Matrix Metalloproteinase-9 Knockdown Research Articles

Fat Mass and Obesity-Associated Protein Regulates Granulosa Cell Aging by Targeting Matrix Metalloproteinase-2 Gene Via an N6-Methyladenosine-YT521-B Homology Domain Family Member 2-Dependent Pathway in Aged Mice.

In this study, we aimed to investigate the molecular mechanisms of RNA N6-methyladenosine (m6A) modification and how its associated proteins affect granulosa cell aging. A granulosa cell senescence model was constructed to detect the differences in total RNA m6A modification levels and the expression of related enzymes. Changes in downstream molecular expression and the effects on the cellular senescence phenotype were explored by repeatedly knocking down and overexpressing the key genes fat mass and obesity-associated protein (FTO), YT521-B homology domain family member 2 (YTHDF2), and matrix metalloproteinase-2 (MMP2). There was an increased total RNA m6A modification and decreased expression of the demethylase FTO and target gene MMP2 in senescent granulosa cells. FTO and MMP2 knockdown promoted granulosa cell senescence, whereas FTO and MMP2 overexpression retarded it. YTHDF2 and FTO can bind to the messenger RNA of MMP2. The extracellular signal-regulated kinase (ERK) pathway, which is downstream of MMP2, retarded the process of granulosa cell senescence through ERK activators. In granulosa cells, FTO can regulate the expression of MMP2 in an m6A-YTHDF2-dependent manner, influencing the activation status of the ERK pathway and contributing to the aging process of granulosa cells.

Hydrogen Sulfide Ameliorates Heart Aging by Downregulating Matrix Metalloproteinase-9.

Aging contributes significantly to cardiovascular diseases and cardiac dysfunction, leading to the upregulation of matrix metalloproteinase-9 (MMP-9) in the heart and a significant decrease in hydrogen sulfide (H2S) content, coupled with impaired cardiac diastolic function. This study explores whether supplementing exogenous hydrogen sulfide during aging ameliorates the decline in H2S concentration in the heart, suppresses MMP-9 expression, and improves the age-associated impairment in cardiac morphology and function. We collected plasma from healthy individuals of different ages to determine the relationship between aging and H2S and MMP-9 levels through Elisa detection and liquid chromatography-tandem mass spectrometry (LC/MC) detection of plasma H2S content. Three-month-old mice were selected as the young group, while 18-month-old mice were selected as the old group, and sodium hydrosulfide (NaHS) was injected intraperitoneally from 15 months old until 18 months old as the old + NaHS group. Plasma MMP-9 content was detected using Elisa, plasma H2S content, cardiac H2S content, and cystathionine gamma-lyase (CSE) activity were detected using LC/MC, and cardiac function was detected using echocardiography. Heart structure was assessed using hematoxylin and eosin staining, Masone staining was used to detect the degree of cardiac fibrosis, while western blot was used to detect the expression of MMP-9, CSE, and aging marker proteins. Knockdown of MMP-9 and CSE in H9c2 cells using small interfering RNA was carried out to determine the upstream-downstream relationship between MMP-9 and CSE. H2S content in the plasma of healthy individuals decreases with escalating age, whereas MMP-9 level rises with age progression. Aging leads to a decrease in H2S levels in the heart and plasma of mice, severe impairment of cardiac diastolic function, interstitial relaxation, and fibrosis of the heart. Supplementing with exogenous H2S can improve these phenomena. H2S maintains the structure and function of the heart by inhibiting the expression of MMP-9 during the aging process.

ADAMTS13 deficiency exacerbates neuroinflammation by targeting matrix metalloproteinase-9 in ischemic brain injury.

Our design aimed to explore the potential involvement of matrix metalloproteinase-9 (MMP-9) in the inflammatory response associated with acute ischemic stroke (AIS). We also aimed to preliminarily examine the potential impact of a disintegrin-like and metalloprotease with thrombospondin type I repeats-13 (ADAMTS13) on MMP-9 in AIS. We conducted oxygen-glucose deprivation models of microglia cells and mice models of AIS with middle cerebral artery occlusion (MCAO). We assessed the expression pattern of MMP-9 with western blotting (WB) and real-time quantitative PCR both in vivo and in vitro. MMP-9 downregulation was achieved by using ACE inhibitors such as trandolapril. For the MCAO model, we used ADAMTS13-deficient mice. We then evaluated the related neurological function scores, cerebral edema and infarct volume. The levels of inflammation-related proteins, such as COX2 and iNOS, were assessed using WB, and the expression of inflammatory cytokines was measured via enzyme-linked immuno sorbent assay in vivo. Our findings indicated that MMP-9 was up-regulated while ADAMTS13 was down-regulated in the MCAO model. Knockdown of MMP-9 reduced both inflammation and ischemic brain injury. ADAMTS13 prevented brain damage, improved neurological function and decreased the inflammation response in mice AIS models. Additionally, ADAMTS13 alleviated MMP-9-induced neuroinflammation in vivo. It showed that ADAMTS13 deficiency exacerbated ischemic brain injury through an MMP-9-dependent inflammatory mechanism. Therefore, the ADAMTS13-MMP-9 axis could have therapeutic potential for the treatment of AIS.

Epithelial-Mesenchymal Transformation Promotes the Progression of Hepatocellular Carcinoma through NF-κB/MMP9 Axis.

Primary liver cancer (PHC) stands as one of the most prevalent malignant diseases in clinical settings. Studies have indicated that transcatheter arterial chemoembolization (TACE) treatment exhibits superior clinical outcomes, potentially increasing the complete necrosis rate in patients with PHC. A correlation exists between the clinical outcomes of TACE surgery and the process of epithelial-mesenchymal transition (EMT), yet the underlying mechanism remains a mystery. Hence, it is crucial to investigate the impact and mechanism of EMT on hepatocellular carcinoma (HCC). Retrospectively, patients with advanced liver cancer who underwent TACE were selected and categorized into two groups based on the assessment of clinical efficacy: the effective group and the ineffective group. The expression levels of nuclear factor-kappa B (NF-κB), matrix metalloproteinase 9 (MMP9), Ki-67, B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X (Bax), Vimentin, E-cadherin, and N-cadherin in tumor tissues were evaluated using reverse transcription-polymerase chain reaction (RT-PCR). In vitro, Huh7 cells were cultured, and lentivirus infections were utilized to inhibit the overexpression of NF-κB and MMP9. The determination of EMT and cell viability was conducted through Cell Counting Kit-8 (CCK-8) assays, RT-PCR, and Western blot. Sixty patients diagnosed with advanced liver cancer were selected for the study. Based on their clinical outcomes, 30 patients with advanced hepatocellular carcinoma were categorized into the effective group, while the remaining 30 patients were categorized into the ineffective group. The results of the Western blot analysis indicated that, in comparison to the effective group, the expression levels of NF-κB, MMP9, Ki-67, Bcl-2, Vimentin, and N-cadherin were significantly higher in the tumor tissues of the ineffective group. Conversely, the expression of Bax and E-cadherin was notably lower in the effective group. Following the individual knockdown of NF-κB and MMP9, the cell experiments revealed a remarkable decrease in the expression levels of Ki-67, Bcl-2, Vimentin, and N-cadherin, whereas the expression of Bax and E-cadherin showed significant elevation (p < 0.05). Furthermore, there was a significant increase in cell viability and a decrease in cell apoptosis after the knockdown of NF-κB and MMP9. The NF-κB/MMP9 signaling axis serves as a pivotal regulator that fosters proliferation and impedes apoptosis in Huh7 cells by modulating the process of EMT.

The IGF-Independent Role of IRS-2 in the Secretion of MMP-9 Enhances the Growth of Prostate Carcinoma Cell Line PC3.

Insulin receptor substrate-2 (IRS-2), a substrate of the insulin-like growth factor (IGF)-I receptor, is highly expressed in the prostate cancer cell line, PC3. We recently demonstrated that extracellular signal-regulated kinase (Erk1/2), a kinase downstream of IGF signaling, is activated in PC3 cells under serum starvation, and this activation can be inhibited by IRS-2 knockdown. Here, we observed that adding an IGF-I-neutralizing antibody to the culture medium inhibited the activation of Erk1/2. Suppression of Erk1/2 in IRS-2 knockdown cells was restored by the addition of a PC3 serum-free conditioned medium. In contrast, the IRS-2-silenced PC3 conditioned medium could not restore Erk1/2 activation, suggesting that IRS-2 promotes the secretion of proteins that activate the IGF signaling pathway. Furthermore, gelatin zymography analysis of the conditioned medium showed that matrix metalloproteinase-9 (MMP-9) was secreted extracellularly in an IRS-2 dependent manner when PC3 was cultured under serum starvation conditions. Moreover, MMP-9 knockdown suppressed Erk1/2 activation, DNA synthesis, and migratory activity. The IRS-2 levels were positively correlated with Gleason grade in human prostate cancer tissues. These data suggest that highly expressed IRS-2 activates IGF signaling by enabling the secretion of MMP-9, which is associated with hyperproliferation and malignancy of prostate cancer cell line, PC3.

Extracellular Vesicles Potentiate Medulloblastoma Metastasis in an EMMPRIN and MMP-2 Dependent Manner.

Extracellular vesicles (EVs) have emerged as pivotal mediators of communication in the tumour microenvironment. More specifically, nanosized extracellular vesicles termed exosomes have been shown to contribute to the establishment of a premetastatic niche. Here, we sought to determine what role exosomes play in medulloblastoma (MB) progression and elucidate the underlying mechanisms. Metastatic MB cells (D458 and CHLA-01R) were found to secrete markedly more exosomes compared to their nonmetastatic, primary counterparts (D425 and CHLA-01). In addition, metastatic cell-derived exosomes significantly enhanced the migration and invasiveness of primary MB cells in transwell migration assays. Protease microarray analysis identified that matrix metalloproteinase-2 (MMP-2) was enriched in metastatic cells, and zymography and flow cytometry assays of metastatic exosomes demonstrated higher levels of functionally active MMP-2 on their external surface. Stable genetic knockdown of MMP-2 or extracellular matrix metalloproteinase inducer (EMMPRIN) in metastatic MB cells resulted in the loss of this promigratory effect. Analysis of serial patient cerebrospinal fluid (CSF) samples showed an increase in MMP-2 activity in three out of four patients as the tumour progressed. This study demonstrates the importance of EMMPRIN and MMP-2-associated exosomes in creating a favourable environment to drive medulloblastoma metastasis via extracellular matrix signalling.

TEM1 up-regulates MMP-2 and promotes ECM remodeling for facilitating invasion and migration of uterine sarcoma

ObjectivesTo explore the correlation between tumor endothelial marker 1 (TEM1) and matrix metalloproteinase 2 (MMP-2) in uterine sarcoma and their roles in the progression of uterine sarcoma.MethodsUterine leiomyosarcoma (uLMS, n = 25) and uterine leiomyoma (n = 25) specimens were collected from a total of 50 patients. Immunohistochemistry assay was conducted to determine the expression of TEM1, MMP-2 and MMP-9. TEM1 over expression (hTEM1) and low expression (shRNA-TEM1) MES-SA cell lines were established as in vitro uterine sarcoma models. MMP-2 mRNA, protein expression and enzymatic activity were verified using qPCR, Western blot and gelatin zymography respectively. MMP-2 expression was downregulated using MMP-2 siRNA in hTEM1 MES-SA cells to better study the role of MMP-2. The invasive and migratory capacities of hTEM1, shRNA-TEM1, and hTEM1 treated with MMP-2 siRNA MES-SA cells were determined using transwell assays. Extracellular matrix (ECM) remodeling mediated by TEM1 was examined using cell-ECM adhesion and fluorescent gelatin-ECM degradation assays. The immunofluorescence of F-actin was examined to analyze the formation of invadopodia. Subcutaneous and intraperitoneal xenografts were established to validate the role of TEM1 in promoting uterine sarcoma metastasis.ResultsTEM1 and MMP-2 were expressed in 92% (n = 23) and 88% (n = 22) of uterine leiomyosarcoma specimens, respectively. Both TEM1 and MMP-2 were highly expressed in 100% (n = 17) of high stage (III-IV) uterine leiomyosarcoma specimens. In addition, TEM1 expression was positively correlated with MMP-2 expression in uterine leiomyosarcoma. The successful establishment of in vitro uterine sarcoma models was confirmed with qPCR and Western blotting tests. TEM1 promoted the invasion and metastasis of uterine sarcoma in vivo and in vitro. MMP-2 expression and activity were up-regulated in hTEM1 cells but down-regulated in shRNA-TEM1 cells. Importantly, MMP-2 knockdown impaired the invasive and migratory capacity of hTEM1 cells. TEM1 promoted ECM remodeling by increasing cell-ECM adhesion and ECM degradation. TEM1 overexpression also induced the formation of invadopodia.ConclusionTEM1 was co-expressed and positively correlated with MMP-2 in uterine leiomyosarcoma specimens. In addition, both TEM1 and MMP-2 were associated with tumor development. TEM1 promoted uterine sarcoma progression by regulating MMP-2 activity and ECM remodeling.

MiR-299-3p Inhibits Nasopharyngeal Carcinoma Cell Proliferation and Migration by Targeting MMP-2

Purpose. Nasopharyngeal carcinoma (NPC) is a type of squamous cell carcinoma that originated from the epithelial cells of the nose and throat, and its incidence ranks the first among head and neck tumors. However, NPC has a unique and complex etiology that is not completely understood. MiR-299-3p was discovered to be abnormally expressed in cancers. However, the involvement of miR-299-3p in the incidence and progression of nasopharyngeal cancer remains unknown. Methods. The miR-299-3p expression in nasopharyngeal cancer samples and cell lines was identified using quantitative PCR (qPCR). Nasopharyngeal cancer cells were evaluated for proliferation, migration, and invasion using MTT, colony formation assay, and Transwell invasion assay. MiRBase and TargetScan databases identified the possible miR-299-3p target genes that were confirmed using a dual-luciferase reporter analysis. Additionally, the miR-299-3p target genes were validated by Western blot, colony formation assay, and Transwell assays. Results. It was found that miR-299-3p expression was low in nasopharyngeal cancer tissues and cell lines, according to qPCR data. Cell proliferation, colony formation, and migration were considerably reduced by miR-299-3p overexpression. Furthermore, matrix metalloproteinase 2 (MMP-2) expression was regulated by miR-299-3p, whereas MMP-2 knockdown significantly inhibited the capacity of nasopharyngeal cancer cells to form colonies and migrate. Overexpression of MMP-2 substantially reduced the miR-299-3p inhibitory impact on nasopharyngeal cancer cell migration and colony formation. Conclusion. The miR-299-3p acts as a tumor suppressor gene to suppress the growth and spread of nasopharyngeal cancer by regulating MMP-2 expression. Therefore, miR-299-3p and MMP-2 could be important therapeutic targets for suppressing nasopharyngeal cancer growth and metastasis.

MMP-9 drives the melanomagenic transcription program through histone H3 tail proteolysis.

Melanoma is a type of skin cancer that develops in pigment-producing melanocytes and often spreads to other parts of the body. Aberrant gene expression has been considered as a crucial step for increasing the risk of melanomagenesis, but how chromatin reorganization contributes to this pathogenic process is still not well understood. Here we report that matrix metalloproteinase 9 (MMP-9) localizes to the nucleus of melanoma cells and potentiates gene expression by proteolytically clipping the histone H3 N-terminal tail (H3NT). From genome-wide studies, we discovered that growth-regulatory genes are selectively targeted and activated by MMP-9-dependent H3NT proteolysis in melanoma cells. MMP-9 cooperates functionally with p300/CBP because MMP-9 cleaves H3NT in a manner that is dependent on p300/CBP-mediated acetylation of H3K18. The functional significance of MMP-9-dependent H3NT proteolysis is further underscored by the fact that RNAi knockdown and small-molecule inhibition of MMP-9 and p300/CBP impede melanomagenic gene expression and melanoma tumor growth. Together, our data establish new functions and mechanisms for nuclear MMP-9 in promoting melanomagenesis and demonstrate how MMP-9-dependent H3NT proteolysis can be exploited to prevent and treat melanoma skin cancer.

MMP-2 gene silencing attenuates age-dependent carotid stiffness via reduction of elastin degradation and increased eNOS activation

Abstract Background and aims Arterial stiffness is a hallmark of vascular aging. Being characterized by a loss of elasticity of large arterial walls, arterial stiffness is associated with an increased risk of cardiovascular disease (CVD). The age-dependent arterial stiffness is primarily attributed to alterations in the elastic and collagen deposition that is regulated by a number of enzymes, including matrix metalloproteinase-2 (MMP-2). Nevertheless, the mechanistic link between age-dependent arterial stiffness and MMP-2 remains unclear. In this study, we investigated the effect and efficacy of therapeutic MMP-2 knockdown using small interfering RNA (siRNA) on age-dependent arterial stiffness. Methods Pulse wave velocity (PWV) was assessed in the right carotid artery of wild-type (WT) mice of different age groups. MMP-2 levels and activity in the carotid artery and plasma of young (3 months) and aged (20–25 months) WT mice were determined. Old WT mice (18–21 months) were treated for 4 weeks with either MMP-2 or scrambled siRNA, in which carotid PWV was assessed at baseline, 2 and 4 weeks after the start of the treatment. Elastin to collagen ratio, desmosin (DES) level, and endothelial nitric oxide synthase (eNOS) pathways were also evaluated and compared. Lastly, levels of circulating MMP-2 and DES, the breakdown product of elastin, were measured in a human cohort (23–86 years old), in whom carotid-femoral PWV was assessed. Results Carotid PWV, as well as both vascular and circulating MMP-2 levels, were elevated with increasing age in WT mice (Figure 1). Therapeutic MMP-2 knockdown in aged WT mice reduced the vascular MMP-2 expression and attenuated age-dependent carotid stiffness. Increased elastin to collagen ratio and a lower plasma DES level were observed on MMP-2 silenced treated animals (Figure 2). Moreover, siMMP-2 treated mice showed enhanced eNOS phosphorylation on Ser1177. A direct interaction between MMP-2 and eNOS was also observed, which, interestingly, is augmented with age. Finally, collected human data showed a higher level of circulating MMP-2 levels on the elderly subjects. In addition, plasma DES level is positively correlated with age and aortic PWV, indicating the involvement of vascular elastin catabolism on arterial stiffness. Conclusions Therapeutic MMP-2 gene silencing, specifically targeting vascular MMP-2, attenuates age-dependent carotid stiffness. This effect is mediated by augmenting eNOS activation and reducing elastin degradation. Thus, our findings indicate MMP-2 as a potential therapeutic target to mitigate age-dependent arterial stiffness and CVD. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): Swiss National Science Foundation,Foundation for Cardiovascular Research–Zurich Heart House Figure 1

MMP-2 knockdown blunts age-dependent carotid stiffness by decreasing elastin degradation and augmenting eNOS activation.

Arterial stiffness is a hallmark of vascular ageing that precedes and strongly predicts the development of cardiovascular diseases. Age-dependent stiffening of large elastic arteries is primarily attributed to increased levels of matrix metalloproteinase-2 (MMP-2). However, the mechanistic link between age-dependent arterial stiffness and MMP-2 remains unclear. Thus, we aimed to investigate the efficacy of MMP-2 knockdown using small-interfering RNA (siRNA) on age-dependent arterial stiffness. Pulse wave velocity (PWV) was assessed in right carotid artery of wild-type (WT) mice from different age groups. MMP-2 levels in the carotid artery and plasma of young (3 months) and old (20-25 months) WT mice were determined. Carotid PWV as well as vascular and circulating MMP-2 were elevated with increasing age in mice. Old WT mice (18- to 21-month old) were treated for 4 weeks with either MMP-2 or scrambled (Scr) siRNA via tail vein injection. Carotid PWV was assessed at baseline, 2 and 4 weeks after start of the treatment. MMP-2 knockdown reduced vascular MMP-2 levels and attenuated age-dependent carotid stiffness. siMMP-2-treated mice showed increased elastin-to-collagen ratio, lower plasma desmosine (DES), enhanced phosphorylation of endothelial nitric oxide synthase (eNOS), and higher levels of vascular cyclic guanosine monophosphate (cGMP). An age-dependent increase in direct protein-protein interaction between MMP-2 and eNOS was also observed. Lastly, DES, an elastin breakdown product, was measured in a patient cohort (n = 64, 23-86 years old), where carotid-femoral PWV was also assessed; here, plasma levels of DES directly correlated with age and arterial stiffness. MMP-2 knockdown attenuates age-dependent carotid stiffness by blunting elastin degradation and augmenting eNOS bioavailability. Given the increasing clinical use of siRNA technology, MMP2 knockdown should be investigated further as a possible strategy to mitigate age-dependent arterial stiffness and related CV diseases.

Multi-layered proteogenomic analysis unravels cancer metastasis directed by MMP-2 and focal adhesion kinase signaling

The role of matrix metalloproteinase-2 (MMP-2) in tumor cell migration has been widely studied, however, the characteristics and effects of MMP-2 in clinical sample of metastatic colorectal cancer (CRC) remain poorly understood. Here, in order to unveil the perturbed proteomic signal during MMP-2 induced cancer progression, we analyzed plasma proteome of CRC patients according to disease progression, HCT116 cancer secretome upon MMP-2 knockdown, and publicly available CRC tissue proteome data. Collectively, the integrative analysis of multi-layered proteomes revealed that a protein cluster containing EMT (Epithelial-to-Mesenchymal Transition)-associated proteins such as CD9-integrin as well as MMP-2. The proteins of the cluster were regulated by MMP-2 perturbation and exhibited significantly increased expressions in tissue and plasma as disease progressed from TNM (Tumor, Node, and Metastasis) stage I to II. Furthermore, we also identified a plausible association between MMP-2 up-regulation and activation of focal adhesion kinase signaling in the proteogenomic analysis of CRC patient tissues. Based on these comparative and integrative analyses, we suggest that the high invasiveness in the metastatic CRC resulted from increased secretion of MMP-2 and CD9-integrin complex mediated by FAK signaling activation.

Therapeutic MMP-2 knockdown blunts age-dependent carotid stiffness by decreasing elastin degradation and augmenting enos activation

Background and Aims: Arterial stiffness is a hallmark of vascular aging that precedes and predicts the development of cardiovascular diseases. Age-dependent arterial stiffness is primarily attributed to increased levels of matrix metalloproteinase-2 (MMP-2). However, the mechanistic link between age-dependent arterial stiffness and MMP-2 remains unclear. Thus, we investigated the efficacy of therapeutic MMP-2 knockdown using small interfering RNA (siRNA) on age-dependent arterial stiffness.

MMP-9 Knockdown Inhibits Oral Squamous Cell Carcinoma Lymph Node Metastasis in the Nude Mouse Tongue-Xenografted Model through the RhoC/Src Pathway.

Oral squamous cell carcinoma (OSCC) is one of the most common types of cancers in developing countries. A major contributor to the high mortality rate of OSCC is the tendency of oral cancer cells to metastasize to lymph nodes around the head and neck during the early stages of cancer development. Matrix metalloproteinase 9 (MMP-9), an endopeptidase, can degrade the extracellular matrix and basement membrane and plays a key role in tumor invasion and metastasis. In vitro, cell migration ability was conducted by scratching assays. We also investigated the interaction abilities between OSCC cells and vascular endothelial cells (ECs) by an adhesion assay and transendothelial migration assay. And we established a BALB/c nude mouse tongue-xenografted metastasis model to investigate the role of MMP-9 and explore its potential underlying mechanism in OSCC growth, lymph node metastasis, and angiogenesis in vivo. The results showed that knockdown of MMP-9 could significantly suppress OSCC cell migration, proliferation, interactions between endothelial cells, xenografted tumor growth, and angiogenesis and simultaneously markedly inhibited OSCC cell metastasis to mouse lymphonodi cervicales superficiales, axillary lymph nodes, and even distant inguinal lymph nodes. Mechanistic studies revealed that knockdown of MMP-9 also led to a decreased expression of RhoC, Src, and F-actin by RT-PCR, western blotting, and immunohistochemistry. And the bioinformatic analysis showed that MMP-9, RhoC, and Src mRNA expression was positively and linearly correlated in OSCC on TCGA database. Together, our findings indicated that MMP-9 plays a very important role in OSCC growth, migration, angiogenesis, and lymph node metastasis, and its potential mechanism may be mediated by RhoC and Src gene expression.

MiR-338-3p inhibits cell growth, invasion, and EMT process in neuroblastoma through targeting MMP-2.

This study aimed to explore the regulatory mechanisms of miR-338-3p and matrix metalloproteinase-2 (MMP-2) in neuroblastoma. Putative target interaction regions of miR-338-3p on MMP-2 were predicted by miRcode and miRbase bioinformatics tools. Relative expression of miRNA-338-3p and MMP-2 in neuroblastoma tissues and GI-LI-N and SK-N-SH cells was determined by reverse transcription polymerase chain reaction experiment. Furthermore, the cell proliferation was determined by Cell Counting Kit-8 assay, the cell apoptosis rate was analyzed by flow cytometry assay, and the cell invasion was evaluated by transwell assay. miR-338-3p expression was downregulated, whereas MMP-2 expression was upregulated in metastasis tissue site compared to that in primary tissue site in total. Furthermore, miR-338-3p overexpression suppressed proliferation, invasion, and epithelial–mesenchymal transition (EMT) of neuroblastoma cells but promoted apoptosis, and the knockdown of MMP-2 triggered similar effects. Furthermore, MMP-2 was directly targeted by miR-338-3p, and overexpression of MMP-2 rescued the inhibitory effects of miR-338-3p on human neuroblastoma cell progression. Collectively, these data demonstrated that miR-338-3p could suppress cell growth, invasion, and EMT pathway and induce apoptosis in neuroblastoma cells by targeting MMP-2. MiR-338-3p sponged MMP-2 to regulate the PI3K/AKT pathway in human neuroblastoma cells.

Everolimus Inhibits the Progression of Ductal Carcinoma In Situ to Invasive Breast Cancer Via Downregulation of MMP9 Expression.

We evaluated the role of everolimus in the prevention of ductal carcinoma in situ (DCIS) to invasive ductal carcinoma (IDC) progression. The effects of everolimus on breast cancer cell invasion, DCIS formation, and DCIS progression to IDC were investigated in a 3D cell culturing model, intraductal DCIS xenograft model, and spontaneous MMTV-Her2/neu mouse model. The effect of everolimus on matrix metalloproteinase 9 (MMP9) expression was determined with Western blotting and IHC in these models and in patients with DCIS before and after a window trial with rapamycin. Whether MMP9 mediates the inhibition of DCIS progression to IDC by everolimus was investigated with knockdown or overexpression of MMP9 in breast cancer cells. Everolimus significantly inhibited the invasion of human breast cancer cells in vitro. Daily intragastric treatment with everolimus for 7 days significantly reduced the number of invasive lesions from intraductal DCIS foci and inhibited DCIS progression to IDC in the MMTV-Her2/neu mouse mammary tumor model. Mechanistically, everolimus treatment decreased the expression of MMP9 in the in vitro and in vivo models, and in breast tissues from patients with DCIS treated with rapamycin for 1 week. Moreover, overexpression of MMP9 stimulated the invasion, whereas knockdown of MMP9 inhibited the invasion of breast cancer cell-formed spheroids in vitro and DCIS in vivo. Knockdown of MMP9 also nullified the invasion inhibition by everolimus in vitro and in vivo. Targeting mTORC1 can inhibit DCIS progression to IDC via MMP9 and may be a potential strategy for DCIS or early-stage IDC therapy.

FoxM1 affects adhesive, migratory, and invasive abilities of human retinoblastoma Y-79 cells by targeting matrix metalloproteinase 2.

Forkhead box protein M1 (FoxM1) is an important transcription factor involved in various pathological processes including tumor metastasis. The changes of adhesive, migratory, and invasive abilities are considered as crucial events in tumor metastasis progression. In this study, we aimed to investigate the correlation between FoxM1 and retinoblastoma (Rb) metastasis and to explore the detailed mechanism. Wound healing, cell adhesion, and invasion assays showed that FoxM1 overexpression induced epithelial-mesenchymal transition in Y-79 cells and inhibited adhesion and subsequently promoted metastasis of Y-79 cells, while FoxM1 knockdown showed the opposite effects. A luciferase reporter assay and chromatin immunoprecipitation assay provided evidence that FoxM1 promoted matrix metalloproteinase 2 (MMP2) transcription by directly binding to and promoting MMP2 promoter. MMP2 knockdown by siRNA transfection attenuated cell metastasis of Y-79 cells induced by FoxM1 overexpression. Furthermore, the FoxM1-binding site mapped between -1167 and -1161bp of the MMP2 promoter was identified. Our results suggested that the FoxM1-MMP2 axis plays an important role in Rb metastasis, which may be a novel target for designing therapeutic regimen to control Rb metastasis.

A pilot study of microRNA expression profiles of the spinal neuron in matrix metalloproteinase-9 knockout mice

Introduction: Matrix metalloproteinase-9 (MMP9) plays a key role in blood–spinal cord barrier dysfunction. MMP9 blockade leads to improved injured locomotor recovery. However, it is still unknown whether MMP9 deficiency affects gene expression or signal transduction pathways in the spinal neuron. Material and Methods: In this study, we first screen the MMP9 knockdown mice with high superoxide dismutase (SOD) expression and low MMP9 expression by polymerase chain reaction analysis. Then, the gene microarrays were used to screen differentially expressed genes in the spinal neuron from MMP-9 knockout and wild-type mice. There were six groups in this experiment, including three negative control groups: SOD_1, SOD_2, and SOD_3, and three experiment groups: SOD_ MMP9_1, SOD_ MMP9_2, and SOD_ MMP9_3. The gene ontology terms were used to predict the potential functions of these differentially expressed genes, and the Kyoto Encyclopedia of Genes and Genomes was used to analyze the potential functions of these target genes in the pathways. Results: We found that the gene expression in the spinal neuron from MMP9 knockout mice was significantly altered compared to wild-type mice. FoxO signaling, axon guidance, ubiquitin-mediated proteolysis, regulation of actin cytoskeleton, and proteoglycans were changed. Discussion and Conclusion: In summary, MMP9 plays a role in spinal neuron signaling and the underlying mechanism may through affecting several signaling pathways.

MMP9 inhibition increases erythropoiesis in RPS14-deficient del(5q) MDS models through suppression of TGF-β pathways

The del(5q) myelodysplastic syndrome (MDS) is a distinct subtype of MDS, associated with deletion of the ribosomal protein S14 (RPS14) gene that results in macrocytic anemia. This study sought to identify novel targets for the treatment of patients with del(5q) MDS by performing an in vivo drug screen using an rps14-deficient zebrafish model. From this, we identified the secreted gelatinase matrix metalloproteinase 9 (MMP9). MMP9 inhibitors significantly improved the erythroid defect in rps14-deficient zebrafish. Similarly, treatment with MMP9 inhibitors increased the number ofcolony forming unit-erythroid colonies and the CD71+erythroid population from RPS14 knockdown human BMCD34+cells. Importantly, we found that MMP9 expression is upregulated in RPS14-deficient cells by monocyte chemoattractant protein 1. Double knockdown of MMP9 and RPS14 increased the CD71+population compared with RPS14 single knockdown, suggesting that increased expression of MMP9 contributes to the erythroid defect observed in RPS14-deficient cells. In addition, transforming growth factorβ(TGF-β) signaling is activated in RPS14 knockdown cells, and treatment with SB431542, a TGF-βinhibitor, improved the defective erythroid development of RPS14-deficient models. We found that recombinant MMP9 treatment decreases the CD71+population through increased SMAD2/3 phosphorylation, suggesting that MMP9 directly activates TGF-βsignaling in RPS14-deficient cells. Finally, we confirmed that MMP9 inhibitors reduce SMAD2/3 phosphorylation in RPS14-deficient cells to rescue the erythroid defect. In summary, these study results support a novel role for MMP9 in the pathogenesis of del(5q) MDS and the potential for the clinical use of MMP9 inhibitors in the treatment of patients with del(5q) MDS.

Exosomal MMP2 derived from mature osteoblasts promotes angiogenesis of endothelial cells via VEGF/Erk1/2 signaling pathway

The skeletal system is a dynamic organ that continuously undergoes coupled trabeculae and blood vessels remodeling, indicating the possible existence of molecular crosstalk between endothelial and osteoblastic cells. Since the cross-talk between bone-forming osteoblasts (OBs) and vessel-forming endothelial cells (ECs) have progressively gained investigators’ attention, few studies focused on the regulatory function of extracellular vesicles derived from OBs on ECs. In this study, the effect of the exosomes derived from mature osteoblasts (MOBs) on the ECs was investigated. Firstly, exosomes derived from mature osteoblasts (MOB-Exos) were isolated and identified by NanoSight light scatter technology, electron microscopy and Western bolting. Fluorescent labeling of MOB-Exos revealed its internalization by ECs. RNA interference technique was used to knock down matrix metalloproteinase-2 (MMP2) in MOB-Exos. Then ECs were co-cultured with MOB-Exos and MMP2 knockdown MOB-Exos. Wound healing migration assay, transwell migration assay, CCK-8 assay and tube formation assay of ECs were conducted to determine the angiogenic capability of ECs. Then the VEGF/Erk1/2 pathway markers were detected by Western blot. Our results showed that MOB-Exos could promote the proliferation, migration and tube formation of ECs. Meanwhile, the promoted angiogenetic capacities of ECs were impaired when MMP2 in MOB-Exos was knocked down. In addition, immunoblotting indicated that MOB-Exos could promote the activation of the VEGF/Erk1/2 pathway of ECs; whereas the activation of the VEGF/Erk1/2 pathway was attenuated when the ECs were co-cultured with the MMP2 knockdown MOB-Exos. In conclusion, the MMP-2 existing in exosomes derived from MOBs could promote the angiogenesis of ECs in vitro, which might be realized through VEGF/Erk1/2 signaling pathway.