as in tumorigenesis and the progression of cancer, especially breast cancer. However, the clinical application of CXCR4 for breast cancer prognosis is still very limited. A meta-analysis based on published studies was performed with the aim of obtaining an accurate evaluation of the relationship between CXCR4 expression and the prognosis of breast cancer.

Methods

A comprehensive search strategy was used to search relevant literature in PubMed, MEDLINE and the ISI Web of Science. The correlation between CXCR4 expression and clinicopathological features and breast cancer prognosis was analyzed. This meta-analysis was carried out using Review Manager 4.2.

Result

Thirteen eligible studies consisting of 3865 participants were included. We found that breast cancers with CXCR4 expression were associated with lymph node status (pooled RR =1.20, 95% CI: 1.01-1.43, P<0.001) and distant metastasis (pooled RR =1.52, 95% CI: 1.17-1.98, P = 0.125). CXCR4 overexpression was significantly associated with disease free survival (DFS) (RR = 0.77, 95% CI = 0.70–0.86, P = 0.554) and overall survival (OS) (RR = 0.70, 95% CI = 0.59–0.83, P = 0.329). However, there was no significant association between CXCR4 expression and some clinical parameters of breast cancer, such as tumor category, ER status, PR status, or c-erbB-2 status.

Conclusion

Our meta-analysis showed that CXCR4 is an efficient prognostic factor for breast cancer. Overexpression of CXCR4 was significantly associated with lymph node status and distant metastasis and indicated poor overall and disease free survival.

CXCR4 as a novel predictive biomarker for metastasis and poor prognosis in colorectal cancer

The clinical significance of CXCR4 expression in colorectal cancer remains unclear. The aim of this study was to investigate the expression and regulatory effects of CXCR4 in colorectal cancer and the association between CXCR4 protein expression and prognosis. The mRNA and protein expression levels of CXCR4 were determined using reverse-transcriptase polymerase chain reaction and immunohistochemistry staining, respectively, and the relationship between the CXCR4 protein level and clinicopathological parameters was analyzed in 720 cases of colorectal cancer. CXCR4 expression was elevated in colorectal cancer tissues compared to pericancerous tissues (P = 0.001). Of the 720 enrolled cases, 208 (28.89%) expressed CXCR4. In univariate analysis, CXCR4 was found to be associated with lymph node metastasis, TNM stage, and liver metastasis (P = 0.001, 0.001, and 0.012, respectively). Further multivariate analysis suggested that histological grade, TNM stage, and CXCR4 expression were related to liver metastasis (P = 0.020, 0.01, and 0.001, respectively). In the Cox regression test, the histological grade, lymph node metastasis, TNM stage, liver metastasis, and CXCR4 expression were found to be independent prognostic factors (P = 0.02, 0.045, 0.01, 0.001, and 0.001, respectively). CXCR4 protein may be a potential biomarker for liver metastasis and an independent marker for survival in colorectal cancer.