Preclinical and clinical evidence of the association of colibactinproducing Escherichia coli with anxiety and depression in colon cancer

BACKGROUND The association between the intestinal microbiota and psychiatric disorders is becoming increasingly apparent.The gut microbiota contributes to colorectal carcinogenesis(CRC),as demonstrated with colibactin-producing Escherichia coli(CoPEC).AIM To evaluate the association between CoPEC prevalence and anxiety-and depressive-like behaviors with both preclinical and clinical approaches.METHODS Patients followed after a CRC surgery and for whom the prevalence of CoPEC has been investigated underwent a psychiatric interview.Results were compared according to the CoPEC colonization.In parallel C57BL6/J wild type mice and mice with a CRC susceptibility were chronically infected with a CoPEC strain.Their behavior was assessed using the Elevated Plus Maze test,the Forced Swimming Test and the Behavior recognition system PhenoTyper®.RESULTS In a limited cohort,all patients with CoPEC colonization presented with psychiatric disorders several years before cancer diagnosis,whereas only one patient(17%)without CoPEC did.This result was confirmed in C57BL6/J wildtype mice and in a CRC susceptibility mouse model(adenomatous polyposis colimultiple intestinal neoplasia/+).Mice exhibited a significant increase in anxiety-and depressive-like behaviors after chronic infection with a CoPEC strain.CONCLUSION This finding provides the first evidence that CoPEC infection can induce microbiota-gut-brain axis disturbances in addition to its procarcinogenic properties.

Gut microbiota imbalance and colorectal cancer

The gut microbiota acts as a real organ. The symbiotic interactions between resident micro-organisms and the digestive tract highly contribute to maintain the gut homeostasis. However, alterations to the microbiome caused by environmental changes(e.g., infection, diet and/or lifestyle) can disturb this symbiotic relationship and promote disease, such as inflammatory bowel diseases and cancer. Colorectal cancer is a complex association of tumoral cells, non-neoplastic cells and a large amount of micro-organisms, and the involvement of the microbiota in colorectal carcinogenesis is becoming increasingly clear. Indeed, many changes in the bacterial composition of the gut microbiota have been reported in colorectal cancer, suggesting a major role of dysbiosis in colorectal carcinogenesis. Some bacterial species have been identified and suspected to play a role in colorectal carcinogenesis, such as Streptococcus bovis, Helicobacter pylori, Bacteroides fragilis, Enterococcus faecalis, Clostridium septicum, Fusobacterium spp. and Escherichia coli. The potential pro-carcinogenic effects of these bacteria are now better understood. In this review, we discuss the possible links between the bacterial microbiota and colorectal carcinogenesis, focusing on dysbiosis and the potential pro-carcinogenic properties of bacteria, such as genotoxicity and other virulence factors, inflammation, host defenses modulation, bacterial derived metabolism, oxidative stress and anti-oxidative defenses modulation. We lastly describe how bacterial microbiota modifications could represent novel prognosis markers and/or targets for innovative therapeutic strategies.

Minimally invasive surgery for gastric cancer: A comparison between robotic, laparoscopic and open surgery

AIM To investigate the role of minimally invasive surgery for gastric cancer and determine surgical, clinical, and oncological outcomes.METHODS This is a propensity score-matched case-control study, comparing three treatment arms: robotic gastrectomy(RG), laparoscopic gastrectomy(LG), open gastrectomy(OG). Data collection started after sharing a specific study protocol. Data were recorded through a tailored and protected web-based system. Primary outcomes: harvested lymph nodes, estimated blood loss, hospital stay, complications rate. Among the secondary outcomes, there are: operative time, R0 resections, POD of mobilization, POD of starting liquid diet and soft solid diet. The analysis includes the evaluation of type and grade of postoperative complications. Detailed information of anastomotic leakages is also provided.RESULTS The present analysis was carried out of 1026 gastrectomies. To guarantee homogenous distribution of cases, patients in the RG, LG and OG groups were 1:1:2 matched using a propensity score analysis with a caliper = 0.2. The successful matching resulted in a total sample of 604 patients(RG = 151; LG = 151; OG = 302). The three groups showed no differences in all baseline patients characteristics, type of surgery(P = 0.42) and stage of the disease(P = 0.16). Intraoperative blood loss was significantly lower in the LG(95.93 ± 119.22) and RG(117.91 ± 68.11) groups compared to the OG(127.26 ± 79.50, P = 0.002). The mean number of retrieved lymph nodes was similar between the RG(27.78 ± 11.45), LG(24.58 ± 13.56) and OG(25.82 ± 12.07) approach. A benefit in favor of the minimally invasive approaches was found in the length of hospital stay(P < 0.0001). A similar complications rate was found(P = 0.13). The leakage rate was not different(P = 0.78) between groups.CONCLUSION Laparoscopic and robotic surgery can be safely performed and proposed as possible alternative to open surgery. The main highlighted benefit is a faster postoperative functional recovery.

Colon cancer-associated B2 Escherichia coli colonize gut mucosa and promote cell proliferation

AIM:To provide further insight into the characterization of mucosa-associated Escherichia coli(E.coli)isolated from the colonic mucosa of cancer patients.METHODS:Phylogroups and the presence of cyclomodulin-encoding genes of mucosa-associated E.coli from colon cancer and diverticulosis specimens weredetermined by PCR.Adhesion and invasion experiments were performed with I-407 intestinal epithelial cells using gentamicin protection assay.Carcinoembryonic antigen-related cell adhesion molecule 6(CEACAM6)expression in T84 intestinal epithelial cells was measured by enzyme-linked immunosorbent assay and by Western Blot.Gut colonization,inflammation and procarcinogenic potential were assessed in a chronic infection model using CEABAC10 transgenic mice.Cell proliferation was analyzed by real-time mRNA quantification of PCNA and immunohistochemistry staining of Ki67.RESULTS:Analysis of mucosa-associated E.coli from colon cancer and diverticulosis specimens showed that whatever the origin of the E.coli strains,86%of cyclomodulin-positive E.coli belonged to B2 phylogroup and most harbored polyketide synthase(pks)island,which encodes colibactin,and/or cytotoxic necrotizing factor(cnf)genes.In vitro assays using I-407 intestinal epithelial cells revealed that mucosa-associated B2 E.coli strains were poorly adherent and invasive.However,mucosa-associated B2 E.coli similarly to Crohn’s disease-associated E.coli are able to induce CEACAM6expression in T84 intestinal epithelial cells.In addition,in vivo experiments using a chronic infection model of CEACAM6 expressing mice showed that B2 E.coli strain11G5 isolated from colon cancer is able to highly persist in the gut,and to induce colon inflammation,epithelial damages and cell proliferation.CONCLUSION:In conclusion,these data bring new insights into the ability of E.coli isolated from patients with colon cancer to establish persistent colonization,exacerbate inflammation and trigger carcinogenesis.

Association of colorectal cancer with pathogenic Escherichia coli: Focus on mechanisms using optical imaging

AIM: To investigate the molecular or cellular mechanisms related to the infection of epithelial colonic mucosa by pks-positive Escherichia coli(E. coli) using optical imaging.METHODS: We choose to evaluate the tumor metabolic activity using a fluorodeoxyglucose analogue as 2-deoxyglucosone fluorescent probes and to correlate it with tumoral volume(mm^3). Inflammation measuring myeloperoxidase(MPO) activity and reactive oxygen species production was monitored by a bioluminescent(BLI) inflammation probe and related to histological examination and MPO levels by enzyme-linked immunosorbent assay(ELISA) on tumor specimens. The detection and quantitation of these two signals were validated on a xenograft model of human colon adenocarcinoma epithelial cells(HCT116) in nude mice infected with a pks-positive E. coli. The inflammatory BLI signal was validated intra-digestively in the colitisCEABAC10 DSS models, which mimicked Crohn's disease. RESULTS: Using a 2-deoxyglucosone fluorescent probe, we observed a high and specific HCT116 tumor uptake in correlation with tumoral volume(P = 0.0036). Using the inflammation probe targeting MPO, we detected a rapid systemic elimination and a significant increase of the BLI signal in the pks-positive E. coli-infected HCT116 xenograft group(P < 0.005). ELISA confirmed that MPO levels were significantly higher(1556 ± 313.6 vs 234.6 ± 121.6 ng/m L P = 0.001) in xenografts infected with the pathogenic E. coli strain. Moreover, histological examination of tumor samples confirmed massive infiltration of pks-positive E. coli-infected HCT116 tumors by inflammatory cells compared to the uninfected group. These data showed that infection with the pathogenic E. coli strain enhanced inflammation and ROS production in tumors before tumor growth. Moreover, we demonstrated that the intra-digestive monitoring of inflammation is feasible in a reference colitis murine model(CEABAC10/DSS).CONCLUSION: Using BLI and fluorescence optical imaging, we provided tools to better understand hostpathogen interactions at the early stage of disease, such as inflammatory bowel disease and colorectal cancer.

Endoscopy-based management decreases the risk of postoperative recurrences in Crohn's disease

AIM: To investigate whether an endoscopy-based management could prevent the long-term risk of postoperative recurrence.METHODS: From the pathology department database, we retrospectively retrieved the data of all the patients operated on for Crohn's disease(CD) in our center(1986-2015). Endoscopy-based management was defined as systematic postoperative colonoscopy(median time after surgery = 9.5 mo) in patients with no clinical postoperative recurrence at the time of endoscopy. RESULTS: From 205 patients who underwent surgery, 161 patients(follow-up > 6 mo) were included. Endoscopic postoperative recurrence occurred in 67.6%, 79.7%, and 95.5% of the patients, respectively 5, 10 and 20 years after surgery. The rate of clinical postoperative recurrence was 61.4%, 75.9%, and 92.5% at 5, 10 and 20 years, respectively. The rate of surgical postoperative recurrence was 19.0%, 38.9% and 64.7%, respectively, 5, 10 and 20 years after surgery. In multivariate analysis, previous intestinal resection, prior exposure to anti-TNF therapy before surgery, and fistulizing phenotype(B3) were postoperative risk factors. Previous perianal abscess/fistula(other perianal lesions excluded), were predictive of only symptomatic recurrence. In multivariate analysis, an endoscopy-based management(n = 49/161) prevented clinical(HR = 0.4, 95%CI: 0.25-0.66, P < 0.001) and surgical postoperative recurrence(HR = 0.30, 95%CI: 0.13-0.70, P = 0.006).CONCLUSION: Endoscopy-based management should be recommended in all CD patients within the first year after surgery as it highly decreases the long-term risk of clinical recurrence and reoperation.

Massive hepatic necrosis with toxic liver syndrome following portal vein ligation

Right portal vein ligation (PVL) is a safe and widespread procedure to induce controlateral liver hypertrophy for the treatment of bilobar colorectal liver metastases. We report a case of a 60-year-old man treated by both right PVL and ligation of the glissonian branches of segment 4 for colorectal liver metastases surrounding the right and median hepatic veins. After surgery, the patient developed massive hepatic necrosis with secondary pulmonary and renal insufficiency requiring transfer to the intensive care unit. This so-called toxic liver syndrome finally regressed after hemofiltration and positive oxygen therapy. Diagnosis of acute congestion of the ligated lobe was suspected. The mechanism suspected was an increase in arterial inflow secondary to portal vein ligation concomitant with a decrease in venous outflow due to liver metastases encircling the right and median hepatic vein. This is the first documented case of toxic liver syndrome in a non-cirrhotic patient with favorable issue, and a rare complication of PVL.

Giant mucinous cystic adenoma with pancreatic atrophy mimicking dorsal agenesis of the pancreas

Mucinous cystic adenoma(MCA) of the pancreas is a rare benign cystic tumor with ovarian-like stroma and lack of communication with the pancreatic ductal sys-tem. The ovarian tissue is incorporated from the left gonad within the dorsal pancreas during embryogen-esis. Consequently, congenital dorsal agenesis of the pancreas(DAP) cannot be associated with MCA. We report the case of a giant MCA associated with atro-phy of the dorsal pancreas mimicking complete DAP. Pancreato-magnetic resonance imaging failed to iden-tify the dorsal pancreas but the absence of diabetes mellitus and compression of the splenic vein with major tributaries rectified the diagnosis of secondary atrophy of the distal pancreas. Unusual proximal location of the cyst in the pancreas may have induced chronic obstruc-tion of both the dorsal pancreatic duct and the splenic vein, with secondary atrophy of the distal pancreas.