Reversion-inducing Cysteine-rich Protein Research Articles

Potential Role of Reversion-Inducing Cysteine-Rich Protein with Kazal Motifs (RECK) in Regulation of Matrix Metalloproteinases (MMPs) Expression in Periodontal Diseases.

Periodontal diseases are characterized by pathological destruction of extracellular matrix (ECM) of periodontal tissues. Matrix metalloproteinases (MMPs) are a significant part of the degradation of ECM. However, the regulation of MMPs expression level in periodontal diseases is as yet undetermined.RECK (reversion-inducing cysteine-rich protein with Kazal motifs), a novel membrane-anchored inhibitor of MMPs, could regulate the expressions of MMP-2, 9 and MT1-MMP as a cell surface-signaling molecule. Thus, we propose that RECK may play an important role in regulating MMPs in the ECM degradation of periodontal diseases. The RECK/MMPs signaling pathway could provide a new approach for prevention and treatment of RECK in periodontal diseases by blocking MMPs.

A Hypothesis for the Role of RECK in Angiogenesis.

Angiogenesis is a key process by which new capillary blood vessels are formed, sustaining the supply of oxygen and other nutrients to the body allowing its growth and wound healing, among others. However, angiogenesis also associates with pathological processes, such us tumor growth. Vascular endothelial cells produce different matrix remodeling enzymes such as matrix metalloproteinases and a-disintegrin and metalloproteinases, which have both positive and negative effects on angiogenesis, regulating the cell environment and signaling. However, little is known about the regulation of the activity of these proteases during vascular development. Reversion-inducing cysteine-rich protein with Kazal motifs (RECK) is a membrane-anchored inhibitor of different matrix metalloproteinases and a-disintegrin and metalloproteinases, being a critical regulator of extracellular matrix remodeling and signaling pathway, particularly Notch, which is critical for the maturation of the growing vessels. Reck knockout mice die in utero showing vascular developmental defects and massive hemorrhages. These defects were not observed in knockout mice for secreted-soluble matrix metalloproteinase inhibitors pointing to an exclusive role of RECK in vascular development and maturation since its location at the plasma membrane. Despite the above, the exact role of RECK in this process has not been clarified. This review is focused to summarize the available information on the role of RECK as membrane anchored matrix metalloproteinases and a-disintegrin and metalloproteinases inhibitor, proposing a hypothesis by which RECK play key roles in the physiology and pathophysiology of the angiogenesis processes.

RECK (reversion-inducing cysteine-rich protein with Kazal motifs) regulates migration, differentiation and Wnt/β-catenin signaling in human mesenchymal stem cells.

The membrane-anchored glycoprotein RECK (reversion-inducing cysteine-rich protein with Kazal motifs) inhibits expression and activity of certain matrix metalloproteinases (MMPs), thereby suppressing tumor cell metastasis. However, RECK's role in physiological cell function is largely unknown. Human mesenchymal stem cells (hMSCs) are able to differentiate into various cell types and represent promising tools in multiple clinical applications including the regeneration of injured tissues by endogenous or transplanted hMSCs. RNA interference of RECK in hMSCs revealed that endogenous RECK suppresses the transcription and biosynthesis of tissue inhibitor of metalloproteinases (TIMP)-2 but does not influence the expression of MMP-2, MMP-9, membrane type (MT)1-MMP and TIMP-1 in these cells. Knockdown of RECK in hMSCs promoted monolayer regeneration and chemotactic migration of hMSCs, as demonstrated by scratch wound and chemotaxis assay analyses. Moreover, expression of endogenous RECK was upregulated upon osteogenic differentiation and diminished after adipogenic differentiation of hMSCs. RECK depletion in hMSCs reduced their capacity to differentiate into the osteogenic lineage whereas adipogenesis was increased, demonstrating that RECK functions as a master switch between both pathways. Furthermore, knockdown of RECK in hMSCs attenuated the Wnt/β-catenin signaling pathway as indicated by reduced stability and impaired transcriptional activity of β-catenin. The latter was determined by analysis of the β-catenin target genes Dickkopf1 (DKK1), axis inhibition protein 2 (AXIN2), runt-related transcription factor 2 (RUNX2) and a luciferase-based β-catenin-activated reporter (BAR) assay. Our findings demonstrate that RECK is a regulator of hMSC functions suggesting that modulation of RECK may improve the development of hMSC-based therapeutical approaches in regenerative medicine.

RECK is not an independent prognostic marker for breast cancer.

BackgroundThe REversion-inducing Cysteine-rich protein with Kazal motif (RECK) is a well-known inhibitor of matrix metalloproteinases (MMPs) and cellular invasion. Although high expression levels of RECK have already been correlated with a better clinical outcome for several tumor types, its main function, as well as its potential prognostic value for breast cancer patients, remain unclear.MethodsThe RECK expression profile was investigated in a panel of human breast cell lines with distinct aggressiveness potential. RECK functional analysis was undertaken using RNA interference methodology. RECK protein levels were also analyzed in 1040 cases of breast cancer using immunohistochemistry and tissue microarrays (TMAs). The association between RECK expression and different clinico-pathological parameters, as well as the overall (OS) and disease-free (DFS) survival rates, were evaluated.ResultsHigher RECK protein expression levels were detected in more aggressive breast cancer cell lines (T4-2, MDA-MB-231 and Hs578T) than in non-invasive (MCF-7 and T47D) and non-tumorigenic (S1) cell lines. Indeed, silencing RECK in MDA-MB-231 cells resulted in elevated levels of pro-MMP-9 and increased invasion compared with scrambled (control) cells, without any effect on cell proliferation. Surprisingly, by RECK immunoreactivity analysis on TMAs, we found no association between RECK positivity and survival (OS and DFS) in breast cancer patients. Even considering the different tumor subtypes (luminal A, luminal B, Her2 type and basal-like) or lymph node status, RECK remained ineffective for predicting the disease outcome. Moreover, by multivariate Cox regression analysis, we found that RECK has no prognostic impact for OS and DFS, relative to standard clinical variables.ConclusionsAlthough it continues to serve as an invasion and MMP inhibitor in breast cancer, RECK expression analysis is not useful for prognosis of these patients.

RECK-Mediated β1-Integrin Regulation by TGF-β1 Is Critical for Wound Contraction in Mice.

Fibroblasts are critical for wound contraction; a pivotal step in wound healing. They produce and modify the extracellular matrix (ECM) required for the proper tissue remodeling. Reversion-inducing cysteine-rich protein with Kazal motifs (RECK) is a key regulator of ECM homeostasis and turnover. However, its role in wound contraction is presently unknown. Here we describe that Transforming growth factor type β1 (TGF-β1), one of the main pro-fibrotic wound-healing promoting factors, decreases RECK expression in fibroblasts through the Smad and JNK dependent pathways. This TGF-β1 dependent downregulation of RECK occurs with the concomitant increase of β1-integrin, which is required for fibroblasts adhesion and wound contraction through the activation of focal adhesion kinase (FAK). Loss and gain RECK expression experiments performed in different types of fibroblasts indicate that RECK downregulation mediates TGF-β1 dependent β1-integrin expression. Also, reduced levels of RECK potentiate TGF-β1 effects over fibroblasts FAK-dependent contraction, without affecting its cognate signaling. The above results were confirmed on fibroblasts derived from the Reck +/- mice compared to wild type-derived fibroblasts. We observed that Reck +/- mice heal dermal wounds more efficiently than wild type mice. Our results reveal a critical role for RECK in skin wound contraction as a key mediator in the axis: TGF-β1—RECK- β1-integrin.

Promoter hypermethylation of the cysteine protease RECK may cause metastasis of osteosarcoma.

The present study examined the role of reversion-inducing cysteine-rich protein with Kazal motifs (RECK) promoter hypermethylation as a causative factor in metastasis of osteosarcoma. Using human pathological samples, it is demonstrated that RECK, a cysteine protease that reversibly regulates expression of matrix metalloproteases like matrix metallopeptidase 9 (MMP9), is transcriptionally inhibited in osteosarcoma, especially metastatic variants. This result comes from its promoter hypermethylation, as evaluated in the present study by methylation-specific PCR reaction. The expression of RECK was also significantly diminished in the metastatic variants of osteosarcoma. This downregulation of RECK in advanced grades of osteosarcoma and metastatic grades was also associated with the increased expression of invadosome-specific markers like MMP9, phospho-FAK, and integrins, suggesting the complex contributions of RECK in the prevention of metastasis and its downregulation as a causative factor in osteosarcoma metastasis.

Reversion-inducing-cysteine-rich Protein with Kazal Motif Is Involved in Intimal Hyperplasia in Carotid Arteries: A New Insight in the Prevention of Restenosis after Vascular Angioplasty

Overexpression of matrix metalloproteinase (MMP) has been implicated in the incidence of restenosis after vascular angioplasty. Reversion-inducing cysteine-rich protein with kazal motifs (RECK) is a membrane-anchored glycoprotein that negatively regulates the activity of MMPs, such as MMP-9 and MMP-2, which play a key role in the angiogenesis during tumor growth. This study was designed to investigate the potential association between RECK and restenosis after vascular angioplasty. Balloon-injured rabbit carotid arterial models were established. Arterial morphology was assessed by hematoxylin-eosin staining. The area of intimal hyperplasia was measured using image microscopy and image analyzer. The messenger RNA (mRNA) expression levels of RECK, MMP-9, and MMP-2 were detected using reverse transcription-polymerase chain reaction (RT-PCR) at 7, 14, and 21 days. Vascular smooth muscle cells (VSMCs) were transfected with RECK small interfering RNA (siRNA). VSMC proliferation rate was detected by MTT assay at 24, 48 and 72 hr. The protein expression of RECK, MMP-9, and MMP-2 was determined by Western blot. MMP-2 and MMP-9 in carotid artery of rats were significantly overexpressed in the injured-artery group, compared with unmanipulated control and contralateral uninjured groups (P < 0.05). With the time of the injury extended, MMP-2 and MMP-9 mRNA levels gradually increased. RECK showed a marked peak of mRNA level at 7 days after injury, compared with unmanipulated control and contralateral uninjured groups (P < 0.001). However, the increasing trend gradually decreased at 14 days after the balloon surgery. RECK mRNA was still detectable at 21 days postoperatively, but the expression level of RECK mRNA in injured and contralateral uninjured groups was significantly lower than that in unmanipulated control group (P < 0.001). The expression level of RECK protein in VSMCs in transfected group was significantly lower compared with that in untransfected group, whereas the expression of MMP-2 and MMP-9 proteins in transfected group was significantly higher compared with that in untransfected group. Over the extension of transfection time, the proliferation of VSMCs in transfected group was increased gradually, compared with negative and blank plasmid controls (P < 0.05). RECK, as siRNA-mediated RECK silencing regulation of MMP-9 and MMP-2, plays an important role in intimal hyperplasia, which provides a new target for prevention and treatment of restenosis after vascular angioplasty.

MiR-21 overexpression improves osteoporosis by targeting RECK.

Osteoporosis is a kind of metabolic bone disorder. MicroRNA-21 (miR-21) has been proven to play an important role in bone formation, whereas its role in osteoporosis is unclear. In the present study, miR-21 expression was inhibited by TNF-α in mesenchymal stem cells (MSCs). TNF-α induced cell apoptosis, and inhibited cell proliferation and differentiation of MSCs. Whereas the effect was reversed by miR-21 mimics. Expression of reversion-inducing cysteine-rich protein with Kazal motifs (RECK) which is a predicted target of miR-21 was inhibited by miR-21 mimics. A luciferase reporter gene assay showed that miR-21 directly bound to RECK 3'-UTR. The effect of TNF-α on MSCs was reversed by RECK siRNA which was consistent with miR-21 mimics. The expression of MT1-MMP was inhibited by TNF-α and enhanced by RECK siRNA and miR-21 mimics. For the in vivo study, an osteoporosis model (OVX) was established by bilateral oophorectomy in mice. The expression of miR-21 decreased and RECK increased in the OVX mice. When treated with lentiviral RECK shRNA, the osteocalcin concentration and alkaline phosphate activity of the OVX mice decreased. The bone mineral density of the right femur mid-diaphysis was improved by RECK shRNA. Collectively, miR-21 modulated the osteoporosis by targeting RECK. These results emphasize the role of miR-21 during osteoporosis and suggest RECK might be a new medical target for osteoporosis.

Ras induces experimental lung metastasis through up-regulation of RbAp46 to suppress RECK promoter activity.

BackgroundMutant Ras plays multiple functions in tumorigenesis including tumor formation and metastasis. Reversion-inducing cysteine-rich protein with Kazal motifs (RECK), a metastasis inhibitor gene, suppresses matrix metalloproteinase (MMP) activity in the metastatic cascade. Clarifying the relationship between Ras and RECK and understanding the underlying molecular mechanism may lead to the development of better treatment for Ras-related tumors.MethodsSuppression subtractive hybridization PCR (SSH PCR) was conducted to identify Ha-rasval12 up-regulated genes in bladder cancer cells. Stable cell lines of human breast cancer (MCF-7-ras) and mouse NIH3T3 fibroblasts (7–4) harboring the inducible Ha-rasval12 oncogene, which could be induced by isopropylthio-β-D-galactoside (IPTG), were used to clarify the relationship between Ras and the up-regulated genes. Chromatin immunoprecipitation (ChIP) assay, DNA affinity precipitation assay (DAPA) and RECK reporter gene assay were utilized to confirm the complex formation and binding with promoters.ResultsRetinoblastoma binding protein-7 (RbAp46) was identified and confirmed as a Ha-rasval12 up-regulated gene. RbAp46 could bind with histone deacetylase (HDAC1) and Sp1, followed by binding to RECK promoter at the Sp1 site resulting in repression of RECK expression. High expression of Ras protein accompanied with high RbAp46 and low RECK expression were detected in 75% (3/4) of the clinical bladder cancer tumor tissues compared to the adjacent normal parts. Ras induced RbAp46 expression increases invasion of the bladder cancer T24 cells and MMP-9 activity was increased, which was confirmed by specific lentiviral shRNAs inhibitors against Ras and RbAp46. Similarly, knockdown of RbAp46 expression in the stable NIH3T3 cells “7-4” by shRNA decreased Ras-related lung metastasis using a xenograft nude mice model.ConclusionsWe confirmed that RbAp46 is a Ha-rasval12 up-regulated gene and binds with HDAC1 and Sp1. Furthermore, RbAp46 binds to the RECK promoter at the Sp1 site via recruitment by Sp1. RECK is subsequently activated, leading to increased MMP9 activity, which may lead to increased metastasis in vivo. Our findings of Ras upregulation of RbAp46 may lead to revealing a novel mechanism of Ras-related tumor cell metastasis.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-015-1155-7) contains supplementary material, which is available to authorized users.

MicroRNA-200b and microRNA-200c promote colorectal cancer cell proliferation via targeting the reversion-inducing cysteine-rich protein with Kazal motifs

MicroRNA-200b and microRNA-200c (miR-200b/c) are 2 of the most frequently upregulated oncomiRs in colorectal cancer cells. The role of miR-200b/c during colorectal tumorigenesis, however, remains unclear. In the present study, we report that miR-200b/c can promote colorectal cancer cell proliferation via targeting the reversion-inducing cysteine-rich protein with Kazal motifs (RECK). Firstly, bioinformatics analysis predicted RECK as a conserved target of miR-200b/c. By overexpressing or knocking down miR-200b/c in colorectal cancer cells, we experimentally validated that miR-200b/c are direct regulators of RECK. Secondly, an inverse correlation between the levels of miR-200b/c and RECK protein was found in human colorectal cancer tissues and cell lines. Thirdly, we demonstrated that repression of RECK by miR-200b/c consequently triggered SKP2 (S-phase kinase-associated protein 2) elevation and p27Kip1 (also known as cyclin-dependent kinase inhibitor 1B) degradation in colorectal cancer cells, which eventually promotes cancer cell proliferation. Finally, promoting tumor cell growth by miR-200b/c-targeting RECK was also observed in the xenograft mouse model. Taken together, our results demonstrate that miR-200b/c play a critical role in promoting colorectal tumorigenesis through inhibiting RECK expression and subsequently triggering SKP2 elevation and p27Kip1 degradation.

Effects of 5-aza-2'deoxycytidine on RECK gene expression and tumor invasion in salivary adenoid cystic carcinoma.

Reversion-inducing cysteine-rich protein with kazal motifs (RECK), a novel tumor suppressor gene that negatively regulates matrix metalloproteinases (MMPs), is expressed in various normal human tissues but downregulated in several types of human tumors. The molecular mechanism for this downregulation and its biological significance in salivary adenoid cystic carcinoma (SACC) are unclear. In the present study, we investigated the effects of a DNA methyltransferase (DNMT) inhibitor, 5-aza-2′deoxycytidine (5-aza-dC), on the methylation status of the RECK gene and tumor invasion in SACC cell lines. Methylation-specific PCR (MSP), Western blot analysis, and quantitative real-time PCR were used to investigate the methylation status of the RECK gene and expression of RECK mRNA and protein in SACC cell lines. The invasive ability of SACC cells was examined by the Transwell migration assay. Promoter methylation was only found in the ACC-M cell line. Treatment of ACC-M cells with 5-aza-dC partially reversed the hypermethylation status of the RECK gene and significantly enhanced the expression of mRNA and protein, and 5-aza-dC significantly suppressed ACC-M cell invasive ability. Our findings showed that 5-aza-dC inhibited cancer cell invasion through the reversal of RECK gene hypermethylation, which might be a promising chemotherapy approach in SACC treatment.

Reck enables cerebrovascular development by promoting canonical Wnt signaling.

The cerebral vasculature provides the massive blood supply that the brain needs to grow and survive. By acquiring distinctive cellular and molecular characteristics it becomes the blood-brain barrier (BBB), a selectively permeable and protective interface between the brain and the peripheral circulation that maintains the extracellular milieu permissive for neuronal activity. Accordingly, there is great interest in uncovering the mechanisms that modulate the formation and differentiation of the brain vasculature. By performing a forward genetic screen in zebrafish we isolated no food for thought (nft (y72)), a recessive late-lethal mutant that lacks most of the intracerebral central arteries (CtAs), but not other brain blood vessels. We found that the cerebral vascularization deficit of nft (y72) mutants is caused by an inactivating lesion in reversion-inducing cysteine-rich protein with Kazal motifs [reck; also known as suppressor of tumorigenicity 15 protein (ST15)], which encodes a membrane-anchored tumor suppressor glycoprotein. Our findings highlight Reck as a novel and pivotal modulator of the canonical Wnt signaling pathway that acts in endothelial cells to enable intracerebral vascularization and proper expression of molecular markers associated with BBB formation. Additional studies with cultured endothelial cells suggest that, in other contexts, Reck impacts vascular biology via the vascular endothelial growth factor (VEGF) cascade. Together, our findings have broad implications for both vascular and cancer biology.

α-Solanine inhibits invasion of human prostate cancer cell by suppressing epithelial-mesenchymal transition and MMPs expression.

α-Solanine, a naturally occurring steroidal glycoalkaloid found in nightshade (Solanum nigrum Linn.), was found to inhibit proliferation and induce apoptosis of tumor cells. However, the mechanism involved in suppression of cancer cell metastasis by α-solanine remains unclear. This study investigates the suppression mechanism of α-solanine on motility of the human prostate cancer cell PC-3. Results show that α-solanine reduces the viability of PC-3 cells. When treated with non-toxic doses of α-solanine, cell invasion is markedly suppressed by α-solanine. α-Solanine also significantly elevates epithelial marker E-cadherin expression, while it concomitantly decreases mesenchymal marker vimentin expression, suggesting it suppresses epithelial-mesenchymal transition (EMT). α-Solanine reduces the mRNA level of matrix metalloproteinase-2 (MMP-2), MMP-9 and extracellular inducer of matrix metalloproteinase (EMMPRIN), but increases the expression of reversion-inducing cysteine-rich protein with kazal motifs (RECK), and tissue inhibitor of metalloproteinase-1 (TIMP-1) and TIMP-2. Immunoblotting assays indicate α-solanine is effective in suppressing the phosphorylation of phosphatidylinositide-3 kinase (PI3K), Akt and ERK. Moreover, α-solanine downregulates oncogenic microRNA-21 (miR-21) and upregulates tumor suppressor miR-138 expression. Taken together, the results suggest that inhibition of PC-3 cell invasion by α-solanine may be, at least in part, through blocking EMT and MMPs expression. α-Solanine also reduces ERK and PI3K/Akt signaling pathways and regulates expression of miR-21 and miR-138. These findings suggest an attractive therapeutic potential of α-solanine for suppressing invasion of prostate cancer cell.

RECK controls breast cancer metastasis by modulating a convergent, STAT3-dependent neoangiogenic switch.

Metastasis is the primary cause of cancer-related death in oncology patients. A comprehensive understanding of the molecular mechanisms that cancer cells usurp to promote metastatic dissemination is critical for the development and implementation of novel diagnostic and treatment strategies. Here we show that the membrane protein RECK (Reversion-inducing cysteine-rich protein with kazal motifs) controls breast cancer metastasis by modulating a novel, non-canonical and convergent signal transducer and activator of transcription factor 3 (STAT3)-dependent angiogenic program. Neoangiogenesis and STAT3 hyperactivation are known to be fundamentally important for metastasis, but the root molecular initiators of these phenotypes are poorly understood. Our study identifies loss of RECK as a critical and previously unknown trigger for these hallmarks of metastasis. Using multiple xenograft mouse models, we comprehensively show that RECK inhibits metastasis, concomitant with a suppression of neoangiogenesis at secondary sites, while leaving primary tumor growth unaffected. Further, with functional genomics and biochemical dissection we demonstrate that RECK controls this angiogenic rheostat through a novel complex with cell surface receptors to regulate STAT3 activation, cytokine signaling, and the induction of both vascular endothelial growth factor and urokinase plasminogen activator. In accordance with these findings, inhibition of STAT3 can rescue this phenotype both in vitro and in vivo. Taken together, our study uncovers, for the first time, that RECK is a novel regulator of multiple well-established and robust mediators of metastasis; thus, RECK is a keystone protein that may be exploited in a clinical setting to target metastatic disease from multiple angles.

Prevention of abdominal aortic aneurysm by anti-microRNA-712 or anti-microRNA-205 in angiotensin II-infused mice.

Abdominal aortic aneurysm (AAA) is characterized as a progressive dilation and degradation of the aortic wall, associated with activation of matrix metalloproteinases (MMPs) and inflammation. Emerging evidence indicates a role for microRNAs (miRNAs) in AAA pathogenesis, but it is unclear whether abdominal aortic endothelial miRNAs play a role in the disease process. We aimed to identify miRNAs in the abdominal aortic endothelium that play a critical role in AAA development. The mouse model of AAA induced by angiotensin II infusion was used in this study. Through a miRNA array and validation study, we initially identified the murine-specific miR-712 and subsequently its human/murine homolog miR-205 as angiotensin II-induced miRNAs in the abdominal aortic endothelium in vivo and in vitro. Mechanistically, miR-712 stimulated MMP activity in the aortic wall by directly targeting 2 MMP inhibitors: tissue inhibitor of metalloproteinase 3 (TIMP3) and reversion-inducing cysteine-rich protein with kazal motifs (RECK). Silencing of miR-712 and miR-205 by using anti-miR-712 and anti-miR-205, respectively, significantly decreased the aortic MMP activity and inflammation, preventing AAA development in angiotensin II-infused ApoE(-/-) mice. Further, upregulation of 4 angiotensin II-sensitive miRNAs, miR-205, -21, -133b, and -378, identified in this murine study were confirmed in human AAA samples compared with nondiseased control. Our results demonstrate that angiotensin II-sensitive miR-712 and its human homolog miR-205 downregulate TIMP3 and RECK, which in turn stimulate aortic MMP activity and inflammation, leading to AAA development. Targeting these miRNAs may be a novel therapeutic strategy to prevent AAA.

RECK overexpression reduces invasive ability in ameloblastoma cells

Ameloblastoma is a frequent odontogenic neoplasm characterized by local invasiveness and high risk of recurrence. Reversion-inducing cysteine-rich protein with Kazal motifs (RECK) is a tumor suppressor that inhibits metastasis and angiogenesis. The aim of this study was to investigate effects of RECK overexpression on invasive potential in ameloblastoma cells. Lentiviral vectors containing human RECK gene were created and subsequently stably transfected into immortalized ameloblastoma cell line hTERT(+) -AM. Functional characteristics of hTERT(+) -AM cells with stable RECK overexpression included proliferation, migration, invasion, and regulation of matrix metalloproteinases (MMP)-2, MMP-9 measured by zymography or commercially available assays. The stable and higher expression of RECK mRNA and protein (P < 0.01) was detected in RECK-transfected hTERT(+) -AM cells. RECK overexpression caused a decrease in migration and invasion (P < 0.01) for hTERT(+) -AM cells and a decrease in activity of MMP-2, MMP-9 (P < 0.01). Proliferation was not affected by RECK overexpression (P > 0.05). Overexpression of RECK gene significantly inhibited cell invasive ability of hTERT(+) -AM cells, suggesting RECK may be a new target for ameloblastoma treatment.

MicroRNA-21 is a unique signature associated with coronary plaque instability in humans by regulating matrix metalloproteinase-9 via reversion-inducing cysteine-rich protein with Kazal motifs

BackgroundCoronary atherosclerotic unstable plaque is one of the leading causes of cardiovascular death. Macrophage-derived matrix metalloproteinase (MMP) 9 is considered for degrading extracellular matrix and collagen, thereby thinning the fibrous cap in plaques. miR-21 is implicated to play an important role in the progression of atherosclerosis. Nevertheless, miR-21 as the biomarker for coronary atherosclerotic unstable plaque remains unknown. We aimed to investigate the prediction role of miR-21 for unstable plaque by pathway study of miR-21 on MMPs and its inhibitor RECK in macrophages. MethodsExpression of miR-21 in macrophages and serum miR-21 as well as MMP-9 was measured in patients with coronary non-calcified plaque, calcified plaque and controls. In vitro experiment was done in human macrophages by over-expressing miR-21 or down-regulating RECK. The regulation of RECK and MMP-9 by miR-21 was evaluated by western blotting and siRNA strategy. ResultsPatients with non-calcified coronary artery lesions had significantly higher miR-21 in macrophages and lower miR-21 serum levels compared to the control and calcified plaque patients. At the same time, the serum levels of MMP-9 were significantly elevated in non-calcified patients. Experiments in vitro indicated that over-expressing miR-21 could induce the expression and secretion of pro-MMP-9 and active-MMP-9 in human macrophages via targeting gene RECK, and knocking down RECK expression by specific siRNA can resemble that of miR-21 over-expression. ConclusionsmiR-21 might be a biomarker for plaque instability by suppressing target gene RECK to promote the expression and secretion of MMP-9 in macrophages.

Expression of RECK and MMP-2 in salivary adenoid cystic carcinoma: Correlation with tumor progression and patient prognosis.

Reversion-inducing cysteine-rich protein with Kazal motifs (RECK), a glycosylphosphatidylinositol-anchored glycoprotein, inhibits the enzymatic activities of certain matrix metalloproteinases (MMPs). RECK has been studied in numerous human tumors, but the expression of RECK in salivary adenoid cystic carcinoma (SACC), and its correlation with patient prognosis, has never been investigated thus far. In the present study, the expression of RECK and MMP-2 was evaluated in two ACC cell lines and in 83 patients with SACC. The results of quantitative polymerase chain reaction and western blot analysis revealed that the ACC-2 and ACC-M cell lines expressed RECK and MMP-2 mRNA and protein. The immunohistochemical staining in the patients demonstrated that positive expression of RECK and MMP-2 was observed in 21/83 (25.3%) and 69/83 (83.1%) cases, respectively, and that RECK expression was significantly associated with the tumor-node-metastasis stage, histological grade and perineural invasion of patients with SACC (P<0.05). Furthermore, there was a significant association between the positive expression of RECK and that of MMP-2 (P<0.0001). Univariate and multivariate analyses confirmed that a lack of RECK expression was an independent and significant factor for the prediction of a poor prognosis. In conclusion, RECK is a promising prognostic marker and potential therapeutic agent in SACC.

Involvement of RECK in gambogic acid induced anti‐invasive effect in A549 human lung carcinoma cells

Gambogic acid (GA), a xanthone derived from the resin of the Garcinia hanburyi, has been demonstrated possessing anti-metastatic activity in vitro and in vivo. Reversion-inducing cysteine-rich protein with Kazal motifs (RECK), a membrane-anchored glycoprotein negatively regulating matrix metalloproteinases (MMPs), plays an important role in tumor invasion and metastasis. The present study investigates the regulatory effect of GA on RECK expression and the role of RECK in GA-induced anti-invasion in A549 human lung cancer cells. Our results showed that GA dose-dependently inhibited cell invasion and suppressed A549 experimental lung metastasis in vivo, which was attributed to RECK up-regulation at both protein and mRNA levels. With small interference RNA (siRNA) blocking RECK expression, we found inhibition of RECK decreased the GA-induced inhibition of MMP-2/9, which was in consistent with the attenuated anti-invasive effect of GA. Further study indicated that GA effectively suppressed Histone deacetylase (HDAC) 1/specificity protein (Sp) 1 binding and Sp1 phosphorylation associating with Extracellular signal-regulated kinases (ERK) signaling blocking, leading to RECK up-regulation. Taken together, these data demonstrate that RECK contributes to GA's anti-invasive activity and provide new evidence for GA being served as a therapeutic candidate for cancer metastasis.

RECK Gene Polymorphisms Influence NSCLC Susceptibility, but not the Chemotherapy Response Status in Chinese Cohort

To test the possible association between reversion-inducing cysteine-rich protein with Kazal motifs (RECK) genetic variants and susceptibility as well as the chemotherapy response status to in patients with advanced non-small cell lung cancer (NSCLC). We recruited 304 patients who were histologically diagnosed as advanced NSCLC (IIIa, IIIb, and IV stage) in our hospital from September 2003 to January 2008. We also enrolled 409 sex- and age-matched healthy volunteers as controls. RECK Gene Polymorphisms were determined. Only the genotype distributions and allele frequencies of rs10814325 T>C were significantly different between NSCLC and controls (both P < 0.001). By multivariate analyses, markedly higher risk for NSCLC was observed in rs10814325 CC genotype (adjusted OR = 2.302, P = 0.012, with TT as reference) after adjustment with age, sex, smoking status, histology, differentiation, and stage. Haplotypes analyses showed that the A(rs11788747)-G(rs16932912)-C(rs10814325) and A(rs11788747)-A(rs16932912A)-C(rs10814325) were associated with higher risk for NSCLC; however, G(rs11788747)-G(rs16932912)-T(rs10814325) and G(rs11788747)-A(rs16932912)-T(rs10814325) haplotypes showed significantly protective roles in the NSCLC risk. The genotype and the allele frequencies of RECK gene were not significantly different between chemotherapy responder and non-responders. Multivariate logistic regression analysis showed no association between the RECK polymorphism and chemotherapy response status in this study. To the best of our knowledge, this is the first study documenting the etiological role of RECK genetic polymorphisms in NSCLC.