Progression Of Colon Adenocarcinoma Research Articles

Canopy FGF signaling regulator 3 affects prognosis, immune infiltration, and PI3K/AKT pathway in colon adenocarcinoma.

Colon adenocarcinoma (COAD) is a malignant tumor of the digestive system. The mechanisms underlying COAD development and progression are still largely unknown. To identify the role of canopy FGF signaling regulator 3 (CNPY3) in the development and progression of COAD by using bioinformatic tools and functional experiments. Bioinformatic data were downloaded from public databases. The associations of clinicopathological features, survival, and immune function with the expression of CNPY3 were analyzed. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses and Gene Set Enrichment Analysis were used to explore the related pathways. Then, quantitative real-time PCR and immunohistochemistry were used for validation of CNPY3 expression in clinical samples and tumor cell lines. Cell lines with CNPY3 knockdown were constructed to further analyze gene functions. The functional experiments included proliferation, invasion, migration and apoptosis assays. In both the TCGA cohort and the merged dataset, elevated CNPY3 expression was observed in tumor tissues. High CNPY3 expression correlated with adverse survival and compromised immune functions. Functional enrichment analysis suggested that the pro-oncogenic properties of CNPY3 might be linked to the PI3K-AKT signaling pathway. CNPY3 expression was validated at both the RNA and protein levels. Functional assays indicated that cell proliferation, invasion, and migration were inhibited and cell apoptosis was promoted after CNPY3 knockdown. Additionally, Western blot results revealed the downregulation of key proteins in the PI3K/AKT pathway following CNPY3 knockdown. PI3K/AKT pathway activator reversed the decrease in proliferation, invasion, and migration and the increase in apoptosis. Notably, CNPY3 knockdown still affected the cells when the pathway was inhibited. This study showed that CNPY3 is upregulated in COAD and might regulate COAD development and progression by the PI3K/AKT pathway. Thus, CNPY3 might be a promising therapeutic target.

Identification and validation of calcium extrusion-related genes prognostic signature in colon adenocarcinoma.

Disruptions in calcium homeostasis are associated with a wide range of diseases, and play a pivotal role in the development of cancer. However, the construction of prognostic models using calcium extrusion-related genes in colon adenocarcinoma (COAD) has not been well studied. We aimed to identify whether calcium extrusion-related genes serve as a potential prognostic biomarker in the COAD progression. We constructed a prognostic model based on the expression of calcium extrusion-related genes (SLC8A1, SLC8A2, SLC8A3, SLC8B1, SLC24A2, SLC24A3 and SLC24A4) in COAD. Subsequently, we evaluated the associations between the risk score calculated by calcium extrusion-related genes and mutation signature, immune cell infiltration, and immune checkpoint molecules. Then we calculated the immune score, stromal score, tumor purity and estimate score using the Estimation of STromal and Immune cells in MAlignant Tumor tissues using Expression data (ESTIMATE) algorithm. The response to immunotherapy was assessed using tumor immune dysfunction and exclusion (TIDE). Finally, colorectal cancer cells migration, growth and colony formation assays were performed in RKO cells with the overexpression or knockdown SLC8A3, SLC24A2, SLC24A3, or SLC24A4. We found that patients with high risk score of calcium extrusion-related genes tend to have a poorer prognosis than those in the low-risk group. Additionally, patients in high-risk group had higher rates of KRAS mutations and lower MUC16 mutations, implying a strong correlation between KRAS and MUC16 mutations and calcium homeostasis in COAD. Moreover, the high-risk group showed a higher infiltration of regulatory T cells (Tregs) in the tumor microenvironment. Finally, our study identified two previously unreported model genes (SLC8A3 and SLC24A4) that contribute to the growth and migration of colorectal cancer RKO cells. Altogether, we developed a prognostic risk model for predicting the prognosis of COAD patients based on the expression profiles of calcium extrusion-related genes, Furthermore, we validated two previously unreported tumor suppressor genes (SLC8A3 and SLC24A4) involved in colorectal cancer progression.

NSUN6 mediates 5-methylcytosine modification of METTL3 and promotes colon adenocarcinoma progression.

Colon adenocarcinoma (COAD) is a common and fatal malignant tumor of digestive system with complex etiology. 5-Methylcytosine (m5C) modification of RNA by the NSUN gene family (NSUN1-NSUN7) and DNMT2 reshape cell biology and regulate tumor development. However, the expression profile, prognostic significance and function of these m5C modifiers in COAD remain largely unclear. By mining multiple integrated tumor databases, we found that NSUN1, NSUN2, NSUN5, and NSUN6 were overexpressed in COAD tumor samples relative to normal samples. Clinically, high expression of NSUN6 was significantly associated with shorter survival (including both disease-free survival and overall survival) in COAD patients. NSUN6 was further confirmed to be upregulated at both tissue and cellular levels of COAD, suggesting that NSUN6 plays a critical role in disease progression. Through comprehensive gene enrichment analysis and cell-based functional validation, it was revealed that NSUN6 promoted the cell cycle progression and cell proliferation of COAD. Mechanistically, NSUN6 upregulates the expression of oncogenic METTL3 and catalyzes its m5C modification in COAD cells. Overexpression of METTL3 significantly relieved the cell cycle inhibition of COAD caused by NSUN6 deficiency. Furthermore, NSUN6 was negatively associated with the abundance of infiltrating immune cells in COAD tumors, such as activated B cells, natural killer cells, effector memory CD8 T cells, and regulatory T cells. Importantly, pan-cancer analysis further uncovered that NSUN6 was dysregulated and heterogeneous in various tumors. Thus our findings extend the role of m5C transferase in COAD and suggest that NSUN6 is a potential biomarker and target for this malignancy.

An innovative prognostic auxiliary for colon adenocarcinoma based on zinc finger protein genes.

The carcinogenesis and progression of colon adenocarcinoma (COAD) are intensively related to the abnormal expression of the zinc finger (ZNF) protein genes. We aimed to employ these genes to provide a reliable prognosis and treatment stratification tool for COAD patients. Cox and the least absolute shrinkage and selection operator (LASSO) regression analysis were applied, utilizing The Cancer Genome Atlas (TCGA) metadata, to build a ZNF protein gene-based prognostic model. Using this model, patients in the training cohort and testing cohort (GSE17537) were labelled as either high or low risk. Kaplan-Meier (KM) survival analysis and time-dependent receiver operating characteristic (ROC) curve analysis were performed in the patients with opposite risk status to assess the predictive ability in each cohort. The potentiality of the mechanism was explored by the estimation of stromal and immune cells in malignant tumor tissues using expression data (ESTIMATE), single-sample gene set enrichment analysis (ssGSEA), gene set enrichment analysis (GSEA), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG). Finally, the degrees of expression of model genes were validated by immunohistochemistry (IHC). The prognostic model consisting of INSM1, PHF21B, RNF138, SYTL4, WRNIP1, ZNF585B, and ZNF514, classified patients into opposite risk statuses. Patients in the high-risk subset had a considerably lower chance of surviving compared to those in the low-risk subset. There is a high probability that these model genes were attached to immune-related biological processes, which can be confirmed by the results of the above mechanistic methods. Moreover, patients in the low-risk subset also significantly outperformed the patients in the high-risk subset when calculating immune cells and function scores. Drug sensitivity and tumor immune dysfunction and exclusion (TIDE) analyses showed a clear difference in the immunological and chemotherapeutic efficacy predictions within the two risk groups. Additionally, the degrees of expression of model genes in high-risk and low-risk subsets presented great discrepancies. The signature may be applied as a predictive classifier to shepherd special medication for COAD patients.

Deubiquitinase BRCC3 promotes the migration, invasion and EMT progression of colon adenocarcinoma by stabilizing MET expression.

Breast cancer type 1 susceptibility protein/breast cancer type 2 susceptibility protein-containing complex subunit 3 (BRCC3), a deubiquitinase (DUBs), is overexpressed in various cancers. However, the underlying biological roles of BRCC3 in adenocarcinoma colon (COAD) have yet to be decrypted. In this work, we explored the potential biological function of BRCC3 in the natural process of COAD cells. The expression levels of BRCC3 in COAD tissues and cell lines were investigated via quantitative real time polymerase chain reaction and western blotting analyses. Meanwhile, short hairpin RNAs targeting BRCC3 (sh-BRCC3) or mesenchymal-epithelial transition factor (MET) (sh-MET) were used to investigate the biological function, including proliferation, apoptosis, migration, invasion, and epithelial-mesenchymal transition (EMT) progression in COAD cells. Furthermore, the expression levels of EMT-related biomarkers were detected with western blotting analysis. Furthermore, we also performed Co-IP assay to identify the correlation between BRCC3 and MET. BRCC3 expression was increased in COAD tissues and cell lines. ShRNA-mediated downmodulation of BRCC3 in COAD cell lines induced EMT progression. BRCC3 knockdown resulted in decreased migration as well as invasion and increased apoptosis of SW480 and Lovo cells. Besides, MET was regulated by BRCC3 and involved in the migration, invasion, and EMT in SW480 and Lovo cells. Finally, we uncovered that the overexpressed MET reversed the effects of BRCC3 knockdown in COAD cell development. BRCC3 acted as a critical factor in the development of COAD by deubiquitinating and stabilizing MET, which might provide an emerging biomarker for the therapeutic and diagnosis strategy of COAD.

Establishing a carcinoembryonic antigen-associated competitive endogenous RNA network and forecasting an important regulatory axis in colon adenocarcinoma patients.

Colorectal cancer is one of the top five malignant tumors in the world in terms of morbidity and mortality. Numerous long non-coding RNAs (lncRNAs) are specifically expressed in tumours and can affect various types of human cancer by participating in competitive endogenous RNA (ceRNA) regulatory networks. However, the specific mechanisms and complex networks of ceRNA regulatory patterns in colon adenocarcinoma (COAD) remain unclear. Using The Cancer Genome Atlas (TCGA) database, we identified the differentially expressed lncRNA, microRNA (miRNA), and messenger RNA (mRNA) between colon cancer and normal tissues, as well as between groups with high and low CEACAM5 expression. Then, we constructed CEACAM5-related ceRNA networks, established the key lncRNA-miRNA-mRNA regulatory axis, and explored the biological mechanisms of this axis and its clinical significance in colon cancer from multiomic aspects. We constructed a ceRNA network of 18 lncRNAs, 177 miRNAs, and 25 mRNAs associated with CEACAM5 and finally established the key LCMT1-AS2/miR-454-3p/ribosomal protein S6 kinase A5 (RPS6KA5) axis associated with overall survival. Subsequent investigations have indicated that this regulatory axis could potentially participate in the progression of COAD and exert influence on the therapeutic outcomes of chemotherapy and immunotherapy. It may be involved in the PI3K-Akt signaling pathway and may modify the tumor immune microenvironment and influence the course of COAD. Additionally, it may be related to ferroptosis, N6-methyladenosine (m6A) methylation, and tumor stemness and interfere with the sensitivity of tumor cells to 5-fluorouracil and immunotherapy. The LCMT1-AS2/RPS6KA5 axis may be instrumental in tumor progression, potentially acting as a prognostic biomarker and therapeutic target.

KLF7 promotes colon adenocarcinoma progression through the PDGFB signaling pathway.

Colon adenocarcinoma (COAD) is the most common malignancy of the digestive tract, which is characterized by a dismal prognosis. No effective treatment has been established presently, thus there is an urgent need to understand the mechanisms driving COAD progression in order to develop effective therapeutic approaches and enhance clinical outcomes. In this study, we found that KLF7 is overexpressed in COAD tissues and correlated with clinicopathological features of COAD. Both gain-of-function and loss-of-function experiments have unequivocally demonstrated that overexpression of KLF7 promotes the growth and metastasis of COAD in vitro and in vivo, while KLF7 knockdown attenuated these effects. Mechanistically, our findings reveal that KLF7 can specifically bind to the promoter region of PDGFB (TGGGTGGAG), thus promoting the transcription of PDGFB and increasing its secretion. Subsequently, secreted PDGFB facilitates the progression of COAD by activating MAPK/ERK, PI3K/AKT, and JAK/STAT3 signaling pathways through PDGFRβ. Additionally, we found that sunitinib can block PDGFB signaling and inhibit COAD progression, offering a promising therapeutic strategy for COAD treatment.

ZNF692 Promotes the Progression of Colon Adenocarcinoma by Regulating HSF4 Expression.

Colon adenocarcinoma (COAD) is one of the most common cancer happened in gastrointestinal tract, with the overall incidence rate of 4%-5% among human beings. Like most malignancies, we uncovered the exact mechanisms of the pathogenesis of colorectal cancer yet. Therefore, there is an urgent need to explore the molecules that can be used as diagnostic maker at early stage. In addition, we also need to define the essential factors that related to the prognosis and treatment of the colon carcinoma. The study was conducted at the Third Affiliated Hospital of Qiqihar Medical University, Qiqihar, China in September 2020. The R language was used to identify the differentially expressed genes. We performed receiver operating characteristic curve analysis to determine the diagnostic markers for COAD. The machine learning strategy was used to assess the effectiveness of genes in the diagnosis of COAD. The molecular mechanism and prognostic value of genes were explored by bioinformatics analysis and molecular experiments. The expression level of heat shock factor 4 (HSF4) was significantly elevated in COAD patients (P=1.89×10-29), according to The Cancer Genome Atlas (TCGA) database. Additionally, survival analysis showed the higher expression level of the HSF4 was correlated with the poor prognosis in COAD. The HSF4 was the target gene of zinc finger protein 692(ZNF692). HSF4 might promote the progression of COAD through the apoptosis pathway. It was diagnostic and prognosis maker of COAD. Furthermore, the upstream gene of HSF4, ZNF692, promotes the progression of colorectal cancer by regulating HSF4 expression.

Hypoxia-induced the upregulation of NDUFA4L2 promoted colon adenocarcinoma progression through ROS-mediated PI3K/AKT pathway.

The NADH dehydrogenase (ubiquinone) 1 alpha subcomplex 4-like 2 (NDUFA4L2) gene has been reported to be upregulated in colorectal cancer (CRC) and is associated with worse prognosis. However, the specific function and underlying mechanism of NDUFA4L2 in colon adenocarcinoma (COAD) under hypoxia has never been investigated. Our study discovered that hypoxia promoted the viability, metastasis, and epithelial-mesenchymal transition (EMT) of COAD cells. Besides, hypoxia-induced HIF-1α upregulated the expression of NDUFA4L2 which served as an oncogene and an independent diagnostic and prognostic marker in COAD. Under hypoxic environment, NDUFA4L2 mediated the viability, metastasis, and epithelial-EMT of COAD cells. Additionally, the ROS-dependent PI3K/Akt signaling was activated by NDUFA4L2 in COAD in hypoxia and NDUFA4L2 facilitated the malignant behaviors of hypoxia-treated COAD cells by elevating ROS production. Collectively, abundant NDUFA4L2 expression induced by HIF-1α under hypoxia promoted the development of COAD through activation of the PI3K/AKT signaling in a ROS-dependent manner, indicating NDUFA4L2 as a promising target in COAD diagnosis and treatment.

Hypomethylation-mediated LINC00346 facilitates cell phenotype progression of colon adenocarcinoma via modulating miR-589-5p/CCL5

The study aimed to investigate the role of LINC00346 in colon adenocarcinoma (COAD) metastasis. qRT-PCR, methylation-specific PCR, immunohistochemistry and western blotting were used to measure the expression levels of LINC00346, miR-589–5p, and CCL5 in COAD cells and tissues. Dual-luciferase assays, RNA immunoprecipitation, and RNA pull-down were used to validate the targeting relationship between LINC00346/CCL5 and miR-589–5p. In vivo experiments were conducted to study the impact of LINC00346 on COAD progression. MTT, colony formation assay, transwell assay and wound healing assay were used to detect the COAD cell proliferation, colony formation, invasion and migration. The results showed that COAD cells and tissues had high expression of LINC00346 and CCL5, and low expression of miR-589–5p. LINC00346 expression was upregulated due to DNA hypomethylation in its promoter region. miR-589–5p targets both LINC00346 and CCL5. LINC00346 facilitated the malignant progression of COAD by preventing the degradation of CCL5 via competitively binding to miR-589–5p. Rescue experiments indicated a ceRNA pattern consisting of LINC00346, miR-589–5p, and CCL5. Overall, LINC00346 promotes COAD progression via the miR-589–5p/CCL5 axis and may be a potential therapeutic target for COAD.

CSRP1 Promotes Colon Adenocarcinoma Growth and Serves as an Independent Risk Biomarker for Worse Prognosis.

Cysteine and Glycine Rich Protein 1 (CSRP1) belongs to the cysteine-rich protein family, which contains a unique double-zinc finger motif and is important for development and cellular differentiation. Abnormal expression of CSRP1 was reported within several malignancies such as prostate cancer and acute myeloid leukemia. Here, we explored function of CSRP1 within colon adenocarcinoma (COAD) for the first time. The mRNA levels of CSRP1 in COADs were obtained from TCGA datasets. CSRP1 protein expressions in COADs were tested via immunohistochemistry staining. Patients' prognosis was evaluated using both univariate analysis and multivariate analysis. Two human COAD originated cancer cell lines, Caco-2, and HT-29, were used for cellular experiments including shRNA knockdown, proliferation assay, and migration assay. In vivo model was established using nude mice xenografts to further validate the role of CSRP1 in COAD progression. The mRNA levels of CSRP1 are elevated in COAD specimens from patients with more advanced tumor stages and higher Carcinoembryonic Antigen (CEA) levels. In addition, higher CSRP1 mRNA level indicates worse COAD prognosis. Consistently, higher CSRP1 protein expression is correlated with worse overall survival according to both univariate and multivariate analysis, indicating that CSRP1 is a new COAD prognostic factor. Furthermore, COAD cells transfected with CSRP1-shRNAs exhibit attenuated proliferation and migration capacities. Finally, growth of xenografts originated from CSRP1-knockdown cells is inhibited comparing to the control ones. Expression of CSRP1 is positively correlated with COAD progression, which can promote tumor growth and migration. Higher CSRP1 can is a novel independent prognostic factor of COAD.

A novel lnc-LAMC2-1:1 SNP promotes colon adenocarcinoma progression by targeting miR-216a-3p/HMGB3

Single nucleotide polymorphisms (SNPs) was associated with altering the secondary structure of long non-coding RNA (lncRNA). Increasing reports showed that lnc-LAMC2-1:1 SNP played an important role in cancer development and invasion. This study is to elucidate the molecular function of lnc-LAMC2-1:1 SNP rs2147578 promoting tumor progression in colon adenocarcinoma (COAD). In this study, we found that the lnc-LAMC2-1:1 SNP rs2147578 was upregulated in COAD cell lines. Furthermore, lnc-LAMC2-1:1 SNP rs2147578 promoted colon cancer migration, invasion, and proliferation. Interestingly, lnc-LAMC2-1:1 SNP rs2147578 positively regulated HMGB3 expression via miR-216a-3p in colon cancer cells. Functional enrichment analysis showed that targeting genes of miR-216a-3p were enriched in regulating the pluripotency of stem cells, MAPK signaling pathway, TNF signaling pathway, neurotrophin signaling pathway, relaxin signaling pathway, and FoxO signaling pathway. Tumor Immune Estimation Resource (TIMER) database revealed that there was a significantly positive correlation between HMGB3 expression and the infiltration of CD8+ T cells, B cells, neutrophils, macrophages, and CD4+ T cells. Finally, HMGB3 overexpression was validated in external data. In conclusions, lnc-LAMC2-1:1 SNP rs2147578 was involved in promoting COAD progression by targeting miR-216a-3p/HMGB3, and this study will provide a novel molecular target for COAD.

LncRNA LINC01232 Enhances Proliferation, Angiogenesis, Migration and Invasion of Colon Adenocarcinoma Cells by Downregulating miR-181a-5p.

LncRNAs play crucial roles in the progression of colon adenocarcinoma (COAD), but the role of LINC01232 in COAD has not received much attention. The present study was designed to explore the related mechanisms of LINC01232 in the progression of COAD. LINC01232, miR-181a-5p, p53, c-myc, Bcl-2, cyclin D1, p16, Bax, VEGF, E-cadherin, vimentin, N-cadherin and SDAD1 expressions were determined by western blot and qRT-PCR. CCK-8, tubule formation, and Transwell assays were employed to detect proliferation, angiogenesis, and migration/invasion of COAD cells, respectively. The relationship between LINC01232 and miR-181a-5p was predicted by LncBase Predicted v.2, and then verified through dual luciferase reporter gene assay. According to the results, LINC01232 was highly expressed in COAD cells and enhanced proliferation, angiogenesis, migration, and invasion of COAD cells. Downregulated LINC01232 promoted expression of p53 and p16, and inhibited c-myc, Bcl-2 and cyclin D1 expressions in COAD cells, while upregulation of LINC01232 generated the opposite effects. LINC01232 was negatively correlated with miR-181a-5p while downregulated miR-181a-5p could reverse the effects of siLINC01232 on cell proliferation, angiogenesis, migration, and invasion. Similarly, miR-181a-5p mimic could also offset the effect of LINC01232 overexpression. SiLINC01232 increased the expressions of Bax and E-cadherin, and decreased the expressions of VEGF, vimentin, N-cadherin and SDAD1, which were partially attenuated by miR-181a-5p inhibitor. Collectively, LINC01232 enhances the proliferation, migration, invasion, and angiogenesis of COAD cells by decreasing miR-181a-5p expression.

Systematic analysis competing endogenous RNA coexpression network as a potentially prediction prognostic biomarker for colon adenocarcinoma.

Colon adenocarcinoma (COAD) is one of the most common types of colon cancer, represents a major public health issue due to its high incidence and mortality. Competing endogenous RNAs (ceRNAs) hypothesis has generated a great interest in the study of molecular biological mechanisms of cancer progression. The aim of this study was to identify potential prediction prognostic biomarker associated with progression of COAD and illuminate regulatory mechanisms. Two RNA sequencing datasets downloaded from the Genotype-Tissue Expression and TCGA. The differentially expressed RNAs were analyzed. Weighted correlation network analysis was used to analyze the similarity of genes model with a trait in the network. Interactions between lncRNAs, miRNAs, and target mRNAs were predicted by MiRcode, starBase, miRTarBase, miRDB, and TargetScan, and the risk score of mRNAs was established. Based on the identified prognostic signature and independent clinical factors, then the nomogram survival model was built. Totally, we identified 3537 differentially expressed mRNAs, 2379 lncRNAs, and 449 microRNAs. Based on the 8 prognosis-associated mRNAs (CCNA2 + CEBPA + NEBL + SOX9 + DLG4 + RIMKLB + TCF7L1 + TUB), the risk score was proposed. After the independent clinical prognostic factors were identified, the nomogram survival model was built. LncRNA-miRNA-mRNA ceRNA network was built by 68 lncRNAs, 4 miRNAs, and 6 mRNAs, which might serve as prognostic biomarkers of COAD. These findings suggest several genes in ceRNA network might be novel important prognostic biomarkers and potential targets for COAD. CeRNA networks could provide further insight into the mRNA-related regulatory mechanism and COAD prognosis.

Development of an exosome-related and immune microenvironment prognostic signature in colon adenocarcinoma.

Background: The correlation between exosomes and the tumor immune microenvironment has been proved to affect tumorigenesis and progression of colon adenocarcinoma (COAD). However, it remained unclear whether exosomes had an impact on the prognostic indications of COAD patients. Methods: Expression of exosome-related genes (ERGs) and clinical data were downloaded from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database. The ERGs associated with prognosis were identified and exosome-related prognostic signature was constructed. Patients in two risk groups were classified according to the risk score calculation formula: Risk score = 1.0132 * CCKBR + 0.2416 * HOXC6 + 0.7618 * POU4F1. The expression of three ERGs was investigated by qRT-PCR. After that, we developed a nomogram predicting the likelihood of survival and verified its predictive efficiency. The differences of tumor immune microenvironment, immune cell infiltration, immune checkpoint and sensitivity to drugs in two risk groups were analyzed. Results: A prognostic signature was established based on the three ERGs (CCKBR, HOXC6, and POU4F1) and patients with different risk group were distinguished. Survival analysis revealed the negative associated of risk score and prognosis, ROC curve analyses showed the accuracy of this signature. Three ERGs expression was investigated by qRT-PCR in three colorectal cancer cell lines. Moreover, risk score was positively correlated with tumor mutational burden (TMB), immune activities, microsatellite instability level, the expression of immune checkpoint genes. Meanwhile, the expression level of three ERGs and the risk score were markedly related with the sensitive response to chemotherapy. Conclusion: The novel signature composed of three ERGs with precise predictive capabilities can be used to predict prognosis and provide a promising therapeutic target for improving the efficacy of immunotherapy.

FKBP4 regulates 5-fluorouracil sensitivity in colon cancer by controlling mitochondrial respiration.

Mitochondrial respiration and metabolism play a key role in the pathogenesis and progression of colon adenocarcinoma (COAD). Here, we report a functional pool of FKBP4, a co-chaperone protein, in the mitochondrial intermembrane space (IMS) of colon cancer cells. We found that IMS-localized FKBP4 is essential for the maintenance of mitochondrial respiration, thus contributing to the sensitivity of COAD cells to 5-fluorouracil (5-FU). Mechanistically, FKBP4 interacts with COA6 and controls the assembly of the mitochondrial COA6/SCO1/SCO2 complex, thereby governing COA6-regulated biogenesis and activity of mitochondrial cytochrome c oxidase (complex IV). Thus, our data reveal IMS-localized FKBP4 as a novel regulator of 5-FU sensitivity in COAD, linking mitochondrial respiration to 5-FU sensitivity in COAD.

Development and validation of a robust necroptosis related classifier for colon adenocarcinoma.

Background: Necroptosis, a novel form of apoptosis, plays a crucial function in the progression of colon adenocarcinoma (COAD) and is expected to be triggered in cancer therapy for enhancing anti-tumor immunity. However, the function of necroptosis in tumors and its relationship with the tumor microenvironment (TME) remains largely unclear. Methods: Necroptosis-related genes (NRGs) were collected from high-quality literature. Using The Cancer Genome Atlas (TCGA) (https://cancergenome.nih.gov) and the Gene Expression Omnibus (GEO) (www.ncbi.nlm.nih.gov/geo) meta-cohorts, a robust risk model was constructed to systematically examine the clinical value, functional status, the role of TME based on the risk model, as also the genomic variations. Results: A risk model containing nine NRGs, including TNF receptor-associated factor (TRAF2), TNF receptor 1 associated via death domain (TRADD), ubiquitin carboxyl-terminal hydrolase 21 (USP21), TNF receptor superfamily, member 6 (FAS), tumor necrosis factor receptor superfamily 10B (TNFRSF10B), mitogen-activated protein kinase 8 (MAPK8), mixed lineage kinase domain-like (MLKL), TNF receptor-associated factor 5 (TRAF5), and recombinant receptor-interacting serine-threonine kinase 3 (RIPK3), was constructed. The risk model’s stability and accuracy were demonstrated in training, as also the validation cohorts; it was verified as an independent prognostic model for COAD. High-risk group patients developed “cold” tumors having active tumor proliferation and immunosuppression, while those in the low-risk group developed “hot” tumors with active immune and cell killing functions. Moreover, a higher number of copy number variations in the genome and fewer somatic mutations were found in high-risk group patients. Furthermore, higher sensitivity towards immunotherapy and chemotherapy was seen in patients of the low-risk group. Conclusion: A reliable risk model based on NRGs to assess patient prognosis and guide clinical decision-making was constructed and validated. Our findings may contribute to the understanding of necroptosis and are expected to aid clinical management and guide precision treatment for patients with COAD.

Low adenylate kinase 5 expression is predictive of poor prognosis and promotes tumour growth by regulating the cell-cycle pathway.

Colon adenocarcinoma (COAD) is one of the most common malignant tumours of the digestive system. Specific molecular markers play an important role in COAD diagnosis and therapy. Adenylate kinase 5 (AK5) is an enzyme that is related to energy metabolism and cancer. However, the exact role of AK5 in the progression of COAD is still unclear. In this study, the expression of AK5 in tissue samples and non-cancerous tissues of COAD patients was assessed by the bioinformatics method and western blot. Kaplan-Meier survival analysis and Cox regression analysis evaluated the prognostic significance of AK5. The biological function of AK5 in tumour progression was assessed by MTT assay, colony formation assay, transwell assay, wound healing assay, western blot and mice xenograft models. The results showed that AK5 expression in tumour tissues was lower than in non-cancerous tissues. Notably, the patients with high AK5 expression possessed a longer overall survival than the low expression patients, and low AK5 expression promoted proliferation and metastasis in COAD cells by regulating the cell-cycle pathway. Importantly, in vivo results showed that reduced AK5 expression is required for tumour growth. This study confirmed the significant role of AK5 in the development and progression of COAD. Therefore, low AK5 expression levels can be an independent prognostic biomarker, which provides new sight for the clinical diagnosis and target therapy of COAD.

Exploring the Interplay between Metabolism and Tumor Microenvironment Based on Four Major Metabolism Pathways in Colon Adenocarcinoma.

Tumor metabolism plays a critical role in tumor progression. However, the interaction between metabolism and tumor microenvironment (TME) has not been comprehensively revealed in colon adenocarcinoma (COAD). We used unsupervised consensus clustering to establish three molecular subtypes (clusters) based on the enrichment score of four major metabolism pathways in TCGA-COAD dataset. GSE17536 was used as a validation dataset. Single-cell RNA sequencing data (GSE161277) was employed to further verify the reliability of subtyping and characterize the correlation between metabolism and TME. Three clusters were identified and they performed distinct prognosis and molecular features. Clust3 had the worst overall survival and the highest enrichment score of glycolysis. 86 differentially expressed genes (DEGs) were identified, in which 11 DEGs were associated with favorable prognosis and 75 DEGs were associated with poor prognosis. Striking correlations were observed between hypoxia and glycolysis, clust3 and hypoxia, and clust3 and angiogenesis (P < 0.001).We constructed a molecular subtyping system which was effective and reliable for predicting COAD prognosis. The 86 identified key DEGs may be greatly involved in COAD progression, and they provide new perspectives and directions for further understanding the mechanism of metabolism in promoting aggressive phenotype by interacting with TME.

ASCL2 Affects the Efficacy of Immunotherapy in Colon Adenocarcinoma Based on Single-Cell RNA Sequencing Analysis.

Colon adenocarcinoma (COAD) is one of the leading causes of cancer-associated deaths worldwide. Patients with microsatellite instability-high (MSI-H) tumors were shown to highly benefit from immune checkpoint inhibitors (ICIs) than patients with microsatellite stable (MSS) tumors. Furthermore, the infiltration of immune cells and the expression of cancer stem cells (CSCs) in COAD were associated with the anti-tumor immune response. However, the potential mechanisms showing the relationship between microsatellite instability and CSCs or tumor-infiltrating immune cells (TIICs) have not been elucidated. Accumulating evidence reveals that achaete-scute family bHLH transcription factor 2 (ASCL2) plays a crucial role in the initiation and progression of COAD and drug resistance. However, the specific biological functions of ASCL2 in COAD remain unknown. In this study, we performed weighted gene co-expression network analysis (WGCNA) between MSS and MSI-H subsets of COAD. The results revealed that ASCL2 was a potential key candidate in COAD. Subsequently, the single-cell RNA-seq revealed that ASCL2 was positively associated with CSCs. Further, ASCL2 was shown to indirectly affect tumor immune cell infiltration by negatively regulating the expression of DUSP4. Finally, we inferred that the immunotherapy-sensitive role of ASCL2/DUSP4 axis on COAD is partly attributed to the activation of WNT/β-catenin pathway. In conclusion, this study revealed that ASCL2 was positively correlated to CSCs and tumor immune infiltration in COAD. Therefore, ASCL2 is a promising predictor of clinical responsiveness to anti-PD-1/PD-L1 therapy in COAD.