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In several types of human cancer, the gene expression of Reprimo, a highly glycosylated protein, is frequently silenced via methylation of its promoter. The aim of this study was to characterize the epigenetic inactivation of Reprimo and its biologic function and clinical relevance in gastric cancer. The correlation between Reprimo methylation and clinical relevance was assessed in 83 primary human gastric cancer tissues. The effects of Reprimo expression were also examined using in vitro and in vivo assays. Reprimo methylation was cancer specific and frequently observed. In two gastric cancer cell lines without Reprimo methylation, we observed faint or weak Reprimo expression under normal conditions and high expression under DNAdamaging conditions. In four gastric cancer cell lines with Reprimo methylation, however, Reprimo expression remained faint even under DNA-damaging conditions, with expression being restored in combination with agents that induce demethylation. Enforced Reprimo expression robustly inhibited cell proliferation and anchorage-independent colony formation and enhanced DNA damage-induced apoptosis. Inverse effects were observed via siRNA-mediated knockdown of endogenous Reprimo. Reprimo expression inhibited tumorigenesis in vivo. Reprimo methylation was also associated with a poor response in patients with gastric cancer treated with chemotherapy (P

BackgroundWe have recently identified HOP hoemobox (HOPX) as a tumor suppressor gene candidate, characterized by tumor-specific promoter DNA hypermethylation in human cancers, and it can remarkably inhibit tumors’ aggressive phenotypes. In this current study, we for the first time examined methylation level of HOPX and tested the functional relevance in pancreatic cancer (PC).MethodsClinical features of HOPX promoter hypermethylation was investigated in 89 PC tissues, and immunohistochemistry was added. We also examined its functional relevance in phenotype assays such as soft agar, proliferation, invasion, and cell cycle analysis.ResultsPC tissues had HOPX gene hypermethylation as compared to the corresponding normal pancreas tissues, and its uniqueness was robust to discriminate tumor from normal tissues (AUC = 0.85, P < 0.0001). Unexpectedly, HOPX was increased in expression in tumor tissues, and immunohistochemistry revealed its predominant expression in the Langerhans islet cells, where HOPX was reduced in expression for PC cells with promoter hypermethylation. HOPX transfectants exhibited G1 arrest with subG1 accumulation, and inhibited tumor forming and invasive ability.ConclusionDefective expression of HOPX which is consistent with promoter DNA hypermethylation may explain aggressive phenotype of pancreatic cancer, and intense expression of HOPX in the Langerhans cells may in turn uniquely contribute to pancreatic carcinogenesis.

Using pharmacological unmasking microarray, we identified promoter DNA methylation of cysteine dioxygenase 1 (CDO1) gene in human cancer. In this study, we assessed the clinicopathological significance of CDO1 methylation in primary breast cancer (BC) with no prior chemotherapy. The CDO1 DNA methylation was quantified by TaqMan methylation specific PCR (Q-MSP) in 7 BC cell lines and 172 primary BC patients with no prior chemotherapy. Promoter DNA of the CDO1 gene was hypermethylated in 6 BC cell lines except SK-BR3, and CDO1 gene expression was all silenced at mRNA level in the 7 BC cell lines. Quantification of CDO1 methylation was developed using Q-MSP, and assessed in primary BC. Among the clinicopathologic factors, CDO1 methylation level was not statistically significantly associated with any prognostic factors. The log-rank plot analysis elucidated that the higher methylation the tumors harbored, the poorer prognosis the patients exhibited. Using the median value of 58.0 as a cut-off one, disease specific survival in BC patients with CDO1 hypermethylation showed significantly poorer prognosis than those with hypomethylation (p = 0.004). Multivariate Cox proportional hazards model identified that CDO1 hypermethylation was prognostic factor as well as Ki-67 and hormone receptor status. The most intriguingly, CDO1 hypermethylation was of robust prognostic relevance in triple negative BC (p = 0.007). Promoter DNA methylation of CDO1 gene was robust prognostic indicator in primary BC patients with no prior chemotherapy. Prognostic relevance of the CDO1 promoter DNA methylation is worthy of being paid attention in triple negative BC cancer.

BackgroundPhosphatase of regenerating liver-3 (PRL-3) has deserved attention as a crucial molecule in the multiple steps of metastasis. In the present study, we examined the mechanisms regulating PRL-3 expression, and assessed the clinical potential of PRL-3-targeted therapy in gastric cancer.MethodsPRL-3 genomic amplification was analyzed using quantitative-polymerase chain reaction and/or fluorescence in situ hybridization in 77 primary gastric tumors. The anticancer activity of PRL-3 inhibitor (1-4-bromo-2-benzylidene rhodanine) treatment was evaluated against cancer cells with different genetic and expression status.ResultsPRL-3 genomic amplification was closely concordant with high level of its protein expression in cell lines, and was found in 20% (8/40) among human primary tumors with its expression, which were all stage III/IV disease (40%, 8/20), but in none (0/37) among those without expression. Additionally, PRL-3 genomic amplification was associated with metastatic lymph node status, leading to advanced stage and thereby poor outcomes in patients with lymph node metastasis (P = 0.021). PRL-3 small interfering RNA robustly repressed metastatic properties, including cell proliferation, invasion, and anchorage-independent colony formation. Although neither PRL-3 genomic amplification nor expression level was responsible for the sensitivity to PRL-3 inhibitor treatment, the inhibitor showed dose-dependent anticancer efficacy, and remarkably induced apoptosis on all the tested cell lines with PRL-3 expression.ConclusionsWe have for the first time, demonstrated that PRL-3 genomic amplification is one of the predominant mechanisms inducing its expression, especially in more advanced stage, and that PRL-3-targeted therapy may have a great potential against gastric cancer with its expression.

PurposeDexamethasone, plus a 5-HT3 receptor antagonist and an NK-1 receptor antagonist are recommended for controlling the chemotherapy-induced nausea and vomiting (CINV) of highly emetogenic chemotherapy. Several days of dexamethasone are effective for CINV; however, dexamethasone also has side effects. The purpose of this trial was to investigate whether the use of a second-generation 5-HT3 receptor antagonist and an NK-1 receptor antagonist could allow a reduced dose of dexamethasone for breast cancer patients receiving highly emetogenic chemotherapy.MethodsEighty breast cancer patients who received an anthracycline-cyclophosphamide combination regimen were enrolled. The patients were randomized to arm A (dexamethasone days 1–3) and arm B (dexamethasone day 1). The primary endpoint was complete response (CR) (no emetic episodes and no rescue medication) during the overall phase (days 1–5). The secondary endpoints were the CR during the delayed phase (days 2–5), complete control (CC) (no emetic episodes, no rescue medication, and no more than mild nausea) during the overall phase, and the safety of this antiemetic therapy.ResultsThere were no significant differences in the rates of CR and CC between arm A and B as follows: CR overall phase—arm A: 82.9 %, 90 % confidence interval [CI] 71.3–90.5 % vs arm B: 82.1 %, 90 % CI 70.0–90.0 %; p = 1.00; CR delayed phase—arm A: 87.8 %, 90 % CI 77.0–93.9 % vs arm B: 94.9 %, 90 % CI 85.6–98.3 %; p = 0.43; CC overall phase—arm A: 48.8 %, 90 % CI 36.4–61.3 % vs arm B: 61.5 %, 90 % CI 48.4–73.2 %; p = 0.27. There were very few adverse events and no severe adverse events associated with this antiemetic therapy.ConclusionsThe results suggest that the antiemetic effect provided by dexamethasone administered for 3 days can be obtained by dexamethasone administered for 1 day.

Metastatic lymph node density (ND) has been reproducibly proven to be a prognostic factor in gastric cancer. The molecular mechanisms that underlie this aggressiveness are underexplored. Here, we aimed to identify molecules associated with this unique phenotype. Tumor specimens from patients with stage III gastric cancer with high or low ND (n = 4 for both) were compared at the mRNA level using Affymetrix microarray (harboring 54,675 genes). The expression data were prioritized, and genes that correlated with ND were selected. Ultimately, the EGFR was validated as such a candidate molecule in patients with primary advanced gastric cancer who underwent standard treatment (n = 167). Expression data of the microarray were prioritized based on gene expression ratio and frequency of gene expression. The first priority genes to be selected were genes that are known to be amplified in cancer, which included NKX2.1, CHST9, CTNND2, SLC25A27, FGFR2, EGFR, and PTGER1. Of these genes, the EGFR gene was of particular interest. EGFR expression in primary gastric cancer was examined using immunohistochemistry (IHC). The Student's t-test elucidated a significant difference in EGFR expression between IHC 2+/3+ and IHC 1+ according to ND (P = 0.0035). The Chi-square test also indicated a significant difference between high and low levels of EGFR immunohistochemical staining (IHC2+/3+ and IHC1+, respectively) and ND status (P = 0.0023). According to the least squares method, as ND increased, the risk that EGFR staining levels changed from IHC 1+ to IHC 2+ also increased. In this study, we determined that high EGFR expression may underlie the aggressive mechanism of advanced gastric cancer with high ND.

BRCAness is defined as the set of traits in which BRCA1 dysfunction, arising from gene mutation, methylation or deletion, results in DNA repair deficiency. In the present study, we addressed BRCAness, therapeutic efficacy, recurrence, and survival in patients with triple negative breast cancer (TNBC) who were treated with neoadjuvant chemotherapy at Kitasato University Hospital, Japan, between April 2006 and October 2012. BRCAness was determined by preoperative core needle biopsy (CNB) specimens and surgical specimens. Assay was performed using Multiplex Ligation-dependent Probe Amplification (MLPA) with P376-B2 BRCA1ness probemix (MRC-Holland, Amsterdam, The Netherlands). The relative copy number ratio of each sample was compared to Human Genomic DNA (Promega, Madison, WI, USA) as reference samples was calculated with Coffalyser.NET default settings. The BRCAness score was calculated with the relative copy number ratio of various DNA sequences. Values of 0.5 or more were determined as the BRCA1-like Type (BRCAness) and those of less than 0.5 as the Sporadic Type to analyze pathological complete response (pCR) rate, recurrence, and survival. pCR (ypT0/Tis/N0) was observed in 15 patients (pCR rate: 37.5%). These patients had no recurrence. Twelve patients recurred, 8 died from breast cancer. The BRCA1-like Type were 22 and Sporadic Type were 18 in CNB specimens. No major differences were observed between the BRCA1-like Type and Sporadic Type with pCR rate, recurrence rate and survival. Twenty four surgical specimens of non-pCR patients were available and 9 were BRCA1-like Type, who had more recurrences (7/9 vs. 5/15), and their relapse-free survival was also lower (p<0.05) than that of Sporadic Type. Seven BRCA1-like Type patients remained BRCA1-like Type in surgical specimens, were worse in recurrence (p<0.01) and survival (p<0.05) compared with 6 patients whose BRCA status in surgical specimens turned to Sporadic Type. New clinical trials assessing the true recurrence (TR) rate of BRCA-type patients are expected since neither platinum-containing drugs nor poly (ADP-ribose) polymerase (PARP) inhibitors are effective against tumors with nonfunctional BRCA genes.