Metastatic colorectal cancer: mechanisms and emerging therapeutics

The role of UBR5 in tumor proliferation and oncotherapy

Ubiquitin (Ub) protein ligase E3 component n-recognin 5 (UBR5), as a crucial Ub ligase, plays a pivotal role in the field of cell biology, attracting significant attention for its functions in regulating protein degradation and signaling pathways. This review delves into the fundamental characteristics and structure of UBR5. UBR5, through ubiquitination, regulates various key proteins, directly or indirectly participating in cell cycle control, thereby exerting a direct impact on the proliferation of tumor cells. Meanwhile, we comprehensively review the expression levels of UBR5 in different types of tumors and its relationship with tumor development, providing key clues for the role of UBR5 in cancer. Furthermore, we summarize the current research status of UBR5 in cancer treatment. Through literature review, we find that UBR5 may play a crucial role in the sensitivity of tumor cells to radiotherapy chemotherapy, and other anti-tumor treatment, providing new insights for optimizing cancer treatment strategies. Finally, we discuss the challenges faced by UBR5 in cancer treatment, and looks forward to the future research directions. With the continuous breakthroughs in technology and in-depth research, we hope to further study the biological functions of UBR5 and lay the foundation for its anti-tumor treatment.

Unveiling intratumoral microbiota: An emerging force for colorectal cancer diagnosis and therapy

Microbes, including bacteria, viruses, fungi, and other eukaryotic organisms, are commonly present in multiple organs of the human body and contribute significantly to both physiological and pathological processes. Nowadays, the development of sequencing technology has revealed the presence and composition of the intratumoral microbiota, which includes Fusobacterium, Bifidobacteria, and Bacteroides, and has shed light on the significant involvement in the progression of colorectal cancer (CRC). Here, we summarized the current understanding of the intratumoral microbiota in CRC and outline the potential translational and clinical applications in the diagnosis, prevention, and treatment of CRC. We focused on reviewing the development of microbial therapies targeting the intratumoral microbiota to improve the efficacy and safety of chemotherapy and immunotherapy for CRC and to identify biomarkers for the diagnosis and prognosis of CRC. Finally, we emphasized the obstacles and potential solutions to translating the knowledge of the intratumoral microbiota into clinical practice.

Identification of BGN positive fibroblasts as a driving factor for colorectal cancer and development of its related prognostic model combined with machine learning

BACKGROUND

Numerous studies have indicated that cancer-associated fibroblasts (CAFs) play a crucial role in the progression of colorectal cancer (CRC). However, there are still many unknowns regarding the exact role of CAF subtypes in CRC.

METHODS

The data for this study were obtained from bulk, single-cell, and spatial transcriptomic sequencing data. Bioinformatics analysis, in vitro experiments, and machine learning methods were employed to investigate the functional characteristics of CAF subtypes and construct prognostic models.

RESULTS

Our study demonstrates that Biglycan (BGN) positive cancer-associated fibroblasts (BGN + Fib) serve as a driver in colorectal cancer (CRC). The proportion of BGN + Fib increases gradually with the progression of CRC, and high infiltration of BGN + Fib is associated with poor prognosis in terms of overall survival (OS) and recurrence-free survival (RFS) in CRC. Downregulation of BGN expression in cancer-associated fibroblasts (CAFs) significantly reduces migration and proliferation of CRC cells. Among 101 combinations of 10 machine learning algorithms, the StepCox[both] + plsRcox combination was utilized to develop a BGN + Fib derived risk signature (BGNFRS). BGNFRS was identified as an independent adverse prognostic factor for CRC OS and RFS, outperforming 92 previously published risk signatures. A Nomogram model constructed based on BGNFRS and clinical-pathological features proved to be a valuable tool for predicting CRC prognosis.

CONCLUSION

In summary, our study identified BGN + Fib as drivers of CRC, and the derived BGNFRS was effective in predicting the OS and RFS of CRC patients.

Advances in Molecular Mechanisms of Gastrointestinal Tumors

Gastrointestinal cancer is one of the most common malignancies worldwide [...].

Impact of Systemic Treatments on Outcomes and Quality of Life in Patients with RAS-Positive Stage IV Colorectal Cancer: A Systematic Review

This systematic review critically evaluates the impact of systemic treatments on outcomes and quality of life (QoL) in patients with RAS-positive stage IV colorectal cancer, with studies published up to December 2023 across PubMed, Scopus, and Web of Science. From an initial pool of 1345 articles, 11 relevant studies were selected for inclusion, encompassing a diverse range of systemic treatments, including panitumumab combined with FOLFOX4 and FOLFIRI, irinotecan paired with panitumumab, regorafenib followed by cetuximab ± irinotecan and vice versa, and panitumumab as a maintenance therapy post-induction. Patient demographics predominantly included middle-aged to elderly individuals, with a slight male predominance. Racial composition, where reported, showed a majority of Caucasian participants, highlighting the need for broader demographic inclusivity in future research. Key findings revealed that the addition of panitumumab to chemotherapy (FOLFOX4 or FOLFIRI) did not significantly compromise QoL while notably improving disease-free survival, with baseline EQ-5D HSI mean scores ranging from 0.76 to 0.78 and VAS mean scores from 70.1 to 74.1. Improvements in FACT-C scores and EQ-5D Index scores particularly favored panitumumab plus best supportive care in KRAS wild-type mCRC, with early dropout rates of 38-42% for panitumumab + BSC. Notably, cetuximab + FOLFIRI was associated with a median survival of 25.7 months versus 16.4 months for FOLFIRI alone, emphasizing the potential benefits of integrating targeted therapies with chemotherapy. In conclusion, the review underscores the significant impact of systemic treatments, particularly targeted therapies and their combinations with chemotherapy, on survival outcomes and QoL in patients with RAS-positive stage IV colorectal cancer, and the need for personalized treatment.

Role of imbalanced gut microbiota in promoting CRC metastasis: from theory to clinical application

Metastasis poses a major challenge in colorectal cancer (CRC) treatment and remains a primary cause of mortality among patients with CRC. Recent investigations have elucidated the involvement of disrupted gut microbiota homeostasis in various facets of CRC metastasis, exerting a pivotal influence in shaping the metastatic microenvironment, triggering epithelial-mesenchymal transition (EMT), and so on. Moreover, therapeutic interventions targeting the gut microbiota demonstrate promise in enhancing the efficacy of conventional treatments for metastatic CRC (mCRC), presenting novel avenues for mCRC clinical management. Grounded in the "seed and soil" hypothesis, this review consolidates insights into the mechanisms by which imbalanced gut microbiota promotes mCRC and highlights recent strides in leveraging gut microbiota modulation for the clinical prevention and treatment of mCRC. Emphasis is placed on the considerable potential of manipulating gut microbiota within clinical settings for managing mCRC.

Cancer Cell-Mimicking Prussian Blue Nanoplatform for Synergistic Mild Photothermal/Chemotherapy via Heat Shock Protein Inhibition

Combined mild-temperature photothermal/chemotherapy has emerged as a highly promising modality for tumor therapy. However, its therapeutic efficacy is drastically compromised by the heat-induced overexpression of heat shock proteins (HSPs) by the cells, which resist heat stress and apoptosis. The purpose of this study was to downregulate HSPs and enhance the mild-temperature photothermal/chemotherapy effect. In detail, the colon cancer cell membrane (CT26M)-camouflaged HSP90 inhibitor ganetespib and the chemotherapeutic agent doxorubicin (DOX)-coloaded hollow mesoporous Prussian blue (HMPB) nanoplatform (named PGDM) were designed for synergistic mild photothermal/chemotherapy via HSP inhibition. In addition to being a photothermal agent with a high efficiency of photothermal conversion (24.13%), HMPB offers a hollow hole that can be filled with drugs. Concurrently, the cancer cell membrane camouflaging enhances tumor accumulation through a homologous targeting mechanism and gives the nanoplatform the potential to evade the immune system. When exposed to NIR radiation, HMPB's photothermal action (44 °C) not only causes tumor cells to undergo apoptosis but also causes ganetespib to be released on demand. This inhibits the formation of HSP90, which enhances the mild photothermal/chemotherapy effect. The results confirmed that the combined treatment regimen of mild photothermal therapy (PTT) and chemotherapy showed a better therapeutic efficacy than the individual treatment methods. Therefore, this multimodal nanoparticle can advance the development of drugs for the treatment of malignancies, such as colon cancer, and has prospects for clinical application.

METTL3 recruiting M2-type immunosuppressed macrophages by targeting m6A-SNAIL-CXCL2 axis to promote colorectal cancer pulmonary metastasis

BACKGROUND

The regulatory role of N6-methyladenosine (m6A) modification in the onset and progression of cancer has garnered increasing attention in recent years. However, the specific role of m6A modification in pulmonary metastasis of colorectal cancer remains unclear.

METHODS

This study identified differential m6A gene expression between  primary colorectal cancer and its pulmonary metastases using transcriptome sequencing and immunohistochemistry. We investigated the biological function of METTL3 gene both in vitro and in vivo using assays such as CCK-8, colony formation, wound healing, EDU, transwell, and apoptosis, along with a BALB/c nude mouse model. The regulatory mechanisms of METTL3 in colorectal cancer pulmonary metastasis were studied using methods like methylated RNA immunoprecipitation quantitative reverse transcription PCR, RNA stability analysis, luciferase reporter gene assay, Enzyme-Linked Immunosorbent Assay, and quantitative reverse transcription PCR.

RESULTS

The study revealed high expression of METTL3 and YTHDF1 in the tumors of patients with pulmonary metastasis of colorectal cancer. METTL3 promotes epithelial-mesenchymal transition in colorectal cancer by m6A modification of SNAIL mRNA, where SNAIL enhances the secretion of CXCL2 through the NF-κB pathway. Additionally, colorectal cancer cells expressing METTL3 recruit M2-type macrophages by secreting CXCL2.

CONCLUSION

METTL3 facilitates pulmonary metastasis of colorectal cancer by targeting the m6A-Snail-CXCL2 axis to recruit M2-type immunosuppressive macrophages. This finding offers new research directions and potential therapeutic targets for colorectal cancer treatment.

Prostate cancer-associated transcript 6 (PCAT6) promotes epithelial-mesenchymal transition and stemness and worsens prognosis in patients with colorectal cancer

Approximately 20% of colorectal cancer (CRC) patients are first diagnosed with metastatic colorectal cancer (mCRC) because they develop symptoms at an advanced stage. Despite advancements in treatment, patients with metastatic disease still experience inferior survival rates. Our objective is to investigate the association between long noncoding RNAs (lncRNAs) and prognosis and to explore their role in mCRC. In this study, we find that elevated expression of PCAT6 is independently linked to unfavourable survival outcomes in The Cancer Genome Atlas (TCGA) data, and this finding is further confirmed in CRC samples obtained from Fudan University Shanghai Cancer Center. Cell lines and xenograft mouse models are used to examine the impact of PCAT6 on tumor metastasis. Knockdown of PCAT6 is observed to impede the metastatic phenotype of CRC, as evidenced by functional assays, demonstrating the suppression of epithelial-mesenchymal transition (EMT) and stemness. Our findings show the significance of PCAT6 in mCRC and its potential use as a prognostic biomarker.

The Differential Effect of Senolytics on SASP Cytokine Secretion and Regulation of EMT by CAFs

The tumor microenvironment (TME) plays an essential role in tumor progression and in modulating tumor response to anticancer therapy. Cellular senescence leads to a switch in the cell secretome, characterized by the senescence-associated secretory phenotype (SASP), which may regulate tumorigenesis. Senolytic therapy is considered a novel anticancer strategy that eliminates the deleterious effects of senescent cells in the TME. Here, we show that two different types of senolytic drugs, despite efficiently depleting senescent cells, have opposite effects on cancer-associated fibroblasts (CAFs) and their ability to regulate epithelial-mesenchymal transition (EMT). We found that senolytic drugs, navitoclax and the combination of dasatinib/quercetin, reduced the number of spontaneously senescent and TNF-induced senescent CAFs. Despite the depletion of senescent cells, the combination of dasatinib/quercetin versus navitoclax increased the secretion of the SASP pro-inflammatory cytokine IL-6. This differential effect correlated with the promotion of enhanced migration and EMT in MC38 colorectal cancer cells. Our results demonstrate that some senolytics may have side effects unrelated to their senolytic activity and may promote tumorigenesis. We argue for more careful and extensive studies of the effects of senolytics on various aspects of tumor progression and tumor resistance to therapy before the senolytic strategy is implemented in the clinic.

CircHAS2 activates CCNE2 to promote cell proliferation and sensitizes the response of colorectal cancer to anlotinib

BACKGROUND

Tyrosine kinase inhibitors (TKIs) are crucial in the targeted treatment of advanced colorectal cancer (CRC). Anlotinib, a multi-target TKI, has previously been demonstrated to offer therapeutic benefits in previous studies. Circular RNAs (circRNAs) have been implicated in CRC progression and their unique structural stability serves as promising biomarkers. The detailed molecular mechanisms and specific biomarkers related to circRNAs in the era of targeted therapies, however, remain obscure.

METHODS

The whole transcriptome RNA sequencing and function experiments were conducted to identify candidate anlotinib-regulated circRNAs, whose mechanism was confirmed by molecular biology experiments. CircHAS2 was profiled in a library of patient-derived CRC organoids (n = 22) and patient-derived CRC tumors in mice. Furthermore, a prospective phase II clinical study of 14 advanced CRC patients with anlotinib-based therapy was commenced to verify drug sensitivity (ClinicalTrials.gov identifier: NCT05262335).

RESULTS

Anlotinib inhibits tumor growth in vitro and in vivo by downregulating circHAS2. CircHAS2 modulates CCNE2 activation by acting as a sponge for miR-1244, and binding to USP10 to facilitate p53 nuclear export as well as degradation. In parallel, circHAS2 serves as a potent biomarker predictive of anlotinib sensitivity, both in patient-derived organoids and xenograft models. Moreover, the efficacy of anlotinib inclusion into the treatment regimen yields meaningful clinical responses in patients with high levels of circHAS2. Our findings offer a promising targeted strategy for approximately 52.9% of advanced CRC patients who have high circHAS2 levels.

CONCLUSIONS

CircHAS2 promotes cell proliferation via the miR-1244/CCNE2 and USP10/p53/CCNE2 bidirectional axes. Patient-derived organoids and xenograft models are employed to validate the sensitivity to anlotinib. Furthermore, our preliminary Phase II clinical study, involving advanced CRC patients treated with anlotinib, confirmed circHAS2 as a potential sensitivity marker.

Understanding the role of DNA methylation in colorectal cancer: Mechanisms, detection, and clinical significance

Colorectal cancer (CRC) is one of the deadliest malignancies worldwide, ranking third in incidence and second in mortality. Remarkably, early stage localized CRC has a 5-year survival rate of over 90%; in stark contrast, the corresponding 5-year survival rate for metastatic CRC (mCRC) is only 14%. Compounding this problem is the staggering lack of effective therapeutic strategies. Beyond genetic mutations, which have been identified as critical instigators of CRC initiation and progression, the importance of epigenetic modifications, particularly DNA methylation (DNAm), cannot be underestimated, given that DNAm can be used for diagnosis, treatment monitoring and prognostic evaluation. This review addresses the intricate mechanisms governing aberrant DNAm in CRC and its profound impact on critical oncogenic pathways. In addition, a comprehensive review of the various techniques used to detect DNAm alterations in CRC is provided, along with an exploration of the clinical utility of cancer-specific DNAm alterations.

Hepatic steatosis predicts metachronous liver metastasis in colorectal cancer patients: a nested case-control study and systematic review

Nearly twenty-five percent of colorectal cancer (CRC) patients develop metachronous colorectal liver metastasis (CRLM) after curative surgery. Hepatosteatosis is the most prevalent liver condition worldwide, but its impact on the incidence of metachronous CRLM is understudied. In the present study, we aimed to investigate the predictive value of hepatic steatosis on the development of metachronous CRLM. First, a nested case-control study was conducted, enrolling stage I to III CRC patients in the National Colorectal Cancer Cohort (NCRCC) database. Metachronous CRLM patients and recurrence-free patients were matched via propensity-score matching. Fatty liver was identified based on treatment-naïve CT scans and the degree of hepatic fibrosis was scored. Multivariable analysis was conducted to investigate the association between fatty liver and metachronous CRLM. In our database, a total of 414 patients were included. Metachronous CRLM patients had considerably higher rates of hepatic steatosis (30.9% versus 15.9%, P<0.001) and highly fibrotic liver (11.6% versus 2.9%, P=0.001) compared to recurrence-free patients. Multivariable analysis showed that fatty liver (odds ratios [OR]=1.99, 95% confidence interval [CI] 1.19-3.30, P=0.008) and fibrotic liver (OR=4.27, 95% CI 1.54-11.81, P=0.005) were associated with high risk of metachronous CRLM. Further, a systematic literature review was performed to assess available evidence on the association between hepatosteatosis and development of metachronous CRLM. In the systematic review, 1815 patients were pooled from eligible studies, and hepatic steatosis remained a significant risk factor for metachronous CRLM (OR=1.90, 95% CI 1.35-2.66, P<0.001, I2=25.3%). In conclusion, our data suggest that patients with a steatotic liver and a high fibrosis score at CRC diagnosis have elevated risk of developing metachronous CRLM.

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.

Identification and validation of a novel six-gene signature based on mucinous adenocarcinoma-related gene molecular typing in colorectal cancer

BACKGROUND AND OBJECTIVES

Colorectal mucinous adenocarcinoma (MAC) is a particular pathological type that has yet to be thoroughly studied. This study aims to investigate the characteristics of colorectal MAC-related genes in colorectal cancer (CRC), explore the role of MAC-related genes in accurately classifying CRC, and further construct a prognostic signature.

METHODS

CRC samples were collected from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO). MAC-related differentially expressed genes (DEGs) were analyzed in TCGA samples. Based on colorectal MAC-related genes, TCGA CRC samples were molecularly typed by the non-negative matrix factorization (NMF). According to the molecular subtype characteristics, the RiskScore signature was constructed through univariate Cox, the least absolute shrinkage and selection operator (LASSO), and multivariate Cox regression analyses. Clinical significance in CRC of the RiskScore signature was analyzed. A nomogram was further built based on the RiskScore signature.

RESULTS

From the colorectal MAC-related genes, three distinct molecular subtypes were identified. A RiskScore signature composed of six CRC subtype-related genes (CALB1, MMP1, HOXC6, ZIC2, SFTA2, and HYAL1) was constructed. Patients with high-RiskScores had the worse prognoses. RiskScores led to differences in gene mutation characteristics, antitumor drug sensitivity, and tumor microenvironment of CRC. A nomogram based on the signature was developed to predict the one-, three-, and five-year survival of CRC patients.

CONCLUSION

MAC-related genes were able to classify CRC. A RiskScore signature based on the colorectal MAC-related molecular subtype was constructed, which had important clinical significance for guiding the accurate stratification of CRC patients.

Construction of an immune predictive model and identification of TRIP6 as a prognostic marker and therapeutic target of CRC by integration of single-cell and bulk RNA-seq data

BACKGROUND

Investigations elucidating the complex immunological mechanisms involved in colorectal cancer (CRC) and accurately predicting patient outcomes via bulk RNA-Seq analysis have been notably limited. This study aimed to identify the immune status of CRC patients, construct a prognostic model, and identify prognostic signatures via bulk RNA sequencing (RNA-seq) and single-cell RNA-seq (scRNA-seq).

METHODS

The scRNA-seq data of CRC were downloaded from Gene Expression Omnibus (GEO). The UCSC Xena database was used to obtain bulk RNA-seq data. Differentially expressed gene (DEG), functional enrichment, and random forest analyses were conducted in order to identify core genes associated with colorectal cancer (CRC) that were relevant to prognosis. A molecular immune prediction model was developed using logistic regression after screening features using the least absolute shrinkage and selection operator (LASSO). The differences in immune cell infiltration, mutation, chemotherapeutic drug sensitivity, cellular senescence, and communication between patients who were at high and low risk of CRC according to the predictive model were investigated. The prognostic genes that were closely associated with CRC were identified by random survival forest (RSF) analysis. The expression levels and clinical significance of the hub genes were analyzed in vitro. The LoVo cell line was employed to ascertain the biological role of thyroid hormone receptor-interacting protein 6 (TRIP6).

RESULTS

A total of seven main cell subtypes were identified by scRNA-seq analysis. A molecular immune predictive model was constructed based on the risk scores. The risk score was significantly associated with OS, stage, mutation burden, immune cell infiltration, response to immunotherapy, key pathways, and cell-cell communication. The functions of the six hub genes were determined and further utilized to establish a regulatory network. Our findings unequivocally confirmed that TRIP6 upregulation was verified in the CRC samples. After knocking down TRIP6, cell proliferation, migration, and invasion of LoVo cells were inhibited, and apoptosis was promoted.

CONCLUSIONS

The molecular predictive model reliably distinguished the immune status of CRC patients. We further revealed that TRIP6 may act as an oncogene in CRC, making it a promising candidate for targeted therapy and as a prognostic marker for CRC.

6-O-endosulfatases in tumor metastasis: heparan sulfate proteoglycans modification and potential therapeutic targets

Metastasis is the leading cause of cancer-associated mortality. Although advances in the targeted treatment and immunotherapy have improved the management of some cancers, the prognosis of metastatic cancers remains unsatisfied. Therefore, the specific mechanisms in tumor metastasis need further investigation. 6-O-endosulfatases (SULFs), comprising sulfatase1 (SULF1) and sulfatase 2 (SULF2), play pivotal roles in the post-synthetic modifications of heparan sulfate proteoglycans (HSPGs). Consequently, these extracellular enzymes can regulate a variety of downstream pathways by modulating HSPGs function. During the past decades, researchers have detected the expression of SULF1 and SULF2 in most cancers and revealed their roles in tumor progression and metastasis. Herein we reviewed the metastasis steps which SULFs participated in, elucidated the specific roles and mechanisms of SULFs in metastasis process, and discussed the effects of SULFs in different types of cancers. Moreover, we summarized the role of targeting SULFs in combination therapy to treat metastatic cancers, which provided some novel strategies for cancer therapy.

Intercellular crosstalk between cancer cells and cancer-associated fibroblasts via exosomes in gastrointestinal tumors

Gastrointestinal (GI) tumors are a significant global health threat, with high rates of morbidity and mortality. Exosomes contain various biologically active molecules like nucleic acids, proteins, and lipids and can serve as messengers for intercellular communication. They play critical roles in the exchange of information between tumor cells and the tumor microenvironment (TME). The TME consists of mesenchymal cells and components of the extracellular matrix (ECM), with fibroblasts being the most abundant cell type in the tumor mesenchyme. Cancer-associated fibroblasts (CAFs) are derived from normal fibroblasts and mesenchymal stem cells that are activated in the TME. CAFs can secrete exosomes to modulate cell proliferation, invasion, migration, drug resistance, and other biological processes in tumors. Additionally, tumor cells can manipulate the function and behavior of fibroblasts through direct cell-cell interactions. This review provides a summary of the intercellular crosstalk between GI tumor cells and CAFs through exosomes, along with potential underlying mechanisms.

Salvianolic Acid B Significantly Suppresses the Migration of Melanoma Cells via Direct Interaction with β-Actin

Melanoma is the most aggressive and difficult to treat of all skin cancers. Despite advances in the treatment of melanoma, the prognosis for melanoma patients remains poor, and the recurrence rate remains high. There is substantial evidence that Chinese herbals effectively prevent and treat melanoma. The bioactive ingredient Salvianolic acid B (SAB) found in Salvia miltiorrhiza, a well-known Chinese herbal with various biological functions, exhibits inhibitory activity against various cancers. A375 and mouse B16 cell lines were used to evaluate the main targets and mechanisms of SAB in inhibiting melanoma migration. Online bioinformatics analysis, Western blotting, immunofluorescence, molecular fishing, dot blot, and molecular docking assays were carried out to clarify the potential molecular mechanism. We found that SAB prevents the migration and invasion of melanoma cells by inhibiting the epithelial-mesenchymal transition (EMT) process of melanoma cells. As well as interacting directly with the N-terminal domain of β-actin, SAB enhanced its compactness and stability, thereby inhibiting the migration of cells. Taken together, SAB could significantly suppress the migration of melanoma cells via direct binding with β-actin, suggesting that SAB could be a helpful supplement that may enhance chemotherapeutic outcomes and benefit melanoma patients.

Unveiling the immune symphony: decoding colorectal cancer metastasis through immune interactions

Colorectal cancer (CRC), known for its high metastatic potential, remains a leading cause of cancer-related death. This review emphasizes the critical role of immune responses in CRC metastasis, focusing on the interaction between immune cells and tumor microenvironment. We explore how immune cells, through cytokines, chemokines, and growth factors, contribute to the CRC metastasis cascade, underlining the tumor microenvironment's role in shaping immune responses. The review addresses CRC's immune evasion tactics, especially the upregulation of checkpoint inhibitors like PD-1 and CTLA-4, highlighting their potential as therapeutic targets. We also examine advanced immunotherapies, including checkpoint inhibitors and immune cell transplantation, to modify immune responses and enhance treatment outcomes in CRC metastasis. Overall, our analysis offers insights into the interplay between immune molecules and the tumor environment, crucial for developing new treatments to control CRC metastasis and improve patient prognosis, with a specific focus on overcoming immune evasion, a key aspect of this special issue.

Efficacy and safety of trifluridine/tipiracil (TAS-102) in patients with metastatic colorectal cancer: a systematic review and meta-analysis

OBJECTIVES

The purpose of this meta-analysis is to evaluate the efficacy and safety of TAS-102 in treating metastatic colorectal cancer (mCRC) using the most recent data available.

METHODS

The literature on the efficacy and safety of TAS-102 versus placebo and/or best supportive care (BSC) in mCRC was obtained through a systematic search of PubMed, Embase, and Web of Science databases through January 2023. Identify the included literature and extract pertinent data, such as the overall survival (OS), progression-free survival (PFS), time to treatment failure (TTF), disease control rate (DCR), incidence of adverse events (AEs) and serious adverse events (SAEs).

RESULTS

There were eight eligible articles that included 2903 patients (1964 TAS-102 versus 939 Placebo and/or BSC). In this meta-analysis, TAS-102 treatment resulted in longer OS, PFS, TTF, and higher DCR in patients with mCRC versus placebo and/or BSC. TAS-102 improved OS and PFS in subgroup analyses of mCRC patients with KRAS wild-type and KRAS mutant-type. In addition, TAS-102 did not increase the incidence of serious adverse events.

CONCLUSION

TAS-102 can enhance the prognosis of mCRC patients whose standard therapy has failed, regardless of KRAS mutation status, and its safety is acceptable.

Tumour-associated macrophage-derived DOCK7-enriched extracellular vesicles drive tumour metastasis in colorectal cancer via the RAC1/ABCA1 axis

BACKGROUND

Metastasis accounts for the majority of deaths among patients with colorectal cancer (CRC). Here, the regulatory role of tumour-associated macrophages (TAMs) in CRC metastasis was explored.

METHODS

Immunohistochemical (IHC) analysis of the TAM biomarker CD163 was conducted to evaluate TAM infiltration in CRC. Transwell assays and an ectopic liver metastasis model were established to evaluate the metastatic ability of tumour cells. RNA sequencing (RNA-seq) and liquid chromatography-mass spectrometry (LC-MS) were applied to identify the differentially expressed genes and proteins in CRC cells and in TAM-derived extracellular vesicles (EVs). Cholesterol content measurement, a membrane fluidity assay and filipin staining were performed to evaluate cholesterol efflux in CRC cells.

RESULTS

Our results showed that TAM infiltration is positively correlated with CRC metastasis. TAMs can facilitate the migration and invasion of MC-38 and CT-26 cells via EVs. According to the RNA-seq data, TAM-EVs increase cholesterol efflux and enhance membrane fluidity in CRC cells by regulating ABCA1 expression, thus affecting the motility of CRC cells. Mechanistically, DOCK7 packaged in TAM-EVs can activate RAC1 in CRC cells and subsequently upregulate ABCA1 expression by phosphorylating AKT and FOXO1. Moreover, IHC analysis of ABCA1 in patients with liver-metastatic CRC indicated that ABCA1 expression is significantly greater in metastatic liver nodules than in primary CRC tumours.

CONCLUSIONS

Overall, our findings suggest that DOCK7 delivered via TAM-EVs could regulate cholesterol metabolism in CRC cells and CRC cell metastasis through the RAC1/AKT/FOXO1/ABCA1 axis. DOCK7 could thus be a new therapeutic target for controlling CRC metastasis.

From the Colon to the Liver: How Gut Microbiota May Influence Colorectal Cancer Metastatic Potential

The gut microbiota's influence on human tumorigenesis is a burning topic in medical research. With the new ontological perspective, which considers the human body and its pathophysiological processes as the result of the interaction between its own eukaryotic cells and prokaryotic microorganisms living in different body niches, great interest has arisen in the role of the gut microbiota on carcinogenesis. Indeed, dysbiosis is currently recognized as a cancer-promoting condition, and multiple molecular mechanisms have been described by which the gut microbiota may drive tumor development, especially colorectal cancer (CRC). Metastatic power is undoubtedly one of the most fearsome features of neoplastic tissues. Therefore, understanding the underlying mechanisms is of utmost importance to improve patients' prognosis. The liver is the most frequent target of CRC metastasis, and new evidence reveals that the gut microbiota may yield an effect on CRC diffusion to the liver, thus defining an intriguing new facet of the so-called "gut-liver axis". In this review, we aim to summarize the most recent data about the microbiota's role in promoting or preventing hepatic metastasis from CRC, highlighting some potential future therapeutic targets.

A perspective on emerging therapies in metastatic colorectal cancer: Focusing on molecular medicine and drug resistance

The majority of cancer cases are colorectal cancer, which is also the second largest cause of cancer-related deaths worldwide. Metastasis is the leading cause of death for patients with colorectal cancer. Metastatic colorectal cancer incidence are on the rise due to a tiny percentage of tumors developing resistant to medicines despite advances in treatment tactics. Cutting-edge targeted medications are now the go-to option for customized and all-encompassing CRC care. Specifically, multitarget kinase inhibitors, antivascular endothelial growth factors, and epidermal growth factor receptors are widely used in clinical practice for CRC-targeted treatments. Rare targets in metastatic colorectal cancer are becoming more well-known due to developments in precision diagnostics and the extensive use of second-generation sequencing technology. These targets include the KRAS mutation, the BRAF V600E mutation, the HER2 overexpression/amplification, and the MSI-H/dMMR. Incorporating certain medications into clinical trials has significantly increased patient survival rates, opening new avenues and bringing fresh viewpoints for treating metastatic colorectal cancer. These focused therapies change how cancer is treated, giving patients new hope and better results. These markers can significantly transform and individualize therapy regimens. They could open the door to precisely customized and more effective medicines, improving patient outcomes and quality of life. The fast-growing body of knowledge regarding the molecular biology of colorectal cancer and the latest developments in gene sequencing and molecular diagnostics are directly responsible for this advancement.

Remodeling of intestinal epithelium derived extracellular vesicles by nanoparticles and its bioeffect on tumor cell migration

Extracellular vesicles (EVs) are an effective tool to elucidate the bioeffect of nanomedicines. To clarify the interaction between oral nanomedicines and intestinal epithelial cells, and their bioeffects on downstream cells, polystyrene nanoparticles (PS-NPs) with different sizes were used as the model nanomedicines for EVs induction. Caco-2 monolayers were selected as the model of the intestinal epithelium and DLD-1 cells as the colorectal cancer model proximal to the gastrointestinal tract. It is found that compared with small-sized (25, 50, 100 nm) PS-NPs, the large-sized (200 and 500 nm) exhibited higher co-localization with multivesicular bodies and lysosomes, and more significant reduction of lysosomal acidification in Caco-2 cells. Proteomic and western-blotting analysis showed that the EVs remodeled by large-sized PS-NPs exhibited a higher extent of protein expression changes. The in vitro and in vivo signaling pathway detection in DLD-1 cells and DLD-1 cell xenograft nude mice showed that the remodeled EVs by large-sized PS-NPs inhibited the activation of multiple signaling pathways including Notch3, EGF/EGFR, and PI3K/Akt pathways, which resulted in the inhibition of tumor cell migration. These results primarily clarify the regulation mechanisms of nanomedicines-EVs-receptor cells chain. It provides a new perspective for the rational design and bioeffect evaluation of oral drug nanomaterials and sets up the fundamental knowledge for novel tumor therapeutics in the future.

Mechanisms of Actinidia chinensis Planch in treating colon cancer based on the integration of network pharmacology, molecular docking, and experimental verification

BACKGROUND

As an anticancer Chinese herbal medicine, the effective components and mechanism of Actinidia chinensis Planch (ACP, Tengligen) in the treatment of colon cancer are still unclear. In the present study, the integration of network pharmacology, molecular docking, and cell experiments was employed to study the effective mechanism of ACP against colon cancer.

METHODS

The Venn diagram and STRING database were used to construct the protein-protein interaction network (PPI) of ACP-colon cancer, and further topological analysis was used to obtain the key target genes of ACP in colon cancer. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were used to visualize the related functions and pathways. Molecular docking between key targets and compounds was determined using software such as AutoDockTools. Finally, the effect of ACP on CT26 cells was observed in vitro.

RESULTS

The study identified 40 ACP-colon key targets, including CASP3, CDK2, GSK3B, and PIK3R1. GO and KEGG enrichment analyses found that these genes were involved in 211 biological processes and 92 pathways, among which pathways in cancer, PI3K-Akt, p53, and cell cycle might be the main pathways of ACP against colon cancer. Molecular docking verified that the key components of ACP could stably bind to the corresponding targets. The experimental results showed that ACP could inhibit proliferation, induce apoptosis, and downregulate the phosphorylation of PIK3R1, Akt, and GSK3B in CT26 cells.

CONCLUSION

ACP is an anti-colon cancer herb with multiple components, and involvement of multiple target genes and signaling pathways. ACP can significantly inhibit proliferation and induce apoptosis of colon cancer cells, which may be closely related to the regulation of PI3K/AKT/GSK3B signal transduction.

The deubiquitinase USP10 mediates crosstalk between the LKB1/AMPK axis and Wnt/β-catenin signaling in cancer

The liver kinase B1 (LKB1)/AMP-activated protein kinase (AMPK) axis pivotally controls cell metabolism and suppresses abnormal growth in various cancers. Wnt/β-catenin is a frequently dysregulated signaling pathway that drives oncogenesis. Here, we discovered a crosstalk mechanism between the LKB1/AMPK axis and Wnt/β-catenin signaling. Activated AMPK phosphorylates the deubiquitinase USP10 to potentiate the deubiquitination and stabilization of the key scaffold protein Axin1. This phosphorylation also strengthens the binding between USP10 and β-catenin and supports the phase transition of β-catenin. Both processes suppress Wnt/β-catenin amplitude in parallel and inhibit colorectal cancer growth in a clinically relevant manner. Collectively, we established a crosstalk route by which LKB1/AMPK regulates Wnt/β-catenin signaling in cancer. USP10 acts as the hub in this process, thus enabling LKB1/AMPK to suppress tumor growth via regulation of both metabolism and cell proliferation.

m6A modified BACE1-AS contributes to liver metastasis and stemness-like properties in colorectal cancer through TUFT1 dependent activation of Wnt signaling

BACKGROUND

Liver metastasis is one of the most important reasons for high mortality of colorectal cancer (CRC). Growing evidence illustrates that lncRNAs play a critical role in CRC liver metastasis. Here we described a novel function and mechanisms of BACE1-AS promoting CRC liver metastasis.

METHODS

qRT-PCR and in situ hybridization were performed to examine the BACE1-AS level in CRC. IGF2BP2 binding to m6A motifs in BACE1-AS was determined by RIP assay and S1m-tagged immunoprecipitation. Transwell assay and liver metastasis mice model experiments were performed to examine the metastasis capabilities of BACE1-AS knockout cells. Stemness-like properties was examined by tumor sphere assay and the expression of stemness biomarkers. Microarray data were acquired to analyze the signaling pathways involved in BACE1-AS promoting CRC metastasis.

RESULTS

BACE1-AS is the most up-regulated in metastatic CRC associated with unfavorable prognosis. Sequence blast revealed two m6A motifs in BACE1-AS. IGF2BP2 binding to these two m6A motifs is required for BACE1-AS boost in metastatic CRC. m6A modified BACE1-AS drives CRC cells migration and invasion and liver metastasis both in vitro and in vivo. Moreover, BACE1-AS maintains the stemness-like properties of CRC cells. Mechanically, BACE1-AS promoted TUFT1 expression by ceRNA network through miR-214-3p. CRC patients with such ceRNA network suffer poorer prognosis than ceRNA-negative patients. Depletion of TUFT1 mimics BACE1-AS loss. BACE1-AS activated Wnt signaling pathway in a TUFT1 dependent manner. BACE1-AS/miR-214-3p/TUFT1/Wnt signaling regulatory axis is essential for CRC liver metastasis. Pharmacologic inhibition of Wnt signaling pathway repressed liver metastasis and stemness-like features in BACE1-AS over-expressed CRC cells.

CONCLUSION

Our study demonstrated BACE1-AS as a novel target of IGF2BP2 through m6A modification. m6A modified BACE1-AS promotes CRC liver metastasis through TUFT1 dependent activation of Wnt signaling pathway. Thus, targeting BACE1-AS and its downstream Wnt signaling pathways may provide a new opportunity for metastatic CRC intervention and treatment.

Expression of an oxysterol-metabolizing enzyme in colorectal cancer and its relation to tumor cell behavior and prognosis

Oxysterols and oxysterol-metabolizing enzymes have been implicated in the pathogenesis of various cancers. However, the distinct function of the oxysterol-metabolizing enzyme cytochrome P450 family 39 Subfamily A Member 1 (CYP39A1) in colorectal cancer (CRC) remains unclear. The aims of the current study were to evaluate whether CYP39A1 affects the oncogenic behaviors of CRC cells and to investigate the prognostic value of its expression in CRC. A CYP39A1 small-interfering RNA was used to block CYP39A1 gene expression in DLD1 and SW480 cells. The expression of CYP39A1 in CRC tissues was investigated by immunohistochemistry. Tumor angiogenesis and lymphangiogenesis were assessed by CD34 and D2-40 immunohistochemical staining, respectively. CYP39A1 knockdown inhibited tumor cell migration and invasion in DLD1 and SW480 cells. Angiogenesis was also inhibited through the decreased expression of vascular endothelial growth factor (VEGF)-A and hypoxia-inducible factor (HIF)-1α, and angiostatin and endostatin expression increased. In addition, CYP39A1 knockdown inhibited the lymphangiogenesis by decreasing the expression of VEGF-C. CYP39A1 expression was increased in CRC tissues compared with normal colorectal mucosa. CYP39A1 expression was associated with tumor stage, depth of invasion, lymph node metastasis, distant metastasis, and poor survival. The microvessel and lymphatic vessel density values of CYP39A1-positive tumors were significantly higher than those of CYP39A1-negative tumors. These results indicate that CYP39A1 is associated with tumor progression by influencing tumor cell angiogenesis and lymphangiogenesis in CRC.

Role of Epithelial to Mesenchymal Transition in Colorectal Cancer

The epithelial-mesenchymal transition (EMT) is a cellular reprogramming process that occurs during embryonic development and adult tissue homeostasis. This process involves epithelial cells acquiring a mesenchymal phenotype. Through EMT, cancer cells acquire properties associated with a more aggressive phenotype. EMT and its opposite, mesenchymal-epithelial transition (MET), have been described in more tumors over the past ten years, including colorectal cancer (CRC). When EMT is activated, the expression of the epithelial marker E-cadherin is decreased and the expression of the mesenchymal marker vimentin is raised. As a result, cells temporarily take on a mesenchymal phenotype, becoming motile and promoting the spread of tumor cells. Epithelial-mesenchymal plasticity (EMP) has become a hot issue in CRC because strong inducers of EMT (such as transforming growth factor β, TGF-β) can initiate EMT and regulate metastasis, microenvironment, and immune system resistance in CRC. In this review, we take into account the significance of EMT-MET in CRC and the impact of the epithelial cells' plasticity on the prognosis of CRC. The analysis of connection between EMT and colorectal cancer stem cells (CCSCs) will help to further clarify the current meager understandings of EMT. Recent advances affecting important EMT transcription factors and EMT and CCSCs are highlighted. We come to the conclusion that the regulatory network for EMT in CRC is complicated, with a great deal of crosstalk and alternate paths. More thorough research is required to more effectively connect the clinical management of CRC with biomarkers and targeted treatments associated with EMT.

Tumor budding and the prognosis of patients with metastatic colorectal cancer: a meta-analysis

PURPOSE

Tumor budding has been suggested to be associated with poor survival of patients with colorectal cancer (CRC). However, it is unclear whether the association remains in patients with metastatic CRC (mCRC). The aim of the systematic review and meta-analysis was to investigate the potential predictive role of tumor budding for the prognosis of patients with mCRC.

METHODS

PubMed, Embase, Cochrane Library, and Web of Science were searched for relevant observational studies comparing the survival outcomes between mCRC patients with high versus low tumor budding. Data collection, literature searching, and statistical analysis were conducted independently by two authors. Using a heterogeneity-incorporating random-effects model, the results were pooled.

RESULTS

In this meta-analysis, 1503 patients from nine retrospective cohort studies were included. Pooled results showed that compared to those with low tumor budding, mCRC patients with high tumor budding were associated with a poor progression-free survival (hazard ratio (HR), 1.65; 95% confidence interval (CI), 1.31 to 2.07, p < 0.001; I2 = 30%) and overall survival (HR, 1.60; 95% CI, 1.33 to 1.93; p < 0.001; I2 = 0%). Influencing analysis by excluding one study at a time showed consistent results (p all < 0.05). Subgroup analyses showed consistent results in tumor budding evaluated from the primary cancer and metastases, in studies with a high tumor budding defined as ≥ 10 or 15 and ≥ 5 buds/HPF and in studies analyzed with univariate and multivariate regression models (p for subgroup difference all > 0.05).

CONCLUSION

A high-degree tumor budding may be associated with poor prognosis in patients with mCRC.