VSL#3 can prevent ulcerative colitis-associated carcinogenesis in mice

AIM To investigate the effects of VSL#3 on tumor formation, and fecal and intestinal mucosal microbiota in azoxymethane/dextran sulfate sodium(AOM/DSS) induced mice model. METHODS C57 BL/6 mice were administered AOM/DSS to develop the ulcerative colitis(UC) carcinogenesis model. Mice were treated with 5-ASA(75 mg/kg/d), VSL#3(1.5 × 109 CFU/d), or 5-ASA combined with VSL#3 by gavage from the day of AOM injection for three months(five days/week). The tumor load was compared in each group, and tumor necrosis factor(TNF-α) and interleukin(IL)-6 levels were evaluated in colon tissue. The stool and intestinal mucosa samples were collected to analyze the differences in the intestinal microbiota by 16 s rDNA sequencing method.RESULTS VSL#3 significantly reduced the tumor load in AOM/DSS-induced mice model and decreased the level of TNF-α and IL-6 in colon tissue. The model group had a lower level of Lactobacillus and higher level of Oscillibacter and Lachnoclostridium in fecal microbiota than the control group. After the intervention with 5-ASA and VSL#3, Bacillus and Lactococcus were increased, while Lachnoclostridium and Oscillibacter were reduced. 5-ASA combined with VSL#3 increased the Lactobacillus and decreased the Oscillibacter. The intestinal mucosal microbiota analysis showed a lower level of Bifidobacterium and Ruminococcaceae_UCG-014 and higher level of Al oprevotel a in the model group as compared to the control group. After supplementation with VSL#3, Bifidobacterium was increased. 5-ASA combined with VSL#3 increased the level of both Lachnoclostridium and Bifidobacterium. CONCLUSION VSL#3 can prevent UC-associated carcinogenesis in mice, reduce the colonic mucosal inflammation levels, and rebalance the fecal and mucosal intestinal microbiota.

Macrophage involvement in the pathological evolution of ulcerative colitis-associated colon cancer and progress of related traditional Chinese medicine drug interventions

Intestinal macrophages are essential players in intestinal inflammation and intestinal immune homeostasis.Intestinal macrophages have the ability to polarize into two distinct phenotypes based on various environmental signals.These phenotypes include the typically activated pro-inflammatory M1 phenotype and the alternatively activated anti-inflammatory M2 phenotype.Under normal circumstances,intestinal macrophages prevent inflammatory damage to the gut.However,when genetic and environmental factors influence the polarization of intestinal macrophages,it can lead to an imbalance in M1/M2 macrophage activation and subsequently an imbalance in the control of intestinal inflammation.It transforms physiological inflammation into pathological intestinal damage.In patients with ulcerative colitis-associated cancer(UC-CRC),intestinal inflammatory disorders are closely associated with intestinal M1/M2 macrophage polarization imbalance.Consequently,restoring the polarization equilibrium of M1/M2 macrophages might be an evidence of traditional Chinese medicine in the treatment of UC-CRC,the pivotal role o effective measure to prevent and treat UC-CRC.This paper aims to examine the clinicalf macrophage polarization in UC-CRC pathogenesis,and the potential mechanisms of traditional Chinese medicine in regulating macrophage polarization to treat UC-CRC.Our goal is to provide novel insights into the clinical practice,basic research,and drug development of UC-CRC.

Expression of interleukin-22/STAT3 signaling pathway in ulcerative colitis and related carcinogenesis

AIM:To investigate the expression of interleukin (IL)-22 and its related proteins in biopsy specimens from patients with ulcerative colitis (UC) and UC-related carcinogenesis. METHODS:Biopsy specimens were obtained from patients with inactive (n = 10), mild-to-moderately active (n = 30), severely active (n = 34), initial (n = 30), and chronic UC (n = 44), as well as UC patients with dysplasia (n = 10). Specimens from patients without colonic abnormalities (n = 20) served as controls. Chronic colitis in experimental mice was induced by 2.5% dextran sodium sulfate. The expression levels of IL-22, IL-23, IL-22R1 and phosphorylated STAT3 (p- STAT3) were determined by immunohistochemistry. Bcl-2, cyclin D1 and survivin expression was detected by Western blotting. RESULTS:Patients with active UC had significantly more IL-22, IL-23, IL-22R1 and p-STAT3-positive cells than the patients with inactive UC and normal controls. Furthermore, IL-22 and related proteins were closely related to the severity of the colitis. The expression of IL-22 and IL-22R1 in the tissue of initial UC was stronger than in that of chronic UC, whereas the expression of p-STAT3 was significantly increased in chronic UC tissues. In dysplasia tissues, the expression level of IL-22 and related proteins was higher compared with controls. Mouse colitis model showed that expression of IL-22, IL-22R1 and IL-23 was increased with time, p-STAT3 and the downstream gene were also remarkably upregulated.CONCLUSION:IL-22/STAT3 signaling pathway may be related to UC and UC-induced carcinogenesis and IL-22 can be used as a biomarker in judging the severity of UC.

Ulcerative colitis-associated colorectal cancer

The association between ulcerative colitis(UC) and colorectal cancer(CRC) has been acknowledged. One of the most serious and life threatening consequences of UC is the development of CRC(UC-CRC). UC-CRC patients are younger, more frequently have multiple cancerous lesions, and histologically show mucinous or signet ring cell carcinomas. The risk of CRC begins to increase 8 or 10 years after the diagnosis of UC. Risk factors for CRC with UC patients include young age at diagnosis, longer duration, greater anatomical extent of colonic involvement, the degree of inflammation, family history of CRC, and presence of primary sclerosing cholangitis. CRC on the ground of UC develop from non-dysplastic mucosa to indefinite dysplasia, lowgrade dysplasia, high-grade dysplasia and finally to invasive adenocarcinoma. Colonoscopy surveillance programs are recommended to reduce the risk of CRC and mortality in UC. Genetic alterations might play a role in the development of UC-CRC. 5-aminosalicylates might represent a favorable therapeutic option for chemoprevention of CRC.

Inflammatory colonic carcinogenesis: A review on pathogenesis and immunosurveillance mechanisms in ulcerative colitis

Ulcerative colitis(UC)is characterized by repeated flare-ups of inflammation that can lead to oncogenic insults to the colonic epithelial.UC-associated carcinogenesis presents a different sequence of tumorigenic events compared to those that contribute to the development of sporadic colorectal cancer.In fact,in UC,the early events are represented by oxidative DNA damage and DNA methylation that can produce an inhibition of oncosuppressor genes,mutation of p53,aneuploidy,and microsatellite instability.Hypermethylation of tumor suppressor and DNA mismatch repair gene promoter regions is an epigenetic mechanism of gene silencing that contribute to tumorigenesis and may represent the first step in inflammatory carcinogenesis.Moreover,p53 is frequently mutated in the early stages of UC-associated cancer.Aneuploidy is an independentrisk factor for forthcoming carcinogenesis in UC.Epithelial cell-T-cell cross-talk mediated by CD80 is a key factor in controlling the progression from low to high grade dysplasia in UC-associated carcinogenesis.

Status of colitis-associated cancer in ulcerative colitis

Surgical therapy for ulcerative colitis(UC) depends on the medical therapy administered for the patient's condition. UC is a benign disease. However, it has been reported that the rare cases of cancer in UC patients are increasing, and such cases have a worse prognosis. Recently, surgical therapy has greatly changed, there has been quite an increase in the number of UC patients with high-grade dysplasia and/or cancer. These lesions are known as colitis-associated cancer(CAC). The relationship between inflammation and tumorigenesis is well-established, and in the last decade, a great deal of supporting evidence has been obtained from genetic, pharmacological, and epidemiological studies. Inflammatory bowel disease, especially UC, is an important risk factor for the development of colon cancer. We should determine the risk factors for UC patients with cancer based on a large body of data, and we should attempt to prevent the increase in the number of such patients using these newly identified risk factors in the near future. Actively introducing the surgical treatment in addition to medical treatment should be considered. Several physicians should analyze UC from their unique perspectives in order to establish new clinically relevant diagnostic and treatment methods in the future. This article discusses CAC, including its etiology, mechanism, diagnosis, and treatment in UC patients.

Clinical usefulness of endoscopic ultrasonography for the evaluation of ulcerative colitis-associated tumors

AIM:To evaluate the clinical usefulness of endoscopic ultrasonography(EUS) for the diagnosis of the invasion depth of ulcerative colitis-associated tumors.METHODS:The study group comprised 13 patients with 16 ulcerative colitis(UC)-associated tumors for which the depth of invasion was preoperatively estimated by EUS.The lesions were then resected endoscopically or by surgical colectomy and were examined histopathologically.The mean age of the subjects was 48.2 ± 17.1 years,and the mean duration of UC was 15.8 ± 8.3 years.Two lesions were treated by endoscopic resection and the other 14 lesions by surgical colectomy.The depth of invasion of UCassociated tumors was estimated by EUS using an ultrasonic probe and was evaluated on the basis of the deepest layer with narrowing or rupture of the colonic wall.RESULTS:The diagnosis of UC-associated tumors by EUS was carcinoma for 13 lesions and dysplasia for 3 lesions.The invasion depth of the carcinomas was intramucosal for 8 lesions,submucosal for 2,the muscularis propria for 2,and subserosal for 1.Eleven(69%) of the 16 lesions arose in the rectum.The macroscopic appearance was the laterally spreading tumor-non-granular type for 4 lesions,sessile type for 4,laterally spreading tumor-granular type for 3,semipedunculated type(Isp) for 2,type 1 for 2,and type 3 for 1.The depth of invasion was correctly estimated by EUS for 15 lesions(94%) but was misdiagnosed as intramucosal for 1 carcinoma with high-grade submucosal invasion.The 2 lesions treated by endoscopic resection were intramucosal carcinoma and dysplasia,and both were diagnosed as intramucosal lesions by EUS.CONCLUSION:EUS provides a good estimation of the invasion depth of UC-associated tumors and may thus facilitate the selection of treatment.

Landscape of cell heterogeneity and evolutionary trajectory in ulcerative colitis-associated colon cancer revealed by single-cell RNA sequencing

Objective:The goal of this study was to get preliminary insight on the intra-tumor heterogeneity in colitisassociated cancer(CAC)and to reveal a potential evolutionary trajectory from ulcerative colitis(UC)to CAC at the single-cell level.Methods:Fresh samples of tumor tissues and adjacent UC tissues from a CAC patient with pT3N1M0 stage cancer were examined by single-cell RNA sequencing(scRNA-seq).Data from The Cancer Genome Atlas(TCGA)and The Human Protein Atlas were used to confirm the different expression levels in normal and tumor tissues and to determine their relationships with patient prognosis.Results:Ultimately,4,777 single-cell transcriptomes(1,220 genes per cell)were examined,of which 2,250(47%)and 2,527(53%)originated from tumor and adjacent UC tissues,respectively.We defined the composition of cancer-associated stromal cells and identified six cell clusters,including myeloid,T and B cells,fibroblasts,endothelial and epithelial cells.Notable pathways and transcription factors involved in these cell clusters were analyzed and described.Moreover,the precise cellular composition and developmental trajectory from UC to UCassociated colon cancer were graphed,and it was predicted that CD74,CLCA1,and DPEP1 played a potential role in disease progression.Conclusions:scRNA-seq technology revealed intra-tumor cell heterogeneity in UC-associated colon cancer,and might provide a promising direction to identify novel potential therapeutic targets in the evolution from UC to CAC.

Huangqin Decoction Delays Progress of Colitis-Associated Carcinogenesis by Regulating Nrf2/HO-1 Antioxidant Signal Pathwayin Mice

Objective:To investigate the effect of Huangqin Decoction(HQD)on nuclear factor erythroid 2 related-factor 2(Nrf2)/heme oxygenase(HO-1)signaling pathway by inducing the colitis-associated carcinogenesis(CAC)model mice with azoxymethane(AOM)/dextran sodium sulfate(DSS).Methods:The chemical components of HQD were analyzed by liquid chromatography-quadrupole-time-of-flight mass spectrometry(LC-Q-TOF-MS/MS)to determine the molecular constituents of HQD.Totally 48 C57BL/6J mice were randomly divided into 6 groups by a random number table,including control,model(AOM/DSS),mesalazine(MS),low-,medium-,and high-dose HQD(HQD-L,HQD-M,and HQD-H)groups,8 mice in each group.Except for the control group,the mice in the other groups were intraperitoneally injected with AOM(10 mg/kg)and administrated with 2.5%DSS orally for 1 week every two weeks(totally 3 rounds of DSS)to construct a colitis-associated carcinogenesis mouse model.The mice in the HQD-L,HQD-M and HQD-H groups were given HQD by gavage at doses of 2.925,5.85,and 11.7 g/kg,respectively;the mice in the MS group was given a suspension of MS at a dose of 0.043 g/kg(totally 11 weeks).The serum levels of malondialdehyde(MDA)and superoxide dismutase(SOD)were measured by enzyme-linked immunosorbent assay.The mRNA and protein expression levels of Nrf2,HO-1,and inhibitory KELCH like ECH-related protein 1(Keap1)in colon tissue were detected by quantitative real-time PCR,immunohistochemistry,and Westem blot,respectively.Results:LC-Q-TOF-MS/MS analysis revealed that the chemical constituents of HQD include baicalin,paeoniflorin,and glycyrrhizic acid.Compared to the control group,significantly higher MDA levels and lower SOD levels were observed in the model group(P<0.05),whereas the expressions of Nrf2 and HO-1 were significantly decreased,and the expression of Keap1 increased(P<0.01).Compared with the model group,serum MDA level was decreased and SOD level was increased in the HQD-M,HQD-H and MS groups(P<0.05).Higher expressions of Nrf2 and HO-1 were observed in the HQD groups.Conclusion:HQD may regulate the expression of Nrf2 and HO-1 in colon tissue,reduce the expression of MDA and increase the expression of SOD in serum,thus delaying the progress of CAC in AOM/DSS mice.

Screening of differentially expressed microRNA in ulcerative colitis related colorectal cancer

Objective:To investigate the differential expression of microRNA(miRNA)in colon between ulcerative colitis(UC)and ulcerative colitis related colorectal cancer(UCRCC).Methods:An UC mouse model was built by dextran sodium sulfate,and an UCRCC mouse model by dextran sodium sulfate and 1,2-diformylhydrazine.RNAs were extracted from the colon,purified and hybridized with fluorescence-labeled miRNA oligonucleotide gene chip.Real-time fluorescence quantitative PCR was used to verity the expression variation of miRNA.SAM was employed for the data analysis.Results:The up-regulated miRNA in colon cancer included has-miR-194,hasmiR-215,has-miR-93,has-miR-192,has-miR-92a,has-miR-29b,and has-miR-20a(median false discovery rate<5%),while the down-regulated miRNAs were has-miR-1231,has-miR-195,has-miR-143,and has-miR-145(median false discovery rate<5%).Conclusions:Significant differential expression of miRNA was found between the UC mouse and UCRCC mouse,which may be related to the onset,erosion and transfer of colorectal cancer.

Interleukin-34 deficiency aggravates development of colitis and colitis-associated cancer in mice

BACKGROUND Although expression of interleukin(IL)-34 is upregulated in active ulcerative colitis(UC),the molecular function and underlying mechanism are largely unclear.AIM To investigate the function of IL-34 in acute colitis,in a wound healing model and in colitis-associated cancer in IL-34-deficient mice.METHODS Colitis was induced by administration of dextran sodium sulfate(DSS),and carcinogenesis was induced by azoxymethane(AOM).Whether the impact of IL-34 on colitis was dependent on macrophages was validated by depletion of macrophages in a murine model.The association between IL-34 expression and epithelial proliferation was studied in patients with active UC.RESULTS IL-34 deficiency aggravated murine colitis in acute colitis and in wound healing phase.The effect of IL-34 on experimental colitis was not dependent on macrophage differentiation and polarization.IL-34-deficient mice developed more tumors than wild-type mice following administration of AOM and DSS.No significant difference was shown in degree of cellular differentiation in tumors between wild-type and IL-34-deficient mice.IL-34 was dramatically increased in the active UC patients as previously reported.More importantly,expression of IL-34 was positively correlated with epithelial cell proliferation in patients with UC.CONCLUSION IL-34 deficiency exacerbates colonic inflammation and accelerates colitis-associated carcinogenesis in mice.It might be served as a potential therapeutic target in UC.

Magnifying chromoscopy, a novel and useful technique for colonoscopy in ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disorder characterized by exacerbations and remissions. The degree of inflammation as assessed by conventional colonoscopy is a reliable parameter of disease activity. However, even when conventional colonoscopy suggests remission and normal mucosal findings, microscopic abnormalities may persist, and relapse may occur later. Patients with long-standing, extensive ulcerative colitis have an increased risk of developing colorectal cancer. Ulcerative colitis-associated colorectal cancer is characterized by an early age at onset, poorly differentiated tumor cells, mucinous carcinoma, and multiple lesions. Early detection of dysplasia and colitic cancer is thus a prerequisite for survival. A relatively new method, magnifying chromoscopy, is thought to be useful for the early detection and diagnosis of dysplasia and colitic cancer, as well as the prediction of relapse.

Lactobacillus bulgaricus inhibits colitis-associated cancer via a negative regulation of intestinal inflammation in azoxymethane/dextran sodium sulfate model

BACKGROUND Colitis-associated cancer(CAC)accounts for 2%-3%of colorectal cancer(CRC)cases preceded by inflammatory bowel diseases(IBD)such as Crohn's disease and ulcerative colitis.Intestinal microbiota has been reported to play a central role in the pathogenesis of IBD and CAC.Recently,numerous prebiotics and probiotics have being investigated as antitumor agents due to their capacity to modulate inflammatory responses.Previous studies have indicated that lactic acid bacteria could be successfully used in managing sporadic CRC,however little is known about their role in CAC.AIM To investigate the effect of the probiotic Lactobacillus bulgaricus(L.bulgaricus)during the development of an experimental model of colitis associated colon cancer(CAC).METHODS C57BL/6 mice received an intraperitoneal injection of azoxymethane(10 mg/kg),followed by three cycles of sodium dextran sulphate diluted in water(5%w/v).Probiotic group received daily L.bulgaricus.Intestinal inflammation was determined by scoring clinical signs.Cytokines levels were determined from colon and/or tumor samples by ELISA BD OptEIATM kits.The level of significance was set at P<0.05.Graphs were generated and statistical analysis performed using the software GraphPad Prism 6.0.RESULTS L.bulgaricus treatment inhibited of total tumor volume and mean size of tumors.In addition,the probiotic also attenuated the clinical signs of intestinal inflammation inducing a decrease in intestinal and tumor levels of IL-6,TNF-α,IL-17,IL-23 and IL-1β.CONCLUSION Our results suggest a potential chemopreventive effect of probiotic on CAC.L.bulgaricus regulates the inflammatory response and preventing CAC.

Increased expression and possible role of chitinase 3-like-1 in a colitis-associated carcinoma model

AIM: To investigate the possible role of chitinase 3-like-1 (CHI3L1) in the progression of colitis-associated carcinoma (CAC).

Diagnostic performance of endoscopic classifications for neoplastic lesions in patients with ulcerative colitis:A retrospective casecontrol study

BACKGROUND It is unclear whether the Japan Narrow-Band Imaging Expert Team(JNET)classification and pit pattern classification are applicable for diagnosing neoplastic lesions in patients with ulcerative colitis(UC).AIM To clarify the diagnostic performance of these classifications for neoplastic lesions in patients with UC.METHODS This study was conducted as a single-center,retrospective case-control study.Twenty-one lesions in 19 patients with UC-associated neoplasms(UCAN)and 23 lesions in 22 UC patients with sporadic neoplasms(SN),evaluated by magnifying image-enhanced endoscopy,were retrospectively and separately assessed by six endoscopists(three experts,three non-experts),using the JNET and pit pattern classifications.The results were compared with the pathological diagnoses to evaluate the diagnostic performance.Inter-and intra-observer agreements were calculated.RESULTS In this study,JNET type 2 A and pit pattern typeⅢ/Ⅳwere used as indicators of low-grade dysplasia,JNET type 2 B and pit pattern typeⅥlow irregularity were used as indicators of highgrade dysplasia to shallow submucosal invasive carcinoma,JNET type 3 and pit pattern typeⅥhigh irregularity/VN were used as indicators of deep submucosal invasive carcinoma.In the UCAN group,JNET type 2 A and pit pattern typeⅢ/Ⅳhad a low positive predictive value(PPV;50.0%and 40.0%,respectively);however,they had a high negative predictive value(NPV;94.7%and 100%,respectively).Conversely,in the SN group,JNET type 2 A and pit pattern typeⅢ/Ⅳhad a high PPV(100%for both)but a low NPV(63.6%and 77.8%,respectively).In both groups,JNET type 3 and pit pattern typeⅥ-high irregularity/VN showed high specificity.The interobserver agreement of JNET classification and pit pattern classification for UCAN among experts were 0.401 and 0.364,in the same manner for SN,0.666 and 0.597,respectively.The intra-observer agreements of JNET classification and pit pattern classification for UCAN among experts were 0.387,0.454,for SN,0.803 and 0.567,respectively.CONCLUSION The accuracy of endoscopic diagnosis using both classifications was lower for UCAN than for SN.Endoscopic diagnosis of UCAN tended to be underestimated compared with the pathological results.

Potential of new anti-cancer agents targeting the nuclear translocation signaling of HB-EGF C-terminal fragments during the development of colitis-associated cancer

In inflammatory bowel diseases (IBD) such as ulcerative colitis (UC) and Crohn’s disease (CD), the duration and severity of inflammation are responsible for the development of colorectal cancer. Inflammatory cytokines such as interleukin (IL)-8 and tumor necrotic factor (TNF)-a, which are released by epithelial and immune cells, are involved in the pathogenesis of colitis-associated cancer. Current treatments for advanced colorectal cancers focus primarily on targeting epidermal growth factor receptor (EGFR) signaling. IL-8 (a G-protein coupled receptor (GPCR) agonist), which is involved in neutrophil recruitment and activation in persistent active colitis, also promotes cleavage of theproheparin-binding epidermal growth factor—like growth factor (proHB-EGF) through a disintegrin and metalloproteinase (ADAM), so that the resulting soluble HB-EGF activates EGFR. In parallel, the carboxy-terminal fragment of proHB-EGF (HB-EGF-CTF) translocates into the inner nuclear membrane, where HB-EGF-CTF binds the nuclear promyelocytic leukemia zinc finger (PLZF) protein, resulting in the nuclear export of the PLZF transcriptional repressor and thereby affecting cell proliferation. Screening for potent chemical inhibitors of the interactions between HB-EGF-CTF and PLZF identified telmisartan (and related compounds in corporating a biphenyl tetrazole moiety) as inhibitors of cell proliferation. Here we focus on the inhibitory effects of these compounds on cell proliferation, demonstrating the potential for targeting the nuclear translocation of HB-EGF-CTF in the treatment of colitis-associated cancer.

IC5, a dithiocarbamate derivative, inhibits colon cancer cell proliferation in vitro and colitis-associated colorectal carcinogenesis in vivo

Colorectal cancer （CRC） is one of the leading causes of cancer-related deaths, and inflammatory bowel diseases and dysregulated cell proliferation play important roles in colorectal carcinogenesis. Therefore, inhibition of inflammatory signaling and cell proliferation is used as a major strategy for chemoprevention of CRC. In the present study, it was found that IC5, a dithiocarbamate derivative, could inhibit the proliferation of LoVo human colon cancer cells in a concentration-dependent manner, with an IC50 of 22 gM. The anti-proliferation effect of IC5 was accompanied by a significant cell cycle arrest in G2/M phase. Further study revealed that IC5 significantly inhibited NF-~B signaling in LoVo cells, suggesting that IC5 could inhibit inflammatory responses. We then evaluated the in vivo efficacy of IC5 to inhibit colitis-associated colorectal carcinogenesis using an azoxymethane （AOM）/dextran sodium sulfate （DSS） mouse model. AOM/DSS treatment resulted in a CRC incidence of 58.3%, while the incidences were decreased to 37.5% and 25% in mice orally administered with 50 and 100 mg/kg IC5, respectively. In addition, IC5 also reduced the plasma levels of alanine aminotransferase and asparatate aminotransferase. Taken together, these results suggested that IC5 could prevent colitis-associated colorectal carcinogenesis, and more attention should be paid to it as a cancer chemopreventive agent in further investigation.

Early detection of ulcerative colitis-associated colorectal cancer

Colitis-associated colorectal cancer(CACC)is one of the most serious complications of inflammatory bowel disease(IBD),particularly in ulcerative colitis(UC);it accounts for approximately 15%of all-causes mortality among IBD patients.Because CACC shows a worse prognosis and higher mortality than sporadic colorectal cancer,early detection is critical.Colonoscopy is primarily recommended for surveillance and several advanced endoscopic imaging techniques are emerging.In addition,recent studies have reported on attempts to develop clinically relevant biomarkers for surveillance using various biosamples,which may become high-performance screening tools in the future,so the best approach and technique for cancer surveillance in long-standing UC patients remain under debate.This review gives a comprehensive description and summary about what progress has been made in terms of early CACC detection.

The membrane-associated E3 ubiquitin ligase MARCH3 downregulates the IL-6 receptor and suppresses colitis-associated carcinogenesis

The IL-6-STAT3 axis is critically involved in inflammation-associated carcinogenesis(IAC).How this axis is regulated to modulate IAC remains unknown.Here,we show that the plasma membrane-associated E3 ubiquitin ligase MARCH3 negatively regulates STAT3 activation triggered by IL-6,as well as another IL-6 subfamily member,Oncostatin M(OSM).MARCH3 is associated with the IL-6 receptorα-chain(IL-6Rα)and its coreceptor gp130.Biochemical experiments indicated that MARCH3 mediates the polyubiquitination of IL-6Rαat K401 and gp130 at K849 following IL-6 stimulation,leading to their translocation to and degradation in lysosomes.MARCH3 deficiency increases IL-6-and OSM-triggered activation of STAT3 and induction of downstream effector genes in various cell types.MARCH3 deficiency enhances dextran sulfate sodium(DSS)-induced STAT3 activation,increases the expression of inflammatory cytokines,and exacerbates colitis,as well as azoxymethane(AOM)/DSS-induced colitis-associated cancer in mice.In addition,MARCH3 is downregulated in human colorectal cancer tissues and associated with poor survival across different cancer types.Our findings suggest that MARCH3 is a pivotal negative regulator of IL-6-induced STAT3 activation,inflammation,and inflammation-associated carcinogenesis.

DMH/DSS复合法诱导小鼠溃疡性结肠炎相关癌变的实验研究

目的探讨DMH腹腔注射结合3%DSS自由饮用法制备溃疡性结肠炎相关癌变小鼠模型。方法适应性喂养1周后,30只BALB/c小鼠按体重随机分为4组,正常组6只,模型Ⅰ组8只,模型Ⅱ组8只,模型Ⅲ组8只。除正常组外,其余3组,分别按15,20,25 mg/kg腹腔注射0.4%DMH,每周2次,继而连续自由饮用3%DSS2周为1循环;连续3个循环。第9周末将全部小鼠脱椎处死,截取全部结肠(回盲部-肛门),肉眼及光镜下观察小鼠结肠组织形态学变化。结果模型Ⅲ组全部小鼠在造模过程中死亡。肉眼见模型Ⅰ组小鼠结肠黏膜充血水肿;模型Ⅱ组小鼠结肠散在、多处息肉状隆起变化;正常组小鼠结肠黏膜未见异常。镜下见模型Ⅰ组小鼠结肠可见腺体萎缩、低级别上皮内瘤变;模型Ⅱ组小鼠结肠可见腺体萎缩、高级别上皮内瘤变,部分癌变;正常组小鼠结肠黏膜未见异常。结论 0.4%DMH 20mg/kg腹腔注射结合3%DSS自由饮用复合法,可以成功复制溃结相关癌变模型,该方法简单易行,与人溃疡性结肠炎相关癌变较为相似,值得推广应用。