Expression of the matrix metalloproteases 2, 14, 24, and 25 and tissue inhibitor 3 as potential molecular markers in advanced human gastric cancer

Salidroside inhibited the proliferation of gastric cancer cells through up-regulating tumor suppressor miR-1343-3p and down-regulating MAP3K6/MMP24 signal molecules

Salidroside inhibited the proliferation of cancer cell. Nevertheless, the mechanism has not been completely clarified. The purpose of the study is to explore the mechanisms of salidroside against gastric cancer. To analyze the changes of microRNA (miRNA) in gastric cancer cells under the treatment of salidroside, the miRNA expression was analyzed by using RNA-seq in cancer cells for 24 h after salidroside treatment. The differentially expressed miRNAs were clustered and their target genes were analyzed. Selected miRNA and target mRNA genes were further verified by q-PCR. The expressions of target genes in cancer cells were detected by immunohistochemistry. Cancer cell apoptotic index was significantly increased after salidroside treatment. The proliferation of gastric cancer cells were blocked at S-phase cell cycle. The expression of 44 miRNAs changed differentially after salidroside treatment in cancer cells. Bioinformatic analysis showed that there were 1384 target mRNAs corresponding to the differentially expressed miRNAs. Surprisingly, salidroside significantly up-regulated the expression of tumor suppressor miR-1343-3p, and down-regulated the expression of MAP3K6, STAT3 and MMP24-related genes. Salidroside suppressed the growth of gastric cancer by inducing the cancer cell apoptosis, arresting the cancer cell cycle and down-regulating the related signal transduction pathways. miRNAs are expressed differentially in gastric cancer cells after salidroside treatment, playing important roles in regulating proliferation and metastasis. Salidroside may suppress the growth of gastric cancer by up-regulating the expression of the tumor suppressor miR-1343-3p and down-regulating the expression of MAP3K6 and MMP24 signal molecules.

Elevated Plasma Levels of MT4-MMP and MT6-MMP; A New Observation in Patients with Thyroid Nodules

BACKGROUND

Based on the critical role of MT4-MMP and MT6-MMP in carcinogenesis, we focused on MT4-MMP and MT6-MMP circulating levels in patients with thyroid nodules.

METHODS

Plasma samples were collected from three groups, including papillary thyroid cancer (PTC; n=30), multinodular goiter (MNG; n=30), and healthy subjects (n=22). Enzyme-linked immunosorbent assay (ELISA) was used to obtain the concentration of MT4-MMP and MT6-MMP in the three groups.

RESULTS

Analysis of data demonstrated increased levels of MT4-MMP (PTC: 4.90±1.35, MNG: 4.89±1.37, and healthy: 3.13±1.42) and MT6-MMP (PTC: 8.29±2.50, MNG: 7.34±2.09, and healthy:5.01±2.13) in thyroid nodules by comparison with healthy subjects (P<0.05). There were no significant differences in the levels of the two MT-MMPs between PTC and MNG (P>0.05). Increased plasma levels of MT4-MMP (odds ratio=2.48; 95% CI: 1.46-4.19; P=0.001) or MT6-MMP (odds ratio=1.81; 95% CI: 1.29-2.53; P=0.001) were associated with increased risk of PTC tumorigenesis. Interestingly, a strong positive association was observed between MT4-MMP and MT6-MMP in the three groups (PTC: r=0.766**, P=0.000; MNG: r=0.856**, P=0.000; healthy r=0.947**, P=0.000). Areas under the ROC curve for MT4-MMP and MT6-MMP were 0.82 and 0.96, respectively. At the cutoff value>4.7 (ng/mL), MT4-MMP and MT6-MMP showed a sensitivity of 63.3% and 90.0%, respectively, with 100% specificity.

CONCLUSION

Our work has led us to imply that the higher levels of MT4-MMP and MT6-MMP are closely linked with both PTC and MNG tumorigenesis. They may probably promote the development of thyroid lesions; however, more research is needed to further clarify the current findings.

Role of non-coding RNA in immune microenvironment and anticancer therapy of gastric cancer

Gastric cancer remains one of the cancers with the highest mortality in the world; therefore, it is very important to investigate its pathogenesis to improve the prognosis of gastric cancer patients. Recently, noncoding RNAs have become a research hotspot in the field of oncology. These RNA molecules play complex roles in the regulation of tumor cells, immune cells, and the tumor microenvironment. Therefore, studying their ability to regulate the gastric cancer immune microenvironment will provide us with a better perspective to understand their potential role in anticancer therapy. In this review, we discuss the regulatory effects of several common noncoding RNAs on the immune microenvironment of gastric cancer and their prospects in anticancer therapy to provide some novel insight into the identification of valuable diagnostic markers and improving the prognosis of gastric cancer patients.

OSgc: A Web Portal to Assess the Performance of Prognostic Biomarkers in Gastric Cancer

Evaluating the prognostic value of genes of interest in different populations of gastric cancer (GC) is difficult and time-consuming for basic and translational researchers even though many datasets are available in public dataset depositories. In the current study, we developed a robust web-based portal called OSgc (Online consensus Survival analysis of gastric cancer) that enables easy and swift verification of known and novel biomarker candidates in GC. OSgc is composed of gene expression profiling data and clinical follow-up information of 1,824 clinical GC cases, which are collected from 7 public independent datasets derived from Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA). By OSgc, users input the official gene symbol and will promptly retrieve the Kaplan-Meier survival plot with hazard ratio (HR) and log rank p value on the output webpage, by which users could assess the prognostic value of interesting genes for GC patients. Five survival end points containing overall survival, progression-free survival, progression-free interval, relapse-free survival, and disease-free survival could be measured in OSgc. OSgc can greatly help cancer biologists and clinicians to explore the effect of gene expression on patient survival. OSgc is freely available without restrictions at http://bioinfo.henu.edu.cn/GC/GCList.jsp.

Loss of REST in breast cancer promotes tumor progression through estrogen sensitization, MMP24 and CEMIP overexpression

BACKGROUND

Breast cancer is the most common malignancy in women, and is both pathologically and genetically heterogeneous, making early detection and treatment difficult. A subset of breast cancers express normal levels of REST (repressor element 1 silencing transcription factor) mRNA but lack functional REST protein. Loss of REST function is seen in ~ 20% of breast cancers and is associated with a more aggressive phenotype and poor prognosis. Despite the frequent loss of REST, little is known about the role of REST in the molecular pathogenesis of breast cancer.

METHODS

TCGA data was analyzed for the expression of REST target genes in breast cancer patient samples. We then utilized gene knockdown in MCF-7 cells in the presence or absence of steroid hormones estrogen and/ progesterone followed by RNA sequencing, as well as chromatin immunoprecipitation and PCR in an attempt to understand the tumor suppressor role of REST in breast cancer.

RESULTS

We show that REST directly regulates CEMIP (cell migration-inducing and hyaluronan-binding protein, KIAA1199) and MMP24 (matrix metallopeptidase 24), genes known to have roles in invasion and metastasis. REST knockdown in breast cancer cells leads to significant upregulation of CEMIP and MMP24. In addition, we found REST binds to RE-1 sites (repressor element-1) within the genes and influences their transcription. Furthermore, we found that the estrogen receptor (ESR1) signaling pathway is activated in the absence of REST, regardless of hormone treatment.

CONCLUSIONS

We demonstrate a critical role for the loss of REST in aggressive breast cancer pathogenesis and provide evidence for REST as an important diagnostic marker for personalized treatment plans.

Role of serum matrix metalloproteinase in the diagnosis of gastric cancer

Objective

To determine the clinical value of a matrix metalloproteinase (MMP) antibody array in diagnosing gastric cancer (GC).

Methods

In this prospective study, serum samples of patients with GC (n=66) and non-neoplastic gastric disease (NGD; n=34) were collected between November 2017 and July 2018. The quantitative measurement of 10 MMP-related proteins was done using MMP arrays and compared between the two groups.

Results

The serum levels of MMPs 3, 8, 9 and tissue inhibitor of metalloproteinases (TIMPs) 1 and 2 were significantly higher in the GC group than in the NGD group (p<0.05). The area under curve (AUC) of the 10 MMP proteins for the diagnosis of GC varied between 0.500 and 0.658. The total AUC of all MMPs was 0.897 (95% CI: 0.837-0.957). The total AUC of the five MMPs (MMPs 3, 8, 9, and TIMPs 1 and 2) was 0.821 (95% CI: 0.733-0.909) for diagnosing GC. Also, the 10-factor and 5-factor predictive models had good diagnostic ability for early GC with an AUC of 0.865 (95% CI: 0.753-0.977) and 0.749 (95% CI: 0.600-0.898), respectively.

Conclusions

The detection of multiple serum MMPs with protein biochip technology is promising to be used as a novel non-invasive tool for facilitating early diagnosis or screening of GC.

Role of extra cellular proteins in gastric cancer progression and metastasis: an update

Background

Gastric cancer (GC) is one of the most common cancers in the world with a high ratio of mortality. Regarding the late diagnosis, there is a high ratio of distant metastasis among GC cases. Despite the recent progresses in therapeutic modalities, there is not still an efficient therapeutic method to increase survival rate of metastatic GC cases.

Main body

Apart from the various intracellular signaling pathways which are involved in tumor cell migration and metastasis, the local microenvironment is also a critical regulator of tumor cell migration. Indeed, the intracellular signaling pathways also exert their final metastatic roles through regulation of extra cellular matrix (ECM). Therefore, it is required to assess the role of extra cellular components in biology of GC.

Conclusion

In the present review, we summarize 48 of the significant ECM components including 17 ECM modifying enzymes, seven extracellular angiogenic factors, 13 cell adhesion and cytoskeletal organizers, seven matricellular proteins and growth factors, and four proteoglycans and extra cellular glycoproteins. This review paves the way of determination of a specific extra cellular diagnostic and prognostic panel marker for the GC patients.

LCN2-interacting proteins and their expression patterns in brain tumors

Lipocalin 2 (LCN2) is a member of the lipocalin family. Elevated expression of LCN2 has been observed in many human tumors, suggesting it might be a potential biomarker and/or therapeutic target in malignancies. In this study, we aimed to explore LCN2 interacting proteins through bioinformatics, as well as their biological functions. Protein-protein interaction networks (PPIN) were constructed using LCN2 and its interacting proteins as the core node. These PPINs were scale free biological networks in which LCN2 and its interacting proteins could connect or cross-talk with at least one partner protein. Both functional and KEGG pathway enrichment analyses identified the known and potential biological functions of the PPIN, such as cell migration and cancer-related pathways. Expression levels of the PPIN proteins, as well as their expression correlations, in five types of brain tumor, were analyzed and integrated into the PPIN to illustrate a dynamic change. A significant correlation was found between the survival time of glioblastoma patients and the expression level of 10 genes (LCN2, MMP9, MMP2, PDE4DIP, L2HGDH, HNRNPA1, DDX31, LOXL2, FAM60A and RNF25). Taken together, our results suggest that LCN2 and its interacting proteins are mostly differentially expressed and have a distinguishing co-expression pattern. They might promote proliferation and migration via cell migration signaling and cancer-related pathways. LCN2 and its interacting proteins might be potential biomarkers in glioblastoma.

High tissue MMP14 expression predicts worse survival in gastric cancer, particularly with a low PROX1

Matrix metalloproteinase 14 (MMP14), a membrane-associated matrix metalloproteinase, has been shown to influence the invasion and metastasis of several solid tumors. Prospero homeobox protein 1 (PROX1), involved in the development and cell fate determination, is also expressed in malignant diseases functioning either as a tumor-suppressing or oncogenic factor. In certain cancers PROX1 appears to transcriptionally suppress MMP14 expression. This study, therefore, aimed to explore the association between MMP14 and PROX1 and understand their potential as prognostic biomarkers in gastric cancer. The cohort consisted of 313 individuals operated for gastric adenocarcinoma between 2000 and 2009 in the Department of Surgery, Helsinki University Hospital. MMP14 and PROX1 expressions were studied using immunohistochemistry in the patient sample and using immunoblotting and immunofluorescence in gastric cancer cell lines. We generated survival curves using the Kaplan-Meier method, determining significance via the log-rank test. A high MMP14 expression associated with being ≥67 years (P = .041), while a positive nuclear PROX1 expression associated with tumors of a diffuse histological type (P = .041) and a high cytoplasmic PROX1 expression (P < .001). Five-year disease-specific survival among patients with a high MMP14 expression was 35.9% (95% confidence interval [CI] 24.9-46.9), compared to 45.3% (95% CI 38.0-52.6) for patients with a low MMP14 (P = .030). Survival was worse specifically among those with a high MMP14 and absent nuclear PROX1 expression (hazard ratio [HR] 1.65; 95% CI 1.09-2.51; P = .019). Thus, this study confirms that a high MMP14 expression predicts a worse survival in gastric cancer, revealing for the first time that survival is particularly worse when PROX1 is low.

The Role of MMP8 in Cancer: A Systematic Review

Matrix metalloproteinases (MMPs) have traditionally been considered as tumor promoting enzymes as they degrade extracellular matrix components, thus increasing the invasion of cancer cells. It has become evident, however, that MMPs can also cleave and alter the function of various non-matrix bioactive molecules, leading to both tumor promoting and suppressive effects. We applied systematic review guidelines to study MMP8 in cancer including the use of MMP8 as a prognostic factor or as a target/anti-target in cancer treatment, and its molecular mechanisms. A total of 171 articles met the inclusion criteria. The collective evidence reveals that in breast, skin and oral tongue cancer, MMP8 inhibits cancer cell invasion and proliferation, and protects patients from metastasis via cleavage of non-structural substrates. Conversely, in liver and gastric cancers, high levels of MMP8 worsen the prognosis. Expression and genetic alterations of MMP8 can be used as a prognostic factor by examination of the tumor and serum/plasma. We conclude, that MMP8 has differing effects on cancers depending on their tissue of origin. The use of MMP8 as a prognostic factor alone, or with other factors, seems to have potential. The molecular mechanisms of MMP8 in cancer further emphasize its role as an important regulator of bioactive molecules.

Identification of Important Invasion-Related Genes in Non-functional Pituitary Adenomas

Non-functioning pituitary adenomas (NFPAs) are locally invasive with high morbidity. The objective of this study was to diagnose important genes and pathways related to the invasiveness of NFPAs and gain more insights into the underlying molecular mechanisms of NFPAs. The gene expression profiles of GSE51618 were downloaded from the Gene Expression Omnibus database with 4 non-invasive NFPA samples, 3 invasive NFPA samples, and 3 normal pituitary gland samples. Differentially expressed genes (DEGs) are screened between invasive NFPA samples and normal pituitary gland samples, followed by pathway and ontology (GO) enrichment analyses. Subsequently, a protein-protein interaction (PPI) network was constructed and analyzed for these DEGs, and module analysis was performed. In addition, a target gene-miRNA network and target gene-TF (transcription factor) network were analyzed for these DEGs. A total of 879 DEGs were obtained. Among them, 439 genes were upregulated and 440 genes were downregulated. Pathway enrichment analysis indicated that the upregulated genes were significantly enriched in cysteine biosynthesis/homocysteine degradation (trans-sulfuration) and PI3K-Akt signaling pathway, while the downregulated genes were mainly associated with docosahexaenoate biosynthesis III (mammals) and chemokine signaling pathway. GO enrichment analysis indicated that the upregulated genes were significantly enriched in animal organ morphogenesis, extracellular matrix, and hormone activity, while the downregulated genes were mainly associated with leukocyte chemotaxis, dendrites, and RAGE receptor binding. Subsequently, ESR1, SOX2, TTN, GFAP, WIF1, TTR, XIST, SPAG5, PPBP, AR, IL1R2, and HIST1H1C were diagnosed as the top hub genes in the upregulated and downregulated PPI networks and modules. In addition, HS3ST1, GPC4, CCND2, and SCD were diagnosed as the top hub genes in the upregulated and downregulated target gene-miRNA networks, while CISH, ISLR, UBE2E3, and CCNG2 were diagnosed as the top hub genes in the upregulated and downregulated target gene-TF networks. The new important DEGs and pathways diagnosed in this study may serve key roles in the invasiveness of NFPAs and indicate more molecular targets for the treatment of NFPAs.

High serum MMP-14 predicts worse survival in gastric cancer

Matrix metalloproteinases (MMPs), endopeptidases with diverse biochemical functions, can promote cancer cell invasion and metastasis by degrading the extracellular matrix. A high matrix metalloproteinase-14 (MMP-14) expression in gastric cancer tissue has been associated with metastasis and poor prognosis. To further understand this association, we investigated serum MMP-14 as a biomarker in gastric cancer patients. The patient cohort consisted of 240 gastric adenocarcinoma patients who underwent surgery at Helsinki University Hospital, Finland, between 2000 and 2009. We determined the soluble MMP-14 serum levels using an enzyme-linked immunosorbent assay. We then calculated the associations between serum levels and clinicopathologic variables using the Mann-Whitney U-test or the Kruskal-Wallis test. We constructed survival curves using the Kaplan-Meier method and calculating the hazard ratios using the Cox proportional hazard model. We revealed a positive association between a high serum MMP-14 level and stages III–IV (p = 0.029), and between a high serum MMP-14 and distant metastasis (p = 0.022). Patients with a low serum MMP-14 had a 5-year disease-specific survival of 49.2% (95% confidence interval [CI] 45.5–52.9), whereas patients with a high serum MMP-14 had a 5-year survival of 22.1% (95% CI 15.2–29.0; p = 0.001). High serum MMP-14 was a statistically significant prognostic factor among patients with an intestinal type of cancer (hazard ratio [HR] 3.54; 95% CI 1.51–8.33; p = 0.004), but not among patients with a diffuse type. The serum MMP-14 level remained an independent prognostic factor in our multivariate survival analysis (HR 1.55; 95% CI 1.02–2.35; p = 0.040). This study indicates for the first time that high serum soluble MMP-14 levels in gastric cancer serves as a marker for a poor prognosis, possibly indicating the presence of distant metastases.

Identification of genomic copy number variations associated with specific clinical features of head and neck cancer

Background

Copy number variations (CNSs) of large genomic regions are an important mechanism implicated in the development of head and neck cancer, however, for most changes their exact role is not well understood. The aim of this study was to find possible associations between gains/losses of genomic regions and clinically distinct subgroups of head and neck cancer patients.

Results

Array comparative genomic hybridization (aCGH) analysis was performed on DNA samples in 64 patients with cancer in oral cavity, oropharynx or hypopharynx. Overlapping genomic regions created from gains and losses were used for statistical analysis. Following regions were overrepresented: in tumors with stage I or II a gain of 2.98 Mb on 6p21.2-p11 and a gain of 7.4 Mb on 8q11.1-q11.23; in tumors with grade I histology a gain of 1.1 Mb on 8q24.13, a loss of a large part of p arm of chromosome 3, a loss of a 1.24 Mb on 6q14.3, and a loss of terminal 32 Mb region of 8p23.3; in cases with affected lymph nodes a gain of 0.75 Mb on 3q24, and a gain of 0.9 Mb on 3q26.32-q26.33; in cases with unaffected lymph nodes a gain of 1.1 Mb on 8q23.3, in patients not treated with surgery a gain of 12.2 Mb on 7q21.3-q22.3 and a gain of 0.33 Mb on 20q11.22.

Conclusions

Our study identified several genomic regions of interest which appear to be associated with various clinically distinct subgroups of head and neck cancer. They represent a potentially important source of biomarkers useful for the clinical management of head and neck cancer. In particular, the PIK3CA and AGTR1 genes could be singled out to predict the lymph node involvement.

Molecular background of the regional lymph node metastasis of gastric cancer

Gastric cancer (GC) is one of the deadliest types of cancer in the world. Lymph node (LN) metastasis is a complex and malignant behavior of GC, involving a sequence of biological processes, including decreased adherence to adjacent cells, extracellular matrix (ECM) degradation and lymphatic channel permeation. LN metastasis is directly associated with the treatment response, local recurrence and long-term survival of patients with GC. Therefore, the molecular mechanisms of LN metastasis in GC development require further investigation. Recently, a large number of clinical studies have focused on the molecular mechanisms and biological markers of tumor invasion and metastasis. However, few articles have broadly summarized LN metastasis in GC, and the molecular mechanisms of LN metastasis are not yet fully understood. In the present review, the molecular mechanisms of LN metastasis in GC will be discussed, including the following aspects: Cell adhesion and movement, ECM degradation, new vessel formation, and molecular pattern differences between metastatic LNs and the primary tumor. This review may lead to a better understanding of LN metastasis in GC, and the identification of new diagnostic markers.

Overexpression of TIMP-3 in Chondrocytes Produces Transient Reduction in Growth Plate Length but Permanently Reduces Adult Bone Quality and Quantity

Bone development and length relies on the growth plate formation, which is dependent on degradative enzymes such as MMPs. Indeed, deletion of specific members of this enzyme family in mice results in important joint and bone abnormalities, suggesting a role in skeletal development. As such, the control of MMP activity is vital in the complex process of bone formation and growth. We generated a transgenic mouse line to overexpress TIMP3 in mouse chondrocytes using the Col2a1-chondrocyte promoter. This overexpression in cartilage resulted in a transient shortening of growth plate in homozygote mice but bone length was restored at eight weeks of age. However, tibial bone structure and mechanical properties remained compromised. Despite no transgene expression in adult osteoblasts from transgenic mice in vitro, their differentiation capacity was decreased. Neonates, however, did show transgene expression in a subset of bone cells. Our data demonstrate for the first time that transgene function persists in the chondro-osseous lineage continuum and exert influence upon bone quantity and quality.

Role of MMP-2 (-1306 C/T) Polymorphism in Pituitary Adenoma

Purpose. To determine if the frequency of the genotype of MMP-2 (-1306 C/T) Rs243865 has an influence on the development of pituitary adenoma (PA). Methods. The study enrolled n = 84 patients with PA and a random sample of the population n = 318 (reference group). The genotyping test of MMP-2 (-1306 C/T) was carried out using the real-time polymerase chain reaction method. Results. Analysis of MMP-2 (-1306 C/T) gene polymorphism has not revealed any differences in the genotype (C/C, C/T, and T/T) distribution between the PA patients and the reference group (as follows: 50%, 44%, and 6% versus 59.75%, 33.96%, and 6.29%). MMP-2 (-1306) C/C genotype was rarely observed in noninvasive PA compared to healthy controls: 35.1% versus 59.75%; p = 0.0049, as well C/C genotype being more frequently detected in nonrecurrence PA compared to healthy controls: 46.5% versus 59.75%; p = 0.0468. MMP-2 (-1306) C/T genotype was more frequently present in PA females compared to healthy controls females: 49.1% versus 33.66%; p = 0.041. Conclusion. Patients with noninvasive and nonrecurrence pituitary adenoma were the carriers of the C/C genotype significantly more frequently than their control counterparts and the C/T genotype in females was more frequent.

Tanshinone IIA decreases the migratory ability of AGS cells by decreasing the protein expression of matrix metalloproteinases, nuclear factor κB-p65 and cyclooxygenase-2

During progression of gastric cancer, degradation of the extracellular matrix by matrix metalloproteinases (MMPs) has been associated with poor prognosis. Tanshinone IIA (Tan-IIA) exerts antitumor activity in a variety of human cancer cells. It is extracted from Danshen (Salviae miltiorrhizae radix), and induces apoptosis and inhibits the proliferation of gastric cancer cells. However, the molecular mechanisms underlying the inhibition of migration in gastric cancer by Tan-IIA have not been fully elucidated. In the present study, AGS cell migration ability was evaluated using a wound-healing assay. The protein expression levels of nuclear factor (NF)-κB-p65, cyclooxygenase (COX)-2, MMP-2, -7, and -9 and β-actin in AGS cells were measured by western blotting. The results demonstrated that AGS cells treated with Tan-IIA exhibit decreased protein expression levels of NF-κB-p65, COX-2, and MMP-2, -7 and -9. The results also indicate that Tan-IIA inhibits migration ability in a dose- and time-dependent manner. These findings demonstrate that Tan-IIA inhibits the migration ability of AGS human gastric cancer cells and that decreasing the protein expression of NF-κB-p65, COX-2, and MMP-2, -7 and -9 may be an underlying molecular mechanism.

MicroRNA-22 inhibits tumor growth and metastasis in gastric cancer by directly targeting MMP14 and Snail

MicroRNAs (miRNAs) deregulation is frequent in human gastric cancers (GCs), but the role of specific miRNAs involved in this disease remains elusive. MiR-22 was previously reported to act as tumor suppressors or oncogenes in diverse cancers. However, their accurate expression, function and mechanism in GC are largely unclear. Here, we found that the expression of miR-22 was significantly reduced in clinical GC tissues compared with paired adjacent normal tissues, and was significantly correlated with a more aggressive phenotype of GC in patients, and miR-22 low expression correlated with poor overall survival. The introduction of miR-22 markedly suppressed GC cell growth, migration and invasion, and inhibition of miR-22 promoted GC cell proliferation, migration and invasion in vitro. We further demonstrated that miR-22 acted as tumor suppressors through targeting extracellular matrix (ECM) remodeling member matrix metalloproteinase 14 (MMP14) and epithelial-to-mesenchymal transition (EMT) inducer Snail in GC. Moreover, ectopic expression of MMP14 or Snail restored inhibitory effects of miR-22 on cell migration and invasion in GC cells, and a negative relationship between the miR-22 expression and MMP14 or Snail mRNA levels was observed in GC. Finally, overexpression of miR-22 suppressed tumor growth, peritoneal dissemination and pulmonary metastasis in vivo. Taken together, we identified that miR-22 is a potent tumor suppressor in GC. MiR-22 downregulation promotes GC invasion and metastasis by upregulating MMP14 and Snail, and then inducing ECM remodeling and EMT. These findings provide a better understanding of the development and progression of GC and may be an important implication for future therapy of the GC.

Increased expression of MMP14 correlates with the poor prognosis of Chinese patients with gastric cancer

The role of matrix metalloproteinase 14 (MMP14) has been identified to involve tumor progression and prognosis. The purpose of this study is to investigate the role of MMP14 in tumor progression and prognosis of gastric cancer. This study indicated that MMP14 mRNA and protein were overexpressed in gastric cancer tissue (P<0.001 and P=0.037, respectively) and significantly associated with clinical stage (P=0.005), lymph node metastasis (P=0.003), and distant metastasis (P=0.017). Moreover, we found that the overexpression of MMP14 was a significant predictor of poor prognosis for gastric cancer patients (P<0.001). Furthermore, we performed a meta-analysis which included 594 cases from 3 studies and showed that MMP14 overexpression was a significantly poor prognostic factor in Chinese patients with gastric cancer and HR (95% CI) was 2.17 (1.64-2.86). In conclusion, MMP14 plays an important role on gastric cancer progression and prognosis and acts as a convictive biomarker for prognostic prediction for Chinese patients with gastric cancer.