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The long non-coding RNA H19 is highly expressed in several cancers, and the functions of H19 vary among cancer cell types. Recently, we reported that H19 contributes to the metastasis of pancreatic ductal adenocarcinoma (PDAC) cells and that inhibition of H19 reduces metastasis in vivo. However, the molecular mechanisms underlying the metastasis-promoting role of H19 in PDAC cells remain poorly elucidated. In this study, we clarified the mechanisms by which H19 regulates PDAC metastasis, with a focus on cancer stem cells (CSCs), by using H19-overexpressing and knockdown PDAC cells. Whereas the sphere-formation and invasion abilities of PDAC cells depended on H19 expression levels, other CSC characteristics of the cells, including stemness-marker expression and anticancer-drug resistance, were unaffected by H19 levels. Furthermore, metalloproteinase activity, a key mediator of invasion, was also independent of H19 expression. By contrast, H19 promoted cell adhesion through regulation of integrin and CD24 expression. Notably, the increased adhesion of H19-overexpressing cells was blocked by an anti-β1-integrin antibody, and this resulted in the inhibition of sphere formation and invasion. Thus, H19 plays critical roles in the CSC self-renewal and cell adhesion of PDAC that lead to invasion and metastasis. Our findings suggest that H19 represents a novel therapeutic target for the metastasis of pancreatic cancer.

// Satoru Ishii 1 , Keishi Yamashita 1 , Hiroki Harada 1 , Hideki Ushiku 2 , Toshimichi Tanaka 1 , Nobuyuki Nishizawa 1 , Keigo Yokoi 1 , Marie Washio 1 , Akira Ema 1 , Hiroaki Mieno 1 , Hiromitsu Moriya 1 , Kei Hosoda 1 , Mina Waraya 3 , Hiroshi Katoh 1 and Masahiko Watanabe 1 1 Department of Surgery, Kitasato University School of Medicine, Sagamihara, Japan 2 Department of Surgery, Kitasato University Medical Center, Saitama, Japan 3 Department of Surgery, Sagamino Hospital, Sagamihara, Japan Correspondence to: Masahiko Watanabe, email: gekaw@med.kitasato-u.ac.jp Keywords: gastric cancer, lymph node ratio, H19, PEG10, IGF2BP3 Received: February 15, 2017 Accepted: June 06, 2017 Published: August 05, 2017 ABSTRACT We previously demonstrated that the lymph node ratio (LNR) is a prognostic factor associated with EGFR expression, among first priority genes amplified or overexpressed in cancer. Here, we investigated the associations between high LNR and second, third, and fourth priority genes. We performed mRNA expression microarray analysis of tumor tissue from patients with stage III gastric cancer and high or low LNRs. Candidate high LNR-associated genes were further evaluated in 39 patients with stage III gastric cancer. The functional relevance of these genes was evaluated in gastric cancer cell lines. We focused on five genes: H19 , PEG10 , IGF2BP3 , CD177, and PGA3 . H19 and PEG10 were confirmed as high LNR-associated genes. H19 , PEG10 , and IGF2BP3 were found to promote each other’s expression. Knocking down H19 or PEG10 using RNAi decreased cell proliferation, invasion, anchorage-independent growth, and chemoresistance. These genes had a mutual relationship in MKN7 cells. H19 knockdown decreased expression of epithelial-mesenchymal transition-associated genes in MKN74 cells to suppress transformation. Thus, H19 promotes epithelial-mesenchymal transition in gastric cancer and is a potential therapeutic target.

// Yanlin Zhang 1, * , Mengyao Zhang 2, * , Weiting Xu 3 , Jianchang Chen 3 , Xiang Zhou 3 1 Department of Neurology, The Second Affiliated Hospital of Soochow University, Suzhou, China 2 Department of Cardiology, The First People’s Hospital of Kunshan Affiliated to Jiangsu University, Kunshan, China 3 Department of Cardiology, The Second Affiliated Hospital of Soochow University, Suzhou, China * These authors have contributed equally to this work Correspondence to: Xiang Zhou, email: zhou-xiang@suda.edu.cn Keywords: H19, miR-675, PA2G4, apoptosis, dilated cardiomyopathy Received: January 02, 2017 Accepted: February 08, 2017 Published: February 20, 2017 ABSTRACT In the previous study, we generated a rat model of dilated cardiomyopathy (DCM) induced by adriamycin and found that the expression of lncRNA H19 was significantly upregulated in myocardial tissue. The present study was aimed to investigate the potential role of H19 in the pathogenesis of adriamycin-induced DCM. H19 knockdown in the myocardium of DCM rats attenuated cardiomyocyte apoptosis and improved left ventricular structure and function. Adriamycin treatment was associated with elevated H19 and miR-675 expression and increased apoptosis in neonatal cardiomyocytes. Enforced expression of miR-675 was found to induce apoptosis in cardiomyocytes with adriamycin treatment and H19-siRNA transfection. The 3’-untranslated region of PA2G4 was cloned downstream of a luciferase reporter construct and cotransfected into HEK293 cells with miR-675 mimic. The results of luciferase assay showed that PA2G4 was a direct target of miR-675. The expression of PA2G4 was reduced in cardiomyocytes transfected with miR-675 mimic. Moreover, H19 knockdown was found to increase PA2G4 expression and suppress apoptosis in cardiomyocytes exposed to adriamycin. In conclusion, our study suggests that H19/miR-675 axis is involved in the promotion of cardiomyocyte apoptosis by targeting PA2G4, which may provide a new therapeutic strategy for the treatment of adriamycin-induced DCM.

// Li Peng 1, 2 , Xiao-Qing Yuan 3, 4, * , Zhao-Yang Liu 1, 2 , Wen-Ling Li 1, 2 , Chao-Yang Zhang 1, 2 , Ya-Qin Zhang 1, 2 , Xi Pan 5 , Jun Chen 1, 2 , Yue-Hui Li 1, 2 , Guan-Cheng Li 1, 2, * 1 Key Laboratory of Carcinogenesis of the Chinese Ministry of Health and the Key Laboratory of Carcinogenesis and Cancer Invasion of Chinese Ministry of Education, Xiangya Hospital, Central South University, Changsha 410078, P.R. China 2 Cancer Research Institute, Central South University, Changsha 410078, P.R. China 3 Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008, P.R. China 4 Institute of Clinical Pharmacology, Central South University, Hunan Key Laboratory of Pharmacogenetics, Changsha 410078, P.R. China 5 Department of Oncology, The third Xiangya Hospital, Central South University, Changsha 410013, P.R. China * These authors have contributed equally to this work Correspondence to: Guan-Cheng Li, email: ligc61@csu.edu.cn or libsun@163.com Keywords: H19, prognosis, female cancers, TCGA, meta-analysis Received: June 30, 2016 Accepted: November 14, 2016 Published: December 01, 2016 ABSTRACT Upregulation of lncRNA H19 expression is associated with an unfavorable prognosis in some cancers. However, the prognostic value of H19 in female-specific cancers has remained uncharacterized. In this study, the prognostic power of high H19 expression in female cancer patients from the TCGA datasets was analyzed using Kaplan-Meier survival curves and Cox’s proportional hazard modeling. In addition, in a meta-analysis of non-female cancer patients from TCGA datasets and 12 independent studies, hazard ratios (HRs) with 95% confidence interval (CI) for overall survival (OS) and disease-free survival (DFS)/relapse-free survival (RFS)/metastasis-free survival (MFS)/progression-free survival (PFS) were pooled to assess the prognostic value of high H19 expression. Kaplan-Meier analysis revealed that patients with uterine corpus cancer and higher H19 expression had a shorter OS (HR=2.710, p

// Chuanjun Zhuo 1, 2, 3, 4, * , Ronghuan Jiang 5, * Xiaodong Lin 1 , Mingjing Shao 6 1 Department of Psychological Medicine, Wenzhou Seventh People’s Hospital, Wenzhou, China 2 Institute of Mental Health, Jining Medical University, Jining, China 3 Department of Psychological Medicine, Tianjin Anding Hospital, Tianjin, China 4 Department of Psychological Medicine, Tianjin Anning Hospital, Tianjin, China 5 Department of Psychological Medicine, Chinese People’s Liberation Army (PLA) General Hospital, Chinese PLA (People’s Liberation Army) Medical School, Beijing, China 6 Department of Cardiology, China-Japan Friendship Hospital, Beijing, China * These authors contributed equally to this work Correspondence to: Chuanjun Zhuo, email: chuanjunzhuotjmh@163.com Mingjing Shao, email: shaomingjing0707@163.com Keywords: H19, DIRAS3, autophagy, diabetic cardiomyopathy Received: October 07, 2016 Accepted: November 04, 2016 Published: November 26, 2016 ABSTRACT We previously generated a rat model of diabetic cardiomyopathy and found that the expression of long non-coding RNA H19 was downregulated. The present study was aimed to explore the pathogenic role of H19 in the development of diabetic cardiomyopathy. Overexpression of H19 in diabetic rats attenuated cardiomyocyte autophagy and improved left ventricular function. High glucose was found to reduce H19 expression and increase autophagy in cultured neonatal cardiomyocytes. The results of RNA-binding protein immunoprecipitation showed that H19 could directly bind with EZH2 in cardiomyocytes. The chromatin immunoprecipitation assays indicated that H19 knockdown could reduce EZH2 occupancy and H3K27me3 binding in the promoter of DIRAS3. In addition, overexpression of H19 was found to downregulate DIRAS3 expression, promote mTOR phosphorylation and inhibit autophagy activation in cardiomyocytes exposed to high glucose. Furthermore, we also found that high glucose increased DIRAS3 expression in cardiomyocytes and DIRAS3 induced autophagy by inhibiting mTOR signaling. In conclusion, our study suggested that H19 could inhibit autophagy in cardiomyocytes by epigenetically silencing of DIRAS3, which might provide novel insights into understanding the molecular mechanisms of diabetic cardiomyopathy.

// Fang-teng Liu 1 , Hua Pan 1 , Guang-feng Xia 1 , Cheng Qiu 1 , Zheng-ming Zhu 1 1 Department of General Surgery, the Second Affiliated Hospital of Nanchang University, Nanchang 330000, Jiangxi Province, P. R. China Correspondence to: Zheng-ming Zhu, email: zzm8654@163.com Keywords: long noncoding RNA, H19, carcinoma, prognosis, meta-analysis Received: April 29, 2016 Accepted: October 17, 2016 Published: November 4, 2016 ABSTRACT Background: Many studies have reported that the expression level of lncRNA H19 was increased in various tumors. LncRNA H19 may play a significant role in cancer occurrence and development. An increased level of H19 was also associated with poor clinical outcomes of cancer patients. Results: 12 eligible studies were screened, with a total of 1437 cancer patients. From the results of meta-analysis, as for prognosis, the patients with high expression of lncRNA H19 were shorter in OS (HR=1.08, 95% CI: 1.05-1.12). Statistical significance was also showed in subgroup meta-analysis stratified by the cancer type, analysis type and sample size. In addition, the patients detected with high H19 expression may be poorer in DFS (HR=1.27; 95% CI = 0.97-1.56). As for clinicopathology, it showed that increased H19 was related to poor histological grades (OR=2.31, 95% CI: 1.12-4.75), positive lymph node metastasis (OR=2.29, 95 % CI: 1.21-4.34) and advanced clinical stage (OR=4.83, 95% CI: 3.16-7.39). Materials and Methods: Eligible studies were collected by retrieving keywords in PubMed, Web of Science, Embase, CNKI and Wanfang database, from 1966 to April 23, 2016. This quantitative meta-analysis was performed with Stata SE12.0 and RevMan5.3 software. It aimed to explore the association between H19 expression level and prognosis and clinicopathology. Conclusions: LncRNA-H19 may be a novel molecular marker for predicting solid tumors. It can also be a predictive factor of clinicopathological features in various cancers. Further studies are needed to verify the clinical utility of H19 in human cancers.

// Qi Wang 1, * , Ningning Cheng 2, * , Xuefei Li 3 , Hui Pan 1 , Chunyu Li 4 , Shengxiang Ren 1 , Chunxia Su 1 , Weijing Cai 1 , Chao Zhao 3 , Limin Zhang 1 , Caicun Zhou 1 1 Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University, Tongji University Medical School Cancer Institute, Shanghai, 200433, P.R. China 2 Department of Radiation Oncology, Shanghai General Hospital, Shanghai Jiaotong University, Shanghai, 201620, P. R. China 3 Department of Lung Cancer and Immunology, Shanghai Pulmonary Hospital, Tongji University, Tongji University Medical School Cancer Institute, Shanghai, 200433, P.R. China 4 International Medical School, Tianjin Medical University, Tianjin, 300070, P.R. China * These authors contributed equally to this work Correspondence to: Caicun Zhou, email: caicunzhoudr@163.com Keywords: long non-coding RNA, lung adenocarcinoma, H19, cisplatin, A549/DDP cells Received: June 29, 2016 Accepted: November 21, 2016 Published: November 29, 2016 ABSTRACT The acquired drug resistance would influence the efficacy of cisplatin-based chemotherapy in non-small-cell lung cancer. The present study aimed to investigate the correlation of long non-coding RNA (lncRNA) H19 with cisplatin-resistance and clinical outcome in lung adenocarcinoma. In our study, the expression of H19 in cisplatin-resistant A549/DDP cells was unregulated. Knockdown of H19 restored the response of A549/DDP cells to cisplatin. H19 -mediated chemosensitivity enhancement was associated with metastasis, induction of G0/G1 cell-cycle arrest, cell proliferation, and increased apoptosis. Furthermore, lncRNA H19 expression was significantly related to TNM stage and metastasis ( P = 0.012). Overexpression of H19 was negatively correlated with cisplatin-based chemotherapy response in patients. Patients with high H19 expression exhibited a significantly shorter median progression-free survival (PFS) [4.7 months] than the low-expression patients (6.3months) [ P = 0.002]. In summary, H19 -mediated regulation of cisplatin resistance in human lung adenocarcinoma cells is demonstrated for the first time. H19 could potentially serve as a molecular marker to predict the clinical outcomes of lung adenocarcinoma patients.

// Dong Han 1, 2, * , Xu Gao 1, 2, * , Meng Wang 3, * , Yu Qiao 1, 2 , Ya Xu 1 , Jing Yang 1 , Nazhen Dong 1 , Jun He 1 , Qian Sun 1 , Guixiang Lv 1 , Changqing Xu 4 , Ji Tao 5 , Ning Ma 1, 2 1 Department of Biochemistry and Molecular Biology, Harbin Medical University, Harbin, China 2 Heilongjiang Academy of Medical Sciences, Harbin, China 3 Department of General Surgery, the Second Affiliated Hospital of Harbin Medical University, Harbin, China 4 Department of Pathophysiology, Harbin Medical University, Harbin, China 5 Department of Gastrointestinal Medical Oncology, the Affiliated Tumor Hospital of Harbin Medical University, Harbin, China * These authors contributed equally to this work Correspondence to: Ning Ma, e-mail: maning2013@163.com Ji Tao, e-mail: taoji66@163.com Keywords: colorectal cancer, long noncoding RNA, H19, poor prognosis, cell proliferation Received: December 14, 2015 Accepted: February 23, 2016 Published: March 14, 2016 ABSTRACT The overall biological role and clinical significance of long non-coding RNA H19 in colorectal cancer (CRC) remain largely unknown. Here, we firstly report that the lncRNA H19 recruits eIF4A3 and promotes the CRC cell proliferation. We observed higher expression of H19 was significantly correlated with tumor differentiation and advanced TNM stage in a cohort of 83 CRC patients. Multivariate analyses revealed that expression of H19 served as an independent predictor for overall survival and disease-free survival. Further experiments revealed that overexpression of H19 promoted the proliferation of CRC cells, while depletion of H19 inhibited cell viability and induced growth arrest. Moreover, expression profile data showed that H19 upregulated a series of cell-cycle genes. Using bioinformatics prediction and RNA immunoprecipitation assays, we identified eIF4A3 as an RNA-binding protein that binds to H19. We confirmed that combining eIF4A3 with H19 obstructed the recruitment of eIF4A3 to the cell-cycle gene mRNA. Our results suggest that H19, as a growth regulator, could serve as a candidate prognostic biomarker and target for new therapies in human CRC.

Long non-coding RNA (lncRNA) genes are emerging as key players in the metastatic cascade. Current evidence indicate that H19 lncRNA and the microRNA(miRNA) miR-675, which is processed from it, play crucial roles in metastasis, through the regulation of critical events specifically the epithelial to mesenchymal (EMT) and the mesenchymal to epithelial transitions (MET). This review summarizes recent mechanistic pathways and tries to put together seemingly conflicting data from different reports under one proposed general scheme underlying the various roles of H19/miR-675 in the metastatic cascade. We propose several approaches to harnessing this knowledge for translational medicine.

// Chao Yang 1,* , Ran Tang 1,* , Xiang Ma 1,* , Younan Wang 1 , Dakui Luo 1 , Zekuan Xu 1 , Yi Zhu 1,2 and Li Yang 1 1 Department of General Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China 2 Jiangsu Province Academy of Clinical Medicine, Institute of Tumor Biology, Nanjing, China * These authors have contributed equally to this work Correspondence to: Li Yang, email: // Keywords : gastric cancer, H19, polymorphism, genotype Received : November 17, 2014 Accepted : March 19, 2015 Published : April 15, 2015 Abstract Long non-coding RNA (lncRNA) H19 is involved in tumor development, progression, and metastasis. This case-control study assessed the association between H19 genetic variants and susceptibility to gastric cancer (GC) in a Chinese Han population. We genotyped four lncRNA H19 single nucleotide polymorphisms (SNPs) (rs217727 C > T, rs2839698 C > T, rs3741216 A > T, rs3741219 T > C) in 500 GC patients and 500 healthy controls. Carriers of variant rs217727T and rs2839698T alleles showed increased GC risk ( P = 0.008 and 0.011, respectively). Compared with the common genotype, CT + TT rs217727 and CT + TT rs2839698 genotypes were associated with significantly increased GC risk ( P = 0.040, adjusted odds ratio [OR] = 1.32, 95% confidence interval [CI] = 1.01–1.71; P = 0.033, adjusted OR = 1.31, 95% CI = 1.02–1.69, respectively). Further stratified analyses revealed that the association between GC risk and variant genotypes of rs217727 was more profound in younger individuals (≤59 years) and non-smokers, while the association between risk and the rare rs2839698 genotype persisted in men and rural subjects. rs2839698 CT and TT genotypes were also associated with higher serum H19 mRNA levels compared with the CC genotype. These findings suggest that lncRNA H19 SNPs may contribute to susceptibility to GC.

To evaluate whether the genetic variants in H19 influence the risk of oral squamous cell carcinoma (OSCC) in a Chinese population, a case-control study was conducted to analyze four functional single nucleotide polymorphisms (SNPs) in H19. The cohort comprised of 444 OSCC cases and 984 healthy controls, and the study further evaluated the biological effect by bioinformatics prediction and functional experiments. Two SNPs, rs217727 and rs2839701, were found to be associated with the risk of OSCC [rs217727: odds ratio (OR) = 1.32, 95% confidence interval (CI) = 1.11–1.58, P = 0.002; rs2839701: OR = 1.23, 95% CI = 1.04–1.46, P = 0.019].Bioinformatics predicted that rs2839701 C>G might alter the secondary structure of H19. In addition, rs2839701 C>G inhibited the transcription activity and was correlated with the decreased expression of downstream gene MRPL23-AS1 that was downregulated in OSCC. The current results suggested that the SNPs in H19 may play a major role in genetic susceptibility to OSCC.

// Hao Li 1 , Beiqin Yu 1 , Jianfang Li 1 , Liping Su 1 , Min Yan 1 , Zhenggang Zhu 1 , Bingya Liu 1 1 Shanghai Key Laboratory of Gastric Neoplasms, Shanghai Institute of Digestive Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, People’s Republic of China. Correspondence: Bingya Liu, email: // Keywords : gastric cancer, long non-coding RNA, H19, microRNA, miR-675 Received : March 04, 2014 Accepted : April 16, 2014 Published : April 18, 2014 Abstract Long non-coding RNAs (lncRNAs) play key roles in the progression and metastasis of some carcinomas. We previously showed that the expression of lncRNA H19 (H19) was higher in gastric cancer (GC) tissues than that in paired noncanerous tissues. However, the underlying mechanisms remain unclear. In this study, H19/miR-675 knockdown models in the MKN45 cell line and ectopic expression models in the SGC7901 cell line were established, and a co-expression network of H19 was generated to identify target genes by RIP and DLR. The results showed that overexpression of H19 promoted the features of GC including proliferation, migration, invasion and metastasis. An H19 co-expression network identified ISM1 as a binding protein of H19, and its expression was positively correlated with that of H19. CALN1 was identified as a target gene of miR-675 and its expression was negatively correlated with that of miR-675. H19 and MiR-675 function in a similar manner. However, H19 RNA actively binds to ISM1 and miR-675 targets CALN1. These differences suggest that H19 plays other roles besides encoding miR-675 in GC. Our results suggest that the effect of H19 in GC is mediated by the direct upregulation of ISM1 and the indirect suppression of CALN1 expression via miR-675.

// Xue-Feng Li 1, * , Xin-Hai Yin 2, * , Jun-Wei Cai 1, * , Ming-Ju Wang 3 , Yu-Qin Zeng 1 , Min Li 1 , Yu-Ming Niu 1, 4 and Ming Shen 5 1 Department of Endocrinology, Taihe Hospital, Hubei University of Medicine, Shiyan 442000, China 2 Department of Oral and Maxillary Surgery, Gui Zhou Provincial People’s Hospital, Guiyang 550000, China 3 Information Resources, Taihe Hospital, Hubei University of Medicine, Shiyan 442000, China 4 Department of Stomatology and Center for Evidence-Based Medicine and Clinical Research, Taihe Hospital, Hubei University of Medicine, Shiyan 442000, China 5 Jiangsu Key Laboratory of Oral Diseases, Department of Dental Implant, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing 210029, China * These authors contributed equally to this work Correspondence to: Yu-Ming Niu, email: niuyuming@yeah.net Ming Shen, email: mingshen85@yahoo.com Keywords: H19, polymorphism, cancer, meta-analysis Received: August 15, 2016 Accepted: March 19, 2017 Published: March 29, 2017 ABSTRACT Previous epidemiological research suggests polymorphisms in long non-coding RNA (lncRNA) H19 are associated with an increased risk of cancer, but the results are inconsistent. We therefore conducted a meta-analysis to more accurately determine the association between lncRNA H19 polymorphisms and cancer risk. The PubMed, Embase, and Science Citation Index online databases were searched and 11 relevant studies involving a total of 33,209 participants were identified. Odds ratios (ORs) and corresponding 95% confidence interval (CIs) from these studies were used to detect associations between H19 polymorphisms and cancer risk using five genetic models. The pooled result suggested that the rs2839698 G>A polymorphism was associated with digestive cancer risk in all five models. Moreover, a protective effect against cancer development was observed for the T allele variant of the rs2107425 C>T polymorphism, especially in Caucasian patient populations. No significant associations were found between lncRNA H19 rs217727 G>A polymorphism and cancer risk. In summary, the rs2839698 G>A and rs2107425 C>T polymorphisms in lncRNA H19 may therefore play opposing roles during cancer development, and their effects may vary depending on cancer type and patient ethnicity.

// Minjie Chu 1, * , Weiyan Yuan 2, * , Shuangshuang Wu 3, * , Zhiquan Wang 4, * , Liping Mao 5 , Tian Tian 1 , Yihua Lu 1 , Bowen Zhu 1 , Yue Yang 1 , Bin Wang 6 , Haiquan Gao 6 , Liying Jiang 1, # , Xun Zhuang 1, # 1 Department of Epidemiology and Biostatistics, School of Public Health, Nantong University, Nantong, Jiangsu, China 2 Department of Gastroenterology, Affiliated Hospital of Nantong University, Nantong, Jiangsu, China 3 Department of Geriatrics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China 4 Center for Disease Control and Prevention of Nantong, Nantong, Jiangsu, China 5 Department of Oncology, the Sixth People's Hospital of Nantong, Nantong, Jiangsu, China 6 Nantong Prison Hospital, Nantong, Jiangsu, China * These authors contributed equally to this work # These authors jointly directed to this work Correspondence to: Minjie Chu, email: chuminjie@ntu.edu.cn Keywords: H19, polymorphism, cancer and meta-analysis Received: June 13, 2016 Accepted: October 03, 2016 Published: October 08, 2016 ABSTRACT H19 refers to a long non-coding RNA (lncRNA) that functions as an oncogenic molecule in different cancer cells. Genetic variants of H19 may affect the activity of certain regulatory factors, which subsequently regulate the aberrant expression of H19 . This feedback loop might be one of the underlying mechanisms influencing tumour susceptibility and prognosis. Although there have been several recent studies that examined possible links between polymorphisms in H19 and cancer risk, the results have been inconclusive. Thus, we performed a meta-analysis to estimate the associations between H19 polymorphisms (rs2107425, rs2839698 and rs217727) and cancer risk. Ten studies comprising 13,392 cases and 18,893 controls were included in the study. Overall, the variant T allele of rs2107425 correlated with a significantly decreased risk of developing cancer (dominant model: OR = 0.86; 95% CI = 0.76–0.98). In addition, a marginally significant association between the rs2839698 and cancer risk was observed (dominant model: OR = 1.09; 95% CI = 0.99–1.20). After stratification for ethnicity, it became apparent that Asians with the variant A allele of rs2839698 exhibited a significantly higher risk of developing cancer (dominant model: OR = 1.11; 95% CI = 1.01–1.23). Interestingly, the rs2839698 variant was also significant associated with an increased risk of cancers of the digestive system (dominant model: OR = 1.23; 95% CI = 1.08–1.41). These findings provided evidence that H19 rs2107425 may modify general cancer susceptibility, while rs2839698 may modify cancer susceptibility based on ethnicity and type. Further experimental studies to evaluate the limits of this hypothesis are warranted, and future functional studies are required to clarify the possible mechanisms.

H19 is a long non-coding RNA precursor of miR-675 microRNA. H19 is increasingly described to play key roles in the progression and metastasis of cancers from different tissue origins. We have previously shown that the H19 gene is activated by growth factors and increases breast cancer cell invasion. In this study, we established H19/miR-675 ectopic expression models of MDA-MB-231 breast cancer cells to further investigate the underlying mechanisms of H19 oncogenic action. We showed that overexpression of H19/miR-675 enhanced the aggressive phenotype of breast cancer cells including increased cell proliferation and migration in vitro, and increased tumor growth and metastasis in vivo. Moreover, we identified ubiquitin ligase E3 family (c-Cbl and Cbl-b) as direct targets of miR-675 in breast cancer cells. Using a luciferase assay, we demonstrated that H19, through its microRNA, decreased both c-Cbl and Cbl-b expression in all breast cancer cell lines tested. Thus, by directly binding c-Cbl and Cbl-b mRNA, miR-675 increased the stability and the activation of EGFR and c-Met, leading to sustained activation of Akt and Erk as well as enhanced cell proliferation and migration. Our data describe a novel mechanism of protumoral action of H19 in breast cancer.

// Bailing Chen 1 , Miaomiao Yu 1 , Qingshan Chang 1 , Yongju Lu 1 , Chitra Thakur 1 , Danjun Ma 1 , Zhengping Yi 1 , Fei Chen 1 1 Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy, Wayne State University, 259 Mack Avenue, Detroit, MI, USA Correspondence: Fei Chen, email: // Keywords : mdig, H19, demethylation, prognosis Received :July 2, 2013 Accepted : August 8, 2013 Published : August 10, 2013 Abstract Mineral dust-induced gene (mdig) had been linked to the development of human lung cancers associated with environmental exposure to mineral dust, tobacco smoke or other carcinogens. In the present studies, we demonstrated that the overexpression of mdig in A549 adenocarcinomic human alveolar type II epithelial cells decreases the heterochromatin conformation of the cells and de-represses the transcription of genes in the tandemly repeated DNA regions. Although mdig can only cause a marginal decrease of the total histone H3 lysine 9 trimethylation (H3K9me3), a significant reduction of H3K9me3 in the promoter region of H19, the paternally imprinted but maternally expressed gene transcribing a large intergenic non-coding RNA (lincRNA), was observed in the cells with mdig overexpression. Silencing mdig by either shRNA or siRNA not only increased the level of H3K9me3 in the promoter region of H19 but also attenuated the transcription of H19 long non-coding RNA. Demethylation assays using immunoprecipitated mdig and histone H3 peptide substrate suggested that mdig is able to remove the methyl groups from H3K9me3. Clinically, we found that higher levels of mdig and H19 expression correlate with poorer survival of the lung cancer patients. Taken together, our results imply that mdig is involved in the regulation of H3K9me3 to influence the heterochromatin structure of the genome and the expression of genes important for cell growth or transformation.