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Emerging studies have focused on ways to treat cancers by modulating T cell activation. However, whether B cell receptor signaling in the tumor microenvironment (TME) can be harnessed for immunotherapy is unclear. Here, we report that an Asia-specific variant of human IgG1 containing a Gly396 to Arg396 substitution (hIgG1-G396R) conferred improved survival of patients with colorectal cancer (CRC). Mice with knockin of the murine functional homolog mIgG2c-G400R recapitulated the alleviated tumorigenesis and progression in murine colon carcinoma models. Immune profiling of the TME revealed broad mobilizations of [IgG1.sup.+] plasma cells, [CD8.sup.+] T cells, [CD103.sup.+] DCs, and active tertiary lymphoid structure formation, suggesting an effective antitumor microenvironment in hIgG1-G396R CRC patients. Mechanistically, this variant potentiated tumorassociated antigen-specific (TAA-specific) plasma cell differentiation and thus antibody production. These elevated TAA-specific IgG2c antibodies in turn efficiently boosted the antibody-dependent tumor cell phagocytosis and TAA presentation to effector [CD8.sup.+] T cells. Notably, adoptive transfer of TAA-specific class-switched memory B cells harboring this variant exhibited therapeutic efficacy in murine tumor models, indicating their clinical potential. All these results prompted a prospective investigation of hIgG1-G396R in patients with CRC as a biomarker for clinical prognosis and demonstrated that manipulating the functionality of [IgG1.sup.+] memory B cells in tumors could improve immunotherapy outcomes., Introduction Effective immune responses are indispensable for optimal cancer treatment; however, tumor cells often evade immune clearance by inhibiting neoantigen presentation and inducing immune silencing in the tumor microenvironment (TME) [...]

Colorectal cancer (CRC) is the third most prevalent and second most lethal cancer globally, with gene mutations and tumor metastasis contributing to its poor prognosis. Single-cell sequencing technology enables high-throughput analysis of the genome, transcriptome, and epigenetic landscapes at the single-cell level. It offers significant insights into analyzing the tumor immune microenvironment, detecting tumor heterogeneity, exploring metastasis mechanisms, and monitoring circulating tumor cells (CTCs). This article provides a brief overview of the technical procedure and data processing involved in single-cell sequencing. It also reviews the current applications of single-cell sequencing in CRC research, aiming to enhance the understanding of intratumoral heterogeneity, CRC development, CTCs, and novel drug targets. By exploring the diverse molecular and clinicopathological characteristics of tumor heterogeneity using single-cell sequencing, valuable insights can be gained into early diagnosis, therapy, and prognosis of CRC. Thus, this review serves as a valuable resource for identifying prognostic markers, discovering new therapeutic targets, and advancing personalized therapy in CRC. [ABSTRACT FROM AUTHOR]

In recent years, the tumour microenvironment (TME) of solid tumours has attracted more and more attention from researchers, especially those non-tumour components such as immune cells. Infiltration of various immune cells causes tumour immune microenvironment (TIME) heterogeneity, and results in different therapeutic effects. Accumulating evidence showed that DNA methylation plays a crucial role in remodelling TIME and is associated with the response towards immune checkpoint inhibitors (ICIs). During carcinogenesis, DNA methylation profoundly changes, specifically, there is a global loss of DNA methylation and increased DNA methylation at the promoters of suppressor genes. Immune cell differentiation is disturbed, and exclusion of immune cells from the TME occurs at least in part due to DNA methylation reprogramming. Therefore, pharmaceutical interventions targeting DNA methylation are promising. DNA methyltransferase inhibitors (DNMTis) enhance antitumor immunity by inducing transcription of transposable elements and consequent viral mimicry. DNMTis upregulate the expression of tumour antigens, mediate immune cells recruitment and reactivate exhausted immune cells. In preclinical studies, DNMTis have shown synergistic effect when combined with immunotherapies, suggesting new strategies to treat refractory solid tumours. [ABSTRACT FROM AUTHOR]

Background: The clinicopathological features, surgical outcomes, and long-term survival of patients with young-onset colon cancer (≤ 40 years old) remain controversial. Methods: The clinicopathologic and follow-up data of patients aged < 40 years with colon cancer between January 2014 and January 2022 were reviewed. The primary objectives were clinical features and surgical outcomes. Long-term survival was investigated as a secondary objective. Results: Seventy patients were included in the study, and no significant rising trend (Z=0, P=1) of these patients was observed over the 8-year study period. Stage IV disease was accompanied by more ulcerative or infiltrating type (84.2% vs. 52.9%, P=0.017) and lymphovascular or perineural invasion (64.7% vs. 25.5%, P=0.003) than stage I–III disease. After a median follow-up time of 41 months (range 8–99 months), the 1-, 3-, and 5-year estimated overall survival (OS) rates were 92.6%, 79.5%, and 76.4%, respectively. The 1-, 3-, and 5-year progression-free survival (PFS) rates were 79.6%, 71.7%, and 71.7%, respectively. Multivariate Cox regression showed that M+ stage (hazard ratio [HR], 3.942; 95% confidence interval [CI], 1.176–13.220, P=0.026) was the only independent risk factor affecting OS. Meanwhile, tumor deposits (HR, 4.807; 95% CI, 1.942–15.488, P=0.009), poor differentiation (HR, 2.925; 95% CI, 1.012–8.454, P=0.047), and M+ stage (HR, 3.540; 95% CI, 1.118–11.202, P=0.032) independently affected PFS. Conclusions: The differences in the clinical features, surgical outcomes, and long-term survival between young adults and elderly colon cancer patients need further investigation. [ABSTRACT FROM AUTHOR]

A gastrointestinal stromal tumor (GIST) is mostly driven by the auto-activated, mutant KIT receptor tyrosine kinase gene or by the platelet-derived growth factor receptor alpha. Inhibition of KIT-signaling is the primary molecular target therapy for GIST, which is performed by the drug imatinib clinically. However, more than half of advanced or metastatic GIST develop secondary resistance to imatinib within 2 years after initiation of treatment, and the mechanism of acquired imatinib-resistant in GIST remains unclear. Therefore, we designed the present study, and firstly analyzed the gene expression profile of imatinib-resistant and sensitive GIST from GEO DataSet and identified 44 differential expressed genes. Then, a model including nine genes with their expressed coefficients was identified as a risk score to predict imatinib-resistant GIST. Internal and external validation of the prediction model was performed through the ROC curve, and the area under the curve was 0.967 (95%CI 0.901–1.000) and 0.917 (95%CI 0.753–1.000), separately. Lastly, the effect of immune, m6A, pyroptosis, and ferroptosis-related genes on imatinib-resistant GIST was also assessed because DNA replication was the most enriched biological function of DEGs after functional annotation, pathway enrichment, and protein-protein interaction network analyses. In conclusion, the present study established a novel model to predict secondary imatinib-resistant GIST. Meanwhile, the bioinformatic mining results provided potential and promising targets for imatinib-resistant therapy. [ABSTRACT FROM AUTHOR]

Aim: The benefits of adjuvant chemotherapy (AC) in colon cancer after complete mesocolic excision (CME) have not been evaluated sufficiently. We reanalysed the ESCME trial data to investigate the survival benefits and establish AC stratified indications. Methods: The data of Stage II and III colon cancer patients who received CME in the ESCME trial were reanalysed. Patients were divided into AC and non‐AC (NAC) groups. The primary outcomes measured were differences in 5‐year cancer‐specific survival and disease‐free survival (DFS) between the groups. Results: Of the 206 patients enrolled in the study, 125 patients (AC, 49; NAC, 76) had Stage II cancer and 111 (AC, 86; NAC, 25) had Stage III cancer. There were no significant differences in the adjusted 5‐year cancer‐specific survival and DFS between the AC and NAC groups. Poor differentiation (hazard ratio [HR] 2.947; 95% CI 1.218–7.131) and RAS mutation (HR 3.140; 95% CI 1.363–7.234) affected the 5‐year DFS significantly in multivariate Cox regression analysis for Stage II and III cancer, respectively. In subgroup analysis, AC significantly improved 5‐year DFS (HR 0.369; 95% CI 0.140–0.978) for Stage III cancer with lymphovascular/perineural invasion compared to NAC. Conclusion: The current indication and benefits of AC for colon cancer patients after CME should be re‐evaluated. AC is more appropriate for Stage III cancer with lymphovascular/perineural invasion. [ABSTRACT FROM AUTHOR]

Neoadjuvant therapy has become a standard treatment for patients with locally advanced rectal cancer to achieve better prognostic outcomes. The response to treatment has been shown to correlate closely with the prognosis. However, current evaluation systems only provide coarse assessment on limited information, due to the lack of accurate and reproducible approach for quantitation of different types of responses. In this study, a novel stain‐free, slide‐free multimodal multiphoton microscopy imaging technique was applied to image rectal cancer tissues after neoadjuvant therapies with high resolution and contrast. Qualitative and quantitative evaluation of tumor, stromal, and inflammatory responses were demonstrated which are consistent with current tumor regression grading system using American Joint Committee on Cancer criteria, showing the great potential of such approach to build a more informative grading system for accurate and standardizable assessment of neoadjuvant therapy in rectal cancer. [ABSTRACT FROM AUTHOR]

Background: As the most widespread mRNAs modification, N6‐methyladenosine (m6A) is dynamically and reversibly modulated by methyltransferases and demethylases. ALKBH5 is a major demethylase, and plays vital roles in the progression of cancers. However, the role and mechanisms of ALKBH5 in colorectal cancer (CRC) is unclear. Results: Herein, we discovered that in CRC, downregulated ALKBH5 was closely related to poor prognosis of CRC patients. Functionally, our results demonstrated that knockdown of ALKBH5 enhanced the proliferation, migration and invasion of LOVO and RKO in vitro, while overexpression of ALKBH5 inhibited the functions of these cells. The results also demonstrated that knockdown of ALKBH5 promoted subcutaneous tumorigenesis of LOVO in vivo, while overexpression of ALKBH5 suppressed this ability. Mechanistically, results from joint analyses of MeRIP‐seq and RNA‐seq indicated that PHF20 mRNA was a key molecule that was regulated by ALKBH5‐mediated m6A modification. Further experiments indicated that ALKBH5 may inhibit stability of PHF20 mRNA by removing the m6A modification of PHF20 mRNA 3′UTR. Conclusions: ALKBH5 suppresses CRC progression by decreasing PHF20 mRNA methylation. ALKBH5‐mediated m6A modification of PHF20 mRNA can serve as a hopeful strategy for the intervention and treatment of CRC. [ABSTRACT FROM AUTHOR]

Accumulating evidence has demonstrated that N6-methyladenosine (m6A) plays important roles in various cancers, making it essential to profile m6A modifications at a transcriptome-wide scale in colorectal cancer (CRC). In the present study, we performed high-throughput sequencing to determine the m6A methylome in CRC. We obtained six pairs of CRC samples and tumour-adjacent normal tissues from Peking University People's Hospital. We used MeRIP-seq to determine that compared to the tumour-adjacent normal tissues, the CRC samples had 1343 dysregulated m6A peaks, and 625 m6A peaks were significantly upregulated and 718 m6A peaks were significantly downregulated. Genes with altered m6A peaks play critical roles in regulating glucose metabolism, RNA metabolism, and cancer stem cells. Furthermore, we identified 297 hypermethylated m6A peaks and 328 hypomethylated m6A peaks in mRNAs through conjoint analyses of MeRIP-seq and RNA-seq data. After analysing these genes with differentially methylated m6A peaks and synchronously differential expression, we identified four genes (WDR72, SPTBN2, MORC2, and PARM1) that were associated with prognosis of colorectal cancer patients by searching The Cancer Genome Atlas (TCGA). Our study suggests that m6A modifications play important roles in tumour progression and survival of CRC patients. The results also indicate that modulating m6A modifications may represent an alternative strategy to predict the survival of cancer patients and interfere with tumour progression in the future. [ABSTRACT FROM AUTHOR]