Common colorectal cancer risk variants in SMAD7 are associated with survival among prediagnostic nonsteroidal anti-inflammatory drug users: a population-based study of postmenopausal women

Association of Body Mass Index With Colorectal Cancer Risk by Genome-Wide Variants

BACKGROUND

Body mass index (BMI) is a complex phenotype that may interact with genetic variants to influence colorectal cancer risk.

METHODS

We tested multiplicative statistical interactions between BMI (per 5 kg/m2) and approximately 2.7 million single nucleotide polymorphisms with colorectal cancer risk among 14 059 colorectal cancer case (53.2% women) and 14 416 control (53.8% women) participants. All analyses were stratified by sex a priori. Statistical methods included 2-step (ie, Cocktail method) and single-step (ie, case-control logistic regression and a joint 2-degree of freedom test) procedures. All statistical tests were two-sided.

RESULTS

Each 5 kg/m2 increase in BMI was associated with higher risks of colorectal cancer, less so for women (odds ratio [OR] = 1.14, 95% confidence intervals [CI] = 1.11 to 1.18; P = 9.75 × 10-17) than for men (OR = 1.26, 95% CI = 1.20 to 1.32; P = 2.13 × 10-24). The 2-step Cocktail method identified an interaction for women, but not men, between BMI and a SMAD7 intronic variant at 18q21.1 (rs4939827; Pobserved = .0009; Pthreshold = .005). A joint 2-degree of freedom test was consistent with this finding for women (joint P = 2.43 × 10-10). Each 5 kg/m2 increase in BMI was more strongly associated with colorectal cancer risk for women with the rs4939827-CC genotype (OR = 1.24, 95% CI = 1.16 to 1.32; P = 2.60 × 10-10) than for women with the CT (OR = 1.14, 95% CI = 1.09 to 1.19; P = 1.04 × 10-8) or TT (OR = 1.07, 95% CI = 1.01 to 1.14; P = .02) genotypes.

CONCLUSION

These results provide novel insights on a potential mechanism through which a SMAD7 variant, previously identified as a susceptibility locus for colorectal cancer, and BMI may influence colorectal cancer risk for women.

Genetic Variation and Hot Flashes: A Systematic Review

CONTEXT

Approximately 70% of women report experiencing vasomotor symptoms (VMS, hot flashes and/or night sweats). The etiology of VMS is not clearly understood but may include genetic factors.

EVIDENCE ACQUISITION

We searched PubMed and Embase in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidance. We included studies on associations between genetic variation and VMS. We excluded studies focused on medication interventions or prevention or treatment of breast cancer.

EVIDENCE SYNTHESIS

Of 202 unique citations, 18 citations met the inclusion criteria. Study sample sizes ranged from 51 to 17 695. Eleven of the 18 studies had fewer than 500 participants; 2 studies had 1000 or more. Overall, statistically significant associations with VMS were found for variants in 14 of the 26 genes assessed in candidate gene studies. The cytochrome P450 family 1 subfamily A member 1 (CYP1B1) gene was the focus of the largest number (n = 7) of studies, but strength and statistical significance of associations of CYP1B1 variants with VMS were inconsistent. A genome-wide association study reported statistically significant associations between 14 single-nucleotide variants in the tachykinin receptor 3 gene and VMS. Heterogeneity across trials regarding VMS measurement methods and effect measures precluded quantitative meta-analysis; there were few studies of each specific genetic variant.

CONCLUSIONS

Genetic variants are associated with VMS. The associations are not limited to variations in sex-steroid metabolism genes. However, studies were few and future studies are needed to confirm and extend these findings.

Comprehensive analysis of colorectal cancer-risk loci and survival outcome: A prognostic role for CDH1 variants

PURPOSE

Genome-wide association studies have identified common single nucleotide polymorphisms (SNPs) at 83 loci associated with colorectal cancer (CRC) risk in European populations. Because germline variation can also influence patient outcome, we studied the relationship between these SNPs and CRC survivorship.

EXPERIMENTAL DESIGN

For the 83 risk loci, 10 lead SNPs were directly genotyped, 72 were imputed and 1 was not genotyped nor imputed, in 1948 unrelated patients with advanced CRC from the clinical trials COIN and COIN-B (oxaliplatin and fluoropyrimidine chemotherapy ± cetuximab). A Cox survival model was used for each variant, and variants classified by pathway, adjusting for known prognostic factors. We imposed a Bonferroni threshold of P = 6.6 × 10-4 for multiple testing. We carried out meta-analyses of published risk SNPs associated with survival.

RESULTS

Univariate analysis identified six SNPs associated with overall survival (OS) (P < 0.05); however, only rs9939049 in CDH1 remained significant beyond the Bonferroni threshold (Hazard Ratio [HR] 1.44, 95% Confidence Intervals [CI]: 1.21-1.71, P = 5.0 × 10-5). Fine mapping showed that rs12597188 was the most significant SNP at this locus and remained significant after adjustment for known prognostic factors beyond multiple testing thresholds (HR 1.23, 95% CI: 1.13-1.34, P = 1.9 × 10-6). rs12597188 was also associated with poor response to therapy (OR 0.61, 95% CI: 0.42-0.87, P = 6.6 × 10-3). No combinations of SNPs within pathways were more significantly associated with survival compared with single variants alone, and no other risk SNPs were associated with survival in meta-analyses.

CONCLUSIONS

The CRC susceptibility SNP rs9939049 in CDH1 influences patient survival and warrants further evaluation as a prognostic biomarker.

Single Nucleotide Polymorphism in SMAD7 and CHI3L1 and Colorectal Cancer Risk

Colorectal cancer (CRC) is one of the leading cancers throughout the world. It represents the third most common cancer and the fourth in mortality. Most of CRC are sporadic, arise with no known high-penetrant genetic variation and with no previous family history. The etiology of sporadic CRC is considered to be multifactorial and arises from the interaction of genetic variants of low-penetrant genes and environmental risk factors. The most common well-studied genetic variation is single nucleotide polymorphisms (SNPs). SNP arises as a point mutation. If the frequency of the sequence variation reaches 1% or more in the population, it is referred to as polymorphism, but if it is lower than 1%, the allele is typically considered as a mutation. Lots of SNPs have been associated with CRC development and progression, for example, genes of TGF-β1 and CHI3L1 pathways. TGF-β1 is a pleiotropic cytokine with a dual role in cancer development and progression. TGF-β1 mediates its actions through canonical and noncanonical pathways. The most important negative regulatory protein for TGF-β1 activity is termed SMAD7. The production of TGF-β can be controlled by another protein called YKL-40. YKL-40 is a glycoprotein with an important role in cancer initiation and metastasis. YKL-40 is encoded by the CHI3L1 gene. The aim of the present review is to give a brief introduction of CRC, SNP, and examples of some SNPs that have been documented to be associated with CRC. We also discuss two important signaling pathways TGF-β1 and CHI3L1 that influence the incidence and progression of CRC.

The RS4939827 polymorphism in the SMAD7 GENE and its association with Mediterranean diet in colorectal carcinogenesis

Background

The objective of our investigation is to study the relationship between the rs4939827 SNP in the SMAD7 gene, Mediterranean diet pattern and the risk of colorectal cancer.

Methods

We examined 1087 cases of colorectal cancer and 2409 population controls with available DNA samples from the MCC-Spain study, 2008–2012. Descriptive statistical analyses, and multivariate logistic mixed models were performed. The potential synergistic effect of rs4939827 and the Mediterranean diet pattern was evaluated with logistic regression in different strata of of adherence to the Mediterranean diet and the genotype.

Results

High adherence to Mediterrenean diet was statistically significantly associated with colorectal cancer risk. A decreased risk for CRC cancer was observed for the CC compared to the TT genotype (OR = 0.65 and 95% CI = 0.51–0.81) of the rs4939827 SNP Also, we could show an association between the Mediterranean diet pattern (protective factor) and rs4939827. Although the decreased risk for the CC genotype was slightly more pronounced in subjects with high adherence to Mediterrenean diet, there was no statistically significant synergistic effect between genotype CC and adherence to the Mediterranean dietary pattern factors.

Conclusion

The SMAD7 gene and specifically the allele C could be protective for colorectal cancer. An independent protective association was also observed between high adherence Mediterranean diet pattern and CRC risk. Findings form this study indicate that high adherence to Mediterranean diet pattern has a protective role for CRC cancer probably involving the Tumor Growth Factor- β pathway in this cancer.

Electronic supplementary material

The online version of this article (10.1186/s12881-017-0485-5) contains supplementary material, which is available to authorized users.

Are SMAD7 rs4939827 and CHI3L1 rs4950928 polymorphisms associated with colorectal cancer in Egyptian patients?

A wide variety of genes have been associated with colorectal cancer (CRC) development and progression. The SMAD7 gene encodes an intracellular protein, which inhibits the transforming growth factor beta (TGF-β) signaling pathway, thereby having a key role in the control of neoplastic processes in various organs. The CHI3L1 gene encodes glycoprotein YKL-40, which plays a role in cell proliferation, anti-apoptosis, and angiogenesis. The present study aimed to evaluate the association of single nucleotide polymorphisms (SNPs) SMAD7 rs4939827 and CHI3L1 rs4950928, as well as circulating TGFβ-1 and YKL-40 levels with CRC in an Egyptian population of 77 CRC patients and 36 healthy controls. Polymorphisms in the SMAD7 rs4939827 and the CHI3L1 rs4950928 genes were determined using the real-time polymerase chain reaction (RT-PCR). Both the SMAD7 rs4939827 TT genotype and the CHI3L1 rs4950928 C allele were associated with the rectal but not the colon cancer. In addition, the C allele of both SMAD7 rs4939827 and CHI3L1 rs4950928 was associated with increased serum levels of TGF-β1 and YKL-40, respectively. In conclusion, our data suggest that SMAD7 rs4939827 and CHI3L1 rs4950928 SNPs have no significant association with CRC. A significant association of SNP in SMAD7 rs4939827 and CHI3L1 rs4950928 was revealed between the rectal cancer and colon cancer patients.

Common genetic variation and survival after colorectal cancer diagnosis: a genome-wide analysis

Genome-wide association studies have identified several germline single nucleotide polymorphisms (SNPs) significantly associated with colorectal cancer (CRC) incidence. Common germline genetic variation may also be related to CRC survival. We used a discovery-based approach to identify SNPs related to survival outcomes after CRC diagnosis. Genome-wide genotyping arrays were conducted for 3494 individuals with invasive CRC enrolled in six prospective cohort studies (median study-specific follow-up = 4.2-8.1 years). In pooled analyses, we used Cox regression to assess SNP-specific associations with CRC-specific and overall survival, with additional analyses stratified by stage at diagnosis. Top findings were followed-up in independent studies. A P value threshold of P < 5×10(-8) in analyses combining discovery and follow-up studies was required for genome-wide significance. Among individuals with distant-metastatic CRC, several SNPs at 6p12.1, nearest the ELOVL5 gene, were statistically significantly associated with poorer survival, with the strongest associations noted for rs209489 [hazard ratio (HR) = 1.8, P = 7.6×10(-10) and HR = 1.8, P = 3.7×10(-9) for CRC-specific and overall survival, respectively). No SNPs were statistically significantly associated with survival among all cases combined or in cases without distant-metastases. SNPs in 6p12.1/ELOVL5 were associated with survival outcomes in individuals with distant-metastatic CRC, and merit further follow-up for functional significance. Findings from this genome-wide association study highlight the potential importance of genetic variation in CRC prognosis and provide clues to genomic regions of potential interest.

The effect of prediagnostic aspirin use on the prognosis of stage III colorectal cancer

BACKGROUND

Many studies have suggested that the regular use of non-steroidal anti-inflammatory drugs (NSAIDs), including aspirin, has a protective effect and survival benefit on colorectal cancer (CRC). However, recent data suggest that CRCs have different responses to NSAIDs depending on the timing of NSAID initiation, duration of NSAID use, and molecular characteristics of the tumor. The aim of this study was to evaluate the effect of long-term prediagnostic aspirin use on the prognosis of stage III CRC.

METHODS

From 2007 to 2009, patients who were diagnosed with stage III CRC were recruited, and their medical records were retrospectively analyzed. Patients were divided into prediagnostic aspirin users (who used aspirin for more than three months continuously before CRC diagnosis) and non-users (who did not use of aspirin and NSAIDs). The two groups were compared in terms of recurrence, cancer-specific mortality, disease-free survival (DFS), and cancer-specific survival. In an experimental study, three CRC cell lines (Caco2, SW480, and DLD-1) were pretreated with aspirin (1 mM) for four days or 28 days to make aspirin-resistant cells, treated with 5-fluorouracil (5-FU; 2 µM), and apoptosis was measured with flow cytometry using Annexin-V and propidium iodide double staining.

RESULTS

Compared with the aspirin non-users (N=565), the prediagnostic aspirin users (N=121) were not different in terms of baseline characteristics including tumor characteristics, except for comorbidities and diabetes medication and statin use, which were higher in the prediagnostic aspirin users. Recurrence and cancer-specific mortality in stage III CRC were significantly higher in prediagnostic aspirin users than non-users (46.7% vs. 32.3%, P=0.003 and 32.2% vs. 19.8%, P=0.003, respectively). Survival analysis using Cox proportional hazards modeling demonstrated that DFS was significantly worse in prediagnostic aspirin users than non-users (HR, 1.525 (1.018-2.286); P=0.041). In cell line experiments, long-term aspirin pretreatment induced an increase in 5-FU-induced apoptosis in SW480 cells compared with control treatment without aspirin pretreatment. However, Caco2 cells showed a significant decrease of apoptosis in the same experiments and no change in DLD1 cells.

CONCLUSION

Prediagnostic long-term aspirin use in stage III CRC could be a negative prognostic factor depending on the characteristics of the CRC.

Nonsteroidal anti-inflammatory drugs in-vitro and in-vivo treatment and Multidrug Resistance Protein 4 expression in human platelets

Platelet Multidrug Resistance Protein 4 (MRP4)-overexpression has a role in reducing aspirin action in patients after by-pass surgery. Aspirin induces platelet MRP4 over-expression, through megakaryocytes genomic modulation. Aim of our work was to verify whether other non-steroidal antiinflammatory drugs (NSAIDs) enhance platelet MRP4 expression and evaluate platelet function in patients who overexpressed MRP4. We evaluated MRP4-mRNA in a human megakacaryoblastic cell line (DAMI), treated with both COX-2 inhibitor (celecoxib) and traditional NSAIDs (diclofenac and naproxen). Osteoarthritis patients, who reported to take NSAIDs twice a week for at least four continuous weeks and a control population, who didn't take any drugs during the previous month, were enrolled. We evaluated platelet MRP4 amount, by both mRNA levels and protein expression (Western-Blot) and ADP induced platelet aggregation. DAMI cells treated with celecoxib, diclofenac, and naproxen showed a significant increase in MRP4-mRNA expression compared to the mock culture. Osteoarthritis patient platelets presented a higher expression of MRP4 (both at mRNA and protein levels) and an increase in ADP-induced platelet aggregation compared to the control population. NSAID treatment induced platelet MRP4 overexpression. Osteoarthritis patients, who overexpress MRP4, showed platelet hyper-reactivity. These evidences could explain in part the increased cardiovascular risk present during NSAID treatment.

A retrospective observational study of the relationship between single nucleotide polymorphisms associated with the risk of developing colorectal cancer and survival

BACKGROUND

There is variability in clinical outcome for patients with apparently the same stage colorectal cancer (CRC). Single nucleotide polymorphisms (SNPs) mapping to chromosomes 1q41, 3q26.2, 6p21, 8q23.3, 8q24.21, 10p14, 11q13, 11q23.1, 12q13.13, 14q22, 14q22.2, 15q13.3, 16q22.1, 18q21.1, 19q13.11, 20p12, 20p12.3, 20q13.33 and Xp22 have robustly been shown to be associated with the risk of developing CRC. Since germline variation can also influence patient outcome the relationship between these SNPs and patient survivorship from CRC was examined.

METHODS

All enrolled into the National Study of Colorectal Cancer Genetics (NSCCG) were genotyped for 1q41, 3q26.2, 6p21, 8q23.3, 8q24.21, 10p14, 11q13, 11q23.1, 12q13.13, 14q22, 14q22.2, 15q13.3, 16q22.1, 18q21.1, 19q13.11, 20p12, 20p12.3, 20q13.33 and xp22 SNPs. Linking this information to the National Cancer Data Repository allowed patient genotype to be related to survival.

RESULTS

The linked dataset consisted of 4,327 individuals. 14q22.22 genotype defined by the SNP rs4444235 showed a significant association with overall survival. Specifically, the C allele was associated with poorer observed survival (per allele hazard ratio 1.13, 95% confidence interval 1.05-1.22, P = 0.0015).

CONCLUSION

The CRC susceptibility SNP rs4444235 also appears to exert an influence in modulating patient survival and warrants further evaluation as a potential prognostic marker.

Germline variation in colorectal risk Loci does not influence treatment effect or survival in metastatic colorectal cancer

BACKGROUND

Colorectal cancer (CRC) risk is partly conferred by common, low-penetrance single nucleotide polymorphisms (SNPs). We hypothesized that these SNPs are associated with outcomes in metastatic CRC.

METHODS

Six candidate SNPs from 8q24, 10p14, 15q13, 18q21 were investigated for their association with response rate (RR), time to progression (TTP) and overall survival (OS) among 524 patients treated on a phase III clinical trial of first-line chemotherapy for metastatic CRC.

RESULTS

rs10795668 was weakly associated with TTP (p = 0.02), but not RR or OS. No other SNPs carried statistically significant HRs for any of the primary outcomes (RR, TTP or OS).

CONCLUSION

Common low-penetrance CRC risk SNPs were not associated with outcomes among patients with metastatic CRC.

Genetic variations in SMAD7 are associated with colorectal cancer risk in the colon cancer family registry

Background

Recent genome-wide studies identified a risk locus for colorectal cancer at 18q21, which maps to the SMAD7 gene. Our objective was to confirm the association between SMAD7 SNPs and colorectal cancer risk in the multi-center Colon Cancer Family Registry.

Materials and Methods

23 tagging SNPs in the SMAD7 gene were genotyped among 1,592 population-based and 253 clinic-based families. The SNP-colorectal cancer associations were assessed in multivariable conditional logistic regression.

Results

Among the population-based families, both SNPs rs12953717 (odds ratio, 1.29; 95% confidence interval, 1.12–1.49), and rs11874392 (odds ratio, 0.80; 95% confidence interval, 0.70–0.92) were associated with risk of colorectal cancer. These associations were similar among the population- and the clinic-based families, though they were significant only among the former. Marginally significant differences in the SNP-colorectal cancer associations were observed by use of nonsteroidal anti-inflammatory drugs, cigarette smoking, body mass index, and history of polyps.

Conclusions

SMAD7 SNPs were associated with colorectal cancer risk in the Colon Cancer Family Registry. There was evidence suggesting that the association between rs12953717 and colorectal cancer risk may be modified by factors such as smoking and use of nonsteroidal anti-inflammatory drugs.

Association of SMAD7 rs12953717 polymorphism with cancer: a meta-analysis

BACKGROUND

Accumulating evidence has suggested that Mothers against decapentaplegic homolog 7 (SMAD7) rs12953717 polymorphism might be related to cancer risk. However, epidemiologic findings have been inconsistent. We therefore performed a meta-analysis to clarify the association between the SMAD7 rs12953717 polymorphism and cancer risk.

METHODS

A comprehensive search was conducted to identify all eligible studies of SMAD7 rs12953717 polymorphism and cancer risk. We used odds ratios (ORs) to assess the strength of the association, and 95% confidence intervals (CIs) to give a sense of the precision of the estimate. Heterogeneity, publication bias, and sensitivity analysis were also explored.

RESULTS

A total of 14 case-control studies, including 16928 cases and 14781 controls, were included in the present meta-analysis. The overall results showed that the variant genotypes were associated with a significantly increased risk of all cancer types (homozygote comparison, OR = 1.23, 95%CI = 1.10-1.38, P<0.01; heterozygote comparison, OR = 1.12, 95%CI = 1.02-1.22, P = 0.02; recessive model, OR = 1.17, 95%CI = 1.07-1.29, P<0.01; dominant model, OR = 1.15, 95%CI = 1.06-1.25, P<0.01; allelic model, OR = 1.12, 95%CI = 1.06-1.18, P<0.01). Further sensitivity analysis confirmed the significant association. In the subgroup analysis by ethnicity, SMAD7 rs12953717 polymorphism was significantly associated with cancer risk in both Caucasians and Asians. In the subgroup analysis by cancer types, SMAD7 rs12953717 polymorphism was significantly associated with colorectal cancer.

CONCLUSIONS

Our investigations demonstrate that rs12953717 polymorphism is associated with the susceptibility of cancer. Large-scale and well-designed case-control studies are necessary to validate the risk identified in the present meta-analysis.

Phenotypic and tumor molecular characterization of colorectal cancer in relation to a susceptibility SMAD7 variant associated with survival

The minor allele (G) of rs4939827, a SMAD7 (18q21) intronic variant, is associated with a lower risk of developing colorectal cancer (CRC) and poorer survival after diagnosis. Our objective was to evaluate the associations of this variant with different tumor phenotype and intratumoral molecular characteristics. We evaluated 1509 CRC cases and 2307 age-matched controls nested within the Nurses' Health Study and the Health Professionals Follow-up Study. We used the TaqMan assay to genotype rs4939827 and logistic regression to assess the association of rs4939827 with risk of CRC according to different phenotypic and molecular characteristics. We found that the minor allele (G) in rs4939827 (SMAD7, 18q21) was associated with a lower risk of developing tumor stage pT1 or pT2 CRC [multivariate odds ratio (OR), 0.73; 95% confidence interval (CI) 0.62-0.87] but not tumor stage pT3 or pT4 (multivariate OR, 1.07; 95% CI 0.93-1.23, P for heterogeneity = 1.2 × 10(-4)). The association between rs4939827 and CRC also significantly differed by methylation of RUNX3 (P for heterogeneity = 0.005). Among those with CRC, the minor allele (G) in rs4939827 was significantly associated with poorer overall survival (hazards ratio, 1.20; 95% CI, 1.02-1.42). We can conclude that the minor allele (G) of the germline intronic SMAD7 variant rs4939827 is associated with a lower risk of CRC with earlier tumor stage and CRC without methylation of the tumor suppressor RUNX3. These findings suggest that individuals with this SMAD7 variant that develop CRC are more probably to have tumors with greater invasiveness and methylation of RUNX3, which potentially contributes to their poorer observed survival.

Association between colorectal cancer susceptibility loci and survival time after diagnosis with colorectal cancer

Genome-wide association studies have identified 16 germline single-nucleotide polymorphisms (SNPs) that are associated with colorectal cancer (CRC) incidence. We examined the relationship between these SNPs and survival of 2611 individuals with CRC, enrolled in 5 cohort studies. We used Cox regression analysis to associate SNPs with overall and CRC-specific survival times. The minor allele in rs4939827 (SMAD7) was associated with reduced overall survival (hazard ratio, 1.16; 95% confidence interval, 1.06-1.27; P = .002) and disease-specific survival (hazard ratio, 1.17; 95% confidence interval, 1.05-1.30; P = .005). Other SNPs were not associated significantly with survival. Common germline variations might be prognostic factors for patients with CRC. A variant in SMAD7 could affect progression of CRC.

Celecoxib down-regulates RECK expression and up-regulates MMP-2 and MMP-9 expression in human gastric cancer cell line MGC-803

AIM: To explore the antitumor mechanisms of celecoxib by investigating the impact of non-steroidal anti-inflammatory drug (NSAID) celecoxib on the expression of RECK, MMP-2 and MMP-9 in human gastric cancer cell line MGC-803.

METHODS: MGC-803 cells were starved in serum-free medium for 24 h and treated with different concentrations of celecoxib (25, 50, and 100 μg/L) for different durations (12, 24, and 48 h). Cell proliferation was determined by MTT assay. The expression of MMP-9, MMP-2 and RECK mRNAs and proteins was detected by RT-PCR and Western blot, respectively.

RESULTS: Celecoxib inhibited MGC-803 cell proliferation in a concentration-dependent manner at 24 and 48 h but not at 12 h. The inhibitory effect was also time-dependent. Cell proliferation was mostly inhibited after treatment with celecoxib at a concentration of 100 μg/L for 48 h. The expression of RECK, MMP-2 and MMP-9 mRNAs showed no significant differences (all P > 0.05) among cells treated with different concentrations of celecoxib for 12 h. After 12 h, celecoxib increased RECK mRNA expression in a concentration- and time-dependent manner, but decreased the expression of MMP-2 and MMP-9. Similar results were also obtained for RECK, MMP-2 and MMP-9 protein expression.

CONCLUSION: Celecoxib inhibits the proliferation and metastasis of MGC-803 cells possibly via mechanisms associated with up-regulation of RECK expression and down-regulation of MMP-2 and MMP-9 expression.