Circulating microRNAs as Promising Biomarkers in Colorectal Cancer

Connection between MiR-490 and CCND1 and GSK3β genes play an effective role in Wnt signaling pathway in colorectal cancer

The Wnt signaling pathway is identified as one of the main disrupted pathways in Colorectal cancer (CRC). Results from studies focusing on this route will aid greatly in the detection and treatment of CRC. MicroRNAs (MiRs), particularly MiR-490, has emerged as key regulator of gene expression in biological pathways, making it an attractive research target. This is notably true for the Wnt signaling pathway, which is usually disordered in CRC tissues. This study aimed to evaluate the expression level of MiR-490 isomiRs and determine some of its key target genes involved in Wnt signaling pathway in CRC tissues and cell lines, based on experimental and bioinformatics analysis. Elevated expression of GSK3β and CCND1 indicate that the progression of CRC tumor is associated with the inhibitory effect of MiR-490 isomiRs on the Wnt/β-catenin signaling pathway. This finding was supported by the observation of a positive connection between the expression pattern of miR-490-3p and 5p, and CCND1 and GSK3β in CRC. The valuable results of this study provide a means of identifying biomarkers with the potential to either inhibit or activate CRC cellular pathways.

Acoustic separation and concentration of exosomes for nucleotide detection: ASCENDx

Efficient isolation and analysis of exosomal biomarkers hold transformative potential in biomedical applications. However, current methods are prone to contamination and require costly consumables, expensive equipment, and skilled personnel. Here, we introduce an innovative spaceship-like disc that allows Acoustic Separation and Concentration of Exosomes and Nucleotide Detection: ASCENDx. We created ASCENDx to use acoustically driven disc rotation on a spinning droplet to generate swift separation and concentration of exosomes from patient plasma samples. Integrated plasmonic nanostars on the ASCENDx disc enable label-free detection of enriched exosomes via surface-enhanced Raman scattering. Direct detection of circulating exosomal microRNA biomarkers from patient plasma samples by the ASCENDx platform facilitated a diagnostic assay for colorectal cancer with 95.8% sensitivity and 100% specificity. ASCENDx overcomes existing limitations in exosome-based molecular diagnostics and holds a powerful position for future biomedical research, precision medicine, and point-of-care medical diagnostics.

Surface-Enhanced Raman Spectroscopy-Based Detection of Micro-RNA Biomarkers for Biomedical Diagnosis Using a Comparative Study of Interpretable Machine Learning Algorithms

Surface-enhanced Raman spectroscopy (SERS) has wide diagnostic applications due to narrow spectral features that allow multiplex analysis. We have previously developed a multiplexed, SERS-based nanosensor for micro-RNA (miRNA) detection called the inverse molecular sentinel (iMS). Machine learning (ML) algorithms have been increasingly adopted for spectral analysis due to their ability to discover underlying patterns and relationships within large and complex data sets. However, the high dimensionality of SERS data poses a challenge for traditional ML techniques, which can be prone to overfitting and poor generalization. Non-negative matrix factorization (NMF) reduces the dimensionality of SERS data while preserving information content. In this paper, we compared the performance of ML methods including convolutional neural network (CNN), support vector regression, and extreme gradient boosting combined with and without NMF for spectral unmixing of four-way multiplexed SERS spectra from iMS assays used for miRNA detection. CNN achieved high accuracy in spectral unmixing. Incorporating NMF before CNN drastically decreased memory and training demands without sacrificing model performance on SERS spectral unmixing. Additionally, models were interpreted using gradient class activation maps and partial dependency plots to understand predictions. These models were used to analyze clinical SERS data from single-plexed iMS in RNA extracted from 17 endoscopic tissue biopsies. CNN and CNN-NMF, trained on multiplexed data, performed most accurately with RMSElabel = 0.101 and 9.68 × 10-2, respectively. We demonstrated that CNN-based ML shows great promise in spectral unmixing of multiplexed SERS spectra, and the effect of dimensionality reduction on performance and training speed.

Tumor circulating biomarkers in colorectal cancer

CRC is a major global health concern and is responsible for a significant number of cancer-related deaths each year. The successful treatment of CRC becomes more difficult when it goes undetected until it has advanced to a later stage. Diagnostic biomarkers can play a critical role in the early detection of CRC, which leads to improved patient outcomes and increased survival rates. It is important to develop reliable biomarkers for the early detection of CRC to enable timely diagnosis and treatment. To date, CRC detection methods such as endoscopy, blood, and stool tests are imperfect and often only identify cases in the later stages of the disease. To overcome these limitations, researchers are turning to molecular biomarkers as a promising avenue for improving CRC detection. Diagnostic information can be provided more reliably through a noninvasive approach using biomarkers such as mRNA, circulating cell-free DNA, micro-RNA, long non-coding RNA, and proteins. These biomarkers can be found in blood, tissue, feces, and volatile organic compounds. The identification of molecular biomarkers with high sensitivity and specificity for early detection of CRC that are safe, cost-effective, and easily measurable remains a significant challenge for researchers. In this article, we will explore the latest advancements in blood-based diagnostic biomarkers for CRC and their potential impact on improving patient survival rates.

LncRNA-miRNA interaction is involved in colorectal cancer pathogenesis by modulating diverse signaling pathways

LncRNAs function as molecular sponges for miRNAs to control their availability for targeting mRNA molecules. This procedure indirectly regulates the expression of cancer-related genes. Some lncRNAs also directly interact with miRNAs, leading to their degradation or sequestration, which can negatively impact gene expression. miRNAs, on the other hand, play a critical role in controlling the expression of genes, including oncogenes and tumor suppressor genes. Multiple types of cancer have been linked to the onset and progression of miRNA dysregulation. Even though there is a lot of potential for treating CRC by targeting the LncRNA-miRNA axis, several challenges remain to be overcome. The specificity of the targeting approach, delivery methods, resistance, safety, and cost-effectiveness are critical research areas that must be addressed to advance this field and improve treatment outcomes for people with CRC.

Novel insights on perils and promises of miRNA in understanding colon cancer metastasis and progression

Colorectal cancer (CRC) is the third highest frequent malignancy and ultimate critical source of cancer-associated mortality around the world. Regardless of latest advances in molecular and surgical targeted medicines that have increased remedial effects in CRC patients, the 5-year mortality rate for CRC patients remains dismally low. Evidence suggests that microRNAs (miRNAs) execute an essential part in the development and spread of CRC. The miRNAs are a type of short non-coding RNA that exhibited to control the appearance of tumor suppressor genes and oncogenes. miRNA expression profiling is already being utilized in clinical practice as analytical and prognostic biomarkers to evaluate cancer patients' tumor genesis, advancement, and counteraction to drugs. By modulating their target genes, dysregulated miRNAs are linked to malignant characteristics (e.g., improved proliferative and invasive capabilities, cell cycle aberration, evasion of apoptosis, and promotion of angiogenesis). This review presents an updated summary of circulatory miRNAs, tumor-suppressive and oncogenic miRNAs, and the potential reasons for dysregulated miRNAs in CRC. Further we will explore the critical role of miRNAs in CRC drug resistance.

Current Understanding on Why Ovarian Cancer Is Resistant to Immune Checkpoint Inhibitors

The standard treatment of ovarian cancer (OC) patients, including debulking surgery and first-line chemotherapy, is unsatisfactory because of recurrent episodes in the majority (~70%) of patients with advanced OC. Clinical trials have shown only a modest (10-15%) response of OC individuals to treatment based on immune checkpoint inhibitors (ICIs). The resistance of OC to therapy is caused by various factors, including OC heterogeneity, low density of tumor-infiltrating lymphocytes (TILs), non-cellular and cellular interactions in the tumor microenvironment (TME), as well as a network of microRNA regulating immune checkpoint pathways. Moreover, ICIs are the most efficient in tumors that are marked by high microsatellite instability and high tumor mutation burden, which is rare among OC patients. The great challenge in ICI implementation is connected with distinguishing hyper-, pseudo-, and real progression of the disease. The understanding of the immunological, molecular, and genetic mechanisms of OC resistance is crucial to selecting the group of OC individuals in whom personalized treatment would be beneficial. In this review, we summarize current knowledge about the selected factors inducing OC resistance and discuss the future directions of ICI-based immunotherapy development for OC patients.

Extracellular Vesicles as Potential Therapeutic Messengers in Cancer Management

A deeper understanding of the communication mechanisms of tumor cells in a tumor microenvironment can improve the development of new therapeutic solutions, leading to a more personalized approach. Recently, the field of extracellular vesicles (EVs) has drawn attention due to their key role in intercellular communication. EVs are nano-sized lipid bilayer vesicles that are secreted by all types of cells and can function as intermediators of intercellular communication with the ability to transfer different cargo (proteins, nucleic acids, sugar…) types among cells. This role of EVs is essential in a cancer context as it can affect tumor promotion and progression and contribute to the pre-metastatic niche establishment. Therefore, scientists from basic, translational, and clinical research areas are currently researching EVs with great expectations due to their potential to be used as clinical biomarkers, which are useful for disease diagnosis, prognosis, patient follow-up, or even as vehicles for drug delivery due to their natural carrier nature. The application of EVs presents numerous advantages as drug delivery vehicles, namely their capacity to overcome natural barriers, their inherent cell-targeting properties, and their stability in the circulation. In this review, we highlight the distinctive features of EVs, their application as efficient drug delivery systems, and their clinical applications.

Insights on the Biomarker Potential of Exosomal Non-Coding RNAs in Colorectal Cancer: An In Silico Characterization of Related Exosomal lncRNA/circRNA–miRNA–Target Axis

Colorectal cancer (CRC) is one of the most common cancer types, ranking third after lung and breast cancers. As such, it demands special attention for better characterization, which may eventually result in the development of early detection strategies and preventive measures. Currently, components of bodily fluids, which may reflect various disease states, are being increasingly researched for their biomarker potential. One of these components is the circulating extracellular vesicles, namely, exosomes, which are demonstrated to carry various cargo. Of importance, the non-coding RNA cargo of circulating exosomes, especially long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), and micro RNAs (miRNAs), may potentially serve as significant diagnostic and prognostic/predictive biomarkers. In this review, we present existing evidence on the diagnostic and prognostic/predictive biomarker value of exosomal non-coding RNAs in CRC. In addition, taking advantage of the miRNA sponging functionality of lncRNAs and circRNAs, we demonstrate an experimentally validated CRC exosomal non-coding RNA-regulated target gene axis benefiting from published miRNA sponging studies in CRC. Hence, we present a set of target genes and pathways downstream of the lncRNA/circRNA–miRNA–target axis along with associated significant Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, which may collectively serve to better characterize CRC and shed light on the significance of exosomal non-coding RNAs in CRC diagnosis and prognosis/prediction.

Potential impact of platelet-to-lymphocyte ratio on prognosis in patients with colorectal cancer: A systematic review and meta-analysis

Background

Numerous studies have confirmed that inflammation promotes the occurrence, development and prognosis of colorectal cancer (CRC).

Objective

This study focuses on the potentially prognostic value of the platelet-to-lymphocyte ratio (PLR) in CRC patients.

Data Sources

This study was registered at PROSPERO (ID: CRD42020219215). Relative studies were searched on PubMed, Cochrane Library, Embase, Web of Science, and clinical trial databases by two back-to-back reviewers. Study Selection and Intervention: Studies were screened according to the predetermined inclusion and exclusion criteria, comparing prognosis differences between low PLR levels and high PLR levels for CRC patients. Main Outcome Measures: Studies were integrated and compared to analyze the value of PLR in predicting overall survival (OS), progression-free survival (PFS), cancer-specific survival (CSS), disease-free survival (DFS) and recurrence-free survival (RFS) of CRC. Results: Outcomes were compared using Review Manager (version 5.4) software from Cochrane Collaboration. A total of 27 literary works, including 13,330 patients, were incorporated into our study. The final results showed that higher PLR levels had worse OS (hazard ratio [HR] = 1.40, 95% confidence interval [CI] = 1.21–1.62, P < 0.00001), DFS (HR = 1.44, 95% CI = 1.09–1.90, P = 0.01) and RFS (HR = 1.48, 95% CI = 1.13–1.94, P = 0.005) than lower PLR levels, respectively. However, there was no evidence of significance for PFS (HR = 1.14, 95% CI = 0.84–1.54, P = 0.40) and CSS (HR = 1.16, 95% CI = 0.88–1.53, P = 0.28) in the final meta-analysis.

Limitations

Our study has the following limitations. First of all, we only included literature published in English, which means that some publication bias may be inevitable. In addition, our study used aggregate data, not individual data; furthermore, we did not define the exact cut-off value representing the PLR level.

Conclusion

An elevated PLR seems to be an adverse prognostic factor affecting survival outcomes in patients with CRC. Meanwhile, more prospective studies are required to confirm our conclusion.

PROSPERO ID: CRD42020219215.

miRNA probe integrated biosensor platform using bimetallic nanostars for amplification-free multiplexed detection of circulating colorectal cancer biomarkers in clinical samples

There is a critical need for sensitive and rapid detection technologies utilizing molecular biotargets such as microRNAs (miRNAs), which regulate gene expression and are a promising class of diagnostic biomarkers for disease detection. Here, we present the development and fabrication of a highly reproducible and robust plasmonic bimetallic nanostar biosensing platform to detect miRNA targets using surfaced-enhanced Raman scattering (SERS)-based gene probes called the inverse Molecular Sentinel (iMS). We investigated and optimized the integration of iMS gene probes onto this SERS substrate, achieving ultra-sensitive detection with limits of detection of 6.8 and 16.7 zmol within the sensing region for two miRNA sequences of interest. Finally, we demonstrated the biomedical usefulness of this nanobiosensor platform with the multiplexed detection of upregulated miRNA targets, miR21 and miR221, from colorectal cancer patient plasma. The resulting SERS data are in excellent agreement with PCR data obtained from patient samples and can distinguish between healthy and cancerous patient samples. These results underline the potential of the iMS-integrated substrate nanobiosensing platform for rapid and sensitive diagnostics of cancer biomarkers for point-of-care applications.

Targeting miR-5088-5p attenuates radioresistance by suppressing Slug

Radiotherapy is widely used for cancer treatment, but paradoxically, it has been reported that surviving cancer cells can acquire resistance, leading to recurrence or metastasis. Efforts to reduce radioresistance are required to increase the effectiveness of radiotherapy. miRNAs are advantageous as therapeutic agents because it can simultaneously inhibit the expression of several target mRNAs. Therefore, this study discovered miRNA that regulated radioresistance and elucidated its signaling mechanism. Our previous study confirmed that miR-5088-5p was associated with malignancy and metastasis in breast cancer. As a study to clarify the relationship between radiation and miR-5088-5p identified as onco-miRNA, it was confirmed that radiation induced hypomethylation of the promoter of miR-5088-5p and its expression increased. On the other hand, miR-5088-5p inhibitors were confirmed to reduce radiation-induced epithelial-mesenchymal transition, stemness, and metastasis by reducing Slug. Therefore, this study showed the potential of miR-5088-5p inhibitors as therapeutic agents to suppress radioresistance.

Diagnosis, Monitoring, and Prognosis of Liquid Biopsy in Cancer Immunotherapy

Liquid biopsy (LB), as a minimally invasive method of gleaning insight into the dynamics of diseases through a patient fluid sample, represents an interesting tool that can advise in disease monitoring, treatment selection, early diagnosis, evaluation of the response, and prognosis. Cancer immunotherapy is a breakthrough in cancer treatment, which is now recognized as the "fourth pillar" of cancer treatment, after surgery, chemotherapy, and radiotherapy. Liquid biopsy offers a different befalling for beneath invasive diagnosis, real-time accommodating monitoring, and analysis options, involving the isolation of circulating biomarkers, such as cell-free DNA (cfDNA), circulating tumor cells (CTCs), exosomes, and microRNAs (miRNAs). The biomarkers herein have great potential to allow the realization of liquid biopsy for predicting the immunotherapy response and precision medicine. Liquid biopsy offers an alternative, less invasive approach to select cancer patients who would benefit from immunotherapy and to monitor patients during their disease course. This review focuses on the use of liquid biopsy in the immunotherapy treatment of patients with cancer. In this review, we addressed the different promising liquid biopsy-based biomarkers in cancer patients that enable the selection of patients who benefit from immunotherapy and the monitoring of patients during this therapy.

Circulating microRNAs as Reliable Tumor Biomarkers: Opportunities and Challenges Facing Clinical Application

MicroRNAs (miRNAs) are involved in the development of human malignancies, and cells have the ability to secrete these molecules into extracellular compartments. Thus, cell-free miRNAs (circulating miRNAs) can potentially be used as biomarkers to evaluate pathophysiological changes. Although circulating miRNAs have been proposed as potential noninvasive tumor biomarkers for diagnosis, prognosis, and response to therapy, their routine application in the clinic is far from being achieved. This review focuses on the recent progress regarding the value of circulating miRNAs as noninvasive biomarkers, with specific consideration of their relevant clinical applications. In addition, we provide an in-depth analysis of the technical challenges that impact the assessment of circulating miRNAs. We also highlight the significance of integrating circulating miRNAs with the standard laboratory biomarkers to boost sensitivity and specificity. The current status of circulating miRNAs in clinical trials as tumor biomarkers is also covered. These insights and general guidelines will assist researchers in experimental practice to ensure quality standards and repeatability, thus improving future studies on circulating miRNAs. SIGNIFICANCE STATEMENT: Our review will boost the knowledge behind the inconsistencies and contradictory results observed among studies investigating circulating miRNAs. It will also provide a solid platform for better-planned strategies and standardized techniques to optimize the assessment of circulating cell-free miRNAs.

Circulating serum miR-1246 and miR-1229 as diagnostic biomarkers in colorectal carcinoma

Background

Colorectal cancer (CRC) is one of the most common cancers worldwide. Although colonoscopy is considered as the "Gold Standard" technique to detect CRC, its application is invasive and cost incurred. Thus, noninvasive or minimally invasive approaches are of utmost importance. The aberrant expression of some microRNAs (miRNAs, miRs) has been suggested in association with CRC pathogenesis. This study aimed to validate if circulating serum miR-1229 and miR-1246 are diagnostic biomarkers for CRC.

Materials and Methods

Serum samples were isolated from 45 CRC patients and also 45 healthy controls (HC). The expression levels of circulating serum-derived miR-1229 and miR-1246 were evaluated by quantitative real-time polymerase chain reaction. Receiver operating characteristic (ROC) curves were constructed to evaluate the CRC diagnostic accuracy of selected miRNAs. Furthermore, the association of candidate miRNAs and clinicopathological characteristics were evaluated. Functional enrichment of the candidate miRNAs was applied using in silico tools.

Results

The expression of miR-1229 and miR-1246 was significantly higher in CRC patients than HC (P < 0.0001) and also was found in association with lymph node metastasis (P < 0.05). We demonstrated a significant up-regulation of serum-derived miR-1246 in advanced tumor-node-metastasis stage III of CRC patients (P < 0.05). Areas under the ROC curve of miR-1229 and miR-1246 were 0.81 and 0.84, respectively (P < 0.0001).

Conclusion

We confirmed the capability of circulating serum miR-1229 and miR-1246 as novel diagnostic biomarkers for CRC.

Updated review of advances in microRNAs and complex diseases: experimental results, databases, webservers and data fusion

MicroRNAs (miRNAs) are gene regulators involved in the pathogenesis of complex diseases such as cancers, and thus serve as potential diagnostic markers and therapeutic targets. The prerequisite for designing effective miRNA therapies is accurate discovery of miRNA-disease associations (MDAs), which has attracted substantial research interests during the last 15 years, as reflected by more than 55 000 related entries available on PubMed. Abundant experimental data gathered from the wealth of literature could effectively support the development of computational models for predicting novel associations. In 2017, Chen et al. published the first-ever comprehensive review on MDA prediction, presenting various relevant databases, 20 representative computational models, and suggestions for building more powerful ones. In the current review, as the continuation of the previous study, we revisit miRNA biogenesis, detection techniques and functions; summarize recent experimental findings related to common miRNA-associated diseases; introduce recent updates of miRNA-relevant databases and novel database releases since 2017, present mainstream webservers and new webserver releases since 2017 and finally elaborate on how fusion of diverse data sources has contributed to accurate MDA prediction.

CDX2 as a Predictive Biomarker Involved in Immunotherapy Response Suppresses Metastasis through EMT in Colorectal Cancer

Background

Studies have confirmed that Caudal Type Homeobox 2 (CDX2) plays a tumor suppressor role in colorectal cancer (CRC) and as a prognostic and predictive marker for colorectal cancer. The epithelial to mesenchymal transition (EMT) is a transdifferentiation process, providing migratory and invasive properties to cancer cells during tumor progression. However, the role of CDX2 during the activation of EMT in CRC maintains controversial.

Aim

To investigate whether CDX2 is associated with EMT in CRC.

Methods

Forty-six CRC patients were included in the study. Expressions of CDX2, E-cadherin, and N-cadherin in all CRC patients were detected by IHC. ROC assays were applied to detect cut-off points for IHC scores to distinguish high and low expressions of CDX2 in 46 CRC samples. The prognostic value of CDX2 was statistically analyzed. MTT, Western blot, invasion, and migration assays in vitro were employed to explore the function of CDX2.

Results

We observed that high expressions of CDX2 and E-cadherin as well as low expressions of N-cadherin were significantly correlated with favorable prognosis. The levels of CDX2 protein exhibited a positive associated with E-cadherin while negative correlation with N-cadherin. Then, the low expression of CDX2 and high expression of CA199 in combination are positively related with poor prognosis. Overexpression of CDX2 reduced expression of MMP-2 and diminished cell proliferation, invasion, and migration, while knockdown CDX2 enhanced MMP-2 expression and increased cell proliferation, invasion, and migration in HCT-116 cells. CDX2 was correlated with expression of EMT markers. Overexpression of CDX2 suppressed the EMT markers indicating that CDX2 suppresses CRC cell viability, invasion, and metastasis through inhibiting EMT. Finally, we found that the expression of CDX2 was negatively associated with Th1 cells, macrophages, Th2 cells, cytotoxic cells, T cells, and T helper cells.

Conclusions

These results indicated CDX2 as prognostic biomarkers involved in immunotherapy response for CRC. CDX2 loss promotes metastasis in CRC through a CDX2-dependent mechanism.

Identification of stage-associated exosome miRNAs in colorectal cancer by improved robust and corroborative approach embedded miRNA-target network

Background

Colorectal cancer (CRC) is a common gastrointestinal tumor with high morbidity and mortality. At the molecular level, patients at different stages present considerable heterogeneity. Although the miRNA in exosome is an effective biomarker to reveal tumor progression, studies based on stage-associated exosome miRNA regulatory network analysis still lacking. This study aims to identify CRC stage-associated exosome miRNAs and reveal their potential function in tumor progression.

Methods

In this study, serum and cellular exosome miRNA expression microarrays associated with CRC were downloaded from GEO database. Stage-common (SC) and stage-specific (SS) differentially expressed miRNAs were extracted and their targets were identified based on 11 databases. Furthermore, miRNA SC and SS regulatory function networks were built based on the CRC phenotypic relevance of miRNA targets, and the corresponding transcription factors were identified. Concurrently, the potential stage-associated miRNAs were identified by receiver-operating characteristic (ROC) curve analysis, survival analysis, drug response analysis, ceRNA analysis, pathway analysis and a comprehensive investigation of 159 publications.

Results

Ten candidate stage-associated miRNAs were identified, with three SC (miR-146a-5p, miR-22-3p, miR-23b-3p) and seven SS (I: miR-301a-3p, miR-548i; IIIA: miR-23a-3p; IV: miR-194-3p, miR-33a-3p, miR-485-3p, miR-194-5p) miRNAs. Additionally, their targets were enriched in several vital cancer-associated pathways such as TGF-beta, p53, and hippo signaling pathways. Moreover, five key hotspot target genes (CCNA2, MAPK1, PTPRD, MET, and CDKN1A) were demonstrated to associated with better overall survival in CRC patients. Finally, miR-23b-3p, miR-301a-3p and miR-194-3p were validated being the most stably expressed stage-associated miRNAs in CRC serum exosomes, cell exosomes and tissues.

Conclusions

These CRC stage-associated exosome miRNAs aid to further mechanism research of tumor progression and provide support for better clinical management in patients with different stages.

The Number of Intraoperative Intestinal Venous Circulating Tumor Cells Is a Prognostic Factor for Colorectal Cancer Patients

Purpose

To assess the association between intestinal venous blood (IVB) circulating tumor cells (CTCs) and clinicopathological parameters in stage I-III colorectal cancer (CRC) patients.

Methods

Participants were retrospectively retrieved, who were admitted to our hospital or took annual physical exams between December 1, 2015 and December 31, 2018. A negative enrichment-immunofluorescence in situ hybridization (NE-imFISH) technique was used to isolate and identify CTCs. Receiver operating characteristic (ROC) curves and Youden index values were used to determine the critical CTC cutoff value for the diagnosis of CRC. Kaplan-Meier and log-rank methods were used to conduct survival analyses, and multivariate Cox regression analyses were employed for multivariate corrections to comprehensively evaluate the value of CTCs in the diagnosis of CRC. Relationships between IVB CTCs, clinicopathological parameters, and prognosis were then analyzed based upon patient postoperative follow-up data.

Results

In total, we retrieved 282 patients including 48 healthy controls, 72 patients with benign colorectal tumors, and 162 CRC patients. CRC patients exhibited significantly higher numbers of CTCs relative to control patients or those with benign disease. CTC numbers in CRC patient peripheral blood (PB) and IVB were closely associated with tumor node metastasis (TNM) staging (P < 0.01), carbohydrate antigen-125 (CA-125) levels (P < 0.001), and KRAS (Kirsten rat sarcoma virus oncogene) mutation status (P < 0.001). The disease-free survival (DFS) of patients in the CTC-negative group was significantly longer than that of patients in the CTC-positive group (24.60 ± 13.31 months vs. 18.70 ± 10.19 months, P < 0.05), with the same being true with respect to their overall survival (OS) (30.60 ± 12.44 months vs. 35.25 ± 11.57 months, P < 0.05). A multivariate analysis revealed that the detection ≥2 CTCs/3.2 ml was independently associated with poorer DFS and OS. CTC counts were independently predictive of CRC patients TNM staging, CA-125, and KRAS mutation status in both univariate and multivariate Cox proportional hazards regression analyses.

Conclusion

CTCs are valuable biomarkers that can be monitored to predict CRC patient disease progression.

miR‑146b‑5p promotes colorectal cancer progression by targeting TRAF6

Increasing evidence highlights the multiple roles of microRNAs (miRs) in the tumorigenesis of colorectal cancer (CRC); however, the molecular mechanism, particularly the target of miR-146b-5p in CRC has not been fully elucidated. The present study aimed to elucidate the influence of miR-146b-5p via regulating tumor necrosis factor receptor-associated factor 6 (TRAF6) in CRC. The expression levels of miR-146b-5p and TRAF6 in CRC tissue and cells were determined by reverse transcription quantitative PCR and western blotting. Binding between miR-146b-5p and TRAF6 was examined using a dual luciferase reporter gene assay. The impact of miR-146b-5p and TRAF6 on proliferation and migration of CRC cells was determined using Cell Counting Kit-8 and Transwell assays, respectively. An animal model of CRC was established to determine the carcinogenic effect of the miR-146b-5p-TRAF6 axis. The results demonstrated that miR-146b-5p was highly expressed in CRC tissue samples compared with in normal adjacent tissue samples and in CRC cells compared with in the normal NCM460 cell line, whereas TRAF6 was expressed at low levels. Overexpression of miR-146b-5p decreased TRAF6 expression in CRC HT29 and SW620 cells. miR-146b-5p targeted and inhibited TRAF6 expression in CRC cells. Furthermore, transfection with a miR-146b-5p mimic promoted the proliferation, migration and invasion of CRC cells and tumor growth; however, these effects were abolished by TRAF6 overexpression. Transfection with a miR-146b-5p inhibitor suppressed the proliferation of CRC cells. Taken together, the results from the present study demonstrated that miR-146b-5p could enhance the initiation and tumorigenesis of CRC by targeting TRAF6. These results will help elucidate the mechanisms underlying CRC development and will facilitate the development of targeted therapy for CRC.

Circulating miRNA expression over the course of colorectal cancer treatment

Colorectal cancer (CRC) is the third-most common cancer type in males and the second-most common cancer type in females, and has the second-highest overall mortality rate worldwide. Approximately 50% of patients in stage I–III develop metastases, mostly localized to the liver. All physiological conditions occurring in the organism are also reflected in the levels of circulating microRNAs (miRNAs/miRs) in patients. miRNAs are a class of small, non-coding, single-stranded RNAs consisting of 18–25 nucleotides, which have important roles in various cellular processes. The aim of the present study was to evaluate a panel of seven circulating miRNAs (miR-106a-5p, miR-210-5p, miR-155-5p, miR-21-5p, miR-103a-3p, miR-191-5p and miR-16-5p) as biomarkers for monitoring patients undergoing adjuvant treatment of CRC. Total RNA was extracted from the plasma of patients with CRC prior to surgery, in the early post-operative period (n=60) and 3 months after surgery (n=14). The levels of the selected circulating miRNAs were measured with the miRCURY LNA miRNA PCR system and fold changes were calculated using the standard ∆∆Cq method. DIANA-miRPath analysis was used to evaluate the role of significantly deregulated miRNAs. The results indicated significant upregulation of miR-155-5p, miR-21-5p and miR-191-5p, and downregulation of miR-16-5p directly after the surgery. In paired follow-up samples, the most significant upregulation was detected for miR-106a-5p and miR-16-5p, and the most significant downregulation was for miR-21-5p. Pathway analysis outlined the role of the differentially expressed miRNAs in cancer development, but the same pathways are also involved in wound healing and regeneration of intestinal epithelium. It may be suggested that these processes should also be considered in studies investigating sensitive and easily detectable circulating biomarkers for recurrence in patients.

Overexpression of small nucleolar RNA SNORD1C is associated with unfavorable outcome in colorectal cancer

Colorectal cancer (CRC) is the second most incident cancer and third leading cause of cancer-related mortality worldwide. Small nucleolar RNAs (snoRNAs) are small non-coding RNAs located in the nucleoli of cells, and play key roles in multiple cancers. However, the role of serum snoRNAs in CRC remains unknown. We analyzed the expression of the snoRNA SNORD1C in the serum of patients with CRC using quantitative real-time polymerase chain reaction (qRT-PCR) (n = 122). The receiver operating characteristic (ROC) curves were estimated, and the area under the ROC curve (AUC) was calculated. Gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) analysis of co-expressed genes was performed using the database for annotation, visualization, and integrated discovery (DAVID), and visualized by R language. The results showed that the expression of SNORD1C in patients with CRC (n = 122) was significantly higher than that in normal individuals (n = 50) and patients with benign colorectal disease (n = 33) (P < 0.05). The overexpression of serum SNORD1C was related to poor tissue differentiation and high carcinoembryonic antigen (CEA) levels (P < 0.05). In the ROC curve analysis, SNORD1C serum expression combined with CEA offered better predictive value for the diagnosis of CRC (AUC = 0.838) compared with SNORD1C (AUC = 0.748) or CEA (AUC = 0.715) alone. High expression of SNORD1C was found to be closely associated with prognosis and unfavorable outcomes in patient with CRC. Therefore, serum SNORD1C may be a noninvasive tumor biomarker for diagnosis of CRC.

The miR-200 Family of microRNAs: Fine Tuners of Epithelial-Mesenchymal Transition and Circulating Cancer Biomarkers

The miR-200 family of microRNAs (miRNAs) includes miR-200a, miR-200b, miR-200c, miR-141 and miR-429, five evolutionarily conserved miRNAs that are encoded in two clusters of hairpin precursors located on human chromosome 1 (miR-200b, miR-200a and miR-429) and chromosome 12 (miR-200c and miR-141). The mature -3p products of the precursors are abundantly expressed in epithelial cells, where they contribute to maintaining the epithelial phenotype by repressing expression of factors that favor the process of epithelial-to-mesenchymal transition (EMT), a key hallmark of oncogenic transformation. Extensive studies of the expression and interactions of these miRNAs with cell signaling pathways indicate that they can exert both tumor suppressor- and pro-metastatic functions, and may serve as biomarkers of epithelial cancers. This review provides a summary of the role of miR-200 family members in EMT, factors that regulate their expression, and important targets for miR-200-mediated repression that are involved in EMT. The second part of the review discusses the potential utility of circulating miR-200 family members as diagnostic/prognostic biomarkers for breast, colorectal, lung, ovarian, prostate and bladder cancers.

Colorectal cancer cell-derived extracellular vesicles transfer miR-221-3p to promote endothelial cell angiogenesis via targeting suppressor of cytokine signaling 3

BACKGROUND

Secreted microRNAs (miRNAs) can serve as promising diagnostic markers for colorectal cancer (CRC). Herein, we evaluated the potential clinical significance of a signature of four circulating serum-derived miRNAs in CRC. We also demonstrated that extracellular vesicles (EVs) containing miR-221-3p could facilitate endothelial cell angiogenesis.

METHODS

The expressions of four circulating serum-derived miRNAs (miR-19a-3p, miR-203-3p, miR-221-3p, and let-7f-5p) were measured by real-time quantitative PCR, and their associations with lymph node metastasis were determined in CRC patients. Receiver operating characteristic curve analysis was used to determine their diagnostic accuracy. EVs were isolated and characterized from the conditioned media of human CRC cells (HCT116 and Caco2). Cell proliferation, transwell migration, and tube formation assays were performed to investigate the pro-angiogenic effect of miR-221-3p transferred by CRC-EVs into the endothelial cells. In silico analysis was used to show the regulatory functions of miR-221-3p on SOCS3, validated by luciferase and Western blotting assays.

RESULTS

The expression levels of serum-derived miR-19a-3p, miR-203-3p, miR-221-3p, and let-7f-5p were significantly higher in CRC than in healthy individuals. The expression of miR-19a-3p, miR-203-3p, and miR-221-3p were positively correlated with the lymph node metastasis status. Moreover, SOCS3 was identified as a direct target of miR-221-3p and the secreted miR-221-3p shuttled by CRC-EVs regulated STAT3/VEGFR-2 signaling axis by targeting SOCS3 in endothelial cells. CRC-EVs promoted endothelial cell proliferation, migration, and the formation of vessel-like structures. The proangiogenic effect of CRC-EVs on the cells was recapitulated by miR-221-3p overexpression, showing the importance of EVs-derived miR-221-3p in promoting endothelial cell angiogenesis.

CONCLUSION

We introduced a signature of four-circulating miRNAs (miR-19a-3p, miR-203-3p, miR-221-3p, and let-7f-5p) as a novel diagnostic biomarker for CRC. Besides, we revealed that miR-221-3p induces endothelial cell angiogenesis in vitro by targeting SOCS3.

The Immunomodulation Potential of Exosomes in Tumor Microenvironment

Exosomes are lipid bilayer particles that originated from almost all types of cells and play an important role in intercellular communication. Tumor-derived exosomes contain large amounts of noncoding RNA, DNA, and proteins, which can be transferred into recipient cells as functional components in exosomes. These exosomal functional constituents depend on the originating cells, and it has been proved that types and numbers of exosomal components differ in cancer patients and healthy individuals. This review summarizes the role of tumor-derived exosomes in immunomodulation and discusses the application of exosomes in immunotherapy in cancers. Overall, exosomes isolated from cancer cells are turned out to promote immune evasion and interfere with immune responses in tumors through inducing apoptosis of CD8+ T cells, facilitating generation of Tregs, suppressing natural killer (NK) cell cytotoxicity, inhibiting maturation and differentiation of monocyte, and enhancing suppressive function of myeloid-derived suppressor cells (MDSCs). Mechanistically, exosomal functional components play a significant role in the immunomodulation in cancers. Moreover, based on the existing studies, exosomes could potentially serve as therapeutic delivery vehicles, noninvasive biomarkers, and immunotherapeutic vaccines for various types of cancers.

Identification of colorectal cancer associated biomarkers: an integrated analysis of miRNA expression

Colorectal cancer is one of the leading causes of cancer-related deaths worldwide. This complex disease still holds severe problems concerning diagnosis due to the high invasiveness nature of colonoscopy and the low accuracy of the alternative diagnostic methods. Additionally, patient heterogeneity even within the same stage is not properly reflected in the current stratification system. This scenario highlights the need for new biomarkers to improve non-invasive screenings and clinical management of patients. MicroRNAs (miRNAs) have emerged as good candidate biomarkers in cancer as they are stable molecules, easily measurable and detected in body fluids thus allowing for non-invasive diagnosis and/or prognosis. In this study, we performed an integrated analysis first using 4 different datasets (discovery cohorts) to identify miRNAs associated with colorectal cancer development, unveil their role in this disease by identifying putative targets and regulatory networks and investigate their ability to serve as biomarkers. We have identified 26 differentially expressed miRNAs which interact with frequently deregulated genes known to participate in commonly altered pathways in colorectal cancer. Most of these miRNAs have high diagnostic power, and their prognostic potential is evidenced by panels of 5 miRNAs able to predict the outcome of stage II and III colorectal cancer patients. Notably, 8 miRNAs were validated in three additional independent cohorts (validation cohorts) including a plasma cohort thus reinforcing the value of miRNAs as non-invasive biomarkers.

MicroRNAs in blood act as biomarkers of colorectal cancer and indicate potential therapeutic targets

Association studies have linked alterations of blood-derived microRNAs (miRNAs) with colorectal cancer (CRC). Here, we performed a microarray-based comparison of the profiles of 2549 miRNAs in 80 blood samples from healthy donors and patients with colorectal adenomas, colorectal diverticulitis and CRC at different stages. Confirmation by quantitative real-time PCR (RT-PCR) was complemented by validation of identified molecules in another 36 blood samples. No variations in miRNA levels were observed in samples from patients with colorectal adenomas and diverticulitis or from healthy donors. However, there were 179 CRC-associated miRNAs of differential abundance compared to healthy controls. Only three - miR-1225-5p, miR-1207-5p and miR-4459 - exhibited increased levels at all CRC stages. Most deregulated miRNAs (128/179, 71%) specifically predicted metastatic CRC. Pathway analysis found several cancer-related pathways to which the miRNAs contribute in various ways. In conclusion, miRNA levels in blood vary throughout CRC progression and affect cellular functions relevant to haematogenous CRC progression and dissemination. The identified biomarker and therapeutic candidates require further confirmation of their clinical relevance.

A systematic approach introduced novel targets in rectal cancer by considering miRNA/mRNA interactions in response to radiotherapy

BACKGROUND

The discovery of miRNA/mRNA interactions in several biological samples prompted the researchers to explore new biomarkers in tumors.

OBJECTIVE

We aimed to investigate the interactions of miRNA/mRNA in response to radiotherapy in the plasma samples of rectal cancer patients.

METHODS

Five microarray datasets related to cancerous and non-cancerous individuals were first used to construct networks. The databases of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were applied to analyze pathway enrichment. The plasma samples were then collected from 55 patients with recently diagnosed rectal cancer and 10 healthy subjects. For radiotherapy courses, the patients have consecutively received 30 sessions of local radiation for six weeks. At last, the expression of selected genes and miRNAs was experimentally measured before and after radiotherapy by qPCR, and the protein levels of the target genes were measured by ELISA assay. We evaluated the therapeutic responses based on the tumor regression grade of the Dworak classification.

RESULTS

We identified 5 up-regulated and 5 down-regulated miRNAs and 8 up-regulated and 3 down-regulated genes of the databases. There was a significant increase in tumor suppressor miRNAs, including miR-101-3p, miR-145-5p, miR-26a-5p, miR-34a-5p, and a significant decrease in oncomiRs, including miR-221-3p and miR-17-5p, after radiotherapy compared to the pre-treatment. Moreover, the up-regulated miR-17-5p and miR-221-5p and the down-regulated miR-101-3p and miR-145-5p were directly related to rectal cancer through the interaction with the Wnt, RAS, PI3K, and TGF-β signaling pathways. An analysis of receiver operating characteristics showed that miRNAs 221, 17, and 23 were response-related in locally advanced rectal cancer patients.

CONCLUSIONS

It seems that monitoring the miRNA/mRNA interactions during radiotherapy can be an appropriate diagnostic tool to track the recovery process and respond to standard therapies.

A Review of Colorectal Cancer in Terms of Epidemiology, Risk Factors, Development, Symptoms and Diagnosis

This review article contains a concise consideration of genetic and environmental risk factors for colorectal cancer. Known risk factors associated with colorectal cancer include familial and hereditary factors and lifestyle-related and ecological factors. Lifestyle factors are significant because of the potential for improving our understanding of the disease. Physical inactivity, obesity, smoking and alcohol consumption can also be addressed through therapeutic interventions. We also made efforts to systematize available literature and data on epidemiology, diagnosis, type and nature of symptoms and disease stages. Further study of colorectal cancer and progress made globally is crucial to inform future strategies in controlling the disease's burden through population-based preventative initiatives.

Association of UGT1A1*6 polymorphism with irinotecan-based chemotherapy reaction in colorectal cancer patients: a systematic review and a meta-analysis

Colorectal cancer (CRC) is a leading cause of cancer-related deaths across the world. Irinotecan (IRI) is commonly used to treat CRC, and IRI-based chemotherapy is linked with adverse reaction and the efficacy of the treatment regimen. The gene UGT1A1 plays a central role in the IRI metabolic pathway. A polymorphism UGT1A1*6 has been widely researched which may be related to response of IRI-based chemotherapy in CRC. All relevant studies were strictly searched from PubMed, Embase, Cochrane Library and Web of Science databases to explore the associations between UGT1A1*6 and response of IRI-based chemotherapy with CRC. Nine articles comprising 1652 patients were included in the final combination. Meta-analysis showed G allele or GG had a lower risk of severe late-onset diarrhea compared with A/AA in allele model and homozygote model (G vs. A: OR = 0.53, 95% CI: 0.28–0.99, P=0.05; GG vs. AA: OR = 0.48, 95% CI: 0.23–0.99, P=0.05), no significant association was observed in other models. In addition, a significant association between UGT1A1*6 and neutropenia was observed in all models (G vs. A: OR = 0.57, 95% CI: 0.46–0.71, P=0.00; GG vs. AA: OR = 0.28, 95% CI: 0.17–0.45, P=0.01; GA vs. AA: OR = 0.42, 95% CI: 0.26–0.70, P=0.00; GG+GA vs. AA: OR = 0.32, 95% CI: 0.20–0.52, P=0.00; GG vs. AA+GA: OR = 0.40, 95% CI: 0.22–0.71, P=0.00), whereas, no relationship was found between UGT1A1*6 and clinical response among the different genotypes. UGT1A1*6 may be considered as a biomarker for IRI-based chemotherapy in CRC.

Circulating miRNA as Biomarkers for Colorectal Cancer Diagnosis and Liver Metastasis

Colorectal cancer (CRC) is the second leading cause of cancer deaths worldwide. Stage IV CRC patients have poor prognosis with a five-year survival rate of 14%. Liver metastasis is the main cause of mortality in CRC patients. Since current screening tests have several drawbacks, effective stable non-invasive biomarkers such as microRNA (miRNA) are needed. We aim to investigate the expression of miRNA (miR-21, miR-19a, miR-23a, miR-29a, miR-145, miR-203, miR-155, miR-210, miR-31, and miR-345) in the plasma of 62 Lebanese Stage IV CRC patients and 44 healthy subjects using RT-qPCR, as well as to evaluate their potential for diagnosis of advanced CRC and its liver metastasis using the Receiver Operating Characteristics (ROC) curve. miR-21, miR-145, miR-203, miR-155, miR-210, miR-31, and miR-345 were significantly upregulated in the plasma of surgery naïve CRC patients when compared to healthy individuals. We identified two panels of miRNA that could be used for diagnosis of Stage IV CRC (miR-21 and miR-210) with an area under the curve (AUC) of 0.731 and diagnostic accuracy of 69% and liver metastasis (miR-210 and miR-203) with an AUC = 0.833 and diagnostic accuracy of 72%. Panels of specific circulating miRNA, which require further validation, could be potential non-invasive diagnostic biomarkers for CRC and liver metastasis.

Extracellular miRNAs as Predictive Biomarkers for Glypican-3-Derived Peptide Vaccine Therapy Response in Ovarian Clear Cell Carcinoma

Ovarian clear cell carcinoma (OCCC) has been treated with surgery and chemotherapy; however, the prognosis remains poor because of chemoresistance. Therefore, immunotherapies are attracting attention, including the GPC3 peptide vaccine, which improves overall survival. However, the response rate is limited and there are no sufficient predictive biomarkers that can identify responders before treatment. Our purpose was to identify circulating serum miRNAs as predictive biomarkers for response to GPC3 peptide vaccine. Eighty-four patients in a phase II trial of a GPC3 peptide vaccine were enrolled and miRNA sequencing was performed on their serum samples. Candidate miRNAs were selected from a group of 14 patients for whom treatment was responsive and validated in an independent group of 10 patients for whom treatment was responsive. Three markedly upregulated miRNAs, miR-375-3p, miR-193a-5p, and miR-1228-5p, were identified, and the combination of those miRNAs demonstrated high value in the prediction of the response. The origin of these miRNAs was assessed by referring to OCCC tissue miRNA profiles, and they were not identified as cancer tissue-related miRNAs. Functional annotation analysis suggested that they were associated with interferon-related pathways. The miRNAs identified herein have great potential to allow the realization of liquid biopsy for predicting the immunotherapy response and precision medicine.

Clinical Perspectives on Liquid Biopsy in Metastatic Colorectal Cancer

Liquid biopsy, which generally refers to the analysis of biological components such as circulating nuclear acids and circulating tumor cells in body fluids, particularly in peripheral blood, has shown good capacity to overcome several limitations faced by conventional tissue biopsies. Emerging evidence in recent decades has confirmed the promising role of liquid biopsy in the clinical management of various cancers, including colorectal cancer, which is one of the most prevalent cancers and the second leading cause of cancer-related deaths worldwide. Despite the challenges and poor clinical outcomes, patients with metastatic colorectal cancer can expect potential clinical benefits with liquid biopsy. Therefore, in this review, we focus on the clinical prospects of liquid biopsy in metastatic colorectal cancer, specifically with regard to the recently discovered various biomarkers identified on liquid biopsy. These biomarkers have been shown to be potentially useful in multiple aspects of metastatic colorectal cancer, such as auxiliary diagnosis of metastasis, prognosis prediction, and monitoring of therapy response.

Profiling microRNAs in uncomplicated pregnancies: Serum vs. plasma

Blood-derived microRNAs (miRNAs/miRs) are ideal clinical biomarkers, as they can be relatively non-invasively extracted and are stable across a range of storage conditions. However, the concentration and profile of miRNAs differ between specific patient groups and starting media, which must be a key consideration before embarking upon uses for clinical applications. The optimum blood-derived starting media for biomarker discovery involving pregnant women with an uncomplicated pregnancy has not been determined. Paired serum and plasma samples were collected from 10 pregnant women with uncomplicated low-risk pregnancies at three time points: i) During the second trimester of pregnancy; ii) during the third trimester; and iii) 6 weeks post-partum. Sample miRNA content was assessed using an Agilent Bioanalyzer Small RNA chip and reverse transcription-quantitative (RT-q)PCR using four constitutively expressed miRNAs: hsa-miR-222-3p, hsa-miR-23a, hsa-miR-30e-5p and hsa-miR-451a. Quality control spike-ins measured RNA extraction (UniSp2) and cDNA extraction (cel-miR-39-3p) efficiency. MiRNA concentration and percentage were significantly higher in the serum vs. plasma samples based on data obtained from the Bioanalyzer; however, RT-qPCR failed to replicate these differences in the majority of comparisons using the ΔCq values of the four constitutively expressed miRNAs. Using the standard deviations of the ΔCq values, the consistency of serum and plasma in terms of miRNA expression levels were equivalent. Thus, clinicians and researchers should take into consideration that different miRNA quantification methods can yield contrasting results with regards to the starting media utilized. Based on the equivalent performance of serum and plasma assessed using RT-qPCR, which is less likely to be influenced by the coagulation process or degraded long RNAs, both starting media assessed in the present study are equally suitable for ongoing biomarker discovery studies involving healthy pregnant women at any gestational time point or immediately postpartum.

LncRNA LINC00511 Acts as an Oncogene in Colorectal Cancer via Sponging miR-29c-3p to Upregulate NFIA

Background

Colorectal cancer (CRC), characterized by high mortality and incidence rate, is one of the most common types of rectum tumors in the gastrointestinal tract worldwide. An increasing number of investigations indicated that long noncoding RNAs (lncRNAs) have been implicated in the growth of a wide range of cancers. Although it has obtained general acceptance that lncRNA LINC00511 plays a significant role in numerous cancers, the regulatory mechanism of LINC00511 in CRC still needs to be explored.

Materials and Methods

Bioinformatics analysis and a wide range of experiments of sphere formation assay, cell proliferation assay, RT-qPCR, colony formation assay, Transwell assay and Western blot assays investigated the function and mechanism of LINC00511 in CRC tissues and cells.

Results

Our results manifested that the expression level of LINC00511 was obviously upregulated in CRC tissues and cells and it accelerated CRC development through facilitating cell proliferation, metastasis and stemness. Molecular mechanism exploration uncovered that LINC00511 acted as a ceRNA competing with NFIA to bind with miR-29c-3p. Through rescue experiments, we discovered that NFIA upregulation partly counteracted the inhibitive effect induced by LINC00511 silencing on CRC progression.

Conclusion

These results revealed that LINC00511 participated in the progression of CRC by targeting the LINC00511/miR-29c-3p/NFIA axis, indicating that LINC00511 may be a potential therapeutic target for CRC treatment.

The potential value of miRNA-223 as a diagnostic biomarker for Egyptian colorectal patients

OBJECTIVES

Colorectal cancer (CRC) is the third lethal malignancy worldwide. Dysregulation of microRNAs (miRNAs) mediates several growth factors signaling pathways and induces abnormal genes expression, which leads to colorectal carcinogenesis. We aimed to comprehensively assess the expression of miRNA-200c, miRNA-203a, miRNA-223 in Egyptian CRC tissue and their corresponding serum samples and to explore if they have any potential prognostic or diagnostic value for CRC patients.

METHODS

A total of 195 subjects (120 CRC patients and 75 healthy controls) participated in exploration and validation sets. The relative expression of miRNA-200c, miRNA-203a, and miRNA-223 was measured in both CRC tissue and serum samples, and the expressed miRNAs were compared in different CRC grades and types and the prognostic value was evaluated.

RESULTS

The expression levels of miRNA-200c and miRNA-203a were reduced in CRC tissue samples than adjacent noncancerous tissues. miRNA-223 level was significantly upregulated in both CRC tissue and serum samples with a positive association between them (r = 0.85, P = 0.001). The miRNA-223 can effectively discriminate CRC patients from controls and can significantly differentiate between colon and rectal cancer patients. The association between serum miRNA-223 expression and CRC development was validated in the second set and the ROC curve showed highly significant prognostic value with 90.1% sensitivity, 87% specificity, and area under the curve of 0.914 (95% confidence interval: 0.830-0.978, P = 0.0001). These results showed the association between miRNA-223 upregulation and the CRC carcinogenesis.

CONCLUSION

Circulating miRNA-223 can be a potential noninvasive prognostic biomarker for Egyptian CRC patients.

miR-96-5p, miR-134-5p, miR-181b-5p and miR-200b-3p heterogenous expression in sites of prostate cancer versus benign prostate hyperplasia-archival samples study

MicroRNAs are involved in various pathologies including cancer. The aim of the study was to assess the level of expression of miR-96-5p, -134-5p, -181b-5p, -200b-3p in FFPE samples of prostate cancer, adjacent cancer-free tissue, and benign prostatic hyperplasia. Samples of 23 FFPE prostate cancer and 22 benign prostatic hyperplasias were dissected and HE stained. Compartments of tumor tissue and adjacent healthy glandular tissue were isolated from each sample using Laser Capture Microdissection. Total RNA was isolated from dissected tissues. Expression of miR-96-5p, miR-134-5p, 181b-5p, and miR-200b-3p was determined by real-time RT-qPCR method. The expression of miR-200b-3p was significantly higher in cancerous prostate: both in adenocarcinomatous glands and in the adjacent, apparently unaffected glands compared to BPH samples. The expression of miR-181b-5p was lower in in both prostate cancer tissues and adjacent tissue compared to BPH samples. Expression of miR-96-5p and miR-134-5p was lower in prostate cancer tissues compared to BPH. Levels of miR-96-5p, miR-134-5p, and 181b-5p negatively correlated with the Gleason score. Given further studies, miR-96-5p, miR-134-5p and especially miR-200b-3p and miR-181b-5p may differentiate BPH and PC.

Updates on "Cancer Genomics and Epigenomics"

The field of "Cancer Genomics and Epigenomes" has been widely investigated for their involvement in cancer to understand the basic processes of different malignancies. The aggregation of genetic and epigenetic alterations also displays a wide range of heterogeneity making it quite necessary to develop personalized treatment strategies. The complex interplay between DNA methylation and chromatin dynamics in malignant cells is one of the major epigenetic mechanisms that lead to gene activation and repression. Hence, each tumor needs to be fully characterized to satisfy the ideas of personalized treatment strategies. The present article addresses various aspects of genome characterization methods and their potential role in the field of cancer genomics and epigenomics.

MiR-196: emerging of a new potential therapeutic target and biomarker in colorectal cancer

Deregulation of microRNAs, as key elements in colorectal cancer (CRC) pathogenesis, is correlated with various stages of this cancer. miR-196 is involved in the initiation and progression of a verity of malignances, especially CRC. miR-196 in CRC cells could target different types of genes with oncogenic and/or tumor suppressor function such as HOX genes, GATA6, SOCS1, SOCS3, ANXA1, DFFA, PDCD4, ZG16 and ING5. Therefore, these genes could be up or down-regulated in cells and subsequently change the capacity of CRC cells in terms of tumor development, progression and, response to therapy. Comprehension of miR-196-associated aberrations underlying the CRC pathogenesis might introduce promising targets for therapy. Additionally, it seems that miR-196 expression profiling, especially circulatory exosomal miR-196, might be useful for diagnosis and prognosis determination of the CRC patients. In this review, at first, we summarize the roles of miR-196 in different types of cancers. After that, a detailed discussion about this miRNA and also their targets in CRC pathogenesis, progression, and response to treatment are represented. Moreover, we highlight the potential utilization of miR-196 and its targets as therapeutic targets and novel biomarkers in early detection and prediction of prognosis in CRC patients.

Investigating potential molecular mechanisms of serum exosomal miRNAs in colorectal cancer based on bioinformatics analysis

Colorectal cancer (CRC) is the most common malignant gastrointestinal tumor worldwide. Serum exosomal microRNAs (miRNAs) play a critical role in tumor progression and metastasis. However, the underlying molecular mechanisms are poorly understood.The miRNAs expression profile (GSE39833) was downloaded from Gene Expression Omnibus (GEO) database. GEO2R was applied to screen the differentially expressed miRNAs (DEmiRNAs) between healthy and CRC serum exosome samples. The target genes of DEmiRNAs were predicted by starBase v3.0 online tool. The gene ontology (GO) and Kyoto Encyclopedia of Genomes pathway (KEGG) enrichment analysis were performed using the Database for Annotation, Visualization and Integrated Discovery (DAVID) online tool. The protein-protein interaction (PPI) network was established by the Search Tool for the Retrieval of Interacting Genes (STRING) visualized using Cytoscape software. Molecular Complex Detection (MCODE) and cytohubba plug-in were used to screen hub genes and gene modules.In total, 102 DEmiRNAs were identified including 67 upregulated and 35 downregulated DEmiRNAs, and 1437 target genes were predicted. GO analysis showed target genes of upregulated DEmiRNAs were significantly enriched in transcription regulation, protein binding, and ubiquitin protein ligase activity. While the target genes of downregulated DEmiRNAs were mainly involved in transcription from RNA polymerase II promoter, SMAD binding, and DNA binding. The KEGG pathway enrichment analyses showed target genes of upregulated DEmiRNAs were significantly enriched in proteoglycans in cancer, microRNAs in cancer, and phosphatidylinositol-3 kinases/Akt (PI3K-Akt) signaling pathway, while target genes of downregulated DEmiRNAs were mainly enriched in transforming growth factor-beta (TGF-beta) signaling pathway and proteoglycans in cancer. The genes of the top 3 modules were mainly enriched in ubiquitin mediated proteolysis, spliceosome, and mRNA surveillance pathway. According to the cytohubba plugin, 37 hub genes were selected, and 4 hub genes including phosphoinositide-3-kinase regulatory subunit 1 (PIK3R1), SRC, cell division cycle 42 (CDC42), E1A binding protein p300 (EP300) were identified by combining 8 ranked methods of cytohubba.The study provides a comprehensive analysis of exosomal DEmiRNAs and target genes regulatory network in CRC, which can better understand the roles of exosomal miRNAs in the development of CRC. However, these findings require further experimental validation in future studies.

An Overview of Promising Biomarkers in Cancer Screening and Detection

Applications of biomarkers have been proved in oncology screening, diagnosis, predicting response to treatment as well as monitoring the progress of the disease. Considering the crucial role played by them during different disease stages, it is extremely important to evaluate, validate, and assess them to incorporate them into routine clinical care. In this review, the role of few most promising and successfully used biomarkers in cancer detection, i.e. PD-L1, E-Cadherin, TP53, Exosomes, cfDNA, EGFR, mTOR with regard to their structure, mode of action, and reports signifying their pathological significance, are addressed. Also, an overview of some successfully used biomarkers for cancer medicine has been presented. The study also summarizes biomarker-driven personalized cancer therapy i.e., approved targets and indications, as per the US FDA. The review also highlights the increasingly prominent role of biomarkers in drug development at all stages, with particular reference to clinical trials. The increasing utility of biomarkers in clinical trials is clearly evident from the trend shown, wherein ~55 percent of all oncology clinical trials in 2019 were seen to involve biomarkers, as opposed to ~ 15 percent in 2001, which clearly proves the essence and applicability of biomarkers for synergizing clinical information with tumor progression. Still, there are significant challenges in the implementation of these possibilities with strong evidence in cost-- effective manner.

A panel of six-circulating miRNA signature in serum and its potential diagnostic value in colorectal cancer

AIM

Colorectal carcinoma (CRC) is one of the most prevalent cancers throughout the world. Circulating serum-derived microRNAs (miRNAs, miRs) can be used as non-invasive biomarkers for CRC diagnosis. This study aimed to identify a panel of six serum exosomal miRNAs as novel diagnostic biomarkers for CRC.

MAIN METHODS

Exosomes were isolated and characterized from the conditioned media of the human colon adenocarcinoma cells (HCT-116 and Caco2). Sera were isolated from peripheral blood of 45 CRC and also 45 healthy individuals. The expression levels and diagnostic value of candidate circulating miRNAs (miR-19a, miR-20a, miR-150, miR-143, miR-145, and let-7a) were measured through quantitative real-time PCR. Receiver operating characteristic (ROC) curves were applied to evaluate the diagnostic accuracy of selected miRNAs. The association of candidate miRNAs and clinicopathological characteristics e.g. tumor node metastasis (TNM) staging and lymph node metastasis (LNM) were further evaluated.

KEY FINDINGS

Circulating serum miR-19a, miR-20a, miR-150, and let-7a were significantly up-regulated in CRC patients, while miR-143 and miR-145 showed a significant down-regulation. The higher levels of miR-143 and miR-145 in patients with TNM stage I-II were detected, whereas miR-19a, miR-20a, miR-150, and let-7a were highly expressed in TNM stage III. The expression levels of miR-19a, miR-20a, and miR-150 were positively correlated with LNM status, while the expression levels of miR-143 and miR-145 were lower in patients with LNM. Area under the ROC curves of miR-19a, miR-20a, miR-150, miR-143, miR-145, and let-7a were 0.87, 0.83, 0.75, 0.76, 0.78 and 0.71, respectively.

SIGNIFICANCE

We established a panel of six-circulating miRNA signature (i.e. miR-19a, miR-20a, miR-143, miR-145, miR-150, and let-7a) in serum as a non-invasive biomarker for CRC diagnosis. These findings confirm that serum-derived miRNAs have a strong potential to be a diagnostic biomarker for patients with CRC.

Biomarkers in Colorectal Cancer: Current Research and Future Prospects

Colorectal cancer (CRC) is a leading cause of death worldwide, despite progress made in detection and management through surgery, chemotherapy, radiotherapy, and immunotherapy. Novel therapeutic agents have improved survival in both the adjuvant and advanced disease settings, albeit with an increased risk of toxicity and cost. However, metastatic disease continues to have a poor long-term prognosis and significant challenges remain due to late stage diagnosis and treatment failure. Biomarkers are a key tool in early detection, prognostication, survival, and predicting treatment response. The past three decades have seen advances in genomics and molecular pathology of cancer biomarkers, allowing for greater individualization of therapy with a positive impact on survival outcomes. Clinically useful predictive biomarkers aid clinical decision making, such as the presence of KRAS gene mutations predicting benefit from epidermal growth factor receptor (EGFR) inhibiting antibodies. However, few biomarkers have been translated into clinical practice highlighting the need for further investigation. We review a range of protein, DNA and RNA-based biomarkers under investigation for diagnostic, predictive, and prognostic properties for CRC. In particular, long non-coding RNAs (lncRNA), have been investigated as biomarkers in a range of cancers including colorectal cancer. Specifically, we evaluate the potential role of lncRNA plasmacytoma variant translocation 1 (PVT1), an oncogene, as a diagnostic, prognostic, and therapeutic biomarker in colorectal cancer.

Roles of miRNAs in Colorectal Cancer: Therapeutic Implications and Clinical Opportunities

Colorectal cancer (CRC) is one of the most disseminated diseases across the globe engaging the digestive system. Various therapeutic methods from traditional to the state-of-the-art ones have been applied in CRC patients, however, the attempts have been unfortunate to lead to a definite cure. MiRNAs are a smart group of non-coding RNAs having the capabilities of regulating and controlling coding genes. By utilizing this stock-in-trade biomolecules, not only disease’s symptoms can be eliminated, there may also be a good chance for the complete cure of the disease in the near future. Herein, we provide a comprehensive review delineating the therapeutic relationship between miRNAs and CRC. To this, various clinical aspects of miRNAs which act as a tumor suppressor and/or an oncogene, their underlying cellular processes and clinical outcomes, and, in particular, their effects and expression level changes in patients treated with chemo- and radiotherapy are discussed. Finally, based on the results deducted from scientific research studies, therapeutic opportunities based on targeting/utilizing miRNAs in the preclinical as well as clinical settings are highlighted.

Altered miRNAs Expression Correlates With Gastroenteropancreatic Neuroendocrine Tumors Grades

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are rare and heterogeneous tumors that present a wide spectrum of different clinical and biological characteristics. Currently, tumor grading, determined by Ki-67 staining and mitotic counts, represents the most reliable predictor of prognosis. This time-consuming approach fails to reach high reproducibility standards thus requiring novel approaches to support histological evaluation and prognosis. In this study, starting from a microarray analysis of paraffin-embedded tissue specimens, we defined the miRNAs signature for poorly differentiated NETs (G3) compared to well-differentiated NETs (G1 and G2) consisting of 56 deregulated miRNAs. We identified 8 miRNAs that were expressed in all GEP-NETs grades but at different level. Among these miRNAs, miR-96-5p expression level was progressively higher from grade 1 to grade 3; inversely, its target FoxO1 expression decreased from grade 1 to grade 3. Our results reveal that the miRNAs expression profile of GEP-NET is correlated with the tumor grade, showing a potential advantage of miRNA quantification that could aid clinicians in the classification of common GEP-NETs subtypes. These findings could reliably support the histological evaluation of GEP-NETs paving the way toward personalized treatment approaches.

Tumor-Derived Exosomes in Immunosuppression and Immunotherapy

Tumor-derived exosomes (TEX) are involved in cancer development, metastasis, and disease progression. They can modulate angiogenesis to elevate the malignant degree of tumor cells. TEX carry immunosuppressive factors affecting the antitumor activities of immune cells. Tumor cells as well as immune cells secrete immunologically active exosomes which affect intercellular communication, antigen presentation, activation of immune cells, and immune surveillance. Cell proliferation and immune response suppression create a favorable microenvironment for tumor. TEX can inhibit immune cell proliferation, induce apoptosis of activated CD8+ Teffs, suppress NK cell activity, interfere with monocyte differentiation, and promote Treg as well as MDSC expansion. Exosomes of microenvironment cells may also contribute to the development of drug resistance in cancer therapy. An important role of TEX in modulating the sensitivity of tumor cells to immunotherapy is a promising area of research to make the cancer therapy more successful.

Daphnane Diterpenoids from Daphne genkwa Inhibit PI3K/Akt/mTOR Signaling and Induce Cell Cycle Arrest and Apoptosis in Human Colon Cancer Cells

Seven new daphnane-type diterpenoids, daphgenkins A-G (1-7), and 15 known analogues (8-22) were isolated from the flower buds of Daphne genkwa. Their structures and absolute configurations were elucidated by spectroscopic data and calculated ECD analyses. The cytotoxicities of all daphnane-type diterpenoids (1-22) obtained were evaluated against three human colon cancer cell lines (SW620, RKO, and LoVo). Compounds 1, 12, and 13 exhibited cytotoxic effects against the SW620 and RKO cell lines, with IC₅₀ values in the range of 3.0-9.7 μM. The most active new compound, 1, with an IC₅₀ value of 3.0 μM against SW620 cells, was evaluated further for its underlying molecular mechanism. Compound 1 induced G₀/G₁ cell cycle arrest, leading to the induction of apoptosis in SW620 cells. Also, it induced cancer cell apoptosis by an increased ratio of Bax/Bcl-2, activated cleaved caspase-3 and caspase-9, and upregulated PARP. Finally, compound 1 significantly inhibited PI3K/Akt/mTOR signaling in SW620 cells. Together, the results suggest that compound 1 may be a suitable lead compound for further biological evaluation.

Current and New Predictors for Treatment Response in Metastatic Colorectal Cancer. The Role of Circulating miRNAs as Biomarkers

Colorectal cancer (CRC) is the third most frequently diagnosed cancer in the world. More than half of all CRC patients will eventually develop metastases and require treatment accordingly, but few validated predictive factors for response to systemic treatments exist. In order to ascertain which patients benefit from specific treatments, there is a strong need for new and reliable biomarkers. We conducted a comprehensive search using the PUBMED database, up to December 2019, in order to identify relevant studies on predictive biomarkers for treatment response in metastatic CRC. We will herein present the currently used and potential biomarkers for treatment response and bring up-to-date knowledge on the role of circulating microRNAs, associated with chemotherapy and targeted therapy regimens used in metastatic CRC treatment. Molecular, tumor-related, disease-related, clinical, and laboratory predictive markers for treatment response were identified, mostly proposed, with few validated. Several circulating microRNAs have already proven their role of prediction for treatment response in CRC, but future clinical studies are needed to confirm their role as biomarkers across large cohorts of patients.

Perspectives of the Application of Liquid Biopsy in Colorectal Cancer

Colorectal cancer (CRC) is one of the most common gastrointestinal tumors and the second leading cause of cancer death worldwide. Since traditional biopsies are invasive and do not reflect tumor heterogeneity or monitor the dynamic progression of tumors, there is an urgent need for new noninvasive methods that can supplement and improve the current management strategies of CRC. Blood-based liquid biopsies are a promising noninvasive biomarker that can detect disease early, assist in staging, monitor treatment responses, and predict relapse and metastasis. Over time, an increasing number of experiments have indicated the clinical utility of liquid biopsies in CRC. In this review, we mainly focus on the development of circulating tumor cells and circulating tumor DNA as key components of liquid biopsies in CRC and introduce the potential of exosomal microRNAs as emerging liquid biopsy markers in clinical application for CRC.