Human macrophage metalloelastase correlates with angiogenesis and prognosis of gastric carcinoma

Prognostic prediction and immune infiltration analysis based on lysosome and senescence state identifies MMP12 as a novel therapy target in gastric cancer

BACKGROUND AND AIMS

As humans undergo the aging process, they become more vulnerable to various types of cancers, including gastric cancer (GC), which is frequently associated with aging. The senescent phenotype is closely linked to lysosomes, but research on the combined impact of senescence and lysosomes on GC prognosis is scarce.

METHODS

To construct and validate a prognostic model for gastric cancer (GC), we obtained gene expression and clinical data of GC patients from Cancer Genome Atlas (TCGA) databases. We employed Least Absolute Shrinkage and Selection Operator (LASSO) Cox regression for model construction and ConsensusClusterPlus R package for generating cluster heatmaps. The model's predictive ability was evaluated through Kaplan-Meier survival analysis and ROC curve analysis. Our analysis included an assessment of the senescence and lysosome state using expression profiles and immune infiltration analysis through CIBERSORT methods. Finally, we validated potential gene targets through cellular experiments.

RESULTS

"In this research, we discovered two subtypes of gastric cancer (GC), Cluster 1 and Cluster 2. These subtypes are characterized by the presence of lysosomes and senescence, and we have identified distinct molecular features unique to each subtype. We observed that Cluster 2 had a lower survival prognosis compared to Cluster 1. Additionally, we have developed a risk prediction model that takes into consideration the presence of lysosomes and senescence. Patients in the high-risk group, as predicted by our model, experienced shorter survival times. Further analysis included immune infiltration, immune checkpoint, and chemotherapy evaluation of GC patients. We have displayed the frequency of mutations and copy number variations (CNVs) in visual formats. Our cellular experiments demonstrated that the MMP12 gene serves as a protective factor in GC cells."

CONCLUSIONS

In conclusion, we have clarified the extensive relationship between lysosomes and senescence in GC and developed a risk signature to forecast the prognosis of GC patients. MMP12 could be a promising protective factor for GC patients and might present a novel concept for anticipating the efficacy of targeted therapies and immunotherapies in GC patients.

Matrix Metalloproteinases Inhibitors in Cancer Treatment: An Updated Review (2013-2023)

Matrix metalloproteinases (MMPs) are identifiable members of proteolytic enzymes that can degrade a wide range of proteins in the extracellular matrix (ECM). MMPs can be categorized into six groups based on their substrate specificity and structural differences: collagenases, gelatinases, stromelysins, matrilysins, metalloelastase, and membrane-type MMPs. MMPs have been linked to a wide variety of biological processes, such as cell transformation and carcinogenesis. Over time, MMPs have been evaluated for their role in cancer progression, migration, and metastasis. Accordingly, various MMPs have become attractive therapeutic targets for anticancer drug development. The first generations of broad-spectrum MMP inhibitors displayed effective inhibitory activities but failed in clinical trials due to poor selectivity. Thanks to the evolution of X-ray crystallography, NMR analysis, and homology modeling studies, it has been possible to characterize the active sites of various MMPs and, consequently, to develop more selective, second-generation MMP inhibitors. In this review, we summarize the computational and synthesis approaches used in the development of MMP inhibitors and their evaluation as potential anticancer agents.

Prognostic and clinicopathological significance of MMP12 in various cancers: a meta-analysis and bioinformatics analysis

Background: Cancer is one of the top causes of mortality worldwide. The matrix metalloproteinase MMP12 is highly expressed in some cancers, but there is a lack of meta-analyses proving the correlation between MMP12 and cancer. Materials & methods: A literature search was performed using Web of Science, PubMed and other databases. Quantitative meta-analysis of the data was carried out. The Cancer Genome Atlas was further used to validate our results. Results: High MMP12 expression was associated with poorer overall survival and poorer 5-year overall survival. Elevated expression of MMP12 predicted shorter overall survival in six cancers and worse disease-free survival in four malignancies based on validation using the Gene Expression Profiling Interactive Analysis online analysis tool. Conclusion: Elevated MMP12 expression is likely a marker of poor prognosis in various cancers.

The Regulatory Network of Gastric Cancer Pathogenesis and Its Potential Therapeutic Active Ingredients of Traditional Chinese Medicine Based on Bioinformatics, Molecular Docking, and Molecular Dynamics Simulation

Objective. This study aims to investigate the functional gene network in gastric carcinogenesis by using bioinformatics; besides, the diagnostic utility of key genes and potential active ingredients of traditional Chinese medicine (TCM) for treatment in gastric cancer have been explored. Methods. The Cancer Genome Atlas and Gene Expression Omnibus databases have been applied to analyze the differentially expressed genes (DEGs) between gastric cancer and normal gastric tissues. Then, the DEGs underwent Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses using the Metascape database. The STRING database and the Cytoscape software were utilized for the protein-protein interaction network of DEGs and hub genes screening. Furthermore, survival and expression analyses of hub genes were conducted using Gene Expression Profiling Interactive Analysis and Human Protein Atlas databases. By using the Comparative Toxicogenomics Database, the hub genes interconnected with active ingredients of TCM were analyzed to provide potential information for the treatment of gastric cancer. After the molecular docking of the active ingredients of TCM to specific hub gene receptor proteins, the molecular dynamics simulation GROMACS was applied to validate the conformation of the strongest binding ability in the molecular docking. Results. A total of 291 significant DEGs were found, from which 12 hub genes were screened out. Among these hub genes, the expressions of five hub genes including COL1A1, COL5A2, MMP12, SERPINE1, and VCAN were significantly correlated with the overall survival. Furthermore, four potential therapeutic active ingredients of TCM were acquired, including quercetin, resveratrol, emodin, and schizandrin B. In addition, the molecular docking results exhibited that the active ingredients of TCM formed stable binding with the hub gene targets. SERPINE1 (3UT3)-Emodin and COL1A1 (7DV6)-Quercetin were subjected to molecular dynamics simulations as conformations of continuing research significance, and both were found to be stably bound as a result of the interaction of van der Waals potentials, electrostatic, and hydrogen bonding. Conclusion. Our findings may provide novel insights and references for the screening of biomarkers, the prognostic evaluation, and the identification of potential active ingredients of TCM for gastric cancer treatment.

Overexpression of the nucleoporin Nup88 stimulates migration and invasion of HeLa cells

Elevated expression of the nucleoporin Nup88, a constituent of the nuclear pore complex, is seen in various types of malignant tumors, but whether this overexpression contributes to the malignant phenotype has yet to be determined. Here, we investigated the effect of the overexpression of Nup88 on the migration and invasion of cervical cancer HeLa cells. The overexpression of Nup88 promoted a slight but significant increase in both migration and invasion, whereas knockdown of Nup88 by RNA interference suppressed these phenotypes. The observed phenotypes in Nup88-overexpressing HeLa cells were not due to the progression of the epithelial-to-mesenchymal transition or activation of NF-κB, which are known to be important for cell migration and invasion. Instead, we identified an upregulation of matrix metalloproteinase-12 (MMP-12) at both the gene and protein levels in Nup88-overexpressing HeLa cells. Upregulation of MMP-12 protein by the overexpression of Nup88 was also observed in one other cervical cancer cell line and two prostate cancer cell lines but not 293 cells. Treatment with a selective inhibitor against MMP-12 enzymatic activity significantly suppressed the invasive ability of HeLa cells induced by Nup88 overexpression. Taken together, our results suggest that overexpression of Nup88 can stimulate malignant phenotypes including invasive ability, which is promoted by MMP-12 expression.

Transcriptomic and microRNA Expression Profiles Identify Biomarkers for Predicting Neo-Chemoradiotherapy Response in Esophageal Squamous Cell Carcinomas (ESCC)

Neo-chemoradiotherapy (nCRT) before surgery is a standard treatment for locally advanced esophageal cancers. However, the treatment outcome of nCRT varied with different patients. This study aimed to identify potential biomarkers for prediction of nCRT-response in patients with esophageal squamous cell carcinoma (ESCC). Microarray datasets of nCRT responder and non-responder samples (access number GSE45670 and GSE59974) of patients with ESCC were downloaded from Gene Expression Omnibus (GEO) database. The mRNA expression profiles of cancer biopsies from four ESCC patients were analyzed before and after nCRT. Differentially expressed genes (DEGs) and miRNAs were screened between nCRT responder and non-responder ESCC samples. Functional enrichment analysis was conducted for these DEGs followed by construction of protein-protein interaction (PPI) network and miRNA-mRNA regulatory network. Finally, univariate survival analysis was performed to identify candidate biomarkers with prognostic values in ESCC. We identified numerous DEGs and differentially expressed miRNAs from nCRT responder group. GO and KEGG analysis showed that the dysregulated genes were mainly involved in biological processes and pathways, including "response to stimulus", "cellular response to organic substance", "regulation of signal transduction", "AGE-RAGE signaling pathway in diabetic complications", and "steroid hormone biosynthesis". After integration of PPI network and miRNA-mRNA network analysis, we found eight genes, TNF, AKR1C1, AKR1C2, ICAM1, GPR68, GNB4, SERPINE1 and MMP12, could be candidate genes associated with disease progression. Univariate cox regression analysis showed that there was no significant correlation between dysregulated miRNAs (such as hsa-miR-34b-3p, hsa-miR-127-5p, hsa-miR-144-3p, and hsa-miR-486-5p, et al.) and overall survival of ESCC patients. Moreover, abnormal expression of MMP12 was significantly correlated with pathological degree, TNM stage, lymph nodes metastasis, and overall survival of ESCC patients (p < 0.05). Taken together, our study identified that MMP12 might be a useful tumor biomarker and therapeutic target for ESCC.

TNM staging for GIT cancers is correlated with the level of MMPs and TGF-β1

Gastrointestinal (GIT) cancers represent the third common cancers worldwide, characterized by rapid progression and higher mortality rate. Matrix metalloproteinases (MMPs) play an important role in cancer metastases. The present study was conducted to estimate and evaluate the role of MMP-7, -9, -10 and -12 and TGF β1 along with conventional biomarkers (CEA and CA19-9) in gastric (GC), pancreatic (PC) and colorectal cancer (CRC) staging system according to tumor size (T), included lymph node (N) and metastasis (M). Seventy-five patients were divided into GC group (n = 25), PC group (n = 25), CRC group (n = 25) and twenty-five healthy subjects (control group). Serum levels of MMP-7, -10 and -12 were assayed simultaneously using luminex multiplex technique. Also, MMP-9, TGF-β1, CA19-9 and CEA were determined by ELISA. MMP-7,-9,-10, -12, TGF-β1 and CEA levels were significantly (p < 0.001) higher in GIT cancer groups compared with control. CA19-9 was significantly (p < 0.001) higher in PC and CRC groups compared with control. MMP-9 was positively correlated with TNM staging in PC patients. MMP-12 was negatively correlated with T in PC and positively correlated with M in CRC group. CA 19-9 was positively correlated with M grade in CRC. Depending on the estimated cutoff values of area under receiver curve; CA19-9 and MMP-7 were excellent diagnostic markers in PC, CEA and MMP-7 were excellent in CRC, and MMP-7 and MMP-9 were excellent in GC. Our findings indicated the clinical utility of MMPs in diagnosis and TNM staging of GIT cancers along with CEA and CA19-9.

Matrix metalloproteinase 12 expression is associated with tumor FOXP3+ regulatory T cell infiltration and poor prognosis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is among the most fatal types of cancer worldwide due to its high rates of recurrence and metastasis. The molecular processes involved in HCC progression require further investigation to identify biomarkers for use in diagnosis and treatment. In the present study, the significance and prognostic value of matrix metallopeptidase 12 (MMP12) expression in human HCC was investigated. MMP12 mRNA expression was investigated using reverse transcription-quantitative polymerase chain reaction analysis of 42 pairs of tumor and non-tumor liver tissues obtained from patients with HCC following surgical treatment. Immunohistochemical staining was used to detect MMP12 and forkhead box P3 (FOXP3) expression in 158 paraffin-embedded HCC tissues. The prognostic value of MMP12 expression was determined using Kaplan-Meier analysis and the Cox proportional hazards model. MMP12 mRNA levels were significantly higher in liver tumor tissues compared with matched non-tumor liver tissues. MMP12 expression and FOXP3⁺ regulatory T cell (Treg) infiltration was positively correlated (r=0.302; P<0.001). MMP12 protein overexpression was positively correlated with tumor size (P=0.018), high serum alpha-fetoprotein levels (P=0.005) and poor overall survival time (P=0.012) in patients with HCC. Furthermore, MMP12 protein level was an independent predictive factor for overall survival time of patients with HCC who underwent curative resection. In conclusion, these results suggest that MMP12 may increase FOXP3⁺ Treg infiltration into tumor tissues, and promote tumor progression and immune evasion of HCC. The overexpression of MMP12 protein is, therefore, a valuable prognostic indicator in patients with HCC.

Gamma-secretase-independent role for cadherin-11 in neurotrophin receptor p75 (p75(NTR)) mediated glioblastoma cell migration

The p75 neurotrophin receptor (p75(NTR)) undergoes γ-secretase-mediated regulated intramembrane proteolysis and is involved in glioblastoma cell migration and invasion. Consistent with previous reports, in this study we show that p75NTR increases U87-MG glioblastoma cell migration, which is reversed by inhibition of γ-secretase activity. However, we show that expression or stabilization of the γ-secretase-generated p75(NTR) intracellular domain (ICD) is not sufficient to induce U87-MG glioblastoma cell migration, and that exogenous expression of p75(NTR) ICD inhibits p75(NTR)-mediated glioblastoma cell (U87-MG and U373-MG) migration. To identify pathways and to determine how p75(NTR) mediates glioblastoma migration we utilized a microarray approach to assess differential gene expression profiles between parental U87-MG and cells stably expressing wild-type p75(NTR), a γ-secretase cleavage-resistant chimeric p75(NTR) mutant (p75FasTM) and the γ-secretase-generated p75(NTR)-ICD, which mimics constitutively cleaved p75(NTR) receptor. In our microarray data analysis we identified a subset of genes that were constitutively up-regulated in wild-type p75(NTR) cells, which were also repressed in p75(NTR) ICD expressing cells. Furthermore, our data revealed among the many differentially expressed genes, cadherin-11 (Cdh-11), matrix metalloproteinase 12 and relaxin/insulin-like family peptide receptor 2 as constitutively up-regulated in wild-type p75(NTR) cells, independent of γ-secretase activity. Consistent with a role in glioblastoma migration, we found that U87-p75(NTR) cells express higher levels of Cdh-11 protein and that siRNA-mediated knockdown of Cdh-11 resulted in a significant decrease in p75(NTR)-mediated glioblastoma cell migration. Therefore, we hypothesize that p75(NTR) can impact U87-MG glioblastoma cell migration in a γ-secretase-independent manner through modulation of specific genes, including Cdh-11, and that both γ-secretase-independent and -dependent mechanisms are involved in p75(NTR)-mediated U87-MG glioblastoma cell migration.

Melanoma cell therapy: Endothelial progenitor cells as shuttle of the MMP12 uPAR-degrading enzyme

The receptor for the urokinase-type plasminogen activator (uPAR) accounts for many features of cancer progression, and is therefore considered a target for anti-tumoral therapy. Only full length uPAR mediates tumor progression. Matrix-metallo-proteinase-12 (MMP12)-dependent uPAR cleavage results into the loss of invasion properties and angiogenesis. MMP12 can be employed in the field of “targeted therapies” as a biological drug to be delivered directly in patient's tumor mass. Endothelial Progenitor Cells (EPCs) are selectively recruited within the tumor and could be used as cellular vehicles for delivering anti-cancer molecules. The aim of our study is to inhibit cancer progression by engeneering ECFCs, a subset of EPC, with a lentivirus encoding the anti-tumor uPAR-degrading enzyme MMP12. Ex vivo manipulated ECFCs lost the capacity to perform capillary morphogenesis and acquired the anti-tumor and anti-angiogenetic activity. In vivo MMP12-engineered ECFCs cleaved uPAR within the tumor mass and strongly inhibited tumor growth, tumor angiogenesis and development of lung metastasis.

The possibility to exploit tumor homing and activity of autologous MMP12-engineered ECFCs represents a novel way to combat melanoma by a “personalized therapy”, without rejection risk.

The i.v. injection of radiolabelled MMP12-ECFCs can thus provide a new theranostic approach to control melanoma progression and metastasis.

Fluid shear promotes chondrosarcoma cell invasion by activating matrix metalloproteinase 12 via IGF-2 and VEGF signaling pathways

Interstitial fluid flow in and around the tumor tissue is a physiologically relevant mechanical signal that regulates intracellular signaling pathways throughout the tumor. Yet, the effects of interstitial flow and associated fluid shear stress on the tumor cell function have been largely overlooked. Using in vitro bioengineering models in conjunction with molecular cell biology tools, we found that fluid shear (2 dyn/cm(2)) markedly upregulates matrix metalloproteinase 12 (MMP-12) expression and its activity in human chondrosarcoma cells. MMP-12 expression is induced in human chondrocytes during malignant transformation. However, the signaling pathway regulating MMP-12 expression and its potential role in human chondrosarcoma cell invasion and metastasis have yet to be delineated. We discovered that fluid shear stress induces the synthesis of insulin growth factor-2 (IGF-2) and vascular endothelial growth factor (VEGF) B and D, which in turn transactivate MMP-12 via PI3-K, p38 and JNK signaling pathways. IGF-2-, VEGF-B- or VEGF-D-stimulated chondrosarcoma cells display markedly higher migratory and invasive potentials in vitro, which are blocked by inhibiting MMP-12, PI3-K, p38 or JNK activity. Moreover, recombinant human MMP-12 or MMP-12 overexpression can potentiate chondrosarcoma cell invasion in vitro and the lung colonization in vivo. By reconstructing and delineating the signaling pathway regulating MMP-12 activation, potential therapeutic strategies that interfere with chondrosarcoma cell invasion may be identified.

Gonadotropin stimulation in mice leads to ovarian accumulation of immature myeloid cells and altered expression of proangiogenic genes

OBJECTIVE

Ovarian hyperstimulation syndrome is associated with increased angiogenesis and vascular leakage. Immature myeloid cells (IMCs) and dendritic cells have been shown to be actively involved in angiogenesis in several disease models in mice and humans. Nevertheless, little is known about the role of these cells in the ovary. As such, this study sought to determine whether alterations in these ovarian myeloid cell populations are associated with gonadotropin stimulation in a mouse model.

STUDY DESIGN

Four-week-old pre-pubertal C57Bl/6 female mice were allocated into three groups: high-dose stimulation (n=4; pregnant mare serum gonadotropins (PMSG) 20U for 2 days), low-dose stimulation (n=5; PMSG 5U for 1 day) and sham-treated controls (n=4). Human chorionic gonadotropin 5U was injected on Day 3, and the mice were killed on Day 5. Ovaries were analysed by flow cytometry, confocal microscopy and quantitative polymerase chain reaction.

RESULTS

Gonadotropin stimulation increased the proportion of CD11b(+)Gr1(+) IMCs among the ovarian myeloid cells: 22.6±8.1% (high dose), 7.2±1.6% (low dose) and 4.1±0.3% (control) (p=0.02). Conversely, gonadotropin stimulation decreased the proportion of ovarian CD11c(+)MHCII(+) dendritic cells: 15.1±1.9% (high dose), 20.7±4.8% (low dose) and 27.3±8.2% (control) (p=0.02). IMCs, unlike dendritic cells, were localized adjacent to PECAM1(+) endothelial cells. Finally, gonadotropin stimulation was associated with increased expression of S100A8, S100A9, Vcan and Dmbt1, and decreased expression of MMP12.

CONCLUSIONS

Gonadotropin stimulation is associated with proangiogenic myeloid cell alterations, reflected by a dose-dependent increase in ovarian IMCs and a parallel decrease in dendritic cells. Recruited IMCs localize strategically at sites of angiogenesis. These changes are associated with differential expression of key proangiogenic genes.

Strain variation in response to lung ischemia: role of MMP-12

Background

Systemic neovascularization of the lung during chronic ischemia has been observed in all mammals studied. However, the proteins that orchestrate the complex interaction of new vessel growth and tunneling through lung tissue matrix have not been described. Although previous work has demonstrated the CXC chemokines are essential growth factors in the process of angiogenesis in mice and rats, key matrix proteins have not been identified.

Methods

Since the degradation of chemokines has been shown to be dependent on metalloproteinases (MMP), we first surveyed gene expression patterns (real time RT-PCR) of several lung matrix proteins in DBA/J (D2) mice and C57Bl/6 (B6) mice, strains known to have divergent parenchymal responses in other lung disease models. We studied changes in the time course of MMP-12 activity in D2 and B6 mice. Functional angiogenesis was determined 14 days after the onset of complete left lung ischemia induced by left pulmonary artery ligation (LPAL), using fluorescent microspheres.

Results

Our results confirmed higher levels of MMP-12 gene expression in D2 mice relative to B6, which corresponded to a phenotype of minimal systemic angiogenesis in D2 mice and more robust angiogenesis in B6 mice (p < 0.01). MMP-12 activity decreased over the course of 14 days in B6 mice whereas it increased in D2 mice (p < 0.05). MMP-12 was associated largely with cells expressing the macrophage marker F4/80. Genetic deficiency of MMP-12 resulted in significantly enhanced neovascularization (p < 0.01 from B6).

Conclusion

Taken together, our results suggest macrophage-derived MMP-12 contributes to angiostasis in the ischemic lung.

Expression of matrix metalloproteinase-12 is correlated with extracapsular spread of tumor from nodes with metastasis in head and neck squamous cell carcinoma

Matrix metalloproteinases (MMPs) play an important role in tumor invasiveness and metastasis. The aim of this study was to investigate the expression pattern of MMPs in the primary tumor of head and neck squamous cell carcinomas (HNSCC) with cervical node metastasis and to correlate the expression of MMP in the primary tumor with the presence of extracapsular spread (ECS) in nodes with metastasis. A retrospective study was conducted. Paraffin blocks were obtained from 40 HNSCC patients with cervical node metastasis who underwent surgery as an initial treatment between 2004 and 2011. Expressions of MMP-2, MMP-3, MMP-12, and MMP-14 were investigated immunohistochemically. MMP-2, MMP-3, MMP-12, and MMP-14 were expressed in 27, 47.5, 55, and 57.5 % of cases, respectively. MMP-12 expression was found to be significantly associated with ECS and correlated with nodal metastasis (p = 0.024, 0.011). No relation was found between MMP expression and survival. MMP-12 expressed in the primary tumor is a molecular marker that may be useful for predicting ECS in HNSCC patients with metastatic nodal disease.

Effects of macrophage metalloelastase on the basic fibroblast growth factor expression and tumor angiogenesis in murine colon cancer

BACKGROUND AND AIM

Previous studies have shown that overexpression of macrophage metalloelastase (MME) suppresses tumor growth in mice. The purpose of this study was to investigate the effects of MME on basic fibroblast growth factor (bFGF) expression and tumor angiogenesis in murine colon cancer.

METHODS

Murine CT-26 colon cancer cells stably transfected with MME were inoculated subcutaneously. Reverse-transcriptase polymerase chain reaction (RT-PCR), immunoblotting, and immunohistochemistry were used to explore the bFGF mRNA and protein expression. Immunohistochemical staining of CD34 was used to measure the microvessel density (MVD).

RESULTS

bFGF mRNA levels in tumor tissues of CT-26-EGFP and nontransfected cells were respectively 2.7-fold (0.56 ± 0.063 vs. 0.21 ± 0.042) and 2.5-fold (0.53 ± 0.066 vs. 0.21 ± 0.042) higher than that in tumors of CT-26-EGFP-MME cells (p < 0.01). bFGF protein levels exhibited a similar trend. Tumors of CT-26-EGFP-MME cells demonstrated a lower microvessel density (9.35 ± 2.79) than control tumors of CT-26-EGFP cells (22.85 ± 3.80) and nontransfected cells (23.45 ± 4.49) (p < 0.001).

CONCLUSIONS

We found that expression of MME inversely correlates with the expression of bFGF and tumor angiogenesis in a model of murine colon cancer. These data indicate that manipulation of MME expression could be a novel modality approach to colon cancer therapy.

Opposing roles of CXCR4 and CXCR7 in breast cancer metastasis

INTRODUCTION

CXCL12-CXCR4 signaling has been shown to play a role in breast cancer progression by enhancing tumor growth, angiogenesis, triggering cancer cell invasion in vitro, and guiding cancer cells to their sites of metastasis. However, CXCR7 also binds to CXCL12 and has been recently found to enhance lung and breast primary tumor growth, as well as metastasis formation. Our goal was to dissect the contributions of CXCR4 and CXCR7 to the different steps of metastasis - in vivo invasion, intravasation and metastasis formation.

METHODS

We overexpressed CXCR4, CXCR7 or both in the rat mammary adenocarcinoma cell line MTLn3. Stable expressors were used to form tumors in severe combined immunodeficiency (SCID) mice, and in vivo invasiveness, intravital motility, intravasation, and metastasis were measured.

RESULTS

We found that CXCR4 overexpression increased the chemotactic and invasive behavior of MTLn3 cells to CXCL12, both in vitro and in vivo, as well as in vivo motility and intravasation. CXCR7 overexpression enhanced primary tumor growth and angiogenesis (as indicated by microvessel density and VEGFA expression), but decreased in vivo invasion, intravasation, and metastasis formation. In vitro, expression of CXCR7 alone had no effect in chemotaxis or invasion to CXCL12. However, in the context of increased CXCR4 expression, CXCR7 enhanced chemotaxis to CXCL12 but decreased invasion in response to CXCL12 in vitro and in vivo and impaired CXCL12 stimulated matrix degradation. The changes in matrix degradation correlated with expression of matrix metalloproteinase 12 (MMP12).

CONCLUSIONS

We find that CXCR4 and CXCR7 play different roles in metastasis, with CXCR4 mediating breast cancer invasion and CXCR7 impairing invasion but enhancing primary tumor growth through angiogenesis.

Prognostic significance of vascular endothelial growth factor expression in gastric carcinoma: a meta-analysis

PURPOSE

The purpose of this study was to comprehensively and quantitatively summarize available evidences for the use of VEGF protein to evaluate the clinicopathological and prognostic role of VEGF expression in Asian patients with gastric cancer.

METHOD

Searches were applied to MEDLINE, EMBASE, and the Cochrane Library databases until June 2010, without language restrictions. A meta-analysis was performed to clarify the impact of VEGF expression on clinicopathological parameters or over survival (OS) in gastric cancer.

RESULTS

Our combined results showed that VEGF expression in Asian patients with gastric cancer was significantly higher in the case-control studies (1,194 patients and 1,618 controls) (odds ratio [OR] = 112.41, 95% confidence interval [CI] = 64.12-197.06). All the analyses estimated favored a stronger link between the high VEGF expression and the poor 5-year overall survival (1,236 patients) (risk ratio [RR] = 2.45, 95% CI = 2.11-2.83, P = 0.000). When stratifying the studies by the pathological variables, the depth of invasion (3,094 patients) (OR = 1.95, 95% CI = 1.40-2.71, P = 0.000), lymph node metastasis (3,240 patients) (OR = 1.82, 95% CI = 1.29-2.57, P = 0.001), distant metastasis (1,980 patients) (OR = 2.76, 95% CI = 1.22-6.25, P = 0.015), vascular invasion (1,803 patients) (OR = 2.61, 95% CI = 2.09-3.27, P = 0.000), and TNM stage (1,819 patients) (OR = 1.92, 95% CI = 1.57-2.36, P = 0.000) provided significant prognostic information.

CONCLUSION

Our results indicate that VEGF can potently predict the overall survival in Asian patients with gastric cancer. Importantly, VEGF may be converted from candidate to the routine clinical setting for clinicians to predict the outcome of single patient with gastric carcinoma.

Overexpression of matrix metalloproteinase-12 (MMP-12) correlates with poor prognosis of hepatocellular carcinoma

Tumour recurrence and metastasis are pressing issues of hepatocellular carcinoma (HCC) patients who receive surgical treatments. Matrix metalloproteinase-12 (MMP-12), previously identified from our animal model, is involved in tumour invasiveness of rat hepatoma. We aimed to investigate the significance and prognostic value of MMP-12 expression in human HCC. MMP-12 mRNA level of 139 pairs of tumour and non-tumour liver tissues of HCC patients after hepatectomy were investigated by quantitative real-time RT-PCR. MMP-12 mRNA was significantly elevated in tumour liver tissues of HCC patients compared to non-tumour and normal liver tissues. By comparing paired tumour and non-tumour liver tissues, MMP-12 mRNA was overexpressed in 58% of tumour tissue of HCC patients. Overexpression of MMP-12 mRNA was significantly correlated with presence of venous infiltration (p=0.004), high serum AFP level (p=0.012), early tumour recurrence (p=0.018) and poor overall survival (p=0.02) of HCC patients. Moreover, MMP-12 mRNA was an independent factor in predicting the 1- and 3-year overall survival of HCC patients after hepatectomy. Our data demonstrated that MMP-12 mRNA may be a valuable prognostic marker for both overall survival and tumour recurrence of HCC patients after liver resection.