Introduction

Angiogenesis is a hallmark of cancer¹ and it plays a critical role in tumor development, especially in the proliferation and progression of colorectal cancer (CRC)^2,3.
Indeed, tumor vasculature prompts tumor growth and metastasis since it not only provides nutrients and oxygen for the rapid proliferation of cancer cells as well as a route for metastatization, but also affects the infiltration of immune cells to the tumor site. Thus, the targeting of angiogenesis has become an attractive strategy against various human malignancies, including CRC⁴_. In fact, tumor-associated vessels are leaky and poorly efficient due to the dismantlement of the basement membrane and the loss of pericytes, thus preventing proficient drug delivery to the tumor⁵_.
In this context, we demonstrated that Multimerin-2, an extracellular matrix glycoprotein deposited along the blood vessels in juxtaposition between endothelial cells and pericytes, mural cells fundamental in vessels stabilization, is key in the maintenance of vascular homoeostasis⁶_. However, the effects of this molecule on pericytes biology and its putative impact on the immune cells’ recruitment are still poorly understood.

Aims & Methods

Immunohistochemistry analysis on colorectal cancer patients’ biopsies revealed that colon cancer associated vessels display a downregulated expression of Multimerin-2. Thus, we aimed to verify the extent of pericyte recruitment by Multimerin-2-devoid vessels in a colon cancer model and to evaluate how Multimerin-2 loss affects the surrounding tumor microenvironment.
Human umbilical vein endothelial cells (HUVEC) and Human brain vascular pericytes (HBVP) were used as in vitro models for proliferation, functional assays, transcriptomic and proteomics analyses. Wild type and Multimerin-2^-/-C57BL/6 mice were subcutaneously injected with the syngeneic colon cancer MC-38 cells and the tumor sections were analysed by immunofluorescence analyses. Animals were then treated with cisplatin six hours prior sacrificing to evaluate the drug delivery.

Results

We demonstrated that Multimerin-2 affects pericytes migration, adhesion, and proliferation. MC-38 xenografts from Multimerin-2^-/-mice displayed lower number of pericytes along the vessels as well as increased hypoxia, likely due to vascular inefficiency. The delivery of drug to the tumors was impaired as assessed by the analysis of cisplatin DNA adducts, following the treatment with the chemotherapy drug.
Importantly, tumors from Multimerin-2^-/-mice also displayed an altered CD68⁺ cells infiltrate, suggesting that Multimerin-2 loss can affect macrophages recruitment to the tumor site. These results are in agreement with the finding that Multimerin-2 devoid endothelium was more permissive for the migration of the monocytic cell line THP-1. Finally, the loss of Multimerin-2 also associates with the expression of cytokines involved in macrophages recruitment.

Conclusion

In conclusion, loss of Multimerin-2 in CRC associates with poor pericyte recruitment, compromised delivery of drugs to the tumor, and an altered immune response. Our results suggest that Multimerin-2 expression could represent a promising marker to predict the efficacy of immunotherapy and the outcome of CRC patients.

References

1. Hanahan, D. & Weinberg, R. A. Hallmarks of Cancer: The Next Generation. Cell 144, 646–674 (2011).
2. Weis, S. M. & Cheresh, D. A. Tumor angiogenesis: molecular pathways and therapeutic targets. Nat Med 17, 1359–1370 (2011).
3. Angiogenesis Factors Involved in the Pathogenesis of Colorectal Cancer. Current Health Sciences Journal 5–11 (2013).
4. Rivera, L. B. & Bergers, G. Tumor angiogenesis, from foe to friend. Science 349, 694–695 (2015).
5. Carmeliet, P. & Jain, R. K. Principles and mechanisms of vessel normalization for cancer and other angiogenic diseases. Nat Rev Drug Discov 10, 417–427 (2011).
6. Pellicani, R. et al. Multimerin-2 maintains vascular stability and permeability. Matrix Biology 87, 11–25 (2020).

Introduction

There are two approaches for neoadjuvant treatment in locally advanced rectal cancer: conventional radiotherapy (RT) with concomitant chemotherapy and hypofractionated RT. In the RAPIDO study, preoperative hypofractionated RT versus conventional chemo-radiotherapy was proven to be equally effective. In our country and in our center (approximately 90%) previously, the standard treatment was conventional RT, however due to the COVID 19 pandemic in 2020, an increase in the use of hypofractionated RT was observed, this because it was a more accessible therapy for patients due to visits. In our country, the results of hypofractionation therapy compared to a conventional one have not been explored, therefore we decided to compare the outcomes between these modalities.

Aims & Methods

To compare early radiotoxicity of conventional vs. hypofractionated RT.
Methods: Retrospective study conducted in a national reference cancer center at National Institute of Cancer (INCAN) at Mexico City, during the period of April 2020 to December 2020.

Results

We analyzed 61 patients with rectal adenocarcinoma. Locally advanced were 91.8% and metastatic 8.2%. By tumor location upper third 11.4%, middle third 16.4%, middle third 72.1%. Regarding treatment, 72.1% received hypofractionation (25Gy in 5 fractions) and 27.9% conventional (45-50.4 Gy in 25-28 fractions). Techniques used 93.4% 3DCRT, 4.9% IMRT and 1.6% VMAT. Regarding general toxicity, it was observed in 30 patients (68%) in the hypofractionated group and 11 patients (64%) in the conventional treatment group p=0.794. Type of radiotoxicity is described in table 1. We observed a greater radiation mucositis grade 3 in the hypofractionated group compared with standard therapy. The other types were similar with no statistical significance. Table 1.

Conclusion

We observed a considerable increase in the use of hypofractionation in which we did not observe proctitis and cystitis in relation to conventional treatment, however caution and special attention must be exercised in radiation mucositis. We can increase the use of hypofractionated treatment with almost similar radiotoxicities. Further prospective studies are required to confirm these findings.

References

Introduction

Radiation therapy is widely used in the treatment of carcinoma in the abdomen and pelvic cavity, but as a side effect, acute and chronic damage to the gastrointestinal tract may occur. It is well known that the rectum is more prone to radiation damage since it is fixed in the pelvis. Acute symptoms of radiation enteritis are mainly associated with inflammation of the intestinal mucosa and loss of normal mucosa, but changes in gastrointestinal motility due to exposure to high-concentration radiation may also be a cause. Previous studies are demonstrating that patients who received radiation therapy had increased bowel movements, symptoms of urgency, and decreased rectal compliance. But there are only limited studies investigated the pattern of changes in the motility of human rectal smooth muscle following irradiation.

Aims & Methods

This study was conducted to investigate changes in motility and their mechanisms after irradiation in human rectum.
Human rectal tissues were obtained immediately in the operating room from patients undergoing colorectal resection. After removing the mucosal layer of rectum, muscle layer was cut in strips of 5-6 mm in length and 2-3 mm in width. The muscle strips were mounted to an isometric force transducer (Biopac Systems, Inc., Goleta, CA, USA) and suspended in 10 ml organ bath containing aerated (97% O₂ and 3% CO₂) and warmed (36.5 ± 0.5°C) KRB solution. The area under the curve (AUC) for 5 min and tone of spontaneous contractions were analyzed to compared the responses to KCl, ACh (acethylcholine), SNP (sodium nitroprusside), a nitric oxide donor, and ATP (adenosine triphosphate), a purinergic receptor agonist. The mechanical responses were recorded and digitized using Acknowledge software (Biopac Systems, Inc., Goleta, CA, USA). Data were analyzed offline using Clampfit (version 10.2. Molecular devices, San Jose, CA, USA). qPCR was performed for expression of VChAT, NOS1 and PDGFRα to quantify cells mediating cholinergic, nitrergic and purinergic neurotransmission.

Results

KCl and ACh increased the tonic contraction and area under the curve (AUC) in a concentration-dependent manner in both normal and irradiated rectum. The difference in contractile pattern between the two groups was not statistically significant. SNP and ATP decreased AUC and reduced tonic contractions in a concentration-dependent manner in both normal and irradiated rectum. The response to SNP between the two groups was not statistically significant. However, the response to ATP reduced significantly in irradiated rectum compared to normal rectum. In addition, expression of VAChT and NOS1 which are related with cholinergic and nitrergic neurotransmission was not different in both normal and irradiated rectum, however, PDGFRα expression which is related with purinergic neurotransmission was significantly decreased in irradiated rectum compared to normal rectum.

Conclusion

In this study, we analyzed contractile changes in irradiated rectum using neurotransmitters. There were no differences in contractile responses to KCl and ACh and in relaxation response to SNP, however, the relaxation response to ATP was significantly reduced in irradiated rectum. Cholinergic and nitrergic neurotransmission were not changed, however, purinergic neurotransmission was decreased in in irradiated rectum.
These results may explain one of the causes by which increased bowel movements, symptoms of urgency, and decreased rectal compliance in irradiated patients.

Introduction

Mast cells are the primary cells that cause acute and chronic colitis due to irradiation causing radiation-induced colitis (RIC). Herein, we investigated whether pre-treatment with tranilast, mast cell inhibitor, could alleviate RIC.

Aims & Methods

A total of 23 Sprague Dawley (SD) rats were randomly divided into three groups control (n=5, C), irradiation group (n=9, RG), and tranilast pre-treated irradiation group (n=9, TG). Tranilast (100 mg/kg) was administered with meal for 10 d to TG, then Gamma ray (20 gray single dose) was irradiated to the pelvis of RG and TG. Ten weeks after irradiation, the rats were euthanized. Rectal tissue samples were stained and the total inflammation score (TIS) and mast cell count were assessed histopathologically. Expression of MUC2, MUC5AC and matrix metalloproteinase (MMP)-9 were also assessed immunohistochemically

Results

Either TIS or some components of TIS including epithelial atypia, vascular sclerosis and colitis cystica profunda, were significantly higher in RG than in TG (p=0.02, 0.038, 0.025, 0.01, respectively). The median number of infiltrating mast cells was significantly higher in the RG (27.5±18.40)) than in TG (6.0±6.02) (P=0.034). Quantitatively, the number of MMP-9-positive cells was significantly higher in the RG (23.67±19.00) than in the TG (10.25±8.45) (p<0.05).

Conclusion

TIS and MMP9 exhibited strong associations (correlation coefficient r=0.6, p<0.05) Immunohistochemically, mucin-lake of CCP showed MUC2 positivity only but was negative for MUC5AC. Conclusively, tranilast pretreatment in RIC shows an anti-inflammatory effect on the RIC with reducing mast cell infiltration and MMP expression

Introduction

The gut-liver axis, the anatomical and physiological connection between the gut and liver, is hypothesized to contribute to the development of portal vein thrombosis (PVT) in patients with end-stage liver disease (ESLD). It has been proposed that the portal vein in patients with ESLD is an inflammatory vascular bed due to the translocation of endotoxins and proinflammatory cytokines from the gut. We hypothesized that a pro-inflammatory gut microbiome in ESLD patients, and elevated levels of the gut microbiota-derived metabolite trimethylamine N-oxide (TMAO) which is an established driver of thrombosis, may contribute to the development of PVT.

Aims & Methods

In this cross-sectional study we investigated whether differences in gut microbiome diversity, bacterial species, metabolic pathway abundances, and TMAO blood levels are associated with presence of PVT in ESLD patients. Fecal samples, serum samples and data from patients with ESLD, as well as living kidney transplant donors (‘healthy controls’), were collected from the TransplantLines Biobank and Cohort Study (NCT02811835). PVT was defined as presence of a thrombus in the portal vein assessed by either radiology or during surgery within a year prior to or after fecal sample collection. We analyzed the fecal samples using Shotgun Metagenomic Sequencing to assess and compare microbiome diversity, microbial taxonomy, and metabolic pathways abundances. TMAO levels were measured in serum samples using a Vantera® Clinical Analyzer (LabCorp, Morrisville, NC, USA).

Results

A total of 102 ESLD patients, of which 23 had PVT, and 246 healthy controls were included. We found no significant difference in microbiome diversity between patients with PVT (median Shannon Diversity Index (SDI): 2.08), and without PVT (median SDI: 1.84; P=0.18). Both ESLD groups had lower microbiome diversity compared to healthy controls (median SDI: 2.55; both P<0.05). A Beta Diversity Analysis confirmed that the gut microbiome of ESLD patients was markedly distinct from that of healthy controls. After false discovery rate correction, Bacteroides fragilis and three species from the family Clostridiales were increased in abundance in ESLD patients with PVT compared to those without PVT. No altered metabolic pathways abundances were observed between both ESLD groups. Overall, altered abundances of 29% (n=49) and 51% (n=86) bacterial species, and 18% (n=96) and 35% (n=191) metabolic pathways were observed between patients with and without PVT, respectively, when compared to healthy controls. TMAO levels were higher in both ESLD patients with (3.30µm) and without PVT (3.00µm) compared to healthy controls (2.70µm) (P = 0.13 and P = 0.84 respectively), with a trend towards higher levels in patients with PVT (P = 0.19).

Conclusion

Although we observed a profound difference in gut microbiota composition between patients with ESLD and healthy controls, our analysis revealed minimal differences in the gut microbiome composition between ESLD patients with or without PVT. These results indicate that a gut microbiome-derived pro-inflammatory state was not associated with the presence of PVT in these patients.

Introduction

Irritable bowel syndrome (IBS) is a bothersome condition with long term pain and bowel symptoms and the most common cause of referral to gastroenterologists in the United Kingdom. Despite this, IBS is poorly understood as a clinical entity. Furthermore, IBS has numerous comorbidities but the full spectrum of these and how they relate to IBS has not been studied.

Aims & Methods

Using clustering analysis on the UK Biobank dataset, an adult cohort (age > 40 years), we aimed to define the top co-morbidities associated with IBS and develop a machine learning model to predict IBS. Co-morbidities in patients based on ICD-10 Summary Diagnosis codes 2 years prior to and 2 years following diagnosis with IBS were assessed and clusters defined. These were compared with a control group of non-IBS patients. Several machine learning algorithms (K-Means, Linear Discriminant Analysis, Gaussian Mixture Models) were compared for accuracy.

Results

Amongst 18000 total adults (aged over 40), 8168 patients coded for IBS, 75% of whom were female. The top ten comorbidities (Table 1) found in IBS patients included diverticular disease, hypertension, hernia, haemorrhoids, osteoarthritis, asthma, gastro-oesophageal reflux disease without oesophagitis, history of psychoactive substance abuse, hypercholesterolaemia, and cholelithiasis. K-Means achieved the highest accuracy (83%) for predicting IBS based on the co-morbidity profile.

Conclusion

Most clusters identified contained obesity, hypercholesterolemia, and hypertension, indicating a possible link with metabolic syndrome. Asthma and allergies suggest a possible cohort of IBS patients with atopy. Further research is needed to establish these links. In clinical practice, this could help both in predicting development of IBS, and also identify the cohorts of IBS on which certain therapies are more likely to work.

References

Drossman, D. A., Camilleri, M., Mayer, E. A., & Whitehead, W. E. (2002). AGA technical review on irritable bowel syndrome. Gastroenterology, 123(6), 2108-2131. doi:10.1053/gast.2002.37095
Snyder, N. (2023, 10 Feb 2023). Irritable bowel syndrome. BMJ Best Practice. Retrieved from https://bestpractice.bmj.com/topics/en-gb/122
Staller, K., Olén, O., Söderling, J., Roelstraete, B., Törnblom, H., Khalili, H., . . . Ludvigsson, J. F. (2021). Diagnostic yield of endoscopy in irritable bowel syndrome: A nationwide prevalence study 1987-2016. Eur J Intern Med, 94, 85-92. doi:10.1016/j.ejim.2021.08.001

Introduction

Upper gastrointestinal bleeding (UGIB) is one of the main potentially life-threatening emergencies encountered in gastroenterology that requires prompt management. For this reason, numerous prognostic scores have been developed to predict the level of risk in patients. However, there are few studies in the literature comparing these scores.

Aims & Methods

The main objective of this study was to compare the performance of the pre-endoscopic scores Glasgow-Blatchford Score (GBS), Rockall Score (pRS), and quick Sequential Organ Failure Assessment (qSOFA) in predicting the severity of UGIB according to predefined criteria.
Methods: This is a retrospective descriptive and analytical study of 102 patients who presented with upper gastrointestinal bleeding at the International University Hospital Cheikh Khalifa over a period of 1 year between October 2021 and October 2022. Scores were calculated for each patient with complete medical records. The data was analyzed using the Jamovi 2.2.5 software. The accuracy of each risk score in predicting clinical criteria was evaluated by the area under the receiver operating characteristic curve (AUROC). A p-value less than 0.05 was considered statistically significant.

Results

The included patients had a mean age of 57.1 years with a slight female predominance (53.9%). GBS was found to be more predictive of the risk of admission to the Intensive care Unit (ICU) and the need for blood transfusion than pRS and qSOFA with an AUROC of 0.914 for these two criteria. GBS was also more predictive of the risk of therapeutic intervention (AUROC 0.882) compared to pRS (AUROC 0.788) and qSOFA (AUROC 0.676). Regarding endoscopic intervention, pRS and GBS were equally able to predict this criterion with moderate power (AUROC pRS 0.721) (AUROC GBS 0.747). qSOFA showed no significant performance, especially in its preferred domain of admission to the ICU (AUROC 0.735) (Table). None of the 3 scores was able to predict the need for surgical intervention.

Table: Comparison of AUC, sensitivity, specificity, PPV and NPV along with cut-off value of Glasgow-Blatchford Score, pre-Rockall, and Quick-Sofa scores to predict the clinical outcomes

Conclusion

At the end of this study, the use of GBS and pRS in daily clinical practice in emergency departments is strongly recommended to predict the need for therapeutic intervention, hospitalization, or re-bleeding episodes. However, it would be interesting to study the usefulness of these prognostic scores, especially qSOFA, through larger prospective studies.

References

1. Cúrdia Gonçalves T, Barbosa M, Xavier S, et al. Optimizing the Risk Assessment in Upper Gastrointestinal Bleeding: Comparison of 5 Scores Predicting 7 Outcomes. GE Port J Gastroenterol. nov 2018;25(6):299‑307.
2. Tham J, Stanley A. Clinical utility of pre-endoscopy risk scores in upper gastrointestinal bleeding. Expert Rev Gastroenterol Hepatol. déc 2019;13(12):1161‑7.
3. Aquarius M, Smeets FGM, Konijn HW, et al. Prospective multicenter validation of the Glasgow Blatchford bleeding score in the management of patients with upper gastrointestinal hemorrhage presenting at an emergency department. Eur J Gastroenterol Hepatol. sept 2015;27(9):1011‑6.
4. Li Y, Lu Q, Song M, Wu K, Ou X. Comparisons of six endoscopy independent scoring systems for the prediction of clinical outcomes for elderly and younger patients with upper gastrointestinal bleeding. BMC Gastroenterol. 13 avr 2022;22(1):187
5. Renukaprasad AK, Narayanaswamy S, R V. A Comparative Analysis of Risk Scoring Systems in Predicting Clinical Outcomes in Upper Gastrointestinal Bleed. Cureus. juill 2022;14(7):e26669
6. Taslidere B, Sonmez E, Özcan AB, Mehmetaj L, Keskin EB, Gulen B. Comparison of the quick SOFA score with Glasgow-Blatchford and Rockall scores in predicting severity in patients with upper gastrointestinal bleeding. Am J Emerg Med. juill 2021;45:29‑36

Disclosure

All co-authors have seen and agree with the contents of the manuscript and there is no conflict of interest.