Objective:The main objective of this study was to investigate the potential use of circulating microRNAs (miRNAs) as biomarkers of colorectal (CR) adenomas.Background:Detection of precancerous lesions such as CR adenoma is a key to reduce CR cancer (CRC) mortality. There is a great need for accurate

A plasma microRNA panel for detection of colorectal adenomas: a step toward more precise screening for colorectal cancer.

Secreted microRNAs (miRNAs) enclosed within extracellular vesicles (EVs) play a pivotal role in intercellular communication by regulating recipient cell gene expression and affecting target cell function. Here, we report the isolation of three distinct EV subtypes from the human colon carcinoma cell line LIM1863 – shed microvesicles (sMVs) and two exosome populations (immunoaffinity isolated A33-exosomes and EpCAM-exosomes). Deep sequencing of miRNA libraries prepared from parental LIM1863 cells/derived EV subtype RNA yielded 254 miRNA identifications, of which 63 are selectively enriched in the EVs - miR-19a/b-3p, miR-378a/c/d, and miR-577 and members of the let-7 and miR-8 families being the most prominent. Let-7a-3p*, let-7f-1-3p*, miR-451a, miR-574-5p*, miR-4454 and miR-7641 are common to all EV subtypes, and 6 miRNAs (miR-320a/b/c/d, miR-221-3p, and miR-200c-3p) discern LIM1863 exosomes from sMVs; miR-98-5p was selectively represented only in sMVs. Notably, A33-Exos contained the largest number (32) of exclusively-enriched miRNAs; 14 of these miRNAs have not been reported in the context of CRC tissue/biofluid analyses and warrant further examination as potential diagnostic markers of CRC. Surprisingly, miRNA passenger strands (star miRNAs) for miR-3613-3p*, -362-3p*, -625-3p*, -6842-3p* were the dominant strand in A33-Exos, the converse to that observed in parental cells. This finding suggests miRNA biogenesis may be interlinked with endosomal/exosomal processing.

/pdf/deep-sequencing-of-rna-from-three-different-extracellular-57mu7v9v2v.pdf

Deep Sequencing of RNA from Three Different Extracellular Vesicle (EV) Subtypes Released from the Human LIM1863 Colon Cancer Cell Line Uncovers Distinct Mirna-Enrichment Signatures

The most important biological function of exosomes is their possible use as biomarkers in clinical diagnosis. Compared with biomarkers identified in conventional specimens such as serum or urine, exosomal biomarkers provide the highest amount of sensitivity and specificity, which can be attributed to their excellent stability. Exosomes, which harbor different types of proteins, nucleic acids and lipids, are present in almost all bodily fluids. The molecular constituents of exosomes, especially exosomal proteins and microRNAs (miRNAs), are promising as biomarkers in clinical diagnosis. This discovery that exosomes also contain messenger RNAs and miRNAs shows that they could be carriers of genetic information. Although the majority of RNAs found in exosomes are degraded RNA fragments with a length of <200 nucleotides, some full-length RNAs might be present that may affect protein production in the recipient cell. In addition, exosomal miRNAs have been found to be associated with certain diseases. Several studies have pointed out miRNA contents of circulating exosomes that are similar to those of originating cancer cells. In this review, the recent advances in circulating exosomal miRNAs as biomarkers in gastrointestinal cancers are discussed. These studies indicated that miRNAs can be detected in exosomes isolated from body fluids such as saliva, which suggests potential advantages of using exosomal miRNAs as noninvasive novel biomarkers.

Circulating exosomes and exosomal microRNAs as biomarkers in gastrointestinal cancer.

Colorectal cancer (CRC) is a major worldwide health problem due to its high prevalence and mortality rate. T-cell intracellular antigen 1 (TIA1) is an important tumor suppressor involved in many aspects of carcinogenesis and cancer development. How TIA1 expression is regulated during CRC development remains to be carefully elucidated. In CRC tissue sample pairs, TIA1 protein and mRNA levels were monitored by Western blot and qRT-PCR, respectively. Combining meta-analysis and miRNA target prediction software, we could predict microRNAs that targeted TIA1. Next, three CRC cell lines (SW480, Caco2 and HT29) were used to demonstrate the direct targeting of TIA1 by miR-19a. In addition, we investigated the biological effects of TIA1 inhibition by miR-19a both in vitro by CCK-8, EdU, Transwell, Ki67 immunofluorescence and Colony formation assays and in vivo by a xenograft mice model. In colorectal cancer (CRC), we found that TIA1 protein, but not its mRNA, was downregulated. We predicted that TIA1 was a target of miR-19a and validated that miR-19a binded directly to the 3’-UTR of TIA1 mRNA. miR-19a could promote cell proliferation and migration in CRC cells and accelerated tumor growth in xenograft mice by targeting TIA1. This study highlights an oncomiR role for miR-19a in regulating TIA1 in CRC and suggests that miR-19a may be a novel molecular therapeutic target for CRC.

/pdf/mir-19a-promotes-colorectal-cancer-proliferation-and-1orrur6p4w.pdf

miR-19a promotes colorectal cancer proliferation and migration by targeting TIA1.

Circulating miR-378 in plasma: a reliable, haemolysis-independent biomarker for colorectal cancer

/pdf/circulating-mir-378-in-plasma-a-reliable-haemolysis-1nagnvq3o1.pdf

The discovery of microRNA, a group of regulatory short RNA fragments, has added a new dimension to the diagnosis and management of neoplastic diseases. Differential expression of microRNA in a unique pattern in a wide range of tumor types enables researches to develop a microRNA-based assay for source identification of metastatic disease of unknown origin. This is just one example of many microRNA-based cancer diagnostic and prognostic assays in various phases of clinical research. Since colorectal cancer (CRC) is a phenotypic expression of multiple molecular pathways including chromosomal instability (CIN), micro-satellite instability (MIS) and CpG islands promoter hypermethylation (CIMP), there is no one-unique pattern of microRNA expression expected in this disease and indeed, there are multiple reports published, describing different patterns of microRNA expression in CRC. The scope of this manuscript is to provide a comprehensive review of the scientific literature describing the dysregulation of and the potential role for microRNA in the management of CRC. A Pubmed search was conducted using the following MeSH terms, "microRNA" and "colorectal cancer". Of the 493 publications screened, there were 57 papers describing dysregulation of microRNA in CRC.

/pdf/the-diagnostic-and-prognostic-role-of-microrna-in-colorectal-2eplb16qiy.pdf

The Diagnostic and Prognostic Role of microRNA in Colorectal Cancer - a Comprehensive review

The first case of anorectal malignant melanoma (ARMM) was reported by Moore in 1857. Anorectal malignant melanoma is an extremely rare malignancy and represents only 0.05% of all malignant colorectal neoplasms and 0.5% to 4.6% of all malignant anorectal cancers that have been described. Up to 67% of patients are found to have distant metastases at the time of initial presentation, which is associated with extremely poor prognosis and median overall survival between 8.0 and 18.6 months. A large series analyzing 85,000 patients with melanoma showed that mucocutaneous melanoma was found in 1.3% only and 24% of these were ARMMs. Highly experienced cancer centers generally treat no

https://www.journalacs.org/article/S1072-7515(13)00229-9/pdf

Anorectal Malignant Melanoma: Extensive 45-Year Review and Proposal for a Novel Staging Classification

Peritoneal surface malignancy (PSM) is a frequent occurrence in the natural history of colorectal cancer (CRC). Although significant advances have been made in screening of CRC, similar progress has yet to be made in the early detection of PSM of colorectal cancer origin. The fact that advanced CRC can be confined to the peritoneal surface without distant dissemination forms the basis for aggressive multi-modality therapy consisting of cytoreductive surgery (CRS) plus hyperthermic intra-peritoneal chemotherapy (HIPEC), and neoadjuvant and/or adjuvant systemic therapy. Reported overall survival with complete CRS+HIPEC exceeds that of systemic therapy alone for the treatment of PSM from CRC, underscoring the advantage of this multi-modality therapeutic approach. Patients with limited peritoneal disease from CRC can undergo complete cytoreduction, which is associated with the best reported outcomes. As early or limited peritoneal carcinomatosis is undetectable by conventional imaging modalities, second look laparotomy is an important means to identify disease in high-risk patients at a stage most amenable to complete cytoreduction. This review focuses on the identification of patients at risk for PSM from CRC and discusses the role of second look laparotomy.

/pdf/patients-at-risk-for-peritoneal-surface-malignancy-of-4roe3vn899.pdf

Patients at Risk for Peritoneal Surface Malignancy of Colorectal Cancer Origin: The Role of Second Look Laparotomy

Peritoneal surface malignancy (PSM) is a heterogeneous form of cancer. A paradigm shift has occurred in the past 50 years; operative intervention in selected patients with limited peritoneal carcinomatosis (PC) is now undertaken with curative intent. Approximately 150,000 patients are diagnosed with colorectal cancer (CRC) in 2012 in the USA and one third die from the disease each year. Approximately 8,000 patients in the USA are diagnosed with synchronous PSM; 8 % with CRC have synchronous peritoneal spread of disease at time of primary resection, and up to 25 % of patients with recurrent CRC have disease confined to the peritoneal cavity. In about 30 %, PSM is the main reason for death in CRC patients, and only ~50 % of patients who develop PSM from CRC may have curative treatment by an R0 resection. The multimodal treatment approach for carefully selected patients with good performance status and limited PC consists of cytoreductive surgery (CRS), followed by hyperthermic intraperitoneal chemotherapy (HIPEC). This treatment approach represents a formidable challenge for patients and surgeons alike, as well as members of the multidisciplinary health-care team. In patients undergoing CRS + HIPEC technique not the only aim; a much broader, holistic view of care is imperative. Such an approach is emphasized in this chapter.

Avital Itzhak

Papers

The Diagnostic and Prognostic Role of microRNA in Colorectal Cancer - a Comprehensive review

Anorectal Malignant Melanoma: Extensive 45-Year Review and Proposal for a Novel Staging Classification

Patients at Risk for Peritoneal Surface Malignancy of Colorectal Cancer Origin: The Role of Second Look Laparotomy

Carcinomatosis: Cytoreduction and Heated Intraperitoneal Chemotherapy (HIPEC) Versus Palliation