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Liu SS, Chan KKL, Chu DKH, Wei TN, Lau LSK, Ngu SF, Chu MMY, Tse KY, Ip PPC, Ng EKO, Cheung ANY, Ngan HYS. Oncogenic microRNA signature for early diagnosis of cervical intraepithelial neoplasia and cancer. Mol Oncol 2018; 12:2009-2022. [PMID: 30221475 PMCID: PMC6275249 DOI: 10.1002/1878-0261.12383] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 09/05/2018] [Accepted: 09/07/2018] [Indexed: 12/11/2022] Open
Abstract
Cervical cancer is one of the leading causes of cancer death in women globally, despite the widespread use of cytology/human papillomavirus (HPV) screening. In the present study, we aimed to identify the potential role of microRNA (miRNA) as a diagnostic biomarker in the detection of cervical pre‐malignant lesions and cancer. In total, we recruited 582 patients with cervical diseases and 145 control individuals. The expression levels of six miRNAs (miR‐20a, miR‐92a, miR‐141, miR‐183*, miR‐210 and miR‐944) were found to be significantly up‐regulated in cervical cancer and pre‐malignant lesions compared to normal cervical samples, indicating that they are oncogenic miRNAs. Receiver operating characteristic curve analysis showed that these six miRNAs can be used to distinguish patients with cervical pre‐malignant lesions or cancer from normal individuals and they also had a good predictive performance, particularly in cervical lesions. Combined use of these six miRNAs further enhanced the diagnostic accuracy over any single miRNA marker, with an area under the curve of 0.998, 0.996 and 0.959, a diagnostic sensitivity of 97.9%, 97.2% and 91.4%, and a specificity of 98.6%, 96.6% and 87.6% for low‐grade lesions, high‐grade lesions and cancer, respectively. This six oncogenic miRNA signature may be suitable for use as diagnostic marker for cervical pre‐malignant lesions and cancer in the near future.
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Affiliation(s)
- Stephanie S Liu
- Department of Obstetrics & Gynaecology, LKS Faculty of Medicine, The University of Hong Kong, SAR, China
| | - Karen K L Chan
- Department of Obstetrics & Gynaecology, LKS Faculty of Medicine, The University of Hong Kong, SAR, China
| | - Daniel K H Chu
- Department of Obstetrics & Gynaecology, LKS Faculty of Medicine, The University of Hong Kong, SAR, China
| | - Tina N Wei
- Department of Obstetrics & Gynaecology, LKS Faculty of Medicine, The University of Hong Kong, SAR, China
| | - Lesley S K Lau
- Department of Obstetrics & Gynaecology, LKS Faculty of Medicine, The University of Hong Kong, SAR, China
| | - Siew F Ngu
- Department of Obstetrics & Gynaecology, LKS Faculty of Medicine, The University of Hong Kong, SAR, China
| | - Mandy M Y Chu
- Department of Obstetrics & Gynaecology, LKS Faculty of Medicine, The University of Hong Kong, SAR, China
| | - Ka Yu Tse
- Department of Obstetrics & Gynaecology, LKS Faculty of Medicine, The University of Hong Kong, SAR, China
| | - Philip P C Ip
- Department of Pathology, LKS Faculty of Medicine, Queen Mary Hospital, The University of Hong Kong, SAR, China
| | - Enders K O Ng
- Pangenia Lifesciences Limited, Billion Centre, Hong Kong, SAR, China
| | - Annie N Y Cheung
- Department of Pathology, LKS Faculty of Medicine, Queen Mary Hospital, The University of Hong Kong, SAR, China
| | - Hextan Y S Ngan
- Department of Obstetrics & Gynaecology, LKS Faculty of Medicine, The University of Hong Kong, SAR, China
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Shin VY, Siu MT, Liu X, Ng EKO, Kwong A, Chu KM. MiR-92 suppresses proliferation and induces apoptosis by targeting EP4/Notch1 axis in gastric cancer. Oncotarget 2018; 9:24209-24220. [PMID: 29849934 PMCID: PMC5966267 DOI: 10.18632/oncotarget.24819] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 02/27/2018] [Indexed: 12/19/2022] Open
Abstract
MiR-92a has been shown to be dysregulated in various cancers and exhibited differential role in carcinogenesis. In this study, we sought to delineate the functional role of miR-92a and its regulatory pathway in gastric cancer. MiR-92a expression were underexpressed in tissues of gastric cancer patients with the area under curve (AUC) of 0.78. Low expression in plasma was due to the increased promoter DNA methylation of miR-92a. Overexpression of miR-92a inhibited cell proliferation and invasion, and induced apoptosis. Furthermore, miR-92a reduced tumor growth in xenograft model. EP4 and Notch 1 were identified to be negatively regulated by miR-92a, and involved in cell growth. Moreover, NF-κB expression was inversely correlated with miR-92a in gastric cancer tissues and suppressed the expression of miR-92. This study unravels the tumor suppressive role of miR-92a involving EP4/Notch 1 signaling regulated by NF-κB in gastric cancer. Further studies on miR-92a and EP4/Notch1 may provide a new treatment strategy for gastric cancer.
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Affiliation(s)
| | - Man-Ting Siu
- Department of Surgery, The University of Hong Kong, Hong Kong SAR
| | - Xin Liu
- Department of Surgery, The University of Hong Kong, Hong Kong SAR
| | - Enders K O Ng
- Department of Surgery, The University of Hong Kong, Hong Kong SAR
| | - Ava Kwong
- Department of Surgery, The University of Hong Kong, Hong Kong SAR.,Department of Surgery, Hong Kong Sanatorium and Hospital, Hong Kong SAR.,Hong Kong Hereditary Breast Cancer Family Registry, Hong Kong SAR
| | - Kent-Man Chu
- Department of Surgery, The University of Hong Kong, Hong Kong SAR
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3
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Chan CM, Lai KKY, Ng EKO, Kiang MN, Kwok TWH, Wang HK, Chan KW, Law TT, Tong DK, Chan KT, Lee NP, Law S. Serum microRNA-193b as a promising biomarker for prediction of chemoradiation sensitivity in esophageal squamous cell carcinoma patients. Oncol Lett 2017; 15:3273-3280. [PMID: 29435069 DOI: 10.3892/ol.2017.7698] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 08/03/2017] [Indexed: 02/06/2023] Open
Abstract
Esophageal squamous cell carcinoma (ESCC) is the most predominantly occurring type of esophageal cancer worldwide. Locally advanced ESCC patients are treated by neoadjuvant chemoradiation for tumor downstaging prior to tumor resection. Patients receiving this treatment have an increased expectation of cure via the following tumor resection and have better survival outcomes. However, not all patients respond well to chemoradiation and poor responders suffer from treatment-associated toxicity and complications without benefits. No method is currently available to predict patient chemoradiation response and to exclude poor responders from ineffective treatment. To address this clinical limitation, the present study aimed to identify non-invasive biomarkers for predicting patient chemoradiation response. Due to the features of microRNA (miRNA) in cancer diagnosis, prognosis and treatment response prediction, serum miRNA arrays were performed to identify potential miRNA(s) that may be used for chemoradiation response prediction in ESCC. Using an miRNA array to compare pre-treatment serum sample pools from 10 good responders and 10 poor responders, the present study identified miR-193b, miR-942 and miR-629* as candidate miRNAs for predicting chemoradiation response. Subsequent validation using reverse transcription-quantitative polymerase chain reaction confirmed that miR-193b, however not miR-942 and miR-629*, were significantly increased in sera from 24 good responders, compared with 23 poor responders. Further analyses using the receiver operating characteristic curve revealed a strong predictive power of serum miR-193b on discriminating good responders from poor responders to chemoradiation. In addition, a high serum level of miR-193b was significantly associated with better survival outcomes. Therefore, serum miR-193b may be considered a promising biomarker for predicting chemoradiation response and post-therapy survival of ESCC patients.
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Affiliation(s)
- Chung Man Chan
- Department of Surgery, The University of Hong Kong, Hong Kong, SAR, P.R. China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, Zhejiang 310003, P.R. China
| | - Kenneth K Y Lai
- Department of Surgery, The University of Hong Kong, Hong Kong, SAR, P.R. China
| | - Enders K O Ng
- Department of Surgery, The University of Hong Kong, Hong Kong, SAR, P.R. China
| | - Mei Na Kiang
- Department of Surgery, The University of Hong Kong, Hong Kong, SAR, P.R. China
| | - Tiffany W H Kwok
- Department of Surgery, The University of Hong Kong, Hong Kong, SAR, P.R. China
| | - Hector K Wang
- Department of Surgery, The University of Hong Kong, Hong Kong, SAR, P.R. China
| | - Kwok Wah Chan
- Department of Pathology, The University of Hong Kong, Hong Kong, SAR, P.R. China
| | - Tsz Ting Law
- Department of Surgery, The University of Hong Kong, Hong Kong, SAR, P.R. China
| | - Daniel K Tong
- Department of Surgery, The University of Hong Kong, Hong Kong, SAR, P.R. China
| | - Kin Tak Chan
- Department of Surgery, The University of Hong Kong, Hong Kong, SAR, P.R. China
| | - Nikki P Lee
- Department of Surgery, The University of Hong Kong, Hong Kong, SAR, P.R. China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, Zhejiang 310003, P.R. China
| | - Simon Law
- Department of Surgery, The University of Hong Kong, Hong Kong, SAR, P.R. China
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Lai CTM, Ng EKO, Chow PC, Kwong A, Cheung YF. Circulating MicroRNA in patients with repaired tetralogy of Fallot. Eur J Clin Invest 2017; 47:574-582. [PMID: 28664568 DOI: 10.1111/eci.12778] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 06/26/2017] [Indexed: 12/12/2022]
Abstract
BACKGROUND Emerging data suggest that heart-related microRNAs (miRs) may serve as circulating biomarkers of myocardial injury. We aimed to determine the circulating profile of miRs in patients with volume-overloaded right ventricles after repair of tetralogy (TOF). MATERIALS AND METHODS A total of 104 TOF patients and 70 controls were recruited. The study was conducted in two phases: (1) determination of circulating heart-related miRs described in left heart diseases (miR-1, miR-133a, miR-208a, miR-208b and miR423-5p) by quantitative real-time PCR in 49 patients and 30 controls and followed by validation in an independent cohort of 55 patients and 40 controls; (2) expression profiling of serum samples from eight patients and eight controls, followed by validation. Alteration in circulating miRNA expression was related to cardiac functional indices as assessed by 2D speckle tracking and 3D echocardiography. RESULTS No significant differences in serum levels of left heart-associated miRNAs were found between patients and controls. Of the candidate 19 miRNAs identified by profiling, upregulation of miR-99b and down-regulation of miR-766 were validated. However, no correlations were found between miRs levels and echo indices. CONCLUSION In young adults with repaired TOF and volume-overloaded right ventricles, circulating levels of miR-99b and miR-766, but not left heart-associated miRNAs, were significantly altered.
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Affiliation(s)
- Clare T M Lai
- Division of Paediatric Cardiology, Department of Paediatrics and Adolescent Medicine, The University of Hong Kong, Hong Kong, China
| | - Enders K O Ng
- Department of Surgery, The University of Hong Kong, Hong Kong, China
| | - Pak-Cheong Chow
- Division of Paediatric Cardiology, Department of Paediatrics and Adolescent Medicine, The University of Hong Kong, Hong Kong, China
| | - Ava Kwong
- Department of Surgery, The University of Hong Kong, Hong Kong, China
| | - Yiu-Fai Cheung
- Division of Paediatric Cardiology, Department of Paediatrics and Adolescent Medicine, The University of Hong Kong, Hong Kong, China
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5
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Shin VY, Ng EKO, Chan VW, Kwong A, Chu KM. A three-miRNA signature as promising non-invasive diagnostic marker for gastric cancer. Mol Cancer 2015; 14:202. [PMID: 26607322 PMCID: PMC4659169 DOI: 10.1186/s12943-015-0473-3] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 11/18/2015] [Indexed: 02/06/2023] Open
Abstract
Background Despite the declining incidence of gastric cancer, mortality rate remains high due to late presentation. We aimed to evaluate the sensitivity of miRNA as a diagnostic marker for gastric cancer in the circulation. Methods Plasma samples from 3 independent groups comprise 123 gastric cancer patients and 111 healthy controls for miRNA profiling from microarray screening. Results Microarray data showed that 25 miRNAs were upregulated in gastric cancer patients and 6 highly expressed miRNAs (miR-18a, miR-140-5p, miR-199a-3p, miR-627, miR-629 and miR-652) were selected for validation. In an independent validation set, levels of miR-627, miR-629 and miR-652 were significantly higher in gastric cancer patients than healthy controls (P <0.0001). An algorithm with improved sensitivity and specificity as gastric cancer classifier was adopted and validated in another random set of 15 plasma samples. Results showed that combination of 3 miRNAs obtained the highest area under curve, with a cut-off at 0.373, with a sensitivity of 86.7 % and a specificity of 85.5 %. Conclusion This study revealed a three-miRNA signature as a promising classifier for gastric cancer, and greatly enhances the feasibility of circulating miRNAs as non-invasive diagnostic marker for this disease. Electronic supplementary material The online version of this article (doi:10.1186/s12943-015-0473-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Vivian Yvonne Shin
- Department of Surgery, Queen Mary Hospital, The University of Hong Kong, Pokfulam, Hong Kong, SAR, China.
| | - Enders K O Ng
- Department of Surgery, Queen Mary Hospital, The University of Hong Kong, Pokfulam, Hong Kong, SAR, China
| | - Vivian W Chan
- Department of Surgery, Queen Mary Hospital, The University of Hong Kong, Pokfulam, Hong Kong, SAR, China
| | - Ava Kwong
- Department of Surgery, Queen Mary Hospital, The University of Hong Kong, Pokfulam, Hong Kong, SAR, China.,Department of Surgery, Hong Kong Sanatorium & Hospital, Hong Kong, SAR, China.,Hong Kong Hereditary Breast Cancer Family Registry, Hong Kong, SAR, China
| | - Kent-Man Chu
- Department of Surgery, Queen Mary Hospital, The University of Hong Kong, Pokfulam, Hong Kong, SAR, China.
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Shin VY, Siu JM, Cheuk I, Ng EKO, Kwong A. Circulating cell-free miRNAs as biomarker for triple-negative breast cancer. Br J Cancer 2015; 112:1751-9. [PMID: 25906045 PMCID: PMC4647231 DOI: 10.1038/bjc.2015.143] [Citation(s) in RCA: 109] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Revised: 03/10/2015] [Accepted: 03/16/2015] [Indexed: 02/06/2023] Open
Abstract
Background: Triple-negative breast cancer (TNBC) accounts for 15–20% of all breast cancer in women globally. This subtype often has early and high recurrence rates resulting in poor survival, partially due to lack of targeted therapies. Therefore, there is an urgent need to identify TNBC-specific biomarkers for early diagnosis and treatment monitoring, and to develop more effective targeted therapy. Methods: By using miRCURY LNA array platform, we compared the differential miRNA expressions in plasma of patient with TNBC (n=5) and non-TNBC (n=5), as well as healthy controls (n=5). Potential miRNAs were then validated in a large cohort of patients by real-time PCR. Results: Ten putative miRNAs from the microarray data that differentially expressed between non-TNBC and healthy controls were identified. In the screening phase (n=90), we selected five miRNAs (miR-92a-3p, miR-342-3p, miR-16, miR-21 and miR-199a-5p) that could discriminate TNBC from non-TNBC for further validation. Results showed that miR-16, miR-21 and miR-199a-5p were underexpressed in TNBC when compared with non-TNBC, and were further validated in a large cohort (n=252). In addition, post-operative plasma levels of miR-16, miR-21 and miR-199a-5p were significantly restored when compared with pre-operative plasma of TNBC. Plasma miR-199a-5p expression in TNBC had significant difference when compared with non-TNBC and healthy controls, the receiver-operator characteristics curve analysis revealed the highest area under curve (AUC=0.8838) among all. The expression levels were associated with TNM stage and tumour subtypes. Conclusions: Our data suggest that miR-199a-5p could be a TNBC-specific marker with diagnostic value and provide insights into targeted therapy in the treatment of TNBC.
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Affiliation(s)
- V Y Shin
- Department of Surgery, the University of Hong Kong, Hong Kong SAR, China
| | - J M Siu
- Department of Surgery, the University of Hong Kong, Hong Kong SAR, China
| | - I Cheuk
- Department of Surgery, the University of Hong Kong, Hong Kong SAR, China
| | - E K O Ng
- Department of Surgery, the University of Hong Kong, Hong Kong SAR, China
| | - A Kwong
- 1] Department of Surgery, the University of Hong Kong, Hong Kong SAR, China [2] The Hong Kong Hereditary Breast Cancer Family Registry, Hong Kong SAR, China
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Co NNC, Chu LO, Chow JKF, Tam JWO, Ng EKO. HPV Prevalence and Detection of Rare HPV Genotypes in Hong Kong Women from Southern China with Cytological Abnormalities. ACTA ACUST UNITED AC 2013. [DOI: 10.5402/2013/312706] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Human papillomavirus (HPV) has been identified as the primary cause of cervical squamous intraepithelial lesion and invasive cervical cancer. The emergence of various commercial HPV genotyping kits with different characteristics facilitates the detection of most high-risk and low-risk HPV genotypes, but the rare HPV types are usually underdiagnosed. In the present study, HPV detection was performed using the GenoFlow HPV Array Test kit (DiagCor Bioscience), which can identify 33 HPV subtypes by specific probes. Besides, a HPV consensus probe (universal probe) was designed to capture not only the 33 genotypes but also rare subtypes. Of the 1643 Southern Chinese women tested between 2012 and 2013, the HPV prevalence was 42.3%, with HPV 52 (139/1643, 8.5%), HPV 81 (89/1643, 5.4%), and HPV 16 (63/1643, 3.8%) being the most frequent subtypes detected. Among all 695 HPV-positive cases, 56 (8.1%) cases were only detected by the universal probe, in which 5 were either ASCUS or LSIL cases. Sequencing results confirmed HPV types 30, 91, and 74, and the intratypic variants of HPV 72 and 82 were present in the 5 cases. The result suggests that some rare HPV subtypes might be involved in cervical lesions.
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Affiliation(s)
- Ngai Na Chloe Co
- Molecular Diagnostics Division, DiagCor Bioscience Incorporation Ltd, Hong Kong SAR, Hong Kong
| | - Lai-On Chu
- Molecular Diagnostics Division, DiagCor Bioscience Incorporation Ltd, Hong Kong SAR, Hong Kong
| | - Joseph K. F. Chow
- Molecular Diagnostics Division, DiagCor Bioscience Incorporation Ltd, Hong Kong SAR, Hong Kong
| | - Joseph W. O. Tam
- Molecular Diagnostics Division, DiagCor Bioscience Incorporation Ltd, Hong Kong SAR, Hong Kong
| | - Enders K. O. Ng
- Molecular Diagnostics Division, DiagCor Bioscience Incorporation Ltd, Hong Kong SAR, Hong Kong
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Ng EKO, Li R, Shin VY, Siu JM, Ma ESK, Kwong A. MicroRNA-143 is downregulated in breast cancer and regulates DNA methyltransferases 3A in breast cancer cells. Tumour Biol 2013; 35:2591-8. [PMID: 24218337 DOI: 10.1007/s13277-013-1341-7] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Accepted: 10/16/2013] [Indexed: 12/12/2022] Open
Abstract
MicroRNAs (miRNAs) are small non-protein-coding RNAs that regulate expression of a wide variety of genes including those involved in cancer development. Here, we investigate the role of miR-143 in breast cancer. In this study, we showed that miR-143 was frequently downregulated in 80% of breast carcinoma tissues compared to their adjacent noncancerous tissues. Ectopic expression of miR-143 inhibited proliferation and soft agar colony formation of breast cancer cells and also downregulated DNA methyltransferase 3A (DNMT3A) expression on both mRNA and protein levels. Restoration of miR-143 expression in breast cancer cells reduces PTEN hypermethylation and increases TNFRSF10C methylation. DNMT3A was demonstrated to be a direct target of miR-143 by luciferase reporter assay. Furthermore, miR-143 expression was observed to be inversely correlated with DNMT3A mRNA and protein expression in breast cancer tissues. Our findings suggest that miR-143 regulates DNMT3A in breast cancer cells. These findings elucidated a tumor-suppressive role of miR-143 in epigenetic aberration of breast cancer, providing a potential development of miRNA-based treatment for breast cancer.
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Affiliation(s)
- Enders K O Ng
- Department of Surgery, The University of Hong Kong, Hong Kong SAR, Hong Kong
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9
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Lai CTM, Ng EKO, Chow PC, Kwong A, Cheung YF. Circulating microRNA expression profile and systemic right ventricular function in adults after atrial switch operation for complete transposition of the great arteries. BMC Cardiovasc Disord 2013; 13:73. [PMID: 24040857 PMCID: PMC3847493 DOI: 10.1186/1471-2261-13-73] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 09/13/2013] [Indexed: 11/16/2022] Open
Abstract
Background Data on the use of circulating microRNAs (miRNAs) as biomarkers of cardiovascular diseases are emerging. Little, however, is known on the expression profile of circulating of microRNAs in congenital heart malformations with a systemic right ventricle that is prone to functional impairment. We aimed to test the hypothesis that circulating miRNA profile is altered in patients late after atrial switch operation for complete transposition of the great arteries (TGA) and further explored possible relationships between alteration of circulating miRNAs and systemic ventricular contractility. Methods Circulating miRNA expression profiling of serum samples from 5 patients and 5 healthy controls was performed. The results were validated in 26 patients and 20 controls using real-time quantitative reverse-transcription polymerase chain reaction for candidate miRNAs with fold changes >3 by expression profiling. Systemic ventricular myocardial acceleration during isovolumic contraction (IVA) was determined by colour tissue Doppler echocardiography. Results Compared with controls, patients had significantly lower systemic ventricular IVA (p = 0.002). Of the 23 upregulated miRNAs identified by profiling, 11 were validated to be increased in patients compared with controls: miR-16, miR-106a, miR-144*, miR-18a, miR-25, miR-451, miR-486-3p, miR-486-5p, miR-505*, let-7e and miR-93. Among the validated 11 miRNAs, miR-18a (r = −0.45, p = 0.002) and miR-486-5p (r = −0.35, p = 0.018) correlated negatively with systemic ventricular IVA for the whole cohort. Conclusions A distinct serum miRNA expression signature exists in adults with complete TGA after atrial switch operation, with serum miR-18a and miR-486-5p being associated with systemic ventricular contractility.
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Affiliation(s)
- Clare T M Lai
- Division of Paediatric Cardiology, Department of Paediatrics and Adolescent Medicine, The University of Hong Kong, Hongkong, China.
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10
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Ng EKO, Li R, Shin VY, Jin HC, Leung CPH, Ma ESK, Pang R, Chua D, Chu KM, Law WL, Law SYK, Poon RTP, Kwong A. Circulating microRNAs as specific biomarkers for breast cancer detection. PLoS One 2013; 8:e53141. [PMID: 23301032 PMCID: PMC3536802 DOI: 10.1371/journal.pone.0053141] [Citation(s) in RCA: 195] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 11/23/2012] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND We previously showed microRNAs (miRNAs) in plasma are potential biomarkers for colorectal cancer detection. Here, we aimed to develop specific blood-based miRNA assay for breast cancer detection. METHODOLOGY/PRINCIPAL FINDINGS TaqMan-based miRNA profiling was performed in tumor, adjacent non-tumor, corresponding plasma from breast cancer patients, and plasma from matched healthy controls. All putative markers identified were verified in a training set of breast cancer patients. Selected markers were validated in a case-control cohort of 170 breast cancer patients, 100 controls, and 95 other types of cancers and then blindly validated in an independent set of 70 breast cancer patients and 50 healthy controls. Profiling results showed 8 miRNAs were concordantly up-regulated and 1 miRNA was concordantly down-regulated in both plasma and tumor tissue of breast cancer patients. Of the 8 up-regulated miRNAs, only 3 were significantly elevated (p<0.0001) before surgery and reduced after surgery in the training set. Results from the validation cohort showed that a combination of miR-145 and miR-451 was the best biomarker (p<0.0001) in discriminating breast cancer from healthy controls and all other types of cancers. In the blind validation, these plasma markers yielded Receiver Operating Characteristic (ROC) curve area of 0.931. The positive predictive value was 88% and the negative predictive value was 92%. Altered levels of these miRNAs in plasma have been detected not only in advanced stages but also early stages of tumors. The positive predictive value for ductal carcinoma in situ (DCIS) cases was 96%. CONCLUSIONS These results suggested that these circulating miRNAs could be a potential specific biomarker for breast cancer screening.
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Affiliation(s)
- Enders K. O. Ng
- Department of Surgery, The University of Hong Kong, Hong Kong, China
- Department of Molecular Pathology, Hong Kong Sanatorium and Hospital, Hong Kong, China
| | - Rufina Li
- Department of Surgery, The University of Hong Kong, Hong Kong, China
| | - Vivian Y. Shin
- Department of Surgery, The University of Hong Kong, Hong Kong, China
| | - Hong Chuan Jin
- Biomedical Research Center, Sir Runrun Shaw Hospital, Medical School of Zhejiang University, Hangzhou, China
| | - Candy P. H. Leung
- Department of Surgery, The University of Hong Kong, Hong Kong, China
| | - Edmond S. K. Ma
- Department of Molecular Pathology, Hong Kong Sanatorium and Hospital, Hong Kong, China
| | - Roberta Pang
- Department of Surgery, The University of Hong Kong, Hong Kong, China
| | - Daniel Chua
- Department of Clinical Oncology, The University of Hong Kong, Hong Kong, China
| | - Kent-Man Chu
- Department of Surgery, The University of Hong Kong, Hong Kong, China
| | - W. L. Law
- Department of Surgery, The University of Hong Kong, Hong Kong, China
| | - Simon Y. K. Law
- Department of Surgery, The University of Hong Kong, Hong Kong, China
| | - Ronnie T. P. Poon
- Department of Surgery, The University of Hong Kong, Hong Kong, China
| | - Ava Kwong
- Department of Surgery, The University of Hong Kong, Hong Kong, China
- Department of Molecular Pathology, Hong Kong Sanatorium and Hospital, Hong Kong, China
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11
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Kwong A, Ng EKO, Law FBF, Wa A, Wong CLP, Wong CHN, Kurian AW, West DW, Ford JM, Ma ESK. Abstract P4-11-02: Novel BRCA1 and BRCA2 genomic rearrangements in Southern Chinese breast/ovarian cancer patients. Cancer Res 2012. [DOI: 10.1158/0008-5472.sabcs12-p4-11-02] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background and Aims: Germline mutations in the two breast cancer susceptibility genes, BRCA1 and BRCA2 account for a significant portion of hereditary breast/ovarian cancer. Most of the BRCA mutations reported in Southern Chinese patients were point mutations, small deletions, and insertions. The spectrum of large genomic rearrangement (LGR) is largely unknown. Here we perform the first study on the LGR of BRCA genes in a Hong Kong Chinese population. We aimed to determine the spectrum of BRCA LGRs in Southern Chinese patients with breast cancer.
Methods: A total of 555 clinically high-risk breast and/or ovarian cancer patients were recruited from the Hong Kong Hereditary Breast Cancer Family Registry, diagnosed from March 2007 to November 2011. Multiplex ligation-dependent probe amplification (MLPA) for detecting BRCA LGRs together with comprehensive BRCA1 and BRCA2 gene sequencing of all coding exons were performed. cDNA sequencing of the LGRs was performed to locate the breakpoint of the deletions.
Results: Overall BRCA1/2 mutation prevalence among this cohort was 12.4% (69/555). Among the 69 mutations identified, 4 novel LGRs (2 in BRCA1 and 2 in BRCA2) were detected only by MLPA but not full gene sequencing. Overall the LGR genes accounted for 5.8% (4/69) of all BRCA mutations in our cohort, 6.9% (2/29) of all BRCA1 mutations and 5% (2/40) of all BRCA2 mutations.
Conclusions: These findings highlight the LGR spectrum of BRCA1 and BRCA2 genes in Southern Chinese breast cancer patients. LGR testing together with BRCA1/2 full gene sequencing is superior to other methods for comprehensive BRCA1/2 analysis in clinical settings.
Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-11-02.
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Affiliation(s)
- A Kwong
- University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Sanitorium & Hospital, Happy Valley, Hong Kong; Hong Kong Hereditary Breast Cancer Family Registry, Happy Valley, Hong Kong; Stanford University School of Medicine, Stanford, CA
| | - EKO Ng
- University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Sanitorium & Hospital, Happy Valley, Hong Kong; Hong Kong Hereditary Breast Cancer Family Registry, Happy Valley, Hong Kong; Stanford University School of Medicine, Stanford, CA
| | - FBF Law
- University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Sanitorium & Hospital, Happy Valley, Hong Kong; Hong Kong Hereditary Breast Cancer Family Registry, Happy Valley, Hong Kong; Stanford University School of Medicine, Stanford, CA
| | - A Wa
- University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Sanitorium & Hospital, Happy Valley, Hong Kong; Hong Kong Hereditary Breast Cancer Family Registry, Happy Valley, Hong Kong; Stanford University School of Medicine, Stanford, CA
| | - CLP Wong
- University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Sanitorium & Hospital, Happy Valley, Hong Kong; Hong Kong Hereditary Breast Cancer Family Registry, Happy Valley, Hong Kong; Stanford University School of Medicine, Stanford, CA
| | - CHN Wong
- University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Sanitorium & Hospital, Happy Valley, Hong Kong; Hong Kong Hereditary Breast Cancer Family Registry, Happy Valley, Hong Kong; Stanford University School of Medicine, Stanford, CA
| | - AW Kurian
- University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Sanitorium & Hospital, Happy Valley, Hong Kong; Hong Kong Hereditary Breast Cancer Family Registry, Happy Valley, Hong Kong; Stanford University School of Medicine, Stanford, CA
| | - DW West
- University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Sanitorium & Hospital, Happy Valley, Hong Kong; Hong Kong Hereditary Breast Cancer Family Registry, Happy Valley, Hong Kong; Stanford University School of Medicine, Stanford, CA
| | - JM Ford
- University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Sanitorium & Hospital, Happy Valley, Hong Kong; Hong Kong Hereditary Breast Cancer Family Registry, Happy Valley, Hong Kong; Stanford University School of Medicine, Stanford, CA
| | - ESK Ma
- University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Sanitorium & Hospital, Happy Valley, Hong Kong; Hong Kong Hereditary Breast Cancer Family Registry, Happy Valley, Hong Kong; Stanford University School of Medicine, Stanford, CA
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Kwong A, Chau WW, Wong CHN, Law FBF, Ng EKO, Suen DTK, Kurian AW, West DW, Ford JM, Ma ESK. Abstract P3-11-02: Male breast cancer: A comparison between BRCA mutation carriers and non-carriers in Hong Kong, Southern China. Cancer Res 2012. [DOI: 10.1158/0008-5472.sabcs12-p3-11-02] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: Male breast cancer is suggested to be biologically different from female breast cancer. The differences in clinicopathology between male and female breast cancer raise the issues of establishing specific strategies and treatment regime for male breast cancer patients. The single most significant risk factor for male breast cancer is a mutation in the BRCA2 gene. The lack of information on hereditary breast cancer in male, particularly in Asians, leaves great but forgiven research area on epidemiological studies for this group of patients.
Methods: All male breast cancer patients and their family members, from a Hong Kong Hereditary and High Risk Breast Cancer Program since year 2007, were recruited in this study. All received genetic counseling and BRCA mutation testing using DNA extracted from blood samples. A questionnaire was administered at their first visit which included questions on their demographics and socioeconomic status. Other information including family history of breast cancer or other kinds of cancer, method of diagnosis, surgical strategies, pathological results, treatment regime, relapse, metastasis, and outcomes were obtained from their medical records. Descriptive analysis was performed describing the background characteristics. Chi-square test and Student's t-test were applied to calculate the associations between BRCA mutation and risk factors. Survival analysis was performed to look for their survival patterns.
Results: Thirty-six male breast cancer patients were recruited between year 2007 and 2012, while 21 were diagnosed before year 2007 (range: 1996 to 2012). Mean, standard deviation, and median follow-up time were 5.75±4.31 and 5.25 years. Seven were found to carry the BRCA mutation. All were BRCA2 mutation and the mutation rate was 19.4% (N = 7). Family history of cancer was found in 52.8% (N = 19). Male BRCA mutation carriers were found to have higher risk of secondary cancer, and their first and second degree family members had higher risk of either breast cancer or other kinds of cancers. T stage in BRCA patients was significantly higher than non-BRCA patients (p = 0.028). All BRCA mutation carriers had ER positive cancers compared with 96.2% who were non-carriers. Half of the male BRCA patients were PR positive compared with higher percentage in non-BRCA patients (50% vs. 80.8%, p = 0.117). Both groups had similar overall (p = 0.962) and disease-free survivals (p = 0.919). The means and standard deviations of 5-year overall survival between BRCA and non-BRCA patients were 2.08±0.25 and 4.24±0.12 years respectively, and 2.08±3.03 and 4.41±1.46 years for disease-free survival.
Conclusions: The prevalence of male breast cancer patients with BRCA2 mutation in Hong Kong is comparable with other similar studies. Male breast cancer patients with BRCA2 mutation are suspected to have higher chance of secondary cancer and familial cancer. Although percentage of ER positive cancers are similar to the two groups, BRCA2 mutation carriers tend to have less PR positive cancers which may suggest a poorer prognosis although due to a small sample size this cannot be shown in this cohort. Further collaborative studies to better understand male breast cancer patients carrying the BRCA mutation is warranted.
Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-11-02.
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Affiliation(s)
- A Kwong
- University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Hereditary Breast Cancer Family Registry, Happy Valley, Hong Kong; Stanford University School of Medicine, Stanford, CA; Hong Kong Sanitorium & Hospital, Happy Valley, Hong Kong
| | - WW Chau
- University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Hereditary Breast Cancer Family Registry, Happy Valley, Hong Kong; Stanford University School of Medicine, Stanford, CA; Hong Kong Sanitorium & Hospital, Happy Valley, Hong Kong
| | - CHN Wong
- University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Hereditary Breast Cancer Family Registry, Happy Valley, Hong Kong; Stanford University School of Medicine, Stanford, CA; Hong Kong Sanitorium & Hospital, Happy Valley, Hong Kong
| | - FBF Law
- University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Hereditary Breast Cancer Family Registry, Happy Valley, Hong Kong; Stanford University School of Medicine, Stanford, CA; Hong Kong Sanitorium & Hospital, Happy Valley, Hong Kong
| | - EKO Ng
- University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Hereditary Breast Cancer Family Registry, Happy Valley, Hong Kong; Stanford University School of Medicine, Stanford, CA; Hong Kong Sanitorium & Hospital, Happy Valley, Hong Kong
| | - DTK Suen
- University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Hereditary Breast Cancer Family Registry, Happy Valley, Hong Kong; Stanford University School of Medicine, Stanford, CA; Hong Kong Sanitorium & Hospital, Happy Valley, Hong Kong
| | - AW Kurian
- University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Hereditary Breast Cancer Family Registry, Happy Valley, Hong Kong; Stanford University School of Medicine, Stanford, CA; Hong Kong Sanitorium & Hospital, Happy Valley, Hong Kong
| | - DW West
- University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Hereditary Breast Cancer Family Registry, Happy Valley, Hong Kong; Stanford University School of Medicine, Stanford, CA; Hong Kong Sanitorium & Hospital, Happy Valley, Hong Kong
| | - JM Ford
- University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Hereditary Breast Cancer Family Registry, Happy Valley, Hong Kong; Stanford University School of Medicine, Stanford, CA; Hong Kong Sanitorium & Hospital, Happy Valley, Hong Kong
| | - ESK Ma
- University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Hereditary Breast Cancer Family Registry, Happy Valley, Hong Kong; Stanford University School of Medicine, Stanford, CA; Hong Kong Sanitorium & Hospital, Happy Valley, Hong Kong
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Kwong A, Ng EKO, Law FBF, Wong HN, Wa A, Wong CLP, Kurian AW, West DW, Ford JM, Ma ESK. Novel BRCA1 and BRCA2 genomic rearrangements in Southern Chinese breast/ovarian cancer patients. Breast Cancer Res Treat 2012; 136:931-3. [PMID: 23099436 PMCID: PMC3511694 DOI: 10.1007/s10549-012-2292-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Accepted: 10/04/2012] [Indexed: 11/28/2022]
Affiliation(s)
- Ava Kwong
- Department of Surgery, The University of Hong Kong, Hong Kong SAR, China
- Cancer Genetics Center, Hong Kong Sanatorium & Hospital, Hong Kong SAR, China
- Hong Kong Hereditary Breast Cancer Family Registry, Hong Kong SAR, China
- Departments of Medicine, Oncology, and Health Research and Policy, Stanford University School of Medicine, Palo Alto, CA USA
| | - Enders K. O. Ng
- Department of Surgery, The University of Hong Kong, Hong Kong SAR, China
- Department of Molecular Pathology, Hong Kong Sanatorium & Hospital, Hong Kong SAR, China
| | - Fian B. F. Law
- Department of Molecular Pathology, Hong Kong Sanatorium & Hospital, Hong Kong SAR, China
| | - H. N. Wong
- Department of Surgery, The University of Hong Kong, Hong Kong SAR, China
| | - Anna Wa
- Department of Surgery, The University of Hong Kong, Hong Kong SAR, China
| | - Chris L. P. Wong
- Department of Molecular Pathology, Hong Kong Sanatorium & Hospital, Hong Kong SAR, China
- Hong Kong Hereditary Breast Cancer Family Registry, Hong Kong SAR, China
| | - Allison W. Kurian
- Departments of Medicine, Oncology, and Health Research and Policy, Stanford University School of Medicine, Palo Alto, CA USA
| | - Dee W. West
- Departments of Medicine, Oncology, and Health Research and Policy, Stanford University School of Medicine, Palo Alto, CA USA
| | - James M. Ford
- Departments of Medicine, Oncology, and Health Research and Policy, Stanford University School of Medicine, Palo Alto, CA USA
| | - Edmond S. K. Ma
- Department of Molecular Pathology, Hong Kong Sanatorium & Hospital, Hong Kong SAR, China
- Hong Kong Hereditary Breast Cancer Family Registry, Hong Kong SAR, China
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Du W, Wang S, Zhou Q, Li X, Chu J, Chang Z, Tao Q, Ng EKO, Fang J, Sung JJY, Yu J. ADAMTS9 is a functional tumor suppressor through inhibiting AKT/mTOR pathway and associated with poor survival in gastric cancer. Oncogene 2012; 32:3319-28. [PMID: 22907434 DOI: 10.1038/onc.2012.359] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Revised: 06/27/2012] [Accepted: 06/30/2012] [Indexed: 12/15/2022]
Abstract
Using genome-wide promoter methylation analysis, we identified a disintegrin-like and metalloprotease with thrombospondin type 1 motif 9 (ADAMTS9) is methylated in cancer. We aim to clarify its epigenetic inactivation, biological function and clinical implication in gastric cancer. ADAMTS9 was silenced in 6 out of 8 gastric cancer cell lines. The loss of ADAMTS9 expression was regulated by promoter hypermethylation and could be restored by demethylation agent. Ectopic expression of ADAMTS9 in gastric cancer cell lines (AGS, BGC823) inhibited cell growth curve in both the cell lines (P<0.0001), suppressed colony formation (P<0.01) and induced apoptosis (P<0.001 in AGS, P<0.01 in BGC823). Moreover, conditioned culture medium from ADAMTS9-transfected cell lines significantly disrupted the human umbilical vein endothelial cell tube formation capacity on Matrigel (P<0.01 in AGS, P<0.001 in BGC823). The in vivo growth of ADAMTS9 cells in nude mice was also markedly diminished after stable expression of ADAMTS9 (P<0.001). On the other hand, ADAMTS9 knockdown promoted cell proliferation (P<0.001). We further revealed that ADAMTS9 inhibited tumor growth by blocking activation of Akt and its downstream target the mammalian target of rapamycin (mTOR). ADAMTS9 also reduced phosphorylation of mTOR downstream targets p70 ribosomal S6 kinase, eIF4E-binding protein and downregulated hypoxia-inducible factor-1α. Therefore, this is the first demonstration that ADAMTS9 is a critical tumor suppressor of gastric cancer progression at least in part through suppression of oncogenic AKT/mTOR signaling. Moreover, promoter methylation of ADAMTS9 was detected in 29.2% (21/72) of primary gastric tumors. Multivariate analysis showed that patients with ADAMTS9 methylation had a poorer overall survival (relative risk (RR)=2.788; 95% confidence interval, 1.474-5.274; P=0.002). Kaplan-Meier survival curves showed that ADAMTS9 methylation was significantly associated with shortened survival in gastric cancer patients (P=0.001, log-rank test). In conclusion, ADAMTS9 acts as a functional tumor suppressor in gastric cancer through inhibiting oncogenic AKT/mTOR signaling pathway. Methylation of ADAMTS9 is an independent prognostic factor of gastric cancer.
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Affiliation(s)
- W Du
- Institute of Digestive Disease and Department of Medicine and Therapeutics, Li Ka Shing Institute of Health Sciences, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong, China
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15
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Cheung KF, Lam CNY, Wu K, Ng EKO, Chong WWS, Cheng ASL, To KF, Fan D, Sung JJY, Yu J. Characterization of the gene structure, functional significance, and clinical application of RNF180, a novel gene in gastric cancer. Cancer 2011; 118:947-59. [PMID: 21717426 DOI: 10.1002/cncr.26189] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Revised: 03/07/2011] [Accepted: 03/23/2011] [Indexed: 12/14/2022]
Abstract
BACKGROUND By using genome-wide methylation screening, the authors identified ring finger protein 180 (RNF180) as preferentially methylated in cancer. This study was undertaken to clarify its structure and functional role in gastric cancer. METHODS The transcription start site and core functional promoter region of RNF180 were revealed by 5' rapid amplification of cDNA ends and luciferase activity assays. Promoter methylation was detected by combined bisulfite restriction analysis and bisulfite genomic sequencing. Cell growth was detected by colony formation assay, apoptosis by annexin V assay, and RNF180 target genes by cDNA microarray. RESULTS The authors revealed the transcription start site of RNF180 gene and identified the functional core promoter region (-202/+372) in the CpG island, which could be silenced by in vitro methylation assay. RNF180 was silenced in 6 of 7 gastric cancer cell lines and significantly down-regulated in primary gastric cancers compared with adjacent normal tissues (P = .001). Loss of gene expression was associated with promoter methylation. Re-expression of RNF180 suppressed cell growth (P < .001) and induced apoptosis (P < .05), which were mediated by up-regulating the antiproliferation regulators MTSS1 and CDKN2A and the proapoptotic mediator TIMP3. Promoter methylation of RNF180 was detected in 76% (150 of 198) of primary gastric cancers and 55% (11 of 20) of intestinal metaplasia, but in none of 23 normal gastric tissues. Methylated RNF180 DNA was detected in the plasma of 56% of gastric cancer patients, but not in healthy controls (P = .003). Patients with low or loss of RNF180 expression had significantly poorer overall survival. CONCLUSIONS RNF180 is a novel potential tumor suppressor in gastric carcinogenesis and has potential clinical utility as a biomarker for gastric cancer patients.
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Affiliation(s)
- Kin-Fai Cheung
- Department of Medicine and Therapeutics, Chinese University of Hong Kong, Shatin, Hong Kong
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16
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Shin VY, Jin HC, Ng EKO, Cho CH, Leung WK, Sung JJY, Chu KM. 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone promoted gastric cancer growth through prostaglandin E receptor (EP2 and EP4) in vivo and in vitro. Cancer Sci 2011; 102:926-33. [DOI: 10.1111/j.1349-7006.2011.01885.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Ng EKO, Leung C, Shin VY, Chan A, Wong CLPL, Ma ESK, Jin HC, Chu KM, Kwong A. Abstract P3-01-02: Quantitative Analysis and Diagnostic Significance of Methylated SLC19A3 DNA in the Plasma of Breast Cancer Patients. Cancer Res 2010. [DOI: 10.1158/0008-5472.sabcs10-p3-01-02] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: Previously, we have examined the methylation status of SLC19A3 (solute carrier family 19, member 3) promoter and found that SLC19A3 was epigenetically down-regulated in gastric cancer. Here, we aim to develop a new biomarker for cancer diagnosis using methylated SLC19A3 DNA in plasma.
Methods: SLC19A3 gene expression was examined by RT-qPCR. Methylation status of SLC19A3 promoter was evaluated by methylation-specific qPCR. A robust and simple methylation-sensitive restriction enzyme digestion and real-time quantitative PCR assay was developed to quantify SLC19A3 DNA methylation in plasma. Results: Expression of SLC19A3 was significantly down-regulated in 80% (12/15) of breast tumors (P < 0.005). Breast tumors had significant increase in methylation percentage when compared to adjacent non-tumor tissues (P < 0.05). A total of 155 independent plasma samples from participants including 60 breast cancer, 45 gastric cancer patients and 60 healthy subjects were analyzed. Plasma methylated SLC19A3 DNA yielded a ROC curve area of 77%, sensitivity of 82% and specificity of 60% in discriminating breast cancer from control subjects. This marker yielded a ROC curve area of 87%, sensitivity of 90.0% and specificity of 62% in discriminating gastric cancer from control subjects. Elevated level in plasma has been detected not only in advanced stages but also early stages of tumors. Intriguingly, of all DCIS cases from breast cancer patients this plasma marker generated a ROC value of 92%, sensitivity of 100% and specificity of 78% in discriminating DCIS cases from controls. Conclusions: These results suggested that aberrant SLC19A3 promoter hypermethylation in plasma may be a novel biomarker for early breast cancer diagnosis.
Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-01-02.
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Affiliation(s)
- EKO Ng
- The University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Sanatorium & Hospital, Hong Kong; Sir Runrun Shaw Hospital, Zhejiang University, China
| | - C Leung
- The University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Sanatorium & Hospital, Hong Kong; Sir Runrun Shaw Hospital, Zhejiang University, China
| | - VY Shin
- The University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Sanatorium & Hospital, Hong Kong; Sir Runrun Shaw Hospital, Zhejiang University, China
| | - A Chan
- The University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Sanatorium & Hospital, Hong Kong; Sir Runrun Shaw Hospital, Zhejiang University, China
| | - CLPL Wong
- The University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Sanatorium & Hospital, Hong Kong; Sir Runrun Shaw Hospital, Zhejiang University, China
| | - ESK Ma
- The University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Sanatorium & Hospital, Hong Kong; Sir Runrun Shaw Hospital, Zhejiang University, China
| | - HC Jin
- The University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Sanatorium & Hospital, Hong Kong; Sir Runrun Shaw Hospital, Zhejiang University, China
| | - KM Chu
- The University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Sanatorium & Hospital, Hong Kong; Sir Runrun Shaw Hospital, Zhejiang University, China
| | - A. Kwong
- The University of Hong Kong, Pokfulam, Hong Kong; Hong Kong Sanatorium & Hospital, Hong Kong; Sir Runrun Shaw Hospital, Zhejiang University, China
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18
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Shin VY, Jin H, Ng EKO, Cheng ASL, Chong WWS, Wong CYP, Leung WK, Sung JJY, Chu KM. NF-κB targets miR-16 and miR-21 in gastric cancer: involvement of prostaglandin E receptors. Carcinogenesis 2010; 32:240-5. [PMID: 21081469 DOI: 10.1093/carcin/bgq240] [Citation(s) in RCA: 128] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Cigarette smoke is one of the risk factors for gastric cancer and nicotine has been reported to promote tumor growth. Deregulation of microRNA (miRNA) and cyclooxygenase-2 (COX-2) expressions are hallmarks of many cancers including gastric cancer. Here, we used an miRNA array platform covering a panel of 95 human miRNAs to examine the expression profile in nicotine-treated gastric cancer cells. We found that miR-16 and miR-21 were upregulated upon nicotine stimulation, transfection with anti-miR-16 or anti-miR-21 significantly abrogated cell proliferation. In contrast, ectopic miR-16 or miR-21 expression exhibited a similar stimulatory effect on cell proliferation as nicotine. Nicotine-mediated IkappaBα degradation and nuclear factor-kappa B (NF-κB) translocation dose-dependently. Knockdown of NF-κB by short interfering RNA (siRNA) or specific inhibitor (Bay-11-7085) markedly suppressed nicotine-induced cell proliferation and upregulation of miR-16 and miR-21. Interestingly, NF-κB-binding sites were located in both miR-16 and miR-21 gene transcriptional elements and we showed that nicotine enhanced the binding of NF-κB to the promoters of miR-16 and miR-21. Furthermore, activation of COX-2/prostaglandin E₂ (PGE₂) signaling in response to nicotine was mediated by the action of prostaglandin E receptors (EP2 and EP4). EP2 or EP4 siRNA or antagonists impaired the nicotine-mediated NF-κB activity, upregulation of miR-16 and miR-21 and cell proliferation. Taken together, these results suggest that miR-16 and miR-21 are directly regulated by the transcription factor NF-κB and yet nicotine-promoted cell proliferation is mediated via EP2/4 receptors. Perhaps this study may shed light on the development of anticancer drugs to improve the chemosensitivity in smokers.
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Affiliation(s)
- Vivian Y Shin
- Department of Surgery, Queen Mary Hospital, The University of Hong Kong, Pokfulam, Hong Kong SAR, China.
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Tsang WP, Ng EKO, Ng SSM, Jin H, Yu J, Sung JJY, Kwok TT. Oncofetal H19-derived miR-675 regulates tumor suppressor RB in human colorectal cancer. Carcinogenesis 2009; 31:350-8. [PMID: 19926638 DOI: 10.1093/carcin/bgp181] [Citation(s) in RCA: 364] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
H19 is an imprinted oncofetal non-coding RNA recently shown to be the precursor of miR-675. The pathophysiological roles of H19 and its mature product miR-675 to carcinogenesis have, however, not been defined. By quantitative reverse transcription-polymerase chain reaction, both H19 and miR-675 were found to be upregulated in human colon cancer cell lines and primary human colorectal cancer (CRC) tissues compared with adjacent non-cancerous tissues. Subsequently, the tumor suppressor retinoblastoma (RB) was confirmed to be a direct target of miR-675 as the microRNA suppressed the activity of the luciferase reporter carrying the 3'-untranslated region of RB messenger RNA that contains the miR-675-binding site. Suppression of miR-675 by transfection with anti-miR-675 increased RB expression and at the same time, decreased cell growth and soft agar colony formation in human colon cancer cells. Reciprocally, enhanced miR-675 expression by transfection with miR-675 precursor decreased RB expression, increased tumor cell growth and soft agar colony formation. Moreover, the inverse relationship between the expressions of RB and H19/miR-675 was also revealed in human CRC tissues and colon cancer cell lines. Our findings demonstrate that H19-derived miR-675, through downregulation of its target RB, regulates the CRC development and thus may serve as a potential target for CRC therapy.
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Affiliation(s)
- Wing Pui Tsang
- Department of Biochemistry, University of Hong Kong, Shatin, N.T., Hong Kong Special Administrative Region, China
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Liu X, Lam EKY, Wang X, Zhang J, Cheng YY, Lam YW, Ng EKO, Yu J, Chan FKL, Jin H, Sung JJY. Promoter hypermethylation mediates downregulation of thiamine receptor SLC19A3 in gastric cancer. Tumour Biol 2009; 30:242-8. [PMID: 19816091 DOI: 10.1159/000243767] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2009] [Accepted: 08/04/2009] [Indexed: 11/19/2022] Open
Abstract
As an important way to inactivate tumor suppressor genes (TSGs) during cancer development, promoter hypermethylation can be used to define novel TSGs and identify biomarkers for cancer diagnosis. SLC19A3 (solute carrier family 19, member 3) was found to be such a biomarker. SLC19A3 expression was downregulated in gastric cancer cell lines (71%, 5/7) and restored after pharmacological demethylation. Notably, hypermethylation of SLC19A3 promoter was detected in gastric cancer cell lines (57%, 4/7), primary gastric carcinoma tissues (51%, 52/101) and precancerous lesion (intestinal metaplasia) tissues (32%, 8/25). Exogenous SLC19A3 expression caused growth inhibition of gastric cancer cells. In summary, SLC19A3 was epigenetically downregulated in gastric cancer. Methylation of SLC19A3 promoter could be a novel biomarker for early gastric cancer development.
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Affiliation(s)
- Xin Liu
- Institute of Digestive Disease, Department of Medicine and Therapeutics, Prince of Wales Hospital, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, SAR, China
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Ng EKO, Chong WWS, Jin H, Lam EKY, Shin VY, Yu J, Poon TCW, Ng SSM, Sung JJY. Differential expression of microRNAs in plasma of patients with colorectal cancer: a potential marker for colorectal cancer screening. Gut 2009. [PMID: 19201770 DOI: 10.1136/gut.2008.167817;] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
OBJECTIVE MicroRNAs (miRNAs) have been shown to offer great potential in the diagnosis of cancer. We investigated whether plasma miRNAs could discriminate between patients with and without colorectal cancer (CRC). METHODS This study was divided into three phases: (1) marker discovery using real-time PCR-based miRNA profiling on plasma, corresponding cancerous and adjacent non-cancerous colonic tissues of five patients with CRC, along with plasma from five healthy individuals as controls; (2) marker selection and validation by real-time quantitative RT-PCR on a small set of plasma; and (3) independent validation on a large set of plasma from 90 patients with CRC, 20 patients with gastric cancer, 20 patients with inflammatory bowel disease (IBD) and 50 healthy controls. RESULTS Of the panel of 95 miRNAs analysed, five were upregulated both in plasma and tissue samples. All the five miRNAs were validated on the plasma of 25 patients with CRC and 20 healthy controls. Both miR-17-3p and miR-92 were significantly elevated in the patients with CRC (p<0.0005). The plasma levels of these markers were significantly reduced after surgery in 10 patients with CRC (p<0.05). Further validation with an independent set of plasma samples (n = 180) indicated that miR-92 differentiates CRC from gastric cancer, IBD and normal subjects. This marker yielded a receiver operating characteristic curve area of 88.5%. At a cut-off of 240 (relative expression in comparison to RNU6B snRNA), the sensitivity was 89% and the specificity was 70% in discriminating CRC from control subjects. CONCLUSION MiR-92 is significantly elevated in plasma of patients with CRC and can be a potential non-invasive molecular marker for CRC screening.
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Affiliation(s)
- E K O Ng
- Institute of Digestive Disease, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR, China
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Ng EKO, Chong WWS, Jin H, Lam EKY, Shin VY, Yu J, Poon TCW, Ng SSM, Sung JJY. Differential expression of microRNAs in plasma of patients with colorectal cancer: a potential marker for colorectal cancer screening. Gut 2009; 58:1375-81. [PMID: 19201770 DOI: 10.1136/gut.2008.167817] [Citation(s) in RCA: 938] [Impact Index Per Article: 62.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVE MicroRNAs (miRNAs) have been shown to offer great potential in the diagnosis of cancer. We investigated whether plasma miRNAs could discriminate between patients with and without colorectal cancer (CRC). METHODS This study was divided into three phases: (1) marker discovery using real-time PCR-based miRNA profiling on plasma, corresponding cancerous and adjacent non-cancerous colonic tissues of five patients with CRC, along with plasma from five healthy individuals as controls; (2) marker selection and validation by real-time quantitative RT-PCR on a small set of plasma; and (3) independent validation on a large set of plasma from 90 patients with CRC, 20 patients with gastric cancer, 20 patients with inflammatory bowel disease (IBD) and 50 healthy controls. RESULTS Of the panel of 95 miRNAs analysed, five were upregulated both in plasma and tissue samples. All the five miRNAs were validated on the plasma of 25 patients with CRC and 20 healthy controls. Both miR-17-3p and miR-92 were significantly elevated in the patients with CRC (p<0.0005). The plasma levels of these markers were significantly reduced after surgery in 10 patients with CRC (p<0.05). Further validation with an independent set of plasma samples (n = 180) indicated that miR-92 differentiates CRC from gastric cancer, IBD and normal subjects. This marker yielded a receiver operating characteristic curve area of 88.5%. At a cut-off of 240 (relative expression in comparison to RNU6B snRNA), the sensitivity was 89% and the specificity was 70% in discriminating CRC from control subjects. CONCLUSION MiR-92 is significantly elevated in plasma of patients with CRC and can be a potential non-invasive molecular marker for CRC screening.
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Affiliation(s)
- E K O Ng
- Institute of Digestive Disease, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR, China
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Li J, Ng EKO, Ng YP, Wong CYP, Yu J, Jin H, Cheng VYY, Go MYY, Cheung PKF, Ebert MPA, Tong J, To KF, Chan FKL, Sung JJY, Ip NY, Leung WK. Identification of retinoic acid-regulated nuclear matrix-associated protein as a novel regulator of gastric cancer. Br J Cancer 2009; 101:691-8. [PMID: 19672268 PMCID: PMC2736823 DOI: 10.1038/sj.bjc.6605202] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Revised: 06/18/2009] [Accepted: 06/30/2009] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Retinoic acid-regulated nuclear matrix-associated protein (RAMP) is a WD40 repeat-containing protein that is involved in various biological functions, but little is known about its role in human cancer. This study aims to delineate the oncogenic role of RAMP in gastric carcinogenesis. METHODS RAMP expression was examined by real-time quantitative RT-PCR, immunohistochemistry and western blotting. Inhibition of RAMP expression was performed by siRNA-mediated knockdown. The functional effects of RAMP on cell kinetics were measured by cell viability assay, colony formation assay and flow cytometry. Cell lines stably expressing RAMP were established to investigate the oncogenic effects of RAMP in vitro. RESULTS Ramp was readily expressed in all seven gastric cancer cell lines and was significantly increased in human gastric cancer tissues when compared with their adjacent non-cancerous tissues (P<0.001). In keeping with this, expression of RAMP protein was higher in gastric cancer tissues compared with their adjacent non-cancerous tissues, whereas moderate protein expression were noted in intestinal metaplasia. Knockdown of RAMP in gastric cancer cells significantly reduced cell proliferation (P<0.01) and soft agar colony formation (P<0.001), but induced apoptosis and G(2)/M arrest. In additional, knockdown RAMP induced cell apoptosis is dependent on functional accumulation of p53 and p21 and induction of cleaved caspases-9, caspases-3 and PARP. Strikingly, overexpression of RAMP promoted anchorage-independent cell growth in soft agar. CONCLUSION Our findings demonstrate that RAMP plays an oncogenic role in gastric carcinogenesis. Inhibition of RAMP may be a promising approach for gastric cancer therapy.
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Affiliation(s)
- J Li
- Institute of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - E K O Ng
- Institute of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Y P Ng
- Department of Biochemistry, Hong Kong University of Science and Technology, Hong Kong, China
| | - C Y P Wong
- Institute of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - J Yu
- Institute of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - H Jin
- Institute of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - V Y Y Cheng
- Institute of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - M Y Y Go
- Institute of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - P K F Cheung
- Institute of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - M P A Ebert
- Department of Medicine II, Technical University of Munich, Munich, Germany
| | - J Tong
- Department of Anatomical and Cellular Pathology, State Key Laboratory in Oncology in South China, The Chinese University of Hong Kong, Hong Kong, China
| | - K F To
- Department of Anatomical and Cellular Pathology, State Key Laboratory in Oncology in South China, The Chinese University of Hong Kong, Hong Kong, China
| | - F K L Chan
- Institute of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - J J Y Sung
- Institute of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - N Y Ip
- Department of Biochemistry, Hong Kong University of Science and Technology, Hong Kong, China
| | - W K Leung
- Institute of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China
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Ng EKO, Tsang WP, Ng SSM, Jin HC, Yu J, Li JJ, Röcken C, Ebert MPA, Kwok TT, Sung JJY. MicroRNA-143 targets DNA methyltransferases 3A in colorectal cancer. Br J Cancer 2009; 101:699-706. [PMID: 19638978 PMCID: PMC2736825 DOI: 10.1038/sj.bjc.6605195] [Citation(s) in RCA: 236] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND MicroRNAs (miRNAs) are 19-25-nucleotides regulatory non-protein-coding RNA molecules that regulate the expressions of a wide variety of genes, including some involved in cancer development. In this study, we investigated the possible role of miR-143 in colorectal cancer (CRC). METHODS Expression levels of human mature miRNAs were examined using real-time PCR-based expression arrays on paired colorectal carcinomas and adjacent non-cancerous colonic tissues. The downregulation of miR-143 was further evaluated in colon cancer cell lines and in paired CRC and adjacent non-cancerous colonic tissues by qRT-PCR. Potential targets of miR-143 were defined. The functional effect of miR-143 and its targets was investigated in human colon cancer cell lines to confirm miRNA-target association. RESULTS Both real-time PCR-based expression arrays and qRT-PCR showed that miR-143 was frequently downregulated in 87.5% (35 of 40) of colorectal carcinoma tissues compared with their adjacent non-cancerous colonic tissues. Using in silico predictions, DNA methyltranferase 3A (DNMT3A) was defined as a potential target of miR-143. Restoration of the miR-143 expression in colon cell lines decreased tumour cell growth and soft-agar colony formation, and downregulated the DNMT3A expression in both mRNA and protein levels. DNMT3A was shown to be a direct target of miR-143 by luciferase reporter assay. Furthermore, the miR-143 expression was observed to be inversely correlated with DNMT3A mRNA and protein expression in CRC tissues. CONCLUSION Our findings suggest that miR-143 regulates DNMT3A in CRC. These findings elucidated a tumour-suppressive role of miR-143 in the epigenetic aberration of CRC, providing a potential development of miRNA-based targeted approaches for CRC therapy.
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Affiliation(s)
- E K O Ng
- Department of Medicine and Therapeutics, Institute of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
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Cheng YY, Jin H, Liu X, Siu JMT, Wong YP, Ng EKO, Yu J, Leung WK, Sung JJY, Chan FKL. Fibulin 1 is downregulated through promoter hypermethylation in gastric cancer. Br J Cancer 2008; 99:2083-7. [PMID: 18985039 PMCID: PMC2607230 DOI: 10.1038/sj.bjc.6604760] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Tumour suppressor genes (TSGs) were frequently inactivated through promoter hypermethylation in gastric carcinoma as well as pre-malignant gastric lesions, suggesting that promoter hypermethylation can be used as a marker to define novel TSGs and also biomarkers for early detection of gastric cancer. In an effort to search for such genes aberrantly methylated in gastric cancer development, fibulin 1 (FBLN1) was found as a candidate TSG epigenetically downregulated in gastric cancer. FBLN1 expression was downregulated in all of gastric cancer cell lines used (100%, 7 out of 7) and the primary gastric carcinoma tissues (84%, 86 out of 102) and significantly restored after pharmacological demethylation. Hypermethylation of the FBLN1 promoter was frequently (71%, 5 out of 7) detected in gastric cancer cell lines and primary gastric carcinoma tissues. Ectopic expression of FBLN1 led to the growth inhibition of gastric cancer cells through the induction of apoptosis. In summary, FBLN1 was identified as a novel candidate TSG epigenetically downregulated in gastric cancer.
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Affiliation(s)
- Y Y Cheng
- Department of Medicine and Therapeutics, Institute of Digestive Disease, Faculty of Medicine, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
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Abstract
Circulating RNA in plasma and serum is a newly developed area for molecular diagnosis. To date, increasing numbers of studies show that plasma and serum RNA could serve as both tumor- and fetal-specific markers for cancer detection and prenatal diagnosis, respectively. Recently, by introducing the highly sensitive one-step real-time quantitative reverse-transcription (RT)-polymerase chain reaction (PCR), these potentially valuable RNA species, which often only exist at low concentrations in plasma and serum, can now be readily detected and quantified. Following the successful quantification of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA in plasma of normal individuals, several placenta-derived mRNA species, including the mRNA transcripts of human placental lactogen (hPL), the beta-subunit of human chorionic gonadotropin (betahCG), and corticotropin-releasing hormone (CRH) were also quantified in plasma of pregnant women. These circulating placental RNA species have provided the fetal-polymorphism-independent markers for prenatal diagnosis. The achievement in detecting the placental RNA in maternal plasma represents a significant step toward the development of RNA markers for noninvasive prenatal gene expression profiling. This detection technique can be extended to access a wide range of disease conditions, such as cancer and trauma. The one-step, real-time quantitative RT-PCR is a highly sensitive and specific, yet practically simple, RNA detection technique. This powerful technology may allow the practical employment of circulating RNA in the high-throughput clinical screening and monitoring applications.
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Affiliation(s)
- Nancy B Y Tsui
- Department of Chemical Pathology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, SAR
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Abstract
The etiologic agent of severe acute respiratory syndrome (SARS) has been identified as a new type of coronavirus, known as SARS-coronavirus (SARS-CoV). Although the SARS epidemic has subsided, many authorities, including the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC), have warned of the possible re-emergence of this highly infectious disease. Although antibody-based diagnosis of SARS has been demonstrated to be a reliable proof of SARS infection, it is not sensitive enough for detection during the early phase of the disease. To date, based on the publicly released full genomic sequences of SARS-CoV, various molecular detection methods based on reverse-transcription polymerase chain reaction (RT-PCR) have been developed. Although most of the assays have initially been focused on RNA extracted from nasopharyngeal aspirates, urine, and stools, several of the more recently developed assays have been based on the analysis of RNA extracted from plasma and serum. Such assays allow the more standardized quantitative expression of viral loads and are potentially useful for early SARS diagnosis. In this chapter, two real-time quantitative RT-PCR systems for the quantification of SARS-CoV RNA in serum are discussed. The two RT-PCR systems, one aimed toward the nucleocapsid region and the other toward the polymerase region of the virus genome, have a detection rate of up to 80% during the first week of illness. These quantitative systems are potentially useful for the early diagnosis of SARS and can also provide viral load information that might assist clinicians in making a prognostic evaluation of an infected individual.
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Affiliation(s)
- Enders K O Ng
- Department of Health, Centre for Health Protection, Government of Hong Kong Special Administrative Region, Hong Kong, SAR
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Abstract
The clinical findings, plasma viral load, cytokines and chemokines of a 4-month-old infant with severe acute respiratory syndrome (SARS) were assessed at different phases of the disease. Ribavirin failed to inhibit SARS coronavirus (SARS-CoV) replication. One-step real time reverse transcription-polymerase chain reaction for plasma SARS-CoV RNA quantification was useful for early diagnosis and monitoring viremia.
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Affiliation(s)
- Frankie W T Cheng
- Department of Pediatrics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, N.T
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29
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Tsui NBY, Chim SSC, Chiu RWK, Lau TK, Ng EKO, Leung TN, Tong YK, Chan KCA, Lo YMD. Systematic micro-array based identification of placental mRNA in maternal plasma: towards non-invasive prenatal gene expression profiling. J Med Genet 2004; 41:461-7. [PMID: 15173234 PMCID: PMC1735812 DOI: 10.1136/jmg.2003.016881] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Poon TCW, Chan KCA, Ng PC, Chiu RWK, Ang IL, Tong YK, Ng EKO, Cheng FWT, Li AM, Hon EKL, Fok TF, Lo YMD. Serial analysis of plasma proteomic signatures in pediatric patients with severe acute respiratory syndrome and correlation with viral load. Clin Chem 2004; 50:1452-5. [PMID: 15178653 PMCID: PMC7108178 DOI: 10.1373/clinchem.2004.035352] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Terence C W Poon
- Centre for Emerging Infectious Diseases, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR, China.
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31
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Ng EKO, El-Sheikhah A, Chiu RWK, Chan KCA, Hogg M, Bindra R, Leung TN, Lau TK, Nicolaides KH, Lo YMD. Evaluation of Human Chorionic Gonadotropin β-Subunit mRNA Concentrations in Maternal Serum in Aneuploid Pregnancies: A Feasibility Study. Clin Chem 2004; 50:1055-7. [PMID: 15161720 DOI: 10.1373/clinchem.2004.031260] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Enders K O Ng
- Departments of Chemical Pathology and Obstetrics & Gynaecology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong SAR
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32
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Rainer TH, Lam NYL, Tsui NBY, Ng EKO, Chiu RWK, Joynt GM, Lo YMD. Effects of Filtration on Glyceraldehyde-3-Phosphate Dehydrogenase mRNA in the Plasma of Trauma Patients and Healthy Individuals. Clin Chem 2004; 50:206-8. [PMID: 14709650 DOI: 10.1373/clinchem.2003.022533] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Timothy H Rainer
- Accident & Emergency Medicine Academic Unit, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR
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33
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Ng EKO, Ng PC, Hon KLE, Cheng WTF, Hung ECW, Chan KCA, Chiu RWK, Li AM, Poon LLM, Hui DS, Tam JS, Fok TF, Lo YMD. Serial analysis of the plasma concentration of SARS coronavirus RNA in pediatric patients with severe acute respiratory syndrome. Clin Chem 2003; 49:2085-8. [PMID: 14633884 PMCID: PMC7108135 DOI: 10.1373/clinchem.2003.024588] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
| | | | | | | | | | | | | | | | - Leo L M Poon
- Department of Microbiology, The University of Hong Kong, Hong Kong Special Administrative Region
| | | | - John S Tam
- Microbiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong SAR
| | | | - Y M Dennis Lo
- Departments of Chemical Pathology
- address correspondence to this author at: Department of Chemical Pathology, The Chinese University of Hong Kong, Room 38023, 1/F Clinical Sciences Building, Prince of Wales Hospital, 30--32 Ngan Shing St., Shatin, New Territories, Hong Kong Special Administrative Region, China; e-mail
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Hung ECW, Chim SSC, Chan PKS, Tong YK, Ng EKO, Chiu RWK, Leung CB, Sung JJY, Tam JS, Lo YMD. Detection of SARS coronavirus RNA in the cerebrospinal fluid of a patient with severe acute respiratory syndrome. Clin Chem 2003; 49:2108-9. [PMID: 14633896 PMCID: PMC7108123 DOI: 10.1373/clinchem.2003.025437] [Citation(s) in RCA: 189] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
| | | | | | | | | | | | - Chi-Bon Leung
- Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong Special Administrative Region
| | - Joseph J Y Sung
- Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong Special Administrative Region
| | | | - Y M Dennis Lo
- Chemical Pathology
- Author for correspondence. Fax 852-2194-6171; e-mail
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35
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Ng EKO, Hui DS, Chan KCA, Hung ECW, Chiu RWK, Lee N, Wu A, Chim SSC, Tong YK, Sung JJY, Tam JS, Lo YMD. Quantitative analysis and prognostic implication of SARS coronavirus RNA in the plasma and serum of patients with severe acute respiratory syndrome. Clin Chem 2003; 49:1976-80. [PMID: 14633867 PMCID: PMC7108161 DOI: 10.1373/clinchem.2003.024125] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Background: The availability of an early diagnostic tool for severe acute respiratory syndrome (SARS) would have major public health implications. We investigated whether the SARS coronavirus (SARS-CoV) can be detected in serum and plasma samples during the early stages of SARS and studied the potential prognostic implications of such an approach. Methods: We developed two real-time quantitative reverse transcription-PCR (RT-PCR) assays, one for the polymerase and the other for the nucleocapsid region of the virus genome, for measuring the concentration of SARS-CoV RNA in serum/plasma samples from SARS patients. Plasma samples were obtained from 12 confirmed SARS patients on the day of hospital admission, as well as on days 7 and 14 after fever onset. Serum samples were also obtained from 23 confirmed SARS patients on the day of hospital admission, 11 of whom subsequently required intensive care. Viral RNA was extracted from the plasma/serum samples. The extracted RNA was subjected to analysis by the RT-PCR assays. Results: The RT-PCR system for the polymerase region detected SARS-CoV RNA in 50% of plasma and 78% of serum samples from SARS patients during the first week of illness. The detection rates for plasma dropped to 25% at day 14 after fever onset. The median serum SARS-CoV concentrations in patients who required and did not require intensive care unit admission during the course of hospitalization were 5800 and 140 copies/mL, respectively (Mann–Whitney test, P <0.005). These data were confirmed by the RT-PCR system for the nucleocapsid region, which showed an even higher detection rate of 87%. The correlation between the results obtained by the two RT-PCR systems was high (Pearson correlation analysis, r = 0.998; P <0.001). Conclusion: Plasma/serum SARS-CoV quantification represents a potentially useful early diagnostic and prognostic tool for SARS.
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Affiliation(s)
| | | | | | | | | | | | - Alan Wu
- Medicine and Therapeutics, and
| | | | | | | | - John S Tam
- Microbiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong Special Administrative Region, China
| | - Y M Dennis Lo
- Departments of Chemical Pathology
- Address correspondence to this author at: Department of Chemical Pathology, The Chinese University of Hong Kong, Room 38023, 1/F Clinical Sciences Bldg., Prince of Wales Hospital, 30-32 Ngan Shing St., Shatin, New Territories, Hong Kong Special Administrative Region, China. E-mail
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36
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Chim SSC, Tsui SKW, Chan KCA, Au TCC, Hung ECW, Tong YK, Chiu RWK, Ng EKO, Chan PKS, Chu CM, Sung JJY, Tam JS, Fung KP, Waye MMY, Lee CY, Yuen KY, Lo YMD. Genomic characterisation of the severe acute respiratory syndrome coronavirus of Amoy Gardens outbreak in Hong Kong. Lancet 2003; 362:1807-8. [PMID: 14654320 PMCID: PMC7119348 DOI: 10.1016/s0140-6736(03)14901-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Severe acute respiratory syndrome (SARS) is a global health concern. In Hong Kong, two major outbreaks, one hospital based and the other in the Amoy Gardens apartments, were identified. The frequency of diarrhoea, admission to intensive care, and mortality differed significantly between the two outbreaks. We did genomic sequencing for viral isolates from five Amoy Gardens patients. The virus sequence was identical in four of these five patients. The sequence data from one hospital case and the four identical community cases had only three nucleotide differences. Alterations in the SARS coronavirus genome are unlikely to have caused the distinctive clinical features of the Amoy Gardens patients, and these results highlight the importance of non-viral genomic factors in this outbreak.
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Affiliation(s)
- SSC Chim
- Department of Chemical Pathology, Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China
| | - SKW Tsui
- Department of Biochemistry, Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China
| | - KCA Chan
- Department of Chemical Pathology, Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China
| | - TCC Au
- Department of Biochemistry, Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China
| | - ECW Hung
- Department of Paediatrics, Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China
| | - YK Tong
- Department of Chemical Pathology, Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China
| | - RWK Chiu
- Department of Chemical Pathology, Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China
| | - EKO Ng
- Department of Chemical Pathology, Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China
| | - PKS Chan
- Department of Microbiology, Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China
| | - CM Chu
- Department of Medicine, United Christian Hospital, Hong Kong
| | - JJY Sung
- Department of Medicine and Therapeutics, Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China
| | - JS Tam
- Department of Microbiology, Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China
| | - KP Fung
- Department of Biochemistry, Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China
| | - MMY Waye
- Department of Biochemistry, Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China
| | - CY Lee
- Department of Biochemistry, Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China
| | - KY Yuen
- Department of Microbiology, Queen Mary Hospital, University of Hong Kong, Hong Kong
| | - YMD Lo
- Department of Chemical Pathology, Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China
- Correspondence to: Prof Y M D Lo, Department of Chemical Pathology, Chinese University of Hong Kong, Room 38023, 1/F Clinical Sciences Building, Prince of Wales Hospital, 30–32 Ngan Shing Street, Shatin, New Territories, Hong Kong Special Administrative Region, China
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Abstract
BACKGROUND Recent studies have demonstrated the existence of circulating mitochondrial DNA in plasma and serum, but the concentrations and physical characteristics of circulating mitochondrial DNA are unknown. The aim of this study was to develop an assay to quantify mitochondrial DNA in the plasma of healthy individuals. METHODS We adopted a real-time quantitative PCR approach and evaluated the specificity of the assay for detecting mitochondrial DNA with a cell line (rho(0)) devoid of mitochondria. The concentrations and physical characteristics of circulating mitochondrial DNA were investigated by experiments conducted in three modules. In module 1, we evaluated the concentrations of mitochondrial DNA in plasma aliquots derived from four blood-processing protocols. In module 2, we investigated the existence of both particle-associated and free forms of mitochondrial DNA in plasma by subjecting plasma to filtration and ultracentrifugation. In module 3, we used filters with different pore sizes to investigate the size characteristics of the particle-associated fraction of circulating mitochondrial DNA. RESULTS The mitochondrial DNA-specific, real-time quantitative PCR had a dynamic range of five orders of magnitude and a sensitivity that enabled detection of one copy of mitochondrial DNA in plasma. In module 1, we found significant differences in the amounts of circulating mitochondrial DNA among plasma aliquots processed by different methods. Data from module 2 revealed that a significant fraction of mitochondrial DNA in plasma was filterable or pelletable by ultracentrifugation. Module 3 demonstrated that filters with different pore sizes removed mitochondrial DNA from plasma to different degrees. CONCLUSIONS Both particle-associated and free mitochondrial DNA are present in plasma, and their respective concentrations are affected by the process used to harvest plasma from whole blood. These results may have implications in the design of future studies on circulating mitochondrial DNA measured in different disease conditions.
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Affiliation(s)
- Rossa W K Chiu
- Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR
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Ng EKO, Leung TN, Tsui NBY, Lau TK, Panesar NS, Chiu RWK, Lo YMD. The concentration of circulating corticotropin-releasing hormone mRNA in maternal plasma is increased in preeclampsia. Clin Chem 2003; 49:727-31. [PMID: 12709362 DOI: 10.1373/49.5.727] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Increased fetal DNA in maternal plasma/serum has been reported in pregnancies complicated by preeclampsia. We hypothesize that fetal RNA may also be increased in maternal plasma in preeclampsia. METHODS We developed a real-time quantitative reverse transcription-PCR assay to measure the concentration of the mRNA of the corticotropin-releasing hormone (CRH) locus. Peripheral blood samples were obtained from healthy pregnant women both before and 2 h after delivery. Peripheral blood samples were also obtained from women suffering from preeclampsia and controls matched for gestational age. Plasma was harvested from these samples, and RNA was extracted. Plasma RNA was subjected to analysis by the reverse transcription-PCR assay. RESULTS CRH mRNA was detected in the plasma of 10 healthy pregnant women in the third trimester. CRH mRNA was found to be cleared very rapidly after cesarean section, with no detectable signal by 2 h postpartum. Plasma CRH mRNA concentrations were 1070 and 102 copies/mL, respectively, in 12 preeclamptic women and 10 healthy pregnant women matched for gestational age (Mann-Whitney test, P <0.001). CONCLUSION Plasma CRH mRNA represents a new molecular marker for preeclampsia. Maternal plasma RNA is gender- and polymorphism-independent and may allow noninvasive gene-expression profiling of an unborn fetus.
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Affiliation(s)
- Enders K O Ng
- Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR
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Ng EKO, Tsui NBY, Lau TK, Leung TN, Chiu RWK, Panesar NS, Lit LCW, Chan KW, Lo YMD. mRNA of placental origin is readily detectable in maternal plasma. Proc Natl Acad Sci U S A 2003; 100:4748-53. [PMID: 12644709 PMCID: PMC153627 DOI: 10.1073/pnas.0637450100] [Citation(s) in RCA: 271] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The discovery of circulating fetal nucleic acid in maternal plasma has opened up new possibilities for noninvasive prenatal diagnosis. Thus far, a gender- and polymorphism-independent fetal-specific target that can be used for prenatal screening and monitoring in all pregnant women has not been reported. In addition, the origin of such circulating nucleic acid has remained unclear. Here we provide direct evidence that the placenta is an important source of fetal nucleic acid release into maternal plasma by demonstrating that mRNA transcripts from placenta-expressed genes are readily detectable in maternal plasma. The surprising stability of such placental mRNA species in maternal plasma and their rapid clearance after delivery demonstrate that such circulating mRNA molecules are practical markers for clinical use. The measurement of such plasma mRNA markers has provided a gender-independent approach for noninvasive prenatal gene expression profiling and has opened up numerous research and diagnostic possibilities.
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Affiliation(s)
- Enders K O Ng
- Department of Chemical Pathology, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong
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Tsui NBY, Ng EKO, Lo YMD. Stability of endogenous and added RNA in blood specimens, serum, and plasma. Clin Chem 2002; 48:1647-53. [PMID: 12324479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
BACKGROUND Circulating RNA in plasma/serum is an emerging field for noninvasive molecular diagnosis. Because RNA is widely thought to be labile in the circulation, we investigated the stability and various preanalytical factors that may affect RNA concentrations in blood specimens. METHODS Blood samples were collected from 65 healthy volunteers. The effects of two preanalytical variables were studied: (a) time delay in processing of EDTA blood and clotted blood after venesection, and (b) freezing and thawing of plasma and serum. The lability of free added RNA in plasma was also investigated. Plasma/serum RNA was measured by a real-time quantitative reverse transcription-PCR assay for glyceraldehyde 3-phosphate dehydrogenase mRNA, whereas DNA was measured by a real-time quantitative PCR assay for the beta-globin gene. RESULTS No significant difference was found for plasma RNA concentrations obtained from uncentrifuged EDTA blood that had been left at 4 degrees C for 0, 6, and 24 h (P =0.182). On the other hand, the serum RNA concentrations increased significantly over 24 h when uncentrifuged clotted blood was stored at 4 degrees C (P <0.05). In comparison, >99% of the free added RNA could no longer be amplified after incubation in plasma for 15 s. Never-frozen plasma, freeze-thawed plasma, and thawed plasma left at room temperature for 1 h showed no significant differences in RNA concentration (P =0.465). No significant difference was observed for freeze-thawed serum (P = 0.430). CONCLUSIONS Plasma RNA is stable in uncentrifuged EDTA blood stored at 4 degrees C, but to obtain a stable serum RNA concentration, uncentrifuged clotted blood should be stored at 4 degrees C and processed within 6 h. A single freeze/thaw cycle produces no significant effect on the RNA concentration of plasma or serum.
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Affiliation(s)
- Nancy B Y Tsui
- Department of Chemical Pathology, Sir Y.K. Pao Cancer Center, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong Special Administrative Region
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Ng EKO, Tsui NBY, Lam NYL, Chiu RWK, Yu SCH, Wong SCC, Lo ESF, Rainer TH, Johnson PJ, Lo YMD. Presence of filterable and nonfilterable mRNA in the plasma of cancer patients and healthy individuals. Clin Chem 2002; 48:1212-7. [PMID: 12142376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
BACKGROUND As RNA is labile, we investigated whether circulating RNA in human plasma may be present in a particle-associated form. METHODS Blood was collected from 27 healthy individuals and 16 hepatocellular carcinoma (HCC) patients. The plasma from each individual was processed by two means: filtration through filters with different pore sizes (from 5 microm to 0.22 microm) and ultracentrifugation. We assessed plasma RNA content by a real-time quantitative reverse transcription-PCR assay for glyceraldehyde-3-phosphate dehydrogenase (GAPDH) transcripts and plasma DNA by a real-time quantitative PCR assay for the beta-globin gene. RESULTS The plasma GAPDH mRNA concentrations in the healthy individuals were significantly different in every pair of these filter sizes (P <0.05 for each pair). Overall, the plasma GAPDH mRNA concentration was higher by a median of 15-fold (interquartile range, 10- to 24-fold) in the paired unfiltered sample than in the sample filtered through a 0.22 microm filter. In contrast, no significant difference was seen in beta-globin DNA concentrations among different pore-size-filtered plasma samples (P = 0.455). Similarly, a significant difference was observed for RNA, but not DNA, between unfiltered plasma and ultracentrifuged plasma (P <0.05). No significant difference in GAPDH mRNA concentrations was seen between the 0.22-microm-filtered plasma samples and the ultracentrifuged plasma samples (P >0.05). In HCC patients, filtration with a 0.22 microm filter produced a median 9.3-fold (interquartile range, 6.9- to 311-fold) reduction in GAPDH mRNA concentration in plasma. Plasma GAPDH mRNA concentrations in HCC patients were significantly higher than those in healthy individuals, both with or without filtration (P <0.0 5 for filtered plasma samples; P <0.005 for unfiltered plasma samples). CONCLUSIONS A substantial proportion of plasma mRNA species is particle-associated. In HCC patients, both circulating particle- and non-particle-associated plasma RNA are increased.
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Affiliation(s)
- Enders K O Ng
- Institute of Molecular Oncology and Department of Chemical Pathology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong Special Administrative Region
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