Blood-based tests for colorectal cancer screening: do they threaten the survival of the FIT test?

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.

CCL3-CCR5 axis promotes cell migration and invasion of colon adenocarcinoma via Akt signaling pathway

BACKGROUND

Infiltration of tumor-associated macrophages (TAMs) can promote tumorigenesis and development. C-C motif chemokine ligand 3 (CCL3) was reported to be derived from TAMs and tumor cells and facilitate the progression of several cancers. Nevertheless, whether CCL3 can be derived from TAMs and tumor cells of colon adenocarcinoma (COAD) is unclarified.

METHODS

Peripheral blood monocytes-derived macrophages were polarized by the conditioned medium from COAD cells to establish TAM-like macrophages (TAM1/2). RT-qPCR and western blotting were used for detection of expression levels of CCL3 and its receptors C-C motif chemokine receptor 1 (CCR1) and CCR5 in TAM1/2 and COAD cells. Immunofluorescence staining was utilized for evaluating CCL3, CD163 and CCR5 expression. The Akt signaling pathway-associated protein levels were measured by western blotting. Transwell assays were used for assessing cell migration and invasiveness.

RESULTS

CCL3 displayed a high level in TAMs and cancer cells of COAD. CCL3 activated the Akt signaling pathway by binding to CCR5. CCL3-CCR5 axis facilitated COAD cell migration and invasiveness by activating the Akt signaling. CCL3 derived from both TAMs and cancer cells contributed to the malignant behaviors of COAD cells. High expression of CCL3/CCR5 was closely associated with poor prognoses of COAD patients.

CONCLUSION

CCL3-CCR5 interaction promotes cell migration and invasiveness, and functions as a prognostic biomarker for COAD.

STAT3-regulated LncRNA LINC00160 mediates cell proliferation and cell metabolism of prostate cancer cells by repressing RCAN1 expression

Long non-coding RNA (LncRNA) LINC00160 was reported to be associated with cancer progression and mediates drug resistance. However, the role of LINC00160 in prostate cancer remains unclear. The study sought to study the function of LINC00160 in prostate cancer. Moreover, the potential mechanism was investigated. Silence of LINC00160 inhibited proliferation and promoted the apoptosis of prostate cancer cells, retarded the glycolysis of prostate cancer cells. By acting as a transcription activator, STAT3 induced LINC00160 expression, which regulated RCAN1 transcription epigenetically via binding to EZH2. Mechanically, LINC00160 mediated prostate cell proliferation and metabolism by repressing RCAN1 expression. In summary, LINC00160 may function as the novel marker for prostate cancer diagnosis and therapy.

The Evaluation of Methylated Septin 9 in Blood Plasma and Tissue Biopsies for the Early Detection for Asymptomatic Colon Cancer

The purpose of this study was to assess the utility of the SEPT9 genetic marker in the early detection of colon cancer patients. A case-control study was conducted on forty newly diagnosed colon cancer patients. The study was done between March 2019 and January 2020, patients from the Gastroenterology and Liver Education Hospital, Al-imamain Al-Kadhimain Medical City, and Baghdad Teaching Hospital were recruited. Colon cancer patients' mean age ± standard deviation was  54.4 ± 10.79 years while the age ± standard deviation of the mean of the control group was 55.1±8.54 years. For septin9 tissue methylation of the controls was done on the non-malignant tissues of the same patients. This study concluded that the percentage of Septin 9 (SEPT9) in the tissue of patients with colon cancer (CC) was the highest value, which is more significant than that of the serum of CC patients. Both of these groups were significantly higher than the percentage of SEPT9 methylation of control tissue and serum. Non-significant differences were obtained in the levels of CEA and CA19-9 between CC patients and controls.

Elevated Ras related GTP binding B (RRAGB) expression predicts poor overall survival and constructs a prognostic nomogram for colon adenocarcinoma

Currently, no articles have explored the roles of RRAGB gene in the occurrence and development of cancer. By means of The Cancer Genome Atlas (TCGA) data mining, we found that this gene might be a novel prognostic predictor for colon adenocarcinoma (COAD). Hence, this article was carried out to explore its roles in COAD and associations with immunity. RRAGB single-gene expression matrix and corresponding clinical information were extracted from TCGA database. Univariate/multivariate cox regression analyses and gene set enrichment analysis (GSEA) were utilized to identify independent prognostic factors and RRAGB related pathways, respectively. Relationships between RRAGB and immunity were also analyzed. Boxplot and K-M survival analysis indicated that RRAGB was not only differently expressed in COAD (P < 0.05), but also significantly associated with overall survival (OS; P < 0.05). Univariate and multivariate Cox hazard regression analyses indicated that RRAGB could serve as an independent prognostic factor for COAD (both P < 0.05). GSEA identified five signaling pathways significantly enriched in the high-RRAGB expression phenotype. Moreover, a RRAGB-based nomogram was successfully constructed and displayed a satisfactory performance. In addition, RRAGB expression was found to be significantly associated with microsatellite instability (MSI), tumor mutational burden (TMB) and immunity. Our results revealed that RRAGB could be a prognostic biomarker for COAD in terms of OS and markedly related to MSI, TMB, and immunity. We also constructed an RRAGB-based nomogram with a satisfactory performance. Further researches should be carried out to validate our findings.

Polyphenols Modulating Effects of PD-L1/PD-1 Checkpoint and EMT-Mediated PD-L1 Overexpression in Breast Cancer

Investigating dietary polyphenolic compounds as antitumor agents are rising due to the growing evidence of the close association between immunity and cancer. Cancer cells elude immune surveillance for enhancing their progression and metastasis utilizing various mechanisms. These mechanisms include the upregulation of programmed death-ligand 1 (PD-L1) expression and Epithelial-to-Mesenchymal Transition (EMT) cell phenotype activation. In addition to its role in stimulating normal embryonic development, EMT has been identified as a critical driver in various aspects of cancer pathology, including carcinogenesis, metastasis, and drug resistance. Furthermore, EMT conversion to another phenotype, Mesenchymal-to-Epithelial Transition (MET), is crucial in developing cancer metastasis. A central mechanism in the upregulation of PD-L1 expression in various cancer types is EMT signaling activation. In breast cancer (BC) cells, the upregulated level of PD-L1 has become a critical target in cancer therapy. Various signal transduction pathways are involved in EMT-mediated PD-L1 checkpoint overexpression. Three main groups are considered potential targets in EMT development; the effectors (E-cadherin and Vimentin), the regulators (Zeb, Twist, and Snail), and the inducers that include members of the transforming growth factor-beta (TGF-β). Meanwhile, the correlation between consuming flavonoid-rich food and the lower risk of cancers has been demonstrated. In BC, polyphenols were found to downregulate PD-L1 expression. This review highlights the effects of polyphenols on the EMT process by inhibiting mesenchymal proteins and upregulating the epithelial phenotype. This multifunctional mechanism could hold promises in the prevention and treating breast cancer.

SDC2 and TFPI2 Methylation in Stool Samples as an Integrated Biomarker for Early Detection of Colorectal Cancer

Background

Detection of aberrant methylated DNA in the stool is an effective early screening method for colorectal cancer (CRC). Previously, reporters identified that syndecan-2 (SDC2) and tissue factor pathway inhibitor 2 (TFPI2) were aberrantly methylated in most CRC tissues. However, the combined diagnostic role of them remains undefined. Our research aimed at probing the role and efficiency of the methylation status of SDC2 and TFPI2 in CRC early screening by using bioinformatics analysis and clinical stool sample validation.

Methods

The promoter and CpG site methylation levels of SDC2 and TFPI2 and their correlation with clinicopathological characteristics of CRC were analyzed using UALCAN, Methsurv, and Wanderer. UCSC Xena was used to perform survival analyses. LinkedOmics was used to do functional network analysis. DNA was isolated and purified from stool, and quantitative methylation-specific PCR (qMSP) was applied to detect methylatedSDC2 and TFPI2.

Results

The results showed that promoter and most CpG site methylation levels of SDC2 and TFPI2 were significantly higher in CRC than in normal tissues. Moreover, SDC2 and TFPI2 methylation showed a positive correlation. Functional network analysis suggested that both methylated SDC2 and TFPI2 were involved in tumor cells’ metabolic programs. Besides, there was a higher positive integrated detection rate in CRC (n=61) with a sensitivity of 93.4% and in adenoma (Ade) (n=16) with a sensitivity of 81.3% than normal with a specificity of 94.3% in stool samples. What is more, integration of methylated SDC2 and TFPI2 showed a higher sensitivity and Youden index than a single gene in detecting Adeor CRC.

Conclusion

Our data indicate that SDC2 and TFPI2 were hypermethylated in CRC, and integrated detection of methylated SDC2 and TFPI2 in stool has the potential to be an effective and noninvasive tool of CRC early screening.

Assessment of Serum MicroRNA-21 Gene Expression for Diagnosis and Prognosis of Colorectal Cancer

BACKGROUND

MicroRNAs (miRNAs) are small, non-coding RNAs that are involved in carcinogenesis through posttranscriptional gene regulatory activity. The current study aimed to evaluate serum miR-21 expression levels as potential biomarkers for diagnosis and prognosis of colorectal cancer (CRC) patients.

METHODS

Quantitative real-time RT-PCR was applied to determine the relative expression level of miR-21 in serum. At the same time, the sensitivity and specificity of this marker were evaluated by receiver operating characteristic (ROC) curve analysis.

RESULTS

miR-21 expression levels of serum were 3.4 and 1.25 in patient and control, respectively (p < 0.05). The sensitivity and specificity of miR-21 were found to be 95.8% and 91.7%, respectively. The high expression level of serum miR-21 were associated with higher local recurrence, TNM staging, PT staging, venous invasion, liver metastasis, and recurrence (p < 0.05).

CONCLUSION

The results of this study indicated that miR-21 expression levels in serum can be considered as a novel non-invasive biomarker for early detection and prognosis of CRC patients.

A New RBPs-Related Signature Predicts the Prognosis of Colon Adenocarcinoma Patients

The dysregulation of RNA binding proteins (RBPs) is closely related to tumorigenesis and development. However, the role of RBPs in Colon adenocarcinoma (COAD) is still poorly understood. We downloaded COAD’s RNASeq data from the Cancer Genome Atlas (TCGA) database, screened the differently expressed RBPs in normal tissues and tumor, and constructed a protein interaction network. COAD patients were randomly divided into a training set (N = 315) and a testing set (N = 132). In the training set, univariate Cox analysis identified 12 RBPs significantly related to the prognosis of COAD. By multivariate COX analysis, we constructed a prognostic model composed of five RBPs (CELF4, LRRFIP2, NOP14, PPARGC1A, ZNF385A) based on the lowest Akaike information criterion. Each COAD patient was scored according to the model formula. Further analysis showed that compared with the low-risk group, the overall survival rate (OS) of patients in the high-risk group was significantly lower. The area under the curve of the time-dependent receiver operator characteristic (ROC) curve was 0.722 in the training group and 0.738 in the test group, which confirmed a good prediction feature. In addition, a nomogram was constructed based on clinicopathological characteristics and risk scores. C-index and calibration curve proved the accuracy in predicting the 1-, 3-, and 5-year survival rates of COAD patients. In short, we constructed a superior prognostic and diagnostic signature composed of five RBPs, which indicates new possibilities for individualized treatment of COAD patients.

Comprehensive analysis of the lncRNA-miRNA-mRNA regulatory network for bladder cancer

Background

Long non-coding RNAs (lncRNAs) are essential regulators for various human cancers. However, these lncRNAs need to be further classified for cancer. In the present study, we identified novel competing endogenous RNA (ceRNA) network for bladder cancer (BC) and explored the gene functions of the ceRNA regulatory network.

Methods

Differential gene expression analysis were performed on The Cancer Genome Atlas Urothelial Bladder Carcinoma (TCGA-BLCA) datasets to identify differentially expressed messenger RNAs (mRNAs), lncRNAs, and microRNAs (miRNAs). Based on the competing endogenous RNA (ceRNA) hypothesis, a lncRNA-miRNA-mRNA network was constructed using the StarBase database and visualization by Cytoscape software. Functional enrichment analyses of Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway were performed via R package ClusterProfiler. The protein-protein interaction network was constructed by STRING database and visualization by Cytoscape. Finally, we used CIBERSORT and the TIMER database to analyze the immune infiltrations for BC.

Results

The regulatory network was constructed via TCGA BLCA cohort. The differential expressions of lncRNA, miRNA, and mRNA were 186, 200, and 2,661, respectively. There were 106 lncRNA, miRNA, and mRNA included in the ceRNA network. In this network, Calcium Voltage-gated Channel Auxiliary Subunit Alpha2delta1 (CACNA2D1, P<0.001), domain containing engulfment adaptor1 (GULP1, P=0.001), latent transforming growth factor beta binding protein 1 (LTBP1, P=0.006), myosin light chain kinase (MYLK, P=0.001), serpin family E member 2 (SERPINE2, P=0.002), spectrin beta non-erythrocytic 2 (SPTBN2, P=0.047), and hsa-miR-590-3p (P<0.001) significantly affected the prognosis of BC patients. Functional enrichment analyses showed that the biological functions included negative regulation of protein phosphorylation, cell morphogenesis, and sensory organ morphogenesis. Important cancer pathways of KEGG included parathyroid hormone synthesis secretion action, the notch signaling pathway, MAPK signaling pathway, the Rap1 signaling pathway, signaling pathways regulating the pluripotency of stem cells, and the transforming growth factor-β signaling pathway. Our findings demonstrated that the ceRNA network has important biological functions and a significant influence on the prognosis of BC.

Conclusions

The lncRNA-miRNA-mRNA network constructed in the present study could provide useful insight into the underlying tumorigenesis of BC, and can determine new molecular biomarkers for the diagnosis and therapeutical treatment of BC.

DNA integrity index as a potential molecular biomarker in colorectal cancer

Background

Efficient approaches for early detection of colorectal cancer offer opportunities to gain better treatment outcomes. Blood-based molecular biomarkers as DNA integrity index (DII) might represent a promising tumor marker in the future. The purpose of this study was to assess the clinical utility of the DII as a potential biomarker for colorectal cancer in 90 colorectal cancer patients, 30 patients with benign colorectal mass, and 30 age- and sex-matched healthy control subjects. PCR was used to assess the concentration of both ALU115 and ALU247. DII was calculated as the ratio of Q247/Q115.

Results

DII was significantly higher in colorectal cancer patients than both patients with benign colorectal mass and healthy controls. ROC curve was plotted using DII and the best cut-off was ≥ 0.60 with diagnostic sensitivity 93.0%, specificity 65.0%, PPV 80.0%, NPV 86.0%, and efficiency 82% with AUC (0.872) while the best cut-off for CEA was ≥ 1.4 ng/mL with diagnostic sensitivity 87.0%, specificity 60.0%, PPV 76%, NPV 75%, and efficiency 76% with AUC (0.79).

Conclusions

Our results suggest that DII is better than CEA as an early marker for colorectal cancer detection and may be used as a candidate biomarker for malignancy.

Lobaplatin Inhibits Prostate Cancer Proliferation and Migration Through Regulation of BCL2 and BAX

Lobaplatin is a diastereometric mixture of platinum (II) complexes, which contain a 1,2-bis (aminomethyl) cyclobutane stable ligand and lactic acid. Previous studies have showed that lobaplatin plays inhibiting roles in various types of tumors. However, the role of lobaplatin in prostate cancer remains unknown. Cell viability was detected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay. Cell proliferation was detected by cell colony formation assay. Cell migration and invasion were determined by transwell migration and invasion assay. Cell apoptosis was detected by flow cytometry. The messenger RNA and protein expression levels were detected by quantitative real-time polymerase chain reaction and Western blot. Lobaplatin treatment inhibits cell viability, cell proliferation, cell migration, and invasion, while promotes cell apoptosis of prostate cancer cell lines DU145 and PC3. Meanwhile, lobaplatin treatment regulates apoptosis by downregulation of BCL2 expression and upregulation of BAX expression levels. Our study suggests lobaplatin inhibits prostate cancer proliferation and migration through regulation of BCL2 and BAX expression.

Clinical value of preoperative methylated septin 9 in Chinese colorectal cancer patients

BACKGROUND

The methylated septin 9 (mSEPT9) assay was the first blood-based test approved by the United States Food and Drug Administration as a colorectal screening test. However, the diagnostic and prognostic role of preoperative mSEPT9 for colorectal cancer (CRC) in Chinese patients is still unknown.

AIM

To improve the understanding of diagnostic and prognostic factors, serum mSEPT9 was detected in Chinese CRC patients.

METHODS

A retrospective analysis of 354 cases, of which 300 had CRC and 54 were normal, was performed in China. Patients’ characteristics, treatments, and laboratory data, including age, the date of surgery, Union for International Cancer Control (UICC) stages, distant metastasis (M), and so on, were collected. Methylation levels of SEPT9 were quantified by quantitative, methylation-specific polymerase chain reaction before surgery. In addition, the effects of mSEPT9 on the occurrence and prognosis of 330 CRC cases from The Cancer Genome Atlas (TCGA) database were evaluated using bioinformatics analyses. Potential prognostic factors for overall survival (OS) and progression-free survival (PFS) were evaluated by Kaplan-Meier univariate analysis.

RESULTS

In Chinese CRC patients, positive mSEPT9 was strongly associated with advanced UICC stages, deeper invasion by the primary tumor, and more distant metastasis. Methylation levels of SEPT9 were stage-dependent and showed a stepwise increase in UICC stages (I–IV), primary tumor categories (T1–T4), regional node categories (N0–N2), and distant metastasis categories (M0–M1). The patients with positive mSEPT9 showed a tendency toward lower PFS. After analyzing TCGA clinical data, the high mSEPT9 group was found to be obviously correlated only with more distant metastasis. The patients with high mSEPT9 levels showed a tendency toward lower OS. Besides, nine meaningful mSEPT9 sites were found to provide guidance for the follow-up studies.

CONCLUSION

MSEPT9 analysis may add valuable information to current tumor staging. Serum mSEPT9 in Chinese CRC patients appears to offer promising novel prognostic markers and might be considered for monitoring CRC recurrence.

lncRNA TINCR participates in ALA-PDT-induced apoptosis and autophagy in cutaneous squamous cell carcinoma

This study aims to investigate whether terminal differentiation-induced ncRNA (TINCR) has an effect on apoptosis and autophagy induced by ALA-PDT in cutaneous squamous cell carcinoma (CSCC). A431 cells were treated with 5-aminolevulinic acid (ALA) solution at different concentrations and for different duration time. A431 cell viability was detected by Cell Counting Kit-8 (CCK-8) assay, relative TINCR messenger RNA expression was detected by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). A431 cell apoptosis was examined by flow cytometry. Relative apoptosis/autophagy-related protein expression was analyzed by Western blot analysis. The effect of TINCR on cell autophagy was detected by RFP-LC3 immunofluorescence assay. Reactive oxygen species concentration was detected by 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescent probe. Relative expressions of ERK1/2 and specificity protein 3 (Sp3) in A43 cells were detected by Western blot analysis and qRT-PCR. Sp3 binding sites were analyzed by ChIP-qPCR. The relative transcription activity was measured with luciferase reporter assay. ALA-PDT treatment at 3.2 mmol/L for 120 minutes significantly promoted TINCR expression in CSCC A431 cells, and TINCR promoted ALA-PDT-induced apoptosis and cell autophagy. Furthermore, ALA-PDT promoted TINCR expression through ERK1/2-SP3 pathway. Sp3 promoted TINCR transcription by binding TINCR promoters. Our data indicated that TINCR involves in ALA-PDT-induced apoptosis and autophagy in CSCC.

Cell-Free Circulating Methylated SEPT9 for Noninvasive Diagnosis and Monitoring of Colorectal Cancer

Identification of early-stage tumor and monitoring therapeutic efficacy and recurrence or metastasis of colorectal cancer (CRC) are urgently warranted for improving the outcome of CRC patients and reducing the disease-related mortality. In this study, we evaluated the diagnostic value of cell-free circulating methylated SEPT9 (mSEPT9) for CRC and beyond CRC and examined the potentiality of mSEPT9 in assessing therapeutic efficacy and monitoring recurrence of CRC. Our results confirmed the favorable diagnostic value of plasma mSEPT9 for CRC, with a sensitivity of 61.22% (95% confidence interval (CI): 51.33%–70.27%) and specificity of 93.7% (95% CI: 91.09%–95.57%) using 2/3 algorithm. The positive rate of mSEPT9 in CRC was correlated with tumor size, histological grade, and general histological type (P < 0.05). Beyond CRC, gastric cancer patients also presented a high positive rate of plasma mSEPT9 (70%). The conversions between preoperative and postoperative plasma mSEPT9 reflected the therapeutic efficacy of curatively intended surgery for CRC patients. The persistent positivity of plasma mSEPT9 after surgery (within 7–14 days) was highly associated with impending recurrences or metastases (within one year), with a sensitivity of 100%. Postoperative mSEPT9 status during follow-up also provided valuable indication for CRC recurrence or metastases, with a good consistency (kappa = 0.818, P = 0.001). Our results verified the reliability of plasma mSEPT9 as a biomarker for noninvasive diagnosis of CRC. More significantly, we revealed its valuable role in appraising CRC therapeutic efficacy and monitoring CRC recurrences or metastases. Further studies with larger sample sizes are needed to verify and elucidate the clinical utility of the promising findings.

An exploration of nucleic acid liquid biopsy using a glucose meter

The development of non-invasive techniques for the diagnosis of cancer, characterization of mutation and monitoring treatment response could greatly reduce the morbidity and mortality caused by cancer. Nevertheless, the extremely low amount of cell free nucleic acids makes liquid biopsy a very challenging task. Herein, taking advantage of the pocket size, reliable quantitative results and simple operation of the pocket-sized personal glucose meter (PGM), we report an approach of circulating microRNA-21 (miR-21) detection with high precision and low cost. Via target-induced release of invertase from the DNA-invertase conjugate, which could convert sucrose into glucose, the detection of miR-21 in serum was linked to PGM readings. Combining the DNAzyme feedback amplification (DFA) program and highly efficient enzymatic turnover, an ultralow detection limit of 7 × 10-16 M for miR-21 was achieved using a PGM as the reporter. The high sensitivity and selectivity of the proposed method meets the requirement of quantifying cell free nucleic acids in serum. In addition, this approach fills the shortage of quantitative RT-PCR and next-generation sequencing in quantifying miRNAs with a short length and greatly reduces the cost of detection. We believe that widely used personal diagnosis devices could hold an important place in the booming area of liquid biopsy.

CDDO-Me reveals USP7 as a novel target in ovarian cancer cells

Deubiquitinating enzyme USP7 has been involved in the pathogenesis and progression of several cancers. Targeting USP7 is becoming an attractive strategy for cancer therapy. In this study, we identified synthetic triterpenoid C-28 methyl ester of 2-cyano-3, 12-dioxoolen-1, 9-dien-28-oic acid (CDDO-Me) as a novel inhibitor of USP7 but not of other cysteine proteases such as cathepsin B and cathepsin D. CDDO-Me inhibits USP7 activity via a mechanism that is independent of the presence of α, β-unsaturated ketones. Molecular docking studies showed that CDDO-Me fits well in the ubiquitin carboxyl terminus-binding pocket on USP7. Given that CDDO-Me is known to be effective against ovarian cancer cells, we speculated that CDDO-Me may target USP7 in ovarian cancer cells. We demonstrated that ovarian cancer cells have higher USP7 expression than their normal counterparts. Knockdown of USP7 inhibits the proliferation of ovarian cancer cells both in vitro and in vivo. Using the cellular thermal shift assay and the drug affinity responsive target stability assay, we further demonstrated that CDDO-Me directly binds to USP7 in cells, which leads to the decrease of its substrates such as MDM2, MDMX and UHRF1. CDDO-Me suppresses ovarian cancer tumor growth in an xenograft model. In conclusion, we demonstrate that USP7 is a novel target of ovarian cancer cells; targeting USP7 may contribute to the anti-cancer effect of CDDO-Me. The development of novel USP7 selective compounds based on the CDDO-Me-scaffold warrants further investigation.

Serological biomarkers in triage of FIT-positive subjects?

FIT-based colorectal cancer screening has been implemented in many countries including Denmark, where 916 colorectal cancer and 4468 high- or medium-risk adenoma patients were identified within April-December 2014, among 16,806 subjects with a positive FIT test. Screening increases the overall requirements for colonoscopy, which may challenge the current capacity. Some countries have increased their initial FIT cut-off level in order to comply with lack of colonoscopy capacity. Many patients with neoplasia will not be detected, however, by using increased FIT cut-off levels. The number of patients with neoplastic lesions missed by increased cut-off levels appears to be much higher than expected. Therefore, tests that identify those patients missed by increased FIT cut-off levels must be developed. Preliminary results of determination of one of several biomarker entities currently under investigation show that nucleosome blood tests may be one option for identifying some of these patients. Implementation of a triage test consisting of FIT, blood-based biomarkers and plus/minus colonoscopy is suggested to identify subjects with FIT levels between the initial and the increased cut-off level that must be offered colonoscopy. In addition, triage may reduce the frequency of unnecessary colonoscopies by 25%.

New trend in colorectal cancer in Germany: are young patients at increased risk for advanced colorectal cancer?

Background

The role of colonoscopy in the screening of colorectal cancer (CRC) has been unequivocally established. In Germany, screening colonoscopy with full insurance reimbursement is available for individuals aged 55 and above, and/or for persons with well-known risk factors for CRC. However, advanced CRC is not uncommon in individuals below 55 years. This study was designed to investigate the incidence of advanced CRC in patients < 55 years.

Methods

A retrospective analysis of data from a prospectively maintained CRC database of a university hospital in Germany was performed. Using the recommended age for screening colonoscopy as cutoff, the study population was divided into two groups: < 55 years (study group) and ≥ 55 years (control group). Both groups were compared with regard to the extent of CRC using the UICC stages. Only surgically managed patients were included for analysis. Advanced CRC was defined as UICC stage III or IV.

Results

Complete follow-up data was available for 609 patients treated between 2009 and 2013. The study group included 83 patients, 42 females and 41 males with a median age of 48.0 ± 10 years, while the control group was made up of 526 patients, 230 females and 296 males with a median age of 75.5 ± 8.3 years. Both groups were comparable with regard to gender distribution, p = 0.24. Significantly more patients from the study group were diagnosed with advanced CRC in comparison to the control group, 56.6 vs. 43.9%, p = 0.03. There was no statistically significant difference amongst both groups with respect to cancer-related mortality, 10.8 vs. 12.5%, p = 0.66.

Conclusion

Patients below the recommended age for screening colonoscopy might be at increased risk for advanced CRC. There is need to decrease the recommended age for screening colonoscopy to prevent CRC or enable an early diagnosis in patients below 55 years.

Mining the fecal proteome: from biomarkers to personalised medicine

INTRODUCTION

Fecal proteomics has gained increased prominence in recent years. It can provide insights into the diagnosis and surveillance of many bowel diseases by both identifying potential biomarkers in stool samples and helping identify disease-related pathways. Fecal proteomics has already shown its potential for the discovery and validation of biomarkers for colorectal cancer screening, and the analysis of fecal microbiota by MALDI-MS for the diagnosis of a range of bowel diseases is gaining clinical acceptance. Areas covered: Based on a comprehensive analysis of the current literature, we introduce the range of sensitive and specific proteomics methods which comprise the current 'Proteomics Toolbox', explain how the integration of fecal proteomics with data processing/bioinformatics has been used for the identification of potential biomarkers for both CRC and other gut-related pathologies and analysis of the fecal microbiome, outline some of the current fecal assays in current clinical practice and introduce the concept of personalised medicine which these technologies will help inform. Expert commentary: Integration of fecal proteomics with other proteomics and genomics strategies as well as bioinformatics is paving the way towards personalised medicine, which will bring with it improved global healthcare.

Improving Participation in Colorectal Cancer Screening: a Randomised Controlled Trial of Sequential Offers of Faecal then Blood Based Non-Invasive Tests

BACKGROUND

Poor participation rates are often observed in colorectal cancer (CRC) screening programs utilising faecal occult blood tests. This may be from dislike of faecal sampling, or having benign bleeding conditions that can interfere with test results. These barriers may be circumvented by offering a blood-based DNA test for screening. The aim was to determine if program participation could be increased by offering a blood test following faecal immunochemical test (FIT) non-participation.

MATERIALS AND METHODS

People were invited into a CRC screening study through their General Practice and randomised into control or intervention (n=600/group). Both groups were mailed a FIT (matching conventional screening programs). Participation was defined as FIT completion within 12wk. Intervention group non-participants were offered a screening blood test (methylated BCAT1/IKZF1). Overall participation was compared between the groups.

RESULTS

After 12wk, FIT participation was 82% and 81% in the control and intervention groups. In the intervention 96 FIT non- participants were offered the blood test - 22 completed this test and 19 completed the FIT instead. Total screening in the intervention group was greater than the control (88% vs 82%, p<0.01). Of 12 invitees who indicated that FIT was inappropriate for them (mainly due to bleeding conditions), 10 completed the blood test (83%).

CONCLUSIONS

Offering a blood test to FIT non-participants increased overall screening participation compared to a conventional FIT program. Blood test participation was particularly high in invitees who considered FIT to be inappropriate for them. A blood test may be a useful adjunct test within a FIT program.

Predicting novel salivary biomarkers for the detection of pancreatic cancer using biological feature-based classification

AIM

The use of saliva as a diagnostic fluid enables non-invasive sampling and thus is a prospective sample for disease tests. This study fully utilized the information from the salivary transcriptome to characterize pancreatic cancer related genes and predict novel salivary biomarkers.

METHODS

We calculated the enrichment scores of gene ontology (GO) and pathways annotated in Kyoto Encyclopedia of Genes and Genomes database (KEGG) for pancreatic cancer-related genes. Annotation of GO and KEGG pathway characterize the molecular features of genes. We employed Random Forest classification and incremental feature selection to identify the optimal features among them and predicted novel pancreatic cancer-related genes.

RESULTS

A total of 2175 gene ontology and 79 KEGG pathway terms were identified as the optimal features to identify pancreatic cancer-related genes. A total of 516 novel genes were predicted using these features. We discovered 29 novel biomarkers based on the expression of these 516 genes in saliva. Using our new biomarkers, we achieved a higher accuracy (92%) for the detection of pancreatic cancer. Another independent expression dataset confirmed that these novel biomarkers performed better than the previously described markers alone.

CONCLUSION

By analyzing the information of the salivary transcriptome, we predict pancreatic cancer-related genes and novel salivary gene markers for detection.

Increased MACC1 levels in tissues and blood identify colon adenoma patients at high risk

Background

Colorectal cancer is a preventable disease if caught at early stages. This disease is highly aggressive and has a higher incidence in African Americans. Several biomarkers and mutations of aggressive tumor behavior have been defined such as metastasis-associated in colon cancer 1 (MACC1) that was associated with metastasis in colorectal cancer patients. Here, we aim to assess colon tissue MACC1 protein and circulating MACC1 transcripts in colon preneoplastic and neoplastic African American patients.

Methods

Patients’ tissue samples (n = 143) have been arranged on three tissue microarrays for normal (n = 26), adenoma (n = 68) and cancer (n = 49) samples. Immunohistochemistry was used to detect MACC1 expression. Blood samples (n = 93) from normal (n = 45), hyperplastic (n = 15) and tubular adenoma (n = 33) patients were used to assess MACC1 transcripts using qRT-PCR. Distribution of continuous variables was tested between different diagnoses with Kruskal–Wallis test. Categorical variables were tested by Chi square test. We assessed the prognostic ability of IHC staining by calculating area under receiver operating characteristics curve (ROC) for adenoma and cancer separately. Differences between groups in terms of MACC1 transcript levels in plasma were calculated by using non-parametric (exact) Wilcoxon-Mann–Whitney tests. We performed all calculations with SPSS, version 21.

Results

In patient tissues, there was a statistically significant difference in MACC1 expression in normal vs. adenoma samples (p = 0.004) and normal vs. cancer samples (p < 0.001). There was however no major difference in MACC1 expression between adenoma vs. cancer cases or tubular adenomas vs tubulovillous adenomas. The area under the curve for both normal vs. adenoma and normal vs. cancer cases were 70 and 67 %, respectively. MACC1 expression was not correlated to age, gender or anatomical sample location. In patient plasma, MACC1 transcripts in adenoma patients were significantly higher than in plasma from normal patients (p = 0.014). However, the difference between normal and hyperplastic plasma MACC1 transcripts was not statistically significant.

Conclusion

Metastasis-associated in colon cancer 1 is expressed at early stages of colorectal oncogenesis within the affected colonic tissue in this patient cohort. The plasma transcripts can be used to stratify African American patients at risk for potential malignant colonic lesions.

Investigation of MicroRNA-21 Expression Levels in Serum and Stool as a Potential Non-Invasive Biomarker for Diagnosis of Colorectal Cancer

Background:

Most cancer studies focus on exploring non-invasive biomarkers for cancer detection. In the present study, we sought to investigate the expression level of microRNA-21 (miR-21), as a potential diagnostic marker, in serum and stool samples from 40 patients with colorectal cancer (CRC) and 40 healthy controls.

Methods:

Quantitative real-time RT-PCR was applied to determine the relative expression level of miR-21 in serum and stool. At the same time, the sensitivity and specificity of this marker was evaluated by receiver operating characteristic (ROC) curve analysis.

Results:

miR-21 expression levels of serum and stool were up-regulated 12.1 (P<0.05, 95% CI: 5.774-34.045) and 10.0 (P<0.05, 95% CI: 0.351-16.260) times in CRC patients, respectively, when compared to the control group. The sensitivity and specificity of miR-21 was found to be 86.05% and 72.97%, respectively (an area under the ROC curve [AUC] of 0.783). The stool miR-21 level in CRC patients was much higher than that in the healthy controls, showing a sensitivity of 86.05% and a specificity of 81.08% (AUC: 0.829). The expression level of miR-21 in stool was able to significantly distinguish CRC tumor, node, metastasis stages III-IV from stages I-II, with a sensitivity and specificity of 88.1% and 81.6%, respectively (AUC: 0.872).

Conclusion:

The results of this study indicated that miR-21 expression levels in serum and stool can be considered as a potential diagnostic biomarker for the diagnosis of CRC patients. However, more studies are required to confirm the validity of miR-21 as a valuable non-invasive diagnostic tool for CRC.

Increased serological cancer-associated biomarker levels at large bowel endoscopy and risk of subsequent primary cancer (†)

BACKGROUND

Frequently, subjects offered colonoscopy due to symptoms of colorectal neoplasia are diagnosed with diverticula. The symptoms may, however, also be related to extra-colonic neoplasia. The present retrospective study evaluated a possible association between increased levels of predefined biomarkers in subjects diagnosed with diverticula and risk of developing a primary malignant disease.

METHODS

During 2004/2005, about 4509 subjects were included in a multicenter study with collection of blood samples before bowel endoscopy. The aim was to evaluate a relation between the protein biomarkers CEA, TIMP-1, CA19-9 and YKL-40 and findings at endoscopy. Diverticula were diagnosed in 1021 subjects. By 31 December 2012, subjects who had developed primary malignancy were identified retrospectively and relation between biomarker levels at endoscopy and risk of developing primary malignancy was calculated. The relation with the four biomarkers was divided into three groups: 0 = none increased; 1 = one increased and 2 = two or more increased.

RESULTS

In the observation period, 148 subjects developed a primary malignant disease. Univariable analyzes of the biomarker levels showed that CEA, TIMP-1 and CA19-9 were significantly associated with development of primary malignancy. A multivariable analysis showed that increased levels were associated with development of malignancy (p < 0.0001). The 1- and 5-year cumulative risks of being diagnosed with a primary malignancy were: group 0: 1.1%/5.5%; group 1: 4.2%/10.1% and group 2: 11.4%/18.8%, respectively.

CONCLUSION

Increased levels of CEA, TIMP-1 and CA19-9 at endoscopy with findings of diverticula were associated with a significantly increased risk of being diagnosed with a subsequent primary malignant disease.

Is distance to chemotherapy an obstacle to adjuvant care among the N.C. Medicaid-enrolled colon cancer patients?

BACKGROUND

Adjuvant chemotherapy for colon cancer has been linked to patient and provider characteristics but little is known about whether distance to chemotherapy providers constitutes an obstacle to chemotherapy.

METHODS

A total of 1,184 Medicaid patients diagnosed with colon cancer in North Carolina in 1999-2002 comprised the sample. Data from the N.C. Central Cancer Registry, N.C. Medicaid Claims, American Hospital Directory and US Census were merged. Logistic regression models were used to estimate the association between chemotherapy receipt and the distance to nearest chemotherapy provider.

RESULTS

Compared to the referent group of SEER-staged II (local) cancer patients living less than 2 miles from the nearest chemotherapy provider, the odds of receiving chemotherapy fell as the distance to the nearest provider increased. The odds ratio (OR) for those living ≥5 to <15 miles away was 0.13 [95% confidence intervals (CI), 0.04-0.39], and OR for those living ≥15 miles away was 0.06 (95% CI, 0.01-0.52). Patients diagnosed with regional, SEER-staged III (regional) cancer were less likely to receive chemotherapy if they lived in rural areas more than 20 miles away from the nearest provider (OR =0.08; 95% CI, 0.01-0.72). However, we found no evidence of association between chemotherapy receipt and distance to the nearest provider for regional cancer patients living in urban areas and those living in rural areas within 20 miles from the nearest chemotherapy provider.

CONCLUSIONS

Distance to provider may be an obstacle to chemotherapy for some groups of low-income colon cancer patients. Relieving travel burdens of rural patients living far from providers may help Medicaid increase guideline-consistent adjuvant care for regional cancer patients.

Evaluation of serum nucleoside diphosphate kinase A for the detection of colorectal cancer

We previously described the over-expression of nucleoside diphosphate kinase A (NDKA) in tumours and serum from colorectal cancer (CRC) patients, suggesting its use as biomarker. In this study we evaluated the diagnostic accuracy of serum NDKA to detect advanced neoplasia (CRC or advanced adenomas). Furthermore, the performance of NDKA was compared with the faecal immunochemical test (FIT). The study population included a case-control cohort and a screening cohort (511 asymptomatic first-degree relatives of CRC patients that underwent a colonoscopy and a FIT). Serum NDKA was elevated in CRC patients in the case-control cohort (p = 0.002). In the screening cohort, NDKA levels were higher for advanced adenomas (p = 0.010) and advanced neoplasia (p = 0.006) compared to no neoplasia. Moreover, elevated NDKA was associated with severe characteristics of adenomas (≥3 lesions, size ≥ 1 cm or villous component). Setting specificity to 85%, NDKA showed a sensitivity of 30.19% and 29.82% for advanced adenomas and advanced neoplasia, respectively. NDKA combined with FIT (100 ng/mL cut-off) detected advanced adenomas and advanced neoplasia with 45.28% and 49.12% sensitivity, with specificity close to 90%. The combination of serum NDKA and FIT can improve the detection of advanced neoplasia, mainly for lesions located on the proximal colon, in asymptomatic individuals with CRC family-risk.

Future microfluidic and nanofluidic modular platforms for nucleic acid liquid biopsy in precision medicine

Nucleic acid biomarkers have enormous potential in non-invasive diagnostics and disease management. In medical research and in the near future in the clinics, there is a great demand for accurate miRNA, mRNA, and ctDNA identification and profiling. They may lead to screening of early stage cancer that is not detectable by tissue biopsy or imaging. Moreover, because their cost is low and they are non-invasive, they can become a regular screening test during annual checkups or allow a dynamic treatment program that adjusts its drug and dosage frequently. We briefly review a few existing viral and endogenous RNA assays that have been approved by the Federal Drug Administration. These tests are based on the main nucleic acid detection technologies, namely, quantitative reverse transcription polymerase chain reaction (PCR), microarrays, and next-generation sequencing. Several of the challenges that these three technologies still face regarding the quantitative measurement of a panel of nucleic acids are outlined. Finally, we review a cluster of microfluidic technologies from our group with potential for point-of-care nucleic acid quantification without nucleic acid amplification, designed to overcome specific limitations of current technologies. We suggest that integration of these technologies in a modular design can offer a low-cost, robust, and yet sensitive/selective platform for a variety of precision medicine applications.

Optimal management of resectable gastric adenocarcinoma

The worldwide incidence of gastric adenocarcinoma has rapidly declined in the past century, but gastric cancer remains the fifth most common malignancy in the world. Approximately half of all cases of gastric cancer are diagnosed in Eastern Asia. In this review, we provide an overview of the landmark studies investigating neoadjuvant and adjuvant therapies in resectable gastric cancer and highlight ongoing efforts to define optimal population-adapted management strategies.