Molecular pathogenesis of sporadic colorectal cancers

Efficient and accurate framework for genome-wide gene-environment interaction analysis in large-scale biobanks

Gene-environment interaction (G×E) analysis elucidates the interplay between genetic and environmental factors. Genome-wide association studies (GWAS) have expanded to encompass complex traits like time-to-event and ordinal traits, which provide richer phenotypic information. However, most existing scalable approaches focus only on quantitative or binary traits. Here we propose SPAGxECCT, a scalable and accurate framework for diverse trait types. SPAGxECCT fits a genotype-independent model and employs a hybrid strategy including saddlepoint approximation (SPA) for accurate p value calculation, especially for low-frequency variants and unbalanced phenotypic distributions. We extend SPAGxECCT to SPAGxEmixCCT, which accounts for population stratification and is applicable to multi-ancestry or admixed populations. SPAGxEmixCCT can further be extended to SPAGxEmixCCT-local, which identifies ancestry-specific G×E effects using local ancestry. Through extensive simulations and real data analyses of UK Biobank data, we demonstrate that SPAGxECCT and SPAGxEmixCCT are scalable to analyze large-scale study cohort, control type I error rates effectively, and maintain power.

Efficacy and safety of KRAS -G12C inhibitors in colorectal cancer: a systematic review of clinical trials

Patients with colorectal cancer (CRC) who have KRAS mutations often see poor results with standard treatments, leaving them with fewer viable options. Over the past few years, new KRAS G12C inhibitors have emerged as a targeted approach for a specific subset of these mutations, though their effectiveness and safety in advanced CRC remain areas of ongoing research. In this systematic review, we identified nine clinical trials including a total of 668 patients, by searching PubMed, Web of Science, CENTRAL, and Embase through October 2024. When sotorasib was used alone, the objective response rate (ORR) ranged from 7.1 to 9.7%, with disease control (DC) rates of 73.8 to 82.3% and a median progression-free survival (PFS) spanning 4-5.6 months. Combining sotorasib with panitumumab, especially at higher doses, raised its ORR to 26.4%. Meanwhile, pairing adagrasib with cetuximab led to a 42% ORR and a median PFS of 6.9 months, surpassing the 19% ORR observed with adagrasib alone. Divarasib monotherapy produced a 36% ORR and an 85.5% DC rate, with a PFS of 5.6 months; in tandem with cetuximab, those numbers climbed to a 62.5% ORR and a PFS of 8.1 months. Common side effects across these trials included diarrhea, nausea, fatigue, and various skin reactions. Overall, KRAS G12C inhibitors appear to offer meaningful benefits for CRC patients, particularly when used alongside EGFR inhibitors like cetuximab or panitumumab. However, further large-scale, randomized trials are needed to refine dosing strategies and gain a clearer picture of both efficacy and potential risks.

A miRNA Signature for Non-Invasive Colorectal Cancer Diagnosis in Morocco: miR-21, miR-29a and miR-92a

Colorectal cancer (CRC) is the third most diagnosed cancer and a leading cause of cancer-related mortality in Morocco, often detected at late stages. Circulating microRNAs (miRNAs) have emerged as promising non-invasive biomarkers for CRC detection, with miR-21, miR-29a, and miR-92a showing significant diagnostic potential. This study aimed to evaluate the expression levels of these miRNAs in a Moroccan population and their efficacy as diagnostic biomarkers.

METHODS

A prospective study was conducted using blood samples from 50 CRC patients and 50 healthy controls. Circulating miRNA expression levels were quantified through reverse transcription quantitative PCR (RT-qPCR), with normalization to miR-1228-3p. Statistical analyses, including the Mann-Whitney U test, Receiver Operating Characteristic (ROC) curve analysis, sensitivity (Sen), and specificity (Spe) evaluations, were performed to assess the diagnostic accuracy of individual miRNAs and their combined performance as panels.

RESULTS

The expression levels of miR-21, miR-29a, and miR-92a were significantly elevated in CRC patients compared to healthy controls (all p < 0.001). ROC analysis demonstrated that miR-92a exhibited the highest individual diagnostic performance (AUC: 0.938), followed by miR-21 (AUC: 0.907) and miR-29a (AUC: 0.898). Sensitivity and specificity were 88% and 90%, 92% and 56%, and 76% and 94%, respectively. Combinatorial analysis revealed that the miR-29a and miR-92a panel achieved the highest diagnostic accuracy (AUC: 0.976), surpassing individual miRNAs and other combinations, highlighting its potential as a robust, non-invasive biomarker panel for CRC.

CONCLUSIONS

This study highlights the potential of the miR-29a and miR-92a combination, which achieved excellent diagnostic efficiency (AUC: 0.976). These findings underscore miRNA utility in enhancing early detection and reducing CRC-related mortality in Morocco.

HER2-targeted therapy in colorectal cancer: a comprehensive review

Colorectal cancer (CRC) is the third most common cancer and the second leading cause of cancer-related deaths worldwide. Despite treatment advancements in the last decades, CRC remains heterogeneous with significant clinical and genetic diversity. Human epidermal growth factor receptor 2 (HER2) proto-oncogene plays a critical role, as its amplification or overexpression leading to abnormal cell proliferation and tumorigenesis. HER2 overexpression or amplification is identified in 2-4% of metastatic CRCs (mCRC) patients, representing a potential therapeutic target. It is also associated with resistance against epidermal growth factor receptor (EGFR)-targeted therapies like cetuximab and panitumumab, for treatment of RAS wild-type mCRC. Although HER2-positive mCRC is rare, assessing HER2 levels is important. Furthermore, anti-HER2 therapies exhibited non-toxic profile and high efficacy in chemorefractory cases. This review delves into modern management of anti-HER2 therapies in CRC with a particular focus on recent advances and current knowledge about the prognostic and predictive value of HER2.

Natural Alternatives in the Treatment of Colorectal Cancer: A Mechanisms Perspective

Colorectal cancer (CRC) is one of the deadliest neoplasia. Intrinsic or acquired resistance is the main cause of failure of therapy regimens that leads to relapse and death in CRC patients. The widely used chemotherapeutic agent 5-fluorouracil (5-FU) remains the mainstay for therapeutic combinations. Unfortunately, chemotherapeutic resistance and side effects are frequent events that compromise the success of these therapies; the dysregulation of enzymes that regulate 5-FU metabolism increases the expression and activity of efflux pumps. Additional tumor cell adaptations such as epithelial-mesenchymal transition (EMT), autophagy shaping of the tumor microenvironment, and inflammation contribute to chemoresistance. Finding new strategies and alternatives to enhance conventional chemotherapies has become necessary. Recently, the study of natural compounds has been gaining strength as an alternative to chemotherapeutics in different cancers. Curcumin, trimethylglycine, resveratrol, artemisinin, and some helminth-derived molecules, among others, are some natural compounds studied in the context of CRC. This review discusses the main benefits, mechanisms, advances, and dark side of conventional chemotherapeutics currently evaluated in CRC treatment. We also analyzed the landscape of alternative non-conventional compounds and their underlying mechanisms of action, which could, in the short term, provide fundamental knowledge to harness their anti-tumor effects and allow them to be used as alternative adjuvant therapies.

Clinical Validation of a Machine Learning-Based Biomarker Signature to Predict Response to Cytotoxic Chemotherapy Alone or Combined with Targeted Therapy in Metastatic Colorectal Cancer Patients: A Study Protocol and Review

Metastatic colorectal cancer (mCRC) is a severe condition with high rates of illness and death. Current treatments are limited and not always effective because the cancer responds differently to drugs in different patients. This research aims to use artificial intelligence (AI) to improve treatment by predicting which therapies will work best for individual patients. By analyzing large sets of patient data and using machine learning, we hope to create a model that can identify which patients will respond to chemotherapy, either alone or combined with other targeted treatments. The study will involve dividing patients into training and validation sets to develop and test the models, avoiding overfitting. Various machine learning algorithms, like random survival forest and neural networks, will be integrated to develop a highly accurate and stable predictive model. The model's performance will be evaluated using statistical measures such as sensitivity, specificity, and the area under the curve (AUC). The aim is to personalize treatments, improve patient outcomes, reduce healthcare costs, and make the treatment process more efficient. If successful, this research could significantly impact the medical community by providing a new tool for better managing and treating mCRC, leading to more personalized and effective cancer care. In addition, we examine the applicability of learning methods to biomarker discovery and therapy prediction by considering recent narrative publications.

Personalized medicine in colorectal cancer: a comprehensive study of precision diagnosis and treatment

Colorectal cancer is a common and fatal disease that affects many people globally. CRC is classified as the third most prevalent cancer among males and the second most frequent cancer among females worldwide. The purpose of this article is to examine how personalized medicine might be used to treat colorectal cancer. The classification of colorectal cancer based on molecular profiling, including the detection of significant gene mutations, genomic instability, and gene dysregulation, is the main topic of this discussion. Advanced technologies and biomarkers are among the detection methods that are explored, demonstrating their potential for early diagnosis and precise prognosis. In addition, the essay explores the world of treatment possibilities by providing light on FDA-approved personalized medicine solutions that provide individualized and precise interventions based on patient characteristics. This article assesses targeted treatments like cetuximab and nivolumab, looks at the therapeutic usefulness of biomarkers like microsatellite instability (MSI) and circulating tumor DNA (ctDNA), and investigates new approaches to combat resistance. Through this, our review provides a thorough overview of personalized medicine in the context of colorectal cancer, ultimately highlighting its potential to revolutionize the field and improve patient care.

The Impact of Nutritional Status and Tumor-Infiltrating Lymphocytes (CD4+ and CD8+) on Chemotherapy Response in Colorectal Cancer Patients

Introduction

The World Health Organization reports that colorectal cancer (CRC) is the second leading cause of cancer-related mortality globally, with an estimated 1.9 million new cases annually. Tumor-infiltrating lymphocytes (TILs) are frequently associated with colorectal cancer and are believed to play a significant role in the immune response to cancer cells. Regarding chemotherapy responses in patients with colorectal cancer, this study aims to investigate the association between nutritional status and infiltrating lymphocyte counts, specifically CD4+ and CD8+.

Materials and Methods

This prospective observational study analyzed the impact of nutritional status using body mass index (BMI) and TILs levels (CD4+/CD8+) on chemotherapy outcomes in CRC patients treated at a tertiary hospital in West Java, Indonesia, from July 2023 to June 2024.

Results

Thirty-six research subjects were included. Eighteen participants had high levels of TILs CD4+ and CD8+ expression. Nutritional status, age, histological type, tumor site, stage, and metastasis showed no significant correlation with the expression of either CD4+ or CD8+. Nutritional status, levels of CD4+ and CD8+ were significantly associated with chemotherapy responses in CRC patients (p<0.001).

Conclusion

Nutritional status and elevated TIL levels (CD4+/CD8+) positively correlate with better chemotherapy response in CRC patients.

Cold-pressed extraction of perilla seed oil enriched with alpha-linolenic acid mitigates tumour progression and restores gut microbial homeostasis in the AOM/DSS mice model of colitis-associated colorectal cancer

The present investigation explores into the influence of dietary nutrients, particularly alpha-linolenic acid (ALA), a plant-derived omega-3 fatty acid abundant in perilla seed oil (PSO), on the development of colitis-associated colorectal cancer (CRC). The study employs a mouse model to scrutinize the effects of ALA-rich PSO in the context of inflammation-driven CRC. Perilla seeds were subjected to oil extraction, and the nutritional composition of the obtained oil was analysed. Male ICR mice, initiated at four weeks of age, were subjected to diets comprising 5%, 10%, or 20% PSO, 10% fish oil, or 5% soybean oil. All groups, with the exception of the control group (5% soybean oil), underwent induction with azoxymethane (AOM) and dextran sulphate sodium (DSS) to instigate CRC. Disease development, colon samples, preneoplastic lesions, dysplasia, and biomarkers were meticulously evaluated. Furthermore, gut microbiota composition was elucidated through 16S rRNA sequencing. The analysis revealed that PSO contained 61.32% ALA and 783.90 mg/kg tocopherols. Mice subjected to diets comprising 5% soybean or 10% fish oil exhibited higher tumour incidence, burden, multiplicity, and aberrant crypt counts. Remarkably, these parameters were significantly reduced in mice fed a 5% PSO diet. Additionally, 5% PSO-fed mice displayed reduced proliferative and pro-inflammatory markers in colon tissues, coupled with an alleviation of AOM/DSS-induced gut dysbiosis. Notably, PSO demonstrated inhibitory effects on colitis-associated CRC in the AOM/DSS mice model, achieved through the suppression of proliferative and pro-inflammatory protein levels, and mitigation of gut dysbiosis, with discernible efficacy observed at a 5% dietary concentration.

Functional links between the microbiome and the molecular pathways of colorectal carcinogenesis

Colorectal cancer (CRC) is a common cancer, with a concerning rise in early-onset CRC cases, signalling a shift in disease epidemiology. Whilst our understanding of the molecular underpinnings of CRC has expanded, the complexities underlying its initiation remain elusive, with emerging evidence implicating the microbiome in CRC pathogenesis. This review synthesizes current knowledge on the intricate interplay between the microbiome, tumour microenvironment (TME), and molecular pathways driving CRC carcinogenesis. Recent studies have reported how the microbiome may modulate the TME and tumour immune responses, consequently influencing cancer progression, and whilst specific bacteria have been linked with CRC, the underlying mechanisms remains poorly understood. By elucidating the functional links between microbial landscapes and carcinogenesis pathways, this review offers insights into how bacteria orchestrate diverse pathways of CRC development, shedding light on potential therapeutic targets and personalized intervention strategies.

Synthetic free fatty acid receptor (FFAR) 2 agonist 4-CMTB and FFAR4 agonist GSK13764 inhibit colon cancer cell growth and migration and regulate FFARs expression in in vitro and in vivo models of colorectal cancer

INTRODUCTION

Free fatty acid receptors (FFARs) are G protein-coupled receptors that divide into 4 subtypes; FFAR2 and FFAR3 are activated by short-chain fatty acids, while FFAR1 and FFAR4 - by long-chain fatty acids. Recent studies show the potential involvement of FFARs in the pathophysiology of colorectal cancer (CRC). A decrease in FFAR2 and FFAR4 gene expression is observed in patients with CRC. The aim of our study was to evaluate the anti-cancer effect of FFAR2 and FFAR4 stimulation by selective synthetic agonists in in vitro and in vivo models of CRC.

MATERIALS AND METHODS

FFAR2 agonist, 4-CMTB, and FFAR4 agonist, GSK137647 were used. Cell viability (CCD 841 CoN and SW-480) was determined after 48 h incubation with tested compounds using MTT assay. Real-time qPCR and Western Blot were used to identify changes in FFARs expression. Migration and invasion were characterized by commercially available tests. Colitis-associated CRC (CACRC) mouse model was induced by azoxymethane and dextran sodium sulfate.

RESULTS

4-CMTB and GSK137647 significantly reduced cancer cell growth as well as migration and invasion capacities. Both synthetic compounds increased FFAR2 and FFAR4 expression in SW-480 cells. Neither 4-CMTB nor GSK137647 influenced the course of AOM/DSS-induced CACRC in mice, however, 4-CMTB elevated FFAR2 protein expression in mouse tissues.

CONCLUSION

We presented that stimulation of FFAR2 and FFAR4 may inhibit CRC cell viability and migration and that the FFAR2 and FFAR4 expression decreased in CRC can be restored by treatment with respective agonists, indicating new promising pharmacological targets in CRC treatment.

Characterizing m6A modification factors and their interactions in colorectal cancer: implications for tumor subtypes and clinical outcomes

BACKGROUND

The study aims to comprehensively combine colorectal cancer data cohorts in order to analyze the effects of various DNA methylation-coding genes on colorectal cancer patients. The annual incidence and mortality of colorectal cancer are very high, and there are no effective treatments for advanced colorectal cancer. DNA methylation is a method widely used to regulate epigenetics in the molecular mechanism study of tumors.

METHOD

Three single-cell cohorts GSE166555, GSE146771, and EMTAB8107, and five transcriptome cohorts GSE17536, GSE39582, GSE72970, and TCGA-CRC (TCGA-COAD and TCGA-READ) were applied in this study. 2 erasers (ALKBH5 and FTO), There are 7 writers (METTL3, METTL14, WTAP, VIRMA, RBM15, RBM15B, and ZC3H13) and 11 readers (YTHDC1, IGF2BP1, IGF2BP2, IGF2BP3, YTHDF1, YTHDF3, YTHDC2, and HNRNPA2B1, YTHDF2, HNRNPC and RBMX), a total of 20 M6A regulators, were used as the basis of the dataset in this study and were applied to the construction of molecular typing and prognostic models. Drugs that are differentially sensitive in methylation-regulated gene-related prognostic models were identified using the ConsensusClusterPlus package, which was also used to identify distinct methylation regulatory expression patterns in colorectal cancer and to model the relationship between tissue gene expression profiles and drug IC50 values. Finally, TISCH2 assessed which immune cells were significantly expressed with M6A scores. The immunosuppression of M6A methylation is spatially explained.

RESULTS

This study used data from 583 CRC patients in the TCGA-CRC cohort. Firstly, the mutation frequency and CNV variation frequency of 20 m6A modification-related factors were analyzed, and the corresponding histogram and heat map were drawn. The study next analyzed the expression variations between mutant and wild forms of the VIRMA gene and explored differences in the expression of these variables in tumor and normal tissues. In addition, the samples were divided into different subgroups by molecular clustering method based on m6A modification, and each subgroup's expression and clinicopathological characteristics were analyzed. Finally, we compared prognostic differences, tumor microenvironment (TME) characteristics, immune cell infiltration, and gene function enrichment among different subpopulations. We also developed a colorectal cancer m6A-associated gene signature and validated its prognostic effects across multiple cohorts. Finally, using single-cell RNA sequencing data, we confirmed that tumor cells show elevated expression of m6A-related gene signatures.

DISCUSSION

This study explored the mutation frequency, expression differences, interactions, molecular clustering, prognostic effect, and association with tumor characteristics of m6A modification-related factors in CRC and validated them at the single-cell level. These results clarify the association between m6A alteration and colorectal cancer (CRC) and offer important insights into the molecular recognition and management of cancer.

Spatial Proteomic Profiling of Colorectal Cancer Revealed Its Tumor Microenvironment Heterogeneity

Colorectal cancer is a predominant malignancy with a second mortality worldwide. Despite its prevalence, therapeutic options remain constrained and surgical operation is still the most useful therapy. In this regard, a comprehensive spatially resolved quantitative proteome atlas was constructed to explore the functional proteomic landscape of colorectal cancer. This strategy integrates histopathological analysis, laser capture microdissection, and proteomics. Spatial proteome profiling of 200 tissue section samples facilitated by the fully integrated sample preparation technology SISPROT enabled the identification of more than 4000 proteins on the Orbitrap Exploris 240 from 2 mm2 × 10 μm tissue sections. Compared with normal adjacent tissues, we identified a spectrum of cancer-associated proteins and dysregulated pathways across various regions of colorectal cancer including ascending colon, transverse colon, descending colon, sigmoid colon, and rectum. Additionally, we conducted proteomic analysis on tumoral epithelial cells and paracancerous epithelium from early to advanced stages in hallmark rectum cancer and sigmoid colon cancer. Bioinformatics analysis revealed functional proteins and cell-type signatures associated with different regions of colorectal tumors, suggesting potential clinical implications. Overall, this study provides a comprehensive spatially resolved functional proteome landscape of colorectal cancer, serving as a valuable resource for exploring potential biomarkers and therapeutic targets.

Natural Stilbenes: Their Role in Colorectal Cancer Prevention, DNA Methylation, and Therapy

The resistance of colorectal cancer (CRC) to conventional therapeutic modalities, such as radiation therapy and chemotherapy, along with the associated side effects, significantly limits effective anticancer strategies. Numerous epigenetic investigations have unveiled that naturally occurring stilbenes can modify or reverse abnormal epigenetic alterations, particularly aberrant DNA methylation status, offering potential avenues for preventing or treating CRC. By modulating the activity of the DNA methylation machinery components, phytochemicals may influence the various stages of CRC carcinogenesis through multiple molecular mechanisms. Several epigenetic studies, especially preclinical research, have highlighted the effective DNA methylation modulatory effects of stilbenes with minimal adverse effects on organisms, particularly in combination therapies for CRC. However, the available preclinical and clinical data regarding the effects of commonly encountered stilbenes against CRC are currently limited. Therefore, additional epigenetic research is warranted to explore the preventive potential of these phytochemicals in CRC development and to validate their therapeutic application in the prevention and treatment of CRC. This review aims to provide an overview of selected bioactive stilbenes as potential chemopreventive agents for CRC with a focus on their modulatory mechanisms of action, especially in targeting alterations in DNA methylation machinery in CRC.

Morphological Changes and Inflammation Preceded the Pathogenesis of 1,2-Dimethylhydrazine-Induced Colorectal Cancer

OBJECTIVE

This study examined the morphological changes in the colonic mucosa and the presence of inflammation in rats induced with 1,2-dimethylhydrazine (DMH) 30 mg/kg BW over 9, 11, and 13 weeks without a latency period.

METHODS

Hematoxylin and eosin staining was performed to assess the morphology and characteristic alteration of the epitheliocytes in the colon. Immunohistochemistry was employed to assess the expression of tumor necrosis factor (TNF)-α and cyclooxygenase-2 (COX-2). The difference in the severity of inflammation and COX-2 expression was examined using one-way analysis of variance. The correlation of COX-2 expression with the severity of inflammation was analyzed using Spearman's rank correlation test.

RESULT

Until week 13, chronic inflammation and non-hyperplastic and hyperplastic aberrant crypt foci occurred. The severity of inflammation gradually shifted from high moderate to low moderate. TNF-α expression was high in all groups; however, COX-2 expression was gradually lower with longer duration of induction, which corresponded with the severity of inflammation.

CONCLUSION

DMH induction until week 13 without a latency period caused chronic inflammation without the formation of adenoma or adenocarcinoma. A very strong correlation was established between COX-2 expression and inflammation.

Studying the Effect of the Host Genetic Background of Juvenile Polyposis Development Using Collaborative Cross and Smad4 Knock-Out Mouse Models

Juvenile polyposis syndrome (JPS) is a rare autosomal dominant disorder characterized by multiple juvenile polyps in the gastrointestinal tract, often associated with mutations in genes such as Smad4 and BMPR1A. This study explores the impact of Smad4 knock-out on the development of intestinal polyps using collaborative cross (CC) mice, a genetically diverse model. Our results reveal a significant increase in intestinal polyps in Smad4 knock-out mice across the entire population, emphasizing the broad influence of Smad4 on polyposis. Sex-specific analyses demonstrate higher polyp counts in knock-out males and females compared to their WT counterparts, with distinct correlation patterns. Line-specific effects highlight the nuanced response to Smad4 knock-out, underscoring the importance of genetic variability. Multimorbidity heat maps offer insights into complex relationships between polyp counts, locations, and sizes. Heritability analysis reveals a significant genetic basis for polyp counts and sizes, while machine learning models, including k-nearest neighbors and linear regression, identify key predictors, enhancing our understanding of juvenile polyposis genetics. Overall, this study provides new information on understanding the intricate genetic interplay in the context of Smad4 knock-out, offering valuable insights that could inform the identification of potential therapeutic targets for juvenile polyposis and related diseases.

The Role of Phytonutrient Kaempferol in the Prevention of Gastrointestinal Cancers: Recent Trends and Future Perspectives

In recent years, kaempferol, a natural flavonoid present in various fruits and vegetables, has received significant attention in gastrointestinal cancer research due to its varied therapeutic effects. Kaempferol has been proven to alter several molecular mechanisms and pathways, such as the PI3/Akt, mTOR, and Erk/MAPK pathway involved in cancer progression, showing its inhibitory effects on cell proliferation, survival, angiogenesis, metastasis, and migration. Kaempferol is processed in the liver and small intestine, but limited bioavailability has been a major concern in the clinical implications of kaempferol. Nano formulations have been proven to enhance kaempferol's efficacy in cancer prevention. The synergy of nanotechnology and kaempferol has shown promising results in in vitro studies, highlighting the importance for more in vivo research and clinical trials to determine safety and efficacy. This review aims to focus on the role of kaempferol in various types of gastrointestinal cancer and how the combination of kaempferol with nanotechnology helps in improving therapeutic efficacy in cancer treatment.

Methylenetetrahydrofolate reductase polymorphic variants C677T and A1298C in rectal cancer in Slavic population: significance for cancer risk and response to chemoradiotherapy

Background: Methylenetetrahydrofolate reductase (MTHFR) single nucleotide polymorphisms (SNPs) have been suggested as risk, prognostic, and predictive factors for colorectal cancer in various populations, but have not been validated so far. The aim of this study was to examine the association of MTHFR C677T (rs1801133) and A1298C (rs1801131) single nucleotide polymorphisms with the risk of rectal cancer as well as the response to neoadjuvant chemoradiotherapy (nCRT) based on 5-Fluorouracil (5-FU)/leucovorin (LV) in the locally advanced setting. Patients and methods: This case-control study included 119 healthy controls and 97 patients with locally advanced rectal cancer (LARC). For MTHFR genotyping, restriction fragment length polymorphism analysis (PCR-RFLP) was employed. Results: In silico analysis highlighted that SNPs C677T and A1298T correlate with MTHFR gene expression, and that gene expression profile correlates with cancer risk and stage. Using dominant and recessive models, it was found that the MTHFR 677CC vs. 677CT+677TT have increased risk of cancer development (odds ratio (OR): 2.27; 95% confidence interval (CI): 1.30-3.95, p = 0.002) as well as 677CC+677CT compared to 677TT (OR: 4.18, 95% CI: 1.16-14.99, p = 0.014). MTHFR 1298AA also shown increased risk for cancer development compared to 1298AC+1298CC (OR:2.0, 95% CI: 1.20-3.59, p = 0.035) Statistical analysis of combined genotypes highlighted the protective role of CT/AC combined genotype (OR: 3.15 95% CI: 1.576-6.279, p = 0.002) while the CC/AA genotype showed an increased risk for rectal cancer development (OR: 2.499, 95% CI: 1.246-5.081, p = 0.016) The carriers of the 677C/1298A haplotype had the highest risk for developing rectal cancer (OR: 1.74; 95% CI: 1.198-2.530, p = 0.002) while the 677T/1298C haplotype seems to provide a protective effect. (OR: 0.44; 95%CI 0.248-0.795, p = 0.003). No significant association with response to chemoradiotherapy was found. Conclusion: Our data point to MTHFR 667C allele and 1298A alleles as low-penetrance risk factors for rectal cancer in our population. To the best of our knowledge, this is the first study of this type performed on the Slavic population in the Western Balkan, as various population-based factors might also be significant our findings can be used for future meta-analyses and the construction of genetic cancer risk prediction panels.

Microbiome Dysbiosis, Dietary Intake and Lifestyle-Associated Factors Involve in Epigenetic Modulations in Colorectal Cancer: A Narrative Review

Background: Colorectal cancer is the second cause of cancer mortality and the third most commonly diagnosed cancer worldwide. Current data available implicate epigenetic modulations in colorectal cancer development. The health of the large bowel is impacted by gut microbiome dysbiosis, which may lead to colon and rectum cancers. The release of microbial metabolites and toxins by these microbiotas has been shown to activate epigenetic processes leading to colorectal cancer development. Increased consumption of a 'Westernized diet' and certain lifestyle factors such as excessive consumption of alcohol have been associated with colorectal cancer.Purpose: In this review, we seek to examine current knowledge on the involvement of gut microbiota, dietary factors, and alcohol consumption in colorectal cancer development through epigenetic modulations.Methods: A review of several published articles focusing on the mechanism of how changes in the gut microbiome, diet, and excessive alcohol consumption contribute to colorectal cancer development and the potential of using these factors as biomarkers for colorectal cancer diagnosis.Conclusions: This review presents scientific findings that provide a hopeful future for manipulating gut microbiome, diet, and alcohol consumption in colorectal cancer patients' management and care.

Current Research on Molecular Biomarkers for Colorectal Cancer in Stool Samples

Colorectal cancer (CRC) is one of the most diagnosed cancers worldwide, with a high incidence and mortality rate when diagnosed late. Currently, the methods used in healthcare to diagnose CRC are the fecal occult blood test, flexible sigmoidoscopy, and colonoscopy. However, the lack of sensitivity and specificity and low population adherence are driving the need to implement other technologies that can identify biomarkers that not only help with early CRC detection but allow for the selection of more personalized treatment options. In this regard, the implementation of omics technologies, which can screen large pools of biological molecules, coupled with molecular validation, stands out as a promising tool for the discovery of new biomarkers from biopsied tissues or body fluids. This review delves into the current state of the art in the identification of novel CRC biomarkers that can distinguish cancerous tissue, specifically from fecal samples, as this could be the least invasive approach.

Potential anticancer properties and mechanisms of thymoquinone in colorectal cancer

Colorectal neoplasms are one of the deadliest diseases among all cancers worldwide. Thymoquinone (TQ) is a natural compound of Nigella sativa that has been used in traditional medicine against a variety of acute/chronic diseases such as asthma, bronchitis, rheumatism, headache, back pain, anorexia, amenorrhea, paralysis, inflammation, mental disability, eczema, obesity, infections, depression, dysentery, hypertension, gastrointestinal, cardiovascular, hepatic, and renal disorders. This review aims to present a detailed report on the studies conducted on the anti-cancer properties of TQ against colorectal cancer, both in vitro and in vivo. TQ stands as a promising natural therapeutic agent that can enhance the efficacy of existing cancer treatments while minimizing the associated adverse effects. The combination of TQ with other anti-neoplastic agents promoted the efficacy of existing cancer treatments. Further research is needed to acquire a more comprehensive understanding of its exact molecular targets and pathways and maximize its clinical usefulness. These investigations may potentially aid in the development of novel techniques to combat drug resistance and surmount the obstacles presented by chemotherapy and radiotherapy.

NTHL1 Gene Mutations in Polish Polyposis Patients-Weighty Player or Vague Background?

Multiple polyposes are heterogeneous diseases with different underlying molecular backgrounds, sharing a common symptom: the presence of transforming into cancerous intestinal polyps. Recent reports have indicated biallelic mutations in the NTHL1 gene, which is involved in base excision repair (BER), as predisposing to an elevated risk of colorectal cancer (CRC). We aimed to evaluate the significance of the p.Q82* truncating variant in predisposition to intestinal polyposis by assessing its frequency in polyposis patients. We genotyped 644 Polish patients and 634 control DNA samples using high-resolution melting analysis (HRM) and Sanger sequencing. We found the p.Q82* variant in four polyposis patients; in three, it was homozygous (OR = 6.90, p value = 0.202). Moreover, the p.R92C mutation was detected in one patient. We also looked more closely at the disease course in patients carrying NTHL1 mutations. Two homozygous patients also presented other neoplasia. In the family case, we noticed the earlier presence of polyps in the proband and early hepatoblastoma in his brother. We cannot univocally confirm the relationship of p.Q82* with an increased risk of CRC. However, homozygous p.Q82* was more frequent by 10-fold in patients without other mutations identified, which makes NTHL1 gene screening in this group reasonable.

Label-free nLC-MS/MS proteomic analysis reveals significant differences in the proteome between colorectal cancer tissues and normal colon mucosa

Despite the discovery of numerous driving and passenger genes that play key roles in cancer characteristics, progress in cancer treatment has not been satisfactory. This is mainly because conventional therapies are neither selective nor targeted. Another important reason is that cancer cells rapidly develop resistance to chemotherapeutic agents due to excessive accumulation of mutations and/or epigenetic changes. In light of this, we believe that the discovery of new targets and key genes/proteins could improve treatment options. In this study, tissue samples (tumor and normal mucosa) were first collected from the colon or rectum by right or left hemicolectomy. Proteomic analysis was then performed using the label-free nLC-MS/MS method. We determined 77 proteins with statistically significant differences in expression levels between cancerous and normal mucosa. While the expression of 76 proteins was decreased in cancer tissues, only one protein (RNA-binding motif protein_X chromosome-RBMX) was increased in colorectal cancer tissues. The bioinformatics portal Metascape was used to determine the biological processes involved. 77 proteins with significantly different expression between cancerous and normal tissues were compared with the UALCAN platform using data from the Clinical Proteomics Tumor Analysis Consortium (CPTAC). The results for 45 of the 77 proteins clearly matched the CPTAC dataset. Western blot studies confirmed that RBMX protein (critical for gene transcription and alternative splicing of various pre-mRNAs) was increased 2.04-fold, while decorin protein (a matrix proteoglycan with tumor suppressor functions) was dramatically decreased by about 6.04-fold in tumor samples compared with normal mucosa.

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.

Impact of previous diverticulitis on 5-year survival and recurrence rates in patients with colorectal cancer

BACKGROUND

Diverticulitis and colorectal cancer (CRC) share epidemiological characteristics, but their relationship remains unknown. It is unclear if prognosis following CRC differ for patients with previous diverticulitis compared to those with sporadic cases and patients with inflammatory bowel disease or hereditary syndromes.

AIM

The aim was to determine 5-year survival and recurrence after colorectal cancer in patients with previous diverticulitis, inflammatory bowel disease and hereditary colorectal cancer compared to sporadic cases.

METHODS

Patients <75 years of age diagnosed with colorectal cancer at Skåne University Hospital Malmö, Sweden, between January 1st 2012 and December 31st 2017 were identified through the Swedish colorectal cancer registry. Data was retrieved from the Swedish colorectal cancer registry and chart review. Five-year survival and recurrence in colorectal cancer patients with previous diverticulitis were compared to sporadic cases, inflammatory bowel disease associated and hereditary colorectal cancer.

RESULTS

The study cohort comprised 1052 patients, 28 (2.7%) with previous diverticulitis, 26 (2.5%) IBD, 4 (1.3%) hereditary syndromes and 984 (93.5%) sporadic cases. Patients with a history of acute complicated diverticulitis had a significantly lower 5-year survival rate (61.1%) and higher recurrence rate (38.9%) compared to sporadic cases (87.5% and 18.8% respectively).

CONCLUSION

Patients with acute complicated diverticulitis had worse 5-year prognosis compared to sporadic cases. The results emphasize the importance of early detection of colorectal cancer in patients with acute complicated diverticulitis.

Identification of Moesin (MSN) as a Potential Therapeutic Target for Colorectal Cancer via the β-Catenin-RUNX2 Axis

CRC is the second leading cause of cancer-related death. The complex mechanisms of metastatic CRC limit available therapeutic choice. Thus, identifying new CRC therapeutic targets is essential. Moesin (MSN), a member of the ezrin-radixin-moesin family, connects the cell membrane to the actin-based cytoskeleton and regulates cell morphology. We investigated the role of MSN in the progression of CRC. GENT2 and oncomine were used to study MSN expression and CRC patient outcomes. MSN-specific shRNAs or MSN-overexpressed plasmid were used to establish MSN-KD and MSN overexpressed cell lines, respectively. SRB, migration, wound healing, and flow cytometry were used to test cell survival and migration. Propidium iodide and annexin V stain were used to analyze the cell cycle and apoptosis. MSN expression was found to be higher in CRC tissues than in normal tissues. Higher MSN expression is associated with poor overall survival, disease-free survival, and relapse-free survival rates in CRC patients. MSN silencing inhibits cell proliferation, adhesion, migration, and invasion in vitro, whereas MSN overexpression accelerates cell proliferation, adhesion, migration, and invasion. RNA sequencing was used to investigate differentially expressed genes, and RUNX2 was discovered as a possible downstream target for MSN. In CRC patients, RUNX2 expression was significantly correlated with MSN expression. We also found that MSN silencing decreased cytoplasmic and nuclear β-catenin levels. Additionally, pharmacological inhibition of β-catenin in MSN-overexpressed cells led to a reduction of RUNX2, and activating β-catenin signaling by inhibiting GSK3β rescued the RUNX2 downregulation in MSN-KD cells. This confirms that MSN regulates RUNX2 expression via activation of β-catenin signaling. Finally, our result further determined that RUNX2 silencing reduced the ability of MSN overexpression cells to proliferate and migrate. MSN accelerated CRC progression via the β-catenin-RUNX2 axis. As a result, MSN holds the potential to become a new target for CRC treatment.

Proteomic Signature of Extracellular Vesicles Associated with Colorectal Cancer

The proteins of extracellular vesicles (EVs) provide proteomic signatures that reflect molecular features of EV-producing cells, including cancer cells. Detection of cancer cell EV proteins is of great interest due to the development of novel predictive diagnostic approaches. Using targeted mass spectrometry with stable-isotope-labeled peptide standards (SIS), we measured in this study the levels of 34 EV-associated proteins in vesicles and whole lysate derived from the colorectal cancer (CRC) cell lines Caco-2, HT29 and HCT116. We also evaluated the abundance of 13 EV-associated proteins (FN1, TLN1, ITGB3, HSPA8, TUBA4A, CD9, CD63, HSPG2, ITGB1, GNAI2, TSG101, PACSIN2, and CDC42) in EVs isolated from blood plasma samples from 11 CRC patients and 20 healthy volunteers. Downregulation of TLN1, ITGB3, and TUBA4A with simultaneous upregulation of HSPG2 protein were observed in cancer samples compared to healthy controls. The proteomic cargo of the EVs associated with CRC represents a promising source of potential prognostic markers.

Porphyromonas gingivalis in Colorectal Cancer and its Association to Patient Prognosis

Microbiota dysbiosis may affect both the development and progression of colorectal cancer (CRC). Large metagenomic studies have highlighted specific oral bacteria linked to CRC including Porphyromonas gingivalis. Few studies have however analysed the implications of this bacterium in CRC progression and survival. In this study, we investigated the intestinal presence of P. gingivalis by qPCR in both faecal and mucosal samples from two different patient cohorts, including patients with precancerous dysplasia or CRC, as well as controls. P. gingivalis was detected in 2.6-5.3% of CRC patients and significantly different levels of P. gingivalis were found in faeces of CRC patients compared to controls (P = 0.028). Furthermore, an association was found between the presence of P. gingivalis in faeces and tumour tissue (P < 0.001). Our findings further suggested a potential link between mucosal P. gingivalis and tumours of MSI subtype (P = 0.040). Last but not least, patients with faecal P. gingivalis were found to have a significantly decreased cancer-specific survival (P = 0.040). In conclusion, P. gingivalis could be linked to patients with CRC and to a worse patient prognosis. Further studies are needed to elucidate the role of P. gingivalis in CRC pathogenesis.

Molecular and Sociodemographic Colorectal Cancer Disparities in Latinos Living in Puerto Rico

BACKGROUND

The incidence of sporadic colorectal cancer (CRC) among individuals <50 years (early-onset CRC) has been increasing in the United States (U.S.) and Puerto Rico. CRC is currently the leading cause of cancer death among Hispanic men and women living in Puerto Rico (PRH). The objective of this study was to characterize the molecular markers and clinicopathologic features of colorectal tumors from PRH to better understand the molecular pathways leading to CRC in this Hispanic subpopulation.

METHODS

Microsatellite instability (MSI), CpG island methylator phenotype (CIMP), and KRAS and BRAF mutation status were analyzed. Sociodemographic and clinicopathological characteristics were evaluated using Chi-squared and Fisher's exact tests.

RESULTS

Of the 718 tumors analyzed, 34.2% (n = 245) were early-onset CRC, and 51.7% were males. Among the tumors with molecular data available (n = 192), 3.2% had MSI, 9.7% had BRAF, and 31.9% had KRAS mutations. The most common KRAS mutations observed were G12D (26.6%) and G13D (20.0%); G12C was present in 4.4% of tumors. A higher percentage of Amerindian admixture was significantly associated with early-onset CRC.

CONCLUSIONS

The differences observed in the prevalence of the molecular markers among PRH tumors compared to other racial/ethnic groups suggest a distinct molecular carcinogenic pathway among Hispanics. Additional studies are warranted.

Targeting HDAC2-Mediated Immune Regulation to Overcome Therapeutic Resistance in Mutant Colorectal Cancer

A large body of clinical and experimental evidence indicates that colorectal cancer is one of the most common multifactorial diseases. Although some useful prognostic biomarkers for clinical therapy have already been identified, it is still difficult to characterize a therapeutic signature that is able to define the most appropriate treatment. Gene expression levels of the epigenetic regulator histone deacetylase 2 (HDAC2) are deregulated in colorectal cancer, and this deregulation is tightly associated with immune dysfunction. By interrogating bioinformatic databases, we identified patients who presented simultaneous alterations in HDAC2, class II major histocompatibility complex transactivator (CIITA), and beta-2 microglobulin (B2M) genes based on mutation levels, structural variants, and RNA expression levels. We found that B2M plays an important role in these alterations and that mutations in this gene are potentially oncogenic. The dysregulated mRNA expression levels of HDAC2 were reported in about 5% of the profiled patients, while other specific alterations were described for CIITA. By analyzing immune infiltrates, we then identified correlations among these three genes in colorectal cancer patients and differential infiltration levels of genetic variants, suggesting that HDAC2 may have an indirect immune-related role in specific subgroups of immune infiltrates. Using this approach to carry out extensive immunological signature studies could provide further clinical information that is relevant to more resistant forms of colorectal cancer.

The Cell Transformation Assay: A Historical Assessment of Current Knowledge of Applications in an Integrated Approach to Testing and Assessment for Non-Genotoxic Carcinogens

The history of the development of the cell transformation assays (CTAs) is described, providing an overview of in vitro cell transformation from its origin to the new transcriptomic-based CTAs. Application of this knowledge is utilized to address how the different types of CTAs, variously addressing initiation and promotion, can be included on a mechanistic basis within the integrated approach to testing and assessment (IATA) for non-genotoxic carcinogens. Building upon assay assessments targeting the key events in the IATA, we identify how the different CTA models can appropriately fit, following preceding steps in the IATA. The preceding steps are the prescreening transcriptomic approaches, and assessment within the earlier key events of inflammation, immune disruption, mitotic signaling and cell injury. The CTA models address the later key events of (sustained) proliferation and change in morphology leading to tumor formation. The complementary key biomarkers with respect to the precursor key events and respective CTAs are mapped, providing a structured mechanistic approach to represent the complexity of the (non-genotoxic) carcinogenesis process, and specifically their capacity to identify non-genotoxic carcinogenic chemicals in a human relevant IATA.

Combinatorial Network of Transcriptional and miRNA Regulation in Colorectal Cancer

Colorectal cancer is one of the leading causes of cancer-associated mortality across the worldwide. One of the major challenges in colorectal cancer is the understanding of the regulatory mechanisms of biological molecules. In this study, we aimed to identify novel key molecules in colorectal cancer by using a computational systems biology approach. We constructed the colorectal protein–protein interaction network which followed hierarchical scale-free nature. We identified TP53, CTNBB1, AKT1, EGFR, HRAS, JUN, RHOA, and EGF as bottleneck-hubs. The HRAS showed the largest interacting strength with functional subnetworks, having strong correlation with protein phosphorylation, kinase activity, signal transduction, and apoptotic processes. Furthermore, we constructed the bottleneck-hubs’ regulatory networks with their transcriptional (transcription factor) and post-transcriptional (miRNAs) regulators, which exhibited the important key regulators. We observed miR-429, miR-622, and miR-133b and transcription factors (EZH2, HDAC1, HDAC4, AR, NFKB1, and KLF4) regulates four bottleneck-hubs (TP53, JUN, AKT1 and EGFR) at the motif level. In future, biochemical investigation of the observed key regulators could provide further understanding about their role in the pathophysiology of colorectal cancer.

Is the combination of immunotherapy with conventional chemotherapy the key to increase the efficacy of colorectal cancer treatment?

Colorectal cancer (CRC) is among the most prevalent and deadly neoplasms worldwide. According to GLOBOCAN predictions, its incidence will increase from 1.15 million CRC cases in 2020 to 1.92 million cases in 2040. Therefore, a better understanding of the mechanisms involved in CRC development is necessary to improve strategies focused on reducing the incidence, prevalence, and mortality of this oncological pathology. Surgery, chemotherapy, and radiotherapy are the main strategies for treating CRC. The conventional chemotherapeutic agent utilized throughout the last four decades is 5-fluorouracil, notwithstanding its low efficiency as a single therapy. In contrast, combining 5-fluorouracil therapy with leucovorin and oxaliplatin or irinotecan increases its efficiency. However, these treatments have limited and temporary solutions and aggressive side effects. Additionally, most patients treated with these regimens develop drug resistance, which leads to disease progression. The immune response is considered a hallmark of cancer; thus, the use of new strategies and methodologies involving immune molecules, cells, and transcription factors has been suggested for CRC patients diagnosed in stages III and IV. Despite the critical advances in immunotherapy, the development and impact of immune checkpoint inhibitors on CRC is still under investigation because less than 25% of CRC patients display an increased 5-year survival. The causes of CRC are diverse and include modifiable environmental factors (smoking, diet, obesity, and alcoholism), individual genetic mutations, and inflammation-associated bowel diseases. Due to these diverse causes, the solutions likely cannot be generalized. Interestingly, new strategies, such as single-cell multiomics, proteomics, genomics, flow cytometry, and massive sequencing for tumor microenvironment analysis, are beginning to clarify the way forward. Thus, the individual mechanisms involved in developing the CRC microenvironment, their causes, and their consequences need to be understood from a genetic and immunological perspective. This review highlighted the importance of altering the immune response in CRC. It focused on drugs that may modulate the immune response and show specific efficacy and contrasted with evidence that immunosuppression or the promotion of the immune response is the answer to generating effective treatments with combined chemotherapeutic drugs.

Investigation of the gut microbiome, bile acid composition and host immunoinflammatory response in a model of azoxymethane-induced colon cancer at discrete timepoints

BACKGROUND

Distinct sets of microbes contribute to colorectal cancer (CRC) initiation and progression. Some occur due to the evolving intestinal environment but may not contribute to disease. In contrast, others may play an important role at particular times during the tumorigenic process. Here, we describe changes in the microbiota and host over the course of azoxymethane (AOM)-induced tumorigenesis.

METHODS

Mice were administered AOM or PBS and were euthanised 8, 12, 24 and 48 weeks later. Samples were analysed using 16S rRNA gene sequencing, UPLC-MS and qRT-PCR.

RESULTS

The microbiota and bile acid profile showed distinct changes at each timepoint. The inflammatory response became apparent at weeks 12 and 24. Moreover, significant correlations between individual taxa, cytokines and bile acids were detected. One co-abundance group (CAG) differed significantly between PBS- and AOM-treated mice at week 24. Correlation analysis also revealed significant associations between CAGs, bile acids and the bile acid transporter, ASBT. Aberrant crypt foci and adenomas were first detectable at weeks 24 and 48, respectively.

CONCLUSION

The observed changes precede host hyperplastic transformation and may represent early therapeutic targets for the prevention or management of CRC at specific timepoints in the tumorigenic process.

TGFβ1 rs1800469 and SMAD4 rs10502913 polymorphisms and genetic susceptibility to colorectal cancer in Bangladeshi population

BACKGROUND

Among Bangladeshi males and females, colorectal cancer is the fourth and fifth most prevalent cancer, respectively. Several studies have shown that the transforming growth factor beta 1 (TGFβ1) gene and SMAD4 gene have a great impact on colorectal cancer.

OBJECTIVE

The present study aimed to investigate whether TGFβ1 rs1800469 and SMAD4 rs10502913 genetic polymorphisms are associated with susceptibility to colorectal cancer in the Bangladeshi population.

METHODS AND MATERIALS

This case-control study was performed on 167 colorectal cancer patients and 162 healthy volunteers, and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was employed for genotyping.

RESULTS

In case of SMAD4 rs10502913 G > A polymorphism, the A allele reduced the colorectal cancer risk significantly (adjusted OR 0.35, 95% CI 0.23-0.52, p < 0.001) when compared to the G allele. It was also found that G/A and A/A genotypes of SMAD4 rs10502913 G > A polymorphism reduced the risk of colorectal cancer in comparison to the G/G genotype (G/A vs. G/G: adjusted OR 0.24, 95% CI 0.12-0.45, p < 0.001 and A/A vs. G/G: adjusted OR 0.06, 95% CI 0.02-0.21, p < 0.001). TGFβ1 rs1800469 C > T polymorphism showed an elevated risk of developing colorectal cancer, although the results were not statistically significant.

CONCLUSION

This study confirms the association of SMAD4 rs10502913 gene polymorphism with colorectal cancer susceptibility among the Bangladeshi population.

Spatial and temporal patterns of colorectal cancer in Asia, 1990-2019

BACKGROUND

Asia accounts for the largest burden of colorectal cancer (CRC) worldwide. This study examines the temporal patterns of CRC in Asia in the last three decades.

METHODS

The data pertaining to CRC burden measured by incidence, mortality, and disability-adjusted-life-years (DALYs) and its risk factors for 49 countries in the Asian continent were drawn from the Global Burden of Disease 2019 study between 1990 and 2019. Mortality-to-incidence ratio (MIR) was employed as a proxy indicator of 5-year survival rates.

RESULTS

In Asia, incident cases more than tripled from 270,851 to 1.1 million, deaths tripled from 183,252 to 560,426, and DALYs more than doubled from 5 million to 13.4 million between 1990 and 2019. The age-standardized incidence rate (ASIR) increased from 14.0/100,000 to 23.9/100,000, age-standardized mortality rate (ASMR) increased from 10.1/100,000 to 12.5/100,000, and MIR decreased from 0.68 to 0.50 between 1990 and 2019. ASIR varied 10-folds across countries from 5.6/100,000 in Bangladesh to 62.0/100,000 in Taiwan in 2019 and ASMR from 4.9/1000 in Bangladesh to 30.3/100,000 in Brunei. In 2019, diet low in milk (18.7%) and whole grains (15.2%) and calcium (16.6%) were the major contributory risk factors in CRC DALYs in 2019.

CONCLUSION

CRC is a fast-rising neoplasm in Asia and its burden can be curtailed by focusing on primary prevention (e.g., diet and physical activity) and secondary prevention through screening. The policy focus and resources must be directed towards capacity building, including cancer infrastructure and quality data availability from cancer registries.

Siah2 inhibitor and the metabolic antagonist Oxamate retard colon cancer progression and downregulate PD1 expression

BACKGROUND

Solid tumors such as colon cancer are characterized by rapid and sustained cell proliferation, which ultimately results in hypoxia, induction of hypoxia-inducible factor-1α (HIF-1α), and activation of glycolysis to promote tumor survival and immune evasion. We hypothesized that a combinatorial approach of menadione (MEN) as an indirect HIF-1α inhibitor and sodium oxamate (OX) as a glycolysis inhibitor may be a promising treatment strategy for colon cancer.

OBJECTIVES

We investigated the potential efficacy of this combination for promoting an antitumor immune response and suppressing tumor growth in a rat model of colon cancer.

METHODS

Colon cancer was induced by once-weekly subcutaneous injection of 20 mg/kg dimethylhydrazine (DMH) for 16 weeks. Control rats received the vehicle and then no further treatment (negative control) or MEN plus OX for 4 weeks (drug control). Dimethylhydrazine-treated rats were then randomly allocated to four groups: DMH alone group and other groups treated with MEN, OX, and a combination of (MEN and OX) for 4 weeks. Serum samples were assayed for the tumor marker carbohydrate antigen (CA19.9), while expression levels of HIF-1α, caspase-3, PHD3, LDH, and PD1 were evaluated in colon tissue samples by immunoassay and qRT-PCR. Additionally, Ki-67 and Siah2 expression levels were examined by immunohistochemistry.

RESULTS

The combination of MEN plus OX demonstrated a greater inhibitory effect on the expression levels of HIF-1α, Siah2, LDH, Ki-67, and PD1, and greater enhancement of caspase-3 and PHD3 expression in colon cancer tissues than either drug alone.

CONCLUSION

Simultaneous targeting of hypoxia and glycolysis pathways by a combination of MEN and OX could be a promising therapy for inhibiting colon cancer cell growth and promoting antitumor immunity [1].

Bile acids as carcinogens in the colon and at other sites in the gastrointestinal system

Colon cancer incidence is associated with a high-fat diet. Such a diet is linked to elevated levels of bile acids in the gastrointestinal system and the circulation. Secondary bile acids are produced by microorganisms present at high concentrations in the colon. Recent prospective studies and a retrospective study in humans associate high circulating blood levels of secondary bile acids with increased risk of colon cancer. Feeding mice a diet containing a secondary bile acid, so their feces have the bile acid at a level comparable to that in the feces of humans on a high-fat diet, also causes colon cancer in the mice. Studies using human cells grown in culture illuminate some mechanisms by which bile acids cause cancer. In human cells, bile acids cause oxidative stress leading to oxidative DNA damage. Increased DNA damage increases the occurrence of mutations and epimutations, some of which provide a cellular growth advantage such as apoptosis resistance. Cells with such mutations/epimutations increase by natural selection. Apoptosis, or programmed cell death, is a beneficial process that eliminates cells with unrepaired DNA damage, whereas apoptosis-resistant cells are able to survive DNA damage using inaccurate repair processes. This results in apoptosis-resistant cells having more frequent mutations/epimutations, some of which are carcinogenic. The experiments on cultured human cells have provided a basis for understanding at the molecular level the human studies that recently reported an association of bile acids with colon cancer, and the mouse studies showing directly that bile acids cause colon cancer. Similar, but more limited, findings of an association of dietary bile acids with other cancers of the gastrointestinal system suggest that understanding the role of bile acids in colon carcinogenesis may contribute to understanding carcinogenesis in other organs.

γδ T cells and their clinical application in colon cancer

In recent years, research has focused on colorectal cancer to implement modern treatment approaches to improve patient survival. In this new era, γδ T cells constitute a new and promising candidate to treat many types of cancer because of their potent killing activity and their ability to recognize tumor antigens independently of HLA molecules. Here, we focus on the roles that γδ T cells play in antitumor immunity, especially in colorectal cancer. Furthermore, we provide an overview of small-scale clinical trials in patients with colorectal cancer employing either in vivo activation or adoptive transfer of ex vivo expanded γδ T cells and suggest possible combinatorial approaches to treat colon cancer.

Genetic and epigenetic characteristics of patients with colorectal cancer from Uruguay

Colorectal cancer (CRC), the 3rd most frequent cancer worldwide, affects both men and women. This pathology arises from the progressive accumulation of genetic and epigenetic alterations. In this study, KRAS, NRAS, PIK3CA, and BRAF gene mutations, mismatch repair (MMR) genes methylation profile, microsatellite instability (MSI) and CpG Island Methylator Phenotype (CIMP) status were assessed. The associations of these molecular features with clinicopathological data were also investigated. A hundred and eight unselected CRC samples and their histological and clinical data, were gathered between 2017 and 2020. The prevalence of KRAS, NRAS and BRAF gene mutations was similar to that described in other populations. 28.7% of tumors were KRAS-mutated, mostly in men, distal location, with a CIMP-negative status. BRAFV600E frequency was 6.5% and associated with MSI (p = 0.048), MLH1-methylated (p < 0.001) and CIMP-High (p < 0.001) status. We also confirmed that BRAFV600E tumors were more prevalent in older women and proximal location. A striking different result was the lack of most common variants in the PIK3CA gene. A complete absence of PIK3CA-mutated tumors in a population has not been previously reported. Among MMR genes, the only with an aberrant methylation pattern was MLH1 gene. Its frequency was 9.25%, lower than previously reported. Methylated tumors were most frequent in patients older than 70 years old and proximal tumor location. Finally, CIMP-High status was mainly observed in moderately differentiated tumors with a rate of 15.7%. Our findings were consistent with previous reports in other populations, but also showed some features unique to our cohort. This study is the first to report the analysis of a large number molecular biomarkers of CRC in Uruguay and one of the few performed in Latin-America.

A review on mechanobiology of cell adhesion networks in different stages of sporadic colorectal cancer to explain its tumorigenesis

Sporadic colorectal cancer (CRC) is strongly linked to extraneous factors, like poor diet and lifestyle, but not to inherent factors like familial genetics. The changes at the epigenomics and signalling pathways are known across the sporadic CRC stages. The catch is that temporal information of the onset, the feedback loop, and the crosstalk of signalling and noise are still unclear. This makes it challenging to diagnose and treat colon cancer effectively with no relapse. Various microbial cells and native cells of the colon, contribute to sporadic CRC development. These cells secrete autocrine and paracrine for their bioenergetics and communications with other cell types. Imbalances of the biochemicals affect the epithelial lining of colon. One side of this epithelial lining is interfacing the dense colon tissue, while the other side is exposed to microbiota and excrement from the lumen. Hence, the epithelial lining is prone to tumorigenesis due to the influence of both biochemical and mechanical cues from its complex surrounding. The role of physical transformations in tumorigenesis have been limitedly discussed. In this context, cellular and tissue structures, and force transductions are heavily regulated by cell adhesion networks. These networks include cell anchoring mechanism to the surrounding, cell structural integrity mechanism, and cell effector molecules. This review will focus on the progression of the sporadic CRC stages that are governed by the underlaying cell adhesion networks within the epithelial cells. Additionally, current and potential technologies and therapeutics that target cell adhesion networks for treatments of sporadic CRC will be incorporated.

Regulation of thymidylate synthase: an approach to overcome 5-FU resistance in colorectal cancer

Thymidylate synthase is the rate-limiting enzyme required for DNA synthesis and overexpression of this enzyme causes resistance to cancer cells. Long treatments with 5-FU cause resistance to Thymidylate synthase targeting drugs. We have also compiled different mechanisms of drug resistance including autophagy and apoptosis, drug detoxification and ABC transporters, drug efflux, signaling pathways (AKT/PI3K, RAS-MAPK, WNT/β catenin, mTOR, NFKB, and Notch1 and FOXM1) and different genes associated with resistance in colorectal cancer. We can overcome 5-FU resistance in cancer cells by regulating thymidylate synthase by natural products (Coptidis rhizoma), HDAC inhibitors, mTOR inhibitors, Folate antagonists, and several other drugs which have been used in combination with TS inhibitors. This review is a compilation of different approaches reported for the regulation of thymidylate synthase to overcome resistance in colorectal cancer cells.

Kaempferol: A potential agent in the prevention of colorectal cancer

Colorectal cancer (CRC) is the third most prevalent cancer in relation to incidence and mortality rate and its incidence is considerably increasing annually due to the change in the dietary habit and lifestyle of the world population. Although conventional therapeutic options, such as surgery, chemo- and radiotherapy have profound impacts on the treatment of CRC, dietary therapeutic agents, particularly natural products have been regarded as the safest alternatives for the treatment of CRC. Kaempferol (KMP), a naturally derived flavonol, has been shown to reduce the production of reactive oxygen species (ROS), such as superoxide ions, hydroxyl radicals, and reactive nitrogen species (RNS), especially peroxynitrite. Furthermore, this flavonol inhibits xanthine oxidase (XO) activity and increases the activities of catalase, heme oxygenase-1 (HO), and superoxide dismutase (SOD) in a wide range of cancer and non-cancer cells. Based on several studies, KMP is also a hopeful anticancer which carries out its anticancer action via suppression of angiogenesis, stimulation of apoptosis, and cell cycle arrest. Due to various applications of KMP as an anticancer flavonol, this review article aims to highlight the current knowledge regarding the role of KMP in CRC.

Natural Small Molecules in Gastrointestinal Tract and Associated Cancers: Molecular Insights and Targeted Therapies

Gastric cancer is one of the most common cancers of the gastrointestinal tract. Although surgery is the primary treatment, serious maladies that dissipate to other parts of the body may require chemotherapy. As there is no effective procedure to treat stomach cancer, natural small molecules are a current focus of research interest for the development of better therapeutics. Chemotherapy is usually used as a last resort for people with advanced stomach cancer. Anti-colon cancer chemotherapy has become increasingly effective due to drug resistance and sensitivity across a wide spectrum of drugs. Naturally-occurring substances have been widely acknowledged as an important project for discovering innovative medications, and many therapeutic pharmaceuticals are made from natural small molecules. Although the beneficial effects of natural products are as yet unknown, emerging data suggest that several natural small molecules could suppress the progression of stomach cancer. Therefore, the underlying mechanism of natural small molecules for pathways that are directly involved in the pathogenesis of cancerous diseases is reviewed in this article. Chemotherapy and molecularly-targeted drugs can provide hope to colon cancer patients. New discoveries could help in the fight against cancer, and future stomach cancer therapies will probably include molecularly formulated drugs.

Genome-wide interrogation of structural variation reveals novel African-specific prostate cancer oncogenic drivers

BACKGROUND

African ancestry is a significant risk factor for advanced prostate cancer (PCa). Mortality rates in sub-Saharan Africa are 2.5-fold greater than global averages. However, the region has largely been excluded from the benefits of whole genome interrogation studies. Additionally, while structural variation (SV) is highly prevalent, PCa genomic studies are still biased towards small variant interrogation.

METHODS

Using whole genome sequencing and best practice workflows, we performed a comprehensive analysis of SVs for 180 (predominantly Gleason score ≥ 8) prostate tumours derived from 115 African, 61 European and four ancestrally admixed patients. We investigated the landscape and relationship of somatic SVs in driving ethnic disparity (African versus European), with a focus on African men from southern Africa.

RESULTS

Duplication events showed the greatest ethnic disparity, with a 1.6- (relative frequency) to 2.5-fold (count) increase in African-derived tumours. Furthermore, we found duplication events to be associated with CDK12 inactivation and MYC copy number gain, and deletion events associated with SPOP mutation. Overall, African-derived tumours were 2-fold more likely to present with a hyper-SV subtype. In addition to hyper-duplication and deletion subtypes, we describe a new hyper-translocation subtype. While we confirm a lower TMPRSS2-ERG fusion-positive rate in tumours from African cases (10% versus 33%), novel African-specific PCa ETS family member and TMPRSS2 fusion partners were identified, including LINC01525, FBXO7, GTF3C2, NTNG1 and YPEL5. Notably, we found 74 somatic SV hotspots impacting 18 new candidate driver genes, with CADM2, LSAMP, PTPRD, PDE4D and PACRG having therapeutic implications for African patients.

CONCLUSIONS

In this first African-inclusive SV study for high-risk PCa, we demonstrate the power of SV interrogation for the identification of novel subtypes, oncogenic drivers and therapeutic targets. Identifying a novel spectrum of SVs in tumours derived from African patients provides a mechanism that may contribute, at least in part, to the observed ethnic disparity in advanced PCa presentation in men of African ancestry.

Modulating the Siah2-PHD3-HIF1α axis and/or autophagy potentially retard colon cancer proliferation possibly, due to the damping of colon cancer stem cells

BACKGROUND

Hypoxic microenvironment of colon cancer is associated with HIF-1α upregulation. HIF-1α response elements are responsible for autophagy induction that promotes tumor proliferation. Moreover, HIF-1α induces tumor cell proliferation via maintaining cancer stem cells (CSCs) survival. Siah2 is E3 ubiquitin ligase that indirectly stabilizes HIF-1α. We hypothesized that dual inhibition of Siah2 as well as autophagy could be a promising approach that may inhibit CSCs growth.

AIM OF THE WORK

This study investigated the possible effect of vitamin K3 as a Siah2 inhibitor and hydroxychloroquine as an autophagy inhibitor in colon cancer management. The effect (if any) of these agents on CSCs growth will be also manipulated.

METHODS

Colon cancer was induced by dimethylhydrazine. MDA and GSH were selected as oxidative stress markers, Expression of HIF-1α, Caspase-3, VEGF, MMP-9, EpCAM, SCF, and CA19.9 were assayed using immunoassay. The Western blot technique was used to assess LC3Ⅰ, CD44, and CD133 whereas RT-PCR was used to investigate PHD3 and CD44 in colon tissues. Additionally, Ki-67 and Siah2 were detected immunohistochemically.

RESULTS

vitamin K3 and hydroxychloroquine either alone or in combination downregulated the expression of Siah2 and HIF-1α through upregulating PHD3 in colon tissues. This combination significantly downregulated MDA, Ki-67, VEGF, and MMP-9 expression and upregulated the expression of GSH and caspase-3. LC3Ⅰ was also upregulated. Interestingly, these therapeutic options were correlated with down-regulation of the cancer stem cell marker such as CD44 and EpCAM.

CONCLUSION

Our results suggested that suppression of both Siah2-PHD3-HIF-1α axis and autophagy retard colon cancer proliferation and dampened CSCs.

Genetic and epigenetic dependencies in colorectal cancer development

Recent studies have mapped key genetic changes in colorectal cancer (CRC) that impact important pathways contributing to the multistep models for CRC initiation and development. In parallel with genetic changes, normal and cancer tissues harbor epigenetic alterations impacting regulation of critical genes that have been shown to play profound roles in the tumor initiation. Cumulatively, these molecular changes are only loosely associated with heterogenous transcriptional programs, reflecting the heterogeneity in the various CRC molecular subtypes and the paths to CRC development. Studies from mapping molecular alterations in early CRC lesions and use of experimental models suggest that the intricate dependencies of various genetic and epigenetic hits shape the early development of CRC via different pathways and its manifestation into various CRC subtypes. We highlight the dependency of epigenetic and genetic changes in driving CRC development and discuss factors affecting epigenetic alterations over time and, by extension, risk for cancer.

Reprogrammed Lipid Metabolism and the Lipid-Associated Hallmarks of Colorectal Cancer

Simple Summary

Colorectal cancer (CRC) is the third-most diagnosed cancer and the second-leading cause of cancer-related deaths worldwide. Limitations in early and accurate diagnosis of CRC gives rise to poor patient survival. Advancements in analytical techniques have improved our understanding of the cellular and metabolic changes occurring in CRC and potentiate avenues for improved diagnostic and therapeutic strategies. Lipids are metabolites with important biological functions; however, their role in CRC is poorly understood. Here, we provide an in-depth review of the recent literature concerning lipid alterations in CRC and propose eight lipid metabolism-associated hallmarks of CRC.

Abstract

Lipids have diverse structures, with multifarious regulatory functions in membrane homeostasis and bioenergetic metabolism, in mediating functional protein–lipid and protein–protein interactions, as in cell signalling and proliferation. An increasing body of evidence supports the notion that aberrant lipid metabolism involving remodelling of cellular membrane structure and changes in energy homeostasis and signalling within cancer-associated pathways play a pivotal role in the onset, progression, and maintenance of colorectal cancer (CRC) and their tumorigenic properties. Recent advances in analytical lipidome analysis technologies have enabled the comprehensive identification and structural characterization of lipids and, consequently, our understanding of the role they play in tumour progression. However, despite progress in our understanding of cancer cell metabolism and lipidomics, the key lipid-associated changes in CRC have yet not been explicitly associated with the well-established ‘hallmarks of cancer’ defined by Hanahan and Weinberg. In this review, we summarize recent findings that highlight the role of reprogrammed lipid metabolism in CRC and use this growing body of evidence to propose eight lipid metabolism-associated hallmarks of colorectal cancer, and to emphasize their importance and linkages to the established cancer hallmarks.

Promising Therapeutic Strategies for Colorectal Cancer Treatment Based on Nanomaterials

Colorectal cancer (CRC) is a global health problem responsible for 10% of all cancer incidences and 9.4% of all cancer deaths worldwide. The number of new cases increases per annum, whereas the lack of effective therapies highlights the need for novel therapeutic approaches. Conventional treatment methods, such as surgery, chemotherapy and radiotherapy, are widely applied in oncology practice. Their therapeutic success is little, and therefore, the search for novel technologies is ongoing. Many efforts have focused recently on the development of safe and efficient cancer nanomedicines. Nanoparticles are among them. They are uniquewith their properties on a nanoscale and hold the potential to exploit intrinsic metabolic differences between cancer and healthy cells. This feature allows them to induce high levels of toxicity in cancer cells with little damage to the surrounding healthy tissues. Graphene oxide is a promising 2D material found to play an important role in cancer treatments through several strategies: direct killing and chemosensitization, drug and gene delivery, and phototherapy. Several new treatment approaches based on nanoparticles, particularly graphene oxide, are currently under research in clinical trials, and some have already been approved. Here, we provide an update on the recent advances in nanomaterials-based CRC-targeted therapy, with special attention to graphene oxide nanomaterials. We summarise the epidemiology, carcinogenesis, stages of the CRCs, and current nanomaterials-based therapeutic approaches for its treatment.

Microbiome Analysis in Patients with Colorectal Cancer by 16S Ribosomal RNA Sequencing in the Southeast of Iran

Background: Colorectal cancer (CRC) is the third most common malignant tumor worldwide. Emerging evidence suggests that dysbiosis of the colon microbiome may be involved in CRC development. Objectives: The present study aimed to compare the composition and diversity of the colon microbiome by high-throughput 16S ribosomal RNA (rRNA) sequencing between CRC patients and healthy controls. Microbiome composition and diversity were also examined based on gender. Methods: The colon microbiome richness and diversity of samples from 17 CRC patients and 13 healthy controls were analyzed by 16S rRNA sequencing. Alpha and beta diversity were calculated to determine the differences in colon microbiome diversity. Results: Alpha and beta diversity showed significant differences between the CRC and healthy control groups regarding the microbiome. Our results showed that CRC samples had the highest richness and diversity. The total number (P ≤ 0.01), phylogenetic diversity (P ≤ 0.01), Chao1 (P ≤ 0.01), Shannon (P ≤ 0.05), and Simpson (P ≤ 0.01) indices were significantly higher in the CRC group than in the healthy control group. In addition, the comparison between females and males showed that the microbiome diversity was higher in the CRC female (CRC-F) group than in other groups. Prevotella, Fusobacterium, Akkermansia, Leptotrichia, Streptococcus, and ParaBacteroides were more commonly observed in the CRC group, while Bacteroides, Enterobacteriaceae (unknown genus), Ruminococcus, and Campylobacter were more commonly observed in the healthy control group. Conclusions: This study showed differences between the CRC and healthy control groups regarding the diversity and composition of the colon microbiome, suggesting a contribution of the microbiome in the development and progression of CRC.