Oncogene-mediated downregulation of RECK, a novel transformation suppressor gene

The alternatively spliced RECK transcript variant 3 is a predictor of poor survival for melanoma patients being upregulated in aggressive cell lines and modulating MMP gene expression in vitro

The reversion-inducing cysteine-rich protein with kazal motifs (RECK) gene was described as a tumor suppressor gene two decades ago. Recently, novel alternatively spliced products of this gene have been identified. Of these, the transcript variant 3 (RECKVar3) was shown to display tumor-facilitating effects in astrocytoma cells in vitro, with a higher RECKVar3/canonical RECK expression ratio being correlated with lower survival rates of patients. However, the regulatory mechanisms through which the cell controls the production and maintenance of these alternative transcripts, as well as their expression in other tumor types, remain elusive. Thus, the aim of this study is to investigate the role of the alternatively spliced transcripts from the RECK gene in melanoma progression as well as their regulation mechanism. To this end, we analyzed data from the Cancer Genome Atlas network and experimental data obtained from a panel of cell lines to show that high levels of RECKVar3 are predictive of poor survival. We also show that the MAPK and PI3K signaling pathways clearly play a role in determining the alternative-to-canonical ratio in vitro. Finally, we show that overexpression of the RECKVar3 protein upregulates matrix metalloproteinases (MMP)-9 and MMP-14 mRNA, while downregulating their inhibitor, tissue inhibitor of metalloproteinase (TIMP)3, and that RECKVar3-specific knockdown in the 1205Lu melanoma cell line hampered upregulation of the MMP9 mRNA promoted by the MEK1/2 inhibitor U0126. Taken together, our data complement the evidence that the RECK gene has a dual role in cancer, contributing to better understanding of the signaling cues, which dictate the melanoma invasive potential.

Low RECK Expression Is Part of the Cervical Carcinogenesis Mechanisms

Human papillomavirus (HPV)-induced carcinogenesis comprises alterations in the expression and activity of matrix metalloproteinases (MMP) and their regulators. Reversion-inducing Cysteine-rich protein with Kazal motifs (RECK) inhibits the activation of specific metalloproteinases and its expression is frequently lost in human cancers. Here we analyzed the role of RECK in cervical carcinogenesis. Cervical cancer derived cell lines over expressing RECK were used to determine tumor kinetics as well as, cellular, immune and molecular properties in vivo. Besides, we analyzed RECK expression in cervical cancer samples. RECK over expression (RECK+) delayed tumor growth and increased overall survival in vivo. RECK+ tumors displayed an increase in lymphoid-like inflammatory infiltrating cells, reduced number and viability of tumor and endothelial cells and lower collagenase activity. RECK+ tumors exhibited an enrichment of cell adhesion processes both in the mouse model and cervical cancer clinical samples. Finally, we found that lower RECK mRNA levels were associated with cervical lesions progression and worse response to chemotherapy in cervical cancer patients. Altogether, we show that increased RECK expression reduced the tumorigenic potential of HPV-transformed cells both in vitro and in vivo, and that RECK down regulation is a consistent and clinically relevant event in the natural history of cervical cancer.

Matrix Metalloproteinases in Bone Resorption, Remodeling, and Repair

Matrix metalloproteinases (MMPs) are the major protease family responsible for the cleavage of the matrisome (global composition of the extracellular matrix (ECM) proteome) and proteins unrelated to the ECM, generating bioactive molecules. These proteins drive ECM remodeling, in association with tissue-specific and cell-anchored inhibitors (TIMPs and RECK, respectively). In the bone, the ECM mediates cell adhesion, mechanotransduction, nucleation of mineralization, and the immobilization of growth factors to protect them from damage or degradation. Since the first description of an MMP in bone tissue, many other MMPs have been identified, as well as their inhibitors. Numerous functions have been assigned to these proteins, including osteoblast/osteocyte differentiation, bone formation, solubilization of the osteoid during bone resorption, osteoclast recruitment and migration, and as a coupling factor in bone remodeling under physiological conditions. In turn, a number of pathologies, associated with imbalanced bone remodeling, arise mainly from MMP overexpression and abnormalities of the ECM, leading to bone osteolysis or bone formation. In this review, we will discuss the functions of MMPs and their inhibitors in bone cells, during bone remodeling, pathological bone resorption (osteoporosis and bone metastasis), bone repair/regeneration, and emergent roles in bone bioengineering.

RECK is not an independent prognostic marker for breast cancer

Background

The 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.

Methods

The 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.

Results

Higher 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.

Conclusions

Although it continues to serve as an invasion and MMP inhibitor in breast cancer, RECK expression analysis is not useful for prognosis of these patients.

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

Background

Mutant 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.

Methods

Suppression subtractive hybridization PCR (SSH PCR) was conducted to identify Ha-ras^val12 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-ras^val12 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.

Results

Retinoblastoma binding protein-7 (RbAp46) was identified and confirmed as a Ha-ras^val12 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.

Conclusions

We confirmed that RbAp46 is a Ha-ras^val12 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 material

The online version of this article (doi:10.1186/s12885-015-1155-7) contains supplementary material, which is available to authorized users.

Sp1 and the 'hallmarks of cancer'

For many years, transcription factor Sp1 was viewed as a basal transcription factor and relegated to a role in the regulation of so-called housekeeping genes. Identification of Sp1's role in recruiting the general transcription machinery in the absence of a TATA box increased its importance in gene regulation, particularly in light of recent estimates that the majority of mammalian genes lack a TATA box. In this review, we briefly consider the history of Sp1, the founding member of the Sp family of transcription factors. We review the evidence suggesting that Sp1 is highly regulated by post-translational modifications that positively and negatively affect the activity of Sp1 on a wide array of genes. Sp1 is over-expressed in many cancers and is associated with poor prognosis. Targeting Sp1 in cancer treatment has been suggested; however, our review of the literature on the role of Sp1 in the regulation of genes that contribute to the 'hallmarks of cancer' illustrates the extreme complexity of Sp1 functions. Sp1 both activates and suppresses the expression of a number of essential oncogenes and tumor suppressors, as well as genes involved in essential cellular functions, including proliferation, differentiation, the DNA damage response, apoptosis, senescence and angiogenesis. Sp1 is also implicated in inflammation and genomic instability, as well as epigenetic silencing. Given the apparently opposing effects of Sp1, a more complete understanding of the function of Sp1 in cancer is required to validate its potential as a therapeutic target.

Low expression of RECK indicates a shorter survival for patients with invasive breast cancer

Expression cloning was used to initially isolate the reversion-inducing cysteine-rich protein with Kazal motifs (RECK) gene as a suppressor of transformation. The gene was found to encode a membrane-anchored regulator of MMPs. Experimental studies showed that RECK can suppress tumor invasion, metastasis, and angiogenesis. However, the clinical impact of RECK remains unclear. To assess the clinical significance of RECK expression in invasive breast cancer, a total of 119 patients with invasive breast cancer were retrospectively examined. Expression of RECK in tumor tissues was assessed by immunohistochemical staining. A significant correlation between RECK expression and 5-year survival rate was documented. The 5-year survival rate for patients with strong RECK expression was significantly higher than that for patients with weakly expressing tumors. Univariate and multivariate analyses confirmed that reduced RECK expression was an independent and significant factor in predicting a poor prognosis. In conclusion, RECK expression is a significant prognostic factor correlated with long-term survival for patients with invasive breast cancer. RECK expression is therefore a potentially useful prognostic marker for breast cancer.

The transformation suppressor gene Reck is required for postaxial patterning in mouse forelimbs

The membrane-anchored metalloproteinase-regulator RECK has been characterized as a tumor suppressor. Here we report that mice with reduced Reck-expression show limb abnormalities including right-dominant, forelimb-specific defects in postaxial skeletal elements. The forelimb buds of low-Reck mutants have an altered dorsal ectoderm with reduced Wnt7a and Igf2 expression, and hypotrophy in two signaling centers (i.e., ZPA and AER) that are essential for limb outgrowth and patterning. Reck is abundantly expressed in the anterior mesenchyme in normal limb buds; mesenchyme-specific Reck inactivation recapitulates the low-Reck phenotype; and some teratogens downregulate Reck in mesenchymal cells. Our findings illustrate a role for Reck in the mesenchymal-epithelial interactions essential for mammalian development.

Effect of RECK gene polymorphisms on hepatocellular carcinoma susceptibility and clinicopathologic features

BACKGROUND

The reversion-inducing-cysteine-rich protein with Kazal motifs (RECK) down-regulation has been confirmed in numerous human cancers and is clinically associated with metastasis. This study investigates the potential associations of RECK single-nucleotide polymorphisms (SNPs) with hepatocellular carcinoma (HCC) susceptibility and its clinicopathologic characteristics.

METHODOLOGY/PRINCIPAL FINDINGS

A total of 135 HCC cancer patients and 501 cancer-free controls were analyzed for four RECK SNPs (rs10814325, rs16932912, rs11788747, and rs10972727) using real-time PCR and PCR-RFLP genotyping analysis. After adjusting for other co-variants, the individuals carrying RECK promoter rs10814325 inheriting at least one C allele had a 1.85-fold [95% confidence interval (CI), 1.03-3.36] risk of developing HCC compared to TT wild type carriers. The HCC patients, who carried rs11788747 with at least one G allele, had a higher distant metastasis risk than wild type probands.

CONCLUSIONS

RECK gene polymorphisms might be a risk factor increasing HCC susceptibility and distant metastasis in Taiwan.

Development of secondary palate requires strict regulation of ECM remodeling: sequential distribution of RECK, MMP-2, MMP-3, and MMP-9

We have evaluated RECK (reversion-inducing-cysteine-rich protein with Kazal motifs), MMP-2 (matrix metalloproteinase-2), MMP-3, and MMP-9 involvement during palate development in mice by using various techniques. Immunohistochemical features revealed the distribution of RECK, MMP-2, and MMP-3 in the mesenchymal tissue and in the midline epithelial seam at embryonic day 13 (E13), MMPs-2, -3, and -9 being particularly expressed at E14 and E14.5. In contrast, RECK was weakly immunostained at these times. Involvement of MMPs was validated by measuring not only their protein expression, but also their activity (zymograms). In situ hybridization signal (ISH) for RECK transcript was distributed in mesenchymal and epithelial regions within palatal shelves at all periods evaluated. Importantly, the results from ISH analysis were in accord with those obtained by real-time polymerase chain reaction. The expression of RECK was found to be temporally regulated, which suggested possible roles in palatal ontogeny. Taken together, our results clearly show that remodeling of the extracellular matrix is finely modulated during secondary palate development and occurs in a sequential manner.

Influence of persistent canine distemper virus infection on expression of RECK, matrix-metalloproteinases and their inhibitors in a canine macrophage/monocytic tumour cell line (DH82)

A morbillivirus infection of tumour cells is known to exert oncolytic activity, but the mechanism of this inhibitory action has not been well defined. Matrix metalloproteinases (MMPs) are important enzymes degrading the extracellular matrix and are often upregulated in malignant neoplasms. Recent studies have demonstrated that RECK may potently suppress MMP-2 and -9 activity, thus inhibiting angiogenesis and metastasis. In this study, real time quantitative polymerase chain reaction (RT-qPCR) was used to determine the effect of persistent infection with canine distemper virus (CDV) infection on the expression of MMPs and their inhibitors (TIMPS) in a canine macrophage/monocytic tumour cell line (DH82). The activity of proMMP-2 and proMMP-9 was also verified zymographically. Following CDV infection, MMP-2, TIMP-1 and TIMP-2 were down-regulated, while RECK was upregulated. These findings suggest that CDV infection restores RECK expression in tumour cells and may interfere with the intracellular processing of MMPs and TIMPs, thus possibly influencing tumour cell behaviour beneficially for the host. However, this needs to be verified in in vivo studies.

Recklessness as a hallmark of aggressive cancer

Cancer recurrence after surgical treatment is a major concern for patients and doctors. Understanding what makes tumors prone to recurrence would be an important step toward its prevention. Accumulating evidence indicates that the level of membrane-associated protease regulator reversion-inducing cysteine-rich protein with Kazal motifs (RECK) expressed in tumor tissue is a good prognostic indicator in several common cancers. Certain members of the matrix metalloproteinase family are often upregulated in advanced cancers and are known to play important roles in tumor angiogenesis, invasion and metastasis. RECK negatively regulates several matrix metalloproteinases. Therefore, RECK itself may well be considered a promising tool or target molecule to be activated in cancer therapy. Here we review the recent advances in RECK research and discuss some of the important issues to be addressed in future studies.

Low expression of reversion-inducing cysteine-rich protein with Kazal motifs (RECK) indicates a shorter survival after resection in patients with adenocarcinoma of the lung

It has been reported that an endogenous matrix metalloproteinase (MMP) inhibitor, reversion-inducing cysteine-rich protein with Kazal motifs (RECK), is able to inhibit tumour angiogenesis, invasion, and metastasis through inhibition of MMP-2, MMP-9, and membrane type-1 (MT1)-MMP (MMP-14) secretion and activity. In this study, using quantitative real-time reverse transcriptase polymerase chain reaction (RT-PCR), we have analysed RECK expression levels in resected non-small-cell lung cancer (NSCLC) tissue and compared these data with the clinicopathological features of these patients to investigate the role of RECK in NSCLC. We have also analysed the expression of MMP-2, MMP-9, and MMP-14 and compared the data with those for RECK expression. Tissue samples of primary lung cancers were obtained from a total of 83 patients [46 with adenocarcinomas (ADC) and 37 with squamous cell carcinomas (SCC)] who underwent curative resection. The samples were taken from 83 tumours and 20 matched normal lung tissue samples as controls. Expressions of RECK in ADC and SCC were significantly lower than in the control. In ADC tissue, the expression of RECK was higher in stage IA than in stage IB-IIIA. There was no such a correlation in SCC. In ADC, univariate analysis for relapse-free survival using Cox regression analysis identified low RECK expression (p=0.036), low MMP-14 expression (p=0.038), and tumour T2 (p=0.034) as significant negative prognostic predictors. However, in SCC, none of the clinicopathological factors assessed, including RECK expression, had prognostic value. In conclusion, our study suggests that suppression of RECK expression is involved in the progression of ADC of the lung and that RECK expression in resected ADC of the lung is a favorable predictor of patients' prognosis.

Expression of reversion-inducing-cysteine-rich protein with Kazal motifs (RECK) as a prognostic indicator in gastric cancer

In this study the expression levels of reversion-inducing-cysteine-rich protein with Kazal motifs (RECK) in gastric cancer cell lines and tissues have been analysed in order to assess their value as a prognostic indicator. The expressions of RECK, activated matrix metalloproteinase (MMP)-7, and vascular endothelial growth factor (VEGF) in gastric cancer tissues and cell lines were evaluated by Western blot analysis; and MMP-2 and MMP-9 were evaluated by gelatin zymography. RECK expression in the context of gastric cancer was also compared with various clinicopathologic parameters and compared to the expression of activated MMP-7, MMP-2, and MMP-9. Fifty-two percent of the 102 gastric cancer tissues and 81.8% of the 11 gastric cancer cell lines exhibited reduced RECK expression. We also detected a significant inverse correlation between RECK expression and macroscopic tumour growth (P=0.018), lymphatic invasion (P=0.018), lymph node metastasis (P=0.000), stage (P=0.000), and MMP-9 (P=0.039). No correlation between RECK expression and MMP-7 and MMP-2, VEGF were detected. Our data strongly supports the hypothesis that RECK is a suppressor of malignancy, and constitutes a good prognostic indicator in gastric cancer.

Invasion of normal human fibroblasts induced by v-Fos is independent of proliferation, immortalization, and the tumor suppressors p16INK4a and p53

Invasion is generally perceived to be a late event during the progression of human cancer, but to date there are no consistent reports of alterations specifically associated with malignant conversion. We provide evidence that the v-Fos oncogene induces changes in gene expression that render noninvasive normal human diploid fibroblasts highly invasive, without inducing changes in growth factor requirements or anchorage dependence for proliferation. Furthermore, v-Fos-stimulated invasion is independent of the pRb/p16(INK4a) and p53 tumor suppressor pathways and telomerase. We have performed microarray analysis using Affymetrix GeneChips, and the gene expression profile of v-Fos transformed cells supports its role in the regulation of invasion, independent from proliferation. We also demonstrate that invasion, but not proliferation, is dependent on the activity of the up-regulated epidermal growth factor receptor. Taken together, these results indicate that AP-1-directed invasion could precede deregulated proliferation during tumorigenesis and that sustained activation of AP-1 could be the epigenetic event required for conversion of a benign tumor into a malignant one, thereby explaining why many malignant human tumors present without an obvious premalignant hyperproliferative dysplastic lesion.