Differential Expression in the Tumor Microenvironment of mRNAs Closely Associated with Colorectal Cancer Metastasis.

BACKGROUND: Metastasis of colorectal cancer (CRC) is a major cause of CRC-related mortality. However, the detailed molecular mechanism of CRC metastasis remains unknown. A recent study showed that the tumor microenvironment, which includes cancer cells and the surrounding stromal cells, plays a major role in tumor invasion and metastasis. Identification of altered messenger RNA (mRNA) expression in the tumor microenvironment is essential to elucidation of the mechanisms responsible for tumor progression. This study investigated the mRNA expression of genes closely associated with metastatic CRC compared with non-metastatic CRC. METHODS: The samples examined were divided into cancer tissue and isolated cancer stromal tissue. The study examined altered mRNA expression in the cancer tissues using The Cancer Genome Atlas (TCGA) (377cases) and in 17 stromal tissues obtained from our laboratory via stromal isolation using an array-based analysis. In addition, 259 patients with CRC were enrolled to identify the association of the candidate markers identified with the prognosis of patients with stage 2 or 3 CRC. The study examined the enriched pathways identified by gene set enrichment analysis (GSEA) based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) module in both the TCGA dataset and isolated stromal tissue. RESULTS: As a result, whereas tenascin-C, secreted phosphoprotein 1 and laminin were expressed in metastatic CRC cells, olfactory receptors (ORs) 11H1 and OR11H4 were expressed in stromal tissue cells isolated from metastatic CRC cases. Finally, upregulated expression of tenascin-C and OR11H4 was correlated with the outcome for CRC patients. CONCLUSION: The authors suggest that upregulated expression levels of tenascin-C and OR11H1 play an important role in CRC progression.

Comprehensive Analysis of microRNA Expression During the Progression of Colorectal Tumors.

BACKGROUND: No effective early diagnostic biomarkers are available for colorectal cancer (CRC). Therefore, we sought to identify new biomarkers that could identify CRC from progression as a pre-cancerous lesion to its invasive form. Recent studies have shown that microRNAs (miRs) are associated with the onset of cancer invasion and progression. AIMS: We hypothesized that the identification of miRs associated with CRC might be useful to detect this disease at early stages. METHODS: We conducted an integrated analysis of 79 isolated colorectal tumor glands, including adenomas, intramucosal cancers, and invasive CRCs that showed a microsatellite stable phenotype using GeneChip miRNA 4.0 microarray assays. The colorectal tumors we examined were divided into 2 cohorts (42 in the first cohort and 37 in the second cohort). RESULTS: First, cluster analysis was performed to stratify expression patterns of multiple miRs that were pooled according to the following criteria: fold change in expression (< -2.0 or > 2.0), p < 0.05, and mature miRs. As a result, the expression patterns of pooled miRs were subdivided into 3 subgroups that were correlated with tumor grade. Each subgroup was characterized by specific miRs. In addition, we found that specific miRs, including miR-140-3p and miR-378i, were closely associated with cancer invasion. Finally, we analyzed paired dysregulated miRs between adenomatous and cancerous components present within the same tumor. DISCUSSION: We showed that several miRs were dysregulated during progression from adenoma to intramucosal cancer. Specific miRs may have key roles in progression from intramucosal tumor to invasive CRC.

Comprehensive analyses of microRNA and mRNA expression in colorectal serrated lesions and colorectal cancer with a microsatellite instability phenotype.

MicroRNA (miRNA) expression is dysregulated in human tumors, thereby contributing to tumorigenesis through altered expression of mRNA. Thus, identification of the relationships between miRNAs and mRNAs is important for evaluating the molecular mechanisms of tumors. In addition, elucidation of the molecular features of serrated lesions is essential in colorectal tumorigenesis. Here, we examined the relationships of miRNA and mRNA expressed in serrated lesions, including 26 sessile serrated lesions (SSLs), 12 traditional serrated adenomas (TSAs), and 11 colorectal cancers (CRCs) with a microsatellite instability (MSI) phenotype using crypt isolation. We divided the samples into the first and second cohorts for validation. Array-based expression analyses were used to evaluate miRNAs and mRNAs with opposite expression patterns in isolated tumor glands. In addition, we validated the relationships of miRNA/mRNA pairs in the second cohort using real-time polymerase chain reaction. We found that the expression of miRNA-5787 was correlated with reciprocal expression of two mRNAs, that is, SRRM2 and POLR2J3, in SSL samples. In TSA samples, two pairs of miRNAs/mRNAs showing opposite expression patterns, that is, miRNA-182-5p/ETF1 and miRNA-200b-3p/MYB, were identified. Ultimately, three pairs of miRNAs/mRNAs with opposite expression patterns, including miRNA-222-3p/SLC26A3, miRNA-6753-3p/FABP1, and miRNA-222-3p/OLFM4, were retained in CRC with an MSI phenotype. Finally, we performed transfection with an miR-222-3p mimic to confirm the expression of SLC26A3 and OLFM4; the results showed that ectopic expression of miR-222-3p moderately suppressed OLFM4 and downregulated SLC26A3 to some extent. Overall, our results provided basic insights into the evaluation of colorectal tumorigenesis of serrated lesions and CRC with an MSI phenotype.

Cribriform-type adenocarcinoma of the colorectum: comprehensive molecular analyses of a distinctive histologic subtype of colorectal cancer.

Colorectal adenocarcinoma (CRA) is characterized by marked heterogeneity and may be composed of an admixture of various histologic patterns, including well-formed gland and cribriform types. Although tumors displaying a prominent or predominant cribriform feature are frequently found in CRA, this type may contain specific histologic variants with a characteristic molecular alteration. We investigated the molecular features of 51 primary CRAs with a predominant cribriform histology using array-based analyses [somatic copy number alterations (SCNAs); mRNA expression]. Mutations (TP53, KRAS, PIK3CA and BRAF) and DNA methylation status were also analyzed. The crypt isolation method was used to obtain isolated tumor glands of each type separately. All patients were classified by their CRA histologic subtype into two groups: well-formed gland and cribriform. Next, we performed cluster analysis to stratify SCNA and mRNA expression patterns between the two subtypes. Two distinctive subgroups were stratified based on patterns of SCNA and mRNA expression and were correlated with each histologic subtype. The cribriform type was characterized by a high frequency of SCNA compared with that of the well-formed gland type and was closely associated with the expression of specific mRNAs. In addition, the frequency of KRAS mutation was significantly higher in the cribriform type than in the well-formed gland type. Finally, there was no difference in DNA methylation status between the two subtypes. Overall, these data suggest that the cribriform type provides important insights into colorectal carcinogenesis, suggesting specific potential histologic implications based on the molecular profile.

Risk factors for short-term re-bleeding in patients with colonic diverticular bleeding: a multicenter retrospective study.

BACKGROUND AND AIM: Few studies have evaluated risk factors for short-term re-bleeding in patients with colonic diverticular bleeding (CDB). We aimed to reveal risk factors for re-bleeding within a month in patients with CDB. METHODS: We retrospectively analyzed clinical course of patients with CDB diagnosed at 10 institutions between 2015 and 2019. Risk factors for re-bleeding within a month were assessed by Cox proportional hazards models. RESULTS: Among 370 patients, 173 (47%) patients had been under the use of antithrombotic agents (ATs) and 34 (9%) experienced re-bleeding within a month. Multivariate analysis revealed that the use of ATs was an independent risk factor for re-bleeding within a month (HR 2.38, 95% CI 1.10-5.50, p = .028). Furthermore, use of multiple ATs and continuation of ATs were found to be independent risk factors for re-bleeding within a month (HR 3.88, 95% CI 1.49-10.00, p = .007 and HR 3.30, 95% CI 1.23-8.63, p = .019, respectively). Two of 370 patients, who discontinued ATs, developed thromboembolic event. CONCLUSIONS: Use of ATs was an independent risk factor for short-term re-bleeding within a month in patients with CDB. This was especially the case for the use of multiple ATs and continuation of ATs. However, discontinuation of ATs may increase the thromboembolic events those patients.

Protective effect of proton pump inhibitors and potassium competitive acid blockers against post-gastric endoscopic submucosal dissection bleeding: a single-center, propensity score-matched analysis.

OBJECTIVES: Both potassium-competitive acid blockers (P-CABs) and proton pump inhibitors (PPIs) are known to be protective against bleeding after gastric endoscopic dissection (ESD) for early gastric cancers. The aim was to compare the effect of PPI and P-CAB treatment against bleeding after gastric ESD. MATERIALS AND METHODS: This was a single-center, retrospective analysis. Among 541 patients who underwent gastric ESD during the period from 2014 to 2019, we recruited subjects who were treated with PPIs (intravenous lansoprazole followed by oral esomeprazole) or a P-CAB before and after ESD. The incidence of post-ESD bleeding was compared between treatment groups. The risks associated with post-ESD bleeding were examined by univariate and multivariate analyses after propensity score-matching. RESULTS: The overall incidence of post-ESD bleeding was not significantly different between patients treated with PPIs (n = 362) and those treated with a P-CAB (n = 156) (3.0% vs 2.6%, respectively; p = .77). Even after propensity score matching (n = 153 in each group), the incidence was not significantly different between groups (2.6% vs 2.6%, respectively; p = 1.00). A multivariate analysis revealed that antithrombotic therapy (OR 4.85, 95% CI 1.14-20.57) was an independent factor associated with post-ESD bleeding. CONCLUSIONS: The incidence of post gastric ESD bleeding is not different between patients treated with PPI and patients treated with P-CAB. Antithrombotic therapy is an independent risk factor associated with post-ESD bleeding.

Resectability of underwater endoscopic mucosal resection for duodenal tumor: A single-center, retrospective pilot study.

BACKGROUND AND AIM: Underwater endoscopic mucosal resection (U-EMR) has been attracting much attention as treatment for patients with nonampullary duodenal epithelial tumors (NADETs). We aim to compare treatment outcomes, including submucosal resectability, between patients undergoing U-EMR and conventional endoscopic mucosal resection (C-EMR) for NADET. METHODS: We conducted a retrospective review of 38 patients with NADET treated by U-EMR or C-EMR. In the resected specimens, we measured the horizontal length, the vertical distance from the muscularis mucosa to the margin at the deepest site, and the overall submucosal area. The submucosal index (SMI) was defined as the overall submucosal area divided by the largest horizontal length. These values and other treatment outcomes were compared between NADETs resected by U-EMR and C-EMR. RESULTS: The median size of lesions was 7 mm with a range of 3-13 mm. Although the incidence of adverse events and the rates of en bloc and R0 resection were not different in the two groups, the median procedure time was significantly shorter in the U-EMR group (11 min vs 13 min; P = 0.045). The median submucosal depth at the deepest site (1.22 mm vs 1.08 mm; P = 0.38) and the median SMI (0.44 vs 0.41; P = 0.42) were not different between groups. CONCLUSIONS: The resectability between NADETs treated by U-EMR and C-EMR was comparable. These results, together with the shorter procedure time required for U-EMR, suggest that U-EMR may have the potential to be the first choice for small to medium-sized NADET.

A case of undifferentiated pleomorphic rectal sarcoma occurring after radiation exposure.

A 72 year-old man was referred to our hospital for a detailed examination of a recurrent rectal polyp. He had past histories of surgery and radiation therapy for prostate cancer at the age of 66 and endoscopic excision of a rectal polyp at the age of 70. Colonoscopy revealed a semi-pedunculated lesion surrounded by friable mucosa, which was positive under positron-emission tomography-computed tomography. Histopathological examination of the endoscopically excised polyp revealed proliferation of atypical cells, characterized by strong pleomorphic or spindle morphology, which was immunohistochemically compatible with undifferentiated pleomorphic sarcoma. We diagnosed this case as sarcoma presumably associated with radiation proctitis.

Genome-wide analysis of colorectal cancer based on gene-based somatic copy number alterations during neoplastic progression within the same tumor.

BACKGROUND: The objective of this study was to elucidate the association between neoplastic progression and somatic copy number alterations (SCNAs) occurring within the same colorectal cancer (CRC) tumor. METHODS: We investigated SCNAs to identify the progression from a high-grade intramucosal lesion (HGIL) to an invasive front lesion (IFL), via an invasive submucosal lesion (ISL), within the same tumor using a crypt isolation method combined with a SNP array. Immunohistochemistry was also performed. RESULTS: We identified 51 amplified genes that potentially promote progression from HGIL to ISL and 6 amplified genes involved in the progression from ISL to IFL. Of the 51 genes involved in HGIL to ISL progression, TORC1, MSLN, and STUB1, which are closely associated with CRC, were identified as candidate markers of submucosal invasion. However, no candidate genes were identified among the six genes associated with ISL to IFL progression. In addition, the number of total SCNAs and the number of gains were correlated with cancer progression (from HGIL to IFL). Finally, immunohistochemistry revealed higher expression of TORC1, MSLN, and STUB1 in ISL than in HGIL. CONCLUSIONS: These results suggest that specific SCNAs are required for acquisition of invasive ability in CRC, and the affected genes are potential markers of invasion.

Appropriate leucine-rich α-2 glycoprotein cut-off value for Japanese patients with ulcerative colitis.

BACKGROUND: It has been suggested that serum leucine-rich α-2 glycoprotein (LRG) could be a novel monitoring biomarker for the assessment of disease activity in inflammatory bowel disease. In particular, the relationship between LRG levels and the endoscopically assessed activity of ulcerative colitis (UC) has become a matter of interest. AIM: To clarify appropriate LRG cut-off values for the prediction of endoscopic and histologic remission in Japanese patients with UC. METHODS: This was a cross-sectional, single-center, observational study of Japanese patients with UC. Among 213 patients with UC, in whom LRG was measured from September 2020 to February 2022, we recruited 30 patients for whom a total colonoscopy and measurements of LRG and C-reactive protein (CRP) were performed on the same day. We retrospectively analyzed correlations between the LRG and CRP levels and endoscopic indices, including the Mayo endoscopic subscore and UC endoscopic index of severity. RESULTS: Correlations between the LRG values and the Mayo endoscopic subscore or UC endoscopic index of severity were significant (r = 0.754, P < 0.0001; r = 0.778, P < 0.0001, respectively). There were also significant correlations between CRP levels and Mayo endoscopic subscore or UC endoscopic index of severity (r = 0.599, P = 0.0005; r = 0.563, P = 0.0012, respectively), although the correlation coefficients were higher for LRG. The LRG cut-off value for predicting endoscopic remission was 13.4 µg/mL for a Mayo endoscopic subscore of 0 [area under the curve (AUC): 0.871; 95% confidence interval (CI): 0.744-0.998], and 13.4 µg/mL for an UC endoscopic index of severity of 0 or 1 (AUC: 0.904; 95%CI: 0.792-1.000). CONCLUSION: LRG may be a surrogate marker for endoscopic activity in UC, with a cut-off value of around 13.4 µg/mL for endoscopically inactive disease.

Genome-wide analysis of mRNA expression identified the involvement of trefoil factor 1 in the development of sessile serrated lesions.

Precursor lesions that progress into colorectal cancer (CRC) could be largely classified into sessile serrated lesions (SSLs), traditional serrated adenoma (TSA), and tubular adenoma (TA). We aimed to determine whether high expression of trefoil factor 1 (TFF1) is closely associated with serrated lesions, particularly SSLs. The samples were divided into the first (12 SSLs, 5 TSAs, and 15 TAs) and second cohorts (15 SSLs, 9 TSAs, and 15 TAs). First, we investigated TFF1 expression in isolated gland samples using array-based and reverse-transcription PCR. Second, we performed immunohistochemical analysis of TFF1 expression in paraffin-embedded tissues obtained from SSL, TSA, TA, and hyperplastic polyp (HP) samples. In addition, we compared TFF1 mRNA levels between SSLs and HPs. TFF1 expression was significantly higher in SSLs than in TSA and TA in both cohorts. Additionally, immunohistochemical staining of TFF1 in the HP, SSL, TSA, and TA samples revealed significant differences in the immunohistochemical scores of TFF1 among the four types of lesions (higher expression in SSLs than in the other three lesions). Finally, there were significant differences in TFF1 mRNA expression levels between SSLs and HPs in paraffin-embedded tissues. However, there was considerable overlap in the immunohistochemical scores and expression levels of TFF1 transcripts between SSLs and HPs. The current findings may help elucidate the molecular mechanisms involved in serrated lesion development. In addition, we suggest that despite the limited practical application, upregulation of TFF1 transcripts may help differentiate SSLs from other lesions.

The mucin phenotype does not affect the endoscopic resection outcome of non-ampullary duodenal epithelial tumors.

Background and study aims Some studies have reported an association between clinicopathological features and mucin phenotypes of non-ampullary duodenal epithelial tumors (NADETs). However, the association between clinical outcomes of endoscopic resection (ER) and mucin phenotypes has not been elucidated. The aim of this retrospective study was to analyze clinical outcomes of ER of NADETs with reference to mucin phenotypes. Patients and methods We retrospectively evaluated the clinical outcomes of ER for NADETs performed from 2006 to 2019 and compared clinicopathological characteristics, ER procedures, and outcomes, including adverse events (AEs) among tumors classified by mucin phenotype. Mucin phenotypes were classified as gastric, gastrointestinal, and intestinal based on immunohistochemical examination. Grade of dysplasia was determined according to the Vienna classification (VCL). Results The proportion of VCL 4/5 was higher in the gastric type (50 %) compared with that in the gastrointestinal (39.1 %, P  = 0.009) and intestinal types (5.4 %, P  = 0.008), respectively. With no statistical difference in tumor size and ER method among the three groups, no significant difference was observed for ER outcomes, i. e., en bloc and R0 resection rates. In the gastrointestinal and intestinal types, AEs occurred in four cases treated with ESD, but none developed in the gastric type. Conclusions This study suggests that the mucin phenotype does not affect resection outcome. However, considering high malignant potential and tendency for low AE rates, the gastric type NADETs may be more appropriate for proactive ER than the others.

Role of barium enema examination for the diagnosis of submucosal invasion depth in T1 colorectal cancers.

BACKGROUND: The indication for endoscopic resection for submucosally invasive colorectal cancer (T1-CRC) depends on the preoperative diagnosis of invasion depth. The aim of this investigation was to evaluate the association between barium enema examination (BE) profile views and depth of submucosal (SM) invasion in CRCs. METHODS: We reviewed the radiographic and endoscopic findings of 145 T1-CRCs diagnosed from 2008 to 2019. We measured the widths of horizontal and vertical rigidity under a BE profile view corresponding to CRC and compared the values with SM invasion depth. Horizontal rigidity was defined as the horizontal length and vertical rigidity as the vertical width of the barium defect corresponding to each target lesion. The most appropriate cut-off values for predicting SM invasion ≥1.8 mm were calculated by receiver operating characteristic curve analysis. RESULTS: Values of horizontal rigidity (r = 0.626, P < 0.05) and vertical rigidity (r = 0.482, P < 0.05) correlated significantly with SM invasion depth. The most appropriate cut-off values for the prediction of SM invasion depth ≥ 1.8 mm were 4.5 mm for horizontal rigidity, with an accuracy of 80.7%; and 0.7 mm for vertical rigidity, with an accuracy of 77.9%. The prevalence of lympho-vascular invasion was significantly different when those cut-off values were applied (43.2% vs. 17.5% for horizontal rigidity, P < 0.005). CONCLUSIONS: In T1-CRC, values of horizontal and vertical rigidities under a BE profile view were correlated with SM invasion depth. While the accuracy of the rigidities for the prediction of SM invasion depth ≥ 1.8 mm was not high, horizontal rigidity may be predictive of lympho-vascular invasion, thus aiding in therapeutic decision-making.

Eosinophilic esophagitis with a severe stenosis: report of a Japanese case.

A 49 years old male, who had had postprandial dysphagia during the preceding 10 years, was referred to our hospital. Esophagogastroduodenoscopy (EGD) revealed longitudinal furrows and concentric rings in the mid to lower esophagus and stenosis in the lower esophagus. Histologic findings from esophageal biopsies showed eosinophilic infiltration (> 15 per high-power field). Under a diagnosis of eosinophilic esophagitis, an endoscopic bougie was performed, which resulted in symptomatic relief. Follow-up EGD revealed that the stenosis had improved, but histologic findings of eosinophilic esophagitis were remaining. Our case suggests that although rare, esophageal stenosis occurs in Japanese patients with EoE, and that the complication may be a consequence of prolonged disease. Other risks and the appropriate treatment for the prevention of stenosis need to be elucidated further.

Loss of color by afterimage masking.

When two images, one depicting colored disks and the other depicting colored windmill patterns, are displayed in succession, the color of the windmills is perceptually replaced by black. The illusion is striking. Experiments confirmed (1) that the luminance contrast between the target patterns and the background must be large and (2) that the disks and windmills must be static on the retina and in register. The illusion is weakened when the windmills and disks have different colors.