Quantitative analysis of methylation status of the PAX1 gene for detection of cervical cancer

Downregulation of PAX1 in OSCC Enhances Stemness and Immunosuppression via IFIT1 and PD-L1 Pathways

OBJECTIVE

Our study investigated how arecoline-induced extracellular vesicle (EV) secretion suppresses PAX1 protein production through DNA hypermethylation and examined whether PAX1 downregulation enhances cancer stemness and immunosuppression in the tumor microenvironment.

MATERIALS AND METHODS

EVs were isolated from SAS/TW2.6 cancer cell lines using ultracentrifugation and identified using transmission electron microscopy. PAX1 DNA methylation was tested in an ISO17025-certified lab, with and without EV pretreatment. Stemness and epithelial-mesenchymal transition markers were assessed by western blotting and 3D culture. PAX1, IFIT1, and PD-L1 co-expression were examined through immunofluorescence. Flow cytometry detected various T cells.

RESULTS

Arecoline-induced EVs enhanced PAX1 methylation, suppressing its tumor-suppressive function. Reduced PAX1 mRNA in OSCCs was linked to larger tumors, nodal metastasis, late-stage disease, areca quid chewing, and poor survival. Downregulated PAX1 protein negatively correlated with IFIT1 and PD-L1 expression. Reduced PAX1 promoted stemness via the IFIT1 pathway, increasing PD-L1 secretion and aiding immune evasion. PD-L1 expression correlated with Treg and CD8+ T cell levels in OSCC tissues, and the CD4+/CD8+ T cell ratio was lower in OSCC patients than in controls.

CONCLUSION

Arecoline-induced EV production, which influences PAX1/IFIT1/PD-L1 function, may serve as a reliable biomarker for targeted therapy in OSCC patients.

Evaluating PAX1/JAM3 methylation for triage in HPV 16/18-infected women

OBJECTIVE

Referring all women who tested positive for human papillomavirus (HPV) 16/18 to colposcopy may lead to potential over-referral issues. Triage tests based on cytology results face challenges in achieving accurate diagnoses. Our study aims to assess the clinical effectiveness of PAX1/JAM3 methylation (CISCER) test as a triage method for HPV 16/18-positive women.

METHODS

From November 2021 to December 2022, a total of 334 women who tested positive for HPV 16/18 and were referred to colposcopy at The Second Affiliated Hospital of Zhejiang University School of Medicine were studied. The clinical utility of the CISCER test, cytology, and the combination of CISCER with cytology as potential triage tests was compared.

RESULTS

We observed a significant increase in the methylation levels of PAX1 gene and JAM3 gene in women with cervical intraepithelial neoplasia (CIN) grade 2 or severe (CIN2+). The CISCER test demonstrated superior triage performance over cytology, even when used in combination with cytology, showing a high sensitivity of 89.0% (95% confidence interval [CI] 82.9-95.1%) and specificity of 95.3% (95% CI 92.6-98.0%). It achieved an area under the curve of 0.921 (95% CI 0.877-0.966) and an odds ratio of 164.02 (95% CI 68.64-391.95). The immediate CIN2+ risk based on positive CISCER results would be 89.0% (95% CI 80.8-94.1%), with an estimated average of 1.12 referrals needed to detect one CIN2+ case. Moreover, CISCER triaging successfully identified all cancer patients and did not miss any CIN3+ cases among women aged ≥ 30.

CONCLUSIONS

The PAX1/JAM3 methylation detection exhibited excellent accuracy in identifying cervical precancerous lesions in HPV 16/18-positive women and could be considered as a triage tool to reduce excessive referrals for colposcopy and overtreatment.

Clinical indications for host-cell DNA methylation markers in cervical screening and management of cervical intraepithelial neoplasia: A review

DNA methylation of host-cell genes is an epigenetic process that regulates gene expression and is associated with cervical cancer development. Studies on the natural history of cervical intraepithelial neoplasia (CIN) and the molecular alterations associated with cervical carcinogenesis led to the identification of several host-cell DNA methylation markers. Over the past years, various studies on methylation markers have shown promising results in terms of diagnostic and prognostic value to improve cervical cancer screening and management of CIN. This review provides an overview of the clinical indications of host-cell DNA methylation markers in cervical screening and management of CIN, and outlines avenues for further applications.

A dual-gene panel of two fragments of methylated IRF4 and one of ZEB2 in plasma cell-free DNA for gastric cancer detection

Early detection is crucial for increasing the survival rate of gastric cancer (GC). We aimed to identify a methylated cell-free DNA (cfDNA) marker panel for detecting GC. The differentially methylated CpGs (DMCs) were selected from datasets of The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. The selected DMCs were validated and further selected in tissue samples (40 gastric cancer and 36 healthy white blood cell samples) and in a quarter sample volume of plasma samples (37 gastric cancer, 12 benign gastric disease, and 43 healthy individuals). The marker combination selected was then evaluated in a normal sample volume of plasma samples (35 gastric cancer, 39 control diseases, and 40 healthy individuals) using real-time methylation-specific PCR (MSP). The analysis of the results compared methods based on 2-ΔΔCt values and Ct values. In the results, 30 DMCs were selected through bioinformatics methods, and then 5 were selected for biological validation. The marker combination of two fragments of IRF4 (IRF4-1 and IRF4-2) and one of ZEB2 was selected due to its good performance. The Ct-based method was selected for its good results and practical advantages. The assay, IRF4-1 and IRF4-2 in one fluorescence channel and ZEB2 in another, obtained 74.3% sensitivity for the GC group at any stage, at 92.4% specificity. In conclusion, the panel of IRF4 and ZEB2 in plasma cfDNA demonstrates good diagnostic performance and application potential in clinical settings.

Cervical cancer screening: efficacy of PAX1 and JAM3 methylation assay in the triage of atypical squamous cell of undetermined significance (ASC-US)

BACKGROUND

Atypical squamous cells of undetermined significance (ASC-US) often present diagnostic challenges with cytology-based results, leading to potential underdiagnosis or overdiagnosis. An effective triage method is essential for managing these cases to reduce unnecessary referrals and treatment.

METHODS

A total of 322 women diagnosed with ASC-US were tested for HPV-DNA and the PAX1 and JAM3 methylation (PAX1m/JAM3m) test in the study.

RESULTS

Methylation levels of PAX1 and JAM3 were significantly elevated in cervical lesions classified as CIN2 or more severe lesions (CIN2+). The methylation assay demonstrated a sensitivity of 83.8% and a specificity of 95.8%, outperforming HPV-DNA testing in differentiating high-grade cervical lesions among women with ASC-US. Moreover, PAX1m/JAM3m testing significantly reduced the colposcopy referral rate for further diagnostic procedures in high-risk HPV-positive women by 79.5%.

CONCLUSIONS

PAX1m/JAM3m testing shows promise as a reliable supplemental method to HPV-DNA testing for the triage of women with cytologic ASC-US. In addition, the molecular triage based on the CISCER assay or single PAX1 or JAM3 methylation, had better effects in the women with non-HPV16/18 group. This approach could potentially minimize overtreatment and unnecessary referrals in clinical practice, enhancing patient management and resource utilization.

SEPT9, H4C6, and RASSF1A methylation in nasopharyngeal swabs: A reflection of potential minimally invasive biomarkers for early screening of nasopharyngeal cancer

The potential value of epigenetic DNA methylation in early cancer screening has been demonstrated. Therefore, in this study, we performed QMS-PCR and quantitative reverse transcription PCR on the genes RASSF1A, H4C6, SEPT9, GSTP1, PAX1, SHOX2, and SOX2, which are common in epithelial cancers. We found hypermethylation in RASSF1A, H4C6 and SEPT9. The mRNA expressions of RASSF1A, H4C6 and SEPT9 in tumor group were significantly different from those in the inflammatory group and healthy group (P < .05). Receiver operating characteristic (ROC) analysis showed that the area under the curve (AUC) of RASSF1A, H4C6 and SEPT9 genes were 0.831, 0.856 and 0.767, respectively. The areas under the AUC curve of SEPT9 + H4C6, SEPT9 + RASSF1A and H4C6 + RASSF1A are 0.946, 0.912 and 0.851, respectively. The diagnostic ability of dual gene combination is better than that of single gene combination, among which SEPT9 and H4C6 combination has the best diagnostic effect. In conclusion, our findings suggest that H4C6, RASSF1A, and SEPT9 methylation occur more frequently in nasopharyngeal carcinoma, and their detection in nasopharyngeal swabs may be a minimally invasive tool for diagnosis of nasopharyngeal carcinoma.

The Role of p16/Ki67 Dual Staining in Cervical Cancer Screening

Cervical cancer screening has enabled a decrease in the incidence and mortality of cervical cancer. Various screening modalities have been studied to date. In many countries, screening is still based on cervical cytology, where cervical cells obtained either on glass or in a liquid medium are examined under a microscope. However, the fact that the vast majority of cervical cancers are a result of persistent infection with high-risk human papillomaviruses (hr-HPV) has led to the implementation of primary HPV screening in many countries. Taking into consideration the fact that the majority of HPV infections are transient and do not cause cervical precancer, effective triage methods are needed to prevent an increase in colposcopy referrals. Among these, the most extensively investigated are HPV genotyping, HPV methylation, and p16/Ki67 dual staining. In this manuscript, we briefly summarize the current knowledge regarding different screening strategies for the prevention of cervical cancer, with a focus on p16/Ki67 dual staining. In addition, we provide an explanation regarding the rationale for the use of various screening modalities based on the molecular biology of cervical cancer and cervical precancerous lesions.

Utilization of PAX1 methylation test for cervical cancer screening of non-HPV16/18 high-risk HPV infection in women

Aim: To evaluate the clinical performance of PAX1 methylation (PAX1m) and cytology for patients with non-HPV16/18 high-risk HPV (hrHPV) infection. Methods: Cervical exfoliated cells from 387 outpatients with non-HPV16/18 hrHPV - positive were collected for cytology and PAX1m assays. Results: The PAX1m level increased with the severity of cytology and histopathology. For cervical intraepithelial neoplasia (CIN)CIN2+/CIN3+, the areas under the curve were both 0.87. The specificity and positive predictive value (PPV) of PAX1m were greater than abnormal cytology (CIN2+ specificity: 75.5 vs 24.8%; PPV: 38.8 vs 18.7%; CIN3+ specificity: 69.3 vs 22.7%; PPV: 14.0 vs 6.7%). Conclusion: PAX1m increased specificity and PPV for CIN2+/CIN3+ compared with cytology for women with non-HPV16/18 hrHPV (+).

Potential applications of DNA methylation testing technology in female tumors and screening methods

DNA methylation is a common epigenetic modification, and the current commonly used methods for DNA methylation detection include methylation-specific PCR, methylation-sensitive restriction endonuclease-PCR, and methylation-specific sequencing. DNA methylation plays an important role in genomic and epigenomic studies, and combining DNA methylation with other epigenetic modifications, such as histone modifications, may lead to better DNA methylation. DNA methylation also plays an important role in the development of disease, and analyzing changes in individual DNA methylation patterns can provide individualized diagnostic and therapeutic solutions. Liquid biopsy techniques are also increasingly well established in clinical practice and may provide new methods for early cancer screening. It is important to find new screening methods that are easy to perform, minimally invasive, patient-friendly, and affordable. DNA methylation mechanisms are thought to have an important role in cancer and have potential applications in the diagnosis and treatment of female tumors. This review discussed early detection targets and screening methods for common female tumors such as breast, ovarian, and cervical cancers and discussed advances in the study of DNA methylation in these tumors. Although existing screening, diagnostic, and treatment modalities exist, the high morbidity and mortality rates of these tumors remain challenging.

Epigenomic integrative analysis pinpoint master regulator transcription factors associated with tumorigenesis in squamous cell carcinoma of oral tongue

Head and Neck Cancer (HNC) is a heterogeneous group of cancers, which includes cancers arising in the oral cavity, nasopharynx, oropharynx, hypopharynx, and larynx. Epidemiological studies have revealed that several factors such as tobacco and alcohol use, exposure to environmental pollutants, viral infection, and genetic factors are risk factors for developing HNC. The squamous cell carcinoma of oral tongue (SCCOT), which is significantly more aggressive than the other forms of oral squamous cell carcinoma, presents a propensity for rapid local invasion and spread, and a high recurrence rate. Dysregulation in the epigenetic machinery of cancer cells might help uncover the mechanisms of SCOOT tumorigenesis. Here, we used DNA methylation changes to identify cancer-specific enhancers that were enriched for specific transcription factor binding sites (TFBS), and potential master regulator transcription factors (MRTF) associated with SCCOT. We identified the activation of MRTFs associated with increased invasiveness, metastasis, epithelial-to-mesenchymal transition, poor prognosis, and stemness. On the other hand, we found the downregulation of MRTFs associated with tumor suppression. The identified MRTFs should be further investigated to clarify their role in oral cancer tumorigenesis and for their potential use as biological markers.

The Role of Methylation of Host and/or Human Papillomavirus (HPV) DNA in Management of Cervical Intraepithelial Neoplasia Grade 2 (CIN2) Lesions

Cervical intraepithelial neoplasia grade 2 (CIN2) is an intermediate stage between CIN 1, which is a low-grade lesion, and CIN3, which is the immediate precursor of cervical cancer (CC). Traditionally, CIN2 was regarded as a high-grade lesion and was treated with conization or ablative methods. In recent years, there has been a shift in the management of younger patients, who are now more often being managed conservatively due to frequent spontaneous CIN2 regression and possible adverse effects of treatment on future pregnancies. Because the risk of progression to CC still exists with conservative management, a personalized approach is needed to identify patients with a higher probability of progression. In this regard, research has focused on the role of host and human papillomavirus (HPV) gene methylation. This systematic review summarizes the current knowledge regarding conservative CIN2 management focusing on the main methylation markers and its implementation in conservative CIN2 management, and it describes major ongoing longitudinal studies on the subject. The review showed that DNA methylation is an accurate predictor of disease progression and a valid triage tool for HPV-positive women, with CIN2 performing better than triage cytology. Because virtually all CCs are methylation-positive, methylation-negative women at baseline have an extremely low risk of CC.

PAX1 Methylation Status in Cervical Scrapes as Novel Diagnostic Biomarker in CIN 2/3 and Invasive Squamous Cell Carcinoma

Objectives

DNA methylation of paired box-1 (PAX-1) gene has been shown to be a potential biomarker for the detection of high-grade cervical intra-epithelial neoplasia (CIN) and invasive cervical cancer. The objective of this pilot study was to quantify and compare methylation percentage of PAX1 gene in benign cervical lesion, pre-invasive and invasive cervical cancer.

Methods

A total of 200 screen positive women (VIA, VILI and Pap test) underwent colposcopy. Cervical scrapes taken were taken and stored for DNA analysis and PAX 1 methylation status. Women with Swede score of 5 or more (n = 98) were biopsied. Cervical scrapes and biopsy were taken from women with obvious cervical growth (n = 14), without prior colposcopy. Sixty women were recruited to the study and allocated into three groups on the basis of histopathology, i.e., benign cervix (Group 1; n = 20), CIN 2/3 (Group 2; n = 20) and invasive cervical carcinoma (Group; n = 20). PAX 1 methylation percentage was calculated from the DNA extracted from the cervical scrapes of the women recruited.

Results

The mean PAX1 methylation percentage in benign lesions, CIN 2/3 and invasive cancer was 9.58% (SD ± 2.37%), 18.21% (SD ± 2.67%) and 24.34% (SD ± 4.09%), respectively, with p-value of < 0.001.

Conclusions

PAX 1 gene methylation has a promising role in identifying high-grade lesions and invasive cancer.

An overview of PAX1: Expression, function and regulation in development and diseases

Transcription factors play multifaceted roles in embryonic development and diseases. PAX1, a paired-box transcription factor, has been elucidated to play key roles in multiple tissues during embryonic development by extensive studies. Recently, an emerging role of PAX1 in cancers was clarified. Herein, we summarize the expression and functions of PAX1 in skeletal system and thymus development, as well as cancer biology and outline its cellular and molecular modes of action and the association of PAX1 mutation or dysregulation with human diseases, thus providing insights for the molecular basis of congenital diseases and cancers.

Methylated ZNF582 as a triage marker for occult cervical cancer and advanced cervical intraepithelial neoplasia

Aim: To explore the appropriate triage methods for women infected with high-risk human papillomavirus (hrHPV). Materials & methods: A total of 424 out of 872 hrHPV-infected women were divided into cervicitis (n = 123), cervical intraepithelial neoplasia grade 1 (CIN1; n = 89), CIN2 (n = 72), CIN3 (n = 87) and cervical cancer (n = 53) groups. Results: The sensitivity/specificity of ZNF582^m, PAX1^m and liquid-based cytology (LBC) for hrHPV-infected women with transformation zone 3 CIN3+ was 83.9/93.1, 77.4/90.6 and 80.6/58.5%, respectively. The ZNF582^m/PAX1^m test had a higher specificity than LBC (p < 0.001) and similar sensitivity to that observed for LBC (p > 0.05). ZNF582^m/PAX1^m improved the positive predictive value of CIN3+ (64.7/60.0%) in low-grade LBC (negative predictive value: 91.7/88.7%). Conclusion: ZNF582^m was superior to PAX1^m and LBC tests in detecting CIN3+ in hrHPV-infected women.

Aberrant Epigenetic Alteration of PAX1 Expression Contributes to Parathyroid Tumorigenesis

CONTEXT

Primary hyperparathyroidism (PHPT) results from the hypersecretion of parathyroid hormone from parathyroid tumors. A transcription factor, namely Paired box1 (PAX1), is active in parathyroid gland development.

OBJECTIVE

We aimed to study potential epigenetic-mediated mechanism of PAX1 gene in sporadic parathyroid adenomas.

METHODS

In parathyroid adenomas tissues, we analyzed the DNA methylation via bisulfite-specific polymerase chain reaction (BSP) and histone modifications via chromatin immunoprecipitation in regulating the differential expression of PAX1.

RESULTS

The results showed that mRNA and protein expression of PAX1 was significantly reduced in parathyroid adenomas. Bisulfite sequencing demonstrated hypermethylation in the promoter region of PAX1 (35%; 14/40) and lower levels of histone 3 lysine 9 acetylation (H3K9ac) were observed on the promoter region of PAX1 (6-fold; P < .004) in parathyroid adenomas. Furthermore, upon treatment with a pharmacologic inhibitor, namely 5'aza-2 deoxycytidine, in rat parathyroid continuous cells, we found re-expression of PAX1 gene.

CONCLUSION

Our study not only reveals expression of PAX1 is epigenetically deregulated but also paves a way for clinical and therapeutic implications in patients with PHPT.

The use of host cell DNA methylation analysis in the detection and management of women with advanced cervical intraepithelial neoplasia: a review

This paper briefly reviews the role of hypermethylation of host cell genes in cervical carcinogenesis and discusses potential clinical applications of methylation analysis in the management of high-risk HPV (hrHPV) -positive women. We argue that methylation assays can be used: 1. for primary triage of hrHPV-positive women to detect cervical cancer and advanced cervical intraepithelial neoplasia (CIN); 2. as secondary triage for women with minor cytological abnormalities to identify those with the highest risk of CIN3 or worse; 3. as exit test for women leaving the screening programme to identify cervical cancer and advanced CIN; and 4. to support management of CIN. TWEETABLE ABSTRACT: This paper discusses potential clinical applications of DNA methylation analysis in the management of women with a high-risk HPV infection.

The application value of PAX1 and ZNF582 gene methylation in high grade intraepithelial lesion and cervical cancer

PURPOSE

To investigate the possibility of using the methylation level of PAX1/ZNF582 gene as molecular marker to differentiate the progression of cervical cancer.

METHODS

From January 2016 to March 2018, 150 patients, who were admitted to Cervical Disease Diagnosis and Treatment Center of Xuzhu Maternity and Child Care Hospital, were enrolled in this study. Patients were classified into chronic cervicitis (for 19 cases), low-grade squamous intraepithelial lesion (LSIL) (18 cases), high-grade squamous intraepithelial lesion (HSIL) (37 cases) and squamous cell carcinoma (SCC) (31 cases). All patients underwent several tests including Thin-prep cytology test (TCT), HPV DNA detection and detection of methylation level of PAX1/ZNF582 genes.

RESULTS

For diagnosis of HSIL, the area under curve (AUC) was 0.878 (95% CI 0.806 ~ 0.950); the threshold for PAX1 was 12.285, the sensitivity and specificity were 91.9% and 72.8%, respectively. The AUC of ZNF582 gene detection was 0.900 (95% CI 0.842 ~ 0.959), the threshold was 11.56, while the sensitivity and specificity were 97.3% and 76.7%, respectively. Among various tests we conducted, PAX gene detection methods showed the highest specificity (97.30%). PAX1/ZNF582 gene detection method demonstrated the highest accuracy.

CONCLUSIONS

For patients with high-grade cervical lesion and cervical cancer, the methylation level of PAX1/ZNF582 gene could be applied as a noteworthy biomarker for diagnosis and for cervical cancer classification.

A Sensitive and Simplified Classifier of Cervical Lesions Based on a Methylation-Specific PCR Assay: A Chinese Cohort Study

Objective

The aim of this study is to assess the diagnostic and screening performance of a standardized methylation-specific real-time PCR assay targeting SOX1 and PAX1 genes for cervical cancer in a Chinese cohort.

Methods

Genomic DNA was extracted from cervical exfoliated cells and converted by sodium bisulfite and then analyzed by qMSP assay. Ct values were collected for PAX1 and SOX1 as target genes and β-actin as an endogenous reference gene. The samples included 295 cervicitis, 111 LSIL (low-grade squamous intraepithelial lesion), 51 HSIL (high-grade squamous intraepithelial lesion) and 30 cervical cancer.

Results

The Ct values decreased with the progression of cervical cancer from cervicitis, through LSIL and HSIL to cancer. The difference in Ct values between cytological grades was highly significant (p≤0.01) between grades either for PAX1 or for SOX1 except the difference between cervicitis and LSIL of SOX1. With the Ct cut-off values of PAX1 gene and SOX1 gene 38.6 and 38 and with the PAX1/SOX1 in combination, the positive rate of methylation in invasive cancer tissues was 100%, in contrast to 11.5% (95% CI: 8.67%–14.33%) in cervicitis tissues, 45.1% (95% CI: 40.68%–49.52%) in LSIL tissues, and 68.5% (95% CI: 64.37%–72.63%) in HSIL tissues. The specificity and sensitivity of differentiating tumors from cervicitis were 0.957 (95% CI: 0.939–0.975) and 1.00, respectively. The specificity and sensitivity of differentiation between cervicitis+LSIL and HSIL+cervical cancer were 0.881 (95% CI: 0.852–0.91) and 0.748 (95% CI: 0.709–0.787), respectively.

Conclusion

PAX1/SOX1 methylation could be translated into clinical practice for cervical neoplasia detection.

Association between dense PAX1 promoter methylation and HPV16 infection in cervical squamous epithelial neoplasms of Xin Jiang Uyghur and Han women

DNA methylation is an epigenetic alteration that may lead to carcinogenesis by silencing key tumor suppressor genes. Hypermethylation of the paired box gene 1 (PAX1) promoter is important in cervical cancer development. Here, PAX1 methylation levels were compared between Uyghur and Han patients with cervical lesions. Data on PAX1 methylation in different cervical lesions were obtained from the Gene Expression Omnibus (GEO) database, whereas data on survival and PAX1 mRNA expression in invasive cervical cancer (ICC) were retrieved from the Cancer Genome Atlas (TCGA) database. MassARRAY spectrometry was used to detect methylation of 19 CpG sites in the promoter region of PAX1, whereas gene mass spectrograms were drawn by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry. Human papillomavirus (HPV) 16 infection was detected by polymerase chain reaction. PAX1 methylation in high-grade squamous intraepithelial lesion (HSIL) and ICC was significantly higher than in normal tissues. PAX1 hypermethylation was associated with poor prognosis and reduced transcription. ICC-specific PAX1 promoter methylation involved distinct CpG sites in Uyghur and Han patients HPV16 infection in HSIL and ICC patient was significantly higher than in normal women (p < 0.05). Our study revealed a strong association between PAX1 methylation and the development of cervical cancer. Moreover, hypermethylation of distinct CpG sites may induce HSIL transformation into ICC in both Uyghur and Han patients. Our results suggest the existence of ethnic differences in the genetic susceptibility to cervical cancer. Finally, PAX1 methylation and HPV infection exhibited synergistic effects on cervical carcinogenesis.

Performance of DNA methylation assays for detection of high-grade cervical intraepithelial neoplasia (CIN2+): a systematic review and meta-analysis

Background

To conduct a meta-analysis of performance of DNA methylation in women with high-grade cervical intraepithelial neoplasia (CIN2+).

Methods

Medline and Embase databases were searched for studies of methylation markers versus histological endpoints. Pooled sensitivity, specificity and positive predictive value (PPV) for CIN2+ were derived from bivariate models. Relative sensitivity and specificity for CIN2+ compared to cytology and HPV16/18 genotyping were pooled using random-effects models.

Results

Sixteen thousand three hundred thirty-six women in 43 studies provided data on human genes (CADM1, MAL, MIR-124-2, FAM19A4, POU4F3, EPB41L3, PAX1, SOX1) and HPV16 (L1/L2). Most (81%) studies evaluated methylation assays following a high-risk (HR)-HPV-positive or abnormal cytology result. Pooled CIN2+ and CIN3+ prevalence was 36.7% and 21.5%. For a set specificity of 70%, methylation sensitivity for CIN2+ and CIN3+ were 68.6% (95% CI: 62.9–73.8) and 71.1% (95% CI: 65.7–76.0) and PPV were 53.4% (95% CI: 44.4–62.1) and 35.0% (95% CI: 28.9–41.6). Among HR-HPV+ women, the relative sensitivity of methylation for CIN2+ was 0.81 (95% CI: 0.63–1.04) and 1.22 (95% CI: 1.05–1.42) compared to cytology of atypical squamous cells of undetermined significance, or greater (ASCUS+) and HPV16/18 genotyping, respectively, while relative specificity was 1.25 (95% CI: 0.99–1.59) and 1.03 (95% CI: 0.94–1.13), respectively.

Conclusion

DNA methylation is significantly higher in CIN2+ and CIN3+ compared to ≤CIN1. As triage test, DNA methylation has higher specificity than cytology ASCUS+ and higher sensitivity than HPV16/18 genotyping.

Tumor-suppressor gene SOX1 is a methylation-specific expression gene in cervical adenocarcinoma

The present study is to analyze the difference of gene methylation in early cervical adenocarcinoma and to find molecular markers for predicting the occurrence and development of cervical adenocarcinoma.A total of 15 cases of primary cervical adenocarcinoma and 10 cases of primary cervical squamous cell carcinoma at stages IB1 or IIA1 were included in the study. Infinium MethylationEPIC BeadChip (850K) was used to screen specifically expressed genes in cervical adenocarcinoma tissues. Bisulfite sequencing polymerase chain reaction (BSP) and quantitative real-time polymerase chain reaction (qRT-PCR) were used to verify the methylation levels in cervical adenocarcinoma, cervical squamous cell carcinoma, and normal cervical tissues.Sex determining region Y-box 1 (SOX1) and cyclin D1 (CCND1) genes participated in multiple signaling pathways, being the central nodes of gene regulatory networks. SOX1 gene, but not CCND1 gene, was a specifically methylated gene in cervical adenocarcinoma according to BSP. According to qRT-PCR, methylation level of SOX1 in cervical adenocarcinoma tissues is significantly different from that in cervical squamous cell carcinoma tissues or normal cervical tissues, and the methylation level of CCND1 in cervical adenocarcinoma tissues or cervical squamous cell carcinoma tissues is significantly different from that in normal cervical tissues.The present study demonstrates that tumor-suppressor gene SOX1 is a methylation-specific expression gene of cervical adenocarcinoma and is expected to become a specific molecular marker for the diagnosis of cervical adenocarcinoma. However, CCND1 gene was not proven to be a specific methylation expression gene in cervical adenocarcinoma in the present study.

Paired Box-1 (PAX1) Activates Multiple Phosphatases and Inhibits Kinase Cascades in Cervical Cancer

DNA methylation alteration, such as global hypomethylation and localized hypermethylation, within the promoters of tumor suppressor genes, is an important risk factor in cervical cancer. The potential use of DNA methylation detection, in cervical cancer screening or triage of mildly abnormal cytology, has recently been demonstrated. In particular, PAX1 DNA methylation testing was approved as an adjunct to cytology, in Taiwan, and is now undergoing registration trials in China. However, the function of PAX1 in cancer biology remains largely unknown. Here, we show that PAX1 inhibits malignant phenotypes upon oncogenic stress. Specifically, PAX1 expression inhibited the phosphorylation of multiple kinases, after challenges with oncogenic growth factors such as EGF and IL-6. Analogously, PAX1 activated a panel of phosphatases, including DUSP1, 5, and 6, and inhibited EGF/MAPK signaling. PAX1 also interacted with SET1B, increasing histone H3K4 methylation and DNA demethylation of numerous phosphatase-encoding genes. Furthermore, hypermethylated PAX1 associated with poor prognosis in cervical cancer. Taken together, this study reveals, for the first time, the functional relevance of PAX1 in cancer biology, and further supports the prospect of targeting multifold oncogenic kinase cascades, which jointly contribute to multiresistance, via epigenetic reactivation of PAX1.

The promising role of PAX1 (aliases: HUP48, OFC2) gene methylation in cancer screening

Background

Paired‐box gene 1 (PAX1), a member of the PAX family, plays a role in pattern formation during embryogenesis, and might be essential for development of the vertebral column.

Methods

PAX1 is silenced by methylation in several cancers and is considered a tumor suppressor gene. Our previous studies reported PAX1 as hypermethylated in cervical cancer tissues, thereby suggesting it as a potential screening marker. Recently, an increasing number of studies have confirmed PAX1 methylation as a promising biomarker in cervical cancer based on its excellent discriminatory ability between high‐grade cervical lesions and normal tissues, resulting in a reduced necessity for referral for colposcopy and biopsy. Additionally, PAX1 is also hypermethylated in other tumors, including those associated with epithelial ovarian cancer, esophageal squamous cell carcinoma, head and neck squamous cell carcinoma, and endometrial carcinoma, and shows relatively good sensitivity and specificity for the detection of these tumors.

Results

This review summarizes reports of PAX1 methylation and its promising role in cancer screening, especially that associated with cervical cancer.

Conclusion

According to current evidence, combined testing for human papillomavirus and PAX1 methylation analysis represents an efficacious cervical cancer‐screening protocol.

Retinoic acid receptor beta promoter methylation and risk of cervical cancer

Cervical cancer is one of the leading causes of death in women worldwide, particularly in developing countries. Human papillomavirus has been reported as one of the key etiologic factors in cervical carcinoma. Likewise, epigenetic aberrations have ability to regulate cancer pathogenesis and progression. Recent research suggested that methylation has been detected already at precancerous stages, which methylation markers may have significant value in cervical cancer screening. The retinoic acid receptor beta (RARβ) gene, a potential tumor suppressor gene, is usually expressed in normal epithelial tissue. Methylation of CpG islands in the promoter region of the RARβ gene has been found to be associated with the development of cervical cancer. To investigate whether RARβ methylation is a potential biomarker that predicts the progression of invasive cancer, we reviewed 14 previously published articles related to RARβ methylation. The majority of them demonstrated that the frequency of RARβ promoter methylation was significantly correlated with the severity of cervical epithelium abnormalities. However, methylation of a single gene may not represent the best approach for predicting disease prognosis. Analyzing combinations of aberrant methylation of multiple genes may increase the sensitivity, and thus this approach may serve as a better tool for predicting disease prognosis.

PAX1 Methylation as a Potential Biomarker to Predict the Progression of Cervical Intraepithelial Neoplasia: A Meta-analysis of Related Studies

OBJECTIVE

The methylation of paired box gene 1 (PAX1) has a great influence on the process of cervical lesion. However, available evidence for the association between PAX1 methylation and cervical intraepithelial neoplasia (CIN) are inconsistent. Here, we systematically reviewed and analyzed PAX1 methylation in progress of CIN.

METHODS

Two investigators independently searched eligible studies of PAX1 methylation and CIN that were published in PubMed, Cochrane Library, EMBASE, and Web of Science databases until November 30, 2016. We extracted clinicopathologic features of CIN and cervical cancel relevant to PAX1 methylation. Odds ratios (ORs) with their 95% confidence intervals (CIs) were used to assess the association between PAX1 methylation and progression of patients with CIN.

RESULTS

Seven studies composed of 1055 patients with various stages of CIN and cervical cancel were eventually included. The results revealed that PAX1 methylation was associated with transition of CIN I to CIN II/III (OR, 0.09; 95% CI, 0.04-0.19) and CIN II/III to cervical cancer (OR, 0.16; 95% CI, 0.05-0.46), and similar results were produced in sensitivity analysis. Also, we found that the OR value was associated with average age and number of patients, publication year, and study location of included articles.

CONCLUSIONS

PAX1 gene methylation was associated with the transition of CIN I to CIN II/III and CIN II/III to cervical cancer, so that it could be an auxiliary biomarker to estimate the risk of CIN progress. Moreover, PAX1 may help to determine appropriate reexaminations and treatment for patients with various stages of CIN.

Quantitative DNA methylation analysis of paired box gene 1 and LIM homeobox transcription factor 1 α genes in cervical cancer

DNA methylation is associated with tumorigenesis and may act as a potential biomarker for detecting cervical cancer. The aim of the present study was to explore the methylation status of the paired box gene 1 (PAX1) and the LIM homeobox transcription factor 1 α (LMX1A) gene in a spectrum of cervical lesions in an Eastern Chinese population. This single-center study involved 121 patients who were divided into normal cervix (NC; n=28), low-grade squamous intraepithelial lesion (LSIL; n=32), high-grade squamous intraepithelial lesion (HSIL; n=34) and cervical squamous cell carcinoma (CSCC; n=27) groups, according to biopsy results. Following extraction and modification of the DNA, quantitative assessment of the PAX1 and LMX1A genes in exfoliated cells was performed using pyrosequencing analysis. Receiver operating characteristic (ROC) curves were generated to calculate the sensitivity and specificity of each parameter and cut-off values of the percentage of methylation reference (PMR) for differentiation diagnosis. Analysis of variance was used to identify differences among groups. The PMR of the two genes was significantly higher in the HSIL and CSCC groups compared with that in the NC and LSIL groups (P<0.001). ROC curve analysis demonstrated that the sensitivity, specificity and accuracy for detection of CSCC were 0.790, 0.837 and 0.809, respectively, using PAX1; and 0.633, 0.357 and 0.893, respectively, using LMX1A. These results indicated that quantitative PAX1 methylation demonstrates potential for cervical cancer screening, while further investigation is required to determine the potential of LMX1A methylation.

Hypermethylated ZNF582 and PAX1 genes in oral scrapings collected from cancer-adjacent normal oral mucosal sites are associated with aggressive progression and poor prognosis of oral cancer

OBJECTIVE

This study assessed whether hypermethylated ZNF582 and PAX1 genes in oral scrapings are correlated with the progression and prognosis of oral squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

Methylation levels of ZNF582 and PAX1 genes in oral scrapings, collected from the cancer and adjacent normal oral mucosal sites of 80 OSCC patients before surgical cancer excision, were quantified using real-time methylation-specific PCR after bisulfite conversion.

RESULTS

Both the mean methylation (M)-indices of ZNF582 and PAX1 genes in oral scrapings were significantly higher at the cancer sites than at the adjacent normal oral mucosal sites (both P < .001). In the oral scrapings collected from the adjacent normal oral mucosal sites, the higher M-index of methylated ZNF582 (ZNF582^m) was significantly correlated with a more advanced clinical stage (P = .04). Moreover, the higher M-index of methylated PAX1 (PAX1^m) was significantly related to larger tumor size (P = .046). When the 80 OSCC patients were classified based on gene methylation tests, using the oral scrapings collected from the adjacent normal oral mucosal sites, we found a significantly shorter 3-year overall survival in ZNF582^m-positive, PAX1^m-positive, and ZNF582^m/PAX1^m-positive OSCC patients than in ZNF582^m-negative (P = .02), PAX1^m-negative (P = .04), and ZNF582^m/PAX1^m-negative OSCC patients (P = .02), respectively. Multivariate Cox regression analyses identified ZNF582^m and ZNF582^m/PAX1^m as independent unfavorable prognostic factors.

CONCLUSION

Hypermethylated ZNF582 and PAX1 genes in the oral scrapings collected from adjacent normal oral mucosal sites rather than cancer sites are associated with aggressive progression and poor prognosis of OSCC.

DNA Methylation Status of PAX1 and ZNF582 in Esophageal Squamous Cell Carcinoma

Hypermethylation of specific gene promoters is an important mechanism of carcinogenesis. A high frequency of promoter methylation of PAX1 and ZNF582 genes has been detected in cervical cancer. In the present study, we investigated the methylation status of PAX1 and ZNF582 genes in esophageal squamous cell carcinoma (ESCC) tissues. Tumor and paracancerous tissues were obtained from 14 ESCC patients. Genomic DNA was extracted from both tumor and paracancerous tissues, and the concentration of DNA were determined. DNA methylation analysis of PAX1 and ZNF582 genes was carried out using quantitative methylation-specific PCR. To assess the diagnostic performance of the two methylated genes for cancer detection, receiver operating characteristic (ROC) curves were generated. Sensitivities and specificities were tested at cut-offs obtained from the ROC curves. The methylation levels of both PAX1 and ZNF582 genes were significantly higher in tumor tissues compared to non-tumor paracancerous tissues. The methylation rates of PAX1 and ZNF582 in ESCC tumor and paracancerous tissues were 100% and 21.4% (p = 0.006), 85.7% and 0% (p < 0.001), respectively. The sensitivities and specificities of PAX1 and ZNF582 methylation for the detection of cancer were 100% and 85.7%, and 78.6% and 100%, respectively. The DNA methylation levels and frequencies of PAX1 and ZNF582 genes were markedly higher in ESCC tumor tissues compared to those in paracancerous tissues. Moreover, the conclusions were verified by using The Cancer Genome Atlas (TCGA) datasets. DNA methylation status of these two genes showed a relatively good sensitivity and specificity for the detection of ESCC tumors. This data suggests that DNA methylation testing holds a great promise for ESCC screening and warrants further prospective population-based studies.

PAX1 and SOX1 methylation as an initial screening method for cervical cancer: a meta-analysis of individual studies in Asians

BACKGROUND

Epigenetic alterations of gene or DNA methylation have been highlighted as promising biomarkers for early cervical cancer screening. Herein, we evaluated the diagnostic performance of paired boxed gene 1 (PAX1) and sex determining region Y-box 1 (SOX1) methylation for cervical cancer detection.

METHODS

Eligible studies were retrieved by searching the electronic databases. Study quality was assessed according to the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) checklist. The bivariate meta-analysis model was employed to plot the summary receiver operator characteristic (SROC) curve using Stata 12.0 software.

RESULTS

The pooled sensitivity of PAX1 methylation was estimated to be 0.73 [95% confidence interval (CI): 0.70-0.75] in differentiating patients with HSIL (high-grade squamous intraepithelial lesion) or CIN3+ (cervical intraepithelial neoplasia type III/worse) or cervical cancer from normal individuals, corresponding to a specificity of 0.87 (95% CI: 0.85-0.89) and area under the curve (AUC) of 0.91. The SOX1 methylation test yielded an AUC of 0.82, under which, the pooled sensitivity was 0.71 (95% CI: 0.67-0.74) and specificity was 0.64 (95% CI: 0.61-0.67). Notably, the stratified analysis suggested that combing parallel testing of PAX1 methylation and human papillomavirus (HPV) DNA (AUC, sensitivity, and specificity of 0.89, 0.75, and 0.81, respectively) achieved higher accuracy than single HPV DNA testing (AUC, sensitivity, and specificity of 0.77, 0.81, and 0.70, respectively).

CONCLUSIONS

PAX1 or SOX1 methylation has a prospect to be an auxiliary biomarker for cervical cancer screening, and parallel testing of PAX1 methylation and HPV DNA in cervical swabs confers an improved diagnostic accuracy than single HPV DNA testing.

FAM19A4 methylation analysis in self-samples compared with cervical scrapes for detecting cervical (pre)cancer in HPV-positive women

BACKGROUND

High-risk human papillomavirus (hrHPV)-positive women require triage to identify those with cervical high-grade intraepithelial neoplasia and cancer (⩾CIN3 (cervical intraepithelial neoplasia grade 3)). FAM19A4 methylation analysis, which detects advanced CIN and cancer, is applicable to different sample types. However, studies comparing the performance of FAM19A4 methylation analysis in hrHPV-positive self-samples and paired physician-taken scrapes are lacking.

METHODS

We compared the performance of FAM19A4 methylation analysis (and/or HPV16/18 genotyping) in self-samples and paired physician-taken scrapes for ⩾CIN3 detection in hrHPV-positive women (n=450,18-66 years).

RESULTS

Overall FAM19A4 methylation levels between sample types were significantly correlated, with strongest correlation in women with ⩾CIN3 (Spearman's ρ 0.697, P<0.001). The performance of FAM19A4 methylation analysis and/or HPV16/18 genotyping did not differ significantly between sample types. In women ⩾30 years, ⩾CIN3 sensitivity of FAM19A4 methylation analysis was 78.4% in self-samples and 88.2% in scrapes (ratio 0.89; CI: 0.75-1.05). In women <30 years, ⩾CIN3 sensitivities were 37.5% and 45.8%, respectively (ratio 0.82; CI: 0.55-1.21). In both groups, ⩾CIN3 specificity of FAM19A4 methylation analysis was significantly higher in self-samples compared with scrapes.

CONCLUSIONS

FAM19A4 methylation analysis in hrHPV-positive self-samples had a slightly lower sensitivity and a higher specificity for ⩾CIN3 compared with paired physician-taken scrapes. With a similarly good clinical performance in both sample types, combined FAM19A4 methylation analysis and HPV16/18 genotyping provides a feasible triage strategy for hrHPV-positive women, with direct applicability on self-samples.

Value of PAX1 Methylation Analysis by MS-HRM in the Triage of Atypical Squamous Cells of Undetermined Significance

BACKGROUND

Detection of cervical high grade lesions in patients with atypical squamous cells of undetermined significance (ASCUS) is still a challenge. Our study tested the efficacy of the paired boxed gene 1 (PAX1) methylation analysis by methylation-sensitive high-resolution melting (MS-HRM) in the detection of high grade lesions in ASCUS and compared performance with the hybrid capture 2 (HC2) human papillomavirus (HPV) test.

MATERIALS AND METHODS

A total of 463 consecutive ASCUS women from primary screening were selected. Their cervical scrapings were collected and assessed by PAX1 methylation analysis (MS-HRM) and high-risk HPV-DNA test (HC2). All patients with ASCUS were admitted to colposcopy and cervical biopsies. The Chi- square test was used to test the differences of PAX1 methylation or HPV infection between groups.

RESULTS

The specificity, sensitivity, and accuracy for detecting CIN2 + lesions were: 95.6%, 82.4%, and 94.6%, respectively, for the PAX1 MS-HRM test; and 59.7%, 64.7%, and 60.0% for the HC2 HPV test.

CONCLUSIONS

The PAX1 methylation analysis by MS-HRM demonstrated a better performance than the high-risk HPV-DNA test for the detection of high grade lesions (CIN2 +) in ASCUS cases. This approach could screen out the majority of low grade cases of ASCUS, and thus reduce the referral rate to colposcopy.

Methylation of Cervical Neoplastic Cells Infected With Human Papillomavirus 16

OBJECTIVE

This study was conducted to evaluate the role of methylation of adenylate cyclase activating peptide 1 (ADCYAP1), paired box gene 1 (PAX1), cell adhesion molecule 1 (CADM1), and T-lymphocyte maturation-associated protein (MAL) during carcinogenesis.

METHODS

We evaluated the methylation of 4 genes by using the cervical carcinoma cell lines (CaSki, SiHa, HeLa, and C33A) and cervical neoplastic cells from 56 subjects with human papillomavirus 16 (HPV16)-infected low-grade squamous intraepithelial lesions (LSILs), 50 subjects with HPV16-infected high-grade squamous intraepithelial lesions (HSILs), and 24 subjects with HPV16-infected invasive cervical cancer who attended Seoul St. Mary's Hospital. Methylation of the 4 genes was evaluated using quantitative bisulfate pyrosequencing.

RESULTS

The ADCYAP1 promoter was hypermethylated in the 4 cell lines (CaSki, 97.40 ± 1.39; SiHa, 82.04 ± 17.02; HeLa, 96.14 ± 2.08; and C33A, 78 ± 10.18). PAX1 and CADM1 were hypermethylated in the HPV16/18-infected cell lines CaSki (PAX1, 91.18 ± 9.91; CADM1, 93.5 ± 7.33), SiHa (PAX1, 96.14 ± 2.08; CADM1, 93.15 ± 8.81), and HeLa (PAX1, 82.04 ± 17.02; CADM1, 92.43 ± 9.95). MAL was hypermethylated in the CaSki cell line (96.04 ± 4.74). Among human cervical neoplastic cells, the methylation indices of ADCYAP1 were 7.8 (95% confidence interval [95% CI], 7.0-8.6) in subjects with LSILs and 39.8 (95% CI, 29.0-54.7) in those with cervical cancer (P < 0.001); for PAX1, 7.2 (95% CI, 6.1-8.5) and 37.8 (95% CI, 27.1-52.7), respectively; for CADM1, 3.5 (95% CI, 3.0-4.0) and 17.7 (95% CI, 10.8-29.1), respectively; for MAL, 2.7 (95% CI, 2.5-3.0) and 13.0 (95% CI, 7.6-22.0), respectively (P < 0.001 for each). Immunohistochemical staining results were positive in the cytoplasm of subjects with low methylation of the 4 gene promoters; however, they were negative in the cytoplasm of those with hypermethylation of the 4 gene promoters.

CONCLUSIONS

The results of this study suggest that the methylation of ADCYAP1, PAX1, CADM1, and MAL may be highly associated with the development of cervical cancer, and that gene expression can be suppressed by gene promoter hypermethylation.

PAX1 methylation as an auxiliary biomarker for cervical cancer screening: a meta-analysis

OBJECTIVE

Several studies have implicated PAX1 epigenetic regulation in cervical neoplasia. The aim of this meta-analysis was to assess PAX1 gene methylation as a potential biomarker in cervical cancer screening.

METHODS

A systematical search of all major databases was performed, in order to include all relevant publications in English until December 31(st) 2014. Studies with insufficient data, conducted in experimental models or associated with other comorbidities were excluded from the meta-analysis. Summary receiver operating characteristics (SROC) for Cervical Intraepithelial Neoplasia grade 2 or worse (CIN2(+)) versus normal, and CIN grade 3 or worse (CIN3(+)) versus normal, were estimated using the bivariate model.

RESULTS

Out of the 20 initially included studies, finally 7 (comprising of 1385 subjects with various stages of CIN and normal cervical pathology) met the inclusion criteria. The sensitivity of CIN2(+) versus normal was estimated to be 0.66 (CI 95%, 0.46-0.81) and the specificity 0.92 (CI 95%, 0.88-0.95). On the other hand, the sensitivity of CIN3(+) versus normal was 0.77 (CI 95%, 0.58-0.89) and the specificity 0.92 (CI 95%, 0.88-0.94). Moreover, the area under the curve (AUC) in the former case was 0.923, and in the latter 0.931.

CONCLUSION

The results of this meta-analysis support the utility of PAX1 methylation as an auxiliary biomarker in cervical cancer screening. PAX1 could be used effectively to increase the specificity of HPV DNA by detecting women with more advanced cervical abnormalities.

Methylation analysis of the FAM19A4 gene in cervical scrapes is highly efficient in detecting cervical carcinomas and advanced CIN2/3 lesions

Primary testing for human papillomavirus (HPV) in cervical screening requires triage to differentiate women with transient infection from those with persistent infection who require more intensive management given their risk for cervical (pre)cancer. In this study, the clinical performance of a novel methylation marker FAM19A4 for the triage of high-risk (hr)HPV-positive women was evaluated. Using a training-validation set approach, we analyzed a FAM19A4 quantitative methylation-specific PCR (qMSP). The training set comprised hrHPV-positive cervical scrapes of 43 women with cervical intraepithelial neoplasia grade 3 or worse (CIN3+) and 135 women with ≤CIN1. The validation set comprised hrHPV-positive cervical scrapes of 52 women with CIN2+, including 33 CIN3+, 19 CIN2, and 166 women with ≤CIN1. The methylation threshold of FAM19A4 qMSP that gave rise to CIN3+ specificity of 70% in the training set was applied in the validation set. This resulted in CIN3+ sensitivity of 75.8% [95% confidence interval (CI), 61.1-90.4] at 67.0% (95% CI, 60.3-73.8) specificity. Next, the validated qMSP was applied to an independent series of hrHPV-positive cervical scrapes of 22 women with cervical cancer, 29 with advanced CIN2/3 [i.e., women with a known preceding hrHPV infection (PHI) lasting ≥5 years as proxy of longer duration of lesion existence], and 19 with early CIN2/3 (i.e., PHI <5 years). All carcinomas (22/22) and advanced CIN2/3 lesions (29/29) were FAM19A4 methylation-positive, compared with 42.1% (8/19; 95% CI, 19.9-64.3) of early CIN2/3 lesions. In conclusion, FAM19A4 is an attractive triage marker for hrHPV-positive women, with a high reassurance for the detection of cervical carcinoma and advanced CIN2/3 lesions.

Clinical implications of (epi)genetic changes in HPV-induced cervical precancerous lesions

Infection of cervical epithelium with high-risk human papilloma virus (hrHPV) might result in productive or transforming cervical intraepithelial neoplasia (CIN) lesions, the morphology of which can overlap. In transforming CIN lesions, aberrations in host cell genes accumulate over time, which is necessary for the ultimate progression to cancer. On the basis of (epi)genetic changes, early and advanced transforming CIN lesions can be distinguished. This paves the way for new molecular tools for cervical screening, diagnosis and management of cervical cancer precursor lesions.

High methylation rate of LMX1A, NKX6-1, PAX1, PTPRR, SOX1, and ZNF582 genes in cervical adenocarcinoma

OBJECTIVE

This study aimed to investigate the status of DNA methylation of 6 genes, LMX1A, NKX6-1, PAX1, PTPRR, SOX1, and ZNF582, previously found from squamous cell carcinomas in adenocarcinomas (ACs) of the uterine cervix.

METHODS

We assessed the methylation status of these genes in 40 ACs, cervical scrapings from 23 ACs, and 67 normal control cervices by real-time quantitative methylation-specific polymerase chain reaction. The results were validated by bisulfite pyrosequencing.

RESULTS

The methylation levels of all the 6 genes in the ACs were significantly higher than those in normal cervical tissues, especially for PAX1, PTPRR, SOX1, and ZNF582. The odds ratios and 95% confidence intervals (CIs) of high methylation levels in PAX1, PTPRR, SOX1, and ZNF582 for the risk of developing an AC were 15.7 (95% CI, 7.0-40.6), 16.9 (95% CI, 7.6-43.0), 32.1 (95% CI, 12.1-124.3), and 25.4 (95% CI, 10.4-78.3), respectively (all P < 0.001). The methylation indices of PAX1, PTPRR, SOX1, and ZNF582 recovered from scrapings of ACs were significantly higher than in normal controls. The odds ratios of these indices for the risk of developing an AC in PAX1, PTPRR, SOX1, and ZNF582 were 6.2 (95% CI, 2.6-15.4), 12.1(95% CI, 3.8-46.4), 6.2 (95% CI, 2.6-15.8), and 20.6 (95% CI, 6.9-77.5), respectively (all P < 0.001).

CONCLUSIONS

Cervical ACs carry aberrantly high methylation rates of PAX1, PTPRR, SOX1, and ZNF582--commonly methylated in squamous cell carcinomas--which might help for AC screening.

DNA methylation of PAX1 as a biomarker for oral squamous cell carcinoma

OBJECTIVES

DNA methylation has been shown to be a promising cancer biomarker. The aim of this study was to evaluate DNA methylation of three transcription factors, sex-determining region Y-box 1 (SOX1), paired box gene 1 (PAX1), and zinc-finger 582 (ZNF582), in detecting oral squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

A case-control study was conducted at Taipei Medical University Hospital in Taiwan with 31 cases of various oral cavity squamous cell carcinomas and 40 controls. Questionnaire data assessing environmental exposure, such as alcohol consumption, cigarette smoking, and betel nut chewing, were obtained from each participant. DNA from oral swabs were analyzed for methylation using quantitative methylation polymerase chain reaction with TaqMan probes. Methylation status was determined using a methylation index.

RESULTS

Methylation levels of SOX1, PAX1, and ZNF582 were significantly higher in cancer patients (p = 0.02, p = 0.02, and p = 0.03, respectively). Patients with highly methylated SOX1, PAX1, and ZNF582 had an increased cancer risk with odds ratios (ORs) of 16.50 (95 % CI = 2.85-96.65), 60.57 (95 % CI = 5.85-629.94), and 5.07 (95 % CI = 1.08-23.76), respectively. Area under the curve (AUC) values were 0.85, 0.78, and 0.78 for PAX1, SOX1, and ZNF582, respectively. When stratified based on environmental exposure, the AUC of PAX1 methylation (PAX1 (m) ) was 0.94 in environmental exposure-naïve subjects and 0.85 for SOX1 methylation in subjects who chewed betel nut. In general, the sensitivity and specificity of PAX1 (m) were 87 and 80 % for OSCC detection. The sensitivity of PAX1 (m) in subjects who chewed betel nut was 83 %, with a specificity of 75 %.

CONCLUSIONS

Testing PAX1 DNA methylation using oral swabs is a promising method for oral cancer detection. Combined assessments regarding betel nut consumption and DNA methylation can improve OSCC screening.

CLINICAL RELEVANCE

The double E (environmental and epigenetic) assessment is a potential strategy in OSCC screening.

Patterns of cellular and HPV 16 methylation as biomarkers for cervical neoplasia

Aberrant promoter methylation of biologically relevant genes in cervical cancer and uneven CpG distribution within the human papillomavirus 16 (HPV 16) enhancer region have been reported. Cervical samples and questionnaires from 151 women screened for cervical cancer in Appalachian Ohio were analyzed. Methylation was measured by bisulfite sequencing in candidate gene sites in ESR1, DCC, p16, and LINE1 elements. Among 89 HPV 16-positive women, CpG sites in the E6 promoter and enhancer regions and the L1 region of the HPV 16 genome were measured. Methylation levels were compared by cervical cytology and HPV 16 status. HPV methylation was low regardless of cytology status, however E6 methylation was significantly higher in women with normal cytology. ESR1 and DCC methylation were significantly higher in HPV 16-positive women. Increased methylation at sites in the E6 promoter region was associated with lower odds of abnormal cytology. Increased methylation in candidate genes was associated with higher odds of abnormal cytology, particularly DCC region 2.4, DCC region 2.6, ESR1 region 3.2, and LINE1 site 1.2. HPV 16 genome CpG methylation was low except for the L1 region. In general, lower HPV 16 methylation and higher candidate gene methylation levels were associated with higher odds of abnormal cytology.

Regulation of cellular miRNA expression by human papillomaviruses

High-risk HPV infection leads to aberrant expression of cellular oncogenic and tumor suppressive miRNAs. A large number of these miRNA genes are downstream targets of the transcription factors c-Myc, p53, and E2F and their expression can therefore be modulated by oncogenic HPV E6 and E7. Cervical cancer represents a unique tumor model for understanding how viral E6 and E7 oncoproteins deregulate the expression of the miR-15/16 cluster, miR-17-92 family, miR-21, miR-23b, miR-34a, and miR-106b/93/25 cluster via the E6-p53 and E7-pRb pathways. Moreover, miRNAs may influence the expression of papillomavirus genes in a differentiation-dependent manner by targeting viral RNA transcripts. Cellular miRNAs affecting HPV DNA replication are of great interest and will be a future focus. We are entering an era focusing on miRNA and noncoding RNA, and the studies on HPV and host miRNA interactions will continue shedding more light on our understanding of the HPV life cycle and the mechanistic underpinnings of HPV-induced oncogenesis. This article is part of a Special Issue entitled: "MicroRNAs in viral gene regulation".

Human papillomavirus and cervical cancer: biomarkers for improved prevention efforts

While organized screening programs in industrialized countries have significantly reduced cervical cancer incidence, cytology-based screening has several limitations. Equivocal or mildly abnormal Pap tests require costly retesting or diagnostic work-up by colposcopy and biopsy. In low-resource countries, it has been difficult to establish and sustain cytology-based programs. Advances in understanding human papillomavirus biology and the natural history of human papillomavirus-related precancers and cancers have led to the discovery of a range of novel biomarkers in the past decade. In this article, we will discuss the potential role of new biomarkers for primary screening, triage and diagnosis in high-resource countries and their promise for prevention efforts in resource constrained settings.

Triage of cervical cytological diagnoses of atypical squamous cells by DNA methylation of paired boxed gene 1 (PAX1)

Detection of cervical high-grade squamous intraepithelial lesions (HSIL) in patients with equivocal cytological abnormalities, such as atypical squamous cells (ASC) of undetermined significance (ASCUS) or inability to exclude high-grade squamous intraepithelial lesions (ASC-H) is still a challenge. This study tested the efficacy of PAX1 methylation analysis in the triage of cervical ASCUS and ASC-H and compared its performance with Hybrid Capture 2 (HC2) HPV test. A hospital-based case-control study was conducted. Cervical scrapings from patients with ASCUS or ASC-H were used for the quantitative methylation analysis of PAX1 methylation by MethyLight and HPV testing by HC2. Patients with ASC-H or ASCUS with repeated abnormal smears underwent colposcopic biopsy and subsequent therapies. Diagnoses were made by histopathology at a follow-up of 2 years. The efficacies of detecting high-grade lesions were compared. Fifty-eight cervical scrapings with cytological diagnosis of ASCUS (n = 41) and ASC-H (n = 17) were analyzed. One of the 41 (2.4%) ASCUS patients and seven of 17 (41.2%) ASC-H patients were confirmed to have HSIL. After dichotomy of the PMR, PAX1 methylation rates were significantly higher in ASC developing HSIL compared with those developing reactive atypia (87.5% vs. 12.5%, P < 0.001). Testing PAX1 methylation in cervical swabs of patients with ASC confers better sensitivity (87.5% vs. 62.5%) and specificity (98.0% vs. 86.0%) than HC2 HPV testing. We show for the first time that PAX1 hypermethylation analysis may be a better choice than HC2 in the triage of ASCUS and ASC-H.

Testing for methylated PCDH10 or WT1 is superior to the HPV test in detecting severe neoplasms (CIN3 or greater) in the triage of ASC-US smear results

OBJECTIVE

Management of equivocal Papanicolaou smear result remains to be challenging even with the aid of human papillomavirus test. Recently, 3 novel methylation-silenced genes, PAX1, WT1, and PCDH10, have been found to be specifically associated with cervical cancer. We compared the performances of methylation test of these genes with human papillomavirus tests in triage of equivocal Papanicolaou smear result.

STUDY DESIGN

Two hundred twenty-two women with Papanicolaou smear results of atypical cells of undetermined significance nested to a multicenter, nation-wide cohort (the T1899 cohort) were studied. Status of cervical neoplasm was diagnosed with colposcopic biopsy. Status of gene methylation was determined by methylation-specific polymerase chain reaction. High-risk human papillomavirus DNA was detected by polymerase chain reaction-reverse line blot hybridization and Hybrid Capture 2.

RESULTS

Cervical intraepithelial neoplasm 1, cervical intraepithelial neoplasm 2, cervical intraepithelial neoplasm 3, carcinoma in situ, carcinoma, and normal cervix were diagnosed in 58, 17, 14, 10, 1, and 120 women, respectively. Methylation of PCDH10, WT1, and PAX1 was highly associated with the severity of cervical neoplasm (P < 10⁻⁹, < 10⁻⁷, and < 10⁻⁵, respectively). In comparison with a negative test result, the odds ratio (95% confidence intervals) for cervical intraepithelial neoplasm 3 or more severe neoplasms for women tested positive for methylation of these 3 genes were 26.4 (9.0-77.3), 18.1 (6.9-47.2), and 10.3 (4.1-25.9), respectively; whereas those positive for human papillomavirus polymerase chain reaction and Hybrid Capture 2 were 10.5 (3.5-31.9) and 5.6 (2.3-21.4). In triage for atypical cells of undetermined significance, each methylation test had less colposcopy referral and false-positive rates, but higher false-negative rate than the human papillomavirus tests. With a combination test of PCDH10 or WT1 methylation, a comparable false-negative rate (P = .62) but much less false-positive rate (P = .002) and colposcopy referral rate (P < 10⁻⁶) were achieved.

CONCLUSION

In triage of atypical cells of undetermined significance Papanicolaou smear results, methylation test of WT1 and PCDH10 is superior to human papillomavirus test in this multicenter cohort. Comparing to current human papillomavirus triage, the new test has only one third of false positivity and half of colposcopy referral, with no compromise of the sensitivity in diagnosis of cervical intraepithelial neoplasm 3 or more severe neoplasms.