Immunotherapy in colorectal cancer: current achievements and future perspective

Mechanisms of myeloid-derived suppressor cell-mediated immunosuppression in colorectal cancer and related therapies

Severe immunosuppression is a hallmark of colorectal cancer (CRC). Myeloid-derived suppressor cells (MDSCs), one of the most abundant components of the tumor stroma, play an important role in the invasion, metastasis, and immune escape of CRC. MDSCs create an immunosuppressive microenvironment by inhibiting the proliferation and activation of immunoreactive cells, including T and natural killer cells, as well as by inducing the proliferation of immunosuppressive cells, such as regulatory T cells and tumor-associated macrophages, which, in turn, promote the growth of cancer cells. Thus, MDSCs are key contributors to the emergence of an immunosuppressive microenvironment in CRC and play an important role in the breakdown of antitumor immunity. In this narrative review, we explore the mechanisms through which MDSCs contribute to the immunosuppressive microenvironment, the current therapeutic approaches and technologies targeting MDSCs, and the therapeutic potential of modulating MDSCs in CRC treatment. This study provides ideas and methods to enhance survival rates in patients with CRC.

Exploration of the Molecular Mechanism of Curcuma aromatica Salisb's Anticolorectal Cancer Activity via the Integrative Approach of Network Pharmacology and Experimental Validation

Curcuma aromatica Salisb (Cur), a well-known herbal medicine, has a wide spectrum of anti-inflammatory, anticarcinogenic, and antioxidant activities. However, the roles of its active compounds and potential mechanisms in colorectal cancer remain unknown. This research utilized network pharmacology and experimental validation to explore the possible mechanisms by which Cur protects against colorectal cancer. The active compounds of Cur and related genes for colorectal cancer were obtained from public databases. The DrugBank database was used to search for anticolorectal cancer drugs licensed through the FDA and their targets, and a "drug-component-target" relationship network was created using the Cytoscape program. The String database produced the PPI network. The ability of these active ingredients to bind to core targets was confirmed by molecular docking using AutoDock Vina. Cell and animal experiments were then carried out. A total of 274 targets were obtained from Cur, 49 of which were potential therapeutic targets. Four key targets, PTGS2, AKT1, TP53, and estrogen receptor 1 (ESR1), were screened via the PPI network and the FDA drug-target network. Molecular docking results revealed that Cur had strong binding abilities to these targets. In vivo and in vitro experiments demonstrated that Cur suppressed the development of colorectal cancer by regulating its targets (PTGS2, AKT1, TP53, and ESR1), which play crucial roles in promoting apoptosis and suppressing cell proliferation, migration, and invasion. Collectively, Cur protects against colorectal cancer by regulating the AKT1/PTGS2/ESR1 and P53 pathways, which lays the groundwork for further research and clinical applications of Cur in colorectal cancer therapy.

Transcription Factor E2F7 Hampers the Killing Effect of NK Cells against Colorectal Cancer Cells via Activating RAD18 Transcription

As a pivotal defensive line against multitudinous malignant tumors, natural killer (NK) cells exist in the tumor microenvironment (TME). RAD18 E3 Ubiquitin Protein Ligase (RAD18) has been reported to foster the malignant progression of multiple cancers, but its effect on NK function has not been mined. Here, the study was designed to mine the mechanism by which RAD18 regulates the killing effect of NK cells on colorectal cancer (CRC) cells. Expression of E2F Transcription Factor 7 (E2F7) and RAD18 in CRC tissues, their correlation, binding sites, and RAD18 enrichment pathway were analyzed by bioinformatics. Expression of E2F7 and RAD18 in cells was assayed by qRT-PCR and western blot. Dual-luciferase assay and chromatin immunoprecipitation (ChIP) assay verified the regulatory relationship between E2F7 and RAD18. CCK-8 assay was utilized to assay cell viability, colony formation assay to detect cell proliferation, lactate dehydrogenase (LDH) test to assay NK cell cytotoxicity, ELISA to assay levels of granulocyte-macrophage colony-stimulating factor (GM-CSF), tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), and immunofluorescence to detect expression of toxic molecules perforin and granzyme B. High expression of RAD18 and E2F7 was found in CRC tissues and cells. Silencing RAD18 could hamper the proliferation of CRC cells, foster viability and cytotoxicity of NK cells, and increase the secretion of GM-CSF, TNF-α, IFN-γ as well as the expression of perforin and granzyme B. Additionally, ChIP and dual-luciferase reporter assay ascertained the binding relationship between RAD18 promoter region and E2F7. E2F7 could activate the transcription of RAD18, and silencing RAD18 reversed the inhibitory effect of E2F7 overexpression on NK cell killing. This work clarified the inhibitory effect of the E2F7/RAD18 axis on NK cell killing in CRC, and proffered a new direction for immunotherapy of CRC in targeted immune microenvironment.

Screening for colorectal cancer: Study on the shedding cells of feces

Objective

The objective of this study was to explore the enrichment efficiency of an improved fecal exfoliated cell enrichment method and its application in colorectal cancer screening.

Material and Methods

Samples were collected from a cohort of 100 colorectal cancer patients being treated at the First Hospital of Hebei Medical University from January 2021 to June 2022. Patient samples were equally divided between control and experimental groups corresponding to the enrichment method being applied to the fecal exfoliated cells. Samples consisted of natural stool and bowel cleansing enema solution samples. The control group received the traditional three-layer integrated screen method, and the experimental group used nano-Fe3O4 folic acid magnetic beads to enrich the fecal exfoliated cells. The morphology of the extracted cells was observed by light microscopy through hematoxylin and eosin staining, and the positive rate of fecal occult blood test (FOBT) and the detection rate of colorectal cancer was compared between the two groups.

Results

The FOBT-positive rates of natural feces and intestinal cleansing liquid in the control group were 74.00% and 90.00%, respectively, and the FOBT-positive rates of natural feces and intestinal cleansing liquid in the experimental group were 76.00% and 92.00%, respectively. The positive FOBT rate was high, and the difference was statistically significant (P = 0.037 and P = 0.029). The sensitivities of natural fecal exfoliation cytology in the control and experimental groups were 82.00% and 92.00%, respectively. The sensitivity of the experimental group was higher than that of the control group, and the difference was not statistically significant (P = 0.137). The sensitivities of the exfoliated cytology examination of the intestinal cleansing liquid in the control and experimental groups were 88.00% and 98.00%, respectively. The sensitivity of the experimental group was significantly higher than that of the control group, and the difference was statistically significant (P = 0.050). Cell smear results show that the exfoliated cells collected by the three-layer integrated sieve method are unevenly distributed, with overlapping cells and a large number of impurities blurring the background, seriously affecting the observation of cell morphology. The cell structure is blurred, stained unevenly, and arranged in a disorderly manner. The exfoliated cells collected by the nanofolic acid magnetic bead enrichment method are relatively evenly distributed, with no overlapping of cells in patches. The background is clear, and the morphology of each cell can be clearly observed. The cell structure is relatively clear, stained evenly, and distributed evenly.

Conclusion

In the cytological examination of fecal exfoliation of colorectal cancer, the nano-Fe3O4 folic acid magnetic bead enrichment method can enrich more target cells compared with the traditional three-layer integrated screen method, improve the detection rate of colorectal cancer, and ensure the exfoliation The cell smears are of higher quality, providing a better sample for clinical assessment of the exfoliated cells. Nano-Fe3O4 folic acid magnetic beads enrichment method can become a simple, efficient, and relatively safe screening method for colorectal cancer, positively affecting early screening developments and diagnosis of 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.

Mining and exploration of rehabilitation nursing targets for colorectal cancer

BACKGROUND

There are often subtle early symptoms of colorectal cancer, a common malignancy of the intestinal tract. However, it is not yet clear how MYC and NCAPG2 are involved in colorectal cancer.

METHOD

We obtained colorectal cancer datasets GSE32323 and GSE113513 from the Gene Expression Omnibus (GEO). After downloading, we identified differentially expressed genes (DEGs) and performed Weighted Gene Co-expression Network Analysis (WGCNA). We then undertook functional enrichment assay, gene set enrichment assay (GSEA) and immune infiltration assay. Protein-protein interaction (PPI) network construction and analysis were undertaken. Survival analysis and Comparative Toxicogenomics Database (CTD) analysis were conducted. A gene expression heat map was generated. We used TargetScan to identify miRNAs that are regulators of DEGs.

RESULTS

1117 DEGs were identified. Their predominant enrichment in activities like the cellular phase of the cell cycle, in cell proliferation, in nuclear and cytoplasmic localisation and in binding to protein-containing complexes was revealed by Gene Ontology (GO). When the enrichment data from GSE32323 and GSE113513 colon cancer datasets were merged, the primary enriched DEGs were linked to the cell cycle, protein complex, cell cycle control, calcium signalling and P53 signalling pathways. In particular, MYC, MAD2L1, CENPF, UBE2C, NUF2 and NCAPG2 were identified as highly expressed in colorectal cancer samples. Comparative Toxicogenomics Database (CTD) demonstrated that the core genes were implicated in the following processes: colorectal neoplasia, tumour cell transformation, inflammation and necrosis.

CONCLUSIONS

High MYC and NCAPG2 expression has been observed in colorectal cancer, and increased MYC and NCAPG2 expression correlates with worse prognosis.

ALKBH5-mediated upregulation of CPT1A promotes macrophage fatty acid metabolism and M2 macrophage polarization, facilitating malignant progression of colorectal cancer

m6A modification has been studied in tumors, but its role in host anti-tumor immune response and TAMs polarization remains unclear. The fatty acid oxidation (FAO) process of TAMs is also attracting attention. A co-culture model of colorectal cancer (CRC) cells and macrophages was used to simulate the tumor microenvironment. Expression changes of m6A demethylase genes FTO and ALKBH5 were screened. ALKBH5 was further investigated. Gain-of-function experiments were conducted to study ALKBH5's effects on macrophage M2 polarization, CRC cell viability, proliferation, migration, and more. Me-RIP and Actinomycin D assays were performed to study ALKBH5's influence on CPT1A, the FAO rate-limiting enzyme. AMP, ADP, and ATP content detection, OCR measurement, and ECAR measurement were used to explore ALKBH5's impact on macrophage FAO level. Rescue experiments validated ALKBH5's mechanistic role in macrophage M2 polarization and CRC malignant development. In co-culture, CRC cells enhance macrophage FAO and suppress m6A modification in M2 macrophages. ALKBH5 was selected as the gene for further investigation. ALKBH5 mediates CPT1A upregulation by removing m6A modification, promoting M2 macrophage polarization and facilitating CRC development. These findings indicate that ALKBH5 enhances fatty acid metabolism and M2 polarization of macrophages by upregulating CPT1A, thereby promoting CRC development.

Cell-mediated barriers in cancer immunosurveillance

The immune cells within the tumor microenvironment (TME) exert multifaceted functions ranging from tumor-antagonizing or tumor-promoting activities. During the initial phases of tumor development, the tumor-antagonizing immune cells in the TME combat cancer cells in an immune surveillance process. However, with time, cancer cells can evade detection and impede the immune cells' effectiveness through diverse mechanisms, such as decreasing immunogenic antigen presentation on their surfaces and/or secreting anti-immune factors that cause tolerance in TME. Moreover, some immune cells cause immunosuppressive situations and inhibit antitumoral immune responses. Physical and cellular-mediated barriers in the TME, such as cancer-associated fibroblasts, tumor endothelium, the altered lipid composition of tumor cells, and exosomes secreted from cancer cells, also mediate immunosuppression and prevent extravasation of immune cells. Due to successful clinical outcomes of cancer treatment strategies the potential barriers must be identified and addressed. We need to figure out how to optimize cancer immunotherapy strategies, and how to combine therapeutic approaches for maximum clinical benefit. This review provides a detailed overview of various cells and molecules in the TME, their association with escaping from immune surveillance, therapeutic targets, and future perspectives for improving cancer immunotherapy.

RAS-Selective Lethal 3-Induced Ferroptosis Promotes the Antitumor Efficiency of Anti-Programmed Cell Death Protein 1 Treatment in Colorectal Cancer

BACKGROUND/AIMS

 Anti-programmed cell death protein 1 (PD-1) treatment has exhibited clinical benefits in colorectal cancer (CRC). However, the low response rate of CRC to immunotherapy is an urgent problem that needs to be solved.

MATERIALS AND METHODS

 MC-38 tumor cells was challenged subcutaneously in the flank of 7-week-old male C57BL/6 mice. The mice were randomly divided into 3 groups, and 200µg/mouse anti-PD-1 antibody and 100 mg/kg RAS-Seletive Lethal 3 (RSL) or phosphate buffer saline (PBS) were intraperitoneally injected every 2 days. The expression of oxidative stress and ferroptosis-related genes was measured by Western blotting, real-time reverse transcription-polymerase chain reaction, Prussian blue staining, and enzyme-linked immunosorbent assay.

RESULTS

 Anti-PD-1 treatment-unresponsive tumors showed stronger immunosuppression than responsive tumors. Notably, the responsive tumors showed higher levels of H2O2 and reactive oxygen species, both of which could impair the antitumor effect of cytotoxic CD8+ T cells. The anti-PD-1 treatment-responsive tumors showed a higher expression of pro-ferroptosis genes and Fe2+ accumulation than those of anti-PD-1 nonresponsive tumors, indicating the potential role of ferroptosis in the efficacy of anti-PD-1 treatment. In MC-38 syngeneic tumor model, (1S, 3R)-RSL3 (RSL), a glutathione peroxidase 4 inhibitor, effectively promoted the antitumor effect of anti-PD-1 treatment in vivo. However, anti-PD-1 treatment did not affect the levels of ferroptosis-related genes in tumor model. Mechanistically, RSL treatment significantly upregulated the frequency of proliferating (ki67+) and cytotoxic (GZMB+) CD8+ T cells. Furthermore, the frequency of tumor neoantigen-specific interferon (IFN)-γ CD8+ T cells showed a significant increase after RSL plus anti-PD-1 treatment.

CONCLUSION

 RSL may be a promising drug for potentiating the antitumor efficiency of anti-PD-1 treatment in CRC.

Sex Difference of Colon Adenoma Pathway and Colorectal Carcinogenesis

Colorectal cancer (CRC) is one of the most common causes of cancer morbidity in both sexes but shows sex differences. First, sex-specific differences in tumor recurrence and survival rates have been reported. For example, the development of CRC is found about 1.5 times higher and 4-8 years earlier in males compared to females, suggesting the protective role of estrogen in the disease. Furthermore, female patients have a higher risk of developing right-sided (proximal) colon cancer than male patients, which is known to have more aggressive clinical character compared to left-sided (distal) colon cancer. That is, left and right CRCs show differences in carcinogenic mechanism, that the chromosomal instability pathway is more common in left colon cancer while the microsatellite instability and serrated pathways are more common in right colon cancer. It is thought that there are sex-based differences on the background of carcinogenesis of CRC. Sex differences of CRC have two aspects, sexual dimorphism (biological differences in hormones and genes) and gender differences (non-biological differences in societal attitudes and behavior). Recently, sex difference of colon adenoma pathway and sexual dimorphism in the biology of gene and protein expression, and in endocrine cellular signaling in the CRC carcinogenesis have been accumulated. In addition, behavioral patterns can lead to differences in exposure to risk factors such as drinking or smoking, diet and physical activity. Therefore, understanding sex/gender-related biological and sociocultural differences in CRC risk will help in providing strategies for screening, treatment and prevention protocols to reduce the mortality and improve the quality of life. In this review, sex/gender differences in colon adenoma pathway and various aspects such as clinicopathological, biological, molecular, and socio-cultural aspects of CRC were described.

Overcoming cold tumors: a combination strategy of immune checkpoint inhibitors

Immune Checkpoint Inhibitors (ICIs) therapy has advanced significantly in treating malignant tumors, though most 'cold' tumors show no response. This resistance mainly arises from the varied immune evasion mechanisms. Hence, understanding the transformation from 'cold' to 'hot' tumors is essential in developing effective cancer treatments. Furthermore, tumor immune profiling is critical, requiring a range of diagnostic techniques and biomarkers for evaluation. The success of immunotherapy relies on T cells' ability to recognize and eliminate tumor cells. In 'cold' tumors, the absence of T cell infiltration leads to the ineffectiveness of ICI therapy. Addressing these challenges, especially the impairment in T cell activation and homing, is crucial to enhance ICI therapy's efficacy. Concurrently, strategies to convert 'cold' tumors into 'hot' ones, including boosting T cell infiltration and adoptive therapies such as T cell-recruiting bispecific antibodies and Chimeric Antigen Receptor (CAR) T cells, are under extensive exploration. Thus, identifying key factors that impact tumor T cell infiltration is vital for creating effective treatments targeting 'cold' tumors.

TMEM160 promotes tumor immune evasion and radiotherapy resistance via PD-L1 binding in colorectal cancer

BACKGROUND

The effectiveness of anti-programmed cell death protein 1(PD-1)/programmed cell death 1 ligand 1(PD-L1) therapy in treating certain types of cancer is associated with the level of PD-L1. However, this relationship has not been observed in colorectal cancer (CRC), and the underlying regulatory mechanism of PD-L1 in CRC remains unclear.

METHODS

Binding of TMEM160 to PD-L1 was determined by co-immunoprecipitation (Co-IP) and GST pull-down assay.The ubiquitination levels of PD-L1 were verified using the ubiquitination assay. Phenotypic experiments were conducted to assess the role of TMEM160 in CRC cells. Animal models were employed to investigate how TMEM160 contributes to tumor growth.The expression and clinical significance of TMEM160 and PD-L1 in CRC tissues were evaluated by immunohistochemistry(IHC).

RESULTS

In our study, we made a discovery that TMEM160 interacts with PD-L1 and plays a role in stabilizing its expression within a CRC model. Furthermore, we demonstrated that TMEM160 hinders the ubiquitination-dependent degradation of PD-L1 by competing with SPOP for binding to PD-L1 in CRC cells. Regarding functionality, the absence of TMEM160 significantly inhibited the proliferation, invasion, metastasis, clonogenicity, and radioresistance of CRC cells, while simultaneously enhancing the cytotoxic effect of CD8 + T cells on tumor cells. Conversely, the upregulation of TMEM160 substantially increased these capabilities. In severely immunodeficient mice, tumor growth derived from lentiviral vector shTMEM160 cells was lower compared with that derived from shNC control cells. Furthermore, the downregulation of TMEM160 significantly restricted tumor growth in immune-competent BALB/c mice. In clinical samples from patients with CRC, we observed a strong positive correlation between TMEM160 expression and PD-L1 expression, as well as a negative correlation with CD8A expression. Importantly, patients with high TMEM160 expression exhibited a worse prognosis compared with those with low or no TMEM160 expression.

CONCLUSIONS

Our study reveals that TMEM160 inhibits the ubiquitination-dependent degradation of PD-L1 that is mediated by SPOP, thereby stabilizing PD-L1 expression to foster the malignant progress, radioresistance, and immune evasion of CRC cells. These findings suggest that TMEM160 holds potential as a target for the treatment of patients with CRC.

TSC22D2 Regulates ACOT8 to Delay the Malignant Progression of Colorectal Cancer

Purpose

Colorectal cancer (CRC) is one of the cancers with high incidence and mortality rates worldwide. In China, there are approximately 400,000 new CRC cases each year, seriously endangering people's life and health. Transforming growth factor β-stimulated clone 22 domain family, member 2 (TSC22D2) is widely expression in cancers, but the role of TSC22D2 in CRC are still unknown.

Methods

Real‑time quantitative PCR (qRT-PCR) and Western blot were applied to determine the TSC22D2 levels. CCK-8, colony formation and transwell assays were used to determine the proliferation and metastasis abilities of CRC cells in vitro. In vivo metastatic potential was assessed using a subcutaneously injected mouse model and. Western-blot and immunoprecipitation experiments were used to study the mechanism of TSC22D2‑mediated metastasis.

Results

We found TSC22D2 was deregulated in CRC tissues and cells and implied poor prognosis. Overexpression TSC22D2 significantly promoted CRC cells proliferation and tumorigenicity both in vitro and vivo, whereas knockdown TSC22D2 resulted in the opposite effects. Importantly using a co-immunoprecipitation (co-IP) assay combined with mass spectrometry analysis to identify TSC22D2-interacting acyl-coenzyme A thioesterases 8 (ACOT8), TSC22D2 maintained stability of ACOT8. Overexpression of TCC22D2 in CRC cells can promote the expression of ACOT8 and inhibit the proliferation and metastasis of CRC cells through EMT mechanism, highlighting the possibility of TSC22D2 as a potential target in CRC development.

Conclusion

In summary, the present study revealed the inhibitory effect of TSC22D2 on the proliferation of colorectal cancer cells, suggesting that TSC22D2 may be an important tumor suppressor and a potential therapeutic target during colorectal carcinogenesis.

Prolyl isomerase Pin1 sculpts the immune microenvironment of colorectal cancer

Pin1, a peptide prolyl cis-trans isomerase, is overexpressed and/or overactivated in many human malignancies. However, whether Pin1 regulates the immunosuppressive TME has not been well defined. In this study, we detected the effect of Pin1 on immune cells and immune checkpoint PD-L1 in the TME of CRC and explored the anti-tumor efficacy of Pin1 inhibitor ATRA combined with PD-1 antibody. We found that Pin1 facilitated the immunosuppressive TME by raising the proportion of myeloid-derived suppressor cells (MDSCs) and declining the percentage of CD8+ T cells and CD4+ T cells. Pin1 restrained PD-L1 protein expression in CRC cells and the effect was tempered by endoplasmic reticulum (ER) stress inducers. Mechanically, Pin1 overexpression decreased the stability of PD-L1 and promoted its degradation by mitigating ER stress. Silencing or inhibiting Pin1 promoted PD-L1 protein expression by inducing ER stress. Hence, Pin1 inhibitor ATRA enhanced the anti-tumor efficacy of PD-1 antibody in the CRC allograft by upregulating PD-L1. Our results reveal the critical and pleiotropic effects of Pin1 on managing the immune cells and immune checkpoint PD-L1 in the TME of CRC, providing a new promising candidate for combination with immunotherapy.

Loss of the epithelial marker CDX1 predicts poor prognosis in early-stage CRC patients

BACKGROUND

We have previously shown that non-curative chemotherapy imposes fetal conversion and high metastatic capacity to cancer cells. From the set of genes differentially expressed in Chemotherapy Resistant Cells, we obtained a characteristic fetal intestinal cell signature that is present in a group of untreated tumors and is sufficient to predict patient prognosis. A feature of this fetal signature is the loss of CDX1.

METHODS

We have analyzed transcriptomic data in public datasets and performed immunohistochemistry analysis of paraffin embedded tumor samples from two cohorts of colorectal cancer patients.

RESULTS

We demonstrated that low levels of CDX1 are sufficient to identify patients with poorest outcome at the early tumor stages II and III. Presence tumor areas that are negative for CDX1 staining in stage I cancers is associated with tumor relapse.

CONCLUSIONS

Our results reveal the actual possibility of incorporating CDX1 immunostaining as a valuable biomarker for CRC patients.

Development of fatty acid metabolism score based on gene signature for predicting prognosis and immunotherapy response in colon cancer

PURPOSE

Metabolic reprogramming is a novel hallmark and therapeutic target of cancer. Our study aimed to establish fatty acid metabolism-associated scores based on gene signature and investigated its effects on immunotherapy in colon cancer.

METHODS

Gene expression and clinical information were collected from Gene Expression Omnibus (GEO) database to identify a gene signature by non-negative matrix factorization (NMF) clustering and Cox regression analysis. Subsequently, we constructed the fatty acid metabolism score (FA-score) model by principal component analysis (PCA) and explored its relativity of prognosis and the response to immunotherapy in colon cancer. Finally, the Cancer Genome Atlas (TCGA) database was introduced and in vitro study was performed for verification.

RESULTS

The FA-score-high group had a higher level of fatty acid metabolism and was associated with worse patient overall survival. Significantly, FA-score correlated closely with the biomarkers of immunotherapy, and the FA-score-high group had a poorer therapeutic efficacy of immune checkpoint blockade. In vitro experiments demonstrated that ACSL5 may be a critical metabolic regulatory target.

CONCLUSIONS

Our study provided a comprehensive analysis of the heterogeneity of fatty acid metabolism in colon cancer. We highlighted the potential clinical utility of fatty acid metabolism-related genes to be biomarkers of colon cancer prognosis and targets to improve the effect of immunotherapy.

NF2 is a candidate diagnosis, prognostic, and immunotherapeutic biomarker: a systematic pan-cancer analysis

Background

Neurofibromin 2 (NF2) regulates diverse cellular events such as transcription, translation, ubiquitination, and micro-RNA biosynthesis. Previous evidence revealed that aberrant expression of NF2 contributes to tumorigenesis in mesothelioma, meningioma, and breast cancer. However, there is no comprehensive pan-cancer analysis to explore NF2's function in cancer diagnosis, prognosis, and immunological prediction.

Methods

By extensive use of data profiles from The Cancer Genome Atlas (TCGA), Genotype-Tissue Expression (GTEx) project, Cancer Cell Line Encyclopedia (CCLE), CIBERSORT, Human Protein Atlas (HPA), and cBioPortal, we employed various bioinformatics methods to explore the role of NF2 in pan-cancer, including analyzing the association between NF2 and tumor diagnosis, prognosis, immune cell infiltration, tumor mutational burden (TMB), and microsatellite instability (MSI). Moreover, the co-expression relationship between NF2 expression with RNA modification genes was also constructed.

Results

Our research indicated that NF2 was highly expressed in most kinds of tumors. NF2 showed an early diagnosis value in 13 types of tumors and was significantly associated with the prognosis in most tumors. The results also verified that NF2 expression was associated with most immune-related cells and signaling pathways in pan-cancer, especially in diffuse large B-cell lymphoma and ovarian serous cystadenocarcinoma. Furthermore, NF2 gene expression was associated with TMB and MSI in many tumors.

Conclusions

Our study reveals that NF2 might be helpful in tumor early diagnosis and prognosis evaluation. The expression of NF2 is highly associated with the tumor immune microenvironment. Additionally, NF2 is a potential biomarker for predicting the efficacy of immune checkpoint inhibitors therapy. Therefore, NF2 can be a promising diagnostic, prognostic, and immunotherapeutic biomarker for many types of tumors.

Clinical implications of PD-L1 expression and pathway-related molecular subtypes in advanced Asian colorectal cancer patients

The expression level of PD-L1 does not accurately predict the prognosis of advanced colorectal cancer (CRC) patients, but it still reflects the tumor microenvironment to some extent. By stratifying PD-L1 status, gene subtypes in PD-L1 positivity-related pathological pathways were analyzed for their relationship to MSI or TMB to provide more individualized treatment options for CRCs. A total of 752 advanced CRCs were included, and their genomic variance was measured by a targeted next generation sequencing panel in this study. MSI and TMB were both measured by NGS, while PD-L1 expression level was measured using the PD-L1 colon 22C3 pharmDx kit. We found RTK/RAS pathway was positively related to high PD-L1 expression, with BRAF V600E and most KRAS mutations (G12 and G13) subtypes showing a significant correlation. Conversely, the Wnt and p53 pathways were negatively related to high PD-L1 expression, with APC C-terminal alterations and other non-inactivation mutations in TP53 making a primary contribution with significant statistical significance. Major subtypes showing a significantly higher proportion of TMB-H or MSI-H were irrespective of PD-L1 status. These findings demonstrate pathological pathways associated with high PD-L1 expression, suggesting that pathway-induced oncogenic constructive PD-L1 upregulation may be the reason for the corresponding patients' primary resistance to immune checkpoint inhibitors (ICIs), rather than a lack of pre-existing immune responses.

Preoperative controlling nutritional status as an optimal prognostic nutritional index to predict the outcome for colorectal cancer

BACKGROUND

The controlling nutritional status (CONUT) score effectively reflects a patient's nutritional status, which is closely related to cancer prognosis. This study investigated the relationship between the CONUT score and prognosis after radical surgery for colorectal cancer, and compared the predictive ability of the CONUT score with other indexes.

AIM

To analyze the predictive performance of the CONUT score for the survival rate of colorectal cancer patients who underwent potentially curative resection.

METHODS

This retrospective analysis included 217 patients with newly diagnosed colorectal. The CONUT score was calculated based on the serum albumin level, total lymphocyte count, and total cholesterol level. The cutoff value of the CONUT score for predicting prognosis was 4 according to the Youden Index by the receiver operating characteristic curve. The associations between the CONUT score and the prognosis were performed using Kaplan-Meier curves and Cox regression analysis.

RESULTS

Using the cutoff value of the CONUT score, patients were stratified into CONUT low (n = 189) and CONUT high groups (n = 28). The CONUT high group had worse overall survival (OS) (P = 0.013) and relapse-free survival (RFS) (P = 0.015). The predictive performance of CONUT was superior to the modified Glasgow prognostic score, the prognostic nutritional index, and the neutrophil-to-lymphocyte ratio. Meanwhile, the predictive performances of CONUT + tumor node metastasis (TNM) stage for 3-year OS [area under the receiver operating characteristics curve (AUC) = 0.803] and 3-year RFS (AUC = 0.752) were no less than skeletal muscle mass index (SMI) + TNM stage. The CONUT score was negatively correlated with SMI (P < 0.01).

CONCLUSION

As a nutritional indicator, the CONUT score could predict long-term outcomes after radical surgery for colorectal cancer, and its predictive ability was superior to other indexes. The correlation between the CONUT score and skeletal muscle may be one of the factors that play a predictive role.

An Analysis Regarding the Association Between DAZ Interacting Zinc Finger Protein 1 (DZIP1) and Colorectal Cancer (CRC)

Colorectal cancer (CRC) is the third most common malignant disease worldwide, and its incidence is increasing, but the molecular mechanisms of this disease are highly heterogeneous and still far from being fully understood. Increasing evidence suggests that fibrosis mediated by abnormal activation of fibroblasts based in the microenvironment is associated with a poor prognosis. However, the function and pathogenic mechanisms of fibroblasts in CRC remain unclear. Here, combining scrna-seq and clinical specimen data, DAZ Interacting Protein 1 (DZIP1) was found to be expressed on fibroblasts and cancer cells and positively correlated with stromal deposition. Importantly, pseudotime-series analysis showed that DZIP1 levels were up-regulated in malignant transformation of fibroblasts and experimentally confirmed that DZIP1 modulates activation of fibroblasts and promotes epithelial-mesenchymal transition (EMT) in tumor cells. Further studies showed that DZIP1 expressed by tumor cells also has a driving effect on EMT and contributes to the recruitment of more fibroblasts. A similar phenomenon was observed in xenografted nude mice. And it was confirmed in xenograft mice that downregulation of DZIP1 expression significantly delayed tumor formation and reduced tumor size in CRC cells. Taken together, our findings suggested that DZIP1 was a regulator of the CRC mesenchymal phenotype. The revelation of targeting DZIP1 provides a new avenue for CRC therapy.

Role of PAX6, TRPA1, BCL11B, MCOLN2, CUX1, EMX1 in colorectal cancer and osteosarcoma

Colorectal cancer is a cancer that arises from the abnormal growth of cells in the colon or rectum. Osteosarcoma (OS) is a common primary bone tumor with high degree of malignancy. The configuration files for colorectal cancer dataset GSE142279 and OS datasets GSE197158 and GSE206448 were downloaded from Gene Expression Omnibus database using the platforms GPL20795, GPL20301, and GPL24676. Differentially expressed genes (DEGs) were screened and weighted gene co-expression network analysis (WGCNA) was performed. Construction and analysis of protein-protein interactions (PPI) network. Functional enrichment analysis, gene set enrichment analysis (GSEA) were performed. A heat map of gene expression was drawn. The Comparative Toxicogenomics Database (CTD) was used to find the diseases most associated with the core genes. TargetScan was used to screen miRNAs regulating DEGs. According to the Gene Ontology (GO) analysis, DEGs are mainly enriched in acetylcholine binding receptor activity involved in Wnt signaling pathway, cell polarity pathway, PI3K-Akt signaling pathway, receptor regulator activity, cytokine-cytokine receptor interaction, transcriptional misregulation in cancer, and inflammation-mediated regulation of tryptophan transport. In the Metascape enrichment analysis, GO enrichment items related to the regulation of Wnt signaling pathway, regulation of muscle system process, and regulation of actin filament-based movement. Eight core genes (CUX1, NES, BCL11B, PAX6, EMX1, MCOLN2, TRPA1, TRPC4) were identified. CTD showed that 4 genes (CUX1, EMX1, TRPA1, BCL11B) were associated with colorectal neoplasms, colorectal tumors, colonic diseases, multiple myeloma, OS, and inflammation. PAX6, TRPA1, BCL11B, MCOLN2, CUX1, and EMX1 are highly expressed in colorectal cancer and OS, and the higher the expression level, the worse the prognosis.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

Anti-PD-1/PD-L1 therapy for colorectal cancer: Clinical implications and future considerations

Colorectal cancer (CRC) is the third most prevalent cancer in the world. The PD-1/PD-L1 pathway plays a crucial role in modulating immune response to cancer, and PD-L1 expression has been observed in tumor and immune cells within the tumor microenvironment of CRC. Thus, immunotherapy drugs, specifically checkpoint inhibitors, have been developed to target the PD-1/PD-L1 signaling pathway, thereby inhibiting the interaction between PD-1 and PD-L1 and restoring T-cell function in cancer cells. However, the emergence of resistance mechanisms can reduce the efficacy of these treatments. To counter this, monoclonal antibodies (mAbs) have been used to improve the efficacy of CRC treatments. mAbs such as nivolumab and pembrolizumab are currently approved for CRC treatment. These antibodies impede immune checkpoint receptors, including PD-1/PD-L1, and their combination therapy shows promise in the treatment of advanced CRC. This review presents a concise overview of the use of the PD-1/PD-L1 blockade as a therapeutic strategy for CRC using monoclonal antibodies and combination therapies. Additionally, this article outlines the function of PD-1/PD-L1 as an immune response suppressor in the CRC microenvironment as well as the potential advantages of administering inflammatory agents for CRC treatment. Finally, this review analyzes the outcomes of clinical trials to examine the challenges of anti-PD-1/PD-L1 therapeutic resistance.

Identification of Comprehensive Biomarkers in Patients With Mismatch Repair-Deficient Colon Adenocarcinoma Based on Parallel Multiomics

Immunocheckpoint inhibitors have shown impressive efficacy in patients with colon cancer and other types of solid tumor that are mismatch repair-deficient (dMMR). Currently, PCR-capillary electrophoresis is one of the mainstream detection methods for dMMR, but its accuracy is still limited by germline mismatch repair (MMR) mutations, the functional redundancy of the MMR system, and abnormal methylation of MutL Homolog 1 promoter. Therefore, this study aimed to develop new biomarkers for dMMR based on artificial intelligence (AI) and pathologic images, which may help to improve the detection accuracy. To screen for the differential expression genes (DEGs) in dMMR patients and validate their diagnostic and prognostic efficiency, we used the expression profile data from the Cancer Genome Atlas (TCGA). The results showed that the expression of Immunoglobulin Lambda Joining 3 in dMMR patients was significantly downregulated and negatively correlated with the prognosis. Meanwhile, our diagnostic models based on pathologic image features showed good performance with area under the curves (AUCs) of 0.73, 0.86, and 0.81 in the training, test, and external validation sets (Jiangsu Traditional Chinese Medicine Hospital cohort). Based on gene expression and pathologic characteristics, we developed an effective prognosis model for dMMR patients through multiple Cox regression analysis (with AUC values of 0.88, 0.89, and 0.88 at 1-, 3-, and 5-year intervals, respectively). In conclusion, our results showed that Immunoglobulin Lambda Joining 3 and nucleus shape-related parameters (such as nuclear texture, nuclear eccentricity, nuclear size, and nuclear pixel intensity) were independent diagnostic and prognostic factors, suggesting that they could be used as new biomarkers for dMMR patients.

Experimental prognostic model integrating N6-methyladenosine-related programmed cell death genes in colorectal cancer

Colorectal cancer (CRC) intricacies, involving dysregulated cellular processes and programmed cell death (PCD), are explored in the context of N6-methyladenosine (m6A) RNA modification. Utilizing the TCGA-COADREAD/CRC cohort, 854 m6A-related PCD genes are identified, forming the basis for a robust 10-gene risk model (CDRS) established through LASSO Cox regression. qPCR experiments using CRC cell lines and fresh tissues was performed for validation. The CDRS served as an independent risk factor for CRC and showed significant associations with clinical features, molecular subtypes, and overall survival in multiple datasets. Moreover, CDRS surpasses other predictors, unveiling distinct genomic profiles, pathway activations, and associations with the tumor microenvironment. Notably, CDRS exhibits predictive potential for drug sensitivity, presenting a novel paradigm for CRC risk stratification and personalized treatment avenues.

Integrated bioinformatics analysis and experimental validation identified CDCA families as prognostic biomarkers and sensitive indicators for rapamycin treatment of glioma

The cell division cycle associated (CDCA) genes regulate the cell cycle; however, their relationship with prognosis in glioma has been poorly reported in the literature. The Cancer Genome Atlas (TCGA) was utilized to probe the CDCA family in relation to the adverse clinical features of glioma. Glioma single-cell atlas reveals specific expression of CDCA3, 4, 5, 8 in malignant cells and CDCA7 in neural progenitor cells (NPC)-like malignant cells. Glioma data from TCGA, the China Glioma Genome Atlas Project (CGGA) and the gene expression omnibus (GEO) database all demonstrated that CDCA2, 3, 4, 5, 7 and 8 are prognostic markers for glioma. Further analysis identified CDCA2, 5 and 8 as independent prognostic factors for glioma. Lasso regression-based risk models for CDCA families demonstrated that high-risk patients were characterized by high tumor mutational burden (TMB), low levels of microsatellite instability (MSI), and low tumor immune dysfunction and rejection (TIDE) scores. These pointed to immunotherapy for glioma as a potentially viable treatment option Further CDCA clustering suggested that the high CDCA subtype exhibited a high macrophage phenotype and was associated with a higher antigen presentation capacity and high levels of immune escape. In addition, hsa-mir-15b-5p was predicted to be common regulator of CDCA3 and CDCA4, which was validated in U87 and U251 cells. Importantly, we found that CDCAs may indicate response to drug treatment, especially rapamycin, in glioma. In summary, our results suggest that CDCAs have potential applications in clinical diagnosis and as drug sensitivity markers in glioma.

Sulforaphane triggers Sirtuin 3-mediated ferroptosis in colorectal cancer cells via activating the adenosine 5'-monophosphate (AMP)-activated protein kinase/ mechanistic target of rapamycin signaling pathway

OBJECTIVE

This study aimed to explore the expression and biological functions of SIRT3 in colorectal cancer cells (HCT-116), the impacts of sulforaphane on the ferroptosis of HCT-116 cells and the involvement of the SIRT3/AMPK/mTOR axis in those effects.

METHODS

SIRT3-overexpressing (OE) and SIRT3-knockout (KO) cell lines were treated with different concentrations of sulforaphane, RSL-3, and IKE. Cell viability, intracellular ROS, MDA, iron levels, as well as mRNA and protein expressions of target genes were measured.

RESULTS

SIRT3 expression in HCT-116 cells was increased by ferroptosis inducers and decreased by ferroptosis inhibitors. SIRT3 overexpression reduced cell viability and increased intracellular levels of ROS, MDA, and iron, whereas SIRT3 knockdown achieved the opposite effects. SIRT3 overexpression suppressed SLC7A11 expression and promoted the activation of AMPK/mTOR pathway. Restoration of SLC7A11 expression blocked the effects of SIRT3 on ferroptosis induction and cell viability inhibition. SIRT3 effects on cell viability and ferroptosis were antagonized by inhibitors of AMPK or mTOR. Moreover, sulforaphane triggered the ferroptosis of HCT-116 cells by activating the SIRT3/AMPK/mTOR axis.

CONCLUSIONS

SIRT3 triggered SLC7A11-mediated ferroptosis in HCT-116 cells, reducing cell viability by activating the AMPK/mTOR pathway, and sulforaphane targets it to inhibit colorectal cancer.

High Expression of SRSF10 Promotes Colorectal Cancer Progression by Aberrant Alternative Splicing of RFC5

BACKGROUND

Colorectal cancer (CRC) remains a global health concern with persistently high incidence and mortality rates. However, the specific pathogenesis of CRC remains poorly understood. This study aims to investigate the role and pathogenesis of serine and arginine rich splicing factor 10 (SRSF10) in colorectal cancer.

METHODS

Bioinformatics analysis was employed to predict SRSF10 gene expression in CRC patients. Functional experiments involving SRSF10 knockdown and overexpression were conducted using CCK8, transwell, scratch assay, and flow cytometry. Additionally, the PRIdictor website was utilized to predict the SRSF10 interaction site with RFC5. The identification of different transcripts of SRSF10-acting RFC5 pre-mRNA was achieved through agarose gel electrophoresis.

RESULT

The knockdown of SRSF10 inhibited the proliferation and migration ability of CRC cells, while promoting apoptosis and altering the DNA replication of CRC cells. Conversely, when SRSF10 was highly expressed, it enhanced the proliferation and migration ability of CRC cells and caused changes in the cell cycle of colorectal cancer cells. This study revealed a change in the replicating factor C subunit 5 (RFC5) gene in colorectal cancer cells following SRSF10 knockdown. Furthermore, it was confirmed that SRSF10 increased RFC5 exon2-AS1(S) transcription variants, thereby promoting the development of colorectal cancer through AS1 exclusion to exon 2 of RFC5.

CONCLUSION

In summary, this study demonstrates that SRSF10 promotes the progression of colorectal cancer by generating an aberrantly spliced exclusion isoform of AS1 within RFC5 exon 2. These findings suggest that SRSF10 could serve as a crucial target for the clinical diagnosis and treatment of CRC.

Advanced Strategies of CAR-T Cell Therapy in Solid Tumors and Hematological Malignancies

Chimeric antigen receptor T-cells, known as CAR-T cells, represent a promising breakthrough in the realm of adoptive cell therapy. These T-cells are genetically engineered to carry chimeric antigen receptors that specifically target tumors. They have achieved notable success in the treatment of blood-related cancers, breathing new life into this field of medical research. However, numerous obstacles limit chimeric antigen receptors T-cell therapy's efficacy, such as it cannot survive in the body long. It is prone to fatigue and exhaustion, leading to difficult tumor elimination and repeated recurrence, affecting solid tumors and hematological malignancies. The challenges posed by solid tumors, especially in the context of the complex solid-tumor microenvironment, require specific strategies. This review outlines recent advancements in improving chimeric antigen receptors T-cell therapy by focusing on the chimeric antigen receptors protein, modifying T-cells, and optimizing the interaction between T-cells and other components within the tumor microenvironment. This article aims to provide an extensive summary of the latest discoveries regarding CAR-T cell therapy, encompassing its application across various types of human cancers. Moreover, it will delve into the obstacles that have emerged in recent times, offering insights into the challenges faced by this innovative approach. Finally, it highlights novel therapeutic options in treating hematological and solid malignancies with chimeric antigen receptors T-cell therapies.

Comprehensive analysis reveals TSPEAR as a prognostic biomarker in colorectal cancer

Background: Colorectal cancer (CRC) is one of the most common malignant tumors and has high morbidity and mortality rates. Previous studies have shown that TSPEAR mutations are involved in the development and progression of gastric cancer and liver cancer. However, the role of TSPEAR in CRC is still unclear. Methods: In The Cancer Genome Atlas (TCGA) database, 590 CRC patients with complete survival information were analyzed. We assessed TSPEAR expression in a pan-cancer dataset from the TCGA database. Cox regression analysis was performed to evaluate factors associated with prognosis. Enrichment analysis via the R package "clusterProfiler" was used to explore the potential function of TSPEAR. The single-sample GSEA (ssGSEA) method from the R package "GSVA" and the TIMER database were used to investigate the association between the immune infiltration level and TSPEAR expression in CRC. The R package "maftools" was used to explore the association between tumour mutation burden (TMB) and TSPEAR expression in CRC. CCK-8 assays and cell invasion assays were used to detect the effect of TSPEAR and TGIF2 on the biological behavior of CRC cells. Results: Pan-cancer analysis revealed that TSPEAR was upregulated in CRC tissues compared to normal tissues and that high TSPEAR expression was associated with poorer overall survival (OS) (p=0.0053). The expression of TSPEAR increased with increasing TNM stage, T stage, N stage, and M stage. The nomogram constructed with TSPEAR, age, and TNM stage showed better predictive value than TSPEAR, age, or TNM stage alone. Immune cell infiltration analysis revealed that high expression of TSPEAR was associated with lower immune cell infiltration. Tumor mutation burden (TMB) analysis indicated that high expression of TSPEAR was associated with lower TMB (p=0.005), and high TMB was associated with shorter OS (p=0.02). CCK-8 assays and cell invasion assays indicated that in vitro knockdown of TSPEAR inhibited the proliferation, migration, and invasion of CRC cells. In addition, TSPEAR expression may be regulated by the upstream transcription factor TGIF2. Conclusion: TSPEAR expression was higher in CRC tissues than in normal tissues. Its upregulation was significantly associated with a poor prognosis. Additionally, TSPEAR plays a significant role in tumor immunity and the biological behavior of CRC cells. Thus, TSPEAR may become a promising prognostic biomarker and therapeutic target for CRC patients.

A study on metabolic characteristics and metabolic markers of gastrointestinal tumors

Tumor cells have significant heterogeneity in metabolism and are closely related to prognosis, gene mutation, and subtype. However, this association has not been demonstrated in reports of gastrointestinal tumors. In this study, we constructed four metabolic subtypes and identified four gene signatures using the expression data and clinical information of 252 metabolism-related genes from TCGA and NCBI databases for gastric adenocarcinoma (STAD) and colorectal cancer (COAD and READ). MC1 had the worst prognosis compared to other classifications. GSig1 was mainly related to drug metabolism and was the highest in MC1 with the worst prognosis, while the other subtypes were mainly related to glucose metabolism pathways. This difference also existed in other different malignant tumors. In addition, metabolic typing was associated with chemotherapeutic drug response and tumor heterogeneity, which indicated that monitoring metabolic typing could contribute to drug efficacy and gene-targeted therapy. In conclusion, we identified differences among subtypes in clinical characteristics such as prognosis and revealed the potential function of metabolic subtype in response to chemotherapeutic agents and oncogene mutations. This work highlighted the potential clinical meaning of metabolic subtype and characteristics in drug therapy and prognosis assessment of malignant tumors.

Integrative analysis of single-cell and bulk RNA seq to reveal the prognostic model and tumor microenvironment remodeling mechanisms of cuproptosis-related genes in colorectal cancer

BACKGROUND

Recently, there has been a great deal interest in cuproptosis, a form of programmed cell death that is mediated by copper. The specific mechanism through which cuproptosis-related genes impact the development of colorectal cancer (CRC) remains unknown.

METHODS

Here, we combined bulk RNA-seq with scRNA-seq to investigate the CRGs functions within CRC. A number of 61 cuproptosis-related genes were chosen for further investigation. Nine prognostic CRGs were identified by Lasso-Cox. The RiskScore was created and the patients have been separated into two different groups, low- and high-RiskScore group. The CIBERSORT, ESTIMATE, MCP-counter, TIDE, and IPS have been employed to score the TME, and GSVA and GSEA were utilized to evaluate the pathway within the both groups. Further, we used cell communication analysis to explore the tumor microenvironment remodeling mechanisms of the COX17 and DLAT based on scRNA-seq. Finally, we used IHC and qPCR to validate the expression of COX17 and DLAT.

RESULTS

AOC3, CCS, CDKN2A, COX11, COX17, COX19, DLD, DLAT, and PDHB have been recognized as prognostic CRGs in CRC. The high-risk group exhibited the worst prognosis, an immune-deficient phenotype, and were more resistant to ICB treatment. Further, scRNA-seq analysis revealed that elevated expression of COX17 in CD4-CXCL13Tfh could contribute to the immune evasion while DLAT had the opposite effect, reversing T cell exhaustion and inducing pyroptosis to boost CD8-GZMKT infiltration.

CONCLUSIONS

The current investigation has developed a prognostic framework utilizing cuproptosis-related genes that is highly effective in predicting prognosis, TME type, and response to immunotherapy in CRC patients. Furthermore, our study reveals a novel finding that elevated levels of COX17 expression within CD4-CXCL13 T cells in CRC mediates T cell exhaustion and Treg infiltration, while DLAT has been found to facilitate the anti-tumor immunity activation through the T cell exhaustion reversal and the induction of pyroptosis.

A liquid biopsy signature of circulating extracellular vesicles-derived RNAs predicts response to first line chemotherapy in patients with metastatic colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is one of the most threatening tumors in the world, and chemotherapy remains dominant in the treatment of metastatic CRC (mCRC) patients. The purpose of this study was to develop a biomarker panel to predict the response of the first line chemotherapy in mCRC patients.

METHODS

Totally 190 mCRC patients treated with FOLFOX or XEOLX chemotherapy in 3 different institutions were included. We extracted the plasma extracellular vesicle (EV) RNA, performed RNA sequencing, constructed a model and generated a signature through shrinking the number of variables by the random forest algorithm and the least absolute shrinkage and selection operator (LASSO) algorithm in the training cohort (n = 80). We validated it in an internal validation cohort (n = 62) and a prospective external validation cohort (n = 48).

RESULTS

We established a signature consisted of 22 EV RNAs which could identify responders, and the area under the receiver operating characteristic curve (AUC) values was 0.986, 0.821, and 0.816 in the training, internal validation, and external validation cohort respectively. The signature could also identify the progression-free survival (PFS) and overall survival (OS). Besides, we constructed a 7-gene signature which could predict tumor response to first-line oxaliplatin-containing chemotherapy and simultaneously resistance to second-line irinotecan-containing chemotherapy.

CONCLUSIONS

The study was first to develop a signature of EV-derived RNAs to predict the response of the first line chemotherapy in mCRC with high accuracy using a non-invasive approach, indicating that the signature could help to select the optimal regimen for mCRC patients.

Integrating scRNA-seq and bulk RNA-seq to characterize infiltrating cells in the colorectal cancer tumor microenvironment and construct molecular risk models

Colorectal cancer (CRC) is a malignancy that is both highly lethal and heterogeneous. Although the correlation between intra-tumoral genetic and functional heterogeneity and cancer clinical prognosis is well-established, the underlying mechanism in CRC remains inadequately understood. Utilizing scRNA-seq data from GEO database, we re-isolated distinct subsets of cells, constructed a CRC tumor-related cell differentiation trajectory, and conducted cell-cell communication analysis to investigate potential interactions across cell clusters. A prognostic model was built by integrating scRNA-seq results with TCGA bulk RNA-seq data through univariate, LASSO, and multivariate Cox regression analyses. Eleven distinct cell types were identified, with Epithelial cells, Fibroblasts, and Mast cells exhibiting significant differences between CRC and healthy controls. T cells were observed to engage in extensive interactions with other cell types. Utilizing the 741 signature genes, prognostic risk score model was constructed. Patients with high-risk scores exhibited a significant correlation with unfavorable survival outcomes, high-stage tumors, metastasis, and low responsiveness to chemotherapy. The model demonstrated a strong predictive performance across five validation cohorts. Our investigation involved an analysis of the cellular composition and interactions of infiltrates within the microenvironment, and we developed a prognostic model. This model provides valuable insights into the prognosis and therapeutic evaluation of CRC.

NAT10 mediated mRNA acetylation modification patterns associated with colon cancer progression and microsatellite status

N4-acetylcytidine (ac4C) is one type of RNA modification found in eukaryotes. RNA acetylation modifications are gradually expanding in oncology. However, the role of RNA acetylation modifications in colorectal cancer and its association with colorectal cancer microsatellite status remain unclear. Using public databases and in vitro experiments, we verified the expression and biological function of NAT10, as the key RNA acetylation modification enzyme, in colorectal cancer. The results showed that NAT10 was highly expressed in colorectal cancer, and significantly promoted colorectal cancer cell proliferation. NAT10 was also involved in several aspects of cell homoeostasis such as ion transport, calcium-dependent phospholipid binding, and RNA stability. NAT10 expression positively correlated with immune infiltration in colorectal cancer. We further constructed a risk regression model for mRNA acetylation in colorectal cancer using acetylation-related differential genes. We found that tumour immune infiltration, microsatellite instability (MSI) proportion, tumour immune mutation burden, and patient response to immunotherapy were positively correlated with risk scores. For the first time, our study showed that the level of mRNA acetylation modification level is elevated in colorectal cancer and positively correlates with immune infiltration and microsatellite status of patients. Based on our findings, NAT10 may be a new target for colorectal cancer treatment.

Comparison of effectiveness and safety of Da Vinci robot's "3 + 1" and "4 + 1" modes of treatment for colorectal cancer

To compare the effectiveness of the Da Vinci Surgical Robot System (DSRS) "3 + 1" and "4 + 1" models for colorectal cancer (CRC). A total of 107 patients with CRC admitted to our hospital from February 2021 to May 2022 were selected for the retrospective analysis. Of these, 57 patients underwent the DSRS "4 + 1" model (control group), while the rest 50 underwent the DSRS "3 + 1" model (research group). The operation time, intraoperative bleeding, number of lymph nodes detected, time of first postoperative urinary catheter removal, time of first feeding, time of first venting and hospitalization were compared between the two groups. The changes of white blood cell (WBC) and C-reactive protein (CRP) levels before and after surgery were detected, and patients' adverse effects and treatment costs between surgery and hospital discharge were counted. The Self-Rating Anxiety Scale (SAS) and the Self-Rating Depression Scale (SDS) were used to assess the psychological state of the patients. There was no difference in operative time, intraoperative bleeding, and number of lymph nodes detected between both groups (P > 0.05), while time to first postoperative urinary catheter removal, time to first feeding, time to first venting, length of stay (LOS), postoperative inflammatory factor levels, incidence of adverse events, and treatment costs were all lower in the research group than in the control group (P < 0.05). SAS and SDS scores decreased after treatment in both groups, but the decrease was more obvious in the research group (P < 0.05). Both DSRS "4 + 1" and "3 + 1" modes have better treatment effects for CRC. However, the "3 + 1" mode has higher safety and lower treatment cost, which can significantly improve the postoperative recovery process of patients and is more worthy to be promoted in clinical practice.

Cordycepin remodels the tumor microenvironment of colorectal cancer by down-regulating the expression of PD-L1

PURPOSE

Colorectal cancer, as a common malignant tumor, poses a serious threat to human life. Cordycepin, derived from Cordyceps militaris extract, which was established as a capable inhibitor of tumor growth. Nevertheless, the precise antitumor mechanism of cordycepin in colorectal cancer cells remains elusive.

METHODS

Herein, our initial focus was to explore the tumor-suppressive impact of cordycepin through its influence on various biological functions in murine colorectal cancer cells, conducted by an in vitro setting. First, we investigated the tumor-suppressive effect of cordycepin on the regulation of biological functions in murine colorectal cancer cells in vitro. Furthermore, we evaluated the in vivo antitumor potential of cordycepin using a mouse preclinical tumor model, and further explored the antitumor mechanism.

RESULTS

Our findings revealed that cordycepin effectively inhibit the proliferation, invasion, and migration of murine colon cancer cells. Moreover, there is a substantial reduction in the expression of PD-L1 observed in tumor cells, in response to cordycepin treatment. Collectively, these results demonstrate the significant tumor-suppressive attributes of cordycepin against colorectal cancer. Consequently, our study lays a solid foundation for the potential clinical utilization of cordycepin in cancer therapy.

CONCLUSION

Cordycepin inhibits the biological functions of colorectal cancer cells and suppresses tumor growth by reducing the expression of PD-L1.

Integrated analysis of single cell and bulk RNA sequencing identifies CTHRC1+ INHBA+ CAF as drivers of colorectal cancer progression

Cancer-associated fibroblasts (CAFs) are a key component of the tumor microenvironment and a critical factor in the progression of colorectal cancer (CRC). The aim of this study was to screen for CAFs specific genes that could serve as promising therapeutic targets for CRC patients. Our findings showed a significant increase in the proportion of fibroblasts in CRC tissues, and a high proportion of fibroblasts was associated with immune escape and poor prognosis in CRC. Collagen triple helix repeat containing 1 (CTHRC1) and inhibin subunit beta A (INHBA) were identified as key genes in the progression of CRC, primarily expressed in CAFs and significantly upregulated in CRC tissues. We defined CTHRC1 and INHBA as cancer-associated fibroblast-related genes (CAFRGs), which were associated with poor prognosis in CRC and macrophage polarization. CAFRGs promoted immune escape and metastasis in CRC and were good predictors of immune therapy response. Drug sensitivity analysis showed that the high expression group of CAFRGs was sensitive to 15 chemotherapy drugs, while the low expression group was sensitive to only 3. Clustering of fibroblasts in the tumor revealed that CTHRC1+ INHBA+ CAF was a poor prognostic factor in CRC and was associated with extracellular matrix remodeling and immune regulation. In conclusion, our study provides new theoretical basis for effective treatment strategies and therapeutic targets for CRC.

Intensified NK cell therapy in combination with low-dose chemoradiotherapy against human colorectal cancer

The therapeutic potential of adoptive natural Killer (NK) cells immunotherapy in combination with chemoradiotherapy, the main treatment modality for colorectal cancer (CRC), has not yet been explored. Here, we aimed to investigate the efficacy of NK cells to potentiate primary tumor control and improve survival outcomes, especially in combination with low-dose chemoradiotherapy. Ex vivo activated NK cells (> 90% purity) from healthy donors were obtained. NK cells were administered intravenously to the CRC-bearing mice and intensified in vivo in combination with low-dose 5-fluorouracil (0.5 mg/kg or 1 mg/Kg) and irradiated tumors with low doses (2 Gy or 4 Gy). Real-time NK cell cytotoxicity demonstrated a synergistic killing effect of a combination of low-dose chemoradiotherapy, mainly through NKp30 and NKG2D, showing a decrease in NK cell degranulation after blocking NKG2D and NKp30. In vivo tumor characteristics after combination treatment showed decreased CD112, CD155, MICA, and MICB expression. Under the combination strategy, 70% of the mice had free lung metastasis and 90% without secondary gross tumors, indicating suppressed distant metastasis to lung and axillary regions. This combination therapy resulted in significantly synergistic antitumor activity against primary solid tumors compared to chemoradiotherapy only. Furthermore, the intensified NK cell administration showed significantly better primary tumor control and survival outcomes than the non-intensified NK cell administration in a human colorectal HT-29 model treated with low-dose chemoradiotherapy. Optimized NK cell therapy combined with low-dose chemoradiotherapy can provide effective therapeutic potential for intractable cold human colorectal cancer.

Single-cell analysis unveils activation of mast cells in colorectal cancer microenvironment

The role of mast cells (MCs) in colorectal cancer (CRC) remains unclear, and a comprehensive single-cell study on CRC MCs has not been conducted. This study used a multi-omics approach, integrating single-cell sequencing, spatial transcriptomics, and bulk tissue sequencing data to investigate the heterogeneity and impact of MCs in CRC. Five MC signature genes (TPSAB1, TPSB2, CPA3, HPGDS, and MS4A2) were identified, and their average expression was used as a marker of MCs. The MC density was found to be lower in CRC compared to normal tissue, but MCs in CRC demonstrated distinct activation features. Activated MCs were defined by high expression of receptors and MC mediators, while resting MCs had low expression. Most genes, including the five MC signature genes, were expressed at higher levels in activated MCs. The MC signature was linked to a better prognosis in both CRC and pan-cancer patient cohorts. Elevated KITLG expression was observed in fibroblasts and endothelial cells in CRC samples compared to normal tissue, and co-localization of MCs with these cell types was revealed by spatial transcriptome analysis. In conclusion, this study finds decreased MC density in CRC compared to normal tissue, but highlights a shift in MC phenotype from CMA1high resting cells to activated TPSAB1high, CPA3high, and KIThigh cells. The elevated KITLG expression in the tumor microenvironment's fibroblasts and endothelial cells may activate MCs through the KITLG-KIT axis, potentially suppressing tumor progression.

Application of sintilimab combined with anlotinib hydrochloride in the clinical treatment of microsatellite stable colorectal cancer

BACKGROUND

Microsatellite stable (MSS) colorectal cancer (CRC) is a common type of tumor with limited treatment options. Sintilimab and anlotinib hydrochloride are two extensively studied anticancer drugs.

AIM

To probe the clinical value of combining sintilimab with anlotinib hydrochloride in MSS CRC treatment.

METHODS

During the period spanning from April 2019 to April 2022, Zhejiang Provincial People’s Hospital accommodated a cohort of 92 patients diagnosed with MSS CRC who were classified into two distinct groups in our study, the observation group and the control group. The control group was administered anlotinib hydrochloride as their designated therapy, whereas the observation group received the additional treatment of sintilimab in conjunction with the therapy assigned to the control group. The administration of treatment occurred in cycles consisting of a duration of 3 wk, and the evaluation of effectiveness took place subsequent to the completion of two consecutive cycles of treatment within both groups. A comparative analysis between the two groups was conducted to assess the short-term efficacy and ascertain the incidence of adverse events transpiring throughout the duration of the treatment period. Changes in the levels of carcinoembryonic antigen, carbohydrate antigen 199 (CA199), CA125, and T cell subsets (CD4+, CD8+, CD4+/CD8+) as well as the assessment of the quality of life using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 were compared between the two groups prior to and subsequent to therapy. Finally, a 1-year follow-up was conducted for both groups of patients, and the survival status was recorded and analyzed.

RESULTS

The short-term effectiveness displayed by the observation group surpassed that exhibited by the control group, with a statistically significant discrepancy (76.09% vs 50.00%), reaching a significance level denoted as P < 0.05. Following the administration of treatment, the observation group manifested a considerable reduction in numerous serum indicators, which were found to be lower than the corresponding pretreatment levels within the same group as well as the post-treatment levels observed in the control group (P < 0.05). Post-treatment, the T lymphocyte subset levels within the observation group demonstrated a remarkable amelioration, surpassing the corresponding pre-treatment levels observed within the same group as well as the post-treatment levels observed in the control group (P < 0.05). Subsequent to the therapeutic intervention, the observation group showcased a notable amelioration in the scores associated with multiple dimensions of life quality. These scores outperformed the pretreatment scores within the same group as well as the post-treatment scores observed in the control group (P < 0.05). The safety levels of drug use in the two group were comparable (19.57% vs 13.04%), and no distinct difference was observed upon comparison (P > 0.05). After the completion of treatment, both groups of patients underwent a 1-year follow-up outside the hospital. Throughout this period, 1 patient within the observation group and 2 patients within the control group became untraceable and were lost to follow-up. During the follow-up period of the observation group, 12 patients died, resulting in a survival rate of 73.33% (33/45), while in the control group, 21 patients died, resulting in a survival rate of 52.27% (23/44). The implementation of Kaplan-Meier survival analysis revealed a conspicuous contrast in survival rates exhibited by the two groups (log-rank = 4.710, P = 0.030).

CONCLUSION

The combination of sintilimab and anlotinib hydrochloride demonstrated favorable efficacy in the treatment of MSS CRC patients, leading to improvements in patient immunity and prognosis. Additionally, it exerted inhibitory effects on the expression of carcinoembryonic antigen, CA199, and CA125.

Perioperative immune checkpoint inhibition for colorectal cancer: recent advances and future directions

For colorectal cancer (CRC), surgical resection remains essential for achieving good prognoses. Unfortunately, numerous patients with locally advanced CRC and metastatic CRC failed to meet surgical indications or achieve pathological complete response after surgery. Perioperative therapy has been proven to effectively lower tumor staging and reduce recurrence and metastasis. Immune checkpoint inhibitors (ICIs) have shown unprecedented prolongation of survival time and satisfactory safety in patients with high microsatellite instability/deficient mismatch repair (MSI-H/dMMR), while the therapeutic effect obtained by patients with mismatch repair-proficient or microsatellite stable (pMMR/MSS) was considered minimal. However, recent studies found that certain CRC patients with dMMR/MSI-H presented intrinsic or acquired immune resistance, and pMMR/MSS CRC patients can also achieve better efficacy. Therefore, more predictors are required for screening patients with potential clinical benefits. Since the discovery of synergistic effects between immunotherapy, chemotherapy, and radiotherapy, different immunotherapy-based therapies have been applied to the perioperative therapy of CRC in an increasing number of research. This review comprehensively summarized the past and current progress of different combinations of immunotherapy in perioperative clinical trials for CRC, focusing on the efficacy and safety, and points out the direction for future development.

Colorectal Liver Metastasis: Can Cytokines Make the Difference?

Colorectal cancer (CRC) is the third leading cause of cancer-related death worldwide. Metastasis is the prime driver of CRC-related mortality, and the liver is the organ most frequently involved. Despite the overall success of current treatments, colorectal liver metastasis (CRLM) is associated with poor prognoses and a survival rate of only 14%. Recent studies have highlighted the importance of the tumor microenvironment (TME) and the crosstalk within it in determining the invasion of distant organs by circulating cancer cells. In the TME, cellular communication is mediated via soluble molecules, among which cytokines have recently emerged as key regulators, involved in every aspect of tumor progression and the metastatic cascade. Indeed, in the serum of CRC patients elevated levels of several cytokines are associated with cancer development and progression. The current review evaluates the role of different cytokines during CRLM development. Additionally, considering the increasing amount of data concerning the importance of cytokine complex networks, we outline the potential of combination treatments using targeted cytokines together with other well-established therapies, such as immune checkpoint blockades, chemotherapy, or gene therapy, to improve therapeutic outcomes.

Construction of disulfidptosis-related lncRNA signature for predicting the prognosis and immune escape in colon adenocarcinoma

Colon adenocarcinoma (COAD) is one of the most frequent types of cancer worldwide. Disulfidptosis has been identified as a new mode of cell death recently. The goal of this study was to explore the possibility of a connection between disulfidptosis and COAD. RNA sequencing data from COAD patients were retrieved from the The Cancer Genome Atlas (TCGA) database for this investigation. R software and various methods were used to identify disulfidptosis-related lncRNAs (DRLs) in COAD, and a prognostic model was created based on 6 DRLs (AP003555.1, AL683813.1, SNHG7, ZEB1-AS1, AC074212.1, RPL37A-DT). The prognostic model demonstrated a good accuracy in predicting the prognosis of COAD patients, according to receiver operating characteristic (ROC) curve and Concordance index (C-index) analyses. Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed significant differences in biological functions and signaling pathways involved in differential genes in risk subgroups, including protein - DNA complex subunit organization, Hippo signaling pathway, Wnt signaling pathway. TIDE analysis was done on risk groupings in this study, and it found that patients in the high-risk group had more immune escape potential and were less probable to react to immunotherapy. Real-time quantitative pcr (qRT-PCR) was used to identify the relatively high expression of 6 DRLs in colon cancer cell lines. In summary, 6 DRLs were identified as possible novel molecular therapy targets for COAD in this investigation. This prognostic model has the potential to be a novel tool for forecasting COAD prognosis in clinical practice, as well as providing new insights on the potential function and mechanism of disulfidptosis in the COAD process.

Clinicopathological significance and prognostic implications of Ube2v1 expression in colorectal cancer

The present study aimed to investigate the expression of ubiquitin-conjugating enzyme E2 variant 1 (Ube2v1) in colorectal cancer (CRC) and its clinical significance. The differential expression of Ube2v1 in CRC tissues and normal intestinal tissues, as well as the association between Ube2v1 expression and the prognosis of patients with CRC were analyzed using bioinformatics analyses. TIMER database analysis revealed higher Ube2v1 expression in CRC tissues than in normal intestinal tissues. Cancerous and normal tissues collected retrospectively from 37 cases of CRC between July, 2022 and June, 2023 were analyzed for Ube2v1 expression using immunohistochemistry, and the associations between Ube2v1 expression and the clinical pathological features of patients with CRC were analyzed. Ube2v1 expression was associated with lymph node metastasis in patients with CRC (P<0.05). However, bioinformatics analysis using the GEPIA2 and HPA database revealed that Ube2v1 was not associated with the overall survival of patients with CRC. On the whole, the present study demonstrates that due to its high expression and association with lymph node metastasis, Ube2v1 may serve as a potential target for the treatment of CRC.

Immune checkpoint inhibitor therapy in neoadjuvant and adjuvant treatment for cancer: A paradigm shift in the treatment of resectable gastrointestinal cancer 3)A paradigm shift in the treatment of colorectal cancer

Immune checkpoint inhibitors, such as anti-programmed cell death-1, programmed cell death ligand-1, and cytotoxic T-lymphocyte antigen-4 monoclonal antibodies, have been notably effective in various types of cancers. Mismatch repair deficiency and microsatellite instability-high tumors have been established as striking biomarkers for response to immune checkpoint inhibitors. These biomarkers show a higher mutational burden, have cancer-associated neoantigens, and dense immune cell infiltration, which generates a robust immune response. For metastatic colorectal cancer, pembrolizumab and nivolumab, with or without ipilimumab, are recommended for chemotherapy-refractory patients, and pembrolizumab is recommended for chemotherapy-naive patients with mismatch repair deficiency and microsatellite instability-high tumors. Conversely, patients with mismatch repair-proficient and microsatellite-stable metastatic colorectal cancer showed no clinical benefit from immune checkpoint inhibitor monotherapy. Currently, combination therapy with anti-programmed cell death-1/programmed cell death ligand-1 and cytotoxic T-lymphocyte antigen-4 monoclonal antibodies or a combination of immune checkpoint inhibitors with molecular targeting agents or radiotherapy have been investigated to modulate immune cells and enhance therapeutic efficacy in mismatch repair-proficient and microsatellite-stable metastatic colorectal cancer. Furthermore, immune checkpoint inhibitors have been developed for neoadjuvant and adjuvant settings. In this review, we summarize the existing clinical data and discuss future perspectives with a focus on immune checkpoint inhibitor-based treatments for colorectal cancer.

Attenuated Salmonella-delivered PD-1 siRNA enhances the antitumor effects of EZH2 inhibitors in colorectal cancer

Immunotherapy has made significant progress in the treatment of malignant tumors. However, strategies to combine immunotherapy with anticancer drugs have attracted great attention due to the low response rate and unique toxicity profile of immunotherapies and the subsequent development of acquired resistance in some initial responders. EZH2, a histone methyl transferase subunit of a Polycomb repressor complex,is highly expressed in a variety of tumors, and targeting EZH2 has become a new strategy for tumor therapy and drug combination. Here，we studied the effect of EZH2 inhibitors on colorectal cancer cells and their combination with immunotherapy. Our results demonstrated that EZH2 inhibitors can not only significantly inhibit the survival of colorectal cancer (CRC) cells and induce apoptosis, effectively inhibit cell invasion and migration, but also cause an increase in the expression of PD-L1 receptors on the cell surface. To determine the effect of EZH2 in combination with immunotherapy, we combine EZH2 inhibitors with PD-1 siRNA delivered by attenuated Salmonella. The vivo experiments have shown that the combination of EZH2 inhibitors and Salmonella-delivered PD-1 siRNA can further inhibit the development of CRC, trigger effective anti-tumor immunity, and improve therapeutic efficacy. Its underlying mechanisms mainly involve synergistic immunomodulation and apoptosis. This study suggests an emerging strategy based on a combination of EZH2 inhibitor and immunotherapy based on PD-1 inhibition.

HER-2 Expression in Colorectal Cancer and Its Correlation with Immune Cell Infiltration

BACKGROUND

This study aimed to investigate the effect of increased HER-2 expression on tumor-infiltrating lymphocytes (TILs) and determine its impact on the prognosis of colorectal cancer (CRC) patients; Methods: HER-2, CD4, CD8, CD19, LY6G, CD56, CD68, CD11b, and EpCam expression in CRC tissues and adjacent paracancerous tissues were assessed using multiplex fluorescence immunohistochemical staining. The correlation between HER-2 expression and the number of TILs in CRC tissues was analyzed. Kaplan-Meier and Cox proportional hazards models were used to analyze survival outcomes; Results: The expression of HER-2 in tumor tissues was higher than that in paracancerous tissues (1.31 ± 0.45 vs. 0.86 ± 0.20, p < 0.05). Additionally, there was an increase in the numbers of CD4+, CD8+, CD19+, and CD68+ cells in CRC tissues (14.11 ± 1.10 vs. 3.40 ± 0.18, p < 0.005; 0.16 ± 0.12 vs. 0.04 ± 0.04, p < 0.005; 0.71 ± 0.46 vs. 0.25 ± 0.13, p < 0.0005; 0.27 ± 0.24 vs. 0.03 ± 0.11, p < 0.05). An increase in HER-2 expression was positively correlated with an increase in CD4, CD8, and CD19 (p < 0.0001). In HER-2-positive CRC tissues, CD68 expression was increased (0.80 ± 0.55 vs. 0.25 ± 0.22, p < 0.05). In HER-2-upregulated CRC tissues, CD4, CD8, CD19, CD68, CD11b, Ly6G, and CD56 expressions were elevated (0.70 ± 0.37 vs. 0.32 ± 0.17, p = 0.03; 0.22 ± 0.13 vs. 0.09 ± 0.06, p = 0.03; 0.31 ± 0.19 vs. 0.12 ± 0.08, p = 0.02; 1.05 ± 0.62 vs. 0.43 ± 0.21, p < 0.01; 1.34 ± 0.81 vs. 0.53 ± 0.23, p < 0.01; 0.50 ± 0.31 vs. 0.19 ± 0.10, p < 0.01; 1.26 ± 0.74 vs. 0.52 ± 0.24, p < 0.01). Furthermore, increased HER-2 expression was an independent risk factor for recurrence-free survival (RFS) in patients (p < 0.01, HR = 3.421); Conclusions: The increased expression of HER-2 and its relationship with immune cells will provide new insights for immunotherapy in CRC patients.