Impact of pelvic dimensions on anastomotic leak after anterior resection for patients with rectal cancer.

AIM: The impact of pelvis on the development of anastomotic leak (AL) in rectal cancer (RC) patients who underwent anterior resection (AR) remains unclear. The aim of this study was to evaluate the impact of pelvic dimensions on the risk of AL. METHODS: A total of 1058 RC patients undergoing AR from January 2013 to January 2016 were enrolled. Pelvimetric parameters were obtained using abdominopelvic computed tomography scans. RESULTS: Univariate analyses showed that pelvic inlet, pelvic outlet, interspinous distance, and intertuberous distance were significantly associated with the risk for AL (P < 0.05). Multivariate analysis confirmed that pelvic inlet and intertuberous distance were independent risk factors for AL (P < 0.05). Significant factors from multivariate analysis were assembled into the nomogram A (without pelvic dimensions) and nomogram B (with pelvic dimensions). The area under curve (AUC) of nomogram B was 0.72 (95% CI 0.67-0.77), which was better than the AUC of nomogram A (0.69, [95% CI 0.65-0.74]), but didn't reach a statistical significance (P = 0.199). Decision curve supported that nomogram B was better than nomogram A. CONCLUSION: Pelvic dimensions, specifically pelvic inlet and intertuberous distance, seemed to be independent predictors for postoperative AL in RC patients. Pelvic inlet and intertuberous distance incorporated with preoperative radiotherapy, preoperative albumin, conversion, and tumor diameter in the nomogram might provide a clinical tool for predicting AL.

Spinal Lymphatic Dysfunction Aggravates the Recovery Process After Spinal Cord Injury.

We aimed to evaluate the role of the spinal lymphatic system in spinal cord injury and whether it has an impact on recovery after spinal cord injury. Flow cytometry was used to evaluate the changes in the number of microvesicles after spinal cord injury. Evans blue extravasation was used to evaluate the function of the lymphatic system. Evans blue extravasation and immunofluorescence were used to evaluate the permeability of blood spinal cord barrier. The spinal cord edema was evaluated by dry and wet weight.Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay was used to evaluate apoptosis after spinal cord injury. Nuclear factor-kappa B pathway was detected by Western blot. Behavioral tests were used to evaluate limb function. Microvesicles released after spinal cord injury can enter the thoracic duct and then enter the blood through the lymph around the spine. After ligation of the thoracic duct, it can aggravate the neuropathological manifestations and limb function after spinal cord injury. The potential mechanism may involve nuclear factor-kappa B pathway.

Genome-Wide Analysis Reveals Hypoxic Microenvironment Is Associated With Immunosuppression in Poor Survival of Stage II/III Colorectal Cancer Patients.

Background: Hypoxia is associated with a poorer clinical outcome and resistance to chemotherapy in solid tumors; identifying hypoxic-related colorectal cancer (CRC) and revealing its mechanism are important. The aim of this study was to assess hypoxia signature for predicting prognosis and analyze relevant mechanism. Methods: Patients without chemotherapy were selected for the identification of hypoxia-related genes (HRGs). A total of six independent datasets that included 1,877 CRC patients were divided into a training cohort and two validation cohorts. Functional annotation and analysis were performed to reveal relevant mechanism. Results: A 12-gene signature was derived, which was prognostic for stage II/III CRC patients in two validation cohorts [TCGA, n = 509, hazard ratio (HR) = 2.14, 95% confidence interval (CI) = 1.18 - 3.89, P = 0.01; metavalidation, n = 590, HR = 2.46, 95% CI = 1.59 - 3.81, P < 0.001]. High hypoxic risk was correlated with worse prognosis in CRC patients without adjuvant chemotherapy (HR = 5.1, 95% CI = 2.51 - 10.35, P < 0.001). After integration with clinical characteristics, hypoxia-related gene signature (HRGS) remained as an independent prognostic factor in multivariate analysis. Furthermore, enrichment analysis found that antitumor immune response was suppressed in the high hypoxic group. Conclusions: HRGS is a promising system for estimating disease-free survival of stage II/III CRC patients. Hypoxia tumor microenvironment may be via inhibiting immune response to promote chemoresistance in stage II/III CRC patients.

Immune-related gene signature in predicting prognosis of early-stage colorectal cancer patients.

AIM: Immune-related genes are associated with the prognosis of colorectal cancer (CRC) patients. The aim of this study was to evaluate the impact of an immune-related gene signature (IRGS) in predicting the prognosis of early-stage CRC patients. METHODS: In total, 309 CRC patients were selected for the identification of prognostic IRGS using the CIT/GSE39582 microarray dataset. Five independent datasets including 1587 CRC patients were divided into a training cohort (n = 566) and two validation cohorts (n = 624 in validation-1 and n = 397 in meta-validation). Prognostic analyses were performed to test the predictive value of IRGS. RESULTS: A prognostic IRGS that included 23 immune-related genes was constructed and significantly stratified patients into immune low-vs. high-risk groups in terms of disease-free survival using patients with early-stage disease (I or II) in the training cohort. Similarly, a higher IRGS was correlated with significantly worse prognosis of early-stage patients in validation-1 and meta-validation cohorts. Compared with Oncotype DX colon, we found that IRGS exhibited an improved survival correlation in the training cohort. After integration with clinical characteristics, IRGS remained as an independent prognostic factor in multivariate analysis. Furthermore, IRGS-stratified immune low-risk group patients gained less benefit from adjuvant chemotherapy in the validation-1 cohort. Several biological processes, including inflammatory response, were enriched among genes in identified the immune high-risk group. Consistent with this finding, the IRGS-identified immune high-risk group exhibited significantly increased immune and stromal cell infiltration. CONCLUSION: The proposed prognostic IRGS is a promising system for estimating DFS of colorectal cancer patients, especially those with early-stage disease.

CD73 promotes colitis-associated tumorigenesis in mice.

Patients with inflammatory bowel disease (IBD) are at a higher risk of developing colitis-associated colorectal cancer. The aim of the present study was to investigate the role of CD73 in IBD-associated tumorigenesis. A mouse model of colitis-associated tumorigenesis (CAT) induced by azoxymethane and dextran sulfate sodium was successfully constructed. Model mice were injected with CD73 inhibitor or adenosine receptor agonist. Colon length, body weight loss and tumor formation were assessed macroscopically. Inflammatory cytokine measurement and RNA sequencing on colon tissues were performed. Inhibition of CD73 by adenosine 5'-(α,ß-methylene) diphosphate (APCP) suppressed the severity of CAT with attenuated weight loss, longer colons, lower tumor number and smaller tumor size compared with the model group. Activation of adenosine receptors using 1-(6-amino-9H-purin-9-yl)-1-deoxy-N-ethyl-ß-D-ribofuranuronamide (NECA) exacerbated CAT. Histological assessment indicated that inhibition of CD73 reduced, while activation of adenosine receptors exacerbated, the histological damage of the colon. Increased expression of pro-inflammatory cytokines (tumor necrosis factor-α and interleukin-6) in colonic tissue was detected in the NECA group. According to RNA sequencing results, potential oncogenes such as arachidonate 15-lipoxygenase (ALOX15), Bcl-2-like protein 15 (Bcl2l15) and N-acetylaspartate synthetase (Nat8l) were downregulated in the APCP group and upregulated in the NECA group compared with the model group. Therefore, inhibition of CD73 attenuated IBD-associated tumorigenesis, while activation of adenosine receptors exacerbated tumorigenesis in a C57BL/6J mouse model. This effect may be associated with the expression of pro-inflammatory cytokines and the regulation of ALOX15, Bcl2l15 and Nat8l.

Immunomodulatory Effect of Urine-derived Stem Cells on Inflammatory Bowel Diseases via Downregulating Th1/Th17 Immune Responses in a PGE2-dependent Manner.

BACKGROUND AND AIMS: Despite the therapeutic promise of stem cell therapy in the treatment of inflammatory bowel diseases [IBD], most donor cell populations have to be obtained via invasive approaches and often remain insufficiently validated. Urine-derived stem cells [USC] were recently shown to have regenerative properties and can be harvested in a safe, low-cost, and noninvasive way. This study aims to evaluate the immunomodulatory effect of USC and their efficacy in the management of IBD. METHODS: Human USC were isolated and expanded from the urine of healthy male adult volunteers [n = 3, age range 24-30 years]. USC were characterised by cell surface marker expression profile and multipotent differentiation. The in vitro immunomodulatory effect of USC was evaluated by co-culturing with human CD4+ T cells upon stimulation with phytohaemagglutinin [PHA]. The proliferation of CD4+ T was measured by fluorescence-activated cell sorting [FACS]. Cytokine array and quantitative real-time polymerase chain reaction [RT-PCR] were applied to examine cytokine levels. In vivo therapeutic value of USC was assessed using a murine colitis model induced by dextran sulphate sodium [DSS] or 2, 4, 6-trinitrobenzene sulphonic acid [TNBS]. The immunomodulatory effect of USC and bone marrow-derived mesenchymal stem cells [BMSC] was compared when co-cultured with CD4+ T cells. The therapeutic efficacy of USC and BMSC on IBD was compared when administered in an acute DSS model in vivo. RESULTS: USC were positive for mesenchymal stem cell markers but were negative for haematopoietic stem cell markers. These cells differentiated into osteo-, adipo-, and chondrogenic cell lineages. Similar to BMSC, the proliferation of CD4+ T cells was significantly inhibited when co-cultured with USC, as a consequence of Th1/Th17 immune response inhibition. Systemic administration of USC significantly ameliorated the clinical and histopathological severity of colitis and increased the survival rate in both acute and chronic murine colitis models. Moreover, implantation of USC led to downregulation of the Th1/Th17 immune responses in a PGE2-dependent manner. CONCLUSIONS: This study demonstrated that implantation of USC reduces inflammation in an IBD rodent model via downregulation of Th1/Th17 immune responses, indicating that USC therapy serves as a potential cell-based therapeutic candidate treatment for IBD.

Differences in pathological changes between two rat models of severe traumatic brain injury.

The rat high-impact free weight drop model mimics the diffuse axonal injury caused by severe traumatic brain injury in humans, while severe controlled cortical impact can produce a severe traumatic brain injury model using precise strike parameters. In this study, we compare the pathological mechanisms and pathological changes between two rat severe brain injury models to identify the similarities and differences. The severe controlled cortical impact model was produced by an electronic controlled cortical impact device, while the severe free weight drop model was produced by dropping a 500 g free weight from a height of 1.8 m through a plastic tube. Body temperature and mortality were recorded, and neurological deficits were assessed with the modified neurological severity score. Brain edema and blood-brain barrier damage were evaluated by assessing brain water content and Evans blue extravasation. In addition, a cytokine array kit was used to detect inflammatory cytokines. Neuronal apoptosis in the brain and brainstem was quantified by immunofluorescence staining. Both the severe controlled cortical impact and severe free weight drop models exhibited significant neurological impairments and body temperature fluctuations. More severe motor dysfunction was observed in the severe controlled cortical impact model, while more severe cognitive dysfunction was observed in the severe free weight drop model. Brain edema, inflammatory cytokine changes and cortical neuronal apoptosis were more substantial and blood-brain barrier damage was more focal in the severe controlled cortical impact group compared with the severe free weight drop group. The severe free weight drop model presented with more significant apoptosis in the brainstem and diffused blood-brain barrier damage, with higher mortality and lower repeatability compared with the severe controlled cortical impact group. Severe brainstem damage was not found in the severe controlled cortical impact model. These results indicate that the severe controlled cortical impact model is relatively more stable, more reproducible, and shows obvious cerebral pathological changes at an earlier stage. Therefore, the severe controlled cortical impact model is likely more suitable for studies on severe focal traumatic brain injury, while the severe free weight drop model may be more apt for studies on diffuse axonal injury. All experimental procedures were approved by the Ethics Committee of Animal Experiments of Tianjin Medical University, China (approval No. IRB2012-028-02) in February 2012.

Preoperative assessment of lymph node metastasis in clinically node-negative rectal cancer patients based on a nomogram consisting of five clinical factors.

BACKGROUND: Currently, reliable approaches for accurate assessment of lymph node metastases (LNM), which is an important indication of preoperative chemoradiotherapy (CRT), are not available for clinically node-negative rectal cancer patients. This study aims to identify clinical factors associated with LNM and to establish a nomogram for LNM prediction in clinically node-negative rectal cancer patients. METHODS: The least absolute shrinkage and selection operator (LASSO) aggression and multivariate logistic regression analyses were applied to identify clinical factors associated with LNM. A nomogram was established to predict the probability of LNM in clinically node-negative rectal cancer patients based on the multivariate logistic regression model. RESULTS: Six potential risk factors were selected on the basis of LASSO aggression analysis, and five of them were identified as independent risk factors for LNM based on multivariate analysis, including MRI-reported tumor location, clinical T classification, MRI-reported tumor diameter, white blood cell count (WBC), and preoperative elevated tumor markers. A nomogram consisting of the five clinical factors was established and showed good discrimination. Decision curve analysis demonstrated that the established nomogram was reliable and accurate for LNM prediction in clinically node-negative rectal cancer patients. CONCLUSIONS: A nomogram based on five clinical factors, including MRI-reported tumor location, clinical T classification, MRI-reported tumor diameter, WBC, and preoperative elevated tumor markers, are useful for assessing LNM in clinically node-negative rectal cancer patients, which is important for preoperative CRT regimens.

Bone marrow-derived CXCR4-overexpressing MSCs display increased homing to intestine and ameliorate colitis-associated tumorigenesis in mice.

BACKGROUND AND OBJECTIVE: Increasing interest has developed in the therapeutic potential of bone marrow-derived mesenchymal stem cells (MSCs) for the treatment of inflammatory bowel disease (IBD) and IBD-induced cancer. However, whether MSCs have the ability to suppress or promote tumor development remains controversial. The stromal cell-derived factor 1 (SDF-1)/C-X-C chemokine receptor type 4 (CXCR4) axis is well known to play a critical role in the homing of MSCs. In this study, we aimed to evaluate the role of CXCR4-overexpressing MSCs on the tumorigenesis of IBD. METHODS: MSCs were transduced with lentiviral vector carrying either CXCR4 or green fluorescent protein (GFP). Chemotaxis and invasion assays were used to detect CXCR4 expression. A mouse model of colitis-associated tumorigenesis was established using azoxymethane and dextran sulfate sodium (DSS). The mice were divided into three groups and then injected with phosphate buffer saline (PBS), MSC-GFP or MSC-CXCR4. RESULTS: Compared with the mice injected with MSC-GFP, the mice injected with MSC-CXCR4 showed relieved weight loss, longer colons, lower tumor numbers and decreased tumor load; expression of pro-inflammatory cytokines decreased, and signal transducer and activator of transcription 3 (STAT3) phosphorylation level in colon tissue was down-regulated. CONCLUSION: CXCR4-overexpressing MSCs exhibited effective anti-tumor function, which may be associated with enhanced homing to inflamed intestinal tissues.

Engulfment and Cell Motility Protein 1 Protects Against DSS-induced Colonic Injury in Mice via Rac1 Activation.

BACKGROUND AND AIMS: Mucosal healing is an emerging therapeutic goal that could result in clinical remission of inflammatory bowel disease [IBD]. We sought to determine the role of engulfment and cell motility protein 1 [ELMO1] in wound healing in vitro and in vivo and to investigate the underlying pathways. METHODS: RNA transcriptome sequencing was performed to detect the expression profiles of mRNA between inflamed tissues and corresponding non-inflamed tissues of IBD patients, followed by Gene Expression Omnibus [GEO] datasets and western blot analysis. The effects of ELMO1 overexpression or knockdown on cell migration and proliferation were determined. The dependence of these effects on Rac1 was assessed using a Rac1 inhibitor [NSC23766] and a Rac1 pull-down assay. We identified the underlying pathways involved by Gene Ontology [GO] analysis. A dextran sulphate sodium [DSS]-induced colitis model was established to evaluate the role of ELMO1 in colonic mucosal healing. RESULTS: ELMO1 was upregulated in inflamed tissues compared with corresponding non-inflamed tissues. ELMO1 overexpression increased cell migration in a Rac1-dependent manner. Depletion of ELMO1, or NSC23766 administration, abolished this effect. GO analysis revealed that ELMO1 overexpression preferentially affected pathways involved in cytoskeletal regulation and wound healing, which was demonstrated by enhanced F-actin staining and increased numbers of extending lamellipodia in cells overexpressing ELMO1. In DSS-induced colitis, systemic delivery of pSin-EF2-ELMO1-Pur attenuated colonic inflammation and promoted recovery from colonic injury. The protective effect of ELMO1 was dependent on Rac1 activation. CONCLUSIONS: ELMO1 protects against DSS-induced colonic injury in mice through its effect on epithelial migration via Rac1 activation.

Conversion is a risk factor for postoperative anastomotic leak in rectal cancer patients - A retrospective cohort study.

AIM: The impact of conversion from laparoscopic surgery to laparotomy on the development of anastomotic leak (AL) in rectal cancer patients following laparoscopic low anterior resection (LAR) with total mesorectal excision (TME) has not been evaluated. The aim of this study was to evaluate the impact of conversion on the risk of AL and develop a prediction nomogram for postoperative AL. METHODS: All rectal cancer patients following laparoscopic LAR with TME from January 2010 to October 2014 were enrolled in the primary cohort. Comparisons of the postoperative anastomotic leak incidence rate between converted patients and non-converted patients were performed using both univariate and multivariate logistic regression analyses. The result of multivariable analysis was used to develop the predicting model and the performance of nomogram was assessed with respect to its calibration, discrimination, and clinical usefulness. An independent validation cohort containing 200 patients from November 2014 to October 2015 was assessed. RESULTS: Of all patients enrolled (n=646), 592 (91.6%) patients underwent totally laparoscopic surgery, and 54 (8.4%) were converted from laparoscopic surgery to laparotomy. Converted group patients were more likely to have a higher body mass index (BMI), prolonged length of stay (LOS), increased overall postoperative complication rates and advanced clinical T stage (T3 or T4), pathological N stage (N1 or N2) and pathological TNM stage (III or IV). The percentage of patients who had preoperative radiotherapy for rectal cancer was higher in non-converted patients. Patients who underwent conversion to laparotomy (n=10, 18.5%) were more likely to suffer from postoperative AL than those undergoing totally laparoscopic surgery (n=38, 6.4%) (P=0.004). Multivariate logistic regression analyses confirmed the association between conversion and postoperative AL (Odds ratio [OR], 95% confidence interval [CI]: 2.71 [1.31-5.63], P=0.007). Conversion, gender, and clinical N stage incorporated in the individualized prediction nomogram showed good discrimination, with a C-index of 0.697 (C-index, 0.621 and 0.772 through internal validation), and good calibration. In the validation cohort, the main results were consistent with the findings of the primary cohort, with a C-index of 0.670 (C-index, 0.562 and 0.777 through internal validation). Decision curve analysis demonstrated that the prediction nomogram was clinically useful. CONCLUSION: Conversion during laparoscopic LAR was found to be associated with an increased risk for the postoperative AL in RC patients. A nomogram model incorporating conversion, gender and patient's clinical N stage seems to offers a useful tool for predicting postoperative AL in these patients.

Male gender is associated with an increased risk of anastomotic leak in rectal cancer patients after total mesorectal excision.

BACKGROUND: The impact of a patient's gender on the development of anastomotic leak (AL) in rectal cancer patients following total mesorectal excision (TME) remains controversial. The aim of this study was to evaluate the association between patients' gender and the risk of AL. METHODS: All rectal cancer patients following TME with a primary anastomosis during the study period from 2010 to 2014 were examined. Comparisons of the post-operative AL incidence rate between male and female patients were performed. RESULTS: Of all patients examined (n = 956), 587 (61.4%) were males and 369 (38.6%) were females. Male patients were more likely to have a history of smoking and drinking alcohol, but less likely to have a history of abdominal surgery compared to female patients. A higher incidence rate of pre-operative bowel obstruction and larger tumor volume in male patients was observed in our study. Of all the patients, 81 (8.5%) developed post-operative AL. More male patients (n = 62, 10.6%) suffered from AL than females (n = 19, 5.1%) (P = 0.003). Multivariate logistic regression analyses confirmed the association between male gender and AL [odds ratio (OR): 2.41, 95% confidence interval (CI): 1.37-4.23, P = 0.002]. Similar results were also obtained in patients who underwent laparoscopic TME (OR: 2.11, 95% CI: 1.15-3.89, P = 0.016). CONCLUSIONS: Male patents were found to have an increased risk for AL following TME with a primary anastomosis. A temporary protecting stoma may help to protect the anastomosis and lessen the risk for AL especially in male patients.