The tumor microenvironment offers favorable conditions for tumor progression, and activated fibroblasts, known as cancer‐associated fibroblasts, play a pivotal role. TP53‐deficient cancer cells are ...known to induce strong fibroblast activation. We aimed to elucidate the oncogenic role of exosomes derived from TP53‐deficient colon cancer cells in fibroblast proliferation and tumor growth. Cancer cell‐derived exosomes (CDEs) were isolated from the conditioned media of cancer cells using a sequential ultracentrifugation method. The effects of exosomes on tumor growth were evaluated using human cell lines (TP53‐WT colon cancer, HCT116; TP53‐mutant colon cancer, HT29; and fibroblasts, CCD‐18Co and WI‐38) and an immune‐deficient nude mouse xenograft model. HCT116 (HCT116sh p53) cells deficient in TP53 accelerated cocultured fibroblast proliferation compared to TP53‐WT HCT116 (HCT116sh control) cells in vitro. Exosomes from HCT116sh p53 cells suppressed TP53 expression of fibroblasts and promoted their proliferation. Xenografts of HCT116sh p53 cells grew significantly faster than those of HCT116sh control cells in the presence of co‐injected fibroblasts, but this difference was diminished by CDE inhibition. Microarray analysis identified upregulation of several microRNAs (miR‐1249‐5p, miR‐6737‐5p, and miR‐6819‐5p) in TP53‐deficient CDEs, which were functionally proven to suppress TP53 expression in fibroblasts. Exosomes derived from TP53‐mutant HT29 cells also suppressed TP53 expression in fibroblasts and accelerated their growth. The proliferative effect of HT29 on cocultured fibroblasts was diminished by inhibition of these miRNAs in fibroblasts. Our results suggest that CDEs play a pivotal role in tumor progression by fibroblast modification. Cancer cell‐derived exosomes might, therefore, represent a novel therapeutic target in colon cancer.
Exosomes derived from cancer cells play a pivotal role in tumor progression through fibroblast modification and might represent a novel therapeutic target in colon cancer.
Background
Indigo Naturalis (IN) is used as a traditional herbal medicine for ulcerative colitis (UC). However, the mechanisms of action of IN have not been clarified. We aimed to evaluate the ...efficacy of IN for ameliorating colonic inflammation. We further investigated the mechanisms of action of IN.
Methods
Colitis severity was assessed in dextran sodium sulfate-induced colitis and trinitrobenzene sulfonic acid-induced colitis models with or without the oral administration of IN or indigo, which is a known major component of IN. Colonic lamina propria (LP) mononuclear cells isolated from IN-treated mice were analyzed with quantitative reverse transcription polymerase chain reaction (qRT-PCR) and flow cytometry. LP and splenic mononuclear cells cultured in vitro with IN or indigo were also analyzed. The role of the candidate receptor for indigo, the aryl hydrocarbon receptor (AhR), was analyzed using
Ahr
-deficient mice.
Results
Colitis severity was significantly ameliorated in the IN and indigo treatment groups compared with the control group. The mRNA expression levels of interleukin (
Il
)-
10
and
Il-22
in the LP lymphocytes were increased by IN treatment. The treatment of splenocytes with IN or indigo increased the expression of anti-inflammatory cytokines and resulted in the expansion of IL-10-producing CD4
+
T cells and IL-22-producing CD3
−
RORγt
+
cells, but not CD4
+
Foxp3
+
regulatory T cells. The amelioration of colitis by IN or indigo was abrogated in
Ahr
-deficient mice, in association with diminished regulatory cytokine production.
Conclusions
IN and indigo ameliorated murine colitis through AhR signaling activation, suggesting that AhR could be a promising therapeutic target for UC.
Deficiency of p53 in cancer cells activates the transformation of normal tissue fibroblasts into carcinoma-associated fibroblasts; this promotes tumor progression through a variety of mechanisms in ...the tumor microenvironment. The role of autophagy in carcinoma-associated fibroblasts in tumor progression has not been elucidated. We aimed to clarify the significance of autophagy in fibroblasts, focusing on the TP53 status in co-cultured human colorectal cancer cell lines (TP53-wild-type colon cancer, HCT116; TP53-mutant colon cancer, HT29; fibroblast, CCD-18Co) in vitro. Autophagy in fibroblasts was significantly suppressed in association with ACTA2, CXCL12, TGFβ1, VEGFA, FGF2, and PDGFRA mRNA levels, when co-cultured with p53-deficient HCT116
cells. Exosomes isolated from the culture media of HCT116
cells significantly suppressed autophagy in fibroblasts via inhibition of ATG2B. Exosomes derived from TP53-mutant HT29 cells also suppressed autophagy in fibroblasts. miR-4534, extracted from the exosomes of HCT116
cells, suppressed ATG2B in fibroblasts. In conclusion, a loss of p53 function in colon cancer cells promotes the activation of surrounding fibroblasts through the suppression of autophagy. Exosomal miRNAs derived from cancer cells may play a pivotal role in the suppression of autophagy.
The safety and efficacy of endoscopic submucosal dissection (ESD) for superficial esophageal neoplasms (SENs) have not been evaluated in a multicenter survey. The aim of this study was to investigate ...the clinical outcomes in a multicenter study that included municipal hospitals.
Of 312 consecutive patients with 373 esophageal lesions treated by ESD at 11 hospitals from May 2005 to December 2012, a total of 368 SENs in 307 patients were retrospectively analyzed.
The median tumor size was 18 mm (range 2 - 85 mm). The median procedure time was 90 minutes (range 12 - 450 minutes). The en bloc resection and complete resection rates were 96.7 % (95 % confidence interval CI 94.4 % - 98.1 %) and 84.5 % (95 %CI 80.5 % - 87.8 %), respectively. Perforation (including mediastinal emphysema), postoperative pneumonia, bleeding, and esophageal stricture, occurred in 5.2 % (95 %CI 3.3 % - 7.9 %), 1.6 % (95 %CI 0.7 % - 3.5 %), 0 %, and 7.1 % (95 %CI 4.9 % - 10.2 %) of patients, respectively. All of these complications were cured conservatively. No procedure-related mortality occurred. Early treatment periods (odds ratio OR = 4.04; P < 0.01) and low volume institutions (OR = 3.03; P = 0.045) were significantly independent risk factors for perforation. The circumference of the lesion was significantly associated with postoperative stricture (OR = 32.3; P < 0.01). The procedure times significantly decreased in the later period of the study (P < 0.01). Follow-up data (median 35 months; range 4 - 98 months) showed significant differences in overall survival (P = 0.03) and recurrence-free survival (P < 0.01) rates between patients with curative and noncurative resections.
Esophageal ESD has become feasible with acceptable complication risks and favorable long term outcomes.
Infectious enteritis is common in patients with inflammatory bowel disease (IBD). This case presented a young woman who underwent remission maintenance therapy for ulcerative colitis (UC). She was ...suspected of having concomitant Clostridioides difficile and Edwardsiella tarda infections. The patient's symptoms did not improve after initial antibiotic therapy; thus, the treatment strategy was modified to include an intravenous corticosteroid to treat the UC flare-up. Her symptoms significantly improved after corticosteroid administration. This is the first report of a case in which concomitant C. difficile and E. tarda infections occurred with UC flare-up.
Background Although conventional endoscopy (CE) and EUS are considered useful for predicting the invasion depth (T-staging) in early gastric cancer (EGC), no effective diagnostic strategy has been ...established. Objective To produce simple CE criteria and to elucidate an efficient diagnostic method by combining CE and EUS for accurate T-staging. Design Single-center retrospective analysis. Setting Academic university hospital. Patients Consecutive patients with EGC from April 2007 to March 2012 who underwent CE and EUS before treatment. Interventions Recorded endoscopic images were independently reviewed by 3 observers. The CE criteria for massive invasion were defined, and their utility and the additional value of EUS were assessed. Main Outcome Measurements The accuracy of CE based on the criteria and the accuracy of EUS. Results Two hundred thirty patients were enrolled: 195 with mucosal cancer or cancer in the submucosa less than 500 μm from the muscularis mucosae and 35 with invasive cancers. Multivariate analysis of the CE findings by 1 observer revealed that an irregular surface and a submucosal tumor–like marginal elevation were significantly associated with massive invasion. The simple CE criteria, consisting of those 2 features, had an overall accuracy of 73% to 82% and no significant differences in the diagnostic yield compared with EUS in all observers. CE accurately revealed mucosal cancer, and EUS efficiently salvaged the lesions that were over-diagnosed by CE. With our strategy, which involved the CE criteria and the optimal use of EUS, the comprehensive accuracy exceeded 85% in each observer. Limitations Retrospective, single-center study. Conclusions We demonstrated a practical strategy for T-staging in EGC using simple CE criteria and EUS.
The incidence of eosinophilic esophagitis (EoE) has been increasing recently. The role of regulatory T cells (Tregs) and correlations with other inflammatory cells in EoE remain unknown. We aim to ...clarify the role of Tregs and their correlations with inflammatory cells in EoE patients.
Biopsies from controls and EoE patients before and after treatments were analyzed. Eosinophil infiltration was evaluated by hematoxylin and eosin staining. Immunohistochemical staining was performed to examine infiltration of T cells, Tregs, and mast cells. Gene expressions of chemokines were evaluated by reverse transcription-quantitative polymerase chain reaction.
Tregs and mast cells were increased in the esophageal epithelial layers of EoE patients. After treatments, Tregs and mast cells were decreased when histologic remission was achieved. Infiltration of Tregs correlated significantly with numbers of eosinophils and mast cells. Filaggrin mRNA was decreased in patients with EoE before treatment and upregulated after treatment, even when histologic remission was not achieved.
Tregs were increased in esophageal epithelium of patients with EoE, and correlated with mast cell infiltration.
Microbiota alteration and IFN-γ-producing CD4+ T cell overactivation are implicated in Crohn's disease (CD) pathogenesis. However, it remains unclear how dysbiosis enhances Th1 responses, leading to ...intestinal inflammation. Here, we identified key metabolites derived from dysbiotic microbiota that induce enhanced Th1 responses and exaggerate colitis in mouse models. Patients with CD showed elevated lysophosphatidylserine (LysoPS) concentration in their feces, accompanied by a higher relative abundance of microbiota possessing a gene encoding the phospholipid-hydrolyzing enzyme phospholipase A. LysoPS induced metabolic reprogramming, thereby eliciting aberrant effector responses in both human and mouse IFN-γ-producing CD4+ T cells. Administration of LysoPS into two mouse colitis models promoted large intestinal inflammation. LysoPS-induced aggravation of colitis was impaired in mice lacking P2ry10 and P2ry10b, and their CD4+ T cells were hyporesponsive to LysoPS. Thus, our findings elaborate on the mechanism by which metabolites elevated in patients with CD harboring dysbiotic microbiota promote Th1-mediated intestinal pathology.
Although several noninvasive and easily accessible biomarkers for inflammatory bowel disease IBD are available, their sensitivity and specificity are not adequate to be used as single markers and do ...not overrule the need for endoscopic evaluation. We previously reported that serum leucine-rich alpha-2 glycoprotein LRG was a novel biomarker for rheumatoid arthritis and IBD. We herein investigated whether LRG could indicate endoscopic activity in patients with ulcerative colitis UC.
Serum LRG concentrations were determined by enzyme-linked immunosorbent assay ELISA in consecutive 129 patients with UC in two tertiary care hospitals, and associations of LRG with clinical and endoscopic activities were evaluated. Clinical activity index CAI < 6 was defined as clinical remission, and mucosal healing MH and complete mucosal healing were defined as Matts' endoscopic grades of 1 or 2 and grade of 1, respectively.
Serum LRG levels were significantly increased and correlated with clinical and endoscopic activities in patients with UC. LRG levels were associated with both clinical and endoscopic activities even in patients with normal serum C-reactive protein CRP levels. Furthermore, LRG levels were significantly lower in patients with complete MH and deep remission. Serial measurements of LRG levels in a subset of patients demonstrated that LRG was significantly elevated during the endoscopically active stage compared with that during the MH stage.
Serum LRG is a novel biomarker for detecting MH during disease course in patients with UC and a surrogate marker of endoscopic inflammation in patients with normal CRP levels.
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