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PRDI-BF1 and RIZ (PR) domain zinc finger protein 14 (PRDM14), first reported in 2007 to be overexpressed in breast cancer, plays an important role in breast cancer proliferation. Subsequent studies reported that PRDM14 is expressed in embryonic stem cells, primordial germ cells, and various cancers. PRDM14 was reported to confer stemness properties to cancer cells. These properties induce cancer initiation, cancer progression, therapeutic resistance, distant metastasis, and recurrence in refractory tumors. Therefore, PRDM14 may be an ideal therapeutic target for various types of tumors. Silencing PRDM14 expression using PRDM14-specific siRNA delivered through an innovative intravenous drug delivery system reduced the size of inoculated tumors, incidence of distant metastases, and increased overall survival in nude mice without causing adverse effects. Therapeutic siRNA targeting PRDM14 is now being evaluated in a human phase I clinical trial for patients with refractory breast cancer, including triple-negative breast cancer.

Aberrant DNA methylation could potentially serve as a biomarker for colorectal neoplasms. In this study, we assessed the feasibility of using DNA methylation detected in bowel lavage fluid (BLF) for colorectal cancer screening. A total of 508 BLF specimens were collected from patients with colorectal cancer (n = 56), advanced adenoma (n = 53), minor polyp (n = 209), and healthy individuals (n = 190) undergoing colonoscopy. Methylation of 15 genes (miR-1-1, miR-9-1, miR-9-3, miR-34b/c, miR-124-1, miR-124-2, miR-124-3, miR-137, SFRP1, SFRP2, APC, DKK2, WIF1, LOC386758, and ZNF582) was then analyzed in MethyLight assays, after which receiver operating characteristic (ROC) curves were analyzed to assess the diagnostic performance of BLF methylation. Through analyzing BLF specimens in a training set (n = 345), we selected the three genes showing the greatest sensitivity for colorectal cancer detection (miR-124-3, 71.8%; LOC386758, 79.5%; and SFRP1, 74.4%). A scoring system based on the methylation of those three genes (M-score) achieved 82% sensitivity and 79% specificity, and the area under the ROC curve (AUC) was 0.834. The strong performance of this system was then validated in an independent test set (n = 153; AUC = 0.808). No significant correlation was found between M-score and the clinicopathologic features of the colorectal cancers. Our results demonstrate that DNA methylation in BLF specimens may be a useful biomarker for the detection of colorectal cancer. Cancer Prev Res; 7(10); 1002–10. ©2014 AACR.

Supplementary Table S2 from Epigenetic Alteration of DNA in Mucosal Wash Fluid Predicts Invasiveness of Colorectal Tumors

Correlation between colorectal lesions and BLF methylation

XLS file - 80K, Genes commonly methylated in background gastric mucosa from patients with intestinal type GC or diffuse type GC

XLS file - 33K, Correlation between RASGRF1 methylation and clinicopathological features in GC

XLS file - 154K, Genes hypermethylated in background gastric mucosae from patients with intestinal type GC

Supplementary Figure S1 Receiver operating characteristic curve analysis of the respective marker genes. Supplementary Figure S2 Ages of CRC patients (upper) and non-CRC individuals (lower) with the indicated M-scores. Each dot represents a single individual. Supplementary Figure S3 Comparison of the methylation results in paired BLF and biopsy specimens from primary tumors. The M-score and the Ct values of the endogenous control Alu repetitive element are indicated on the top. The methylation status of the three marker genes in the BLF and biopsy specimens is shown below. Supplementary Figure S4 CTC and colonoscopic views of the CRC of case 5 in Table 6 are shown. The polypoid adenoma portion is indicated by the red arrow and the flat adenocarcinoma portion is indicated by the yellow arrow.

Although conventional colonoscopy is considered the gold standard for detecting colorectal tumors, accurate staging is often difficult because advanced histology may be present in small colorectal lesions. We collected DNA present in mucosal wash fluid from patients undergoing colonoscopy and then assessed the methylation levels of four genes frequently methylated in colorectal cancers to detect invasive tumors. We found that methylation levels in wash fluid were significantly higher in patients with invasive than those with noninvasive tumors. Cytologic and K-ras mutation analyses suggested that mucosal wash fluid from invasive tumors contained greater numbers of tumor cells than wash fluid from noninvasive tumors. Among the four genes, levels of mir-34b/c methylation had the greatest correlation with the invasion and showed the largest area under the receiver operating characteristic curve (AUC = 0.796). Using cutoff points of mir-34b/c methylation determined by efficiency considerations, the sensitivity/specificity were 0.861/0.657 for the 13.0% (high sensitivity) and 0.765/0.833 for the 17.8% (well-balanced) cutoffs. In the validation test set, the AUC was also very high (0.915), the sensitivity/specificity were 0.870/0.875 for 13.0% and 0.565/0.958 for 17.8%. Using the diagnostic tree constructed by an objective algorithm, the diagnostic accuracy of the invasiveness of colorectal cancer was 91.3% for the training set and 85.1% for the test set. Our results suggest that analysis of the methylation of DNA in mucosal wash fluid may be a good molecular marker for predicting the invasiveness of colorectal tumors. Cancer Prev Res; 4(5); 674–83. ©2011 AACR.

Results of ROC curve analysis for detection of CRC using BLF methylation

Sequences of primers used in this study

Supplementary Figure S1 from Epigenetic Alteration of DNA in Mucosal Wash Fluid Predicts Invasiveness of Colorectal Tumors

XLS file - 78K, Genes hypermethylated in background gastric mucosae from patients with diffuse type GC

Supplementary Data from A Single Recombinant Adenovirus Expressing p53 and p21-targeting Artificial microRNAs Efficiently Induces Apoptosis in Human Cancer Cells

PDF file - 8K, Gene promoter hypermethylation in GIST samples.

PDF file - 5K, Logistic regression analysis for the association between metastasis and LINE-1 methylation in high-risk category GIST patients.

PDF file - 364K, Reproducibility of bisulfite pyrosequencing analysis.

Supplementary Data from Genomic Screening for Genes Silenced by DNA Methylation Revealed an Association between RASD1 Inactivation and Dexamethasone Resistance in Multiple Myeloma

Purpose: Epigenetic changes such as DNA methylation play a key role in the development and progression of multiple myeloma. Our aim in the present study was to use genomic screening to identify genes targeted for epigenetic inactivation in multiple myeloma and assess their role in the development of resistance to dexamethasone.Experimental Design: Gene expression was examined using microarray screening, reverse transcription-PCR, and real-time quantitative PCR. DNA methylation was examined using bisulfite PCR, bisulfite sequencing, and bisulfite pyrosequencing in 14 multiple myeloma cell lines, 87 multiple myeloma specimens, and 12 control bone marrow samples. WST-8 assays were used to assess cell viability after treatment with 5-aza-2′-deoxycytidine and/or dexamethasone.Results: Microarray analysis was done to screen for genes up-regulated by 5-aza-2′-deoxycytidine. In RPMI8226 cells, 128 genes were up-regulated, whereas 83 genes were up-regulated in KMS12PE cells. Methylation of 22 genes with CpG islands in their 5′ regions, including RASD1, was confirmed. Methylation of RASD1 was associated with its inactivation, which correlated with resistance to dexamethasone. Treating multiple myeloma cells with 5-aza-2′-deoxycytidine restored sensitivity to dexamethasone. Methylation of RASD1 was also detected in a subset of primary multiple myeloma specimens, and the levels of methylation were increased after repeated antitumor treatments. Gene signature analysis revealed various genes to be synergistically induced by treatment with a combination of 5-aza-2′-deoxycytidine plus dexamethasone.Conclusion: Our findings indicate that epigenetic inactivation of genes, including RASD1, plays a key role in the development of dexamethasone resistance in multiple myeloma. Moreover, they show the utility of demethylation therapy in cases of advanced multiple myeloma.

Purpose: Gastrointestinal stromal tumors (GIST) are the most important mesenchymal tumors of the gastrointestinal tract. The vast majority of GISTs exhibit activating mutations of KIT or PDGFRA, but epigenetic alteration of GISTs is largely unknown. In this study, we aimed to clarify the involvement of DNA methylation in GIST malignancy.Experimental Design: A total of 106 GIST specimens were studied. Levels of LINE-1 methylation were analyzed using bisulfite pyrosequencing. In addition, methylation of three other repetitive sequences (Alu Yb8, Satellite-α, and NBL2) was similarly analyzed, and CpG island hypermethylation was analyzed using MethyLight. Array-based comparative genomic hybridization (array CGH) was carried out in 25 GIST specimens.Results: LINE-1 hypomethylation was significantly correlated with risk, and high-risk GISTs exhibited significantly lower levels of LINE-1 methylation than low-risk (61.3% versus 53.2%; P = 0.001) or intermediate-risk GISTs (60.8% versus 53.2%; P = 0.002). Hypomethylation of Satellite-α and NBL2 was also observed in high-risk GISTs. By contrast, promoter hypermethylation was relatively infrequent (CDH1, 11.2%; MLH1, 9.8%; SFRP1, 1.2%; SFRP2, 11.0%; CHFR, 9.8%; APC, 6.1%; CDKN2A, 0%; RASSF1A, 0%; RASSF2, 0%) and did not correlate with LINE-1 methylation or risk. Array CGH analysis revealed a significant correlation between LINE-1 hypomethylation and chromosomal aberrations.Conclusions: Our data suggest that LINE-1 hypomethylation correlates significantly with the aggressiveness of GISTs and that LINE-1 methylation could be a useful marker for risk assessment. Hypomethylation may increase the malignant potential of GISTs by inducing accumulation of chromosomal aberrations. Clin Cancer Res; 16(21); 5114–23. ©2010 AACR.

Purpose: Gene transfer involving p53 is viewed as a potentially effective cancer therapy, but does not result in a good therapeutic response in all human cancers. The activation of p53 induces either cell cycle arrest or apoptosis. Cell cycle arrest in response to p53 activation is mediated primarily through the induction of the cyclin-dependent kinase inhibitor p21. Because p21 also has an inhibitory effect on p53-mediated apoptosis, the suppression of p53-induced p21 expression would be expected to result in the preferential induction of apoptosis. However, p21 also has tumor-suppressive properties. In this study, we developed an adenovirus vector that expresses p53 and suppresses p21 simultaneously to enhance p53-mediated apoptosis.Experimental Design: We constructed a replication-deficient recombinant adenovirus (Ad-p53/miR-p21) that enabled cocistronic expression of the p53 protein and artificial microRNAs that targeted p21, and examined the therapeutic effectiveness of this vector in vitro and in vivo.Results: The levels of p21 were significantly attenuated following infection with Ad-p53/miR-p21. In colorectal and hepatocellular carcinoma cells, infection with Ad-p53/miR-p21 augmented apoptosis as compared with an adenovirus that expressed p53 alone (Ad-p53/miR-control). Ad-p53/miR-p21 also significantly increased the chemosensitivity of cancer cells to adriamycin (doxorubicin). In a xenograft tumor model in nude mice, tumor volume was significantly decreased following the direct injection of Ad-p53/miR-p21 into the tumor, as compared with the injection of Ad-p53/miR-control.Conclusion: These results suggest that adenovirus-mediated transduction of p53 and p21-specific microRNAs may be useful for gene therapy of human cancers.

PDF file - 507K, Chromosomal aberrations and their frequencies determined through array CGH analysis.

Supplementary Figures 1-7 from Epigenetic Silencing of MicroRNA-34b/c and B-Cell Translocation Gene 4 Is Associated with CpG Island Methylation in Colorectal Cancer

Supplementary Figures 1-3 from Gene Amplification and Overexpression of PRDM14 in Breast Cancers

Supplementary Figure Legends 1-7 from Epigenetic Silencing of MicroRNA-34b/c and B-Cell Translocation Gene 4 Is Associated with CpG Island Methylation in Colorectal Cancer

Formation of the T-cell factor-4 (TCF-4) and β-catenin nuclear complex is considered crucial to embryonic development and colorectal carcinogenesis. We previously reported that poly(ADP-ribose) polymerase-1 (PARP-1) interacts with the TCF-4 and β-catenin complex and enhances its transcriptional activity. However, its biological significance remains unexplained. Using immunoprecipitation and mass spectrometry, we found that two Ku proteins, Ku70 and Ku80, were also associated with the complex. Knockdown of Ku70 by RNA interference increased the amount of β-catenin associated with TCF-4 and enhanced the transcriptional activity. PARP-1 competed with Ku70 for binding to TCF-4. Treatment with bleomycin, a DNA-damaging alkylating agent, induced polyADP-ribosylation of PARP-1 protein and inhibited its interaction with TCF-4. Bleomycin conversely increased the amounts of Ku70 coimmunoprecipitated with TCF-4 and removed β-catenin from TCF-4. We propose a working model in which the transcriptional activity of TCF-4 is regulated by the relative amount of Ku70, PARP-1, and β-catenin proteins binding to TCF-4. Identification of the functional interaction of Ku70 as well as PARP-1 with the TCF-4 and β-catenin transcriptional complex may provide insights into a novel linkage between DNA damage recognition/repair and Wnt signaling. [Cancer Res 2007;67(3):911–8]

XLS file - 23K, GO analysis of differentially expressed genes in GISTs with and without miR-196a overexpression

XLS file - 28K, Correlation between miR-196a expression and the GIST risk category in different organs

Supplementary Figures 1-5 from Epigenetic Inactivation of the Circadian Clock Gene BMAL1 in Hematologic Malignancies

Supplementary Table 5 from Genome-wide Profiling of Chromatin Signatures Reveals Epigenetic Regulation of MicroRNA Genes in Colorectal Cancer

Supplementary Table 2 from Epigenetic Silencing of MicroRNA-34b/c and B-Cell Translocation Gene 4 Is Associated with CpG Island Methylation in Colorectal Cancer

Supplementary Figures 1-3 from Ku70 and Poly(ADP-Ribose) Polymerase-1 Competitively Regulate β-Catenin and T-Cell Factor-4–Mediated Gene Transactivation: Possible Linkage of DNA Damage Recognition and Wnt Signaling

Supplementary Figures 1-5 from A Requirement for DICER to Maintain Full Promoter CpG Island Hypermethylation in Human Cancer Cells

Supplementary Table 1 from Epigenetic Inactivation of the Circadian Clock Gene BMAL1 in Hematologic Malignancies

XLS file - 196K, Genes upregulated by HOTAIR knockdown in GIST-T1 cells

Methods paragraph, 4 Figures, 6 Tables

Supplementary Table 1 from Gene Amplification and Overexpression of PRDM14 in Breast Cancers

XLS file - 47K, Predicted miR-196a target genes whose expression was reduced in GISTs overexpressing miR-196a

XLS file - 28K, Correlation between miR-196a expression and the GIST risk category