Immunotherapy in colorectal cancer: current achievements and future perspective

Saffron improves the efficacy of immunotherapy for colorectal cancer through the IL-17 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Saffron is one of the traditional medicinal herbs, which contains various active ingredients, such as safranal, crocin, saffron acid, etc. It has anti-inflammatory, antioxidant, and anti-cancer properties, and is widely used in clinical practice. The anti-cancer efficacy of saffron has been previously confirmed, but its anti-cancer mechanism in colorectal cancer remains unclear.

OBJECTIVE

We investigated the effect of active compounds of saffron on the efficacy of immunotherapy for colorectal cancer.

METHODS

TCMSP and liquid chromatography-mass spectrometry analysis (LC-MS), GeneCards, and DisGeNET databases were used to identify the active compounds of saffron, drug targets and the disease targets of colorectal cancer. They were then subjected to Gene Ontology Enrichment (GO) and Signalling Pathway Enrichment (KEGG) analyses. The core targets and corresponding compounds were selected for molecular docking. The effect of active components of saffron on the proliferation of CT26 and HCT116 cells was investigated using the cell counting kit-8 (CCK-8). In vitro experiments were conducted by subcutaneous injection of CT26 cells to establish a colon cancer model. Enzyme-linked immunosorbent assay (ELISA), western blotting (WB), real-time polymerase chain reaction (RT-PCR), immunohistochemistry (IHC), and flow cytometry (FCM) were employed to validate the effects of saffron on colorectal cancer immunotherapy.

RESULTS

1. LC-MS analysis revealed that the main active component of saffron extract was crocin. The active chemicals of saffron intersected with 170 colorectal cancer targets, with 17 predicting targets for saffron treatment. GO and KEGG enrichment analyses revealed that the active components of saffron can prevent colorectal cancer development by enhancing Th17 cell differentiation and the IL-17 signaling pathway. 2. In vitro studies revealed that saffron alcohol extract, crocin, and safranal can suppress the proliferation of CT26 and HCT116 cells. 3. In vivo studies showed that crocin and safranal can increase the body mass and decrease the tumor mass of loaded mice, decrease the serum level of IL-17, and lower the mRNA expression level of IL-17, IL-6, TNF-α, TGF-β, and PD-L1 and IL-17, PD-L1 protein in tumors. This inhibitory effect was strengthened after combined immunotherapy. In addition, saffron modulated CD4+ and CD8+ T cells and the CD4+/CD8+T ratio in mouse spleens.

CONCLUSION

The active components of saffron can reduce the expression of inflammatory factors and ameliorate the immunological microenvironment of tumors via the IL-17 signaling pathway, thereby improving the efficacy of immunotherapy for colorectal cancer. This study provides pharmacological support for the application of saffron in enhancing the efficacy of immunotherapy for colorectal cancer.

The trends and hotspots of immunotherapy for metastatic colorectal cancer from 2013 to 2022: A bibliometric and visual analysis

An increasing body of research indicates that immunotherapy has demonstrated substantial effectiveness in the realm of metastatic colorectal cancer(mCRC), especially among patients with deficient mismatch repair (dMMR) or microsatellite instability-high (MSI-H) (dMMR/MSI-H mCRC). This study constitutes the inaugural bibliometric and visual analysis of immunotherapy related to mCRC during the last decade. Between 2013 and the conclusion of 2022, we screened 306 articles from Web of Science and subjected them to analysis using CiteSpace and VOSviewer. The United States stood out as the primary contributor in this area, representing 33.33% of the publications, with China following closely at 24.51%. The most prolific institution has the lowest average citation rate. Sorbonne University were the most highly cited institutions. Notably, Frontiers In Oncology published the largest quantity of articles. Andre, Thierry, and Overman, Michael J. were prominent authors known for their prolific output and the high citation rates of their work. The focus areas in this field encompass "tumor microenvironment," "liver metastasis," "tumor-associated macrophages," "combination therapy" and "gut microbiota." Some keywords offer promise as potential biomarkers for evaluating the effectiveness of immunotherapeutic interventions.

Association between microsatellite instability status, clinicopathological features and mitochondrial DNA amplification in patients with colorectal cancer

The relationship between BRAF-V600E mutations, mitochondrial DNA amplification and microsatellite instability-high (MSI-H) in colorectal cancer (CRC) has yet to be fully elucidated. The aim of the present study was to assess the association between the MSI status and BRAF-V600E gene mutations/clinicopathological features/mitochondrial DNA amplification in CRC. A non-interventional study analysis was performed using the clinicopathological features of 455 patients with CRC. Immunohistochemistry was used to evaluate four mismatch repair proteins (MutS homolog 2, MutS homolog 6, MutL homolog 1 and postmeiotic segregation increased 2), Ki-67 index, and programmed cell death protein 1 (PD-1) and programmed cell death-ligand 1 (PD-L1) expression. Additionally, PCR coupled with capillary electrophoresis were used to ascertain the MSI status. Moreover, amplification refractory mutation system-PCR was used to detect BRAF-V600E gene mutation and fluorescence in situ hybridization analysis was used to assess mitochondrial DNA. A total of 455 patients were divided into the MSI high (MSI-H) group (n=52) and microsatellite stability (MSS) group (n=403) based on their MSI status. Compared with the results of immunohistochemistry of four mismatch repair proteins, the consistency rate between mismatch repair protein deficiency and MSI was 94.23%. There were significant differences in PD-L1, primary tumor site, clinical stage, degree of differentiation, tumor size, lymph node metastasis and the occurrence of multiple primary tumors between the MSI-H group and MSS group (P<0.05 or P<0.001). However, there were no significant differences for sex, age, PD-1, Ki-67 expression and BRAF-V600E. The 24-60-month survival rate of the patients in the MSI-H group was significantly higher than that of those in the MSS group (P<0.05). Furthermore, the number of mitochondrial DNA was significantly amplified in the MSI-H group. In conclusion, the present study demonstrated that the combined detection of PD-L1 and MSI in patients with CRC can provide more accurate and effective guidance for personalized treatment.

Effect of colorectal cancer stem cells on the development and metastasis of colorectal cancer

The relevant mechanism of tumor-associated macrophages (TAMs) in the treatment of colorectal cancer patients with immune checkpoint inhibitors (ICIs) is discussed, and the application prospects of TAMs in reversing the treatment tolerance of ICIs are discussed to provide a reference for related studies. As a class of drugs widely used in clinical tumor immunotherapy, ICIs can act on regulatory molecules on cells that play an inhibitory role - immune checkpoints - and kill tumors in the form of an immune response by activating a variety of immune cells in the immune system. The sensitivity of patients with different types of colorectal cancer to ICI treatment varies greatly. The phenotype and function of TAMs in the colorectal cancer microenvironment are closely related to the efficacy of ICIs. ICIs can regulate the phenotypic function of TAMs, and TAMs can also affect the tolerance of colorectal cancer to ICI therapy. TAMs play an important role in ICI resistance, and making full use of this target as a therapeutic strategy is expected to improve the immunotherapy efficacy and prognosis of patients with colorectal cancer.

Natural compounds modulate the mechanism of action of tumour-associated macrophages against colorectal cancer: a review

Colorectal cancer (CRC) exhibits a substantial morbidity and mortality rate, with its aetiology and pathogenesis remain elusive. It holds significant importance within the tumour microenvironment (TME) and exerts a crucial regulatory influence on tumorigenesis, progression, and metastasis. TAMs possess the capability to foster CRC pathogenesis, proliferation, invasion, and metastasis, as well as angiogenesis, immune evasion, and tumour resistance. Furthermore, TAMs can mediate the prognosis of CRC. In this paper, we review the mechanisms by which natural compounds target TAMs to exert anti-CRC effects from the perspective of the promotional effects of TAMs on CRC, mainly regulating the polarization of TAMs, reducing the infiltration and recruitment of TAMs, enhancing the phagocytosis of macrophages, and regulating the signalling pathways and cytokines, and discuss the potential value and therapeutic strategies of natural compounds-targeting the TAMs pathway in CRC clinical treatment.

LINC01764 promotes colorectal cancer cells proliferation, metastasis, and 5-fluorouracil resistance by regulating glucose and glutamine metabolism via promoting c-MYC translation

Few biomarkers are available for predicting chemotherapeutic response and prognosis in colorectal cancer (CRC). Long-noncoding RNAs (lncRNAs) are essential for CRC development and growth. Therefore, studying lncRNAs may reveal potential predictors of chemotherapy response and prognosis in CRC. LINC01764 was analyzed using datasets from Fudan University Shanghai Cancer Center's advanced CRC patients' RNA-seq and The Cancer Genome Atlas datasets. Gene set enrichment analysis was employed to detect related pathways. Cotransfection experiments, RNA pulldown assays, RNA-binding protein immunoprecipitation, protein synthesis activity, and dual-luciferase reporter assays were performed to determine interactions among LINC01764, hnRNPK, and c-MYC. High LINC01764 expression correlates with metastasis, a poor response to FOLFOX/XELOX chemotherapy, and a poor prognosis in CRC. LINC01764 enhance glycolysis and glutamine metabolism to promote CRC cells proliferation, metastasis, and 5-fluorouracil (5-FU) resistance. LINC01764 specifically binds to hnRNPK, facilitating its interaction with c-MYC mRNA and promoting internal ribosome entry site (IRES)-dependent translation of c-MYC, thereby exerting oncogenic effects. LINC01764 induced 5-FU chemoresistance by upregulating the c-MYC, glucose, and glutamine metabolism pathways, which downregulated UPP1, crucial for activating 5-FU. Conclusively, LINC01764 promotes CRC progression and 5-FU resistance through hnRNPK-mediated-c-MYC IRES-dependent translational regulation, which suggests its potential as a predictor of CRC chemotherapy response and prognosis.

WDR77 in Pan-Cancer: Revealing expression patterns, genetic insights, and functional roles across diverse tumor types, with a spotlight on colorectal cancer

OBJECTIVE

Despite its involvement in regulating various cellular functions, the expression and role of WD repeat-containing protein 77 (WDR77) in cancer remain elusive. This study aims to explore the expression and potential roles of WDR77 across multiple cancers, with a particular focus on its relevance in colorectal cancer (CRC).

METHODS

We obtained WDR77 RNA-seq data, mutations, CNVs, and DNA methylation data from the TCGA, GTEx, and GEO databases to investigate its expression patterns and prognostic value. Additionally, we examined the correlation between WDR77 expression and somatic mutations, copy number variations, DNA methylation, and mRNA modifications. We utilized GSVA, GSEA algorithms, and CRISPR KO data from the Dependency Map database to explore WDR77's potential biological functions. The association between WDR77 and the tumor immune microenvironment was investigated using ESTIMATE and IOBR algorithms. Finally, we assessed WDR77 expression in CRC and its impact on cell proliferation through qRT-PCR, Western blotting, immunohistochemistry, CCK8, colony formation, and EdU assays.

RESULTS

WDR77 was upregulated in various tumors and correlated with poor patient prognosis. Its high expression positively correlated with pathways related to cell proliferation and negatively correlated with immune-related pathways. In CRC, WDR77 expression was associated with specific clinical features, genomic alterations, and immune microenvironment characteristics. Experimental validation confirmed upregulated WDR77 expression in CRC tissues and cells, with WDR77 knockdown significantly inhibiting CRC cell proliferation.

CONCLUSION

WDR77 holds potential as an oncogene and biological marker in various cancers, particularly CRC.

Copper and Colorectal Cancer

Minerals constitute only 5% of the typical human diet but are vital for health and functionality. Copper, a trace element, is absorbed by the human gut at 30-40% from diets typical of industrialized countries. The liver produces metallothioneins, which store copper. Copper is crucial for mitochondrial respiration, pigmentation, iron transport, antioxidant defense, hormone production, and extracellular matrix biosynthesis. Copper deficiency, often caused by mutations in the ATP7A gene, results in Menkes disease, an X-linked recessive disorder. On the contrary, Wilson disease is characterized by toxic copper accumulation. Cuproptosis, a unique form of cell death regulated by copper, is a subtype of necrosis induced by enhanced mitochondrial metabolism and intracellular copper accumulation. This process can reduce the malignant potential of tumor cells by inhibiting glucose metabolism. Therapeutically, copper and its complexes have shown efficacy in malignancy treatments. The disruption of copper homeostasis and excessive cuproplasia are significant in colorectal cancer development and metastasis. Therefore, manipulating copper status presents a potential therapeutic target for colorectal cancer, using copper chelators to inhibit copper formation or copper ion carriers to promote cuproptosis. This review highlights the role of copper in human physiology and pathology, emphasizing its impact on colorectal cancer and potential therapeutic strategies. Future AI-based approaches are anticipated to accelerate the development of new compounds targeting cuproptosis and copper disruption in colorectal cancer.

Photothermal Fe3O4 nanoparticles induced immunogenic ferroptosis for synergistic colorectal cancer therapy

Photothermal therapy (PTT) is a promising non-invasive treatment that has shown great potential in eliminating tumors. It not only induces apoptosis of cancer cells but also triggers immunogenic cell death (ICD) which could activate the immune system against cancer. However, the immunosuppressive tumor microenvironment (TIME) poses a challenge to triggering strong immune responses with a single treatment, thus limiting the therapeutic effect of cancer immunotherapy. In this study, dual-targeted nano delivery system (GOx@FeNPs) combined with αPD-L1 immune checkpoint blocker could inhibit colorectal cancer (CRC) progression by mediating PTT, ferroptosis and anti-tumor immune response. Briefly, specific tumor delivery was achieved by the cyclic arginine glycyl aspartate (cRGD) peptide and anisamide (AA)  in GOx@FeNPs which not only had a good photothermal effect to realize PTT and induce ICD, but also could deplete glutathione (GSH) and catalyze the production of reactive oxygen species (ROS) from endogenous H2O2. All these accelerated the Fenton reaction and augmented the process of PTT-induced ICD. Thus, a large amount of tumor specific antigen was released to stimulate the maturation of dendritic cells (DCs) in lymph nodes and enhance the infiltration of CD8+ T cells in tumor. At the same time, the combination with αPD-L1 has favorable synergistic effectiveness against CRC with tumor inhibition rate over 90%. Furthermore, GOx@FeNPs had good magnetic resonance imaging (MRI) capability under T2-weighting owing to the presence of Fe3+, which is favorable for integrated diagnosis and treatment systems of CRC. By constructing a dual-targeted GOx@FeNPs nanoplatform, PTT synergistically combined with ferroptosis was realized to improve the immunotherapeutic effect, providing a new approach for CRC immunotherapy.

Construction and validation of an immune-related gene signature predictive of survival and response to immunotherapy for colorectal cancer

Colorectal cancer is a common malignant tumor with the second incidence rate and the third mortality rate worldwide. In this study, we identified and validated an immune-related gene signature, explored the clinical and molecular characteristics of the signature-defined risk groups, and assessed its ability in predicting prognosis, immune cell infiltration and immunotherapy responses. The Cancer Genome Atlas database was used as the training set while GSE39582 database as the validation set. Immune-related hub genes were selected by the Least Absolute Shrinkage and Selection Operator-penalized Cox regression model, and the signature was then constructed by the selected genes and their relevant coefficients. Prognostic performance of the signature and the signature-base nomogram models were assessed by time-dependent receiver operating characteristic curves and calibration plots in both training and validation cohorts. Clinical and mutation-related data were downloaded and analyzed to explore their associations with signature-defined risk groups. Proportions of infiltrated immune cells was estimated via CIBERSORT algorithm and immunotherapy response was evaluated by immunophenoscore and tumor immune dysfunction and exclusion scores. Seven among 790 immune-related differentially-expressed genes were selected and use to construct the signature. The signature and signature-base nomograms showed promising prognostic performance in both training and validation cohorts. Signature-defined high-risk group was associated with advanced disease, poor pathological prognostic factors and less active immune infiltration microenvironment. Besides, the response to immunotherapy of high-risk group was predicted to be poorer by immunophenoscore and tumor immune dysfunction and exclusion scores. Our signature proved its efficacy in predicting prognosis, tumor immune microenvironment and responses to immunotherapy in colorectal cancer.

DC-derived CXCL10 promotes CTL activation to suppress ovarian cancer

This study investigates the role of dendritic cells (DCs), with a focus on their CXCL10 marker gene, in the activation of cytotoxic T lymphocytes (CTLs) within the ovarian cancer microenvironment and its impact on disease progression. Utilizing scRNA-seq data and immune infiltration analysis, we identified a diminished DC presence in ovarian cancer. Gene analysis pinpointed CXCL10 as a key regulator in OV progression via its influence on DCs and CTLs. Prognostic analysis and in vitro experiments substantiated this role. Our findings reveal that DC-derived CXCL10 significantly affects CTL activation and proliferation. Reduced CXCL10 levels hinder CTL cytotoxicity, promoting ovarian cancer cell migration and invasion. Experimental studies using animal models have provided further evidence that the capacity of CTLs to suppress tumor development is significantly diminished when treated with DCs that have low expression of CXCL10. Dendritic cell-derived CXCL10 emerges as a pivotal factor in restraining ovarian cancer growth and metastasis through the activation of cytotoxic T lymphocytes. This study sheds light on the crucial interplay within the ovarian cancer microenvironment, offering potential therapeutic targets for ovarian cancer treatment.

CAR-T and CAR-NK as cellular cancer immunotherapy for solid tumors

In the past decade, chimeric antigen receptor (CAR)-T cell therapy has emerged as a promising immunotherapeutic approach for combating cancers, demonstrating remarkable efficacy in relapsed/refractory hematological malignancies in both pediatric and adult patients. CAR-natural killer (CAR-NK) cell complements CAR-T cell therapy by offering several distinct advantages. CAR-NK cells do not require HLA compatibility and exhibit low safety concerns. Moreover, CAR-NK cells are conducive to "off-the-shelf" therapeutics, providing significant logistic advantages over CAR-T cells. Both CAR-T and CAR-NK cells have shown consistent and promising results in hematological malignancies. However, their efficacy against solid tumors remains limited due to various obstacles including limited tumor trafficking and infiltration, as well as an immuno-suppressive tumor microenvironment. In this review, we discuss the recent advances and current challenges of CAR-T and CAR-NK cell immunotherapies, with a specific focus on the obstacles to their application in solid tumors. We also analyze in depth the advantages and drawbacks of CAR-NK cells compared to CAR-T cells and highlight CAR-NK CAR optimization. Finally, we explore future perspectives of these adoptive immunotherapies, highlighting the increasing contribution of cutting-edge biotechnological tools in shaping the next generation of cellular immunotherapy.

Antitumor effect of polyphyllin I (PPI) on colorectal cancer: Evidence from patient-derived organoids and Notch signaling suppression

Colorectal cancer (CRC) is a malignant tumor with a high incidence, ranking first among gastrointestinal malignancies. We investigated the impact of polyphyllin I (PPI), a natural compound found in Paris polyphylla, on CRC. PPI has been documented to exhibit anticancer activity against various tumors. This study aimed to assess the effects of PPI on colorectal cancer and explore its potential mechanisms. Our research demonstrated that PPI inhibited proliferation, promoted apoptosis, and induced G2 cell-cycle arrest in a dose-dependent manner. Additionally, our results indicated that PPI suppressed Notch signaling by downregulating the Notch1 receptor, its ligand Jagged1, and the downstream target Hes1 expression. Furthermore, we confirmed the antitumor effect of PPI on patient-derived organoids. In conclusion, our study indicates that PPI impedes the growth of colon cancer by suppressing the Notch signaling pathway.

Differential expression of ST6GALNAC1 and ST6GALNAC2 and their clinical relevance to colorectal cancer progression

Colorectal cancer (CRC) has become a significant global health concern and ranks among the leading causes of morbidity and mortality worldwide. Due to its malignant nature, current immunotherapeutic treatments are used to tackle this issue. However, not all patients respond positively to treatment, thereby limiting clinical effectiveness and requiring the identification of novel therapeutic targets to optimise current strategies. The putative ligand of Siglec-15, Sialyl-Tn (STn), is associated with tumour progression and is synthesised by the sialyltransferases ST6GALNAC1 and ST6GALNAC2. However, the deregulation of both sialyltransferases within the literature remain limited, and the involvement of microRNAs (miRNAs) in STn production require further elucidation. Here, we identified miRNAs involved in the regulation of ST6GALNAC1 via a computational approach and further analysis of miRNA binding sites were determined. In silico tools predicted miR-21, miR-30e and miR-26b to regulate the ST6GALNAC1 gene, all of which had shown significant upregulated expression in the tumour cohort. Moreover, each miRNA displayed a high binding affinity towards the seed region of ST6GALNAC1. Additionally, enrichment analysis outlined pathways associated with several cancer hallmarks, including epithelial to mesenchymal transition (EMT) and MYC targets associated with tumour progression. Furthermore, our in silico findings demonstrated that the ST6GALNAC1 expression profile was significantly downregulated in CRC tumours, and its low expression correlated with poor survival outcomes when compared with patient survival data. In comparison to its counterpart, there were no significant differences in the expression of ST6GALNAC2 between normal and malignant tissues, which was further evidenced in our immunohistochemistry analysis. Immunohistochemistry staining highlighted significantly higher expression was more prevalent in normal human tissues with regard to ST6GALNAC1. In conclusion, the integrated in silico analysis highlighted that STn production is not reliant on deregulated sialyltransferase expression in CRC, and ST6GALNAC1 expression is regulated by several oncomirs. We proposed the involvement of other sialyltransferases in the production of the STn antigen and CRC progression via the Siglec-15/Sia axis.

Deciphering EIF3D's Role in Immune Regulation and Malignant Progression: A Pan-Cancer Analysis with a Focus on Colon Adenocarcinoma

Background

EIF3D, a key component of the eukaryotic translation initiation factor 3 (EIF3) complex, is critical in selectively translating mRNAs with atypical cap structures. Its relationship with colon adenocarcinoma (COAD) development and immune infiltration, however, remains under-explored. This study delves into EIF3D's role in COAD using bioinformatics and in vitro experimentation.

Materials and Methods

We analyzed EIF3D expression levels utilizing TCGA, GTEx, CPTAC, and TISIDB databases. The TISCH database and ssGSEA method helped in assessing EIF3D's link with the tumor immune microenvironment. EIF3D expression in CRC cells was gauged via real-time PCR. Cell proliferation was assessed using CCK8 and colony formation assays, while migration capabilities were tested through Transwell assays. Flow cytometry facilitated cell cycle distribution and apoptosis analysis. ChIP-qPCR identified transcription factors regulating EIF3D, and bulk sequencing explored EIF3D's pathways in promoting COAD.

Results

EIF3D upregulation is a common feature in various tumors, especially in COAD, correlating with poor prognosis in many cancer types. It showed significant associations with immune cell and cancer-associated fibroblast (CAF) infiltration across multiple tumors. Additionally, it is closely associated with molecular and immune subtypes of multiple tumors, including COAD. Single-cell analyses depicted EIF3D's distribution and proportion in CRC immune cells. In vitro findings indicated EIF3D knockdown curtailed proliferation and migration, inducing G0/G1 arrest in COAD cells. Moreover, bulk sequencing revealed EIF3D knockdown interferes with multiple cancer-related pathways, likely by curtailing cell cycle and DNA replication activities to regulate cell proliferation.

Conclusion

EIF3D emerges as a potential prognostic biomarker for tumor progression and immune infiltration, particularly in COAD, potentially predicting immunotherapy efficacy. Additionally, EIF3D represents a multifaceted target implicated in COAD's malignant progression.

pH and ROS Dual-Responsive Autocatalytic Release System Potentiates Immunotherapy of Colorectal Cancer

The immunosuppressive microenvironment severely limits the responsiveness of colorectal cancer (CRC) to immunotherapy. Herein, a pH and reactive oxygen species (ROS) dual-responsive autocatalytic release system (TPDM/PGA) is constructed to reverse the immunosuppressive microenvironment and potentiate CRC immunotherapy. Dihydroartemisinin (DHA) and mitoxantrone (MTO) are conjugated to ROS-responsive polyethylenimine (TP) via a ROS-cleavable linker, respectively, and then coated with polyglutamic acid (PGA) to endow pH and ROS dual-responsiveness. The dissociation of PGA within the acidic TME facilitates its deep penetration and cell internalization, while the intracellular released DHA and MTO in response to high levels of H2O2 further produced a large amount of ROS, forming positive feedback to accelerate drug release and exacerbate oxidative stress. TPDM/PGA collaboratively reversed the immunosuppressive microenvironment and induced a strong anti-tumor immune response when combined with anti-PD-L1 antibody, significantly inhibiting tumor growth and prolonging the survival time of CT26 and MC38 tumor-bearing mice. The excellent therapeutic effect, together with the good tolerance, make TPDM/PGA a promising candidate for enhanced immunotherapy of colorectal cancer.

Fusobacterium Nucleatum Promotes Microsatellite Instability in Colorectal Carcinoma Through Up-regulation of miRNA-155-5p-Targeted Inhibition of MSH6 via the TLR4/NF-κB Signaling Pathway

Fusobacterium nucleatum (Fn) is significantly associated with poor prognosis in colorectal carcinoma (CRC), however, mechanisms of Fn in DNA mismatch repair (MMR) and microsatellite instability (MSI) in CRC have not been fully elucidated. Clinical samples are collected to analyze the relationship between Fn abundance and microsatellite stability. Tumor cells are treated with Fn to detect the expression of proteins related to toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (Myd88), mutS homolog 6 (MSH6), and nuclear factor-κB (NF-κB) signaling pathways, respectively. Combined with the prediction results from TargetScan, the regulatory role of microRNA upstream of MSH6 is demonstrated. The effect of this regulatory axis on CRC development is demonstrated using a nude mouse tumor model. Compared with microsatellite stability (MSS)-type CRC patients, MSI-type showed higher Fn abundance. Fn treatment of CRC cells activated TLR4/Myd88/NF-κB signaling pathway, transcriptionally activating miRNA-155-5p expression, thereby negatively regulating MSH6. Fn treatment accelerated the malignant progression of CRC in mice, and this process is inhibited by miRNA-155-5p antagomir. Fn in CRC upregulated miRNA-155-5p by activating TLR4/NF-κB signaling to inhibit MSH6, and this regulatory pathway may affect MSS of cancer cells.

Evaluation of the efficacy and safety of first- and second-line immunotherapy in patients with metastatic colorectal cancer: a systematic review and network meta-analysis based on randomized controlled trials

Background

A multitude of randomized controlled trials (RCTs) conducted in both the initial and subsequent treatment settings for patients diagnosed with metastatic colorectal cancer (mCRC) have provided clinical evidence supporting the efficacy of immunotherapy with the use of immune checkpoint inhibitors (ICIs). In light of these findings, the U.S. Food and Drug Administration (FDA) has authorized the use of several ICIs in specific subpopulations of mCRC patients. Nevertheless, there remains a dearth of direct comparative RCTs evaluating various treatment options. Consequently, the most effective ICI therapeutic strategy for microsatellite-stable (MSS) subgroup and microsatellite instability (MSI) subgroup in the first- and second-line therapies remains undefined. To address this gap, the present study employs a Bayesian network meta-analysis to ascertain the most effective first- and second-line ICI therapeutic strategies.

Methods

A comprehensive literature search was conducted across multiple databases, including PubMed, EMBASE, Cochrane Library, and Web of Science, with the retrieval date ranging from the databases' inception to August 20, 2024. A total of 875 studies were identified, and seven were ultimately included in the analysis after a screening process. A systematic review and network meta-analysis were conducted on the basis of the search results.

Results

This comprehensive analysis, comprising seven RCTs, evaluated first-line and second-line immunotherapy regimens in 1,358 patients diagnosed with mCRC. The treatments under investigation consisted of five initial treatments, including three focusing on MSS patients and two on MSI patients, as well as two secondary immunotherapy regimens, both focusing on MSS patients. A total of 1051 individuals underwent first-line treatment, while 307 received second-line treatment. The application of ICIs proved to offer varying degrees clinical benefits when compared to standard-of-care therapy alone, both in two subgroups of the first and the second treatment phases. Of particular note is the performance of Nivolumab combination with ipilimumab, which demonstrated superior efficacy in improving progression-free survival (PFS) (HR=0.21; 95% CI, 0.13-0.34),. Moreover, the treatment demonstrated an optimal safety profile, with a relatively low risk of adverse events (OR = 0.33; 95% CI, 0.19-0.56), compared to other first-line treatment modalities for MSI subgroup. Regarding MSS subgroup, the improvement of PFS by Nivolumab plus standard-of-care (SOC) was relatively significant (HR = 0.74; 95% CI, 0.53-1.02). In the realm of second-line therapies for MSS subgroup, the administration of Atezolizumab plus SOC has proven to be an effective approach for prolonging PFS, exhibiting an HR of 0.66 (95% CI, 0.44-0.99). These findings underscore the clinical benefits and safety profiles of ICIs in the treatment of mCRC across various treatment lines.

Conclusions

The clinical application of ICIs in both first- and second-line treatment strategies for patients with mCRC yields substantial therapeutic benefits. A detailed assessment in this study indicates that first-line treatment with Nivolumab combination with ipilimumab may represent an efficacious and well-tolerated therapeutic approach for MSI subgroup. In terms of MSS subgroup in first-line therapy, Nivolumab plus SOC may be a relative superior choice. In the context of second-line therapy for MSS subgroup, it is evident that a combination of Atezolizumab and SOC represents a preferable option for enhancing PFS. Furthermore, it is noteworthy that other ICIs treatment regimens also exhibit great value in various aspects, with the potential to inform the development of future clinical treatment guidelines and provide a stronger rationale for the selection of ICIs in both first- and second-line therapeutic strategies for mCRC.

Systematic review registration

https://www.crd.york.ac.uk/prospero/#recordDetails, identifier CRD42024543400.

Analysis of the role of CHPF in colorectal cancer tumorigenesis and immunotherapy based on bioinformatics and experiments

BACKGROUND

Chondroitin polymerizing factor (CHPF) has been found to be involved in the development of numerous cancers and correlated with poor prognosis. However, its role in the tumorigenesis and development of colorectal cancer (CRC) remains unknown.

METHODS

In our research, we explored CHPF expression and clinicopathological characteristics using The Cancer Genome Atlas Program (TCGA), UALCAN, GSE9348, TIMER2.0 and The Human Protein Atlas (HPA) database, in addition, we validated CHPF expression in CRC cell lines by Real-Time Quantitative PCR (qRT-PCR) and Western blot (WB). KM-Plotter, PrognoScan and TCGA were also utilized to verify its prognosis value in CRC. Small-interfer RNA (Si-RNA) was used to perform Cell Counting Kit-8 (CCK8), colony formation, 5-ethynyl-2'-deoxyuridine (EDU), transwell and wound healing assays to testify its function on the tumor progression. Based on TCGA database, we probed potential biological mechanism by which CHPF play its role via clusterProfiler package and GEPIA database and we validated their correlation by WB assay. Moreover, we explored its potential association with the tumor microenvironment (TME), immune infiltrated cells, immune checkpoints, tumor mutation burden (TMB) as well as microsatellite instability (MSI), and investigated immunotherapy sensitivity via Tumor Immune Dysfunction and Exclusion (TIDE) algorithm as well as potentially effective therapeutic drugs via pRRophetic algorithm.

RESULTS

CHPF was identified upregulated in CRC tissues and cells, correlated with poor prognosis, and nodal metastasis status, stage and histological subtype. Down-regulation of CHPF inhibited CRC cell proliferation, migration and its expression correlated with wnt pathway key molecules. In addition, high expression of CHPF was positively correlated with TME scores, Regulatory T cells (Tregs) cell infiltration degree, Programmed death-1 (PD-1), MSI-high (MSI-H), and TIDE scores, however, not with TMB. Targeted drug analysis showed that patients with high CHPF expression were more sensitive to telatinib, recaparib, serdemetan, and trametinib.

CONCLUSION

CHPF could promote the proliferation and migration of CRC cells and lead to poor prognosis, possibly through wnt pathways as well as changes in TME. Patients with high expression of CHPF had poor efficacy in immunotherapy, which might be related to Tregs cell infiltration. Above all, it might offer more reliable guidance for future immunotherapy.

Curcumin suppresses colorectal tumorigenesis through restoring the gut microbiota and metabolites

BACKGROUND

Curcumin has been reported to have activity for prevention and therapy of CRC, yet its underlying mechanisms remain largely unknown. Recently, emerging evidence suggests that the gut microbiota and its metabolites contribute to the causation and progression of Colorectal cancer (CRC). In this study, we aimed to investigate if curcumin affects the tumorigenesis of CRC by modulating gut microbiota and its metabolites.

METHODS

Forty male C57BL/6JGpt mice were randomly divided into four groups: negative control (NC), curcumin control, CRC model, and curcumin treatment (CRC-Cur) groups. CRC mouse model was induced by using azoxymethane (AOM) and dextran sodium sulfate (DSS), and the mice in CRC model and curcumin treatment groups received oral PBS or curcumin (150 mg/kg/day), respectively. Additionally, fecal samples were collected. 16 S rRNA sequencing and Liquid Chromatography Mass Spectrometry (LC-MS)-based untargeted metabolomics were used to observe the changes of intestinal flora and intestinal metabolites.

RESULTS

Curcumin treatment restored colon length and structural morphology, and significantly inhibited tumor formation in AOM/DSS-induced CRC model mice. The 16S rRNA sequencing analysis indicated that the diversity and richness of core and total species of intestinal microflora in the CRC group were significantly lower than those in the NC group, which were substantially restored in the curcumin treatment group. Curcumin reduced harmful bacteria, including Ileibacterium, Monoglobus and Desulfovibrio, which were elevated in CRC model mice. Moreover, curcumin increased the abundance of Clostridia_UCG-014, Bifidobacterium and Lactobacillus, which were decreased in CRC model mice. In addition, 13 different metabolites were identified. Compared to the NC group, ethosuximide, xanthosine, and 17-beta-estradiol 3-sulfate-17-(beta-D-glucuronide) were elevated in the CRC model group, whereas curcumin treatment significantly reduced their levels. Conversely, glutamylleucine, gamma-Glutamylleucine, liquiritin, ubenimex, 5'-deoxy-5'-fluorouridine, 7,8-Dihydropteroic acid, neobyakangelicol, libenzapril, xenognosin A, and 7,4'-dihydroxy-8-methylflavan were decreased in the CRC group but notably upregulated by curcumin. Kyoto Encyclopedia of Genes and Genome (KEGG) pathway analysis revealed enrichment in seven pathways, including folate biosynthesis (P < 0.05).

CONCLUSIONS

The gut microecological balance was disrupted in AOM/DSS-induced CRC mice, accompanied by metabolite dysbiosis. Curcumin restored the equilibrium of the microbiota and regulated metabolites, highly indicating that curcumin may alleviate the development of AOM/DSS induced colorectal cancer in mice by regulating intestinal flora homeostasis and intestinal metabolites.

Chemotherapy combined with lenvatinib and PD-1 may be a potential better alternative option for advanced unresectable intrahepatic cholangiocarcinoma: a retrospective real-world study

Background

Currently, the prognosis of advanced intrahepatic cholangiocarcinoma (ICC) is poor, and the current treatment methods are not effective.

Objective

The aim of this study was to evaluate the anticancer efficacy of chemotherapy combined with PD-1 inhibitors and tyrosine kinase inhibitors (TKIs) in patients with ICC.

Methods

We retrospectively screened patients with advanced intrahepatic cholangiocarcinoma (ICC) who received chemotherapy combined with lenvatinib and PD-1. We evaluated overall survival (OS), progression-free survival (PFS), the objective response rate (ORR), the disease control rate (DCR), the tumor shrinkage rate, and safety.

Results

We enrolled 95 patients with ICC and divided them into three groups with a median follow-up duration of 15.1 months. The chemotherapy group (chemo-regimen group), chemotherapy combined with immune checkpoint inhibitors (dual-regimen group), and chemotherapy combined with lenvatinib (triple-regimen group) had median OS times of 13.1 months, 20.8 months, and 39.6 months, respectively. Notably, the triple-regimen group had a significantly longer OS than did the chemo-regimen and dual-regimen groups. The chemo-regimen group, dual-regimen group, and triple-regimen group reported median PFS durations of 4.8 months, 11.9 months, and 23.4 months, respectively. Both combination groups exhibited significantly longer PFS than the chemotherapy-only group (P<0.05). The ORRs of the chemo-regimen, dual-regimen, and triple-regimen groups were 18.2%, 55.5%, and 54.7%, respectively. The DCRs were 72.7%, 90%, and 96.2%, respectively, indicating significantly better outcomes in the combination therapy groups.

Conclusion

The combination of chemotherapy with PD-1 inhibitors and lenvatinib demonstrates considerable efficacy and tolerability as a treatment strategy for patients with advanced ICC.

Novel regimens and treatment strategies in neoadjuvant therapy for colorectal cancer: A systematic review

Objective

The objective of this systematic review was to describe novel regimens and treatment strategies in neoadjuvant therapy for colorectal cancer (CRC). The aim was to summarize the current advancements in neoadjuvant chemotherapy (NACT) for CRC, including the use of cytotoxic drugs, targeted treatments, and immunotherapy. The analysis aimed to provide insights into the potential benefits and drawbacks of these novel approaches and highlight the need for further research to optimize NACT use in CRC and improve patient outcomes.

Methods

From October 20, 2023, to December 10, 2023, a comprehensive literature search was conducted across multiple databases, including PubMed, Ovid, Web of Science, the Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, Embase, and Scopus. Studies addressing the use of and treatment strategies for CRC and neoadjuvant therapies were included. Screening was conducted in two steps, initially by title and abstract and then by full-text articles. English-language articles were considered, while preprints, non-English publications, and articles published as grey literature were excluded from the study. A total of 85 studies were selected for further analysis after screening and filtering.

Results

After filtering out duplicates and items that were irrelevant to our research query from the initial database search's 510 results, 397 unique articles were found. Eighty-five studies were chosen for additional analysis after the articles underwent two rounds of screening.

Conclusion

The review concluded that neoadjuvant therapy for CRC has evolved beyond conventional approaches and holds promise for improving patient outcomes. Future prospects for advancing neoadjuvant approaches are promising, with ongoing clinical trials investigating the refinement of strategies, identification of predictive biomarkers, and optimization of patient selection. The adoption of novel regimens, precision medicine, and immunotherapy offers opportunities to redefine treatment paradigms and enhance patient care in CRC.

Safety and Efficacy of Vicriviroc (MK-7690) in Combination With Pembrolizumab in Patients With Advanced or Metastatic Microsatellite Stable Colorectal Cancer

BACKGROUND

Pembrolizumab, a monoclonal antibody against PD-1, has shown limited efficacy in patients with microsatellite stable or mismatch repair proficient (MSS/pMMR) metastatic colorectal cancer (CRC). We evaluated vicriviroc (small-molecule C-C motif chemokine ligand 5 antagonist) plus pembrolizumab in patients with advanced or metastatic MSS/pMMR CRC.

PATIENTS AND METHODS

This open-label, phase 2 trial (NCT03631407) enrolled adults with histologically confirmed, locally advanced, unresectable or metastatic CRC that was MSS per local assessment. All patients had received previous treatment with standard therapies. Patients were randomized 1:1 to vicriviroc 150 mg orally once daily plus pembrolizumab 200 mg intravenously every 3 weeks or vicriviroc 250 mg orally once daily plus pembrolizumab 200 mg intravenously every 3 weeks for up to 35 cycles (2 years). Primary endpoints were the objective response rate (ORR) as assessed by the investigator per RECIST v1.1, dose-limiting toxicities (DLTs), adverse events (AEs), and discontinuations due to AEs.

RESULTS

Forty patients were enrolled and treated. ORR was 5% (95% CI, 0.1%-24.9%) in both treatment groups. There were no complete responses; 1 patient in each treatment group experienced a partial response. No patient in the vicriviroc 150 mg plus pembrolizumab group experienced a DLT. Two patients in the vicriviroc 250 mg plus pembrolizumab group experienced DLTs (1 grade 4 encephalopathy and 1 grade 4 pneumonitis).

CONCLUSION

The combination of vicriviroc at doses of 150 or 250 mg plus pembrolizumab 200 mg showed limited antitumor activity in patients with advanced or metastatic MSS/pMMR CRC. Toxicity with the combination was manageable.

Circ_0007422 Knockdown Inhibits Tumor Property and Immune Escape of Colorectal Cancer by Decreasing PDL1 Expression in a miR-1256-Dependent Manner

Circular RNAs (circRNAs) are a group of important molecules involved in the progression of various cancers, including colorectal cancer (CRC). Here, we aim to investigate the role and molecular mechanism of circ_0007422 in regulating CRC malignant progression. The expression levels of circ_0007422, miR-1256, and PDL1 were detected by qRT-PCR. Cell viability, proliferation, apoptosis, invasion, and self-replication ability were analyzed by CCK-8, EdU, flow cytometry, transwell, and spheroid formation experiments, respectively. Protein levels were determined by western blotting assay. CRC cells were co-cultured with CD8 + T cells, phytohemagglutinin-stimulated peripheral blood mononuclear cells (PBMCs), or cytokine-induced killer (CIK) cells in vitro, and CD8 + T-cell apoptosis, IFN-γ and TNF-α levels, and survival rate of CRC cells were analyzed to reveal the role of circ_0007422 in antitumor immunity. The relationship between miR-1256 and circ_0007422 or PDL1 was identified by a dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. A xenograft tumor model was established to verify the function of circ_0007422 in tumor growth in vivo. Immunohistochemistry (IHC) assay was used to detect positive expression rates of Ki67, E-cadherin, N-cadherin, and PDL1 expression in primary tumors from CRC cells. Circ_0007422 was upregulated in CRC tissues and cells and its knockdown inhibited proliferation, invasion, self-replication ability, and immune escape and promoted apoptosis of CRC cells. Additionally, circ_0007422 bound to miR-1256, which was identified to target PDL1. MiR-1256 inhibition reversed the effects of circ_0007422 knockdown on the tumor properties and immune escape of CRC cells. Moreover, miR-1256 introduction interacted with PDL1 to suppress proliferation, invasion, self-replication ability, and immune escape and promote apoptosis of CRC cells. Further, circ_0007422 knockdown hampered tumorigenesis of CRC cells in vivo. Circ_0007422 knockdown inhibited tumor property and immune escape of colorectal cancer through the miR-1256/PDL1 pathway, providing a potential novel therapeutic target for CRC.

Intervention of epithelial mesenchymal transition against colon cancer cell growth and metastasis based on SOX21/POU4F2/Hedgehog signaling axis

AIMS

Colon cancer poses a major threat to human health and a heavy burden on the national economy. As a member of the SOX transcription factor family, SRY-box transcription factor 21 (SOX21) is associated with various cancers, but its mechanism of action in colon cancer remains unclear. This study focused on the molecular mechanisms of transcription factor SOX21 in proliferation and metastasis of colon cancer cells.

MAIN METHODS

We analyzed SOX21 expression level and its impact on survival in colon cancer patients by bioinformatics analysis. We used public databases for gene correlation, GSEA enrichment analysis. Cell function experiments (colony formation assay, wound healing assay, Transwell migration and invasion assay) were utilized to determine the impact of SOX21 silencing and over-expression on cell proliferation and metastasis. The luciferase reporter assay, CUT&RUN-qPCR assay and Methylation Specific PCR were used to explore SOX21-POU class 4 homeobox 2 (POU4F2) molecular interactions. The molecular mechanisms were verified by Quantitative real-time PCR and Western blot analysis.

KEY FINDINGS

SOX21 is highly expressed and affects the overall survival of colon cancer patients. SOX21 can attenuates POU4F2 methylation state by binding with it. In addition, this interaction facilitate its transcriptional activation of Hedgehog pathway, mediates epithelial-mesenchymal transition (EMT), consequently promoting the proliferation and metastasis of colon cancer cells.

SIGNIFICANCE

Our study reveals that SOX21 is an oncogenic molecule and suggests its regulatory role in colon carcinogenesis and progression, providing new insights into the treatment of this disease.

Non-invasive CT radiomic biomarkers predict microsatellite stability status in colorectal cancer: a multicenter validation study

BACKGROUND

Microsatellite instability (MSI) status is a strong predictor of response to immunotherapy of colorectal cancer. Radiogenomic approaches promise the ability to gain insight into the underlying tumor biology using non-invasive routine clinical images. This study investigates the association between tumor morphology and the status of MSI versus microsatellite stability (MSS), validating a novel radiomic signature on an external multicenter cohort.

METHODS

Preoperative computed tomography scans with matched MSI status were retrospectively collected for 243 colorectal cancer patients from three hospitals: Seoul National University Hospital (SNUH); Netherlands Cancer Institute (NKI); and Fondazione IRCCS Istituto Nazionale dei Tumori, Milan Italy (INT). Radiologists delineated primary tumors in each scan, from which radiomic features were extracted. Machine learning models trained on SNUH data to identify MSI tumors underwent external validation using NKI and INT images. Performances were compared in terms of area under the receiving operating curve (AUROC).

RESULTS

We identified a radiomic signature comprising seven radiomic features that were predictive of tumors with MSS or MSI (AUROC 0.69, 95% confidence interval [CI] 0.54-0.84, p = 0.018). Integrating radiomic and clinical data into an algorithm improved predictive performance to an AUROC of 0.78 (95% CI 0.60-0.91, p = 0.002) and enhanced the reliability of the predictions.

CONCLUSION

Differences in the radiomic morphological phenotype between tumors MSS or MSI could be detected using radiogenomic approaches. Future research involving large-scale multicenter prospective studies that combine various diagnostic data is necessary to refine and validate more robust, potentially tumor-agnostic MSI radiogenomic models.

RELEVANCE STATEMENT

Noninvasive radiomic signatures derived from computed tomography scans can predict MSI in colorectal cancer, potentially augmenting traditional biopsy-based methods and enhancing personalized treatment strategies.

KEY POINTS

Noninvasive CT-based radiomics predicted MSI in colorectal cancer, enhancing stratification. A seven-feature radiomic signature differentiated tumors with MSI from those with MSS in multicenter cohorts. Integrating radiomic and clinical data improved the algorithm's predictive performance.

Enhancing Colorectal Cancer Immunotherapy: The Pivotal Role of Ferroptosis in Modulating the Tumor Microenvironment

Colorectal cancer (CRC) represents a significant challenge in oncology, with increasing incidence and mortality rates worldwide, particularly among younger adults. Despite advancements in treatment modalities, the urgent need for more effective therapies persists. Immunotherapy has emerged as a beacon of hope, offering the potential for improved outcomes and quality of life. This review delves into the critical interplay between ferroptosis, an iron-dependent form of regulated cell death, and immunotherapy within the CRC context. Ferroptosis's influence extends beyond tumor cell fate, reshaping the tumor microenvironment (TME) to enhance immunotherapy's efficacy. Investigations into Ferroptosis-related Genes (OFRGs) reveal their pivotal role in modulating immune cell infiltration and TME composition, closely correlating with tumor responsiveness to immunotherapy. The integration of ferroptosis inducers with immunotherapeutic strategies, particularly through novel approaches like ferrotherapy and targeted co-delivery systems, showcases promising avenues for augmenting treatment efficacy. Furthermore, the expression patterns of OFRGs offer novel prognostic tools, potentially guiding personalized and precision therapy in CRC. This review underscores the emerging paradigm of leveraging ferroptosis to bolster immunotherapy's impact, highlighting the need for further research to translate these insights into clinical advancements. Through a deeper understanding of the ferroptosis-immunotherapy nexus, new therapeutic strategies can be developed, promising enhanced efficacy and broader applicability in CRC treatment, ultimately improving patient outcomes and quality of life in the face of this formidable disease.

Endothelial cell heterogeneity in colorectal cancer: tip cells drive angiogenesis

This study aims to uncover the heterogeneity of endothelial cells (ECs) in colorectal cancer (CRC) and their crucial role in angiogenesis, with a special focus on tip cells. Using single-cell RNA sequencing to profile ECs, our data suggests that CRC ECs predominantly exhibit enhanced angiogenesis and decreased antigen presentation, a shift in phenotype largely steered by tip cells. We also observed that an increase in the density and proportion of tip cells correlates with CRC occurrence, progression, and poorer patient prognosis. Furthermore, we identified endothelial cell-specific molecule 1 (ESM1), specifically expressed in tip cells, sustains a VEGFA-KDR-ESM1 positive feedback loop, promoting angiogenesis and CRC proliferation and migration. We also found the enrichment of KDR in tip cells and spotlight a unique long-tail effect in VEGFA expression: while VEGFA is primarily expressed by epithelial cells, the highest level of VEGFA expression is found in individual myeloid cells. Moreover, we observed that effective PD-1 blockade immunotherapy significantly reduced tip cells, disrupting the VEGFA-KDR-ESM1 positive feedback loop in the process. Our investigation into the heterogeneity of ECs in CRC at a single-cell level offers important insights that may contribute to the development of more effective immunotherapies targeting tip cells in CRC.

Meta-analysis of robotic-assisted NOSE versus traditional TWSR in colorectal cancer surgery: postoperative outcomes and efficacy

BACKGROUND

This meta-analysis aimed to assess the safety and efficacy of robotic-assisted natural orifice specimen extraction surgery (NOSE) compared to traditional robotic transabdominal wall specimen retrieval surgery (TWSR) for colorectal cancer.

METHODS

A systematic search was conducted in three electronic databases (PubMed, Web of Science and Embase) from inception to August 2023. Primary outcomes included postoperative complications, the number of lymph nodes harvested, overall survival and disease-free survival. Secondary outcomes included the postoperative visual analog scale (VAS) score, the additional use of analgesics, the restoration of gastrointestinal function, blood loss, the mean operation time, and length of postoperative hospital stay.

RESULTS

In this meta-analysis, a total of 717 patients from 6 observational studies met the inclusion criteria. Compared with the TWSR group, the NOSE group had greater benefits in terms of overall postoperative complications [odds ratios (OR) 0.55; 95% confidence intervals (CI) = 0.34 to 0.89; P = 0.01, I2 = 0%)], the number of lymph nodes harvested [weighted mean differences (WMD) = 1.18; 95% CI = 0.15 to 2.21; P = 0.02, I2 = 0%)], the rate of wound infection (OR 0.17; 95% CI = 0.04 to 0.80; P = 0.02, I2 = 0%), the passed flatus time (WMD =  - 0.35 days; 95% CI =  - 0.60 to - 0.10; P = 0.007, I2 = 73%), the additional use of analgesics (OR 0.25; 95% CI = 0.15 to 0.40; P < 0.001, I2 = 0%), the diet recovery time (WMD =  - 0.56; 95% CI =  - 1.00 to - 0.11; P = 0.01, I2 = 78%) and the postoperative VAS score (WMD =  - 1.23; 95% CI =  - 1.63 to - 0.83; P < 0.001, I2 = 65%). There were no significant differences in the blood loss (WMD =  - 5.78 ml; 95% CI =  - 17.57 to 6.00; P = 0.34, I2 = 90%), mean operation time (WMD = 14.10 min; 95% CI =  - 3.76 to 31.96; P = 0.12) (I2 = 93%), length of postoperative hospital stay (WMD =  - 0.47 day; 95% CI =  - 0.98 to 0.03; P = 0.07, I2 = 51%), incidences of postoperative ileus (OR 1.0; 95% CI = 0.22 to 4.46; P = 1.00, I2 = 0%), anastomotic leakage (OR 0.73; 95% CI = 0.33 to 1.60; P = 0.43, I2 = 0%), and intra-abdominal abscess (OR 1.59; 95% CI = 0.47 to 5.40; P = 0.46, I2 = 0%), or 3-year overall survival [hazard ratio (HR) = 1.07, 95% CI = 0.60 to 1.94; P = 0.81)] or disease-free survival (HR = 0.94, 95% CI = 0.54 to 1.63; P = 0.82, I2 = 0%).

CONCLUSION

This meta-analysis showed that the NOSE group had better postoperative outcomes than did the TWSR group and that NOSE was a safe and viable alternative to TWSR. More large-sample reviews and further randomized trials are warranted.

Immunotherapy for colorectal cancer

Colorectal cancer is the third most common cancer and the second most lethal cancer in the world. The main cause of the disease is due to dietary and behavioral factors. The treatment of this complex disease is mainly based on traditional treatments, including surgery, radiotherapy, and chemotherapy. Due to its high prevalence and high morbidity, more effective treatments with fewer side effects are urgently needed. In recent years, immunotherapy has become a potential therapeutic alternative and one of the fastest-developing treatments. Immunotherapy inhibits tumor growth by activating or enhancing the immune system to recognize and attack cancer cells. This review presents the latest immunotherapies for immune checkpoint inhibitors, cell therapy, tumor-infiltrating lymphocytes, and oncolytic viruses. Some of these have shown promising results in clinical trials and are used in clinical treatment.

Potential role of the intratumoral microbiota in colorectal cancer immunotherapy

Colorectal cancer (CRC) has been one of the most common malignancies worldwide. Despite the advances in current therapies, the mortality rate of CRC remains high. Among them, immunotherapy has achieved satisfactory results in some CRC patients, however, how to expand the use of immunotherapy in CRC patients remains an urgent challenge. Surprisingly, the intratumoral microbiota has been found in multiple tumor tissues, including CRC. It has been demonstrated that the intratumoral microbiota is associated with the progression and treatment of CRC, and is able to enhance or decrease anti-tumor immune responses via different mechanisms as well as influence the immunotherapy efficacy, providing new potential therapeutic targets for CRC immunotherapy. In this review, we focus on the characteristics of the intratumoral microbiota, its roles in the genesis and development of CRC, its modulation of anti-tumor immune responses and immunotherapy, and propose potential applications of the intratumoral microbiota in CRC immunotherapy. Additionally, we propose possible directions for future research on the intratumoral microbiota related to CRC immunotherapy.

Nilotinib boosts the efficacy of anti-PDL1 therapy in colorectal cancer by restoring the expression of MHC-I

BACKGROUND

Although immune checkpoint inhibitors (ICIs) have revolutionized the landscape of cancer treatment, only a minority of colorectal cancer (CRC) patients respond to them. Enhancing tumor immunogenicity by increasing major histocompatibility complex I (MHC-I) surface expression is a promising strategy to boost the antitumor efficacy of ICIs.

METHODS

Dual luciferase reporter assays were performed to find drug candidates that can increase MHC-I expression. The effect of nilotinib on MHC-I expression was verified by dual luciferase reporter assays, qRT-PCR, flow cytometry and western blotting. The biological functions of nilotinib were evaluated through a series of in vitro and in vivo experiments. Using RNA-seq analysis, immunofluorescence assays, western blotting, flow cytometry, rescue experiments and microarray chip assays, the underlying molecular mechanisms were investigated.

RESULTS

Nilotinib induces MHC-I expression in CRC cells, enhances CD8+ T-cell cytotoxicity and subsequently enhances the antitumor effects of anti-PDL1 in both microsatellite instability and microsatellite stable models. Mechanistically, nilotinib promotes MHC-I mRNA expression via the cGAS-STING-NF-κB pathway and reduces MHC-I degradation by suppressing PCSK9 expression in CRC cells. PCSK9 may serve as a potential therapeutic target for CRC, with nilotinib potentially targeting PCSK9 to exert anti-CRC effects.

CONCLUSION

This study reveals a previously unknown role of nilotinib in antitumor immunity by inducing MHC-I expression in CRC cells. Our findings suggest that combining nilotinib with anti-PDL1 therapy may be an effective strategy for the treatment of CRC.

LINC00460/miR-186-3p/MYC feedback loop facilitates colorectal cancer immune escape by enhancing CD47 and PD-L1 expressions

BACKGROUND

Long non-coding RNAs (LncRNAs) have been implicated as critical regulators of cancer tumorigenesis and progression. However, their functions and molecular mechanisms in colorectal cancer (CRC) still remain to be further elucidated.

METHODS

LINC00460 was identified by differential analysis between human CRC and normal tissues and verified by in situ hybridization (ISH) and qRT-PCR. We investigated the biological functions of LINC00460 in CRC by in vitro and in vivo experiments. We predicted the mechanism and downstream functional molecules of LINC00460 by bioinformatics analysis, and confirmed them by dual luciferase reporter gene assay, RNA immunoprecipitation (RIP), RNA pull-down, etc. RESULTS: LINC00460 was found to be significantly overexpressed in CRC and associated with poor prognosis. Overexpression of LINC00460 promoted CRC cell immune escape and remodeled a suppressive tumor immune microenvironment, thereby promoting CRC proliferation and metastasis. Mechanistic studies showed that LINC00460 served as a molecular sponge for miR-186-3p, and then promoted the expressions of MYC, CD47 and PD-L1 to facilitate CRC cell immune escape. We also demonstrated that MYC upregulated LINC00460 expression at the transcriptional level and formed a positive feedback loop.

CONCLUSIONS

The LINC00460/miR-186-3p/MYC feedback loop promotes CRC cell immune escape and subsequently facilitates CRC proliferation and metastasis. Our findings provide novel insight into LINC00460 as a CRC immune regulator, and provide a potential therapeutic target for CRC patients.

Identification and analysis of key genes related to efferocytosis in colorectal cancer

The impact of efferocytosis-related genes (ERGs) on the diagnosis of colorectal cancer (CRC) remains unclear. In this study, efferocytosis-associated biomarkers for the diagnosis of CRC were identified by integrating data from transcriptome sequencing and public databases. Finally, the expression of biomarkers was validated by real-time quantitative polymerase chain reaction (RT-qPCR). Our study may provide a reference for CRC diagnosis.

BACKGROUND

It has been shown that some efferocytosis related genes (ERGs) are associated with the development of cancer. However, it is still uncertain how ERGs may influence the diagnosis of colorectal cancer (CRC).

METHODS

In our study, the CRC cohorts were gained from transcriptome sequencing and the gene expression omnibus (GEO) database (GSE71187). Efferocytosis related biomarkers with diagnostic utility for CRC were identified through combining differentially expressed analysis, machine learning algorithms, and receiver operating characteristic (ROC) analysis. Then, infiltration abundance of immune cells between CRC and control was evaluated. The regulatory networks (including mRNA-miRNA-lncRNA and miRNA/transcription factors (TF)-mRNA networks) were created. Finally, the expression of biomarkers was validated via real-time quantitative polymerase chain reaction (RT-qPCR).

RESULTS

There were 3 biomarkers (ELMO3, P2RY12, and PDK4) related diagnosis for CRC patients gained. ELMO3 was highly expressed in CRC group, while P2RY12 and PDK4 was lowly expressed. Besides, the infiltrating abundance of 3 immune cells between CRC and control groups was significantly differential, namely activated CD4 memory T cells, macrophages M0, and resting mast cells. We then constructed a mRNA-miRNA-lncRNA network containing 3 mRNAs, 33 miRNAs, and 22 lncRNAs, and a miRNA/TF-mRNA network including 3 mRNAs, 33 miRNAs, and 7 TFs. Additionally, RT-qPCR results revealed that the expression trends of all biomarkers were consistent with the transcriptome sequencing data and GSE71187.

CONCLUSION

Taken together, this study provides three efferocytosis related biomarkers (ELMO3, P2RY12, and PDK4) for diagnosis of CRC, providing a scientific reference for further studies of CRC.

Icariside I enhances the effects of immunotherapy in gastrointestinal cancer via targeting TRPV4 and upregulating the cGAS-STING-IFN-I pathway

Gastrointestinal cancer is among the most common cancers worldwide. Immune checkpoint inhibitor-based cancer immunotherapy has become an innovative approach in cancer treatment; however, its efficacy in gastrointestinal cancer is limited by the absence of infiltration of immune cells within the tumor microenvironment. Therefore, it is therefore urgent to develop a novel therapeutic drug to enhance immunotherapy. In this study, we describe a previously unreported potentiating effect of Icariside I (ICA I, GH01), the main bioactive compound isolated from the Epimedium species, on anti-tumor immune responses. Mechanistically, molecular docking and SPR assay result show that ICA I binding with TRPV4. ICA I induced intracellular Ca2+ increasing and mitochondrial DNA release by targeting TRPV4, which triggered cytosolic ox-mitoDNA release. Importantly, these intracellular ox-mitoDNA fragments were taken up by immune cells in the tumor microenvironment, which amplified the immune response. Moreover, our study shows the remarkable efficacy of sequential administration of ICA I and anti-α-PD-1 mAb in advanced tumors and provides a strong scientific rationale for recommending such a combination therapy for clinical trials. ICA I enhanced the anti-tumor effects with PD-1 inhibitors by regulating the TRPV4/Ca2+/Ox-mitoDNA/cGAS/STING axis. We expect that these findings will be translated into clinical therapies, which will benefit more patients with cancer in the near future.

GJA4 expressed on cancer associated fibroblasts (CAFs)-A 'promoter' of the mesenchymal phenotype

BACKGROUND

Colorectal cancer (CRC) is the third most common cancer worldwide. Connexin is a transmembrane protein involved in gap junctions (GJs) formation. Our previous study found that connexin 37 (Cx37), encoded by gap junction protein alpha 4 (GJA4), expressed on fibroblasts acts as a promoter of CRC and is closely related to epithelial-mesenchymal transition (EMT) and tumor immune microenvironment. However, to date, the mechanism concerning the malignancy of GJA4 in tumor stroma has not been studied.

METHODS

Hematoxylin-eosin (HE) and immunohistochemical (IHC) staining were used to validate the expression and localization of GJA4. Using single-cell analysis, enrichment analysis, spatial transcriptomics, immunofluorescence staining (IF), Sirius red staining, wound healing and transwell assays, western blotting (WB), Cell Counting Kit-8 (CCK8) assay and in vivo experiments, we investigated the possible mechanisms of GJA4 in promoting CRC.

RESULTS

We discovered that in CRC, GJA4 on fibroblasts is involved in promoting fibroblast activation and promoting EMT through a fibroblast-dependent pathway. Furthermore, GJA4 may act synergistically with M2 macrophages to limit T cell infiltration by stimulating the formation of an immune-excluded desmoplasic barrier. Finally, we found a significantly correlation between GJA4 and pathological staging (P < 0.0001) or D2 dimer (R = 0.03, P < 0.05).

CONCLUSION

We have identified GJA4 expressed on fibroblasts is actually a promoter of the tumor mesenchymal phenotype. Our findings suggest that the interaction between GJA4+ fibroblasts and M2 macrophages may be an effective target for enhancing tumor immunotherapy.

How have US colorectal cancer mortality trends changed in the past 20 years?

In the last two decades, colorectal cancer (CRC) mortality has been decreasing in the United States. However, the mortality trends for the different subtypes of CRC, including different sides of colon, rectosigmoid, and rectal cancer remain unclear. We analyzed the mortality trends of different subtypes of CRC based on Centers for Disease Control and Prevention's Wide-Ranging Online Data for Epidemiologic Research data from 1999 to 2020. We calculated age-adjusted mortality rates (AAMR) per 100,000 individuals and examined the trends over time by estimating the average annual percent change (AAPC) using the Joinpoint Regression Program. Our study shows that the overall CRC rates decreased significantly from 26.42 to 15.98 per 100,000 individuals, with an AAPC of -2.41. However, the AAMR of rectosigmoid cancer increased significantly from 0.82 to 1.08 per 100,000 individuals, with the AAPC of +1.10. Men and Black individuals had the highest AAMRs respectively (23.90 vs. 26.93 per 100,000 individuals). The overall AAMR of CRC decreased for those aged ≥50 years but increased significantly from 1.02 to 1.58 per 100,000 individuals for those aged 15-49 years, with an AAPC of +0.75. Rural populations had a higher AAMR than the urban populations (22.40 vs. 19.60 per 100,000 individuals). Although overall CRC mortality declined, rising trends in young-onset CRC and rectosigmoid cancer warrant attention. Disparities persist in terms of sex, race, and geographic region, and urbanization level, emphasizing the need for targeted public health measures.

Effectiveness of magnetic resonance imaging and spiral computed tomography in the staging and treatment prognosis of colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is a prevalent cancer type in clinical settings; its early signs can be difficult to detect, which often results in late-stage diagnoses in many patients. The early detection and diagnosis of CRC are crucial for improving treatment success and patient survival rates. Recently, imaging techniques have been hypothesized to be essential in managing CRC, with magnetic resonance imaging (MRI) and spiral computed tomography (SCT) playing a significant role in enhancing diagnostic and treatment approaches.

AIM

To explore the effectiveness of MRI and SCT in the preoperative staging of CRC and the prognosis of laparoscopic treatment.

METHODS

Ninety-five individuals admitted to Zhongshan Hospital Xiamen University underwent MRI and SCT and were diagnosed with CRC. The precision of MRI and SCT for the presurgical classification of CRC was assessed, and pathological staging was used as a reference. Receiver operating characteristic curves were used to evaluate the diagnostic efficacy of blood volume, blood flow, time to peak, permeability surface, blood reflux constant, volume transfer constant, and extracellular extravascular space volume fraction on the prognosis of patients with CRC.

RESULTS

Pathological biopsies confirmed the following CRC stages: 23, 23, 32, and 17 at T1, T2, T3, and T4, respectively. There were 39 cases at the N0 stage, 22 at N1, 34 at N2, 44 at M0 stage, and 51 at M1. Using pathological findings as the benchmark, the combined use of MRI and SCT for preoperative TNM staging in patients with CRC demonstrated superior sensitivity, specificity, and accuracy compared with either modality alone, with a statistically significant difference in accuracy (P < 0.05). Receiver operating characteristic curve analysis revealed the predictive values for laparoscopic treatment prognosis, as indicated by the areas under the curve for blood volume, blood flow, time to peak, and permeability surface, blood reflux constant, volume transfer constant, and extracellular extravascular space volume fraction were 0.750, 0.683, 0.772, 0.761, 0.709, 0.719, and 0.910, respectively. The corresponding sensitivity and specificity values were also obtained (P < 0.05).

CONCLUSION

MRI with SCT is effective in the clinical diagnosis of patients with CRC and is worthy of clinical promotion.

Advances and prospects of biomarkers for immune checkpoint inhibitors

Immune checkpoint inhibitors (ICIs) activate anti-cancer immunity by blocking T cell checkpoint molecules such as programmed death 1 (PD-1) and cytotoxic T lymphocyte-associated protein 4 (CTLA-4). Although ICIs induce some durable responses in various cancer patients, they also have disadvantages, including low response rates, the potential for severe side effects, and high treatment costs. Therefore, selection of patients who can benefit from ICI treatment is critical, and identification of biomarkers is essential to improve the efficiency of ICIs. In this review, we provide updated information on established predictive biomarkers (tumor programmed death-ligand 1 [PD-L1] expression, DNA mismatch repair deficiency, microsatellite instability high, and tumor mutational burden) and potential biomarkers currently under investigation such as tumor-infiltrated and peripheral lymphocytes, gut microbiome, and signaling pathways related to DNA damage and antigen presentation. In particular, this review aims to summarize the current knowledge of biomarkers, discuss issues, and further explore future biomarkers.

A novel antitumor mechanism of triptonide in colorectal cancer: inducing ferroptosis via the SLC7A11/GPX4 axis

Colorectal cancer (CRC) is a prevalent malignancy affecting the human digestive tract. Triptonide has been shown to have some anticancer activity, but its effect in CRC is vague. Herein, we examined the effect of triptonide on CRC. In this study, the results of bioinformatics analysis displayed that triptonide may regulate ferroptosis in CRC by modulating GPX4 and SLC7A11. In HCT116 and LoVo cells, the expression levels of GPX4 and SLC7A11 were significantly reduced after triptonide management versus the control group. Triptonide inhibited proliferation, but promoted ferroptosis in CRC cells. SLC7A11 upregulation overturned the effects of triptonide on proliferation and ferroptosis in CRC cells. Triptonide inhibited activation of the PI3K/AKT/Nrf2 signaling in CRC cells. Activation of the PI3K/AKT signaling or Nrf2 upregulation overturned the effects of triptonide on proliferation and ferroptosis in CRC cells. Triptonide suppressed CRC cell growth in vivo by modulating SLC7A11 and GPX4. In conclusion, Triptonide repressed proliferation and facilitated ferroptosis of CRC cells by repressing the SLC7A11/GPX4 axis through inactivation of the PI3K/AKT/Nrf2 signaling.

Optimal glycaemic control and the reduced risk of colorectal adenoma and cancer in patients with diabetes: a population-based cohort study

OBJECTIVE

Whether varying degrees of glycaemic control impact colonic neoplasm risk in patients with diabetes mellitus (DM) remains uncertain.

DESIGN

Patients with newly diagnosed DM were retrieved from 2005 to 2013. Optimal glycaemic control at baseline was defined as mean haemoglobin A1c (HbA1c)<7%. Outcomes of interest included colorectal cancer (CRC) and colonic adenoma development. We used propensity score (PS) matching with competing risk models to estimate subdistribution HRs (SHRs). We further analysed the combined effect of baseline and postbaseline glycaemic control based on time-weighted mean HbA1c during follow-up.

RESULTS

Of 88 468 PS-matched patients with DM (mean (SD) age: 61.5 (±11.7) years; male: 47 127 (53.3%)), 1229 (1.4%) patients developed CRC during a median follow-up of 7.2 (IQR: 5.5-9.4) years. Optimal glycaemic control was associated with lower CRC risk (SHR 0.72; 95% CI 0.65 to 0.81). The beneficial effect was limited to left-sided colon (SHR 0.71; 95% CI 0.59 to 0.85) and rectum (SHR 0.71; 95% CI 0.57 to 0.89), but not right-sided colon (SHR 0.86; 95% CI 0.67 to 1.10). Setting suboptimal glycaemic control at baseline/postbaseline as a reference, a decreased CRC risk was found in optimal control at postbaseline (SHR 0.79), baseline (SHR 0.71) and both time periods (SHR 0.61). Similar associations were demonstrated using glycaemic control as a time-varying covariate (HR 0.75). A stepwise greater risk of CRC was found (Ptrend<0.001) with increasing HbA1c (SHRs 1.34, 1.30, 1.44, 1.58 for HbA1c 7.0% to <7.5%, 7.5% to <8.0%, 8.0% to <8.5% and ≥8.5%, respectively). Optimal glycaemic control was associated with a lower risk of any, non-advanced and advanced colonic adenoma (SHRs 0.73-0.87).

CONCLUSION

Glycaemic control in patients with DM was independently associated with the risk of colonic adenoma and CRC development with a biological gradient.

Effects of the Combination of Noise Reduction Earplugs with White Noise and Rational Emotional Therapy on Emotional States of Inpatients with Colorectal Cancer

OBJECTIVE

The aim of the study was to explore the effects of the combination of noise reduction earplugs with white noise and rational emotional therapy on the emotional states of inpatients with colorectal cancer (CRC).

METHODS

The study selected 152 CRC patients who received inpatient treatment in our hospital from January 2020 to January 2022 as the research objects. According to different nursing intervention modes, these patients were divided into the observation group (OG, n = 73, conventional nursing + noise reduction earplugs with white noise + rational emotional therapy) and the control group (CG, n = 79, conventional nursing) to compare the emotional status, sleep quality, and other indicators between the two groups.

RESULTS

After 2 and 6 weeks of intervention, the severity of illness and global impression in the OG were notably lower than those in the CG. The OG had remarkably higher efficacy indexes than the CG (p < 0.05). The OG had overtly lower Montgomery-Asberg Depression Scale (MADRS) scores and Pittsburgh sleep quality index (PSQI) scores than the CG (p < 0.05).

CONCLUSION

The combination of noise reduction earplugs with white noise and rational emotional therapy can improve the emotion and sleep states of patients, with certain positive effects, which can be used as a potential nursing plan for CRC patients.

Cimetidine repurposed as a potential immunomodulatory agent against colorectal carcinoma: A systematic review

OBJECTIVE

To determine the survival benefit and immunomodulatory effects of cimetidine pre-, peri- or post-operatively in patients with colorectal cancer (CRC).

METHODS

A systematic review was conducted using PubMed and Cochrane Library to retrieve randomized control trials (RCTs) that investigated the effects of cimetidine on survival and immunomodulation via improvement in tumor infiltrating lymphocytes (TILs) and peripheral blood lymphocytes. The review was carried out in accordance with the extended Preferred Reporting Items for Systematic Reviews and Meta-analyses.

RESULTS

Four studies with the total of 267 patients were included in this systematic review. Treatment duration varied from 5 days to 1 year. Two studies reported a significant TIL response in the resected specimens after administering cimetidine, while one RCT showed an escalation of CD3, CD4 and CD57 lymphocytes in peripheral blood compared to the baseline following cimetidine treatment (p < 0.01). Of the three trials that examined the effects of cimetidine on survival, only two studies revealed significant survival benefit while the remaining study only showed a trend towards survival benefit.

CONCLUSION

Repurposing of existing drugs like cimetidine has a potential to offer a survival benefit by acting as an immunomodulatory agent in patients undergoing curative resection for CRC. However, the heterogeneity seen in current studies and the evolvement of adjunctive therapies for CRC warrant large-scale, well-designed prospective RCTs to establish the efficacy of cimetidine in CRC.

Clinicopathological significance and prognostic analysis of p21 and EGFR in colorectal cancer: a retrospective analysis on 12 319 cases in China

AIMS

Colorectal cancer (CRC) is the third most common malignancy worldwide. Accurate pathological diagnosis and predictive abilities for treatment response and prognosis are crucial for patients with CRC. This study aims to analyse the expressions of p21 and EGFR in CRC and their relationships with clinicopathological characteristics and prognosis to enhance diagnostic and prognostic evaluations.

METHODS

This study conducted a retrospective analysis of p21 and EGFR expressions in 12 319 Chinese patients with CRC using immunohistochemistry. The relationships between these expressions and clinicopathological characteristics and survival outcomes were explored through statistical and survival analyses.

RESULTS

Differential expressions of p21 and EGFR in CRC were closely related to clinicopathological characteristics and significantly impacted overall survival (OS). p21 expression was associated with the primary tumour site, mucinous subtype, lymphovascular invasion, perineural invasion, circumferential resection margin, T stage, N stage, tumour, node, metastases (TNM) stage, and mismatch repair status. EGFR expression was related to mucinous subtype, tumour differentiation, lymphovascular invasion, perineural invasion, tumour size, T stage, N stage, TNM stage and BRAF gene mutation. p21 and EGFR expressions were positively correlated (r=0.11). High p21 expression correlated with favourable OS, whereas high EGFR expression predicted poorer OS. A prognostic nomogram incorporating these biomarkers and clinical variables demonstrated robust predictive power for patient survival rates.

CONCLUSION

p21 and EGFR serve as potential indicators for pathological diagnosis, risk stratification, and predicting treatment efficacy and prognosis in patients with CRC. The study's findings provide valuable references for personalised treatment and prognosis evaluation in clinical practice.

Spatiotemporal heterogeneity of LMOD1 expression summarizes two modes of cell communication in colorectal cancer

Cellular communication (CC) influences tumor development by mediating intercellular junctions between cells. However, the role and underlying mechanisms of CC in malignant transformation remain unknown. Here, we investigated the spatiotemporal heterogeneity of CC molecular expression during malignant transformation. It was found that although both tight junctions (TJs) and gap junctions (GJs) were involved in maintaining the tumor microenvironment (TME), they exhibited opposite characteristics. Mechanistically, for epithelial cells (parenchymal component), the expression of TJ molecules consistently decreased during normal-cancer transformation and is a potential oncogenic factor. For fibroblasts (mesenchymal component), the expression of GJs consistently increased during normal-cancer transformation and is a potential oncogenic factor. In addition, the molecular profiles of TJs and GJs were used to stratify colorectal cancer (CRC) patients, where subtypes characterized by high GJ levels and low TJ levels exhibited enhanced mesenchymal signals. Importantly, we propose that leiomodin 1 (LMOD1) is biphasic, with features of both TJs and GJs. LMOD1 not only promotes the activation of cancer-associated fibroblasts (CAFs) but also inhibits the Epithelial-mesenchymal transition (EMT) program in cancer cells. In conclusion, these findings demonstrate the molecular heterogeneity of CC and provide new insights into further understanding of TME heterogeneity.

Comprehensive analysis of the relationship between ubiquitin-specific protease 21 (USP21) and prognosis, tumor microenvironment infiltration, and therapy response in colorectal cancer

BACKGROUND

Ubiquitin-specific proteases family is crucial to host immunity against pathogens. However, the correlations between USP21 and immunosurveillance and immunotherapy for colorectal cancer (CRC) have not been reported.

METHODS

The differential expression of USP21 between CRC tissues and normal tissues was analyzed using multiple public databases. Validation was carried out in clinical samples through qRT-PCR and IHC. The correlation between USP21 and the prognosis, as well as clinical pathological characteristics of CRC patients, was investigated. Moreover, cell models were established to assess the influence of USP21 on CRC growth and progression, employing CCK-8 assays, colony formation assays, and wound-healing assays. Subsequently, gene set variation analysis (GSVA) was used to explore the potential biological functions of USP21 in CRC. The study also examined the impact of USP21 on cytokine levels and immune cell infiltration in the tumor microenvironment (TME). Finally, the effect of USP21 on the response to immunotherapy and chemotherapy in CRC was analyzed.

RESULTS

The expression of USP21 was significantly upregulated in CRC. High USP21 is correlated with poor prognosis in CRC patients and facilitates the proliferation and migration capacities of CRC cells. GSVA indicated an association between low USP21 and immune activation. Moreover, low USP21 was linked to an immune-activated TME, characterized by high immune cell infiltration. Importantly, CRC with low USP21 exhibited higher tumor mutational burden, high PD-L1 expression, and better responsiveness to immunotherapy and chemotherapeutic drugs.

CONCLUSION

This study revealed the role of USP21 in TME, response to therapy, and clinical prognosis in CRC, which provided novel insights for the therapeutic application in CRC.

The lncRNA TRG-AS1 promotes the growth of colorectal cancer cells through the regulation of P2RY10/GNA13

BACKGROUND

The lncRNA TRG-AS1 and its co-expressed gene P2RY10 are important for colorectal cancer (CRC) occurrence and development. The purpose of our research was to explore the roles of TRG-AS1 and P2RY10 in CRC progression.

METHODS

The abundance of TRG-AS1 and P2RY10 in CRC cell lines (HT-29 and LoVo) and normal colon cells FHC was determined and difference between CRC cells and normal cells was compared. LoVo cells were transfected with si-TRG-AS1 and si-P2RY10 constructs. Subsequently, the viability, colony formation, and migration of the transfected cells were analyzed using cell counting kit-8, clonogenicity, and scratch-wound/Transwell® assays, respectively. Cells overexpressing GNA13 were used to further explore the relationship between TRG-AS1 and P2RY10 along with their downstream functions. Finally, nude mice were injected with different transfected cell types to observe tumor formation in vivo.

RESULTS

TRG-AS1 and P2RY10 were significantly upregulated in HT-29 and LoVo compared to FHC cells. TRG-AS1 knockdown and P2RY10 silencing suppressed the viability, colony formation, and migration of LoVo cells. TRG-AS1 knockdown downregulated the expression of P2RY10, GNA12, and GNA13, while P2RY10 silencing downregulated the expression of TRG-AS1, GNA12, and GNA13. Additionally, GNA13 overexpression reversed the cell growth and gene expression changes in LoVo cells induced by TRG-AS1 knockdown or P2RY10 silencing. In vivo experiments revealed that CRC tumor growth was suppressed by TRG-AS1 knockdown and P2RY10 silencing.

CONCLUSIONS

TRG-AS1 knockdown repressed the growth of HT-29 and LoVo by regulating P2RY10 and GNA13 expression.

Identification of EGR4 as a prospective target for inhibiting tumor cell proliferation and a novel biomarker in colorectal cancer

EGR4 (Early Growth Response 4) is a member of the EGR family, involving in tumorigenesis. However, the function and action mechanism of EGR4 in the pathogenesis of colorectal cancer (CRC) remain unclear. To address this, we assessed the prognosis of CRC based on EGR4 using the Kaplan-Meier plotter tool and tissue microarray. The abundance of immunoinfiltration was evaluated through ssGSEA, TISIDB, and TIMER. In vitro experiments involving knockdown or overexpression of EGR4 were performed, and RNA-sequencing was conducted to explore potential mechanisms. Furthermore, we used oxaliplatin and 5-fluorouracil to validate the impact of EGR4 on chemo-resistance. Pan-cancer analysis and tissue microarray showed that EGR4 was highly expressed in CRC and significantly correlated with an unfavorable prognosis. Moreover, EGR4 expression was associated with immunoinfiltration and cancer-associated fibroblasts in the CRC microenvironment. Functional enrichment demonstrated that high-expressional EGR4 were involved in chromatin and nucleosome assembly. Additionally, EGR4 promoted the proliferation of CRC cells. Mechanistically, EGR4 upregulated TNFα to activate the NF-κB signaling pathway, and its knockdown reduced p65 nuclear translocation. Importantly, combining shEGR4 with oxaliplatin and 5-fluorouracil significantly inhibited CRC proliferation. Taken together, these findings provide new insights into the potential prognosis and therapeutic targets of EGR4 in CRC.

Navigating colorectal cancer prognosis: A Treg-related signature discovered through single-cell and bulk transcriptomic approaches

BACKGROUND

The significance of regulatory T cells (Tregs) in colorectal cancer is unclear.

METHODS

The single-cell sequencing data for colorectal cancer, specifically GSE132465 and GSE188711, were retrieved from the GEO database. Simultaneously, bulk transcriptome data were obtained from the UCSC Xena website. To delve into the heterogeneity of Treg cells and identify key genes at the single-cell sequencing level, we employed dimensionality reduction techniques alongside clustering and conducted differential expression gene analysis. For the bulk transcriptome data, we utilized weighted co-expression network analysis to investigate critical gene modules. Additionally, we employed COX regression and Lasso regression methodologies to construct prognostic models, thereby assessing patient outcomes. To facilitate outcome evaluation, nomograms were constructed. The integration of these diverse approaches aims to comprehensively study colorectal cancer, encompassing single-cell heterogeneity, key gene identification, and prognosis modeling using both single-cell and bulk transcriptome data. Polymerase chain reaction (PCR) experiments are used to verify mRNA expression levels of key genes. The analysis software was R software (version 4.3.2).

RESULTS

Through single-cell sequencing analysis and bulk transcriptome analysis, we constructed a prognostic model composed with Treg-associated signatures. The high-risk group demonstrated significantly worse prognosis compared with the low-risk group, highlighting the clinical relevance of our models. PCR confirmed that the key gene DEAH-box helicase 15 (DHX15) was significantly overexpressed in colorectal cancer.

CONCLUSIONS

The prognostic models developed in this study offer a potential tool for risk assessment, guiding treatment decisions for colorectal cancer patients.

Interferon-induced transmembrane protein 2 is a prognostic marker in colorectal cancer and promotes its progression by activating the PI3K/AKT pathway

BACKGROUND

Interferon-induced transmembrane protein 2 (IFITM2) is involved in repressing viral infection. This study aim to investigate the expression of IFITM2 in colorectal cancer (CRC) and explore its effect on cell proliferation, migration, and invasion.

METHODS

We analyzed The Cancer Genome Atlas (TCGA) database for IFITM2 expression in colorectal cancer and used western blots to detect IFITM2 protein in specimens and cell lines of colorectal cancers. To assess the association between IFITM2 and clinical features, both univariate and multivariate cox regression analysis were conducted. Kaplan-Meier plots were used in the TCGA database to assess IFITM2 gene expression's prognostic significance. Silencing IFITM2 in SW480 and HCT116 cells was achieved by transient transfection with siRNA. Proliferation of CRCs was examined using Cell Counting Kit-8. The effect of IFITM2 on the migration and invasion of CRC cells was studied using wound healing and transwell assays. Gene set enrichment analysis (GSEA) was used to examine IFITM2-associated pathways and Western blotting was used to confirm it.

RESULTS

IFITM2 was over-expressed in the CRC tissues and cells, with high IFITM2 expression related to the tumor N, M, and pathologic stages. The presence of IFITM2 significantly impacted patient survival in CRC. The proliferation of SW480 and HCT116 cells was suppressed when IFITM2 was silenced, resulting in weakened migration and invasion of CRC cells. GSEA analysis showed that IFITM2 was positively related to the phosphoinositide 3-kinase (PI3K)/AKT pathway, and western blot results confirmed that IFITM2 activated it.

CONCLUSIONS

IFITM2 was over-expressed in CRC and modulated the PI3K/AKT pathway to promote CRC cells proliferation and metastasis.