Colon Cancer Samples Research Articles

Identification and validation of an immunotherapeutic signature for colon cancer based on the regulatory patterns of ferroptosis and their association with the tumor microenvironment

The integrated landscape of ferroptosis regulatory patterns and their association with colon microenvironment have been demonstrated in recent studies. However, the ferroptosis-related immunotherapeutic signature for colon cancer (CC) remains unclear. We comprehensively evaluated 1623 CC samples, identified patterns of ferroptosis modification based on ferroptosis-associated genes, and systematically correlated these patterns with tumor microenvironment (TME) cell infiltration characteristics. In addition, the ferroptosis-regulated gene score (FRG-score) was constructed to quantify the pattern of ferroptosis alterations in individual tumors. Three distinct patterns of ferroptosis modification were identified, including antioxidant defense, iron toxicity, and lipid peroxidation. The characteristics of TME cell infiltration under these three patterns were highly consistent with the three immune phenotypes of tumors, including immune-inflamed, immune-excluded and immune-desert phenotypes. We also demonstrated that evaluation of ferroptosis regulatory patterns within individual tumors can predict tumor inflammatory status, tumor subtype, TME stromal activity, genetic variation, and clinical outcome. Immunotherapy cohorts confirmed that patients with low FRG-scores showed remarkable therapeutic and clinical benefits. Furthermore, the hub gene apolipoprotein L6 (APOL6), a drug-sensitive target associated with cancer cell ferroptosis, was identified through our proposed novel key gene screening process and validated in CC cell lines and scRNA-seq.

FOXD3 Suppresses the Proliferation of CRC Bone Metastatic Cells via the Ras/Raf/MEK/ERK Signaling Pathway.

The improvements in the treatment of colorectal cancer (CRC) and prolongation of survival time have improved the incidence of bone metastasis. Forkhead box D3 (FOXD3) is involved in the development of CRC. However, the role and mechanism of FOXD3 in CRC bone metastases development are unknown. Using the combined bioinformatics and cytology experimental analyses, this study aimed to explore the mechanistic role of FOXD3 in the bone metastasis of colon cancer, thereby aiding in the treatment of colon cancer bone metastasis and identification of drug-targeting markers. First, the changes in the expression levels of the FOXD3 gene and differentially expressed genes (DEGs) between the colon cancer samples and colon cancer metastases were obtained from The Cancer Genome Atlas (TCGA) database. Then, the correlations of the FOXD3 gene with the DEGs were identified. Next, the effects of the FOXD3 on the proliferation and invasion abilities of colon cancer bone metastatic cells were identified using Cell Counting Kit-8 (CCK8) and Transwell cell migration assays, respectively. In addition, Western blot analysis was used to identify the expression levels of the proteins related to the EGFR/Ras/Raf/MEK/ERK (EGFR/ERK) signaling pathway and epithelial-to-mesenchymal transition (EMT). FOXD3 was downregulated in colon cancer and could interact with multiple DEGs in colon cancer bone metastases. FOXD3 gene knockdown could increase the proliferation of human colon cancer bone metastatic cells and their invasive ability. FOXD3 gene knockdown could activate the expression of EGFR/ERK signaling pathway-related proteins and inhibit/promote the expression of EMT-related proteins, which in turn promoted the proliferation and metastasis of LoVo cells from colon cancer bone metastases. Overall, this study demonstrated that the downregulation of the FOXD3 gene might promote the proliferation of colon cancer bone metastatic cell lines through the EGFR/ERK pathway and promote their migration through EMT, thereby serving as a promising therapeutic target.

Exploring the Molecular Targets and Therapeutic Potential of Coptisine in Colon Cancer: A Network Pharmacology Approach.

Colon cancer is a frequent malignancy, and surgery is still the primary therapy for people with colon cancer. Other treatments, including radiation, chemotherapy, and biologic therapy, may be utilized as a supplement. Chemotherapy, a prominent treatment for colon cancer, has failed to provide positive outcomes. This necessitates the development of more effective and less harmful treatment drugs. Coptisine was discovered to inhibit the development of colon cancer cell line HCT-116 in vivo, decrease the growth of HCT-116 cells, and cause apoptosis in vitro in colon cancer. Coptisine (COP) has shown antitumor activity in colon cancer, but its molecular mechanism and its molecular targets have not been fully understood. In this study, the biological behavior was verified in vitro. The targets of Huanglian alkaloids on colon cancer were predicted, and the protein-protein interaction (PPI) network was constructed. The core targets of safranine for colon cancer were extracted and analyzed by GO and KEGG enrichment to identify the possible molecular mechanisms of safranine treatment. Western blot was used to detect the changes of related pathway proteins in colon cancer cells. The differential expression of hub genes in colon cancer was analyzed using the GEPIA2 website. The binding ability of safranine to the target was verified by molecular docking. Finally, the targets were preliminarily verified by q-PCR analysis. Coptisine can inhibit the survival, migration, and proliferation of colon cancer cells DLD1 and HCT-116. Based on network pharmacology, ninety-one targets for colon cancer were screened. ESR1, ALB, AR, CDK2, PARP1, HSP90AB1, IGF1R, CCNE1, and CDC42 were found in the top 10. Enrichment analysis showed that these targets were mainly related to pathways in cancer, FC γ R-mediated phagocytosis, prostate cancer, progesterone-mediated oocyte maturation, the oestrogen signal pathway, proteoglycan in cancer and the PI3K-Akt signal pathway. WB results showed that after the treatment of colon cancer DLD1 cells with coptisine, the expression of P-AKT and AKT decreased, that of its downstream protein Bcl-2 decreased, and that of BAX increased. Differential expression analysis of hub genes showed that CCNE1, CDK2, HSP90AB1, and CHEK2 were upregulated in colon cancer samples, and molecular docking showed that these targets had a good ability to bind to coptisine. After the treatment of colon cancer DLD1 cells with coptisine, q-PCR results showed that CCNE1 and HSP90AB1 were significantly downregulated, while CDK2 and CHEK2 had no significant changes. Coptisine may be a candidate drug for the treatment of colon cancer, and its therapeutic effect may be related to the cancer pathway and PI3K-Akt signalling pathway. CCNE1 and HSP90AB1 may be potential targets of coptisine in the treatment of colon cancer.

SiRNF8 Delivered by DNA Framework Nucleic Acid Effectively Sensitizes Chemotherapy in Colon Cancer.

The evident side effects and decreased drug sensitivity significantly restrict the use of chemotherapy. However, nanoparticles based on biomaterials are anticipated to address this challenge. Through bioinformatics analysis and colon cancer samples, we initially investigated the expression level of RNF8 in colon cancer. Next, we constructed nanocarrier for delivering siRNF8 based on DNA tetrahedron (si-Tet), and Doxorubicin (DOX) was further intercalated into the DNA structure (si-DOX-Tet) for combination therapy. Further, the effects and mechanism of RNF8 inhibition on the sensitivity of colon cancer cells to DOX chemotherapy have also been studied. RNF8 expression was increased in colon cancer. Agarose gel electrophoresis, transmission electron microscopy, and size distribution and potential analysis confirmed the successful preparation of the two nanoparticles, with particle sizes of 10.29 and 37.29 nm, respectively. Fluorescence imaging reveals that the carriers can be internalized into colon cancer cells and escape from lysosomes after 12 hours of treatment, effectively delivering siRNF8 and DOX. Importantly, Western blot analysis verified treatment with 50nM si-Tet silenced RNF8 expression by approximately 50% in colon cancer cells, and combined treatment significantly inhibited cell proliferation. Furthermore, the CCK-8 assay demonstrated that si-Tet treatment enhanced the sensitivity of colon cancer cells to the three chemotherapeutic drugs. Significant more DNA damage was detected after treatment with both si-Tet or si-DOX-Tet. Further flow cytometry analysis revealed that si-DOX-Tet treatment led to significantly more apoptosis, approximately 1.6-fold higher than treatment with DOX alone. Mechanistically, inhibiting RNF8 led to decreased ABCG2 expression and DOX efflux, but increased DNA damage, thereby enhancing the chemotherapeutic effect of DOX. We have successfully constructed si-DOX-Tet. By inhibiting the expression of RNF8, it enhances the chemotherapy sensitivity of DOX. Therefore, this tetrahedral FNA nanocarrier offers a new approach for the combined treatment of colon cancer.

Differential expression and regulation of ADAD1, DMRTC2, PRSS54, SYCE1, SYCP1, TEX101, TEX48, and TMPRSS12 gene profiles in colon cancer tissues and their in vitro response to epigenetic drugs.

Colon cancer (CC) is a significant cause of death worldwide, particularly in Saudi Arabia. To increase the accuracy of diagnosis and treatment, it is important to discover new specific biomarkers for CC. The main objectives of this research are to identify potential specific biomarkers for the early diagnosis of CC by analyzing the expressions of eight cancer testis (CT) genes, as well as to analyze how epigenetic mechanisms control the expression of these genes in CC cell lines. Tissue samples were collected from 15 male patients with CC tissues and matched NC tissues for gene expression analysis. The expression levels of specific CT genes, including ADAD1, DMRTC2, PRSS54, SYCE1, SYCP1, TEX101, TEX48, and TMPRSS12, were assessed using quantitative techniques. To validate the gene expression patterns, we used publicly available CC statistics. To investigate the effect of inhibition of DNA methylation and histone deacetylation on CT gene expression, in vitro experiments were performed using HCT116 and Caco-2 cell lines. There was no detected expression of the genes neither in the patient samples nor in NC tissues, except for TEX48, which exhibited upregulation in CC samples compared to NC tissues in online datasets. Notably, CT genes showed expression in testis samples. In vitro, experiments demonstrated significant enhancement in mRNA expression levels of ADAD1, DMRTC2, PRSS54, SYCE1, SYCP1, TEX101, TEX48, and TMPRSS12 following treatment with 5-aza-2'-deoxycytidine and trichostatin A in HCT116 and Caco-2 cell lines. Epigenetic treatments modify the expression of CT genes, indicating that these genes can potentially be used as biomarkers for CC. The importance of conducting further research to understand and target epigenetic mechanisms to improve CC treatment cannot be overemphasized.

Comprehensive characterization of PKHD1 mutation in human colon cancer.

The PKHD1 (Polycystic Kidney and Hepatic Disease 1) gene is essential for producing fibrocystin or polyductin, which is crucial in various cellular functions. Mutations in PKHD1 have been found to be involved in the development and progression of colorectal cancer (CRC). Along with APC, TP53, and KRAS, PKHD1 is one of the most frequently mutated genes in CRC. PKHD1 expression is governed by the Wnt/PCP pathway, often dysregulated in CRC. Targeting this pathway, crucial for CRC progression, could unveil potential therapeutic strategies for colon cancer treatment. This study examined an in-house dataset of 3702 colon cancer samples, analyzing mutation landscapes, clinical features, tumor mutational burden (TMB), microsatellite instability (MSI), and chromosomal instability (CIN) score. For the survival analysis of PKHD1 patients, survival data of 436 colon adenocarcinoma samples were obtained from TCGA dataset. Additionally, 433 samples from TCGA with RNA-seq data were used for the assessment of immune cell infiltration and gene set enrichment analysis. Polycystic Kidney and Hepatic Disease 1 mutation was detected in 424 colon cancer patients from our in-house cohort and was associated with increased TMB, higher MSI, and lower CIN score. Importantly, within the TCGA dataset, PKHD1 mutations were identified as an independent prognostic factor, not merely correlated with established prognostic biomarkers, and were associated with poorer overall survival outcomes. In terms of immune response, these mutations correlated with increased enrichment scores for 12 immune cell types, including B cell plasma, macrophages, and naive CD4+ T cells. Additionally, interferon alpha and interferon-gamma gene sets were significantly down-regulated in patients with PKHD1 mutations (FDA q-value < 0.1). Overall, these findings suggest that PKHD1 may be a potential biomarker for the prognosis of colon cancer and provide some insight for personalized immunotherapy.

FTHL17, PRM2, CABYR, CPXCR1, ADAM29, and CABS1 are highly expressed in colon cancer patients and are regulated in vitro by epigenetic alterations

BackgroundColon cancer is a serious public health issue and a major cause of cancer-related mortality worldwide, including Saudi Arabia. Knowledge of genes associated with colon cancer development and progression is essential for identifying new cancer-specific biomarkers to improve the diagnosis of colon cancer. MethodsThe expression levels of FTHL17, PRM2, CABYR, CPXCR1, ADAM29, and CABS1 in 15 adjacent colon cancer and normal colon tissue samples from male patients were investigated using reverse transcription polymerase chain reaction (RT-PCR) and quantitative RT-PCR (qRT-PCR) assays. qRT-PCR analysis was also used to determine whether reducing DNA methyltransferase (via 5-aza-2′-deoxycytidine treatment) or histone deacetylation (via trichostatin treatment) increased the expression levels of the tested genes. ResultsThe analysis of the 15 colon cancer and adjacent normal colon tissue samples revealed that all six genes were expressed in both groups, but their expression levels were significantly higher in the colon cancer group. Furthermore, the mRNA expression levels of the FTHL17, PRM2, CABYR, CPXCR1, and ADAM29 genes were considerably upregulated after treatment of HCT116 and Caco-2 cells with 5-aza-2′-deoxycytidine and trichostatin. However, the CABS1 gene was activated only with trichostatin treatment. ConclusionsThe findings of this study suggest that FTHL17, PRM2, CABYR, CPXCR1, ADAM29, and CABS1 are suitable candidate biomarkers of colon cancer and their expressions are regulated by hypomethylation and hyperacetylation.

Transcript CD81-215 may be a long noncoding RNA of stromal origin with tumor-promoting role in colon cancer.

The role of tetraspanin CD81 in malignant transformation is best studied in colorectal cancer, and it appears that other transcripts beside the fully coding mRNA may also be dysregulated in malignant cells. Recent data from a comprehensive pan-cancer transcriptome analysis demonstrated differential activity of two alternative CD81 gene promoters in malignant versus nonmalignant gut mucosa. The promoter active in gut mucosa gives rise to transcripts CD81-203 and CD81-213, while the promoter active in colon and rectal cancer gives rise to transcripts CD81-205 and CD81-215. Our study aimed to explore the biomarker potential of the transcripts from the alternative CD81 gene promoters in colon cancer, as well as to investigate their structure and potential function using in silico tools. The analysis of the transcripts'expression in several colon cell lines cultivated in 2D and 3D and a set of colon cancer and healthy gut mucosa samples by qPCR and RNA sequencing suggested their low expression and stromal origin. Expression patterns in tumor and nontumor tissue along with in silico data suppose that the transcript CD81-215 may be a noncoding RNA of stromal origin with possible involvement in signaling related to malignant transformation.

Data Mining Suggests That CXCL14 Gene Silencing in Colon Cancer Is Due to Promoter Methylation.

CXCL14 is one of the most evolutionarily conserved members of the chemokine family and is constitutionally expressed in multiple organs, suggesting that it is involved in the homeostasis maintenance of the system. CXCL14 is highly expressed in colon epithelial cells and shows obvious gene silencing in clinical colon cancer samples, suggesting that its silencing is related to the immune escape of cancer cells. In this paper, we analyzed the expression profiles of multiple human clinical colon cancer datasets and mouse colon cancer models to reveal the variation trend of CXCL14 expression during colitis, colon polyps, primary colon cancer, and liver metastases. The relationship between CXCL14 gene silencing and promoter hypermethylation was revealed through the colorectal carcinoma methylation database. The results suggest that CXCL14 is a tumor suppressor gene in colorectal carcinoma which is activated first and then silenced during the process of tumor occurrence and deterioration. Promoter hypermethylation is the main cause of CXCL14 silencing. The methylation level of CXCL14 is correlated with the anatomic site of tumor occurrence, positively correlated with patient age, and associated with prognosis. Reversing the hypermethylation of CXCL14 may be an epigenetic therapy for colon cancer.

Aluminium bioaccumulation in colon cancer, impinging on epithelial-mesenchymal-transition and cell death

We investigated the presence of aluminium (Al) in human colon cancer samples and its potential association with biological processes involved in cancer progression, such as epithelial to mesenchymal transition (EMT) and cell death. 25 consecutive colon samples were collected from patients undergoing colonic resection. Both neoplastic and normal mucosa were collected from each patient and subjected to histological, ultrastructural and immunohistochemical analyses. Moreover, colon samples from two Al-positive patients underwent multi-omic analyses, including whole genome sequencing and RNA sequencing (RNAseq). Morin staining, used to identify in situ aluminium bioaccumulation, showed the presence of Al in tumor areas of 24 % of patients. Transmission electron microscopy and energy-dispersive X-ray microanalysis confirmed the presence of Al specifically in intracytoplasmic electrondense nanodeposits adjacent to mitochondria of colon cancer cells. Immunohistochemical analyses for vimentin and nuclear β-catenin were performed to highlight the occurrence of the EMT phenomenon in association to Al bioaccumulation. Al-positive samples showed a significant increase in both the number of vimentin-positive and nuclear β-catenin-positive cancer cells compared to Al-negative samples. Moreover, Al-positive samples exhibited a significant decrease in the number of apoptotic cells, as well as the expression of the anti-apoptotic molecule BCL-2. Multi-omic analyses revealed a higher tumor mutational burden (TMB) in Al-positive colon cancers (n = 2) compared to a control cohort (n = 100). Additionally, somatic mutations in genes associated with EMT (GATA3) and apoptosis (TP53) were observed in Al-positive colon cancers. In conclusion, this study provides the first evidence of Al bioaccumulation in colon cancer and its potential role in modulating molecular pathways involved in cancer progression, such as EMT and apoptosis. Understanding the molecular mechanisms underlying Al toxicity might contribute to improve strategies for prevention, early detection, and targeted therapies for the management of colon cancer patients.

LncRNA SBF2 Antisense RNA 1 Accelerates the Progression of Colon Cancer via PI3K/Akt/mTOR Signaling Pathway by Targeting miR-506-3p/ZEB1 Axis

Colon cancer is a severe digestive system malignant tumor. It is particularly urgent to make a thorough inquiry into colon cancer. The role of lncRNA SBF2 Antisense RNA 1 (SBF2-AS1) in the progression of this disease was explored. RT-PCR was undertaken to detect lncRNA SBF2-AS1 expression, miR-506-3p, and ZEB1 in normal HIEC, HCT116, LoVo, SW480, and SW620 cells. Sh-SBF2-AS1, miR-506-3p mimic, ZEB1 inhibitor, and controls were transfected. Proliferation was verified by CCK-8 assay. Invasion and migration ability were monitored via wound healing and Transwell assay. The colon cancer model was established to research the role of lncRNA SBF2-AS1 in vivo. LncRNA SBF2-AS1 was with high level in colon cancer samples, and the survival rate was positively related to SBF2-AS1 level of patients. Down-expressed SBF2-AS1 decreased the development of colon cells. Furthermore, we predicted SBF2-AS1 targeted binding to miR-506-3p and proved that the downstream gene was ZEB1 by the bioinformatic and experimental means. In addition, we observed that the tumor-accelerate effects of SBF2-AS1 in colon cancer were mediated by PI3K/Akt/mTOR pathway. Finally, we referred that sh-SBF2-AS1 effectively inhibits the development of colon cancer in vivo. LncRNA SBF2-AS1 has involved the PI3K/Akt/mTOR signaling pathway of colon cancer via regulating the miR-506-3p/ZEB1 axis.

Integrative analysis reveals a four-gene signature for predicting survival and immunotherapy response in colon cancer patients using bulk and single-cell RNA-seq data.

Colon cancer (CC) ranks as one of the leading causes of cancer-related mortality globally. Single-cell transcriptome sequencing (scRNA-seq) offers precise gene expression data for distinct cell types. This study aimed to utilize scRNA-seq and bulk transcriptome sequencing (bulk RNA-seq) data from CC samples to develop a novel prognostic model. scRNA-seq data was downloaded from the GSE161277 database. R packages including "Seurat", "Harmony", and "singleR" were employed to categorize eight major cell types within normal and tumor tissues. By comparing tumor and normal samples, differentially expressed genes (DEGs) across these major cell types were identified. Gene Ontology (GO) enrichment analyses of DEGs for each cell type were conducted using "Metascape". DEGs-based signature construction involved Cox regression and least absolute shrinkage operator (LASSO) analyses, performed on The Cancer Genome Atlas (TCGA) training cohort. Validation occurred in the GSE39582 and GSE33382 datasets. The expression pattern of prognostic genes was verified using spatial transcriptome sequencing (ST-seq) data. Ultimately, an established prognostic nomogram based on the gene signature and age was established and calibrated. Sensitivity to chemotherapeutic drugs was predicted with the "oncoPredict" R package. Using scRNA-Seq data, we examined 33,213 cells, categorizing them into eight cell types within normal and tumor samples. GO enrichment analysis revealed various cancer-related pathways across DEGs in these cell types. Among the 55 DEGs identified via univariate Cox regression, four independent prognostic genes emerged: PTPN6, CXCL13, SPINK4, and NPDC1. Expression validation through ST-seq confirmed PTPN6 and CXCL13 predominance in immune cells, while SPINK4 and NPDC1 were relatively epithelial cell-specific. Creating a four-gene prognostic signature, Kaplan-Meier survival analyses emphasized higher risk scores correlating with unfavorable prognoses, confirmed across training and validation cohorts. The risk score emerged as an independent prognostic factor, supported by a reliable nomogram. Intriguingly, drug sensitivity analysis unveiled contrasting anti-cancer drug responses in the two risk groups, suggesting significant clinical implications. We developed a novel prognostic four-gene risk model, and these genes may act as potential therapeutic targets for CC.

Biological functions and molecular subtypes regulated by miR-142-3p in colon cancer.

MicroRNA-142-3p (miR-142-3p) has been reported to be implicated in colon cancer; however, the possible regulatory mechanisms and molecular subtypes regulated by miR-142-3p have not been fully elucidated. This study aimed to investigate the biological functions and regulatory mechanism of miR-142-3p in colon cancer. The expression level of miR-142-3p in colon cancer was analyzed based on the mRNA and miRNA expression datasets of colon cancer retrieved from The Cancer Genome Atlas. Target genes of miR-142-3p were also predicted. Based on these target genes, the functions and subtypes of miR-142-3p were investigated. The metabolic and tumor-related pathways, immune microenvironment, and target gene expression between the 2 subtypes were analyzed. MiR-142-3p was upregulated in tumor tissues, and its high expression indicated a poor prognosis. A total of 39 target genes were predicted, which were significantly involved in autophagy- and metabolism-related functions and pathways. Based on these target genes, the colon cancer samples were clustered into 2 subtypes. There were 35 metabolism-related pathways that were significantly different between the 2 clusters. The immune and stromal scores in cluster 2 were higher than those in cluster 1, whereas the tumor purity of cluster 2 was significantly lower than that of cluster 1. TP53INP2 expression in cluster 2 was higher than that in cluster 1. MiR-142-3p may promote colon cancer progression via autophagy- and metabolism-related pathways. MiR-142-3p may be served as a candidate target for the treatment of colon cancer.

SNTB1 regulates colorectal cancer cell proliferation and metastasis through YAP1 and the WNT/β-catenin pathway

ABSTRACT Colorectal cancer is a common type of digestive tract cancer with a significant morbidity and death rate across the world, partially attributing to the metastasis-associated problems. In this study, integrative bioinformatics analyses were performed to identify genes that might contribute to colorectal cancer metastasis, and 293 genes were dramatically increased and 369 genes were decreased within colon cancer samples. Among up-regulated genes, top five genes correlated with colorectal cancer patient’s prognosis were verified for expression in clinical samples and syntrophin beta 1 (SNTB1) was the most up-regulated. In vitro, SNTB1 knockdown suppresses the malignant behaviors of colorectal cancer cells, including cell viability, colony formation capacity, as well as the abilities to migrate and invade. Furthermore, SNTB1 knockdown decreased the levels of Wnt1, C-Jun, C-Myc, TCF7, and cyclin D1, and inhibited EMT in both cell lines. In vivo, SNTB1 knockdown inhibited tumor growth and metastasis in nude mice models. SNTB1 positively regulated Yes1 associated transcriptional regulator (YAP1) expression; YAP1 partially reversed the effects of SNTB1 on colorectal cancer cell phenotypes and the Wnt/β-catenin/MYC signaling. In conclusion, SNTB1 knockdown inhibits colorectal cancer cell aggressiveness in vitro and tumor growth and metastasis in vivo through the Wnt/β-catenin/MYC signaling; YAP1 might mediate SNTB1 functions on colorectal cancer.

Rapid assessment of 3-dimensional intra-tumor heterogeneity through cycling temperature capillary electrophoresis

ObjectiveTumors are heterogeneous three-dimensional masses populated by numerous cell types, including distinct sub-clones of cancerous cells. Various sub-clones within the same tumor mass may respond differently to cancer treatment, and intra-tumor heterogeneity contributes to acquired therapeutic resistance. Thus, one tissue biopsy will in most cases not be representative of the entire genetic landscape of a tumor mass. In this study, we aimed to establish an easily accessible, low cost method to address intra-tumor heterogeneity in three dimensions, for a limited number of DNA alterations.ResultsThis study includes analyses of the three-dimensional (3D) distribution of DNA mutations in human colon cancer and mouse mammary gland tumor tissue samples. We used laser capture microdissection for the unbiased collection of tissue in several XY-planes throughout the tumor masses. Cycling temperature capillary electrophoresis was used to determine mutant allele frequency. High-resolution distribution maps of KRAS and Trp53 mutations were generated for each XY-plane in human and mouse tumor samples, respectively. To provide a holistic interpretation of the mutation distribution, we generated interactive 3D heatmaps giving an easily interpretable understanding of the spatial distribution of the analyzed mutations. The method described herein provides an accessible way of describing intra-tumor heterogeneity for a limited number of mutations.

Transcription activation of SPINK4 by ELF-1 augments progression of colon cancer by regulating biological behaviors

BackgroundSPINK4 was highly expressed in colorectal cancer and resulted in worse prognosis of colorectal cancer patients. However, the expression and function of SPINK4 in colon cancer have not been revealed. MethodsAnalysis from GEPIA website showed the expression and function of SPINK4 in colon cancer samples. Colon cancer cell lines were applied to detect the biological function of SPINK4. Functionally, the transcriptional factor of SPINK4 has been predicted and verified. Finally, the associations between transcriptional factor and SPINK4 have been confirmed. ResultsSPINK4 expression was obviously increased in colon cancer samples. HCT-116 and DXH-1 cells in si-SPINK4–1 or si-SPINK4–2 group displayed an obvious reduction in its proliferation, cell cycle, invasion and migration compared to those in the si-control group. Moreover, transcriptional factor ELF-1 bound to the promoter of SPINK4 and affected its expression in colon cancer cells. High ELF-1 expression was presented in colon cancer samples and resulted in worse prognosis of colon cancer patients. Additionally, si-SPINK4 antagonized the function of ELF-1 overexpression in modulating colon cancer cell proliferation, cell cycle and mobility. ConclusionsOur findings afforded a theoretical basis for further research on the treatment of colon cancer based on the control of ELF-1/SPINK4 expression.

Clinical plasma cells-related genes to aid therapy in colon cancer

The tumor immune microenvironment (TIME) of colon cancer (CC) has been associated with extensive immune cell infiltration (IMI). Increasing evidence demonstrated that plasma cells (PC) have an extremely important role in advance of antitumor immunity. Nonetheless, there is a lack of comprehensive analyses of PC infiltration in clinical prognosis and immunotherapy in CC. This study systematically addressed the gene expression model and clinical information of CC patients. Clinical samples were obtained from the TCGA (The Cancer Genome Atlas) databases. Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), GSVA, and the MAlignant Tumors using Expression data (ESTIMATE) algorithm were employed to research the potential mechanism and pathways. Immunophenoscore (IPS) was obtained to evaluate the immunotherapeutic significance of risk score. Half maximal inhibitory concentration (IC50) of chemotherapeutic medicine was predicted by employing the pRRophetic algorithm. A total of 513 CC samples (including 472 tumor samples and 41 normal samples) were collected from the TCGA-GDC database. Significant black modules and 313 candidate genes were considered PC-related genes by accessing WGCNA. Five pivotal genes were established through multiple analyses, which revealed excellent prognostic. The underlying correlation between risk score with tumor mutation burden (TMB) was further explored. In addition, the risk score was obviously correlated with various tumor immune microenvironment (TIME). Also, risk CC samples showed various signaling pathways activity and different pivotal sensitivities to administering chemotherapy. Finally, the biological roles of the CD177 gene were uncovered in CC.

A pyroptosis-related gene signature that predicts immune infiltration and prognosis in colon cancer.

Colon cancer (CC) is a highly heterogeneous malignancy associated with high morbidity and mortality. Pyroptosis is a type of programmed cell death characterized by an inflammatory response that can affect the tumor immune microenvironment and has potential prognostic and therapeutic value. The aim of this study was to evaluate the association between pyroptosis-related gene (PRG) expression and CC. Based on the expression profiles of PRGs, we classified CC samples from The Cancer Gene Atlas and Gene Expression Omnibus databases into different clusters by unsupervised clustering analysis. The best prognostic signature was screened and established using least absolute shrinkage and selection operator (LASSO) and multivariate COX regression analyses. Subsequently, a nomogram was established based on multivariate COX regression analysis. Next, gene set enrichment analysis (GSEA) and gene set variation analysis (GSVA) were performed to explore the potential molecular mechanisms between the high- and low-risk groups and to explore the differences in clinicopathological characteristics, gene mutation characteristics, abundance of infiltrating immune cells, and immune microenvironment between the two groups. We also evaluated the association between common immune checkpoints and drug sensitivity using risk scores. The immunohistochemistry staining was utilized to confirm the expression of the selected genes in the prognostic model in CC. The 1163 CC samples were divided into two clusters (clusters A and B) based on the expression profiles of the 33 PRGs. Genes with prognostic value were screened from the DEGs between the two clusters, and an eight PRGs prognostic model was constructed. GSEA and GSVA of the high- and low-risk groups revealed that they were mainly enriched in inflammatory response-related pathways. Compared to those in the low-risk group, patients in the high-risk group had worse overall survival, an immunosuppressive microenvironment, and worse sensitivity to immunotherapy and drug treatment. Our findings provide a foundation for future research targeting pyroptosis and new insights into prognosis and immunotherapy from the perspective of pyroptosis in CC.

Ubiquitinomics revealed disease- and stage-specific patterns relevant for the 3PM approach in human sigmoid colon cancers.

The patients with sigmoid colorectal cancer commonly show high mortality and poor prognosis. Increasing evidence has demonstrated that the ubiquitinated proteins and ubiquitination-mediated molecular pathways influence the growth and aggressiveness of colorectal cancer. It emphasizes the scientific merits of quantitative ubiquitinomics in human sigmoid colon cancer. We hypothesize that the ubiquitinome and ubiquitination-mediated pathway networks significantly differ in sigmoid colon cancers compared to controls, which offers the promise for in-depth insight into molecular mechanisms, discovery of effective therapeutic targets, and construction of reliable biomarkers in the framework of predictive, preventive, and personalized medicine (PPPM; 3P medicine). The first ubiquitinome analysis was performed with anti-K-ε-GG antibody beads (PTMScan ubiquitin remnant motif [K-ε-GG])-based label-free quantitative proteomics and bioinformatics to identify and quantify ubiquitination profiling between sigmoid colon cancer tissues and para-carcinoma tissues. A total of 100 human sigmoid colon cancer samples that included complete clinical information and the corresponding gene expression data were obtained from The Cancer Genome Atlas (TCGA). Ubiquitination was the main way of protein degradation; the relationships between differentially ubiquitinated proteins (DUPs) and their differently expressed genes (DEGs) and between DUPs and their differentially expressed proteins (DEPs) were analyzed between cancer tissues and control tissues. The overall survival of those DUPs was obtained with Kaplan-Meier method. A total of 1249 ubiquitinated sites within 608 DUPs were identified in human sigmoid colon cancer tissues. KEGG pathway network analysis of these DUPs revealed 35 statistically significant signaling pathways, such as salmonella infection, glycolysis/gluconeogenesis, and ferroptosis. Gene Ontology (GO) analysis of 608 DUPs revealed that protein ubiquitination was involved in 98 biological processes, 64 cellular components, 51 molecule functions, and 26 immune system processes. Protein-protein interaction (PPI) network of 608 DUPs revealed multiple high-combined scores and co-expressed DUPs. The relationship analysis between DUPs and their DEGs found 4 types of relationship models, including DUP-up (increased ubiquitination level) and DEG-up (increased gene expression), DUP-up and DEG-down (decreased gene expression), DUP-down (decreased ubiquitination level) and DEG-up, and DUP-down and DEG-down. The relationship analysis between DUPs and their DEPs found 4 types of relationship models, including DUP-up and DEP-up (increased protein expression), DUP-up and DEP-down (decreased protein expression), DUP-down and DEP-up, and DUP-down and DEP-down. Survival analysis found 46 overall survival-related DUPs in sigmoid colon cancer, and the drug sensitivity of overall survival-related DUPs were identified. The study provided the first differentially ubiquitinated proteomic profiling, ubiquitination-involved signaling pathway network changes, and the relationship models between protein ubiquitination and its gene expression and between protein ubiquitination and its protein expression, in human sigmoid colon cancer. It offers the promise for deep insights into molecular mechanisms of sigmoid colon cancer, and discovery of effective therapeutic targets and biomarkers for patient stratification, predictive diagnosis, prognostic assessment, and personalized treatment in the context of 3P medicine. The online version contains supplementary material available at 10.1007/s13167-023-00328-2.

Expression Pattern of DAB Adaptor Protein 2 in Left- and Right-Side Colorectal Carcinoma.

Left-sided and right-sided colorectal cancer (L-CRC and R-CRC) have relatively different clinical pictures and pathophysiological backgrounds. The aim of this study was to investigate the presence of DAB adapter protein 2 (DAB2) as a potential molecular mechanism that contributes to this diversity in terms of malignancy and responses to therapy. The expression of the suppressor gene DAB2 in colon cancer has already been analyzed, but its significance has not been fully elucidated. Archived samples from 34 patients who underwent colon cancer surgery were included in this study, with 13 patients with low-grade CRC and 21 with high-grade CRC. Twenty of the tumors were R-CRC, while 14 were L-CRC. DAB2 expression was analyzed immunohistochemically in the tumor tissue and the colon resection margin was used as a control. Tumors were divided into L-CRC and R-CRC, with splenic flexure as the cutoff point for each side. The results showed that R-CRC had lower DAB2 protein expression compared to L-CRC (p = 0.01). High-grade tumors had reduced DAB2 expression compared to low-grade tumors (p = 0.02). These results are consistent with the analysis of DAB2 gene expression data that we exported from the TCGA Colon and Rectal Cancer Study (COADREAD). In 736 samples of colon cancer, lower DAB2 gene expression was found in R-CRC compared to L-CRC (p < 0.0001). DAB2 gene expression was significantly higher in the sigmoid colon than in the cecum and ascending colon (p < 0.01). The analysis confirmed a lower expression of the DAB2 in tumors with positive microsatellite instability (p < 0.001). In conclusion, DAB2 has a role in the biological differences between R-CRC and L-CRC and its therapeutic and diagnostic potential needs to be further examined.