Detection and Clinical Significance of DLC1 Gene Methylation in Serum DNA from Colorectal Cancer Patients. Chin J Cancer Res. 2011;23:283-287. [PMID: 23359753 DOI: 10.1007/s11670-011-0283-0]

Detection and clinical significance of CEACAM5 methylation in colorectal cancer patients

Colorectal cancer (CRC) is a globally common cancer, and the serum carcinoembryonic antigen (sCEA) is widely applied as a diagnostic and prognostic tumor marker in CRC. This study aimed to elucidate the mechanism of CEA expression and corresponding clinical features to improve prognostic assessments. In CRC cells, hypomethylation of the CEACAM5 promoter enhanced CEA expression in HCT116 and HT29 cells with 5-aza-2'-deoxycytidine (5-Aza-dC) treatment. Our clinical data indicated that 64.7% (101/156) of CRC patients had an sCEA level above the normal range, and 76.2% (77/101) of those patients showed a lower average CpG methylation level of the CEACAM5 promoter. The methylation analysis showed that both CRC cell lines and patient samples shared the same critical methylation CpG regions at -200 to -500 and -1000 to -1400 bp of the CEACAM5 promoter. Patients with hypermethylation of the CEACAM5 promoter showed features of a BRAF mutation, TGFB2 mutation, microsatellite instability-high, and preference for right-sided colorectal cancer and peritoneal seeding presentation that had a similar clinical character to the consensus molecular subtype 1 (CMS1) of colorectal cancer. Additionally, hypermethylation of the CEACAM5 promoter combined with evaluated sCEA demonstrated the worst survival among the patients. Therefore, the methylation status of the CEACAM5 promoter also served as an effective biomarker for assessing disease prognosis. Results indicated that DNA methylation is a major regulatory mechanism for CEA expression in colorectal cancer. Moreover, our data also highlighted that patients in a subgroup who escaped from inactivation by DNA methylation had distinct clinical and pathological features and the worst survival.

Using Circulating Tumor DNA as a Novel Biomarker to Screen and Diagnose Colorectal Cancer: A Meta-Analysis

(1) Background: Circulating tumor DNA (ctDNA) has emerged as a promising biomarker for many kinds of tumors. However, whether ctDNA could be an accurate diagnostic biomarker in colorectal cancer (CRC) remains to be clarified. The aim of this study was to evaluate the diagnostic accuracy of ctDNA in CRC. (2) Methods: PubMed, Web of Science, and Cochrane databases were searched to identify studies reporting the use of ctDNA to screen and diagnose CRC, and all relevant studies published until October 2022 were enrolled for our analysis. These studies were divided into three primer subgroups: the subgroup of quantitative or qualitative analysis of ctDNA and the subgroup of septin9 (SEPT9) methylation assay. (3) Results: A total of 79 qualified articles with 25,240 subjects were incorporated into our meta-analysis. For quantitative studies, the combined sensitivity (SEN), specificity (SPE), and diagnostic odds ratio (DOR) were 0.723 (95% CI: 0.623-0.803), 0.920 (95% CI: 0.827-0.966), and 23.305 (95% CI: 9.378-57.906), respectively, yielding an AUC of 0.860. The corresponding values for qualitative studies were 0.610 (95% CI: 0.566-0.651), 0.891 (95% CI: 0.878-0.909), 12.569 (95% CI: 9.969-15.848), and 0.823, respectively. Detection of SEPT9 methylation depicted an AUC of 0.879, with an SEN of 0.679 (95% CI: 0.622-0.732), an SPE of 0.903 (95% CI: 0.878-0.923), and a DOR of 20.121 (95% CI:14.404-28.106), respectively. (4) Conclusion: Blood-based ctDNA assay would be a potential novel biomarker for CRC screening and diagnosis. Specifically, quantitative analysis of ctDNA or qualitative analysis of SEPT9 methylation exhibited satisfying diagnostic efficiency. Larger sample studies are needed to further confirm our conclusions and to make the ctDNA approach more sensitive and specific.

Tumor suppressor gene DLC1: Its modifications, interactive molecules, and potential prospects for clinical cancer application

Deleted in liver cancer 1 (DLC1) is a recognized tumor suppressor gene that negatively regulates Rho family proteins by hydrolyzing the active GTP-bound state to its inactive GDP-bound state. Active Rho proteins play a positive role in tumorigenesis. Numerous in vitro and in vivo experiments have shown that DLC1 is downregulated or inactivated in various solid tumors, which may be due to the following five reasons: genomic deletion, epigenetic modification and ubiquitin-dependent proteasomal degradation may cause DLC1 underexpression; phosphorylation at the post-translation level may cause DLC1 inactivation; and failure to localize at focal adhesions (FAs) may prevent DLC1 from exerting full activity. All of the causes could be attributed to molecular binding. Experimental evidence suggests that direct or indirect targeting of DLC1 is feasible for cancer treatment. Therefore, elucidating the interaction of DLC1 with its binding partners might provide novel targeted therapies for cancer. In this review, we summarized the binding partners of DLC1 at both the gene and protein levels and expounded a variety of anticancer drugs targeting DLC1 to provide information about DLC1 as a cancer diagnostic indicator or therapeutic target.

Knocking out matrix metalloproteinase 12 causes the accumulation of M2 macrophages in intestinal tumor microenvironment of mice

MMP12 is mainly secreted by macrophages, is involved in macrophage development, and decomposes the extracellular matrix. Herein, we investigated whether macrophages would change in the intestinal tumor microenvironment after MMP12 knockout. Apc^Min/+;MMP12^-/-mice were obtained by crossbreeding Apc^Min/+ mice with MMP12 knockout mice (MMP12^-/- mice). The data showed that the number and volume of intestinal tumors were significantly increased in Apc^Min/+;MMP12^-/- mice compared with Apc^Min/+ mice. Additionally, the tumor biomarkers CA19-9, CEA, and β-catenin appeared relatively early in intestinal tumors in Apc^Min/+;MMP12^-/- mice. The results demonstrated that knocking out MMP12 accelerated the tumor growth and pathological process. On further investigation of its mechanism, the proportions of M2 macrophages in the spleen and among peritoneal macrophages were significantly up-regulated in Apc^Min/+;MMP12^-/- mice. Expression of M2 macrophage-related genes was up-regulated in tumor and peritoneal macrophages. The M2-related cytokine levels of IL-4 and IL-13 were increased in the serum of Apc^Min/+;MMP12^-/-mice. In vitro, bone marrow-derived M2 macrophages were obtained by treating bone marrow cells with IL-4 and IL-13, and these M2 macrophages secreted cytokines being changed. This finding reveals the crucial role of MMP12 in macrophage development and provides a new target for the control of macrophage polarization. Knocking out MMP12 causes intestinal M2 macrophage accumulation in tumor microenvironment, promoting the growth of intestinal tumors in Apc^Min/+ mice.

DNA Methylation-Based Testing in Liquid Biopsies as Detection and Prognostic Biomarkers for the Four Major Cancer Types

Lung, breast, colorectal, and prostate cancers are the most incident worldwide. Optimal population-based cancer screening methods remain an unmet need, since cancer detection at early stages increases the prospects of successful and curative treatment, leading to a lower incidence of recurrences. Moreover, the current parameters for cancer patients' stratification have been associated with divergent outcomes. Therefore, new biomarkers that could aid in cancer detection and prognosis, preferably detected by minimally invasive methods are of major importance. Aberrant DNA methylation is an early event in cancer development and may be detected in circulating cell-free DNA (ccfDNA), constituting a valuable cancer biomarker. Furthermore, DNA methylation is a stable alteration that can be easily and rapidly quantified by methylation-specific PCR methods. Thus, the main goal of this review is to provide an overview of the most important studies that report methylation biomarkers for the detection and prognosis of the four major cancers after a critical analysis of the available literature. DNA methylation-based biomarkers show promise for cancer detection and management, with some studies describing a "PanCancer" detection approach for the simultaneous detection of several cancer types. Nonetheless, DNA methylation biomarkers still lack large-scale validation, precluding implementation in clinical practice.

Circulating Tumor DNA Analysis: Clinical Implications for Colorectal Cancer Patients. A Systematic Review

Background

Liquid biopsies could improve diagnosis, prognostication, and monitoring of colorectal cancer (CRC). Mutation, chromosomal copy number alteration, and methylation analysis in circulating tumor DNA (ctDNA) from plasma or serum has gained great interest. However, the literature is inconsistent on preferred candidate markers, hampering a clear direction for further studies and clinical translation. This review assessed the potential of ctDNA analysis for clinical utility.

Methods

A systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines was conducted up to December 3, 2018, followed by methodological quality assessment. Primary endpoints were accuracy for detection, prognostication, and monitoring.

Results

Eighty-four studies were included. For CRC detection, sensitivity was 75% using ctDNA mutation analysis and up to 96% using copy number analysis. Septin 9 (SEPT9) hypermethylation analysis showed sensitivities of 100% and specificities of 97%. Regarding prognostication, ctDNA KRAS mutations were associated with oncological outcome and could predict response to anti-epidermal growth factor receptor therapy. For monitoring, sequential ctDNA KRAS mutation analysis showed promise for detection of relapses or therapy resistance.

Conclusions

This comprehensive overview of ctDNA candidate markers demonstrates SEPT9 methylation analysis to be promising for CRC detection, and KRAS mutation analysis could assist in prognostication and monitoring. Prospective evaluation of marker panels in clinical decision making should bring ctDNA analysis into practice.

Significant association of PRMT6 hypomethylation with colorectal cancer

BACKGROUND

Protein arginine N-methyltransferase 6 (PRMT6) was deemed to be indispensable in the variety of biological processes. Upregulated PRMT6 was found in various human diseases including cancer. Herein, we investigated the performance of PRMT6 methylation in the diagnosis for CRC.

METHODS

A quantitative methylation-specific polymerase chain reaction (qMSP) method was used to measure PRMT6 promoter methylation. The percentage of methylated reference (PMR) was applied to represent gene methylation level.

RESULTS

Our data indicated that PRMT6 promoter methylation levels were significantly lower in CRC tissues than those in paired nontumor tissues (median PMR: 36.93% vs 63.12%, P = 1E-6) and normal intestinal tissues (median PMR: 36.93% vs 506.55%, P = 8E-12). We further examined the potential role of PRMT6 hypomethylation by the receiver operating characteristic (ROC) curve. Our results showed that the area under the curve (AUC) was 0.644 (95% CI = 0.596-0.733) between CRC tissues and paired nontumor tissues, 0.958 (95% CI = 0.919-0.998) between CRC tissues and normal intestinal tissues, and 0.899 (95% CI = 0.825-0.972) between paired nontumor tissues and normal intestinal tissues.

CONCLUSION

Our study firstly indicated that the hypomethylation of PRMT6 promoter could be a novel diagnostic biomarker for CRC.

Molecular biomarkers for an early diagnosis, effective treatment and prognosis of colorectal cancer: Current updates

Colorectal cancer (CRC) is the third most prevalent cancer in the world. Globally, it has been estimated that about 1.4 million new cases of colorectal cancer are diagnosed every year. CRC is a multifactorial disease that arises due to genetics as well as epigenetic alterations in a number of oncogenes, tumor suppressor genes, mismatch repair genes, as well as cell cycle regulating genes in colon mucosal cells. These molecular alterations have been considered as potential CRC biomarkers because they can provide the physicians with diagnostic, prognostic and treatment response information. The goal is to identify relevant, cheap and applicable biomarkers that contribute to patient management decisions, resulting in direct benefits to patients. In this review, we will outline the most currently available and developing tumor tools, and blood molecular biomarkers. Also, we will illustrate their diagnostic, therapeutic and prognostic applications.

Diagnostic Performance of DNA Hypermethylation Markers in Peripheral Blood for the Detection of Colorectal Cancer: A Meta-Analysis and Systematic Review

DNA hypermethylation in blood is becoming an attractive candidate marker for colorectal cancer (CRC) detection. To assess the diagnostic accuracy of blood hypermethylation markers for CRC in different clinical settings, we conducted a meta-analysis of published reports. Of 485 publications obtained in the initial literature search, 39 studies were included in the meta-analysis. Hypermethylation markers in peripheral blood showed a high degree of accuracy for the detection of CRC. The summary sensitivity was 0.62 [95% confidence interval (CI), 0.56-0.67] and specificity was 0.91 (95% CI, 0.89-0.93). Subgroup analysis showed significantly greater sensitivity for the methylated Septin 9 gene (SEPT9) subgroup (0.75; 95% CI, 0.67-0.81) than for the non-methylated SEPT9 subgroup (0.58; 95% CI, 0.52-0.64). Sensitivity and specificity were not affected significantly by target gene number, CRC staging, study region, or methylation analysis method. These findings show that hypermethylation markers in blood are highly sensitive and specific for CRC detection, with methylated SEPT9 being particularly robust. The diagnostic performance of hypermethylation markers, which have varied across different studies, can be improved by marker optimization. Future research should examine variation in diagnostic accuracy according to non-neoplastic factors.

Noninvasive DNA methylation biomarkers in colorectal cancer: A systematic review

OBJECTIVE

To summarize the current evidence on the biomarkers associated with DNA methylation in the screening and diagnosis of colorectal cancer (CRC).

METHODS

A literature search was conducted on the databases of PubMed and Web of Science to identify articles published from 1 January 2000 to 6 June 2015 with language striction. Stuides focusing on the association between noninvasive biomarkers indicating DNA methylation and CRC were included.

RESULTS

Altogether 74 studies were finally included in the study. Varied genetic markers in the feces and blood samples were hypermethylated in patients with CRC than in the healthy controls. Some of them could even be detected at the early stage of the tumors. The sensitivity of the genetic markers was superior to that of fecal occult blood test and carcinoembryonic antigen. Multitarget DNA assays using a combination of different methylated genes could improve the diagnostic sensitivity.

CONCLUSIONS

Genetic markers might be minimally invasive, economical and accurate for the screening and surveillance of CRC. Large multicenter studies evaluating these biomarkers systematically and prospectively not only in CRC but also in other types of cancers are needed in the future.

Value of DNA methylation markers in colorectal cancer screening

Colorectal cancer (CRC) is one of the most common malignant tumors in the world. Recognizing CRC at an early stage by population-based screening is crucial in the prevention and treatment of CRC. Numerous candidate genes, which play important roles in the development and progression of CRC, have been found to be hyper-methylated in the promoter regions in recent studies. The promoter fragments of those hyper-methylated genes in tumor tissues have also been detected in the blood and fecal specimens, with higher sensitivity and specificity than traditional markers in the screening of CRC, including carcino-embryonic antigen (CEA) and fecal occult blood test. Here, we will discuss what we have already known about the DNA methylation markers for CRC screening and the potential research direction in the future.

DNA methylation biomarkers as diagnostic and prognostic tools in colorectal cancer

Colorectal cancer (CRC) is the third most common type of cancer and is responsible for 9 % of cancer deaths in both men and women in the USA for 2013. It is a heterogenous disease, and its three classification types are microsatellite instability, chromosomal instability, and CpG island methylator phenotype. Biomarkers are molecules, which can be used as indicators of cancer. They have the potential to achieve great sensitivities and specificities in diagnosis and prognosis of CRC. DNA methylation biomarkers are epigenetic markers, more specifically genes that become silenced after aberrant methylation of their promoter in CRC. Some methylation biomarkers like SEPT9 (ColoVantage®) and vimentin (ColoSure(TM)) are already commercially available. Other blood and fecal-based biomarkers are currently under investigation and clinical studies so that they can be used in the near future. Biomarker panels are also currently being studied since they show great potential in diagnosis as they can combine robust biomarkers to achieve even greater sensitivities than single markers. Finally, methylation-sensitive microRNAs (miRNAs) are very promising markers, and their investigation as biomarkers, is only at primitive stage.

Epigenetic alteration: new insights moving from tissue to plasma - the example of PCDH10 promoter methylation in colorectal cancer

Background:

Tumour-released DNA in blood represents a promising biomarker for cancer detection. Although epigenetic alterations such as aberrant promoter methylation represent an appealing perspective, the discordance existing between frequencies of alterations found in DNA extracted from tumour tissue and cell-free DNA (cfDNA) has challenged their practical clinical application. With the aim to explain this bias of agreement, we investigated whether protocadherin 10 (PCDH10) promoter methylation in tissue was associated with methylation pattern in matched cfDNA isolated from plasma of patients with colorectal cancer (CRC), and whether the strength of concordance may depend on levels of cfDNA, integrity index, as well as on different clinical–pathological features.

Methods:

A quantitative methylation-specific PCR was used to analyse a selected CpG site in the PCDH10 promoter of 67 tumour tissues, paired normal mucosae, and matched plasma samples. The cfDNA integrity index and cfDNA concentration were assessed using a real-time PCR assay.

Results:

The PCDH10 promoter methylation was detected in 63 out of 67 (94.0%) surgically resected colorectal tumours and in 42 out of 67 (62.7%) plasma samples. The median methylation rate in tumour tissues and plasma samples was 43.5% (6.3–97.8%) and 5.9% (0–80.9%), respectively. There was a significant correlation between PCDH10 methylation in cfDNA and tumour tissue in patients with early CRC (P<0.0001). The ratio between plasma and tissue methylation rate increases with increasing cfDNA integrity index in early-stage cancers (P=0.0299) and with absolute cfDNA concentration in advanced cancers (P=0.0234).

Conclusion:

Our findings provide new insight into biological aspects modulating the concordance between tissues and plasma methylation profiles.

DLC1 as a regulator of proliferation, invasion, cell cycle, and apoptosis in cutaneous squamous cell carcinoma

Increasing evidence has demonstrated that the tumor suppressor gene deleted in liver cancer-1 (DLC1) is tightly implicated in the development and progression of tumors and is verified to be downregulated in a variety of tumors. However, the roles and precise molecular mechanisms of DLC1 in cutaneous squamous cell carcinoma (cutaneous SCC) remain to be elucidated. In the present study, we confirmed the reduced level in cutaneous SCC tissues and cells, and DLC1 mRNA relative level in cutaneous SCC tissues with lymph node metastasis (0.801 ± 0.079) was markedly lower than those without lymph node metastasis (1.245 ± 0.071) (P < 0.0001). Importantly, the survival rates of patients with low DLC1 level were lower than those with high DLC1 level (P = 0.0051). Further investigation revealed that DLC1 overexpression inhibited proliferation and arrested cell cycle at G0/G1 phase in A431 cells, which may be tightly associated with upregulation of p21 protein and downregulation of cyclin D1 and cdk2 proteins. Moreover, the decreases of FAK and p-FAK as well as the increase of E-cadherin level mediated by elevated DLC1 level suppressed invasion in A431 cells. Additionally, DLC1 overexpression induced apoptosis coupled with elevations of Bax level and caspase-3 activity and decrease of Bcl-2 level in A431 cells. Taken altogether, our data presented herein suggest that DLC1 plays a pivotal role in the development and progression of cutaneous SCC, which may be in part achieved by regulating the signaling pathway related to proliferation, invasion, cell cycle, and apoptosis in cutaneous SCC cells.