Combination therapy for colorectal cancer with anti-PD-L1 and cancer vaccine: A multiscale mathematical model of tumor-immune interactions.

Colorectal cancer (CRC) is currently ranked as the third most frequent human cancer and the fourth leading cause of cancer-related deaths worldwide. Macrophages and immune cell subsets infiltrate the tumor microenvironment (TME) and modulate several cellular events and metabolic processes in CRC. Therefore, CRC-TME-infilitrating macrophages are thought to play a significant role in CRC progression, and could hence be potential therapeutic targets in CRC. Several lines of evidence suggest that the Wingless/Integrated (WNTs) family of signaling proteins plays a crucial role in CRC development and progression. Numerous studies have established that Wnt pathway signaling is involved in CRC-TME interaction; CRC-immune cell interaction in particular. Mounting experimental evidence point to the possibility that the TME in CRC can reciprocally modulate the Wnt/β-catenin pathway. Lastly, several studies have elaborated on the effect of drugs that disrupt the Wnt/β-catenin pathway as means of hindering CRC growth and progression. In this review, we discuss the multifaceted role of Wnt/β-catenin pathway in CRC and its TME as well as CRC-TME interactions. We also elaborate on the potential therapeutic utility of Wnt/β-catenin pathway-related targets in CRC.

BackgroundSerine/arginine-rich splicing factor 9 (SRSF9) is a classical RNA-binding protein that is essential for regulating gene expression programs through its interaction with target RNA. Whether SRSF9 plays an essential role in colorectal cancer (CRC) progression and can serve as a therapeutic target is largely unknown. Here, we highlight new findings on the role of SRSF9 in CRC progression and elucidate the underlying mechanism.MethodsCRC cell lines and clinical tissue samples were used. qRT-PCR, Western blotting, immunohistochemistry (IHC), gain- and loss-of-function assays, animal xenograft model studies, bioinformatic analysis, methylated single-stranded RNA affinity assays, gene-specific m6A quantitative qRT-PCR, dual-luciferase reporter assays and RNA stability assays were performed in this study.ResultsThe expression level of SRSF9 was higher in CRC cell lines than that in an immortal human intestinal epithelial cell line. Overexpression of SRSF9 was positively associated with lymph node metastasis and Dukes stage. Functionally, SRSF9 promoted cell proliferation, migration and invasion in vitro and xenograft growth. The results of bioinformatic analysis indicated that DSN1 was the downstream target of SRSF9. In CRC cells and clinical tissue samples, the expression of SRSF9 was positively associated with the expression of DSN1. Knockdown of DSN1 partially inhibited the SRSF9-induced phenotype in CRC cells. Mechanistically, we further found that SRSF9 is an m6A-binding protein and that m6A modifications were enriched in DSN1 mRNA in CRC cells. Two m6A modification sites (chr20:36773619–36773620 and chr20:36773645–chr20:36773646) in the SRSF9-binding region (chr20:36773597–36773736) of DSN1 mRNA were identified. SRSF9 binds to DSN1 in an m6A motif- and dose-dependent manner. SRSF9 modulates the expression of DSN1 in CRC cells. Such expression regulation was largely impaired upon methyltransferase METTL3 knockdown. Moreover, knockdown of SRSF9 accelerated DSN1 mRNA turnover, while overexpression of SRSF9 stabilized DSN1 mRNA in CRC cells. Such stabilizing was also weakened upon METTL3 knockdown.ConclusionOverexpression of SRSF9 was associated with lymph node metastasis and Dukes stage in CRC. Knockdown of DSN1 eliminated the effects by SRSF9 overexpression in CRC. Our results indicated that SRSF9 functions as an m6A-binding protein (termed “reader”) by enhancing the stability of DSN1 mRNA in m6A-related manner. Our study is the first to report that SRSF9-mediated m6A recognition has a crucial role in CRC progression, and highlights SRSF9 as a potential therapeutic target for CRC management.

Ran GTPase activating protein 1 (RanGAP1) has been implicated in various diseases, but its role in colorectal cancer (CRC) progression remains unclear. Using tumor tissues and public databases, we found that RanGAP1 was significantly upregulated in CRC tissues and was associated with poor prognosis of patients. N6-methyladenosine (m6A) was found to play an important role in higher expression of RanGAP1. MeRIP-seq, RIP-qPCR, Luciferase reporter assays and other related experiment elucidated the molecular mechanism underlying m6A modification of RanGAP1. Besides, cell function experiments and xenograft tumor models corroborated the function of RanGAP1 in CRC progression. By RNA-seq and related analysis, RanGAP1 was verified to influent CRC progression via the Mitogen-Activated Protein Kinase (MAPK) signaling pathway. Therefore, N6-methyladenosine modification of RanGAP1 by METTL3/YTHDF1 plays a role in CRC progression through the MAPK pathway and could be a potential biomarker and therapeutic target for CRC.Schematic diagram showed that N6-methyladenosine modification of RanGAP1 promotes CRC progression via the MAPK signaling pathway.

Histone demethylases (HDMs) play a pivotal role in colorectal cancer (CRC) progression through dynamic epigenetic regulation. This review summarizes the role and therapeutic potential of HDM in CRC. HDMs primarily target lysine (K) for demethylation (lysine demethylase, KDM). The KDM family is divided into the lysine-specific demethylase family and the Jumonji C domain-containing family. HDMs play complex roles in CRC cell proliferation, invasion, migration, stemness, epithelial-mesenchymal transition, immune response, and chemoresistance through epigenetic regulation of different histone demethylation sites. Increasing evidence suggests that KDM may interact with certain factors and regulate CRC tumorigenesis by modulating multiple signaling pathways and affecting the transcription of target genes. These processes may be regulated by upstream genes and thus form a complex epigenetic regulatory network. However, the potential roles and regulatory mechanisms of some HDMs in CRC remain understudied. Preclinical studies have revealed that small-molecule inhibitors targeting HDM impact the activity of specific genes and pathways by inhibiting specific HDM expression, thereby reshaping the tumorigenic landscape of CRC. However, the clinical translational potential of these inhibitors remains unexplored. In conclusion, HDMs play a complex and critical role in CRC progression by dynamically regulating histone methylation patterns. These HDMs shape the malignant behavior of CRC by influencing the activity of key pathways and target genes through epigenetic reprogramming. Targeting HDM may be a promising direction for CRC treatment. Further exploration of the role of specific HDMs in CRC and the therapeutic potential of HDM-specific inhibitors is needed in the future.

Mitochondrial dysfunction is closely related to tumor development. Adenine nucleotide translocator 1 (ANT1), which promotes ADP/ATP translocation across the inner mitochondrial membrane, is an important protein involved in mitochondrial function and plays a role in a variety of diseases, including cancers. However, its role in colorectal cancer (CRC) progression remains poorly understood. This study aims to explore the potential role of ANT1 in CRC and its relationship with mitophagy. Through immunohistochemical analysis, we find that ANT1 expression is significantly higher in the tumor tissues of CRC patients than in adjacent normal tissues and that its overexpression is associated with poor prognosis. Further experiments demonstrate that ANT1 knockdown significantly inhibits CRC cell proliferation, migration, and invasion and leads to mitochondrial dysfunction, increased ROS production, and apoptosis by suppressing mitophagy. Mechanistically, ANT1 knockdown downregulates the PINK1/Parkin pathway, thereby inhibiting mitophagy activity. Notably, PINK1 overexpression partially rescues the cellular dysfunction induced by ANT1 knockdown, suggesting a potential role for PINK1 in reversing the suppression of mitophagy. In vivo xenograft models also show that ANT1 knockdown markedly inhibits tumor growth. In conclusion, ANT1 may play a critical role in CRC progression by regulating mitophagy, providing a basis for its potential as a therapeutic target.

Tropomodulin-2 (TMOD2) is upregulated in the nuclear compartment of highly liver metastatic colorectal cancer (CRC) cells. Its role in cancer and CRC progression is functionally undefined, despite its analysis in COAD and READ TCGA datasets revealing a correlation between high TMOD2 expression, advanced disease stages, and poorer survival in CRC patients. We aimed here to explore the role of TMOD2 in CRC and liver metastasis using functional proteomics, tumour samples, bioinformatics, and in vitro and in vivo CRC models. Stable overexpression and stable depletion of TMOD2 in isogenic CRC cells revealed its impact on tumorigenic and metastatic properties. TMOD2 overexpression enhanced cell adhesion, anchorage-independent growth, and migration, while stably TMOD2 depletion reduced them. In vivo, TMOD2-overexpressing cells formed larger tumours and enhanced liver colonisation of CRC cells. Clinically, TMOD2 protein levels demonstrated strong discriminatory ability between metastatic and non-metastatic CRC patients. Proteomic analyses allowed the identification of TMOD2-associated proteins involved in cytoskeletal dynamics, secretion, and focal adhesions, with further validation implicating STAG1 and MARCKS as mediators of TMOD2-driven pathways. Our findings demonstrate that TMOD2 plays a role in CRC progression by modulating cytoskeletal dynamics, enhancing cell adhesion and promoting liver metastasis, positioning TMOD2 as a target for therapeutic intervention in CRC.

Colorectal cancer (CRC) is a leading cause of cancer-related deaths in the United States with 53,200 deaths projected in 2020. Although methods to detect CRC are available, it remains a major problem and is a leading cause of cancer-related deaths. Hence, there is a dire need to identify novel signaling pathways as targets for therapy. Based on a bedside observation where CRC patients complained about dysgeusia or taste alterations even before being discovered with cancer, we looked at the expression of the 25 bitter taste receptors (TAS2R1-50, TAS2R60). In addition to the oral activity, these receptors are found in the lung, the heart, thyroid, and gastrointestinal muscles. Taste receptors utilize G-protein coupled receptors (GPCRs) and signal through G-βγ activation of PLCβ2, IP3-mediated release of Ca2+ and activation of TRPM5, leading to the release of ATP as a transmitter to activate gustatory afferents. Recently, a few TAS2 receptors have been shown to be upregulated in various cancers, but nothing is known about their expression in CRC. Hence, we first started by mining the Cancer Genome Atlas (TCGA) database. In TCGA, we observed that TAS2R38 is upregulated in 16 different cancers, including CRC. Moreover, higher expression of the TAS2R38 correlated with lower overall survival in CRC patients. We confirmed TAS2R38 overexpression in CRC tissues and cell lines by immunohistochemistry and RT-PCR. Also, in the functional assay, N-(3-oxododecanoyl)-L-homoserine lactone (OdDHL), a TAS2R38 agonist, treatment activated calcium mobilization in HCT116 and DLD1 cells. OdDHL also increased interleukin (IL)-6 and IL-8 mRNA levels in the CRC cell lines. To determine whether expression of the receptor is affected in vivo, we performed studies in the dextran sodium sulfate (DSS)-induced acute colitis model and colitis-associated cancer model (azoxymethane (AOM)-DSS) in C57BL/6 mice. TAS2R138, the murine homolog of human TAS2R38 is upregulated in crypt epithelial cells in both the DSS-induced acute colitis and AOM/DSS tumors. The tumor microenvironment plays an important role in CRC progression. The immune cell infiltration in the CRC tumor is heterogenous. Macrophages, dendritic cells, neutrophils and lymphocytes, such as T cells have been studied in CRC and different populations of these cells were reported to control tumor progression. We found that TAS2R138 mRNA is increased in F4/80-positive macrophages, CD11c-positive dendritic cells and Ly6G-positive neutrophils in the DSS-induced acute colitis model. Immunofluorescence analysis of tissues from AOM/DSS induced tumors showed that TAS2R38 colocalizes with F4/80 macrophages suggesting that these cells express TAS2R138. Similar colocalization of TAS2R138 was found with Ly6G and CD11c. These observations suggest that TAS2R38 may play a critical role in CRC progression in part by modulating immune cells.

Integrative epitranscriptomic and transcriptomic characterization in human colorectal cancer.

Increasing knowledge of the underlying signaling pathways and molecular defects involved in colorectal cancer growth or progression enabled the discovery of several prognostic and predictive biomarkers, leading to the development of novel molecularly targeted therapies. The mitogen-activated protein kinase (MAPK) signaling pathway plays a critical role in colorectal cancer progression. Mutations in BRAF, a principal effector of Ras in this signaling cascade, are found in 10% of colorectal cancer and play a clear pathogenic role, particularly in patients with metastatic disease. Intense efforts have therefore focused on targeting BRAF as an oncogenic driver, with mixed early results. This article summarizes the molecular and clinical features of BRAF mutant colorectal cancer, the prognostic and predictive role of BRAFV600E mutation in colorectal cancer, initial clinical trial results in targeting BRAFV600E, and the more recent preclinical insights into potential mechanisms of resistance to BRAF inhibition that have now led to a number of rationale-driven combination therapeutic strategies.

Colorectal cancer (CRC) is the third most common type of cancer; however, the molecular mechanisms underlying colorectal tumor metastasis and growth remain elusive. Recently, accumulating evidence has indicated that long non‑coding RNAs (lncRNAs) play a critical role in CRC progression and metastasis; however, the biological role and clinical significance of lncRNA 00152 (lnc00152) in CRC remains largely unknown. Thus, in this study, lnc00152 expression was measured in 80human CRC tissue samples, 40non‑cancerous tissue samples, and 3CRC cell lines (SW480, SW620 and LoVo) using RT‑qPCR. We examined the effects of lnc00152 on CRC cells following transfection with lnc00152 overexpression plasmid or respective siRNA invitro and invivo. Luciferase assays revealed the mechanism driving competitive endogenous RNA (ceRNA). We identified that lnc00152 was aberrantly overexpressed in colorectal tumors and cancer cells and that lnc00152 was modulated by miRNA‑206. lnc00152 overexpression enhanced the proliferative and invasive ability of CRC cells invitro, promoted tumor growth invivo, and was associated with the shorter overall survival of patients with CRC. In addition, lnc00152 overexpression promoted epithelial-mesenchymal transition(EMT) and increased neuropilin‑1 (NRP1) expression in the CRC cells. By contrast, lnc00152 silencing exerted a counteractive effect. Collectively, these findings demonstrate the critical role of lnc00152 in tumor growth and progression in CRC, and identify a novel therapeutic target associated with CRC development and progression.

SLC2A3 is a membrane transporter that belongs to the solute carrier family, whose function includes transmembrane transport and glucose transmembrane transport activity. To clarify the expression and role of SLC2A3 in colorectal cancer (CRC), we analyzed the TCGA and GEO databases and found that SLC2A3 mRNA levels were significantly higher in CRC tissues than that in adjacent non-tumor tissues. Furthermore, high expression of SLC2A3 predicted poor overall survival and disease free survival for CRC patients. For validation, we collected 174 CRC samples and found that SLC2A3 expression was higher in CRC tissues than that in adjacent non-tumor colorectal mucosa tissues by immunohistochemistry staining. Further study showed that high expression of SLC2A3 was enriched in epithelial–mesenchymal transition (EMT) classical pathway, interferon-γ pathway by GSEA analysis enrichment, indicating that SLC2A3 may play a key role in the progression of CRC through EMT and immune response, which also has been validated by the global gene expression profiling of human CRC cell lines. The expression of SLC2A3 was positively correlated with CD4 and CD8+T cells by using TIMER and EPIC algorithm, respectively. SLC2A3 knockdown suppressed migration and inhibited the expression of Vimentin and MMP9 in CRC cell line SW480 and RKO. Meanwhile, PD-L1 expression was also significantly attenuated in SW480 and RKO cells transfected with SLC2A3 siRNA. The result suggests that SLC2A3 may be involved in the immune response of CRC by regulating PD-L1 immune checkpoint. In our series, SLC2A3 and PD-L1 positive expression was 74% (128/174) and 22% (39/174) of CRC, respectively. SLC2A3 expression was significantly associated with perineural invasion in CRC patients. In conclusion, SLC2A3 may play an important role in progression of CRC by regulating EMT and PD-L1 mediated immune responses.

BackgroundOnco-immunogenic molecule CD155 is overexpressed in various tumor microenvironments (TME) including in colorectal cancer (CRC). Tumor-associated macrophages (TAMs) are the most abundant immune cells in CRC TME and play a...

Kif18A, a member of the kinesin superfamily of molecular motor proteins, is a microtubule depolymerase and a key regulator of chromosome congregation. Kif18A's role in cancer progression has not been well defined. Our hypothesis is that Kif18A has a role in the progression of colorectal cancer (CRC). To investigate this expression of Kif18A, mRNA was assessed by quantitative real-time PCR in 113 operative specimens of primary CRC. Kif18A was overexpressed and significantly (p < 0.0001) higher in CRC than in normal colon tissue. Kif18A overexpression in CRC significantly correlated with clinicopathologic factors such as tumor stage (p < 0.0001), lymphatic invasion (p = 0.001), lymph node metastasis (p = 0.01), venous invasion (p = 0.002) and peritoneal dissemination (p = 0.02), suggesting that it has a key role in CRC progression. In multivariate analysis, high Kif18A expression had independent significance for poorer overall survival after resection of CRC (p = 0.037). To demonstrate Kif18A's role in CRC progression, we performed translational and in situ studies. Using in vitro studies on CRC cell lines, we evaluated Kif18A's role in proliferation, migration and invasion. CRC cells transfected with Kif18A cDNA demonstrated significant enhanced migration (p < 0.01) and invasion (p = 0.018) compared to mock-transfected cells. When Kif18A was targeted with specific small interfering RNA, CRC cells had significantly reduced proliferation (p < 0.01), migration (p < 0.01) and invasion (p < 0.05). The in vitro and translational studies demonstrated that Kif18A expression is related to events of metastasis and is a significant factor for CRC progression.

Colorectal cancer (CRC) is a common malignant tumor with high incidence and mortality. Tumor-associated macrophages (TAMs) play a crucial role in CRC progression, with M2 polarization promoting CRC development. The present study explored the role of the CXCL10/CXCR3 axis in the M2 polarization of TAMs in CRC. Bioinformatics analysis of three gene expression omnibus (GEO) datasets identified differentially expressed genes, with CXCL10 selected as a target due to its upregulation in CRC and various cancers via the Cancer Genome Atlas (TCGA) database mining. Subsequent experiments demonstrated that CRC cells overexpressed CXCL10, which promoted M2 polarization of macrophages by activating the rapidly accelerated fibrosarcoma (RAF)/extracellular signal-regulated kinase (ERK) pathway. CXCL10-overexpressed CRC cells increased M2 macrophage markers like CD206 and arginase 1 (Arg1), reduced M1 markers CD86 and inducible nitric oxide synthase (iNOS), and enhanced interleukin-10 (IL-10) release while decreasing IL-6 and tumor necrosis factor-alpha (TNF-α). CXCL10-overexpressed CRC cells also inhibited macrophage phagocytic capacity and lysosomal enzyme activity, crucial for tumor immunotherapy. Furthermore, macrophages stimulated by CXCL10-overexpressed CRC cells facilitated CRC cell proliferation and invasion. Inhibitors of CXCR3 or RAF reversed these effects, confirming that CXCL10 promoted M2 polarization via the CXCR3/RAF/ERK pathway. Overall, the CXCL10/CXCR3 axis played a key role in CRC progression by inducing M2 polarization of macrophages via the RAF/ERK pathway, suggesting that CXCL10/CXCR3 axis may be a potential therapeutic target for CRC immunotherapy.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12672-025-04081-y.

Colorectal cancer (CRC) is influenced by perturbations in the colonic microbiota, characterized by an imbalance favoring pathogenic bacteria over beneficial ones. This dysbiosis contributes to CRC initiation and progression through mechanisms such as carcinogenic metabolite production, inflammation induction, DNA damage, and oncogenic signaling activation. Understanding the role of external factors in shaping the colonic microbiota is crucial for mitigating CRC progression. This study aims to elucidate the gut microbiome's role in CRC progression by analyzing paired tumor and mucosal tissue samples obtained from the colon walls of 17 patients. Through sequencing of the V3-V4 region of the 16S rRNA gene, we characterized the tumor microbiome and assessed its association with clinical variables. Our findings revealed a significant reduction in alpha diversity within tumor samples compared to paired colon biopsy samples, indicating a less diverse microbial environment within the tumor microenvironment. While both tissues exhibited dominance of similar bacterial phyla, their relative abundances varied, suggesting potential colon-specific effects. Fusobacteriota enrichment, notably in the right colon, may be linked to MLH1 deficiency. Taxonomy analysis identified diverse bacterial genera, with some primarily associated with the colon wall and others unique to this region. Conversely, several genera were exclusively expressed in tumor tissue. Functional biomarker analysis identified three key genes with differential abundance between tumor microenvironment and colon tissue, indicating distinct metabolic activities. Functional biomarker analysis revealed three key genes with differential abundance: K11076 (putrescine transport system) and K10535 (nitrification) were enriched in the tumor microenvironment, while K11329 (SasA-RpaAB circadian timing mediator) dominated colon tissue. Metabolic pathway analysis linked seven metabolic pathways to the microbiome. Collectively, these findings highlight significant gut microbiome alterations in CRC and strongly suggest that long-term dysbiosis profoundly impacts CRC progression.