Prevalence and significance of M541L single nucleotide polymorphism in the central European cohort of gastrointestinal stromal tumor patients.

BACKGROUND: Single nucleotide polymorphisms can create a genetic microenvironment in some tumors that affects the course of treatment, resistance, etc. Whether single nucleotide polymorphisms have an impact on gastrointestinal stromal tumor (GIST) development and disease progression is not yet accurately verified. KIT SNPM541L in exon 10 correlates with a worse prognosis of many cancers. The impact of KIT SNPM541L in GISTs is relatively unknown and, therefore, its analyses could have potential in patient therapy and could provide more detailed information on tumor character, clinical presentation, or tumor behavior in treatment. AIM: The aim of the study was the analysis of the biological and clinical significance of the KIT SNPM541L polymorphism in exon 10. MATERIALS AND METHODS: Paraffin sample tissues were obtained from the National GIST Register in Martin. Retrospective samples from 177 GIST patients were divided into several groups. Detection of SNPM541L was performed by Sanger sequencing. Statisitical analyses were performed to determine the prevalence of KIT SNPM541L in the Slovak GIST cohort, to search for correlation between c-KIT status and clinicopathological, molecular and biological data. RESULTS: Overall, 29 samples out of 177 showed KIT SNPM541L polymorphism. CONCLUSION: Our results do not support the association between KIT SNPM541L and increased risk of relapse in localized primary GISTs. Additionally, we found a positive correlation between KIT SNPM541L occurrence and earlier onset of relapse in PDGFRa and WT subgroup of GISTs.

Rhus coriaria L. (Sumac) Demonstrates Oncostatic Activity in the Therapeutic and Preventive Model of Breast Carcinoma.

Comprehensive scientific data provide evidence that isolated phytochemicals or whole plant foods may beneficially modify carcinogenesis. The aim of this study was to evaluate the oncostatic activities of Rhus coriaria L. (sumac) using animal models (rat and mouse), and cell lines of breast carcinoma. R. coriaria (as a powder) was administered through the diet at two concentrations (low dose: 0.1% (w/w) and high dose: 1 % (w/w)) for the duration of the experiment in a syngeneic 4T1 mouse and chemically-induced rat mammary carcinoma models. After autopsy, histopathological and molecular analyses of tumor samples in rodents were performed. Moreover, in vitro analyses using MCF-7 and MDA-MB-231 cells were conducted. The dominant metabolites present in tested R. coriaria methanolic extract were glycosides of gallic acid (possible gallotannins). In the mouse model, R. coriaria at a higher dose (1%) significantly decreased tumor volume by 27% when compared to controls. In addition, treated tumors showed significant dose-dependent decrease in mitotic activity index by 36.5% and 51% in comparison with the control group. In the chemoprevention study using rats, R. coriaria at a higher dose significantly reduced the tumor incidence by 20% and in lower dose non-significantly reduced tumor frequency by 29% when compared to controls. Evaluations of the mechanism of oncostatic action using valid clinical markers demonstrated several positive alterations in rat tumor cells after the treatment with R. coriaria. In this regard, histopathological analysis of treated tumor specimens showed robust dose-dependent decrease in the ratio of high-/low-grade carcinomas by 66% and 73% compared to controls. In treated rat carcinomas, we found significant caspase-3, Bax, and Bax/Bcl-2 expression increases; on the other side, a significant down-regulation of Bcl-2, Ki67, CD24, ALDH1, and EpCam expressions and MDA levels. When compared to control specimens, evaluation of epigenetic alterations in rat tumor cells in vivo showed significant dose-dependent decrease in lysine methylation status of H3K4m3 and H3K9m3 and dose-dependent increase in lysine acetylation in H4K16ac levels (H4K20m3 was not changed) in treated groups. However, only in lower dose of sumac were significant decreases in the expression of oncogenic miR210 and increase of tumor-suppressive miR145 (miR21, miR22, and miR155 were not changed) observed. Finally, only in lower sumac dose, significant decreases in methylation status of three out of five gene promoters-ATM, PTEN, and TIMP3 (PITX2 and RASSF1 promoters were not changed). In vitro evaluations using methanolic extract of R. coriaria showed significant anticancer efficacy in MCF-7 and MDA-MB-231 cells (using Resazurin, cell cycle, annexin V/PI, caspase-3/7, Bcl-2, PARP, and mitochondrial membrane potential analyses). In conclusion, sumac demonstrated significant oncostatic activities in rodent models of breast carcinoma that were validated by mechanistic studies in vivo and in vitro.

Monosomy 3 Influences Epithelial-Mesenchymal Transition Gene Expression in Uveal Melanoma Patients; Consequences for Liquid Biopsy.

Despite outstanding advances in diagnosis and the treatment of primary uveal melanoma (UM), nearly 50% of UM patients develop metastases via hematogenous dissemination, driven by the epithelial-mesenchymal transition (EMT). Despite the failure in UM to date, a liquid biopsy may offer a feasible non-invasive approach for monitoring metastatic disease progression and addressing protracted dormancy. To detect circulating tumor cells (CTCs) in UM patients, we evaluated the mRNA expression of EMT-associated transcription factors in CD45-depleted blood fraction, using qRT-PCR. ddPCR was employed to assess UM-specific GNA11, GNAQ, PLCß4, and CYSLTR2 mutations in plasma DNA. Moreover, microarray analysis was performed on total RNA isolated from tumor tissues to estimate the prognostic value of EMT-associated gene expression. In total, 42 primary UM and 11 metastatic patients were enrolled. All CD45-depleted samples were negative for CTC when compared to the peripheral blood fraction of 60 healthy controls. Tumor-specific mutations were detected in the plasma of 21.4% patients, merely, in 9.4% of primary UM, while 54.5% in metastatic patients. Unsupervised hierarchical clustering of differentially expressed EMT genes showed significant differences between monosomy 3 and disomy 3 tumors. Newly identified genes can serve as non-invasive prognostic biomarkers that can support therapeutic decisions.

BRAF mutations in KIT/PDGFRA positive gastrointestinal stromal tumours (GISTs): Is their frequency underestimated?

BRAF V600E mutations in GISTs are considered to be one of the mutational events in KIT/PDGFRA negative or positive GISTs, respectively. BRAF mutated GISTs usually do not respond to imatinib treatment, even more GISTs with imatinib sensitive KIT mutation. However, they are almost phenotypically and morphologically identical with KIT/PDGFRA positive GISTs. In general, due to the small number of BRAF mutations in GIST and because of the rarity of concomitant BRAF/KIT or BRAF/PDGFRA mutations, their frequency may be depreciated. The aim of this study was BRAF mutation detection in KIT/PDGFRA positive GISTs and their verification by other molecular methods. We applied the sensitive droplet digital PCR on 35 randomly selected KIT/PDGFRA positive GISTs to detect V600E mutations. We have established two criteria for the evaluation of samples: false positive rate (FPR) based on the negative controls; Limit of Detection (LoD) based on the serial dilution of positive control from RKO cell line harboring heterozygous V600E mutation in constant wild-type DNA background. Results from ddPCR were verified by other molecular methods: allele-specific PCR, dideoxysequencing, competitive allele-specific TaqMan PCR (castPCR). FPR was determined as 5 (∼4.4) positive droplets, and LoD was assessed to 3.4293 copies/µL what is the method sensitivity of 0.0162 %. We identified eight KIT/PDGFRA positive patients with concomitant V600E mutation. The five of them were in coexistence with KIT mutation and three with PDGFRA mutation. We also included the liver metastasis, but data from primary tumour were not available. We achieved the very high sensitivity of the ddPCR method for detecting BRAF mutation in GISTs to have importance from the point of view of therapy.

Chemopreventive and Therapeutic Efficacy of Cinnamomum zeylanicum L. Bark in Experimental Breast Carcinoma: Mechanistic In Vivo and In Vitro Analyses.

Comprehensive oncology research suggests an important role of phytochemicals or whole plant foods in the modulation of signaling pathways associated with anticancer action. The goal of this study is to assess the anticancer activities of Cinnamomum zeylanicum L. using rat, mouse, and cell line breast carcinoma models. C. zeylanicum (as bark powder) was administered in the diet at two concentrations of 0.1% (w/w) and 1% (w/w) during the whole experiment in chemically induced rat mammary carcinomas and a syngeneic 4T1 mouse model. After autopsy, histopathological and molecular evaluations of mammary gland tumors in rodents were carried out. Moreover, in vitro analyses using MCF-7 and MDA-MB-231 cells were performed. The dominant metabolites present in the tested C. zeylanicum essential oil (with relative content over 1%) were cinnamaldehyde, cinnamaldehyde dimethyl acetal, cinnamyl acetate, eugenol, linalool, eucalyptol, limonene, o-cymol, and α-terpineol. The natural mixture of mentioned molecules demonstrated significant anticancer effects in our study. In the mouse model, C. zeylanicum at a higher dose (1%) significantly decreased tumor volume by 44% when compared to controls. In addition, treated tumors showed a significant dose-dependent decrease in mitotic activity index by 29% (0.1%) and 45.5% (1%) in comparison with the control group. In rats, C. zeylanicum in both doses significantly reduced the tumor incidence by 15.5% and non-significantly suppressed tumor frequency by more than 30% when compared to controls. An evaluation of the mechanism of anticancer action using valid oncological markers showed several positive changes after treatment with C. zeylanicum. Histopathological analysis of treated rat tumor specimens showed a significant decrease in the ratio of high-/low-grade carcinomas compared to controls. In treated rat carcinomas, we found caspase-3 and Bax expression increase. On the other hand, we observed a decrease in Bcl-2, Ki67, VEGF, and CD24 expressions and MDA levels. Assessment of epigenetic changes in rat tumor cells in vivo showed a significant decrease in lysine methylation status of H3K4m3 and H3K9m3 in the high-dose treated group, a dose-dependent increase in H4K16ac levels (H4K20m3 was not changed), down-regulations of miR21 and miR155 in low-dose cinnamon groups (miR22 and miR34a were not modulated), and significant reduction of the methylation status of two out of five gene promoters-ATM and TIMP3 (PITX2, RASSF1, PTEN promoters were not changed). In vitro study confirmed results of animal studies, in that the essential oil of C. zeylanicum displayed significant anticancer efficacy in MCF-7 and MDA-MB-231 cells (using MTS, BrdU, cell cycle, annexin V/PI, caspase-3/7, Bcl-2, PARP, and mitochondrial membrane potential analyses). As a conclusion, C. zeylanicum L. showed chemopreventive and therapeutic activities in animal breast carcinoma models that were also significantly confirmed by mechanistic evaluations in vitro and in vivo.

DNA Methylation Status in Cancer Disease: Modulations by Plant-Derived Natural Compounds and Dietary Interventions.

The modulation of the activity of DNA methyltransferases (DNMTs) represents a crucial epigenetic mechanism affecting gene expressions or DNA repair mechanisms in the cells. Aberrant modifications in the function of DNMTs are a fundamental event and part of the pathogenesis of human cancer. Phytochemicals, which are biosynthesized in plants in the form of secondary metabolites, represent an important source of biomolecules with pleiotropic effects and thus provide a wide range of possible clinical applications. It is well documented that phytochemicals demonstrate significant anticancer properties, and in this regard, rapid development within preclinical research is encouraging. Phytochemicals affect several epigenetic molecular mechanisms, including DNA methylation patterns such as the hypermethylation of tumor-suppressor genes and the global hypomethylation of oncogenes, that are specific cellular signs of cancer development and progression. This review will focus on the latest achievements in using plant-derived compounds and plant-based diets targeting epigenetic regulators and modulators of gene transcription in preclinical and clinical research in order to generate novel anticancer drugs as sensitizers for conventional therapy or compounds suitable for the chemoprevention clinical setting in at-risk individuals. In conclusion, indisputable anticancer activities of dietary phytochemicals linked with proper regulation of DNA methylation status have been described. However, precisely designed and well-controlled clinical studies are needed to confirm their beneficial epigenetic effects after long-term consumption in humans.

Mutation analysis of POLE gene in patients with early-onset colorectal cancer revealed a rare silent variant within the endonuclease domain with potential effect on splicing.

The colorectal cancer harbor germline, somatic or epimutations in mismatch repair genes, MUTYH or POLE gene, which lead to the hypermutated and ultramutator phenotypes with increased immune response. The mutations in POLE gene were reported to occur more frequently in early-onset colorectal cancer (EOCRC), and the patients are strong candidates for checkpoint inhibitor therapy. Here, we report mutation analysis within the endonuclease domain of the POLE gene in the cohort of patients with EOCRC in order to identify recurrent or new mutations and evaluate their association with the presence of tumor-infiltrating lymphocytes (TILs) and peritumoral lymphoid reaction. We have shown a significant association between MSI tumors and TILs (p = 0.004). Using sensitive single-tube nested PCR with subsequent Sanger sequencing, we have found in one female patient diagnosed at age 48 with rectal adenocarcinoma with mucinous elements staged pT3pN2pM1 a silent variant within the exon 9 NM_006231.3 c.849 C > T, NP_00622.2 p.Leu283 = recorded in dSNP as rs1232888774 with MAF = 0.00002. In silico prediction, result showed possible involvement into splicing; therefore, this rare variant can be involved into EOCRC pathogenesis. In the time of precise medicine, it is important to develop screening strategies also for less common conditions such as EOCRC allowing to predict tailored therapy for younger patients suffering from CRC that harbor mutations in the POLE gene.

Anticancer Activities of Thymus vulgaris L. in Experimental Breast Carcinoma in Vivo and in Vitro.

Naturally-occurring mixtures of phytochemicals present in plant foods are proposed to possess tumor-suppressive activities. In this work, we aimed to evaluate the antitumor effects of Thymus vulgaris L. in in vivo and in vitro mammary carcinoma models. Dried T. vulgaris (as haulm) was continuously administered at two concentrations of 0.1% and 1% in the diet in a chemically-induced rat mammary carcinomas model and a syngeneic 4T1 mouse model. After autopsy, histopathological and molecular analyses of rodent mammary carcinomas were performed. In addition, in vitro evaluations using MCF-7 and MDA-MB-231 cells were carried out. In mice, T. vulgaris at both doses reduced the volume of 4T1 tumors by 85% (0.1%) and 84% (1%) compared to the control, respectively. Moreover, treated tumors showed a substantial decrease in necrosis/tumor area ratio and mitotic activity index. In the rat model, T. vulgaris (1%) decreased the tumor frequency by 53% compared to the control. Analysis of the mechanisms of anticancer action included well-described and validated diagnostic and prognostic markers that are used in both clinical approach and preclinical research. In this regard, the analyses of treated rat carcinoma cells showed a CD44 and ALDH1A1 expression decrease and Bax expression increase. Malondialdehyde (MDA) levels and VEGFR-2 expression were decreased in rat carcinomas in both the T. vulgaris treated groups. Regarding the evaluations of epigenetic changes in rat tumors, we found a decrease in the lysine methylation status of H3K4me3 in both treated groups (H3K9m3, H4K20m3, and H4K16ac were not changed); up-regulations of miR22, miR34a, and miR210 expressions (only at higher doses); and significant reductions in the methylation status of four gene promoters-ATM serin/threonine kinase, also known as the NPAT gene (ATM); Ras-association domain family 1, isoform A (RASSF1); phosphatase and tensin homolog (PTEN); and tissue inhibitor of metalloproteinase-3 (TIMP3) (the paired-like homeodomain transcription factor (PITX2) promoter was not changed). In vitro study revealed the antiproliferative and proapoptotic effects of essential oils of T. vulgaris in MCF-7 and MDA-MB-231 cells (analyses of 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) (MTS); 5-bromo-20-deoxyuridine (BrdU); cell cycle; annexin V/PI; caspase-3/7; Bcl-2; PARP; and mitochondrial membrane potential). T. vulgaris L. demonstrated significant chemopreventive and therapeutic activities against experimental breast carcinoma.

Stratification of patients with colorectal cancer without the recorded family history.

Colorectal cancer (CRC) is a multifactorial disease and one of the most malignant tumours. In addition to the sporadic form, familial occurrences, particularly hereditary non-polyposis CRC-Lynch syndrome (LS)-are often observed. LS is caused by a germline mutation in mismatch repair (MMR) genes, whose task it is to correct errors in the DNA structure that result from its replication. The aim of the present study was to stratify CRC patients using molecular diagnostics and next generation sequencing, according to the chosen criteria [positive for microsatellite instability (MSI) and negative for a BRAF mutation and MutL homolog 1 (MLH1) methylation], and subsequently to detect pathological germline mutations in MMR genes in Slovak patients. To exclude patients with MSI from further testing, the present study detected the BRAF V600E mutation and examined MLH1 methylation status. From the 300 CRC patients, 37 cases with MSI were identified. In the MSI-positive samples, 13 cases of BRAF V600E mutation were recorded. In 24 BRAF-negative patients, 11 cases of epigenetic methylation of MLH1 and 12 cases without MLH1 methylation suspected for LS were detected, and it was not possible to analyse the methylation phenotype of 1 sample. Thus, the present study reports the novel deletion of four nucleotides, 1627_1630del AAAG (Glu544Lysfs*26) in MSH6, probably associated with LS. A second case with a nonsense mutation in MSH was also detected, namely MMR_c.1030C>T (p.Q344X).

Droplet digital PCR revealed high concordance between primary tumors and lymph node metastases in multiplex screening of KRAS mutations in colorectal cancer.

The proto-oncogene KRAS belongs among the most frequently mutated genes in all types of cancer and is also very important oncogene related to colorectal tumors. The detection of mutations in this gene in primary tumor is a predictive biomarker for the anti-EGFR therapy in metastatic CRC (mCRC); however, the patients with wild-type KRAS can also show resistance to the personalized medicine. The droplet-based digital PCR technology has improved the analytical sensitivity of the mutations detection, which led us to the idea about the optimization of this approach for KRAS testing. In this study, we report the application of ddPCR technology in order to analyze the presence of KRAS mutations in primary tumor and matched metastasis in lymph nodes (LNs) from patients with mCRC and address the question, whether the improvement in the detection method can lower the discrepancies of KRAS mutations detection between the primary tumor and regional LNs. Genomic DNA with wtKRAS and commercial DNA with mtKRAS (G12D) were used to set up the ddPCR reaction. Formalin-fixed paraffin-embedded tissues from primary tumor and positive lymph node from 31 patients with mCRC were analyzed using ddPCR and Sanger sequencing. KRAS status of primary tumors was known; however, the mutation status of lymph nodes was not detected previously. From 31 samples of primary tumors, our results corresponded to results from IVD kit in 30 cases. For one patient, ddPCR detected KRAS mutation in comparison with negative result of the IVD kit. In the samples of metastatic infiltrated LNs, ddPCR detected 16 samples as a WT KRAS and 15 lymph nodes showed positivity for KRAS mutation, whereby Sanger sequencing found KRAS mutations in 8 cases only. We also found two cases where genetic conditions of KRAS gene differed between primary tumor and infiltrated lymph node, both "low-grade" adenocarcinoma. Our study approved that ddPCR method is adequate technique with high sensitivity and in the future may be used as a diagnostic tool for evaluation of KRAS mutations, especially in infiltrated LNs of patients with mCRC.

Methylation of the first exon in the erythropoietin receptor gene does not correlate with its mRNA and protein level in cancer cells.

BACKGROUND: Erythropoietin receptor (EPOR) is a functional membrane-bound cytokine receptor. Erythropoietin (EPO) represents an important hematopoietic factor for production, maturation and differentiation of erythroid progenitors. In non-hematopoietic tissue, EPO/EPOR signalization could also play cytoprotective and anti-apoptotic role. Several studies identified pro-stimulating EPO/EPOR effects in tumor cells; however, numerous studies opposed this fact due to the usage of unspecific EPOR antibodies and thus potential absence or very low levels of EPOR in tumor cells. It seems that this problem is more complex and therefore we have decided to focus on EPOR expression at several levels such as the role of methylation in the regulation of EPOR expression, identification of possible EPOR transcripts and the presence of EPOR protein in selected tumor cells. METHODS: Methylation status was analysed by bisulfite conversion reaction, PCR and sequencing. The expression of EPOR was monitored by quantitative RT-PCR and western blot analysis. RESULTS: In this study we investigated the methylation status of exon 1 of EPOR gene in selected human cancer cell lines. Our results indicated that CpGs methylation in exon 1 do not play a significant role in the regulation of EPOR transcription. However, methylation status of EPOR exon 1 was cell type dependent. We also observed the existence of two EPOR splice variants in human ovarian adenocarcinoma cell line - A2780 and confirmed the expression of EPOR protein in these cells using specific A82 anti-EPOR antibody. CONCLUSION: We outlined the methylation status of all selected cancer cell lines in exon 1 of EPOR gene and these results could benefit future investigations. Moreover, A82 antibody confirmed our previous results demonstrating the presence of functional EPOR in human ovarian adenocarcinoma A2780 cells.

Droplet digital PCR for detection of BRAF V600E mutation in formalin-fixed, paraffin-embedded melanoma tissues: a comparison with Cobas® 4800, Sanger sequencing, and allele-specific PCR.

Cutaneous melanoma has the worst prognosis of all skin cancers. Although emerging targeted therapies, such as B-Raf kinase inhibitor vemurafenib, improve prognosis they require an accurate and sensitive means of detecting the pathogenic BRAF V600E mutation. We compared the sensitivity of four BRAF V600E detection methods in formalin-fixed, paraffin-embedded melanoma biopsies from 87 consecutive melanoma patients with Breslow stage I-V disease (staging based on the depth of tumor of invasion). The methods assessed were the widely used Cobas® 4800 system based on real-time PCR amplification, Sanger sequencing, allele-specific PCR (AS-PCR), and droplet digital PCR (ddPCR). The BRAF V600E mutation was found in 8 (9.2%), 23 (26.4%), 23 (26.4%) and 31 (35.6%) biopsies, respectively. The limit of detection (LoD) was determined by three different methods: Poisson confidence limits, calibration regression and Tzonev's method. Pair-wise agreement between the methods was as follows: Cobas vs. Sanger, P = 0.33; Cobas® 4800 vs. AS-PCR, P = 0.33; Cobas® 4800 vs. ddPCR, P = 0.65; Sanger vs. AS-PCR, P = 1; Sanger vs. ddPCR, P = 0.08; AS-PCR vs. ddPCR, P = 0.06. Multinomial logistic regression was used for predictive modeling of the Breslow-Clark score; ddPCR emerged as the best predictor, the other predictors were mitotic activity, type of malignant melanoma and patient's age. Our results demonstrate that ddPCR is the most sensitive method of detecting the BRAF V600E mutation.

Detection of mutations in the BRAF gene in patients with KIT and PDGFRA wild-type gastrointestinal stromal tumors.

Gastrointestinal stromal tumors (GISTs) are characterized by mutations in exons 9, 11, 13, and 17 of KIT or exons 12, 14, and 18 of PDGFRA gene. However, approximately 10 to 15 % of GISTs lack the mutations in KIT and PDGFRA, and these are referred to as wild-type GISTs which are less sensitive to tyrosine-kinase inhibitors. The aim of this study was to detect BRAF mutations in patients with wild-type GISTs. We applied a sensitive allele-specific PCR, which was optimized using the V600E mutation-harboring cell line RKO, followed by verification of the results by dideoxy sequencing. We selected 149 GIST patients without detectable mutations in KIT and PDGFRA genes from the Slovak national GIST register and analyzed biopsy specimens for the presence of BRAF mutations in exon 15. We identified nine patients with the V600E mutation. The BRAF-driven GISTs were primary gastric (n = 3), small intestinal (n = 3), colon (n = 1), and of uncertain origin (n = 1). We also included a liver metastasis of a patient with a simultaneous KIT exon 11-mutated intra-abdominal metastasis. We conclude that genome analysis of wild-type GISTs for mutations should include the BRAF gene, as its mutation status contributes to understanding of pathogenesis and might be important for decisions on therapy.

Methylation pattern of CDH1 promoter and its association with CDH1 gene expression in cytological cervical specimens.

Cervical cancer is the fourth leading cause of cancer mortality in females worldwide. Infection with high-risk human papillomavirus (HPV) is essential but insufficient to cause cervical cancer, and the clearance of HPV infection is mediated by the immune system. The deficit of molecules responsible for adhesion may play a role in the development of cervical cancer. E-cadherin is encoded by the cadherin 1 (CDH1) gene, and is involved in cell adhesion by forming adherens junctions. The aim of present study was to investigate the methylation pattern of the CDH1 promoter and to identify the association between CDH1 promoter hypermethylation, CDH1 gene expression and HPV infection in cervical specimens obtained from 93 patients with low-grade squamous intraepithelial lesions (SILs), high-grade SILs or squamous cell carcinomas, and from 47 patients with normal cervical cytology (HPV-negative). The methylation pattern of the CDH1 promoter was investigated by methylation-specific polymerase chain reaction and quantitative pyrosequencing. CDH1 gene expression was measured by relative quantification. CDH1 methylation was significantly higher in both types of lesions and in cervical cancer than in normal samples, and CDH1 gene expression was significantly reduced during SIL progression (P=0.0162). However, the influence of HPV infection or HPV E6 expression on the methylation pattern of the CDH1 gene or its gene expression levels could not be confirmed. The present results support that the methylation of the CDH1 gene is age-related in patients with cervical lesions (P=0.01085), and therefore, older patients could be more susceptible to cancer than younger patients. The important methylation of the CDH1 promoter occurred near the transcription factor binding sites on nucleotides -13 and +103, which are close to the translational start codon. These results suggest that methylation at these sites may be an important event in the transcriptional regulation of E-cadherin, and in patients harboring these methylated cytosines, this event may facilitate HPV-driven carcinogenesis.