Neoadjuvant immunotherapy in primary and metastatic colorectal cancer

Adding first-line PD-1 inhibition to anti-VEGF and XELOX in pMMR metastatic colorectal cancer: Steppingstones, stumbling blocks, and next phase

In the randomized, double-blind, multicenter study by Wang et al.,1 the addition of serplulimab (a PD-1 antibody) to anti-VEGF (HLX04; a bevacizumab biosimilar) together with chemotherapy (XELOX) was deemed to be tolerable and safe and may improve progression-free survival. However, even if adverse events were comparable, oncological endpoints including survival need to be confirmed in the next phase 3 study.

Multifaceted bioinformatic analysis of m6A-related ferroptosis and its link with gene signatures and tumour-infiltrating immune cells in gliomas

Whether N6-Methyladenosine (m6A)- and ferroptosis-related genes act on immune responses to regulate glioma progression remains unanswered. Data of glioma and corresponding normal brain tissues were fetched from the TCGA database and GTEx. Differentially expressed genes (DEGs) were identified for GO and KEGG enrichment analyses. The FerrDb database was based to yield ferroptosis-related DEGs. Hub genes were then screened out using the cytoHubba database and validated in clinical samples. Immune cells infiltrating into the glioma tissues were analysed using the CIBERSORT R script. The association of gene signature underlying the m6A-related ferroptosis with tumour-infiltrating immune cells and immune checkpoints in low-grade gliomas was analysed. Of 6298 DEGs enriched in mRNA modifications, 144 were ferroptosis-related; NFE2L2 and METTL16 showed the strongest positive correlation. METTL16 knockdown inhibited the migrative and invasive abilities of glioma cells and induced ferroptosis in vitro. NFE2L2 was enriched in the anti-m6A antibody. Moreover, METTL16 knockdown reduced the mRNA stability and level of NFE2L2 (both p < 0.05). Proportions of CD8+ T lymphocytes, activated mast cells and M2 macrophages differed between low-grade gliomas and normal tissues. METTL16 expression was negatively correlated with CD8+ T lymphocytes, while that of NFE2L2 was positively correlated with M2 macrophages and immune checkpoints in low-grade gliomas. Gene signatures involved in the m6A-related ferroptosis in gliomas were identified via bioinformatic analyses. NFE2L2 interacted with METTL16 to regulate the immune response in low-grade gliomas, and both molecules may be novel therapeutic targets for gliomas.

Immunotherapy for colorectal cancer

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

Bioinformatic Analyses and Integrated Machine Learning to Predict prognosis and therapeutic response Based on E3 Ligase-Related Genes in colon cancer

Purpose: Colorectal cancer is the third most common cause of cancer death worldwide. We probed the correlations between E3 ubiquitin ligase (E3)-related genes (ERGs) and colon cancer prognosis and immune responses. Methods: Gene expression profiles and clinical data of patients with colon cancer were acquired from the TCGA, GTEx, GSE17537 and GSE29621 databases. ERGs were identified by coexpression analysis. WGCNA and differential expression analysis were subsequently conducted. Consensus clustering identified two molecular clusters. Differential analysis of the two clusters and Cox regression were then conducted. A prognostic model was constructed based on 10 machine learning algorithms and 92 algorithm combinations. The CIBERSORT, ssGSEA and TIMER algorithms were used to estimate immune infiltration. The OncoPredict algorithm and The Cancer Immunome Atlas (TCIA) predicted susceptibility to chemotherapeutic and targeted drugs and immunotherapy sensitivity. CCK-8, scratch-wound and RT‒PCR assays were subsequently conducted. Results: Two ERG-associated clusters were identified. The prognosis and immune function of patients in cluster A were superior to those of patients in cluster B. We constructed a prognostic model with perfect predictive capability and validated it in internal and external colon cancer datasets. We discovered significant discrepancies in immune infiltration and immune checkpoints between different risk groups. The group with high-risk had a reduced half-maximal inhibitory concentration (IC50) for some routine antitumor drugs and reduced susceptibility to immunotherapy. In vitro experiments demonstrated that the ectopic expression of PRELP inhibited the migration and proliferation of CRC cells. Conclusions: In summary, we identified novel molecular subtypes and developed a prognostic model, which will help a lot in the advancement of better forecasting and therapeutic approaches.

PD-1/PD-L1 axis: implications in immune regulation, cancer progression, and translational applications

The PD-1/PD-L1 axis is a complex signaling pathway that has an important role in the immune system cells. Programmed cell death protein 1 (PD-1) acts as an immune checkpoint on the T lymphocytes, B lymphocytes, natural killer (NK), macrophages, dendritic cells (DCs), monocytes, and myeloid cells. Its ligand, the programmed cell death 1 ligand (PD-L1), is expressed in the surface of the antigen-presenting cells (APCs). The binding of both promotes the downregulation of the T cell response to ensure the activation to prevent the onset of chronic immune inflammation. This axis in the tumor microenvironment (TME) performs a crucial role in the tumor progression and the escape of the tumor by neutralizing the immune system, the engagement of PD-L1 with PD-1 in the T cell causes dysfunctions, neutralization, and exhaustion, providing the tumor mass production. This review will provide a comprehensive overview of the functions of the PD-1/PD-L1 system in immune function, cancer, and the potential therapeutic implications of the PD-1/PD-L1 pathway for cancer management.

Multifactorial risk prediction analysis of liver metastasis in colorectal cancer: incorporating programmed cell death ligand 1 combined positive score and other factors

BACKGROUND

The occurrence of liver metastasis significantly affects the prognosis of colorectal cancer (CRC). Existing research indicates that primary tumor location, vascular invasion, lymph node metastasis, and abnormal preoperative tumor markers are risk factors for CRC liver metastasis. Positive expression of programmed cell death ligand 1 (PD-L1) may serve as a favorable prognostic marker for nasopharyngeal and gastric cancers, in which combined positive score (CPS) quantifies the level of PD-L1 expression. This study aimed to explore CPS as a potential risk factor for CRC liver metastasis and integrate other independent risk factors to establish a novel predictive model for CRC liver metastasis.

METHODS

A retrospective analysis was conducted on 437 patients with CRC pathologically diagnosed at The Second Xiangya Hospital of Central South University from January 1, 2019, to December 31, 2021. Data were collected, including CPS, age, gender (male and female), primary tumor location, Ki-67 expression, pathologic differentiation, neural invasion, vascular invasion, lymph node metastasis, and preoperative tumor markers. The optimal cutoff point for the continuous variable CPS was determined using the Youden index, and all CPSs were dichotomized into high- and low-risk groups based on this threshold (scores below the threshold were considered high risk, and score above the threshold were considered low risk). Univariate logistic regression analysis was employed to identify risk factors for CRC liver metastasis, followed by multivariate logistic regression analysis to integrate the selected risk factors. The predictive model was validated through the construction of receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA). A nomogram was constructed for visualization.

RESULTS

The determined cutoff point for PD-L1 CPS was 4.5, with scores below this threshold indicating a high risk of CRC liver metastasis. In addition, primary tumor origin other than the rectum, presence of pericolonic lymph node metastasis, and abnormal levels of tumor markers carcinoembryonic antigen and cancer antigen 19-9 were identified as independent risk factors for CRC liver metastasis. The constructed clinical prediction model demonstrated good predictive ability and accuracy, with an area under the ROC curve of 0.871 (95% CI, 0.838-0.904).

CONCLUSION

The exploration and validation of CPS as a novel predictor of CRC liver metastasis were performed. Based on these findings, a new clinical prediction model for CRC liver metastasis was developed by integrating other independent risk factors. The DCA, clinical impact curve, and nomogram graph constructed on the basis of this model have significant clinical implications and guide clinical practice.

Myasthenia gravis due to anti-PD-1 treatment for an advanced colon cancer patient: a case report and literature review

With the advancement of cancer treatment technologies, immunotherapy has begun to be widely utilized. Colon cancer is one of the most common types of cancer, with metastasis being a frequent occurrence in late-stage patients. Hence, immunotherapy, as an emerging and potentially effective treatment modality, merits exploration to enhance patient survival rates and clinical benefits. However, various immune-related adverse events cannot be entirely avoided. Myasthenia gravis induced by immunotherapy serves as a rare but potentially lethal adverse event, and it has been increasingly reported. Understanding the mechanisms of irAEs can aid in controlling the side effects induced by treatment. Here, we reported a case of myasthenia gravis occurring after anti-PD-1 therapy for late-stage colon cancer.

The safety and efficacy of neoadjuvant immunochemotherapy following laparoscopic gastrectomy for gastric cancer: a multicentre real-world clinical study

BACKGROUND

The safety and efficacy of neoadjuvant immunochemotherapy (nICT) for locally advanced gastric cancer (LAGC) remain controversial.

METHODS

Patients with LAGC who received either nICT or neoadjuvant chemotherapy (nCT) at 3 tertiary referral teaching hospitals in China between January 2016 and October 2022 were analyzed. After propensity-score matching (PSM), comparing the radiological response, pathological response rate, perioperative outcomes, and early recurrence between the two groups.

RESULTS

After PSM, 585 patients were included, with 195 and 390 patients comprising the nICT and nCT groups, respectively. The nICT group exhibited a higher objective response rate (79.5% vs. 59.0%; P <0.001), pathological complete response rate (14.36% vs. 6.41%; P =0.002) and major pathological response rate (39.49% vs. 26.15%; P =0.001) compared with the nCT group. The incidence of surgical complications (17.44% vs. 16.15%, P =0.694) and the proportion of perioperative textbook outcomes (80.0% vs. 81.0%; P =0.767) were similar in both groups. The nICT group had a significantly lower proportion of early recurrence than the nCT group (29.7% vs. 40.8%; P =0.047). Furthermore, the multivariable logistic analysis revealed that immunotherapy was an independent protective factor against early recurrence [odds ratio 0.62 (95% CI 0.41-0.92); P =0.018]. No significant difference was found in neoadjuvant therapy drug toxicity between the two groups (51.79% vs. 45.38%; P =0.143).

CONCLUSIONS

Compared with nCT, nICT is safe and effective, which significantly enhanced objective and pathological response rates and reduced the risk for early recurrence among patients with LAGC.

TRIAL REGISTRATION

Clinical Trials.gov.

Targeting tumor-infiltrating CCR8+ regulatory T cells induces antitumor immunity through functional restoration of CD4+ Tconvs and CD8+ T cells in colorectal cancer

BACKGROUND

Chemokine (C-C motif) receptor 8 (CCR8) is a chemokine receptor selectively expressed on tumor-infiltrating regulatory T cells (Tregs). Strong immunosuppression mediated by CCR8+ Tregs observed in breast and lung malignancies suggest for their functional significance in cancer therapy. To date, detailed characterization of tumor-infiltrating CCR8+ Tregs cells in colorectal cancer (CRC) is limited.

METHODS

To study the presence and functional involvement of CCR8+ Tregs in CRC, we analyzed the proportions of CCR8-expressing T cells in different T cell subsets in tumor and adjacent normal tissues and peripheral blood mononuclear cells (PBMCs) from CRC patients by Flow cytometry. Also, we compared the distribution of CCR8+ T cells in malignant tissues and peripheral lymphoid organs from a subcutaneous CRC murine model. Bioinformatic analysis was performed to address the significance of CCR8 expression levels in CRC prognosis, immune regulatory gene expression profiles and potential molecular mechanisms associated with CCR8+ Tregs in CRC tumors. Further, we administrated an anti-CCR8 monoclonal antibody to CT26 tumor-bearing mice and examined the antitumor activity of CCR8-targeted therapy both in vivo and in an ex vivo confirmative model.

RESULTS

Here, we showed that Tregs was predominantly presented in the tumors of CRC patients (13.4 ± 5.8, p < 0.0001) and the CRC subcutaneous murine model (35.0 ± 2.6, p < 0.0001). CCR8 was found to be preferentially expressed on these tumor-infiltrating Tregs (CRC patients: 63.6 ± 16.0, p < 0.0001; CRC murine model: 65.3 ± 9.5, p < 0.0001), which correlated with poor survival. We found that majority of the CCR8+ Tregs expressed activation markers and exhibited strong suppressive functions. Treatment with anti-CCR8 antibody hampered the growth of subcutaneous CRC tumor through effectively restoring the anti-tumor immunity of CD4+ conventional T cells (CD4+ Tconvs) and CD8+ T cells, which was confirmed in the ex vivo examinations.

CONCLUSIONS

Collectively, these findings illustrate the importance of CCR8+ Tregs for an immunosuppressive microenvironment in CRC tumors by functional inhibition of CD4+ Tconvs and CD8+ T cells, and suggest for the applicable value of CCR8-targeted therapy for CRC.

The survival prediction of advanced colorectal cancer received neoadjuvant therapy-a study of SEER database

PURPOSE

The aim of study was to screen factors associated with the overall survival of colorectal cancer patients with lymph nodes metastasis who received neoadjuvant therapy and construct a nomogram model.

METHODS

All enrolled subjects of the SEER database were randomly assigned to the training and testing group in a ratio of 3:2. The patients of Tangdu Hospital were seemed as validation group. Univariate cox regression analysis, lasso regression and random forest survival were used to screen variables related to the survival of advanced CRC patients received neoadjuvant therapy in the training group. Area under curves were adopted to evaluate the 1,3,5-year prediction value of the optimal model in three cohorts. Calibration curves were drawn to observe the prediction accuracy of the nomogram model. Decision curve analysis was used to assess the potential clinical value of the nomogram model.

RESULTS

A total of 1833 subjects were enrolled in this study. After random allocation, 1055 cases of the SEER database served as the training group, 704 cases as the testing group and 74 patients from our center as the external validation group. Variables were screened by univariate cox regression used to construct a nomogram survival prediction model, including M, age, chemotherapy, CEA, perineural invasion, tumor size, LODDS, liver metastasis and radiation. The AUCs of the model for predicting 1-year OS in the training group, testing and validation group were 0.765 (0.703,0.827), 0.772 (0.697,0.847) and 0.742 (0.601,0.883), predicting 3-year OS were 0.761 (0.725,0.780), 0.742 (0.699,0.785), 0.733 (0.560,0.905) and 5-year OS were 0.742 (0.711,0.773), 0.746 (0.709,0.783), 0.838 (0.670,0.980), respectively. The calibration curves showed the difference between prediction probability of the model and the actual survival was not significant in three cohorts and the decision curve analysis revealed the practice clinical application value. And the prediction value of model was better for young CRC than older CRC patients.

CONCLUSION

A nomogram model including LODDS for the prognosis of advanced CRC received neoadjuvant therapy was constructed and verified based on the SEER database and single center practice. The accuracy and potential clinical application value of the model performed well, and the model had better predictive value for EOCRC than LOCRC.

GAME-SCORE predicts pathological and radiological response to chemotherapy in patients with colorectal liver metastases

BACKGROUND

Genetic And Morphological Evaluation (GAME) score is the newest prognostic model for patient with colorectal liver metastases (CRLMs). Pathological and radiological responses to neoadjuvant chemotherapy (NAC) are key factors for prognostic stratification of these patients. The present study aims to evaluate the GAME-score's ability to predict pathological and radiologic responses to NAC.

METHODS

CRLM patients who underwent liver resection after NAC from January 2010 to December 2021 were categorized by GAME scores: low risk (LR, 0-1), moderate risk (MR, 2-3), and high risk (HR, ≥4). Correlations between groups and radiological/pathological features were analyzed. Poor pathological response was defined as Tumor Regression Grade 4-5.

RESULTS

Of 1054 liver resections for CRLMs, 448 were included. GAME scores were LR: 80 (18 %), MR: 228 (51 %), and HR: 140 (31 %). In this cohort, HR-GAME scores were associated with lower pathological response (LR: 67.1 %, MR: 74.9 %, HR: 82.6 %; p = 0.010). Radiologic progression occurred in 10 % of HR patients, significantly more than in LR (3.8 %) and MR (3.5 %) groups (p = 0.011). Multivariable analysis for independent predictors of pathological response confirmed HR-GAME (RR 1.843, p=0.025) along with age higher than 70 years (RR 2.111, p=0.022) and irinotecan-based NAC (RR 3.066, p < 0.001). For radiological progression disease after NAC, the HR-GAME score (RR 2.77, p=0.016) was the only independent predictor. HR-GAME scores were also associated with higher rates of mucinous differentiation (p = 0.021), satellitosis (p = 0.001), vascular invasion (p = 0.011), and perineural invasion (p = 0.010).

CONCLUSIONS

GAME score category should be considered into planning of therapeutic strategy of patients with CRLMs.

Non-operative management after immune checkpoint inhibitors for early-stage, dMMR/MSI-H gastrointestinal cancers

Surgery is a standard treatment for early-stage gastrointestinal cancers, often preceded by neoadjuvant chemo(radio)therapy or followed by adjuvant therapy. While leading to cure in a proportion of patients, it has some drawbacks such as intra/post-operative complications, mutilation and life-long functional sequelae. Further to the unprecedented efficacy data from studies of immune checkpoint inhibitors for advanced mismatch repair deficient/microsatellite instable (dMMR/MSI-H) tumours, a strong interest has recently emerged for the investigation of such agents in the neoadjuvant setting. Although limited by the exploratory design and small sample size, trials of neoadjuvant immune checkpoint inhibitors for early-stage dMMR/MSI-H gastrointestinal cancers have consistently reported complete response rates ranging from 70 % to 100 %. As a result, the question has arisen as to whether surgery is still needed or organ-preserving strategies should be offered to this especially immuno-sensitive population. In this article, we discuss the available evidence for neoadjuvant immune checkpoint inhibitors in dMMR/MSI-H gastrointestinal cancers and analyse opportunities and challenges to the implementation of non-operative management approaches in this setting.

Senescence-related signatures predict prognosis and response to immunotherapy in colon cancer

Background

Colorectal cancer (CRC) is one of the most common cancers. Cellular senescence plays a vital role in carcinogenesis by activating many pathways. In this study, we aimed to identify biomarkers for predicting the survival and recurrence of CRC through cellular senescence-related genes.

Methods

Utilizing The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases, RNA-sequencing data and clinical information for CRC were collected. A risk model for predicting overall survival was established based on five differentially expressed genes using least absolute shrinkage and selection operator-Cox regression (LASSO-Cox regression), receiver operating characteristic (ROC), and Kaplan-Meier analyses. The study also delved into both the tumor microenvironment and the response to immunotherapy. Moreover, we gathered clinical sample data from our center in order to confirm the findings of public database analysis.

Results

Through ROC and Kaplan-Meier analyses, a risk model was developed using five cellular senescence-related genes [i.e., CDKN2A, SERPINE1, SNAI1, CXCL1, and ETS2] to categorize patients into high- and low-risk groups. In the TCGA-colon adenocarcinoma (COAD) and GEO-COAD cohorts, the high-risk group was associated with a bleaker forecast (P<0.05), immune cell inactivation, and insensitivity to immunotherapy in IMvigor210 database (http://research-pub.gene.com/IMvigor210CoreBiologies/). Clinical samples were then used to confirm that ETS2 and CDKN2A could serve as independent prognostic biomarkers in CRC.

Conclusions

Gene signatures related to cellular senescence, specifically involving CDKN2A and ETS2, are emerging as promising biomarkers for predicting CRC prognosis and guiding immunotherapy.

Challenges and Opportunities for Precision Surgery for Colorectal Liver Metastases

The incidence of colorectal cancer and colorectal liver metastases (CRLM) is increasing globally due to an interaction of environmental and genetic factors. A minority of patients with CRLM have surgically resectable disease, but for those who have resection as part of multimodal therapy for their disease, long-term survival has been shown. Precision surgery-the idea of careful patient selection and targeting of surgical intervention, such that treatments shown to be proven to benefit on a population level are the optimal treatment for each individual patient-is the new paradigm of care. Key to this is the understanding of tumour molecular biology and clinically relevant mutations, such as KRAS, BRAF, and microsatellite instability (MSI), which can predict poorer overall outcomes and a poorer response to systemic therapy. The emergence of immunotherapy and hepatic artery infusion (HAI) pumps show potential to convert previously unresectable disease to resectable disease, in addition to established systemic and locoregional therapies, but the surgeon must be wary of poor-quality livers and the spectre of post-hepatectomy liver failure (PHLF). Volume modulation, a cornerstone of hepatic surgery for a generation, has been given a shot in the arm with the advent of liver venous depletion (LVD) ensuring significantly more hypertrophy of the future liver remnant (FLR). The optimal timing of liver resection for those patients with synchronous disease is yet to be truly established, but evidence would suggest that those patients requiring complex colorectal surgery and major liver resection are best served with a staged approach. In the operating room, parenchyma-preserving minimally invasive surgery (MIS) can dramatically reduce the surgical insult to the patient and lead to better perioperative outcomes, with quicker return to function.

YTHDF1's grip on CRC vasculature: insights into LINC01106 and miR-449b-5p-VEGFA axis

BACKGROUND

Investigating the unexplored territory of lncRNA m6A modification in colorectal cancer (CRC) vasculature, this study focuses on LINC01106 and YTHDF1.

METHODS

Clinical assessments reveal upregulated LINC01106 promoting vascular generation via the miR-449b-5p-VEGFA pathway.

RESULTS

YTHDF1, elevated in CRC tissues, emerges as an adverse prognostic factor. Functional experiments showcase YTHDF1's inhibitory effects on CRC cell dynamics. Mechanistically, Me-CLIP identifies m6A-modified LINC01106, validated as a YTHDF1 target through Me-RIP.

CONCLUSIONS

This study sheds light on the YTHDF1-mediated m6A modification of LINC01106, presenting it as a key player in suppressing CRC vascular generation.

Total Neoadjuvant Therapy With PD-1 Blockade for High-Risk Proficient Mismatch Repair Rectal Cancer

Importance

Total neoadjuvant therapy (TNT) is the standard treatment for locally advanced rectal cancer, especially for patients with high-risk factors. However, the efficacy of TNT combined with immunotherapy for patients with proficient mismatch repair (pMMR) rectal cancer is unknown.

Objectives

To evaluate the safety and efficacy of TNT with induction chemoimmunotherapy followed by long-course chemoradiation in patients with high-risk, pMMR rectal cancer and to identify potential molecular biomarkers associated with treatment efficacy.

Design, Setting, and Participants

This cohort study was a single-arm phase 2 trial conducted at Gastrointestinal Cancer Center, Peking University Cancer Hospital & Institute, from June 2020 to October 2021. Biopsies and plasma were collected before treatment for whole-exome sequencing and cell-free DNA sequencing, respectively. Data were analyzed from May 2022 to September 2022.

Interventions

Participants received 3 cycles of induction oxaliplatin and capecitabine combined with camrelizumab and radiotherapy (50.6 Gy in 22 fractions) with concurrent capecitabine. Patients without disease progression received 2 cycles of consolidation oxaliplatin/capecitabine.

Main Outcomes and Measures

The primary end point was pathologic complete response rate.

Results

Of 25 patients enrolled (19 men [76%]; 6 women [24%]; median [IQR] age, 58 [48-64] years), 22 patients (88%) completed the TNT schedule. The pathologic complete response rate was 33.3% (7/21). Twelve patients (48%) achieved clinical complete response, and 4 patients (16%) chose to watch and wait. R0 resection was achieved in 21 of 21 patients, and the major pathologic response rate was 38.1% (8/21). The most common adverse event was nausea (80%, 20/25); grade 3 toxic effects occurred in 9 of 25 patients (36%). Patients with tumor shrinkage of 50% or greater after induction oxaliplatin/capecitabine and camrelizumab or clinical complete response had higher percentages of LRP1B mutation. Mutation of LRP1B was associated with high tumor mutation burden and tumor neoantigen burden. Patients with high tumor mutation burden all benefited from therapy.

Conclusions and Relevance

This study found that TNT with induction chemoimmunotherapy followed by long-course chemoradiation was safe and effective for patients with high-risk rectal cancer with pMMR status. Longer follow-up and larger clinical studies are needed to validate this innovative regimen. There is also an urgent need to further validate the predictive value of LRP1B and discover other novel biomarkers with potential predictive value for rectal cancer.

Colorectal cancer survival disparities in the five regions of Georgia

BACKGROUND/OBJECTIVE

The objective of this study was to examine 5-year colorectal cancer survival rates. We also determined whether demographics, tumor characteristics, and treatment modality were associated with 5-year CRC survival in the Clayton, West Central, East Central, Southeast, and Northeast Georgia regions because the significant higher CRC mortality rates in these regions in comparison to the overall rates in the State of Georgia.

METHODS

We conducted a retrospective cohort analysis using data from the 1975-2016 Surveillance, Epidemiology, and End Results program aggregated CRC patients to these five regions. Five-year CRC survival was calculated and stratified by the five regions of Georgia, using the Kaplan-Meier method with log-rank test. Cox proportional hazard regression was used to examine the mentioned association in these five regions.

RESULTS

Among 11,023 CRC patients, 5-year CRC survival was lowest in Clayton (65.9%) compared to the West Central (69.0%), East Central (68.2%), Southeast (70.5%), and Northeast regions (69.5%) (p-value = 0.02). In multivariable analysis, greater risk of CRC death was found in the Clayton region compared to the West Central (HR, 1.12; 95%, 1.00-1.25) region when adjusting for demographics, tumor characteristics, and treatment modality. Among Clayton Georgians, age of 75+ years (HR, 2.13; 95%, 1.56-2.89), grade 3 & 4 tumors (HR, 2.22; 95%, 1.64-3.00), and distant stage (HR, 20.95; 95%, 15.99-27.45) were negatively associated with CRC survival.

CONCLUSION

We observed place-based differences in CRC survival with significantly lower survival rates in the Clayton region. Factors associated with higher risk of CRC death include older age at diagnosis, high-grade tumors, and distant stage CRC among Clayton Georgians. Our study provides important evidence to all relevant stakeholders in furthering the development of culturally tailored CRC screening interventions aimed at CRC early detection and improved outcomes.

Effect of preoperative programmed death-1 or programmed death ligand-1 immune check point inhibition on complications after surgery for primary head and neck cancer

BACKGROUND

There is sparse literature on the effect of preoperative immunotherapy on complications after surgery for primary head and neck squamous cell carcinoma (HNSCC). The objectives are to compare complication rates in patients receiving surgery with and without neoadjuvant immune checkpoint inhibitors (nICI) for primary HNSCC and to evaluate factors associated with increased odds of surgical complications.

METHODS

A retrospective review of patients who underwent ablation and free flap reconstruction or transoral robotic surgery (TORS) for primary HNSCC between 2017-2021 was conducted. Complications were compared between patients who underwent surgery with or without nICI before and after propensity score matching. Regression analysis to estimate odds ratios was performed.

RESULTS

A total of 463 patients met inclusion criteria. Free flap reconstruction constituted 28.9% of patients and TORS constituted 71.1% of patients. nICI was administered in 83 of 463 (17.9%) patients. There was no statistically significant difference in surgical, medical, or overall complications between patients receiving surgery with or without nICI. In the unmatched cohort, multivariable model identified non-White race, former/current smoking history, free flap surgery, and perineural invasion as factors significantly associated with increased complications. In the matched cohort, multivariable model identified advanced age and free flap surgery as factors significantly associated with increased complications.

PLAIN LANGUAGE SUMMARY

It is safe to give immunotherapy before major surgery in patients who have head and neck cancer. Advanced age, non-White race, current/former smoking, free flap surgery, and perineural invasion may be associated with increased the odds of surgical complications.

A prediction nomogram for perineural invasion in colorectal cancer patients: a retrospective study

BACKGROUND

Perineural invasion (PNI), as the fifth recognized pathway for the spread and metastasis of colorectal cancer (CRC), has increasingly garnered widespread attention. The preoperative identification of whether colorectal cancer (CRC) patients exhibit PNI can assist clinical practitioners in enhancing preoperative decision-making, including determining the necessity of neoadjuvant therapy and the appropriateness of surgical resection. The primary objective of this study is to construct and validate a preoperative predictive model for assessing the risk of perineural invasion (PNI) in patients diagnosed with colorectal cancer (CRC).

MATERIALS AND METHODS

A total of 335 patients diagnosed with colorectal cancer (CRC) at a single medical center were subject to random allocation, with 221 individuals assigned to a training dataset and 114 to a validation dataset, maintaining a ratio of 2:1. Comprehensive preoperative clinical and pathological data were meticulously gathered for analysis. Initial exploration involved conducting univariate logistic regression analysis, with subsequent inclusion of variables demonstrating a significance level of p < 0.05 into the multivariate logistic regression analysis, aiming to ascertain independent predictive factors, all while maintaining a p-value threshold of less than 0.05. From the culmination of these factors, a nomogram was meticulously devised. Rigorous evaluation of this nomogram's precision and reliability encompassed Receiver Operating Characteristic (ROC) curve analysis, calibration curve assessment, and Decision Curve Analysis (DCA). The robustness and accuracy were further fortified through application of the bootstrap method, which entailed 1000 independent dataset samplings to perform discrimination and calibration procedures.

RESULTS

The results of multivariate logistic regression analysis unveiled independent risk factors for perineural invasion (PNI) in patients diagnosed with colorectal cancer (CRC). These factors included tumor histological differentiation (grade) (OR = 0.15, 95% CI = 0.03-0.74, p = 0.02), primary tumor location (OR = 2.49, 95% CI = 1.21-5.12, p = 0.013), gross tumor type (OR = 0.42, 95% CI = 0.22-0.81, p = 0.01), N staging in CT (OR = 3.44, 95% CI = 1.74-6.80, p < 0.001), carcinoembryonic antigen (CEA) level (OR = 3.13, 95% CI = 1.60-6.13, p = 0.001), and platelet-to-lymphocyte ratio (PLR) (OR = 2.07, 95% CI = 1.08-3.96, p = 0.028).These findings formed the basis for constructing a predictive nomogram, which exhibited an impressive area under the receiver operating characteristic (ROC) curve (AUC) of 0.772 (95% CI, 0.712-0.833). The Hosmer-Lemeshow test confirmed the model's excellent fit (p = 0.47), and the calibration curve demonstrated consistent performance. Furthermore, decision curve analysis (DCA) underscored a substantial net benefit across the risk range of 13% to 85%, reaffirming the nomogram's reliability through rigorous internal validation.

CONCLUSION

We have formulated a highly reliable nomogram that provides valuable assistance to clinical practitioners in preoperatively assessing the likelihood of perineural invasion (PNI) among colorectal cancer (CRC) patients. This tool holds significant potential in offering guidance for treatment strategy formulation.

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.

Multimodal Management of Colorectal Liver Metastases: State of the Art

Liver is the most common site of colorectal cancer (CRC) metastases. Treatment of CRC liver metastases (CRLM) includes different strategies, prevalently based on the clinical and oncological intent. Valid approaches in liver-limited or liver-prevalent disease include surgery, percutaneous ablative procedures (radiofrequency ablation, microwave ablation), intra-arterial perfusional techniques (chemo-embolization, radio-embolization) as well as stereotactic radiotherapy. Systemic treatments, including chemotherapy, immunotherapy and other biological agents, are the only options for patients with no chance of locoregional approaches. The use of chemotherapy in other settings, such as neoadjuvant, adjuvant or conversion therapy of CRLM, is commonly accepted in the clinical practice, although data from several clinical trials have been mostly inconclusive. The optimal integration of all these strategies, when applicable and clinically indicated, should be ever considered in patients affected by CRLM based on clinical evidence and multidisciplinary experience. Here we revised in detail all the possible therapeutic approaches of CRLM focusing on the current evidences, the studies still in progress and the often contradictory data.

Personalizing adjuvant therapy for patients with colorectal cancer

The current standard-of-care adjuvant treatment for patients with colorectal cancer (CRC) comprises a fluoropyrimidine (5-fluorouracil or capecitabine) as a single agent or in combination with oxaliplatin, for either 3 or 6 months. Selection of therapy depends on conventional histopathological staging procedures, which constitute a blunt tool for patient stratification. Given the relatively marginal survival benefits that patients can derive from adjuvant treatment, improving the safety of chemotherapy regimens and identifying patients most likely to benefit from them is an area of unmet need. Patient stratification should enable distinguishing those at low risk of recurrence and a high chance of cure by surgery from those at higher risk of recurrence who would derive greater absolute benefits from chemotherapy. To this end, genetic analyses have led to the discovery of germline determinants of toxicity from fluoropyrimidines, the identification of patients at high risk of life-threatening toxicity, and enabling dose modulation to improve safety. Thus far, results from analyses of resected tissue to identify mutational or transcriptomic signatures with value as prognostic biomarkers have been rather disappointing. In the past few years, the application of artificial intelligence-driven models to digital images of resected tissue has identified potentially useful algorithms that stratify patients into distinct prognostic groups. Similarly, liquid biopsy approaches involving measurements of circulating tumour DNA after surgery are additionally useful tools to identify patients at high and low risk of tumour recurrence. In this Perspective, we provide an overview of the current landscape of adjuvant therapy for patients with CRC and discuss how new technologies will enable better personalization of therapy in this setting.

Programmed death ligand-1 (PD-L1) clone 22C3 expression in resected colorectal cancer as companion diagnostics for immune checkpoint inhibitor therapy: A comparison study and inter-rater agreement evaluation across proposed cut-offs and predictive (TPS, CPS and IC) scores

BACKGROUND

Expression of programmed death ligand-1 (PD-L1) guides the use of immune checkpoint inhibitors (ICI) in several cancers. In colorectal cancer (CRC), ICI are only approved for metastatic CRC, while several studies suggest high efficacy even in operable CRC. The aim of this study was to investigate the inter-rater agreement of PD-L1 as a companion diagnostic marker.

METHODS

Specimens from resected stage I-III CRC (n = 166 tumors) were stained with PD-L1 22C3 clone. PD-L1 expression was scored by two pathologists as tumor proportion score (TPS), combined positive score (CPS) and immune cell score (IC). Inter-rater agreement was tested using three different agreement coefficients.

RESULTS

Raw scores of the two pathologists had 'good' to 'excellent' correlation. Spearman's rho for TPS=0.917 (95 %CI 0.839-0.995), for CPS=0.776 (95 %CI 0.726-0.826) and IC=0.818 (95 %CI 0.761-0.875). For TPS, kappa (κ)-agreements for both the ≥1 % and ≥10 % cutoffs had excellent correlation. For CPS the ≥1 % and ≥10 % cutoffs demonstrated κ=0.32 (95 %CI 0.12-0.51) and κ=0.36 (95 %CI 0.25-0.48) respectively. Cutoffs for IC showed κ=0.53 (95 %CI 0.18-0.79) for the ≥1 % cutoff, and κ=0.61 (95 %CI 0.48-0.73) for the ≥10 % cutoff. Gwet's agreement coefficient (AC1) showed higher agreement coefficients than κ-values for most, but not all cut-offs.

CONCLUSION

Agreement for PD-L1 was good to excellent for raw scores. Agreement variation across several criteria and cut-offs suggests the need for more robust criteria for PD-L1 as a companion diagnostic marker.

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.

Clinical trials of neoadjuvant immune checkpoint inhibitors for early-stage operable colon and rectal cancer

BACKGROUND

Immune checkpoint inhibitors (ICI) have become first-line treatment for metastatic colorectal cancer (CRC) with deficient mismatch repair (dMMR). Despite the remarkable response reported in preliminary trials, the role of ICI in patients with early-stage, operable CRC remains unclear. The aim of this study was to investigate trials on neoadjuvant ICI in operable CRC.

MATERIALS AND METHODS

Scoping review of clinical trial registries (Clinicaltrials.gov and EU clinical trial registers) and PubMed/Medline database of trials on neoadjuvant ICI for operable CRC was done up to December 2022.

RESULTS

Some 40 trials investigating neoadjuvant ICI for early-stage, operable CRC were identified, including five published trials and three conference abstracts. Preclinical phase I/II trial predominated with only three clinical phase III trials. Few trials investigated neoadjuvant ICI as the only intervention (monotherapy). Trials in rectal cancer were designed for combined ICI with chemo(radio)therapy, only 8 trials stating an MSI/dMMR status for inclusion, one designed for MSS/pMMR only and, the rest agnostic for MMR status. Thirty-eight (95%) trials investigated programmed cell death protein 1 (PD-1) or programmed cell death ligand 1 (PD-L1) inhibitors. PD-1/PD-L1 inhibitors were combined with vascular endothelial growth factor (VEGF) inhibitor or with cytotoxic T-lymphocyte-associated protein-4 (CTLA-4) inhibitor, in two trials each, respectively. Pathological complete response as primary outcome after surgery was the most frequently used study endpoint. In rectal cancer, six trials included a "watch and wait" strategy for patients with complete clinical response. No "watch and wait" study design for colon cancer after neoadjuvant ICI were identified.

CONCLUSION

High response rates from neoadjuvant ICI in early-stage colon and rectal cancer are reported in phase I/II studies. Contemporary trial designs are heterogeneous, with few comparable inclusion criteria, use of several drug combinations and durations and, wide variation of endpoints reported. Harmonizing clinical and translational aspects including survival data is needed for improved future trial designs with clinical impact.

Unraveling TIMP1: a multifaceted biomarker in colorectal cancer

Background: The pathogenic genes of colorectal cancer (CRC) have not yet been fully elucidated, and there is currently a lack of effective therapeutic targets. This study used bioinformatics methods to explore and experimentally validate the most valuable biomarkers for colorectal cancer and further investigate their potential as targets. Methods: We analyzed differentially expressed genes (DEGs) based on the Gene Expression Omnibus (GEO) dataset and screened out hub genes. ROC curve and univariate Cox analysis of The Cancer Genome Atlas (TCGA) dataset revealed the most diagnostically and prognostically valuable genes. Immunohistochemistry (IHC) experiments were then conducted to validate the expression level of these selected genes in colorectal cancer. Gene set enrichment analysis (GSEA) was performed to evaluate the enriched signaling pathways associated with the gene. Using the CIBERSORT algorithm in R software, we analyzed the immune infiltrating cell abundance in both high and low gene expression groups and examined the gene's correlation with immune cells and immune checkpoints. Additionally, we performed drug sensitivity analysis utilizing the DepMap database, and explored the correlation between gene expression levels and ferroptosis based on the The Cancer Genome Atlas dataset. Results: The study identified a total of 159 DEGs, including 7 hub genes: SPP1, MMP1, CXCL8, CXCL1, TIMP1, MMP3, and CXCL10. Further analysis revealed TIMP1 as the most valuable diagnostic and prognostic biomarker for colorectal cancer, with IHC experiments verifying its high expression. Additionally, GSEA results showed that the high TIMP1 expression group was involved in many cancer signaling pathways. Analysis of the TCGA database revealed a positive correlation between TIMP1 expression and infiltration of macrophages (M0, M1, M2) and neutrophils, as well as the expression of immune checkpoint genes, including CTLA-4 and HAVCR2. Drug sensitivity analysis, conducted using the DepMap database, revealed that colorectal cancer cell lines exhibiting elevated levels of TIMP1 expression were more responsive to certain drugs, such as CC-90003, Pitavastatin, Atuveciclib, and CT7001, compared to those with low levels of TIMP1. Furthermore, TIMP1 expression was positively correlated with that of ferroptosis-related genes, such as GPX4 and HSPA5. Conclusion: TIMP1 can be used as a biomarker for colorectal cancer and is associated with the immunological microenvironment, drug sensitivity, and ferroptosis inhibition in this disease.

From organ preservation to selective surgery: How immunotherapy changes colorectal surgery?

The emergence of immunotherapy has revolutionized the traditional treatment paradigm of colorectal cancer (CRC). Among them, immune checkpoint blockade has become the first-line treatment for metastatic colorectal cancer (mCRC) and has made significant progress in the treatment of locally advanced colorectal cancer (LACRC). We reviewed a series of clinical trials that have made breakthrough progress. We will emphasize the breakthrough progress in achieving organ preservation in patients with high microsatellite instability or DNA mismatch repair deficiency (MSI-H/dMMR), and based on this, we propose the concept of selective surgery, which includes selectively removing or preserving lymph nodes, with the aim of proving our idea through more research in the future.

Single-cell analysis reveals cellular reprogramming in advanced colon cancer following FOLFOX-bevacizumab treatment

Introduction

The combination of FOLFOX and bevacizumab (FOLFOX-Bev) is a promising treatment for advanced colorectal cancer (CRC). However, the response of the tumor microenvironment to FOLFOX-Bev is still largely unexplored.

Methods

We conducted single-cell transcriptomic analysis of CRC samples derived from a patient before and after treatment to gain insights into the cellular changes associated with FOLFOX-Bev treatment.

Results

We found that cancer cells with high proliferative, metastatic, and pro-angiogenic properties respond better to FOLFOX-Bev treatment. Moreover, FOLFOX-Bev enhances CD8+ T cell cytotoxicity, thereby boosting the anti-tumor immune response. Conversely, FOLFOX-Bev impairs the functionality of tumor-associated macrophages, plasma cells, and cancer-associated fibroblasts, leading to a decrease in VEGFB-mediated angiogenesis. Furthermore, FOLFOX-Bev treatment reset intercellular communication, which could potentially affect the function of non-cancer cells.

Discussion

Our findings provide valuable insights into the molecular mechanisms underlying the response of advanced CRC to FOLFOX-Bev treatment and highlight potential targets for improving the efficacy of this treatment strategy.

Immunotherapies in non-metastatic gastrointestinal cancers

PURPOSE

Over the last decade, immune checkpoint inhibitors (ICI) have emerged as cornerstone in the treatment of many metastatic tumour types, including gastrointestinal cancers. In many solid tumours, the effective therapies in the metastatic field are progressively brought into the curative setting. Consequently, earlier tumoural settings have become a field of experiment for immunotherapies. In melanoma, lung, and bladder cancers, excellent results were recorded, possibly explained by differences in the tumour microenvironment between metastatic and non-metastatic settings. In gastrointestinal (GI) Oncology, nivolumab is the first immune checkpoint inhibitor to become a standard-of-care adjuvant treatment after curative surgery for oesophagal or gastroesophageal junction cancer.

RECENT FINDINGS

We herein discuss the results of a selection of the most relevant studies presented/published over the last 18 months testing immunotherapies in non-metastatic GI cancers. Among immunotherapies, ICI have been investigated in pre-, peri- and postoperative setting across tumour types, alone or in combination with chemo- and/or radiotherapy. Vaccines are also a new field of investigation.

SUMMARY

Promising results from two studies (NCT04165772 and NICHE-2 study) demonstrating never-seen-before responses to neoadjuvant immunotherapy in MMR deficient (dMMR) colorectal cancers raise hope for improving the patients' outcome and developing organ-sparing strategies in this situation.

IL8 derived from macrophages inhibits CD8+ T-cell function by downregulating TIM3 expression through IL8-CXCR2 axis in patients with advanced colorectal cancer

BACKGROUND

T cell immunoglobulin and mucin domain-containing protein 3 (TIM3) is a vital immune checkpoint that regulates the immune response. However, the specific role of TIM3 in patients with colorectal cancer (CRC) have rarely been studied. In this study, we investigated the effect of TIM3 on CD8⁺ T cells in CRC and explored the mechanism of TIM3 regulation in tumor microenvironment (TME).

METHODS

Peripheral blood and tumor tissues of patients with CRC were collected to evaluate TIM3 expression using flow cytometry. Cytokines in the serum of healthy donors and patients with early- and advanced-stage CRC were screened using a multiplex assay. The effects of interleukin-8 (IL8) on TIM3 expression on CD8⁺ T cells were analyzed using cell incubation experiments in vitro. The correlation between TIM3 or IL8 and prognosis was verified using bioinformatics analysis.

RESULTS

TIM3 expression on CD8⁺ T cells was obviously reduced in patients with advanced-stage CRC, whereas a lower TIM3 expression level was associated with poorer prognosis. Macrophage-derived IL8, which could inhibit TIM3 expression on CD8⁺ T cells, was significantly increased in the serum of patients with advanced CRC. In addition, the function and proliferation of CD8⁺ and TIM3⁺CD8⁺ T cells were inhibited by IL8, which was partly depending on TIM3 expression. The inhibitory effects of IL8 were reversed by anti-IL8 and anti-CXCR2 antibodies.

CONCLUSIONS

In summary, macrophages-derived IL8 suppresses TIM3 expression on CD8⁺ T cells through CXCR2. Targeting the IL8/CXCR2 axis may be an effective strategy for treating patients with advanced CRC.

Relationship between SUVmax on 18F-FDG PET and PD-L1 expression in liver metastasis lesions after colon radical operation

PURPOSE

Our study was to investigate the correlation correlation between FDG uptake and PD-L1 expression of liver metastasis in patients with colon cancer, and to determine the value of FDG-PET in predicting PD-L1 expression in liver metastasis of colon cancer.

METHODS

A total of 72 patients with confirmed liver metastasis of colon cancer were included in this retrospective study. The PD-L1 expression and immune cell infiltrating of tumors were determined through immunohistochemistry staining. The SUVmax of liver metastasis lesions were assessed using ¹⁸ F-FDG PET/CT. The correlation between PD-L1 expression and the clinicopathological were evaluated by the Cox proportional hazards model and the Kaplan-Meier survival analysis.

RESULTS

PD-L1 expression was significantly correlated with FDG uptake (SUVmax), tumor size, differentiation, survival and cytotoxic T cells infiltration in liver metastasis of colon cancer (P < 0.05). And liver metastases with high counts of infiltrating cytotoxic T cells showed greater FDG uptake than those with low counts of infiltrating cytotoxic T cells. The SUVmax of liver metastases and the degree of differentiation of metastases were closely related to PD-L1 expression, and were independent risk factors.The combined assessment of SUVmax values and tthe degree of differentiation of metastase can help determine PD-L1 expression in liver metastasis of colon cancer.

CONCLUSIONS

FDG uptake in liver metastasis of colon cancer was positively correlated with the PD-L1 expression and the number of cytotoxic T cells infiltration. The joint evaluation of two parameters, SUVmax and degree of differentiation, can predict PD-L1 expression in liver metastases.

Cancer nanomedicine in preoperative therapeutics: Nanotechnology-enabled neoadjuvant chemotherapy, radiotherapy, immunotherapy, and phototherapy

Surgical resection remains a mainstay in the treatment of malignant solid tumors. However, the use of neoadjuvant treatments, including chemotherapy, radiotherapy, phototherapy, and immunotherapy, either alone or in combination, as a preoperative intervention regimen, have attracted increasing attention in the last decade. Early randomized, controlled trials in some tumor settings have not shown a significant difference between the survival rates in long-term neoadjuvant therapy and adjuvant therapy. However, this has not hampered the increasing use of neoadjuvant treatments in clinical practice, due to its evident downstaging of primary tumors to delineate the surgical margin, tailoring systemic therapy response as a clinical tool to optimize subsequent therapeutic regimens, and decreasing the need for surgery, with its potential for increased morbidity. The recent expansion of nanotechnology-based nanomedicine and related medical technologies provides a new approach to address the current challenges of neoadjuvant therapy for preoperative therapeutics. This review not only summarizes how nanomedicine plays an important role in a range of neoadjuvant therapeutic modalities, but also highlights the potential use of nanomedicine as neoadjuvant therapy in preclinical and clinic settings for tumor management.

Molecular subtypes and tumor microenvironment infiltration signatures based on cuproptosis-related genes in colon cancer

Background

Colon cancer is one of the common cancers, and its prognosis remains to be improved. The role of cuproptosis as a newly discovered form of cell death in the development of colon cancer has not been determined.

Methods

Based on 983 colon cancer samples in the TCGA database and the GEO database, we performed a comprehensive genomic analysis to explore the molecular subtypes mediated by cuproptosis-related genes. Single-sample gene set enrichment analysis (ssGSEA) was utilized to quantify the relative abundance of each cell infiltrate in the TME. A risk score was established using least absolute shrinkage and selection operator regression (LASSO), and its predictive ability for colon cancer patients was verified to explore its guiding value for treatment.

Results

We identified two distinct cuproptosis-related molecular subtypes in colon cancer. These two distinct molecular subtypes can predict clinicopathological features, prognosis, TME activity, and immune-infiltrating cells. A risk model was developed and its predictive ability was verified. Compared with patients in the high-risk score group, patients in the low-risk score group were characterized by lower tumor microenvironment score, higher stem cell activity, lower tumor mutational burden, lower microsatellite instability, higher sensitivity to chemotherapeutics, and better immunotherapy efficacy.

Conclusion

This study contributes to understanding the molecular characteristics of cuproptosis-related subtypes. We demonstrate a critical role for cuproptosis genes in colon cancer s in the TME. Our study contributes to the development of individualized treatment regimens for colon cancer.

Delivery of Engineered Primary Tumor-Derived Exosomes Effectively Suppressed the Colorectal Cancer Chemoresistance and Liver Metastasis

Liver metastasis is one of the major causes of colorectal cancer (CRC)-related morbidity and mortality. Delivering small interfering RNAs (siRNAs) or noncoding RNAs has been reported as a promising method to target liver metastasis and chemoresistance in CRC. Here, we report a noncoding RNA delivery system using exosomes derived from primary patient cells. Coiled-coil domain-containing protein 80 (CCDC80) was strongly associated with CRC liver metastasis and chemoresistance, a finding validated by bioinformatic analysis and clinical specimens. Silencing CCDC80 significantly increased sensitivity to chemotherapy agents in OXA-resistant cell lines and a mouse model. The primary cell-derived exosome delivery system was designed to simultaneously deliver siRNAs targeting CCDC80 and increase chemotherapy sensitivity in the distant CRC liver metastasis mouse models and patient-derived xenograft mouse models. We further validated the antitumor effect in an ex vivo model of chemoresistant CRC organoids and a patient-derived organoid xenograft model. Tumor-bearing mice treated with the siRNA-delivering exosomes and hepatectomy showed ideal overall survival. Our results provide a therapeutic target and represent a possible therapeutic alternative for patients with CRC and distant metastasis and in cases of chemoresistance.

Neoadjuvant Pembrolizumab in Localized Microsatellite Instability High/Deficient Mismatch Repair Solid Tumors

PURPOSE

Pembrolizumab significantly improves clinical outcomes in advanced/metastatic microsatellite instability high (MSI-H)/deficient mismatch repair (dMMR) solid tumors but is not well studied in the neoadjuvant space.

METHODS

This is a phase II open-label, single-center trial of localized unresectable or high-risk resectable MSI-H/dMMR tumors. Treatment is pembrolizumab 200 mg once every 3 weeks for 6 months followed by surgical resection with an option to continue therapy for 1 year followed by observation. To continue on study, patients are required to have radiographic or clinical benefit. The coprimary end points are safety and pathologic complete response. Key secondary end points are response rate and organ-sparing at one year for patients who declined surgery. Exploratory analyses include interrogation of the tumor immune microenvironment using imaging mass cytometry.

RESULTS

A total of 35 patients were enrolled, including 27 patients with colorectal cancer and eight patients with noncolorectal cancer. Among 33 evaluable patients, best overall response rate was 82%. Among 17 (49%) patients who underwent surgery, the pathologic complete response rate was 65%. Ten patients elected to receive one year of pembrolizumab followed by surveillance without surgical resection (median follow-up of 23 weeks [range, 0-54 weeks]). An additional eight did not undergo surgical resection and received less than 1 year of pembrolizumab. During the study course of the trial and subsequent follow-up, progression events were seen in six patients (four of whom underwent salvage surgery). There were no new safety signals. Spatial immune profiling with imaging mass cytometry noted a significantly closer proximity between granulocytic cells and cytotoxic T cells in patients with progressive events compared with those without progression.

CONCLUSION

Neoadjuvant pembrolizumab in dMMR/MSI-H cancers is safe and resulted in high rates of pathologic, radiographic, and endoscopic response, which has implications for organ-sparing strategies.

Karyopherin Subunit Alpha 1 Enhances the Malignant Behaviors of Colon Cancer Cells via Promoting Nuclear Factor-κB p65 Nuclear Translocation

BACKGROUND/AIMS

Aberrant nuclear factor-κB p65 (NF-κB p65) nuclear import commonly occurs in multiple cancers, including colon cancer. According to BioGRID, we noted that Karyopherin subunit alpha 1 (KPNA1), an important molecular transporter between the nucleus and the cytoplasm, may interact with NF-κB p65. KPNA1 itself is highly expressed in colon adenocarcinoma samples (N = 286) based on The Cancer Genome Atlas (TCGA) database. We aimed to explore the role of KPNA1 in colonic carcinogenesis and to determine whether NF-κB p65 nuclear translocation was involved.

METHODS

KPNA1 expressions at mRNA and protein levels were analyzed in colon cancer tissues. The regulatory effect of KPNA1 on malignant biological properties was detected in SW480 and HCT116 colon cancer cells. Coimmunoprecipitation and immunofluorescence were performed to verify the relationship between KPNA1 and NF-κB p65. KPNA1 ubiquitination was also preliminarily investigated.

RESULTS

KPNA1 was firstly confirmed as a significantly upregulated gene in our collected clinical colon cancer samples (N = 35). KPNA1 depletion inhibited cell proliferation, induced cell cycle arrest, and diminished migratory and invasive capacity of SW480 and HCT116 cells. Colon cancer cells overexpressing KPNA1 acquired more aggressive behaviors. KPNA1 acted as a transporter to induce the nuclear accumulation of NF-κB p65, thereby activating NF-κB signaling pathway in colon cancer cells. Furthermore, HECT, C2, and WW Domain-Containing E3 Ubiquitin (HECW2) interacted with KPNA1 to induce its ubiquitination. KPNA1 labeled with polyubiquitins was degraded through ubiquitin-proteasome system.

CONCLUSION

The present study uncovers a role of KPNA1-NF-κB p65 axis in promoting colonic carcinogenesis.

Current Strategy to Treat Immunogenic Gastrointestinal Cancers: Perspectives for a New Era

Since pembrolizumab, an anti-programmed death-1 (PD-1) antibody, showed a dramatic response to immunogenic cancers with microsatellite instability-high (MSI-H) and/or deficient mismatch repair (dMMR) in the pilot clinical trial KEYNOTE-016, subsequent studies have confirmed durable responses of anti-PD-1 inhibitors for MSI-H/dMMR solid tumors. As immunotherapy is described as a "game changer," the therapeutic landscape for MSI-H/dMMR solid tumors including gastrointestinal cancers has changed considerably in the last decade. An MSI/MMR status has been established as the predictive biomarker for immune checkpoint blockades, playing an indispensable role in the clinical practice of patients with MSI-H/dMMR tumors. Immunotherapy is also now investigated for locally advanced MSI-H/dMMR gastrointestinal cancers. Despite this great success, a few populations with MSI-H/dMMR gastrointestinal cancers do not respond to immunotherapy, possibly due to the existence of intrinsic or acquired resistance mechanisms. Clarifying the underlying mechanisms of resistance remains a future task, whereas attempts to overcome resistance and improve the efficacy of immunotherapy are currently ongoing. Herein, we review recent clinical trials with special attention to MSI-H/dMMR gastrointestinal cancers together with basic/translational findings, which provide their rationale, and discuss perspectives for the further therapeutic development of treatment in this field.

Neoadjuvant immunotherapy for colorectal cancer: Right regimens, right patients, right directions?

Neoadjuvant chemoradiotherapy (NACRT) or chemotherapy (NACT) followed by radical resection and then adjuvant therapy is considered the optimal treatment model for locally advanced colorectal cancer (LACRC). A recent total neoadjuvant therapy (TNT) strategy further improved the tumour regression rate preoperatively and reduced local-regional recurrence in locally advanced rectal cancer (LARC). However, distant metastasis was still high, and little overall survival benefit was obtained from these preoperative treatment models. According to mismatch repair protein expression, MSI-H/dMMR and non-MSI-H/pMMR statuses were defined in colorectal cancer (CRC) patients. Due to the special features of biologics in MSI-H/dMMR CRC patients, this subgroup of patients achieved little treatment efficacy from chemoradiotherapy but benefited from immune checkpoint inhibitors (ICIs). The KEYNOTE-177 trial observed favourable survival outcomes in metastatic CRC patients treated with one-line pembrolizumab with tolerable toxicity. Given the better systemic immune function, increased antigenic exposure, and improved long-term memory induction before surgery, neoadjuvant ICI (NAICI) treatment was proposed. The NICHE trial pioneered the use of NAICI treatment in LACRC, and recent reports from several phase II studies demonstrated satisfactory tumour downsizing in CRC. Preclinical rationales and preliminary early-phase human trials reveal the feasibility of NAICI therapy and the therapeutic efficacy provided by this treatment model. Better tumour regression before surgery also increases the possibility of organ preservation for low LARC. However, the optimal treatment strategy and effective biomarker identification for beneficiary selection remain unknown, and potential pitfalls exist, including tumour progression during neoadjuvant treatment due to drug resistance and surgery delay. Given these foundations and questions, further phase II or III trials with large samples need to be conducted to explore the right regimens for the right patients.

N6-methyladenosine RNA modification in PD-1/PD-L1: Novel implications for immunotherapy

Cancer immunotherapy has been shown to achieve significant antitumor effects in a variety of malignancies. Out of all the immune checkpoint molecules, PD-1/PD-L1 inhibitor therapy has achieved great success. However, only some cancer patients benefit from this treatment strategy owing to drug resistance. Therefore, identifying the underlying modulators of the PD-1/PD-L1 pathway to completely comprehend the mechanisms of anti-PD-1/PD-L1 treatment is crucially important. Recent research has validated that m6A modification plays a critical role in the PD-1/PD-L1 axis, thus regulating the immune response and immunotherapy strategies. In this review, we summarized the latest research on the regulation of m6A modification in PD-1/PD-L1 pathways in cancer proliferation, invasion, and prognosis based on different kinds of cancers and discussed the possible mechanisms. We also reviewed m6A-associated lncRNAs in the regulation of the PD-1/PD-L1 pathway. More importantly, we outlined the influence of m6A modulation on anti-PD-1 therapy and m6A-related molecules that could predict the curative effect of anti-PD-1/PD-L1 therapy. Further studies exploring the definitive regulation of m6A on the PD1/PD-1 pathway and immunotherapy are needed, which may address some of the current limitations in immunotherapy.

Artificial Intelligence-Assisted Transcriptomic Analysis to Advance Cancer Immunotherapy

The emergence of immunotherapy has dramatically changed the cancer treatment paradigm and generated tremendous promise in precision medicine. However, cancer immunotherapy is greatly limited by its low response rates and immune-related adverse events. Transcriptomics technology is a promising tool for deciphering the molecular underpinnings of immunotherapy response and therapeutic toxicity. In particular, applying single-cell RNA-seq (scRNA-seq) has deepened our understanding of tumor heterogeneity and the microenvironment, providing powerful help for developing new immunotherapy strategies. Artificial intelligence (AI) technology in transcriptome analysis meets the need for efficient handling and robust results. Specifically, it further extends the application scope of transcriptomic technologies in cancer research. AI-assisted transcriptomic analysis has performed well in exploring the underlying mechanisms of drug resistance and immunotherapy toxicity and predicting therapeutic response, with profound significance in cancer treatment. In this review, we summarized emerging AI-assisted transcriptomic technologies. We then highlighted new insights into cancer immunotherapy based on AI-assisted transcriptomic analysis, focusing on tumor heterogeneity, the tumor microenvironment, immune-related adverse event pathogenesis, drug resistance, and new target discovery. This review summarizes solid evidence for immunotherapy research, which might help the cancer research community overcome the challenges faced by immunotherapy.

Phenolic Phytochemicals for Prevention and Treatment of Colorectal Cancer: A Critical Evaluation of In Vivo Studies

Colorectal cancer (CRC) is the third most diagnosed and second leading cause of cancer-related death worldwide. Limitations with existing treatment regimens have demanded the search for better treatment options. Different phytochemicals with promising anti-CRC activities have been reported, with the molecular mechanism of actions still emerging. This review aims to summarize recent progress on the study of natural phenolic compounds in ameliorating CRC using in vivo models. This review followed the guidelines of the Preferred Reporting Items for Systematic Reporting and Meta-Analysis. Information on the relevant topic was gathered by searching the PubMed, Scopus, ScienceDirect, and Web of Science databases using keywords, such as "colorectal cancer" AND "phenolic compounds", "colorectal cancer" AND "polyphenol", "colorectal cancer" AND "phenolic acids", "colorectal cancer" AND "flavonoids", "colorectal cancer" AND "stilbene", and "colorectal cancer" AND "lignan" from the reputed peer-reviewed journals published over the last 20 years. Publications that incorporated in vivo experimental designs and produced statistically significant results were considered for this review. Many of these polyphenols demonstrate anti-CRC activities by inhibiting key cellular factors. This inhibition has been demonstrated by antiapoptotic effects, antiproliferative effects, or by upregulating factors responsible for cell cycle arrest or cell death in various in vivo CRC models. Numerous studies from independent laboratories have highlighted different plant phenolic compounds for their anti-CRC activities. While promising anti-CRC activity in many of these agents has created interest in this area, in-depth mechanistic and well-designed clinical studies are needed to support the therapeutic use of these compounds for the prevention and treatment of CRC.

Meta-analysis of neoadjuvant immunotherapy for non-metastatic colorectal cancer

Background

Immunotherapy has been approved for the treatment of metastatic colorectal cancer. The efficacy and safety of neoadjuvant immunotherapy for the treatment of non-metastatic colorectal cancer remains unclear. We tried to explore clinical effect of neoadjuvant immunotherapy in the treatment of non-metastatic colorectal cancer.

Methods

We searched the databases (PubMed, Wanfang Embase, Cochrane Library and China National Knowledge Infrastructure databases) to obtain suitable articles up to September 2022. The primary outcomes of pathological complete response (pCRs), major pathological response (MPR), objective response rate (ORR), R0-resection and anus preserving rate were collected and evaluated. Secordary outcomes (pCRs and MPR) of subgroup analysis between deficient mismatch repair/microsatellite instability-high group (dMMR/MSI-H) and proficient mismatch repair/microsatellite stable group (pMMR/MSS) and outcomes for rectal cancer were analyzed for the final results.

Results

We included ten articles and 410 cases of non-metastatic colorectal cancer with neoadjuvant immunotherapy. There were 113 (27.5%) cases with the dMMR/MSI-H status and 167 (40.7%) cases with the pMMR/MSS status. pCRs was found in 167/373 (44.6%) patients (ES: 0.49, 95% CI: 0.36 to 0.62, P<0.01, chi² = 65.3, P<0.01, I ² = 86.2%) and MPR was found in 194/304 (63.8%) patients (ES: 0.66, 95% CI: 0.54 to 0.78, P<0.01, chi² = 42.55, P<0.01, I ² = 81.2%) with the random-effects model and huge heterogeneity. In the subgroup analysis, pCRs was higher in the dMMR/MSI-H group than the pMMR/MSS group in the fixed-effects model with minimal heterogeneity (OR: 3.55, 95% CI: 1.74 to 7.27, P<0.01, chi² = 1.86, P=0.6, I ² = 0%). pCRs was found in 58/172 (33.9%) rectal cancer patients (ES: 0.33, 95% CI: 0.26 to 0.40, P<0.01, chi² = 3.04, P=0.55, I ² = 0%) with the fixed-effects model and little heterogeneity.

Conclusion

Neoadjuvant immunotherapy could increase pCRs and MPR rate for non-metastatic colorectal cancer. Neoadjuvant immunotherapy could achieve better pCRs rate in dMMR/MSI-H group than in the pMMR/MSS group. Neoadjuvant immunotherapy could be another treatment option for non-metastatic colorectal cancer.

Systematic review registration

https://www.crd.york.ac.uk/prospero/#myprospero, identifier CRD42022350523.

A novel machine learning model based on ubiquitin-related gene pairs and clinical features to predict prognosis and treatment effect in colon adenocarcinoma

BACKGROUND

Ubiquitin and ubiquitin-like (UB/UBL) conjugations are essential post-translational modifications that contribute to cancer onset and advancement. In colon adenocarcinoma (COAD), nonetheless, the biological role, as well as the clinical value of ubiquitin-related genes (URGs), is unclear. The current study sought to design and verify a ubiquitin-related gene pairs (URGPs)-related prognostic signature for predicting COAD prognoses.

METHODS

Using univariate, least absolute shrinkage and selection operator (LASSO), and multivariate Cox regression, URGP's predictive signature was discovered. Signatures differentiated high-risk and low-risk patients. ROC and Kaplan-Meier assessed URGPs' signature. Gene set enrichment analysis (GSEA) examined biological nomogram enrichment. Chemotherapy and tumor immune microenvironment were also studied.

RESULTS

The predictive signature used six URGPs. High-risk patients had a worse prognosis than low-risk patients, according to Kaplan-Meier. After adjusting for other clinical characteristics, the URGPs signature could reliably predict COAD patients. In the low-risk group, we found higher amounts of invading CD4 memory-activated T cells, follicular helper T cells, macrophages, and resting dendritic cells. Moreover, low-risk group had higher immune checkpoint-related gene expression and chemosensitivity.

CONCLUSION

Our research developed a nomogram and a URGPs prognostic signature to predict COAD prognosis, which may aid in patient risk stratification and offer an effective evaluation method of individualized treatment in clinical settings.

Construction of cuproptosis‑associated prognostic signature in colon adenocarcinoma based on bioinformatics and RT‑qPCR analysis

Colon adenocarcinoma (COAD) is the most common pathological subtype of colon cancer with a high degree of malignancy. Cuproptosis is a newly discovered copper-dependent cell death pattern distinguished from all the other known programmed cell death. Hence, it can be used as a potential therapeutic target for cancer. The present study aimed to clarify the relationship between cuproptosis and prognosis of COAD. The variations of 12 cuproptosis-associated genes based on 623 patients with COAD were comprehensively identified. It was found that 8 out of 12 were differentially expressed in tumors and normal tissues and CDKN2A showed a higher prognostic value. Therefore, two molecular subtypes were explored and the subtype A, with higher expression of cuproptosis-associated genes, showed more enrichment of immune pathways and survival advantage over those with lower cuproptosis-associated genes expression. The risk score and a nomogram predicting pattern were constructed to quantify a single patient and the risk score could serve as an independent prognostic factor by multivariate Cox regression analysis (P<0.001, HR: 1.350, 95% CI: 1.189-1.534). The expression levels of key prognostic genes (PMM2, ACOX1, KDM3A, HSPB1, PPARGC1A, UPK3B and EPHB2) was analyzed by HCT-116 colon cancer cells and HT-29 colorectal cancer cells using reverse transcription-quantitative PCR. The high-risk group, characterized by higher immune infiltration, increased microsatellite instability-high, high tumor mutation burden and high expression level of immune checkpoints, indicated higher drug sensitivity. In conclusion, our analysis confirms the potential role of cuproptosis-associated genes in the prognosis of COAD and it will provide new ideas for immunotherapy.

Integrating machine learning and single-cell trajectories to analyze T-cell exhaustion to predict prognosis and immunotherapy in colon cancer patients

Introduction

The incidence of colon adenocarcinoma (COAD) has recently increased, and patients with advanced COAD have a poor prognosis due to treatment resistance. Combining conventional treatment with targeted therapy and immunotherapy has shown unexpectedly positive results in improving the prognosis of patients with COAD. More study is needed to determine the prognosis for patients with COAD and establish the appropriate course of treatment.

Methods

This study aimed to explore the trajectory of T-cell exhaustion in COAD to predict the overall survival and treatment outcome of COAD patients. Clinical data were derived from the TCGA-COAD cohort through "UCSC", as well as the whole genome data. Prognostic genes driving T-cell trajectory differentiation were identified on the basis of single-cell trajectories and univariate Cox regression. Subsequently, T-cell exhaustion score (TES) was created by iterative LASSO regression. The potential biological logic associated with TES was explored through functional analysis, immune microenvironment assessment, immunotherapy response prediction, and in vitro experiments.

Results

Data showed that patients with significant TES had fewer favorable outcomes. Expression, proliferation, and invasion of COAD cells treated with TXK siRNA were also examined by cellular experiments. Both univariate and multivariate Cox regression indicated that TES was an independent prognostic factor in patients with COAD; in addition, subgroup analysis supported this finding. Functional assay revealed that immune response and cytotoxicity pathways are associated with TES, as the subgroup with low TES has an active immune microenvironment. Furthermore, patients with low TES responded better to chemotherapy and immunotherapy.

Conclusion

In this study, we systematically explored the T-cell exhaustion trajectory in COAD and developed a TES model to assess prognosis and provide guidelines for the treatment decision. This discovery gave rise to a fresh concept for novel therapeutic procedures for the clinical treatment of COAD.

Histopathological Growth Pattern in Colorectal Liver Metastasis and The Tumor Immune Microenvironment

Almost half of all patients with colorectal cancer present with or eventually develop metastasis, most frequently in the liver. Understanding the histopathological growth patterns and tumor immune microenvironment of colorectal liver metastases may help determine treatment strategies and assess prognosis. A literature search was conducted to gather information on cancer biology, histopathological growth patterns, and the tumor immune microenvironment in colorectal liver metastases, including their mechanisms and their impact on clinical outcomes. A first consensus on histopathological growth patterns emerged in 2017, identifying five growth patterns. Later studies found benefits from a two-tier system, desmoplastic and non-desmoplastic, incorporated into the updated 2022 consensus. Furthermore, the tumor immune microenvironment shows additional characteristic features with relevance to cancer biology. This includes density of T-cells (CD8+), expression of claudin-2, presence of vessel co-option versus angiogenesis, as well as several other factors. The relation between histopathological growth patterns and the tumor immune microenvironment delineates distinct subtypes of cancer biology. The distinct subtypes are found to correlate with risk of metastasis or relapse, and hence to clinical outcome and long-term survival in each patient. In order to optimize personalized and precision therapy for patients with colorectal liver metastases, further investigation into the mechanisms of cancer biology and their translational aspects to novel treatment targets is warranted.

Immune-related gene-based prognostic index for predicting survival and immunotherapy outcomes in colorectal carcinoma

Introduction

Colorectal cancer shows high incidence and mortality rates. Immune checkpoint blockade can be used to treat colorectal carcinoma (CRC); however, it shows limited effectiveness in most patients.

Methods

To identify patients who may benefit from immunotherapy using immune checkpoint inhibitors, we constructed an immune-related gene prognostic index (IRGPI) for predicting the efficacy of immunotherapy in patients with CRC. Transcriptome datasets and clinical information of patients with CRC were used to identify differential immune-related genes between tumor and para-carcinoma tissue. Using weighted correlation network analysis and Cox regression analysis, the IRGPI was constructed, and Kaplan-Meier analysis was used to evaluate its predictive ability. We also analyzed the molecular and immune characteristics between IRGPI high-and low-risk subgroups, performed sensitivity analysis of ICI treatment, and constructed overall survival-related receiver operating characteristic curves to validate the IRGPI. Finally, IRGPI genes and tumor immune cell infiltration in CRC model mice with orthotopic metastases were analyzed to verify the results.

Results

The IRGPI was constructed based on the following 11 hub genes: ADIPOQ, CD36, CCL24, INHBE, UCN, IL1RL2, TRIM58, RBCK1, MC1R, PPARGC1A, and LGALS2. Patients with CRC in the high-risk subgroup showed longer overall survival than those in the low-risk subgroup, which was confirmed by GEO database. Clinicopathological features associated with cancer progression significantly differed between the high- and low-risk subgroups. Furthermore, Kaplan-Meier analysis of immune infiltration showed that the increased infiltration of naïve B cells, macrophages M1, and regulatory T cells and reduced infiltration of resting dendritic cells and mast cells led to a worse overall survival in patients with CRC. The ORC curves revealed that IRGPI predicted patient survival more sensitive than the published tumor immune dysfunction and rejection and tumor inflammatory signature.

Discussion

Thus, the low-risk subgroup is more likely to benefit from ICIs than the high-risk subgroup. CRC model mice showed higher proportions of Tregs, M1 macrophages, M2 macrophages and lower proportions of B cells, memory B cell immune cell infiltration, which is consistent with the IRGPI results. The IRGPI can predict the prognosis of patients with CRC, reflect the CRC immune microenvironment, and distinguish patients who are likely to benefit from ICI therapy.

Downregulation of MACC1 facilitates the reversal effect of verapamil on the chemoresistance to active metabolite of irinotecan in human colon cancer cells

The aim of this study is to investigate the reversal effect of verapamil (VER) on chemoresistance to irinotecan (CPT-11) in human colon cancer cells and relevant mechanisms. Cell counting kit-8 (CCK-8) test and colony-forming unit (CFU) experiment results show that VER strengthens the sensitivity of human colon cancer cell line HT29 to CPT-11 but has a small effect on SW480 cells. High-throughput transcriptome sequencing, RT-PCR, and Western blot results show that the inhibition of metastasis-associated in colon cancer-1 (MACC1) expression by VER is the key factor for reversal effect on chemoresistance to CPT-11. Transfection experiments further show that VER can reverse the resistance of human colon cancer cells to SN-38, the active metabolite of CPT-11, when MACC1 is overexpressed. The nude mouse transplantation tumor experiment provides an in vivo proof that VER can strengthen sensitivity to CPT-11 in drug-resistant human colon cancer cells, and the effect might be related to the inhibited expression of MACC1. In summary, VER might strengthen the reversal effect of VER on chemoresistance to CPT-11 in human colon cancer cells and facilitate the apoptosis of human colon cancer cells by downregulating MACC1 expression.