Features Of Colorectal Cancer Research Articles

Detection and characterization of colorectal cancer by autofluorescence lifetime imaging on surgical specimens.

Colorectal cancer (CRC) ranks among the most prevalent malignancies worldwide, driving a quest for comprehensive characterization methods. We report a characterization of the ex vivo autofluorescence lifetime fingerprint of colorectal tissues obtained from 73 patients that underwent surgical resection. We specifically target the autofluorescence characteristics of collagens, reduced nicotine adenine (phosphate) dinucleotide (NAD(P)H), and flavins employing a fiber-based dual excitation (375nm and 445nm) optical imaging system. Autofluorescence-derived parameters obtained from normal tissues, adenomatous lesions, and adenocarcinomas were analyzed considering the underlying clinicopathological features. Our results indicate that differences between tissues are primarily driven by collagen and flavins autofluorescence parameters. We also report changes in the autofluorescence parameters associated with NAD(P)H that we tentatively attribute to intratumoral heterogeneity, potentially associated to the presence of distinct metabolic subpopulations. Changes in autofluorescence signatures of malignant tumors were also observed with lymphatic and venous invasion, differentiation grade, and microsatellite instability. Finally, we characterized the impact of radiative treatment in the autofluorescence fingerprints of rectal tissues and observed a generalized increase in the mean lifetime of radiated adenocarcinomas, which is suggestive of altered metabolism and structural remodeling. Overall, our preliminary findings indicate that multiparametric autofluorescence lifetime measurements have the potential to significantly enhance clinical decision-making in CRC, spanning from initial diagnosis to ongoing management. We believe that our results will provide a foundational framework for future investigations to further understand and combat CRC exploiting autofluorescence measurements.

Impact ofCOVID-19 Pandemic on the Clinical and Pathologic Characteristics ofColorectal Cancer: A Retrospective Multicenter Study in South Korea.

The COVID-19 pandemic has influenced various aspects of colorectal cancer (CRC) patient care, including diagnosis, treatment, and outcomes. This study assesses the pandemic's impact on CRC patients. We performed a retrospective analysis of medical records for CRC patients who underwent surgery at five hospitals affiliated with Hallym University from January 2017 to December 2022. Patients were divided into two groups: the pre-COVID group (2017-2019) and the COVID group (2020-2022). Among 2038 patients, 987 (48.4%) were in the pre-COVID group, and 1051 (51.6%) were in the COVID group. The COVID group had more patients with two or more comorbidities (P < 0.001) and a higher incidence of rectal cancer (P = 0.010). While the rates of laparoscopic surgeries were similar, the COVID group had increased emergency surgeries (P = 0.005) and diversion procedures (P = 0.002). Additionally, the COVID group faced more overall complications (P < 0.001) and severe complications (Grade III-V, P = 0.004). There was a rise in lymphovascular invasion (P < 0.001) and T4 stage tumors (P < 0.001) within the COVID group. Despite these differences, both groups had similar 2-year overall survival rates (P = 0.409). Although patients treated during the COVID period experienced more frequent stoma formation, complications, and adverse prognostic factors, there were no differences in short-term oncologic outcomes, which was likely due to the follow-up period being insufficient to detect differences in OS.

RAS/RAF mutations and microsatellite instability status in primary colorectal cancers according to HER2 amplification.

HER2 amplification-associated molecular alterations and clinicopathologic features in colorectal cancers (CRCs) have not been well established. In this study, we assessed the prevalence of HER2 amplification and microsatellite instability (MSI) status of 992 patients with primary CRC. In addition, molecular alterations of HER2 amplified and unamplified CRCs were examined and compared by next-generation sequencing. HER2 amplifications were found in 41 (4.1%) of 992 primary CRCs. HER2 amplification was identified in 1.0% of the right colonic tumors, 5.1% of the left colonic tumors, and 4.8% of the rectal tumors. Approximately 95% of HER2 amplification was observed in the left colon and rectum. Seven (87.5%) of eight metastatic tumors showed HER2 amplification. Most clinicopathologic features were unrelated to HER2 amplification except tumor size and MSI status. All 41 HER2 amplified CRCs were microsatellite stable. In a molecular analysis of frequently identified somatic mutations in CRCs, HER2 amplified CRCs showed a lower rate of KRAS mutations (24.4%) but a higher rate of TP53 mutations (83%) than unamplified CRCs. No BRAF and NRAS mutations were identified in HER2 amplified CRCs. Our study suggests that HER2 amplified CRCs are mutually exclusive of MSI and harbor less frequent KRAS/NRAS/BRAF mutations but frequent T53 mutations.

Association of the TRIM family protein with survival outcomes and clinicopathological features in colorectal cancer: a systematic review and meta-analysis

BackgroundThe tripartite motif (TRIM) proteins have been reported to play crucial roles in various malignancies. However, the clinical significance of TRIM proteins in colorectal cancer (CRC) remains controversial. This study aimed to evaluate the association between TRIM proteins and the clinicopathological features and survival outcomes in patients with CRC.MethodsWe performed a meta-analysis to investigate whether TRIM is a prognostic factor in CRC. PubMed, Embase, Web of Science, CNKI and Weipu databases were searched to identify eligible studies that evaluated the association between TRIM proteins and overall survival (OS), as well as the clinicopathological features of patients with CRC. Hazard ratios (HR) or odds ratios (OR) with 95% confidence interval (CI) were derived and pooled using a fixed-effects model.ResultsFrom inception to March 2023, we extracted study characteristics and prognostic data for each identified study. Twelve studies enrolling 1608 patients were eligible for inclusion. Data on OS and recurrence-free survival (RFS) were available for 12 and 2 studies, respectively. The pooled analysis results showed a significant correlation between the elevated TRIM proteins and shorter OS (HR = 2.42, 95% CI: 1.96–2.99) and worse RFS (HR = 2.51, 95% CI: 1.78–3.54) in patients with CRC. The combined ORs indicated that TRIM protein over-expression was significantly associated with advanced TNM stage (OR = 2.26, 95% CI: 1.25–4.10), deep tumor invasion (OR = 2.01, 95% CI: 1.04–3.88), lymph node metastasis (OR = 2.99, 95% CI: 2.19–4.09) and perineural invasion (OR = 1.95, 95% CI: 1.18–3.23).ConclusionsOur findings suggest that TRIM proteins can predict tumor progression and poor prognosis in CRC. Therefore, TRIM proteins may be promising therapeutic targets for patients with CRC.Graphical

Characterization of colorectal cancer by hierarchical clustering analyses of five immune cell markers.

The present study analyzed the expression of five independent immunohistochemical markers, CD4, CD8, CD66b, CD68, and CD163, on immune cells within the colorectal cancer (CRC) tumor microenvironment (TME). Using hierarchical clustering, patients were successfully classified according to significant associations with clinicopathological features and/or survival. Patients with mismatch repair-proficient (pMMR) CRC were categorized into four groups with survival differences (p = 0.0084): CD4Low , CD4High , MΦHigh , and CD8Low . MΦHigh tumors showed significantly higher expression of CD47 (p < 0.0001), a phagocytosis checkpoint molecule. These tumors contained significantly greater numbers of PD-1+ (p < 0.0001), TIM-3+ (p < 0.0001), and SIRPA+ (p < 0.0001) immune cells. Notably, 10% of the patients with pMMR CRC expressed PD-L1 (CD274) on tumor cells with significantly worse survival (p = 0.00064). The Cox proportional hazards model identified MΦ High (hazard ratio [HR] = 2.02, 95%, p = 0.032), CD8Low (HR = 2.45, p = 0.011), and tumor PD-L1 expression (HR = 2.74, p = 0.0061) as potential risk factors. PD-L1-PD-1 and/or CD47-SIRPA axes targeting immune checkpoint therapies might be considered for patients with pMMR CRC according to their tumor cells and tumor immune microenvironment characteristics.

Notch receptor/ligand diversity: contribution to colorectal cancer stem cell heterogeneity.

Cancer cell heterogeneity is a key contributor to therapeutic failure and post-treatment recurrence. Targeting cell subpopulations responsible for chemoresistance and recurrence seems to be an attractive approach to improve treatment outcome in cancer patients. However, this remains challenging due to the complexity and incomplete characterization of tumor cell subpopulations. The heterogeneity of cells exhibiting stemness-related features, such as self-renewal and chemoresistance, fuels this complexity. Notch signaling is a known regulator of cancer stem cell (CSC) features in colorectal cancer (CRC), though the effects of its heterogenous signaling on CRC cell stemness are only just emerging. In this review, we discuss how Notch ligand-receptor specificity contributes to regulating stemness, self-renewal, chemoresistance and cancer stem cells heterogeneity in CRC.

Correlation between Stool DNA-based SDC2 Methylation Tests Combined with Tumor Markers with Pathological Features in Colorectal Cancer.

Colorectal cancer (CRC) screening is the most efficient strategy to reduce disease-related mortality. In this study, we aimed to investigate the association of a methylation-based stool DNA test with serum protein biomarker panel (CEA, CA125, CA199, and AFP) in CSC patients and their relationship with pathological features to improve the diagnostic efficacy and applicability in CSC in the Chinese population. In this double-blinded case-control study, we enrolled 150 participants from our hospital, including 50 CRC patients, 50 adenomas, and 50 healthy controls. We compared the cycling threshold (Ct) values of stool DNA-based SDC2 measured by quantitative methylation-specific PCR (MSP) in the three groups. We also evaluated the differences and correlation between serum concentrations of tumor biomarker and pathological features in patients with CSC, including TNM stage (I, II, III), tumor size, and lymph node metastasis. The discrimination performance of indexes was assessed using sensitivity, specificity, and the area under the receiver operating characteristic curve (AUC). CSC was more common in middle-aged people and men. The methylation-based stool DNA test was not significantly correlated with other tumor indicators except CEA, and the difference was statistically significant. Compared with the normal control group, the combined diagnostic value of the methylation-based stool DNA test and tumor indicators was significantly higher than individual biomarkers alone, especially the methylation-based stool DNA test combined with CEA and AFP, which improved the AUC to 0.96. This combination can increase the positive rate of pathological stage diagnosis. Combining a methylation-based stool DNA test with CEA and AFP can significantly improve the diagnostic value of CRC and can be used to confirm the diagnosis of colorectal cancer. This combination can also be used as a reliable indicator identifying early-stage CRC patients and pathology. A large-scale study is underway to further define the clinical application of this method for the diagnosis of CRC among Chinese populations.

Plasma lipid-based machine learning models provides a potential diagnostic tool for colorectal cancer patients

Colorectal cancer is the second leading cause of cancer-related death across the world. So far, screening method for colorectal cancer are limited to blood test, imaging test, and digital rectal examination, that are either invasive or ineffective. So, this study aims to explore novel, more convenient and effective diagnostic method for colorectal cancer. First, the experiment cohort was randomly split to train set and test set, and LC-MS-based plasma lipidomics was applied to identify lipid features in colorectal cancer. Second, univariate and multivariate analyses were performed to screen for significantly differentially expressed lipids. Third, single-lipid-based ROC analysis and multiple-lipid-based machine learning modeling were conducted to assess differential lipids’ diagnostic performance. Lastly, survival analyses were used to evaluate lipids’ prognostic values. In total, 41 differential lipids were screened out, 10 were upregulated and 31 were downregulated in CRC. Only CerP(d15:0_22:0 + O) showed fine predictive accuracy in single-lipid-based ROC analysis. Among the four machine learning models, SVM showed best predictive performance with accuracy (in predicting test set) of 1.0000 (95 %CI: 0.8806, 1.0000), that can be reached by modeling with only 14 lipids. Four lipids had significant prognostic values, that were TG(11:0_18:0_18:0) (HR: 0.34), TG(18:0_18:0_18:1) (HR: 0.34), PC(22:1_12:3) (HR: 2.22), LPC(17:0) (HR: 3.16). In conclusion, this study discovered novel lipid features that have potential diagnostic and prognostic values, and showed combination of plasma lipidomics and machine learning modeling could have outstanding diagnostic performance and may serve as a convenient and more accessible way to aid in clinical diagnosis of colorectal cancer.

An Orthotopic Patient-Derived Xenograft (PDX) Model Allows the Analysis of Metastasis-Associated Features in Colorectal Cancer.

Metastasis is the primary cause of death in patients with colorectal cancer (CRC), urging the need for preclinical models that recapitulate the metastatic process at the individual patient level. We used an orthotopic patient-derived xenograft (PDX) obtained through the direct implantation of freshly dissociated CRC cells in the colon of immunocompromised mice to model the metastatic process. Ortho-PDX engraftment was associated to a specific set of molecular features of the parental tumor, such as epithelial-to-mesenchymal transition (EMT), TGF-β pathway activation, increased expression of stemness-associated factors and higher numbers of circulating tumor cells (CTCs) clusters expressing the metastatic marker CD44v6. A parallel analysis of orthotopic/metastatic xenografts and organoids showed that tumor cells underwent mesenchymal-to-epithelial transition at the metastatic site and that metastasis-derived organoids had increased chemotherapy resistance. These observations support the usefulness of ortho-PDX as a preclinical model to study metastasis-related features and provide preliminary evidence that EMT/stemness properties of primary colorectal tumors may be crucial for orthotopic tumor engraftment.

Abstract 2172: Tumor break load is a biologically relevant characteristic of genomic instability with prognostic value for patients with localized colorectal cancer

Abstract Background: Genomic instability is a common feature of colorectal cancer (CRC). More than 80% of CRCs exhibit chromosomal instability (CIN) and 15-20% microsatellite instability (MSI). MSI results in a high ‘tumor mutational burden’ (TMB) and is associated with relatively good prognosis in localized CRC. However, for the large group of CIN CRC patients with localized disease it remains unclear who has a relatively good prognosis and who is at high risk of disease recurrence. CIN is characterized by excessive somatic copy number aberrations (SCNAs), which is often summarized as the ‘fraction genome altered’ (FGA). In addition, CIN is also characterized by excessive chromosomal rearrangement structural variants (SVs). We quantitated the chromosomal breaks as the ‘Tumor Break Load’ (TBL) to investigate the biological impact and clinical relevance of chromosomal breakage in colorectal cancer. Aim: To investigate the biological impact and clinical relevance of TBL in CRC. Data and Methods: We used SCNA, RNA-Seq, and Disease-Free Survival (DFS) data from 633 CRC samples from The Cancer Genome Atlas project. For validation purposes, we used SCNA and DFS data from an independent series of 72 CRC samples. TBL was calculated as the sum of SCNA-associated chromosomal breaks. We used the 25% and 75% quantiles of the TBL distribution as predefined high and low TBL groups to train an RNA expression-based classifier that identifies TBL-associated expression phenotypes as an indicator of biological impact. Results: Within the group of microsatellite stable (MSS) CRC samples there was a large variety in TBL (median TBL of 54 [1-308]). TBL was poorly correlated with TMB (R2: 0.06) and FGA (R2: 0.07). Using RNA expression data as a phenotypic representation of genomic instability, MSI and MSS CRC samples could be classified with high accuracy (AUC: 0.99, p &amp;lt; 0.01), confirming the well-known impact of MSI on tumor biology. Using the same methodology within the group of MSS samples, the TBL could also be classified with high accuracy (AUC: 0.88; p &amp;lt; 0.01). Moreover, high TBL was associated with poor DFS in stage II-III localized MSS CRC (HR: 6.1; p = 0.007). This result was validated in an independent data series of 72 untreated stage II-III localized MSS CRC patients (HR: 3.0; p &amp;lt; 0.02). Conclusion: TBL is a characteristic of chromosomal instability that is largely independent from TMB and FGA, with significant impact on tumor biology. Our data indicate that the TBL may be used as a valuable prognostic biomarker for DFS in patients with localized colorectal cancer. Citation Format: Soufyan Lakbir, Jaap Heringa, Gerrit A. Meijer, Sanne Abeln, Remond J. Fijneman. Tumor break load is a biologically relevant characteristic of genomic instability with prognostic value for patients with localized colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2172.

Activating IL-6/STAT3 Enhances Protein Stability of Proteasome 20S α+β in Colorectal Cancer by miR-1254.

A widely recognized feature of colorectal cancer (CRC) is an increase in cytokine levels, which result in an inflammatory environment in the tumor. Interleukin-6 (IL-6) is a robust protumor cytokine. Several studies suggest that IL-6 plays a role in the development of tumors. Most intracellular protein breakdown occurs in eukaryotes via the ubiquitin-proteasome pathway; this mechanism may also be involved in cancer pathogenesis. The tumor tissues and paracancerous tissues were collected from 90 patients with colorectal cancer. The expressions of pSTAT3, proteasome 20S α+β, miR-1254, and PSMD1 in tissues were detected by immunohistochemistry, ELISA, and qRT-PCR, and the effects of pSTAT3 and proteasome 20s α+β expressions on the survival of patients were studied. HCT116 and HCT116-R cells were cultured and added IL-6, AG490, STAT3 plasmid, or overexpression/knockdown of miR-1254 in cells. Immunofluorescence, western blot, qRT-PCR, double luciferase gene reporter assay, and flow cytometry were used to detect the expression of pSTAT3, STAT3, proteasome 20s α+β, miR-1254, and PSMD1 and cell cycle. The nude mouse xenograft model was constructed and divided into 3 groups: PBS group, IL-6 treatment group, and IL-6+miR-1254 mimic group. After 28 days, the tumor tissues were collected, and the expressions of miR-1254, pSTST3, proteasome 20s α+β, and PSMD1 in the tissues were detected by qRT-PCR and immunohistochemistry, respectively. Our study discovered that the level of proteasome 20S α+β had a strong connection with pSTAT3 in CRC patients. They were also linked to the development and clinical outcome of CRC. In addition, we found that IL-6 dramatically increased the expression of proteasome 20S α+β and pSTAT3; however, it did not affect the proteasome 20S α+β mRNA synthesis. Circulating proteasome concentration correlated with tumor tissue proteasome 20S α+β. STAT3 could occupy the miR-1254 promoter to inhibit transcription, and it could suppressed miR-1254 which targeted PSMD10, promoting proteasome 20S α+β protein stability. This is a prospective target for developing a new colorectal cancer therapy strategy.

SPDL1 Is an Independent Predictor of Patient Outcome in Colorectal Cancer.

Spindle Apparatus Coiled-Coil Protein 1 (SPDL1) is a relatively recently identified coiled-coil domain containing protein and an important determinant of DNA fidelity by ensuring faithful mitosis. Hence, SPDL1 is suspected to underlie genomic (in-)stability in human cancers, yet its exact roles in these diseases remain largely underexplored. Given that genomic instability (GIN) is a crucial feature in colorectal cancer (CRC), we primarily asked whether the expression of this protein may account for differences in clinicopathological features and survival rates of CRC patients. Protein expression was evaluated by immunohistochemistry in the institutional tissue microarray (TMA), and gene expression by the analysis of publicly available datasets. To place the prognostic relevance in a predicted biological context, gene co-expression set around SPDL1 identified by public data mining was annotated and assessed for enrichment in gene ontology (GO) categories, BRITE hierarchies, and Reactome pathways. The comparison with adjacent normal tissue revealed a high expression of SPDL1 protein in a subset of tumor cases (48.84%), and these had better prognosis than the SPDL1-low expression counterpart even after adjustment for multiple confounders. SPDL1-high expression within tumors was associated with a median 56-month survival advantage, but not with any clinicopathological characteristics of our cohort. In the TCGA cohort, SPDL1 was overexpressed in tumor tissue and positively associated with improved survival, chromosome instability phenotype, and various GIN markers. In addition to the genes critically involved in the cell cycle and mitosis, a gene set co-expressed with SPDL1 contained checkpoint members of both chromosome segregation and DNA replication, as well as those associated with defective DNA repair, and retrograde vesicle-mediated transport. In conclusion, SPDL1 is an independent predictor of CRC patient survival in a possible connection with chromosomal instability.

Clinical characteristics of colonoscopy in 448 patients in the Zanzibar Archipelago: a cross-sectional study.

Introductionthe aim was to investigate the demographic characteristics, primary colonoscopy findings, main indications, and feature of colorectal cancer (CRC) patients at Mnazi Mmoja Referral Hospital in the Zanzibar Archipelago, Tanzania.Methodsbetween December 2013 and October 2021, a total of 448 eligible participants were finally enrolled in present cross-sectional study. Demographic information and primary colonoscopy findings of each participant were retrieved.Resultsamong all enrolled subjects, 205 (45.80%) are females, remaining 243 (54.20%) are males. The median age of present cross-sectional study was 47 years old (ranging from 8 to 90 years). The main presenting indications included diarrhea (22.54%), abdominal pain (21.21%), hematochezia (18.53%), difficult defecation (16.96%), mucoid stool (10.49%), and anemia (8.70%). The common identified colonoscopy findings comprised colitis (28.57%), colonic polyps (25.22%), CRC (17.63%), inflammatory bowel disease (IBD) (13.52%), hemorrhoids (4.24%), and colonic diverticulum (4.02%), respectively. Unconditional logistic regression analyses demonstrated the elder group had significant higher risk of CRC (OR, 1.03; 95% CI, 1.01-1.03, P< 0.001), meanwhile a significant higher possibility of suffering hematochezia (OR, 2.29; 95% CI, 1.32-3.99, P=0.003) and anemia (OR, 2.96; 95% CI, 1.46-6.00, p= 0.003) in CRC group.Conclusionthe present study demonstrated that colitis, colonic polyps, CRC, and IBD are the most common colonoscopy diagnoses in Zanzibar. The indication of hematochezia or anemia showed a statistically higher risk of CRC.

A Novel Prognostic Biomarker Panel for Early-Stage Colon Carcinoma.

Simple SummaryDecision about treatment choice in early-stage colon cancer may be difficult for clinicians because of a lack of published data. Colon cancer is a very heterogeneous disease, but some previous efforts have helped us elucidate potential biomarkers for characterizing patients. Our goal is to create a panel of biomarkers capable of differentiating patients with a low, medium, and high risk of death or relapse. Our results suggest that, by combining PD-L1, GLUT-1, and mismatch repair proteins in a biomarker panel, patients could be significantly and evenly divided into one of these three groups. The resulting biomarker panel has the potential clinical value that, by being able to classify a patient with early colon cancer as being at high risk of death or tumor evolution, they could benefit from a more aggressive early treatment, while this approach might not be needed for low-risk patients.Molecular characterization of colorectal cancer has helped us understand better the biology of the disease. However, previous efforts have yet to provide significant clinical value in order to be integrated into clinical practice for patients with early-stage colon cancer (CC). The purpose of this study was to assess PD-L1, GLUT-1, e-cadherin, MUC2, CDX2, and microsatellite instability (dMMR) and to propose a risk-panel with prognostic capabilities. Biomarkers were immunohistochemically assessed through tissue microarrays in a cohort of 144 patients with stage II/III colon cancer. A biomarker panel consisting of PD-L1, GLUT-1, dMMR, and potentially CDX2 was constructed that divided patients into low, medium, and high risk of overall survival or disease-free survival (DFS) in equally sized groups. Compared with low-risk patients, medium-risk patients have almost twice the risk of death (HR = 2.10 (0.99–4.46), p = 0.054), while high-risk patients have almost four times the risk (HR = 3.79 (1.77–8.11), p = 0.001). The multivariate goodness of fit was 0.756 and was correlated with Kaplan–Meier curves (p = 0.002). Consistent results were found for DFS. This study provides a critical basis for the future development of an immunohistochemical assessment capable of discerning early-stage CC patients as a function of their prognosis. This tool may aid with treatment personalization in daily clinical practice and improve survival outcomes.

Integrative Analysis of Biomarkers Through Machine Learning Identifies Stemness Features in Colorectal Cancer

Background: Cancer stem cells (CSCs), which are characterized by self-renewal and plasticity, are highly correlated with tumor metastasis and drug resistance. To fully understand the role of CSCs in colorectal cancer (CRC), we evaluated the stemness traits and prognostic value of stemness-related genes in CRC.Methods: In this study, the data from 616 CRC patients from The Cancer Genome Atlas (TCGA) were assessed and subtyped based on the mRNA expression-based stemness index (mRNAsi). The correlations of cancer stemness with the immune microenvironment, tumor mutational burden (TMB), and N6-methyladenosine (m6A) RNA methylation regulators were analyzed. Weighted gene co-expression network analysis (WGCNA) was performed to identify the crucial stemness-related genes and modules. Furthermore, a prognostic expression signature was constructed using the Lasso-penalized Cox regression analysis. The signature was validated via multiplex immunofluorescence staining of tissue samples in an independent cohort of 48 CRC patients.Results: This study suggests that high-mRNAsi scores are associated with poor overall survival in stage IV CRC patients. Moreover, the levels of TMB and m6A RNA methylation regulators were positively correlated with mRNAsi scores, and low-mRNAsi scores were characterized by increased immune activity in CRC. The analysis identified 34 key genes as candidate prognosis biomarkers. Finally, a three-gene prognostic signature (PARPBP, KNSTRN, and KIF2C) was explored together with specific clinical features to construct a nomogram, which was successfully validated in an external cohort.Conclusion: There is a unique correlation between CSCs and the prognosis of CRC patients, and the novel biomarkers related to cell stemness could accurately predict the clinical outcomes of these patients.

A novel 111indium-labeled dual carbonic anhydrase 9-targeted probe as a potential SPECT imaging radiotracer for detection of hypoxic colorectal cancer cells

Tumor hypoxia is a common feature in colorectal cancer (CRC), and is associated with resistance to radiotherapy and chemotherapy. Thus, a specifically targeted probe for the detection of hypoxic CRC cells is urgently needed. Carbonic anhydrase 9 (CA9) is considered to be a specific marker for hypoxic CRC diagnosis. Here, a nuclear imaging Indium-111 (111In)-labeled dual CA9-targeted probe was synthesized and evaluated for CA9 detection in in vitro, in vivo, and in human samples. The CA9-targeted peptide (CA9tp) and CA9 inhibitor acetazolamide (AAZ) were combined to form a dual CA9-targeted probe (AAZ-CA9tp) using an automatic microwave peptide synthesizer, which then was conjugated with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) for radioisotope (111In) labeling (111In-DOTA-AAZ-CA9tp). The assays for cell binding, stability, and toxicity were conducted in hypoxic CRC HCT15 cells. The analyses for imaging and biodistribution were performed in an HCT15 xenograft mouse model. The binding and distribution of 111In-DOTA-AAZ-CA9tp were detected in human CRC samples using microautoradiography. AAZ-CA9tp possessed good CA9-targeting ability in hypoxic HCT15 cells. The dual CA9-targeted radiotracer showed high serum stability, high surface binding, and high affinity in vitro. After exposure of 111In-DOTA-AAZ-CA9tp to the HCT15-bearing xenograft mice, the levels of 111In-DOTA-AAZ-CA9tp were markedly and specifically increased in the hypoxic tumor tissues compared to control mice. 111In-DOTA-AAZ-CA9tp also targeted the areas of CA9 overexpression in human colorectal tumor tissue sections. The results of this study suggest that the novel 111In-DOTA-AAZ-CA9tp nuclear imaging agent may be a useful tool for the detection of hypoxic CRC cells in clinical practice.

Colorectal Cancer Stage-Specific Fecal Bacterial Community Fingerprinting of the Taiwanese Population and Underpinning of Potential Taxonomic Biomarkers.

Despite advances in the characterization of colorectal cancer (CRC), it still faces a poor prognosis. There is growing evidence that gut microbiota and their metabolites potentially contribute to the development of CRC. Thus, microbial dysbiosis and their metabolites associated with CRC, based on stool samples, may be used to advantage to provide an excellent opportunity to find possible biomarkers for the screening, early detection, prevention, and treatment of CRC. Using 16S rRNA amplicon sequencing coupled with statistical analysis, this study analyzed the cause–effect shift of the microbial taxa and their metabolites that was associated with the fecal gut microbiota of 17 healthy controls, 21 polyps patients, and 21 cancer patients. The microbial taxonomic shift analysis revealed striking differences among the healthy control, polyps and cancer groups. At the phylum level, Synergistetes was reduced significantly in the polyps group compared to the healthy control and cancer group. Additionally, at the genus level and in association with the cancer group, a total of 12 genera were highly enriched in abundance. In contrast, only Oscillosprira was significantly higher in abundance in the healthy control group. Comparisons of the polyps and cancer groups showed a total of 18 significantly enriched genera. Among them, 78% of the genera associated with the cancer group were in higher abundance, whereas the remaining genera showed a higher abundance in the polyps group. Additionally, the comparison of healthy control and polyp groups showed six significantly abundant genera. More than 66% of these genera showed a reduced abundance in the polyps group than in healthy controls, whereas the remaining genera were highly abundant in the polyps group. Based on tumor presence and absence, the abundance of Olsenella and Lactobacillus at the genus level was significantly reduced in the patient group compared to healthy controls. The significant microbial function prediction revealed an increase in the abundance of metabolites in the polyps and cancer groups compared to healthy controls. A correlation analysis revealed a higher contribution of Dorea in the predicted functions. This study showed dysbiosis of gut microbiota at the taxonomic level and their metabolic functions among healthy subjects and in two stages of colorectal cancer, including adenoma and adenocarcinoma, which might serve as potential biomarkers for the early diagnosis and treatment of CRC.

The effects of SNAI1 rs6125849 gene polymorphism on metastasis and survival in colorectal cancer: Preliminary results from Turkish subjects

BackgroundSince metastasis is one of the leading causes of high mortality in colorectal cancer, uncovering the molecular mechanisms underlying metastatic process has become important to find new treatment approaches. With this perspective, in this study we investigated effects of epithelial-mesenchymal transition (EMT) inducer SNAI1 rs6125849 gene polymorphism on different features of colorectal cancer. Material and methodsA total of 141 Turkish subjects consisting of 72 colorectal cancer patients and 69 healthy controls were included in the study. SNAI1 rs6125849 genotype analyses were performed with Agena MassARRAY platform. ResultsWe did not find any significant difference between case and control groups for rs6125849 genotypes. All metastatic patients were detected to have homozygous mutant (AA) genotype. Heterozygous and homozygous mutant genotypes (GA + AA) were more common in metastatic colorectal cancer patients compared to those with homozygous wild type (GG) genotype (p = 0.066). We also detected positive, albeit low but significant correlation between rs6125849 genotypes in codominant and dominant models (r = 0.250, p = 0.034 and r = 0.234, p = 0.048, respectively). Overall survival times was found to be considerably higher patients with A allele (Log rank: 3.04, p = 0.081). ConclusionAccording to our preliminary results, we may speculate that SNAI1 gene G > A variation may result with a metastatic phenotype and shorter overall survival. Due to limited number of patients in our study group, further in vitro and in vivo studies are required to understand the role of SNAI1 rs6125849 variation on metastasis and survival functions.

Abstract 2523: Novel genomic characterization in late stage colorectal cancer

Abstract Introduction: Colorectal cancer patients with high-level microsatellite instability benefit more from immune checkpoint inhibitor therapy, but they only account for around 15% of all colorectal cancer patients. The remaining patients are still lack of effective therapeutic biomarkers. For patients in late stage without optimal treatment, it is essential to find novel biomarkers which can be used to select appropriate therapies and therefore improve patients' overall survival. Methods: We used whole-exome sequencing to analyze 114 colorectal cancer samples. The samples included 86 primary late stage tumors and 28 metastatic tumors from liver, lung and other organs. The primary samples were further divided into different groups based on their tumor location (sideness) and microsatellite status (MS) since these indications are of great significance in clinical presentation and treatment. We then assessed somatic genomic lesions, copy number variations, germline gene alterations and mutational signatures in the above three pairs of comparisons respectively (primary vs. metastatic, right- vs. left-sided, MS instable vs. stable). Results: There were significant differences between the analyzed pairs. For the primary and metastatic samples, the most prominent difference was the copy number variation which happened in 25 genes in the metastatic samples and only one gene in the primary samples (gain of IL12) (p = 0.036). For the right- and left-sided comparison, SNP/Indel mutations were the most prominent. They happened more frequently in the right-sided than the left-sided tumors and those are rare genes in colorectal cancer, including BCL11A (p = 0.018), DICER1 (p = 0.038), NR4A3 (p = 0.004), NIN (p = 0.008) and FBXW7 (p = 0.019). For the MSI-MSS comparison, tumor mutation burden (TMB) stands out high in the MSI group compared to the MSS group (p &amp;lt; 0.0001). In addition, dozens of significantly mutated genes were observed in the MSI samples (p &amp;lt; 0.0001), such as KMT2B, ACVR2A, KMT2D, ASXL1, TCF7L2 and etc. However, TP53 occurred mainly in the MSS patients (p = 0.0007). Conclusion: Our study enables a deeper understanding of the genomic characterization of colorectal cancer from an integrated view. Copy number variations, gene mutations, and TMB were found to be the most significant differences between the comparison groups of primary vs. metastatic samples, left vs. right sided samples, and MSI vs. MSS samples respectively. Genomic differences between metastatic and primary samples may be potential therapeutic targets for metastatic colorectal cancer. Citation Format: Jianxia Li, Qianchao Wu, Jianwei Zhang, Huabin Hu, Yue Cai, Jiayu Lin, Jun Liu, Yanhong Deng. Novel genomic characterization in late stage colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2523.

Mediterranean Diet to Prevent the Development of Colon Diseases: A Meta-Analysis of Gut Microbiota Studies.

Gut microbiota dysbiosis is a common feature in colorectal cancer (CRC) and inflammatory bowel diseases (IBD). Adoption of the Mediterranean diet (MD) has been proposed as a therapeutic approach for the prevention of multiple diseases, and one of its mechanisms of action is the modulation of the microbiota. We aimed to determine whether MD can be used as a preventive measure against cancer and inflammation-related diseases of the gut, based on its capacity to modulate the local microbiota. A joint meta-analysis of publicly available 16S data derived from subjects following MD or other diets and from patients with CRC, IBD, or other gut-related diseases was conducted. We observed that the microbiota associated with MD was enriched in bacteria that promote an anti-inflammatory environment but low in taxa with pro-inflammatory properties capable of altering intestinal barrier functions. We found an opposite trend in patients with intestinal diseases, including cancer. Some of these differences were maintained even when MD was compared to healthy controls without a defined diet. Our findings highlight the unique effects of MD on the gut microbiota and suggest that integrating MD principles into a person’s lifestyle may serve as a preventive method against cancer and other gut-related diseases.