8434

RECK

reversion-inducing-cysteine-rich protein with kazal motifs;RECK;reversion-inducing-cysteine-rich protein with kazal motifs

membrane-anchored glycoprotein (metastasis and invasion)|reversion-inducing cysteine-rich protein with Kazal motifs|suppression of tumorigenicity 15 (reversion-inducing-cysteine-rich protein with kazal motifs)|suppression of tumorigenicity 5 (reversion-in

9p13.3

protein-coding

Neuroblastoma is the most common malignant tumour in infancy; the reversion-inducing cysteine-rich protein with Kazal motifs gene (RECK) is a tumour suppressor gene. Previous studies show that RECK inhibits tumour invasion and metastasis through negative regulation of the matrix metalloproteinase (MMP)-2, MMP-9 and MMP-14. Therefore, we wanted to detect the expression of RECK and MMP-14 in neuroblastomas to assess the correlation between the expression levels of these proteins, and to investigate the roles in the metastasis and development of the tumour. PV-6000 immunohistochemistry method was used to detect the expression levels of RECK and MMP-14 in 36 samples of neuroblastoma tissue. Samples from paraffin wax-embedded specimens and the complete clinicopathological data of 36 neuroblastoma and 10 ganglioneuroma patients were collected. The rate of expression of the RECK protein in the neuroblastoma was low (16.7%). Furthermore, it reduced with the increase in the invasive depth and distant metastasis (P = 0.015; P < 0.05). The rate of expression of the MMP-14 protein in the neuroblastoma was high (58.3%) and increased with the increase in the extent of invasive depth and distant metastasis (P = 0.002; P < 0.05). The expression of the RECK protein correlated negatively with that of MMP-14 (r = -0.418; P < 0.05). Low levels of the RECK protein are expressed in the neuroblastoma, while the MMP-14 protein is expressed at high levels. The RECK and MMP-14 proteins may serve as markers in the estimation of the extent of metastasis and dissemination of the neuroblastoma.

Our previous study demonstrates that HER-2/Neu oncogene inhibits a matrix metalloproteinase inhibitor and tumor metastasis suppressor RECK to promote metastasis. Conversely, the effect of RECK on the oncogenic function of HER-2/Neu is unknown. Ectopic expression of RECK in 293T cells and HER-2/Neu-overexpressing breast cancer cells shows that RECK and HER-2/Neu are co-localized and these two proteins can be co-immunoprecipitated. RECK inhibits HER-2/Neu receptor dimerization and autophosphorylation, which causes reduction of ERK and AKT kinase activity and down-regulation of HER-2/Neu target genes. RECK expression is reduced in 58.8% of breast cancer tissues and is associated with lymph node invasion supporting its anti-metastatic role. Collectively, we provide the first evidence that RECK can negatively regulate oncogenic activity of HER-2/Neu by inhibiting receptor dimerization.

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.

AIM AND BACKGROUND: Cervical cancer remains the third most common cancer in women globally after breast and colorectal cancer. Well-characterized biomarkers are necessary for early diagnosis and to predict metastatic progression and effective therapy. MiRNAs can regulate gene expression, cell growth, differentiation and apoptosis by targeting mRNAs for translational repression or degradation in tumor cells. The present study was conducted to assess expression of miR93, miR200a, RECK, MMP2, MMP9 in invasive cervical carcinoma, and analyze their clinical significance. METHOD: A total of 116 patients with invasive cervical carcinoma and 100 patients undergoing hysterectomy for benign lesions were retrospectively examined. Quantitative real-time PCR was performed to determine expression of miR93 and miR200a while RECK, MMP2, MMP9 and MVD were assessed by immunohistochemical staining. RESULTS: Cervical carcinoma patients demonstrated up-regulation of miR-93, miR-200a, MMP2 and MMP9, with down-regulation of RECK as compared to benign lesion tissues. RECK was significantly inversely related to invasion and lymphatic metastasis. The 5-year survival rate for patients with strong RECK expression was significantly higher than that with weakly expressing tumors. CONCLUSION: MiR-93 and miR-200a are associated with metastasis and invasion of cervical carcinoma. Thus together with RECK they are potential prognostic markers for cervical carcinoma. RECK cooperating with MMP2, MMP9 expression is a significant prognostic factor correlated with long-term survival for patients with invasive cervical carcinoma.

BACKGROUND: Reversion-inducing-cysteine-rich protein with Kazal motifs (RECK) has been implicated in the attenuation of tumor metastasis by negatively regulating metalloproteinase (MMP) levels. RECK gene expression is downregulated in many solid tumors, with this downregulation being associated with poor prognosis. This study evaluated the role of RECK in cholangiocarcinoma (CCA). METHODS: The expression of RECK, MMP-2, and MMP-9 in paraffin sections of hamster and human CCA specimens was analyzed by immunohistochemistry. Functional analysis of RECK was performed in RECK small interfering (si) RNA knockdown CCA cell lines. The effect of aspirin on RECK status and function was evaluated using Western blotting, gelatin zymography, invasion and proliferation assays, and PhosphoELISArray analysis of Ras downstream mediators. RESULTS: Hamster tissues showed high RECK expression in hyperplastic biliary duct epithelia, low RECK expression in precancerous lesions, and no RECK expression in CCA. In human specimens, RECK was highly expressed in normal biliary cells, whereas intrahepatic CCA showed low levels of expression. Downregulation of RECK was correlated with tumor metastasis (P < 0.01) and shorter patient survival (P < 0.02). RECK expression levels were inversely correlated with MMP-2 and MMP-9 expression (P < 0.05). SiRNA RECK-depleted M139 CCA cells exhibited increased MMP-2/-9 gelatinase activities and invasiveness. Aspirin (500 muM) demonstrated myriad effects in human CCA cell lines, including growth suppression, reduced phosphorylation of Akt/Erk/c-Jun, elevation of RECK expression, inhibition of MMP-2/MMP-9 activity, and enhanced invasiveness. CONCLUSIONS: RECK functions as a metastasis suppressor in CCA; upregulation of RECK expression could provide a potential therapy to improve the prognosis of this type of cancer.

Down-regulation of RECK, an important metastasis suppressor gene, has been found in human colon cancer. However, the molecular mechanism for this down- regulation and its biological significance are still unclear. In the present study, we investigated whether down-regulation of RECK is caused by epigenetic inactivation via promoter methylation and tested the effect of DNA methyltransferase (DNMT) inhibitor on RECK expression and cell invasion. The mRNA and protein levels of RECK in colon tumor tissues and their normal counterparts were compared. We found that down-regulation of RECK was found in 48% of the twenty five tumors analyzed. MSP analysis demonstrated that methylation of RECK promoter was detected in 44% (11/25) of the tumor tissues and a strong correlation between down-regulation and promoter methylation was found (P = 0.028). Promoter methylation was also found in SW480 and SW620 human colon cancer cell lines. DNA methyltransferase (DNMT) inhibitor 5-azacytidine reversed promoter methylation, restored RECK expression and suppressed invasion by these two cell lines. Restoration of RECK is critical for 5-azacytidine-mediated suppression of cell invasion because inhibition of RECK by a specific antibody significantly attenuated the anti-invasive ability of 5-azacytidine. Taken together, our results suggest that down-regulation of the metastasis suppressor RECK in colon cancer is associated with promoter methylation and that a DNMT inhibitor may restore RECK expression to inhibit cell invasion.

Matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9) and membrane-type matrix metalloproteinase 1 (MT1-MMP) are involved in colorectal cancer invasion and metastasis. Reversion-inducing cysteine-rich protein with Kazal motifs (RECK) inhibits MMP-2, MMP-9 and MT1-MMP. We examined the clinicopathological significance of the relative expression of these genes in patients with colorectal cancer, especially with regard to metastasis. We studied surgical specimens of cancer tissue and adjacent normal mucosa obtained from 205 patients with untreated colorectal carcinoma. MMP-2, MMP-9, MT1-MMP, RECK and beta-actin mRNA of cancer tissue and adjacent normal mucosa were measured by quantitative real-time reverse-transcriptase polymerase chain reaction. MT1-MMP gene expression was higher in cancer tissue than in adjacent normal mucosa. In contrast, MMP-2, MMP-9 and RECK gene expression levels were lower in cancer tissue than in adjacent normal mucosa. As for the relationship between the gene expression and clinicopathological factors, MMP-2 expression correlated with the depth of invasion, venous invasion and liver metastasis; MMP-9 and RECK expression correlated with venous invasion. There were positive correlations among the gene expression levels of MMP-2, MMP-9 and RECK. MMP-2 gene expression was considered a useful predictor of liver metastasis from colorectal cancer.

RECK, a glycosylphosphatidylinositol-anchored glycoprotein, inhibits the enzymatic activities of some matrix metalloproteinases (MMP), thereby suppressing tumor cell metastasis; however, the detailed mechanism is still obscure. In this study, we compared the gene expression profiles between mock- and RECK-transfected HT1080 cells and showed that RECK decreases MMP-9 mRNA levels but not other MMP mRNA levels. Moreover, treatment with RECK-specific siRNA increased MMP-9 mRNA in RECK-expressing cells. The promoter assay showed that MMP-9 promoter activity was suppressed by RECK and that RECK-mediated suppression of MMP-9 promoter activity requires 12-O-tetradecanoylphorbol-13-acetate-responsive element (TRE) and kappaB sites. Moreover, the binding ability of Fra-1 and c-Jun to TRE within the MMP-9 promoter region was suppressed by RECK. Thus, these results show that RECK is a negative regulator of MMP-9 transcription.

AIM: To investigate the relation between RECK methylation and clinicopathological characteristics of gastric cancer patients and evaluate the role of RECK methylation in peritoneal metastasis of gastric cancer. METHODS: Methylation of RECK gene in 40 paired samples of gastric cancer and its corresponding adjacent normal mucosa, lymph nodes and peritoneal irrigation fluid was detected by methylation-specific polymerase chain reaction. RESULTS: Aberrant methylation of RECK gene was detected in 27.5% (11/40) of the adjacent normal mucosa samples, in 47.5% (19/40) of gastric cancer samples, in 57.1% (12/21) of the lymph node samples, and in 35% (14/40) of peritoneal irrigation fluid samples, respectively, with a significant difference between the adjacent normal mucosa and lymph node samples (P = 0.023). Presence of RECK methylation in the primary tumor samples was significantly correlated with tumor invasion (P = 0.023). The accuracy of RECK methylation in peritoneal lavage fluid samples for the diagnosis of peritoneal metastasis of gastric cancer was 72.5% (26/40), with a sensitivity of 66.7% (6/9) and a specificity of 74.2% (23/31). CONCLUSION: Aberrant methylation of RECK gene may provide useful information for the early diagnosis and treatment of peritoneal metastasis of gastric cancer.

Invasive behavior is the pathological hallmark of malignant gliomas, being responsible for the failure of surgery, radiation, and chemotherapy. Matrix metalloproteinases (MMPs) are essential for proper ECM remodeling and invasion. The tumor and metastasis suppressor RECK protein regulates at least three members of the MMPs family: MMP-2, MMP-9, and MT1-MMP. In order to mimic the in vivo invasion process, A172 and T98G, respectively, non-invasive and invasive human glioblastoma cell lines, were cultured onto uncoated (control) or type I collagen gel-coated surface, and maintained for up to 7 days to allow establishment of the invasive process. We show that the collagen substrate causes decreased growth rates and morphological alterations correlated with the invasive phenotype. Electronic transmission microscopy of T98G cells revealed membrane invaginations resembling podosomes, which are typically found in cells in the process of crossing tissue boundaries, since they constitute sites of ECM degradation. Real time PCR revealed higher RECK mRNA expression in A172 cells, when compared to T98G cells and, also, in samples obtained from cultures where the invasive process was fully established. Interestingly, the collagen substrate increases RECK expression in A172 cells and the same tendency is displayed by T98G cells. MMPs-2 and -9 displayed higher levels of expression and activity in T98G cells, and their activities are also upregulated by collagen. Therefore, we suggest that: (1) RECK downregulation is critical for the invasiveness process displayed by T98G cells; (2) type 1 collagen could be employed to modulate RECK expression in glioblastoma cell lines. Since a positive correlation between RECK expression and patients survival has been noted in several types of tumors, our results may contribute to elucidate the complex mechanisms of malignant gliomas invasiveness.

Reversion-inducing cysteine-rich protein with Kazal motifs (RECK), a tumor and metastasis suppressor gene, is critical for the regulation of the invasive and metastatic activities of tumor cells. RECK is down-regulated in some malignancies and its expression is positively correlated with survival of patients with cancer. Patients with malignant glioma have poor prognosis. Since RECK expression decreases as the tumor stage progresses from less invasive grade II glioma to invasive glioblastoma multiforme, up-regulation of RECK by natural or synthetic agents might be a valuable therapeutic option for glioma. Histone deacetylase inhibitors and non-steroidal anti-inflammatory drugs have been widely used clinically and demonstrated to increase RECK expression in cancer cells, thus they might be used as RECK inducers. In this article, the functions of RECK and the role of RECK in glioma are reviewed, with emphasis on the potential application of RECK inducers in the treatment of glioma.

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.

RECK is a membrane-anchored glycoprotein that may negatively regulate matrix metalloproteinase activity to suppress tumor invasion and metastasis. Our previous study indicated that oncogenic RAS inhibited RECK expression via a histone deacetylation mechanism. In this study, we address whether DNA methyltransferases (DNMT) participate in the inhibition of RECK by RAS. Induction of Ha-RAS(Val12) oncogene increased DNMT3b, but not DNMT1 and DNMT3a, expression in 2-12 cells. In addition, induction of DNMT3b by RAS was through the extracellular signal-regulated kinase signaling pathway. Oncogenic RAS increased the binding of DNMT3b to the promoter of RECK gene and this binding induced promoter methylation, which could be reversed by 5'-azacytidine and DNMT3b small interfering RNA (siRNA). The MEK inhibitor U0126 also reversed RAS-induced DNMT3b binding and RECK promoter methylation. Treatment of 5'-azacytidine and DNMT3b siRNA restored RECK expression in 2-12 cells and potently suppressed RAS-stimulated cell invasion. In addition, the inhibitory effect of 5'-azacytidine on RAS-induced cell invasion was attenuated after knockdown of RECK by siRNA. Interestingly, human lung cancer cells harboring constitutively activated RAS exhibited lower RECK expression and higher promoter methylation of RECK gene. 5'-Azacytidine and DNMT3b siRNA restored RECK expression in these cells and effectively suppressed invasiveness. Collectively, our results suggest that RAS oncogene induces RECK gene silencing through DNMT3b-mediated promoter methylation, and DNMT inhibitors may be useful for the treatment of RAS-induced metastasis.

RECK is a membrane-anchored glycoprotein which may negatively regulate matrix metalloproteinase (MMP) activity to suppress tumor invasion and metastasis. In this study, recombinant proteins corresponding to the residues 285-368 (named as CKM which contained cysteine knot motif), 605-799 (named as K123 which contained three Kazal motifs), 676-799 (named as K23 which contained the last two Kazal motifs) and full-length RECK were produced and their anti-cancer effects were tested. Full-length RECK and K23 but not K123 and CKM inhibited MMP9 secretion and activity. In addition, RECK and K23 inhibited invasion but not migration of metastatic lung cancer cells in vitro. Protein binding and kinetic study indicated that K23 physically interacted with MMP-9 and inhibited its activity by a non-competitive manner. Moreover, K23 reduced metastatic tumor growth in lungs of nude mice. Taken together, our results suggest that the K23 motifs of RECK protein can inhibit MMP-9 secretion and activity and attenuate metastasis of lung cancer cells.

RECK is a membrane-anchored glycoprotein that may negatively regulate matrix metalloproteinase activity to suppress tumor invasion and metastasis. Our previous study indicated that oncogenic RAS inhibited RECK expression via a histone deacetylation mechanism. In this study, we address whether DNA methyltransferases (DNMT) participate in the inhibition of RECK by RAS. Induction of Ha-RAS(Val12) oncogene increased DNMT3b, but not DNMT1 and DNMT3a, expression in 2-12 cells. In addition, induction of DNMT3b by RAS was through the extracellular signal-regulated kinase signaling pathway. Oncogenic RAS increased the binding of DNMT3b to the promoter of RECK gene and this binding induced promoter methylation, which could be reversed by 5'-azacytidine and DNMT3b small interfering RNA (siRNA). The MEK inhibitor U0126 also reversed RAS-induced DNMT3b binding and RECK promoter methylation. Treatment of 5'-azacytidine and DNMT3b siRNA restored RECK expression in 2-12 cells and potently suppressed RAS-stimulated cell invasion. In addition, the inhibitory effect of 5'-azacytidine on RAS-induced cell invasion was attenuated after knockdown of RECK by siRNA. Interestingly, human lung cancer cells harboring constitutively activated RAS exhibited lower RECK expression and higher promoter methylation of RECK gene. 5'-Azacytidine and DNMT3b siRNA restored RECK expression in these cells and effectively suppressed invasiveness. Collectively, our results suggest that RAS oncogene induces RECK gene silencing through DNMT3b-mediated promoter methylation, and DNMT inhibitors may be useful for the treatment of RAS-induced metastasis.

Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) has been suggested to be involved in tumor metastasis. However, the molecular mechanism of LMP1-induced metastasis is largely unknown. In this study, we investigated the effect of LMP1 on the expression of RECK, a metastasis suppressor gene, in an EBV-negative nasopharyngeal carcinoma (NPC) cell line. Our data demonstrated that LMP1 induced downregulation of RECK via transcription repression in TW04 cells. In addition, we found that LMP1 acted via an Sp1 site to inhibit RECK promoter activity. We next studied the signaling pathway that mediated the effect of LMP1 on RECK expression. Our results showed that LMP1 potently stimulated the activity of extracellular signal-regulated kinases (ERKs) and inhibition of ERK activity by PD98059 antagonized LMP1-induced downregulation of RECK. Conversely, the c-Jun N-terminal kinase inhibitor SP600125 and p38(HOG) kinase inhibitor SB203580 had little effect. We also found that the expression of LMP1 increased the invasive ability of TW04 cells. The importance of RECK in LMP1-induced invasiveness was supported by three observations. First, restoration of RECK expression by PD98059 reduced LMP1-induced release of active MMP-9. Second, suppression of PD98059-induced RECK expression by small interference RNA abolished the inhibitory action of PD98059 on LMP1-induced invasiveness. Third, coexpression of RECK with LMP1 in TW04 cells effectively suppressed cell invasiveness induced by LMP1. Taken together, these results suggest that LMP1 inhibits RECK expression via the ERK/Sp1 signaling pathway and this inhibition is a critical step for LMP1-induced tumor metastasis.

OBJECTIVE: To determine the expression of MTA1 and RECK gene in nasopharyngeal carcinoma (NPC) and its correlation with clinicopathological features. METHOD: In situ hybridization was used to detect the expression of MTA1 and RECK mRNA in 60 cases of primary NPC (30 cases with, 30 cases without cervical lymph node metastasis), 10 cases of metastatic lymph node (MLN) and 20 cases of chronic nasopharyngitis tissue (CNT). RESULT: 1) Positive rates of MTA1 mRNA expression in CNT, NPC and MLN were 30.0% (6/20), 71.7% (43/60) and 80.0% (8/10), respectively. The positive expressions of MTA1 in NPC and MLN were significantly higher than in CNT (P<0.05). The MTA1 mRNA expression in NPC with lymph node metastasis was significantly higher than in NPC without lymph node metastasis (83.3% vs. 60.0%, P<0.05). 2) Positive rates of RECK mRNA expression in CNT, NPC and MLN were 85.0% (17/20), 26.7% (16/60) and 30.0% (3/10), respectively. The positive expression of RECK in NPC and MLN were significantly lower than in CNT (P< 0.05). The RECK mRNA expression in NPC with lymph node metastasis was significantly lower than in NPC without lymph node metastasis (13.3% vs. 40.0%, P<0.05). 3) Abnormal expression of MTA1 and RECK mRNA in NPC had no correlation with gender, age, T-stage and clinical stage (P>0.05), while they had positive relationship with lymph node metastasis, tumor recurrence and the post-treatment 5-year survival periods of NPC (P<0.05). The expression of RECK mRNA was negatively correlated with the expression of MTA1 mRNA in NPC (r = - 0.541, P<0.05). CONCLUSION: These data suggest that the aberrant expression of MTA1 and RECK gene may be involved in the invasion and metastasis of NPC. They may be good biomarkers for evaluating the cervical lymph node metastasis, recurrence and prognosis of NPC.

OBJECTIVES: We investigated the expression and clinical value of MTA1 and RECK genes in patients with nasopharyngeal carcinoma (NPC). METHODS: We examined MTA1 and RECK expression in nasopharyngeal tissue from patients with chronic nasopharyngitis, lymph nodes with metastasis of NPC, and primary NPC tumor tissue by means of in situ hybridization and analyzed their correlation with the clinicopathologic features of NPC. RESULTS: The positive expression of MTA1 in the NPC tissues and metastatic lymph nodes was significantly higher than that in the chronic nasopharyngitis tissues (p < 0.05). The positive expression of RECK in the NPC tissues and metastatic lymph nodes was significantly lower than that in the chronic nasopharyngitis tissues (p < 0.05). The RECK expression level was inversely correlated with the MTA1 expression level in the NPC tissues (p < 0.05). The increased MTA1 and decreased RECK expressions in the NPC tissues had no association with gender, age, T-stage, or clinical stage (p > 0.05). However, they had a positive correlation with cervical lymph node metastasis, tumor recurrence, and 5-year overall survival rate of the patients with NPC (p < 0.05). Moreover, multivariate analysis showed that MTA1 and RECK expressions were independent prognostic factors for survival (p < 0.05). CONCLUSIONS: The conversely abnormal expression levels of MTA1 and RECK may be collectively involved in progression of malignancies and may serve as molecular predictors for metastasis, recurrence, and prognosis of NPC.

In the present study, we addressed the molecular mechanism of the downregulation of reversion-inducing-cysteine-rich protein with Kazal motifs (RECK), a critical tumor suppressor that can potently inhibit angiogenesis and metastasis, in non-small cell lung cancer and its clinical significance. The methylation status of the RECK gene promoter was studied by methylation-specific polymerase chain reaction. RECK mRNA and protein levels were investigated by reverse transcription-polymerase chain reaction and western blot analysis. Downregulation of RECK was observed in 60% of the 55 tumors analyzed. Using methylation-specific polymerase chain reaction analysis methylation of the RECK promoter was detected in 63.6% (35/55) of the tumor tissues. A strong correlation between downregulation and promoter methylation was found in these tumors (P = 0.000005). More importantly, downregulation of RECK significantly correlated with lymph node metastasis (P = 0.038). mutation of codon 12 of the K-ras gene was detected in 25.5% (14/55) of lung tumor tissues. Statistical analysis indicated that K-ras mutation was linked with RECK promoter methylation (P = 0.047) and downregulation (P = 0.023). Promoter methylation was also detected in human lung cancer cell lines, and the DNA methyltransferase inhibitor 5'-azacytidine reversed the expression of RECK and reduced the invasive ability of these cell lines. Collectively, our results suggest that downregulation of the metastasis suppressor RECK is caused by promoter methylation in non-small cell lung cancer and is associated with K-ras mutation and lymph node metastasis.

Oral cancer is the fourth common male cancer and causally associated with environmental carcinogens in Taiwan. The reversion-inducing-cysteine-rich protein with Kazal motifs (RECK) has a significant effect on tumorigenesis by limiting angiogenesis and invasion of tumors through the extracellular matrix. RECK downregulation has been confirmed in many human cancers and associated with lymph node metastasis clinically. In the present hospital-based case-controlled study, the demographic, RECK genotype and clinicopathologic data from 341 male oral cancer patients and 415 cancer-free controls were investigated. We found that RECK rs10814325, rs16932912, rs11788747 or rs10972727 polymorphisms were not associated with oral cancer susceptibility. Among 488 smokers, RECK polymorphisms carriers with betel quid chewing have a 7.62-fold [95% confidence interval (CI), 2.96-19.64] to 25.33-fold (95% CI, 9.57-67.02) risk to have oral cancer compared with RECK wild-type carrier without betel quid chewing. Among 352 betel quid chewers, RECK polymorphisms carriers with smoking have a 6.68-fold (95% CI, 1.21-36.93) to 18.57-fold (95% CI, 3.80-90.80) risk to have oral cancer compared with those who carried wild-type without smoking. In 263 betel quid chewing oral cancer patients, RECK rs10814325 polymorphism have a 2.26-fold (95% CI, 1.19-4.29) risk to have neck lymph node metastasis compared with RECK wild-type carrier. These results support that gene-environment interactions between the RECK polymorphisms, smoking and betel quid may alter oral cancer susceptibility and metastasis.

The aim of this study was to analyze the clinical significance of reversion-inducing-cysteine-rich protein with Kazal motifs (RECK) promoter methylation in pancreatic ductal adenocarcinoma (PDA). Methylation-specific polymerase chain reaction was used to examine the promoter methylation status of RECK in 60 pairs of PDA tissue samples and adjacent non-cancerous tissue samples. Statistical analyses were applied to test the associations between RECK promoter methylation status, clinicopathologic factors, and prognosis. The rate of RECK promoter methylation was significantly higher in PDA tissues than in adjacent non-cancerous tissues (P < 0.001). RECK methylation status was significantly associated with clinical stage (P = 0.017), histological differentiation (P = 0.046), and lymph node metastasis (P = 0.003), but was not associated with gender, age, and tumor location (all P > 0.05). Additionally, RECK promoter methylation is associated with malignant behavior and poor prognosis. In conclusion, determination of RECK promoter methylation status in tumor tissues may assist in the identification of patients who require aggressive postoperative intervention in order to improve prognosis.

OBJECTIVE: Reversion-inducing cysteine-rich protein with kazal motifs (RECK) may negatively regulate matrix metalloproteinase 9 (MMP9) activity and suppress tumor invasion and metastasis. The aim of this study was to investigate whether RECK and MMP were involved in regulating middle ear carcinoma invasion and metastasis. METHODS: RECK and MMP9 were measured in 30 middle ear squamous cell carcinoma tissues and 20 adjacent normal external ear canal skin tissues using immunohistochemical analysis. RESULTS: The positive rate of RECK expression in the middle ear squamous cell carcinoma was much lower than that in the normal external ear canal skin. In contrast, the positive rate of MMP9 expression was higher in middle ear squamous cell carcinoma tissue than that in normal external ear canal skin tissue. The expressions of RECK and MMP9 were correlated with the histological grade and tumor stage, but not with patient age or gender. CONCLUSIONS: RECK and MMP9 are involved in middle ear squamous cell carcinoma and may serve as markers to evaluate progression and metastasis.