Colorectal cancer (CRC), a major global health concern, necessitates innovative treatments. Chimeric antigen receptor (CAR) T cells have shown promises, yet they grapple with challenges. The spotlight pivots to the rising heroes: CAR natural killer (NK) cells, offering advantages such as higher safety profiles, cost-effectiveness, and efficacy against solid tumors. Nevertheless, the specific mechanisms underlying CAR NK cell trafficking and their interplay within the complex tumor microenvironment require further in-depth exploration. Herein, we provide insights into the design and engineering of CAR NK cells, antigen targets in CRC, and success in overcoming resistance mechanisms with an emphasis on the potential for clinical trials.
Colorectal Neoplasms/immunology* ; Humans ; Killer Cells, Natural/metabolism* ; Receptors, Chimeric Antigen/genetics* ; Immunotherapy, Adoptive/methods* ; Tumor Microenvironment/immunology* ; Animals

Colorectal cancer (CRC) is one of the leading causes of cancer-related morbidity and mortality worldwide, highlighting the urgent need for novel preventive and therapeutic strategies. Emerging research highlights the crucial role of the gut microbiota, including bacteria, fungi, viruses, and their metabolites, in the pathogenesis of CRC. Dysbiosis, characterized by an imbalance in microbial composition, contributes to tumorigenesis through immune modulation, metabolic reprogramming, and genotoxicity. Specific bacterial species, such as Fusobacterium nucleatum and enterotoxigenic Bacteroides fragilis , along with fungal agents like Candida species, have been implicated in CRC progression. Moreover, viral factors, including Epstein-Barr virus and human cytomegalovirus, are increasingly recognized for their roles in promoting inflammation and immune evasion. This review synthesizes the latest evidence on host-microbiome interactions in CRC, emphasizing microbial metabolites, such as short-chain fatty acids and bile acids, which may act as both risk factors and therapeutic agents. We further discuss the latest advances in microbiota-targeted clinical applications, including biomarker-assisted diagnosis, next-generation probiotics, and microbiome-based interventions. A deeper understanding of the role of gut microbiome in CRC pathogenesis could pave the way for diagnostic, preventive, and personalized therapeutic strategies.
Humans ; Dysbiosis/microbiology* ; Colorectal Neoplasms/metabolism* ; Gastrointestinal Microbiome/physiology* ; Animals

OBJECTIVE: To explore the role of the natural compound hesperidin in glycolysis, the key ratelimiting enzyme, in colorectal cancer (CRC) cell lines. METHODS: In vitro, HCT116 and SW620 were treated with different doses of hesperidin (0-500 µmol/L), cell counting kit-8 and colone formation assays were utilized to detected inhibition effect of hesperidin on CRC cell lines. Transwell and wound healing assays were performed to detect the ability of hesperidin (0, 25, 50 and 75 µmol/L) to migrate CRC cells. To confirm the apoptotic-inducing effect of hesperidin, apoptosis and cycle assays were employed. Western blot, glucose uptake, and lactate production determination measurements were applied to determine inhibitory effects of hesperidin (0, 25 and 50 µmol/L) on glycolysis. In vivo, according to the random number table method, nude mice with successful tumor loading were randomly divided into vehicle, low-dose hesperidin (20 mg/kg) and high-dose hesperidin (60 mg/kg) groups, with 6 mice in each group. The body weights and tumor volumes of mice were recorded during 4-week treatment. The expression of key glycolysis rate-limiting enzymes was determined using Western blot, and glucose uptake and lactate production were assessed. Finally, protein interactions were probed with DirectDIA Quantitative Proteomics, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. RESULTS: Hesperidin could inhibit CRC cell line growth (P<0.05 or P<0.01). Moreover, hesperidin presented an inhibitory effect on the migrating abilities of CRC cells. Hesperidin also promoted apoptosis and cell cycle alterations (P<0.05). The immunoblotting results manifested that hesperidin decreased the levels of hexokinase 2, glucose transporter protein 1 (GLUT1), GLUT3, L-lactate dehydrogenase A, 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 2 (PFKFB2), PFKFB3, and pyruvate kinase isozymes M2 (P<0.01). It remarkably suppressed tumor xenograft growth in nude mice. GO and KEGG analyses showed that hesperidin treatment altered metabolic function. CONCLUSION Hesperidin inhibits glycolysis and is a potential therapeutic choice for CRC treatment.
Hesperidin/therapeutic use* ; Colorectal Neoplasms/metabolism* ; Glycolysis/drug effects* ; Animals ; Humans ; Apoptosis/drug effects* ; Mice, Nude ; Cell Movement/drug effects* ; Cell Line, Tumor ; Cell Proliferation/drug effects* ; Glucose/metabolism* ; Cell Cycle/drug effects* ; Mice, Inbred BALB C ; Mice ; HCT116 Cells ; Lactic Acid

OBJECTIVES: Oxaliplatin (OXA) and 5-fluorouracil (5-FU) are 2 commonly used chemotherapeutic agents for colorectal cancer (CRC). MicroRNAs (miRNAs, miRs) play crucial roles in the development of chemoresistance in various cancers. However, the role and mechanism of miR-224-5p in regulating CRC chemoresistance remain unclear. This study aims to investigate the function of miR-224-5p in chemoresistant CRC cells and the underlying mechanisms. METHODS: CRC datasets GSE28702 and GSE69657 were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed miRNAs between drug-sensitive and resistant groups (OXA or 5-FU) were analyzed, and miR-224-5p was identified as the target miRNA. Chemoresistant cell lines HCT15-OXR, HCT15-5-FU, SW480-OXR, and SW480-5-FU were established. Transient transfections were performed using miR-224-5p mimics, inhibitors, and their respective negative controls (control mimic, control inhibitor) in these cell lines. Cells were treated with different concentrations of OXA or 5-FU post-transfection, and the half-maximal inhibitory concentration (IC₅₀) was determined using the cell counting kit-8 (CCK-8) assay. Cell proliferation was assessed by CCK-8 and colony formation assays. The expression levels of miR-224-5p, LC3, and P62 were measured by real-time polymerase chain reaction (real-time PCR) and/or Western blotting. Autophagic flux was assessed using a tandem fluorescent-tagged LC3 reporter assay. TargetScan 8.0, miRTarBase, miRPathDB, and HADb were used to predict B-cell lymphoma-2 (Bcl-2) as a potential miR-244-5p target, which was further validated by dual-luciferase reporter assays. RESULTS: Chemoresistant CRC cells exhibited down-regulated miR-224-5p expression, whereas up-regulation of miR-224-5p enhanced chemotherapy sensitivity. Exposure to OXA or 5-FU significantly increased autophagic activity in chemoresistant CRC cells, which was reversed by miR-224-5p overexpression. Dual-luciferase assays verified Bcl-2 as a direct target of miR-224-5p. CONCLUSIONS MiR-224-5p regulates chemoresistance in CRC by modulating autophagy through direct targeting of Bcl-2.
Humans ; MicroRNAs/physiology* ; Colorectal Neoplasms/drug therapy* ; Drug Resistance, Neoplasm/genetics* ; Autophagy/drug effects* ; Fluorouracil/pharmacology* ; Oxaliplatin ; Cell Line, Tumor ; Proto-Oncogene Proteins c-bcl-2/metabolism* ; Gene Expression Regulation, Neoplastic

OBJECTIVES: To explore the expression of hexokinase 2 (HK2) in colorectal cancer (CRC) and its possible mechanisms for regulating tumor cell behaviors and tumor immune microenvironment. METHODS: We analyzed HK2 expression in CRC and its impact on patient prognosis and tumor immune microenvironment using public databases. HK2 expression was also examined in 8 CRC and paired adjacent tissues using immunohistochemistry, Western blotting and RT-qPCR. In cultured CRC cell lines CT26 and HCT116 with low HK2 expression, the effects of lentivirus-mediated HK2 overexpression and JAK/STAT3 inhibitors on cell proliferation, migration, and invasion were assessed using CCK-8 assay, colony formation assay and Transwell assay and in a subcutaneous tumor-bearing mouse model; the changes were also observed in MC38 and CACO2 cells with high HK2 expressions following treatment with HK2 inhibitor 3-BP. Western blotting was performed to verify the relationship between HK2 and JAK/STAT signaling pathway protein expressions. RESULTS: Informatics analyses suggested that HK2 expression was significantly higher in CRC tissues than in adjacent tissues (P<0.001), and patients with high HK2 expressions had worse prognosis (P=0.09). In the 8 clinical CRC tissues, HK2 expressions were significantly higher in the tumor tissues than in the adjacent tissues (P<0.01). In CT26 and HCT116 cells, HK2 overexpression significantly enhanced cell proliferation, migration and invasion, while in HK2-overexpressing MC38 and CACO2 cells, inhibiting HK2 with 3-BP strongly suppressed these changes. HK2 overexpression promoted STAT3 phosphorylation, and JAK/STAT3 inhibitors effectively suppressed tumor cell proliferation, migration and invasion. TIMER and MCPcounter analyses indicated correlations between HK2 and immune cells, and TCGA and GEO analyses suggested significant positive correlations between HK2 and the immune checkpoints including PDCD1. CONCLUSIONS HK2 is upregulated in CRC to promote tumor cell proliferation, migration and invasion possibly by activating the JAK-STAT signaling pathway and modulating tumor immune microenvironment.
Humans ; Colorectal Neoplasms/metabolism* ; Cell Proliferation ; Hexokinase/genetics* ; Tumor Microenvironment ; Cell Movement ; Signal Transduction ; Animals ; STAT3 Transcription Factor/metabolism* ; Mice ; Neoplasm Invasiveness ; Cell Line, Tumor ; Janus Kinases/metabolism* ; HCT116 Cells ; Caco-2 Cells

OBJECTIVES: To investigate the role of DTX2 in regulating biological behaviors of oxaliplatin-resistant colorectal cancer cells (CRC/OXA cells). METHODS: CCK8 assay was used to determine the inhibition rate of oxaliplatin-treated CRC cells. A CRC/OXA cell line was constructed, in which DTX2 expression level was detected. The cells were transfected with a DTX2-shRNA plasmid or co-transfected with DTX2-shRNA and pcDNA-Notch2, and the changes in cell proliferation, migration and invasion ability were evaluated using plate cloning assay, scratch assay and Transwell invasion assay. The expression levels of Notch2, NICD and epithelial-mesenchymal transition (EMT) proteins of the transfected cells were detected with Western blotting. In a nude mouse model bearing SW620/OXA cell xenografts, the effects of DTX2 knockdown and Notch2 overexpression in the implanted cells on tumor growth and protein expressions were tested. RESULTS: The IC₅₀ of oxaliplatin was 6.00 μmol/L in SW620 cells and 8.00 μmol/L in LoVo cells. CRC/OXA cells showed a significantly increased expression of DTX2. DTX2 knockdown in CRC/OXA cells significantly inhibited cell proliferation, migration and invasion, and these effects were reversed by co-transfection of the cells with pcDNA-Notch2. DTX2 knockdown significantly reduced the expression levels of Notch2, NICD and vimentin proteins and increased E-cadherin expression in CRC/OXA cells, and co-transfection with pcDNA-Notch2 potently attenuated the changes in these proteins. In the tumor-bearing mice, DTX2 overexpression obviously promoted the growth of SW620/OXA cell xenograft, enhanced the protein expressions of Notch2, NICD and vimentin, and lowered the expression of E-cadherin. CONCLUSIONS High expression of DTX2 promotes proliferation, migration, invasion and EMT of CRC/OXA cells through the Notch2 signaling pathway, suggesting the potential of DTX2 as a target to improve the efficacy of oxaliplatin.
Epithelial-Mesenchymal Transition ; Humans ; Cell Proliferation ; Oxaliplatin ; Colorectal Neoplasms/metabolism* ; Animals ; Drug Resistance, Neoplasm ; Receptor, Notch2/metabolism* ; Cell Line, Tumor ; Mice, Nude ; Cell Movement ; Organoplatinum Compounds/pharmacology* ; Neoplasm Invasiveness ; Mice

OBJECTIVES: To investigate the regulatory role of Ral guanine nucleotide dissociation stimulator-like 1 (RGL1) in metastasis of colorectal cancer (CRC). METHODS: We analyzed the differential expression of RGL1 between metastatic and non-metastatic CRC in GEO database, and examined its expression in 25 patients with metastatic CRC and 25 patients with non-metastatic CRC treated in Zhujiang Hospital between January, 2020 and December, 2022 using quantitative PCR (qPCR) and immunohistochemistry. HCT116 cell lines with stable RGL1 overexpression and SW480 cells with RGL1 knockdown were established using lentiviral vecors, and the changes in invasion and migration abilities of the cells were assessed using Transwell invasion and migration assays. The transduced cells were injected into the serosa of the cecum of nude mice, and tumor growth and liver metastasis were observed 8 weeks later. Fibronectin adhesion assays and immunofluorescence experiments were employed to assess the relationship between RGL1 and focal adhesion formation, and co-immuno-precipitation assays were performed to explore the interaction between RGL1 and GTPase activation. RESULTS: Compared with non-metastatic CRC, metastatic CRC showed significantly upregulated expression of RGL1. HCT116 cells overexpressing RGL1 exhibited obviously enhanced migration and invasion in vitro with increased capacity for liver metastasis in nude mice. RGL1 overexpression strongly accelerated focal adhesion assembly, facilitated the formation of motile focal adhesions, and enhanced the binding of activated CDC42/RAC1 complex to RGL1. CONCLUSIONS RGL1 is highly expressed in metastatic CRC and promotes distant metastasis of CRC by activating the CDC42/RAC1 complex to facilitate the formation of motile focal adhesions. These findings suggest that RGL1 can potentially serve as a therapeutic target for CRC metastasis.
Humans ; Colorectal Neoplasms/metabolism* ; cdc42 GTP-Binding Protein/metabolism* ; Animals ; Mice, Nude ; rac1 GTP-Binding Protein/metabolism* ; Cell Movement ; Mice ; Focal Adhesions/metabolism* ; Neoplasm Metastasis ; Cell Line, Tumor ; HCT116 Cells ; Up-Regulation ; Neoplasm Invasiveness ; Adaptor Proteins, Signal Transducing ; Female ; Rho Guanine Nucleotide Exchange Factors

OBJECTIVES: To explore the correlation of ELFN1 expression level with prognosis of colorectal cancer and its regulatory role in colorectal cancer cell proliferation and metastasis. METHODS: We analyzed the expression levels of ELFN1 across 33 cancer types using publicly available databases and identified differential genes related to ELFN1 in colorectal cancer. Gene function annotation and enrichment analysis were used to identify the involved signaling pathways. Logistic analysis, Kaplan-Meier analysis and Cox regression analysis were performed to evaluate the correlation between ELFN1 expression and clinicopathological parameters and survival of colorectal cancer patients. qPCR and Western blotting were used to validate the expression levels of ELFN1 in different colorectal cancer cell lines and tissues, and Transwell and EDU experiments were carried out to assess the effect of ELFN1 knockdown on biological behaviors of SW480 cells. RESULTS: ELFN1 was highly expressed in 14 cancers, and its expression was significantly higher in colon cancer tissues than in adjacent tissues. A high expression of ELFN1 mRNA was associated with a poorer overall survival of colorectal cancer patients. Cox regression analysis indicated that ELFN1 expression was an independent prognostic factor for overall survival of the patients. ELFN1 was significantly enriched in tumor metastasis and proliferation and participated in several tumor signaling pathways. The colon cancer cell lines showed significantly higher expression levels of ELFN1 than normal cells, ELFN1 knockdown obviously inhibited proliferation and migration of SW480 cells in vitro. CONCLUSIONS ELFN1 is overexpressed in colorectal cancer and is associated with poor clinical prognosis of the patients. A high ELFN1 expression is associated with malignant phenotypes of colorectal cancer and promotes cancer cell proliferation and metastasis, suggesting its potential as a prognostic biomarker for colorectal cancer.
Humans ; Colorectal Neoplasms/diagnosis* ; Cell Proliferation ; Prognosis ; Cell Line, Tumor ; Biomarkers, Tumor/metabolism* ; Neoplasm Metastasis ; Gene Expression Regulation, Neoplastic ; Nerve Tissue Proteins/metabolism* ; Female ; Male

The nervous system is the dominant regulatory system in the human body. The traditional theory is that tumors lack innervation. However, an increasing number of studies have shown complex bidirectional interactions between tumors and the nervous system. Globally, colorectal cancer (CRC) is the third most common cancer. With the rise of tumor neuroscience, the role of nervous system imbalances in the occurrence and development of CRC has attracted increasing amounts of attention. However, there are still many gaps in the research on the interactions and mechanisms involved in the nervous system in CRC. This article systematically reviews emerging research on the bidirectional relationships between the nervous system and CRC, focusing on the following areas: (1) Effects of the nervous system on colon cancer. (2) Effects of CRC on the nervous system. (3) Treatment of CRC associated with the nervous system.
Humans ; Colorectal Neoplasms/therapy* ; Animals ; Nervous System/metabolism*

Dysregulated RNA splicing is a well-recognized characteristic of colorectal cancer (CRC); however, its intricacies remain obscure, partly due to challenges in profiling full-length transcript variants at the single-cell level. Here, we employ high-depth long-read scRNA-seq to define the full-length transcriptome of colorectal epithelial cells in 12 CRC patients, revealing extensive isoform diversities and splicing alterations. Cancer cells exhibited increased transcript complexity, with widespread 3'-UTR shortening and reduced intron retention. Distinct splicing regulation patterns were observed between intrinsic-consensus molecular subtypes (iCMS), with iCMS3 displaying even higher splicing factor activities and more pronounced 3'-UTR shortening. Furthermore, we revealed substantial shifts in isoform usage that result in alterations of protein sequences from the same gene with distinct carcinogenic effects during tumorigenesis of CRC. Allele-specific expression analysis revealed dominant mutant allele expression in key oncogenes and tumor suppressors. Moreover, mutated PPIG was linked to widespread splicing dysregulation, and functional validation experiments confirmed its critical role in modulating RNA splicing and tumor-associated processes. Our findings highlight the transcriptomic plasticity in CRC and suggest novel candidate targets for splicing-based therapeutic strategies.
Humans ; Colorectal Neoplasms/metabolism* ; RNA Isoforms/metabolism* ; Single-Cell Analysis ; RNA Splicing ; Gene Expression Regulation, Neoplastic ; RNA, Neoplasm/metabolism* ; Transcriptome