Biological implications and therapeutic significance of DNA methylation regulated genes in cervical cancer

Efficient enrichment of free target sequences in an integrated microfluidic device for point-of-care detection systems

Nucleic acid biomarker detection has great importance in the diagnosis of disease, the monitoring of disease progression and the classification of patients according to treatment decision making. Nucleic acid biomarkers found in the blood of patients have generated a lot of interest due to the possibility of being detected non-invasively which makes them ideal for monitoring and screening tests and particularly amenable to point-of-care (POC) or self-testing. A major challenge to POC molecular diagnostics is the need to enrich the target to optimise detection. In this work, we describe a microfabricated device for the enrichment of short dsDNA target sequences, which is especially valuable for potential detection methods, as it improves the probability of effectively detecting the target in downstream analyses. The device integrated a heating element and a temperature sensor with a microfluidic chamber to carry out the denaturation of the dsDNA combined with blocking-probes to enrich the target. This procedure was validated by fluorescence resonance energy transfer (FRET) technique, labelling DNA with a fluorophore and a quencher. As proof of concept, a 23-mer long dsDNA sequence corresponding to the L858R mutation of the EGFR gene was used. The qualitative results obtained determined that the most optimal blocking rate was obtained with the incorporation of 11/12-mer blocking-probes at a total concentration of 6 μM. This device is a powerful DNA preparation tool, which is an indispensable initial step for subsequent detection of sequences via nucleic acid hybridisation methods.

Pathological Changes and Pregnancy Outcomes in Cervical Intraepithelial Neoplasia Patients After Cold Knife Conization

Objective

Analyze women treated with underwent cold knife conization (CKC) to remove advanced squamous intraepithelial lesions (CIN) of the cervix. The histopathological upgrading of the lesions previously detected on vaginal biopsy and postoperative pregnancy outcomes of were investigated, to identify high-risk subgroups in women.

Methods

A retrospective study was conducted at the First Central Hospital of Baoding City from June 2019 to December 2022 to analyze confirmed cases of Cervical Intraepithelial Neoplasia CIN-II and CIN-III. Investigation of pathological changes in postoperative pathological tissues, and to perform binary logistic analysis to identify risk factors for histopathological escalation in postoperative lesions. We analyze the effects of CKC surgery on pregnancy outcomes in patients by comparing against a control group of healthy pregnant women.

Results

Out of the 176 patients diagnosed with CIN-II who underwent cervical biopsy, 39 (22.16%) were found to have a final specimen diagnosis of CIN-III, while 7 (3.98%) were downgraded to CIN-I. Among the 108 patients diagnosed with CIN-III who underwent cervical biopsy, 7 cases (6.48%) were ultimately confirmed to have CIN-III. Ki67-positive, p16-positive (OR = 1.13, 95% CI 1.01-1.15), and colposcopy biopsy for CIN-II (OR = 1.59, 95% CI 1.33-3.6) were independent risk factors for pathological upgrade after CKC. Compared with healthy pregnant women, CIN patients had higher rates of premature birth (14.4%), premature rupture of the fetal membrane (13.6%), and cesarean section (37.5%) (P < 0.05). The mode of conception, abortion rate, ectopic pregnancy rate, and postpartum hemorrhage were not different between healthy pregnant women and CIN patients (P > 0.05).

Conclusion

Following cervical multi-point biopsy or CKC, along with pathological examination, the accurate diagnosis of cervical lesions is crucial as it allows for more precise identification of such lesions. Additionally, CKC increases the risk of premature birth, premature rupture of membranes, and the need for cesarean section.

Regeneration and anti-inflammatory effects of stem cells and their extracellular vesicles in gynecological diseases

There are many gynecological diseases, among which breast cancer (BC), cervical cancer (CC), endometriosis (EMs), and polycystic ovary syndrome (PCOS) are common and difficult to cure. Stem cells (SCs) are a focus of regenerative medicine. They are commonly used to treat organ damage and difficult diseases because of their potential for self-renewal and multidirectional differentiation. SCs are also commonly used for difficult-to-treat gynecological diseases because of their strong directional differentiation ability with unlimited possibilities, their tendency to adhere to the diseased tissue site, and their use as carriers for drug delivery. SCs can produce exosomes in a paracrine manner. Exosomes can be produced in large quantities and have the advantage of easy storage. Their safety and efficacy are superior to those of SCs, which have considerable potential in gynecological treatment, such as inhibiting endometrial senescence, promoting vascular reconstruction, and improving anti-inflammatory and immune functions. In this paper, we review the mechanisms of the regenerative and anti-inflammatory capacity of SCs and exosomes in incurable gynecological diseases and the current progress in their application in genetic engineering to provide a foundation for further research.

PAX1 and SEPT9 methylation analyses in cervical exfoliated cells are highly efficient for detecting cervical (pre)cancer in hrHPV-positive women

Studies have investigated PAX1 and SEPT methylation were closely associated with cervical cancer. For this study, we verified the expressions of PAX1 and SEPT9 methylation in 236 hrHPV women cervical exfoliated cells by using quantitative methylation-specific PCR and we further explored their diagnostic value in cervical (pre)cancer detection. Our results identified that the methylation rates and levels of PAX1 and SEPT9 increased with cervical lesion severity. For a diagnosis of cervical (pre)cancer, the area under the curve (AUC) of PAX1 methylation was 0.77 (95% CI 0.71-0.83) and the AUC of SEPT9 methylation was 0.86 (95% CI 0.81∼0.90). Analyses of the PAX1 and SEPT9 methylation statuses alone or combined with commonly used tests can efficiently identify cervical (pre)cancer. In particular, SEPT9 methylation might serve as an effective and powerful biomarker for the diagnosis of cervical (pre)cancer and as an alternative triage test in HPV-based cervical (pre)cancer screening programs.Impact StatementWhat is already known on this subject? This subject showed that PAX1 and SEPT9 methylation were closely associated with cervical cancer. The methylation rates and levels of PAX1 and SEPT9 increased with cervical lesion severity and reached a peak in cervical cancer exfoliated cells. We further assessed the diagnostic performances of PAX1 and SEPT9 methylation in cervical cancer screening. In detecting cervical (pre)cancer, the sensitivity values of PAX1 and SEPT9 methylation were up to 61.18% and 82.35%, respectively, and the specificity values of PAX1 and SEPT9 methylation were up to 95.36% and 86.75%, respectively. Moreover, the ROC curve analysis showed AUC values of 0.77 for PAX1 methylation and 0.86 for SEPT9 methylation tests, which were significantly superior to other commonly used tests. These findings suggest that PAX1 and SEPT9 methylation detection may have great clinical potential in cervical cancer screening.What the results of this study add? The rates and levels of PAX1 and SEPT9 methylation increased with the severity of the cervical lesions. For a diagnosis of cervical (pre)cancer, the area under the curve (AUC) of PAX1 methylation was 0.77 (95% CI 0.71-0.83), and the sensitivity and specificity values were 61.18% and 95.36%, respectively. The AUC value of the SEPT9 methylation was 0.86 (95% CI 0.81 ∼ 0.90), and the sensitivity and specificity values were 82.35% and 86.75%, respectively. Compared with the various tests we conducted, the PAX1 methylation showed the highest specificity (95.36%), and the SEPT9 methylation demonstrated the highest accuracy(86.00%).What the implications are of these findings for clinical practice and/or further research? The methylation levels of PAX1 and SEPT9 had a certain predictive effect on the severity of cervical lesions in hrHPV-positive women. In addition, SEPT9 methylation analysis performs better than PAX1 methylation analysis and commonly used tests in cervical exfoliated cells for detecting cervical (pre)cancer in hrHPV-positive women. SEPT9 methylation analysis merits consideration as an effective and objective, alternative triage test in HPV-based cervical (pre)cancer screening programs.

Epigenome-wide methylation and progression to high-grade cervical intraepithelial neoplasia (CIN2+): a prospective cohort study in the United States

BACKGROUND

Methylation levels may be associated with and serve as markers to predict risk of progression of precancerous cervical lesions. We conducted an epigenome-wide association study (EWAS) of CpG methylation and progression to high-grade cervical intraepithelial neoplasia (CIN2 +) following an abnormal screening test.

METHODS

A prospective US cohort of 289 colposcopy patients with normal or CIN1 enrollment histology was assessed. Baseline cervical sample DNA was analyzed using Illumina HumanMethylation 450K (n = 76) or EPIC 850K (n = 213) arrays. Participants returned at provider-recommended intervals and were followed up to 5 years via medical records. We assessed continuous CpG M values for 9 cervical cancer-associated genes and time-to-progression to CIN2+. We estimated CpG-specific time-to-event ratios (TTER) and hazard ratios using adjusted, interval-censored Weibull accelerated failure time models. We also conducted an exploratory EWAS to identify novel CpGs with false discovery rate (FDR) < 0.05.

RESULTS

At enrollment, median age was 29.2 years; 64.0% were high-risk HPV-positive, and 54.3% were non-white. During follow-up (median 24.4 months), 15 participants progressed to CIN2+. Greater methylation levels were associated with a shorter time-to-CIN2+ for CADM1 cg03505501 (TTER = 0.28; 95%CI 0.12, 0.63; FDR = 0.03) and RARB Cluster 1 (TTER = 0.46; 95% CI 0.29, 0.71; FDR = 0.01). There was evidence of similar trends for DAPK1 cg14286732, PAX1 cg07213060, and PAX1 Cluster 1. The EWAS detected 336 novel progression-associated CpGs, including those located in CpG islands associated with genes FGF22, TOX, COL18A1, GPM6A, XAB2, TIMP2, GSPT1, NR4A2, and APBB1IP.

CONCLUSIONS

Using prospective time-to-event data, we detected associations between CADM1-, DAPK1-, PAX1-, and RARB-related CpGs and cervical disease progression, and we identified novel progression-associated CpGs.

IMPACT

Methylation levels at novel CpG sites may help identify individuals with ≤CIN1 histology at higher risk of progression to CIN2+ and inform risk-based cervical cancer screening guidelines.

Phytochemicals in cervical cancer: an epigenetic overview

Cervical cancer is the fourth most common female malignancy worldwide and a complex disease that typically starts with HPV infection. Various genetic and epigenetic alterations are implicated in its development. The current cervical cancer therapies have unsatisfactory outcomes due to their serious adverse effects, necessitating the need for safe, effective preventive and therapeutic modalities. Phytochemicals have been addressed in cervical cancer prevention and treatment, and further understanding the epigenetics of cervical cancer pathogenesis is critical to investigate new preventive and therapeutic modalities. Addressing the epigenetic mechanisms of potential phytochemicals will provide an overview of their use individually or in combination. The primary aim of this review is to highlight the epigenetic effects of the phytochemicals addressed in cervical cancer therapy.

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.

Advances in epigenetic modifications and cervical cancer research

Cervical cancer (CC) is an important public health problem for women, and perspectives and information regarding its prevention and treatment are quickly evolving. Human papilloma virus (HPV) has been recognized as a major contributor to CC development; however, HPV infection is not the only cause of CC. Epigenetics refers to changes in gene expression levels caused by non-gene sequence changes. Growing evidence suggests that the disruption of gene expression patterns which were governed by epigenetic modifications can result in cancer, autoimmune diseases, and various other maladies. This article mainly reviews the current research status of epigenetic modifications in CC based on four aspects, respectively DNA methylation, histone modification, noncoding RNA regulation and chromatin regulation, and we also discuss their functions and molecular mechanisms in the occurrence and progression of CC. This review provides new ideas for early screening, risk assessment, molecular targeted therapy and prognostic prediction of CC.

Vertical transmission of Human papillomavirus: experience from a center of southern Italy

BACKGROUND

Human papillomavirus (HPV) represents a group of DNA viruses, sexually transmitted, and widely accepted as a cause of invasive squamous cell carcinomas. The virus prevalence is critical worldwide. However, the possibility of perinatal transmission during pregnancy is not well understood as well as the risks for the newborn.

METHODS

Our study analyzed pregnant women referred to the obstetric outpatient room of the Department of Gynecology and Obstetrics of Sant'Anna and San Sebastiano University Hospital in Caserta, Italy. Cervicovaginal samples were achieved from patients during the first trimester and tested for HPV. The specimen was repeated during the third trimester for HPV-positive patients. After the birth, we took a placenta sample and an eye, pharyngeal, mouth, and genital samples in children from HPV positive mothers, at 36-48 hours after birth and three and six months.

RESULTS

We found out a high prevalence of HPV infections in the recruited patients: 71 participants were positive at the HPV test in the first trimester (45%), and 17 (14%) showed a positivity in the placental samples. However, there was a low prevalence of viral infection in newborns, and six newborns were positive for HPV at birth (9%).

CONCLUSIONS

HPV vertical transmission represents a critical obstetric topic, and the transplacental passage of the virus represents a possible cause. However, further studies are necessary to deepen the pathological mechanism and assess the risks for the newborn.

DNA hypermethylation of CADM1, PAX5, WT1, RARβ, and PAX6 genes in oropharyngeal cancer associated with human papillomavirus

Recently, an increasing incidence of HPV-induced oropharyngeal squamous cell carcinoma (OPSCC) has been observed. Moreover, locoregionally advanced stages require a combined modal approach, and the prognosis is poor. Therefore, it is essential to find early diagnostic and prognostic biomarkers. DNA methylation changes play a crucial role in the process of carcinogenesis and are often investigated as promising biomarkers in many types of cancer. For analysis of DNA methylation levels of selected tumour suppressor genes in HPV-positive and HPV-negative samples (including primary tumours and corresponding metastases of metastasizing OPSCCs, primary tumours of non-metastasizing OPSCCs, and control samples), methylation-specific MLPA and methylation-specific high-resolution melting analyses were used. A significant difference in methylation between OPSCCs and the control group was observed in WT1, PAX6 (P < 0.01) and CADM1, RARβ (P < 0.05) genes. CADM1 and WT1 hypermethylation was detected mostly in HPV-positive samples; all but one HPV-negative samples were unmethylated. Moreover, hypermethylation of PAX5 gene was observed in metastases compared with control samples and was also associated with shorter overall survival of all patients (P < 0.05). Associations described herein between promoter methylation of selected genes and clinicopathological data could benefit OPSCC patients in the future by improvement in screening, early detection, and prognosis of the disease.

The HPV Induced Cancer Resource (THInCR): a Suite of Tools for Investigating HPV-Dependent Human Carcinogenesis

Human papillomaviruses (HPVs) are highly infectious and cause the most common sexually transmitted viral infections. They induce hyperproliferation of squamous epithelial tissue, often forming warts. Virally encoded proteins reprogram gene expression and cell growth to create an optimal environment for viral replication. In addition to their normal roles in infection, functional alterations induced by viral proteins establish conditions that frequently contribute to human carcinogenesis. In fact, ~5% of human cancers are caused by HPVs, with virtually all cervical squamous cell carcinomas (CESC) and an increasing number of head and neck squamous cell carcinomas (HNSC) attributed to HPV infection. The Cancer Genome Atlas (TCGA) molecularly characterized thousands of primary human cancer samples in many cancer types, including CESC and HNSC, and created a comprehensive atlas of genomic, epigenomic, and transcriptomic data. This publicly available genome-wide information provides an unprecedented opportunity to expand the knowledge of the role that HPV plays in human carcinogenesis. While many tools exist to mine these data, few, if any, focus on the comparison of HPV-positive cancers with their HPV-negative counterparts or adjacent normal control tissue. We have constructed a suite of web-based tools, The HPV Induced Cancer Resource (THInCR), to utilize TCGA data for research related to HPV-induced CESC and HNSC. These tools allow investigators to gain greater biological and medical insights by exploring the impacts of HPV on cellular gene expression (mRNA and microRNA), altered gene methylation, and associations with patient survival and immune landscape features. These tools are accessible at https://thincr.ca/. IMPORTANCE The suite of analytical tools of THInCR provides the opportunity to investigate the roles that candidate target genes identified in cell lines or other model systems contribute to in actual HPV-dependent human cancers and is based on large-scale TCGA data sets. Expression of target genes, including both mRNA and microRNA, can be correlated with HPV gene expression, epigenetic changes in DNA methylation, patient survival, and numerous immune features, like leukocyte infiltration, interferon gamma response, T cell response, etc. Data from these analyses may immediately provide evidence to validate in vitro observations, reveal insights into mechanisms of virus-mediated alterations in cell growth, behavior, gene expression, and innate and adaptive immunity and may help hypothesis generation for further investigations.

Tumor DNA Methylation Profiles Enable Diagnosis, Prognosis Prediction, and Screening for Cervical Cancer

Background

DNA-methylation-based machine learning algorithms have demonstrated powerful diagnostic capabilities, and these tools are currently emerging in many fields of tumor diagnosis and patient prognosis prediction. This work aimed to identify novel DNA methylation diagnostic biomarkers for differentiating cervical cancer (CC) from normal tissues, as well as a prognostic prediction model to predict survival of CC patients.

Methods

The methylation profiles with the available clinical characteristics were downloaded from the Gene Expression Omnibus (GEO) database and The Cancer Genome Atlas (TCGA) program. We first screened out the differential methylation sites in CC and normal tissues and performed multiple statistical analyses to discover DNA methylation diagnostic markers that are used to distinguish CC and normal control. Then, we developed a methylation-based survival model to improve risk stratification.

Results

A diagnostic prediction panel consists of five CpG markers that could predict cervical cancer versus normal tissue with highly correct rate of 100%, and cg16428251, cg22341310, and cg23316360 which in diagnostic prediction panel all could yield high sensitivity and specificity for detection of CC and normal in six cohorts (area under curve [AUC] > 0.8), in addition to excellent performance in discriminating between CC and normal sample. The diagnostic marker panel also effectively predicted the CIN3 versus normal tissue with high accuracy in two datasets (AUC = 0.80, 0.789, respectively). Furthermore, a prognostic prediction model aggregated two CpG markers that effectively stratified the prognosis of high-risk and low-risk groups (training cohort: hazard ratio [HR] 4, 95% CI: 1.7–9.6, P = 0.0021; testing cohort: hazard ratio [HR] 1.9, 95% CI: 1.2–3.1, P = 0.0072).

Conclusion

The findings of our study showed that DNA methylation markers are of great value in the diagnosis and prognosis of CC.

Accelerated Epigenetic Age Among Women with Invasive Cervical Cancer and HIV-Infection in Nigeria

Background

Invasive cervical cancer (ICC) is a serious public health burden in Nigeria, where human immunodeficiency virus (HIV) remains highly prevalent. Previous research suggested that epigenetic age acceleration (EAA) could play a role in detection of HIV-associated ICC. However, little research has been conducted on this topic in Africa where the population is most severely affected by HIV-associated ICC. Here, we investigated the association between ICC and EAA using cervical tissues of ICC-diagnosed Nigerian women living with HIV.

Methods

We included 116 cervical tissue samples from three groups of Nigerian women in this study: (1) HIV+/ICC+ (n = 39); (2) HIV+/ICC- (n = 53); and (3) HIV-/ICC + (n = 24). We utilized four DNA methylation-based EAA estimators; IEAA, EEAA, GrimAA, and PhenoAA. We compared EAA measurements across the 3 HIV/ICC groups using multiple linear regression models. We also compared EAA between 26 tumor tissues and their surrounding normal tissues using paired t-tests. We additionally performed a receiver operating characteristics (ROC) curve analysis to illustrate the area under the curve (AUC) of EAA in ICC.

Results

We found the most striking associations between HIV/ICC status and PhenoAge acceleration (PhenoAA). Among HIV-positive women, PhenoAA was on average 13.4 years higher in women with ICC compared to cancer-free women (P = 0.005). PhenoAA was 20.7 and 7.1 years higher in tumor tissues compared to surrounding normal tissues among HIV-positive women (P = 0.009) and HIV-negative women (P = 0.284), respectively. We did not find substantial differences in PhenoAA between HIV-positive and HIV-negative women with ICC.

Conclusion

PhenoAA is associated with ICC in HIV-infected women in our study. Our findings suggest that PhenoAA may serve as a potential biomarker for further risk stratification of HIV-associated ICC in Nigeria and similar resource-constrained settings.

Performance of DNA methylation-based biomarkers in the cervical cancer screening program of northern Portugal: A feasibility study

Cervical cancer remains a health concern. Effective screening programs are critical to reduce the incidence and mortality. High-risk HPV (hr-HPV) testing as primary screening tool discloses high sensitivity but suboptimal specificity. Adequate triage tests to reduce unnecessary colposcopy referrals and overdiagnosis/overtreatment are crucial. Hence, we aimed to validate a panel of DNA methylation-based markers as triage test for women hr-HPV+ in the population-based Regional Cervical Cancer Screening Program of Northern Portugal. Firstly, CADM1, MAL, FAM19A4 and hsa-miR124-2 promoter methylation levels were assessed by multiplex QMSP in a testing set of 402 FFPE tissue samples (159 normal samples and 243 cervical lesions, including 39 low-grade intraepithelial squamous lesions [LSIL], 59 high-grade intraepithelial squamous lesions [HSIL] and 145 cancerous lesions). Then, preliminary validation was performed in 125 hr-HPV+ cervical scrapes (including 59 normal samples, 30 LSIL, 34 HSIL and 2 cancerous lesions). Higher MAL^me , FAM19A4^me and hsa-miR124-2^me methylation levels were disclosed in histological HSIL or worse (HSIL+) in testing set. Individually, markers depicted over 86% specificity for HSIL+ detection. In validation set, all these genes significantly differed between histological HSIL+ and low-grade squamous intraepithelial lesions or less. In combination, these markers reached 74% specificity and 61% sensitivity for identification of histological HSIL+. We concluded that host gene methylation might constitute a useful referral triage tool of hr-HPV+ women enrolled in the Cervical Cancer Screening Program of Northern Portugal.

Molecular markers for cervical cancer screening

INTRODUCTION

Cervical cancer remains a significant healthcare problem, notably in low- to middle-income countries. While a negative test for hrHPV has a predictive value of more than 99.5%, its positive predictive value is less than 10% for CIN2+ stages. This makes the use of a so-called triage test indispensable for population-based screening to avoid referring women, that are ultimately at low risk of developing cervical cancer, to a gynecologist. This review will give an overview of tests that are based on epigenetic marker panels and protein markers.

AREAS COVERED

There is a medical need for molecular markers with a better predictive value to discriminate hrHPV-positive women that are at risk of developing cervical cancer from those that are not. Areas covered are epigenetic and protein markers as well as health economic considerations in view of the fact that most cases of cervical cancer arise in low-to-middle-income countries.

EXPERT OPINION

While there are biomarker assays based on changes at the nucleic acid (DNA methylation patterns, miRNAs) and at the protein level, they are not widely used in population screening. Combining nucleic acid-based and protein-based tests could improve the overall specificity for discriminating CIN2+ lesions that carry a low risk of progressing to cervical cancer within the screening interval from those that carry an elevated risk. The challenge is to reduce unnecessary referrals without an undesired increase in false-negative diagnoses resulting in cases of cervical cancer that could have been prevented. A further challenge is to develop tests for low-and middle-income countries, which is critical to reduce the worldwide burden of cervical cancer.

Antineoplastic action of sulforaphane on HeLa cells by modulation of signaling pathways and epigenetic pathways

BACKGROUND

Epigenetic modifications alter signaling and molecular pathways and are an important therapeutic target. This study examined the effect of sulforaphane on molecular targets in HeLa cells.

METHODS

Quantitative PCR of various molecular targets was performed. Activity of epigenetic enzymes was measured by ELISA and molecular docking analysis was conducted. Promoter methylation of some tumour suppressor genes was quantified using PCR based methylation array. In-silico protein-protein interaction network analysis was performed to understand the effect of transcriptional changes.

RESULTS

Quantitative PCR demonstrated the transcriptional modulation of genes involved in proliferation, metastasis, inflammation, signal transduction pathways and chromatin modifiers. Sulforaphane reduced the enzymatic activity of DNA methyl transferases, histone deacetylases and histone methyltransferases. Molecular docking results suggest that sulforaphane competitively inhibited several DNA methyl transferases and histone deacetylases. Promoter 5'CpG methylation levels of selected tumour suppressor genes was found to be reduced which correlated with their transcriptional increase as well modulation of epigenetic enzymes. Further, protein-protein interaction network analysis discerned the participation of genes towards cancer pathways. Functional enrichment and pathway-based analysis represented the modulation of epigenetic and signaling pathways on sulforaphane treatment.

CONCLUSIONS

The modulation in transcriptional status of epigenetic regulators, genes involved in tumorigenesis resulting in tumour suppressor genes demethylation and re-expression underscores the mechanism behind the anti-cancer effect of sulforaphane on HeLa cells.

CD155 Promotes the Progression of Cervical Cancer Cells Through AKT/mTOR and NF-κB Pathways

Expression of the immunoglobulin superfamily member CD155 was increased in a variety of human malignancies, but the role of CD155 in tumorigenesis and tumor development in cervical cancer has not been elucidated. In this study, immunohistochemistry and enzyme-linked immunosorbent assay analyses showed that CD155 expression gradually increases with the degree of cervical lesions. In vitro and in vivo, reducing the expression of CD155 inhibited cell proliferation, cell viability and tumor formation and arrested the cell cycle in G0/G1 phase. Antibody array-based profiling of protein phosphorylation revealed that CD155 knockdown can inhibited the AKT/mTOR/NF-κB pathway and activated autophagy and apoptosis; the opposite effects were observed upon CD155 has overexpression. We proved that there is an interaction between CD155 and AKT by immunoprecipitation. We further confirmed the mechanism between CD155 and AKT/mTOR/NF-κB through rescue experiments. AKT knockdown reversed the anti-apoptotic effects and activation of the AKT/mTOR/NF-κB pathway induced by CD155 overexpression. Our research demonstrated that CD155 can interact with AKT to form a complex, activates the AKT/mTOR/NF-κB pathway and inhibit autophagy and apoptosis. Thus, CD155 is a potential screening and therapeutic biomarker for cervical cancer.

ZNF471 modulates EMT and functions as methylation regulated tumor suppressor with diagnostic and prognostic significance in cervical cancer

Cervical cancer (CC) is a leading cause of cancer-related death among women in developing countries. However, the underlying mechanisms and molecular targets for therapy remain to be fully understood. We investigated the epigenetic regulation, biological functions, and clinical utility of zinc-finger protein 471 (ZNF471) in CC. Analysis of cervical tissues and five independent public datasets of CC showed significant hypermethylation of the ZNF471 gene promoter. In CC cell lines, promoter DNA methylation was inversely correlated with ZNF471 expression. The sensitivity and specificity of the ZNF471 hypermethylation for squamous intraepithelial lesion (SIL) vs tumor and normal vs tumor was above 85% with AUC of 0.937. High methylation and low ZNF471 expression predicted poor overall and recurrence-free survival. We identified -686 to +114 bp as ZNF471 promoter, regulated by methylation using transient transfection and luciferase assays. The promoter CpG site methylation of ZNF471 was significantly different among cancer types and tumor grades. Gal4-based heterologous luciferase reporter gene assays revealed that ZNF471 acts as a transcriptional repressor. The retroviral mediated overexpression of ZNF471 in SiHa and CaSki cells inhibited growth, proliferation, cell migration, invasion; delayed cell cycle progression in vitro by increasing cell doubling time; and reduced tumor growth in vivo in nude mice. ZNF471 overexpression inhibited key members of epithelial-mesenchymal transition (EMT), Wnt, and PI3K-AKT signaling pathways. ZNF471 inhibited EMT by directly targeting vimentin as analyzed by bioinformatic analysis, ChIP-PCR, and western blotting. Thus, ZNF471 CpG specific promoter methylation may determine the prognosis of CC and could function as a potential tumor suppressor by targeting EMT signaling.

Detection of DKK-1 gene methylation in exfoliated cells of cervical squamous cell carcinoma and its relationship with high risk HPV infection

PURPOSE

To detect the methylation of Dickkopf-associated protein 1 (DKK-1) gene promoter in cervical exfoliated cells and to study its clinical significance in cervical squamous cell carcinoma (CSCC) and its relationship with high-risk HPV infection.

METHODS

Methylation-specific PCR (MSP) was utilized to detect the methylation of DKK-1 gene promoter in cervical exfoliated cells from 40 patients with CSCC and 40 patients with chronic cervicitis in the Affiliated Hospital of Inner Mongolia Medical University. The methylation rate of DKK-1 gene promoter in different clinicopathological factors and its relationship with high-risk HPV infection was compared, and different detection methods were compared.

RESULT

The degree of methylation of DKK-1 gene promoter in CSCC group was significantly higher than that in cervicitis group (P < 0.05). In CSCC group, the degree of methylation was significantly different in high-risk HPV infection, histological differentiation, tumor size, lymph node metastasis and the International Federation of Gynecology and Obstetrics (FIGO) staging (all P < 0.05). The degree of methylation is not related to the type of high-risk HPV infection (P > 0.05). The one-year survival rate of CSCC patients with high-risk HPV positive and DKK-1 gene promoter methylation is relatively low, only 74.1%. The sensitivity, specificity and accuracy of DKK-1 gene methylation combined with high-risk HPV detection were 96.7%, 78.0% and 85.0%, respectively.

CONCLUSION

Methylation of DKK-1 gene promoter in cervical exfoliated cells of patients with CSCC is related to high-risk HPV infection and different clinicopathological factors, but the degree of methylation of DKK-1 gene is not related to the type of high-risk HPV infection. It may become an indicator different from HPV typing detection, which may play a shunt role in suggesting whether further invasive cervical examination is needed and reduce cervical invasive examination and overtreatment. It may be related to the survival rate of patients, which can be used to estimate the development and prognosis of CSCC and may play a good role in early warning in follow-up monitoring of CSCC after treatment. DKK1 gene methylation combined with HPV detection can improve the sensitivity, specificity and accuracy of diagnosis, which may improve the detection rate of early CSCC and make up for the deficiency of HPV and TCT detection. That may become a non-invasive screening method for CSCC.

An Insight into the Role of UTF1 in Development, Stem Cells, and Cancer

The curiosity to understand the mechanisms regulating transcription in pluripotent cells resulted in identifying a unique transcription factor named Undifferentiated embryonic cell transcription factor 1 (UTF1). This proline-rich, nuclear protein is highly conserved among placental mammals with prominent expression observed in pluripotent, germ, and cancer cells. In pluripotent and germ cells, its role has been implicated primarily in proper cell differentiation, whereas in cancer, it shows tissue-specific function, either as an oncogene or a tumor suppressor gene. Furthermore, UTF1 is crucial for germ cell development, spermatogenesis, and maintaining male fertility in mice. In addition, recent studies have demonstrated the importance of UTF1 in the generation of high quality induced Pluripotent Stem Cells (iPSCs) and as an excellent biomarker to identify bona fide iPSCs. Functionally, UTF1 aids in establishing a favorable chromatin state in embryonic stem cells, reducing "transcriptional noise" and possibly functions similarly in re-establishing this state in differentiated cells upon their reprogramming to generate mature iPSCs. This review highlights the multifaceted roles of UTF1 and its implication in development, spermatogenesis, stem, and cancer cells.

Dietary isothiocyanates inhibit cancer progression by modulation of epigenome

Cell cycle, growth, survival and metabolism are tightly regulated together and failure in cellular regulation leads to carcinogenesis. Several signaling pathways like the PI3K, WNT, MAPK and NFKb pathway exhibit aberrations in cancer and help achieve hallmark capabilities. Clinical research and in vitro studies have highlighted the role of epigenetic alterations in cancer onset and development. Altered gene expression patterns enabled by changes in DNA methylation, histone modifications and RNA processing have proven roles in cancer hallmark acquisition. The reversible nature of epigenetic processes offers robust therapeutic targets. Dietary bioactive compounds offer a vast compendium of effective therapeutic moieties. Isothiocyanates (ITCs) sourced from cruciferous vegetables demonstrate anti-proliferative, pro-apoptotic, anti-inflammatory, anti-migratory and anti-angiogenic effect against several cancers. ITCs also modulate the redox environment, modulate signaling pathways including PI3K, MAPK, WNT, and NFkB. They also modulate the epigenetic machinery by regulating the expression and activity of DNA methyltransferases, histone modifiers and miRNA. This further enhances their transcriptional modulation of key cellular regulators. In this review, we comprehensively assess the impact of ITCs such as sulforaphane, phenethyl isothiocyanate, benzyl isothiocyanate and allyl isothiocyanate on cancer and document their effect on various molecular targets. Overall, this will facilitate consolidation of the current understanding of the anti-cancer and epigenetic modulatory potential of these compounds and recognize the gaps in literature. Further, we discuss avenues of future research to develop these compounds as potential therapeutic entities.

Prognostic alternative splicing signature in cervical squamous cell carcinoma

Basing on alternative splicing events (ASEs) databases, the authors herein aim to explore potential prognostic biomarkers for cervical squamous cell carcinoma (CESC). mRNA expression profiles and relevant clinical data of 223 patients with CESC were obtained from The Cancer Genome Atlas (TCGA). Correlated genes, ASEs and percent-splice-in (PSI) were downloaded from SpliceSeq, respectively. The PSI values of survival-associated alternative splicing events (SASEs) were used to construct the basis of a prognostic index (PI). A protein-protein interaction (PPI) network of genes related to SASEs was generated by STRING and analysed with Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Consequently, 41,776 ASEs were discovered in 19,724 genes, 2596 of which linked with 3669 SASEs. The PPI network of SASEs related genes revealed that TP53 and UBA52 were core genes. The low-risk group had a longer survival period than high-risk counterparts, both groups being defined according to PI constructed upon the top 20 splicing events or PI on the overall splicing events. The AUC value of ROC reached up to 0.88, demonstrating the prognostic potential of PI in CESC. These findings suggested that ASEs involve in the pathogenesis of CESC and may serve as promising prognostic biomarkers for this female malignancy.

Molecular landscape of recurrent cervical cancer

Cervical cancer (CC) is a major gynecological problem in developing and underdeveloped countries. Despite the significant advancement in early detection and treatment modalities, several patients recur. Moreover, the molecular mechanisms responsible for CC recurrence remains obscure. The patients with CC recurrence often show poor prognosis and significantly high mortality rates. The clinical management of recurrent CC depends on treatment history, site, and extent of the recurrence. Owing to poor prognosis and limited treatment options, recurrent CC often presents a challenge to the clinicians. Several in vitro, in vivo, and patient studies have led to the identification of the critical molecular changes responsible for CC recurrence. Both aberrant genetic and epigenetic modifications leading to altered cell signaling pathways have been reported to impact CC recurrence. Researchers are currently trying to dissect the molecular pathways in CC and translate these findings for better management of disease. This article attempts to review the existing knowledge of disease relapse, accompanying challenges, and associated molecular players in CC.

Epigallocatechin gallate inhibits HeLa cells by modulation of epigenetics and signaling pathways

This study examines the effect of epigallocatechin gallate (EGCG) on signaling pathways, epigenetic modulators and tumour suppressor genes in cervical cancer cells, HeLa. qRT-PCR, ELISA-based enzymatic assays and in silico studies were used to catalogue the modulation of these genes by EGCG treatment. qRT-PCR showed transcriptional modulation of several epigenetic modifiers including DNA methyltransferases and histone modifiers (DNMT1, DNMT3B, DNMT3A, AURKA, AURKC, AURKB, KDM4A, KDM5C, PRMT7, PRMT6, UBE2B, HDAC5, HDAC6, HDAC7 and HDAC11. Furthermore, ELISA-based assays showed that EGCG lowered the activity of DNA methyltransferases, histone deacetylases and histone methyltransferases (H3K9). Molecular docking results suggests that EGCG may competitively inhibit some epigenetic enzymes (DNMT1, DNMT3A, HDAC2, HDAC3, HDAC4, HDAC7 and EZH2). A functional outcome of these epigenetic alterations could be inferred from the reversal of promoter hypermethylation of tumour suppressor genes by quantitative methylation array and transcriptional re-expression of tumour suppressor genes including TP73, PTEN, SOCS1, CDH1, RARβ, and DAPK1 by qRT-PCR. Downregulation of key signaling moieties of PI3K, Wnt and MAPK pathways, cell cycle regulators, metastasis regulators and pro-inflammatory moieties including TERT, CCNB1, CCNB2, MMP2, MMP7. PIK3C2B, PIK3CA, MAPK8 and IL6 was also observed. In silico protein-protein interaction network analysis followed by KEGG analysis discerned the active participation of gene sets towards cancer pathways. This study comprehensively explains EGCG's anti-cancer mechanism via the synchronized transcriptional alteration of several molecular targets across different signaling pathways and reversal of tumour suppressor gene silencing through modulation of epigenetic enzymes.

Methylation-driven genes and their prognostic value in cervical squamous cell carcinoma

Background

Abnormal gene methylation is crucial for tumor progression. This study explored a cluster of methylation-driven genes involved in cervical squamous cell carcinoma (CESC).

Methods

The data on RNA expression, methylation and clinical outcomes of CESC patients were downloaded from The Cancer Genome Atlas (TCGA) database. Protein-protein interaction (PPI) network was constructed. Gene Ontology (GO) and KEGG analyses were performed to identify the biological functions of methylation-driven genes, and univariable and multivariate Cox analyses to screen out the key prognostic genes. A risk signature was established and its predictive value was evaluated with Kaplan-Meier and ROC curves. The key genes were further investigated by Cox regression analyses, gene set enrichment analysis (GSEA), and methylation site analysis. Additionally, "rms" package was used for establishing nomogram and calibrate curve.

Results

We found 144 differentially expressed methylation-driven genes. A risk model was constructed with three key prognostic genes (ITGA5, HHEX and S1PR4). The risk score was an independent risk factor for CESC prognosis. Lowly-expressed and hypermethylated ITGA5, highly-expressed and hypomethylated HHEX and S1PR4 were associated with better CESC prognosis. The methylation sites and biological functions enriched in ITGA5, HHEX and S1PR4 were uncovered. Additionally, the nomogram also validated the performance of risk model.

Conclusions

Methylation-driven ITGA5, HHEX and S1PR4 are associated with CESC development. The three genes might serve as potential targets in the treatment of CESC.

HOXA5 inhibits the proliferation and neoplasia of cervical cancer cells via downregulating the activity of the Wnt/β-catenin pathway and transactivating TP53

HOXA5 is considered a regulator involved in embryonic development and cellular differentiation and a tumor suppressor. Nevertheless, its biological role in cervical carcinoma is still unclear. In the present study, immunohistochemistry showed that HOXA5 expression gradually decreased as the degree of cervical lesions deepened. Ectopic expression of HOXA5 restrained cell proliferation, decreased cell viability, and inhibited tumor formation in vitro and in vivo. Furthermore, the expression of HOXA5 could arrest cell cycle from G0/G1 to S phase. RNA-seq revealed that p21 and cyclinD1 were involved in this process. Moreover, the gene set enrichment analysis and the TOP/FOP reporter assay both suggested that HOXA5 could restrain the activity of the Wnt/β-catenin pathway. Further study using dual-luciferase reporter assay and quantitative chromatin immunoprecipitation assay demonstrated that HOXA5 could directly bind to the TAAT motif within the promoter of TP53 by its HD domain and transactivate TP53, which can upregulate p21. Altogether, our data suggest that HOXA5 inhibits the proliferation and neoplasia via repression activity of the Wnt/β-catenin pathway and transactivating TP53 in cervical cancer.

Host-Directed Antiviral Therapy

Antiviral drugs have traditionally been developed by directly targeting essential viral components. However, this strategy often fails due to the rapid generation of drug-resistant viruses. Recent genome-wide approaches, such as those employing small interfering RNA (siRNA) or clustered regularly interspaced short palindromic repeats (CRISPR) or those using small molecule chemical inhibitors targeting the cellular "kinome," have been used successfully to identify cellular factors that can support virus replication. Since some of these cellular factors are critical for virus replication, but are dispensable for the host, they can serve as novel targets for antiviral drug development. In addition, potentiation of immune responses, regulation of cytokine storms, and modulation of epigenetic changes upon virus infections are also feasible approaches to control infections. Because it is less likely that viruses will mutate to replace missing cellular functions, the chance of generating drug-resistant mutants with host-targeted inhibitor approaches is minimized. However, drug resistance against some host-directed agents can, in fact, occur under certain circumstances, such as long-term selection pressure of a host-directed antiviral agent that can allow the virus the opportunity to adapt to use an alternate host factor or to alter its affinity toward the target that confers resistance. This review describes novel approaches for antiviral drug development with a focus on host-directed therapies and the potential mechanisms that may account for the acquisition of antiviral drug resistance against host-directed agents.

A 10-gene prognostic methylation signature for stage I-III cervical cancer

PURPOSE

Cervical cancer (CC) patients usually have poor prognosis. The present study aims to find a DNA methylation signature for predicting survival of CC patients.

METHODS

We selected CC patients at pathological stage I-III with corresponding information on radiotherapy and overall survival (OS) from TCGA. Differential expression and methylation analysis was done between patients with and without radiotherapy. We selected feature genes using recursive feature elimination algorithm to build a support vector machine classifier. DNA methylation biomarkers predictive of prognosis were identified using a LASSO Cox-Proportional Hazards model to construct a prognostic scoring model. The classifier and the prognostic model were tested on the training set and the validation set. Nomogram combining risk score and prognostic clinical factors were used.

RESULTS

We obtained 497 differentially expressed genes (DEGs) and 865 differentially methylated genes (DMGs). Fifteen feature genes were selected from the 292 common genes between the DEGs and the DMGs to construct a classification model for radiotherapy. A DNA methylation signature including 10 genes was identified and used to establish a prognostic scoring model. The 10-gene methylation signature could effectively separate patients into two risk groups with markedly different OS time. Predictive capability of the methylation signature was successfully confirmed on the validation set. A nomogram comprised of risk score, radiotherapy, and recurrence was applied, with calibration plots displaying good concordance between predicted and actual OS. The DEGs were involved in 12 KEGG pathways most of which were correlated with metastasis and proliferation of various cancers, such as pathways in cancer, basal cell carcinoma, transcriptional misregulation in cancer and ECM-receptor interaction.

CONCLUSION

We Identified a 10-gene methylation signature for risk stratification of CC patients at pathological stages I-III, and ten methylation biomarkers might be novel therapeutic targets for CC.

Long Non-Coding RNA LINC01783 Promotes the Progression of Cervical Cancer by Sponging miR-199b-5p to Mediate GBP1 Expression

BACKGROUND

Long non-coding RNA showed potential regulating effects in oncogenesis. Highly expressed LncRNA LINC01783 is observed in cervical cancer. However, the specific pathogenesis of cervical cancer is still unclear.

METHODS

Differential lncRNAs in cervical cancer were identified based on TCGA dataset. Subsequently, qRT-PCR was utilized for testing the LINC01783 expression in cervical cancer cell lines and normal human cervical epithelial cell line HcerEpic. CCK-8, EdU, Wound healing assay, Transwell assay and flow cytometry were used for detecting proliferative and migratory potential, cell cycle and apoptosis of cervical cancer cells, respectively. To identify the potential target of LINC01783, bioinformatics assay and dual-luciferase reporter gene assay were performed. Moreover, to clarify their interactions and roles in regulating the progression of cervical cancer, Western blot assay and RIP assay were carried out.

RESULTS

Our results revealed LINC01783 is overexpressed in cervical cancer cells. Overexpressed LINC01783 considerably accelerated the cell proliferation, migration and invasion of cervical cancer cells while restrained cell apoptosis of them. Moreover, LINC01783 positively regulated the GBP1 expression via competitively binding to miR-199b-5p.

CONCLUSION

LINC01783 is involved in the progression of cervical cancer through competitively binding to miR-199b-5p to mediate GBP1 expression.

Genistein Modulates Signaling Pathways and Targets Several Epigenetic Markers in HeLa Cells

BACKGROUND

Several epigenetic changes are responsible for transcriptional alterations of signaling pathways and tumour suppressor genes (TSGs) contributing to carcinogenesis. This study was aimed to examine the effect of the phytochemical, genistein on various molecular targets in HeLa cells.

METHODS

Quantitative PCR was used to analyze the expression of various molecular targets. Biochemical assays were employed to study the epigenetic enzymes. To correlate the transcriptional status of the selected TSGs and epigenetic modulation, their promoter 5'CpG methylation levels were evaluated by quantitative methylation array followed by methylation specific restriction digestion.

RESULTS

The expression of several genes involved in the cell cycle regulation, migration, inflammation, phosphatidylinositol 3-kinase (PI3K) and mitogen activated kinase-like protein (MAPK) pathway were found to be modulated including CCNB1, TWIST1, MMP14, TERT, AKT1, PTPRR, FOS and IL1A. Genistein modulated the expression of DNA methyltransferases (DNMTs), histone deacetylases (HDACs), histone methyltransferases (HMTs), demethylases, and histone phosphorylases. Furthermore, genistein decreased the activity of DNMTs, HDACs, and HMTs and reduced global DNA methylation levels. Promoter methylation of several TSGs, including FHIT, RUNX3, CDH1, PTEN, and SOC51, was lowered with corresponding transcriptional increase. Network analysis indicated similar effect of genistein.

CONCLUSION

This study presents a comprehensive mechanism of action of genistein showcasing effective epigenetic modulation and widespread transcriptional changes resulting in restoration of tumour suppressor gene expression. This study corroborates the development of genistein as a candidate for anti-cancer therapy.

Quercetin modifies 5'CpG promoter methylation and reactivates various tumor suppressor genes by modulating epigenetic marks in human cervical cancer cells

The central role of epigenomic alterations in carcinogenesis has been widely acknowledged, particularly the impact of DNA methylation on gene expression across all stages of carcinogenesis is considered vital for both diagnostic and therapeutic strategies. Dietary phytochemicals hold great promise as safe anticancer agents and effective epigenetic modulators. This study was designed to investigate the potential of a phytochemical, quercetin as a modulator of the epigenetic pathways for anticancer strategies. Biochemical activity of DNA methyltransferases (DNMTs), histone deacetylases (HDACs), histone methyltransferases (HMTs), and global genomic DNA methylation was quantitated by an enzyme-linked immunosorbent assay based assay in quercetin-treated HeLa cells. Molecular docking studies were performed to predict the interaction of quercetin with DNMTs and HDACs. Quantitative methylation array was used to assess quercetin-mediated alterations in the promoter methylation of selected tumor suppressor genes (TSGs). Quercetin induced modulation of chromatin modifiers including DNMTs, HDACs, histone acetyltransferases (HAT) and HMTs, and TSGs were assessed by quantitative reverse transcription PCR (qRT-PCR). It was found that quercetin modulates the expression of various chromatin modifiers and decreases the activity of DNMTs, HDACs, and HMTs in a dose-dependent manner. Molecular docking results suggest that quercetin could function as a competitive inhibitor by interacting with residues in the catalytic cavity of several DNMTs and HDACs. Quercetin downregulated global DNA methylation levels in a dose- and time-dependent manner. The tested TSGs showed steep dose-dependent decline in promoter methylation with the restoration of their expression. Our study provides an understanding of the quercetin's mechanism of action and will aid in its development as a candidate for epigenetic-based anticancer therapy.

Screening of Cervical Cancer with Self-Collected Cervical Samples and Next-Generation Sequencing

Cervical cancer is the second leading cause of death in female genital malignancies. Persistent infection with high-risk HPV is closely related to cervical intraepithelial neoplasia (CIN). Wide-scale HPV screening has already been implemented in developed countries. However, with advances in HPV testing methods, there are presently no better methods for the management of the increasing number of high-risk HPV-positive women except for periodic review. In order to improve screening coverage and achieve better triage of those women, we present current HPV testing methods with self-collected cervical samples, focusing on recent advances in next-generation sequencing (NGS) technologies as a promising screening technology for cervical cancer precursors.

The unique DEK oncoprotein in women's health: A potential novel biomarker

Breast and cervical cancer are the first and fourth cancer types with the highest prevalence in women, respectively. The developmental profiles of cancer in women can vary by genetic markers and cellular events. In turn, age and lifestyle influence in the cellular response and also on the cancer progression and relapse. The human DEK protein, a histone chaperone, belongs to a specific subclass of chromatin topology modulators, being involved in the regulation of DNA-dependent processes. These epigenetic mechanisms have dynamic and reversible nature, have been proposed as targets for different treatment approaches, especially in tumor therapy. The expression patterns of DEK vary between healthy and cancer cells. High expression of DEK is associated with poor prognosis in many cancer types, suggesting that DEK takes part in oncogenic activities via different molecular pathways, including inhibition of senescence and apoptosis. The focus of this review was to highlight the role of the DEK protein in these two female cancers.

Interleukin-6 determines protein stabilization of DNA methyltransferases and alters DNA promoter methylation of genes associated with insulin signaling and angiogenesis

Individuals with type 2 diabetes (T2D) display vascular insulin resistance and decreased nitric oxide production leading to vasoconstriction and atherosclerosis. Soluble factors such as pro-inflammatory molecules, and various genetic and epigenetic mechanisms have been implicated to induce insulin resistance in vascular endothelial cells. Epigenetic mechanisms such as altered promoter DNA methylation have been demonstrated in development and progression of metabolic disorders and atherosclerosis. However, underlying precise epigenetic mechanisms regulating cross talk between insulin signaling genes and inflammation in vascular cells remains to be fully understood. Human endothelial cells when (a) treated with interleukin-6 (IL-6) and insulin together, (b) pretreated with IL-6, and (c) under hyperinsulinemic conditions led to a state of vascular insulin resistance resulting in decreased Akt/eNOS activation and subsequent stabilization of STAT3 phosphorylation. IL-6 abrogated insulin effects on angiogenesis in 3D spheroid and matrigel assays. IL-6-induced insulin resistance was associated with decreased activity of DNA methyltransferase isoforms and global DNA hypomethylation, which inversely correlated with S-phase of cell cycle. CpG microarray analysis in IL-6 treated endothelial cells revealed promoters associated hypo- and hypermethylation of 199 and 98 genes respectively. Promoter DNA methylation status of genes associated with insulin signaling and angiogenesis such as RPS6KA2, PIK3R2, FOXD3, EXOC7, MAP3K8, ITPKB, EPHA6, IGF1R, and FOXC2 were validated by bisulfite DNA sequencing. Concentration and time-dependent analysis revealed that IL-6 reduced DNMT1 and DNMT3B but not DNMT3A protein levels. Our data indicate a causal link between IL-6-induced changes in global and promoter-specific DNA methylation, due to reduced DNMT1 and DNMT3B protein levels leading to altered expression of critical genes involved in insulin signaling and angiogenesis.

Recent findings on epigenetic gene abnormalities involved in uterine cancer

Selective aberrant genetic effects that do not depend on abnormal DNA sequences are referred to as epigenetic abnormalities and are involved in carcinogenesis. In uterine cancer, various genes involved in apoptosis, cell cycle, DNA repair, cell proliferation and cell adhesion are abnormally methylated, resulting in gene silencing. Reversal of such epigenetic abnormalities in cancer cells is a potential strategy for cancer therapy, and studies on epigenetic abnormalities and treatment methods in uterine cancer are in progress. These include the evaluation of 5-hydroxymethylcytosine, which is present in cancer tissues at lower levels compared with those in normal tissues, as a prognostic marker in cervical cancer; combination therapy with 5-azacytidine and cisplatin; combination treatment focusing on tumor necrosis factor-related apoptosis-inducing ligand in cervical cancer; studies focusing on DNA mismatch repair in endometrial cancer; and use of a demethylating agent to reactivate tumor suppressor genes and inhibit tumor proliferation. Detection of epigenetic changes using biomarkers may be used for histological classification, evaluation of disease progression and identification of compounds that are able to modulate epigenetic changes and may be useful for uterine cancer treatment.

Modulation of DNA methylation by human papillomavirus E6 and E7 oncoproteins in cervical cancer

Human papillomaviruses (HPVs) are double stranded circular DNA viruses that infect cutaneous and mucosal epithelial cells. Almost 99% of cervical cancer has a HPV infection. The early oncoproteins E6 and E7 are important in this cellular transformation process. Epigenetic mechanisms have long been known to result in decisive alterations in DNA, leading to alterations in DNA-protein interactions, alterations in chromatin structure and compaction and significant alterations in gene expression. The enzymes responsible for these epigenetic modifications are DNA methyl transferases (DNMTs), histone acetylases and deacetylases. Epigenetics has an important role in cancer development by modifying the cellular micro environment. In this review, the authors discuss the role of HPV oncoproteins E6 and E7 in modulating the epigenetic mechanisms inside the host cell. The oncoproteins induce the expression of DNMTs which lead to aberrant DNA methylations and disruption of the normal epigenetic processes. The E7 oncoprotein may additionally directly bind and induce methyl transferase activity of the enzyme. These modulations lead to altered gene expression levels, particularly the genes involved in apoptosis, cell cycle and cell adhesion. In addition, the present review discusses how epigenetic mechanisms may be targeted for possible therapeutic interventions for HPV mediated cervical cancer.

Tumor markers of uterine cervical cancer: a new scenario to guide surgical practice?

Since the introduction of Pap smear screening, the incidence and mortality of cervical cancer (CC) have been reduced drastically in USA and in other western states. Nevertheless, CC still remains the main cause of death from gynecological cancer in developing countries where screening programs are scant or inexistent. This evidence highlights the efficacy of screening, and the wide use of Human Papilloma Viruses (HPV) vaccines in developed countries. More and more people are, consequentially, undergoing a screening procedure, usually combined with HPV DNA test, increasing the early diagnosis of intraepithelial HPV-related lesions. The long transit time from early cervical lesion to invasive cancer provides an opportunity to identify pre-cancerous lesions where treatment result is maximum. In fact, when an invasive CC occurs, the overall survival rate strictly depends on stage of disease with an average survival of 70% at 5 years. Under the pressure of this reality, researches have made efforts to individuate cancer markers as indicator of specific cancer events. Some markers were showed to be able to detect those intraepithelial lesions have more chance to evolve to invasive forms (p16^ink4a, p16, E-cadherin, Ki67, pRb, p53). Markers such as CEA, SCC-Ag, CD44, have been developed to detect invasive forms. Although cancer markers actually are not used only for early diagnosis, they may be useful in others fields of application such as evaluation and monitoring of treatments to improve diagnosis and treatment of CC.

Methylomics of nitroxidative stress on precancerous cells reveals DNA methylation alteration at the transition from in situ to invasive cervical cancer

Epigenetic dysregulation is important in cervical cancer development, but the underlying mechanism is largely unknown. Increasing evidence indicates that DNA methylation is sensitive to changes in microenvironmental factors, such as nitric oxide (NO) in the chronic inflammatory cervix. However, the epigenomic effects of NO in cancer have not been investigated. In this study, we explored the methylomic effects of nitroxidative stress in HPV-immortalized precancerous cells. Chronic NO exposure promoted the acquisition of malignant phenotypes such as cell growth, migration, invasion, and anchorage-independent growth. Epigenetic analysis confirmed hypermethylation of PTPRR. Whole-genome methylation analysis showed BOLA2B, FGF8, HSPA6, LYPD2, and SHE were hypermethylated in cells. The hypermethylation BOLA2B, FGF8, HSPA6, and SHE was confirmed in cervical scrapings from invasive cancer, but not in CIN3/CIS, CIN2 and CIN1 (p=0.019, 0.023, 0.023 and 0.027 respectively), suggesting the role in the transition from in situ to invasive process. Our results reveal that nitroxidative stress causes epigenetic changes in HPV-infected cells. Investigation of these methylation changes in persistent HPV infection may help identify new biomarkers of DNA methylation for cervical cancer screening, especially for precancerous lesions.

Aberrant gene-specific DNA methylation signature analysis in cervical cancer

Multicomponent molecular modifications such as DNA methylation may offer sensitive and specific cervical intraepithelial neoplasia and cervical cancer biomarkers. In this study, we tested cervical tissues at various stages of tumor progression for 5-methylcytosine and 5-hydroxymethylcytosine levels and also DNA promoter methylation profile of a panel of genes for its diagnostic potential. In total, 5-methylcytosine, 5-hydroxymethylcytosine, and promoter methylation of 33 genes were evaluated by reversed-phase high-performance liquid chromatography, enzyme-linked immunosorbent assay based technique, and bisulfate-based next generation sequencing. The 5-methylcytosine and 5-hydroxymethylcytosine contents were significantly reduced in squamous cell carcinoma and receiver operating characteristic curve analysis showed a significant difference in (1) 5-methylcytosine between normal and squamous cell carcinoma tissues (area under the curve = 0.946) and (2) 5-hydroxymethylcytosine levels among normal, squamous intraepithelial lesions and squamous cell carcinoma. Analyses of our next generation sequencing results and data from five independent published studies consisting of 191 normal, 10 low-grade squamous intraepithelial lesions, 21 high-grade squamous intraepithelial lesions, and 335 malignant tissues identified a panel of nine genes ( ARHGAP6, DAPK1, HAND2, NKX2-2, NNAT, PCDH10, PROX1, PITX2, and RAB6C) which could effectively discriminate among the various groups with sensitivity and specificity of 80%-100% (p < 0.05). Furthermore, 12 gene promoters (ARHGAP6, HAND2, LHX9, HEY2, NKX2-2, PCDH10, PITX2, PROX1, TBX3, IKBKG, RAB6C, and DAPK1) were also methylated in one or more of the cervical cancer cell lines tested. The global and gene-specific methylation of the panel of genes identified in our study may serve as useful biomarkers for the early detection and clinical management of cervical cancer.

Molecular approaches for HPV genotyping and HPV-DNA physical status

Persistent infection with high-risk human papillomavirus (HPV) genotypes is the leading cause of cervical cancer development. To this end several studies have focused on designing molecular assays for HPV genotyping, which are considered as the gold standard for the early diagnosis of HPV infection. Moreover, the tendency of HPV DNA to be integrated into the host chromosome is a determining event for cervical oncogenesis. Thus, the establishment of molecular techniques was promoted in order to investigate the physical status of the HPV DNA and the locus of viral insertion into the host chromosome. The molecular approaches that have been developed recently facilitate the collection of a wide spectrum of valuable information specific to each individual patient and therefore can significantly contribute to the establishment of a personalised prognosis, diagnosis and treatment of HPV-positive patients. The present review focuses on state of the art molecular assays for HPV detection and genotyping for intra-lesion analyses, it examines molecular approaches for the determination of HPV-DNA physical status and it discusses the criteria for selecting the most appropriate regions of viral DNA to be incorporated in HPV genotyping and in the determination of HPV-DNA physical status.

Combined clinical and genetic testing algorithm for cervical cancer diagnosis

Background

Opportunistic screening in hospitals is widely used to effectively reduce the incidence rate of cervical cancer in China and other developing countries. This study aimed to identify clinical risk factor algorithms that combine gynecologic examination and molecular testing (paired box gene 1 (PAX1) or zinc finger protein 582 (ZNF582) methylation or HPV16/18) results to improve diagnostic accuracy.

Methods

The delta Cp of methylated PAX1 and ZNF582 was obtained via quantitative methylation-specific PCR in a training set (57 CIN2− and 43 cervical intraepithelial neoplasia ≥grade 3 (CIN3+) women), and the individual and combination gene sensitivities and specificities were determined. The detection accuracy of three algorithms combining gynecologic findings and genetic test results was then compared in a randomized case-control study comprising 449 women referred for colposcopic examination by gynecologists in the outpatient department of Xiangya Hospital between November 2011 and March 2013.

Results

Significant association was observed between CIN3+ and methylated PAX1 or ZNF582 in combination with HPV16/18 (OR:15.52, 95 % CI:7.73–31.18). The sensitivities and specificities of methylated PAX1 or ZNF582 combined with HPV16/18 for CIN3+ women were 89.2 and 76.0 %, or 85.4 and 80.1 %, respectively. Of the three algorithms applied to cohort data and validated in the study, two indicated 100 % sensitivity in detecting cervical cancer and a low rate of referrals for colposcopy.

Conclusions

These algorithms might contribute to precise and objective cervical cancer diagnostics in the outpatient departments of hospitals in countries with high mortality and low screening rates or areas with uneven resource distribution.

Electronic supplementary material

The online version of this article (doi:10.1186/s13148-016-0232-3) contains supplementary material, which is available to authorized users.

Dietary phytochemicals as epigenetic modifiers in cancer: Promise and challenges

The influence of diet and environment on human health has been known since ages. Plant-derived natural bioactive compounds (phytochemicals) have acquired an important role in human diet as potent antioxidants and cancer chemopreventive agents. In past few decades, the role of epigenetic alterations such as DNA methylation, histone modifications and non-coding RNAs in the regulation of mammalian genome have been comprehensively addressed. Although the effects of dietary phytochemicals on gene expression and signaling pathways have been widely studied in cancer, the impact of these dietary compounds on mammalian epigenome is rapidly emerging. The present review outlines the role of different epigenetic mechanisms in the regulation and maintenance of mammalian genome and focuses on the role of dietary phytochemicals as epigenetic modifiers in cancer. Above all, the review focuses on summarizing the progress made thus far in cancer chemoprevention with dietary phytochemicals, the heightened interest and challenges in the future.