Therapeutic landscape and future direction of metastatic colorectal cancer

Durable response to third-line combination therapy in a metastatic colorectal cancer patient with BRAF V600E mutation: A case report

In metastatic colorectal cancer (mCRC), the BRAFV600E mutation subtype is one of the subtypes with the worst prognosis. The long-term abnormal activation of multiple signaling pathways caused by the BRAF V600E mutation is closely related to the formation of BRAF inhibitor resistance and drug-resistant tumor cell subpopulations. These factors significantly impact the survival and prognosis of CRC patients. Therefore, treating mCRC patients with the BRAFV600E mutation, particularly in later stages, is challenging. We reported a case of an mCRC patient with the BRAF V600E mutation in the primary and metastatic tumors. After the failure of second-line treatment, this patient received a combination therapy including immunotherapy (tislelizumab), radiotherapy, and targeted therapy (fruquintinib). Through comprehensive imaging evaluations and continuous monitoring of tumor markers, we were astonished to observe that the patient has achieved and maintained a complete response (CR) for over 12 months. This case supports the efficacy of combination therapy in mCRC patients with the BRAF V600E mutation.

Comparative efficacy of cetuximab combined with FOLFOX or CAPEOX in first-line treatment of RAS/BRAF wild-type metastatic colorectal cancer: a multicenter case-control study

FOLFOX combined with cetuximab is a recommended first-line treatment regimen for RAS/BRAF wild-type metastatic colorectal cancer (mCRC). CAPEOX combined with cetuximab differs from the FOLFOX regimen by using oral capecitabine instead of continuous infusion of fluorouracil, offering greater convenience and cost-effectiveness with higher patient acceptance. However, the comparative efficacy of these two regimens remains debatable, necessitating further evidence to explore any differences in their efficacy. This study collected medical records of mCRC patients who were treated with CAPEOX or FOLFOX combined with cetuximab from 1 October 2021 to 16 October 2023 at Harbin Medical University Cancer Hospital and the First Hospital of Shanxi Medical University. Eligible patients were selected based on inclusion criteria and followed up through the hospital's follow-up system and telephone interviews. Kaplan-Meier survival analysis and Cox proportional hazards regression analysis were used to assess patients' progression-free survival (PFS) and overall survival (OS). A total of 71 eligible patients were enrolled in this study; 43 patients received CAPEOX combined with cetuximab (Group A, n  = 43), and 28 patients received FOLFOX combined with cetuximab (Group B, n  = 28). The two groups achieved similar median PFS (mPFS) and median OS (mOS), with mPFS of 18 months and 12 months, respectively ( P  = 0.23), and mOS of 33 months and 20 months, respectively ( P  = 0.21), with no statistically significant differences. The results of this study demonstrated that CAPEOX combined with cetuximab is an equally viable option for first-line treatment of RAS/BRAF wild-type mCRC as FOLFOX combined with cetuximab.

Understanding the cellular and molecular heterogeneity in colorectal cancer through the use of single-cell RNA sequencing

The very prevalent nature, genetic variability, and intricate tumor microenvironment (TUME) of colorectal cancer (COREC) are its defining features. In order to better understand the molecular and cellular make-up of COREC, this work used single-cell RNA sequencing (SRNAS) to isolate and characterize important cell types as well as their interactions within the TUME. Our analysis of 51,204 cells yielded six distinct types: epithelial, fibroblast, endothelial, T&NK, B, and myeloid. C3 B cells were shown to be the most active in immunological regulation, according to chemokine signaling study, which was one of seven clusters of B cells that were thoroughly subtyped. The examination of copy number variation (CONUV) revealed a great deal of genetic variability, especially in epithelial cells. We traced the activity of three key transcription factor clusters (M1, M2, and M3) across all B cell subtypes using transcription factor analysis. We created a predictive model that correctly sorts patients according to survival results by using marker genes from C3 B cells. In addition, the relationship between genetic changes and the immune system was better understood by tumor mutational burden (TUMUB) and immune infiltration studies. Our research sheds light on the genetic complexity and cellular variety of COREC, which in turn opens up new possibilities for targeted treatments and individualized approaches to patient care.

Using bioinformatics methods to elucidate fatty acid-binding protein 4 as a potential biomarker for colon adenocarcinoma

BACKGROUND

Colon adenocarcinoma (COAD) ranks second in terms of cancer-related deaths. We found that fatty acid-binding protein 4 (FABP4), which is related to cell adhesion and immunity, affects the occurrence and development of COAD. This study focused on the possibility of using FABP4 as a biomarker for COAD and constructed a nomogram for predicting the survival of COAD patients.

AIM

To verify the possibility of using FABP4 as a biomarker for COAD.

METHODS

A total of 453 COAD tissue samples, along with 41 normal tissue samples, were obtained from The Cancer Genome Atlas database. The difference in FABP4 expression between COAD tissues and normal tissues was analyzed, and the results were verified by immunohistochemistry. The WGCNA algorithm links FABP4 expression with an enrichment analysis and with immune cell infiltration pathways. The biological functions of FABP4 and its coexpressed genes were explored through enrichment analyses. The ESTIMATE, CIBERSORT and ssGSEA methods were used for the immune infiltration analysis. Finally, risk scores were calculated by a Cox analysis. A nomogram was constructed by combining risk scores with routine clinicopathological factors. We assessed the accuracy of survival predictions based on the C-index. The C-index ranges from 0.5 to 1.0, and in general, a C-index value greater than 0.65 indicates a reasonable estimate. The results were validated using the Gene Expression Omnibus (GEO) database.

RESULTS

FABP4 was significantly differentially expressed in COAD. It is a promising auxiliary biomarker for screening and diagnosis. Enrichment analyses suggested that FABP4 may influence the invasion and progression of COAD through cell adhesion. The immunological analysis revealed that FABP4 expression in COAD was significantly positively correlated with immune cell infiltration. Moreover, a nomogram to predict the survival of COAD patients was successfully constructed by integrating the calculated risk scores of 15 candidate genes and routine clinicopathological factors. This nomogram could effectively predict 1-year, 3-year, and 5-year survival (C-index = 0.786) and was verified (C-index = 0.73).

CONCLUSION

This study established FABP4 as an effective biomarker for screening, assisting in the diagnosis and determining the prognosis.

Lipopolysaccharide Induces Resistance to CAR-T Cell Therapy of Colorectal Cancer Cells through TGF-β-Mediated Stemness Enhancement

Chimeric antigen receptor-T (CAR-T) cell therapy is a cellular immunotherapy that has emerged in recent years, and increasing studies showed that therapeutic resistance to CAR-T cell therapy presents in colorectal cancer patients. Lipopolysaccharide (LPS), a component of the cell wall of Gram-negative bacteria, is known to preserve a high concentration in the colon. Whether LPS is a contributing factor to the development of resistance in colorectal cancer cells against CAR-T cell therapy remains unclear. For in vivo experiments, colorectal cancer cells COLO205 were pretreated with LPS for 24 h and then were injected into nude mice through the tail vein, followed by CAR-T cells transplantation one day later. Later, the number of tumors in the lung tissues of the mice was observed. The in vitro experiments were performed on COLO205 cells, which were treated with LPS for 24 h. The effect of LPS on the stemness of COLO205 and SW620 cells was observed by using the colony formation assay and spheroidization experiments. The effect of LPS on the expression of stemness-related genes, including CD44, SOX2, and NANOG, was observed by qRT-PCR assay, Western blotting assay, and immunofluorescence staining. Inhibitors of TGF-β and the MYD88 inhibitor were used to study the mechanisms by which LPS induces the stemness enhancement and resistance to CAR-T cell therapy of COLO205 cells. The correlation between MYD88 and TGFB1, as well as the correlation between TGFB1 and stemness-related genes was analyzed using the TCGA database. Both the in vivo assay of nude mice and the in vitro assay showed that LPS pretreatment could induce resistance to CAR-T cell therapy of colorectal cancer cells. LPS could enhance COLO205 and SW620 cells stemness presented by upregulation of CD44, SOX2, and NANOG. The reverse interfering assay using the TGF-β inhibitor indicated that the autosecretion of TGF-β induced by LPS played a critical role in the stemness enhancement of colorectal cancer cells. The TCGA database analysis revealed a strong positive correlation between MYD88 and TGFB1. Additionally, TGFB1 has been found to upregulate the expression of genes associated with stemness. Further mechanism studies showed that the TLR4/MYD88 pathway medicates LPS-induced TGF-β expression. Our results suggested that LPS-induced resistance to CAR-T cell therapy of colorectal cancer cells through stemness enhancement. TLR4/MYD88 signal pathway-dependent TGF-β expression was involved in stemness enhancement and CAR-T cell therapy resistance. In conclusion, our findings help us to understand the underlying mechanisms of CAR-T cell therapy resistance and indicate that inhibitors of TGF-β and MYD88 are promising targeting candidates to promote a therapeutic effect of CAR-T cell therapy in colorectal cancer in the clinic.

EGF-Upregulated lncRNA ESSENCE Promotes Colorectal Cancer Growth through Stabilizing CAD and Ferroptosis Defense

Epidermal growth factor receptor/mitogen-activated protein kinase (EGFR/MAPK) signaling is highly activated in various types of cancer. The long noncoding RNAs induced by this pathway and their roles in colorectal cancer (CRC) have not been fully elucidated. In this study, based on the profiling of long noncoding RNAs triggered by EGFR/MAPK signaling, we identified that ESSENCE (EGF [epidermal growth factor] Signal Sensing CAD's Effect; ENST00000415336), which is mediated by the transcription factor early growth response factor 1, functions as a potent oncogenic molecule that predicts poor prognosis in CRC. Mechanistically, ESSENCE directly interacts with carbamoyl-phosphate synthetase 2, aspartate transcarbamylase, and dihydroorotase (CAD) and competitively attenuates CAD degradation mediated by its newly discovered E3 ligase KEAP1, thereby suppressing ferroptosis and promoting CRC progression. Importantly, combinational treatment of the mitogen-activated extracellular signal-regulated kinase inhibitor selumetinib and ferroptosis inducer sulfasalazine synergistically suppresses ESSENCE-high CRC in a patient-derived xenograft mouse model. Taken together, these findings demonstrate the crucial role of ESSENCE in mediating CRC progression by regulating CAD stabilization and suggest a therapeutic strategy of targeting the ESSENCE-CAD axis in CRC.

Neoadjuvant chemotherapy combined with bevacizumab for resectable colorectal liver metastasis with risk factors for recurrence: a multicenter real-world study

Background

Currently, guidelines prohibit the addition of targeted drugs in neoadjuvant chemotherapy (NAC) for initially resectable colorectal liver metastasis (CRLM).

Objective

Nevertheless, efficacy data of NAC combined with bevacizumab (Bev) for initially resectable CRLM with risk factors for recurrence (RFR) are lacking.

Designs

We conducted a multicenter real-world cohort study to retrospectively analyze the efficacy and feasibility of NAC combined with Bev for CRLM with RFR.

Methods

The patients were divided into the NAC alone group and NAC combined with the Bev group. We designated progression-free survival (PFS), objective response rate (ORR), and overall survival (OS) as the outcomes. Kaplan-Meier, Cox proportional hazards regression models, and subgroup analysis were utilized. RFR was a clinical risk score of 3-5. Subgroup analysis was applied to explore which subgroup was more suitable for NAC combined with Bev.

Results

Between 2015 and 2020, this multicenter real-world study encompassed 335 CRLM patients from six medical centers who underwent curative hepatectomy following NAC. Two hundred seventeen patients were in the NAC alone group, and 118 received NAC combined with Bev. The NAC alone group exhibited an ORR of 51.15%, compared to 66.95% in the NAC combined with Bev (p = 0.005). The R0 resection rates achieved 91.71% for the NAC alone group and 94.92% for the NAC combined with Bev (p = 0.276). Three-year PFS rate was 27.6% for NAC alone and 41.5% for the NAC combined with the Bev group (p = 0.006). Furthermore, the 3-year OS was calculated to be 57.0% for the NAC alone and 66.7% for the NAC combined with Bev patients (p = 0.079).

Conclusion

For initially resectable CRLM patients with RFR, NAC combined with Bev exhibited a higher ORR and longer PFS.

Chinese clinical trial registry

ChiCTR2400082966.

Protein arginine methyltransferase 6 enhances immune checkpoint blockade efficacy via the STING pathway in MMR-proficient colorectal cancer

BACKGROUND

The emergence of immunotherapy has revolutionized the paradigm of cancer treatment with immune checkpoint blockades (ICB) in solid cancers, including colorectal cancer (CRC). However, only a small subset of CRC patients harboring deficient mismatch repair (dMMR) or microsatellite instability-high (MSI-H) benefits from ICB therapy. A very limited response to ICB therapy has been achieved in MMR-proficient CRC, representing a significant challenge limiting the clinical application of immunotherapy. MMR is the critical DNA repair pathway that maintains genomic integrity by correcting DNA mismatches, which is mediated by the MutSα or MutSβ complex consisting of MSH2 with MSH6 and MSH3, respectively. Given that MMR status directs effective immune response, we sought to determine whether targeting MMR capacity boosts ICB efficacy.

METHODS

Azoxymethane/dextran sodium sulfate (AOM/DSS)-induced CRC and xenograft model were used to evaluate the function of PRMT6 and response to PRMT6 inhibitor EPZ020411 and combination therapy of PD1 and EPZ020411. Biochemical assays were performed to elucidate the underlying mechanism of PRMT6-mediated MSH2 methylation and immune evasion.

RESULTS

We have identified PRMT6 as a crucial regulator of MMR capacity via MSH2 dimethylation at R171 and R219. Such a modification abrogates its MMR capacity and prevents the recruitment of MSH3 and MSH6. PRMT6 loss or inhibition triggers cytosolic DNA accumulation and cGAS-STING signaling activation, leading to enhanced immune response in PRMT6-deficient colon tumors or xenografts. Pharmacological inhibition of PRMT6 using EPZ020411 promotes mutagenesis and destabilizes MutSα or MutSβ assembly, and prolonged EPZ020411 exposure maintains an MSI-like phenotype in microsatellite stability (MSS) cells. EPZ020411 treatment sensitizes ICB efficacy of MSS cells, but not MSI cells in vivo. Similar effects have been observed in MSS colon tumors induced by AOM/DSS.

CONCLUSIONS

Our study provides a preclinical proof of concept to overcome resistance to immunotherapy by targeting PRMT6 in CRC with MSS.

Precision medicine in colorectal cancer: genomics profiling and targeted treatment

Precision medicine has revolutionized the treatment of colorectal cancer by enabling a personalized approach tailored to each patient's unique genetic characteristics. Genomic profiling allows for the identification of specific mutations in genes such as KRAS, BRAF, and PIK3CA, which play a crucial role in cell signaling pathways that regulate cell proliferation, apoptosis, and differentiation. This information enables doctors to select targeted therapies that inhibit specific molecular pathways, maximizing treatment effectiveness and minimizing side effects. Precision medicine also facilitates adaptive monitoring of tumor progression, allowing for adjustments in therapy to maintain treatment effectiveness. While challenges such as high costs, limited access to genomic technology, and the need for more representative genomic data for diverse populations remain, collaboration between researchers, medical practitioners, policymakers, and the pharmaceutical industry is crucial to ensure that precision medicine becomes a standard of care accessible to all. With continued advances and support, precision medicine has the potential to improve treatment outcomes, reduce morbidity and mortality rates, and enhance the quality of life for colorectal cancer patients worldwide.

A novel anti-HER2/EGFR bispecific antibody-drug conjugate demonstrates promising antitumor efficacy and overcomes resistance to HER2- or EGFR-targeted ADCs

HER2 and EGFR are frequently co-expressed in various tumors. While antibody-drug conjugates (ADCs) targeting HER2, such as T-DM1 and T-Dxd, have shown remarkable antitumor effects in clinical responses, their effectiveness is constrained by drug resistance. EGFR amplification or high expression is one of the factors that lead to resistance against HER2-targeted ADCs. Likewise, the amplification of HER2 may lead to the development of resistance to EGFR-targeted therapies. To overcome these challenges, we, therefore, developed a bispecific antibody (B2C4) that targets HER2 and EGFR. B2C4 exhibited strong binding affinity and internalization activity in tumor cells with high expression of HER2 and EGFR, as well as in those with high expression of either target. B2C4 was then conjugated with vc-MMAE to create a bispecific ADC (B2C4-MMAE) with an average DAR of 4.05. By effectively engaging both arms of the bispecific ADC, B2C4-MMAE demonstrated significant antitumor activity in tumor cells and animal models that were unresponsive HER2- or EGFR-targeted ADCs. B2C4-MMAE could serve as an alternative therapeutic option for tumors that are resistant to single-target treatments. Additionally, B2C4-MMAE exhibited potential in treating tumors resistant to T-Dxd, underscoring its promise as a treatment for challenging cases.

Construction of hot tumor classification models in gastrointestinal cancers

BACKGROUND

Gastrointestinal (GI) cancers account for more than one-third of cancer-related mortality, and the prognosis for late-stage patients remains poor. Immunotherapy has been proven to extend the survival of patients at advanced stages; however, challenges persist in patient selection and overcoming drug resistance. Tumor-infiltrating lymphocytes (TILs) and tertiary lymphoid structures (TLS) in the tumor microenvironment (TME) have been found to be associated with anti-tumor immune responses. 'Hot tumors' with high levels of infiltration tend to respond better to immune checkpoint inhibitor (ICI) therapy, making them potential biomarkers for ICI treatment.

METHODS

To explore potential biomarkers for predicting immunotherapy response and prognosis in GI cancers, we downloaded the gene expression profiles of seven GI cancers from The Cancer Genome Atlas (TCGA) database and characterized their TME, classifying the samples into hot/cold tumor subgroups. Furthermore, we developed a computational framework to construct cancer-specific hot tumor classification models with only a few genes. External independent datasets and qPCR experiments were used to verify the performance of our few-gene models.

RESULTS

We constructed cancer-specific few-gene models to identify hot tumors for GI cancers with only two to nine genes. The results showed that B cells are important for hot tumor determination, and the identified hot tumors are significantly associated with TLS. They not only overexpress TLS marker genes but are also associated with the presence of TLS in whole-slide images. Further, a two-gene qPCR model was developed to effectively distinguish between hot and cold tumor subgroups in cholangiocarcinoma, providing an opportunity for stratifying patients with hot tumors in clinical settings.

CONCLUSIONS

In conclusion, our established few-gene models, which can be easily integrated into clinical practice, can distinguish hot and cold tumor subgroups, and may serve as potential biomarkers for predicting ICI response.

Regulatory function of endoplasmic reticulum stress in colorectal cancer: Mechanism, facts, and perspectives

Colorectal cancer (CRC) is an exceedingly common and profoundly impactful malignancy of the digestive system, posing a grave threat to human health. Endoplasmic reticulum stress (ERS) is an intracellular biological reaction that mobilizes the unfolded protein response (UPR) to tackling dysregulation in protein homeostasis. This process subtly modulates the cell to either restore normal cellular function or steer it towards apoptosis. The high metabolic demands of CRC cells sculpt a rigorous tumor microenvironment (TME), compelling CRC cells to experience ERS. Adaptive responses induced by mild ERS furnish the necessary conditions for the survival of CRC cells, whereas the cell death mechanisms triggered by sustained ERS could be considered a prospective strategy for cancer therapy. Considering the complex regulation of ERS in cancer development, this article offers a comprehensive review of the molecular mechanisms through which ERS influences CRC fate. It provides crucial insights for exploring the role of ERS in the occurrence and progression of CRC, laying a new theoretical foundation for devising precise therapeutic strategies targeting ERS. Furthermore, by synthesizing extensive clinical and preclinical studies, we delve into therapeutic strategies targeting ERS, including the potential of targeting ERS in immunotherapy, the utilization of native compounds, advancements in proteasome inhibitors, and the potential synergies of these strategies with traditional chemotherapy agents and emerging therapeutic approaches.

Trypsin-instructed bioactive peptide nanodrugs with cascading transformations to improve chemotherapy against colon cancer

Chemotherapy remains an effective treatment for colon cancer but is hampered by its limited response rate. Bioactive peptides, marked with intracellular transformations, have been reported as an effective approach to boosting chemotherapeutic activity. Herein, a promising trypsin-responsive bioactive peptide-based nanodrug is constructed, which could significantly prolong the drug retention time in vivo by cascading transformations and improve chemotherapeutic efficacy. Initially, 1-Pept co-assembles with Dox into a few nanofibers called 1-Pept/Dox NFs, inducing an enhanced cellular uptake via caveolae-mediated endocytosis by avoiding lysosomal degradation and further promoting perinuclear transportation, thus enlarging the drug efficacy in target areas. After nanofiber disassembly, the released 1-Pept converts into Pept under the catalysis of intracellular overexpressed trypsin, which then reassembles into denser Pept NFs, inducing a cascade of effects including disruption of the cytoskeleton, mitochondrial dysfunction, and activation of caspase-3. By the synergism of Pept NFs and Dox, caspase-3 can be further activated, and cause greater damage to nuclear, thereby leading to tumor ablation. As the first example of employing trypsin-mediated nanodrugs with cascading transformations to promote chemotherapeutic activity, this work promises a strategy for novel therapies for efficiently combating colon cancer.

Localized Drug Delivery in Different Gastrointestinal Cancers: Navigating Challenges and Advancing Nanotechnological Solutions

Different types of cancers affect the gastrointestinal tract (GIT), starting from the oral cavity and extending to the colon. In general, most of the current research focuses on the systemic delivery of the therapeutic agents, which leads to undesired side effects and a limited enhancement in the therapeutic outcomes. As a result, localized delivery within gastrointestinal (GI) cancers is favorable in overcoming these limitations. However, the localized delivery via oral administration faces many challenges related to the complex structure of GIT (varied pH levels and transit times) as well as the harsh environment within tumor cells (hypoxia, efflux pumps, and acidity). To overcome these obstacles, nano-drug delivery systems (NDDs) have been designed and proved their potential by exploiting these challenges in favor of offering a specific delivery to the desired target. The current review begins with an overview of different GI cancers and their impact globally. Then, it discusses the current treatment approaches and their corresponding limitations. Additionally, the different challenges associated with localized drug delivery for GI cancers are summarized. Finally, the review discusses in detail the recent therapeutic and diagnostic applications of NDDs that have been conducted in oral, esophageal, gastric, colon, and liver cancers, aiming to offer valuable insights into the current and future state of utilizing NDDs for the local treatment of GI cancers.

Discussion on the optimization of personalized medication using information systems based on pharmacogenomics: an example using colorectal cancer

Pharmacogenomics (PGx) is a powerful tool for clinical optimization of drug efficacy and safety. However, due to many factors affecting drugs in the real world, PGx still accounts for a small proportion of actual clinical application scenarios. Therefore, based on the information software, pharmacists use their professional advantages to integrate PGx into all aspects of pharmaceutical care, which is conducive to promoting the development of personalized medicine. In this paper, the establishment of an information software platform is summarized for the optimization of a personalized medication program based on PGx. Taking colorectal cancers (CRC) as an example, this paper also discusses the role of PGx in different working modes and participation in drug management of CRC patients by pharmacists with the help of information systems. Finally, we summarized the recommendations of different PGx guidelines to provide reference for the follow-up personalized pharmaceutical care.

Dysregulation of DNA methylation in colorectal cancer: biomarker, immune regulation, and therapeutic potential

Colorectal cancer (CRC) is one of the most prevalent malignancies worldwide, with morbidity and mortality ranking third and second among all cancers, respectively. As a result of a sequence of genetic and DNA methylation alterations that gradually accumulate in the healthy colonic epithelium, colorectal adenomas and invasive adenocarcinomas eventually give rise to CRC. Global hypomethylation and promoter-specific DNA methylation are characteristics of CRC. The pathophysiological role of aberrant DNA methylation in malignant tumors has garnered significant interest in the last few decades. In addition, DNA methylation has been shown to play a critical role in influencing immune cell function and tumor immune evasion. This review summarizes the most recent research on DNA methylation changes in CRC, including the role of DNA methylation-related enzymes in CRC tumorigenesis and biomarkers for diagnosis, predictive and prognostic. Besides, we focus on the emerging potential of epigenetic interventions to enhance antitumor immune responses and improve the CRC clinical practice.

Biomimetic Nano-delivery of Small-Molecule Piceatannol Modulates Tumor Stemness and Suppresses Colorectal Cancer Metastasis via Hippo/YAP1/SOX9 Signaling

Suppressing tumor metastasis is a crucial strategy for improving survival rates in patients with colorectal cancer (CRC), with cancer stem cells (CSCs) being the primary drivers of metastasis. Current therapeutic approaches targeting CSCs are limited, and their molecular mechanisms remain unclear. To address this challenge, a biomimetic nanoparticle delivery system, CMD-BHQ3-PTL/DOX@RBCM is developed, to deliver the stem cell regulator, piceatannol (PTL). This system used carboxymethyl dextran (CMD) and Black Hole Quencher 3 (BHQ3) to encapsulate PTL and the cytotoxic drug doxorubicin (DOX) within a red blood cell membrane (RBCm), enhancing stability and biocompatibility while allowing gradual drug release under hypoxic conditions. The effects of PTL are investigated on CSCs using molecular biology experiments, plasmid construction, and high-throughput sequencing and elucidated the molecular mechanisms underlying this biomimetic nanoparticle delivery system. The therapeutic efficacy of PTL is validated at the tissue level using subcutaneous and metastatic tumor models in human and murine systems. The results demonstrated that CMD-BHQ3-PTL/DOX@RBCM effectively addressed the challenges of specificity and biocompatibility in vivo, significantly inhibiting CSC-related tumor metastasis. This inhibitory effect is closely associated with the Hippo/YAP1/SOX9 pathway. This study highlights the effectiveness of the pH-responsive biomimetic nanoparticle system CMD-BHQ3-PTL/DOX@RBCm in delivering PTL to tumor sites, with SOX9 and its upstream Hippo/YAP1 pathway playing a critical role in the underlying mechanism.

METTL1 mediates PKM m7G modification to regulate CD155 expression and promote immune evasion in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is characterized by poor responsiveness to immune evasion and immunotherapy. RNA 7-methylguanine (m7G) modification plays a key role in tumorigenesis. However, the mechanisms by which m7G-modified RNA metabolism affects tumor progression are not fully understood, nor is the contribution of m7G-modified RNA to the CRC immune microenvironment.

METHODS

The expression levels of Methyltransferase-like 1 (METTL1) and m7G in human tissues were determined. In this study, the effect of METTL1 on RNA m7G levels was evaluated, the effect of METTL1 on PKM mRNA modification was confirmed, the expression level of the PKM2 protein was detected, and the mechanism involved RT‒qPCR, Western blot, RNA stability analysis and RIP analysis. Lactate and H3K9 lactylation (H3K9la) induced by METTL1/PKM2 were analyzed via the extracellular acidification rate (ECAR) and lactic acid assays. Cut&Run was used to detect METTL1/PKM2-induced CD155 (PVR) transcription. In addition, METTL1 knockout mice were studied in vivo with CD155 blockers.

RESULTS

We demonstrated that m7G RNA METTL1 enhances PKM2 expression by acting on PKM mRNA, leading to tumor progression and increased glycolysis. Specifically, METTL1 mediates m7G methylation of PKM mRNA and enhances the expression of its encoded PKM2, which in turn enhances glycolysis, promotes H3K9la, and activates METTL1 transcription, creating a positive feedback loop. Moreover, increased PKM2 dimer expression and nuclear translocation activated CD155 expression and induced CRC immune evasion.

CONCLUSIONS

Our findings reveal a general mechanism by which METTL1/PKM2/H3K9la signaling regulates RNA metabolism and highlight METTL1 targeting as a potential strategy for CRC immunotherapy.

Unraveling the complexities of colorectal cancer and its promising therapies - An updated review

Colorectal cancer (CRC) continues to be a global health concern, necessitating further research into its complex biology and innovative treatment approaches. The etiology, pathogenesis, diagnosis, and treatment of colorectal cancer are summarized in this thorough review along with recent developments. The multifactorial nature of colorectal cancer is examined, including genetic predispositions, environmental factors, and lifestyle decisions. The focus is on deciphering the complex interactions between signaling pathways such as Wnt/β-catenin, MAPK, TGF-β as well as PI3K/AKT that participate in the onset, growth, and metastasis of CRC. There is a discussion of various diagnostic modalities that span from traditional colonoscopy to sophisticated molecular techniques like liquid biopsy and radiomics, emphasizing their functions in early identification, prognostication, and treatment stratification. The potential of artificial intelligence as well as machine learning algorithms in improving accuracy as well as efficiency in colorectal cancer diagnosis and management is also explored. Regarding therapy, the review provides a thorough overview of well-known treatments like radiation, chemotherapy, and surgery as well as delves into the newly-emerging areas of targeted therapies as well as immunotherapies. Immune checkpoint inhibitors as well as other molecularly targeted treatments, such as anti-epidermal growth factor receptor (anti-EGFR) as well as anti-vascular endothelial growth factor (anti-VEGF) monoclonal antibodies, show promise in improving the prognosis of colorectal cancer patients, in particular, those suffering from metastatic disease. This review focuses on giving readers a thorough understanding of colorectal cancer by considering its complexities, the present status of treatment, and potential future paths for therapeutic interventions. Through unraveling the intricate web of this disease, we can develop a more tailored and effective approach to treating CRC.

Limited Efficacy of Anti-EGFR Monoclonal Antibodies in Colorectal Cancer Patients with Rare RAS Variants: Analysis of the C-CAT Database

Epidermal growth factor receptor (EGFR) inhibition is crucial in treating RAS wild-type metastatic colorectal cancer, yet current testing methods may miss rare RAS variants affecting treatment efficacy. We analyzed 4122 colorectal cancer patients receiving anti-EGFR antibodies from the Center for Cancer Genomics and Advanced Therapeutics database, identifying 54 patients (1.3%) with rare RAS variants undetectable by standard testing. These patients showed significantly lower response rates to anti-EGFR therapy (28.3%) compared to RAS wild-type cases (44.6%, p = 0.003). Disease control rates were also lower in rare variant cases (60.9%) versus wild-type cases (80.0%). Most common rare variants included KRAS Q22K, A59E, and A11_G12insGA. Comprehensive genomic profiling revealed additional alterations in TP53 (90.7%), APC (87.0%), and non-V600E BRAF mutations (25.9%). Our findings suggest that rare RAS variants predict poor anti-EGFR therapy response, highlighting the potential benefit of comprehensive genomic profiling before treatment initiation. This study provides real-world evidence supporting the clinical relevance of rare RAS variants in treatment decision-making for colorectal cancer. Future studies should focus on developing cost-effective comprehensive testing strategies and evaluating alternative treatment approaches for patients with rare RAS variants.

HER-2 SMASH

PURPOSE

Human epidermal growth factor-2 (HER-2) targeted drugs are used in only HER-2 overexpressed cancers. However, only a small portion of these cancer types are HER-2 overexpressed. In this study, we aimed to upregulate HER-2 receptors in MCF-7 breast cancer and HT-29 colon cancer cell cultures, which these cells are not HER-2 upregulated in natural status.

METHODS

We used a 10-day non-cytotoxic lapatinib dose to upregulate HER-2 receptors. HER-2 levels of these cell lines were tested with ELISA and immunofluorescence tests before and after 10 days of lapatinib administration. After upregulation of HER-2, we administered trastuzumab, and T-DM1 to these cell lines to observe whether there is an increase in anticancer activity. We used a cell viability test to show the cytotoxicity of trastuzumab and T-DM1. Also, we used ELISA and immunofluorescence for HER-2 pathway proteins to understand the mechanism of increased anti-cancer activity.

RESULTS

We showed that administration of lapatinib for 10 days leads to overexpression of HER-2 receptors on both MCF-7 and HT-29 cells. A significant increase in the cytotoxicity of trastuzumab or T-DM1 was observed after 10 days of lapatinib administration.

CONCLUSION

We named this method the smash method, which is the volleyball term. In volleyball, the ball is raised while low and quickly hits the ground again, just like we do with the HER-2 receptor. The smash method can switch HER-2 negative or HER-2 low tumors into HER-2 overexpressed, iatrogenically. Thus, we can use her2-targeted therapies in all cancer patients instead of a small portion.

High tumor mutational burden assessed through next-generation sequencing predicts favorable survival in microsatellite stable metastatic colon cancer patients

BACKGROUND

Microsatellite instability (MSI) is a well-established predictive biomarker for immune checkpoint inhibitor (ICI) response in metastatic colon cancer. Both high MSI and tumor mutational burden (TMB) are markers of genomic instability. However, the prognostic and predictive value of TMB in patients with microsatellite stable (MSS) tumors remains unclear.

METHODS

We evaluated the prognostic significance of TMB levels in MSS metastatic colon cancer patients undergoing standard treatments. Tumor responses were assessed using RECIST v1.1 criteria. Comprehensive clinical and molecular profiling was conducted, including next-generation sequencing (NGS) for TMB evaluation with the TruSight Oncology® kit. Overall survival (OS) was the primary endpoint. Multivariate Cox regression analysis was utilized to assess the relationship among potential prognostic factors.

RESULTS

Among 102 MSS metastatic colon cancer patients, high TMB (> 10 mut/mb) was associated with a significantly longer median OS compared to low TMB (70.0 vs 45.0 months, respectively; HR: 0.45; 95% CIs 0.21 to 0.96; P = 0.0396). Multivariate analysis, adjusting for age, gender, number of metastatic sites, response to first-line chemotherapy, RAS mutational status, and liver involvement, identified TMB as an independent prognostic factor, along with response to first-line chemotherapy.

CONCLUSIONS

Our results highlight the prognostic significance of TMB in MSS metastatic colon cancer patients, suggesting its potential role in patient stratification and treatment decision-making.

Survival Outcomes with Regorafenib and/or Trifluridine/Tipiracil Sequencing to Rechallenge with Third-Line Regimens in Metastatic Colorectal Cancer: A Multicenter Retrospective Real-World Subgroup Comparison from the ReTrITA Study

BACKGROUND

There is ongoing discussion around the optimal course of treatment for metastatic colorectal cancer (mCRC) following the second line. Trifluridine/tipiracil (T) and regorafenib (R) have been the mainstay of therapy in this situation, as they both increased overall survival (OS) in comparison to a placebo. Despite the paucity of evidence, therapy rechallenge is also recognized as an option for practical use. In the third-line scenario of mCRC, we planned to investigate the survival outcomes using (T) and (R), both with and without prior rechallenge treatment.

MATERIALS AND METHODS

Between 2012 and 2023, we examined the medical records of 1156 patients with refractory mCRC who were enrolled in the multicenter retrospective ReTrITA study. We then separated the patients into two cohorts based on the rechallenge therapy that was given before regorafenib and/or trifluridine/tipiracil at 17 Italian centres.

RESULTS

A total of 981 patients underwent T and/or R therapy, while 175 patients had therapy rechallenge before T and/or R. The median overall survival (mOS) for patients treated with T/R and R/T sequences in the rechallenge therapy cohort was 14.5 months and 17.6 months, respectively (p = 0.1955). A statistically significant survival benefit was observed in patients who received monotheraphy with R (mOS: 6 months) compared to the T group (mOS: 4.2 months) (p = 0.0332). In the same cohort, a median progression-free survival (mPFS) benefit was demonstrated in favour of the R/T group (11.3 months) vs. 9 months of the reverse sequence (p = 0.4004). In the no-rechallenge cohort, the mOS was statistically longer in the R/T sequence than in the T/R sequence (16.2 months vs. 12.3 months, respectively; p = 0.0014). In terms of the mPFS, we saw the same significant result for the adoption of R/T treatment (11.5 months vs. 8.4 months, respectively; p < 0.0001). The two monotherapy groups did not reveal any significant differences.

CONCLUSIONS

This study suggests that rechallenge therapy may improve survival rates in the third-line treatment of mCRC, particularly if it is administered before sequential R/T treatment. This could allow for the extension of mCRC treatment choices until prospective studies are finished or randomised trials are performed.

LC-MS metabolomics analysis of serum metabolites during neoadjuvant chemoradiotherapy in locally advanced rectal cancer

BACKGROUND

This study aimed to investigate the serum metabolite profiles during neoadjuvant chemoradiotherapy (NCRT) in locally advanced rectal cancer (LARC) using liquid chromatography-mass spectrometry (LC-MS) metabolomics analysis.

METHODS

60 serum samples were collected from 20 patients with LARC before, during, and after radiotherapy. LC-MS metabolomics analysis was performed to identify the metabolite variations. Functional annotation was applied to discover altered metabolic pathways. The key metabolites were screened and their ability to predict sensitivity to radiotherapy was calculated using random forests and ROC curves.

RESULTS

The results showed that NCRT led to significant changes in the serum metabolite profiles. The serum metabolic profiles showed an apparent separation between different time points and different sensitivity groups. Moreover, the functional annotation showed that the differential metabolites were associated with a series of important metabolic pathways. Pre-radiotherapy (3Z,6Z)-3,6-Nonadiena and pro-radiotherapy 1-Hydroxyibuprofen showed good predictive performance in discriminating the sensitive and non-sensitive group to NCRT, with an AUC of 0.812 and 0.75, respectively. Importantly, the combination of different metabolites significantly increased the predictive ability.

CONCLUSION

This study demonstrated the potential of LC-MS metabolomics for revealing the serum metabolite profiles during NCRT in LARC. The identified metabolites may serve as potential biomarkers and therapeutic targets for the management of this disease. Furthermore, the understanding of the affected metabolic pathways may help design more personalized therapeutic strategies for LARC patients.

Colorectal cancer with BRAF V600E mutation: Trends in immune checkpoint inhibitor treatment

Colorectal cancer (CRC) with BRAF V600E mutation presents a formidable scientific and clinical challenge due to its aggressive nature and poor response to standard therapeutic approaches. BRAF V600E mutation-induced conspicuous activation of the MAPK pathway contributes to the relentless tumor progression. Nevertheless, the efficacy of multi-targeted MAPK pathway inhibition remains suboptimal in clinical practice. Patients with high microsatellite instability (MSI-H) have shown favorable results with immune checkpoint inhibitors (ICIs). The combination of the MAPK pathway inhibition with ICIs has recently emerged as a promising regimen to improve clinical outcomes in the microsatellite stable (MSS) subgroup of BRAF V600E-mutant metastatic CRC patients. In this review, we elucidate the unique tumor biology of BRAF V600E-mutant CRC, with a particular focus on the immune features underlying the rationale for ICI treatments in the MSI-H and MSS subpopulations, then highlight the trends in clinical trials of the ICI therapy for BRAF V600E-mutant metastatic CRC.

Resveratrol and p53: How are they involved in CRC plasticity and apoptosis?

BACKGROUND

Colorectal cancer (CRC), which is mainly caused by epigenetic and lifestyle factors, is very often associated with functional plasticity during its development. In addition, the malignant plasticity of CRC cells underscores one of their survival abilities to functionally adapt to specific stresses, including inflammation, that occur during carcinogenesis. This leads to the generation of various subsets of cancer cells with phenotypic diversity and promotes epithelial-mesenchymal transition (EMT), formation of cancer cell stem cells (CSCs) and metabolic reprogramming. This can enhance cancer cell differentiation and facilitate tumorigenic potential, drug resistance and metastasis.

AIM OF REVIEW

The tumor protein p53 acts as one of the central suppressors of carcinogenesis by regulating its target genes, whose proteins are involved in the plasticity of cancer cells, autophagy, cell cycle, apoptosis, DNA repair. The aim of this review is to summarize the latest published research on resveratrol's effect in the prevention of CRC, its regulatory actions, specifically on the p53 pathway, and its treatment options.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Resveratrol, a naturally occurring polyphenol, is a potent inducer of a variety of tumor-controlling. However, the underlying mechanisms linking the p53 signaling pathway to the functional anti-plasticity effect of resveratrol in CRC are still poorly understood. Therefore, this review discusses novel relationships between anti-cellular plasticity/heterogeneity, pro-apoptosis and modulation of tumor protein p53 signaling in CRC oncogenesis, as one of the crucial mechanisms by which resveratrol prevents malignant phenotypic changes leading to cell migration and drug resistance, thus improving the ongoing treatment of CRC.

The SCRUM-MONSTAR Cancer-Omics Ecosystem: Striving for a Quantum Leap in Precision Medicine

The SCRUM-Japan MONSTAR-SCREEN consortium is a nationwide molecular profiling project employing artificial intelligence-driven multiomics analyses for patients with advanced malignancies, aiming to develop novel therapeutics and diagnostics and deliver effective drugs to patients. Concurrently, studies assessing molecular residual disease-based precision medicine for resectable solid tumors, including CIRCULATE-Japan, are ongoing. The substantial data generated by these platforms are stored within a state-of-the-art supercomputing infrastructure, VAPOR CONE. Since 2015, our project has registered over 24,000 patients as of December 2023. Among 16,144 patients with advanced solid tumors enrolled in MONSTAR-SCREEN projects, 5.0% have participated in matched clinical trials, demonstrating a 29.2% objective response rate and 14.8-month median survival (95% CI, 13.4-16.3) for patients treated in the matched clinical trials. Notably, patients who received matched therapy demonstrated significantly prolonged overall survival compared with those who did not (hazard ratio 0.77; 95% confidence interval, 0.71-0.83). Significance: Our nationwide molecular profiling initiative played pivotal roles in facilitating the enrollment of patients with advanced solid tumors into matched clinical trials and highlighted the substantial survival benefits of patients treated with matched therapy. We aim to facilitate an industry-academia data-sharing infrastructure ecosystem, fostering new drug discovery paradigms and precision medicine.

JAML overexpressed in colorectal cancer promotes tumour proliferation by activating the PI3K-AKT-mTOR signalling pathway

The expression and biological function of junctional adhesion molecule-like protein (JAML) in colorectal cancer (CRC) remain unclear. Paraffin tissue samples from 50 cases of CRC were collected to determine the expression of JAML. JAML was overexpressed or knock-down in CRC cells to evaluated the proliferation, migration and invasion in vitro and in vivo. Western-blot and others were applied to explore the mechanisms. The study showed that JAML was highly expressed within cancer tissues in 50% (25/50) of patients with CRC, and was correlated with higher TNM stage (p < 0.05). Patients of JAML-high group had poorer overall survival compared to JAML-low group (p = 0.0362, HR = 0.4295, 95% CI of 0.1908-0.9667). The tumour infiltrating lymphocytes (TILs) was lower in the JAML-high group than in the JAML-low group (p < 0.05). Overexpression of JAML promoted the proliferation, migration, and invasion of CRC by activating the PI3K-AKT-mTOR signalling pathway both in vitro and in vivo. TILs were reduced in JAML-high tumour tissues by decreasing chemokines such as CCL20 and CXCL9/10/11. Our study identified JAML, a potentially ideal target that is specifically highly expressed in CRC tissues, which promoted tumour proliferation, impaired T-lymphocytes infiltration, provided a promising therapeutic strategy for patients with CRC.

Multi-stage mechanisms of tumor metastasis and therapeutic strategies

The cascade of metastasis in tumor cells, exhibiting organ-specific tendencies, may occur at numerous phases of the disease and progress under intense evolutionary pressures. Organ-specific metastasis relies on the formation of pre-metastatic niche (PMN), with diverse cell types and complex cell interactions contributing to this concept, adding a new dimension to the traditional metastasis cascade. Prior to metastatic dissemination, as orchestrators of PMN formation, primary tumor-derived extracellular vesicles prepare a fertile microenvironment for the settlement and colonization of circulating tumor cells at distant secondary sites, significantly impacting cancer progression and outcomes. Obviously, solely intervening in cancer metastatic sites passively after macrometastasis is often insufficient. Early prediction of metastasis and holistic, macro-level control represent the future directions in cancer therapy. This review emphasizes the dynamic and intricate systematic alterations that occur as cancer progresses, illustrates the immunological landscape of organ-specific PMN creation, and deepens understanding of treatment modalities pertinent to metastasis, thereby identifying some prognostic and predictive biomarkers favorable to early predict the occurrence of metastasis and design appropriate treatment combinations.

Third-line treatment and beyond in metastatic colorectal cancer: What do we have and what can we expect?

Colorectal cancer remains the third most common cancer worldwide and the second cause of cancer-related death. Treatment advances and precision oncological medicine for these tumours have been stalled in comparison to those for other common tumours such as lung and breast cancer. However, the recent publication of the SUNLIGHT trial results with the trifluridine/tipiracil (TAS-102)-bevacizumab combination and the irruption of new molecular targets with guided treatments have opened new possibilities in third-line metastatic colorectal cancer management. Anti-EGFR rechallenge, anti-HER2 targeted therapies or the promising results of Pressurised Intraperitoneal Aerosol Chemotherapy (PIPAC), are some of the available options that may modify what is presumably third-line colorectal treatment. Hereby, we present the evidence of the different treatment options in third-line colorectal cancer and beyond, as well as the possibilities of sequencing them.

The performance of large language model-powered chatbots compared to oncology physicians on colorectal cancer queries

BACKGROUND

Large language model (LLM)-powered chatbots have become increasingly prevalent in healthcare, while their capacity in oncology remains largely unknown. To evaluate the performance of LLM-powered chatbots compared to oncology physicians in addressing colorectal cancer queries.

METHODS

This study was conducted between August 13, 2023, and January 5, 2024. A total of 150 questions were designed, and each question was submitted three times to eight chatbots: ChatGPT-3.5, ChatGPT-4, ChatGPT-4 Turbo, Doctor GPT, Llama-2-70B, Mixtral-8x7B, Bard, and Claude 2.1. No feedback was provided to these chatbots. The questions were also answered by nine oncology physicians, including three residents, three fellows, and three attendings. Each answer was scored based on its consistency with guidelines, with a score of 1 for consistent answers and 0 for inconsistent answers. The total score for each question was based on the number of corrected answers, ranging from 0 to 3. The accuracy and scores of the chatbots were compared to those of the physicians.

RESULTS

Claude 2.1 demonstrated the highest accuracy, with an average accuracy of 82.67%, followed by Doctor GPT at 80.45%, ChatGPT-4 Turbo at 78.44%, ChatGPT-4 at 78%, Mixtral-8x7B at 73.33%, Bard at 70%, ChatGPT-3.5 at 64.89%, and Llama-2-70B at 61.78%. Claude 2.1 outperformed residents, fellows, and attendings. Doctor GPT outperformed residents and fellows. Additionally, Mixtral-8x7B outperformed residents. In terms of scores, Claude 2.1 outperformed residents and fellows. Doctor GPT, ChatGPT-4 Turbo, and ChatGPT-4 outperformed residents.

CONCLUSIONS

This study shows that LLM-powered chatbots can provide more accurate medical information compared to oncology physicians.

BRAF mutations and the association of V600E with CD133 and CDX2 expression in a Pakistani colorectal carcinoma cohort

BACKGROUND

Despite a high incidence of colorectal carcinoma, data regarding genetic aberrations in colorectal carcinoma (CRC) patients in Pakistan is scarce. This study aimed to determine the frequency of BRAFV600E mutations in colorectal carcinoma tissue in the Pakistani population and to associate BRAFV600E expression with CD133, a marker of colorectal stem cells, and CDX2 marker of differentiation.

METHODS

Sanger Sequencing of exon 15 (426 bp) including the hotspot V600E was performed on formalin-fixed-paraffin-embedded (FFPE) CRC tissue samples of 115 patients. The samples were subjected to immunohistochemistry (IHC) to assess the expression of BRAFV600E, CDX2, and CD133. Additionally, homology modelling and docking were performed to investigate novel deletions revealed in sequencing.

RESULTS

Twenty-four (20.8%) BRAF variants were identified in the coding region, with V600E mutations detected in 14 (12.2% )cases (GenBank: PP003258.1; Pop Set: 2678087296). Moreover, a wide spectrum of novel non-V600E mutations (8.6%) were identified, including deletions and missense variations. In-silico analysis revealed that due to large deletions in the coding region of three samples, the affinity of the anti-BRAF drugs (Encorafenib and Vemurafenib) for the active site decreased in comparison to the wild type. The IHC analysis showed that BRAFV600E expression was significantly associated with CD133 expression (χ2(1, n=115) = 26.351; p = < 0.001) and with CDX2 expression (χ2(1, n=115) = 14.88; p = 0.001). Multivariate analysis using binary logistic regression revealed association of BRAFV600E mutations with age (OR = 1.123; CI = 1.024-1.232; p = 0.014), gender (OR = 0.071; CI = 0.006-0.831; p = 0.035), grade (0.007; CI = 0-0.644) and CD133 expression (OR = 65.649; CI = 2.153-2001.556; p = 0.016).

CONCLUSION

The present study demonstrates a notably high V600E frequency (12.2%) in comparison to global reported data, which ranges from 0.4 to 18%. This finding reflects the importance of upfront BRAF testing of the genetically distinct population of Pakistan. Previously unreported mutations identified in the sample may be of clinical significance and warrant further investigation. The concomitant high expression and significant association between CD133 and BRAFV600E represent vital actionable genes that may be targeted together to improve CRC patient management.

The burgeoning spatial multi-omics in human gastrointestinal cancers

The development and progression of diseases in multicellular organisms unfold within the intricate three-dimensional body environment. Thus, to comprehensively understand the molecular mechanisms governing individual development and disease progression, precise acquisition of biological data, including genome, transcriptome, proteome, metabolome, and epigenome, with single-cell resolution and spatial information within the body's three-dimensional context, is essential. This foundational information serves as the basis for deciphering cellular and molecular mechanisms. Although single-cell multi-omics technology can provide biological information such as genome, transcriptome, proteome, metabolome, and epigenome with single-cell resolution, the sample preparation process leads to the loss of spatial information. Spatial multi-omics technology, however, facilitates the characterization of biological data, such as genome, transcriptome, proteome, metabolome, and epigenome in tissue samples, while retaining their spatial context. Consequently, these techniques significantly enhance our understanding of individual development and disease pathology. Currently, spatial multi-omics technology has played a vital role in elucidating various processes in tumor biology, including tumor occurrence, development, and metastasis, particularly in the realms of tumor immunity and the heterogeneity of the tumor microenvironment. Therefore, this article provides a comprehensive overview of spatial transcriptomics, spatial proteomics, and spatial metabolomics-related technologies and their application in research concerning esophageal cancer, gastric cancer, and colorectal cancer. The objective is to foster the research and implementation of spatial multi-omics technology in digestive tumor diseases. This review will provide new technical insights for molecular biology researchers.

Mechanisms of metastatic colorectal cancer

Despite extensive research and improvements in understanding colorectal cancer (CRC), its metastatic form continues to pose a substantial challenge, primarily owing to limited therapeutic options and a poor prognosis. This Review addresses the emerging focus on metastatic CRC (mCRC), which has historically been under-studied compared with primary CRC despite its lethality. We delve into two crucial aspects: the molecular and cellular determinants facilitating CRC metastasis and the principles guiding the evolution of metastatic disease. Initially, we examine the genetic alterations integral to CRC metastasis, connecting them to clinically marked characteristics of advanced CRC. Subsequently, we scrutinize the role of cellular heterogeneity and plasticity in metastatic spread and therapy resistance. Finally, we explore how the tumour microenvironment influences metastatic disease, emphasizing the effect of stromal gene programmes and the immune context. The ongoing research in these fields holds immense importance, as its future implications are projected to revolutionize the treatment of patients with mCRC, hopefully offering a promising outlook for their survival.

Recent developments in immunotherapy for gastrointestinal tract cancers

The past few decades have witnessed the rise of immunotherapy for Gastrointestinal (GI) tract cancers. The role of immune checkpoint inhibitors (ICIs), particularly programmed death protein 1 (PD-1) and PD ligand-1 antibodies, has become increasingly pivotal in the treatment of advanced and perioperative GI tract cancers. Currently, anti-PD-1 plus chemotherapy is considered as first-line regimen for unselected advanced gastric/gastroesophageal junction adenocarcinoma (G/GEJC), mismatch repair deficient (dMMR)/microsatellite instability-high (MSI-H) colorectal cancer (CRC), and advanced esophageal cancer (EC). In addition, the encouraging performance of claudin18.2-redirected chimeric antigen receptor T-cell (CAR-T) therapy in later-line GI tract cancers brings new hope for cell therapy in solid tumour treatment. Nevertheless, immunotherapy for GI tumour remains yet precise, and researchers are dedicated to further maximising and optimising the efficacy. This review summarises the important research, latest progress, and future directions of immunotherapy for GI tract cancers including EC, G/GEJC, and CRC.

Assessment of KRASG12C inhibitors for colorectal cancer

Colorectal cancer (CRC) is a highly prevalent and lethal cancer worldwide. Approximately 45% of CRC patients harbor a gain-in-function mutation in KRAS. KRAS is the most frequently mutated oncogene accounting for approximately 25% of all human cancers. Gene mutations in KRAS cause constitutive activation of the KRAS protein and MAPK/AKT signaling, resulting in unregulated proliferation and survival of cancer cells and other aspects of malignant transformation, progression, and metastasis. While KRAS has long been considered undruggable, the FDA recently approved two direct acting KRAS inhibitors, Sotorasib and Adagrasib, that covalently bind and inactivate KRASG12C. Both drugs showed efficacy for patients with non-small cell lung cancer (NSCLC) diagnosed with a KRASG12C mutation, but for reasons not well understood, were considerably less efficacious for CRC patients diagnosed with the same mutation. Thus, it is imperative to understand the basis for resistance to KRASG12C inhibitors, which will likely be the same limitations for other mutant specific KRAS inhibitors in development. This review provides an update on clinical trials involving CRC patients treated with KRASG12C inhibitors as a monotherapy or combined with other drugs. Mechanisms that contribute to resistance to KRASG12C inhibitors and the development of novel RAS inhibitors with potential to escape such mechanisms of resistance are also discussed.

Cadherin 17 Nanobody-Mediated Near-Infrared-II Fluorescence Imaging-Guided Surgery and Immunotoxin Delivery for Colorectal Cancer

Surgery and targeted therapy are of equal importance for colorectal cancer (CRC) treatment. However, complete CRC tumor resection remains challenging, and new targeted agents are also needed for efficient CRC treatment. Cadherin 17 (CDH17) is a membrane protein that is highly expressed in CRC and, therefore, is an ideal target for imaging-guided surgery and therapeutics. This study utilizes CDH17 nanobody (E8-Nb) with the near-infrared (NIR) fluorescent dye IRDye800CW to construct a NIR-II fluorescent probe, E8-Nb-IR800CW, and a Pseudomonas exotoxin (PE)-based immunotoxin, E8-Nb-PE38, to evaluate their performance for CRC imaging, imaging-guided precise tumor excision, and antitumor effects. Our results show that E8-Nb-IR800CW efficiently recognizes CDH17 in CRC cells and tumor tissues, produces high-quality NIR-II images for CRC tumors, and enables precise tumor removal guided by NIR-II imaging. Additionally, fluorescent imaging confirms the targeting ability and specificity of the immunotoxin toward CDH17-positive tumors, providing the direct visible evidence for immunotoxin therapy. E8-Nb-PE38 immunotoxin markedly delays the growth of CRC through the induction of apoptosis and immunogenic cell death (ICD) in multiple CRC tumor models. Furthermore, E8-Nb-PE38 combined with 5-FU exerts synergistically antitumor effects and extends survival. This study highlights CDH17 as a promising target for CRC imaging, imaging-guided surgery, and drug delivery. Nanobodies targeting CDH17 hold great potential to construct NIR-II fluorescent probes for surgery navigation, and PE-based toxins fused with CDH17 nanobodies represent a novel therapeutic strategy for CRC treatment. Further investigation is warranted to validate these findings for potential clinical translation.

Therapeutic strategies targeting the epidermal growth factor receptor signaling pathway in metastatic colorectal cancer

More than 1.9 million new colorectal cancer (CRC) cases and 935000 deaths were estimated to occur worldwide in 2020, representing about one in ten cancer cases and deaths. Overall, colorectal ranks third in incidence, but second in mortality. More than half of the patients are in advanced stages at diagnosis. Treatment options are complex because of the heterogeneity of the patient population, including different molecular subtypes. Treatments have included conventional fluorouracil-based chemotherapy, targeted therapy, immunotherapy, etc. In recent years, with the development of genetic testing technology, more and more targeted drugs have been applied to the treatment of CRC, which has further prolonged the survival of metastatic CRC patients.

Navigating through novelties concerning mCRC treatment-the role of immunotherapy, chemotherapy, and targeted therapy in mCRC

Over the course of nearly six decades since the inception of initial trials involving 5-FU in the treatment of mCRC (metastatic colorectal cancer), our progressive comprehension of the pathophysiology, genetics, and surgical techniques related to mCRC has paved the way for the introduction of novel therapeutic modalities. These advancements not only have augmented the overall survival but have also positively impacted the quality of life (QoL) for affected individuals. Despite the remarkable progress made in the last two decades in the development of chemotherapy, immunotherapy, and target therapies, mCRC remains an incurable disease, with a 5-year survival rate of 14%. In this comprehensive review, our primary goal is to present an overview of mCRC treatment methods following the latest guidelines provided by the National Comprehensive Cancer Network (NCCN), the American Society of Clinical Oncology (ASCO), and the American Society of Colon and Rectal Surgeons (ASCRS). Emphasis has been placed on outlining treatment approaches encompassing chemotherapy, immunotherapy, targeted therapy, and surgery's role in managing mCRC. Furthermore, our review delves into prospective avenues for developing new therapies, offering a glimpse into the future of alternative pathways that hold potential for advancing the field.

Stress-induced Rab11a-exosomes induce amphiregulin-mediated cetuximab resistance in colorectal cancer

Exosomes are secreted vesicles made intracellularly in the endosomal system. We have previously shown that exosomes are not only made in late endosomes, but also in recycling endosomes marked by the monomeric G-protein Rab11a. These vesicles, termed Rab11a-exosomes, are preferentially secreted under nutrient stress from several cancer cell types, including HCT116 colorectal cancer (CRC) cells. HCT116 Rab11a-exosomes have particularly potent signalling activities, some mediated by the epidermal growth factor receptor (EGFR) ligand, amphiregulin (AREG). Mutant activating forms of KRAS, a downstream target of EGFR, are often found in advanced CRC. When absent, monoclonal antibodies, such as cetuximab, which target the EGFR and block the effects of EGFR ligands, such as AREG, can be administered. Patients, however, inevitably develop resistance to cetuximab, either by acquiring KRAS mutations or via non-genetic microenvironmental changes. Here we show that nutrient stress in several CRC cell lines causes the release of AREG-carrying Rab11a-exosomes. We demonstrate that while soluble AREG has no effect, much lower levels of AREG bound to Rab11a-exosomes from cetuximab-resistant KRAS-mutant HCT116 cells, can suppress the effects of cetuximab on KRAS-wild type Caco-2 CRC cells. Using neutralising anti-AREG antibodies and an intracellular EGFR kinase inhibitor, we show that this effect is mediated via AREG activation of EGFR, and not transfer of activated KRAS. Therefore, presentation of AREG on Rab11a-exosomes affects its ability to compete with cetuximab. We propose that this Rab11a-exosome-mediated mechanism contributes to the establishment of resistance in cetuximab-sensitive cells and may explain why in cetuximab-resistant tumours only some cells carry mutant KRAS.

Antitumor effect of tubeimoside-I on murine colorectal cancers through PKM2-dependent pyroptosis and immunomodulation

Induction of cancer cell death is an established treatment strategy, but chemotherapy drug-mediated apoptosis can be evaded by many tumors. Pyroptosis is a type of inflammatory programmed cell death (PCD) that is important for organism immunity. Tubeimoside-I (TBMS1) is a plant-derived component that exhibits antitumor activity. However, it is unclear how TBMS1 induces pyroptosis to inhibit colorectal cancer (CRC). In this study, we demonstrated that TBMS1 is able to induce pyroptosis in murine CRC cells and releases pro-inflammatory cytokines. Mechanistically, we found that TBMS1 inhibits CRC cell proliferation and migration and induces pyroptosis by activating caspase-3 and cleaving gasdermin E (GSDME) through the inhibition of PKM2. In the animal experiments, TBMS1 attenuated the weight of solid tumors, increased the proportion of CD8+ cytotoxic T cells, and reduced the content of M2-type macrophages in the spleen of tumor-bearing mice. Furthermore, TBMS1 inhibited M2-type polarization by blocking STAT6 pathway activation in RAW 264.7 cells. To sum up, our findings suggest that TBMS1 triggers pyroptosis in CRC by acting on the PKM2/caspase-3/GSDME signaling pathway. Additionally, it modulates the antitumor immune response in CRC murine models. This study provides a promising basis for the potential use of TBMS1 in treating CRC.

Future direction of total neoadjuvant therapy for locally advanced rectal cancer

Despite therapeutic advancements, disease-free survival and overall survival of patients with locally advanced rectal cancer have not improved in most trials as a result of distant metastases. For treatment decision-making, both long-term oncologic outcomes and impact on quality-of-life indices should be considered (for example, bowel function). Total neoadjuvant therapy (TNT), comprised of chemotherapy and radiotherapy or chemoradiotherapy, is now a standard treatment approach in patients with features of high-risk disease to prevent local recurrence and distant metastases. In selected patients who have a clinical complete response, subsequent surgery might be avoided through non-operative management, but patients who do not respond to TNT have a poor prognosis. Refined molecular characterization might help to predict which patients would benefit from TNT and non-operative management. Specifically, integrated analysis of spatiotemporal multi-omics using artificial intelligence and machine learning is promising. Three prospective trials of TNT and non-operative management in Japan, the USA and Germany are collaborating to better understand drivers of response to TNT. Here, we address the future direction for TNT.

Advances in Precision Medicine Approaches for Colorectal Cancer: From Molecular Profiling to Targeted Therapies

Precision medicine is transforming colorectal cancer treatment through the integration of advanced technologies and biomarkers, enhancing personalized and effective disease management. Identification of key driver mutations and molecular profiling have deepened our comprehension of the genetic alterations in colorectal cancer, facilitating targeted therapy and immunotherapy selection. Biomarkers such as microsatellite instability (MSI) and DNA mismatch repair deficiency (dMMR) guide treatment decisions, opening avenues for immunotherapy. Emerging technologies such as liquid biopsies, artificial intelligence, and machine learning promise to revolutionize early detection, monitoring, and treatment selection in precision medicine. Despite these advancements, ethical and regulatory challenges, including equitable access and data privacy, emphasize the importance of responsible implementation. The dynamic nature of colorectal cancer, with its tumor heterogeneity and clonal evolution, underscores the necessity for adaptive and personalized treatment strategies. The future of precision medicine in colorectal cancer lies in its potential to enhance patient care, clinical outcomes, and our understanding of this intricate disease, marked by ongoing evolution in the field. The current reviews focus on providing in-depth knowledge on the various and diverse approaches utilized for precision medicine against colorectal cancer, at both molecular and biochemical levels.

CD177 drives the transendothelial migration of Treg cells enriched in human colorectal cancer

Objectives

Regulatory T (Treg) cells regulate immunity in autoimmune diseases and cancers. However, immunotherapies that target tumor-infiltrating Treg cells often induce unwanted immune responses and tissue inflammation. Our research focussed on exploring the expression pattern of CD177 in tumor-infiltrating Treg cells with the aim of identifying a potential target that can enhance immunotherapy effectiveness.

Methods

Single-cell RNA sequencing (scRNA-seq) data and survival data were obtained from public databases. Twenty-one colorectal cancer patient samples, including fresh tumor tissues, peritumoral tissues and peripheral blood mononuclear cells (PBMCs), were analysed using flow cytometry. The transendothelial activity of CD177+ Treg cells was substantiated using in vitro experiments.

Results

ScRNA-seq and flow cytometry results indicated that CD177 was exclusively expressed in intratumoral Treg cells. CD177+ Treg cells exhibited greater activation status and expressed elevated Treg cell canonical markers and immune checkpoint molecules than CD177- Treg cells. We further discovered that both intratumoral CD177+ Treg cells and CD177-overexpressing induced Treg (iTreg) cells had lower levels of PD-1 than their CD177- counterparts. Moreover, CD177 overexpression significantly enhanced the transendothelial migration of Treg cells in vitro.

Conclusions

These results demonstrated that Treg cells with higher CD177 levels exhibited an enhanced activation status and transendothelial migration capacity. Our findings suggest that CD177 may serve as an immunotherapeutic target and that overexpression of CD177 may improve the efficacy of chimeric antigen receptor T (CAR-T) cell therapy.

Inhibition of Aurora B kinase (AURKB) enhances the effectiveness of 5-fluorouracil chemotherapy against colorectal cancer cells

BACKGROUND

5-Fluorouracil (5-FU) remains a core component of systemic therapy for colorectal cancer (CRC). However, response rates remain low, and development of therapy resistance is a primary issue. Combinatorial strategies employing a second agent to augment the therapeutic effect of chemotherapy is predicted to reduce the incidence of treatment resistance and increase the durability of response to therapy.

METHODS

Here, we employed quantitative proteomics approaches to identify novel druggable proteins and molecular pathways that are deregulated in response to 5-FU, which might serve as targets to improve sensitivity to chemotherapy. Drug combinations were evaluated using 2D and 3D CRC cell line models and an ex vivo culture model of a patient-derived tumour.

RESULTS

Quantitative proteomics identified upregulation of the mitosis-associated protein Aurora B (AURKB), within a network of upregulated proteins, in response to a 24 h 5-FU treatment. In CRC cell lines, AURKB inhibition with the dihydrogen phosphate prodrug AZD1152, markedly improved the potency of 5-FU in 2D and 3D in vitro CRC models. Sequential treatment with 5-FU then AZD1152 also enhanced the response of a patient-derived CRC cells to 5-FU in ex vivo cultures.

CONCLUSIONS

AURKB inhibition may be a rational approach to augment the effectiveness of 5-FU chemotherapy in CRC.

Epigenetic Alteration in Colorectal Cancer: Potential Diagnostic and Prognostic Implications

Colorectal cancer (CRC), a prevalent malignant tumor of the digestive system, ranks as the third and second in global incidence and mortality, respectively, in 2020, with 1.93 million new cases (≈10% of all cancers). There are 940,000 deaths (≈9.4% of all cancers), and the incidence of CRC in younger patients (under 50 years of age) has become a new trend. The pathogenesis of CRC is primarily attributed to a series of genetic and epigenetic abnormalities within normal colonic epithelial cells, coupled with the reshaping of the tumor microenvironment in the surrounding stroma. This process leads to the transformation of colorectal adenomas into invasive adenocarcinomas. Although genetic changes are known to be the primary driving force in the occurrence and progression of CRC, recent research indicates that epigenetic regulation serves as a crucial molecular marker in cancer, playing a significant role in the pathological and physiological control of interactions between genetics and the environment. This review discusses the current global epidemiology of CRC, its risk factors, and preventive treatment strategies. The current study explores the latest advancements in the epigenetic regulation of CRC, including DNA methylation, histone modifications, and non-coding RNAs (ncRNAs). These developments hold potential as screening tools, prognostic biomarkers, and therapeutic targets for CRC.

Therapeutic and diagnostic applications of antisense peptide nucleic acids

Peptide nucleic acids (PNAs) are synthetic nucleic acid analogs with a neutral N-(2-aminoethyl) glycine backbone. PNAs possess unique physicochemical characteristics such as increased resistance to enzymatic degradation, ionic strength and stability over a wide range of temperatures and pH, and low intrinsic electrostatic repulsion against complementary target oligonucleotides. PNA has been widely used as an antisense oligonucleotide (ASO). Despite the favorable characteristics of PNA, in comparison with other ASO technologies, the use of antisense PNA for novel therapeutics has lagged. This review provides a brief overview of PNA, its antisense mechanisms of action, delivery strategies, and highlights successful applications of PNA, focusing on anti-pathogenic, anti-neurodegenerative disease, anti-cancer, and diagnostic agents. For each application, several studies are discussed focusing on the different target sites of the PNA, design of different PNAs and the therapeutic outcome in different cell lines and animal models. Thereafter, persisting limitations slowing the successful integration of antisense PNA therapeutics are discussed in order to highlight actionable next steps in the development and optimization of PNA as an ASO.

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.

Evaluating AI in medicine: a comparative analysis of expert and ChatGPT responses to colorectal cancer questions

Colorectal cancer (CRC) is a global health challenge, and patient education plays a crucial role in its early detection and treatment. Despite progress in AI technology, as exemplified by transformer-like models such as ChatGPT, there remains a lack of in-depth understanding of their efficacy for medical purposes. We aimed to assess the proficiency of ChatGPT in the field of popular science, specifically in answering questions related to CRC diagnosis and treatment, using the book "Colorectal Cancer: Your Questions Answered" as a reference. In general, 131 valid questions from the book were manually input into ChatGPT. Responses were evaluated by clinical physicians in the relevant fields based on comprehensiveness and accuracy of information, and scores were standardized for comparison. Not surprisingly, ChatGPT showed high reproducibility in its responses, with high uniformity in comprehensiveness, accuracy, and final scores. However, the mean scores of ChatGPT's responses were significantly lower than the benchmarks, indicating it has not reached an expert level of competence in CRC. While it could provide accurate information, it lacked in comprehensiveness. Notably, ChatGPT performed well in domains of radiation therapy, interventional therapy, stoma care, venous care, and pain control, almost rivaling the benchmarks, but fell short in basic information, surgery, and internal medicine domains. While ChatGPT demonstrated promise in specific domains, its general efficiency in providing CRC information falls short of expert standards, indicating the need for further advancements and improvements in AI technology for patient education in healthcare.

Novel GSH-responsive prodrugs derived from indole-chalcone and camptothecin trigger apoptosis and autophagy in colon cancer

Antineoplastic agents that target tubulin have shown efficacy as chemotherapeutic drugs, yet they are often constrained by multidrug resistance (MDR) and unwanted side effects. A multi-targeted strategy demonstrates great potency in reducing toxicity and enhancing efficacy and provides an alternative way for attenuating MDR. In this study, a series of dual-targeted anti-cancer agents based on indole-chalcone derivatives and the camptothecin (CPT) scaffold were synthesized. Among them, 14-1 demonstrated superior anti-proliferative activity than its precursor 13-1, CPT or their physical mixtures against tested cancer cells, including multidrug-resistant variants, while exhibited moderate cytotoxicity toward human normal cells. Mechanistic studies revealed that 14-1 acted as a glutathione-responsive prodrug, inducing apoptosis by substantially enhancing intracellular uptake of CPT, inhibiting tubulin polymerization, increasing the accumulation of intracellular reactive oxygen species, and initiating a mitochondrion-dependent apoptotic pathway. Moreover, 14-1 notably induced autophagy and suppressed topoisomerase I activity to further promote apoptosis. Importantly, 14-1 displayed potent inhibitory effect on tumor growth in paclitaxel (PTX)-resistant colorectal cancer (HCT-116/PTX) xenograft models without inducing obvious toxicity compared with CPT- or combo-treated group. These results suggest that 14-1 holds promise as a novel candidate for anti-cancer therapy, particularly in PTX-resistant cancers.