The gut ileal mucosal virome is disturbed in patients with Crohn's disease and exacerbates intestinal inflammation in mice.

Gut bacteriome dysbiosis is known to be implicated in the pathogenesis of inflammatory bowel disease (IBD). Crohn's disease (CD) is an IBD subtype with extensive mucosal inflammation, yet the mucosal virome, an empirical modulator of the bacteriome and mucosal immunity, remains largely unclear regarding its composition and role. Here, we exploited trans-cohort CD patients and healthy individuals to compositionally and functionally investigate the small bowel (terminal ileum) virome and bacteriome. The CD ileal virome was characterised by an under-representation of both lytic and temperate bacteriophages (especially those targeting bacterial pathogens), particularly in patients with flare-up. Meanwhile, the virome-bacteriome ecology in CD ileal mucosa was featured by a lack of Bifidobacterium- and Lachnospiraceae-led mutualistic interactions between bacteria and bacteriophages; surprisingly it was more pronounced in CD remission than flare-up, underlining the refractory and recurrent nature of mucosal inflammation in CD. Lastly, we substantiated that ileal virions from CD patients causally exacerbated intestinal inflammation in IBD mouse models, by reshaping a gut virome-bacteriome ecology preceding intestinal inflammation (microbial trigger) and augmenting microbial sensing/defence pathways in the intestine cells (host response). Altogether, our results highlight the significance of mucosal virome in CD pathogenesis and importance of mucosal virome restoration in CD therapeutics.

Multi-Task Learning With Hierarchical Guidance for Locating and Stratifying Submucosal Tumors.

Locating and stratifying the submucosal tumor of the digestive tract from endoscopy ultrasound (EUS) images are of vital significance to the preliminary diagnosis of tumors. However, the above problems are challenging, due to the poor appearance contrast between different layers of the digestive tract wall (DTW) and the narrowness of each layer. Few of existing deep-learning based diagnosis algorithms are devised to tackle this issue. In this article, we build a multi-task framework for simultaneously locating and stratifying the submucosal tumor. And considering the awareness of the DTW is critical to the localization and stratification of the tumor, we integrate the DTW segmentation task into the proposed multi-task framework. Except for sharing a common backbone model, the three tasks are explicitly directed with a hierarchical guidance module, in which the probability map of DTW itself is used to locally enhance the feature representation for tumor localization, and the probability maps of DTW and tumor are jointly employed to locally enhance the feature representation for tumor stratification. Moreover, by means of the dynamic class activation map, probability maps of DTW and tumor are reused to enforce the stratification inference process to pay more attention to DTW and tumor regions, contributing to a reliable and interpretable submucosal tumor stratification model. Additionally, considering the relation with respect to other structures is beneficial for stratifying tumors, we devise a graph reasoning module to replenish non-local relation knowledge for the stratification branch. Experiments on a Stomach-Esophagus and an Intestinal EUS dataset prove that our method achieves very appealing performance on both tumor localization and stratification, significantly outperforming state-of-the-art object detection approaches.

An immune, stroma, and epithelial-mesenchymal transition-related signature for predicting recurrence and chemotherapy benefit in stage II-III colorectal cancer.

BACKGROUND: Debates exist on the treatment decision of the stage II/III colorectal cancer (CRC) due to the insufficiency of the current TNM stage-based risk stratification system. Epithelial-mesenchymal transition (EMT) and tumor microenvironment (TME) have both been linked to CRC progression in recent studies. We propose to improve the prognosis prediction of CRC by integrating TME and EMT. METHODS: In total, 2382 CRC patients from seven datasets and one in-house cohort were collected, and 1640 stage II/III CRC patients with complete survival information and gene expression profiles were retained and divided into a training cohort and three independent validation cohorts. Integrated analysis of 398 immune, stroma, and epithelial-mesenchymal transition (ISE)-related genes identified an ISE signature independently associated with the recurrence of CRC. The underlying biological mechanism of the ISE signature and its influence on adjuvant chemotherapy was further explored. RESULTS: We constructed a 26-gene signature which was significantly associated with poor outcome in Training cohort (p < 0.001, HR [95%CI] = 4.42 [3.25-6.01]) and three independent validation cohorts (Validation cohort-1: p < 0.01, HR [95%CI] = 1.70 [1.15-2.51]; Validation cohort-2: p < 0.001, HR [95% CI] = 2.30 [1.67-3.16]; Validation cohort-3: p < 0.01, HR [95% CI] = 2.42 [1.25-4.70]). After adjusting for known clinicopathological factors, multivariate cox analysis confirmed the ISE signature's independent prognostic value. Subgroup analysis found that stage III patients with low ISE score might benefit from adjuvant chemotherapy (p < 0.001, HR [95%CI] = 0.15 [0.04-0.55]). Hypergeometric test and enrichment analysis revealed that low-risk group was enriched in thr immune pathway while high-risk group was associated with the EMT pathway and CMS4 subtype. CONCLUSION: We proposed an ISE signature for robustly predicting the recurrence of stage II/III CRC and help treatment decision by identifying patients who will not benefit from current standard treatment.

Landscape of the gut archaeome in association with geography, ethnicity, urbanization, and diet in the Chinese population.

BACKGROUND AND AIMS: The human gut is home to a largely underexplored microbiome component, the archaeome. Little is known of the impact of geography, urbanization, ethnicity, and diet on the gut archaeome in association with host health. We aim to delineate the variation of the human gut archaeome in healthy individuals and its association with environmental factors and host homeostasis. METHODS: Using metagenomic sequencing, we characterized the fecal archaeomes of 792 healthy adult subjects from 5 regions in China, spanning 6 ethnicities (Han, Zang, Miao, Bai, Dai, and Hani), consisting of both urban and rural residents for each ethnicity. In addition, we sampled 119 host variables (including lifestyle, diet, and blood parameters) and interrogated the influences of those factors, individually and combined, on gut archaeome variations. RESULTS: Population geography had the strongest impact on the gut archaeome composition, followed by urbanization, dietary habit, and ethnicity. Overall, the metadata had a cumulative effect size of 11.0% on gut archaeome variation. Urbanization decreased both the α-diversity (intrinsic microbial diversity) and the ß-diversity (inter-individual dissimilarities) of the gut archaeome, and the archaea-to-bacteria ratios in feces, whereas rural residents were enriched for Methanobrevibacter smithii in feces. Consumption of buttered milk tea (a characteristic diet of the rural Zang population) was associated with increased abundance of M. smithii. M. smithii was at the central hub of archaeal-bacterial interactions in the gut microecology, where it was positively correlated with the abundances of a multitude of short chain fatty acid (SCFA)-producing bacteria (including Roseburia faecis, Collinsella aerofaciens, and Prevotella copri). Moreover, a decreased abundance of M. smithii was associated with increased human blood levels of cholinesterase in the urban population, coinciding with the increasing prevalence of noncommunicable diseases (such as dementia) during urbanization. CONCLUSIONS: Our data highlight marked contributions of environmental and host factors (geography, urbanization, ethnicity, and habitual diets) to gut archaeome variations across healthy individuals, and underscore the impact of urbanization on the gut archaeome in association with host health in modern society. Video Abstract.

Predicting prognosis and immunotherapy response among colorectal cancer patients based on a tumor immune microenvironment-related lncRNA signature.

Long non-coding RNAs (lncRNAs) remodel the tumor immune microenvironment (TIME) by regulating the functions of tumor-infiltrating immune cells. It remains uncertain the way that TIME-related lncRNAs (TRLs) influence the prognosis and immunotherapy response of colorectal cancer (CRC). Aiming at providing survival and immunotherapy response predictions, a CRC TIME-related lncRNA signature (TRLs signature) was developed and the related potential regulatory mechanisms were explored with a comprehensive analysis on gene expression profiles from 97 immune cell lines, 61 CRC cell lines and 1807 CRC patients. Stratifying CRC patients with the TRLs signature, prolonged survival was observed in the low-risk group, while the patients in the high-risk group had significantly higher pro-tumor immune cells infiltration and higher immunotherapy response rate. Through the complex TRLs-mRNA regulation network, immunoregulation pathways and immunotherapy response pathways were found to be differently activated between the groups. In conclusion, the CRC TRLs signature is capable of making prognosis and immunotherapy response predictions, which may find application in stratifying patients for immunotherapy in the bedside.

DNA Repair-Related Gene Signature in Predicting Prognosis of Colorectal Cancer Patients.

Background: Increasing evidence have depicted that DNA repair-related genes (DRGs) are associated with the prognosis of colorectal cancer (CRC) patients. Thus, the aim of this study was to evaluate the impact of DNA repair-related gene signature (DRGS) in predicting the prognosis of CRC patients. Method: In this study, we retrospectively analyzed the gene expression profiles from six CRC cohorts. A total of 1,768 CRC patients with complete prognostic information were divided into the training cohort (n = 566) and two validation cohorts (n = 624 and 578, respectively). The LASSO Cox model was applied to construct a prediction model. To further validate the clinical significance of the model, we also validated the model with Genomics of Drug Sensitivity in Cancer (GDSC) and an advanced clear cell renal cell carcinoma (ccRCC) immunotherapy data set. Results: We constructed a prognostic DRGS consisting of 11 different genes to stratify patients into high- and low-risk groups. Patients in the high-risk groups had significantly worse disease-free survival (DFS) than those in the low-risk groups in all cohorts [training cohort: hazard ratio (HR) = 2.40, p < 0.001, 95% confidence interval (CI) = 1.67-3.44; validation-1: HR = 2.20, p < 0.001, 95% CI = 1.38-3.49 and validation-2 cohort: HR = 2.12, p < 0.001, 95% CI = 1.40-3.21). By validating the model with GDSC, we could see that among the chemotherapeutic drugs such as oxaliplatin, 5-fluorouracil, and irinotecan, the IC50 of the cell line in the low-risk group was lower. By validating the model with the ccRCC immunotherapy data set, we can clearly see that the overall survival (OS) of the objective response rate (ORR) with complete response (CR) and partial response (PR) in the low-risk group was the best. Conclusions: DRGS is a favorable prediction model for patients with CRC, and our model can predict the response of cell lines to chemotherapeutic agents and potentially predict the response of patients to immunotherapy.

The enhanced cell cycle related to the response to adjuvant therapy in pancreatic ductal adenocarcinoma.

A major clinical challenge for treating patients with pancreatic ductal adenocarcinoma (PDAC) is identifying those that may benefit from adjuvant chemotherapy versus those that will not. Thus, there is a need for a robust and convenient biomarker for predicting chemotherapy response in PDAC patients. In this study, network inference was conducted by integrating the differentially expressed cell cycle signatures and target genes between the basal-like subtype and classical subtype of PDAC. As a result from this statistical analysis, two dominant cell cycle genes, RASAL2 and ASPM, were identified. Based on the expression levels of these two genes, we constructed a "Enhanced Cell Cycle" scoring system (ECC score). Patients were given an ECC score, and respectively divided into ECC-high and ECC-low groups. Survival, pathway enrichment, immune environment characteristics, and chemotherapy response analysis' were performed between the two groups in a total of 891 patients across 5 cohorts. ECC-high patients exhibited shortened recurrence-free survival (RFS) and overall survival (OS) rates. In addition, it was found that adjuvant chemotherapy could significantly improve the outcome of the ECC-high patients while ECC-low patients did not benefit from adjuvant chemotherapy. It was also found that there was less CD8+ T cell, natural killer (NK) cell, M1 macrophage, and plasma cell infiltration in ECC-high patients when compared to ECC-low patients. Also, the expression of CD73, an immune suppressor gene, and it's related hypoxia pathway were elevated in the ECC-high group when compared to the ECC-low group. In conclusion, this study showed that patients characterized as ECC-high not only had reduced RFS and OS rates, but were also more sensitive to adjuvant chemotherapy and could potentially be less sensitive to immune checkpoint inhibitors. Being able to characterize patients by these parameters would allow doctors to make more informed decisions on patient treatment regimens.

Identification of an Autophagy-Related Gene Signature for the Prediction of Prognosis in Early-Stage Colorectal Cancer.

Purpose: A certain number of early-stage colorectal cancer (CRC) patients suffer tumor recurrence after initial curative resection. In this context, an effective prognostic biomarker model is constantly in need. Autophagy exhibits a dual role in tumorigenesis. Our study aims to develop an autophagy-related gene (ATG) signature-based on high-throughput data analysis for disease-free survival (DFS) prognosis of patients with stage I/II CRC. Methods: Gene expression profiles and clinical information of CRC patients extracted from four public datasets were distributed to discovery and training cohort (GSE39582), validation cohort (TCGA CRC, n = 624), and meta-validation cohort (GSE37892 and GSE14333, n = 420). Autophagy genes significantly associated with prognosis were identified. Results: Among 655 autophagy-related genes, a 10-gene ATG signature, which was significantly associated with DFS in the training cohort (HR, 2.76[1.56-4.82]; p = 2.06 × 10-4), was constructed. The ATG signature, stratifying patients into high and low autophagy risk groups, was validated in the validation (HR, 2.29[1.15-4.55]; p = 1.5 × 10-2) and meta-validation cohorts (HR, 2.5[1.03-6.06]; p = 3.63 × 10-2) and proved to be prognostic in a multivariate analysis. Functional analysis revealed enrichment of several immune/inflammatory pathways in the high autophagy risk group, where increased infiltration of T regulatory cells (Tregs) and decreased infiltration of M1 macrophages were observed. Conclusion: Our study established a prognostic ATG signature that effectively predicted DFS for early-stage CRC patients. Meanwhile, the study also revealed the possible relationship among autophagy process, immune/inflammatory response, and tumorigenesis.

Citrate-Based Self-Circulation Anticoagulation Protocol for Discontinuity of Continuous Renal Replacement Therapy.

BACKGROUND/AIMS: Continuous renal replacement therapy (CRRT) has been used widely in the treatment of critically ill children for its continuity. However, sometimes we have to interrupt the continuity for necessary surgeries or blood transfusions. Our objective was to demonstrate a feasible self-circulation anticoagulation protocol based on citrate (CSAP) to address discontinuity during CRRT. METHODS: We conducted a prospective observational study of 57 pediatric patients undergoing 88 CRRT sessions that were receiving CSAP during the treatment discontinuity period by using an anticoagulation regimen containing 5 mL 4% sodium citrate in 50 mL of saline to maintain the continuity. We documented the reasons for CSAP and the total duration of the treatment. We assessed the in-line pressure recordings, blood routine examination, blood electrolytes, and blood gas analysis before, throughout, and after the period of CSAP. RESULTS: The average duration of CSAP was 118.5 ± 45.3 min. There was no significant increase in arterial pressures, venous pressures, and transmembrane pressures and no significant decreases in blood cell counts observed at the end of the CSAP, compared to the data recorded at the beginning of the CSAP. Compared to before the CSAP, there was no significant change in the ratio of total to ionized calcium, Na+, HCO3-, and pH value after CSAP. CONCLUSIONS: CSAP might be a safe, effective, and easy approach for use during the treatment discontinuity of CRRT in children.

Predictability of gastric intestinal metaplasia by patchy lavender color seen on linked color imaging endoscopy.

We aimed to investigate the ability of linked color imaging (LCI) versus white light endoscopy (WLE) to detect gastric intestinal metaplasia (GIM). One hundred and seven participants who underwent upper gastrointestinal endoscopy were included. Under WLE endoscopy, biopsies were performed on any suspected abnormal mucosal changes. Under LCI endoscopy, we tested whether the specific color feature of patchy lavender color (PLC) pathologically indicated GIM. Biopsies were randomly performed in participants who had neither PLC nor suspected lesions. The detection abilities of LCI and WLE were assessed by comparison of histological and endoscopic findings. A total of 41 participants had histological GIM. The total diagnostic accuracy rate for GIM by LCI was 79.44%, higher than that of WLE (40.19%) (P < 0.001). Moreover, LCI with targeted biopsies showed a significantly increased ability to detect GIM (P < 0.001). PLC observed in the gastric mucosa on LCI can guide endoscopic biopsies and increase the detection rate of GIM. Thus, LCI could be a good tool for detecting GIM. ClinicalTrials.gov Identifier: ChiCTR-DDD-17011326).

Clinical utility of double-balloon enteroscopy in children: A single-centre experience in South China.

AIM: Double-balloon enteroscopy (DBE) is a useful tool for the evaluation and treatment of small bowel disease. Limited clinical data are available regarding the indications, clinical findings and safety associated with the use of DBE in children. The aim of this study is to investigate the utility and safety of DBE in children. METHODS: A total of 72 DBE procedures were performed on 61 children at the Sixth Affiliated Hospital, Sun Yat-sen University, between 1 April 2013 and 31 December 2017. The clinical data were analysed retrospectively. RESULTS: DBE was attempted 72 times in 61 children (45 boys and 16 girls) of an age range between 6 and 14 years (mean age: 11.9 years). The most common indication for DBE was occult gastrointestinal bleeding and abdominal pain. The positive rate of abnormal findings was 77.5% (55/72). Most children showed non-specific enteritis and Crohn's disease. Eight children underwent successful therapeutic enteroscopy. No serious complication was observed in any child in this case series. CONCLUSION: DBE can be a useful diagnostic and therapeutic tool for small bowel disorders in children.

Overexpression of G protein-coupled receptor 31 as a poor prognosticator in human colorectal cancer.

AIM: To investigate the expression of G protein-coupled receptor 31 (GPR31) and its clinical significance in human colorectal cancer (CRC). METHODS: To determine the association between the GPR31 expression and the prognosis of patients, we obtained paraffin-embedded pathological specimens from 466 CRC patients who underwent initial resection. A total of 321 patients from the First Affiliated Hospital of Sun Yat-sen University from January 1996 to December 2008 were included as a training cohort, whereas 145 patients from the Sixth Affiliated Hospital of Sun Yat-sen University from January 2007 to November 2008 were included as a validation cohort. We examined GPR31 expression levels in CRC tissues from two independent cohorts via immunohistochemical staining. All patients were categorized into either a GPR31 low expression group or a GPR31 high expression group. The clinicopathological factors and the prognosis of patients in the GPR31 low expression group and GPR31 high expression group were compared. RESULTS: We compared the clinicopathological factors and the prognosis of patients in the GPR31 low expression group and GPR31 high expression group. Significant differences were observed in the number of patients in pM classification between patients in the GPR31 low expression group and GPR31 high expression group (P = 0.007). The five-year survival and tumor-free survival rates of patients were 84.3% and 82.2% in the GPR31 low expression group, respectively, and both rates were 59.7% in the GPR31 high expression group (P < 0.05). Results of the Cox proportional hazard regression model revealed that GPR31 upregulation was associated with shorter overall survival and tumor-free survival of patients with CRC (P < 0.05). Multivariate analysis identified GPR31 expression in colorectal cancer as an independent predictive factor of CRC patient survival (P < 0.05). CONCLUSION: High GPR31 expression levels were found to be correlated with pM classification of CRC and to serve as an independent predictive factor of poor survival of CRC patients.

[Effect of miR-26b on the invasion and metastasis of colorectal cancer].

OBJECTIVE: To investigate the role of miR-26b in the invasion and metastasis of colorectal cancer. METHODS: Data of public chip databases were extracted to analyze the relationship between miR-26b expression and lymph node metastasis. Two types of colorectal cancer cell lines, Caco2 and DLD1, were selected, and the miR-26b-high colorectal cancer cell line was constructed using the method of lentivirus infection. The effects of up-regulating miR-26b expression on the invasion and metastasis of colorectal cancer cells were analyzed by Transwell migration and invasion experiment and wound healing assay. The effect of up-regulating miR-26b expression on stem cell phenotype of colorectal cancer cells was analyzed by sphere-formation assay. RESULTS: The microarray detection results showed that the expression of miR-26b in tumor tissues of patients with lymph node metastasis was significantly higher than those without lymph node metastasis[(12.04±0.20) vs. (11.31±0.19), t=2.646, P = 0.010]. In the in vitro experiment section, the Transwell experiment results showed that the number of invasive cells [(16.40±1.36) vs. (3.80±0.86), t=7.814, P=0.000] and migrating cells [(33.40±2.93) vs. (8.80±2.40), t=6.505, P=0.000] in miR-26b-high colorectal cancer cells was significantly higher as compared to miR-26b-low cells(all P<0.05). Would healing assay also confirmed that the migration speed of miR-26b-high colorectal cancer cells was significantly accelerated. Both the rate and the density of sphere formation were higher in miR-26b-high colorectal cancer cells than those in miR-26b-low colorectal cancer cells [Caco2:(168.3±11.7) vs. (54.2±10.8), t=7.185,P=0.002; DLD1:(4 076.0±409.8) vs.(1 613.0±210.1), t=5.349, P=0.006]. CONCLUSION: miR-26b may promote the invasion and metastasis of colorectal cancer by accelerating the migration and invasion of colorectal cancer cells and enhancing the stem cell phenotype of tumor cells.

Prohibitin and the extracellular matrix are upregulated in murine alveolar epithelial cells with LPS­induced acute injury.

Inflammation of epithelial and endothelial cells accelerates the progress of acute lung injury (ALI), and pulmonary fibrosis is the leading cause of mortality in patients with acute respiratory distress syndrome. Interleukin­6 (IL­6) is a pleiotropic cytokine implicated in the pathogenesis of a number of immune­mediated disorders, and is involved in pulmonary fibrosis. Prohibitin (PHB) is a highly conserved protein implicated in various cellular functions, including proliferation, apoptosis, tumor suppression, transcription and mitochondrial protein folding. PHB was identified to be associated with a variety of pulmonary diseases, including pulmonary fibrosis. Based on the lipopolysaccharide (LPS)­induced cell model of ALI, the present study examined the expression of PHB and the extracellular matrix (ECM) in the process of pulmonary inflammation. MLE­12 cells were divided into 2 groups: The control group was administered sterile PBS; the treatment group was administered 500 ng/ml LPS for 12 h. The mRNA expression of IL­6 in the treatment group was significantly upregulated compared with the control group (P<0.05). The protein expression of IL­6 in the treatment group was markedly increased compared with the control group (P<0.05). ECM components, including collagen­IV and fibronectin, in the treatment group were markedly increased when compared with the control group (P<0.05). The mRNA and protein expression levels of PHB1 and PHB2 were significantly upregulated following treatment with LPS (both P<0.05). The present study identified that PHB and ECM component levels increased in the LPS­induced ALI cell model, and further investigations may be performed to verify the detailed mechanism.

MicroRNA-143 Targets ATG2B to Inhibit Autophagy and Increase Inflammatory Responses in Crohn's Disease.

Background: Dysfunctional autophagy is recognized as a contributing factor in many chronic inflammatory diseases, including Crohn's disease (CD). Genetic analyses have found that microRNA (miRNA) levels are altered in the intestinal tissues of CD patients. Methods: The Sequencing Alternative Poly-Adenylation Sites (SAPAS) method was used to compare the 3' end of the total mRNA sequence of 3 surgical specimens of CD patients (including inflamed tissues and corresponding noninflamed tissues in each case). The levels of autophagy-related 2B (ATG2B), LC3, and miR-143 were compared between inflamed tissues and noninflamed tissues using immunoblot and quantitative reverse transcription polymerase chain reaction. Luciferase assays were used to verify the interactions between miR-143 and ATG2B. Autophagy was measured by immunoblot analyses of LC3 and transmission electron microscopy. Inflammatory cytokines and IκBα were analyzed to evaluate the effect of miR-143 on inflammatory response. Results: The tandem repeat 3'-UTR of ATG2B was longer in inflamed tissues than in corresponding noninflamed tissues and contained an miR-143 target site. miR-143 expression was elevated, whereas ATG2B and LC3-II were downregulated in inflamed tissues. The direct interaction between miR-143 and ATG2B was verified by a 3'-UTR dual-luciferase reporter assay. Constitutive expression of miR-143 or depletion of ATG2B in cultured intestinal epithelial cells inhibited autophagy, reduced IκBα levels, and increased inflammatory responses. Conclusions: miR-143 may induce bowel inflammation by regulating ATG2B and autophagy, suggesting that miR-143 might play a critical role in the development of CD. Therefore, miR-143 could be a promising novel target for gene therapy in CD patients.

Global stability of multi-group viral models with general incidence functions.

In this paper, strongly connected and non-strongly connected multi-group viral models with time delays and general incidence functions are considered. Employing the Lyapunov functional method and a graph-theoretic approach, we show that the global dynamics of the strongly connected system are determined by the basic reproduction number under some reasonable conditions for incidence functions. In addition, we find a more complex and more interesting result for multi-group viral models with non-strongly connected networks because of the basic reproduction numbers corresponding to each strongly connected component. Finally, we provide simulations for non-strongly connected multi-group viral models to support our conclusion.

Activation of KLF4 expression by small activating RNA promotes migration and invasion in colorectal epithelial cells.

RNA activation mediated by small double-stranded RNAs targeting promoter sequence named small activating RNAs (saRNAs) is one of the mechanisms for gene activation. Artificial regulation of gene expression through RNA activation does not affect the alteration of the genomic DNA sequences or exogenous plasmid DNA, therefore it is a relative manageable approach for gene perturbation. KLF4 is a member of zinc-finger transcription factors and its functions in colorectal cells are still controversial. In order to elucidate the functions of KLF4, we synthesized saRNAs that target the promoter regions of KLF4 and transfected into varied colorectal epithelial cell lines. We found the KLF4 gene expression is specifically increased in the human normal epithelial cell NCM460 and colorectal epithelial cancer cell Caco-2 and HCT116, but not in other human colorectal epithelial cell lines. In addition, we observed that saRNAs induced overexpression of KLF4 could promote cell migration/invasion in NCM460 and HCT116 cell lines. This effect is mediated partly by inducing EMT and facilitating nuclear translocation of ß-catenin.

MicroRNA 26b promotes colorectal cancer metastasis by downregulating phosphatase and tensin homolog and wingless-type MMTV integration site family member 5A.

Invasion and metastasis are crucially important factors in the survival of malignant tumors. Epithelial-mesenchymal transition (EMT) is an early step in metastatic progression and the presence of cancer stem cells is closely related to tumor survival, proliferation, metastasis, and recurrence. Herein we report that ectopic overexpression of microRNA 26b (miR-26b) in colorectal cancer (CRC) cell lines promoted EMT and stem cell-like phenotypes in vitro. Furthermore, miR-26b directly targeted and suppressed multiple tumor suppressors, including phosphatase and tensin homolog (PTEN) and wingless-type MMTV integration site family member 5A (WNT5A). Notably, miR-26b is markedly upregulated in tumor samples from patients with lymphatic metastases. These results indicate that miR-26b promotes CRC metastasis by downregulating PTEN and WNT5A, and may represent a therapeutic target for metastatic CRC.

[Influence of CCL21 on the invasion and metastasis of colorectal cancer].

OBJECTIVE: To investigate the influence of CCL21 on the invasion and metastasis of colorectal cancer (CRC). METHODS: CCL21 over-expressing CRC cell line was constructed by lentivirus infection and CCL21 low-expressing CRC cell line was constructed by lipofection. The effects of CCL21 on the invasion and metastasis of CRC cells and the stem cell-like phenotype were investigated by Transwell migration, invasion assay, wound healing assay and sphere formation assay. RESULTS: Real-time quantitative PCR and western blot confirmed that the expression of CCL21 was up-regulated by lentiviral transfection and down-regulated by siRNA liposome transfection. In vitro, Transwell assays showed that the invasion and migration in CCL21 over-expressing CRC cells decreased significantly as compared to those of CCL21 low-expressing cells. In wound healing assay, the CCL21 over-expressing CRC cells showed a significantly lower rate of migration. In addition, the sphere formation rate and density of CCL21 over-expressing CRC cells were lower than those with low-expression of CCL21. CONCLUSION: CCL21 can suppress the migration and invasion of CRC cells and weaken their stem cell-like phenotype.

Supercritical carbon dioxide-developed silk fibroin nanoplatform for smart colon cancer therapy.

PURPOSE: To deliver insoluble natural compounds into colon cancer cells in a controlled fashion. MATERIALS AND METHODS: Curcumin (CM)-silk fibroin (SF) nanoparticles (NPs) were prepared by solution-enhanced dispersion by supercritical CO2 (SEDS) (20 MPa pressure, 1:2 CM:SF ratio, 1% concentration), and their physicochemical properties, intracellular uptake efficiency, in vitro anticancer effect, toxicity, and mechanisms were evaluated and analyzed. RESULTS: CM-SF NPs (<100 nm) with controllable particle size were prepared by SEDS. CM-SF NPs had a time-dependent intracellular uptake ability, which led to an improved inhibition effect on colon cancer cells. Interestingly, the anticancer effect of CM-SF NPs was improved, while the side effect on normal human colon mucosal epithelial cells was reduced by a concentration of ~10 µg/mL. The anticancer mechanism involves cell-cycle arrest in the G0/G1 and G2/M phases in association with inducing apoptotic cells. CONCLUSION: The natural compound-loaded SF nanoplatform prepared by SEDS indicates promising colon cancer-therapy potential.