MLCK-mediated intestinal permeability promotes immune activation and visceral hypersensitivity in PI-IBS mice

BACKGROUND

Alterations in intestinal permeability regulated by tight junctions (TJs) are associated with immune activation and visceral hypersensitivity in irritable bowel syndrome (IBS). Myosin light chain kinase (MLCK) is an important mediator of epithelial TJ. The aim of this study is to investigate the role of MLCK in the pathogenesis of IBS using a post infectious IBS (PI-IBS) mouse model.

METHODS

Trichinella spiralis-infected PI-IBS mouse model was used. Urine lactulose/mannitol ratio was measured to assess intestinal epithelial permeability. Western blotting was used to evaluate intestinal TJ protein (zonula occludens-1) and MLCK-associated protein expressions. Immune profile was assessed by measuring Th (T helper) 1/Th2 cytokine expression. Visceral sensitivity was determined by abdominal withdrawal reflex in response to colorectal distension.

RESULTS

Eight weeks after inoculation with T. spiralis, PI-IBS mice developed decreased pain and volume thresholds during colorectal distention, increased urine lactulose/mannitol ratio, elevated colonic Th1/Th2 cytokine ratio, and decreased zonula occludens-1 expression compared to the control mice. MLCK expression was dramatically elevated in the colonic mucosa of PI-IBS mice compared to the control mice, alongside increased pMLC/MLC and decreased MLCP expression. Administration of MLCK inhibitor and TJ blocker both reversed the increased intestinal permeability, visceral hypersensitivity, and Th1-dominant immune profile in PI-IBS mice.

CONCLUSION

MLCK is a pivotal step in inducing increased intestinal permeability promoting low-grade intestinal immune activation and visceral hypersensitivity in PI-IBS mice. MLCK inhibitor may provide a potential therapeutic option in the treatment of IBS.

Altered Intestinal Microbiota with Increased Abundance of Prevotella Is Associated with High Risk of Diarrhea-Predominant Irritable Bowel Syndrome

Alterations in gut microbiota are postulated to be an etiologic factor in the pathogenesis of irritable bowel syndrome (IBS). To determine whether IBS patients in China exhibited differences in their gut microbial composition, fecal samples were collected from diarrhea-predominant IBS (IBS-D) and healthy controls and evaluated by 16S ribosomal RNA gene sequence and quantitative real-time PCR. A mouse model of postinfectious IBS (PI-IBS) was established to determine whether the altered gut microbiota was associated with increased visceral hypersensitivity. The results indicated that there were significant differences in the bacterial community profiles between IBS-D patients and healthy controls. Prevotella was more abundant in fecal samples from IBS-D patients compared with healthy controls (p < 0.05). Meanwhile, there were significant reductions in the quantity of Bacteroides, Bifidobacteria, and Lactobacillus in IBS-D patients compared with healthy controls (p < 0.05). Animal models similarly showed an increased abundance of Prevotella in fecal samples compared with control mice (p < 0.05). Finally, after the PI-IBS mice were cohoused with control mice, both the relative abundance of Prevotella and visceral hypersensitivity of PI-IBS mice were decreased. In conclusion, the altered intestinal microbiota is associated with increased visceral hypersensitivity and enterotype enriched with Prevotella may be positively associated with high risk of IBS-D.

Transcriptome profiling to identify key mediators of granulosa cell proliferation upon FSH stimulation in the goose (Anser cygnoides)

1. The low reproductive performance of geese has seriously hampered the development of the industry. Reproductive performance, particularly the egg laying rate mainly depends on the development of the follicle. Previous studies have shown that follicle-stimulating hormone (FSH) plays an important role in the process of follicular development, but the exact underlying mechanism remains unclear. 2. This study showed that FSH stimulated granulosa cell proliferation in a dose-dependent manner. The effect of FSH treatment on granulosa cell proliferation was greatest at a dose of 100 mIU/ml FSH for 24 h. 3. Secondly, the effect of different concentrations of FSH on goose granulosa cell proliferation was investigated, and de novo transcriptome assembly and gene expression analysis performed using short-read sequencing technology (Illumina). High-throughput sequencing results yielded 62.61 M reads and 7.8 G base pairs from granulosa cells treated with 100 mIU/ml FSH. These reads were assembled into 65,757 unigenes (mean length: 705 bp) with an N50 of 903 bp. A total of 110 upregulated and 510 downregulated differentially expressed genes (DEGs) were identified by RNA-seq. 4. Functional analysis by gene ontology (GO) and KEGG pathway annotation indicated that hormone biosynthesis (GO:0042446), positive regulation of hormone secretion (GO:0046887), steroid biosynthesis, oxidative phosphorylation and carbon metabolism pathways were involved in FSH-mediated proliferation of goose granulosa cells. 5. After screening, a group of key responsive genes including superoxide dismutase 1, fatty acyl-CoA reductase 1, transforming growth factor-beta receptor-associated protein 1 and follistatin were tested by real-time reverse transcription PCR to confirm differential expression in granulosa cells stimulated by FSH. 6. FSH-stimulated goose granulosa cells and DEG profiling data provided comprehensive gene expression information at the transcriptional level that could promote better understanding of the molecular mechanisms underlying follicle development in response to FSH stimulation.

DNA methylation and copy number variation analyses of human embryonic stem cell-derived neuroprogenitors after low-dose decabromodiphenyl ether and/or bisphenol A exposure

The polybrominated diphenyl ether flame retardants decabromodiphenyl ether (BDE-209) and bisphenol A (BPA) are environmental contaminants that can cross the placenta and exert toxicity in the developing fetal nervous system. Copy number variants (CNVs) play a role in a number of genetic disorders and may be implicated in BDE-209/BPA teratogenicity. In this study, we found that BDE-209 and/or BPA exposure decreased neural differentiation efficiency of human embryonic stem cells (hESCs), although there was a >90% induction of neuronal progenitor cells (NPCs) from exposed hESCs. However, the mean of CNV numbers in the NPCs with BDE-209 + BPA treatment was significantly higher compared to the other groups, whereas DNA methylation was lower and DNA methyltransferase(DNMT1 and DNMT3A) expression were significantly decreased in all of the BDE-209 and/or BPA treatment groups compared with the control groups. The number of CNVs in chromosomes 3, 4, 11, 22, and X in NPCs with BDE-209 and/or BPA exposure was higher compared to the control group. In addition, CNVs in chromosomes 7, 8, 14, and 16 were stable in hESCs and hESCs-derived NPCs irrespective of BDE-209/BPA exposure, and CNVs in chromosomes 20 q11.21 and 16 p13.11 might be induced by neural differentiation. Thus, BDE-209/BPA exposure emerges as a potential source of CNVs distinct from neural differentiation by itself. BDE-209 and/or BPA exposure may cause genomic instability in cultured stem cells via reduced activity of DNA methyltransferase, suggesting a new mechanism of human embryonic neurodevelopmental toxicity caused by this class of environmental toxins.

Micro-inflammation in functional dyspepsia: A systematic review and meta-analysis

Functional dyspepsia (FD) is a gastrointestinal disorder of unknown etiology. Although micro-inflammation appears to be important in the pathogenesis, studies evaluating immune activation in FD have been inconsistent. A systematic review of literature and meta-analysis was performed to compare immunologic cell counts and cytokine levels in the mucosa and peripheral blood of individuals with FD and healthy controls. PubMed, Embase, and the Cochrane library were searched. Data on immunologic cell counts and cytokines levels among individuals with FD and control groups were extracted and compared by calculating standard mean differences (SMD). Thirty-seven studies met the inclusion criteria. Mast cell (SMD = 0.94, 95%CI 0.26-1.62, P = .007) and eosinophil counts (SMD = 0.36, 95%CI 0.06-0.68, P = .03) in the stomach were increased, among individuals with FD compared to controls. Similarly, mast cell (SMD = 0.66, 95%CI 0.20-1.13, P = 0.005) and eosinophil (SMD = 0.95, 95%CI 0.66-1.24; P < .001) counts in the duodenum were also increased in those with FD compared to controls. In a subgroup analysis, elevated eosinophil counts in the duodenum were observed in both post-prandial distress syndrome (SMD = 0.97, 95%CI 0.46-1.47, P = .0002) and epigastric pain syndrome subtypes (SMD = 1.16, 95%CI 0.48-1.83, P = .0008). No differences in mucosal intraepithelial lymphocyte, enterochromaffin cell, and neutrophil counts, as well as, peripheral interlukin-6 (IL-6) and IL-10 levels were observed among individuals with FD and controls. Micro-inflammation in the form of local immune cell infiltration, particularly eosinophils and mast cells, characterizes the pathogenesis of FD.

ERAP1/ERAP2 and RUNX3 polymorphisms are not associated with ankylosing spondylitis susceptibility in Chinese Han

Previous studies show that endoplasmic reticulum‐associated aminopeptidase (ERAP1/ERAP2) and runt‐related transcription factor 3 (RUNX3) gene polymorphisms are associated with AS (ankylosing spondylitis) in European Caucasians. However, contradictory results were reported in different Asian populations. The purpose of this study was to determine whether eleven candidate single nucleotide polymorphisms (SNPs) in ERAP1/ERAP2 and six in RUNX3 genes confer susceptibility to AS with or without acute anterior uveitis (AAU) [AS⁺AAU⁺ or AS⁺AAU^–] in Chinese Han. Therefore, a case–control association study was performed in 882 AS⁺AAU^–, 884 AS⁺AAU⁺ and 1727 healthy controls. Genotyping was performed using the iPLEXGold genotyping assay. A meta‐analysis was performed to assess the association of polymorphisms of ERAP1 with AS susceptibility in Asian populations. No association was found between SNPs of ERAP1/ERAP2/RUNX3 and susceptibility of AS with or without AAU. A case–control study between patients with human leucocyte antigen HLA‐B27‐positive and healthy controls also failed to demonstrate an association of the tested SNP with AS with or without AAU. Moreover, a meta‐analysis showed that there was no association of rs30187, rs27037, rs27980, rs27434 and rs27582 in ERAP1 with AS in Chinese Han. Taken together, 17 SNPs in ERAP1/ERAP2 and RUNX3 genes did not confer disease susceptibility to AS in Chinese Han.

Effects of purified Omphalia lapidescens protein on metastasis, cell cycle, apoptosis and the JAK-STAT signaling pathway in SGC-7901 human gastric cells

Gastric cancer is one of the most common cancers globally with high rates of morbidity and mortality. Purified Omphalia lapidescens protein (pPeOp) is a protein extracted from the sclerotium of Omphalia lapidescens. The present study aimed to investigate the effects of pPeOp on the viability, migration, cell cycle progression and apoptosis of SGC-7901 cells. The expression of numerous proteins, namely matrix metallopeptidase (MMP)2, MMP9, p53, caspase-3, B-cell lymphoma (Bcl)-2, cyclin A2, cyclin B1, cyclin D1, cyclin dependent kinase (CDK)1, CDK2 and CDK4, were investigated using western blot analysis and reverse transcription-quantitative polymerase chain reaction. The results of the present study demonstrated that treating SGC-7901 cells with pPeOp markedly suppressed their migration, induced their apoptosis and arrested their progression in S phase. pPeOp also downregulated the expression of migration-associated proteins (MMP2 and MMP9) and cyclin-associated proteins (cyclin A2, cyclin B1, cyclin D1, CDK1, CDK2 and CDK4) in a dose-dependent manner. Cells treated with pPeOp significantly upregulated caspase-3 and p53 and downregulated Bcl-2. Finally, the impact of pPeOp on three key nodes of the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway were investigated and it was revealed that expression levels of JAK1, JAK2 and STAT3 were significantly downregulated following treatment. Together, the results of the present study suggested that pPeOp suppresses metastasis, arrests cell cycle, induces apoptosis and inhibits the JAK-STAT signaling pathway in SGC-7901 cells. Therefore, pPeOp may serve as a novel therapeutic agent for patients with gastric cancer.

Impact of gluten consumption in patients with functional dyspepsia: A case-control study

BACKGROUND AND AIM

Dietary factors and immune dysfunction may induce symptoms in patients with functional dyspepsia (FD). The aim of the study was to evaluate whether gluten consumption impacts symptom onset in patients with FD and to evaluate for possible histologic alterations in the duodenum of patients with FD.

METHODS

We prospectively enrolled 101 patients newly diagnosed with FD and 31 asymptomatic controls. Specific FD symptoms and gluten consumption patterns were evaluated by self-reported questionnaires. Tight junction protein (claudin-1) expression and presence of intraepithelial lymphocyte (IEL) infiltration in the bulb (D1) and second portion (D2) of the duodenum were assessed by immunohistochemistry.

RESULTS

Wheat bun consumption had higher frequency (P = 0.047) and increased average consumption (P = 0.01) scores in patients with FD compared with the control group. Of the 101 patients with FD, early satiety (P = 0.03) was associated with increased wheat bun consumption frequency score. On histologic evaluation, claudin-1 expression was decreased in D1 (0.003 ± 0.001 vs 0.012 ± 0.002, P = 0.003) and D2 (0.002 ± 0.0004 vs 0.012 ± 0.001, P < 0.001), while duodenal IEL counts were increased in D1 (15.5 ± 7.8 vs 3.1 ± 2.5, P < 0.001) and D2 (20.6 ± 7.7 vs 5.8 ± 3.4, P < 0.001) among patients with FD compared with the control group. Finally, Helicobacter pylori infection was associated with increased IELs in D1 (20.6 ± 7.0 vs 14.2 ± 7.4, P = 0.001) among patients with FD.

CONCLUSIONS

Among patients with FD, gluten-rich food may lead to symptom onset, specifically early satiety. Intestinal epithelial barrier dysfunction characterized by decreased claudin-1 expression and mucosal immune activation demonstrated by IEL infiltration may contribute to the pathogenesis of FD.

KRAS and TP53 mutations in inflammatory bowel disease-associated colorectal cancer: a meta-analysis

Although KRAS and TP53 mutations are common in both inflammatory bowel disease-associated colorectal cancer (IBD-CRC) and sporadic colorectal cancer (S-CRC), molecular events leading to carcinogenesis may be different. Previous studies comparing the frequency of KRAS and TP53 mutations in IBD-CRC and S-CRC were inconsistent. We performed a meta-analysis to compare the presence of KRAS and TP53 mutations among patients with IBD-CRC, S-CRC, and IBD without dysplasia. A total of 19 publications (482 patients with IBD-CRC, 4,222 with S-CRC, 281 with IBD without dysplasia) met the study inclusion criteria. KRAS mutation was less frequent (RR=0.71, 95%CI 0.56-0.90; P=0.004) while TP53 mutation was more common (RR=1.24, 95%CI 1.10-1.39; P<0.001) in patients with IBD-CRC compared to S-CRC. Both KRAS (RR=3.09, 95%CI 1.47-6.51; P=0.003) and TP53 (RR=2.15, 95%CI 1.07-4.31 P=0.03) mutations were more prevalent in patients with IBD-CRC compared to IBD without dysplasia. In conclusion, IBD-CRC and S-CRC appear to have biologically different molecular pathways. TP53 appears to be more important than KRAS in IBD-CRC compared to S-CRC. Our findings suggest possible roles of TP53 and KRAS as biomarkers for cancer and dysplasia screening among patients with IBD and may also provide targeted therapy in patients with IBD-CRC.

Marital status is associated with superior survival in patients with esophageal cancer: a Surveillance, Epidemiology, and End Results study

The impact of marital status on survival among patients with esophageal cancer has not been evaluated in the U.S. population in depth. The aim of the study was to investigate the impact of marital status on survival among patients diagnosed with esophageal cancer. The Surveillance, Epidemiology, and End Results (SEER) database was utilized to identify patients diagnosed with esophageal cancer between 1973 and 2013. Cox regression analysis was performed to evaluate for association between marital status on both cancer-specific and overall survival. Of the 69,139 patients with esophageal cancer, 35,863 (52%) had adenocarcinoma and 21,573 (31%) had distant SEER stage. At the time of diagnosis, 39,805 (57%) patients were married, 10,116 (15%) were single, 8,417 (12%) were divorced or separated, and 10,801 (16%) were widowed. Married patients had superior cancer-specific and overall survival compared to unmarried patients. Multivariate analysis demonstrated that single (adjusted hazard ratio (HR)=1.14, 95%CI 1.11-1.17; P<0.001), divorced or separated (HR=1.16, 95%CI 1.13-1.19; P<0.001), and widowed (HR=1.22, 95%CI 1.19-1.26; P<0.001) compared to married patients had higher risk of death from all causes. In conclusion, marital status was associated with superior survival among U.S. patients with esophageal cancer in a large population-based study.

Reduced interstitial cells of Cajal and increased intraepithelial lymphocytes are associated with development of small intestinal bacterial overgrowth in post-infectious IBS mouse model

OBJECTIVE

Intestinal dysmotility and immune activation are likely involved in the pathogenesis of small intestinal bacteria overgrowth (SIBO) in irritable bowel syndrome (IBS). We aimed at investigating the role of interstitial cells of Cajal (ICC) and intestinal inflammation in the development of SIBO using a post-infectious IBS (PI-IBS) mouse model.

MATERIALS AND METHODS

NIH mice were randomly infected with Trichinella spiralis. Visceral sensitivity and stool pattern were assessed at 8-weeks post-infection (PI). Intestinal bacteria counts from jejunum and ileum were measured by quantitative real-time PCR to evaluate the presence of SIBO. ICC density, intraepithelial lymphocytes (IELs) counts, and intestinal cytokine levels (IL1-β, IL-6, toll-like receptor-4 (TLR-4), IL-10) in the ileum were examined.

RESULTS

PI-IBS mice demonstrated increased visceral sensitivity compared with the control group. One-third of the PI-IBS mice developed SIBO (SIBO+/PI-IBS) and was more likely to have abnormal stool form compared with SIBO negative PI-IBS (SIBO-/PI-IBS) mice but without difference in visceral sensitivity. SIBO+/PI-IBS mice had decreased ICC density and increased IELs counts in the ileum compared with SIBO-/PI-IBS mice. No difference in inflammatory cytokine expression levels were detected among the groups except for increased TLR-4 in PI-IBS mice compared with the control group.

CONCLUSIONS

Development of SIBO in PI-IBS mice was associated with reduced ICC density and increased IELs counts in the ileum. Our findings support the role of intestinal dysmotility and inflammation in the pathogenesis of SIBO in IBS and may provide potential therapeutic targets.

[Analysis of maternal deaths in Shanghai from 1996 to 2015]

Objective: To analyze the trend of maternal mortality ratio (MMR) and cause of death in Shanghai from 1996 to 2015. Methods: To collect the material about the maternal death and the maternal death audit from 1996 to 2015, and to analyze the MMR, the cause of death and the result of the maternal death audit of Shanghai from 1996 to 2015 retrospectively. Results: (1) The change of MMR: the MMR in Shanghai decreased from 28.84 per 100 000 live births in 1996 to 6.66 per 100 000 live births in 2015. (2) The characteristic of maternal death: the proportion of Shanghai citizens was 27.4%(121/441) and the proportion of migrant women was 72.6%(320/441). The women with advanced maternal age was 8.2% (20/243) since 1996 to 2005, and increased to 16.7% (33/198) since 2006 to 2015. Maternal deaths during pregnancy increased from 27.6%(67/243) in the first 10 years (1996-2005) to 35.4%(70/198) in the recent 10 years (2006-2015) . The intrapartum maternal deaths was 6.2%(15/243) in the first 10 years and in the recent 10 years it was zero. The proportion of postpartum deaths in the first 10 years and in the recent 10 years were 66.3% (161/243) and 64.6%(128/198) respectively. (3) The cause of maternal death: During the recent 10 years, indirect obstetric causes [63.1%(125/198)] was more than direct obstetric causes [36.9% (73/198) ] for the first time. The death causes changed significantly. Postpartum hemorrhage remained the leading cause of maternal deaths, but the specific mortality rate (SMR) of postpartum hemorrhage decreased significantly from 7.42 per 100 000 live births in the first 10 years to 1.51 per 100 000 live births in the recent 10 years. The maternal deaths because of heart disease and cerebrovascular disease rose to the second and the forth reasons. (4) Maternal death audit: the avoidable maternal death ratio decreased from 3.66 per 100 000 live births in the first 10 years to 1.86 per 100 000 live births in the recent 10 years. Conclusions: During the past 20 years, the MMR of Shanghai decreased significantly and was close to the level of developed countries. In recent years, the causes of maternal death become more complicated. With the implementation of the second child policy, women with high risk factors increase, so government investment, policy support should be strengthened to optimize the management.

Comparison of transvaginal surgery and methotrexate/mifepristone-combined transcervical resection in the treatment of cesarean scar pregnancy

OBJECTIVE

To explore the safety and efficiency of transvaginal surgical treatment of cesarean scar pregnancy (CSP).

PATIENTS AND METHODS

A retrospective analysis of 54 CSP patients that received treatment in our hospital from October 2011 to September 2015 was performed, dividing two groups: Group A (n=34) received transvaginal cesarean scar pregnancy focus clearance surgery while Group B (n=20) received transcervical resection following methotrexate/mifepristone-combined treatment. The basic clinical findings were collected and analyzed, along with the curative effects between the two groups.

RESULTS

Differences in age (30.91 ± 4.59 years vs. 31.91 ± 5.53 years) for gravidity (2.97 ± 1.24 times vs. 2.75 ± 1.48 times), cesarean section (1.24 ± 0.43 vs. 1.20 ± 0.41), time interval from last cesarean section (56.53 ± 32.93 months vs. 58.70 ± 39.44 months), menelipsis (51.35 ± 10.90 days vs. 57.85 ± 16.62 days), pre-operative serum-hCG (27953.65 ± 37517.10 mIU/L vs. 17368.24 ± 35094.14 mIU/L), operation time (43.34 ± 12.38 min vs 40.07 ± 16.88 min), menstruation recovery time (1.23 ± 0.53 months vs. 1.55 ± 0.76 months) were not statistically significant (p > 0.05). The differences in the intraoperative blood loss (43.34 ± 12.38 ml vs. 40.07 ± 16.88 ml), average hospital stay (7.61 ± 2.47 days vs. 12.42 ± 3.64 days), time for β-hCG to return to normal (18.50 ± 8.19 mIU/L vs. 29.00 ± 12.96 mIU/L) between the two groups were statistically significant (p < 0.05). Group A was significantly lower than Group B.

CONCLUSIONS

Transvaginal surgery is an effective and relatively safe treatment option for CSP patients.

Etoposide and cisplatin versus paclitaxel and carboplatin with concurrent thoracic radiotherapy in unresectable stage III non-small cell lung cancer: a multicenter randomized phase III trial

Background

The optimal chemotherapy regimen administered currently with radiation in patients with stage III non-small cell lung cancer (NSCLC) remains unclear. A multicenter phase III trial was conducted to compare the efficacy of concurrent thoracic radiation therapy with either etoposide/cisplatin (EP) or carboplatin/paclitaxel (PC) in patients with stage III NSCLC.

Patients and methods

Patients were randomly received 60-66 Gy of thoracic radiation therapy concurrent with either etoposide 50 mg/m2 on days 1-5 and cisplatin 50 mg/m2 on days 1 and 8 every 4 weeks for two cycles (EP arm), or paclitaxel 45 mg/m2 and carboplatin (AUC 2) on day 1 weekly (PC arm). The primary end point was overall survival (OS). The study was designed with 80% power to detect a 17% superiority in 3-year OS with a type I error rate of 0.05.

Results

A total of 200 patients were randomized and 191 patients were treated (95 in the EP arm and 96 in the PC arm). With a median follow-up time of 73 months, the 3-year OS was significantly higher in the EP arm than that of the PC arm. The estimated difference was 15.0% (95% CI 2.0%-28.0%) and P value of 0.024. Median survival times were 23.3 months in the EP arm and 20.7 months in the PC arm (log-rank test P = 0.095, HR 0.76, 95%CI 0.55-1.05). The incidence of Grade ≥2 radiation pneumonitis was higher in the PC arm (33.3% versus 18.9%, P = 0.036), while the incidence of Grade ≥3 esophagitis was higher in the EP arm (20.0% versus 6.3%, P = 0.009).

Conclusion

EP might be superior to weekly PC in terms of OS in the setting of concurrent chemoradiation for unresectable stage III NSCLC.

Trial registration ID

NCT01494558.

PTPRO represses ERBB2-driven breast oncogenesis by dephosphorylation and endosomal internalization of ERBB2

The plasma membrane-associated tyrosine phosphatase PTPRO is frequently transcriptionally repressed in cancers and signifies poor prognosis of breast cancer patients. In this study, deletion of Ptpro in MMTV-Erbb2 transgenic mice dramatically shortened the mammary tumor latency and accelerated tumor growth due to loss of Ptpro within the breast cancer cells but not in surrounding tissue as confirmed by hetero-transplantation studies. Both in vitro and in vivo data demonstrated that the phosphatase activity was required for the inactivation of ERBB2 and its downstream signaling. PTPRO regulated the phosphorylation status of ERBB2 at Y1248. Co-immunoprecipitation and proximity ligation assay (Duolink) indicated that PTPRO directly physically interacted with ERBB2. Moreover, PTPRO phosphatase activity shortened the half-life of ERBB2 by increasing endocytotic degradation. PTPRO reexpression by demethylation treatment using 5-azacytidine reduced the proliferation and colony formation potential in ERBB2-positive breast cancer cells. Taken together, PTPRO inhibited ERBB2-driven breast cancer through dephosphorylation leading to dual effects of ERBB2 signaling suppression and endosomal internalization of ERBB2, Therefore, reexpression of PTPRO may be a potential therapy for ERBB2-overexpressing breast cancer.