Detection Of Methylation Research Articles

Assessment of PAX1 and JAM3 methylation triage efficacy across HPV genotypes and age groups in high-risk HPV-positive women in China

ObjectiveThis study aimed to evaluate the clinical utility of PAX1/JAM3 methylation (CISCER) test in triaging high-risk human papillomavirus (hrHPV)-positive women.MethodsWe enrolled women who underwent opportunistic screening at Cervical Disease outpatient clinics of Xuzhou Maternity and Child Health Hospital, and Yueyang Central Hospital from December 2022 to May 2024. The effectiveness of CISCER and cytology tests in triaging hrHPV+ patients was analyzed.ResultsAmong the 436 study participants, 283 (64.9%) had no cervical intraepithelial neoplasia (CIN), while 53 (12.2%) had CIN1, 40 (9.2%) had CIN2, 34 (7.8%) had CIN3, and 26 (5.9%) had cervical cancers. The CISCER tests identified all cases of cervical cancer, particularly 2 hrHPV-negative adenocarcinoma cases. In 396 hrHPV+ individuals, the sensitivity of CISCER tests for detecting CIN2+ lesions was 92.6% (95% CI: 87.2-97.9%), with a specificity of 95.7% (95% CI: 93.4-98%), and an area under the receiver operating characteristic curve (AUC) of 0.941 (95% CI: 0.903-0.979), outperforming cytology tests in both HPV16/18+ and non-16/18 hrHPV+ women. Notably, CISCER demonstrated 100% (95% CI: 90-100%) sensitivity in women aged≥50 and 100% (95%CI: 93.6-100%) specificity in women aged<30. Among CIN2+ women, 37.2% (including 3 cancer) showed low-grade cytological changes that could be detected by CISCER. Meanwhile, 52% of CIN2- women exhibited cytological abnormalities but had negative CISCER results. The immediate CIN3+ risk based on positive CISCER results was 54% (95% CI: 43.8-63.9%).ConclusionThe PAX1/JAM3 methylation detection using cervical exfoliated cells showed superior triage performance for hrHPV-positive patients compared to traditional strategies.

Tuning the Sensitivity of MoS2 Nanopores: From Labeling to Labeling-Free Detection of DNA Methylation.

DNA methylation discrimination is often challenged by complicated pretreatment, insufficient sensitivity, and suboptimal accuracy. Here, single-molecule readout of DNA methylation is reported using single-layer MoS2 nanopores. By tuning pore dimension, the sensitivity of MoS2 nanopores is manipulated, empowering both labeling and labeling-free strategies for DNA methylation discrimination. With methyl-CpG-binding domain protein 1 (MBD1)-labeled methylated DNA translocation in customized nanopores, multiple methylated sites with distance as short as 70bp in double strand DNA can be resolved. To further improve spatial resolution, small MoS2 nanopores are engineered with single-nucleotide sensitivity, realizing labeling-free methylation detection with single-nucleotide resolution to recognize two nucleotides with only one methyl difference. This study demonstrates the availability of engineered MoS2 nanopores in DNA methylation detection, underscoring their potential for epigenetic alteration research at the single-molecule level.

Abstract A014: A methylation state specific targeted background depletion technique for enrichment of ctDNA fraction

Abstract Liquid biopsy continues to be a focus of the cancer diagnostics industry, primarily due to the non-invasive nature of sample collection, however the low levels of circulating tumor DNA (ctDNA) remain a challenge. Methylation has emerged as a promising biomarker for detecting ctDNA, yet detecting the cancerous signal in an excess of non-cancerous, unmethylated cfDNA in the background has been proven difficult. Harbinger Health has developed a novel method that depletes unmethylated background at the CpG-level from specific genomic regions of interest, resulting in an enrichment of the ctDNA fraction. We developed a background cfDNA depletion method that utilizes the endonuclease activity and the specificity of CRISPR/Cas12a to remove unmethylated DNA fragments at ctDNA methylation biomarker sites. First, we identified cancer-informative regions that showed consistent contiguous elevated methylation states in cancer compared to normal samples. We then designed guide RNAs that specifically bind and cut unmethylated CpG sites within the target regions. Cas depletion of bisulfite-converted DNA enriches cancer informative signal for bioanalysis. To test validity of our Cas complex designs, we created model samples that mimic fully unmethylated and fully methylated species. We spiked these cfDNA models into a background of genomic DNA from 5% to 0.01%. In triplicate, we examined cutting efficiency, multiplexing and specificity of Cas to unmethylated species of model DNA. Results were assessed using qPCR by comparing differences in Ct with and without Cas treatment. Additionally, we applied this depletion step during our library preparation process to show utility in methylation analysis of low tumor content liquid biopsy samples. Using both the model sample dilution series and bisulfite converted cfDNA samples, which represent a range of cancerous and background methylation signal, we deplete unmethylated targets using Cas prior to indexing PCR. This rendered unmethylated targets non-amplifiable, removing them from analysis. Results were assessed using both qPCR and sequencing data, such as methylated read counts over the target region. We demonstrated our analytical approach efficiently depletes non-cancer cfDNA by on average 9-fold, which increases the fraction of ctDNA signal and can be multiplexed. This background signal depletion driven by CRISPR is sensitive and specific, maintaining methylated DNA signal detection down to 0.01% at inputs of 10ng DNA. Our Cas-mediated depletion of background signal method has proven useful for enriching rare methylated fragments over background by improving the signal to noise ratio. This technique is novel by harnessing the specificity of CRISPR to target DNA in both a sequence and methylation state specific manner. The depletion of precise methylation states at the CpG-level make it suitable for use in multiple bioassays. Citation Format: Caitlin Gilley, Miguel Williams, Emily Neaga, Sarah Falotico, Kade Pettie, Anthony Shuber. A methylation state specific targeted background depletion technique for enrichment of ctDNA fraction [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr A014.

Abstract A035: A real-time PCR method for the detection of cancer-specific methylation patterns in cfDNA

Abstract Non-invasive liquid biopsy tests are proving to be the next frontier in cancer diagnostics with methylation emerging as a reliable biomarker for low levels of circulating tumor DNA (ctDNA). There is a rising interest in sensitive, low-cost liquid biopsy assays to detect low copies of hypermethylated ctDNA in an excess background of non-cancer-associated hypomethylated cell- free DNA (cfDNA). Real-time quantitative methylation-specific PCR (qMSP) allows for the detection of low abundance methylated fragments. qMSP approaches have previously been developed but are predominantly designed to target a specific CpG site. To date we are not aware of any qMSP approaches that target pan-cancer-associated methylation patterns across multiple CpG sites. Harbinger Health has developed a qMSP method with locked nucleic acid (LNA) blockers that target methylation haplotypes, allowing for multiplex enrichment and quantification of cancer-specific methylation patterns. Using targeted bisulfite sequencing, we identified ten pan-cancer-informative CpG-dense regions which showed consistent contiguous elevated methylation states in cancer cfDNA and low levels of methylation in non-cancer cfDNA. We designed qMSP assays for these regions and LNA blockers which bind to unmethylated target CpG sites, outcompeting the hydrolysis probe through a high Tm differential. This prevented non-specific probe hybridization. The qMSP-LNA assays were evaluated in simplex and multiplex using cell line DNA in a titration of hypermethylated “ctDNA” spiked into hypomethylated “cfDNA” to simulate varying ctDNA levels, and then validated with cancer and non-cancer cfDNA samples at 5 ng input, equivalent to 1450 haploid copies. The percentage of methylated DNA was estimated by the ratio of methylated copies (qMSP-LNA) to total copies (internal reference), which were quantified by standard curves. The qMSP-LNA assays detected low abundance methylated DNA fragments down to 23 target copies. LNA blockers completely depleted background signal originating from unmethylated DNA with high specificity, showing no inhibition of methylated DNA detection. When tested in cfDNA samples which varied in conversion efficiency, discordant methylation states, and methylation abundance, the assays reproducibly amplified and detected highly methylated fragments which correspond to cancer signal. Harbinger Health has developed qMSP-LNA assays for contiguous CpG biomarkers which differentiate cancer and non-cancer samples from only ten pan-cancer-informative regions. The qMSP-LNA method detected low abundance fragments with specific methylation patterns with high specificity and sensitivity. The assay reproducibly detected methylated DNA in cfDNA samples that represent a clinically relevant range of methylation signal and will be further validated in a larger cohort of cancer and non-cancer cfDNA samples. Due to the high specificity and sensitivity, this cost-effective PCR method may provide utility and improve access for early cancer detection and monitoring. Citation Format: Emily Neaga, Caitlin Gilley, Sarah Falotico, Mayur Gurnani, Zhenyu Zhang, Jocelyn Charlton, Miguel Williams, Anthony Shuber. A real-time PCR method for the detection of cancer-specific methylation patterns in cfDNA [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr A035.

Abstract B050: Frequent monitoring of NSCLC immunotherapy using an mDETECT liquid biopsy reveals unexpected complexity and opportunities

Abstract We have developed a version of our "methylation DETection of Circulating Tumour" DNA (mDETECT) assay that is able to sensitively and quantitatively monitor Non-Small Cell Lung Cancer (NSCLC). We used this assay to frequently assess the tumour burden of a small cohort (17 individuals) of patients undergoing first line monotherapy with pembrolizumab for metastatic disease. Patients were tested weekly or biweekly in the period immediately after initiation of treatment with radiological assessment being done at approximately 3 months. Radiologically non-responding patients showed constant or increased mDETECT levels over the 3 month time frame. Responding patients showed 2 different patterns, with some showing dramatically increasing mDETECT levels for a short period of time followed by a rapid decrease. Other responders showed an immediate decrease within the first few week of treatment. In both responder groups these decreases were associated with a longer term response. Continued monitoring did reveal eventual progression in some of these patients with increasing mDETECT levels being seen 4 to 6 months before radiological changes. In some non-responding patients complex responses were seen, with mDETECT levels varying significantly over time. In one non-responding patient the addition of carboplatin to their treatment regime did produce a temporary improvement in their mDETECT levels. Frequent assessment of tumour burden by a liquid biopsy such as mDETECT offers the opportunity to rapidly determine a patient's response to therapy and potentially modify treatments to improve responses. Citation Format: Christopher R Mueller, Keira Parr, Mihaela Mates, Andrew Robinson, Harriet Feilotter, Keira Frosst. Frequent monitoring of NSCLC immunotherapy using an mDETECT liquid biopsy reveals unexpected complexity and opportunities [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr B050.

Abstract B013: An mDETECT assay for monitoring treatment response in metastatic breast cancer patients

Abstract Metastatic breast cancer treatment response is currently assessed every 3-6 months and this long delay results in many patients undergoing ineffective and toxic treatments for long periods of time. We have developed the methylation DETEction of Circulating Tumour DNA (mDETECT) assay, a targeted DNA methylation-based Next Generation Sequencing liquid biopsy that detects cancer-specific patterns in all subtypes of breast cancer. The assay targets 60 differentially hypermethylated regions in breast cancer across the genome and assesses over 400 individual CpGs with an average of 8 CpGs per target amplicon. The assay has been assessed on DNA from 73 breast cancer tumour samples which on average had 40 regions hypermethylated per patient with similar rates across all subtypes. We will present results from plasma samples from locally advanced and metastatic breast cancer patients along with plasma from age-matched, healthy female controls. A prospective, multi-centre observational cohort study to monitor metastatic breast cancer patients using the mDETECT liquid biopsy as they undergo treatment is active and recruiting patients. Blood is drawn with every standard-of-care blood draw for up to 3 years. Plasma has been assessed using the mDETECT assay to determine the methylation status of the DNA at each time point. 35 patients have been enrolled to date with ongoing recruitment up to 150 patients. Patients are being monitored with the mDETECT assay for earlier detection of disease progression on a treatment. They will also be monitored through treatment changes to assess a patient’s initial response to a given treatment. Changes in mDETECT levels will be correlated with clinical response to determine if the mDETECT breast cancer assay can detect a response to treatment at an earlier timepoint. This assay could allow for improved monitoring of treatment response allowing clinicians to make informed decisions, improving outcomes and prolonging patient’s lives. Citation Format: Keira Frosst, Brooke Wilson, Katrina Cristall, Catherine Crawford-Brown, Christopher R Mueller. An mDETECT assay for monitoring treatment response in metastatic breast cancer patients [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr B013.

Matching excellence: Oxford Nanopore Technologies' rise to parity with Pacific Biosciences in genome reconstruction of non-model bacterium with high G+C content.

The reconstruction of complete bacterial genomes is essential for microbial research, offering insights into genetic content, ontology and regulation. While Pacific Biosciences (PacBio) provides high-quality genomes, its cost remains a limitation. Oxford Nanopore Technologies (ONT) offers long reads at a lower cost, yet its error rate raises scepticism. Recent ONT advancements, such as new Flow cells (R10.4.1), chemistry (V14) and duplex mode, improve data quality. Our study compares ONT with PacBio and Illumina, including hybrid data. We used Propionibacterium freudenreichii, a bacterium with a genome known for being difficult to reconstruct. By combining data from ONT's Native Barcoding and a custom-developed BARSEQ method, we achieved high-quality, near-perfect genome assemblies. Our findings demonstrate, for the first time, that the combination of nanopore-only long-native with shorter PCR DNA reads (~3 kb) results in high-quality genome reconstruction, comparable to hybrid data assembly from two sequencing platforms. This endorses ONT as a cost-effective, stand-alone strategy for bacterial genome reconstruction. Additionally, we compared methylated motif detection between PacBio and ONT R10.4.1 data, showing that results comparable to PacBio are achievable using ONT, especially when utilizing the advanced Nanomotif tool.

Precise Methylation Detection of Tumor Suppressor Gene Promoters by Magnetic Enrichment and Nano Silver Adduct-Promoted Surface-Enhanced Raman Scattering.

Noninvasive liquid biopsies can be used for early tumor diagnosis by identifying the methylation level of the tumor suppressor genes (TSGs)-a reliable index for cancer evaluation. However, identifying trace circulating genes from specimens remains challenging. This work introduces a novel method that combines magnetic isolation and surface-enhanced Raman scattering (SERS) to concentrate and detect the methylated TSG promotors. A superparamagnetic iron oxide nanoparticle modified with streptavidin is prepared as a universal magnetic bead. Biotin-terminated probe single-strand DNA (ssDNA) is immobilized on the magnetic beads through biotin-streptavidin bioconjugation. Artificial target ssDNA fragments with various methylation levels are applied as a promoter gene model. Concentrated double-strand DNA (dsDNA) is produced by a hybridizing probe and target ssDNA on magnetic nanobeads, as well as an additional magnetic isolation process. The well-prepared DNA adduct, which consists of 3nm cisplatin-modified Ag nanoclusters, can specifically bind with guanine-cytosine base pairs of dsDNA. Ag-nanoparticle-induced localized SERS amplified signals of 5-methylcytosine (5-mC) from the dsDNA in Raman spectra, enabling accurate methylation level measurement in mixtures of 0-1µm methylated DNA, with a detection limit of 0.05µm. This method shows promise for enabling the methylation level evaluation of various TSGs and promoters in early cancer liquid biopsies.

LAMP-MS for Locus-Specific Visual Quantification of DNA 5mC and RNA m6A Using Ultra-Low Input.

Enhancing the effectiveness of utilizing circulating cell-free DNA (cfDNA) for disease screening remains a challenge, necessitating improved sensitivity, specificity, cost-efficiency, and patient adherence. We present here LAMP-MS, an innovative technology that integrates linear amplification with single-base quantitative nucleic acid mass spectrometry on silicon chips. This approach overcomes several limitations in utilizing cfDNA 5-methylcytosine (5mC) status for colorectal cancer (CRC) screening. LAMP-MS enables unbiased amplification of as little as 1 ng of cfDNA, site-specifically quantify methylation levels of tens to hundreds of 5mC sites, thereby facilitating cost-effective, high-resolution quantitative detection of cfDNA methylation markers. We have validated the accuracy of DNA methylation determination using DNA probes and cfDNA from patient plasma samples, confirmed by mass spectrometric peak areas. Additionally, we have further shown this Mass Array technology could be expanded to also quantify RNA m6A modification sites. Combining the ability to work with ultra-low input materials and a visually interpretable output, LAMP-MS stands out as a promising method for real-world applications in clinics and laboratories for nucleic acid methylation detection and quantification.

LAMP‐MS for Locus‐Specific Visual Quantification of DNA 5mC and RNA m6A Using Ultra‐Low Input

Enhancing the effectiveness of utilizing circulating cell‐free DNA (cfDNA) for disease screening remains a challenge, necessitating improved sensitivity, specificity, cost‐efficiency, and patient adherence. We present here LAMP‐MS, an innovative technology that integrates linear amplification with single‐base quantitative nucleic acid mass spectrometry on silicon chips. This approach overcomes several limitations in utilizing cfDNA 5‐methylcytosine (5mC) status for colorectal cancer (CRC) screening. LAMP‐MS enables unbiased amplification of as little as 1 ng of cfDNA, site‐specifically quantify methylation levels of tens to hundreds of 5mC sites, thereby facilitating cost‐effective, high‐resolution quantitative detection of cfDNA methylation markers. We have validated the accuracy of DNA methylation determination using DNA probes and cfDNA from patient plasma samples, confirmed by mass spectrometric peak areas. Additionally, we have further shown this Mass Array technology could be expanded to also quantify RNA m6A modification sites. Combining the ability to work with ultra‐low input materials and a visually interpretable output, LAMP‐MS stands out as a promising method for real‐world applications in clinics and laboratories for nucleic acid methylation detection and quantification.

Highly specific multiplex DNA methylation detection for liquid biopsy of colorectal cancer

BackgroundCirculating tumor DNA (ctDNA) has emerged as a useful biomarker for cancer detection and prognosis. In this study, we developed a strategy for developing a highly specific multiplex qPCR assay to detect methylated ctDNA in the blood of colorectal cancer (CRC) patients and investigated the potential use for the detection and prognosis of CRC. MethodsBisulfite conversion and amplicon sequencing were used to confirm potential CRC-specific DNA methylation markers. The selected DNA methylation candidates were validated by qMSP. The six best-performing markers were used to develop a new single-tube multiplex quantitative methylation-specific PCR assay (mqMSP). The mqMSP assay was applied to analyze plasma samples from 114 CRC patients, 47 patients with advanced adenoma, 45 patients with benign polyps, and 57 healthy controls. The clinical performance of the assay and associations with clinical outcomes were assessed. ResultsSix DNA methylation biomarkers were confirmed to be specifically hypermethylated in CRC tumor tissues. The newly developed mqMSP assay detected CRC with extremely high specificity (specificity of 98.2 %, with sensitivity of 67.5 %). The detection rate of ctDNA was significantly correlated with tumor size and clinical stage, with ctDNA methylation levels in the blood markedly increased with larger tumor size, poor differentiation, and advanced stage. Moreover, high preoperative methylated ctDNA level was associated with worse recurrence-free survival and overall survival. ConclusionWe provided a strategy for identification of multiple highly-specific DNA methylation markers for designing multiplex DNA methylation assays for liquid biopsies of CRC. The newly developed assay has potential for CRC early detection, and prognosis.

Circulating tumor DNA methylation detection as biomarker and its application in tumor liquid biopsy: advances and challenges.

Circulating tumor DNA (ctDNA) methylation, an innovative liquid biopsy biomarker, has emerged as a promising tool in early cancer diagnosis, monitoring, and prognosis prediction. As a noninvasive approach, liquid biopsy overcomes the limitations of traditional tissue biopsy. Among various biomarkers, ctDNA methylation has garnered significant attention due to its high specificity and early detection capability across diverse cancer types. Despite its immense potential, the clinical application of ctDNA methylation faces substantial challenges pertaining to sensitivity, specificity, and standardization. In this review, we begin by introducing the basic biology and common detection techniques of ctDNA methylation. We then explore recent advancements and the challenges faced in the clinical application of ctDNA methylation in liquid biopsies. This includes progress in early screening and diagnosis, identification of clinical molecular subtypes, monitoring of recurrence and minimal residual disease (MRD), prediction of treatment response and prognosis, assessment of tumor burden, and determination of tissue origin. Finally, we discuss the future perspectives and challenges of ctDNA methylation detection in clinical applications. This comprehensive overview underscores the vital role of ctDNA methylation in enhancing cancer diagnostic accuracy, personalizing treatments, and effectively monitoring disease progression, providing valuable insights for future research and clinical practice.

Clinical significance of peripheral blood DDR1 and CtBP gene methylation detection in patients with acute pancreatitis

ABSTRACT To investigate the clinical value of methylation levels of peripheral blood DDR1 and CtBP genes in evaluating the severity of acute pancreatitis (AP). Collect 90 blood samples from AP patients and healthy volunteers, and test methylation levels of SPINK1, STAT3, KIT, CFTR, DDR1, CtBP1, CtBP2 genes by bisulfite amplicon sequencing (BSAS). The gene methylation and clinical predictors of SAP early prediction were determined by univariate and multifactorial analysis, respectively. (1) The methylation level of CtBP1 gene and MCTSI score were independent predictors of SAP, with AUC values of 0.723 and 0.8895, respectively. (2) The methylation levels of DDR1, CtBP2, CFTR and SPINK1 genes were statistically significant in HC group vs AP group, HC group vs MAP group, and HC group vs SAP group. (3) The combined detection of CtBP1 gene methylation level and MCTSI score predicted the sensitivity, specificity, AUC, and 95%CI of SAP were 0.750, 0.957, 0.902, and 0.816–0.989, respectively. (1) The methylation level of CtBP1 gene in peripheral blood is an independent risk factor for predicting SAP and is a potentially good predictor of SAP, and the combined testing with the MCTSI score does not further significantly improve the early predictive value for SAP. (2) The methylation levels of DDR1, SPINK1, CtBP2, and CFTR genes were potential indicators for recognizing AP.

Performance of DNA methylation and blood-borne tumor indicators in detecting colorectal neoplasia and adenomas: a comparative study with the fecal occult blood test.

To evaluate the performance of stool methylated syndecan2 (mSDC2), methylated septin9 (mSEPT9), fecal occult blood test (FOBT), carcinoembryonic antigen (CEA), carbohydrate antigen 125 (CA125) and carbohydrate antigen 199 (CA199) in detecting colorectal neoplasia and adenomas. Blood-borne CEA, CA125, and CA199 levels were measured by electrochemiluminescence. The SDC2 methylation was detected by Methylation Detection Kit for Human SDC2 Gene (Real time PCR), and the SEPT9 methylation was detected by the Septin9 Gene Methylation Detection Kit based on PCR fluorescent probe assay. The colonoscopy combined with tissue biopsy pathology was used as a validation criterion for colorectal neoplasia. In detecting colorectal neoplasia, the AUCs of mSDC2, FOBT and mSEPT9 were 0.935 (95% CI: 0.915-0.956, P<0.001), 0.824 (95% CI: 0.617-1.000, P<0.001) and 0.671 (95% CI: 0.511-0.831, P<0.001), respectively. The sensitivity of mSDC2, FOBT and mSEPT9 were 100.0%, 66.7% and 40.0%, respectively. But the AUC of CEA, CA125 and CA199 were not statistically significant for colorectal neoplasia (all P>0.05). The combined application of mSEPT9 and mSDC2 showed the best predictive performance (AUC: 0.956, 95% CI: 0.887~1.000). For adenomas, the AUC of FOBT was extremely low (AUC: 0.524, 95% CI: 0.502-0.545, P=0.004). The CEA, CA125, CA199, mSEPT9 and mSDC2 were not statistically significant in detecting adenomas (all P>0.05). For individual tests, FOBT and mSDC2 are relatively better indicators for detecting colorectal neoplasia compared to mSEPT9, CEA, CA125 and CA199. The combined form of mSEPT9 and mSDC2 to detect colorectal neoplasia has good predictive performance. However, none of these indicators demonstrated significant predictive power for detecting adenomas in our study.

A novel methylation-detection panel for HPV associated high-grade squamous intraepithelial lesion and cervical cancer screening

Cervical cancer (CC) was considered to be the most common gynaecological cancer, with an estimated 342,000 deaths worldwide each year, as the majority of patients were diagnosed at an advanced stage of the disease. The purpose of this study was to evaluate the predictive value of multi-locus methylation assay for the early detection of CC. The cervical exfoliated cell samples from 492 HPV-positive females with cervical lesions were collected and subjected to methylation detection of gene FAM19A4, EPB41L3 and PAX1 after bisulfite conversion. The levels of gene methylation in patients with different severity of cervical lesions were evaluated and compared. The receiver-operating characteristic (ROC) curve was established and efficacy indexes such as sensitivity, specificity and area under the curve (AUC) were calculated to assess the diagnostic value of DNA methylation detection at multiple gene loci for CC. The methylation levels of FAM19A4, EPB41L3 and PAX1 were significantly increased with the grade of cervical squamous intraepithelial lesions. The sensitivities of FAM19A4, EPB41L3 and PAX1 alone for high-grade squamous intraepithelial lesion (HSIL) and CC diagnosis were 84.6%, 86.3% and 88.0%, respectively; when three markers were combined by a logistic regression model, the sensitivity was 88.0%, with a high specificity of 97.7% and AUC of 0.957 (95% CI 0.937–0.977). Methylation status of FAM19A4, EPB41L3 and PAX1 were highly specific and effective for monitoring the progression of cervical lesions and the tri-gene methylation assay could be used as a triage tool for CC early screening.

Methods for Detection and Mapping of Methylated and Hydroxymethylated Cytosine in DNA.

The chemical modifications of DNA are of pivotal importance in the epigenetic regulation of cellular processes. Although the function of 5-methylcytosine (5mC) has been extensively investigated, the significance of 5-hydroxymethylcytosine (5hmC) has only recently been acknowledged. Conventional methods for the detection of DNA methylation frequently lack the capacity to distinguish between 5mC and 5hmC, resulting in the combined reporting of both. The growing importance of 5hmC has prompted the development of a multitude of methods for the qualitative and quantitative analysis of 5hmC in recent years, thereby facilitating researchers' understanding of the mechanisms underlying the onset and progression of numerous diseases. This review covers both established and novel methods for the detection of cytosine modifications, including 5mC, 5hmC, 5-formylcytosine (5fC) and 5-carboxylcytosine (5caC), with a particular focus on those that allow for accurate mapping and detection, particularly with third-generation sequencing. The review aims to help researchers choose the most appropriate methods based on their specific research goals and budget.

Interlaboratory consistency of SDC2 promoter methylation detection in colorectal cancer using the post-optimized materials

Interlaboratory consistency of SDC2 promoter methylation detection in colorectal cancer using the post-optimized materials

Detecting m6A RNA modification from nanopore sequencing using a semisupervised learning framework.

Direct nanopore-based RNA sequencing can be used to detect posttranscriptional base modifications, such as N6-methyladenosine (m6A) methylation, based on the electric current signals produced by the distinct chemical structures of modified bases. A key challenge is the scarcity of adequate training data with known methylation modifications. We present Xron, a hybrid encoder-decoder framework that delivers a direct methylation-distinguishing basecaller by training on synthetic RNA data and immunoprecipitation (IP)-based experimental data in two steps. First, we generate data with more diverse modification combinations through in silico cross-linking. Second, we use this data set to train an end-to-end neural network basecaller followed by fine-tuning on IP-based experimental data with label smoothing. The trained neural network basecaller outperforms existing methylation detection methods on both read-level and site-level prediction scores. Xron is a standalone, end-to-end m6A-distinguishing basecaller capable of detecting methylated bases directly from raw sequencing signals, enabling de novo methylome assembly.

Improved detection of methylation in ancient DNA

Reconstructing premortem DNA methylation levels in ancient DNA has led to breakthrough studies such as the prediction of anatomical features of the Denisovan. These studies rely on computationally inferring methylation levels from damage signals in naturally deaminated cytosines, which requires expensive high-coverage genomes. Here, we test two methods for direct methylation measurement developed for modern DNA based on either bisulfite or enzymatic methylation treatments. Bisulfite treatment shows the least reduction in DNA yields as well as the least biases during methylation conversion, demonstrating that this method can be successfully applied to ancient DNA.

Green florescent carbon dots synthesized from various household green wastes for detection of parathion methyl pesticide

The purpose of the current study was to examine the use of green household wastes, such as lemon peel, bottle gourd peel (BG), culinary banana peel, and sugarcane bagasse, as a source for synthesizing carbon dots (C-dots) and to determine how the composition of the material affected the functional characteristics of the C-dots and its interaction behaviour for detection of pesticide. The synthesized C-dots showed green fluorescence with varying particle sizes and red shifting fluorescence with more than 100 nm Stokes shift, indicating time and excitation dependent luminescence behaviour. C-dots produced from bottle gourd (BG) peel had a positive impact on the functional characteristics with a maximum emission of 514 nm and excitation of 410 nm. The SAED and TEM pattern confirmed its amorphous structure. The hydronium ion diameter and the quantum yield were 0.99 nm and 3.1 % respectively. Contributing towards food safety, the synthesized C-dots from BG showed significant behaviour in the detection of parathion methyl (MP) like organophosphorus pesticide (OP) as it conjugated with iron and 1 ppm of parathion methyl, which exhibited “Turn-Off-On” fluorescence behaviour with noticeable changed in intensity and act as a promising qualitative tool for detection of parathion methyl in real sample. The intensity of FL and concentration of OP is directly proportional which is established by the investigated OP in vegetable, fruit and water samples. The significance of iron and MP-OP was also investigated in the presence of other metal ions and pesticides and showed that the C-dots synthesized probe solution was reliable and sensitive towards the detection of MP-OP in real samples.