Aberrant methylation of NPY, PENK, and WIF1 as a promising marker for blood-based diagnosis of colorectal cancer. BMC Cancer. 2013;13:566. [PMID: 24289328 PMCID: PMC4219483 DOI: 10.1186/1471-2407-13-566]

Minimal residual disease in colorectal cancer. Tumor-informed versus tumor-agnostic approaches: unraveling the optimal strategy

BACKGROUND

Circulating tumor DNA (ctDNA) analysis has emerged as a minimally invasive tool for detecting minimal residual disease (MRD) in colorectal cancer (CRC) patients. This enables dynamic risk stratification, earlier recurrence detection and optimized post-surgical treatment. Two primary methodologies have been developed for ctDNA-based MRD detection: tumor-informed strategies, which identify tumor-specific mutations through initial tissue sequencing to guide ctDNA monitoring, and tumor-agnostic approaches, which utilize predefined panels to detect common cancer-associated genomic or epigenomic alterations directly from plasma without prior tissue analysis. The debate over which is superior in terms of sensitivity, specificity, cost-effectiveness and clinical feasibility remains unsolved.

DESIGN

This review summarizes studies published up to November 2024, exploring the utility and performance of tumor-informed and tumor-agnostic approaches for ctDNA analysis in CRC. We evaluate the strengths and limitations of each methodology, focusing on sensitivity, specificity and clinical outcomes.

RESULTS

Both strategies demonstrate clinical utility in post-operative risk stratification and guiding adjuvant chemotherapy decisions in CRC patients. Tumor-informed approaches generally exhibit superior sensitivity and specificity for recurrence prediction, attributed to their personalized tumor profile designs. However, these methods are limited by the need for prior tissue sequencing and higher associated costs. In contrast, tumor-agnostic approaches offer broader applicability due to their reliance on plasma-only analysis, although with relatively lower sensitivity. Technological advancements, including fragmentomics and multi-omic integrations, are expanding the capabilities of ctDNA-based MRD detection, enhancing the performance of both approaches.

CONCLUSIONS

While tumor-informed strategies currently offer higher precision in MRD detection, tumor-agnostic approaches are gaining traction due to their convenience and improving performance metrics. The integration of novel technologies in ongoing clinical trials may redefine the optimal approach for MRD detection in CRC, paving the way for more personalized and adaptive patient management strategies.

EpigenPlot: An interactive web platform for DNA methylation-based biomarker and drug target discovery in colorectal cancer

BACKGROUND AND PURPOSE

Genome-wide methylation studies have significantly advanced our understanding of colorectal adenocarcinoma progression and biomarker discovery. Aberrant DNA methylation plays a crucial role in gene expression regulation during cancer transformation, highlighting the need to identify differentially methylated regions (DMRs) as potential diagnostic and therapeutic markers. However, an integrated resource to explore and validate methylation alterations across colorectal cancer stages has been lacking. We aimed to develop a platform that integrates existing methylation data, systematically identifies DMRs and provides a tool for further investigation.

EXPERIMENTAL APPROACH

We created a database combining Illumina HumanMethylation450K and EPIC data from normal colon, adenoma and adenocarcinoma tissues, comprising 2346 samples from 19 datasets. Methylation levels were analysed in six gene regions, and comparisons between tissue types were made using Mann-Whitney, Kruskal-Wallis and ROC tests.

KEY RESULTS

Both adenoma and adenocarcinoma samples exhibited a general decrease in methylation compared to healthy tissue. Differential methylation in genes such as ITGA4, NPY, IGFL1 and LRRC4 was validated. The strongest DMRs were observed in the C1orf70 gene's 5'UTR and TSS200 regions, with AUC values of 0.98 in both of the HM450K and EPIC datasets. We established an interactive web-based platform accessible at https://epigenplot.com/ enabling future analysis of individual gene regions.

CONCLUSIONS AND IMPLICATIONS

Our study provides an integrated database of DNA methylation profiles across normal, adenoma and adenocarcinoma tissues, offering a valuable resource for biomarker discovery. The integrated web platform can serve as a tool for the development of methylation-based therapies in the future.

Inverted U-shaped association between the systemic immune-inflammation index and colorectal polyps in Chinese patients: a cross-sectional study

Purpose

The systemic immune-inflammation index (SII) has been found to be associated with various inflammatory and neoplastic diseases. The aim of this study was to investigate the relationship between the SII and colorectal polyps (CPs) in Chinese patients.

Methods

This was a cross-sectional study. We retrospectively collected data from 3,028 Chinese patients who underwent physical examinations, including colonoscopy, from 2018 to 2022. We conducted a comparative analysis of patient characteristics among those with adenomatous polyps, non-adenomatous polyps, and individuals without CPs using descriptive statistics. We calculated the SII for each group and assessed the relationship between SII values and the presence of CPs.

Results

Our study included 3,028 individuals, of whom 1,432 (47.29%) had colorectal polyps. After adjusting for confounding variables, the natural logarithm of the SII (Ln-SII) was significantly associated with the prevalence of adenomatous polyps in both males and females, with an odds ratio (OR) of 0.76 [95% confidence interval (CI): 0.65-0.88, p = 0.0003]. An inverted U-shaped relationship was observed between Ln-SII and the prevalence of colorectal polyps, including both adenomatous and non-adenomatous polyps, with a cut-off point at 5.78 (5.39 for adenomatous polyps and 5.79 for non-adenomatous polyps). Below this cut-off point, a significant association with colorectal polyps was identified, with an OR of 1.73 (95% CI: 1.25-2.40, p = 0.0009). Specifically, for adenomatous polyps, the OR was 2.91 (95% CI: 1.03-8.20, p = 0.0437), and for non-adenomatous polyps, the OR was 1.86 (95% CI: 1.31-2.65, p = 0.0006). Beyond the cut-off point, the association between Ln-SII and colorectal polyps remained significant, with an OR of 0.56 (95% CI: 0.46-0.68, p < 0.0001). In the adenomatous polyps group, the OR was 0.57 (95% CI: 0.43-0.74, p < 0.0001), and in the non-adenomatous polyps group, the OR was 0.57 (95% CI: 0.46-0.70, p < 0.0001).

Conclusion

The inverted U-shaped association between Ln-SII and the risk of colorectal polyps highlights the potential relevance of monitoring variations in SII and suggests that SII may be a promising predictor for colorectal polyp development.

A prospective study of methylated ctDNA in patients undergoing treatment for liver metastases from colorectal cancer

BACKGROUND

Decision regarding local treatment of colorectal liver metastases (CRLM) is a multidisciplinary assessment, and liver intervention should be performed when the metastases are deemed resectable. There is no standard biomarker to aid neither this decision nor the postoperative treatment decisions. The present prospective, observational study aimed to investigate the potential clinical utility of a combined tumor-specific and organ-specific methylated circulating DNA assay in the perioperative setting of CRLM.

MATERIAL AND METHODS

The study included 56 cases with CRLM. Blood samples were drawn preoperatively and postoperatively. Multiplex methylation analysis of the markers NPY, KANK1, and GAL3ST3 (meth-ctDNA) was performed using droplet digital PCR.

RESULTS

The assay detected preoperative and postoperative meth-ctDNA in 37 % and 46 % of patients, respectively. Patients with negative preoperative meth-ctDNA had a longer median PFS compared to those with positive preoperative meth-ctDNA (HR = 2.2, 95 % CI 1.2-3.9, p < 0.01). In a multivariate analysis, preoperative negative meth-ctDNA was identified as a strong independent predictor of PFS (HR = 3.3, 95 % CI 1.5-7.2, p < 0.01). Similarly, patients with negative postoperative meth-ctDNA had longer median PFS (HR = 3.0, 95 % CI = 1.6-5.6, p < 0.001) and OS (HR = 4.1, 95 % CI 1.9-9.1, p < 0.001) compared to those with positive postoperative meth-ctDNA.

CONCLUSION

Preoperative meth-ctDNA may serve as an important biomarker to inform the multidisciplinary assessment and treatment planning of CRLM. Negative meth-ctDNA may indicate the optimal timing for liver intervention, whereas positive meth-ctDNA may indicate initiation or re-orientation of chemotherapy, or immediate local intervention. Our results confirm postoperative negative meth-ctDNA as a strong prognostic marker of survival.

Circulating methylated HOXA9 tumor DNA as a biomarker for mortality in recurrent breast cancer: An exploratory study

Methylated homeobox A9 (meth-HOXA9) circulating tumor DNA may be a relevant biomarker in breast cancer, although its clinical significance remains unknown. The present exploratory study aimed to investigate the association between meth-HOXA9 and mortality in patients with recurrent breast cancer. The cohort study enrolled 51 patients with breast cancer recurrence from the Department of Oncology, Vejle Hospital, University Hospital of Southern Denmark (Vejle, Denmark). Tissue samples from primary surgery and biopsies, and plasma samples obtained at the time of recurrence were analyzed for meth-HOXA9 using a methylation-specific droplet digital polymerase chain reaction. Using Cox regression, hazard ratios (HRs) for mortality with 95% confidence intervals (CIs) comparing patients with detectable and undetectable meth-HOXA9 in both tumor tissue and plasma were estimated. Among the 50 patients with data on tumor tissue meth-HOXA9, there was no association between meth-HOXA9 in the primary tumor and mortality (HR 1.09, 95% CI 0.47-2.52). A total of 34 patients had data on plasma meth-HOXA9 at the time of recurrence. Detectable plasma meth-HOXA9 was associated with higher mortality (HR 3.95, 95% CI 1.50-10.37). Among the 20 patients with data on both plasma and metastatic tissue meth-HOXA9, meth-HOXA9 was detectable in 90% of metastases and 65% of plasma samples. In conclusion, detectable plasma meth-HOXA9 was significantly associated with higher mortality in recurrent breast cancer; therefore, plasma meth-HOXA9 may prove useful as a prognostic marker in patients with breast cancer.

Implementation of a MSRE ddPCR method for the detection of methylated WIF1 and NPY genes in colorectal cancer patients

BACKGROUND

Colorectal cancer is a worldwide leading cause of death accounting for high-rate mortality. Mutations in the epidermal growth factor receptor and RAS/MAPK pathways, as well as altered methylation genes profiles, have been described as molecular mechanisms promoting and sustaining tumour development and progression. Aberrant methylation is a well-known epigenetic mechanism involved in gene regulation; particularly several genes were reported as hypermethylated in CRC. Recently, it was shown that epigenetic alterations in genes such as neuropeptide y, proenkephalin and Wnt inhibitory factor 1 can be used as promising disease biomarkers. Almost all methods developed for the DNA methylation analysis combined next generation sequencing, conventional qRT-PCR or ddPCR with the prior DNA modification with sodium bisulfite.

METHODS AND RESULTS

We implemented a ddPCR method to assess the methylation status of Wnt inhibitory factor 1 and neuropeptide y using the methylation sensitive restriction enzyme approach that does not impact on DNA quality and guarantees the discrimination of DNA methylation independent of bisulfite conversion.

CONCLUSIONS

We showed that this method is robust and sensitive also allowing the monitoring of CRC disease progression when applied to circulating free DNA samples from liquid biopsies, proving to be a fast and easy to implement assay to be used for the monitoring of the methylation pattern of clinically relevant target genes.

Endogenous Opioid Peptides After Floatation Therapy in Resistance-Trained Men

ABSTRACT

Kraemer, WJ, Caldwell, LK, Post, EM, Volek, JS, Hagen, JM, Newton, RU, Häkkinen, K, Omonije, O, and Maresh, CM. Endogenous opioid peptides after floatation therapy in resistance trained men. J Strength Cond Res 38(10): 1808-1812, 2024-Floatation-restricted environmental stimulation therapy (Float-REST) has shown improvements in muscle soreness and fatigue. To determine whether float influences the release of beta-endorphin (β-End) and proenkephalin (ProEnk) after acute heavy resistance exercise, 11 healthy resistance-trained men (age: 22.5 ± 2.3 years; height: 176.4 ± 6.0 cm; body mass: 85.7 ± 6.2 kg, back squat one-repetition maximum: 153.1 ± 20.1 kg; strength-to-mass ratio: 1.8 ± 0.2) completed a within-subject, cross-over controlled study design. Subjects completed 2 exercise testing blocks separated by a 2-week washout. In one block, a 1-hour float session followed the high-intensity resistance exercise protocol (6 × 10 back squats at 80% 1RM, 2 minutes rest). By contrast, recovery in the alternate block consisted of a passive sensory-stimulating control. Blood samples were collected at 5 time points-before exercise, immediately after exercise, after1-hour recovery treatment, 24 hours after exercise, and 48 hours after exercise. Samples were analyzed in duplicate for β-End and ProEnk using ELISA immunoassays. Mean differences were assessed using repeated-measures ANOVA. Plasma β-End demonstrated the expected significant (p ≤ 0.05) increase following resistance exercise in both treatment conditions. There were no significant changes with exercise stress for ProEnk precursor peptide. The absence of significant differential changes following Float-REST suggests that these opioid peptides may not underlie the deep relaxation experiences commonly reported with this intervention in trained men. However, practically, it shows that β-End remains consistently similarly increased to high-intensity exercise stress. However, the ProEnk concentrations are detectable and stable but do not respond to the workout protocol, which, as a primary opioid peptide precursor, suggests paracrine cybernetics in the circulation may exist.

Circulating tumor cells: from new biological insights to clinical practice

The primary reason for high mortality rates among cancer patients is metastasis, where tumor cells migrate through the bloodstream from the original site to other parts of the body. Recent advancements in technology have significantly enhanced our comprehension of the mechanisms behind the bloodborne spread of circulating tumor cells (CTCs). One critical process, DNA methylation, regulates gene expression and chromosome stability, thus maintaining dynamic equilibrium in the body. Global hypomethylation and locus-specific hypermethylation are examples of changes in DNA methylation patterns that are pivotal to carcinogenesis. This comprehensive review first provides an overview of the various processes that contribute to the formation of CTCs, including epithelial-mesenchymal transition (EMT), immune surveillance, and colonization. We then conduct an in-depth analysis of how modifications in DNA methylation within CTCs impact each of these critical stages during CTC dissemination. Furthermore, we explored potential clinical implications of changes in DNA methylation in CTCs for patients with cancer. By understanding these epigenetic modifications, we can gain insights into the metastatic process and identify new biomarkers for early detection, prognosis, and targeted therapies. This review aims to bridge the gap between basic research and clinical application, highlighting the significance of DNA methylation in the context of cancer metastasis and offering new avenues for improving patient outcomes.

Methylated ctDNA predicts early recurrence risk in patients undergoing resection of initially unresectable colorectal cancer liver metastases

Background

Patients with initially unresectable colorectal cancer liver metastases (IU-CRLM) might benefit from using an effective systemic treatment followed by resection of liver metastases but the curative success rate is quite low. Indeed, nearly one-third of patients exhibit early recurrence within the first 6 months after surgery, and these individuals often have poor overall survival.

Objectives

This study aims to clarify the application value of serial circulating tumor DNA (ctDNA) analysis in predicting the clinical outcome of IU-CRLM patients following liver metastasectomy.

Design

A retrospective study was conducted on a cohort of patients with IU-CRLM between February 2018 and April 2021.

Methods

Plasma samples at different time points during CRLM treatment [baseline (BL), preoperation (PRE), postoperation (POST), end-of-treatment (EOT), and progressive disease (PD)] were retrospectively collected from patients with initially unresectable CRLM enrolled at the Sun Yat-sen University Cancer Center. Dynamic changes of SEPTIN 9 (SEPT9) and Neuropeptide Y (NPY) methylated circulating tumor DNA (MetctDNA) levels in serial plasma samples were detected using droplet-digital PCR (ddPCR).

Results

SEPT9 and NPY genes were hypermethylated in colon cancer cell lines and tissues while no difference was observed between primary and metastatic tumors. Patients with MetctDNA positive at POST or EOT had significantly lower recurrence-free survival (RFS) compared to patients with MetctDNA negative at these time points [POST: Hazard ratio (HR) 9.44, 95% confidence interval (CI) 5.15-17.30, p < 0.001; EOT: HR 11.48, 95% CI 3.27-40.31, p < 0.001]. Multivariate analysis demonstrated that POST (OR 33.96, 95% CI 4.03-286.10, p = 0.001) and EOT (OR 18.36, 95% CI 1.14-295.71, p = 0.04) MetctDNA was an independent risk factor for early recurrence. Time-dependent receiver operating characteristic curve (T-ROC) analysis revealed that area under the curve (AUC) value was greatest at the relapse time point of 6 months post-intervention, with POST-AUC and EOT-AUC values of 0.74 (95% CI 0.66-0.81) and 0.73 (95% CI 0.53-0.94), respectively. Serial MetctDNA analysis showed that RFS was significantly lower in patients with no MetctDNA clearance compared with those with MetctDNA clearance (HR 26.05, 95% CI 4.92-137.81, p < 0.001).

Conclusion

Our study confirmed that serial ctDNA analysis of NPY and SEPT9 gene methylation could effectively predict early recurrence in IU-CRLM patients, especially at POST and EOT.

DNA methylation modulates epigenetic regulation in colorectal cancer diagnosis, prognosis and precision medicine

Colorectal cancer (CRC) is a multifaceted disease influenced by the interplay of genetic and environmental factors. The clinical heterogeneity of CRC cannot be attributed exclusively to genetic diversity and environmental exposures, and epigenetic markers, especially DNA methylation, play a critical role as key molecular markers of cancer. This review compiles a comprehensive body of evidence underscoring the significant involvement of DNA methylation modifications in the pathogenesis of CRC. Moreover, this review explores the potential utility of DNA methylation in cancer diagnosis, prognostics, assessment of disease activity, and prediction of drug responses. Recognizing the impact of DNA methylation will enhance the ability to identify distinct CRC subtypes, paving the way for personalized treatment strategies and advancing precision medicine in the management of CRC.

Advances in blood DNA methylation-based assay for colorectal cancer early detection: a systematic updated review

Aim

A systematic review was conducted to summarize the methylated circulating tumor DNA (ctDNA) markers reported over the last decade for early detection of colorectal cancer (CRC) and to identify the main technical challenges that are impeding their clinical implementation.

Background

CRC is a major cause of cancer deaths worldwide, but early detection is key for successful treatment. Non-invasive methods such as methylated ctDNA testing show promise for improving detection and monitoring of CRC.

Methods

A comprehensive search was performed using Web of Science, PubMed, and Scopus up to December 30, 2023, limited to articles published in the last 10 years (after 2012), while including advanced adenoma/stage 0 or stage I/II samples in biomarker validation.

Results

After identifying 694 articles, removing duplicates and screening titles, abstracts, and full texts, a total of 62 articles were found to meet the inclusion criteria. Among the single biomarkers, MYO1-G, SEPT9, SDC2, and JAM3 revealed the highest sensitivity for polyps and stage I/II CRC. For multi-biomarkers with suitable sensitivity, combinations of SFRP1, SFRP2, SDC2, PRIMA1, or ALX4, BMP3, NPTX2, RARB, SDC2, SEPT9, VIM or ZFHX4, ZNF334, ELOVL2, UNC5C, LOC146880, SFMBT2, GFRA1 were identified for polyps and stage I/II CRC.

Conclusion

Enhancing sensitivity and specificity of molecular screening methods is crucial for improving CRC detection. Identifying a select few valuable biomarkers is key to reducing costs, despite challenges posed by low ctDNA levels in plasma, particularly in early-stage cancers.

ctDNA-guided adjuvant treatment after radical-intent treatment of metastatic spread from colorectal cancer-the first interim results from the OPTIMISE study

BACKGROUND

Patients with detectable ctDNA after radical-intent treatment of metastatic spread from colorectal cancer (mCRC) have a very high risk of recurrence, which may be prevented with intensified adjuvant chemotherapy (aCTh). In the OPTIMISE study, we investigate ctDNA-guided aCTh after radical-intent treatment of mCRC. Here we present results from the preplanned interim analysis.

MATERIAL AND METHODS

The study is an open-label 1:1 randomized clinical trial comparing ctDNA-guided aCTh against standard of care (SOC), with a run-in phase investigating feasibility measures. Key inclusion criteria; radical-intent treatment for mCRC and clinically eligible for triple-agent chemotherapy. Patients underwent a PET-CT scan before randomization. ctDNA analyses of plasma samples were done by ddPCR, detecting CRC-specific mutations and methylation of the NPY gene. In the ctDNA-guided arm, ctDNA positivity led to an escalation strategy with triple-agent chemotherapy, and conversely ctDNA negativity led to a de-escalation strategy by shared-decision making. Patients randomized to the standard arm were treated according to SOC. Feasibility measures for the run-in phase were; the inclusion of 30 patients over 12 months in two Danish hospitals, compliance with randomization >80%, rate of PET-CT-positive findings <20%, and eligibility for triple-agent chemotherapy >80%.

RESULTS

Thirty-two patients were included. The rate of PET-CT-positive cases was 22% (n = 7/32). Ninety-seven percent of the patients were randomized. Fourteen patients were randomly assigned to SOC and sixteen to ctDNA-guided adjuvant treatment and follow-up. All analyses of baseline plasma samples in the ctDNA-guided arm passed the quality control, and 19% were ctDNA positive. The median time to result was three working days. All ctDNA-positive patients were eligible for triple-agent chemotherapy.

CONCLUSION

The study was proven to be feasible and continues in the planned large-scale phase II trial. Results from the OPTIMISE study will potentially optimize the adjuvant treatment of patients undergoing radical-intent treatment of mCRC, thereby improving survival and reducing chemotherapy-related toxicity.

The Importance of Feasibility Assessment in the Design of ctDNA Guided Trials - Results From the OPTIPAL II Study

INTRODUCTION

Both quantitative and molecular changes in ctDNA can hold important information when treating metastatic colorectal cancer (mCRC), but its clinical utility is yet to be established. Before conducting a large-scale randomized trial, it is essential to test feasibility. This study investigates whether ctDNA is feasible for detecting patients who will benefit from treatment with epidermal growth factor receptor inhibitors and the prognostic value of circulating tumor DNA (ctDNA) response.

MATERIALS AND METHODS

Patients with mCRC, who were considered for systemic palliative treatment and were eligible for ctDNA analysis. Mutational testing on cell-free DNA (cfDNA) was done by ddPCR. ctDNA response from baseline to the third treatment cycle was evaluated in patients with detectable ctDNA at baseline. ctDNA maximum response was defined as undetectable ctDNA at the third treatment cycle, ctDNA partial response as any decrease in the ctDNA level, and ctDNA progression as any increase in the ctDNA level.

RESULTS

Forty-nine patients were included. The time to test results for mutational testing on cfDNA was significantly shorter than on tumor tissue (p < .001). Progression-free survival were 11.2 months (reference group), 7.5 months (HR = 10.7, p= .02), and 4.6 months (HR = 11.4, p= .02) in patients with ctDNA maximum response, partial response, and progression, respectively. Overall survival was 31.2 months (reference group), 15.2 months (HR = 4.1, p= .03), and 9.0 months (HR = 2.6, p= .03) in patients with ctDNA maximum response, partial response, and progression, respectively.

CONCLUSION

Pretreatment mutational testing on cfDNA in daily clinic is feasible and can be applied in randomized clinical trials evaluating the clinical utility of ctDNA. Early dynamics in ctDNA during systemic treatment hold prognostic value.

Prognostic impact of early ctDNA dynamics during chemotherapy of metastatic cancer

Aim: Clinical utility of the dynamics of ctDNA is sparse. This study aimed at evaluating the prognostic impact of early ctDNA dynamics in patients with metastatic cancer treated with chemotherapy. Materials & methods: The ctDNA dynamics were evaluated in 595 patients with metastatic cancer using droplet digital PCR. Results: Patients with an increase in ctDNA after one treatment cycle (n = 73; 12.2%) had an overall survival of 5.6 months compared with 8.6 months in patients with stable or decreasing ctDNA (n = 328; 55.1%) and 21.0 months in patients with undetectable ctDNA (p < 0.001; hazard ratio: 0.47; 95% CI: 0.41-0.53). Conclusion: Early ctDNA dynamics hold important prognostic information and have great implications for evaluation with the perspective of a more individualized treatment strategy.

Circulating DNA and frequency of colorectal cancer brain metastases in a presumed high-risk group

This explorative prospective observational pilot study investigated if suggested risk factors, rectal cancer and lung metastases, could add to a relevant detection rate of asymptomatic brain metastases (BM) from colorectal cancer (CRC). Secondary, prognostic biological aspects were investigated by translational analysis of plasma samples. The study enrolled patients with rectal cancer and lung metastases. At inclusion, patients underwent a standard MRI scan of the brain. Cell-free DNA (cfDNA) level was measured by a direct fluorescence assay (DFA), and circulating tumor DNA (ctDNA) by ddPCR. BM was detected in one of twenty-nine included patients. Patients had higher cfDNA levels than healthy subjects (p < 0.01). Patients with the primary tumor in situ had higher cfDNA levels than those with resected primary tumor (p < 0.01). Patients with liver involvement had higher cfDNA levels (p = 0.12) and circulating tumor DNA levels (p = 0.01) than those without liver involvement. In conclusion, the modest incidence of BM does not justify routine MRI of the brain in this selected population. cfDNA by DFA could be a valuable tool when planning treatment and follow-up for CRC patients. Future studies should focus on identifying further characteristics and biomarkers associated with a high risk of BM, enhancing the possibility for early intervention.

Response prediction by mutation- or methylation-specific detection of ctDNA dynamics in pretreated metastatic colorectal cancer

Background

Serial analysis of circulating tumor DNA (ctDNA) levels is a promising tool for both relapse prediction in the curative setting, as well as predicting clinical benefit from systemic treatment in metastasic colorectal cancer (mCRC). Most data in this context are derived from treatment naive patients.

Objective

To predict progressive disease (PD) as early as possible through monitoring of changes in ctDNA levels during systemic treatment in pretreated patients with mCRC.

Design

A prospective, single-center, observational study.

Methods

Patients treated beyond first-line were prospectively included between February 2020 and September 2021. Blood for ctDNA detection was taken before every treatment cycle from start of treatment until first restaging by CT-scan. ctDNA was detected by mutation- (mut-ctDNA) and methylation-specific ddPCR. Receiver Operating Characteristic (ROC)-analysis was used to describe sensitivity and specificity for prediction of PD at restaging for all time points.

Results

A total of 42 patients were included who all carried a mutation in tumor tissue. Detection rate of mut-ctDNA was 88.1% and 74.4% for meth-ctDNA. Absolute ctDNA levels before treatment were prognostic in terms of overall survival. Levels of ctDNA were significantly higher in patients with PD at restaging. Median time from start of treatment to restaging was 93 days (95% CI 88.8-96). After a median of 19 days of treatment (95% CI 16.1-20.2), a decline of either mutation- or methylation-specific ctDNA levels of ⩽58% predicted PD at restaging with a sensitivity/specificity of 92.9/85.7% and 85.7/100%, respectively. Median time to restaging was 66 days (95% CI 56.8-75.2). There was no significant increase of sensitivity/specificity at later time points of ctDNA measurements.

Conclusion

Monitoring early changes of ctDNA levels either by mut- or meth-ctDNA allows for early prediction of PD in pretreated patients with mCRC. This has the potential to complement RECIST-based treatment assessment with the aim to switch potentially insufficient treatments as early as possible, which is of particular interest in higher treatment lines.

Epigenome-wide methylation analysis of colorectal carcinoma, adenoma and normal tissue reveals novel biomarkers addressing unmet clinical needs

BACKGROUND

Biomarker discovery in colorectal cancer has mostly focused on methylation patterns in normal and colorectal tumor tissue, but adenomas remain understudied. Therefore, we performed the first epigenome-wide study to profile methylation of all three tissue types combined and to identify discriminatory biomarkers.

RESULTS

Public methylation array data (Illumina EPIC and 450K) were collected from a total of 1 892 colorectal samples. Pairwise differential methylation analyses between tissue types were performed for both array types to "double evidence" differentially methylated probes (DE DMPs). Subsequently, the identified DMPs were filtered on methylation level and used to build a binary logistic regression prediction model. Focusing on the clinically most interesting group (adenoma vs carcinoma), we identified 13 DE DMPs that could effectively discriminate between them (AUC = 0.996). We validated this model in an in-house experimental methylation dataset of 13 adenomas and 9 carcinomas. It reached a sensitivity and specificity of 96% and 95%, respectively, with an overall accuracy of 96%. Our findings raise the possibility that the 13 DE DMPs identified in this study can be used as molecular biomarkers in the clinic.

CONCLUSIONS

Our analyses show that methylation biomarkers have the potential to discriminate between normal, precursor and carcinoma tissues of the colorectum. More importantly, we highlight the power of the methylome as a source of markers for discriminating between colorectal adenomas and carcinomas, which currently remains an unmet clinical need.

Neuropeptide Y Peptide Family and Cancer: Antitumor Therapeutic Strategies

Currently available data on the involvement of neuropeptide Y (NPY), peptide YY (PYY), and pancreatic polypeptide (PP) and their receptors (YRs) in cancer are updated. The structure and dynamics of YRs and their intracellular signaling pathways are also studied. The roles played by these peptides in 22 different cancer types are reviewed (e.g., breast cancer, colorectal cancer, Ewing sarcoma, liver cancer, melanoma, neuroblastoma, pancreatic cancer, pheochromocytoma, and prostate cancer). YRs could be used as cancer diagnostic markers and therapeutic targets. A high Y1R expression has been correlated with lymph node metastasis, advanced stages, and perineural invasion; an increased Y5R expression with survival and tumor growth; and a high serum NPY level with relapse, metastasis, and poor survival. YRs mediate tumor cell proliferation, migration, invasion, metastasis, and angiogenesis; YR antagonists block the previous actions and promote the death of cancer cells. NPY favors tumor cell growth, migration, and metastasis and promotes angiogenesis in some tumors (e.g., breast cancer, colorectal cancer, neuroblastoma, pancreatic cancer), whereas in others it exerts an antitumor effect (e.g., cholangiocarcinoma, Ewing sarcoma, liver cancer). PYY or its fragments block tumor cell growth, migration, and invasion in breast, colorectal, esophageal, liver, pancreatic, and prostate cancer. Current data show the peptidergic system's high potential for cancer diagnosis, treatment, and support using Y2R/Y5R antagonists and NPY or PYY agonists as promising antitumor therapeutic strategies. Some important research lines to be developed in the future will also be suggested.

Colon cancer transcriptome

Over the last four decades, methodological innovations have continuously changed transcriptome profiling. It is now feasible to sequence and quantify the transcriptional outputs of individual cells or thousands of samples using RNA sequencing (RNA-seq). These transcriptomes serve as a connection between cellular behaviors and their underlying molecular mechanisms, such as mutations. This relationship, in the context of cancer, provides a chance to unravel tumor complexity and heterogeneity and uncover novel biomarkers or treatment options. Since colon cancer is one of the most frequent malignancies, its prognosis and diagnosis seem to be critical. The transcriptome technology is developing for an earlier and more accurate diagnosis of cancer which can provide better protectivity and prognostic utility to medical teams and patients. A transcriptome is a whole set of expressed coding and non-coding RNAs in an individual or cell population. The cancer transcriptome includes RNA-based changes. The combined genome and transcriptome of a patient may provide a comprehensive picture of their cancer, and this information is beginning to affect treatment decision-making in real-time. A full assessment of the transcriptome of colon (colorectal) cancer has been assessed in this review paper based on risk factors such as age, obesity, gender, alcohol use, race, and also different stages of cancer, as well as non-coding RNAs like circRNAs, miRNAs, lncRNAs, and siRNAs. Similarly, they have been examined independently in the transcriptome study of colon cancer.

Plasma cell-free DNA methylome profiling in pre- and post-surgery oral cavity squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC), a highly heterogeneous disease that involves multiple anatomic sites, is a leading cause of cancer-related mortality worldwide. Although the utility of noninvasive biomarkers based on circulating cell-free DNA (cfDNA) methylation profiling has been widely recognized, limited studies have been reported so far regarding the dynamics of cfDNA methylome in oral cavity squamous cell carcinoma (OCSCC). It is hypothesized in this study that comparison of methylation profiles in pre- and postsurgery plasma samples will reveal OCSCC-specific prognostic and diagnostic biomarkers. As a strategy to further prioritize tumor-specific targets, top differential methylated regions (DMRs) were called by reanalyzing methylation data from paired tumor and normal tissue collected in the the cancer genome atlas head-neck squamous cell carcinoma (TCGA) head and neck cancer cohort. Matched plasma samples from eight patients with OCSCC were collected at Moffitt Cancer Center before and after surgical resection. Plasma-derived cfDNA was analyzed by cfMBD-seq, which is a high-sensitive methylation profiling assay. Differential methylation analysis was then performed based on the matched samples profiled. In the top 200 HNSCC-specific DMRs detected based on the TCGA data set, a total of 23 regions reached significance in the plasma-based DMR test. The top five validated DMR regions (ranked by the significance in the plasma study) are located in the promoter regions of genes PENK, NXPH1, ZIK1, TBXT, and CDO1, respectively. The genome-wide cfDNA DMR analysis further highlighted candidate biomarkers located in genes SFRP4, SOX1, IRF4, and PCDH17. The prognostic relevance of candidate genes was confirmed by survival analysis using the TCGA data. This study supports the utility of cfDNA-based methylome profiling as a promising noninvasive biomarker source for OCSCC and HNSCC.

Blood-based DNA methylation signatures in cancer: A systematic review

DNA methylation profiles are in dynamic equilibrium via the initiation of methylation, maintenance of methylation and demethylation, which control gene expression and chromosome stability. Changes in DNA methylation patterns play important roles in carcinogenesis and primarily manifests as hypomethylation of the entire genome and the hypermethylation of individual loci. These changes may be reflected in blood-based DNA, which provides a non-invasive means for cancer monitoring. Previous blood-based DNA detection objects primarily included circulating tumor DNA/cell-free DNA (ctDNA/cfDNA), circulating tumor cells (CTCs) and exosomes. Researchers gradually found that methylation changes in peripheral blood mononuclear cells (PBMCs) also reflected the presence of tumors. Blood-based DNA methylation is widely used in early diagnosis, prognosis prediction, dynamic monitoring after treatment and other fields of clinical research on cancer. The reversible methylation of genes also makes them important therapeutic targets. The present paper summarizes the changes in DNA methylation in cancer based on existing research and focuses on the characteristics of the detection objects of blood-based DNA, including ctDNA/cfDNA, CTCs, exosomes and PBMCs, and their application in clinical research.

Establishment of clinical predictive model based on the study of influence factors in patients with colorectal polyps

Background

Colorectal cancer (CRC) is the most common gastrointestinal malignancy and is generally thought to be caused by the transformation of colorectal polyps. It has been shown that early detection and removal of colorectal polyps may reduce the mortality and morbidity of colorectal cancer.

Objective

Based on the risk factors associated with colorectal polyps, an individualized clinical prediction model was built to predict and evaluate the possibility of developing colorectal polyp.

Methods

A case-control study was conducted. Clinical data were collected from 475 patients who underwent colonoscopy at the Third Hospital of Hebei Medical University from 2020 to 2021. All clinical data were then divided into training sets and validation sets by using R software (7:3). A multivariate logistic analysis was performed to identify the factors associated with colorectal polyps according to the training set, and a predictive nomogram was created by R software based on the multivariate analysis. The results were internally validated by receiver operating characteristic (ROC) curves, calibration curves, and externally validated by validation sets.

Results

Multivariate logistic regression analysis showed that age (OR = 1.047, 95% CI = 1.029-1.065), history of cystic polyp (OR = 7.596, 95% CI = 0.976-59.129), and history of colorectal diverticulums (OR = 2.548, 95% CI = 1.209-5.366) were independent risk factors for colorectal polyps. History of constipation (OR = 0.457, 95% CI = 0.268-0.799) and fruit consumption (OR = 0.613, 95% CI 0.350-1.037) were protective factors for colorectal polyps. The nomogram demonstrated good accuracy for predicting colorectal polyps, with both C index and AUC being 0.747 (95% CI = 0.692-0.801). The calibration curves showed good agreement between the predicted risk by the nomogram and real outcomes. Both internal and external validation of the model showed good results.

Conclusion

In our study, the nomogram prediction model is reliable and accurate, which can help early clinical screening of patients with high-risk colorectal polyps, improve polyp detection rate, and reduce the incidence of colorectal cancer (CRC).

Role of non-coding RNAs and exosomal non-coding RNAs in retinoblastoma progression

Retinoblastoma (RB) is a rare aggressive intraocular malignancy of childhood that has the potential to affect vision, and can even be fatal in some children. While the tumor can be controlled efficiently at early stages, metastatic tumors lead to high mortality. Non-coding RNAs (ncRNAs) are implicated in a number of physiological cellular process, including differentiation, proliferation, migration, and invasion, The deregulation of ncRNAs is correlated with several diseases, particularly cancer. ncRNAs are categorized into two main groups based on their length, i.e. short and long ncRNAs. Moreover, ncRNA deregulation has been demonstrated to play a role in the pathogenesis and development of RB. Several ncRNAs, such as miR-491-3p, miR-613,and SUSD2 have been found to act as tumor suppressor genes in RB, but other ncRNAs, such as circ-E2F3, NEAT1, and TUG1 act as tumor promoter genes. Understanding the regulatory mechanisms of ncRNAs can provide new opportunities for RB therapy. In the present review, we discuss the functional roles of the most important ncRNAs in RB, their interaction with the genes responsible for RB initiation and progression, and possible future clinical applications as diagnostic and prognostic tools or as therapeutic targets.

Identification and validation of methylated PENK gene for early detection of bladder cancer using urine DNA

Background

Early detection of bladder cancer (BCa) offers patients a favorable outcome and avoids the need for cystectomy. Development of an accurate and sensitive noninvasive BCa diagnostic test is imperative. DNA methylation is an early epigenetic event in the development of BCa. Certain specific aberrant methylations could serve as useful biomarkers. The aim of this study was to identify methylation biomarkers for early detection of BCa.

Methods

CpG methylation microarray analysis was conducted on primary tumors with varying stages (T1—T4) and paired nontumor tissues from nine BCa patients. Bisulfite-pyrosequencing was performed to confirm the methylation status of candidate genes in tissues and urine sediments (n = 51). Among them, PENK was selected as a potential candidate and validated using an independent set of 169 urine sediments (55 BCa, 25 benign urologic diseases, 8 other urologic cancers, and 81 healthy controls) with a quantitative methylation-specific real time PCR (mePENK-qMSP). All statistical analyses were performed using MedCalc software version 9.3.2.0.

Results

CpG methylation microarray analysis and stepwise validation by bisulfite-pyrosequencing for tissues and urine sediments supported aberrant methylation sites of the PENK gene as potential biomarkers for early detection of BCa. Clinical validation of the mePENK-qMSP test using urine sediment-DNA showed a sensitivity of 86.5% (95% CI: 71.2 – 95.5%), a specificity of 92.5% (95% CI: 85.7 – 96.7%), and an area under ROC of 0.920 (95% CI: 0.863 – 0.959) in detecting Ta high-grade and advanced tumor stages (T1-T4) of BCa patients. Sensitivities for Ta low-grade, Ta high-grade, T1 and T2-T4 were 55.6, 83.3, 88.5, and 100%, respectively. Methylation status of PENK was not correlated with sex, age or stage, while it was associated with the tumor grade of BCa.

Conclusions

In this study, we analyzed the comprehensive patterns of DNA methylation identified that PENK methylation possesses a high potential as a biomarker for urine-based early detection of BCa. Validation of PENK methylation confirms that it could significantly improve the noninvasive detection of BCa.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-10275-2.

NPY Gene Methylation in Circulating Tumor DNA as an Early Biomarker for Treatment Effect in Metastatic Colorectal Cancer

Despite several limitations, the Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1) are still the gold standard in response evaluation of metastatic colorectal cancer (mCRC). The aim of the present study was to investigate hypermethylated neuropeptide Y circulating tumor DNA (meth-NPY) as an early biomarker for treatment effect and monitoring in 70 mCRC patients receiving first-line treatment in the FOLFOXIRI-Toco trial. Meth-NPY was analyzed using droplet digital PCR, and the response rate was defined as the fraction of patients converting from a baseline detectable level to an undetectable level after the first treatment cycle (responders). A significant increase in meth-NPY was defined as a value with no overlap between the 95% CI of the current and preceding measurement. Progression-free survival (PFS) was significantly longer in meth-NPY responders compared to non-responders, 10.1 and 7.6 months, respectively (p = 0.02, HR = 0.43). Patients with response according to RECIST 1.1 had a PFS of 10.1 compared to 7.3 months for non-responders (p = 0.17, HR = 0.65). A significant increase in meth-NPY was found with a median of 49 days before radiological progression. In conclusion, early meth-NPY response proved superior to response according to RECIST 1.1 with respect to predicting improved PFS. Meth-NPY is an early indicator of progression, allowing treatment reorientation at an earlier timepoint.

The Interaction Between Epigenetic Changes, EMT, and Exosomes in Predicting Metastasis of Colorectal Cancers (CRC)

Worldwide, colorectal cancer (CRC) ranks as the third most common malignancy, and the second most deadly with nearly one million attributable deaths in 2020. Metastatic disease is present in nearly 25% of newly diagnosed CRC, and despite advances in chemotherapy, less than 20% will remain alive at 5 years. Epigenetic change plays a key role in the epithelial-to-mesenchymal transition (EMT), which is a crucial phenotype for metastasis and mainly includes DNA methylation, non-coding RNAs (ncRNAs), and N6-methyladenosine (m6A) RNA, seemingly valuable biomarkers in CRCs. For ncRNAs, there exists a “molecular sponge effect” between long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), and microRNAs (miRNAs). The detection of exosomes is a novel method in CRC monitoring, especially for predicting metastasis. There is a close relationship between exosomes and EMT in CRCs. This review summarizes the close relationship between epigenetic changes and EMT in CRCs and emphasizes the crucial function of exosomes in regulating the EMT process.

Prognostic value and biological function of LRRN4 in colorectal cancer

Background

Several nervous and nerve-related biomarkers have been detected in colorectal cancer (CRC) and can contribute to the progression of CRC. However, the role of leucine-rich repeat neuronal 4 (LRRN4), a recently identified neurogenic marker, in CRC remains unclear.

Methods

We examined the expression and clinical outcomes of LRRN4 in CRC from TCGA-COREAD mRNA-sequencing datasets and immunohistochemistry in a Chinese cohort. Furthermore, colony formation, flow cytometry, wound healing assays and mouse xenograft models were used to investigate the biological significance of LRRN4 in CRC cell lines with LRRN4 knockdown or overexpression in vitro and in vivo. In addition, weighted coexpression network analysis, DAVID and western blot analysis were used to explore the potential molecular mechanism.

Results

We provide the first evidence that LRRN4 expression, at both the mRNA and protein levels, was remarkably high in CRC compared to controls and positively correlated with the clinical outcome of CRC patients. Specifically, LRRN4 was an independent prognostic factor for progression-free survival and overall survival in CRC patients. Further functional experiments showed that LRRN4 promoted cell proliferation, cell DNA synthesis and cell migration and inhibited apoptosis. Knockdown of LRRN4 can correspondingly decrease these effects in vitro and can significantly suppress the growth of xenografts. Several biological functions and signaling pathways were regulated by LRRN4, including proteoglycans in cancer, glutamatergic synapse, Ras, MAPK and PI3K. LRRN4 knockdown resulted in downregulation of Akt, p-Akt, ERK1/2 and p-ERK1/2, the downstream of the Ras/MAPK signaling pathway, overexpression of LRRN4 leaded to the upregulation of these proteins.

Conclusions

Our results suggest that LRRN4 could be a biological and molecular determinant to stratify CRC patients into distinct risk categories, and mechanistically, this is likely attributable to LRRN4 regulating several malignant phenotypes of neoplastic cells via RAS/MAPK signal pathways.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02579-x.

Prognostic Impact of Circulating Methylated Homeobox A9 DNA in Patients Undergoing Treatment for Recurrent Ovarian Cancer

Methylated Homeobox A9 circulating tumor DNA (meth-HOXA9) has been suggested as a blood-based biomarker in epithelial ovarian cancer (EOC), although its prognostic significance remains unproven. The aim of the present study was to investigate the prognostic impact of meth-HOXA9 in patients with recurrent EOC. DNA was purified from 4 mL plasma and, following bilsulfite conversion, meth-HOXA9 was analyzed using a methylation-specific droplet digital PCR. Detection of meth-HOXA9 was reported as a percentage of total DNA and as a binary variable (detectable and undetectable). Meth-HOXA9 status and its dynamics during palliative treatment were correlated with overall survival (OS) as the primary endpoint. At baseline, meth-HOXA9 was detected in 65.9% (83/126) of the patients. The median OS was 8.9 and 17.9 months in patients with detectable and undetectable meth-HOXA9 at baseline (hazard ratio: 2.04, p = 0.002), which remained significant in the multivariate analysis. Median OS in patients with an increase in meth-HOXA9 after one treatment cycle was 5.3 months compared to 33 months in patients with undetectable meth-HOXA9 (p < 0.001). Meth-HOXA9 was significantly related to poor survival and may serve as a prognostic marker in patients with recurrent EOC. The longitudinal monitoring of meth-HOXA9 is clinically feasible with the perspective of aiding clinical decision making.

DNA methylation-based diagnostic, prognostic, and predictive biomarkers in colorectal cancer

DNA methylation is an epigenetic mechanism regulating gene expression. Changes in DNA methylation were suggested to be useful biomarkers for diagnosis, and for the determination of prognosis and treatment response. Here, we provide an overview of methylation-based biomarkers in colorectal cancer. First, we start with the two methylation-based diagnostic biomarkers already approved for colorectal cancer, SEPT9 and the combination of NDRG4 and BMP3. Then, we provide a list-based overview of new biomarker candidates depending on the sample source including plasma, stool, urine, and surgically removed tumor tissues. The most often identified markers like SDC2, VIM, APC, MGMT, SFRP1, SFRP2, and NDRG4 have distinct functions previously linked to tumor progression. Although numerous studies have identified tumor-specific methylation changes, most of these alterations were observed in a single study only. The lack of validation in independent samples means low reproducibility and is a major limitation. The genome-wide determination of methylation status (methylome) can provide data to solve these issues. In the third section of the review, methylome studies focusing on different aspects related to CRC, including precancerous lesions, CRC-specific changes, molecular subtypes, aging, and chemotherapy response are summarized. Notably, techniques simultaneously analyzing a large set of regions can also uncover epigenetic regulation of genes which have not yet been associated with tumorigenesis previously. A remaining constraint of studies published to date is the low patient number utilized in these preventing the identification of clinically valuable biomarker candidates. Either future large-scale studies or the integration of already available methylome-level data will be necessary to uncover biomarkers sufficiently robust for clinical application.

The detection of specific hypermethylated WIF1 and NPY genes in circulating DNA by crystal digital PCR™ is a powerful new tool for colorectal cancer diagnosis and screening

Background

In oncology, liquid biopsy is of major relevance from theranostic point of view. The searching for mutations in circulating tumor DNA (ctDNA) in case of colorectal cancers (CRCs) allows the optimization of patient care. In this context, independent of mutation status biomarkers are required for its detection to confirm the presence of ctDNA in liquid biopsies. Indeed, the hypermethylation of NPY and WIF1 genes appear to be an ideal biomarker for the specific detection of ctDNA in CRCs. The objective of this work is to develop the research of hypermethylation of NPY and WIF1 by Crystal Digital PCR™ for the detection of ctDNA in CRCs.

Methods

Detection of hypermethylated NPY and WIF1 was developed on Cristal digital PCR™. Biological validation was performed from a local cohort of 22 liquid biopsies and 23 tissue samples from patients with CRC. These patients were treated at the University Hospital of Besancon (France).

Results

The local cohort study confirmed that NPY and WIF1 were significantly hypermethylated in tumor tissues compared to adjacent non-tumor tissues (WIF1 p < 0.001; NPY p < 0.001; non-parametric Wilcoxon paired-series test). Histological characteristics, tumor stages or mutation status were not correlated to the methylation profiles. On the other hand, hypermethylation of NPY or WIF1 in liquid biopsy had a 95.5% [95%CI 77–100%] sensitivity and 100% [95%CI 69–100%] specificity.

Conclusion

Using Crystal digital PCR™, this study shows that hypermethylation of NPY and WIF1 are constant specific biomarkers of CRCs regardless of a potential role in carcinogenesis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08816-2.

Analysis of HOXA9 methylated ctDNA in ovarian cancer using sense-antisense measurement

DNA promoter methylation is an early event in tumorigenesis and holds promise as a valuable marker in ovarian cancer (OC). It can be measured using circulating tumor specific DNA (ctDNA) isolated from the bloodstream. Sensitivity, however, is a limiting factor of its diagnostic feasibility in OC. DNA methylation analyses are based on bisulfite conversion, resulting in two DNA strands that are no longer complementary. The current standard strategy would then target only one of the double stranded DNA strands, but the potential to increase the sensitivity by targeting both DNA strands is available. In this study, we aimed at evaluating the diagnostic potential of methylated HOXA9 ctDNA in OC by targeting both the DNA sense and antisense strand. Methylated HOXA9 was detected in the plasma of 47/79 (59.5%) patients with newly diagnosed OC using sense-antisense droplet digital PCR. Simultaneous sense-antisense measurement increased the sensitivity by 14.6% (51.9% to 59.5%) as compared to antisense only. In patients with FIGO stage I-II disease the sensitivity was increased by 25%. In conclusion, simultaneous measurement targeting both DNA strands can increase the sensitivity and the analytical approach appears valuable in the diagnostic setting of OC.

Validating Methylated HOXA9 in Bronchial Lavage as a Diagnostic Tool in Patients Suspected of Lung Cancer

Diagnosing lung cancer requires invasive procedures with high risk of complications. Methylated tumor DNA in bronchial lavage has previously shown potential as a diagnostic biomarker. We aimed to develop and validate methylated HOXA9 in bronchial lavage as a diagnostic biomarker of lung cancer. Participants were referred on suspicion of lung cancer. Ten mL lavage fluid was collected at bronchoscopy for analysis of methylated HOXA9 based on droplet digital PCR according to our previously published method. HOXA9 status was compared with the final diagnosis. The Discovery and Validation cohorts consisted of 101 and 95 consecutively enrolled participants, respectively. In the discovery cohort, the sensitivity and specificity were 73.1% (95% CI 60.9-83.2%) and 85.3% (95% CI 68.9-95.0%), respectively. In the validation cohort, the values were 80.0% (95% CI 66.3-90.0%) and 75.6% (95% CI 60.5-87.1%), respectively. A multiple logistic regression model including age, smoking status, and methylated HOXA9 status resulted in an AUC of 84.9% (95% CI 77.3-92.4%) and 85.9% (95% CI 78.4-93.4%) for the Discovery and Validation cohorts, respectively. Methylated HOXA9 in bronchial lavage holds potential as a supplementary tool in the diagnosis of lung cancer with a clinically relevant sensitivity and specificity. It remained significant when adjusting for age and smoking status.

miR-340 Promotes Retinoblastoma Cell Proliferation, Migration and Invasion Through Targeting WIF1

Background

MicroRNAs (miRNAs) function as important regulators of gene expression involved in tumor pathogenesis, including retinoblastoma. However, the expression profiles and potential roles in retinoblastoma are still largely unclear.

Material and Methods

Differentially expressed miRNAs (DEmiRs) and genes (DEGs) in retinoblastoma were extracted from Gene Expression Omnibus (GEO) repository. Expression levels of miR-340 and WIF1 were detected in retinoblastoma tissues and cell lines by qRT-PCR. Both gain-of-function and loss-of-function experiments were performed to explore the effects of miR-340 on cell proliferation, migration and invasion. Bioinformatics analysis and luciferase reporter assay were used to explore the interaction between miR-340 and WIF1.

Results

A total of 11 DEmiRs were identified in retinoblastoma tissue and blood samples. Among them, we validated that miR-340 was the most highly expressed miRNA and correlated with tumor size, ICRB stage and optic nerve invasion. miR-340 was observed to enhance the proliferation, migration and invasion capacity of retinoblastoma cells. We then identified 26 DEGs from 3 retinoblastoma GEO datasets and subsequently constructed a miRNA–mRNA regulatory network. Further analysis revealed that WIF1 was a direct target of miR-340. Moreover, overexpression of WIF1 could repress retinoblastoma progression induced by miR-340 in vitro and in vivo.

Conclusion

Collectively, miR-340 functioned as an oncomiRNA to promote retinoblastoma cell proliferation, migration and invasion via regulating WIF1. Our data also provided multiple miRNAs and genes that may contribute to a better understanding of retinoblastoma pathogenesis.

Updates on Clinical Use of Liquid Biopsy in Colorectal Cancer Screening, Diagnosis, Follow-Up, and Treatment Guidance

Colorectal cancer (CRC) is one of the most common cancers worldwide, being the third most diagnosed in the world and the second deadliest. Solid biopsy provides an essential guide for the clinical management of patients with colorectal cancer; however, this method presents several limitations, in particular invasiveness, and cannot be used repeatedly. Recently, clinical research directed toward the use of liquid biopsy, as an alternative tool to solid biopsy, showed significant promise in several CRC clinical applications, as (1) detect CRC patients at early stage, (2) make treatment decision, (3) monitor treatment response, (4) predict relapses and metastases, (5) unravel tumor heterogeneity, and (6) detect minimal residual disease. The purpose of this short review is to describe the concept, the characteristics, the genetic components, and the technologies used in liquid biopsy in the context of the management of colorectal cancer, and finally we reviewed gene alterations, recently described in the literature, as promising potential biomarkers that may be specifically used in liquid biopsy tests.

Methylated circulating tumor DNA as a biomarker for colorectal cancer diagnosis, prognosis, and prediction

Worldwide, colorectal cancer (CRC) is a deadly disease whose death rate ranks second among cancers though its incidence ranks third. Early CRC detection is key and is associated with improved survival outcomes. However, existing tests for CRC diagnosis have several weaknesses thus rendering them inefficient. Moreover, reliable prognostic tests that can predict the overall cancer outcome and recurrence of the disease as well as predictive markers that can assess effectiveness of therapy are still lacking. Thus, shifting to noninvasive liquid biopsy or blood-based biomarkers is vital to improving CRC diagnosis, prognosis, and prediction. Methylated circulating tumor DNA (ctDNA) has gained increased attention as a type of liquid biopsy that is tumor-derived fragmented DNA with epigenetic alterations. Methylated ctDNA are more consistently present in blood of cancer patients as compared to mutated ctDNA. Hence, methylated ctDNA serves as a potential biomarker for CRC that is worth investigating. In this review, we explore what has been reported about methylated ctDNA as a biomarker for CRC diagnosis that can distinguish between CRC patients or those having adenoma and healthy controls as validated specifically through ROC curves. We also examine methylated ctDNA as a biomarker for CRC prognosis and prediction as confirmed through robust statistical analyses. Finally, we discuss the major technical challenges that limits the use of methylated ctDNA for clinical application and suggest possible recommendations to enhance its usage.

Association of ZNF331 and WIF1 methylation in peripheral blood leukocytes with the risk and prognosis of gastric cancer

Background

Peripheral blood leukocyte (PBL) DNA methylation may serve as a surrogate marker to evaluate the susceptibility to and prognosis of gastric cancer (GC). In this study, blood-derived DNA methylation levels of two tumour-related genes, namely, ZNF331 and WIF1, and their impacts on the risk and prognosis of GC were evaluated.

Methods

In total, 398 GC cases and 397 controls were recruited for the study. Then, all cases were followed up for 5 years. ZNF331 and WIF1 promoter methylation status in PBLs was measured using a methylation-sensitive high-resolution melting method. Logistic and Cox regression models were used to analyse the correlation between gene methylation and the risk and prognosis of GC. Confounders were balanced through propensity score (PS) matching.

Results

High ZNF331 methylation significantly decreased GC risk after PS adjustment (OR = 0.580, 95% CI: 0.375–0.898, P = 0.015), which also presented in males (OR = 0.577, 95% CI: 0.343–0.970, P = 0.038). However, WIF1 methylation was not associated with GC risk. Additionally, significant combined effects between ZNF331 methylation and the intake of green vegetables and garlic were observed (OR = 0.073, 95% CI: 0.027–0.196, P < 0.001 and OR = 0.138, 95% CI: 0.080–0.238, P < 0.001, respectively). Furthermore, ZNF331 and WIF1 methylation had no impact on the prognosis of GC.

Conclusion

ZNF331 methylation in PBLs may affect GC risk in combination with the consumption of green vegetables and garlic and may act as a potential biomarker of GC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08199-4.

Toward Colorectal Cancer Biomarkers: The Role of Genetic Variation, Wnt Pathway, and Long Noncoding RNAs

Colorectal cancer (CRC) is the third leading cause of death worldwide, comprising nearly 8% of cancer-related deaths per year. In South Korea, for example, CRC is the second most common cancer in men, and third in women. This study reports on the association of CRC with genetic variations in long noncoding RNAs, activators, and inhibitors of a cell proliferation pathway. Five normal colon mucosa tissue samples and their matched five-stage IV CRC samples were evaluated (dataset Gene Expression Omnibus accession: GSE50760). We identified more than 5000 differentially expressed genes (DEGs). The Wnt pathway had the greatest portion of DEGs, including activators, inhibitors, and associated long noncoding RNAs (lncRNAs), suggesting the importance of Wnt pathway in CRC. The following genes were aberrantly expressed: WIF1, SFRP4, CD82, WNT2, WNT3, WNT5A, HOTAIR, CRNDE, and UCA1. Notably, HOTAIR is known to silence WIF1, and WIF1 inhibits the Wnt ligands to negatively regulate the pathway. The lncRNA CRNDE positively regulates WNT5A, while UCA1 positively regulates WNT2 and WNT3. We note that HOTAIR was unable to silence WIF1. CRNDE and UCA1 were found to be upregulated, which may explain the high expression of the WIF1 targets. Furthermore, 10 single-nucleotide polymorphisms (SNPs) were identified in five of the candidate genes above. A possible novel SNP in CD82, chr11:44619242T > C, was predicted to introduce a ZBTB7A binding site. These SNPs are hypothesized to contribute to aberrant and discrepant regulation of the Wnt pathway in a context of CRC pathogenesis. These findings collectively inform future research on diagnostics and therapeutics innovation in CRC.

The prognostic impact of circulating homeobox A9 methylated DNA in advanced non-small cell lung cancer

BACKGROUND

The homeobox A9 gene encodes a transcription factor, and aberrantly methylated homeobox A9 in the circulation has been suggested as a prognostic marker in early stage non-small cell lung cancer (NSCLC). The aim of the present study was to investigate the prognostic impact of methylated homeobox A9 in plasma from patients with advanced NSCLC.

METHODS

Blood samples were prospectively collected from patients with NSCLC stage III and IV receiving standard first line chemotherapy. Sampling took place before treatment initiation and subsequently before each treatment cycle. Plasma was stored at -80 °C until analysis. DNA was extracted, and following bisulfite conversion methylated homeobox A9 was analyzed by methylation specific droplet digital polymerase chain reaction. Detection of methylated homeobox A9 was assessed as a binary variable. The primary endpoint was overall survival (OS).

RESULTS

A total of 231 patients were included. At baseline methylated homeobox A9 was detected in 78.5% of the patients with a clear correlation to survival. The median OS for patients with and without detectable methylated homeobox A9 was 7.4 and 11.1 months, respectively [hazard ratio (HR) 1.79, 95% confidence interval (CI): 1.35-2.38, P<0.001]. The difference increased after the first cycle of treatment. At this time point the median OS was 6.2 and 15.6 months for patients with and without detectable methylated homeobox A9, respectively (HR 2.07, 95% CI: 1.58-2.73, P<0.001). The independent prognostic impact of detectable methylated homeobox A9 after one treatment cycle assessed by multiple Cox regression including known prognostic factors resulted in a HR of 3.79 (2.19-6.54, P<0.001) compared to undetectable methylated homeobox A9.

CONCLUSIONS

Measurable methylated homeobox A9 after the first treatment cycle may serve as a valuable prognostic marker in patients with advanced NSCLC. Routine clinical application with treatment reconsideration calls for further studies, preferably in prospective clinical trials.

DNA methylation markers detected in blood, stool, urine, and tissue in colorectal cancer: a systematic review of paired samples

PURPOSE

Methylated cell-free DNA in liquid biopsies are promising non-invasive biomarkers for colorectal cancer (CRC). Optimal markers would have high sensitivity and specificity for early detection of CRC and could be detected in more than one type of material from the patient. We systematically reviewed the literature on DNA methylation markers of colorectal cancer, detected in more than one type of material, regarding their potential as contributors to a panel for screening and follow-up of CRC.

METHODS

The databases MEDLINE, Web of Science, and Embase were systematically searched. Data extraction and review was performed by two authors independently. Agreement between methylation status in tissue and other materials (blood/stool/urine) was analyzed using the McNemar test and Cohen's kappa.

RESULTS

From the 51 included studies, we identified seven single markers with sensitivity ≥ 75% and specificity ≥ 90% for CRC. We also identified one promising plasma panel and two stool panels. The correspondence of methylation status was evaluated as very good for four markers, but only marginal for most of the other markers investigated (12 of 21).

CONCLUSION

The included studies reported only some of the variables and markers of interest and included few patients. Hence, a meta-analysis was not possible at this point. Larger, prospective studies must be designed to study the discordant detection of markers in tissue and liquid biopsies. When reporting their findings, such studies should use a standardized format.

Cell free DNA as an evolving liquid biopsy biomarker for initial diagnosis and therapeutic nursing in Cancer- An evolving aspect in Medical Biotechnology

Cell-free DNA (cfDNA) is present in numerous body fluids in addition to initiates generally from blood cells. It is undoubtedly the utmost promising tool among all components of liquid biopsy. Liquid biopsy is a specialized method investigating the nonsolid biological tissue by revealing of circulating cells, cell free DNA etc. that enter body fluids. Since, cancer cells disengage from compact tumors circulate in peripheral blood, evaluating blood of cancer patients holds the opportunities for capture and molecular level analysis of various tumor-derived constituents. Cell free DNA samples can deliver a significant perceptions into oncology, for instance tumor heterogeneity, instantaneous tumor development, response to therapy and treatment, comprising immunotherapy and mechanisms of cancer metastasis. Malignant growth at any phase can outhouse tumor cells in addition to fragments of neoplasticity causing DNA into circulatory system giving noble sign of mutation in the tumor at sampling time. Liquid biopsy distinguishes diverse blood based evolving biomarkers comprising circulating tumor cells (CTCs), circulating tumor DNA (ctDNA) or cfDNA, circulating RNA (cfRNA) and exosomes. Cell free DNA are little DNA fragments found circulating in plasma or serum, just as other fluids present in our body. Cell free DNA involves primarily double stranded nuclear DNA and mitochondrial DNA, present both on a surface level and in the lumen of vesicles. The probable origins of the tumor-inferred portion of cfDNA are apoptosis or tumor necrosis, lysis of CTCs or release of DNA from the tumor cells into circulation. The evolution of innovations, refinement and improvement in therapeutics for determination of cfDNA fragment size and its distribution provide significant information related with pathological conditions of the cell, thus emerging as promising indicator for clinical output in medical biotechnology.

Liquid Biopsy as a Tool Exploring in Real-Time Both Genomic Perturbation and Resistance to EGFR Antagonists in Colorectal Cancer

The treatment of metastatic colorectal cancer (mCRC) has improved since the introduction of the epithelial growth factor receptor (EGFR) inhibitors as cetuximab and panitumumab. However, only patients with peculiar genomic profiles benefit from these targeting therapies. In fact, the molecular integrity of RAS genes is a predominant factor conditioning both primary and acquired resistance in non-responders although additional molecular derangements induced by selective anti-EGFR pressure may concur to the failure of those disease treatment, liquid biopsy (LB) appears as a surrogate of tissue biopsy, provides the genomic information to reveal tumor resistance to anti-EGFR agents, the detection of minimal residual disease before adjuvant therapies, and the discovery of tumor molecular status suitable for rechallenging treatments with EGFR antagonists. LB investigates circulating tumor cells (CTCs), cell-free tumor DNA (ctDNA), and tumor-derived exosomes. In mCRC, ctDNA analysis has been demonstrated as a useful method in the mutational tracking of defined genes as well as on tumor burden and detection of molecular alterations driving the resistance to anti-EGFR targeting treatments. However, despite their efficiency in molecular diagnosis and prognostic evaluation of mCRC, the affordability of these procedures is prevalently restricted to research centers, and the lack of consensus validation prevents their translation to clinical practice. Here, we revisit the major mechanisms responsible for resistance to EGFR blockade and review the different methods of LB potentially useful for treatment options in mCRC.

The Application of Circulating Tumor DNA in the Screening, Surveillance, and Treatment Monitoring of Colorectal Cancer

Precision medicine with genetic profiling of tumor tissue has become an essential part of routine clinical practice in colorectal cancer. However, tissue genetic profiling suffers from clonal evolution, tumor heterogeneity, and time needed to deliver critical information for prompt clinical decision making. In contrast, liquid biopsy with plasma circulating tumor DNA provides genetic and epigenetic information from both the primary and metastatic colorectal cancer, which can potentially capture tumor heterogeneity and evolution with time and treatment. In addition, liquid biopsy with circulating tumor DNA is minimally invasive, quicker, and easily repeatable with high patient compliance to provide both qualitative and quantitative molecular information in real-time. We provide an overview on the potential clinical applications of circulating tumor DNA in the screening, surveillance, and treatment monitoring of colorectal cancer.

Evolution of RAS Mutational Status in Liquid Biopsies During First-Line Chemotherapy for Metastatic Colorectal Cancer

Treatment options for patients with metastatic colorectal cancer (mCRC) are limited. This particularly affects the largest group of patients with RAS mutations, who are considered ineligible for therapy with antiEGFR antibodies. In this liquid biopsy-based study, we performed the first in-depth analysis of the RAS mutational status in initially RAS-mutated patients during first-line therapy. RAS status of twelve patients with initially RAS-mutated mCRC was monitored longitudinally in 69 liquid biopsy samples. We focused on patients with stable disease (SD) or partial remission (PR) during first-line therapy (11 patients). Detection of fragmented RAS-mutated circulating cell-free tumor DNA (ctDNA) in plasma was performed by digital-droplet PCR (ddPCR) and BEAMing. Patients' total tumor masses were determined by measuring the tumor volumes using CT scan data. All patients with PR or SD at first follow-up showed a significant decrease of RAS mutational load. In ten patients (91%), the ctDNA-based RAS mutational status converted to wild-type in ddPCR and BEAMing. Remarkably, conversions were observed early after the first cycle of chemotherapy. Plasma concentration of ctDNA was controlled by determination of methylated WIF1-promotor ctDNA burden as a second tumor marker for mCRC. Persistent presence of methylated WIF1-promotor fragments confirmed the ongoing release of ctDNA during treatment. In patients with initially RAS-mutated mCRC, RAS mutations rapidly disappeared during first-line therapy in liquid biopsy, independent of type and intensity of chemotherapy and irrespective of anti-VEGF treatments. Following our results demonstrating conversion of RAS-mutational status, potential effectiveness of anti-EGFR antibodies in selected patients becomes an attractive hypothesis for future studies.

Diagnostic performance of various liquid biopsy methods in detecting colorectal cancer: A meta-analysis

Liquid biopsy is a promising method in detecting colorectal cancer (CRC). However, previous meta‐analyses only focused on the diagnostic performance of cell‐free DNA (cfDNA). Therefore, we firstly evaluated the overall performance of all liquid biopsy methods. The pooled sensitivities, specificities, diagnostic odds ratios, and area under curve (AUC) of summary receiver operating characteristic curve for all liquid biopsy methods, exosomes, circulating tumor cells (CTCs), and cfDNA were calculated, respectively. A total of 62 articles involving 18 739 individuals were included. Fifty‐one articles were about cfDNA, five articles were about CTCs, and six articles were about exosomes. The overall performance of all liquid biopsy methods had a pooled sensitivity, specificity, and AUC of 0.77 (95% confidence interval [CI] 0.76‐0.78), 0.89 (95% CI 0.88‐0.90), and 0.9004, respectively. The sensitivities were 0.82 (95% CI 0.79‐0.85), 0.76 (95% CI 0.72‐0.80), and 0.76 (95% CI 0.75‐0.77) for CTCs, exosomes, and cfDNA, respectively. The specificities were 0.97 (95% CI95% CI 0.95‐0.99), 0.92 (95% CI 0.89‐0.94), and 0.88 (95% CI 0.87‐0.89) for CTCs, exosomes, and cfDNA, respectively. The AUC were 0.9772, 0.9037, and 0.8963 for CTCs, exosomes, and cfDNA, respectively. The overall performance of all liquid biopsy methods had great diagnostic value in detecting CRC, regardless of subtypes. Among all liquid biopsy methods, CTCs showed the best diagnostic performance.

"Decision for adjuvant treatment in stage II colon cancer based on circulating tumor DNA:The CIRCULATE-PRODIGE 70 trial"

BACKGROUND

Adjuvant treatment for stage II colon cancer remains debated. Finding a tool to select patients at risk for disease recurrence may help the clinical decision. Circulating tumor DNA (ctDNA) has been reported recently as a potential predictive marker for disease recurrence. We thus aim to test its ability to better select stage II colon cancer patients for adjuvant therapy.

METHODS

This national, phase III trial (NCT00002019-000935-15) conducted in more than 100 centers in France, plans to screen around 2640 patients in order to randomize (2:1; minimization method) 198 ctDNA positive patients. Patients aged 18 to 75 years with ECOG performance status ≤1 with R0 surgical resection of a pT3-T4aN0 colon or high rectum adenocarcinoma will be randomized within 63 days after curative-intent surgery, to adjuvant mFOLFOX6 (oxaliplatin 85 mg/m², leucovorin 400 mg/m², and 5-FU bolus 400 mg/m2 then 5FU Continuous infusion 2.4 g/m²) every two weeks for 12 cycles or observation. Patients will be followed for maximum 7 years. A gain of 17.5% in 3-yr disease free survival (DFS) is expected (42.5% in the experimental arm vs. 25% in the control arm; HR:0.62; α, 5% [two-sided log-rank test]; 1-β, 80%). Secondary endpoints include 2-yr DFS, overall survival, and toxicity. Recruitement began End of January 2020.

Early identification of treatment benefit by methylated circulating tumor DNA in metastatic colorectal cancer

Background:

The early identification of treatment effect is wanted in several settings, including the management of metastatic colorectal cancer (mCRC). A potential universal marker is circulating tumor DNA (ctDNA). Our prospective study explored the association between progression-free survival (PFS) and overall survival (OS), and early change of ctDNA after one cycle of chemotherapy in patients with mCRC.

Methods:

The study included mCRC patients receiving standard first line combination chemotherapy with 5-Fluorouracil (FU), oxaliplatin, and bevacizumab. Hypermethylated neuropeptide Y (NPY) ctDNA (meth-ctDNA) served as a marker analyzed by droplet digital polymerase chain reaction (PCR). The meth-ctDNA level was analyzed in plasma before treatment start and again before cycle two. The patients were divided into two groups according to the dynamics of meth-ctDNA. Low ctDNA (LctDNA) included patients with zero or values of meth-ctDNA decreasing to a level including zero in the 95% confidence interval. High ctDNA (HctDNA) included all other patients (stable, increasing, or slightly decreasing values). The two groups were compared as to PFS and OS.

Results:

The study included 123 patients. The PFS in the two groups differed significantly with a median of 9.2 and 6.7 months in LctDNA and HctDNA, respectively (p = 0.0005). This translated into a 12-month difference in OS with a median of 25.4 and 13.5 months, respectively (p = 0.0001).

Conclusions:

Early therapeutic reconsideration is of utmost importance. A low level of meth-ctDNA after one cycle of chemotherapy in the first line setting is a potential marker for excellent clinical outcomes. The clinical utility should be confirmed in randomized clinical trials.

The Neuropeptide System and Colorectal Cancer Liver Metastases: Mechanisms and Management

Colorectal cancer (CRC), classified as the third most prevalent cancer worldwide, remains to be a clinical and research challenge. It is estimated that ~50% of CRC patients die from distant metastases, with treatment of this complication still posing significant difficulties. While liver metastasis (LM) cascade is known in the literature, its mechanisms are still unclear and remain studied in different research models. A connection is suggested between nervous system dysfunctions and a range of Neurotransmitters (Nts) (including Neuropeptides, NPs), Neurotrophins (Ntt) and their receptors (Rs) in CRC liver metastasis development. Studies on the role of NP/NP-Rs in the progression and metastasis of CRC, show the complexity of brain–tumor interactions, caused by their different forms of release to the extracellular environment (endocrine, autocrine, paracrine and neurocrine). Many stages of LM are connected to the activity of pro-inflammatory, e.g., Corticotropin-releasing Hormone Receptor 1 (CRHR1), Neuropeptide Y (NPY) and Neurotensin (NT), anti-inflammatory, e.g., Calcitonin Gene-related Peptide (CGRP), CRHR2 and Vasoactive Intestinal Polypeptide (VIP) or dual role neuropeptides, e.g., Substance P (SP). The regulation of the local immunological profile (e.g., CRH/CRHRs), dysfunctions of enteroprotective role of NPs on epithelial cells (e.g., NT/NT-R), as well as structural-functional changes in enteric nervous system innervation of the tumor are also important. More research is needed to understand the exact mechanisms of communication between the neurons and tumor cells. The knowledge on the mechanisms regulating tumor growth and different stages of metastasis, as well as effects of the action of a numerous group of Nts/NPs/Ntt as growth factors, have implications for future therapeutic strategies. To obtain the best treatment outcomes, it is important to use signaling pathways common for many NPs, as well to develop a range of broad-spectrum antagonists. This review aims to summarize the current knowledge on the importance of neuroactive molecules in the promotion of the invasion-metastasis cascade in CRC, as well as the improvements of clinical management of CRC liver metastasis.

Colorectal Cancer Invasion and Atrophy of the Enteric Nervous System: Potential Feedback and Impact on Cancer Progression

Colorectal cancer (CRC) invasion within the large intestine wall results in the replacement of normal tissue architecture by tumour mass. Cancer cells digest the extracellular matrix (ECM) by the release of proteolytic enzymes. The disintegration of matrix ground substance activates several deposited growth factors which stimulate cell proliferation. Stromal (mainly fibroblasts), immune and cancer cells dominate in this area and become involved in a network of multimodal interactions which significantly induce proliferation of colon cancer cells, inhibit their apoptosis and promote their spreading within the local tumour microenvironment. Cancer invasion destroys nerve fibres and neurons of the local enteric nervous system (ENS) and induces subsequent atrophy of the submucosal and myenteric plexuses in areas adjacent to the cancer boundary. Interestingly, the reduction of plexuses' size is accompanied by the increased number of galanin-immunoreactive neurons and increased galanin content in parts of the colon located close to the tumour. Galanin, a neuroprotective peptide, may inhibit the extrinsic pathway of apoptosis and in this way promote cancer cell survival. The possible role of acetylcholine and some ENS neuropeptides was also discussed. Invasion of cancer cells spreads along nerve fibres with the involvement of locally-released neutrophins which promote, via their specific receptors, cancer cell proliferation and pro-survival signalling pathways. Thus, during CRC development cancer cells and neurons of the ENS release many neurotransmitters/neuropeptides which affect key cellular signalling pathways promoting cancer cell proliferation and pro-survival phenotype. The multiple interactions between ENS neurons, cancer cells and other cell types present in the colon wall increase cancer cell invasiveness and have a negative impact on the course of CRC.

Prognostic Value of Serum NPY Hypermethylation in Neoadjuvant Chemoradiotherapy for Rectal Cancer: Secondary Analysis of a Randomized Trial

OBJECTIVES

Long-term prevention of metastatic disease remains a challenge in locally advanced rectal cancer, and robust pretreatment prognostic factors for metastatic progression are lacking. We hypothesized that detecting circulating tumor-specific DNA (ctDNA) based on hypermethylation of the neuropeptide Y gene (meth-ctDNA) could be a prognostic marker in the neoadjuvant setting; we examined this in a secondary, explorative analysis of a prospective trial.

MATERIALS AND METHODS

Serum samples were prospectively collected in a phase III trial for locally advanced rectal cancer. Positivity for and fractional abundance of meth-ctDNA in baseline samples were estimated. Overall survival (OS) and the rate of distant metastases were compared between meth-ctDNA positive and negative patients; other prognostic factors were controlled for in multivariate Cox regression. Importance of quantitative load was examined by considering the fractional abundance of meth-ctDNA relative to total circulating DNA.

RESULTS

Baseline serum samples were available for 146 patients. In total, 30 patients had presence of meth-ctDNA, with no correlation with cT (P=0.8) or cN (P=0.6) stages. Median follow-up was 10.6 years for OS and 5.1 years for freedom from distant metastases. Patients with meth-ctDNA had significantly worse 5-year OS (47% vs. 69%), even when controlling for other prognostic factors (hazard ratio=2.08; 95% confidence interval, 1.23-1.51). This seemed mainly driven by disparity in the rate of distant metastases (55% vs. 72% at 5 y, P=0.01); hazard ratio=2.20 (95% confidence interval, 1.19-4.07, P=0.01) in multivariate analysis. Increased quantitative load was highly significant for worse outcomes.

CONCLUSIONS

Meth-ctDNA could be a potential prognostic marker in the neoadjuvant setting and may, if validated, identify patients at increased risk of distant metastases.