Saskia M Wilting

VU University Medical Center, Amsterdamo, North Holland, Netherlands

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Publications (30)164.76 Total impact

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    ABSTRACT: Abstract 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 seven 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.
    Epigenetics: official journal of the DNA Methylation Society 01/2015; 10(1). DOI:10.4161/15592294.2014.990787 · 5.11 Impact Factor
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    ABSTRACT: For many high-dimensional studies, additional information on the variables, like (genomic) annotation or external p-values, is available. In the context of binary and continuous prediction, we develop a method for adaptive group-regularized (logistic) ridge regression, which makes structural use of such 'co-data'. Here, 'groups' refer to a partition of the variables according to the co-data. We derive an empirical Bayes estimate of group-specific penalties, which possesses several nice properties: i) it is analytical; ii) it adapts to the informativeness of the co-data for the data at hand; iii) only one global penalty parameter requires tuning by cross-validation. In addition, the method allows use of multiple types of co-data at little extra computational effort. We show that the group-specific penalties may lead to a larger distinction between 'near-zero' and relatively large regression parameters, which facilitates post-hoc variable selection. The method, termed 'GRridge', is implemented in an easy-to-use R-package. It is demonstrated on two cancer genomics studies, which both concern the discrimination of precancerous cervical lesions from normal cervix tissues using methylation microarray data. For both examples, GRridge clearly improves the predictive performance of ordinary ridge regression. In addition, we show that for the second study the relatively good predictive performance is maintained when selecting only 35 variables.
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    ABSTRACT: To determine which changes in the host cell genome are crucial for cervical carcinogenesis, alongitudinal in vitro model system of HPV-transformed keratinocytes was profiled in a genomewidemanner. Four cell lines affected with either HPV16 or HPV18 were assayed at 8 sequential timepoints for gene expression (mRNA) and gene copy number (DNA) using high-resolution microarrays.Available methods for temporal differential expression analysis are not designed for integrativegenomic studies.
    BMC Bioinformatics 10/2014; 15(1):327. DOI:10.1186/1471-2105-15-327 · 2.67 Impact Factor
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    ABSTRACT: Methylation markers were studied for their suitability to triage human papillomavirus (HPV)-positive women by testing self-collected cervico-vaginal lavage specimens. For this purpose, we analyzed 355 hrHPV-positive self-collected specimens with three methylation markers, that is, CADM1-m18, MAL-m1 and miR-124-2 by quantitative methylation-specific PCR. The areas under the receiver-operating characteristic (ROC) curve for end-point cervical intraepithelial neoplasia grade 3 or worse (CIN3+) were 0.637 for CADM1-m18, 0.767 for MAL-m1 and 0.762 for miR-124-2. This indicates that CADM1-m18 is not suitable as single marker. By varying the thresholds of both markers in the bi-marker panels CADM1-m18/MAL-m1, CADM1-m18/miR-124-2 and MAL-m1/miR-124-2 upper and lower ROC curves were obtained, depicting the maximum and minimum CIN3+ sensitivity, respectively, at given specificity. For all these bi-marker combinations, the upper curves were similar. However, for the MAL-m1/miR-124-2 panel, the distance between upper and lower ROC curves was closest and this panel displayed the highest assay thresholds, indicating that this combination was most robust. At clinical specificities of 50 and 70%, the MAL-m1/miR-124-2 sensitivity for detection of CIN3+ ranged from 77.0 to 87.8% and from 64.9 to 71.6%, respectively. At 70% specificity thresholds no carcinomas were missed. By comparison, the CIN3+ sensitivity of HPV16/18 genotyping on the self-sampled lavage specimens was 58.1% (95%CI: 46.6-68.8) at a specificity of 87.7% (95%CI: 83.2-91.2). In conclusion, methylation analysis is a promising triage tool that in combination with HPV-DNA testing offers feasible, full molecular screening on self-collected cervico-vaginal lavage specimens.
    International Journal of Cancer 08/2014; 135(4). DOI:10.1002/ijc.28723 · 5.01 Impact Factor
  • Cancer Research 08/2013; 73(8 Supplement):2971-2971. DOI:10.1158/1538-7445.AM2013-2971 · 9.28 Impact Factor
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    ABSTRACT: The pathogenetic role, including its target genes, of recurrent 3p12-p14 loss in cervical cancer has remains unclear. To determine the onset of the event during carcinogenesis, we used microarray techniques and found that the loss was the most frequent 3p event, occurring in 61% of 92 invasive carcinomas, in only 2% of 43 high-grade intraepithelial lesions (CIN2/3), and in 33% of 6 CIN3 lesions adjacent to invasive carcinomas, suggesting a role in acquisition of invasiveness or early during the invasive phase. We performed an integrative DNA copy number and expression analysis of 77 invasive carcinomas, where all genes within the recurrent region were included. We selected eight genes, THOC7, PSMD6, SLC25A26, TMF1, RYBP, SHQ1, EBLN2, and GBE1, which were highly downregulated in cases with loss, as confirmed at the protein level for RYBP and TMF1 by immunohistochemistry. The eight genes were subjected to network analysis based on the expression profiles, revealing interaction partners of proteins encoded by the genes that were coordinately regulated in tumors with loss. Several partners were shared among the eight genes, indicating crosstalk in their signaling. Gene ontology analysis showed enrichment of biological processes like apoptosis, proliferation, and stress response in the network and suggested a relationship between downregulation of the eight genes and activation of tumorigenic pathways. Survival analysis showed prognostic impact of the eight gene signature that was confirmed in a validation cohort of 74 patients and was independent of clinical markers. These results support the role of the eight candidate genes as targets of the 3p12-p14 loss in cervical cancer and suggest that the strong selection advantage of the loss during carcinogenesis might be caused by a synergetic effect of several tumorigenic processes controlled by these targets.
    The Journal of Pathology 05/2013; 230(1). DOI:10.1002/path.4168 · 7.33 Impact Factor
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    ABSTRACT: Abstract The process of occurrence of genomic aberrations over time in the genetic material of cancer cells reflects the progression of the cancer. Modern technologies like aCGH (array Comparative Genomic Hybridization) and MPS (Massive Parallel Sequencing) provide high-resolution measurements of DNA copy number aberrations, that reveal the full scale of genomic aberrations. A continuous time Markov chain model is proposed to describe the accumulation of aberrations over time. Time however is a latent variable (with the number of aberrations as a proxy). Integrating out time, yields the distribution of the observed DNA copy number data. The model parameters are estimated from high-dimensional DNA copy number data by means of penalized maximum pseudo- and likelihood and method of moments procedures. Having fitted the model, posterior time estimates of the advancement of each sample's cancer are obtained and the most likely locations of a sample's aberrations are predicted. The three estimation methods are compared in a simulation study. The paper closes with an application of the proposed methodology on cancer data.
    Statistical Applications in Genetics and Molecular Biology 01/2013; 12(2):143-74. DOI:10.1515/sagmb-2012-0020 · 1.52 Impact Factor
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    ABSTRACT: Deregulated expression of microRNAs (miRNAs) is common and biologically relevant in cervical carcinogenesis and appears only partly related to chromosomal changes. We recently identified 34 miRNAs showing decreased expression in high-grade cervical intraepithelial neoplasia (CIN) and carcinomas not associated with a chromosomal loss, 6 of which were located within a CpG island. This study aimed to investigate to what extent these miRNAs are subject to DNA methylation-mediated transcriptional repression in cervical carcinogenesis. Methylation-specific PCR (MSP) analysis on a cell line panel representing different stages of human papillomavirus (HPV) induced transformation revealed an increase in methylation of hsa-miR-149, -203 and -375 with progression to malignancy, whereas expression of these miRNAs was restored upon treatment with a demethylating agent. All three miRNAs showed significantly increased levels of methylation in cervical carcinomas, whereas methylation levels of hsa-miR-203 and -375 were also significantly increased in high-grade CIN. A pilot analysis showed that increased hsa-miR-203 methylation was also detectable in HPV-positive cervical scrapes of women with high-grade CIN compared with controls. Similar to recent findings on hsa-miR-375, ectopic expression of hsa-miR-203 in cervical cancer cells decreased both the proliferation rate and anchorage independent growth. We found evidence for methylation-mediated transcriptional repression of hsa-miR-149, -203 and -375 in cervical cancer. Methylation of the latter two was already apparent in precancerous lesions and represent functionally relevant events in HPV-mediated transformation. Increased hsa-miR-203 methylation was detectable in scrapes of women with high-grade CIN, indicating that methylated miRNAs may provide putative markers to assess the presence of (pre)cancerous lesions.
    Epigenetics: official journal of the DNA Methylation Society 01/2013; 8(2). DOI:10.4161/epi.23605 · 5.11 Impact Factor
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    ABSTRACT: Cervical cancer results from persistent infection with high-risk human papillomavirus (hrHPV). Common genetic aberrations in cervical (pre)cancers encompass large genomic regions with numerous genes, hampering identification of driver genes. This study aimed to identify genes functionally involved in HPV-mediated transformation by analysis of focal aberrations (<3 Mb) in high-grade cervical intraepithelial neoplasia (hgCIN). Focal chromosomal aberrations were determined in high-resolution array comparative genomic hybridization data of 60 hgCIN. Genes located within focal aberrations were validated using 2 external gene expression datasets or qRT-PCR. Functional roles of candidate genes EYA2 (20q13) and hsa-miR-375 (2q35) were studied by siRNA-mediated knock-down and overexpression, respectively, in hrHPV-containing cell lines. We identified 74 focal aberrations encoding 305 genes. Concurrent altered expression in hgCIN and/or cervical carcinomas compared with normal cervical samples was shown for ATP13A3, HES1, OPA1, HRASLS, EYA2, ZMYND8, APOBEC2, and NCR2. Gene silencing of EYA2 significantly reduced viability, migratory capacity, and anchorage-independent growth of HPV16-transformed keratinocytes. For hsa-miR-375, a direct correlation between a (focal) loss and significantly reduced expression was found. Downregulation of hsa-miR-375 expression was confirmed in an independent series of cervical tissues. Ectopic expression of hsa-miR-375 in 2 cervical carcinoma cell lines reduced cellular viability. Our data provide a proof of concept that chromosomal aberrations are actively contributing to HPV-induced carcinogenesis and identify EYA2 and hsa-miR-375 as oncogene and tumor suppressor gene, respectively. © 2012 Wiley Periodicals, Inc.
    Genes Chromosomes and Cancer 01/2013; 52(1). DOI:10.1002/gcc.22006 · 3.84 Impact Factor
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    ABSTRACT: High-grade cervical intraepithelial neoplasia (CIN2/3) represents a heterogeneous disease both with respect to clinical behavior and chromosomal aberrations detected. We hypothesized that the extent of chromosomal aberrations reflects the duration of their existence. Chromosomal profiles were determined of CIN3 of women with a known 5-year history of high-risk human papillomavirus virus (hrHPV) infection, in which duration of prior hrHPV infection was considered a proxy for duration of CIN3 existence. Eleven women had a <5 year preceding hrHPV infection (CIN3<5yrPHI) and 24 had a PHI lasting ≥5 years (CIN3≥5yrPHI). For comparison, six CIN3 adjacent to squamous cell carcinomas (CIN3-SCC), the corresponding SCCs, and six CIN1 were included. Unsupervised hierarchical clustering analysis of the chromosomal profiles revealed two clusters. One was characterized by a low number of chromosomal aberrations and included all CIN1, 81.8% of CIN3<5yrPHI and 33.3% of CIN3≥5yrPHI. Samples in the second cluster, displaying multiple aberrations, included 18.2% of CIN3<5yrPHI, 66.7% CIN3≥5yrPHI, all except one CIN3-SCC and all SCCs. The number of genomic aberrations increased according to lesion grade and also with longer duration of PHI. The increase in aberrations in CIN3≥5yrPHI compared to <5yrPHI was highly significant (p = 0.001), suggesting that CIN3≥5yrPHI represent more severe lesions. In conclusion, longer duration of preceding hrHPV infection is associated with an increased number of chromosomal aberrations. Hence, CIN3 with a longer duration of existence are likely more prone to have an increased short-term risk of cervical cancer.
    International Journal of Cancer 08/2012; 131(4):E579-85. DOI:10.1002/ijc.26496 · 5.01 Impact Factor
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    ABSTRACT: 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. In this study, miRNA expression in normal cervical squamous epithelium, high-grade precancerous lesions (cervical intraepithelial neoplasia (CIN2-3)), squamous cell carcinomas (SCCs) and adenocarcinomas (AdCAs) was integrated with previously generated chromosomal profiles of the same samples. Significantly differential expression during the consecutive stages of cervical SCC development was observed for 106 miRNAs. Of these differentially expressed miRNAs, 27 showed early transiently altered expression in CIN2-3 lesions only, 46 miRNAs showed late altered expression in SCCs only and 33 showed continuously altered expression in both CIN2-3 and SCCs. Altered expression of five 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. Functional analyses were performed for hsa-miR-9, representing a potential oncogene with increased expression linked to a chromosomal gain of 1q. Hsa-miR-9 overexpression was found to increase cell viability, anchorage-independent growth and migration in vitro. Upon organic raft culturing, hsa-miR-9 hampered differentiation and induced proliferation in all strata of the epithelial layer. These findings support a potential oncogenic function of hsa-miR-9 in cervical cancer. In summary, differential expression of 106 miRNAs, partly associated with chromosomal alterations, was observed during cervical SCC development. Altered expression of hsa-miR-9 associated with a chromosomal gain of chromosome 1q was shown to be functionally relevant, underlining the importance of deregulated miRNA expression in cervical carcinogenesis.Oncogene advance online publication, 13 February 2012; doi:10.1038/onc.2012.20.
    Oncogene 02/2012; 32(1). DOI:10.1038/onc.2012.20 · 8.56 Impact Factor
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    ABSTRACT: The development of cervical cancer and its high-grade precursor lesions (Cervical Intraepithelial Neoplasia grade 2/3 [CIN2/3]) result from a persistent infection with high-risk human papillomavirus (hrHPV) types and the accumulation of (epi)genetic host cell aberrations. Epidemiological studies have demonstrated variable CIN2/3 and cancer risks between different hrHPV types. Recent genomic profiling studies revealed substantial heterogeneity in the chromosomal aberrations detected in morphologically indistinguishable CIN2/3 suggestive of varying cancer risk. The current study aimed to investigate whether CIN2/3 with different hrHPV types vary with respect to their chromosomal profiles, both in terms of the number of aberrations and chromosomal loci affected. Chromosomal profiles were determined of 43 p16INK4a-immunopositive CIN2/3 of women with long-term hrHPV infection (≥ 5 years). Sixteen lesions harboured HPV16, 3 HPV18, 14 HPV31, 1 HPV33, 4 HPV45, 1 HPV51, 2 HPV52 and 2 HPV58. Unsupervised hierarchical clustering analysis of the chromosomal profiles revealed two major clusters, characterised by either few or multiple chromosomal aberrations, respectively. A majority of 87.5% of lesions with HPV16 were in the cluster with relatively few aberrations, whereas no such unbalanced distribution was seen for lesions harbouring other hrHPV types. Analysis of the two most prevalent types (HPV16 and HPV31) in this data set revealed a three-fold increase in the number of losses in lesions with HPV31 compared to HPV16-positive lesions. In particular, losses at chromosomes 2q, 4p, 4q, 6p, 6q, 8q & 17p and gain at 1p & 1q were significantly more frequent in HPV31-positive lesions (FDR < 0.2). Chromosomal aberrations in CIN2/3 are at least in part related to the hrHPV type present. The relatively low number of chromosomal aberrations observed in HPV16-positive CIN2/3 suggests that the development of these lesions is less dependent on genetic insult than those caused by other types like HPV31.
    BMC Cancer 01/2012; 12:36. DOI:10.1186/1471-2407-12-36 · 3.32 Impact Factor
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    ABSTRACT: Given the lower specificity for high-grade cervical lesions of high-risk human papillomavirus (hrHPV) testing compared to cytology, additional triage testing for hrHPV test-positive women is needed to detect high-grade cervical lesions. Here, we tested whether combined methylation analysis for cell adhesion molecule 1 (CADM1) and T-lymphocyte maturation associated protein (MAL), both functionally involved in cervical carcinogenesis, could serve as such a triage marker. Four quantitative methylation-specific PCRs (qMSP), two for CADM1 (regions M12 and M18) and MAL (regions M1 and M2) each, were applied to 261 cervical tissue specimens ranging from no neoplasia to carcinoma. When qMSPs were combined and positivity for at least one of the qMSPs in the combination was taken into account, the highest positivity rates for cervical intraepithelial neoplasia grade 3 (CIN3) lesions (97%) and squamous cell- and adeno-carcinomas (99%) were obtained by combining a single CADM1 marker with a single MAL marker. Subsequent qMSP analysis of 70 GP5+/6+-PCR hrHPV-positive scrapings revealed that a two-marker panel consisting of CADM1-M18 and MAL-M1 was most discriminative, detecting 90% of women with CIN3 (n = 30), whereas it showed a positive result in only 13.5% of women without cervical disease (n = 40). Finally, we applied hrHPV GP5+/6+-PCR testing followed by CADM1-M18/MAL-M1 methylation analysis to a cohort of 79 women visiting the outpatient colposcopy clinic. hrHPV testing revealed a sensitivity of 97% and a specificity of 33% for CIN3+. Additional CADM1-M18/MAL-M1 methylation analysis on the hrHPV-positive women increased the specificity to 78% with a sensitivity of 70%. In conclusion, the methylation marker panel CADM1-M18 and MAL-M1 may serve as an alternative molecular triage tool for hrHPV-positive women.
    International Journal of Cancer 11/2011; 129(9):2218 - 2225. DOI:10.1002/ijc.25890 · 5.01 Impact Factor
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    ABSTRACT: Autofluorescence bronchoscopy (AFB) is a valid strategy for detecting premalignant endobronchial lesions. However, no biomarker can reliably predict lung cancer risk of subjects with AFB-visualized premalignant lesions. The present study set out to identify AFB-visualized squamous metaplastic (SqM) lesions with malignant potential by DNA copy number profiling. Regular AFB examinations in 474 subjects at risk of lung cancer identified six subjects with SqM lesions at baseline, and carcinoma in situ or carcinoma (carcinoma in situ or greater) at the initial SqM site at follow-up bronchoscopy. These progressive SqM lesions were compared for immunostaining pattern and array comparative genomic hybridization-based chromosomal profiles with 23 SqM lesions of subjects who remained cancer-free. Specific DNA copy number alterations (CNAs) linked to cancer risk were identified and accuracy of CNAs to predict endobronchial cancer in this series was determined. At baseline, p53, p63, and Ki-67 immunostaining were not predictive for a differential clinical outcome of SqM lesions. The mean number of CNAs in baseline SqM of cases was significantly higher compared with control subjects (P < 0.01). Chromosomal regions significantly more frequently altered in SqM of cases were 3p26.3-p11.1, 3q26.2-q29, 9p13.3-p13.2, and 17p13.3-p11.2 (family-wise error rate <0.10). CNAs were specifically detected at the site of future cancer. In cases, baseline-detected CNAs persisted in subsequent biopsies taken from the initial site, and levels increased toward cancer progression. In this series, a model based on CNAs at 3p26.3-p11.1, 3q26.2-29, and 6p25.3-24.3 predicted cancer with 97% accuracy. The data suggest that the presence of specific CNAs in SqM lesions predict endobronchial cancer.
    American Journal of Respiratory and Critical Care Medicine 07/2011; 184(8):948-56. DOI:10.1164/rccm.201102-0218OC · 11.99 Impact Factor
  • Cancer Research 07/2011; 71(8 Supplement):4959-4959. DOI:10.1158/1538-7445.AM2011-4959 · 9.28 Impact Factor
  • Cancer Research 07/2011; 71(8 Supplement):2718-2718. DOI:10.1158/1538-7445.AM2011-2718 · 9.28 Impact Factor
  • Cancer Genetics and Cytogenetics 11/2010; 203(1):49-49. DOI:10.1016/j.cancergencyto.2010.07.015 · 1.93 Impact Factor
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    ABSTRACT: A substantial number of microRNAs (miRNAs) is subject to epigenetic silencing in cancer. Although epigenetic silencing of tumour suppressor genes is an important feature of cervical cancer, little is known about epigenetic silencing of miRNAs. Since DNA methylation-based silencing of hsa-miR-124 occurs in various human cancers, we studied the frequency and functional effects of hsa-miR-124 methylation in cervical carcinogenesis. Quantitative MSP analysis of all 3 loci encoding the mature hsa-miR-124 (hsa-miR-124-1/-2/-3) showed methylation in cervical cancer cell lines SiHa, CaSki and HeLa as well as in late passages of human papillomavirus (HPV) type 16 or 18 immortalised keratinocytes. Treatment of SiHa cells with a demethylating agent reduced hsa-miR-124 methylation levels and induced hsa-miR-124 expression. In HPV-immortalised keratinocytes increased methylation levels were related to reduced hsa-miR-124 expression and higher mRNA expression of IGFBP7, a potential hsa-miR-124 target gene. Ectopic hsa-miR-124 expression in SiHa and CaSki cells decreased proliferation rates and migratory capacity. Combined hsa-miR-124-1 and/or hsa-miR-124-2 methylation analysis of 139 cervical tissue specimens showed an increasing methylation frequency from 0% in normal tissues up to 93% in cervical carcinomas. Increased methylation levels of hsa-miR-124-1 and hsa-miR-124-2 were significantly correlated with reduced hsa-miR-124 expression in cervical tissue specimens. Combined hsa-miR-124-1 and/or hsa-miR-124-2 methylation analysis of 43 cervical scrapes of high-risk HPV positive women was predictive of underlying high-grade lesions. DNA methylation-based silencing of hsa-miR-124 is functionally involved in cervical carcinogenesis and may provide a valuable marker for improved detection of cervical cancer and its high-grade precursor lesions.
    Molecular Cancer 06/2010; 9:167. DOI:10.1186/1476-4598-9-167 · 5.40 Impact Factor
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    ABSTRACT: We recently identified MAL (T-lymphocyte maturation associated protein) as the most down-regulated gene in cervical oncogenesis. Here, we examined the mechanism underlying MAL silencing, its functional role in cervical carcinogenesis, and the relevance of detecting MAL alterations for risk assessment of hrHPV-positive women. MAL mRNA expression and promoter methylation were analysed in primary keratinocytes, hrHPV-immortalized keratinocytes, cervical cancer cell lines, biopsies, and scrapings by quantitative (methylation-specific) PCR. SiHa cells were transfected with MAL cDNA and assayed for proliferation, migration, and anchorage-independent growth. MAL mRNA was (nearly) undetectable in all HPV-immortalized and cervical cancer cells, but could be up-regulated upon methylation inhibition. MAL promoter methylation at two promoter regions (M1 and M2) was detected in all HPV-immortalized cells and cancer cells. Ectopic expression of MAL in SiHa cells suppressed proliferation, migration, and anchorage-independent growth. None (0/22) of normal cervical biopsies, 9% (6/66) of CIN1 lesions, 53% (34/64) of CIN3 lesions, 90% (85/94) of cervical squamous cell carcinomas (SCCs), and 93% (26/28) of cervical adenocarcinomas (AdCAs) demonstrated MAL promoter methylation at both promoter regions. Moreover, detection of MAL promoter methylation in cervical scrapings was predictive for underlying high-grade lesions. Both in biopsies and in scrapings, MAL promoter methylation was significantly correlated with reduced mRNA expression. MAL gene silencing by promoter methylation is a frequent and biologically essential event in HPV-induced cervical carcinogenesis. Hence, MAL promoter methylation and/or mRNA expression analysis on cervical scrapings may provide a valuable diagnostic tool to improve the detection of CIN3, SCC, and AdCA.
    The Journal of Pathology 11/2009; 219(3):327-36. DOI:10.1002/path.2598 · 7.33 Impact Factor
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    ABSTRACT: It is well known that a persistent infection with high-risk human papillomavirus (hrHPV) is causally involved in the development of squamous cell carcinomas of the uterine cervix (CxSCCs) and a subset of SCCs of the head and neck (HNSCCs). The latter differ from hrHPV-negative HNSCCs at the clinical and molecular level. To determine whether hrHPV-associated SCCs arising from different organs have specific chromosomal alterations in common, we compared genome-wide chromosomal profiles of 10 CxSCCs (all hrHPV-positive) with 12 hrHPV-positive HNSCCs and 30 hrHPV-negative HNSCCs. Potential organ-specific alterations and alterations shared by SCCs in general were investigated as well. Unsupervised hierarchical clustering resulted in one mainly hrHPV-positive and one mainly hrHPV-negative cluster. Interestingly, loss at 13q and gain at 20q were frequent in HPV-positive carcinomas of both origins, but uncommon in hrHPV-negative HNSCCs, indicating that these alterations are associated with hrHPV-mediated carcinogenesis. Within the group of hrHPV-positive carcinomas, HNSCCs more frequently showed gains of multiple regions at 8q whereas CxSCCs more often showed loss at 17p. Finally, gains at 3q24-29 and losses at 11q22.3-25 were frequent (>50%) in all sample groups. In this study hrHPV-specific, organ-specific, and pan-SCC chromosomal alterations were identified. The existence of hrHPV-specific alterations in SCCs of different anatomical origin, suggests that these alterations are crucial for hrHPV-mediated carcinogenesis.
    BMC Medical Genomics 06/2009; 2:32. DOI:10.1186/1755-8794-2-32 · 3.91 Impact Factor