The Role of Neuropilin-2 in the Epithelial to Mesenchymal Transition of Colorectal Cancer: A Systematic Review

Neuropilin-2 (NRP-2) expression has been found in various investigations on the expression and function of NRP-2 in colorectal cancer. The link between NRP-2 and colorectal cancer, as well as the mechanism that regulates it, is still mostly unclear. This systematic review was carried out according to the Cochrane guidelines for systematic reviews. We searched PubMed, Embase®, MEDLINE, Allied & Complementary MedicineTM, Medical Toxicology & Environmental Health, DH-DATA: Health Administration for articles published before 1 October 2021. The following search terms were used: “neuropilin-2” “neuropilin 2”, “NRP2” and “NRP-2”, “colorectal cancer”, “colon cancer”. Ten articles researching either tumor tissue samples, cell lines, or mice models were included in this review. The majority of human primary and metastatic colon cancer cell lines expressed NRP-2 compared to the normal colonic mucosa. NRPs have been discovered in human cancers as well as neovasculature. The presence of NRP-2 appears to be connected to the epithelial–mesenchymal transition’s function in cancer dissemination and metastatic evolution. The studies were heterogeneous, but the data assessed indicates NRP-2 might have an impact on the metastatic potential of colorectal cancer cells. Nevertheless, further research is needed.

A Necessary Role for Increased Biglycan Expression during L1-Mediated Colon Cancer Progression

Aberrant activation of Wnt/β-catenin signaling and downstream β-catenin-TCF target genes is a hallmark of colorectal cancer (CRC) development. We identified the immunoglobulin-like cell adhesion receptor L1CAM (L1) as a target of β-catenin-TCF transactivation in CRC cells. Overexpression of L1 in CRC cells confers enhanced proliferation, motility, tumorigenesis, and liver metastasis, and L1 is exclusively localized at invasive areas of human CRC tissue. Several genes are induced after L1 transfection into CRC cells by a mechanism involving the L1-ezrin-NF-κB pathway. We conducted a secretomic analysis of the proteins in the culture medium of L1-overexpressing CRC cells. We detected a highly increased level of biglycan, a small leucine-rich ECM component, and a signaling molecule. We found that induction of biglycan is required for the cellular processes conferred by L1, including enhanced proliferation, motility, tumorigenesis, and liver metastasis. The suppression of endogenous biglycan levels or a point mutation in the L1 ectodomain that regulates cell–cell adhesion mediated by L1 blocked the enhanced tumorigenic properties conferred by L1. The mechanism of biglycan induction by L1 involves the L1-NF-κB pathway. Blocking NF-κB signaling in L1 expressing cells suppressed the induction of biglycan and the tumorigenic properties conferred by L1. Biglycan expression was undetectable in the normal colonic mucosa, but expressed at highly increased levels in the tumor tissue, especially in the stroma. The therapeutic strategies to target biglycan expression might provide a useful approach for CRC treatment in L1-overexpressing tumors.

Colonic actinomycosis presenting as a palpable colonic mass with normal colonic mucosa

Colonic actinomycosis is rare and can present as an ill-defined intra-abdominal mass that can be difficult to differentiate from colon cancer. This case report aims to share the details of this case and provide diagnostic clues. A 63-year-old female presented with a palpable right-sided abdominal mass. Computed tomography (CT) revealed irregular thickening of the colonic hepatic flexure, and colonoscopy detected no abnormalities. Five months later, the patient returned with an increase in the mass size. Repeat CT revealed lesion expansion, with suspected abdominal wall invasion. Extended right-hemicolectomy with abdominal wall wedge resection was performed, and the histological results were compatible with actinomycosis infection. Colonic actinomycosis is a rare chronic inflammatory disease. Normal colonic mucosa during colonoscopy, with clinical and imaging findings, may help physicians diagnose the condition preoperatively.

Immunohistochemical expression of clusterin in colorectal carcinoma

Background and objective: Colorectal cancer is a heterogeneous malignancy characterized by a wide range of genetic and epigenetic alterations. Clusterin is a heterodimeric glycoprotein widely expressed in a variety of tissues and secreted in many body fluids. Increased clusterin expression has been reported in the normal colonic mucosa, benign polyps, and colorectal carcinoma. This study aimed to detect the frequency of the clusterin immunoexpression in colorectal carcinoma and determine its association with some clinicopathological parameters. Methods: Sixty formalin-fixed paraffin-embedded sections of colorectal adenocarcinoma were obtained and randomly selected from the histopathology laboratory at Rizgary Teaching Hospital and some private histopathology laboratories in Erbil city over two years between December 2016 and December 2018. All patients had been diagnosed to have primary colorectal adenocarcinoma and had undergone surgery. The clinicopathological characteristics of the tumors were revised, and the specimens were analyzed immunohistochemically using anticlusterin mouse monoclonal antibody. Results: Twenty eight cases (46.6%) were labeled as clusterin positive, while 32 cases (53.4%) were negative for clusterin expression. Clusterin expression was significantly associated with the tumor type (Non-mucinous) (P = 0.01) and tumor grade (well to moderately differentiated) (P = 0.03). At the same time, no significant association was found between clusterin immunoexpression and other clinicopathological characteristics like age, gender, tumor site, and tumor stage. Conclusion: Our study indicated that clusterin is overexpressed in some colorectal carcinomas and is significantly associated with histological type and grade. These results suggest that clusterin may play a role in colorectal carcinogenesis. Further studies are required to understand the possible mechanism of clusterin association with carcinogenesis and cancer progression. Keywords: Colorectal cancer; Clusterin; Immunohistochemistry.

Nanomolar EP4 Receptor Potency and Expression of Eicosanoid- Related Enzymes in Normal Appearing Colonic Mucosa From Patients with Colorectal Neoplasia

BackgroundAberrations in cyclooxygenase and lipoxygenase (LOX) pathways in non-neoplastic, normal appearing mucosa from patients with colorectal neoplasia (CRN), could hypothetically qualify as predisposing CRN-markers. To test this hypothesis, biopsies were obtained during colonoscopy from macroscopically normal colonic mucosa from patients with and without CRN. Prostaglandin E2 (PGE2) receptors, EP1-4, were examined in Ussing-chambers by exposing biopsies to selective EP receptor agonists, antagonists and PGE2. Furthermore, mRNA expression of EP receptors, prostanoid synthases and LOX enzymes were evaluated using qPCR technology.Results Data suggest that PGE2 binds to high and low affinity EP receptors. In particular, PGE2 demonstrated EP4 receptor potency in the low nanomolar range. Similar results were detected using EP2 and EP4 agonists. In CRN patients, mRNA-levels were higher for EP1 and EP2 receptors and for enzymes prostaglandin-I synthase, 5-LOX, 12-LOX and 15-LOX. ConclusionIn conclusion, normal appearing colonic mucosa from CRN patients demonstrates deviating expression in eicosanoid pathways, indicating a likely predisposition for early CRN development. Moreover, PGE2 potency activates high affinity EP4 receptor subtypes, supporting relevance of testing EP4 antagonists in colorectal cancer management.

DNA Methylation Signatures and the Contribution of Age-Associated Methylomic Drift to Carcinogenesis in Early-Onset Colorectal Cancer

We investigated aberrant DNA methylation (DNAm) changes and the contribution of ageing-associated methylomic drift and age acceleration to early-onset colorectal cancer (EOCRC) carcinogenesis. Genome-wide DNAm profiling using the Infinium HM450K on 97 EOCRC tumour and 54 normal colonic mucosa samples was compared with: (1) intermediate-onset CRC (IOCRC; diagnosed between 50–70 years; 343 tumour and 35 normal); and (2) late-onset CRC (LOCRC; >70 years; 318 tumour and 40 normal). CpGs associated with age-related methylation drift were identified using a public dataset of 231 normal mucosa samples from people without CRC. DNAm-age was estimated using epiTOC2. Common to all three age-of-onset groups, 88,385 (20% of all CpGs) CpGs were differentially methylated between tumour and normal mucosa. We identified 234 differentially methylated genes that were unique to the EOCRC group; 13 of these DMRs/genes were replicated in EOCRC compared with LOCRCs from TCGA. In normal mucosa from people without CRC, we identified 28,154 CpGs that undergo ageing-related DNAm drift, and of those, 65% were aberrantly methylated in EOCRC tumours. Based on the mitotic-based DNAm clock epiTOC2, we identified age acceleration in normal mucosa of people with EOCRC compared with normal mucosa from the IOCRC, LOCRC groups (p = 3.7 × 10−16) and young people without CRC (p = 5.8 × 10−6). EOCRC acquires unique DNAm alterations at 234 loci. CpGs associated with ageing-associated drift were widely affected in EOCRC without needing the decades-long accrual of DNAm drift as commonly seen in intermediate- and late-onset CRCs. Accelerated ageing in normal mucosa from people with EOCRC potentially underlies the earlier age of diagnosis in CRC carcinogenesis.

DNA methylation signatures and the contribution of age-associated methylomic drift to carcinogenesis in early-onset colorectal cancer

BackgroundThe role of DNA methylation (DNAm) in the carcinogenesis of colorectal cancer (CRC) diagnosed <50years of age (early-onset CRC or EOCRC) is currently unknown. We investigated aberrant DNAm changes and the contribution of ageing-associated methylomic drift, and age acceleration to EOCRC carcinogenesis.MethodsGenome-wide DNAm profiling using the Infinium HM450K on 97 EOCRC tumour and 54 normal colonic mucosa samples was compared with: 1) intermediate-onset CRC (IOCRC; diagnosed between 50-70 years; 343 tumour and 35 normal); and 2) late-onset CRC (LOCRC; >70 years; 318 tumour and 40 normal). CpGs associated with age-related methylation drift were identified using a public dataset of 231 normal mucosa samples from people without CRC. DNAm-age was estimated using epiTOC2.ResultsCommon to all three age-of-onset groups, 88,385 (20% of all CpGs) CpGs were differentially methylated between tumour and normal mucosa. We identified 234 differentially methylated genes that were unique to the EOCRC group. In normal mucosa from people without CRC, we identified 28,154 CpGs that undergo ageing-related DNAm drift and of those, 65% were aberrantly methylated in EOCRC tumours. Based on the mitotic-based DNAm clock epiTOC2, we identified age acceleration in normal mucosa of people with EOCRC compared with normal mucosa from the IOCRC, LOCRC groups (p=3.7×10−16) and young people without CRC (p=5.8×10−6).ConclusionEOCRC acquires unique DNAm alterations at 234 loci. CpGs associated with ageing-associated drift were widely affected in EOCRC without needing the decades-long accrual of DNAm drift as commonly seen in intermediate- and late-onset CRCs. We found accelerated ageing in normal mucosa from people with EOCRC, as evidenced by a faster stem-cell division rate, potentially contributing to EOCRC carcinogenesis.