ABSTRACT
BACKGROUND: Chronic inflammation is a risk factor for head and neck squamous cell carcinoma (HNSCC) and other diseases. Prostanoid receptors are clearly involved in the development of many types of cancer. However, their role is not simple and is poorly understood in HNSCC. METHODS: Methylation profiles of prostanoid receptor family genes were generated for tumour samples obtained from 274 patients with HNSCC, including 69 hypopharynx, 51 larynx, 79 oral cavity, and 75 oropharynx tumour samples, by quantitative methylation-specific PCR. Promoter methylation was then evaluated with respect to various clinical characteristics and patient survival. RESULTS: The mean number of methylated genes per sample was 2.05 ± 2.59 (range 0 to 9). Promoters of PTGDR1, PTGDR2, PTGER1, PTGER2, PTGER3, PTGER4, PTGFR, PTGIR, and TBXA2R were methylated in 43.8%, 18.2%, 25.5%, 17.5%, 41.2%, 8.0%, 19.3%, 20.4%, and 11.3% of the samples, respectively. Methylation indices for prostanoid receptor family genes tended to be higher as the number of TET methylation events increased. Patients with 5-9 methylated genes had a significantly lower survival rate than that of patients with 0-4 methylated genes (log-rank test, P= 0.007). In multivariate analyses, PTGDR1 methylation was most highly correlated with recurrence in patients with hypopharyngeal cancer (P = 0.014). A similar correlation was observed for PTGER4 in patients with laryngeal cancer (P = 0.046). Methylation of the PTGIR and TBXA2R promoters was positively correlated with recurrence in oropharyngeal cancer (P = 0.028 and P = 0.006, respectively). Moreover, Patients with 5-9 methylated genes were extremely lower of 5hmC levels (P = 0.035) and was correlated with increasing expression of DNMT3A and DNMT3B (P < 0.05 and P < 0.05, respectively). CONCLUSION: We characterised the relationship between the methylation status of prostanoid receptor genes and recurrence in HNSCC. These results provide new perspectives for the development of molecular targeted treatment approaches.
Subject(s)
Carcinoma, Squamous Cell , Epigenesis, Genetic , Head and Neck Neoplasms , Carcinoma, Squamous Cell/genetics , DNA Methylation/genetics , Female , Head and Neck Neoplasms/genetics , Humans , Male , Neoplasm Recurrence, Local/genetics , Prognosis , Prostaglandins , Receptors, Prostaglandin , Squamous Cell Carcinoma of Head and Neck/geneticsABSTRACT
BACKGROUND: Cytology-based screening methods for cervical adenocarcinoma (ADC) and to a lesser extent squamous-cell carcinoma (SCC) suffer from low sensitivity. DNA hypermethylation analysis in cervical scrapings may improve detection of SCC, but few methylation markers have been described for ADC. We aimed to identify novel methylation markers for the early detection of both ADC and SCC. RESULTS: Genome-wide methylation profiling for 20 normal cervices, 6 ADC and 6 SCC using MethylCap-seq yielded 53 candidate regions hypermethylated in both ADC and SCC. Verification and independent validation of the 15 most significant regions revealed 5 markers with differential methylation between 17 normals and 13 cancers. Quantitative methylation-specific PCR on cervical cancer scrapings resulted in detection rates ranging between 80% and 92% while between 94% and 99% of control scrapings tested negative. Four markers (SLC6A5, SOX1, SOX14 and TBX20) detected ADC and SCC with similar sensitivity. In scrapings from women referred with an abnormal smear (n=229), CIN3+ sensitivity was between 36% and 71%, while between 71% and 93% of adenocarcinoma in situ (AdCIS) were detected; and CIN0/1 specificity was between 88% and 98%. Compared to hrHPV, the combination SOX1/SOX14 showed a similar CIN3+ sensitivity (80% vs. 75%, respectively, P>0.2), while specificity improved (42% vs. 84%, respectively, P < 10-5). CONCLUSION: SOX1 and SOX14 are methylation biomarkers applicable for screening of all cervical cancer types.
Subject(s)
Adenocarcinoma in Situ/genetics , Biomarkers, Tumor/genetics , Carcinoma, Adenosquamous/genetics , Carcinoma, Squamous Cell/genetics , DNA Methylation , Uterine Cervical Dysplasia/genetics , Uterine Cervical Neoplasms/genetics , Adenocarcinoma in Situ/pathology , Adult , Aged , Carcinoma, Adenosquamous/pathology , Carcinoma, Squamous Cell/pathology , Case-Control Studies , Early Detection of Cancer , Female , Gene Expression Profiling , Genetic Predisposition to Disease , Genome-Wide Association Study , Glial Cell Line-Derived Neurotrophic Factor Receptors/genetics , Glycine Plasma Membrane Transport Proteins/genetics , Humans , Middle Aged , Phenotype , Predictive Value of Tests , Prognosis , Reproducibility of Results , SOXB1 Transcription Factors/genetics , SOXB2 Transcription Factors/genetics , T-Box Domain Proteins/genetics , Uterine Cervical Neoplasms/pathology , Vaginal Smears , Uterine Cervical Dysplasia/pathologyABSTRACT
BACKGROUND: Related to genetic alteration, frequent promoter hypermethylation is also a contributing factor in the development of human cancers. Recently, we discovered numerous novel genes that were aberrantly methylated in hepatocellular carcinoma (HCC) by using Infinium HumanMethylation27 BeadChip array. We utilized a quantitative methylation-specific PCR (Q-MSP) system for the evaluation of PAX6 methylation in 29 normal controls and 160 paired HCC tissues and their adjacent non-tumor tissues. We verified the correlation between the methylation status of PAX6 and clinical characteristics with different viral status. RESULTS: Paired-box 6 promoter methylation was observed in 39.4 %, 15.6 %, and 3.4 % in primary HCCs, adjacent non-tumors, and normal control tissues, respectively. Methylation of the PAX6 promoter region in HCCs significantly increased compared with control tissues. PAX6 was frequently methylated in HCV-positive HCC tissues (61.3 %) and rarely methylated in HBV-positive (22.1 %) and double-negative HCC tissues (33.3 %). CONCLUSIONS: Our data suggests that promoter hypermethylation of PAX6 is a common event in HCCs and the association of PAX6 methylation in clinicopathological features is divergent with different viral status.
Subject(s)
Carcinoma, Hepatocellular/virology , DNA Methylation , Hepatitis B/genetics , Hepatitis C/genetics , Liver Neoplasms/virology , PAX6 Transcription Factor/genetics , Aged , Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/pathology , Cell Line, Tumor , Female , Gene Expression Regulation, Neoplastic , Humans , Liver Neoplasms/genetics , Liver Neoplasms/pathology , Male , Middle Aged , Promoter Regions, GeneticABSTRACT
High-risk human papillomavirus (hrHPV)-induced immortalization and malignant transformation are accompanied by DNA methylation of host genes. To determine when methylation is established during cell immortalization and whether it is hrHPV-type dependent, DNA methylation was studied in a large panel of HPVE6E7-immortalized keratinocyte cell lines. These cell lines displayed different growth behaviors, i.e., continuous growth versus crisis period prior to immortalization, reflecting differential immortalization capacities of the 7 HPV-types (16/18/31/33/45/66/70) studied. In this study, cells were monitored for hypermethylation of 14 host genes (APC, CADM1, CYGB, FAM19A4, hTERT, mir124-1, mir124-2, mir124-3, MAL, PHACTR3, PRDM14, RASSF1A, ROBO3, and SFRP2) at 4 different stages during immortalization. A significant increase in overall methylation levels was seen with progression through each stage of immortalization. At stage 1 (pre-immortalization), a significant increase in methylation of hTERT, mir124-2, and PRDM14 was already apparent, which continued over time. Methylation of ROBO3 was significantly increased at stage 2 (early immortal), followed by CYGB (stage 3) and FAM19A4, MAL, PHACTR3, and SFRP2 (stage 4). Methylation patterns were mostly growth behavior independent. Yet, hTERT methylation levels were significantly increased in cells that just escaped from crisis. Bisulfite sequencing of hTERT confirmed increased methylation in immortal cells compared to controls, with the transcription core and known repressor sites remaining largely unmethylated. In conclusion, HPV-induced immortalization is associated with a sequential and progressive increase in promoter methylation of a subset of genes, which is mostly independent of the viral immortalization capacity.
Subject(s)
Cell Transformation, Viral/genetics , DNA Methylation , Genome, Human , Keratinocytes/metabolism , Alphapapillomavirus/pathogenicity , Alphapapillomavirus/physiology , Cell Line, Tumor , Cells, Cultured , Humans , Keratinocytes/pathology , Keratinocytes/virologyABSTRACT
Hypermethylation has been shown in the promoter region of the thyroid hormone receptor ß1 (TRß1) gene in several human tumors. However, its role in gastric cancer formation is still unclear. In the study, we analyzed mRNA expression of TRß1 gene using real-time quantitative PCR (qPCR). A quantitative methylation-specific PCR (Q-MSP) assay was used to determine the methylation status of the TRß1 gene promoter region in 46 pair-matched gastric neoplastic and adjacent non-neoplastic tissues. The results showed that TRß1 mRNA expression was significantly reduced in gastric cancer specimens. The methylation of promoter of TRß1 gene in gastric cancer tissues was significantly higher than in adjacent normal tissues. Promoter hypermethylation of the TRß1 gene correlated with tumor infiltration, lymph node metastasis, and distant metastasis, but it was not associated with other clinicopathological characteristics. We treated gastric cancer cell lines MKN-45, MKN-28, SGC-7901, NCI-N87, and SNU-1 with 5-Aza-2-deoxycytidine (5-Aza-dC). The results showed the expression of TRß1 mRNA was increased in MKN-45, MKN-28, SGC-7901, but not increased in NCI-N87 and SNU-1. These results suggest that the TRß1 gene plays important roles in the development of gastric cancer partially through epigenetic mechanisms.
Subject(s)
DNA Methylation , Down-Regulation , Promoter Regions, Genetic/genetics , Stomach Neoplasms/genetics , Thyroid Hormone Receptors beta/genetics , Azacitidine/analogs & derivatives , Azacitidine/pharmacology , Cell Line , Cell Line, Tumor , Decitabine , Enzyme Inhibitors/pharmacology , Female , Gene Expression Regulation, Neoplastic/drug effects , Humans , Lymphatic Metastasis , Male , Middle Aged , Reverse Transcriptase Polymerase Chain Reaction , Stomach Neoplasms/pathologyABSTRACT
Gastric cancer is one of the most common malignancies and remains the second leading cause of cancer-related death worldwide. Over 70% of new cases and deaths occur in developing countries. In the early years of the molecular biology revolution, cancer research mainly focuses on genetic alterations, including gastric cancer. Epigenetic mechanisms are essential for normal development and maintenance of tissue-specific gene expression patterns in mammals. Disruption of epigenetic processes can lead to altered gene function and malignant cellular transformation. Recent advancements in the rapidly evolving field of cancer epigenetics have shown extensive reprogramming of every component of the epigenetic machinery in cancer, including DNA methylation, histone modifications, nucleosome positioning, noncoding RNAs, and microRNAs. Aberrant DNA methylation in the promoter regions of gene, which leads to inactivation of tumor suppressor and other cancer-related genes in cancer cells, is the most well-defined epigenetic hallmark in gastric cancer. The advantages of gene methylation as a target for detection and diagnosis of cancer in biopsy specimens and non-invasive body fluids such as serum and gastric washes have led to many studies of application in gastric cancer. This review focuses on the most common and important phenomenon of epigenetics, DNA methylation, in gastric cancer and illustrates the impact epigenetics has had on this field.