Leveraging a KRAS-based signature to predict the prognosis and drug sensitivity of colon cancer and identifying SPINK4 as a new biomarker.

KRAS is one of the leading mutations reported in colon cancer. However, there are few studies on the application of KRAS related signature in predicting prognosis and drug sensitivity of colon cancer patient. We identified KRAS related differentially expressed genes (DEGs) using The Cancer Genome Atlas (TCGA) database. A signature closely related to overall survival was recognized with Kaplan-Meier survival analysis and univariate cox regression analysis. Then we validated this signature with overall expression score (OE score) algorithm using both scRNA-seq and bulk RNA-seq data. Based on this signature, we performed LASSO cox regression to establish a prognostic model, and corresponding scores were calculated. Differences in genomic alteration, immune microenvironment, drug sensitivity between high- and low-KRD score groups were investigated. A KRAS related signature composed of 80 DEGs in colon cancer were recognized, among which 19 genes were selected to construct a prognostic model. This KRAS related signature was significantly correlated with worse prognosis. Furthermore, patients who scored lower in the prognostic model presented a higher likelihood of responding to chemotherapy, targeted therapy and immunotherapy. Furthermore, among the 19 selected genes in the model, SPINK4 was identified as an independent prognostic biomarker. Further validation in vitro indicated the knockdown of SPINK4 promoted the proliferation and migration of SW48 cells. In conclusion, a novel KRAS related signature was identified and validated based on clinical and genomic information from TCGA and GEO databases. The signature was proved to regulate genomic alteration, immune microenvironment and drug sensitivity in colon cancer, and thus might serve as a predictor for individual prognosis and treatment.

Colorectal cancer tissue-originated spheroids reveal tumor intrinsic signaling pathways and mimic patient clinical chemotherapeutic response as a rapid and valid model.

Locally advanced colorectal cancer requires preoperative chemotherapy to reduce local recurrence and metastasis rates, but it remains difficult to predict the tumor will be sensitive to which treatments. The patient-derived organoids (PDOs) are considered an effective platform for predicting tumor drug responses in precision oncology. However, it has the limitation of being time-consuming in practical applications, especially in neoadjuvant treatment. Here we used cancer tissue-originated spheroids (CTOS) method to establish organoids from a heterogeneous population of colorectal cancer specimens, and evaluated the capacity of CTOS to predict clinical drug responses. By analyzing the relationship of the activities of drug-treated CTOS, drug targets and target-related pathways, tumor intrinsic effective-target-related pathways can be identified. These pathways were highly matched to the abnormal pathways indicated by whole-exome sequencing. Based on this, we used half effective concentration gradients to classify CTOS as sensitive or resistant to chemotherapy regimens within a week, for predicting neoadjuvant treatment outcomes for colorectal cancer patients. The drug sensitivity test results are highly matched to the clinical responses to treatment in individual patients. Thus, our data suggested that CTOS models can be effectively screened ex vivo to identify pathways sensitive to chemotherapies. These data also supported organoid research for personalized clinical medication guidance immediately after diagnosis in patients with advanced colorectal cancer.

High ligation versus low ligation of the inferior mesenteric artery in laparoscopic rectal cancer surgery: a retrospective study on surgical and long-term outcome.

BACKGROUND: In laparoscopic low anterior resection for rectal cancer surgery, there has been controversy to whether the inferior mesenteric artery (IMA) should be ligated at the origin of its aorta (high ligation (HL)) or below the branches of the left colonic artery (LCA) (low ligation (LL)). This study was intended to clarify oncological outcome and long-term prognosis of retrospective analysis. METHODS: Analyzed the cases who underwent laparoscopic low anterior resection (LAR) in Shanghai Ruijin Hospital from January 2015 to December 2016, 357patients scheduled into 2 groups according to the level of IMA ligation: HL (n = 247) versus LL (n = 110). RESULTS: The primary endpoint is long-term outcomes, and the secondary endpoint is the incidence rate of major postoperative complications. There were no significant differences in 5-year overall survival (P = 0.92) and 5-year disease-free survival (P = 0.41). There were no differences between the clinical baseline levels in each group. The incidence of low anterior resection syndrome (LARS) in the two groups was statistically significant (P = 0.037). No significant differences were observed in operative time (P = 0.092) and intraoperative blood loss (P = 0.118). In the HL group, 6 cases (2.4%) had additional colonic excision due to poor anastomotic blood supply; none of the colonic anastomosis in the low ligation group had ischemic manifestations, and length from the proximal margin (P = 0.076), length from the distal margin (P = 0.184), the total number of lymph nodes excised (P = 0.065), and anastomotic leakage incidence (P = 0.33). CONCLUSION: Low ligation of the IMA which reserved LCA with vascular root lymph node dissection in laparoscopic low anterior resection for rectal cancer surgery may help protect the blood supply of the anastomosis, and will not increase postoperative complications while enhance recovery, without compromising radical excision and long-term prognosis.

FOXD1 promotes chemotherapy resistance by enhancing cell stemness in colorectal cancer through ß­catenin nuclear localization.

Forkhead box D1 (FOXD1) serves a critical role in colorectal cancer (CRC). FOXD1 expression is an independent prognostic factor in patients with CRC; however, the molecular mechanism and signaling pathway of FOXD1 that regulates cell stemness and chemoresistance has not been fully characterized. The aim of the present study was to further validate the effect of FOXD1 on the proliferation and migration of CRC cells, and to delve into the possible potential of FOXD1 in the clinical treatment of CRC. The effect of FOXD1 on cell proliferation was assessed using Cell Counting Kit 8 (CCK­8) and colony formation assays. The effect of FOXD1 on cell migration was assessed by wound­healing and Transwell assays. The effect of FOXD1 on cell stemness was assessed by spheroid formation in vitro and limiting dilution assays in vivo. The expression of stemness associated proteins, leucine rich repeat containing G protein­coupled receptor 5 (LGR5), OCT4, Sox2 and Nanog, and epithelial­mesenchymal transition associated proteins, E­cadherin, N­cadherin and vimentin, were detected by western blotting. Proteins interrelationships were assessed by a co­immunoprecipitation assay. Oxaliplatin resistance was assessed using CCK­8 and apoptosis assays in vitro, and using a tumor xenograft model in vivo. By constructing FOXD1 overexpression and knockdown stably transfected strains of colon cancer cells, it was revealed that the overexpression of FOXD1 increased CRC cell stemness and chemoresistance. By contrast, knockdown of FOXD1 produced the opposite effects. These phenomena were caused by the direct interaction between FOXD1 and ß­catenin, thus promoting its nuclear translocation and the activation of downstream target genes, such as LGR5 and Sox2. Notably, inhibition of this pathway with a specific ß­catenin inhibitor (XAV­939) could impair the effects induced by the overexpression of FOXD1. In summary, these results indicated that FOXD1 may promote cell stemness and the chemoresistance of CRC by binding directly to ß­catenin and enhancing ß­catenin nuclear localization; therefore, it may be considered a potential clinical target.

IL-17A-mediated mitochondrial dysfunction induces pyroptosis in colorectal cancer cells and promotes CD8 + T-cell tumour infiltration.

BACKGROUND: Interleukin-17A (IL-17A), a proinflammatory cytokine primarily secreted by Th17 cells, γδT cells and natural killer T (NKT) cells, performs essential roles in the microenvironment of certain inflammation-related tumours by regulating cancer growth and tumour elimination proved in previous literature. In this study, the mechanism of IL-17A that induces mitochondrial dysfunction promoted pyroptosis has been explored in colorectal cancer cells. METHOD: The records of 78 patients diagnosed with CRC were reviewed via the public database to evaluate clinicopathological parameters and prognosis associations of IL-17A expression. The colorectal cancer cells were treated with IL-17A, and the morphological characteristics of those cells were indicated by scanning electron microscope and transmission electron microscope. After IL-17A treatment, mitochondrial dysfunction was tested by mitochondrial membrane potential (MMP) and reactive oxygen species (ROS). The expression of pyroptosis associated proteins including cleaved caspase-4, cleaved gasdermin-D (GSDMD), IL-1ß, receptor activator of nuclear NOD-like receptor family pyrin domain containing 3 (NLRP3), apoptosis-associated speck like protein containing a card (ASC), and factor-kappa B was measured through western blotting. RESULTS: Positive IL-17A protein expression was observed in CRC compared to the non-tumour tissue. IL-17A expression indicates a better differentiation, earlier stage, and better overall survival in CRC. IL-17A treatment could induce mitochondrial dysfunction and stimulate intracellular reactive oxygen species (ROS) production. Furthermore, IL-17A could promote pyroptosis of colorectal cancer cells and significantly increase the secretion of inflammatory factors. Nevertheless, the pyroptosis induced by IL-17A could be inhibited through the pre-treatment with Mito-TEMPO (a mitochondria-targeted superoxide dismutase mimetic with superoxide and alkyl radical scavenging properties) or Z-LEVD-FMK (caspase-4 inhibitor, fluoromethylketone). Additionally, after being treated with IL-17A, an increasing number of CD8 + T cells showed in mouse-derived allograft colon cancer models. CONCLUSION: IL-17A, as a cytokine mainly secreted by γδT cells in the colorectal tumour immune microenvironment, can regulate the tumour microenvironment in multiple ways. IL-17A could induce mitochondrial dysfunction and pyroptosis through the ROS/NLRP3/caspase-4/GSDMD pathway, and promote intracellular ROS accumulation. In addition, IL-17A can promote the secretion of inflammatory factors such as IL-1ß、IL-18 and immune antigens, and recruit CD8 + T cells to infiltrate tumours.

Intracorporeal versus extracorporeal anastomosis in laparoscopic right colectomy: a retrospective study.

BACKGROUND: The surgical procedure for laparoscopic right colectomy (LRC) is not standardized. Some published studies show the superiority of ileocolic anastomosis (IIA), but the evidence so far is insufficient. This study aimed to investigate the potential advantages in postoperative recovery and safety of IIA in LRC. METHODS: A total of 114 patients who underwent LRC with IIA (n = 58) or extracorporeal ileocolic anastomosis (EIA, n = 56) between January 2019 and September 2021 were enrolled. We collected certain factors as clinical features, intraoperative characteristics, oncological outcomes, postoperative recovery, and short-term outcomes. Our primary outcome was time to gastrointestinal (GI) function recovery. Secondary outcomes were postoperative complications within 30 days, postoperative pain, and length of hospital stay. RESULTS: Faster GI recovery and less postoperative pain were observed in patients with IIA compared to EIA [time to first flatus: (2.4 ± 0.7) vs (2.8 ± 1.0) days, p < 0.01; time to liquid intake: (3.5 ± 0.7) vs (4.0 ± 1.1) days, p = 0.01; postoperative visual analogue scale score: (3.9 ± 1.0) vs (4.3 ± 0.6), p = 0.02]. No significant differences were detected in oncological outcomes or postoperative complications. IIA, rather than EIA, tended to be performed in patients with higher body mass index [(23.93 ± 3.52) vs (22.36 ± 2.87) kg/m2, p = 0.01]. CONCLUSIONS: IIA is associated with faster GI function recovery and less postoperative pain and may be more favorable for obese patients.

Cytokine concentration in peripheral blood of patients with colorectal cancer.

Introduction: The role of tumour secretory cytokines and peripheral circulatory cytokines in tumour progression has received increasing attention; however, the role of tumour-related inflammatory cytokines in colorectal cancer (CRC) remains unclear. In this study, the concentrations of various cytokines in the peripheral blood of healthy controls and patients with CRC at different stages were compared. Methods: Peripheral blood samples from 4 healthy participants and 22 colorectal cancer patients were examined. Luminex beads were used to evaluate concentration levels of 40 inflammatory cytokines in peripheral blood samples. Results: In peripheral blood, compared with healthy controls and early stage (I + II) CRC patients, advanced CRC (III + IV) patients had increased concentrations of mononuclear/macrophage chemotactic-related proteins (CCL7, CCL8, CCL15, CCL2, and MIF), M2 polarization-related factors (IL-1ß, IL-4), neutrophil chemotactic and N2 polarization-related cytokines (CXCL2, CXCL5, CXCL6, IL-8), dendritic cells (DCs) chemotactic-related proteins (CCL19, CCL20, and CCL21), Natural killer (NK) cell related cytokines (CXCL9, CXCL10), Th2 cell-related cytokines (CCL1, CCL11, CCL26), CXCL12, IL-2, CCL25, and CCL27, and decreased IFN-γ and CX3CL1 concentrations. The differential upregulation of cytokines in peripheral blood was mainly concentrated in CRC patients with distant metastasis and was related to the size of the primary tumour; however, there was no significant correlation between cytokine levels in peripheral blood and the propensity and mechanism of lymph node metastasis. Discussion: Different types of immune cells may share the same chemokine receptors and can co-localise in response to the same chemokines and exert synergistic pro-tumour or anti-tumour functions in the tumour microenvironment. Chemokines and cytokines affect tumour metastasis and prognosis and may be potential targets for treatment.

Dysbiosis of human tumor microbiome and aberrant residence of Actinomyces in tumor-associated fibroblasts in young-onset colorectal cancer.

Colorectal cancer (CRC) is the third most common form of cancer, and the incidence of sporadic young-onset colorectal cancer (yCRC) has been increasing. Microbiota residing in the tumor microenvironment are emerging tumor components. The colonic microbiome differs between patients with CRC and healthy controls; however, few studies have investigated the role of the tumor microbiota in disease diagnosis and tumorigenesis of yCRC. We performed 16S rRNA sequencing analysis to identify the microbiome in CRC and found that tumor microbial diversity decreased in yCRC. Proteobacteria and Firmicutes were the most abundant phyla in all CRC samples, and Actinomyces and Schaalia cardiffensis were the key microbiota in the yCRC group. Correlation analysis revealed that Actinomyces co-occurred with various pro-tumor microbial taxa, including Bacteroidia, Gammaproteobacteria, and Pseudomonas. An independent cohort was used to validate the results. The Actinomyces in CRC was co-localized with cancer-associated fibroblasts and activated the TLR2/NF-κB pathway and reduces CD8+ T lymphocyte infiltration in CRC microenvironment. This study suggests that tumoral microbiota plays an important role in promoting tumorigenesis and therefore has potential as a promising non-invasive tool and intervention target for anti-tumor therapy.

Combination of FOXD1 and Plk2: A novel biomarker for predicting unfavourable prognosis of colorectal cancer.

Colorectal cancer (CRC) is a worldwide disease with worse survival. Our objective is to identify previously unrecognized prognostic factors to better evaluate disease progression. Seven GEO datasets were collected and analysed using R software, followed by KEGG enrichment analysis and TFs network construction. LASSO-COX analysis was performed to select the most useful prognostic features. COX model was used to analyse prognostic factors associated with OS. The survival curve was constructed using Kaplan-Meier analysis. A Nomogram model was also constructed to predict prognosis. A total of 3559 differentially expressed genes (DEGs) and 66 differentially expressed transcription factors were identified. FOXD1 was identified as the most differentially expressed factor of TFs covering the most downstream DEGs and independent risk prognostic factor. Next, FOXD1 expression was detected using immunohistochemical staining in 131 CRC patients' tissue and the association between FOXD1 expression and clinicopathologic features was analysed. High expression of FOXD1 was correlated with TNM stage and pathological differentiation. Multivariate COX regression analyses confirmed that FOXD1 high-expression, TNM stage and tumour differentiation were independent prognostic risk factor of OS and DFS. Patients with high expression of FOXD1 were more likely to have poor overall survival and disease-free survival. The combination of FOXD1 and Plk2 which we have previously reported allowed us to predict the survival of post-surgical CRC patients more accurately, adding to the former prognostic model based on the TNM Stage. The results showed that patients with high expression of both FOXD1 and Plk2 have the worst survival. A combination of FOXD1 and Plk2 can better evaluate patients' survival.

KLF5 inhibition overcomes oxaliplatin resistance in patient-derived colorectal cancer organoids by restoring apoptotic response.

Oxaliplatin resistance is a major challenge in the treatment of colorectal cancer (CRC). Many molecular targeted drugs for refractory CRC have been developed to solve CRC drug resistance, but their effectiveness and roles in the progression of CRC and oxaliplatin resistance remain unclear. Here, we successfully constructed CRC PDOs and selected the Kruppel-like factor 5 (KLF5) inhibitor ML264 as the research object based on the results of the in vitro drug screening assay. ML264 significantly restored oxaliplatin sensitivity in CRC PDOs by restoring the apoptotic response, and this effect was achieved by inhibiting the KLF5/Bcl-2/caspase3 signaling pathway. Chromatin immunoprecipitation (ChIP) and luciferase reporter assays verified that KLF5 promoted the transcription of Bcl-2 in CRC cells. KLF5 inhibition also overcame oxaliplatin resistance in xenograft tumors. Taken together, our study demonstrated that ML264 can restore oxaliplatin sensitivity in CRC PDOs by restoring the apoptotic response. KLF5 may be a potential therapeutic target for oxaliplatin-resistant CRC. PDOs have a strong potential for evaluating inhibitors and drug combination therapy in a preclinical environment.

CCL7 and TGF-ß secreted by MSCs play opposite roles in regulating CRC metastasis in a KLF5/CXCL5-dependent manner.

CXCL5 is overexpressed in colorectal cancer (CRC) and promotes distant metastasis and angiogenesis of tumors; however, the underlying mechanism that mediates CXCL5 overexpression in CRC remains unclear. Here, we successfully extracted and identified primary mesenchymal stromal cells (MSCs) and verified the promoting effects of tumor-associated MSCs on CRC proliferation and metastasis in vivo and in vitro. We found that MSCs not only promoted the expression of CXCL5 by secreting CCL7 but also secreted TGF-ß to inhibit this process. After secretion, CCL7/CCR1 activated downstream CBP/P300 to acetylate KLF5 to promote CXCL5 transcription, while TGF-ß reversed the effect of KLF5 on transcription activation by regulating SMAD4. Taken together, our results indicate that MSCs in the tumor microenvironment promoted the progression and metastasis of CRC and regulated the expression of CXCL5 in CRC cells by secreting CCL7 and TGF-ß. KLF5 is the key site of these processes and plays a dual role in CXCL5 regulation. MSCs and their secreted factors may serve as potential therapeutic targets in the tumor environment.

Effect of Microstructure on the Onset Strain and Rate per Strain of Deformation-Induced Martensite Transformation in Q&P Steel by Modeling.

The effect of microstructure on the onset strain and rate of deformation-induced martensitic transformation (DIMT) in Q&P steel is studied by a mean-field micromechanics model, in which the residual austenite (RA) and primary martensite (M) phases are treated as elastoplastic particles embedded into the ferrite (F) matrix. The results show that when the volume fraction of the RA increases with a constant fraction of the M, the onset strain of DIMT increases and transformation rate decreases, in contrast to the case of the RA fraction effect with a fixed F fraction. Increasing the volume fraction of the M postpones the DIMT, regardless of the corresponding change from the RA or F fraction, which is similar to the effect of the RA fraction with the constant M but to a higher degree. Conversely, when increasing the fraction of the matrix F, the onset strain of DIMT increases and the rate decreases, and the effect is greater when the corresponding fraction change comes from the M rather than from the RA. Moreover, when the aspect ratio of the RA increases, the onset strain of DIMT decreases with a gradual increase in transformation rate, in agreement with the experimental observation that the equiaxial austenite is more stable in Q&P steels. However, the aspect ratio effect of the M is opposite to that of the RA, indicating that the lath-shaped primary martensite could protect the austenite from DIMT.

Platelet infiltration predicts survival in postsurgical colorectal cancer patients.

Platelets promote tumor growth and metastasis in several tumor types. Recent research has found platelets can extravasate and infiltrate into the tumor stroma and interact with the tumor microenvironment. The prognostic role of platelet infiltration in colorectal cancer (CRC) remains controversial. A pan-cancer survival analysis was performed to find the potential prognostic value of platelet infiltration in patients with cancer. A survival analysis and a nomogram prognostic model were established to further confirm the results with data from our center. The correlations between patient outcomes and tumor-infiltrating platelets (TIPs) were identified by immunohistochemical staining for CD42b. The prognostic accuracy and discriminative ability of the nomogram were determined by the concordance index (C-index) and a calibration curve. The pan-cancer survival analysis showed platelet infiltration can lead to a poor prognosis in patients with several types of cancers, including CRC. Platelet infiltration was associated with overall survival (OS) and disease-free survival (DFS) in both primary and validation cohorts. The C-index values of the nomogram for predicting OS and DFS were 0.774 and 0.769, respectively, which were higher than that of the TNM staging system alone. Our study found platelet infiltration has a potential prognostic value regarding postsurgical survival in CRC patients. The proposed nomogram resulted in a more accurate prognostic prediction for postsurgical CRC patients.

Sintering and Mechanical Properties of (SiC + TiCx)p/Fe Composites Synthesized from Ti3AlC2, SiC, and Fe Powders.

Ceramic-particle-reinforced iron matrix composites (CPR-IMCs) have been used in many fields due to their excellent performance. In this study, using the fast resistance-sintering technology developed by our team, iron matrix composites (IMCs) reinforced by both SiC and TiCx particles were fabricated via the addition of SiC and Ti3AlC2 particles, and the resulting relative densities of the sintering products were up to 98%. The XRD and EDS analyses confirmed the in situ formation of the TiCx from the decomposition of Ti3AlC2 during sintering. A significant hybrid reinforcing effect was discovered in the (SiC + TiCx)p/Fe composites, where the experimental strength and hardness of the (SiC + TiCx)p/Fe composites were higher than the composites of monolithic SiCp/Fe and (TiCx)p/Fe. While, under the condition of constant particle content, the elongation of the samples reinforced using TiCx was the best, those reinforced by SiC was the lowest, and those reinforced by (SiC + TiCx) fell in between, which means the plastic response of (SiC + TiCx)p/Fe composites obeyed the rule of mixture. The successful preparation of IMCs based on the hybrid reinforcement mechanism provides an idea for the optimization of IMCs.

Retrospective research of neoadjuvant therapy on tumor-downstaging, post-operative complications, and prognosis in locally advanced rectal cancer.

BACKGROUND: Neoadjuvant therapy (NAT) is becoming increasingly important in locally advanced rectal cancer. Hence, such research has become a problem. AIM: To evaluate the downstaging effect of NAT, its impact on postoperative complications and its prognosis with different medical regimens. METHODS: Seventy-seven cases from Shanghai Ruijin Hospital affiliated with Shanghai Jiaotong University School of Medicine were retrospectively collected and divided into the neoadjuvant radiochemotherapy (NRCT) group and the neoadjuvant chemotherapy (NCT) group. The differences between the two groups in tumor regression, postoperative complications, rectal function, disease-free survival, and overall survival were compared using the χ 2 test and Kaplan-Meier analysis. RESULTS: Baseline data showed no statistical differences between the two groups, whereas the NRCT group had a higher rate of T4 (30/55 vs 5/22, P < 0.05) than the NCT groups. Twelve cases were evaluated as complete responders, and 15 cases were evaluated as tumor regression grade 0. Except for the reduction rate of T stage (NRCT 37/55 vs NCT 9/22, P < 0.05), there was no difference in effectiveness between the two groups. Preoperative radiation was not a risk factor for poor reaction or anastomotic leakage. No significant difference in postoperative complications and disease-free survival between the two groups was observed, although the NRCT group might have better long-term overall survival. CONCLUSION: NAT can cause tumor downstaging preoperatively or even complete remission of the primary tumor. Radiochemotherapy could lead to better T downstaging and promising overall survival without more complications.

Effect of different reinforcement methods on anastomotic leakage prevention after laparoscopic double anastomosis.

BACKGROUND AND OBJECTIVES: To investigate the effects of different suture reinforcement methods for anastomotic leakage and other postoperative complications after the use of a laparoscopic double stapling technique (DST). METHODS: We collected the data of 124 patients who underwent laparoscopic radical resection of colorectal cancer from July 2017 to September 2018 at our institution. Patients were divided into three groups according to the suture reinforcement methods: intermittent, continuous suture reinforcement, and non-reinforcement (n = 41, 41, and 42, respectively). One-way analysis of variance, χ2 , Fisher's exact, and nonparametric tests were used for statistical analysis. RESULTS: Among the 124 patients, there were no statistically significant differences in operation times, intraoperative blood loss, postoperative hospital stays and recovery of bowel movement. Nine patients were diagnosed with anastomotic leakage (AL). The incidences of serious AL in the intermittent and continuous suture reinforcement groups were lower than that in the control group, with lower reoperation rate, shorter average lengths of stay and lower treatment costs of two experimental groups. CONCLUSION: Intermittent and continuous sutures after laparoscopic DST is effective, safe, and feasible on anastomotic leakage prevention. These procedures could be popularized in rectal surgery on patients with high risk of AL.

High versus low ligation of the inferior mesenteric artery during laparoscopic rectal cancer surgery: A prospective study of surgical and oncological outcomes.

BACKGROUND AND OBJECTIVES: There is controversy regarding whether the inferior mesenteric artery (IMA) should be ligated at its origin from the aorta (high ligation, HL) or below the branch of the left colic artery (low ligation, LL) during surgery for rectal cancer. METHODS: This prospective study randomized 95 patients with histologically proven rectal cancer (clinical stages I-III based on the 8th American Joint Committee on Cancer guidelines) to undergo HL (n = 47) or LL with lymph node dissection at the root of the IMA (n = 48). RESULTS: Only two intraoperative adverse events were observed (two HL patients experienced anastomotic ischemia and underwent extended bowel excision and splenic flexure mobilization). The LL group had a significantly shorter time to first flatus (p < .0001). No significant differences were observed in operative time (p = .14), intraoperative blood loss (p = .21), distance from the upper margin (p = .77), distance from the lower margin (p = .35), harvested lymph nodes (p = .33), or anastomotic leakage (p = .44), 2-year overall survival (p = .97), or 2-year disease-free survival (p = .42). CONCLUSION: During laparoscopic low anterior resection, a combination of LL at the IMA and vascular root lymph node dissection may help protect the blood supply of the anastomosis, reduce postoperative complications, and enhance recovery, without compromising radical excision.

CXCL5 induces tumor angiogenesis via enhancing the expression of FOXD1 mediated by the AKT/NF-κB pathway in colorectal cancer.

The mechanisms underlying the role of CXCL5 in tumor angiogenesis have not been fully defined. Here, we examined the effect of CXCL5 on tumor angiogenesis in colorectal cancer (CRC). Immunohistochemistry was used to monitor the expression of CXCL5 and CD31 in CRC patients' tissues. HUVEC cell lines stably transfected with shCXCR2 and shFOXD1 lentivirus plasmids were used in an in vitro study. Based on some molecular biological experiments in vitro and in vivo, we found that CXCL5 was upregulated in tumor tissues and that its level positively correlated with the expression of CD31. Next, we used recombinant human CXCL5 (rhCXCL5) to stimulate HUVECs and found that their tube formation ability, proliferation, and migration were enhanced by the activation of the AKT/NF-κB/FOXD1/VEGF-A pathway in a CXCR2-dependent manner. However, silencing of CXCR2 and FOXD1 or inhibition of the AKT and NF-κB pathways could attenuate the tube formation ability, proliferation, and migration of rhCXCL5-stimulated HUVECs in vitro. rhCXCL5 can promote angiogenesis in vivo in Matrigel plugs, and the overexpression of CXCL5 can also increase microvessel density in vivo in a subcutaneous xenotransplanted tumor model in nude mice. Taken together, our findings support CXCL5 as an angiogenic factor that can promote cell metastasis through tumor angiogenesis in CRC. Furthermore, we propose that FOXD1 is a novel regulator of VEGF-A. These observations open new avenues for therapeutic application of CXCL5 in tumor anti-angiogenesis.

Identification of key genes and pathways involved in microsatellite instability in colorectal cancer.

Microsatellite instability (MSI) has emerged as one of the key biological features of colorectal cancer (CRC). However, controversies remain regarding the association between the MSI status and clinicopathological characteristics of CRC. Therefore, it is crucial to identify potential key genes and pathways associated with MSI in CRC. In the present study, the GSE25071 gene expression profile was retrieved, with thirty­eight cases of microsatellite stable (MSS), five of MSI­High (MSI­H) and three of MSI­Low (MSI­L) CRC patients. The differentially expressed genes (DEGs) were analyzed by Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes pathway enrichment, gene set enrichment analysis (GSEA) and gene co­expression network analysis. Weighted gene correlation network analysis (WGCNA) was used for the gene modules and correlation of clinical traits. A total of forty­nine DEGs were identified between MSI­H and MSS, including six upregulated and forty­three downregulated DEGs. Only the DEGs of MSI­H and MSS were subjected to subsequent analysis (limited number of DEGs of MSI­L and MSS, MSI­H and MSI­L). RNA metabolic process, endoplasmic reticulum and chemokine receptor binding were the top ranked terms in GO enrichment. The hub genes of co­expression network of DEGs included zinc finger protein (ZNF) 813, ZNF426, ZNF611, ZNF320 and ZNF573. The GSEA of MSI­H and MSS indicated that the mammalian target of rapamycin complex 1 signaling was significantly enriched with a nominal P­value of 0.038 and normalized enrichment score of 0.446. The WGCNA results showed that the pink module was the top in correlation with MSI status (R2=0.5, P=0.0004). The genes in the pink module were significantly enriched in proteins targeting to endoplasmic reticulum, cytosolic part, structural constituent of ribosome and ribosome pathway. The hub genes identified in the pink module were ribosomal protein L12 (RPL12), RPS3A, RPS9, RPL27A, RPL7, RPL28, RPL14, RPS17, mitochondrial ribosomal protein L16, and G elongation factor, mitochondrial 2. The present study identified key genes and pathways associated with MSI, providing insightful mechanisms.