Matrix metalloproteinase-13 expression is associated with bone marrow microinvolvement and prognosis in non-small cell lung cancer

CBX4 deletion promotes tumorigenesis under KrasG12D background by inducing genomic instability

Chromobox protein homolog 4 (CBX4) is a component of the Polycomb group (PcG) multiprotein Polycomb repressive complexes 1 (PRC1), which is participated in several processes including growth, senescence, immunity, and tissue repair. CBX4 has been shown to have diverse, even opposite functions in different types of tissue and malignancy in previous studies. In this study, we found that CBX4 deletion promoted lung adenocarcinoma (LUAD) proliferation and progression in KrasG12D mutated background. In vitro, over 50% Cbx4L/L, KrasG12D mouse embryonic fibroblasts (MEFs) underwent apoptosis in the initial period after Adeno-Cre virus treatment, while a small portion of survival cells got increased proliferation and transformation abilities, which we called selected Cbx4-/-, KrasG12D cells. Karyotype analysis and RNA-seq data revealed chromosome instability and genome changes in selected Cbx4-/-, KrasG12D cells compared with KrasG12D cells. Further study showed that P15, P16 and other apoptosis-related genes were upregulated in the primary Cbx4-/-, KrasG12D cells due to chromosome instability, which led to the large population of cell apoptosis. In addition, multiple pathways including Hippo pathway and basal cell cancer-related signatures were altered in selected Cbx4-/-, KrasG12D cells, ultimately leading to cancer. We also found that low expression of CBX4 in LUAD was associated with poorer prognosis under Kras mutation background from the human clinical data. To sum up, CBX4 deletion causes genomic instability to induce tumorigenesis under KrasG12D background. Our study demonstrates that CBX4 plays an emerging role in tumorigenesis, which is of great importance in guiding the clinical treatment of lung adenocarcinoma.

Circular RNAs: novel actors of Wnt signaling pathway in lung cancer progression

Circular RNAs (CircRNAs) are a class of regulatory RNA transcripts, which are ubiquitously expressed in eukaryotes. CircRNA dysregulation has been shown to disrupt the interaction of the Wnt/β-catenin pathway, which regulates several biological processes involved in tumorigenesis, thereby contributing to the development and progression of cancer. Interactions of tumor-derived circRNAs with the Wnt/β-catenin signaling pathway provide both clinical diagnostic biomarkers and promising therapeutic targets. In this review, we outlined current evidence on the roles of circRNAs associated with the Wnt/β-catenin pathway in regulating lung cancer formation and development. We believe that our findings will assist in the advancement or establishment of circRNA-based lung cancer therapeutic approaches.

Matrix Metallopeptidase-Gene Signature Predicts Stage I Lung Adenocarcinoma Survival Outcomes

Tumor recurrence poses a significant challenge to the clinical management of stage I lung adenocarcinoma after curative surgical resection. Matrix metalloproteinases (MMPs) increase expression and correlate with recurrence and metastasis in surgically resected non-small cell lung cancer. However, the impact of MMPs on survival outcome varies, and their roles in patients with stage I lung adenocarcinoma remain unclear. In two discovery cohorts, we first analyzed 226 stage I-II lung adenocarcinoma cases in the GSE31210 cohort using a clustering-based method and identified a 150-gene MMP cluster with increased expression in tumors associated with worse survival outcomes. A similar analysis was performed on 517 lung adenocarcinoma cases in the Cancer Genome Atlas cohort. A 185-gene MMP cluster was identified, which also showed increased expression in tumors and correlated with poor survival outcomes. We further streamlined from the discovery cohorts a 36-gene MMP signature significantly associated with recurrence and worse overall survival in patients with stage I lung adenocarcinoma after surgical resection. After adjusting for covariates, the high MMP-gene signature expression remained an independent risk factor. In addition, the MMP-gene signature showed enrichment in epidermal growth factor receptor wild-type lung tumors, especially for those with Kirsten rat sarcoma virus mutations. Using an independent validation cohort, we further validated the MMP-gene signature in 70 stage I lung adenocarcinoma cases. In conclusion, MMP-gene signature is a potential predictive and prognostic biomarker to stratify patients with stage I lung adenocarcinoma into subgroups based on their risk of recurrence for aiding physicians in deciding the personalized adjuvant therapeutics.

Approaches Toward Targeting Matrix Metalloproteases for Prognosis and Therapies in Gynecological Cancer: MicroRNAs as a Molecular Driver

Gene expression can be regulated by small non-coding RNA molecules like microRNAs (miRNAs) which act as cellular mediators necessary for growth, differentiation, proliferation, apoptosis, and metabolism. miRNA deregulation is often observed in many human malignancies, acting both as tumor-promoting and suppressing, and their abnormal expression is linked to unrestrained cellular proliferation, metastasis, and perturbation in DNA damage as well as cell cycle. Matrix Metalloproteases (MMPs) have crucial roles in both growth, and tissue remodeling in normal conditions, as well as in promoting cancer development and metastasis. Herein, we outline an integrated interactive study involving various MMPs and miRNAs and also feature a way in which these communications impact malignant growth, movement, and metastasis. The present review emphasizes on important miRNAs that might impact gynecological cancer progression directly or indirectly via regulating MMPs. Additionally, we address the likely use of miRNA-mediated MMP regulation and their downstream signaling pathways towards the development of a potential treatment of gynecological cancers.

Current progress and mechanisms of bone metastasis in lung cancer: a narrative review

Lung cancer is a kind of malignant tumor with rapid progression and poor prognosis. Distant metastasis has been the main cause of mortality among lung cancer patients. Bone is one of the most common sites. Among all lung cancer patients with bone metastasis, most of them are osteolytic metastasis. Some serious clinical consequences like bone pain, pathological fractures, spinal instability, spinal cord compression and hypercalcemia occur as well. Since the severity of bone metastasis in lung cancer, it is undoubtedly necessary to know how lung cancer spread to bone, how can we diagnose it and how can we treat it. Here, we reviewed the process, possible mechanisms, diagnosis methods and current treatment of bone metastasis in lung cancer. We divided the process of bone metastasis in lung cancer into three steps: tumor invasion, tumor cell migration and invasion in bone tissue. It may be influenced by genetic factors, microenvironment and other adhesion-related factors. Imaging examination, laboratory examination, and pathological examination are used to diagnose lung cancer metastasis to bone. Surgery, radiotherapy, targeted therapy, bisphosphonate, radiation therapy and chemotherapy are the common clinical treatment methods currently. We also found some problems remained to be solved. For example, drugs for skeletal related events mainly target on osteoclasts at present, which increase the ratio of patients in osteoporosis and fractures in the long term. In all, this review provides the direction for future research on bone metastasis in lung cancer.

Gremlin-1 Promotes Metastasis of Breast Cancer Cells by Activating STAT3-MMP13 Signaling Pathway

Gremlin-1 (GREM1), one of the bone morphogenetic protein (BMP) antagonists, can directly bind to BMPs. GREM1 is involved in organogenesis, tissue differentiation, and organ fibrosis. Recently, numerous studies have reported the oncogenic role of GREM1 in cancer. However, the role of GREM1 in metastasis of breast cancer cells and its underlying mechanisms remain poorly understood. The role of GREM1 in breast cancer progression was assessed by measuring growth, migration, and invasion of breast cancer cells. An orthotopic breast cancer mouse model was used to investigate the role of GREM1 in lung metastasis of breast cancer cells. GREM1 knockdown suppressed the proliferation of breast cancer cells, while its overexpression increased their growth, migration, and invasion. Cells with Grem1-knockdown showed much lower tumor growth rates and lung metastasis than control cells. GREM1 enhanced the expression of matrix metalloproteinase 13 (MMP13). A positive correlation between GREM1 and MMP13 expression was observed in breast cancer patients. GREM1 activated signal transducer and activator of transcription 3 (STAT3) transcription factor involved in the expression of MMP13. Our study suggests that GREM1 can promote lung metastasis of breast cancer cells through the STAT3-MMP13 pathway. In addition, GREM1 might be a promising therapeutic target for breast cancer metastasis.

Monocyte Chemoattractant Protein-1 promotes cancer cell migration via c-Raf/MAPK/AP-1 pathway and MMP-9 production in osteosarcoma

Background

Osteosarcoma is generally reported among younger individuals and has a very poor prognosis, particularly for the development of metastasis. However, more effective metastatic biomarkers and therapeutic methods are absent. Monocyte chemoattractant protein-1 (MCP-1) is involved in cancer progression and inflammatory recruitment. Although previous studies have reported higher serum MCP-1 levels in patients with osteosarcoma, the role of MCP-1 in osteosarcoma progression remains to be addressed.

Methods

The osteosarcoma cell migratory ability was assessed by transwell migration assay. The MCP-1 and MMP-9 expression levels were analyzed by Western blot and qPCR. The signal activation was conducted by Western blot. The in vivo mouse experiment and tumor tissue array were performed to confirm our findings in vitro.

Results

The present study demonstrates that MCP-1 regulates cell mobility through matrix metalloproteinase (MMP)-9 expression in osteosarcoma cells. Moreover, MCP-1 promotes MMP-9 expression, cell migration, and cell invasion by mediating CCR2, c-Raf, MAPK, and AP-1 signal transduction. Using MCP-1 knockdown stable cell lines, we found that MCP-1 knockdown reduces MMP-9 expression and cell mobility. Finally, we found high MCP-1 expression levels in osteosarcoma specimens.

Conclusions

Our results provide prognostic value of MCP-1 in osteosarcoma by promoting MMP-9 expression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-020-01756-y.

Matrix metalloproteinase family gene polymorphisms and lung cancer susceptibility: an updated meta-analysis

Background

Many studies have investigated the association between matrix metalloproteinase polymorphisms and lung cancer susceptibility. However, the results are still controversial. To clarify these associations, we conducted a meta-analysis.

Methods

A systematic search of studies was conducted in PubMed, Embase, and China National Knowledge Infrastructure. Overall and subgroup analysis stratified by ethnicity was conducted. OR with 95% CI was used to assess the strength of the association. Furthermore, false-positive report probability (FPRP) tests were also performed for associations obtained in this meta-analysis.

Results

Twenty-four studies, including 10,099 cases and 9,395 controls, were analyzed. Nine polymorphisms were reported. For MMP1 -1607 1G/2G and MMP7 -181 A/G, increased lung cancer risk was found in Asians. For MMP2 -1306 C/T and MMP2 -735 C/T, decreased lung cancer risk was found in both “diverse populations” and Asians. For MMP9 -1562, C/T decreased lung cancer risk was found in both “diverse populations” and Caucasians. For MMP13 -77A/G, the A/G genotype decreased lung cancer risk in Asians. However, only associations between MMP1 -1607 1G/2G, MMP2 -1306 C/T, MMP2 -735 C/T, and MMP7 -181 A/G and lung cancer risk were considered noteworthy according to FPRP tests. There was no association between MMP3 -1171 5A/6A, MMP9 R279Q, and MMP12 -82A/G and lung cancer risk.

Conclusions

Our meta-analysis suggested that MMP1 -1607 1G/2G and MMP7 -181 A/G were risk factors for lung cancer, while MMP2 -1306 C/T, MMP2 -735 C/T, MMP9 -1562 C/T, and MMP13 -77A/G might be protective factors. However, results for MMP9 -1562 C/T and MMP13 -77A/G should be interpreted with caution due to the probability of false-positive reports.

CircRNA_100876 Is Upregulated in Gastric Cancer (GC) and Promotes the GC Cells' Growth, Migration and Invasion via miR-665/YAP1 Signaling

The present study aimed to investigate the biological function and relative mechanisms of circRNA_100876 in gastric cancer (GC). To this end, quantitative real-time polymerase chain reaction (RT-qPCR) was performed to examine the expression of circRNA_100876 and miR-665 in GC tissues and cells, and circRNA_100876 expression was depleted by the transfection of circ_100876-targeting siRNAs. CCK-8, flow cytometry, and Transwell assays were applied to examine GC cell cycle distribution, proliferation, apoptosis, migration, and invasion abilities. Proteins related to apoptosis and epithelial-mesenchymal transition (EMT) were detected by western blotting. Luciferase reporter assays were conducted to verify the direct target site between circRNA_100876 and miR-665. Our study confirmed that circRNA_100876 was highly expressed in GC lesions compared with the adjacent normal tissues (P < 0.001). High circRNA_100876 expression was negatively associated with survival outcome (P = 0.000). Furthermore, the down-regulation of circRNA_100876 could inhibit GC cell proliferation, invasion, and migration by suppressing the EMT pathway. Further study suggested that circRNA_100876 could act as a competing endogenous RNA by sequestering miR-665, and luciferase activity assay indicated that circRNA_100876 could bind directly with miR-665. Moreover, we found that Yes-associated protein 1 (YAP1) was the downstream target gene of miR-665, miR-665 knockdown could up-regulate YAP1 expression in MKN45 cells, and YAP1 knockdown could inhibit MKN45 cell proliferation, migration and invasion. Therefore, we demonstrated that circRNA_100876 over-expression in GC could promote GC tumor growth, migration and invasion and exert its effects through miR-665/YAP1 signaling.

The prognostic values of matrix metalloproteinases in ovarian cancer

Objective

To investigate the prognostic significance of 23 matrix metalloproteinase (MMP) genes in patients diagnosed with ovarian carcinoma.

Methods

The prognostic significance of 23 MMP genes in patients diagnosed with ovarian carcinoma was investigated using the Kaplan–Meier plotter (KM plotter), which uses the gene expression data and overall survival information of patients with ovarian cancer that were downloaded from the Gene Expression Omnibus, Cancer Biomedical Informatics Grid and The Cancer Genome Atlas cancer datasets. The correlation between mRNA levels of individual MMPs (MMP2, MMP9, MMP10, MMP12, MMP13 and MMP25) and clinicopathological features (histological subtype, pathological grade and clinical stage) were investigated. The MMP protein level profiles in normal ovarian tissues and ovarian cancer tissues were examined using the Human Protein Atlas database.

Results

The results showed that high mRNA levels of MMP2 and MMP13 were associated with a worse overall survival in patients with ovarian cancer, whereas high mRNA levels of MMP9, MMP10, MMP12 and MMP25 were associated with a better overall survival. The protein levels of MMP2, MMP9, MMP10 and MMP25 in ovarian cancer tissues were elevated compared with normal ovarian tissues.

Conclusions

This study demonstrated that MMPs can be a reliable prognostic biomarker for ovarian cancer.

Contribution of dysregulated circRNA_100876 to proliferation and metastasis of esophageal squamous cell carcinoma

Purpose

Accumulating evidence demonstrates that circRNAs regulate diverse cellular processes and cancer progression. However, it remains unclear whether circRNAs play any functional role in esophageal squamous cell carcinoma (ESCC).

Materials and methods

The significance of circRNA_100876 in ESCC was analyzed by studying circRNA_100876 expression in ESCC tissues and the association between circRNA_100876 expression and clinicopathologic parameters. The biological effects of circRNA_100876 knockdown by lentivirus-mediated siRNAs on cell proliferation, cell cycle, apoptosis, and migration were investigated in vitro and in vivo.

Results

CircRNA_100876 expression was upregulated (P<0.05) and was negatively correlated with survival outcome (P<0.05) in ESCC. Inhibition of proliferation, migration, invasion, and epithelial–mesenchymal transition progression was confirmed after circRNA_100876 depletion.

Conclusion

Dysregulation of circRNA_100876 expression leads to poor prognosis in ESCC by accelerating cell proliferation and metastasis.

Matrix Metalloproteinase Inhibitors in Cancer Therapy: Turning Past Failures Into Future Successes

The matrix metalloproteinases (MMP) are a family of proteolytic enzymes that degrade multiple components of the extracellular matrix. A large body of experimental and clinical evidence has implicated MMPs in tumor invasion, neoangiogenesis, and metastasis, and therefore they represent ideal pharmacologic targets for cancer therapy. From the 1990s to early 2000s, synthetic inhibitors of MMPs (MMPI) were studied in various cancer types. Unexpectedly, despite strongly promising preclinical data, all trials were unsuccessful in reducing tumor burden or improving overall survival; in addition, MMPIs had unforeseen, severe side effects. Two main reasons can explain the failure of MMPIs in clinical trials. It has now become apparent that some MMPs have antitumor effects; therefore, the broad-spectrum MMPIs used in the initial trials might block these MMPs and result in tumor progression. In addition, although MMPs are involved in the early stages of tumor progression, MMPIs were tested in patients with advanced disease, beyond the stage when these compounds could be effective. As more specific MMPIs are now available, MMP targeting could be reconsidered for cancer therapy; however, new trials should be designed to test their antimetastatic properties in early-stage tumors, and endpoints should focus on parameters other than decreasing metastatic tumor burden. Mol Cancer Ther; 17(6); 1147-55. ©2018 AACR.

Ataxia-telangiectasia mutated activation mediates tumor necrosis factor-alpha induced MMP-13 up-regulation and metastasis in lung cancer cells

Despite that ataxia-telangiectasia mutated (ATM) is involved in IL-6 promoted lung cancer chemotherapeutic resistance and metastasis, the exact role of ATM in tumor necrosis factor-alpha (TNF-α) increasing tumor migration is still elusive. In the present study, we demonstrated that TNF-α promoted lung cancer cell migration by up-regulation of matrix metalloproteinase-13 (MMP-13). Notably, by gene silencing or kinase inhibition, we proposed for the first time that ATM is a key up-stream regulator of TNF-α activated ERK/p38-NF-κB pathway. The existence of TNF-α secreted in autocrine or paracrine manner by components of tumor microenvironment highlights the significance of TNF-α in inflammation-associated tumor metastasis. Importantly, in vivo lung cancer metastasis test showed that ATM depletion actually reduce the number of metastatic nodules and cancer nests in lung tissues, verifying the critical role of ATM in metastasis. In conclusion, our findings demonstrate that ATM, which could be activated by lung cancer-associated TNF-α, up-regulate MMP-13 expression and thereby augment tumor metastasis. Therefore, ATM might be a promising target for prevention of inflammation-associated lung cancer metastasis.

SK-216, a Novel Inhibitor of Plasminogen Activator Inhibitor-1, Suppresses Lung Metastasis of Human Osteosarcoma

Lung metastasis constitutes the leading cause of the death in patients with osteosarcoma. We have previously reported that plasminogen activator inhibitor-1 (PAI-1) regulates the invasion and lung metastasis of osteosarcoma cells in a mouse model and as well as in clinical samples. In the present study, we examined the anti-metastatic effect of SK-216, a small compound PAI-1 inhibitor, in human 143B osteosarcoma cells. An in vitro study showed that SK-216 treatment suppressed invasion activity by inhibiting PAI-1 expression in 143B cells, but had no influence on their proliferation or migration. 143B cells treated with SK-216 exhibited reduced matrix metalloproteinase-13 (MMP-13) secretion in a dose-dependent manner. Moreover, intraperitoneal injection of SK-216 into mouse models resulted in downregulation of PAI-1 expression levels in the primary tumors and showed suppression of lung metastases without influencing the proliferative activity of the tumor cells in the primary lesions. These results indicate that SK-216, a PAI-1 inhibitor, may serve as a novel drug to prevent lung metastasis in human osteosarcoma.

Expression analysis of matrix metalloproteinase-13 in human gastric cancer in the presence of Helicobacter Pylori infection

BACKGROUND

Matrix metalloproteinases (MMPs) can degrade essentially the extracellular matrix (ECM) components. MMPs are important regulators of tumor growth; hence the enzymes are considered as important targets for cancer therapy. MMP-13 is specially activated in gastric cancer and promotes the invasiveness of the primary tumors. Helicobacter Pylori (H.pylori) interacts with gastric epithelial cells and stimulates it to produce MMP-13in vitro.

OBJECTIVE

The relation between MMP-13 gene expression and clinicopathological characteristics of gastric cancer in the presence of H.pylori infection was investigated in fifty patients.

METHODS

The level of MMP-13 gene expression was measured by quantitative Real-time PCR method and was evaluated between two groups of normal and carcinomatous tissues.

RESULTS

The results showed 30% elevation of MMP-13 expression in tumor tissues. H.pylori infection did not have a significant effect on the expression of MMP-13. There was a correlation between gene expression and tumor type (P value = 0.032). In addition, there was a significant correlation between MMP-13 gene expression and tumor stage in intestinal group (P value = 0.023).

CONCLUSIONS

Based on the results, it might be concluded that in intestinal group, immune system plays an important role in reducing gene expression. Results also showed over expression (60%) in diffuse group. These findings suggest that using MMP-13 inhibitors in diffuse group might contribute to the control of tumor growth.

Circular RNAs: Biogenesis, Function, and a Role as Possible Cancer Biomarkers

Circular RNAs (circRNAs) are a class of noncoding RNAs (ncRNAs) that form covalently closed continuous loop structures, lacking the terminal 5' and 3' ends. CircRNAs are generated in the process of back-splicing and can originate from different genomic regions. Their unique circular structure makes circRNAs more stable than linear RNAs. In addition, they also display insensitivity to ribonuclease activity. Generally, circRNAs function as microRNA (miRNA) sponges and have a regulatory role in transcription and translation. They may be also translated in a cap-independent manner in vivo, to generate specific proteins. In the last decade, next-generation sequencing techniques, especially RNA-seq, have revealed great abundance and also dysregulation of many circRNAs in various diseases, suggesting their involvement in disease development and progression. Regarding their high stability and relatively specific differential expression patterns in tissues and extracellular environment (e.g., body fluids), they are regarded as promising novel biomarkers in cancer. Therefore, we focus this review on describing circRNA biogenesis, function, and involvement in human cancer development and address the potential of circRNAs to be effectively used as novel cancer diagnostic and prognostic biomarkers.

Identification of dysregulated long non-coding RNAs/microRNAs/mRNAs in TNM I stage lung adenocarcinoma

Lung adenocarcinoma (LUAD) is the primary subtype in lung cancer, which is the leading cause of cancer-related death worldwide. This study aimed to investigate the aberrant expression profiling of long non-coding RNA (lncRNA) in TNM I stage (stage I) LUAD. The lncRNA/mRNA/miRNA expression profiling of stage I LUAD and adjacent non-tumor tissues from 4 patients were measured by RNA-sequencing. Total of 175 differentially expressed lncRNAs (DELs), 1321 differentially expressed mRNAs (DEMs) and 94 differentially expressed microRNAs (DEMIs) were identified in stage I LUAD. DEMI-DEM regulatory network consisted of 544 nodes and 1123 edge; miR-200 family members had high connectivity with DEMs. In DEL-DEM co-expression network, CDKN2B-AS1, FENDRR and LINC00312 had the high connectivity with DEMs, which co-expressed with 105, 63 and 61 DEMs, respectively. DEL-DEMI-DEM network depicted the links among DELs, DEMI and DEMs. Identified DEMs were significantly enriched in cell adhesion molecules, focal adhesion and tight junction of Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways; and enriched in cell adhesion, angiogenesis and regulation of cell proliferation of Gene Ontology biological processes. Quantitative real-time polymerase chain reaction results were generally consistent with our bioinformatics analyses. LINC00312 and FENDRR had diagnostic value for LUAD patients in The Cancer Genome Atlas database. Our study might lay the foundation for illumination of pathogenesis of LUAD and identification of potential therapeutic targets and novel diagnosis biomarkers for LUAD patients.

Progress in the research on the mechanism of bone metastasis in lung cancer

Lung cancer is still the predominant cause of cancer-associated mortality worldwide. The bone metastasis of lung cancer brings great suffering to the patient. Previous advances have provided insights into the mechanism of bone metastasis. Previous research has investigated lung cancer stem cells and three steps were determined for the lung cancer cells to metastasize to the bone: i) Escaping from the primary tumor; ii) moving in the circulation; iii) colonizing in the bone. Key molecules are involved in each of these process. Although there is a close association and similarity, dynamic microenvironments affect these processes. The receptor activator of nuclear factor-κB (RANK)/RANKL axis serves a vital role in the regulation of the generation and activation of osteoclasts during the osteolytic lesion. However, the specific molecules for the lung cancer cells to metastasize to the bone require further research and exploration. The present study aimed to investigate the relative molecular mechanisms of bone metastasis in lung cancer in recent years, providing a general understanding about the features of lung cancer preferences to bone, and discussing other things that require investigation.

PAI-1, a target gene of miR-143, regulates invasion and metastasis by upregulating MMP-13 expression of human osteosarcoma

Despite recent improvements in the therapy for osteosarcoma, 30–40% of osteosarcoma patients die of this disease, mainly due to its lung metastasis. We have previously reported that intravenous injection of miR‐143 significantly suppresses lung metastasis of human osteosarcoma cells (143B) in a mouse model. In this study, we examined the biological role and mechanism of miR‐143 in the metastasis of human osteosarcoma cells. We identified plasminogen activator inhibitor‐1 (PAI‐1) as a direct target gene of miR‐143. To determine the role of PAI‐1 in human osteosarcoma cells, siRNA was transfected into 143B cells for knockdown of PAI‐1 expression. An in vitro study showed that downregulation of PAI‐1 suppressed cell invasion activity, but not proliferation. Moreover, injection of PAI‐1 siRNA into a primary lesion in the osteosarcoma mouse model inhibited lung metastasis compared to control siRNA‐injected mice, without influencing the proliferative activity of the tumor cells. Subsequent examination using 143B cells revealed that knockdown of PAI‐1 expression resulted in downregulation of the expression and secretion of matrix metalloproteinase‐13 (MMP‐13), which is also a target gene of miR‐143 and a proteolytic enzyme that regulates tumor‐induced osteolysis. Immunohistochemical analysis using clinical samples showed that higher miR‐143 expressing cases showed poor expression of PAI‐1 in the primary tumor cells. All such cases belonged to the lung metastasis‐negative group. Moreover, the frequency of lung metastasis‐positive cases was significantly higher in PAI‐1 and MMP‐13 double‐positive cases than in PAI‐1 or MMP‐13 single‐positive or double‐negative cases (P < 0.05). These results indicated that PAI‐1, a target gene of miR‐143, regulates invasion and lung metastasis via enhancement of MMP‐13 expression and secretion in human osteosarcoma cells, suggesting that these molecules could be potential therapeutic target genes for preventing lung metastasis in osteosarcoma patients.

Interleukin 6 trigged ataxia-telangiectasia mutated activation facilitates lung cancer metastasis via MMP-3/MMP-13 up-regulation

Our previous studies show that the phosphorylation of ataxia-telangiectasia mutated (ATM) induced by interleukin 6 (IL-6) treatment contributes to multidrug resistance formation in lung cancer cells, but the exact role of ATM activation in IL-6 increased metastasis is still elusive. In the present study, matrix metalloproteinase-3 (MMP-3) and MMP-13 were firstly demonstrated to be involved in IL-6 correlated cell migration. Secondly, IL-6 treatment not only increased MMP-3/MMP-13 expression but also augmented its activities. Thirdly, the inhibition of ATM phosphorylation efficiently abolished IL-6 up-regulating MMP-3/MMP-13 expression and increasing abilities of cell migration. Most importantly, the in vivo test showed that the inhibition of ATM abrogate the effect of IL-6 on lung cancer metastasis via MMP-3/MMP-13 down-regulation. Taken together, these findings demonstrate that IL-6 inducing ATM phosphorylation increases the expression of MMP-3/MMP-13, augments the abilities of cell migration, and promotes lung cancer metastasis, indicating that ATM is a potential target molecule to overcome IL-6 correlated lung cancer metastasis.

Association of matrix metalloproteinase family gene polymorphisms with lung cancer risk: logistic regression and generalized odds of published data

Many studies have reported the association between the matrix metalloproteinase (MMP) polymorphisms and lung cancer susceptibility, but the results were inconclusive. We conducted a meta-analysis, using a comprehensive strategy based on the logistic regression and a model-free approach, to derive a more precise estimation of the relationship between MMP1, MMP2, MMP9 and MMP13 polymorphisms with lung cancer risk. A total of 22 case-control studies including 8202 cases and 7578 controls were included in this meta-analysis. For MMP1-1607 1G/2G, increased lung cancer risk was found among Asians in additive model(OR = 1.34, 95%CI:1.18-1.53) and with model-free approach(OR_G = 1.41, 95%CI:1.21-1.65). For MMP2-1306 C/T and -735 C/T, based on the model-free approach, a significantly reduced risk was found in Asians(MMP2-1306 C/T:OR_G = 0.49,95%CI:0.42-0.57; MMP2-735 C/T: OR_G = 0.71, 95%CI:0.61-0.84). For MMP9-1562 C/T, a significantly increased risk was found among Asians(OR = 2.73, 95%CI:1.74-4.27) with model-free approach. For MMP13-77A/G, there was no association between this polymorphism and lung cancer risk in the recessive model(OR = 1.02, 95%CI:0.83-1.26) and with the model-free approach(OR_G = 0.95, 95%CI:0.76-1.17). Therefore, this meta-analysis suggests that the MMP1-1607 1G/2G, MMP2-1306 C/T, MMP2-735 C/T, MMP9 -1562 C/T polymorphisms were risk factors for lung cancer among Asians, while MMP13 -77A/G polymorphism was not associated with lung cancer risk.

MMP-13 In-Vivo Molecular Imaging Reveals Early Expression in Lung Adenocarcinoma

Introduction

Several matrix metalloproteinases (MMPs) are overexpressed in lung cancer and may serve as potential targets for the development of bioactivable probes for molecular imaging.

Objective

To characterize and monitor the activity of MMPs during the progression of lung adenocarcinoma.

Methods

K-ras^LSL-G12D mice were imaged serially during the development of adenocarcinomas using fluorescence molecular tomography (FMT) and a probe specific for MMP-2, -3, -9 and -13. Lung tumors were identified using FMT and MRI co-registration, and the probe concentration in each tumor was assessed at each time-point. The expression of Mmp2, -3, -9, -13 was quantified by qRT-PCR using RNA isolated from microdissected tumor cells. Immunohistochemical staining of overexpressed MMPs in animals was assessed on human lung tumors.

Results

In mice, 7 adenomas and 5 adenocarcinomas showed an increase in fluorescent signal on successive FMT scans, starting between weeks 4 and 8. qRT-PCR assays revealed significant overexpression of only Mmp-13 in mice lung tumors. In human tumors, a high MMP-13 immunostaining index was found in tumor cells from invasive lesions (24/27), but in none of the non-invasive (0/4) (p=0.001).

Conclusion

MMP-13 is detected in early pulmonary invasive adenocarcinomas and may be a potential target for molecular imaging of lung cancer.

ANGPTL2 increases bone metastasis of breast cancer cells through enhancing CXCR4 signaling

Bone metastasis of breast cancer cells is a major concern, as it causes increased morbidity and mortality in patients. Bone tissue-derived CXCL12 preferentially recruits breast cancer cells expressing CXCR4 to bone metastatic sites. Thus, understanding how CXCR4 expression is regulated in breast cancer cells could suggest approaches to decrease bone metastasis of breast tumor cells. Here, we show that tumor cell-derived angiopoietin-like protein 2 (ANGPTL2) increases responsiveness of breast cancer cells to CXCL12 by promoting up-regulation of CXCR4 in those cells. In addition, we used a xenograft mouse model established by intracardiac injection of tumor cells to show that ANGPTL2 knockdown in breast cancer cells attenuates tumor cell responsiveness to CXCL12 by decreasing CXCR4 expression in those cells, thereby decreasing bone metastasis. Finally, we found that ANGPTL2 and CXCR4 expression levels within primary tumor tissues from breast cancer patients are positively correlated. We conclude that tumor cell-derived ANGPTL2 may increase bone metastasis by enhancing breast tumor cell responsiveness to CXCL12 signaling through up-regulation of tumor cell CXCR4 expression. These findings may suggest novel therapeutic approaches to treat metastatic breast cancer.

Collagenolytic matrix metalloproteinases in chronic obstructive lung disease and cancer

Chronic obstructive pulmonary disease (COPD) and lung cancer result in significant morbidity and mortality worldwide. In addition to the role of environmental smoke exposure in the development of both diseases, recent epidemiological studies suggests a connection between the development of COPD and lung cancer. Furthermore, individuals with concomitant COPD and cancer have a poor prognosis when compared with individuals with lung cancer alone. The modulation of molecular pathways activated during emphysema likely lead to an increased susceptibility to lung tumor growth and metastasis. This review summarizes what is known in the literature examining the molecular pathways affecting matrix metalloproteinases (MMPs) in this process as well as external factors such as smoke exposure that have an impact on tumor growth and metastasis. Increased expression of MMPs provides a unifying link between lung cancer and COPD.

Elevated matrix metalloproteinase-7 expression promotes metastasis in human lung carcinoma

Background

Matrix metalloproteinase 7 (MMP-7) promotes tumor invasion and metastasis in several cancers. However, its role in lung cancer progression is understudied. In this study, we investigated the correlation between MMP-7 expression and lung cancer pathology.

Methods

We searched the databases PubMed, Embase, Web of Science, Cochrane Library, CISCOM, CINAHL, China BioMedicine (CBM) and China National Knowledge Infrastructure (CNKI) for scientific literature relevant to MMP-7 and lung cancer. Carefully selected studies were pooled and ORs with 95% CI were calculated. Subgroup analyses and publication bias were analyzed to understand the retrieved data in greater detail. Version 12.0 STATA software was used for statistical analysis.

Results

We retrieved a total of 121 studies through database searches. Finally, 14 cohort studies satisfied our inclusion/exclusion criteria, and these 14 studies, published between 2004 and 2012, were selected for meta-analysis to understand the influence of MMP-7 expression in lung cancer progression. Our results showed consistent differences in MMP-7 expression when comparisons were made between TNM I-II versus III-IV (OR = 1.82, 95% CI: 1.19 to 2.78, P = 0.006); histologic grade 1 to 2 versus 3 to 4 (OR = 1.67, 95% CI: 1.14 to 2.42, P = 0.008); and lymph node-negative versus lymph node-positive samples (OR = 2.81, 95% CI: 1.73 to 4.58, P <0.001), with significantly higher MMP-7 expression levels found in the more advanced stages. Subgroup analysis showed that age was not the factor influencing the associations between histologic grade, LN metastasis and MMP-7 expression in lung cancer patients, as both under 60 and over 60 age groups showed strong correlations (all P <0.05). However, when TNM staging was analyzed for its association with MMP-7 expression, only patients under age 60 showed a statistically significant correlation.

Conclusions

Our meta-analysis results revealed that MMP-7 overexpression is associated with advanced TNM and histological grades, and is linked to aggressive LN metastasis in lung cancer patients; thus MMP-7 is a useful biomarker to assess the disease status in lung cancers.

Metastasis review: from bench to bedside

Cancer is the final result of uninhibited cell growth that involves an enormous group of associated diseases. One major aspect of cancer is when cells attack adjacent components of the body and spread to other organs, named metastasis, which is the major cause of cancer-related mortality. In developing this process, metastatic cells must successfully negotiate a series of complex steps, including dissociation, invasion, intravasation, extravasation, and dormancy regulated by various signaling pathways. In this review, we will focus on the recent studies and collect a comprehensive encyclopedia in molecular basis of metastasis, and then we will discuss some new potential therapeutics which target the metastasis pathways. Understanding the new aspects on molecular mechanisms and signaling pathways controlling tumor cell metastasis is critical for the development of therapeutic strategies for cancer patients that would be valuable for researchers in both fields of molecular and clinical oncology.

Increased circulating Lin(-/low) CD33(+) HLA-DR(-) myeloid-derived suppressor cells in hepatocellular carcinoma patients

AIM

Myeloid-derived suppressor cells (MDSC) can be induced or expanded in tumor-bearing mice and cancer patients. The frequency of MDSC denoted here as Lin(-/low) CD33(+) HLA-DR(-) was investigated in hepatocellular carcinoma (HCC) patients. The clinical relevance of MDSC and patients' characteristics were examined. Also, MDSC-related immune regulatory pathways in these patients were discussed.

METHODS

The quantity of MDSC was tested in peripheral blood of patients with HCC (n = 63) and healthy donors (n = 56). The expressions of interferon (IFN)-γ, vascular endothelial growth factor (VEGF), cyclooxygenase (COX)-2, matrix metalloproteinase (MMP)-13, nitric oxide synthase (NOS)-2 and arginase (ARG)-1 were analyzed. Co-culturing with anti-CD3/CD28-stimulated T lymphocytes was used to determine the suppressive effect of MDSC on the T lymphocytes.

RESULTS

Patients with treatment-naive HCC had an increased subpopulation of Lin(-/low) CD33(+) HLA-DR(-) cells in the peripheral blood mononuclear cells (PBMC) with characteristics of MDSC and associated to the stage (P = 0.0004). Patients with splenomegaly had a higher frequency of circulating MDSC. Also, COX-2, MMP-13 and VEGF were expressed differently associated with the alteration of MDSC.

CONCLUSION

Our study provides evidence showing an increased population of Lin(-/low) CD33(+) HLA-DR(-) MDSC in the peripheral blood of HCC patients. Our data also suggest that MMP-13 and COX-2 in PBMC may play a new important role companied with MDSC in HCC patients.

Matrix metalloproteinases in cancer: their value as diagnostic and prognostic markers and therapeutic targets

Biomarkers are used as tools in cancer diagnostics and in treatment stratification. In most cancers, there are increased levels of one or several members of the matrix metalloproteinases (MMPs). This is a family of proteolytic enzymes that are involved in many phases of cancer progression, including angiogenesis, invasiveness, and metastasis. It has therefore been expected that MMPs could serve as both diagnostic and prognostic markers in cancer patients, but despite a huge number of studies, it has been difficult to establish MMPs as cancer biomarkers. In the present paper, we assess some of the challenges associated with MMP research as well as putative reasons for the conflicting data on the value of these enzymes as diagnostic and prognostic markers in cancer patients. We also review the prognostic value of a number of MMPs in patients with lung, colorectal, breast, and prostate cancers. The review also discusses MMPs as potential target molecules for therapeutic agents and new strategies for development of such drugs.

The relationship of metalloproteinase gene polymorphisms and lung cancer

BACKGROUND

We analyzed the relationship between matrix metalloproteinase (MMP)-2, -7, and -13 gene expression and polymorphisms and disease susceptibility and prognosis in patients who had undergone surgery for non-small-cell lung cancers.

MATERIALS AND METHODS

The study group consisted of 132 patients who had undergone radical surgery for non-small-cell lung cancers. The control group consisted of 80 healthy volunteers. We isolated deoxyribonuclease samples for use in analyzing gene polymorphisms from pathology blocks for the patient group and from blood samples for the control group. We identified MMP gene polymorphisms with polymerase chain reaction and restriction fragment length polymorphisms. Results were compared with those of the control group to evaluate disease susceptibility, correlation with other clinical parameters, and with survival and prognosis by using appropriate statistical methods.

RESULTS

When we compared polymorphisms pertaining to MMP genes in healthy controls and lung tumor DNA, we observed a decrease in the MMP-2 (-735) polymorphism GG genotype and increases in the MMP-13 (A77G) polymorphism AG and GG genotypes (P = 0.008, P = 0.047, and P = 0.047, respectively). For the MMP-7 (-181) polymorphism, the genotype did not differ significantly for disease susceptibility. Median overall survival time was 25.5 mo in the MMP-13 AA/AG genotypes and 9.3 mo in the GG genotype.

CONCLUSIONS

Decreases in the MMP-2 (-735) polymorphism GG genotype and increases in the MMP-13 (A77G) polymorphism AG and GG genotypes increase the risk for lung cancer. Furthermore, the presence of the MMP-13 (A77G) polymorphism GG genotype is an unfavorable prognostic factor.

The CXCL12/CXCR4 autocrine loop increases the metastatic potential of non-small cell lung cancer in vitro

The CXCL12/CXCR4 endocrine axis has been demonstrated to play a pivotal role in organ-specific metastasis of many different types of tumors, but the precise role of the CXCL12/CXCR4 autocrine loop remains poorly understood. In this study, we constructed a functional CXCL12/CXCR4 autocrine loop in A549 cells using a gene transfection technique to evaluate its effect on the metastasis of non-small cell lung cancer (NSCLC). Our results demonstrated that the CXCL12/CXCR4 autocrine loop significantly promoted the motility, proliferation and invasiveness of the A549 cells, suggesting a key role of the CXCL12/CXCR4 autocrine loop in NSCLC metastasis. In addition, these findings suggest that targeted therapies directed against CXCR4 should consider the CXCL12 expression status of the NSCLC to be treated, since tumors with autocrine overexpression of CXCL12 may be more suitable for the application of chemokine-based anti-cancer therapies.

Micrometastasis in non-small-cell lung cancer: Detection and staging

BACKGROUND:

The clinical relevance of bone marrow micrometastasis (BMM) in non–small-cell lung cancer is undetermined, and the value of such analyses in advanced stage patients has not been clearly assessed previously. This study was conducted to estimate the accuracy of both polymerase chain reaction (PCR) and immunohistochemistry (IHC) in micrometastases detection and determine the best site for bone marrow biopsy in order to find micrometastasis.

METHODS:

This prospective cross-sectional study was performed in the Department of Thoracic Surgery, Alzahra University Hospital from September 2008 to June 2009. To evaluate the bone marrow, a 3-cm rib segment and an aspirated specimen from the iliac bone prior to tumor resection were taken. PCR and IHC were performed for each specimen to find micrometastasis.

RESULTS:

Of 41 patients, 14 (34%) were positive for BMM by PCR compared with two positive IHC (4.8%). All BMMs were diagnosed in rib segments, and iliac specimens were all free from metastatic lesion. Our data showed no significant association between variables such as age, sex, histology, tumor location, side of tumor, involved lobe, smoking, or weight loss and presence of BMM.

CONCLUSION:

PCR could use as a promising method for BMM detection. BMM in a sanctuary site (rib) is not associated with advanced stages of lung cancer. In addition, when predictor variables such as age, sex, histology, tumor location, smoking, or weight loss are analyzed, no correlation can be found between micrometastasis prevalence and any of those variables.

Increased miR-708 expression in NSCLC and its association with poor survival in lung adenocarcinoma from never smokers

PURPOSE

miRNA plays an important role in human disease and cancer. We seek to investigate the expression status, clinical relevance, and functional role of miRNA in non-small cell lung cancer.

EXPERIMENTAL DESIGN

We conducted miRNA expression profiling in matched lung adenocarcinoma and uninvolved lung using 56 pairs of fresh-frozen (FF) and 47 pairs of formalin-fixed, paraffin-embedded (FFPE) samples from never smokers. The most differentially expressed miRNA genes were evaluated by Cox analysis and log-rank test. Among the best candidate, miR-708 was further examined for differential expression in two independent cohorts. Functional significance of miR-708 expression in lung cancer was examined by identifying its candidate mRNA target and through manipulating its expression levels in cultured cells.

RESULTS

Among the 20 miRNAs most differentially expressed between tested tumor and normal samples, high expression level of miR-708 in the tumors was most strongly associated with an increased risk of death after adjustments for all clinically significant factors including age, sex, and tumor stage (FF cohort: HR, 1.90; 95% CI, 1.08-3.35; P = 0.025 and FFPE cohort: HR, 1.93; 95% CI, 1.02-3.63; P = 0.042). The transcript for TMEM88 gene has a miR-708 binding site in its 3' UTR and was significantly reduced in tumors high of miR-708. Forced miR-708 expression reduced TMEM88 transcript levels and increased the rate of cell proliferation, invasion, and migration in culture.

CONCLUSIONS

miRNA-708 acts as an oncogene contributing to tumor growth and disease progression by directly downregulating TMEM88, a negative regulator of the Wnt signaling pathway in lung cancer.

An MMP13-selective inhibitor delays primary tumor growth and the onset of tumor-associated osteolytic lesions in experimental models of breast cancer

We investigated the effects of the matrix metalloproteinase 13 (MMP13)-selective inhibitor, 5-(4-{4-[4-(4-fluorophenyl)-1,3-oxazol-2-yl]phenoxy}phenoxy)-5-(2-methoxyethyl) pyrimidine-2,4,6(1H,3H,5H)-trione (Cmpd-1), on the primary tumor growth and breast cancer-associated bone remodeling using xenograft and syngeneic mouse models. We used human breast cancer MDA-MB-231 cells inoculated into the mammary fat pad and left ventricle of BALB/c Nu/Nu mice, respectively, and spontaneously metastasizing 4T1.2-Luc mouse mammary cells inoculated into mammary fat pad of BALB/c mice. In a prevention setting, treatment with Cmpd-1 markedly delayed the growth of primary tumors in both models, and reduced the onset and severity of osteolytic lesions in the MDA-MB-231 intracardiac model. Intervention treatment with Cmpd-1 on established MDA-MB-231 primary tumors also significantly inhibited subsequent growth. In contrast, no effects of Cmpd-1 were observed on soft organ metastatic burden following intracardiac or mammary fat pad inoculations of MDA-MB-231 and 4T1.2-Luc cells respectively. MMP13 immunostaining of clinical primary breast tumors and experimental mice tumors revealed intra-tumoral and stromal expression in most tumors, and vasculature expression in all. MMP13 was also detected in osteoblasts in clinical samples of breast-to-bone metastases. The data suggest that MMP13-selective inhibitors, which lack musculoskeletal side effects, may have therapeutic potential both in primary breast cancer and cancer-induced bone osteolysis.

MicroRNA-143 regulates human osteosarcoma metastasis by regulating matrix metalloprotease-13 expression

Pulmonary metastases are the main cause of death in patients with osteosarcoma, however, the molecular mechanisms of metastasis are not well understood. To detect lung metastasis-related microRNA (miRNA) in human osteosarcoma, we compared parental (HOS) and its subclone (143B) human osteosarcoma cell lines showing lung metastasis in a mouse model. miR-143 was the most downregulated miRNA (P < 0.01), and transfection of miR-143 into 143B significantly decreased its invasiveness, but not cell proliferation. Noninvasive optical imaging technologies revealed that intravenous injection of miR-143, but not negative control miRNA, significantly suppressed lung metastasis of 143B (P < 0.01). To search for miR-143 target mRNA in 143B, microarray analyses were performed using an independent RNA pool extracted by two different comprehensive miR-143-target mRNA collecting systems. Western blot analyses revealed that MMP-13 was mostly protein downregulated by miR-143. Immunohistochemistry using clinical samples clearly revealed MMP-13-positive cells in lung metastasis-positive cases, but not in at least three cases showing higher miR-143 expression in the no metastasis group. Taken together, these data indicated that the downregulation of miR-143 correlates with the lung metastasis of human osteosarcoma cells by promoting cellular invasion, probably via MMP-13 upregulation, suggesting that miRNA could be used to develop new molecular targets for osteosarcoma metastasis.

Matrix metalloproteinase (MMP)-13 regulates mammary tumor-induced osteolysis by activating MMP9 and transforming growth factor-beta signaling at the tumor-bone interface

The tropism of breast cancer cells for bone and their tendency to induce an osteolytic phenotype are a result of interactions between breast cancer cells and stromal cells and are of paramount importance for bone metastasis. However, the underlying molecular mechanisms remain poorly understood. We hypothesize that tumor-stromal interaction alters gene expression in malignant tumor cells and stromal cells creating a unique expression signature that promotes osteolytic breast cancer bone metastasis and that inhibition of such interactions can be developed as targeted therapeutics. Microarray analysis was performed to investigate gene expression profiling at the tumor-bone (TB) interface versus the tumor alone area from syngenic mice injected with three different syngenic mammary tumor cell lines that differ in their metastatic potential. We identified matrix metalloproteinase 13 (MMP13), receptor activator of NF-kappaB ligand (RANKL), and integrins binding sialoprotein to be genes upregulated at the TB interface and validated. To determine the functional role of MMP13 in tumor-induced osteolysis, mice with Cl66 mammary tumors were treated with MMP13 antisense oligonucleotides (MMP13-ASO) or control scrambled oligonucleotides (control-ASO). Knockdown of MMP13 expression at the TB interface leads to significant reduction in bone destruction and in the number of activated osteoclasts at the TB interface. Further analysis to evaluate the mechanism of MMP13-dependent osteolytic bone metastasis revealed that MMP13-ASO treatment decreased active MMP9, RANKL levels, and transforming growth factor-beta signaling at the TB interface. Together, our data indicate that upregulation of MMP13 at the TB interface is important in tumor-induced osteolysis and suggest that MMP13 is a potential therapeutic target for breast cancer bone metastasis.

Matrix metalloproteinase (MMP)-13 regulates mammary tumor-induced osteolysis by activating MMP9 and transforming growth factor-beta signaling at the tumor-bone interface

The tropism of breast cancer cells for bone and their tendency to induce an osteolytic phenotype are a result of interactions between breast cancer cells and stromal cells and are of paramount importance for bone metastasis. However, the underlying molecular mechanisms remain poorly understood. We hypothesize that tumor-stromal interaction alters gene expression in malignant tumor cells and stromal cells creating a unique expression signature that promotes osteolytic breast cancer bone metastasis and that inhibition of such interactions can be developed as targeted therapeutics. Microarray analysis was performed to investigate gene expression profiling at the tumor-bone (TB) interface versus the tumor alone area from syngenic mice injected with three different syngenic mammary tumor cell lines that differ in their metastatic potential. We identified matrix metalloproteinase 13 (MMP13), receptor activator of NF-kappaB ligand (RANKL), and integrins binding sialoprotein to be genes upregulated at the TB interface and validated. To determine the functional role of MMP13 in tumor-induced osteolysis, mice with Cl66 mammary tumors were treated with MMP13 antisense oligonucleotides (MMP13-ASO) or control scrambled oligonucleotides (control-ASO). Knockdown of MMP13 expression at the TB interface leads to significant reduction in bone destruction and in the number of activated osteoclasts at the TB interface. Further analysis to evaluate the mechanism of MMP13-dependent osteolytic bone metastasis revealed that MMP13-ASO treatment decreased active MMP9, RANKL levels, and transforming growth factor-beta signaling at the TB interface. Together, our data indicate that upregulation of MMP13 at the TB interface is important in tumor-induced osteolysis and suggest that MMP13 is a potential therapeutic target for breast cancer bone metastasis.

Chloramphenicol causes mitochondrial stress, decreases ATP biosynthesis, induces matrix metalloproteinase-13 expression, and solid-tumor cell invasion

Overuse and abuse of antibiotics can increase the risk of cancer. Chloramphenicol can inhibit both bacterial and mitochondrial protein synthesis, causing mitochondrial stress and decreased ATP biosynthesis. Chloramphenicol can accelerate cancer progression; however, the underlying mechanisms of chloramphenicol in carcinogenesis and cancer progression are still unclear. We found that chloramphenicol can induce matrix metalloproteinase (MMP)-13 expression and increase MMP-13 protein in conditioned medium, resulting in an increase in cancer cell invasion. Chloramphenicol also activated c-Jun N-terminal kinases (JNK) and phosphatidylinositol 3-kinase (PI-3K)/Akt signaling, leading to c-Jun protein phosphorylation. The activated c-Jun protein has been proven to activate binding to the MMP-13 promoter and also upregulate the amount of MMP-13. Both the SP 600125 (JNK inhibitor) and LY 294002 (PI-3K/Akt inhibitor) can inhibit chloramphenicol-induced c-Jun phosphorylation, MMP-13 expression, and cell invasion. Overexpression of the dominant-negative JNK and PI-3K p85 subunit also negate chloramphenicol-induced responses. Other antibiotics that cause mitochondrial stress and a decrease in ATP biosynthesis also induce MMP-13 expression. These findings suggest that chloramphenicol-induced PI-3K/Akt, JNK phosphorylation, and activator protein 1 activation might function as a novel mitochondrial stress signal that result in an increase of MMP-13 expression and MMP-13-associated cancer cell invasion. The findings of this study confirms that chloramphenicol, and other 70S ribosomal inhibitors, should be administered with caution, especially during cancer therapy.

Prognostic significance of matrix metalloproteinase-1 levels in peripheral plasma and tumour tissues of lung cancer patients

Matrix metalloproteinase-1 (MMP-1) participates in a variety of physiological and pathological processes. We previously found that MMP-1 was one of the lung cancer-related proteins detectable in peripheral blood. To validate our preliminary observations and explore the clinical significance of MMP-1 for lung cancer further, we carried out the present study. The concentrations of MMP-1 in circulating plasma specimens of 170 lung cancer patients and 70 healthy individuals were measured by an enzyme-linked immunosorbance assay. The expression status of the MMP-1 in archival tissue samples from 122 lung cancer patients was examined by immunohistochemical analysis. The correlation between the MMP-1 levels and prognosis of the lung cancer patients was then assessed statistically. Protein levels of MMP-1 were considerably raised in the plasma from lung cancer patients relative to those in healthy controls. The high plasma MMP-1 levels were associated with advanced-stage of the disease and significantly lower overall survival rate of the patients. Coincidently, MMP-1 protein extraordinarily overexpressed in the tumour tissues of lung cancer; and the up-regulated MMP-1 was associated with the progression (including tumour size, staging and lymphatic invasion), especially with decreased survival rate of the patients. Statistic analysis revealed that MMP-1 protein levels had an independent influence on survival. MMP-1 levels were elevated in both tumour tissue and blood; the latter may serve as an independent predictor for survival of lung cancer patients. MMP-1 protein levels in plasma/serum thus represent a potential and clinically relevant biomarker for the prognosis of patients with lung cancers.

The IGF-I receptor can alter the matrix metalloproteinase repertoire of tumor cells through transcriptional regulation of PKC-{alpha}

The IGF-I receptor (IGF-IR) was identified as a tumor progression factor, but its role in invasion and metastasis has been the subject of some controversy. Previously we reported that in murine lung carcinoma M-27 cells, overexpression of IGF-IR increased the synthesis and activation of matrix metalloproteinase (MMP)-2 via Akt/phosphatidylinositol 3-kinase signaling. In contrast, we show here that in these and other cells, IGF-IR overexpression reduced the constitutive and phorbol 12-myristate 13-acetate (PMA)-inducible expression of three protein kinase C (PKC)-regulated metalloproteinases, MMP-3, MMP-9, and MMP-13, in cultured cells as well as in vivo in sc tumors. To elucidate the underlying mechanism, we analyzed the effect of IGF-IR on PKC expression and activity using wild-type and IGF-IR-overexpressing (M-27(IGFIR)) tumor cells. Our results show that overexpression and activation of IGF-IR reduced PKC-alpha expression, PKC activity, and downstream ERK1/2 signaling, and these effects were reversed in cells expressing kinase (Y(1131,1135,1136)F) or C-terminal (Y(1250/51)F) domain mutants of IGF-IR. This reduction was due to transcriptional down-regulation of PKC-alpha as evidenced by reduced PKC-alpha mRNA expression in a phosphatidylinositol 3-kinase-dependent manner and a blockade of PKC-alpha promoter activation as revealed by a reporter gene assay. Finally, reconstitution of PKC-alpha levels could restore MMP-9 expression levels in these cells. Collectively, these results show that IGF-IR can inhibit PKC-alpha gene transcription and thereby block the synthesis of PMA-regulated MMPs, suggesting that within the same cells, IGF-IR can act as both a positive and negative regulator of MMP expression and function.

Osteopontin increases migration and MMP-9 up-regulation via alphavbeta3 integrin, FAK, ERK, and NF-kappaB-dependent pathway in human chondrosarcoma cells

Tumor malignancy is associated with several features such as proliferation ability and frequency of metastasis. Osteopontin (OPN), which abundantly expressed in bone matrix, is involved in cell adhesion, migration, invasion and proliferation via interaction with its receptor, that is, alphavbeta3 integrin. However, the effect of OPN on migration activity in human chondrosarcoma cells is mostly unknown. Here we found that OPN increased the migration and expression of matrix metalloproteinase (MMP)-9 in human chondrosarcoma cells (JJ012 cells). RGD peptide, alphavbeta3 monoclonal antibody and MAPK kinase (MEK) inhibitors (PD98059 and U0126) but not RAD peptide inhibited the OPN-induced increase of the migration and MMP-9 up-regulation of chondrosarcoma cells. OPN stimulation increased the phosphorylation of focal adhesion kinase (FAK), MEK and extracellular signal-regulated kinase (ERK). In addition, treatment of JJ012 cells with NF-kappaB inhibitor (PDTC) or IkappaB protease inhibitor (TPCK) inhibited OPN-induced cell migration and MMP-9 up-regulation. Stimulation of JJ012 cells with OPN also induced IkappaB kinase alpha/beta (IKK alpha/beta) phosphorylation, IkappaBalpha phosphorylation, p65 Ser(536) phosphorylation, and kappaB-luciferase activity. The OPN-mediated increases in MMP-9 and kappaB-luciferase activities were inhibited by RGD peptide, PD98059 or FAK and ERK2 mutant. Taken together, our results indicated that OPN enhances the migration of chondrosarcoma cells by increasing MMP-9 expression through the alphavbeta3 integrin, FAK, MEK, ERK and NF-kappaB signal transduction pathway.