Strategy For Treatment Of Colorectal Cancer Research Articles

MMR status of colorectal carcinomas at a tertiary cancer care centre in Central India

Microsatellite instability (MSI) and mismatch repair (MMR) deficiency are important biomarkers in colorectal cancer (CRC) that have clinical implications for patient management and treatment. MMR deficiency can lead to MSI, which is characterized by alterations in the length of microsatellite DNA sequences. Clinical applications of MMR deficiency in colorectal adenocarcinoma are as a prognostic marker as well as Predictive marker for adjuvant chemotherapy and immunotherapy. To assess the MMR status of colorectal adenocarcinomas.: This was a retrospective study of 127 colorectal adenocarcinomas cases. All the samples were either biopsies or surgically resected tumor tissues from patients of Carcinoma Colon and rectum. Immunohistochemistry was performed on Roche Ventana Benchmark XT autostainer.: MLH-1, PMS2, MSH2 and MSH6 expression was retained in the tumor cells in 106 cases and it was lost in 21 cases. Among various clinicopathological variables, tumor site and AJCC pStage were found to be significantly associated with dMMR tumors. Patients of colorectal adenocarcinomas were benefited by MMR testing as it influenced the adjuvant treatment in all Stage IIA cases as well as all metastatic cases. Incorporating MMR testing into routine clinical practice can help optimize patient management and treatment strategies in CRC.

Research progress of DNA methylation in colorectal cancer (Review).

DNA methylation is one of the earliest and most significant epigenetic mechanisms discovered. DNA methylation refers, in general, to the addition of a methyl group to a specific base in the DNA sequence under the catalysis of DNA methyltransferase, with S‑adenosine methionine as the methyl donor, via covalent bonding and chemical modifications. DNA methylation is an important factor in inducing cancer. There are different types of DNA methylation, and methylation at different sites plays different roles. It is well known that the progression of colorectal cancer (CRC) is affected by the methylation of key genes. The present review did not only discuss the potential relationship between DNA methylation and CRC but also discussed how DNA methylation affects the development of CRC by affecting key genes. Furthermore, the clinical significance of DNA methylation in CRC was highlighted, including that of the therapeutic targets and biomarkers of methylation; and the importance of DNA methylation inhibitors was discussed as a novel strategy for treatment of CRC. The present review did not only focus upon the latest research findings, but earlier reviews were also cited as references to older literature.

Integrated analysis of tumor-associated macrophages and M2 macrophages in CRC: unraveling molecular heterogeneity and developing a novel risk signature.

Emerging investigations have increasingly highlighted the critical role of tumor-associated macrophages (TAMs) and M2 macrophages in cancer development, progression, and metastasis, marking them as potential targets in various cancer types. The main objective of this research is to discover new biomarkers associated with TAM-M2 macrophages in colorectal cancer (CRC) and to dissect the molecular heterogeneity of CRC by combining single-cell RNA sequencing and bulk RNA-seq data. By utilizing weighted gene co-expression network analysis (WGCNA), we acquired TAM-M2-associated genes by intersecting TAM marker genes obtained from scRNA-seq data with module genes of M2 macrophages derived from bulk RNA-seq data. We employed least absolute shrinkage and selection operator (LASSO) Cox analysis to select predictive biomarkers from these TAM-M2-related genes. Quantitative polymerase chain reaction (qPCR) was employed to validate the mRNA expression levels of the genes identified in the screening. This led to the development of the TAM-M2-related signature (TAMM2RS). We also conducted functional and immune landscape analyses of different risk groups. The combination of scRNA-seq and bulk RNA-seq analyses yielded 377 TAM-M2-related genes. DAPK1, NAGK, and TRAF1 emerged as key prognostic genes in CRC, which were identified through LASSO Cox analysis. Utilizing these genes, we constructed and validated the TAMM2RS, demonstrating its effectiveness in predicting survival in CRC patients. Our research offers a thorough investigation into the molecular mechanisms associated with TAM-M2 macrophages in CRC and unveils potential therapeutic targets, offering new insights for treatment strategies in colorectal cancer.

Drug repurposing-based nanoplatform via modulating autophagy to enhance chemo-phototherapy against colorectal cancer

Multi-modal combination therapy is regarded as a promising approach to cancer treatment. Combining chemotherapy and phototherapy is an essential multi-modal combination therapy endeavor. Ivermectin (IVM) is a potent antiparasitic agent identified as having potential antitumor properties. However, the fact that it induces protective autophagy while killing tumor cells poses a challenge to its further application. IR780 iodide (IR780) is a near-infrared (NIR) dye with outstanding photothermal therapy (PTT) and photodynamic therapy (PDT) effects. However, the hydrophobicity, instability, and low tumor uptake of IR780 limit its clinical applications. Here, we have structurally modified IR780 with hydroxychloroquine, an autophagy inhibitor, to synthesize a novel compound H780. H780 and IVM can form H780-IVM nanoparticles (H-I NPs) via self-assembly. Using hyaluronic acid (HA) to modify the H-I NPs, a novel nano-delivery system HA/H780-IVM nanoparticles (HA/H-I NPs) was synthesized for chemotherapy-phototherapy of colorectal cancer (CRC). Under NIR laser irradiation, HA/H-I NPs effectively overcame the limitations of IR780 and IVM and exhibited potent cytotoxicity. In vitro and in vivo experiment results showed that HA/H-I NPs exhibited excellent anti-CRC effects. Therefore, our study provides a novel strategy for CRC treatment that could enhance chemo-phototherapy by modulating autophagy.

Perioperative and oncological outcomes following robotic en bloc multivisceral resection for colorectal cancer.

As multidisciplinary treatment strategies for colorectal cancer have improved, aggressive surgical resection has become commonplace. Multivisceral and extended resections offer curative-intent resection with significant survival benefit. However, limited data exist regarding the feasibility and oncological efficacy of performing extended resection via a minimally invasive approach. The aim of this study was to determine the perioperative and long-term outcomes following robotic extended resection for colorectal cancer. We describe the population of patients undergoing robotic multivisceral resection for colorectal cancer at our single institution. We evaluated perioperative details and investigated short- and long-term outcomes, using the Kaplan-Meier method to analyse overall and recurrence-free survival. Among the 86 patients most tumours were T3 (47%) or T4 (47%) lesions in the rectum (78%). Most resections involved the anterior compartment (72%): bladder (n = 13), seminal vesicle/vas deferens (n = 27), ureter (n = 6), prostate (n = 15) and uterus/vagina/adnexa (n = 27). Three cases required conversion to open surgery; 10 patients had grade 3 complications. The median hospital stay was 4 days. Resections were R0 (>1 mm) in 78 and R1 (0 to ≤1 mm) in 8, with none being R2. The average nodal yield was 26 and 48 (55.8%) were pN0. Three-year overall survival was 88% and median progression-free survival was 19.4 months. Local recurrence was 6.1% and distant recurrence was 26.1% at 3 years. Performance of multivisceral and extended resection on the robotic platform allows patients the benefit of minimally invasive surgery while achieving oncologically sound resection of colorectal cancer.

S100A6 mediated epithelial-mesenchymal transition affects chemosensitivity of colorectal cancer to oxaliplatin

PurposeTo investigate the mechanism by which S100 calcium-binding protein A6 (S100A6) affects colorectal cancer (CRC) cells to oxaliplatin (L-OHP) chemotherapy, and to explore new strategies for CRC treatment. MethodsS100A6 expression was assessed in both parental and L-OHP-resistant CRC cells using western blotting, quantitative real-time polymerase chain reaction (qRT-PCR), and enzyme-linked immunosorbent assays (ELISA). Lentiviral vectors were utilized to induce the knockdown of S100A6 expression, followed by comprehensive evaluations of cell proliferation, apoptosis, and epithelial-mesenchymal transition (EMT). Additionally, RNA-seq analysis was conducted to identify genes associated with the knockdown of S100A6. ResultsElevated S100A6 expression in CRC tissues correlated with an adverse prognosis in patients with CRC. Higher expression of S100A6 was also observed in L-OHP-resistant CRC cells, which showed enhanced proliferation, migration, invasion, and antiapoptotic capabilities. Notably, the knockdown of S100A6 expression resulted in decreased proliferation, increased apoptosis, and suppression of EMT and tumorigenicity in L-OHP-resistant CRC cells. Transcriptome sequencing reveals a noteworthy association between S100A6 and vimentin expression. Application of the EMT agonist, transforming growth factor β (TGF-β), induces EMT in CRC cells. S100A6 expression positively correlates with TGF-β expression. TGF-β facilitated the expression of EMT-related molecules and reduced the chemosensitivity of L-OHP in S100A6-knockdown cells. ConclusionIn conclusion, the knockdown of S100A6 may overcome the L-OHP resistance of CRC cells by modulating EMT.

Research progress of intestinal microbiota in targeted therapy and immunotherapy of colorectal cancer

Colorectal cancer (CRC) is one of the most common malignancies of the digestive tract, with increasing morbidity and mortality worldwide, and is the third most common malignancy in the world. At present, the main treatment methods for CRC include surgery, chemotherapy, targeted therapy, and immunotherapy. Regulation of the gut microbiota is one of the most promising new strategies for CRC treatment. Gut microbiota interacts with host cells to regulate many physiological processes, such as energy acquisition, metabolism, and immune responses. Recent studies have found that a combination of gut microbiota with targeted therapy and immunotherapy could improve the therapeutic effect of colon cancer compared with treatment alone. This article reviews the mechanism of microbiota regulation in CRC and the latest progress of intestinal microbiota in targeted therapy and immunotherapy of CRC, which is helpful in developing potential prevention or treatment strategies for colorectal cancer.

Improved Immune Response for Colorectal Cancer Therapy Triggered by Multifunctional Nanocomposites with Self-Amplifying Antitumor Ferroptosis.

Ferroptosis, as a type of regulated cell death, can trigger the release of damage-associated molecular patterns from cancer cells and lead to the enhancement of immune recognition. Fenton reaction-mediated chemodynamic therapy could initiate ferroptosis by generating lipid peroxides, but its efficiency would be greatly restricted by the insufficient H2O2 and antioxidant system within the tumor. Herein, this work reports the successful preparation of H2O2 self-supplied and glutathione (GSH)-depletion therapeutic nanocomposites (Cu2O@Au) through in situ growth of Au nanoparticles on the surface of cuprous oxide (Cu2O) nanospheres. Upon delivery into cancer cells, the released Cu2O could consume endogenous H2S within colorectal cancer cells to form Cu31S16 nanoparticles, while the released Au NPs could catalyze glucose to generate H2O2 and gluconic acid. The self-supplying endogenous H2O2 and lower acidity could amplify the Cu ion-induced Fenton-like reaction. Meanwhile, the consumption of glucose would reduce GSH generation by disrupting the pentose phosphate pathway. Additionally, the Cu2+/Cu+ catalytic cycle promotes the depletion of GSH, leading to lipid peroxide accumulation and ferroptosis. It was found that the onset of ferroptosis triggered by Cu2O@Au could initiate immunologic cell death, promote dendritic cell maturation and T-cell infiltration, and finally enhance the antitumor efficacy of the PD-L1 antibody. In summary, this collaborative action produces a remarkable antitumor effect, which provides a promising treatment strategy for colorectal cancer.

Peptide mimetic NC114 induces growth arrest by preventing PKCδ activation and FOXM1 nuclear translocation in colorectal cancer cells.

The peptide mimetic, NC114, is a promising anticancer compound that specifically kills colorectal cancer cells without affecting normal colon epithelial cells. In our previous study, we observed that NC114 inhibited the Wnt/β-catenin pathway, with significant downregulation of both Ser 675-phosphorylated β-catenin and its target genes, cyclin D1 and survivin. However, the molecular mechanism responsible for its cytotoxic effect has not yet been fully characterized. In the present study, we demonstrated that NC114 prevented cell cycle progression from S to G2/M phase by downregulating cell cycle-related gene expression, and also induced growth arrest in SW480 and HCT-116 colorectal cancer cells. A novel covariation network analysis combined with transcriptome analysis revealed a series of signaling cascades affected by NC114 treatment, and identified protein kinase C-δ (PKCδ) and forkhead box protein M1 (FOXM1) as important regulatory factors for NC114-induced growth arrest. NC114 treatment inhibits the activation of PKCδ and its kinase activity, which suppresses MEK/ERK signaling. Attenuated MEK/ERK signaling then results in a reduction in FOXM1 phosphorylation and subsequent nuclear translocation of FOXM1 and β-catenin. Consequently, formation of a T-cell factor-4 (TCF4)/β-catenin transcription complex in the nucleus is inhibited and transcription of its target genes, such as cell cycle-related genes, is downregulated. The efficacy of NC114 on tumor growth was confirmed in a xenograft model. Collectively, elucidation of the mechanism by which NC114 induces growth arrest in colorectal cancer cells should provide a novel therapeutic strategy for colorectal cancer treatment.

Classification of molecular subtypes for colorectal cancer and development of a prognostic model based on necroptosis-related genes

BackgroundNecroptosis could regulate immunity in cancers, and stratification of colorectal cancer (CRC) subtypes based on key genes related to necroptosis might be a novel strategy for CRC treatment. MethodThe RNA-sequencing data of CRC and other 31 types of cancers were obtained from The Cancer Genome Atlas (TCGA) database. Consensus clustering was performed based on protein-coding genes (PCGs) related to necroptosis score calculated by single sample gene set enrichment analysis (ssGSEA). Module genes showing a significant positive correlation with the necroptosis score were identified by weighted correlation network analysis (WGCNA) and further used to develop a risk stratification model applying least absolute shrinkage and selection operator (LASSO) and Cox regression analysis. The risks score for each sample in CRC cohorts, immunotherapy cohorts and pan-cancer study cohorts was calculated. ResultTwo subgroups (C1 cluster and C2 cluster) of CRC were identified based on the necroptosis score. Compared with C1 cluster, the survival possibility of C2 cluster was greatly reduced, the levels of necroptosis score, immune cell infiltration, immune score and expression of immune checkpoint molecules were significantly increased and immunotherapy response was less active. Low-risk patients defined by the risk model had a significant survival advantage than high-risk counterparts in both CRC and the other 31 cancer types. Furthermore, the risk model was also more efficient than the Tumor Immune Dysfunction and Exclusion (TIDE) tool in predicting OS and immunotherapy response for the samples in the immunotherapy cohort. ConclusionCRC patients were classified by necroptosis score-related PCGs, and a risk model was designed to evaluate the immunotherapy and prognosis of patients with CRC. The current molecular subtype and prognostic model could help stratify patients with different risks and predict their prognosis and immunotherapy sensitivity.

Assessing the Therapeutic Impacts of HAMLET and FOLFOX on BRAF-Mutated Colorectal Cancer: A Study of Cancer Cell Survival and Mitochondrial Dynamics In Vitro and Ex Vivo.

Background and Objectives: Colorectal cancer (CRC) is a major global health challenge. The BRAF V600E mutation, found in 8-12% of CRC patients, exacerbates this by conferring poor prognosis and resistance to therapy. Our study focuses on the efficacy of the HAMLET complex, a molecular substance derived from human breast milk, on CRC cell lines and ex vivo biopsies harboring this mutation, given its previously observed selective toxicity to cancer cells. Materials and Methods: we explored the effects of combining HAMLET with the FOLFOX chemotherapy regimen on CRC cell lines and ex vivo models. Key assessments included cell viability, apoptosis/necrosis induction, and mitochondrial function, aiming to understand the mutation-specific resistance or other cellular response mechanisms. Results: HAMLET and FOLFOX alone decreased viability in CRC explants, irrespective of the BRAF mutation status. Notably, their combination yielded a marked decrease in viability, particularly in the BRAF wild-type samples, suggesting a synergistic effect. While HAMLET showed a modest inhibitory effect on mitochondrial respiration across both mutant and wild-type samples, the response varied depending on the mutation status. Significant differences emerged in the responses of the HT-29 and WiDr cell lines to HAMLET, with WiDr cells showing greater resistance, pointing to factors beyond genetic mutations influencing drug responses. A slight synergy between HAMLET and FOLFOX was observed in WiDr cells, independent of the BRAF mutation. The bioenergetic analysis highlighted differences in mitochondrial respiration between HT-29 and WiDr cells, suggesting that bioenergetic profiles could be key in determining cellular responses to HAMLET. Conclusions: We highlight the potential of HAMLET and FOLFOX as a combined therapeutic approach in BRAF wild-type CRC, significantly reducing cancer cell viability. The varied responses in CRC cell lines, especially regarding bioenergetic and mitochondrial factors, emphasize the need for a comprehensive approach considering both genetic and metabolic aspects in CRC treatment strategies.

Genetic Alterations of NF-κB and Its Regulators: A Rich Platform to Advance Colorectal Cancer Diagnosis and Treatment.

Colorectal cancer (CRC) is the third leading cause of cancer mortality in the United States, with an estimated 52,000 deaths in 2023. Though significant progress has been made in both diagnosis and treatment of CRC in recent years, genetic heterogeneity of CRC-the culprit for possible CRC relapse and drug resistance, is still an insurmountable challenge. Thus, developing more effective therapeutics to overcome this challenge in new CRC treatment strategies is imperative. Genetic and epigenetic changes are well recognized to be responsible for the stepwise development of CRC malignancy. In this review, we focus on detailed genetic alteration information about the nuclear factor (NF)-κB signaling, including both NF-κB family members, and their regulators, such as protein arginine methyltransferase 5 (PRMT5), and outer dynein arm docking complex subunit 2 (ODAD2, also named armadillo repeat-containing 4, ARMC4), etc., in CRC patients. Moreover, we provide deep insight into different CRC research models, with a particular focus on patient-derived xenografts (PDX) and organoid models, and their potential applications in CRC research. Genetic alterations on NF-κB signaling components are estimated to be more than 50% of the overall genetic changes identified in CRC patients collected by cBioportal for Cancer Genomics; thus, emphasizing its paramount importance in CRC progression. Consequently, various genetic alterations on NF-κB signaling may hold great promise for novel therapeutic development in CRC. Future endeavors may focus on utilizing CRC models (e.g., PDX or organoids, or isogenic human embryonic stem cell (hESC)-derived colonic cells, or human pluripotent stem cells (hPSC)-derived colonic organoids, etc.) to further uncover the underpinning mechanism of these genetic alterations in NF-κB signaling in CRC progression. Moreover, establishing platforms for drug discovery in dishes, and developing Biobanks, etc., may further pave the way for the development of innovative personalized medicine to treat CRC in the future.

A Synergistic Approach Therapy for Colorectal Cancer Based on Exosomes and Exploitation of Metabolic Pathways

In order to reduce the side effects of traditional chemotherapy in the treatment of colorectal cancer (CRC), a new drug delivery system has been developed in this work, based on exosomes that can host two drugs that act synergistically: farnesol (that stops the cell cycle) and paclitaxel (prevents microtubule system depolymerization). Firstly, exosomes were isolated from different cell cultures (from colorectal cancer and from fibroblast as example of normal cell line) by different methods and characterized by western blot, TEM and DLS, and results showed that they express classical protein markers such as CD9 and HSP-70 and they showed spherical morphology with sizes from 93 nm to 129 nm depending on the source. These exosomes were loaded with both drugs and its effect was studied in vitro. The efficacy was studied by comparing the viability of cell cultures with a colorectal cancer cell line (HCT-116) and a normal cell line (fibroblast HS-5). Results showed that exosomes present a specific effect with more reduction in cell viability in tumour cultures than healthy ones. In summary, exosomes are presented in this work as a promising strategy for colorectal cancer treatment.

Deficiency of SR-B1 reduced the tumor load of colitis-induced or APCmin /+ -induced colorectal cancer.

Colorectal cancer (CRC) is one of the most common tumors in the world. Cholesterol plays an important role in the pathogenesis of tumors. One of the cholesterol transporters, scavenger receptor class B type 1 (SR-B1), a multi-ligand membrane receptor protein, is expressed in the intestines which also highly expressed in various tumors. But the potential mechanism of SR-B1 in CRC development has not been reported. This study aimed to clarify the importance of SR-B1 in the development and prognosis of CRC as much as possible to provide a possible strategy in CRC treatment. In this study, we used SR-B1 gene knockdown mice to study the effect of SR-B1 on colitis-induced or APCmin/+ -induced CRC. The expression of related molecules were detected through the immunohistochemistry and hematoxylin-eosin staining, western blot analysis, and Flow cytometry. The gene expression and microbiota in microenvironment of CRC mice were analyzed through eukaryotic mRNA sequencing and 16S rRNA high-throughput sequencing. The results showed that SR-B1 knockdown reduced the tumor load of colitis-induced or APCmin/+ -induced CRC. SR-B1 knockdown improved the immune microenvironment by affecting the level of tumor-associated macrophage (TAM), mononuclear myeloid-derived suppressor cells (M-MDSCs), granulocytic myeloid-derived suppressor cells (G-MDSCs), programmed cell death-ligand 1 (PD-L1), and human leukocyte antigen class I-B (HLA-B), and also reduced the level of low-density lipoprotein receptor (LDL-R), and increased the level of ATP binding cassette transporter A1 (ABCA1) to regulate the cholesterol metabolism, and regulated the expression of related genes and intestinal microbiota. SR-B1 knockdown can also trigger the anti-CRC effect of anti-PD 1 in colitis-induced CRC. SR-B1 deficiency significantly improved the immunity in tumor microenvironment of colitis-induced or APCmin/+ -induced CRC. In addition, the microbiota changes caused by SR-B1 deficiency favor improving the immune response to chemotherapeutic drugs and anti-PD1 therapy. The mechanism of action of SR-B1 deficiency on the development of CRC still needs further in-depth research. This study provides a new treatment strategy for treating CRC by affecting the expression of SR-B1 in intestine.

Combination of irinotecan silicasome nanoparticles with radiation therapy sensitizes immunotherapy by modulating the activation of the cGAS/STING pathway for colorectal cancer

Our previous clinical trial (Identifier: NCT02605265) revealed that addition of irinotecan (IRIN) to neoadjuvant chemoradiotherapy for rectal cancer could improve the curative effect. However, the adverse effects caused by IRIN limited the wide application of IRIN chemoradiotherapy. This study aimed to explore the mechanism under the synergistic effects of IRIN plus radiation therapy in colorectal cancer (CRC) cells and optimization of IRIN delivery via a silicasome nanocarrier in vivo. Our results revealed that compared with single IRIN or radiation treatment, IRIN combined with radiation therapy remarkably activated the intracellular cGAS/STING pathway, and promoted the expression levels of major histocompatibility complex class I (MHC-I) and programmed death ligand 1 (PD-L1). Further, a silicasome (mesoporous silica nanoparticle coated with lipid bilayer) nanocarrier was utilized to improve the delivery of IRIN with enhanced efficacy and reduced side effects. In the MC38 CRC syngeneic tumor model, IRIN silicasome combined with radiation therapy demonstrated a greater antitumor efficacy than free IRIN plus radiation therapy. Flow cytometry showed the increased number of CD4+ T cells, CD8+ T cells, and dendritic cells (DCs) in tumor in the IRIN silicasome plus radiation group. The immunofluorescence staining further confirmed the activated immune microenvironment with the elevated interferon-γ (IFN-γ) deposition. Besides, the antitumor effect of IRIN silicasome plus radiation therapy was synergistically enhanced by anti-PD-1 immunotherapy. These findings indicated that the combination of IRIN silicasome with radiation therapy could sensitize immunotherapy by manipulating the cGAS/STING pathway serving as a new strategy for CRC treatment.

The potential therapeutic applications of CRISPR/Cas9 in colorectal cancer.

The application of the CRISPR-associated nuclease 9 (Cas9) system in tumor studies has led to the discovery of several new treatment strategies for colorectal cancer (CRC), including the recognition of novel target genes, the construction of animal mass models, and the identification of genes related to chemotherapy resistance. CRISPR/Cas9 can be applied to genome therapy for CRC, particularly regarding molecular-targeted medicines and suppressors. This review summarizes some aspects of using CRISPR/Cas9 in treating CRC. Further in-depth and systematic research is required to fully realize the potential of CRISPR/Cas9 in CRC treatment and integrate it into clinical practice.

Comprehensive analysis identifies novel targets of gemcitabine to improve chemotherapy treatment strategies for colorectal cancer.

Gemcitabine (GEM) is a second-line anticancer drug of choice for some colorectal cancer (CRC) patients, and GEM inability to be commonly available in the clinic due to the lack of clarity of the exact action targets. The half maximal inhibitory concentration (IC50) of GEM treatment for 42 CRC cell lines were accessed from the Genomics of Drug sensitivity in Cancer (GDSC) database. High-throughput sequencing data of CRC patients were captured in The Cancer Genome Atlas (TCGA) and Weighted correlation network analysis (WGCNA) was conducted. Pearson correlations were derived for GEM potency-related genes. Differential analysis was conducted in the TCGA cohort to obtain CRC development-related genes (CDRGs), and univariate COX model analysis was performed on CDRGs overlapping with GEM potency-related genes to obtain CDRGs affecting CRC prognosis. Hub genes affecting GEM potency were identified by Spearman correlation. CALB2 and GPX3 were identified as potential targets for GEM treatment of CRC via prognostic analysis, which we also observed to be elevated with elevated clinical stage in CRC patients. The enhanced expression of CALB2 and GPX3 genes identified in the pathway analysis might inhibit the body metabolism as well as activate immune and inflammation related pathways. In addition, we found that CALB2 and GPX3 could also be considered as prognostic biomarkers in pan-cancer. Finally, we found that CALB2 and GPX3 were remarkably associated with the drug sensitivity of MG-132, Dasatinib, Shikonin, Midostaurin, MS-275, and Z-LNle-CHO, which were expected to be the drugs of choice for GEM combination. CALB2 and GPX3 represent prognostic biomarkers for CRC and they might be potential action targets for GEM. Our study offered innovative ideas for GEM administration strategies.

Single cell transcriptomics to identify immunological ACKR1+ DCs and their effect on clinical outcomes in left-sided CRC.

e15550 Background: Myeloid cells play critical roles in the growth and metastasis of malignant tumors with both protumor and antitumor capabilities. Plenty of studies have reported they participated in modulating tumor inflammation and angiogenesis, and therapeutic strategies targeting myeloid cells are ongoing in pre-clinical and clinical trials. The functions of myeloid cells and their subtypes in left-sided and right-side CRC remain unclear. Methods: A published scRNA-seq dataset (Pelka et al., 2021) with 21 samples from left-sided CRC and 79 from right-sided CRC (colorectal cancer) was obtained. Seurat (Stuart et al., 2019) was used to perform dimensionality reduction and differential expression analysis, and the cell subtypes in the myeloid cells were identified to study the associations between clinical outcomes and different tumor tissue sites of CRC. We also obtained an immunotherapy dataset from TISMO to identify associations between cell subtypes and immunotherapy outcomes. Results: Systematic comparisons of myeloid cells (n = 39,167) from left-sided and right-sided CRC revealed that highly expressed genes from right-sided CRC showed protumor capability and those from left-sided CRC showed antitumor activity. Specifically, left-sided CRC harbored a significant (p = 0.018) higher proportion of ACKR1+ DCs compared to right-sided CRC. ACKR1+ DCs might be immunological as its marker genes were significantly positively correlated with CD8+T cells and highly enriched in APC(antigen processing presentation)-related pathways. TCGA survival analysis revealed that the higher expression of the marker genes in ACKR1+ DC was associated with better overall survival (OS, p = 0.0088). Furthermore, immunotherapy biopsy showed ACKR1+ DCs subtype significantly enriched in immunotherapy responsive group compared to non-responsive group in colon cancer (p = 0.019), melanoma (p = 0.0058) and renal adenocarcinoma (p = 3.3e-06) among the obtained TISMO dataset. Conclusions: We identified an immunological ACKR1+ DCs subtype, which was highly enriched in left-sided CRC and was correlated with better clinical outcomes and immunotherapy responses. Those findings might provide potential therapeutic target and help better understand the mechanism of treatment strategies in CRC.

Role of gut microbiota and bacterial metabolites in mucins of colorectal cancer.

Colorectal cancer (CRC) is a major health burden, accounting for approximately 10% of all new cancer cases worldwide. Accumulating evidence suggests that the crosstalk between the host mucins and gut microbiota is associated with the occurrence and development of CRC. Mucins secreted by goblet cells not only protect the intestinal epithelium from microorganisms and invading pathogens but also provide a habitat for commensal bacteria. Conversely, gut dysbiosis results in the dysfunction of mucins, allowing other commensals and their metabolites to pass through the intestinal epithelium, potentially triggering host responses and the subsequent progression of CRC. In this review, we summarize how gut microbiota and bacterial metabolites regulate the function and expression of mucin in CRC and novel treatment strategies for CRC.

Spontaneous regression of advanced transverse colon cancer with deficient mismatch repair: a case report

BackgroundSpontaneous regression (SR) of cancer occurs in 1 in 60,000–100,000 patients. This phenomenon has been reported in almost all cancer types, most commonly neuroblastoma, renal cell carcinoma, malignant melanoma, and lymphoma/leukemia. However, SR in colorectal cancer (CRC) is extremely rare, particularly in advanced cases. Hence, this report describes a very rare case of spontaneous regression of advanced transverse colon cancer.Case presentationA 76-year-old female with anemia was diagnosed with a type II well-differentiated adenocarcinoma in the middle transverse colon. Two months later, a second colonoscopy examination was performed for preoperative marking, and it revealed tumor shrinkage and a shift to type 0–IIc morphology. Endoscopic tattooing was then performed, followed by a laparoscopic partial resection of the transverse colon with D3 lymph node dissection. However, the resected specimen contained no tumor, and colonoscopy showed no tumor remnants in the remaining colon. Histopathological examination revealed mucosal regeneration and a mucus nodule in between the submucosal and muscular layers, with no cancer cells detected. Immunohistochemical analysis revealed the loss of MutL homolog 1 (MLH1) and postmeiotic segregation increased 2 (PMS2) expression in the cancer cells of biopsied specimens, suggesting deficient mismatch repair (dMMR). The patient continues to be followed up until 6 years postoperatively, and no recurrence has been observed. In this study, we also reviewed similar reported cases of spontaneous regression of cancer involving dMMR.ConclusionThis study presents a rare case of spontaneous regression of advanced transverse colon cancer wherein dMMR is strongly involved. However, further accumulation of similar cases is needed to elucidate this phenomenon and to develop new treatment strategies for CRC.