Introduction

Colorectal cancer (CRC) is a leading global malignancy and a major cause of cancer-related mortality. Exosomes—small extracellular vesicles—mediate intercellular communication by transferring microRNAs, which regulate gene expression and influence tumor behavior. Elevated levels of miR-1290 have been observed in CRC patient blood and tumor tissues. However, the biological function of exosomal miR-1290 in CRC progression remains poorly understood.

Aims & Methods

Plasma and tissue samples from CRC patients and healthy individuals were collected with ethical approval. Exosomes were isolated from patient plasma and CRC cell line-conditioned media using ultracentrifugation and membrane affinity methods. In vitro, CRC cells were transfected with miR-1290 mimics or inhibitors to assess effects on proliferation (CCK-8, EdU assays), clonogenicity (colony formation), apoptosis (flow cytometry), and migration (transwell assay). Candidate miR-1290 targets were predicted bioinformatically, and CBFA2T3 was validated by dual-luciferase reporter assay. Stable CBFA2T3-overexpressing CRC cell lines were established to evaluate phenotypic rescue. In vivo, CRC xenografts in nude mice were treated with exosomes derived from miR-1290–overexpressing or control cells. Tumor growth and expression of Ki-67 and PCNA were analyzed.

Results

Plasma exosomal miR-1290 levels were lowest in healthy controls and progressively increased across advanced adenoma, early-stage CRC, and advanced CRC groups. Notably, miR-1290 distinguished advanced CRC from controls with an AUC of 0.77 and moderately distinguished early CRC (AUC = 0.69). Consistent with clinical findings, miR-1290 expression was significantly elevated in CRC tissues versus adjacent normal mucosa and in CRC cell lines compared to normal colonic epithelial cells. CRC cells also secreted exosomes enriched in miR-1290. In vitro, miR-1290 mimics enhanced CRC cell proliferation, DNA synthesis, and clonogenic potential, without significantly affecting apoptosis or migration. Bioinformatic analysis identified CBFA2T3 as a key target of miR-1290. Dual-luciferase assays confirmed direct binding of miR-1290 to the 3′-UTR of CBFA2T3, resulting in its downregulation. In CRC cells, miR-1290 upregulation—via mimics or exosomal transfer—decreased CBFA2T3 mRNA and protein levels. Restoration of CBFA2T3 expression significantly counteracted miR-1290-induced proliferation and colony formation. In vivo, nude mice injected with CRC cells and treated with miR-1290–enriched exosomes developed significantly larger tumors compared to controls. Tumors exhibited reduced CBFA2T3 levels and elevated expression of proliferation markers Ki-67 and PCNA, supporting the tumor-promoting role of exosomal miR-1290.

Conclusion

Exosomal miR-1290 correlates with CRC progression and shows promise as a non-invasive diagnostic biomarker. Functionally, it promotes CRC proliferation and tumor growth by targeting and downregulating the tumor suppressor CBFA2T3, highlighting its potential as a therapeutic target.

Introduction

Although traditionally regarded as a vestigial organ, the appendix is increasingly recognized for its potential role in modulating gut immunity and contributing to the development of significant inflammatory or neoplastic intestinal diseases [1]. However, the underlying mechanisms linking the appendix to these immune and pathological processes remain poorly understood. This study aimed to investigate the relationship between the local immune microenvironment and the mutational landscape of rectal carcinomas in the context of prior or progressive appendectomy status.

Aims & Methods

This study aimed to investigate the relationship between the local immune microenvironment and the mutational landscape of rectal carcinomas in the context of prior or progressive appendectomy status.
Patients enrolled in the IMMUNOREACT 1 and 2 studies (NCT04915326 and NCT04917263, respectively) were stratified according to appendectomy status. Immunohistochemical analysis was performed to assess a range of immune markers, including CD3, CD4, CD8, CD8β, Tbet, FoxP3, PD-L1, MSH6, PMS2, and CD80. Additionally, flow cytometry was employed to evaluate the percentage of epithelial cells expressing CD80, CD86, CD40, HLA-ABC, or HLA-DR, as well as to quantify activated CD8+ T cells, CD4+ Th1 cells, and regulatory T cells (Tregs). Non-parametric tests were used.

Results

In this cohort, 41 patients out of 163 underwent appendectomy for other causes (e.g. appendicitis) before having been diagnosed with a rectal cancer. When the two groups were compared for microenvironmental features, in the normal mucosa of patients who had a previous appendectomy there was a higher rate of epithelial cells expressing HLA-abc (p=0,04) and a higher expression of CTLA4 on CD3+ T cells (p=0,03) when compared to appendectomy-naive patients. Within the rectal cancer tissue, a higher expression of CD86 on epithelial (cancer) cells expression was found in patients who already had an appendectomy (p=0,03). In therapy naïve patients, previous appendectomy was associated to a higher activation of CD4+ T helpers (expression of CD25), (p=0.04), and to tendency of higher rate of epithelial cells expressing HLA-abc (p=0,06) and of T cells expressing CTLA-4 (p=0.08). In patients who had neoadjuvant therapy, lower level of PD-L1 on the leukocyte surface were observed in patients who had a previous appendectomy (p=0.039).

Conclusion

Our findings suggest that prior appendectomy may be associated with distinct alterations in the local immune microenvironment of rectal carcinomas, including increased expression of antigen-presenting and immune-regulatory molecules such as HLA-BC, CTLA4, and CD86. In therapy naïve patients, appendectomy seem to increase the activation of T helper cells counterbalanced by an increase of the number of T cells expressing CTLA-4. These immune shifts in both tumour tissue and adjacent healthy mucosa support the hypothesis that the appendectomy may in somehow alter the interaction between epithelia cells and intraepithelial T cells. Further trancriptomic ​analysis will shed light on the effect of appendectomy on mucosal microevironment of ​rectal cancer patients.

References

1. Collard MK, Tourneur-Marsille J, Uzzan M, Albuquerque M, Roy M, Dumay A, Freund JN, Hugot JP, Guedj N, Treton X, Panis Y, Ogier-Denis E. The Appendix Orchestrates T-Cell Mediated Immunosurveillance in Colitis-Associated Cancer. Cell Mol Gastroenterol Hepatol. 2023;15(3):665-687.

Introduction

A large proportion of Inflammatory Bowel Disease (IBD) patients also develop liver diseases, predominantly primary sclerosing cholangitis (PSC), and more than 80% of PSC patients also have IBD. Coexistence of both diseases in patients, increase of five times the risk of developing a colorectal cancer, and causes liver transplantation failure. Both of IBD and PSC have no curative treatment yet, and the impact of IBD on liver homeostasis and reciprocally the impact of PSC on intestinal barrier (IB) remain largely unknown.

Aims & Methods

The aims of the study were to investigate the impact of (1) mouse models of IBD on liver homeostasis and (2) the impact of mouse models of PSC on IB integrity. Two models of colitis have been used. A model was conducted by adding 3% DSS in drinking water for five days, followed by two days of regular water. The second model of colitis was performed using a pre-sensitizing step involving subcutaneous injection of 2% oxazolone and five day later, a rectal injection of 1.5% oxazolone. As PSC mouse models, we used intra-peritoneal injection of 1µL/g mice weight of CCl₄ twice a week for 8 weeks and another model with a 0.1% diethyl 1,4-dihydro-2,4,6-trimethyl-3,5-pyridinedicarboxylate within diet for 3 weeks. Colitis and cholangitis severities were monitored by food consumption, macroscopic observations as well as calculation of Disease Activity Index which sum up scores of weight loss, bleeding and stool consistency. Fecal samples were tested for calprotectin and lipocalin by ELISA to estimate gut inflammation. Intestinal permeability (IP) was investigated in vivo by estimation of FITC-Dextran quantity in mice’s sera after oral administration and at mice sacrifice in ileum and colon tissues by measuring the flux of fluorescein sodium salt in Ussing chamber. To study liver homeostasis, we performed pathological analysis (H&E and Sirius red staining), and real-time PCR with a focus on fibrosis markers, bile acids metabolism and metabolic pathways.

Results

IBD models induced strong alteration of colonic homeostasis including increased fecal markers of inflammation (Calprotectin and Lipocalin-2) and tissues mRNA expression of inflammatory cytokines (Ifng…). These models of colitis were also accompanied by elevated IP and impaired liver genes expression level of fibrosis (Col3a1) and fatty acids metabolism (Fasn…), as well as cholesterol and bile acids transporters (Abcb11…). This was found to be correlated with impaired enterohepatic circulation of bile acids in the gut. Furthermore, an increase expression of mRNA markers of inflammation (Cxcl1…) was only observed in the liver of the DSS colitis model. However, no alteration of liver homeostasis, including infiltrated immune cells or fibrosis was revealed by histological analysis. PSC mouse models induced strong alterations of liver homeostasis and were associated with altered gut homeostasis shown by a strong increased IP.

Conclusion

Our data demonstrate that IBD colitis models impair liver homeostasis, while PSC models disrupt intestinal integrity. The data obtained from both IBD and PSC models demonstrated a significant increase in intestinal permeability, thereby underscoring it’s potential as an association between those diseases. Further investigations are ongoing in ours models as a next step will be to study a combination of both protocols to explore disease progression and severity.

References

Rabiee, Anahita, and Marina G Silveira. “Primary sclerosing cholangitis.” Translational gastroenterology and hepatology vol. 6 29. 5 Apr. 2021, doi:10.21037/tgh-20-266
Kim, You Sun et al. “Primary sclerosing cholangitis (PSC) and inflammatory bowel disease (IBD): a condition exemplifying the crosstalk of the gut-liver axis.” Experimental & molecular medicine vol. 55,7 (2023): 1380-1387. doi:10.1038/s12276-023-01042-9

Introduction

Gastrointestinal (GI) endoscopy requires not only technical skills but also strong non-technical abilities like communication, teamwork, and decision-making. Traditional training is often individualized, with little focus on interdisciplinary collaboration. Role Swapping (RS) — where physicians and nurses exchange tasks during simulated procedures — may enhance teamwork and mutual understanding.

Aims & Methods

A prospective pilot study was conducted involving 22 participants (10 endoscopists, 12 nurses) using in-silico colonoscopy simulators. The training included a pre-simulation skills assessment, theoretical onsite classes, randomized role-swapping simulation sessions, and a post-simulation evaluation after two weeks. Technical skills, non-technical skills (assessed via NOTSS and SPLINTS frameworks), and satisfaction were evaluated using validated questionnaires. Wilcoxon tests compared pre- and post-training scores.

Results

RS in simulated GI endoscopy training significantly enhanced both technical and non-technical competencies among participants. Post-training assessments using validated tools showed improvements across all evaluated domains. Situational awareness, decision-making, communication, teamwork, and leadership skills all exhibited statistically significant gains. Participants improved their ability to gather information (p=0.02), understand data (p=0.008), and anticipate future scenarios (p=0.002). Decision-making skills were notably enhanced, with better option consideration (p<0.001), more transparent communication of decisions (p=0.001), and greater adaptability to dynamic conditions (p<0.001). Communication improvements included more effective information exchange (p=0.007), better shared understanding (p=0.035), and increased team coordination (p=0.001). Leadership skills were also significantly strengthened, particularly in setting standards (p=0.002) and supporting teammates (p=0.012). Regarding technical skills, endoscopists reported substantial confidence improvements in tasks traditionally performed by nurses. Significant progress was observed in preparing endoscopic equipment (p=0.016), medication dilution (p=0.016), patient discharge procedures (p=0.014), instrument arrangement during interventional colonoscopies (p=0.026), and setup of patient monitoring systems (p=0.041). Confidence also increased in tasks initially rated as low-confidence, such as proper waste disposal after GI procedures (p=0.01). Nurses, conversely, enhanced their technical capabilities related to GI endoscopy performance. They showed greater proficiency in advancing the colonoscope (p=0.004), reducing loops (p=0.007), navigating angled turns (p=0.007), executing ancillary maneuvers (p=0.038), and conducting thorough mucosal inspections during withdrawal (p=0.036). Improvements were also seen in colonoscope insertion (p=0.026), understanding of colonoscopy quality indicators (p=0.011), and lesion identification (p=0.046). Participant feedback revealed high satisfaction with the RS training experience. Participants appreciated the opportunity to engage in cross-disciplinary tasks, reporting that the simulation increased their mutual respect, role awareness, and confidence in collaborative practices.

Conclusion

Role swapping during simulated GI endoscopy training enhanced both technical and non-technical skills and fostered better collaboration between nurses and physicians. This innovative educational approach shows potential to improve clinical practice quality and patient safety.

References

1. Hedges AR, Johnson HJ, Kobulinsky LR, et al. Effects of Cross-Training on Medical Teams’ Teamwork and Collaboration: Use of Simulation. Pharmacy (Basel) 2019; 7: 13.
2. de Laurentis C, Pirillo D, Di Cristofori A, et al. Boosting teamwork between scrub nurses and neurosurgeons: exploring the value of a role-played hands-on, cadaver-free simulation and systematic review of the literature. Front Surg 2024; 11: 1386887.