Activation of lncRNA DANCR by H3K27 acetylation regulates proliferation of colorectal cancer cells.

The long noncoding DANCR functions as a tumor oncogene in many cancers, including colorectal cancer (CRC). However, the molecular mechanism of DANCR in CRC has not been explored. This study probed the function and potential mechanism by which DANCR contributes to the progression of CRC. The obtained data indicated that DANCR is overexpressed in CRC tissues and cell lines. Knockdown of DANCR hindered CRC cell proliferation, which was mediated by cyclin D1 and CDK4. Bioinformatic analysis, luciferase reporter assays and subcellular fractionation verified that DANCR directly binds to miR-508-5p. Moreover, DANCR acts as a miR-508-5p ceRNA to regulate expression of ATF1. In addition, upregulation of DANCR is attributed to H3K27 acetylation at the promoter region. In conclusion, our study confirmed that activation of lncRNA DANCR by H3K27 acetylation has an oncogenic role in CRC progression and provides a potential therapeutic target for CRC.

Mettl14-mediated m6 A modification regulates the abnormal differentiation of small intestinal epithelial stem cells in diabetic state.

Diabetes mellitus (DM) and its related complications are a global epidemic characterized by high morbidity and mortality. However, little is known about diabetic enteropathy (DE) and its the potential underlying mechanism. Intestinal epithelial stem cells (IESCs) were harvested from experimental mice, and the levels of dominant N6-methyladenosine (m6 A)-related enzyme were detected by RT-PCR, Western blotting, immunohistochemistry. The role of Mettl14 in the abnormal differentiation of intestinal epithelial cells (IECs) during DM was confirmed by knockdown experiments. RT-PCR, MeRIP, and bioinformatics analysis were carried out to confirm the downstream target of Mettl14. Through bioinformatics analysis, RT-PCR, and Western blotting, we further analyzed the differentiation-related gene in the IECs from mice with DM. In this study, the levels of Mettl14 and m6 A were higher in db/db mice than that in control mice. And abnormal differentiation of IECs in DM was associated with Mettl14 overexpression. Additionally, Mettl14 is a major determinant of IESCs identity and organoid-forming upon DM state. Mechanistically, we revealed that the candidate binding target of Mettl14 was Fzd2 mRNA and affected Fzd2 stability. Moreover, Mettl14 downregulation was observed to attenuate the abnormal differentiation of IECs through modulating Fzd2 m6A modification in DM state. Together, our results provide definitive evidence for the essential role of Mettl14 in differentiation of IESCs in DM state.

A solitary rectal juvenile polyp with chicken skin­like changes in the surrounding mucosa in an adult: A case report.

The majority of colorectal polyps in adults are adenomatous polyps, while hamartoma polyps are rare. Juvenile polyps are the most common type of polyp in children; however, they are rare in adults. Fecal calprotectin (FCP) is commonly elevated in inflammatory bowel disease and is rarely studied in juvenile rectal polyps. Reports of elevated FCP in solitary juvenile rectal polyps of adults are rare. A 57-year-old female was admitted to The Affiliated Hospital of Qingdao University (Qingdao, China) for treatment due to intermittent stool with mucus and blood. Colonoscopy revealed a solitary polyp in the rectum with a diameter of ~2.0 cm, a short and wide subpedicle, with congested and swollen mucosa on the surface and chicken skin-like changes in the surrounding mucosa. The patient had no family history of colorectal polyps or cancer. Endoscopic submucosal dissection was used to remove the polyp. Histopathological examination indicated that the polyp was a juvenile polyp and no signs of malignancy were found. The present case report describes details on this case of an adult patient with a solitary juvenile rectal polyp with chicken skin-like changes in the surrounding mucosa and high FCP.

[Retracted] Long noncoding RNA UCID sponges miR­152­3p to promote colorectal cancer cell migration and invasion via the Wnt/ß­catenin signaling pathway.

Following the publication of the above paper, it was drawn to the Editor's attention by a concerned reader that there appeared to be matching data panels comparing between the Transwell invasion and migration assays shown in Figs. 2C and 5C; moreover, one of the data panels shown in Fig. 2D had previously appeared in a paper written largely by different authors (the author 'T­D Shan' was held in common) at different research institutes in the journal Oncotarget in 2016 [Shan T­D, Xu, J­H, Yu T, Li J­Y, Zhao L­N, Ouyang H, Luo S, Lu X­J, Huang C­Z, Lan Q­S et al: Knockdown of linc­POU3F3 suppresses the proliferation, apoptosis, and migration resistance of colorectal cancer. Oncotarget 7: 961­975, 2016]. Finally, an independent investigation of these data in the Editorial Office revealed that, in addition to the data shared between Figs. 2 and 5, there were overlapping data panels both within Fig. 5C and within the wound healing assay data shown in Fig. 3B. Owing to the fact that the contentious data in the above article had already been published prior to its submission to Oncology Reports, and given the number of cases of overlapping data panels both within and between figures in the artce itself, the Editor has decided that this paper should be retracted from the Journal. After having been in contact with the authors, they did not agree with the decision to retract the paper. The Editor apologizes to the readership for any inconvenience caused. [Oncology Reports 44: 1194­1295, 2020; DOI: 10.3892/or.2020.7670].

The lncRNA Tincr Regulates the Abnormal Differentiation of Intestinal Epithelial Stem Cells in the Diabetic State Via the miR-668-3p/Klf3 Axis.

BACKGROUND: Diabetes mellitus (DM) is among the most common chronic diseases, and diabetic enteropathy (DE), which is a complication caused by DM, is a serious health condition. Long noncoding RNAs (lncRNAs) are regulators of DE progression. OBJECTIVE: However, the mechanisms of action of multiple lncRNAs involved in DE remain poorly understood. METHODS: Reverse transcription-quantitative PCR (RT-qPCR) and in situ hybridization were used to analyze terminal differentiation-induced lncRNA (Tincr) expression in intestinal epithelial cells (IECs) in the DM state. Microarray analysis, bioinformatics analysis, and luciferase reporter assays were used to identify the genes targeted by Tincr. The role of miR-668-3p was then explored by up- and down-regulating its expression in vitro and in vivo. RESULTS: In this study, we observed that the level of lncRNA Tincr was increased in IECs in the DM state. More importantly, Tincr was associated with abnormal intestinal epithelial stem cell (IESC) differentiation in DM. Our mechanistic study demonstrated that Tincr is a major marker of Lgr5+ stem cells in DM. In addition, we investigated whether Tincr directly targets miR-668-3p and whether miR-668-3p targets Klf3. Our findings showed that Tincr sponged miR-668-3p, which attenuated abnormal IESC differentiation in DM by regulating Klf3 expression. CONCLUSION: This study presents evidence of an essential role for Tincr in IESC differentiation in DM.

Effect of endoscopic resection of gastrointestinal stromal tumors in the stomach under double-channel gastroscopy: A retrospective observational study.

We aimed to investigate the safety and efficacy of endoscopic resection for the treatment of gastric gastrointestinal stromal tumors (GISTs) under single-channel gastroscopy and double-channel gastroscopy. We identified 154 patients with GISTs of the stomach who underwent endoscopic resection and were retrospectively analyzed at our hospital between May 2016 and March 2020, including 49 patients by single-channel gastroscopy and 105 patients by double-channel gastroscopy. We observed the clinical efficacy, complications, and safety of endoscopic resection of gastric GISTs, and the data were evaluated retrospectively. All patients underwent endoscopic resection successfully, without conversion to open surgery. In the single-channel gastroscopy group, 7 patients had lesions in the gastric cardia, 17 in the gastric fundus, 20 in the gastric corpus, and 5 in the gastric antrum. In the double-channel gastroscopy group, 13 patients had lesions in the gastric cardia, 34 in the gastric fundus, 46 in the gastric body, 10 in the gastric antrum, 1 in the pylorus, and 1 in the gastric angular incisure. The double-channel gastroscopy group had a shorter operation time than the single-channel gastroscopy group (59.9 ± 34.9 minutes vs 74.8 ± 26.7 minutes; P = .009 and P < .01, respectively), while they also had a lower perforation rate than the single-channel gastroscopy group (34.3% vs 51.0%; P = .048 and P < .05, respectively). No residual or recurrent lesions were discovered in any patients by gastroscopy reexamination. Both single-channel gastroscopy and double-channel gastroscopy can provide safe, effective, feasible endoscopic resection. However, double-channel gastroscopy has some distinct advantages in endoscopic resection.

Rspo3 regulates the abnormal differentiation of small intestinal epithelial cells in diabetic state.

BACKGROUND: The complications caused by diabetes mellitus (DM) are the focus of clinical treatment. However, little is known about diabetic enteropathy (DE) and its potential underlying mechanism. METHODS: Intestinal epithelial cells (IECs) and intestinal epithelial stem cells (IESCs) were harvested from BKS.Cg-Dock7m+/+Leprdb/JNju (DM) mice, and the expression of R-Spondin 3 (Rspo3) was detected by RT-qPCR, Western blotting, immunohistochemistry, and immunofluorescence. The role of Rspo3 in the abnormal differentiation of IECs during DM was confirmed by knockdown experiments. Through miRNA expression profiling, bioinformatics analysis, and RT-qPCR, we further analyzed the differentiation-related miRNAs in the IECs from mice with DM. RESULTS: Abnormal differentiation of IECs was observed in the mice with DM. The expression of Rspo3 was upregulated in the IECs from the mice with DM. This phenomenon was associated with Rspo3 overexpression. Additionally, Rspo3 is a major determinant of Lgr5+ stem cell identity in the diabetic state. Microarray analysis, bioinformatics analysis, and luciferase reporter assays revealed that microRNA (miR)-380-5p directly targeted Rspo3. Moreover, miR-380-5p upregulation was observed to attenuate the abnormal differentiation of IECs by regulating Rspo3 expression. CONCLUSIONS: Together, our results provide definitive evidence of the essential role of Rspo3 in the differentiation of IECs in DM.

Long intergenic noncoding RNA 00665 promotes proliferation and inhibits apoptosis in colorectal cancer by regulating miR-126-5p.

Long intergenic noncoding RNAs (lincRNAs) regulate a series of biological processes, and their anomalous expression plays critical roles in the progression of multiple malignancies, including colorectal cancer (CRC). Although many studies have reported the oncogenic function of LINC00665 in multiple cancers, few studies have explored its role in CRC. The aim of this study was to assess the effect of LINC00665 on the malignant behaviors of CRC and explore the underlying regulatory mechanism of LINC00665. LINC00665 was significantly upregulated in CRC. A loss-of-function assay revealed that LINC00665 downregulation inhibited the proliferation and promoted the apoptosis of CRC cells, which was mediated by cyclin D1, CDK4, caspase-9 and caspase-3. Through mechanistic exploration, we found that miR-126-5p directly bound to LINC00665. Moreover, LINC00665 and miR-126-5p both regulated PAK2 and FZD3 expression. Mechanistically, miR-126-5p was predicted and further verified as a target of both PAK2 and FZD3. These findings demonstrate that LINC00665 might play an important pro-proliferative and antiapoptotic role in CRC and might be a potential biomarker and a new therapeutic target for CRC.

Long intergenic noncoding RNA 00908 promotes proliferation and inhibits apoptosis of colorectal cancer cells by regulating KLF5 expression.

Long intergenic noncoding RNAs (lincRNAs) play a vital role in the occurrence and progression of cancer. The mechanism of lincRNAs in colorectal cancer (CRC) has not been fully elucidated. In this context, an integrated comparative long noncoding RNA (lncRNA) microarray technology was used to determine the expression profile of lncRNAs in CRC. The roles of LINC00908 are unclear. We found that LINC00908 was significantly upregulated in CRC. Inhibition of LINC00908 resulted in reduced cell proliferation and G1 cell cycle arrest, which was mediated by cyclin D1, cyclin-dependent kinase 4, and phosphorylated retinoblastoma. Moreover, inhibition of LINC00908-induced apoptosis through the intrinsic apoptosis signaling pathway, as shown by the activation of caspase-9 and caspase-3. Mechanistically, miR-143-3p directly bound to LINC00908. miR-143-3p expression was negatively correlated with LINC00908 expression in CRC tissue. Functional experiments revealed opposing roles for miR-143-3p and LINC00908, suggesting that LINC00908 negatively regulates miR-143-3p. Mechanistically, miR-143-3p directly targets LINC00908. The KLF5 inhibitor ML264 affected proliferation and apoptosis, indicating that LINC00908 may act as a competing endogenous RNA to facilitate the expression of the miR-143-3p target gene KLF5. Thus, LINC00908 has an important proliferative and antiapoptotic role in CRC by regulating the cell cycle and intrinsic apoptosis. LINC00908 could be a potential biomarker and a new therapeutic target for CRC.

Silencing long non-coding RNA CASC9 inhibits colorectal cancer cell proliferation by acting as a competing endogenous RNA of miR-576-5p to regulate AKT3.

Increasing studies have shown that long non-coding RNAs (lncRNAs) are regarded as important regulators in the occurrence and development of colorectal cancer (CRC). Although lncRNA CASC9 has been studied in CRC, the detailed regulatory mechanism of CASC9 in CRC is still unclear. In this study, we found that CASC9 was significantly upregulated in CRC tissues and cell lines compared to normal controls and that aberrant expression was associated with the tumor-node-metastasis (TNM) stage of CRC. Functionally, CASC9 depletion efficiently inhibited the proliferation of CRC cells and induced cell apoptosis in vitro. Mechanistically, CASC9 was mainly enriched in the cytoplasm of CRC cells and interacted directly with miR-576-5p. Downregulation of miR-576-5p reversed the inhibitory effect of CASC9 siRNA on CRC cell progression. Furthermore, AKT3 has been identified as a downstream target of miR-576-5p. Spearman's correlation analysis revealed that AKT3 was negatively correlated with miR-576-5p but positively correlated with CASC9. Downregulation of miR-576-5p restored the effect of CASC9 silencing on AKT3 expression. Therefore, silencing CASC9 could downregulate the expression of AKT3 by reducing the competitive binding of CASC9 to miR-576-5p, thus suppressing CRC cell proliferation and promoting cell apoptosis. In summary, we identified CASC9 as an oncogenic lncRNA in CRC and defined the CASC9/miR-576-5p/AKT3 axis, which might be considered a potential therapeutic target for CRC patients, as a novel molecular mechanism implicated in the proliferation and apoptosis of CRC.

Long noncoding RNA UCID sponges miR­152­3p to promote colorectal cancer cell migration and invasion via the Wnt/ß­catenin signaling pathway.

Research has shown that long noncoding RNAs (lncRNAs) play significant roles in colorectal cancer (CRC). However, the role of lnc­UCID (lncRNA upregulating CDK6 by interacting with DHX9) in CRC remains largely unknown. In the present study, analyses revealed that lnc­UCID was markedly upregulated in CRC compared with that in normal specimens. Functional experiments showed that the depletion of lnc­UCID inhibited CRC cell invasion and migration significantly, while overexpression of lnc­UCID had the opposite effect. A candidate target of lnc­UCID, microRNA miR­152­3p, was identified using bioinformatic analysis. Moreover, in CRC tissue, we noted an inverse correlation between miR­152­3p and lnc­UCID expression levels. Overexpression and knockdown experiments revealed opposing roles for miR­152­3p and lnc­UCID, suggesting that lnc­UCID negatively regulates miR­152­3p. Luciferase reporter assays demonstrated that miR­152­3p directly targets lnc­UCID. The results suggest that lnc­UCID acts as an endogenous miRNA sponge, competing for miR­152­3p binding and thereby regulating the miRNA's targets. Overall, we propose that the lnc­UCID/miR­152­3p/Wnt/ß­catenin signaling axis represents a novel mechanism that explains the migration and invasion of CRC.

Downregulation of lncRNA MALAT1 suppresses abnormal proliferation of small intestinal epithelial stem cells through miR­129­5p expression in diabetic mice.

The problems caused by diabetes mellitus (DM) and its related complications are gaining increasing attention. In our previous study, the abnormal proliferation of small intestinal epithelial cells (IECs) were observed in diabetic mice. However, little is known regarding the potential underlying mechanism. In the present study, the abnormal proliferation of IECs in DM and the marked upregulation of metastasis associated lung adenocarcinoma transcript 1 (MALAT1) was observed. Additionally, knockdown of MALAT1 significantly reduced abnormal IESC proliferation in DM mice. Bioinformatics analysis and luciferase reporter assays revealed that microRNA (miR)­129­5p was directly targeted by MALAT1. Moreover, the results of the bioinformatics prediction and luciferase assays demonstrated that MALAT1 directly interacted with SRY­box 9 (SOX9). Furthermore, MALAT1 silencing was observed to attenuate the abnormal proliferation of IESCs through the SOX9­mediated WNT/ß­catenin signaling pathway. Knockdown of MALAT1 downregulated SOX9 expression by binding to miR­129­5p, thereby inhibiting the abnormal proliferation of IESCs via the WNT/ß­catenin signaling pathway.

Knockdown of lncRNA H19 inhibits abnormal differentiation of small intestinal epithelial cells in diabetic mice.

Diabetes mellitus (DM) comprises a group of metabolic diseases characterized by insulin deficiency or resistance and hyperglycemia. We previously reported the presence of abnormal differentiation of small intestinal epithelial cells (IECs) in diabetic mice, but the exact mechanism of this phenomenon has not been thoroughly elucidated to date. In this study, we found that H19 was markedly upregulated in IECs of DM mice. H19 knockdown significantly inhibited abnormal differentiation of IECs in DM mice. Bioinformatics analysis identified miR-141-3p as a candidate for H19. Based on luciferase reporter assays, we found that miR-141-3p directly targeted H19. Luciferase reporter assays also showed that miR-141-3p could directly target ß-catenin. Furthermore, H19 might act as an endogenous "sponge" by competing for miR-141-3p binding to regulate miRNA targets in vitro and in vivo. In summary, our findings provide the first evidence supporting the role of H19 in IECs of DM mice, and miR-141-3p targets not only protein-coding genes but also the lncRNA H19.

The lncRNA ZEB1-AS1 sponges miR-181a-5p to promote colorectal cancer cell proliferation by regulating Wnt/ß-catenin signaling.

Long noncoding RNAs (lncRNAs) are important regulators of the biological functions and underlying molecular mechanisms of colorectal cancer (CRC). However, the role of the lncRNA ZEB1-AS1 in CRC is not thoroughly understood. In this study, we found that ZEB1-AS1 was markedly upregulated in CRC. ZEB1-AS1 knockdown significantly suppressed CRC cell proliferation and induced apoptosis, whereas enhanced expression of ZEB1-AS1 had the opposite effect. Bioinformatics analysis identified miR-181a-5p as a candidate target of ZEB1-AS1. Moreover, we found an inverse correlation between ZEB1-AS1 and miR-181a-5p expression in CRC tissue. Inhibition of miR-181a-5p significantly upregulated ZEB1-AS1, whereas overexpression of miR-181a-5p had the opposite effect, suggesting that ZEB1-AS1 is negatively regulated by miR-181a-5p. Using luciferase reporter and RIP assays, we found that miR-181a-5p directly targets ZEB1-AS1. Importantly, ZEB1-AS1 may act as an endogenous 'sponge' to regulate miRNA targets by competing for miR-181a-5p binding. In summary, our findings provide the evidence supporting the role of ZEB1-AS1 as an oncogene in CRC. Our study also demonstrates that miR-181a-5p targets not only protein-coding genes but also the lncRNA ZEB1-AS1.

Wnt and Nodal signaling simultaneously induces definitive endoderm differentiation of mouse embryonic stem cells.

Induced differentiation of definitive endoderm (DE) from embryonic stem cells (ESCs) has been the recent focus of studies investigating regeneration and transplantation of organs of the digestive system. Poor cell survival is the most important challenge to DE differentiation from ESCs. This study aimed to optimize culture conditions to promote the differentiation of mouse ESCs into DE, and to investigate the roles of the Wnt and Nodal signaling pathways in the DE differentiation. The mouse ESCs were treated with or without leukemia inhibitory factor, Wnt3a and Activin A alone or together, and examined the DE differentiation by the DE marker CXCR4 and the ESC marker Oct4. The result showed the optimal induction of differentiation was achieved in cells simultaneously treated with Wnt3a and Activin A. Induction of CXCR4 was also earlier when there was simultaneous activation of Wnt and Nodal signaling compared to the groups treated with only Wnt3a or Activin A alone. These findings provide the basis for the induced differentiation of ESCs for the generation of functional, mature cells of gastrointestinal lineage, which can be potentially used for cell replacement therapy, disease modeling, as well as drug discovery studies.

Association of Bactericidal Dysfunction of Paneth Cells in Streptozocin-Induced Diabetic Mice with Insulin Deficiency.

BACKGROUND Type 1 diabetes mellitus (T1DM) is associated with increased risks of enteric infection. Paneth cells constitute the first line of the gut defense. Little is known about the impact of T1DM on the bactericidal function of intestinal Paneth cells. MATERIAL AND METHODS A T1DM mouse model was induced by intraperitoneal injection of streptozocin. The analysis of intestinal microbiota and the mucosal bactericidal assay were conducted to evaluate intestinal innate defense. Numbers of Paneth cells and their expression of related antimicrobial peptides were analyzed. Expression of total insulin receptor (IR) mRNA and relative levels of IR-A/IR-B were analyzed. The primary mouse small intestinal crypt culture was used to analyze the effect of insulin and glucose on the expression of related antimicrobial peptides of Paneth cells. RESULTS In T1DM mice, bacterial loads were increased and there was an alteration in the composition of the intestinal microflora. Exogenous bacteria had better survival in the small bowel of the T1DM mice. The expression of Paneth cell-derived antimicrobial peptides was significantly decreased in the T1DM mice, although the number of Paneth cells was increased. Relative levels of IR-A/IR-B in Paneth cells of diabetic mice were elevated, but the total IR mRNA did not change. Insulin treatment restored the expression of antimicrobial peptides and normalized the microbiota in the gut of T1DM mice. Subsequently, in vitro culture assay demonstrated that insulin rather than glucose was essential for the optimal expression of Paneth cell-derived antimicrobial peptides. CONCLUSIONS The bactericidal function of intestinal Paneth cells was impaired in STZ-induced diabetic mice, resulting in the altered intestinal flora, and insulin was essential for the optimal expression of Paneth cell-derived antimicrobial peptides.

Overexpression of miR-429 impairs intestinal barrier function in diabetic mice by down-regulating occludin expression.

Diabetes mellitus (DM) is a group of metabolic diseases characterised by insulin deficiency/resistance and hyperglycaemia. We previously reported the presence of an impaired tight junction and decreased expression of occludin (Ocln) and zonula occludens-1 (ZO-1) in the intestinal epithelial cells (IECs) of type 1 DM mice, but the exact mechanism remains unclear. In this study, we investigated the role of microRNAs (miRNAs) in impairing the tight junction in IECs of DM mice. Using an integrated comparative miRNA microarray, miR-429 was found to be up-regulated in IECs of type 1 DM mice. Then, miR-429 was confirmed to directly target the 3'-UTR of Ocln, although it did not target ZO-1. Moreover, miR-429 down-regulated the Ocln expression in IEC-6 cells in vitro. Finally, exogenous agomiRNA-429 was shown to down-regulate Ocln and induce intestinal barrier dysfunction in normal mice, while exogenous antagomiRNA-429 up-regulated Ocln in vivo and improved intestinal barrier function in DM mice. In conclusion, increased miR-429 could down-regulate the expression of Ocln by targeting the Ocln 3'-UTR, which impaired intestinal barrier function in DM mice.

MEK/ERK pathway activation by insulin receptor isoform alteration is associated with the abnormal proliferation and differentiation of intestinal epithelial cells in diabetic mice.

In previous studies, we have reported the abnormal proliferation and differentiation of intestinal epithelial cells (IECs) in diabetes mellitus (DM) mice. The insulin receptor (IR) and its downstream mitogen-activated protein kinase kinase (MAPKK also known as MEK)/extracellular-regulated protein kinase (ERK) pathway is a classic pathway associated with cell proliferation and differentiation. The purpose of the present study is to investigate the role of the MEK/ERK pathway in abnormal proliferation and differentiation of IECs in DM mice. DM mouse models were induced by intraperitoneal injection of streptozotocin. The expression levels of the IR and its isoforms in IECs of DM mice and in IEC-6 cells were investigated. To ensure that the downstream pathways were monitored, QPCR and Western blotting were performed to detect the expression levels of MEK1/2, ERK1/2, PI3K, and Akt. Moreover, siRNA for IR-A and U0126, a specific inhibitor of MEK, were used to further investigate the relationship between the IR/MEK/ERK pathway and abnormal proliferation and differentiation of IECs in DM mice. In DM mice, excessive proliferation, disturbed differentiation, and a high ratio of IR-A/IR-B were detected in IECs. The expression levels of MEK1, MEK2, and ERK1/2 and their phosphorylated proteins in DM mice were significantly higher than those in the control group (P < 0.05), which could be offset by using siRNA for IR-A. The abnormal proliferation and differentiation of IECs in DM mice were normalized after the in vivo administration of U0126. The abnormal proliferation and differentiation of IECs in DM mice are associated with high IR-A/IR-B ratio and increased IR/MEK/ERK pathway activity.