Biology Of Colorectal Cancer Research Articles

The discovery and simulation analysis of a novel mutation c.40 G < T (V14F) in the NRAS gene in patients with colorectal cancer in Saudi Arabia

BackgroundColorectal cancer (CRC) is the most diagnosed cancer in men and the second most common cancer in women and remains associated with high morbidity and mortality in Saudi Arabia. The current understanding of genetic heterogeneity of colorectal cancer biology encourages the identification of the genetic causes of CRC in the Saudi population. MethodsIn this study, we ascertained 89 CRC patients’ tumor samples from Saudi Arabia and investigated the molecular alterations of the NRAS proto-oncogene, GTPase (NRAS) gene by sequencing the collected CRC tumor tissue samples to identify gene mutations. The impact of mutations was analyzed using different bioinformatics tools including Missense3D algorithm of Swiss Model platform, molecular dynamics simulations using YASARA DYNAMICS and Protein Variation Effect Analyzer (PROVEAN) tool. ResultsWe identified a novel mutation c.40 G > T, in one patient in whom valine was replaced by phenylalanine (V14F). Notably, we also identified another mutation in the same codon c.40 G > A where valine is replaced by isoleucine (V14I). Our in-silico analysis revealed that this novel mutation alters the binding affinity of the NRAS gene substantially, and as a result, could have lethal consequences on the downstream signaling genes and pathways including MAPK and PI3K involved in regulating CRC growth and progression. ConclusionsThese findings provide insights into the molecular etiology of CRC in general and particularly in the Saudi population. Thus, these findings in NRAS mutation testing may also guide further treatment modalities, and more personalized therapy may be optimized.

In-Depth Proteomic Analysis of Paraffin-Embedded Tissue Samples from Colorectal Cancer Patients Revealed TXNDC17 and SLC8A1 as Key Proteins Associated with the Disease.

A deeper understanding of colorectal cancer (CRC) biology would help to identify specific early diagnostic markers. Here, we conducted quantitative proteomics on FFPE healthy, adenoma, and adenocarcinoma tissue samples from six stage I sporadic CRC patients to identify dysregulated proteins during early CRC development. Two independent quantitative 10-plex TMT experiments were separately performed. After protein extraction, trypsin digestion, and labeling, proteins were identified and quantified by using a Q Exactive mass spectrometer. A total of 2681 proteins were identified and quantified after data analysis and bioinformatics with MaxQuant and the R program. Among them, 284 and 280 proteins showed significant upregulation and downregulation (expression ratio ≥1.5 or ≤0.67, p-value ≤0.05), respectively, in adenoma and/or adenocarcinoma compared to healthy tissue. Ten dysregulated proteins were selected to study their role in CRC by WB, IHC, TMA, and ELISA using tissue and plasma samples from CRC patients, individuals with premalignant colorectal lesions (adenomas), and healthy individuals. In vitro loss-of-function cell-based assays and in vivo experiments using three CRC cell lines with different metastatic properties assessed the important roles of SLC8A1 and TXNDC17 in CRC and liver metastasis. Additionally, SLC8A1 and TXNDC17 protein levels in plasma possessed the diagnostic ability of early CRC stages.

Ubiquitin-specific protease 10 determines colorectal cancer outcome by modulating epidermal growth factor signaling via inositol polyphosphate-4-phosphatase type IIB

Although there have been advances in understanding colorectal cancer (CRC) pathogenesis, significant gaps still exist, highlighting the need for deeper insights. Dysregulated protein homeostasis, including perturbations in the epidermal growth factor receptor (EGFR) pathway, remains a focal point in CRC pathogenesis. Within this context, the roles of ubiquitin ligases and deubiquitinases have attracted attention, but exploration of their precise contributions is still in its early stages. To address this gap, we investigated the involvement of the deubiquitinase USP10 in CRC. Our in vitro and in vivo study reveals a new paradigm in CRC biology and unravels a novel mechanistic axis, demonstrating for the first time the involvement of inositol polyphosphate 4-phosphatase type II B (INPP4B) in USP10-mediated CRC modulation. Specifically, our study demonstrates that the loss of USP10 results in reduced sensitivity to the EGFR tyrosine kinase inhibitors gefitinib and osimertinib. This is accompanied by a decrease in the activation of the AKT1/PKB pathway upon EGF stimulation, which is mediated by INPP4B. Importantly, in vivo xenograft experiments validate these findings and highlight the crucial role of USP10, particularly in conjunction with INPP4B, in driving CRC progression. The findings enhance our understanding of CRC pathobiology and reveal a new regulatory axis involving USP10 and INPP4B in CRC progression. This unique insight identifies USP10 and INPP4B as potential therapeutic targets in CRC.

Therapeutic strategies for colorectal cancer: antitumor efficacy of dopamine D2 receptor antagonists.

Colorectal cancer (CRC) is one of the leading causes of death, accounting for more than half a million deaths annually. Even worse, an increasing number of cancer cases are diagnosed yearly, and two and a half million new cancer cases are estimated to be diagnosed in 2035. Some antipsychotic drugs, especially those targeting dopamine receptor (DR) D2, demonstrated anticancer activity. Studies have revealed the potential of DRD2 antagonists as anticancer therapeutics, whether alone or as an adjuvant, in treating breast cancer, lung cancer, and others. Emerging evidences indicate DRD2 is involved in the CRC biology, and the association between DRD2 and CRC could be utilized in treating CRC. This study selected DRD2 antagonists with anticancer activity to elucidate the possibility of DRD2 antagonists as new therapeutics for treating CRC.

Ruthenium drug BOLD-100 regulates BRAFMT colorectal cancer cell apoptosis through AhR/ROS/ATR signaling axis modulation.

Patients with class I V600EBRAF-mutant (MT) colorectal cancer (CRC) have a poor prognosis and their response to combined anti-BRAF/EGFR inhibition remains limited. There is clearly an unmet need in further understanding the biology of V600EBRAFMT CRC. We have used differential gene expression of BRAFWT and MT CRC cells to identify pathways underpinning BRAFMT CRC. We tested a panel of molecularly/genetically subtyped CRC cells for their sensitivity to the Unfolded Protein Response (UPR) activator BOLD-100. To identify novel combination strategies for BOLD-100, we performed RNA sequencing and high-throughput drug screening. Pathway enrichment analysis identified that the UPR and DNA repair pathways were significantly enriched in BRAFMT CRC. We found that oncogenic BRAF plays a crucial role in mediating response to BOLD-100. Using a systems biology approach, we identified V600EBRAFMT-dependent activation of the replication stress response kinase ATR as a key mediator of resistance to BOLD-100. Further analysis identified acute increases in BRAFMT-dependent-reactive oxygen species (ROS) levels following treatment with BOLD-100 that was demonstrated to promote ATR/CHK1 activation and apoptosis. Furthermore, activation of ROS/ATR/CHK1 following BOLD-100 was found to be mediated through the AHR transcription factor and CYP1A1. Importantly, pharmacological blockade of this resistance pathway with ATR inhibitors synergistically increased BOLD-100-induced apoptosis and growth inhibition in BRAFMT models. These results unveil possible novel therapeutic opportunity for BRAFMT CRC. Implications: BOLD-100 induces BRAFMT-dependent replication stress, and targeted strategies against replication stress (eg. by using ATR inhibitors) in combination with BOLD-100 may serve as a potential novel therapeutic strategy for clinically aggressive BRAFMT CRC.

The Old: Is There Any Role for Screening Colonoscopy after the Age of 75? The Surgeon's Perspective

AbstractGuidelines recommend individualized decision making for screening colonoscopy for colorectal cancer (CRC) in patients after the age of 75 years due to low additional benefits. That should be taken with a grain of salt, as these recommendations are based on expert opinion and simulation models which do not consider (1) the differences in pathogenesis and cancer biology of CRC in elderly; (2) the risks of colonoscopy in this patient population; (3) and the impact of new surgical and nonsurgical therapies for CRC. In this review, our goal is to bring a surgeon's perspective to understand the role of screening colonoscopy in patients older than 75 years.

An overview of chemically induced rodent models for sporadic colorectal cancer: Histopathological and translational perspectives.

Globally, colorectal cancer (CRC) is one of the most frequently diagnosed human gastrointestinal neoplasia and the second leading cause of cancer-related death in both men and women. Despite considerable efforts currently devoted to the study of the biology and treatment of CRC, patient prognosis and survival are still poor. Sporadic CRC is a complex multistep disease and usually emerges in the setting of lifestyle and dietary changes mainly observed in industrialized countries with high human development index (HDI) (westernized style). The molecular pathogenesis of sporadic CRC presents genetic heterogeneity with APC, RAS, PIK3CA, TGFBR, SMAD4, and TP53 mutations usually detected during the progression of this malignancy. The establishment of sporadic CRC models has become essential for both basic and translational research to improve our understanding of the pathophysiology, unravel new molecular drivers, and preventive/therapeutic improvement of this malignancy. Chemically induced rodent models of sporadic CRC recapitulate most key morphological and genetic/epigenetic events observed during the promotion and progression of this malignancy, establishing effective diagnostic and prevention strategies to be translated into clinical practice. The present review gathers the main features of the state-of-the-art evidence on chemically induced rodent models, widely applied for translational modelling of sporadic CRC with a specific focus on histopathology and prevention perspectives. Our narrative review reinforces the persistent value of these bioassays and encourages the use of multimodel strategies for further investigations.

Colorectal Cancer Stem Cell Biomarkers: Biological Traits and Prognostic Insights.

Due to self-renewal, differentiation, and limitless proliferation properties, Cancer Stem Cells (CSCs) increase the probability of tumor development. These cells are identified by using CSC markers, which are highly expressed proteins on the cell surface of CSCs. Recently, the therapeutic application of CSCs as novel biomarkers improved both the prognosis and diagnosis outcome of colorectal Cancer. In the present review, we focused on a specific panel of colorectal CSC markers, including LGR5, ALDH, CD166, CD133, and CD44, which offers a targeted and comprehensive analysis of their functions. The selection criteria for these markers cancer were based on their established significance in Colorectal Cancer (CRC) pathogenesis and clinical outcomes, providing novel insights into the CSC biology of CRC. Through this approach, we aim to elevate understanding and stimulate further research for developing effective diagnostic and therapeutic strategies in CRC.

Clinical Challenges of Consensus Molecular Subtype CMS4 Colon Cancer in the Era of Precision Medicine.

Over the past decade, our understanding of the diversity of colorectal cancer has expanded significantly, raising hopes of tailoring treatments more precisely for individual patients. A key achievement in this direction was the establishment of the consensus molecular classification, particularly identifying the challenging consensus molecular subtype (CMS) CMS4 associated with poor prognosis. Because of its aggressive nature, extensive research is dedicated to the CMS4 subgroup. Recent years have unveiled molecular and microenvironmental features at the tissue level specific to CMS4 colorectal cancer. This has paved the way for mechanistic studies and the development of preclinical models. Simultaneously, efforts have been made to easily identify patients with CMS4 colorectal cancer. Reassessing clinical trial results through the CMS classification lens has improved our understanding of the therapeutic challenges linked to this subtype. Exploration of the biology of CMS4 colorectal cancer is yielding potential biomarkers and novel treatment approaches. This overview aims to provide insights into the clinico-biological characteristics of the CMS4 subgroup, the molecular pathways driving this subtype, and available diagnostic options. We also emphasize the therapeutic challenges associated with this subtype, offering potential explanations. Finally, we summarize the current tailored treatments for CMS4 colorectal cancer emerging from fundamental and preclinical studies.

Abstract 401: The impact of DNA structural variants on PRKN gene function and colorectal cancer pathogenesis

Abstract Background: Cancer is caused by somatic DNA alterations, such as single nucleotide variants, somatic copy number alterations and structural variants (SVs). PRKN is among the genes most frequently affected by SVs in colorectal cancer (CRC), with 37% of primary cancers and 56% of metastatic lesions having focal deletions in PRKN. PRKN encodes the E3 ubiquitin ligase Parkin, which regulates the biological activity and degradation of substrates via post-translational modifications. The genomic location of PRKN is within a common fragile site. Therefore, it remains unclear whether the high frequency of SVs in PRKN are passenger events due to genomic instability or driver events of CRC pathogenesis. Aim: Our study aims to investigate the impact of SVs on the functionality of Parkin in CRC pathogenesis. Methods: We used publicly available DNA deep whole genome sequencing (WGS) and tumor-matched RNA sequencing data (n=394) to estimate the impact of SVs in PRKN on tumor biology. For this, the transcriptome-wide p-value distribution generated by differential expression analysis was used as a measure of biological impact. The HCT116-MLH1-repaired cell line and patient-derived adenoma organoids were genetically modified using CRISPR/Cas9 to mimic the SVs observed in patient material and analyze their impact. RNA-sequencing, whole proteome and ubiquitin remnant-specific proteomics were used to assess the effect of SVs on gene function and identify altered biological processes. Results: Analysis of WGS and RNA sequencing of patient material showed that SVs in PRKN have a large impact on CRC biology, comparable to the impact of mutations in TP53 (impact score 0.379 vs 0.332). The most pronounced effects are seen in the ubiquitin-like, RING0 and RING1 domains. These domains are important for recognition and/or binding to ubiquitin, E2 ubiquitin-conjugating enzymes and substrates. In the HCT116-MLH1-repaired CRC cell line, hemizygous introduction of an SV in PRKN had minimal effects on genome-wide gene expression. In contrast, homozygous deletion altered the expression of nearly 2000 genes. Analyses of ubiquitin motif remnants showed differential ubiquitination of proteins involved in DNA repair following the introduction of an SV in PRKN in the CRC cell line. These proteins include TOP2A (Log2 fold change (L2FC) = -3.69, P = 5.71−5), RAD18 (L2FC = -4.55, P = 1.35−4) and Spartan (SPRTN; L2FC = -2.57, P = 7.43−4). Conclusion: SVs in PRKN have a high impact on tumor biology and result in aberrant gene expression and post-translational modifications of proteins related to DNA repair. Further research will expand to the patient-derived adenoma organoids and focus on understanding if these recurrent somatic alterations contribute to genomic instability and the development of CRC pathogenesis. Citation Format: Elisabeth J. van Bree, Soufyan Lakbir, Carmen Rubio-Alarcón, Renske de Wit, Anne Bolijn, Pien Delis-van Diemen, Marianne Tijssen, Ellen Stelloo, Harma Feitsma, Gerrit A. Meijer, Beatriz Carvalho, Sanne Abeln, Remond J. Fijneman. The impact of DNA structural variants on PRKN gene function and colorectal cancer pathogenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 401.

Abstract 6614: Integrating single-cell RNA-seq and large genome-wide association study data to identify colorectal cancer cell-of-origin populations

Abstract Background: Single-cell RNA sequencing (scRNA-seq) enables the precise identification of distinct cell populations and the measurement of gene expression within each population. Recently, integrating scRNA-seq and genome-wide association study (GWAS) data has shown promise in identifying cell-of-origin populations in human diseases. Colorectal cancer (CRC) progresses through a phenotypic continuum from normal colon to adenoma, and ultimately CRC. However, the specific disease cell-of-origin populations underlying each stage of CRC development at a single-cell resolution have not been well studied. Additionally, while transcriptome-wide association studies (TWAS) have identified more than 200 putative risk genes in CRC, the precise disease cell-of-origin populations associated with these genes remain elusive. Materials and methods: We analyzed scRNA-seq datasets from 31 normal colon, 8 colon serrated polyps, and 15 conventional adenoma tissues of individuals participated the Colorectal Molecular Atlas Project (COLON MAP). We next conducted an integrative analysis of the aforementioned scRNA-seq data, with extensive epigenomics data and summary statistics from a large CRC GWAS conducted among European ancestry populations (78,473 CRC cases and 107,143 controls) using single-cell disease relevance score (scDRS), to investigate cell-of-origin populations underlying the CRC development. We conducted correlation analysis between gene expression and individual cell risk scores derived from scDRS. Additionally, we performed differential expression analysis comparing disease cell-of-origin populations with other cell populations at each stage. Results: We identified multiple cell-of-origin populations associated with CRC, including absorptive cells (ABS) (P &amp;lt; 1 × 10-4) and goblet cells (GOB) (P &amp;lt; 7 × 10-3) in the normal colon, ABS (P &amp;lt; 2 × 10-3), enteroendocrine cells (EE) (P &amp;lt; 0.04), and serrated-specific cells (SSC) (P &amp;lt; 1 × 10-4) in serrated polyps, and ABS (P &amp;lt; 9 × 10-3) and SSC (P &amp;lt; 6 × 10-4) in adenomas. Among the previously reported 205 risk genes from TWAS, a majority show high correlations of their expressions with the risk scores of the single cells (median value R2 = 0.07, 0.14, 0.137 at normal colon, serrated polyps, adenoma, respectively). Moreover, 57 of these TWAS-reported genes (27.8% of 205 genes) exhibited evidence of differential expression in disease cell-of-origin populations compared to other cell populations at a nominal p-value &amp;lt; 0.05 in at least one stage (Binomial test, P &amp;lt; 0.01 for all). Conclusion: This study reveals the cell-of-origin populations that influence the development of CRC, and provides evidence of the role of risk genes in these populations. These findings are crucial for identifying causal genes and understanding the cellular mechanisms that drive the biology and etiology of CRC. Citation Format: Chao Li, Zhishan Chen, Qing Li, Jungyoon Choi, Quanhu Sheng, Wanqing Wen, Xiang Shu, Xiao-ou Shu, Jirong Long, Qiuyin Cai, Bhuminder Singh, Martha J. Shrubsole, Ken Lau, Wei Zheng, Xingyi Guo. Integrating single-cell RNA-seq and large genome-wide association study data to identify colorectal cancer cell-of-origin populations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6614.

Abstract 4344: Comprehensive analysis of LINE-1 transposable elements in colorectal cancer

Abstract Background: Colorectal cancer (CRC) is the third most frequent cancer worldwide, and approximately a third of patients die from the disease. There is therefore an urgent need to better understand CRC biology. A particular feature in (colorectal) cancer is the activation of LINE-1 (L1) retrotransposons: DNA fragments which propagate to other places in the genome through an RNA intermediate. Per genome, about 100-150 genomic L1 copies are still retrotransposition-competent, but repressed in most somatic tissues. Their role in tumor development is currently unknown. Recently, the PCAWG consortium characterized the landscape of somatic L1 retrotranspositions in a series of primary cancers of different origin, and identified 124 recurrently active L1 source regions. However, only a limited number of these concerned CRC. Aim: This study aims to perform a comprehensive analysis of L1 activity in a large cohort of metastatic colorectal cancer. Methods: To this end, we retrieved data from the Hartwig Medical Foundation, comprising deep (106x) whole genome sequencing (WGS) data from metastatic CRC (n=745), to compare to breast (n=888) and lung cancer samples (n=640). We determined L1 activity as the number of somatic L1 insertions reported by the HMF DNA analysis pipeline and used the activity of each of the 124 L1 sources as previously reported by the PCAWG consortium. Results: 99% of mCRC samples (n=741) displayed at least 1 somatic L1 retrotransposition, with at least 10 retrotranspositions in 89% of samples. L1 retrotransposition is more prevalent in mCRC than in metastatic lung and breast cancer, in which only 40% and 20% had at least 10 retrotranspositions per sample, respectively. Each cancer type showed a unique profile of active L1 sources. We did not observe a clear preference of L1 insertions for a single genomic region. However, in CRC, the gene most frequently affected in an exon was APC (n=13), an important tumor-suppressor gene. An analysis of somatic SNVs and SVs confirmed an association of mutations in some known L1 regulators such as TP53 with increased L1 activity, whereas mutations in others showed no change in the number of somatic retrotranspositions. Conclusions: We conclude that somatic L1 retrotranspositions are highly prevalent in metastatic colorectal cancer. Presence of L1 insertions in APC suggests retrotranspositions start very early in CRC development and prompts further investigation into earlier CRC stages. Citation Format: Renske de Wit, Soufyan Lakbir, Caterina Buranelli, Gerrit A. Meijer, Sanne Abeln, Remond J. Fijneman. Comprehensive analysis of LINE-1 transposable elements in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4344.

The activation of HAMP promotes colorectal cancer cell proliferation through zinc-mediated upregulation of SMAD4 expression.

Colorectal cancer (CRC) poses a significant challenge in digestive system diseases, and emerging evidence underscores the critical role of zinc metabolism in its progression. This study aimed to investigate the clinical implications of genes at the intersection of zinc metabolism and CRC. We downloaded CRC prognosis-related genes and zinc metabolism-related genes from public databases. Then, the overlapping genes were screened out, and bioinformatics analysis was performed to obtain the hub gene associated with CRC prognosis. Subsequently, in vitro assays were carried out to investigate the expression of this hub gene and its exact mechanism between zinc metabolism and CRC. HAMP was identified as the hub CRC prognostic gene from overlapping zinc metabolism-related and CRC prognostic genes. In vitro analysis showed HAMP was over-expressed in CRC, and its knockdown inhibited RKO and HCT-116 cell invasion and migration significantly. ZnSO4 induced HAMP up-regulation to promote cell proliferation, while TPEN decreased HAMP expression to inhibit cell proliferation. Importantly, we further found that ZnSO4 enhanced SMAD4 expression to augment HAMP promoter activity and promote cell proliferation in CRC. HAMP stands out as an independent prognostic factor in CRC, representing a potential therapeutic target. Its intricate regulation by zinc, particularly through the modulation of SMAD4, unveils a novel avenue for understanding CRC biology. This study provides valuable insights into the interplay between zinc metabolism, HAMP, and CRC, offering promising clinical indicators for CRC patients. The findings present a compelling case for further exploration and development of targeted therapeutic strategies in CRC management.

A perspective on emerging therapies in metastatic colorectal cancer:Focusing on molecular medicine and drug resistance.

The majority of cancer cases are colorectal cancer, which is also the second largest cause of cancer-related deaths worldwide. Metastasis is the leading cause of death for patients with colorectal cancer. Metastatic colorectal cancer incidence are on the rise due to a tiny percentage of tumors developing resistant to medicines despite advances in treatment tactics. Cutting-edge targeted medications are now the go-to option for customized and all-encompassing CRC care. Specifically, multitarget kinase inhibitors, antivascular endothelial growth factors, and epidermal growth factor receptors are widely used in clinical practice for CRC-targeted treatments. Rare targets in metastatic colorectal cancer are becoming more well-known due to developments in precision diagnostics and the extensive use of second-generation sequencing technology. These targets include the KRAS mutation, the BRAF V600E mutation, the HER2 overexpression/amplification, and the MSI-H/dMMR. Incorporating certain medications into clinical trials has significantly increased patient survival rates, opening new avenues and bringing fresh viewpoints for treating metastatic colorectal cancer. These focused therapies change how cancer is treated, giving patients new hope and better results. These markers can significantly transform and individualize therapy regimens. They could open the door to precisely customized and more effective medicines, improving patient outcomes and quality of life. The fast-growing body of knowledge regarding the molecular biology of colorectal cancer and the latest developments in gene sequencing and molecular diagnostics are directly responsible for this advancement.

Limitations in the management of colorectal cancer in sub-Saharan Africa

Colorectal cancer (CRC) was regarded as a rare disease in native West Africans. It is now accepted as an established disease with a rising incidence. The CRC is now known to be a complex tumour with different aetiopathological pathways. With all cancers early detection is important if one aims to cure the patient. A summary of the clinical features include: Unexplained ill-health and anaemia in patients with cancer of the caecum and ascending colon; palpable abdominal mass for colon cancer; rectal bleeding and tenesmus for carcinoma of the rectum; palpable mass on digital rectal examination in at least 75% of cases. The current complete management of this disease involves extirpative surgery and adjuvant treatment with a combination of cytotoxic chemotherapy and tailored therapy. This presentation will look at ways in which seamless management of CRC in this environment is hampered. The ‘PATIENT’ factor: Ignorance (which leads to unfavourable health-seeking behaviour) Poverty (goes for all developing countries) Gullibility (under which falls religion and alternative treatment) Cultural taboos (which lead to refusal of colostomy-based treatments) Aversion of the sequelae of rectal cancer treatment especially in males where up to 30% of patients are under the age of 40 years. Late presentation (effect of 1–5) The ‘COUNTRY’ factor: Politics: inadequate budget for health Workers not enough; current brain drain of doctors, major cancer centres are stretched. Infra-structure: There is a glaring lack of any population screening programme, a lack of public enlightenment messages for awareness and only two government centres have functioning radiotherapy machines. Staplers and cytotoxic drugs have to be imported, thus are expensive and out of reach of the common man. The ‘GENETICS’ factor: The biology of CRC in the native African is different from that of Caucasians and more aggressive. Carcinomatosis peritonei is frequent. There’s also the emergence of unusual metastases to the lungs and spine, bypassing the liver. A summary of the findings by Nigerian researchers on the molecular biology of native Nigerian CRC showed MSI (Not otherwise stated) occurred in 23–53% of Nigerian CRC, MSI-H seen in 28.1–43%. KRAS in 21% while BRAF was seen in 4.5%. The significance of these results may mean that we might not be administering the right combination chemotherapy in over 50% of our patients. Some studies have shown that patients with MSI-H CRC appear to have ineffectual or even detrimental responses to 5FU-based adjuvant chemotherapy. We all know that 5FU is the cornerstone of most of the combination chemotherapy we administer to patients (FOLFOX, FOLFIRI, CapeOX, XelOX). In addition, the 2012 study on BRAF and KRAS in Nigerians by Abdulkareem et al. also suggests that Nigerian patients may benefit more from anti-EGFR therapy (Cetuximab, Panitumumab) than Caucasians. However, cost implications will make prescribing these drugs a mere academic exercise in most Nigerian patients.

The extracellular matrix in peritoneal metastatic carcinoma

The peritoneum is a relatively common site for the metastasis of cancers that develop near the peritoneal cavity, such as gastric cancer, colorectal cancer (CRC), ovarian cancer, and low-grade appendiceal mucinous adenocarcinoma (LAMN). Peritoneal metastasis (PM) results from direct implantation and growth or microvascular metastasis of cancer cells to the peritoneum and is often associated with a poor prognosis. The biological features of peritoneal metastatic tumours are significantly altered, and the tumour microenvironment (TME) is profoundly abnormal. The extracellular matrix (ECM), a highly dynamic part of the TME, exhibits unique biological properties and influences tumour cells (TCs) behaviour and invasion. In this review, I focus on the hallmarks of cancer; the biology of CRC, PM from CRC, LAMN and pseudomyxoma peritonei (PMP, resulting from the intraperitoneal spread of LAMN); and the structural features of the cancer ECM and mucus and their roles in tumour growth, TCs invasion and drug resistance. The study of the ECM has led to a deeper understanding of peritoneal metastatic tumours and provides new insights for developing new biomarkers and targeted drugs.

Murine models of colorectal cancer: the azoxymethane (AOM)/dextran sulfate sodium (DSS) model of colitis-associated cancer.

Colorectal cancer (CRC) is the third most common cancer. It is a heterogeneous disease, including both hereditary and sporadic types of tumors. CRC results from complex interactions between various genetic and environmental factors. Inflammatory bowel disease is an important risk factor for developing CRC. Despite growing understanding of the CRC biology, preclinical models are still needed to investigate the etiology and pathogenesis of the disease, as well as to find new methods of treatment and prevention. The purpose of this review is to describe existing murine models of CRC with a focus on the models of colitis-associated CRC. This manuscript could be relevant for experimental biologists and oncologists. We checked PubMed and Google from 01/2018 to 05/2023 for reviews of CRC models. In addition, we searched PubMed from 01/2022 to 01/2023 for articles using the azoxymethane (AOM)/dextran sulfate sodium (DSS) CRC model. Existing murine models of CRC include spontaneous, genetically engineered, transplantation, and chemically induced models. For the study of colitis-associated cancer (CAC), the AOM/DSS model is predominantly used. This model is very similar in histological and molecular characteristics to the human CAC, and is highly reproducible, inexpensive, and easy to use. Despite its popularity, the AOM/DSS model is not standardized, which makes it difficult to analyze and compare data from different studies. Each model demonstrates particular advantages and disadvantages, and allows to reproduce different subtypes or aspects of the pathogenesis of CRC.

Molecular pathology of colorectal cancer: The Saudi situation in perspective.

Colorectal cancer (CRC) is one of the most common cancers worldwide, and one of the most common causes of cancer deaths. In recent times, significant advancements have been made in elucidating the molecular alterations of the disease, and the results have been an improved understanding of CRC biology, as well as the discovery of biomarkers of diagnostic, prognostic, and therapeutic significance. In this review, an evaluation is carried out of the molecular pathology research of CRC emanating from Saudi Arabia. The verdict is that the data on the molecular alterations in CRC from Saudi patients is at best modest. This dearth of molecular pathology data is aptly reflected in the paucity of molecular markers recommended for testing by the Saudi National Cancer Centre guidelines for CRC management. Large scale multi-institutional and multiregional translational studies are required to generate molecular data that would inform diagnostic, prognostic, and risk-stratification guidelines for Saudi CRC patients.

Colorectal cancer and therapy response: a focus on the main mechanisms involved.

The latest GLOBOCAN 2021 reports that colorectal cancer (CRC) is the second leading cause of cancer-related death worldwide. Most CRC cases are sporadic and associated with several risk factors, including lifestyle habits, gut dysbiosis, chronic inflammation, and oxidative stress. To summarize the biology of CRC and discuss current therapeutic interventions designed to counteract CRC development and to overcome chemoresistance. Literature searches were conducted using PubMed and focusing the attention on the keywords such as "Current treatment of CRC" or "chemoresistance and CRC" or "oxidative stress and CRC" or "novel drug delivery approaches in cancer" or "immunotherapy in CRC" or "gut microbiota in CRC" or "systematic review and meta-analysis of randomized controlled trials" or "CSCs and CRC". The citations included in the search ranged from September 1988 to December 2022. An additional search was carried out using the clinical trial database. Rounds of adjuvant therapies, including radiotherapy, chemotherapy, and immunotherapy are commonly planned to reduce cancer recurrence after surgery (stage II and stage III CRC patients) and to improve overall survival (stage IV). 5-fluorouracil-based chemotherapy in combination with other cytotoxic drugs, is the mainstay to treat CRC. However, the onset of the inherent or acquired resistance and the presence of chemoresistant cancer stem cells drastically reduce the efficacy. On the other hand, the genetic-molecular heterogeneity of CRC often precludes also the efficacy of new therapeutic approaches such as immunotherapies. Therefore, the CRC complexity made of natural or acquired multidrug resistance has made it necessary the search for new druggable targets and new delivery systems. Further knowledge of the underlying CRC mechanisms and a comprehensive overview of current therapeutic opportunities can provide the basis for identifying pharmacological and biological barriers that render therapies ineffective and for identifying new potential biomarkers and therapeutic targets for advanced and aggressive CRC.

EZH2 Expression and Survival for ER+/tamoxifen Treated Breast Cancer Patients with rs2302427 C>G: A Novel Prognostic and Risk Predictive Biomarker

Overexpression of the EZH2 gene silences several genes involved in DNA repair, cell-cell adhesion, and tumor suppressor genes, resulting in the development of several types of cancers. In the present study, a genetic polymorphism analysis was performed by selecting three SNPs (rs.2302427C>G, rs.3757441C>T, and rs.6950683T>C) of the EZH2 gene based on our previous in silico studies. A total of 250 breast cancer patients and 250 healthy individuals were recruited for the study. Patients with pre-operative breast cancer with different clinical-pathological variables and age-matched healthy women were recruited for the EZH2 gene expression analysis. The genetic polymorphism analysis revealed two SNPs (rs.2302427C>G and rs.6950683T>C) of the three studied SNPs of the EZH2 gene have a protective role in all three genetic models. The haplotype analysis predicted that two haplotypes ACGT and ACGC were significantly associated with a lower risk of breast cancer. Three significant findings of the SNP rs.2302427C>G (Asp193His) i.e., protective role against breast cancer, survival advantage in ER+/tamoxifen treated breast cancer patients, and decreased expression due to the presence of mutant GG genotype, suggests considering it as an important prognostic biomarker for a good survival outcome of breast cancer patients treated with ER+/tamoxifen. Compared with other studies, the other SNP rs.3757441T>C was observed to have a protective effect in breast cancer biology but plays an antagonistic role in colorectal cancer (CRC) biology. To our knowledge, this is the first detailed study on computationally validated EZH2 SNPs in breast cancer.