Epigenetic Subgroups of Esophageal and Gastric Adenocarcinoma with Differential GATA5 DNA Methylation Associated with Clinical and Lifestyle Factors

BACKGROUND: Adenocarcinomas located near the gastroesophageal junction have unclear etiology and are difficult to classify. We used DNA methylation analysis to identify subtype-specific markers and new subgroups of gastroesophageal adenocarcinomas, and studied their association with epidemiological risk factors and clinical outcomes. METHODOLOGY/PRINCIPAL FINDINGS: We used logistic regression models and unsupervised hierarchical cluster analysis of 74 DNA methylation markers on 45 tumor samples (44 patients) of esophageal and gastric adenocarcinomas obtained from a population-based case-control study to uncover epigenetic markers and cluster groups of gastroesophageal adenocarcinomas. No distinct epigenetic differences were evident between subtypes of gastric and esophageal cancers. However, we identified two gastroesophageal adenocarcinoma subclusters based on DNA methylation profiles. Group membership was best predicted by GATA5 DNA methylation status. We analyzed the associations between these two epigenetic groups and exposure using logistic regression, and the associations with survival time using Cox regression in a larger set of 317 tumor samples (278 patients). There were more males with esophageal and gastric cardia cancers in Cluster Group 1 characterized by higher GATA5 DNA methylation values (all p<0.05). This group also showed associations of borderline statistical significance with having ever smoked (p-value = 0.07), high body mass index (p-value = 0.06), and symptoms of gastroesophageal reflux (p-value = 0.07). Subjects in cluster Group 1 showed better survival than those in Group 2 after adjusting for tumor differentiation grade, but this was not found to be independent of tumor stage. CONCLUSIONS/SIGNIFICANCE: DNA methylation profiling can be used in population-based studies to identify epigenetic subclasses of gastroesophageal adenocarcinomas and class-specific DNA methylation markers that can be linked to epidemiological data and clinical outcome. Two new epigenetic subgroups of gastroesophageal adenocarcinomas were identified that differ to some extent in their survival rates, risk factors of exposure, and GATA5 DNA methylation

Prospective study of oncologic outcomes after laparoscopic modified complete mesocolic excision for non-metastatic right colon cancer (PIONEER study): study protocol of a multicentre single-arm trial

Abstract Background The introduction of complete mesocolic excision (CME) with central vascular ligation (CVL) for right-sided colon cancer has improved the oncologic outcomes. Recently, we have introduced a modified CME (mCME) procedure that keeps the same principles as the originally described CME but with a more tailored approach. Some retrospective studies have reported the favourable oncologic outcomes of laparoscopic mCME for right-sided colon cancer; however, no prospective multicentre study has yet been conducted. Methods This study is a multi-institutional, prospective, single-arm study evaluating the oncologic outcomes of laparoscopic mCME for adenocarcinoma arising from the right side of the colon. A total of 250 patients will be recruited from five tertiary referral centres in South Korea. The primary outcome of this study is 3-year disease-free survival. Secondary outcome measures include 3-year overall survival, incidence of surgical complications, completeness of mCME, and distribution of metastatic lymph nodes. The quality of laparoscopic mCME will be assessed on the basis of photographs of the surgical specimen and the operation field after the completion of lymph node dissection. Discussion This is a prospective multicentre study to evaluate the oncologic outcomes of laparoscopic mCME for right-sided colon cancer. To the best of our knowledge, this will be the first study to prospectively and objectively assess the quality of laparoscopic mCME. The results will provide more evidence about oncologic outcomes with respect to the quality of laparoscopic mCME in right-sided colon cancer. Trial registration ClinicalTrials.gov ID: NCT03992599 (June 20, 2019). The posted information will be updated as needed to reflect protocol amendments and study progress

Heterodimerization of Glycosylated Insulin-Like Growth Factor-1 Receptors and Insulin Receptors in Cancer Cells Sensitive to Anti-IGF1R Antibody

Identification of predictive biomarkers is essential for the successful development of targeted therapy. Insulin-like growth factor 1 receptor (IGF1R) has been examined as a potential therapeutic target for various cancers. However, recent clinical trials showed that anti-IGF1R antibody and chemotherapy are not effective for treating lung cancer.In order to define biomarkers for predicting successful IGF1R targeted therapy, we evaluated the anti-proliferation effect of figitumumab (CP-751,871), a humanized anti-IGF1R antibody, against nine gastric and eight hepatocellular cancer cell lines. Out of 17 cancer cell lines, figitumumab effectively inhibited the growth of three cell lines (SNU719, HepG2, and SNU368), decreased p-AKT and p-STAT3 levels, and induced G 1 arrest in a dose-dependent manner. Interestingly, these cells showed co-overexpression and altered mobility of the IGF1R and insulin receptor (IR). Immunoprecipitaion (IP) assays and ELISA confirmed the presence of IGF1R/IR heterodimeric receptors in figitumumab-sensitive cells. Treatment with figitumumab led to the dissociation of IGF1-dependent heterodimeric receptors and inhibited tumor growth with decreased levels of heterodimeric receptors in a mouse xenograft model. We next found that both IGF1R and IR were N-linked glyosylated in figitumumab-sensitive cells. In particular, mass spectrometry showed that IGF1R had N-linked glycans at N913 in three figitumumab-sensitive cell lines. We observed that an absence of N-linked glycosylation at N913 led to a lack of membranous localization of IGF1R and figitumumab insensitivity.The data suggest that the level of N-linked glycosylated IGF1R/IR heterodimeric receptor is highly associated with sensitivity to anti-IGF1R antibody in cancer cells

The B subunits of cholera and Escherichia coli heat-labile toxins enhance the immune responses in mice orally immunised with a recombinant live P-fimbrial vaccine for avian pathogenic E. coli

This study aimed to investigate the adjuvant effect of recombinant attenuated Salmonella expressing cholera toxin B subunit (CTB) and Escherichia coli heat-labile enterotoxin B subunit (LTB) for the P-fimbriae subunit-based vaccine of avian pathogenic E. coli (APEC) in a murine model. The PapA-specific sIgA and IgG responses were significantly enhanced after immunisation with the Salmonella-PapA vaccine in the presence of CTB or LTB. The group immunised with the Salmonella-LTB strain promoted Th1-type immunity, whereas that immunised with the Salmonella-CTB strain produced Th2-type immunity. We concluded that both Salmonella-CTB and -LTB strains can enhance the immune response to PapA, and that the LTB strain may be a more effective adjuvant for APEC vaccination, which requires higher Th1-type immunity for protection. Thus, our findings provide evidence that immunisation with an adjuvant, LTB, is one of the strategies of developing effective vaccines against P-fimbriated APEC

BRAF Activation Initiates but Does Not Maintain Invasive Prostate Adenocarcinoma

Prostate cancer is the second leading cause of cancer-related deaths in men. Activation of MAP kinase signaling pathway has been implicated in advanced and androgen-independent prostate cancers, although formal genetic proof has been lacking. In the course of modeling malignant melanoma in a tyrosinase promoter transgenic system, we developed a genetically-engineered mouse (GEM) model of invasive prostate cancers, whereby an activating mutation of BRAFV600E–a mutation found in ∼10% of human prostate tumors–was targeted to the epithelial compartment of the prostate gland on the background of Ink4a/Arf deficiency. These GEM mice developed prostate gland hyperplasia with progression to rapidly growing invasive adenocarcinoma without evidence of AKT activation, providing genetic proof that activation of MAP kinase signaling is sufficient to drive prostate tumorigenesis. Importantly, genetic extinction of BRAFV600E in established prostate tumors did not lead to tumor regression, indicating that while sufficient to initiate development of invasive prostate adenocarcinoma, BRAFV600E is not required for its maintenance

Changes in Hepatic Gene Expression upon Oral Administration of Taurine-Conjugated Ursodeoxycholic Acid in ob/ob Mice

Nonalcoholic fatty liver disease (NAFLD) is highly prevalent and associated with considerable morbidities. Unfortunately, there is no currently available drug established to treat NAFLD. It was recently reported that intraperitoneal administration of taurine-conjugated ursodeoxycholic acid (TUDCA) improved hepatic steatosis in ob/ob mice. We hereby examined the effect of oral TUDCA treatment on hepatic steatosis and associated changes in hepatic gene expression in ob/ob mice. We administered TUDCA to ob/ob mice at a dose of 500 mg/kg twice a day by gastric gavage for 3 weeks. Body weight, glucose homeostasis, endoplasmic reticulum (ER) stress, and hepatic gene expression were examined in comparison with control ob/ob mice and normal littermate C57BL/6J mice. Compared to the control ob/ob mice, TUDCA treated ob/ob mice revealed markedly reduced liver fat stained by oil red O (44.2±5.8% vs. 21.1±10.4%, P<0.05), whereas there was no difference in body weight, oral glucose tolerance, insulin sensitivity, and ER stress. Microarray analysis of hepatic gene expression demonstrated that oral TUDCA treatment mainly decreased the expression of genes involved in de novo lipogenesis among the components of lipid homeostasis. At pathway levels, oral TUDCA altered the genes regulating amino acid, carbohydrate, and drug metabolism in addition to lipid metabolism. In summary, oral TUDCA treatment decreased hepatic steatosis in ob/ob mice by cooperative regulation of multiple metabolic pathways, particularly by reducing the expression of genes known to regulate de novo lipogenesis

Identification of MicroRNA-21 as a Biomarker for Chemoresistance and Clinical Outcome Following Adjuvant Therapy in Resectable Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis. The high risk of recurrence following surgical resection provides the rationale for adjuvant therapy. However, only a subset of patients benefit from adjuvant therapy. Identification of molecular markers to predict treatment outcome is therefore warranted. The aim of the present study was to evaluate whether expression of novel candidate biomarkers, including microRNAs, can predict clinical outcome in PDAC patients treated with adjuvant therapy.Formalin-fixed paraffin embedded specimens from a cohort of 82 resected Korean PDAC cases were analyzed for protein expression by immunohistochemistry and for microRNA expression using quantitative Real-Time PCR. Cox proportional hazards model analysis in the subgroup of patients treated with adjuvant therapy (N = 52) showed that lower than median miR-21 expression was associated with a significantly lower hazard ratio (HR) for death (HR = 0.316; 95%CI = 0.166–0.600; P = 0.0004) and recurrence (HR = 0.521; 95%CI = 0.280–0.967; P = 0.04). MiR-21 expression status emerged as the single most predictive biomarker for treatment outcome among all 27 biological and 9 clinicopathological factors evaluated. No significant association was detected in patients not treated with adjuvant therapy. In an independent validation cohort of 45 frozen PDAC tissues from Italian cases, all treated with adjuvant therapy, lower than median miR-21 expression was confirmed to be correlated with longer overall as well as disease-free survival. Furthermore, transfection with anti-miR-21 enhanced the chemosensitivity of PDAC cells.. These data provide evidence that miR-21 may allow stratification for adjuvant therapy, and represents a new potential target for therapy in PDAC

Comparison of CpG island hypermethylation and repetitive DNA hypomethylation in premalignant stages of gastric cancer, stratified for Helicobacter pylori infection

CpG island hypermethylation and genomic DNA hypomethylation are found not only in gastric cancers but also in associated premalignant lesions. Helicobacter pylori infection induces aberrant CpG island hypermethylation in gastric mucosae. However, little is known about the relationship between H. pylori infection and aberrant methylation in premalignant lesions. The present study characterized methylation changes in a subset of genes and repetitive DNA elements (ALU, LINE-1, SAT2) and examined their relationship with H. pylori infection in premalignant lesions of gastric cancers. We performed MethyLight analysis of 25 genes and SAT2 and COBRA analysis of ALU and LINE-1 in 212 gastric tissue samples. H. pylori infection was closely associated with enhanced hypermethylation of CpG island loci in chronic gastritis samples, but this association was not found among intestinal metaplasias, gastric adenomas and gastric cancers. The number of methylated genes was greater in intestinal metaplasia and gastric adenoma samples than in chronic gastritis samples, regardless of H. pylori infection. Methylation of repetitive DNA elements in gastric lesions generally decreased with progression of the gastric lesion along the multistep carcinogenesis. No difference was noted in the number of methylated genes in chronic gastritis or intestinal metaplasia between gastric cancer patients and non-cancer subjects. In conclusion, we found that there was no enhanced CpG island hypermethylation in gastric cancer and premalignant lesions in association with H. pylori infection and our findings suggest that CpG island hypermethylation and repetitive DNA hypomethylation are enhanced with progression of the gastric lesion through the multistep carcinogenesis, regardless of the status of H. pylori infection. Copyright (C) 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.Qian XM, 2008, CANCER LETT, V263, P107, DOI 10.1016/j.canlet.2007.12.023Yoo EJ, 2008, VIRCHOWS ARCH, V452, P515, DOI 10.1007/s00428-008-0596-7Leung WK, 2008, LANCET ONCOL, V9, P279, DOI 10.1016/S1470-2045(08)70072-XKang GH, 2008, LAB INVEST, V88, P161, DOI 10.1038/labinvest.3700707Kaise M, 2008, HELICOBACTER, V13, P35Lauwers GY, 2007, GASTROENTEROL CLIN N, V36, P813, DOI 10.1016/j.gtc.2007.08.008Ushijima T, 2007, J BIOCHEM MOL BIOL, V40, P142Cho NY, 2007, J PATHOL, V211, P269, DOI 10.1002/path.2106LAUWERS GY, 2007, GASTROENTEROL CLIN N, V36, pR6Nakajima T, 2006, CANCER EPIDEM BIOMAR, V15, P2317, DOI 10.1158/1055-9965.EPI-06-0436Ogino S, 2006, J MOL DIAGN, V8, P209, DOI 10.2353/jmoldx.2006.050135Ehrlich M, 2006, ONCOGENE, V25, P2636, DOI 10.1038/sj.onc.1209145Maekita T, 2006, CLIN CANCER RES, V12, P989, DOI 10.1158/1078-0432.CCR-05-2096Sato F, 2006, CANCER, V106, P483, DOI 10.1002/cncr.21657Vauhkonen M, 2006, BEST PRACT RES CL GA, V20, P651, DOI 10.1016/j.bpg.2006.03.016Karpf AR, 2005, CANCER RES, V65, P8635, DOI 10.1158/0008-5472Weisenberger DJ, 2005, NUCLEIC ACIDS RES, V33, P6823, DOI 10.1093/nar/gki987Jemal A, 2004, CA-CANCER J CLIN, V54, P8Yamanaka M, 2003, INT J CANCER, V106, P382, DOI 10.1002/ijc.11227Kang GH, 2003, LAB INVEST, V83, P635, DOI 10.1097/01.LAB.0000067481.08984.3FBariol C, 2003, AM J PATHOL, V162, P1361Ehrlich M, 2002, ONCOGENE, V21, P5400, DOI 10.1038/sj.onc.1205651Waki T, 2002, AM J PATHOL, V161, P399Terry MB, 2002, SEMIN RADIAT ONCOL, V12, P111, DOI 10.1053/srao.30814Asaka M, 2001, HELICOBACTER, V6, P294Rashid A, 2001, AM J PATHOL, V159, P1129Leung WK, 2001, CANCER, V91, P2294Kang GH, 2001, CANCER RES, V61, P2847Shimoyama T, 2000, VIRCHOWS ARCH, V436, P585Asaka M, 1997, GASTROENTEROLOGY, V113, pS56Cravo M, 1996, GUT, V39, P434FORMAN D, 1995, ALIMENT PHARM THERAP, V9, P71SATO F, 1995, AM J SURG PATHOL S1, V19, pS37STEMMERMANN GN, 1994, CANCER, V74, P5561

Hypermethylation of the COX-2 gene is a potential prognostic marker for cervical cancer

AIM: The aim of the present study was to evaluate the DNA hypermethylation profiles of 14 genes known to be associated with tumor behavior and their clinical significance in cervical cancer. METHOD: The clinical features of 82 patients with stage IB cervical cancer were analyzed in terms of DNA hypermethylation of 14 genes (hMLH1, p16, COX-2, CDH1, APC, DAPK, MGMT, p14, RASSF1A, RUNX3, TIMP3, FHIT, THBS1, and HLTF). RESULTS: Of 14 genes investigated, only hypermethylation of COX-2 showed significant association with poor disease-free survival (P = 0.001). To further investigate an alteration in COX-2 expression by DNA hypermethylation, immunohistochemistry for COX-2 protein was performed in the cervical cancer tissues. We found no significant association between hypermethylation and expression patterns of the COX-2 gene. CONCLUSIONS: The present results suggest that DNA hypermethylation of the COX-2 gene may be a potential prognostic marker in early stage cervical cancer, the underlying mechanism of which is independent of gene silencing