Initiation Of Colorectal Cancer Research Articles

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

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. 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. 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. 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.

The crosstalk between intestinal bacterial microbiota and immune cells in colorectal cancer progression.

Different types of cells that are involved in tumor immunity play a significant part in antitumor therapy. The intestinal microbiota consist of the trillions of diverse microorganisms that inhabit the gastrointestinal tract. Recently, much emphasis has been paid to the link between these symbionts and colorectal cancer (CRC). This association might be anything from oncogenesis and cancer development to resistance or susceptibility to chemotherapeutic medicines. Cancer patients have a significantly different microbial composition in their guts compared to healthy persons. The microbiome may play a role in the development and development of cancer through the modulation of tumor immunosurveillance, as shown by these studies; however, the specific processes underlying this role are still poorly understood. This review focuses on the relationship between the intestinal bacterial microbiota and immune cells to determine how the commensal microbiome influences the initiation and development of CRC.

SiRNA-based delivery nanoplatform attenuates the CRC progression via HIF1α-AS2

Colorectal cancer (CRC) is one of the most common malignancies and the leading causes of cancer-related deaths in the world. However, the molecular mechanisms of colorectal carcinogenesis and metastasis remain unknown. Long non-coding RNAs (lncRNAs) have been implicated to be in the initiation and malignant progression of CRC. In this study, we identified a novel oncogenic lncRNA HIF1α-AS2 in CRC patients by combination with lncRNA microarray and qRT-PCR. HIF1α-AS2 is upregulated progressively in adjacent non-tumor tissues to adenoma to CRC and contributes to CRC aggressive phenotypes. RNA-sequence assays and luciferase reporter assays were performed to reveal that upregulation of lncRNA HIF1α-AS2 may lead to the increased expression of HIF1α via competitively binding to miR-155–5p, miR-340–5p, miR-580–5p and miR-590–3p in CRC initiation, whereas HIF1α may work as a cellular sponge to directly interact with the RMRP promoter to promote RMRP transcription determined by chromatin immunoprecipitation and RNA-sequence assays. Data from RNA Binding Protein Immunoprecipitation and mass spectrometry revealed that RMRP-mediated an increased level of IGF2 expression promotes CRC progression and metastasis by competitively sponging IGF2R. Lastly, we developed mPEG-DSPE liposomes encapsulated with siRNA HIF1α-AS2, which exhibited desirable physicochemical properties along with narrow well-dispersion stability and significantly prevented the progression of CRC, indicating that mPEG-DSPE-liposome-encapsulated HIF1α-AS2 siRNA might be a potential biomarker and therapeutic target for CRC therapy.

SLC11A1 associated with tumor microenvironment is a potential biomarker of prognosis and immunotherapy efficacy for colorectal cancer.

Colorectal cancer (CRC) is one of the most lethal cancers of the digestive system. The tumor microenvironment (TME) plays a central role in the initiation and development of CRC. However, little is known about the modulation mechanism of the TME in CRC. In our study, we attempted to identify a biomarker related to the TME modulation that could serve as a potential prognostic biomarker for CRC. We identified differentially expressed genes between the ImmuneScore high/low and StromalScore high/low groups. Using univariate COX regression analysis and hub gene analysis (cytoHubba), SLC11A1 was identified as the only candidate gene for subsequent analysis. CIBERSORT, EPIC, MCPcounter, and immunogenic cell death were performed to evaluate the effect of SLC11A1 on the TME. We also collected samples and performed Real-time quantitative PCR to verify the expression levels of SLC11A1 in CRC and adjacent normal tissues. The IMvigor210 cohort, TIDE score, and immunophenoscore (IPS) were used to analyze the association between SLC11A1 and immunotherapy efficacy. SLC11A1 was highly expressed in CRC tissues compared with its expression in normal colorectal tissues and was associated with poor prognosis and advanced clinicopathological stages. Gene set enrichment analysis showed that TGF-β pathways, JAK-STAT pathways, and angiogenesis were significantly enriched in the high-SLC11A1 group. Single-cell analysis validated the correlation between SLC11A1 and the TME. Using CIBERSORT, EPIC, and MCPcounter algorithms, we found that there was more macrophage and fibroblast infiltration in the SLC11A1 high-expression group. Meanwhile, high-SLC11A1 patients had lower IPS scores, higher TIDE scores, and fewer immunotherapy benefits than those of low-SLC11A1 patients. In conclusion, SLC11A1 plays a crucial role in the TME and could serve as a potential biomarker for poor prognosis and immunotherapy efficacy in CRC.

Effects of gut microbiota on immune responses and immunotherapy in colorectal cancer.

Accumulating evidence suggests that gut microbial dysbiosis is implicated in colorectal cancer (CRC) initiation and progression through interaction with host immune system. Given the intimate relationship between the gut microbiota and the antitumor immune responses, the microbiota has proven to be effective targets in modulating immunotherapy responses of preclinical CRC models. However, the proposed putative mechanisms of how these bacteria affect immune responses and immunotherapy efficacy remains obscure. In this review, we summarize recent findings of clinical gut microbial dysbiosis in CRC patients, the reciprocal interactions between gut microbiota and the innate and/or the adaptive immune system, as well as the effect of gut microbiota on immunotherapy response in CRC. Increased understanding of the gut microbiota-immune system interactions will benefit the rational application of microbiota to the clinical promising biomarker or therapeutic strategy as a cancer immunotherapy adjuvant.

Intestinal Apc-inactivation induces HSP25 dependency.

The majority of colorectal cancers (CRCs) present with early mutations in tumor suppressor gene APC. APC mutations result in oncogenic activation of the Wnt pathway, which is associated with hyperproliferation, cytoskeletal remodeling, and a global increase in mRNA translation. To compensate for the increased biosynthetic demand, cancer cells critically depend on protein chaperones to maintain proteostasis, although their function in CRC remains largely unexplored. In order to investigate the role of molecular chaperones in driving CRC initiation, we captured the transcriptomic profiles of murine wild type and Apc-mutant organoids during active transformation. We discovered a strong transcriptional upregulation of Hspb1, which encodes small heat shock protein 25 (HSP25). We reveal an indispensable role for HSP25 in facilitating Apc-driven transformation, using both invitro organoid cultures and mouse models, and demonstrate that chemical inhibition of HSP25 using brivudine reduces the development of premalignant adenomas. These findings uncover a hitherto unknown vulnerability in intestinal transformation that could be exploited for the development of chemopreventive strategies in high-risk individuals.

Metabolism and Colorectal Cancer.

Reprogrammed metabolism is a hallmark of colorectal cancer (CRC). CRC cells are geared toward rapid proliferation, requiring nutrients and the removal of cellular waste in nutrient-poor environments. Intestinal stem cells (ISCs), the primary cell of origin for CRCs, must adapt their metabolism along the adenoma-carcinoma sequence to the unique features of their complex microenvironment that include interactions with intestinal epithelial cells, immune cells, stromal cells, commensal microbes, and dietary components. Emerging evidence implicates modifiable risk factors related to the environment, such as diet, as important in CRC pathogenesis. Here, we focus on describing the metabolism of ISCs, diets that influence CRC initiation, CRC genetics and metabolism, and the tumor microenvironment. The mechanistic links between environmental factors, metabolic adaptations, and the tumor microenvironment in enhancing or supporting CRC tumorigenesis are becoming better understood. Thus, greater knowledge of CRC metabolism holds promise for improved prevention and treatment.

The Incredible Potential of Exosomes as Biomarkers in the Diagnosis of Colorectal Cancer.

Colorectal cancer (CRC) is common cancer that is one of the leading causes of cancerrelated deaths around the world. The creation of new biomarkers for this disease is an important public health strategy for lowering the disease's mortality rate. According to new research, exosomes may be important sources of biomarkers in CRC. Exosomes are nanometer-sized membrane vesicles (30-200 nm) secreted by normal and cancer cells that transport RNA and proteins between cells and are thought to help with intercellular communication. Exosomes have been linked to CRC initiation and progression, and some differentially expressed RNAs and proteins in exosomes have been identified as potential cancer detection candidates. As a result, studying the relationship between exosomes and CRC may aid in the development of new biomarkers for the disease. This article discusses the importance of exosomes as biomarkers in the diagnosis of CRC, as well as their use in the treatment of CRC metastasis, chemoresistance, and recrudescence. The benefits and drawbacks of using exosomes as tumour markers are also discussed.

The Ion Channel Gene KCNAB2 Is Associated with Poor Prognosis and Loss of Immune Infiltration in Lung Adenocarcinoma.

The malignancy with the greatest global mortality rate is lung cancer. Lung adenocarcinoma (LUAD) is the most common subtype. The evidence demonstrated that voltage-gated potassium channel subunit beta-2 (KCNAB2) significantly participated in the initiation of colorectal cancer and its progression. However, the biological function of KCNAB2 in LUAD and its effect on the tumor immune microenvironment are still unknown. In this study, we found that the expression of KCNAB2 in tissues of patients with LUAD was markedly downregulated, and its downregulation was linked to accelerated cancer growth and poor clinical outcomes. In addition, low KCNAB2 expression was correlated with a deficiency in immune infiltration. The mechanism behind this issue might be that KCNAB2 influenced the immunological process such that the directed migration of immune cells was affected. Furthermore, overexpression of KCNAB2 in cell lines promoted the expression of CCL2, CCL3, CCL4, CCL18, CXCL9, CXCL10, and CXCL12, which are necessary for the recruitment of immune cells. In conclusion, KCNAB2 may play a key function in immune infiltration and can be exploited as a predictive biomarker for evaluating prognosis and a possible immunotherapeutic target.

Colorectal cancer, Vitamin D and microbiota: A double-blind Phase II randomized trial (ColoViD) in colorectal cancer patients

BackgroundSeveral studies suggest a role of gut microbiota in colorectal cancer (CRC) initiation and progression. Vitamin D (vitD) blood levels are also inversely correlated with CRC risk and prognosis. However, these factors’ interplay remains unknown. Methods74 CRC patients after standard treatment were randomized to 1-year 2000 IU/day vitD or placebo. Baseline and post-treatment fecal microbiota for shotgun metagenomics sequencing was collected. Coda-lasso and Principal Component Analysis were used to select and summarize treatment-associated taxa and pathways. Associations between vitD and taxa/pathways were investigated with logistic regression. Mediation analysis was performed to study if treatment-associated taxa mediated the effect of supplementation on 25(OH)D levels. Cox proportional-hazards model was used for disease-free survival (DFS). Results60 patients were analyzed. Change in alpha diversity (Shannon: p = 0.77; Simpson: p = 0.63) and post-treatment beta diversity (p = 0.70) were comparable between arms. Post-treatment abundances of 63 taxa and 32 pathways differed between arms. The 63 taxa also mediated the effect of supplementation on 25(OH)D (p = 0.02). There were sex differences in vitD levels, microbiota and pathways. Pathways of essential amino acids’ biosynthesis were more abundant in supplemented women. Fusobacterium nucleatum presence at baseline was associated with worse DFS (p = 0.02). Those achieving vitD sufficiency (25(OH)D≥30 ng/ml) had lower post-treatment abundances (p = 0.05). Women were more likely to have F. nucleatum post-treatment (p = 0.02). ConclusionsVitD supplementation may contribute shaping the gut microbiota and the microbiota may partially mediate the effect of supplementation on 25(OH)D. The observed sex-specific differences highlight the necessity of including sex/gender as a variable in microbiome studies.

Targeting lncRNA/Wnt axis by flavonoids: A promising therapeutic approach for colorectal cancer.

Despite the dramatic advances in our understanding of the etiology of colorectal cancer (CRC) in recent decades, effective therapeutic strategies are still urgently needed. Oncogenic mutations in the Wnt/β-Catenin pathway are hallmarks of CRC. Moreover, long non-coding RNAs (lncRNAs) as molecular managers are involved in the initiation, progression, and metastasis of CRC. Therefore, it is important to further explore the interaction between lncRNAs and Wnt/β-Catenin signaling pathway for targeted therapy of CRC. Natural phytochemicals have not toxicity and can target carcinogenesis-related pathways. Growing evidences suggest that flavonoids are inversely associated with CRC risk. These bioactive compounds could target carcinogenesis pathways of CRC and reduced the side effects of anti-cancer drugs. The review systematically summarized the progress of flavonoids targeting lncRNA/Wnt axis in the investigations of CRC, which will provide a promising therapeutic approach for CRC and develop nutrition-oriented preventive strategies for CRC based on epigenetic mechanisms. In the field, more epidemiological and clinical trials are required in the future to verify feasibility of targeting lncRNA/Wnt axis by flavonoids in the therapy and prevention of CRC.

C-MYC Protein Stability Is Sustained by MAPKs in Colorectal Cancer.

Simple SummaryColorectal cancer (CRC) is the most common gastrointestinal tract malignancy. Previous reports have shown that cancerous phenotypes in the intestine are dependent on c-MYC target gene expression. Unfortunately, finding c-MYC inhibitors has proven difficult because c-MYC does not have a deep surface-binding pocket. Considering that c-MYC is maintained upregulated through β-catenin-mediated transcriptional activation and ERK-mediated post-translational stabilization, and since we have previously demonstrated that c-MYC transcriptional activation is affected by p38α as a β-catenin chromatin-associated kinase, here, we investigated p38α’s involvement in c-MYC protein stabilization in CRC. Interestingly, we found that p38α sustains c-MYC’s stability by preventing its ubiquitination and proteasomal degradation. Moreover, we showed that p38α inhibitors exhibit a synthetic lethality effect when used in combination with MEK inhibitors in CRC cells. Our findings identify p38α as a promising therapeutic target that acts on the pharmacologically “undruggable” c-MYC protein, with implications for countering c-MYC-mediated CRC proliferation, metastasization, and chemoresistance. c-MYC is one of the most important factors involved in colorectal cancer (CRC) initiation and progression; indeed, it is found to be upregulated in up to 80% of sporadic cases. During colorectal carcinogenesis, c-MYC is maintained upregulated through β-catenin-mediated transcriptional activation and ERK-mediated post-translational stabilization. Our data demonstrate that p38α, a kinase involved in CRC metabolism and survival, contributes to c-Myc protein stability. Moreover, we show that p38α, like ERK, stabilizes c-MYC protein levels by preventing its ubiquitination. Of note, we found that p38α phosphorylates c-MYC and interacts with it both in vitro and in cellulo. Extensive molecular analyses in the cellular and in vivo models revealed that the p38α kinase inhibitors, SB202190 and ralimetinib, affect c-MYC protein levels. Ralimetinib also exhibited a synthetic lethality effect when used in combination with the MEK1 inhibitor trametinib. Overall, our findings identify p38α as a promising therapeutic target, acting directly on c-MYC, with potential implications for countering c-MYC-mediated CRC proliferation, metastatic dissemination, and chemoresistance.

Comprehensive characterization of ubiquitinome of human colorectal cancer and identification of potential survival-related ubiquitination

BackgroundAccording to the Global Cancer Statistics in 2020, the incidence and mortality of colorectal cancer (CRC) rank third and second among all tumors. The disturbance of ubiquitination plays an important role in the initiation and development of CRC, but the ubiquitinome of CRC cells and the survival-relevant ubiquitination are poorly understood.MethodsThe ubiquitinome of CRC patients (n = 6) was characterized using our own data sets of proteomic and ubiquitin-proteomic examinations. Then, the probable survival-relevant ubiquitination was searched based on the analyses of data sets from public databases.ResultsFor the ubiquitinomic examination, we identified 1690 quantifiable sites and 870 quantifiable proteins. We found that the highly-ubiquitinated proteins (n ≥ 10) were specifically involved in the biological processes such as G-protein coupling, glycoprotein coupling, and antigen presentation. Also, we depicted five motif sequences frequently recognized by ubiquitin. Subsequently, we revealed that the ubiquitination content of 1172 proteins were up-regulated and 1700 proteins were down-regulated in CRC cells versus normal adjacent cells. We demonstrated that the differentially ubiquitinated proteins were relevant to the pathways including metabolism, immune regulation, and telomere maintenance. Then, integrated with the proteomic datasets from the Clinical Proteomic Tumor Analysis Consortium (CPTAC) (n = 98), we revealed that the increased ubiquitination of FOCAD at Lys583 and Lys587 was potentially associated with patient survival. Finally, we depicted the mutation map of FOCAD and elucidated its potential functions on RNA localization and translation in CRC.ConclusionsThe findings of this study described the ubiquitinome of CRC cells and identified abnormal ubiquitination(s) potentially affecting the patient survival, thereby offering new probable opportunities for clinical treatment.

S151 Examination of Downregulated miRNAs and Associated Pathways in Colorectal Cancer: A Systematic Review

Introduction: Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths worldwide. Many biological molecules play a significant role in the pathogenesis of CRC including miRNAs, small RNA molecules that regulate the translation and stability of specific target mRNAs. Given the involvement of miRNAs on all fronts of CRC including pathogenesis, diagnosis, prognosis and potential therapy, it is imperative to fully understand their role within this deadly disease. With this study, we examined unique miRNAs which were upregulated in patients with CRC. Methods: We searched PubMed and the Cochrane Database of Systematic Reviews (CDSR) through Wiley from 2016 to 2022 for keywords “miRNA”,” micro-RNA”, “colon cancer”, “colorectal cancer”, “CRC”. From this data, we performed computational analysis using MicroInspector, miRanda, PicTar, RNA22, DIANA, softwares and identified unique upregulated miRNAs. We further examined the list of the biological pathways identified from predicted target genes of downregulated miRNAs and selected the top 4 pathways of clinical significance. We then filtered common miRNAs between these selected pathways and identified unique miRNAs between the top 4 pathways. Results: Through our computational analysis, we identified 59 upregulated miRNAs from studies of patients with CRC. We then identified a list of the biological pathways identified from downregulated miRNAs target genes. We also highlighted the relevant pathways which are associated with cancer including: MAPK signaling pathway (p -value 2.79 E-08), ErbB signaling (p-value 6.69E-08), PI3K-Akt (p-value 2.87E-06). We further investigated the highlighted pathways and found unique miRNAs associated with these pathways. Namely, hsa-mir-296-3p and hsa-mir-198-3p were identified, suggesting that these miRNAs may play an important role in those pathways. (Table) Conclusion: MicroRNAs play an important role in CRC initiation, progression, and development through manipulation of cell stemness, angiogenesis, apoptosis, and the epithelial–mesenchymal transition (EMT) of tumor cells. With this study we identified unique clinically relevant metabolic pathways of CRC affected by downregulated miRNAs. We also identified the unique miRNAs hsa-mir-296b-3p and hsa-mir-198-3p. Further work is necessary to identify specific roles of these miRNA candidates as biological markers or therapeutic targets for patients with CRC. Table 1. - List of the biological pathways identified from predicted target genes of downregulated miRNAs Pathway p-value #genes #miRNAs ECM-receptor interaction 4.97E-32 58 23 Proteoglycans in cancer 6.89E-12 124 26 Focal adhesion 5.81E-09 137 27 MAPK signaling pathway 2.79E-08 158 26 ErbB signaling pathway 6.69E-08 60 25 Renal cell carcinoma 4.80E-07 49 25 Axon guidance 1.08E-06 83 27 Regulation of actin cytoskeleton 2.17E-06 129 27 PI3K-Akt signaling pathway 2.87E-06 197 28 Rap1 signaling pathway 3.71E-06 127 26

Exosomal noncoding RNAs in colorectal cancer: An overview of functions, challenges, opportunities, and clinical applications.

Colorectal cancer (CRC) is the third most threatening malignancy worldwide. Colorectal tumors transfer information with their tumor microenvironment (TME) and communicate together which can be detected through exosome transmission. Exosomes are important regulators made by different types of cells in all body fluids containing RNA, DNA, metabolites, and proteins. Recently, Exosome-derived noncoding RNAs (ncRNAs) applications have gained great consideration based on their potential role in the different pathological processes. Therefore, in this review, we summarized the recent discoveries on exosomal ncRNAs function in CRC initiation and development, and drug resistance to provide a novel insight into exosomal ncRNAs' clinical application and their potential to be biomarkers for CRC patients.

S262 Impact of Younger Age Inclusion on Adenoma Detection Rate in an African American Predominant Screening Population

Introduction: Recent guidelines have lowered the age for initiation of colorectal cancer (CRC) screening to 45. The current benchmark for adenoma detection rate (ADR) for screening colonoscopy in men and women 50 years and older are 30% and 20%, respectively. It is unclear if the adenoma detection rate (ADR) will need to be lowered to accommodate for a younger patient population with a presumably lower adenoma burden. Our study’s objective was to evaluate the ADR in a largely African American population comparing 45–49-year-old men and women to those 50 and older Methods: We performed a retrospective review of our endoscopy database for all patients ages 45-73 who underwent average-risk screening colonoscopy at our institution. All average-risk screening colonoscopies for patients 50 years and older in the year 2017 and colonoscopies for patients younger than 50 from 2017 to 2021. We analyzed patients’ race, age, pathologic findings, and bowel preparation. Colonoscopies were excluded if the cecum was not reached, or the bowel preparation was inadequate. Statistical analysis was performed utilizing Chi-square testing with significance set at a P < 0.05 Results: A total of 1267 average-risk colonoscopies were performed for patients between 45-73 years. After applying our exclusion criteria, 1152 colonoscopies were analyzed, Table. The overall ADR was 35.4%, with a statistically significant difference between patients ≥50 years and < 50 years (38.4% vs 28.7%, p=0.002). ADR correlated with age, Figure. ADR for males was higher than females (41.4% vs 30.4%, p< 0.001). There was no statistically significant difference in ADR between African Americans and non-African Americans (35.2% vs 35.6%, p=0.822) Conclusion: In our predominantly African American patient population undergoing average-risk screening colonoscopy, we found an increase in ADR with age. Despite the inclusion of patients 45-49 years of age with a lower adenoma burden, ADR thresholds recommended by the GI societies were still attainable in this patient population. Endoscopists with a large young patient panel should expect a lower ADR but should not expect a drop in the ADR below the 25% benchmarkFigure 1.: Adenoma Detection Rate Correlation with Age Table 1. - Patient characteristics in patients with or without adenomas. (N=1152) Patient characteristic (N, %) Adenoma: N (%) No Adenoma: N (%) P-value Gender Female (626, 54.3) Male (526, 45.7) 190 (30.4)218 (41.4) 436 (69.6)308 (58.6) < 0.001 Race African American (952, 82.6%) Non-African American (160, 13.9) Unknown (40, 3.5) 335 (35.2)57 (35.6)16 (40.0) 617 (64.8)103 (64.4)24 (60.0) 0.822 Age, Years < 50 (349, 30.3) ≥50 (803, 69.7) 100 (28.7)308 (38.4) 249 (71.3)495 (61.6) 0.002

Wnt signaling modulator DKK4 inhibits colorectal cancer metastasis through an AKT/Wnt/β-catenin negative feedback pathway

Aberrant activation of the Wnt/β-catenin signaling pathway is implicated in most malignant cancers, especially in the initiation and progression of colorectal cancer (CRC). DKK4 is a classical inhibitory molecule of the Wnt/β-catenin pathway, but its role in CRC is ambiguous, and the molecular mechanism remains unclear. Here, we determined DKK4 expression was significantly upregulated in 23 CRC cell lines and 229 CRC tissues when analyzed by quantitative PCR and immunohistochemistry, respectively. Our analysis of tissue samples indicated the survival time of CRC patients with high DKK4 expression was longer than that of patients with medium-low DKK4 expression. We examined the effects of DKK4 on cell proliferation and metastasis by cell counting kit-8 assays, transwell assays, and subcutaneous and metastatic mouse tumor models, and we discovered that DKK4 silencing promoted the metastasis of CRC cells both invitro and invivo. Our RNA-seq analysis revealed that AKT2, FZD6, and JUN, which play important roles in AKT and Wnt signaling, were significantly increased after DKK4 knockdown. DKK4 represses Wnt/β-catenin signaling by repressing FZD6 and AKT2/s552 β-catenin in CRC. Further experiments revealed recombinant Wnt3a and LiCl could induce DKK4 expression. Moreover, our bioinformatics analysis and luciferase reporter assays identified posttranscriptional regulators of DKK4 in CRC cells. In summary, DKK4 is elevated in CRC and inhibits cell metastasis by a novel negative feedback mechanism of the Wnt3a/DKK4/AKT/s552 β-catenin regulatory axis to restrict overactivation of Wnt activity in CRC. Therefore, DKK4 restoration may be applied as a potential CRC therapeutic strategy.

Assessing Putative Markers of Colorectal Cancer Stem Cells: From Colonoscopy to Gene Expression Profiling.

Cancer stem cells (CSCs) are proposed to be involved in colorectal cancer (CRC) initiation, growth, and metastasis. The aim of our pilot study was to assess possible correlations between the clinicopathological characteristics of CRC patients and CSCs gene expression patterns, in order to provide insight into new methods for patient stratification and targeted therapeutic strategies. Our study involved 60 CRC patients, and the following three specific CSC genes were targeted: PROM1/CD133, ALCAM/CD166 and HCAM /CD44. Data are presented as relative mRNA expression of target genes to GAPDH. The expression of total CD133 and CD166 was assessed in paired samples of CRC tumors and adjacent tissue, while CD44 was assessed in similar samples. The qRT-PCR analysis detected all three targeted genes to different extents, in both normal and tumor tissue. In nine cases (15.69%), total CD133 had a higher expression in tumor tissue, whilst in 28 cases (47.06%) the expression was higher in non-malignant peritumor tissue. The total CD166 expression was increased in tumor tissue compared with paired non-invaded peritumor samples in eight cases (13.73%), whilst in eight cases (13.73%) the expression was higher in non-malignant peritumor tissue. Total CD44 expression was higher in tumor tissue compared with paired non-invaded peritumor samples in 47 cases (78.95%). In the remaining cases the difference between paired samples was biologically insignificant. In conclusion, our study suggests that qRT-PCR is feasible in assessing the gene expression profiles of CSCs from CRC, and a promising pathway to be followed for determining how often a person needs screening by colonoscopy and at which age to start. This could improve CRC diagnosis and early patient stratification, and open the way for new oncologic treatment development.

Colorectal Cancer Initiative

The objective of this project was to improve the number of patients between the age of 50-75 years at Riverside Medical Center who perform colorectal cancer (CRC) screening after implementation of an intervention in the form of a letter that was sent out to a specific group of patients who had failed to meet any form of screening for colorectal cancer.

Cuproptosis patterns and tumor immune infiltration characterization in colorectal cancer.

Faced with the high heterogeneity and poor prognosis of colorectal cancer (CRC), this study sought to find new predictive prognostic strategies to improve the situation. Cuproptosis is a novel cell death mechanism that relies on copper regulation. However, the role of cuproptosis-related gene (CRG) in CRC remains to be elucidated. In this study, we comprehensively assessed the CRG landscape in CRC based on The Cancer Genome Atlas (TCGA). We identified differential expression and genetic alterations of CRG in CRC. CRG is highly correlated with initiation, progression, prognosis, and immune infiltration of CRC. We construct a risk score signature containing 3 CRGs based on LASSO. We explored the correlation of CRG-Score with clinicopathological features of CRC. Age, stage, and CRG-Score were integrated to construct a nomogram. The nomogram has robust predictive performance. We also understand the correlation of CRG-Score with CRC immune landscape. CRG-Score can effectively predict the immune landscape of CRC patients. Low-risk CRC patients have greater immunogenicity and higher immune checkpoint expression. Low-risk CRC patients may be better candidates for immunotherapy. At the same time, we also predicted more sensitive drugs in the high-risk CRC patients. In conclusion, the CRG risk score signature is a strong prognostic marker and may help provide new insights into the treatment of individuals with CRC.