Project description:Cervical cancer develops from pre-cancerous high-grade cervical intraepithelial neoplasia (CIN) lesions harbouring a transforming infection with high-risk human papillomavirus (hrHPV), which is characterised by p16INK4a overexpression. Since it takes one or more decades for these pre-cancerous lesions to progress to invasive squamous cell carcinomas (SCCs), it is obvious that they are heterogeneous in terms of duration of existence and progression risk. We performed array-based comparative genomic hybridisation (array CGH) of 46 p16INK4a immuno-positive CIN2/3 lesions to determine whether this heterogeneity is reflected in their chromosomal profiles. Chromosomal profiles of CIN2/3 lesions were related to those of invasive cervical squamous cell carcinomas (SCCs) and promoter methylation of the CADM1 gene, a tumour suppressor gene known to be functionally involved in the tumorigenic phenotype of cervical cancer cells. Frequent alterations found in CIN2/3 lesions included gains located at chromosome 1, 3, 7 and 20 and losses located at 4, 11, 16, 17 and 19. Unsupervised hierarchical clustering identified two subsets of CIN2/3 lesions, chromosomal profiles of one of which closely resembled invasive SCCs. Gains of 1, 3q and 20 were characteristic for CIN2/3 lesions with chromosomal signatures resembling carcinomas. In addition, dense promoter methylation of the CADM1 gene was significantly more frequent in these CIN2/3 lesions (p=0.004). No chromosomal alterations were detected in one p16INK4a positive and five p16INK4a negative CIN1 lesions. These findings suggest that biomarkers associated with gains at chromosomes 1, 3q and 20 are potential hallmarks of advanced p16INK4a positive CIN2/3 lesions with a high short-term risk of progression. Genomic DNA of 46 high-grade cervical lesions was hybridised to 5K CGH BAC microarrays (5K) produced at the Microarray facility of the VU Medical Center. In total 4632 BAC clones with known chromosomal location were spotted in triplicate, which included the 1Mb resolution Sanger BAC clone set and a subset of clones from the Children’s Hospital Oakland Research Institute (CHORI). All samples were labelled with Cy3 and hybridised together with a pool of normal male reference DNA labelled with Cy5. Hybridisations were essentially performed as described by Snijders et al (Nature Genetics 2001). Both pre-hybridisation and hybridisation were performed in a hybridisation station (HybStation12 – Perkin Elmer Life Sciences). Hybridised arrays were scanned using a G2505B scanner (Agilent, Wilmington, DE, USA). Spots were quantified using ImaGene 5.6.1 software (BioDiscovery Ltd, Marina del Rey, CA, USA) with default settings for the flagging of bad quality spots. Genomic DNA of 6 CIN1 lesions was hybridised on CGH oligo microarrays (44K) produced by Agilent following the manufacturer’s protocol against the same normal reference pool. Hybridised arrays were scanned using the same scanner (G2505B, Agilent). Quantification of these arrays was done using Feature Extraction software version 9.5.1 (Agilent).

Project description:Epigenetic modifications, such as aberrant DNA promoter methylation is frequently observed in cervical cancer. Identification of hypermethylated regions maybe useful for discrimination between normal cervical epithelium and high-grade cervical intraepithelial neoplasia (CIN2/3) or worse may improve current cervical cancer population-based screening programs. In this study, the DNA methylome of high-grade CIN lesions were characterised using genome-wide methylation screening to identify potential biomarkers for early diagnosis of cervical neoplasia. Methyl-DNA Immunoprecipitation (MeDIP) combined with DNA microarray was used to compare DNA methylation profiles of epithelial cells derived from high-grade CIN lesions with normal cervical epithelium resulting in the identification of hypermethylated differentially methylated regions (DMRs). Validation of 9 selected DMRs by MSP or BSP in cervical tissue revealed methylation in 63.2-94.7% high-grade CIN and in 59.3-100% cervical carcinomas. QMSP for the two most significant high-grade CIN-specific methylation markers was applied exploring test performance in a large series of cervical scrapings. Frequency and relative level of methylation were significantly different between normal and cancer samples (p<0.001). Clinical validation of both markers in cervical scrapings from patients referred with an abnormal cervical smear, confirmed that frequency and relative level of methylation were related with increasing severity of the underlying CIN lesion (p<0.001) and the ROC analysis was discriminative (p<0.005). These possible methylation markers represent COL25A1 and KATNAL2 promoters and their observed increased methylation upon progression is in agreement with their biological function (cytoskeleton regulation). In conclusion, our newly identified hypermethylated DMRs represent specific DNA methylation patterns in high-grade CIN lesions and could be potential biomarkers for early detection. Epigenetic modifications, such as aberrant DNA promoter methylation is frequently observed in cervical cancer. Identification of hypermethylated regions maybe useful for discrimination between normal cervical epithelium and high-grade cervical intraepithelial neoplasia (CIN2/3) or worse may improve current cervical cancer population-based screening programs. In this study, the DNA methylome of high-grade CIN lesions were characterised using genome-wide methylation screening to identify potential biomarkers for early diagnosis of cervical neoplasia. Methyl-DNA Immunoprecipitation (MeDIP) combined with DNA microarray was used to compare DNA methylation profiles of epithelial cells derived from high-grade CIN lesions with normal cervical epithelium resulting in the identification of hypermethylated differentially methylated regions (DMRs). Validation of 9 selected DMRs by MSP or BSP in cervical tissue revealed methylation in 63.2-94.7% high-grade CIN and in 59.3-100% cervical carcinomas. QMSP for the two most significant high-grade CIN-specific methylation markers was applied exploring test performance in a large series of cervical scrapings. Frequency and relative level of methylation were significantly different between normal and cancer samples (p<0.001). Clinical validation of both markers in cervical scrapings from patients referred with an abnormal cervical smear, confirmed that frequency and relative level of methylation were related with increasing severity of the underlying CIN lesion (p<0.001) and the ROC analysis was discriminative (p<0.005). These possible methylation markers represent COL25A1 and KATNAL2 promoters and their observed increased methylation upon progression is in agreement with their biological function (cytoskeleton regulation). In conclusion, our newly identified hypermethylated DMRs represent specific DNA methylation patterns in high-grade CIN lesions and could be potential biomarkers for early detection. MeDIP with subsequent microarray analysis was performed on DNA isolated from frozen macrodissected epithelial tissue of CIN3 lesions (n=15) and normal cervices (n=10).

Project description:Little is known about the alterations in microRNA (miRNA) expression patterns during the consecutive stages of cervical cancer development and their association with chromosomal instability and epigenetic changes. We integrated miRNA expression profiles in normal cervical squamous epithelium, high-grade precancerous lesions (CIN2-3), squamous cell carcinomas (SCC) and adenocarcinomas (AdCAs) with previously generated chromosomal profiles of the same samples. In addition, the DNA methylation status of downregulated miRNAs located in a CpG island was determined. Significantly differential expression during the consecutive stages of cervical SCC development was observed for 106 miRNAs. Altered expression of 5 significantly differentially expressed miRNAs, hsa-miR-9 (1q23.2), hsa-miR-15b (3q25.32), hsa-miR-28-5p (3q27.3), hsa-miR-100 and hsa-miR-125b (both 11q24.1) was directly linked to frequent chromosomal alterations. Another 9 significantly downregulated miRNAs were located within a CpG island. Three of these 9 miRNAs, hsa-miR-203, hsa-miR-572, and hsa-miR-638, showed increased methylation in cervical cancer cell lines and HPV-immortalised cells compared to primary keratinocytes. Functional analyses were performed for hsa-miR-9, representing a potential oncogene with increased expression linked to a chromosomal gain, and hsa-miR-203, representing a potential tumour suppressor gene silenced by DNA methylation. Hsa-miR-9 and hsa-miR-203 were found to alter cell viability and anchorage independent growth in vitro, respectively, supporting their oncogenic and tumour suppressive function in cervical cancer. In conclusion, differential expression of 106 miRNAs, partly associated with chromosomal alterations and epigenetic changes, was observed during cervical SCC development. Altered expression of hsa-miR-9 and hsa-miR-203 was shown to be functionally relevant, underlining the importance of deregulated miRNA expression in cervical carcinogenesis. 10 squamous cell carcinomas of the cervix, 9 adenocarcinomas of the cervix, 18 high-grade cervical intraepithelial neoplasias (CIN2-3), and 10 cervical squamous epithelial samples with normal histology were analysed using single channel (Cy3) miRNA microarrays from Agilent (G4471A-016436).

Project description:Epigenetic modifications, such as aberrant DNA promoter methylation is frequently observed in cervical cancer. Identification of hypermethylated regions maybe useful for discrimination between normal cervical epithelium and high-grade cervical intraepithelial neoplasia (CIN2/3) or worse may improve current cervical cancer population-based screening programs. In this study, the DNA methylome of high-grade CIN lesions were characterised using genome-wide methylation screening to identify potential biomarkers for early diagnosis of cervical neoplasia. Methyl-DNA Immunoprecipitation (MeDIP) combined with DNA microarray was used to compare DNA methylation profiles of epithelial cells derived from high-grade CIN lesions with normal cervical epithelium resulting in the identification of hypermethylated differentially methylated regions (DMRs). Validation of 9 selected DMRs by MSP or BSP in cervical tissue revealed methylation in 63.2-94.7% high-grade CIN and in 59.3-100% cervical carcinomas. QMSP for the two most significant high-grade CIN-specific methylation markers was applied exploring test performance in a large series of cervical scrapings. Frequency and relative level of methylation were significantly different between normal and cancer samples (p<0.001). Clinical validation of both markers in cervical scrapings from patients referred with an abnormal cervical smear, confirmed that frequency and relative level of methylation were related with increasing severity of the underlying CIN lesion (p<0.001) and the ROC analysis was discriminative (p<0.005). These possible methylation markers represent COL25A1 and KATNAL2 promoters and their observed increased methylation upon progression is in agreement with their biological function (cytoskeleton regulation). In conclusion, our newly identified hypermethylated DMRs represent specific DNA methylation patterns in high-grade CIN lesions and could be potential biomarkers for early detection. Epigenetic modifications, such as aberrant DNA promoter methylation is frequently observed in cervical cancer. Identification of hypermethylated regions maybe useful for discrimination between normal cervical epithelium and high-grade cervical intraepithelial neoplasia (CIN2/3) or worse may improve current cervical cancer population-based screening programs. In this study, the DNA methylome of high-grade CIN lesions were characterised using genome-wide methylation screening to identify potential biomarkers for early diagnosis of cervical neoplasia. Methyl-DNA Immunoprecipitation (MeDIP) combined with DNA microarray was used to compare DNA methylation profiles of epithelial cells derived from high-grade CIN lesions with normal cervical epithelium resulting in the identification of hypermethylated differentially methylated regions (DMRs). Validation of 9 selected DMRs by MSP or BSP in cervical tissue revealed methylation in 63.2-94.7% high-grade CIN and in 59.3-100% cervical carcinomas. QMSP for the two most significant high-grade CIN-specific methylation markers was applied exploring test performance in a large series of cervical scrapings. Frequency and relative level of methylation were significantly different between normal and cancer samples (p<0.001). Clinical validation of both markers in cervical scrapings from patients referred with an abnormal cervical smear, confirmed that frequency and relative level of methylation were related with increasing severity of the underlying CIN lesion (p<0.001) and the ROC analysis was discriminative (p<0.005). These possible methylation markers represent COL25A1 and KATNAL2 promoters and their observed increased methylation upon progression is in agreement with their biological function (cytoskeleton regulation). In conclusion, our newly identified hypermethylated DMRs represent specific DNA methylation patterns in high-grade CIN lesions and could be potential biomarkers for early detection.

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