PEG1/MEST and IGF2 DNA methylation in CIN and in cervical cancer

Moura A, Filho ODMM, Pessoa C, Miranda Furtado CL. Hypomethylation at H19DMR in penile squamous cell carcinoma is not related to HPV infection

Penile squamous cell carcinoma (SCC) is a rare and aggressive tumour mainly related to lifestyle behaviour and human papillomavirus (HPV) infection. Environmentally induced loss of imprinting (LOI) at the H19 differentially methylated region (H19DMR) is associated with many cancers in the early events of tumorigenesis and may be involved in the pathogenesis of penile SCC. We sought to evaluate the DNA methylation pattern at H19DMR and its association with HPV infection in men with penile SCC by bisulfite sequencing (bis-seq). We observed an average methylation of 32.2% ± 11.6% at the H19DMR of penile SCC and did not observe an association between the p16INK4a+ (p = 0.59) and high-risk HPV+ (p = 0.338) markers with methylation level. The average methylation did not change according to HPV positive for p16INK4a+ or hrHPV+ (35.4% ± 10%) and negative for both markers (32.4% ± 10.1%) groups. As the region analysed has a binding site for the CTCF protein, the hypomethylation at the surrounding CpG sites might alter its insulator function. In addition, there was a positive correlation between intense polymorphonuclear cell infiltration and hypomethylation at H19DMR (p = 0.035). Here, we report that hypomethylation at H19DMR in penile SCC might contribute to tumour progression and aggressiveness regardless of HPV infection.

HPV16-miRNAs exert oncogenic effects through enhancers in human cervical cancer

BACKGROUND

Cervical cancer is a human papillomavirus (HPV)-related disease. HPV type 16 (HPV16), which is the predominant cause of cervical cancer, can encode miRNAs (HPV16-miRNAs). However, the role of HPV16-miRNAs in the pathogenesis of cervical cancer remains unclear.

METHODS

Human cervical cancer cell lines SiHa (HPV16-positive) and C33A (HPV-negative), and cervical cancer tissues were collected to investigate the expression levels of two HPV16-miRNAs (HPV16-miR-H1 and HPV16-miR-H6). The overexpression and knockdown of HPV16-miR-H1 and HPV16-miR-H6 were performed using the lentiviral vector system and miRNA inhibitors, respectively. RNA-sequencing (RNA-seq) analysis and H3K27ac chromatin immunoprecipitation and sequencing (CHIP-seq) experiments were utilized to explore the roles of HPV16-miR-H1 and HPV16-miR-H6 facilitated by enhancers. CCK8, EdU, transwell, and wound healing assays were performed to verify the effects of HPV16-miR-H1 and HPV16-miR-H6 on cell proliferation and migration.

RESULTS

HPV16-miR-H1 and HPV16-miR-H6 were highly expressed in both SiHa cells and tissue samples from HPV16-positive cervical cancer patients. RNA-seq analysis showed that HPV16-miR-H1 and HPV16-miR-H6 induced the upregulation of numerous tumor progression-associated genes. H3K27ac CHIP-seq experiments further revealed that HPV16-miR-H1 and HPV16-miR-H6 modulated the expression of critical genes by regulating their enhancer activity. The functional study demonstrated that HPV16-miR-H1 and HPV16-miR-H6 increased the migratory capacity of SiHa cells.

CONCLUSIONS

Our data shed light on the role of HPV16-encoded miRNAs in cervical cancer, particularly emphasizing their involvement in the miRNA-enhancer-target gene system. This novel regulatory mechanism of HPV16-miRNAs provides new insights and approaches for the development of therapeutic strategies by targeting HPV16-positive cervical cancer.

Epigenetic signature of ionizing radiation in therapy-related AML patients

Therapy-related acute myeloid leukaemia (t-AML) is a late side effect of previous chemotherapy (ct-AML) and/or radiotherapy (rt-AML) or immunosuppressive treatment. t-AMLs, which account for ∼10-20 % of all AML cases, are extremely aggressive and have a poor prognosis compared to de novo AML. Our hypothesis is that exposure to radiation causes genome-wide epigenetic changes in rt-AML. An epigenome-wide association study was undertaken, measuring over 850K methylation sites across the genome from fifteen donors (five healthy, five de novo, and five t-AMLs). The study predominantly focussed on 94K sites that lie in CpG-rich gene promoter regions. Genome-wide hypomethylation was discovered in AML, primarily in intergenic regions. Additionally, genes specific to AML were identified with promoter hypermethylation. A two-step validation was conducted, both internally, using pyrosequencing to measure methylation levels in specific regions across fifteen primary samples, and externally, with an additional eight AML samples. We demonstrated that the MEST and GATA5 gene promoters, which were previously identified as tumour suppressors, were noticeably hypermethylated in rt-AML, as opposed to other subtypes of AML and control samples. These may indicate the epigenetic involvement in the development of rt-AML at the molecular level and could serve as potential targets for drug therapy in rt-AML.

Research progress on the role and mechanism of DNA damage repair in germ cell development

In the complex and dynamic processes of replication, transcription, and translation of DNA molecules, a large number of replication errors or damage can occur which lead to obstacles in the development process of germ cells and result in a decreased reproductive rate. DNA damage repair has attracted widespread attention due to its important role in the maintenance and regulation of germ cells. This study reports on a systematic review of the role and mechanism of DNA damage repair in germline development. First, the causes, detection methods, and repair methods of DNA damage, and the mechanism of DNA damage repair are summarized. Second, a summary of the causes of abnormal DNA damage repair in germ cells is introduced along with common examples, and the relevant effects of germ cell damage. Third, we introduce the application of drugs related to DNA damage repair in the treatment of reproductive diseases and related surgical treatment of abnormal DNA damage, and summarize various applications of DNA damage repair in germ cells. Finally, a summary and discussion is given of the current deficiencies in DNA damage repair during germ cell development and future research development. The purpose of this paper is to provide researchers engaged in relevant fields with a further systematic understanding of the relevant applications of DNA damage repair in germ cells and to gain inspiration from it to provide new research ideas for related fields.

Human umbilical cord blood mesenchymal stem cells-derived exosomal microRNA-503-3p inhibits progression of human endometrial cancer cells through downregulating MEST

Endometrial cancer (EC) is a group of epithelial malignant tumors that occur in the endometrium. The specific pathogenesis is not revealed, hence, the goal of this study was to investigate the influence of human umbilical cord blood mesenchymal stem cells (hUMSCs)-derived exosomal microRNA-503-3p (miR-503-3p) on human EC cells by mediating mesoderm-specific transcript (MEST). The binding relationship between MiR-503-3p and MEST was searched. HUMSCs were collected and exosomes (Exos) were isolated and identified. Human EC cell lines HEC-1B and RL95-2 were transfected with elevated miR-503-3p or silenced MEST vector or co-cultured with Exos to figure their roles in biological functions of EC cells. The in vitro effect of miR-503-3p, MEST, and Exos on EC cells was further verified in vivo. MEST was a target of miR-503-3p. Overexpression of miR-503-3p or reduction of MEST suppressed the biological functions of EC cells. Enhanced MEST expression mitigated the role of upregulated miR-503-3p on the growth of EC cells. HUMSCs-derived Exos suppressed EC cell growth, upregulated miR-503-3p-modified HUMSCs-derived Exos had a more obvious inhibitory effect on EC cell growth. The anti-tumor effect of elevated miR-503-3p, silenced MEST, and HUMSCs-derived Exos were verified in nude mice. This study highlights that hUMSCs-derived exosomal miR-503-3p inhibits EC development by suppressing MEST, which is of great benefit to EC therapy.

Cellular architecture of human brain metastases

Brain metastasis (BrM) is the most common form of brain cancer, characterized by neurologic disability and an abysmal prognosis. Unfortunately, our understanding of the biology underlying human BrMs remains rudimentary. Here, we present an integrative analysis of >100,000 malignant and non-malignant cells from 15 human parenchymal BrMs, generated by single-cell transcriptomics, mass cytometry, and complemented with mouse model- and in silico approaches. We interrogated the composition of BrM niches, molecularly defined the blood-tumor interface, and revealed stromal immunosuppressive states enriched with infiltrated T cells and macrophages. Specific single-cell interrogation of metastatic tumor cells provides a framework of 8 functional cell programs that coexist or anticorrelate. Collectively, these programs delineate two functional BrM archetypes, one proliferative and the other inflammatory, that are evidently shaped through tumor-immune interactions. Our resource provides a foundation to understand the molecular basis of BrM in patients with tumor cell-intrinsic and host environmental traits.

Transcriptional epigenetic regulation of Fkbp1/Pax9 genes is associated with impaired sensitivity to platinum treatment in ovarian cancer

Background

In an effort to contribute to overcoming the platinum resistance exhibited by most solid tumors, we performed an array of epigenetic approaches, integrating next-generation methodologies and public clinical data to identify new potential epi-biomarkers in ovarian cancer, which is considered the most devastating of gynecological malignancies.

Methods

We cross-analyzed data from methylome assessments and restoration of gene expression through microarray expression in a panel of four paired cisplatin-sensitive/cisplatin-resistant ovarian cancer cell lines, along with publicly available clinical data from selected individuals representing the state of chemoresistance. We validated the methylation state and expression levels of candidate genes in each cellular phenotype through Sanger sequencing and reverse transcription polymerase chain reaction, respectively. We tested the biological role of selected targets using an ectopic expression plasmid assay in the sensitive/resistant tumor cell lines, assessing the cell viability in the transfected groups. Epigenetic features were also assessed in 189 primary samples obtained from ovarian tumors and controls.

Results

We identified PAX9 and FKBP1B as potential candidate genes, which exhibited epigenetic patterns of expression regulation in the experimental approach. Re-establishment of FKBP1B expression in the resistant OVCAR3 phenotype in which this gene is hypermethylated and inhibited allowed it to achieve a degree of platinum sensitivity similar to the sensitive phenotype. The evaluation of these genes at a translational level revealed that PAX9 hypermethylation leads to a poorer prognosis in terms of overall survival. We also set a precedent for establishing a common epigenetic signature in which the validation of a single candidate, MEST, proved the accuracy of our computational pipelines.

Conclusions

Epigenetic regulation of PAX9 and FKBP1B genes shows that methylation in non-promoter areas has the potential to control gene expression and thus biological consequences, such as the loss of platinum sensitivity. At the translational level, PAX9 behaves as a predictor of chemotherapy response to platinum in patients with ovarian cancer. This study revealed the importance of the transcript-specific study of each gene under potential epigenetic regulation, which would favor the identification of new markers capable of predicting each patient’s progression and therapeutic response.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-021-01149-8.

Non-CpG methylation-a key epigenetic modification in cancer

The methylation of cytosine residues that precede adenine/thymine or other cytosine nucleotides instead of guanine in DNA is known as non-CpG methylation. It is a pronounced epigenetic modification with a central role in gene regulation similar to CpG methylation. Due to technological limitations, the locus-specific role of non-CpG methylation was scarcely understood. At present, high-throughput analyses and improved enrichment methods can elucidate the role of genome-wide non-CpG methylation distributions. Although the functional basis of non-CpG methylation in regulating gene expression control is known, its role in cancer development is yet to be ascertained. This review sheds light on the possible mechanism of non-CpG methylation in embryos and developed tissues with a special focus on cancer development and progression. In particular, the maintenance and alteration of non-CpG methylation levels and the crucial factors that determine this level of non-CpG methylation and its functional role in cancer are discussed.

Association between PEG3 DNA methylation and high-grade cervical intraepithelial neoplasia

Background

Epigenetic mechanisms are hypothesized to contribute substantially to the progression of cervical intraepithelial neoplasia (CIN) to cervical cancer, although empirical data are limited.

Methods

Women (n = 419) were enrolled at colposcopic evaluation at Duke Medical Center in Durham, North Carolina. Human papillomavirus (HPV) was genotyped by HPV linear array and CIN grade was ascertained by biopsy pathologic review. DNA methylation was measured at differentially methylated regions (DMRs) regulating genomic imprinting of the IGF2/H19, IGF2AS, MESTIT1/MEST, MEG3, PLAGL1/HYMAI, KvDMR and PEG10, PEG3 imprinted domains, using Sequenom-EpiTYPER assays. Logistic regression models were used to evaluate the associations between HPV infection, DMR methylation and CIN risk overall and by race.

Results

Of the 419 participants, 20 had CIN3+, 52 had CIN2, and 347 had ≤ CIN1 (CIN1 and negative histology). The median participant age was 28.6 (IQR:11.6) and 40% were African American. Overall, we found no statistically significant association between altered methylation in selected DMRs and CIN2+ compared to ≤CIN1. Similarly, there was no significant association between DMR methylation and CIN3+ compared to ≤CIN2. Restricting the outcome to CIN2+ cases that were HR-HPV positive and p16 staining positive, we found a significant association with PEG3 DMR methylation (OR: 1.56 95% CI: 1.03–2.36).

Conclusions

While the small number of high-grade CIN cases limit inferences, our findings suggest an association between altered DNA methylation at regulatory regions of PEG3 and high grade CIN in high-risk HPV positive cases.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13027-021-00382-3.

In-utero stress and mode of conception: impact on regulation of imprinted genes, fetal development and future health

BACKGROUND

Genomic imprinting is an epigenetic gene regulatory mechanism; disruption of this process during early embryonic development can have major consequences on both fetal and placental development. The periconceptional period and intrauterine life are crucial for determining long-term susceptibility to diseases. Treatments and procedures in assisted reproductive technologies (ART) and adverse in-utero environments may modify the methylation levels of genomic imprinting regions, including insulin-like growth factor 2 (IGF2)/H19, mesoderm-specific transcript (MEST), and paternally expressed gene 10 (PEG10), affecting the development of the fetus. ART, maternal psychological stress, and gestational exposures to chemicals are common stressors suspected to alter global epigenetic patterns including imprinted genes.

OBJECTIVE AND RATIONALE

Our objective is to highlight the effect of conception mode and maternal psychological stress on fetal development. Specifically, we monitor fetal programming, regulation of imprinted genes, fetal growth, and long-term disease risk, using the imprinted genes IGF2/H19, MEST, and PEG10 as examples. The possible role of environmental chemicals in genomic imprinting is also discussed.

SEARCH METHODS

A PubMed search of articles published mostly from 2005 to 2019 was conducted using search terms IGF2/H19, MEST, PEG10, imprinted genes, DNA methylation, gene expression, and imprinting disorders (IDs). Studies focusing on maternal prenatal stress, psychological well-being, environmental chemicals, ART, and placental/fetal development were evaluated and included in this review.

OUTCOMES

IGF2/H19, MEST, and PEG10 imprinted genes have a broad developmental effect on fetal growth and birth weight variation. Their disruption is linked to pregnancy complications, metabolic disorders, cognitive impairment, and cancer. Adverse early environment has a major impact on the developing fetus, affecting mostly growth, the structure, and subsequent function of the hypothalamic-pituitary-adrenal axis and neurodevelopment. Extensive evidence suggests that the gestational environment has an impact on epigenetic patterns including imprinting, which can lead to adverse long-term outcomes in the offspring. Environmental stressors such as maternal prenatal psychological stress have been found to associate with altered DNA methylation patterns in placenta and to affect fetal development. Studies conducted during the past decades have suggested that ART pregnancies are at a higher risk for a number of complications such as birth defects and IDs. ART procedures involve multiple steps that are conducted during critical windows for imprinting establishment and maintenance, necessitating long-term evaluation of children conceived through ART. Exposure to environmental chemicals can affect placental imprinting and fetal growth both in humans and in experimental animals. Therefore, their role in imprinting should be better elucidated, considering the ubiquitous exposure to these chemicals.

WIDER IMPLICATIONS

Dysregulation of imprinted genes is a plausible mechanism linking stressors such as maternal psychological stress, conception using ART, and chemical exposures with fetal growth. It is expected that a greater understanding of the role of imprinted genes and their regulation in fetal development will provide insights for clinical prevention and management of growth and IDs. In a broader context, evidence connecting impaired imprinted gene function to common diseases such as cancer is increasing. This implies early regulation of imprinting may enable control of long-term human health, reducing the burden of disease in the population in years to come.

DNA methylation data-based molecular subtype classification related to the prognosis of patients with cervical cancer

Cervical cancer is one of the leading female health-killers among all types of malignancies globally. Human papillomavirus infection combined with genetic and epigenetic alterations have been indicated to be closely associated with the pathogenesis, progression, and malignant transformation of cervical cancer. Notably, during the complex tumorigenesis process, a series of DNA methylations occurs early and is the most frequent molecular behavior. In this study, to exploit the specific DNA methylation sites influencing the prognosis of patients with cervical cancer, 275 samples were downloaded from The Cancer Genome Atlas database and further analyzed. As a result, 1253 CpGs were found to have a significant correlation with patient prognosis and were further selected for the consistent clustering of samples into six subgroups. Specifically, the samples in every subgroup were different regarding the following: race, age, tumor stage, receptor status, histological type, metastasis status, and patient prognosis. In addition, we calculated the levels of methylation sites in all subgroups, with 79 methylation sites (corresponding to 81 genes) screened as the intrasubgroup-specific methylation sites. Moreover, signaling pathway enrichment analysis was conducted on the genes of the corresponding promoter regions of the above-described specific methylation sites, revealing that these genes were enriched in biological pathways closely associated with tumors, such as the cyclic guanosine monophosphate-dependent protein kinase and focal adhesion signaling pathways. Finally, the least absolute shrinkage and selection operator algorithm was employed to establish a prognostic prediction model for cervical cancer patients, with training and test sets used for testing and validation, respectively. In summary, the specific DNA methylation site-based classification is able to reflect the heterogeneity of cervical cancer tissue, contributing to the development of personalized therapy and the accurate prediction of patient prognosis.

The use of molecular markers for cervical screening of women living with HIV in South Africa

Supplemental Digital Content is available in the text

To determine the performance of molecular screening strategies for detection of cervical intraepithelial neoplasia grade 3 or worse (CIN3+) in comparison with cytology screening in women living with HIV.

Long intergenic noncoding RNA LINC00284 knockdown reduces angiogenesis in ovarian cancer cells via up-regulation of MEST through NF-κB1

Ovarian cancer (OC) is one of the major causes of cancer-related mortality in women worldwide. Long noncoding RNAs might play a role as oncogenes or tumor suppressors. Therefore, we investigated the effect and underlying mechanisms of long intergenic noncoding RNA (LINC00) 284 on angiogenesis in OC cells. Expression of LINC00284 in OC tissues and cells was determined. Next, the interaction between LINC00284 and mesoderm-specific transcript (MEST) was evaluated. Subsequently, OC cells were transfected with overexpressed (oe)-LINC00284, silenced (si)-LINC00284, si-NF-κB1, oe-MEST, or si-MEST plasmids to investigate the underlying mechanism of LINC00284 in OC. Afterwards, the expression of matrix metalloproteinase (MMP)-2, MMP-9, B-cell lymphoma 2 (Bcl-2), Bcl-2-associated protein x (Bax), VEGF, and CD31 was determined to assess the effect of LINC00284 on OC cell proliferation, invasion, migration angiogenesis, and apoptosis. Finally, the effect of LINC00284 on tumorigenesis was investigated in nude mice models of OC. LINC00284 was highly expressed in OC. si-LINC00284 increased expression of MEST. si-LINC00284 or si-NF-κB1 led to the reduction in cell proliferation, migration, invasion, tube formation, angiogenesis, and tumorigenic ability and promoted apoptosis in OC by down-regulating MMP-2, MMP-9, Bcl-2, VEGF, and CD31 and up-regulating Bax. These effects were all reversed following the si-MEST. In vivo experiments found the same results, confirming the aforementioned findings. Taken together, LINC00284 is involved in angiogenesis during OC development by recruiting NF-κB1 and down-regulating MEST.-Ruan, Z., Zhao, D. Long intergenic noncoding RNA LINC00284 knockdown reduces angiogenesis in ovarian cancer cells via up-regulation of MEST through NF-κB1.

IGF2 is Deregulated During the Development of Uterine Cervical Carcinoma in Indian Patients

Uterine cervical carcinoma (CACX) is one of the leading causes of deaths in Indian women. Chromosomal alterations including 11p15.5 locus were reported in CACX. Consequently, we strived for the first time to understand the molecular status of the candidate gene Insulin-like growth factor 2, IGF2 (11p15.5) in Indian CACX patients (n = 128). DNA copy number (CN) analysis using CGH-SNP analysis showed no genetic alteration and it was further validated by comparison with publicly available CN datasets. But promoter hypo-methylation during the progression of CACX was observed and also found to be concordant with publicly available DNA methylation datasets. Interestingly, we found diverse expression of IGF2 transcript in both normal cervical epithelium (NCE) and CACX tumors. Similar heterogeneous expression pattern was seen in publicly available expression datasets as well. Finally, protein expression analysis in NCE showed concordance with transcript expression but tumors showed frequent low expression. Log-rank test showed a difference (p-value = 0.057) in overall survival between cases with and without alteration for IGF2 in Indian CACX patients. Collectively, our study proposes that regulation of IGF2 expression in NCE appeared to be multifaceted and deregulation during the development of CACX resulted in the differential expression.

Long non-coding RNA FAM83H-AS1 is regulated by human papillomavirus 16 E6 independently of p53 in cervical cancer cells

High-risk human papillomavirus (HPV) infection is one of the first events in the process of carcinogenesis in cervical and head and neck cancers. The expression of the viral oncoproteins E6 and E7 are essential in this process by inactivating the tumor suppressor proteins p53 and Rb, respectively, in addition to their interactions with other host proteins. Non-coding RNAs, such as long non-coding RNAs (lncRNAs) have been found to be dysregulated in several cancers, suggesting an important role in tumorigenesis. In order to identify host lncRNAs affected by HPV infection, we expressed the high-risk HPV-16 E6 oncoprotein in primary human keratinocytes and measured the global lncRNA expression profile by high-throughput sequencing (RNA-seq). We found several host lncRNAs differentially expressed by E6 including GAS5, H19, and FAM83H-AS1. Interestingly, FAM83H-AS1 was found overexpressed in HPV-16 positive cervical cancer cell lines in an HPV-16 E6-dependent manner but independently of p53 regulation. Furthermore, FAM83H-AS1 was found to be regulated through the E6-p300 pathway. Knockdown of FAM83H-AS1 by siRNAs decreased cellular proliferation, migration and increased apoptosis. FAM83H-AS1 was also found to be altered in human cervical cancer tissues and high expression of this lncRNA was associated with worse overall survival, suggesting an important role in cervical carcinogenesis.

Stressful Newborn Memories: Pre-Conceptual, In Utero, and Postnatal Events

Early-life stressful experiences are critical for plasticity and development, shaping adult neuroendocrine response and future health. Stress response is mediated by the autonomous nervous system and the hypothalamic-pituitary-adrenal (HPA) axis while various environmental stimuli are encoded via epigenetic marks. The stress response system maintains homeostasis by regulating adaptation to the environmental changes. Pre-conceptual and in utero stressors form the fetal epigenetic profile together with the individual genetic profile, providing the background for individual stress response, vulnerability, or resilience. Postnatal and adult stressful experiences may act as the definitive switch. This review addresses the issue of how preconceptual in utero and postnatal events, together with individual differences, shape future stress responses. Putative markers of early-life adverse effects such as prematurity and low birth weight are emphasized, and the epigenetic, mitochondrial, and genomic architecture regulation of such events are discussed.

HPV16-Related Cervical Cancers and Precancers Have Increased Levels of Host Cell DNA Methylation in Women Living with HIV

Data on human papillomavirus (HPV) type-specific cervical cancer risk in women living with human immunodeficiency virus (WLHIV) are needed to understand HPV–HIV interaction and to inform prevention programs for this population. We assessed high-risk HPV type-specific prevalence in cervical samples from 463 WLHIV from South Africa with different underlying, histologically confirmed stages of cervical disease. Secondly, we investigated DNA hypermethylation of host cell genes ASCL1, LHX8, and ST6GALNAC5, as markers of advanced cervical disease, in relation to type-specific HPV infection. Overall, HPV prevalence was 56% and positivity increased with severity of cervical disease: from 28.0% in cervical intraepithelial neoplasia (CIN) grade 1 or less (≤CIN1) to 100% in invasive cervical cancer (ICC). HPV16 was the most prevalent type, accounting for 9.9% of HPV-positive ≤CIN1, 14.3% of CIN2, 31.7% of CIN3, and 45.5% of ICC. HPV16 was significantly more associated with ICC and CIN3 than with ≤CIN1 (adjusted for age, OR_MH 7.36 (95% CI 2.33–23.21) and 4.37 (95% CI 1.81–10.58), respectively), as opposed to non-16 high-risk HPV types. Methylation levels of ASCL1, LHX8, and ST6GALNAC5 in cervical scrapes of women with CIN3 or worse (CIN3+) associated with HPV16 were significantly higher compared with methylation levels in cervical scrapes of women with CIN3+ associated with non-16 high-risk HPV types (p-values 0.017, 0.019, and 0.026, respectively). When CIN3 and ICC were analysed separately, the same trend was observed, but the differences were not significant. Our results confirm the key role that HPV16 plays in uterine cervix carcinogenesis, and suggest that the evaluation of host cell gene methylation levels may monitor the progression of cervical neoplasms also in WLHIV.

A comprehensive overview of genomic imprinting in breast and its deregulation in cancer

Genomic imprinting plays an important role in growth and development. Loss of imprinting (LOI) has been found in cancer, yet systematic studies are impeded by data-analytical challenges. We developed a methodology to detect monoallelically expressed loci without requiring genotyping data, and applied it on The Cancer Genome Atlas (TCGA, discovery) and Genotype-Tissue expression project (GTEx, validation) breast tissue RNA-seq data. Here, we report the identification of 30 putatively imprinted genes in breast. In breast cancer (TCGA), HM13 is featured by LOI and expression upregulation, which is linked to DNA demethylation. Other imprinted genes typically demonstrate lower expression in cancer, often associated with copy number variation and aberrant DNA methylation. Downregulation in cancer frequently leads to higher relative expression of the (imperfectly) silenced allele, yet this is not considered canonical LOI given the lack of (absolute) re-expression. In summary, our novel methodology highlights the massive deregulation of imprinting in breast cancer.

Predicting cervical intraepithelial neoplasia recurrence in HIV-infected and -noninfected women by detecting aberrant promoter methylation in the CDH1, TIMP3, and MGMT genes

PURPOSE

Aberrant DNA methylation is present in virtually all types of human cancer. There is no clear evidence that methylation status can predict bad prognosis in patients with CIN recurrence in HIV infected. This study evaluates the relationship between aberrant methylation of CpG islands of CDH1, TIMP3 and MGMT genes and CIN recurrence in HIV-infected and -noninfected women.

METHODS

This is a nested case-control study involving 33 cases with CIN recurrence and 114 controls without recurrence, HIV infected and noninfected, treated with LEEP, between 1999 and 2004. Recurrence diagnosis was established after biopsy. Genes methylation profile was assessed by MSP-PCR technique in formalin-fixed, paraffin-embedded cone specimens. Statistical analysis was performed to compare categorical variables, using χ² test with Yates correction and Fisher's exact test. Multivariate analysis was carried out using logistic regression.

RESULTS

CIN recurrence was more frequent in women with glandular involvement (OR 11.6; 95% CI 2.93-45.89) and compromised surgical margins (OR 2.5; 95% CI 0.87-7.27) in the cervical cone and in HIV-infected women (OR 2.47; 95% CI 0.87-7.05). One methylated allele of CDH1, TIMP3 and MGMT genes was present in 87.9% women with CIN recurrence. Promoter hypermethylation of TIMP3 and MGMT was detected in women with CIN recurrence and without CIN recurrence independent of HIV infection with significant difference between groups (p = 0.04 and p = 0.02, respectively).

CONCLUSIONS

CIN recurrence was associated with glandular involvement and compromised margins in cone biopsy and HIV infection. The presence of CpG islands hemimethylation in TIMP3 and MGMT genes is a promising triage method in CIN recurrence.

Detection of hypermethylated genes as markers for cervical screening in women living with HIV

INTRODUCTION

To evaluate the performance of hypermethylation analysis of ASCL1, LHX8 and ST6GALNAC5 in physician-taken cervical scrapes for detection of cervical cancer and cervical intraepithelial neoplasia (CIN) grade 3 in women living with HIV (WLHIV) in South Africa.

METHODS

Samples from a prospective observational cohort study were used for these analyses. Two cohorts were included: a cohort of WLHIV who were invited for cervical screening (n = 321) and a gynaecologic outpatient cohort of women referred for evaluation of abnormal cytology or biopsy proven cervical cancer (n = 108, 60% HIV seropositive). Cervical scrapes collected from all subjects were analysed for hypermethylation of ASCL1, LHX8 and ST6GALNAC5 by multiplex quantitative methylation specific PCR (qMSP). Histology endpoints were available for all study subjects.

RESULTS

Hypermethylation levels of ASCL1, LHX8 and ST6GALNAC5 increased with severity of cervical disease. The performance for detection of CIN3 or worse (CIN3+ ) as assessed by the area under the receiver operating characteristic (ROC) curves (AUC) was good for ASCL1 and LHX8 (AUC 0.79 and 0.81 respectively), and moderate for ST6GALNAC5 (AUC 0.71). At a threshold corresponding to 75% specificity, CIN3+ sensitivity was 72.1% for ASCL1 and 73.8% for LHX8 and all samples from women with cervical cancer scored positive for these two markers.

CONCLUSIONS

Hypermethylation analysis of ASCL1 or LHX8 in cervical scrape material of WLHIV detects all cervical carcinomas with an acceptable sensitivity and good specificity for CIN3+ , warranting further exploration of these methylation markers as a stand-alone test for cervical screening in low-resource settings.

DNA methylation of imprinted gene control regions in the regression of low-grade cervical lesions

The role of host epigenetic mechanisms in the natural history of low-grade cervical intraepithelial neoplasia (CIN1) is not well characterized. We explored differential methylation of imprinted gene regulatory regions as predictors of the risk of CIN1 regression. A total of 164 patients with CIN1 were recruited from 10 Duke University clinics for the CIN Cohort Study. Participants had colposcopies at enrollment and up to five follow-up visits over 3 years. DNA was extracted from exfoliated cervical cells for methylation quantitation at CpG (cytosine-phosphate-guanine) sites and human papillomavirus (HPV) genotyping. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated using Cox regression to quantify the effect of methylation on CIN1 regression over two consecutive visits, compared to non-regression (persistent CIN1; progression to CIN2+; or CIN1 regression at a single time-point), adjusting for age, race, high-risk HPV (hrHPV), parity, oral contraceptive and smoking status. Median participant age was 26.6 years (range: 21.0-64.4 years), 39% were African-American, and 11% were current smokers. Most participants were hrHPV-positive at enrollment (80.5%). Over one-third of cases regressed (n = 53, 35.1%). Median time-to-regression was 12.6 months (range: 4.5-24.0 months). Probability of CIN1 regression was negatively correlated with methylation at IGF2AS CpG 5 (HR = 0.41; 95% CI = 0.23-0.77) and PEG10 DMR (HR = 0.80; 95% CI = 0.65-0.98). Altered methylation of imprinted IGF2AS and PEG10 DMRs may play a role in the natural history of CIN1. If confirmed in larger studies, further research on imprinted gene DMR methylation is warranted to determine its efficacy as a biomarker for cervical cancer screening.

Integrated analysis of genome-wide DNA methylation and gene expression profiles identifies potential novel biomarkers of rectal cancer

DNA methylation was regarded as the promising biomarker for rectal cancer diagnosis. However, the optimal methylation biomarkers with ideal diagnostic performance for rectal cancer are still limited. To identify new molecular markers for rectal cancer, we mapped DNA methylation and transcriptomic profiles in the six rectal cancer and paired normal samples. Further analysis revealed the hypermethylated probes in cancer prone to be located in gene promoter. Meanwhile, transcriptome analysis presented 773 low-expressed and 1,161 over-expressed genes in rectal cancer. Correction analysis identified a panel of 36 genes with an inverse correlation between methylation and gene expression levels, including 10 known colorectal cancer related genes. From the other 26 novel marker genes, GFRA1 and GSTM2 were selected for further analysis on the basis of their biological functions. Further experiment analysis confirmed their methylation and expression status in a larger number (44) of rectal cancer samples, and ROC curves showed higher AUC than SEPT9, which has been used as a biomarker in rectal cancer. Our data suggests that aberrant DNA methylation of contiguous CpG sites in methylation array may be potential diagnostic markers of rectal cancer.

Hypoxic regulation of MYBL1, MEST, TCF3, TCF8, GTF2B, GTF2F2 and SNAI2 genes expression in U87 glioma cells upon IRE1 inhibition

We investigated the impact of IRE1/ERN1 (inositol requiring enzyme 1/endoplasmic reticulum to nucleus signaling 1) knockdown on hypoxic regulation of the expression of a subset of proliferation and migration-related genes in U87 glioma cells. It was shown that hypoxia leads to up-regulation of the expression of MEST and SNAI2, to down-regulation – of MYBL1, TCF8 and GTF2F2 genes at the mRNA level in control glioma cells. At the same time hypoxia did not affect the expression of TCF3 and GTF2B transcription factor genes. In turn, inhibition of IRE1 modified the effect of hypoxia on the expression of all studied genes, except MYBL1 and GTF2B. For instance, IRE1 knockdown decreased sensitivity to hypoxia of the expression of MEST, TCF8 and SNAI2 genes and increased sensitivity to hypoxia of GTF2F2 expression. At the same time, IRE1 inhibition introduced sensitivity to hypoxia of the expression of TCF3 gene in glioma cells. The present study demonstrated that the inhibition of IRE1 in glioma cells affected the hypoxic regulation of the expression of studied genes in various directions, though hypoxic conditions did not abolish the effect of IRE1 inhibition on the expression of respective genes. To the contrary, in case of SNAI2, GTF2F2 and MEST hypoxic conditions magnified the effect of IRE1 inhibition on the expression of respective genes in glioma cells.

Selection of women at risk for cervical cancer in an HIV-infected South African population

OBJECTIVE

Cervical cancer is the leading cause of cancer-related death in women in South Africa. This study evaluates DNA methylation levels in cervical (pre)cancer and aims to assess the value of high-risk human papillomavirus (hrHPV) testing and methylation analysis, alone or in combination, on physician-taken cervical scrapes to detect cervical cancer, and cervical intraepithelial neoplasia grade 3 (CIN3) in an HIV-infected South African population.

DESIGN

Prospective observational multicentre cohort study.

METHODS

Women from a cohort of women living with HIV (n = 355) and a referral cohort (n = 109, 60% HIV seropositive) were included. Cervical scrapes were collected for hrHPV testing and methylation analysis of cell adhesion molecule 1, T-lymphocyte maturation-associated protein, and microRNA124-2 genes. Histologic endpoints were available for all participants. Performance for detection of CIN3 or worse (CIN3+) was determined in the cohort of women living with HIV and different testing strategies were compared.

RESULTS

HrHPV and methylation positivity rates increased with severity of cervical disease in the two study cohorts, each reaching 100% in samples of women with carcinoma. HrHPV testing showed a sensitivity for CIN3+ of 83.6%, at a specificity of 67.7%. Methylation analysis showed a comparable CIN3+ sensitivity of 85.2%, but a significantly lower specificity of 49.6%. HrHPV testing with reflex methylation analysis showed a CIN3+ sensitivity of 73.8%, at a specificity of 81.5%.

CONCLUSION

In this HIV-infected South African population, stratifying hrHPV-positive women with reflex methylation analysis detects all cervical carcinomas and yields an acceptable sensitivity and specificity for CIN3+.

Network analyses elucidate the role of SMYD3 in esophageal squamous cell carcinoma

SMYD3 is a member of the SET and myeloid-Nervy-DEAF-1 (MYND) domain-containing protein family of methyltransferases, which are known to play critical roles in carcinogenesis. Expression of SMYD3 is elevated in various cancers, including esophageal squamous cell carcinoma (ESCC), and is correlated with the survival time of patients with ESCC. Here, we dissect gene expression data, from a previously described KYSE150 ESCC cell line in which SMYD3 had been knocked down, by integration with the protein-protein interaction (PPI) network, to find the new potential biological roles of SMYD3 and subsequent target genes. By construction of a specific PPI network, differentially expressed genes (DEGs), following SMYD3 knockdown, were identified as interacting with thousands of neighboring proteins. Enrichment analyses from the DAVID Functional Annotation Chart found significant Gene Ontology (GO) terms associated with transcription activities, which were closely related to SMYD3 function. For example, YAP1 and GATA3 might be a target gene for SMYD3 to regulate transcription. Enrichment annotation of the total DEG PPI network by GO 'Biological Process' generated a connected functional map and found 532 significant terms, including known and potential biological roles of SMYD3 protein, such as expression regulation, signal transduction, cell cycle, cell metastasis, and invasion. Subcellular localization analyses found that DEGs and their interacting proteins were distributed in multiple layers, which might reflect the intricate biological processes at the spatial level. Our analysis of the PPI network has provided important clues for future detection of the biological roles and mechanisms, as well as the target genes of SMYD3.

Maternal inflammatory diet and adverse pregnancy outcomes: Circulating cytokines and genomic imprinting as potential regulators?

Excessive inflammation during pregnancy alters homeostatic mechanisms of the developing fetus and has been linked to adverse pregnancy outcomes. An anti-inflammatory diet could be a promising avenue to combat the pro-inflammatory state of pregnancy, particularly in obese women, but we lack mechanistic data linking this dietary pattern during pregnancy to inflammation and birth outcomes. In an ethnically diverse cohort of 1057 mother-child pairs, we estimated the relationships between dietary inflammatory potential [measured via the energy-adjusted dietary inflammatory index (E-DII™)] and birth outcomes overall, as well as by offspring sex and maternal pre-pregnancy body mass index (BMI). In a subset of women, we also explored associations between E-DII, circulating cytokines (n = 105), and offspring methylation (n = 338) as potential modulators of these relationships using linear regression. Adjusted regression models revealed that women with pro-inflammatory diets had elevated rates of preterm birth among female offspring [β = -0.22, standard error (SE) = 0.07, P<0.01], but not male offspring (β=0.09, SE = 0.06, P<0.12) (P_interaction = 0.003). Similarly, we observed pro-inflammatory diets were associated with higher rates of caesarean delivery among obese women (β = 0.17, SE = 0.08, P = 0.03), but not among women with BMI <25 kg/m² (P_interaction = 0.02). We observed consistent inverse associations between maternal inflammatory cytokine concentrations (IL-12, IL-17, IL-4, IL-6, and TNFα) and lower methylation at the MEG3 regulatory sequence (P<0.05); however, results did not support the link between maternal E-DII and circulating cytokines. We replicate work by others on the association between maternal inflammatory diet and adverse pregnancy outcomes and provide the first empirical evidence supporting the inverse association between circulating cytokine concentrations and offspring methylation.

P53 Mutation and Epigenetic Imprinted IGF2/H19 Gene Analysis in Mesenchymal Stem Cells Derived from Amniotic Fluid, Amnion, Endometrium, and Wharton's Jelly

Mesenchymal stem cells (MSC) are promising cells for medical therapy. In in vitro expansion, MSC can give rise to progeny with genomic and epigenomic alterations, resulting in senescence, loss of terminal differentiation, and transformation to cancer. However, MSC genome protects its genetic instability by a guardian function of the P53 tumor suppressor gene and epigenetic balance system during MSC culture. Mutations of P53 and epigenetic alterations have been reported to disrupt the quality and quantity of MSC and initiate tumorigenesis. We monitor P53 and epigenetic changes in MSC derived from amniotic fluid (AF-MSC), amnion membrane (AM-MSC), endometrium (EM-MSC), and Wharton's jelly (WJ-MSC) by the missense mutation analysis of the P53 gene and the expression levels of P53, and epigenetic insulin-like growth factor 2 (IGF2) and H19-imprinted genes. Our work demonstrates a variation of P53 expression among different MSC types. AF-MSC has a high P53 expression level with retaining a stability of P53 expression throughout a long culture period, whereas EM-MSC and WJ-MSC showed variation of P53 gene expression during culture. Epigenetic analysis showed a stable H19 expression pattern in AF-MSC, AM-MSC, and EM-MSC culture, whereas H19 expression fluctuated in WJ-MSC culture. We conclude that gene instability can be found during in vitro MSC expansion. With awareness to MSC quality and safety in MSC transformation risk, P53 mutation and IGF2 and H19-imprinted gene analysis should be applied to monitor in therapeutic-grade MSC. We also demonstrated that AF-MSC is one of the most interesting MSC for medical therapy because of its high genomic stability and epigenetic fidelity.

The IGF axis in HPV associated cancers

Human papillomaviruses (HPV) infect and replicate in stratified epithelium at cutaneous and mucosal surfaces. The proliferation and maintenance of keratinocytes, the cells which make up this epithelium, are controlled by a number of growth factor receptors such as the keratinocyte growth factor receptor (KGFR, also called fibroblast growth factor receptor 2b (FGFR2b)), the epithelial growth factor receptor (EGFR) and the insulin-like growth factor receptors 1 and 2 (IGF1R and IGF2R). In this review, we will delineate the mutation, gene transcription, translation and processing of the IGF axis within HPV associated cancers. The IGFs are key for developmental and postnatal growth of almost all tissues; we explore whether this crucial axis has been hijacked by HPV.

Disparities in Cervical Cancer Incidence and Mortality: Can Epigenetics Contribute to Eliminating Disparities?

Screening for uterine cervical intraepithelial neoplasia (CIN) followed by aggressive treatment has reduced invasive cervical cancer (ICC) incidence and mortality. However, ICC cases and carcinoma in situ (CIS) continue to be diagnosed annually in the United States, with minorities bearing the brunt of this burden. Because ICC peak incidence and mortality are 10-15 years earlier than other solid cancers, the number of potential years of life lost to this cancer is substantial. Screening for early signs of CIN is still the mainstay of many cervical cancer control programs. However, the accuracy of existing screening tests remains suboptimal. Changes in epigenetic patterns that occur as a result of human papillomavirus infection contribute to CIN progression to cancer, and can be harnessed to improve existing screening tests. However, this requires a concerted effort to identify the epigenomic landscape that is reliably altered by HPV infection specific to ICC, distinct from transient changes.

Integrated analysis reveals candidate mRNA and their potential roles in uterine leiomyomas

AIM

Uterine leiomyomas (UL) are the most common pelvic tumors, and the etiology and pathophysiology are not well understood. We aimed to elucidate the genes responsible for UL development.

METHODS

Integrated analyses of four datasets of mRNA profiling for UL were performed. Functional annotation of differentially expressed genes (DEG) was used to systematically characterize the global expression profiles. The UL-specific protein-protein interaction network was constructed.

RESULTS

Integrated analysis led to the discovery of 2167 DEG (1042 upregulated and 1125 downregulated). The aberrant expression of NAV2, KIF5C, DCX, CAPN6, COL4A2, ALDH1A1, and DPT may play important roles in UL tumorigenesis. In addition, the dysregulation of MEST, LGALS3, and TLR3 may be involved in the progression of UL by a common mechanism. Functional annotation showed that extracellular matrix receptor interaction may be more active and cause the extracellular matrix abnormally formed in UL. Moreover, focal adhesion and cell adhesion molecules may play roles in the development of UL. Furthermore, chemokine signaling pathway and cytokine-cytokine receptor interaction were most probably involved in the development of UL.

CONCLUSION

In conclusion, our study observed that a set of aberrantly expressed genes and the related biochemical pathways may lead to transformation of normal myometrium in pathological focuses.

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

Cervical cancer is the second most common cancer among women worldwide. About 528,000 women are diagnosed with cervical cancer contributing to around 266,000 deaths, across the globe every year. Out of these, the burden of 226,000 (85%) deaths occurs in the developing countries, who are less resource intensive to manage the disease. This is despite the fact that cervical cancer is amenable for early detection due to its long and relatively well-known natural history prior to its culmination as invasive disease. Infection with high risk human papillomavirus (hrHPVs) is essential but not sufficient to cause cervical cancer. Although it was thought that genetic mutations alone was sufficient to cause cervical cancer, the current epidemiological and molecular studies have shown that HPV infection along with genetic and epigenetic changes are frequently associated and essential for initiation, development and progression of the disease. Moreover, aberrant DNA methylation in host and HPV genome can be utilized not only as biomarkers for early detection, disease progression, diagnosis and prognosis of cervical cancer but also to design effective therapeutic strategies. In this review, we focus on recent studies on DNA methylation changes in cervical cancer and their potential role as biomarkers for early diagnosis, prognosis and targeted therapy.

Intraplacental gene therapy with Ad-IGF-1 corrects naturally occurring rabbit model of intrauterine growth restriction

Intrauterine growth restriction (IUGR) due to placental insufficiency is a leading cause of perinatal complications for which there is no effective prenatal therapy. We have previously demonstrated that intraplacental injection of adenovirus-mediated insulin-like growth factor-1 (Ad-IGF-1) corrects fetal weight in a murine IUGR model induced by mesenteric uterine artery branch ligation. This study investigated the effect of intraplacental Ad-IGF-1 gene therapy in a rabbit model of naturally occurring IUGR (runt) due to placental insufficiency, which is similar to the human IUGR condition with onset in the early third trimester, brain sparing, and a reduction in liver weight. Laparotomy was performed on New Zealand White rabbits on day 21 of 30 days of gestation and litters were divided into five groups: Control (first position)+phosphate-buffered saline (PBS), control+Ad-IGF-1, runt (third position)+PBS, runt+Ad-IGF-1, and runt+Ad-LacZ. The effect of IGF-1 gene therapy on fetal, placental, liver, heart, lung, and musculoskeletal weights of the growth-restricted pups was examined. Protein expression after gene transfer was seen along the maternal-fetal placenta interface (n=12) 48 hr after gene therapy. There was minimal gene transfer detected in the pups or maternal organs. At term, compared with the normally grown first-position control, the runted third-position pups demonstrated significantly lower fetal, placental, liver, lung, and musculoskeletal weights. The fetal, liver, and musculoskeletal weights were restored to normal by intraplacental Ad-IGF-1 gene therapy (p<0.01), with no change in the placental weight. Intraplacental gene therapy is a novel strategy for the treatment of IUGR caused by placental insufficiency that takes advantage of an organ that will be discarded at birth. Development of nonviral IGF-1 gene delivery using placenta-specific promoters can potentially minimize toxicity to the mother and fetus and facilitate clinical translation of this novel therapy.

Methylation Levels of CADM1, MAL, and MIR124-2 in Cervical Scrapes for Triage of HIV-Infected, High-Risk HPV-Positive Women in Kenya

OBJECTIVES

To evaluate the value of cervical cell methylation markers in screening HIV-infected women also positive for high-risk human papillomavirus (hrHPV).

DESIGN

Cross-sectional and prospective.

METHODS

Two hundred forty-eight HIV-infected hrHPV-positive women enrolled in a cervical cancer screening study in Nairobi, Kenya, had colposcopy-directed biopsy and histological diagnoses. Exfoliated cervical cells were used to measure methylation levels of the CADM1, MAL, and MIR124-2 genes using quantitative methylation-specific polymerase chain reaction. Methylation levels were summarized as cycle threshold (Ct) ratios compared with the β-actin gene. Median Ct ratios were compared across histological diagnoses, with 95% confidence intervals calculated by bootstrapping. Methylation levels at 6 months were assessed in 128 women who remained hrHPV positive.

RESULTS

All 3 methylation markers showed significantly (P < 0.001) raised median Ct ratios in women with cervical intraepithelial neoplasia (CIN) grade 3 compared with women with a normal cervix. When markers were combined into a single test, the area under the receiver operating characteristic curve for prediction of CIN2 or worse (CIN2+) was 0.80. When the test was calibrated to have similar specificity, sensitivity of the combined tri-marker test for CIN2+ was comparable with cytology [atypical squamous cells of undetermined significance or worse] (89% and 95%, respectively) and superior to visual inspection with acetic acid (85% vs 70%) and HPV16/18 genotyping (65% vs 40%). Among women with no CIN2+ at baseline and persistent hrHPV at 6-month follow-up, MAL-m1 and MIR124-2 Ct ratios increased significantly.

CONCLUSIONS

Methylation markers in combination with HPV testing may offer a full molecular screening strategy to the many HIV-infected women who are also hrHPV positive.

Genotype-Epigenotype Interaction at the IGF2 DMR

Paternally expressed Insulin-like Growth Factor II (IGF2) encodes a gene whose protein product functions as a potent growth mitogen. Overexpression of IGF2 has been implicated in a wide number of disorders and diseases. IGF2 is regulated in part by differential methylation of the two parentally derived alleles. The differentially methylated region (DMR) located upstream of the imprinted promoters of IGF2 exhibits plasticity under environmental stress and is hypomethylated in several types of cancer. Through bisulfite pyrosequencing and confirmation by nucleotide sequencing, we discovered a CpG to CpC transversion that results in hypomethylation of one of the three CpGs comprising this DMR. The presence of the polymorphism introduces a genetic rather than an environmentally-driven epigenetic source of hypomethylation that is additive to non-genetic sources.

IL-10, IL-15, IL-17, and GMCSF levels in cervical cancer tissue of Tanzanian women infected with HPV16/18 vs. non-HPV16/18 genotypes

Background

Despite comparable screening rates for precancerous lesions, higher incidence and mortality related to cervical cancer in minority women persists. Recent evidence suggests that minority women with precancerous cervical lesions harbor a wider range of human papillomavirus (HPV) genotypes, many of these distinct from HPV16/18, those most commonly found in Caucasian women. The goal of the analysis was to determine if inflammatory cytokines and chemokines varied by HPV 16/18 versus other genotypes in cervical cancer tissues from Tanzanian women.

Methods

HPV genotypes and concentrations of chemokines and cytokines were measured from homogenized fresh tumor tissue of thirty-one women with invasive cervical cancer (ICC). Risk factors for cervical cancer including age, parity, hormonal contraceptive use and cigarette smoking were obtained by questionnaire. Generalized linear models were used to evaluate differences between chemokines/cytokine levels in women infected with HPV16/18 and those infected with other HPV genotypes.

Results

After adjusting for age, parity and hormonal contraceptives, IL-17 was found significantly more frequently in invasive cervical cancer samples of women infected with HPV16/18 compared to women infected with other HPV genotypes (p = 0.033). In contrast, higher levels for granular macrophage colony-stimulating factor (p = 0.004), IL-10 (p = 0.037), and IL-15 (p = 0.041) were found in ICC tissues of women infected with genotypes other than HPV16/18 when compared to those of women infected with HPV16/18.

Conclusions

While the small sample size limits inference, our data suggest that infection with different HPV genotypes is associated with distinct pro-inflammatory cytokine expression profiles; whether this explains some of the racial differences observed in cervical cancer is still unclear. Future studies are needed to confirm these findings.

Electronic supplementary material

The online version of this article (doi:10.1186/s13027-015-0005-1) contains supplementary material, which is available to authorized users.

Aging and DNA methylation

In this Opinion article, we summarize how changes in DNA methylation occur during aging in mammals and discuss examples of how such events may contribute to the aging process. We explore mechanisms that could facilitate DNA methylation changes in a site-specific manner and highlight a model in which region-specific DNA hypermethylation during aging is facilitated in a competitive manner by destabilization of the Polycomb repressive complex.

In vitro lead exposure changes DNA methylation and expression of IGF2 and PEG1/MEST

Epigenetic processes, such as changes in DNA methylation, likely mediate the link between environmental exposures in utero and altered gene expression. Differentially methylated regions (DMRs) that regulate imprinted genes may be especially vulnerable to environmental exposures since imprinting is established and maintained largely through DNA methylation, resulting in expression from only one parental chromosome. We used the human embryonic kidney cell line, HEK-293, to investigate the effects of exposure to physiologically relevant doses of lead acetate (Pb) on the methylation status of nine imprinted gene DMRs. We assessed mean methylation after seventy-two hours of Pb exposure (0-25 μg/dL) using bisulfite pyrosequencing. The PEG1/MEST and IGF2 DMRs had maximum methylation decreases of 9.6% (20 μg/dL; p<0.005) and 3.8% (25 μg/dL; p<0.005), respectively. Changes at the MEG3 DMRs had a maximum decrease in methylation of 2.9% (MEG3) and 1.8% (MEG3-IG) at 5 μg/dL Pb, but were not statistically significant. The H19, NNAT, PEG3, PLAGL1, and SGCE/PEG10 DMRs showed a less than 0.5% change in methylation, across the dose range used, and were deemed non-responsive to Pb in our model. Pb exposure below reportable/actionable levels increased expression of PEG1/MEST concomitant with decreased methylation. These results suggest that Pb exposure can stably alter the regulatory capacity of multiple imprinted DMRs.

HPV genotypes and cervical intraepithelial neoplasia in a multiethnic cohort in the southeastern USA

PURPOSE

For poorly understood reasons, invasive cervical cancer (ICC) incidence and mortality rates are higher in women of African descent. Oncogenic human papillomavirus (HPV) genotypes distribution may vary between European American (EA) and African-American (AA) women and may contribute to differences in ICC incidence. The current study aimed at disentangling differences in HPV distribution among AA and EA women.

METHODS

Five-hundred and seventy-two women were enrolled at the time of colposcopic evaluation following an abnormal liquid-based cytology screen. HPV infections were detected using HPV linear array, and chi-squared tests and linear regression models were used to compare HPV genotypes across racial/ethnic groups by CIN status.

RESULTS

Of the 572 participants, 494 (86 %) had detectable HPV; 245 (43 %) had no CIN lesion, 239 (42 %) had CIN1, and 88 (15 %) had CIN2/3. Seventy-three percent of all women were infected with multiple HPV genotypes. After adjusting for race, age, parity, income, oral contraception use, and current smoking, AAs were two times less likely to harbor HPV 16/18 (OR 0.48, 95 % CI 0.21-0.94, p = 0.03) when all women were considered. This association remained unchanged when only women with CIN2/3 lesions were examined (OR 0.22, 95 % CI 0.05-0.95, p = 0.04). The most frequent high-risk HPV genotypes detected among EAs were 16, 18, 56, 39, and 66, while HPV genotypes 33, 35, 45, 58, and 68 were the most frequent ones detected in AAs.

CONCLUSIONS

Our data suggest that while HPV 16/18 are the most common genotypes among EA women with CIN, AAs may harbor different genotypes.

Cancer diagnostic classifiers based on quantitative DNA methylation

Epigenetic change is part of the carcinogenic process and a deep reservoir for biomarker discovery. Reversible methylation of cytosines is noteworthy because it can be measured accurately and easily by various molecular methods and DNA methylation patterns are linked to important tumourigenic pathways. Clinically relevant methylation changes are known in common human cancers such as cervix, prostate, breast, colon, bladder, stomach and lung. Differential methylation may have a central role in the development and outcome of most if not all human malignancies. The advent of deep sequencing holds great promise for epigenomics, with bioinformatics tools ready to reveal large numbers of new targets for prognosis and therapeutic intervention. This review focuses on two selected cancers, namely cervix and prostate, which illustrate the more general themes of epigenetic diagnostics in cancer. Also discussed is differential methylation of specific human and viral DNA targets and laboratory methods for measuring methylation biomarkers.