Differential squamous cell fates elicited by NRF2 gain of function versus KEAP1 loss of function.

Clinical evidence has revealed that high-level activation of NRF2 caused by somatic mutations in NRF2 (NFE2L2) is frequently detected in esophageal squamous cell carcinoma (ESCC), whereas that caused by somatic mutations in KEAP1, a negative regulator of NRF2, is not. Here, we aspire to generate a mouse model of NRF2-activated ESCC using the cancer-derived NRF2L30F mutation and cancer driver mutant TRP53R172H. Concomitant expression of NRF2L30F and TRP53R172H results in formation of NRF2-activated ESCC-like lesions. In contrast, while squamous-cell-specific deletion of KEAP1 induces similar NRF2 hyperactivation, the loss of KEAP1 combined with expression of TRP53R172H does not elicit the formation of ESCC-like lesions. Instead, KEAP1-deleted cells disappear from the esophageal epithelium over time. These findings demonstrate that, while cellular NRF2 levels are similarly induced, NRF2 gain of function and KEAP1 loss of function elicits distinct fates of squamous cells. The NRF2L30F mutant mouse model developed here will be instrumental in elucidating the mechanistic basis leading to NRF2-activated ESCC.

The ß-TrCP-Mediated Pathway Cooperates with the Keap1-Mediated Pathway in Nrf2 Degradation In Vivo.

Nrf2 activates cytoprotective gene expression, and Nrf2 activity is regulated through at least two protein degradation pathways: the Keap1-mediated and ß-TrCP-mediated pathways. To address the relative contributions of these pathways, we generated knock-in mouse lines expressing an Nrf2SA mutant that harbored two substitution mutations of serine residues interacting with ß-TrCP. The homozygous (Nrf2SA/SA) mice grew normally, with Nrf2 levels comparable to those of wild-type (WT) mice under unstressed conditions. However, when Keap1 activity was suppressed, high levels of Nrf2 accumulated in Nrf2SA/SA macrophages compared with that in WT macrophages. We crossed Nrf2SA/SA mice with mice in which Keap1 was knocked down to two different levels. We found that the Nrf2SA/SA mutation induced higher Nrf2 activity when the Keap1 level was strongly reduced, and these mice showed severe growth retardation. However, activation and growth retardation were not evident when Keap1 was moderately suppressed. These increases in Nrf2 activity induced by the Nrf2SA mutation caused severe hyperplasia and hyperkeratosis in the esophageal epithelium but did not cause abnormalities in the other tissues/organs examined. These results indicate that the ß-TrCP-mediated pathway cooperates with the Keap1-mediated pathway to regulate Nrf2 activity, which is apparent when the Keap1-mediated pathway is profoundly suppressed.

Cellular Nrf2 Levels Determine Cell Fate during Chemical Carcinogenesis in Esophageal Epithelium.

Nrf2 is essential for cytoprotection against carcinogens, and through systemic Nrf2 knockout mice, Nrf2-deficient cells were shown to be susceptible to chemical carcinogens and prone to developing cancers. However, the oncogenic potential of Nrf2-deficient epithelial cells surrounded by normal cells in the esophagus could not be assessed by previous models, and the fate of Nrf2-deficient cells in such situations remains elusive. In this study, therefore, we generated mice that harbor almost equal levels of cells with Nrf2 deleted and those with Nrf2 intact in the basal layer of the esophageal epithelium, utilizing inducible Cre-mediated recombination of Nrf2 alleles in adults through moderate use of tamoxifen. In this mouse model, epithelial cells with Nrf2 deleted were maintained with no obvious decrease or phenotypic changes for 12 weeks under unstressed conditions. Upon exposure to the carcinogen 4-nitroquinoline-1-oxide (4NQO), the cells with Nrf2 deleted accumulated DNA damage and selectively disappeared from the epithelium, so almost all 4NQO-induced tumors originated from cells with Nrf2 intact and not from those with Nrf2 deleted. We propose that cells with Nrf2 deleted do not undergo carcinogenesis due to selective elimination upon exposure to 4NQO, indicating that cellular Nrf2 abundance and the epithelial environment determine the cell fate or oncogenic potential of esophageal epithelial cells in 4NQO-induced carcinogenesis.

A Case of Bilateral Acute Inferior Limb Ischemia in a Patient With Ulcerative Colitis.

A patient was diagnosed with ulcerative colitis (UC) in 2010. In March 2015, she had abdominal pain, diarrhea, bloody stool, and UC has relapsed. In June 2015, pain and sensory disturbance of both lower limbs appeared. Blood flow at the distal femoral artery was not confirmed with magnetic resonance angiography, and it was diagnosed as bilateral acute inferior limb ischemia. Arterial thrombolectomy with Fogarty's balloon catheter was performed and blood flow was improved. The severity of UC was moderate with Mayo score 8. Thrombosis is considered to be a complication with a high incidence in inflammatory bowel disease. Reports of arterial thrombosis are very rare. It is important to evaluate the risk of bleeding and thrombosis in active or severe cases in UC and need to do thrombotic prophylactic treatment simultaneously with UC treatment.

Endoscopic score vs blood cell indices for determining timing of immunomodulator withdrawal in quiescent ulcerative colitis.

While immunomodulators (IMs) are used as key drugs in remission maintenance treatment for ulcerative colitis (UC), there has been no evidence to date for determining monitoring methods and drug withdrawal. Therefore, we examined if a decrease in white blood cell count (WBC) and an elevation in mean cell volume (MCV) could be used as optimization indices and if mucosal healing (MH) could be a rationale for determining the time of IM withdrawal. Subjects were 89 UC patients who were using IMs and for whom clinical remission had been maintained. Those with a Rachmilewitz Clinical Activity Index score of 4 or lower and those with a Mayo endoscopic subscore (MES) of 0 or 1 were defined as MH. The remission maintenance rates of the following comparative groups were examined: an IM continuation group and an IM withdrawal group; an IM continuation group with a WBC of less than 3000 or a MCV of 100 or greater and an IM continuation group with a WBC of 3000 or greater and a MCV of 99 or lower; an IM continuation group of patients for whom MH had been achieved and an IM continuation group of patients for whom MH had not been achieved; and an IM withdrawal group with a MES of 0 and an IM withdrawal group with a MES of 1. A significantly higher remission maintenance rate was observed in the IM continuation group compared to the withdrawal group (p < 0.01). No significant difference was observed between the IM continuation group with a WBC of less than 3000 or a MCV of 100 or greater and the IM continuation group with a WBC of 3000 or greater and a MCV of 99 or lower (p = 0.08). Higher remission maintenance rates were observed in the IM continuation group of patients for whom MH had been achieved compared to the IM continuation group of patients for whom MH had not been achieved (p = 0.03). No significant difference was observed between the IM withdrawal group with MES 0 and the IM withdrawal group with MES 1. (p = 0.48). This retrospective study showed that remission maintenance could be firmly obtained by continuing IM administration in case of endoscopic MH; however, MH was not an indicator of IM withdrawal.

Safety and Efficacy of Nonanesthesiologist-Administrated Propofol during Endoscopic Submucosal Dissection of Gastric Epithelial Tumors.

OBJECTIVE: There is no consensus regarding administration of propofol for performing endoscopic submucosal dissection (ESD) in patients with comorbidities. The aim of this study was to evaluate the safety and efficacy of propofol-induced sedation administered by nonanesthesiologists during ESD of gastric cancer in patients with comorbidities classified according to the American Society of Anesthesiologists (ASA) physical status. METHODS: Five hundred and twenty-two patients who underwent ESD for gastric epithelial tumors under sedation by nonanesthesiologist-administrated propofol between April 2011 and October 2017 at Dokkyo Medical University Hospital were enrolled in this study. The patients were divided into 3 groups according to the ASA physical status classification. Hypotension, desaturation, and bradycardia were evaluated as the adverse events associated with propofol. The safety of sedation by nonanesthesiologist-administrated propofol was measured as the primary outcome. RESULTS: The patients were classified according to the ASA physical status classification: 182 with no comorbidity (ASA 1), 273 with mild comorbidity (ASA 2), and 67 with severe comorbidity (ASA 3). The median age of the patients with ASA physical status of 2/3 was higher than the median age of those with ASA physical status of 1. There was no significant difference in tumor characteristics, total amount of propofol used, or ESD procedure time, among the 3 groups. Adverse events related to propofol in the 522 patients were as follows: hypotension (systolic blood pressure < 90 mmHg) in 113 patients (21.6%), respiratory depression (SpO2 < 90%) in 265 patients (50.8%), and bradycardia (pulse rate < 50 bpm) in 39 patients (7.47%). There was no significant difference in the incidences of adverse events among the 3 groups during induction, maintenance, or recovery. No severe adverse event was reported. ASA 3 patients had a significantly longer mean length of hospital stay (8 days for ASA 1, 9 days for ASA 2, and 9 days for ASA 3, P = 0.003). However, the difference did not appear to be clinically significant. CONCLUSIONS: Sedation by nonanesthesiologist-administrated propofol during ESD is safe and effective, even for at-risk patients according to the ASA physical status classification.

Severe acute pancreatitis with inflammation extending to the scrotum.

Extension of inflammation into the scrotum is rare in acute pancreatitis. If inflammation spreads in the scrotum, it may become severe. Clinicians should be aware of this condition as a possible complication. Proactive imaging testing is recommended when complaining of cyst swelling or testicular pain.

Multicenter study of endoscopic preoperative biliary drainage for malignant hilar biliary obstruction: E-POD hilar study.

BACKGROUND AND AIM: Endoscopic nasobiliary drainage (ENBD) is often recommended in preoperative biliary drainage (PBD) for hilar malignant biliary obstruction (MBO), but endoscopic biliary stent (EBS) is also used in the clinical practice. We conducted this large-scale multicenter study to compare ENBD and EBS in this setting. METHODS: A total of 374 cases undergoing PBD including 281 ENBD and 76 EBS for hilar MBO in 29 centers were retrospectively studied. RESULTS: Extrahepatic cholangiocarcinoma (ECC) accounted for 69.8% and Bismuth-Corlette classification was III or more in 58.8% of the study population. Endoscopic PBD was technically successful in 94.6%, and adverse event rate was 21.9%. The rate of post-endoscopic retrograde cholangiopancreatography pancreatitis was 16.0%, and non-endoscopic sphincterotomy was the only risk factor (odds ratio [OR] 2.51). Preoperative re-intervention was performed in 61.5%: planned re-interventions in 48.4% and unplanned re-interventions in 31.0%. Percutaneous transhepatic biliary drainage was placed in 6.4% at the time of surgery. The risk factors for unplanned procedures were ECC (OR 2.64) and total bilirubin ≥ 10 mg/dL (OR 2.18). In surgically resected cases, prognostic factors were ECC (hazard ratio [HR] 0.57), predraiange magnetic resonance cholangiopancreatography (HR 1.62) and unplanned re-interventions (HR 1.81). EBS was not associated with increased adverse events, unplanned re-interventions, or a poor prognosis. CONCLUSIONS: Our retrospective analysis did not demonstrate the advantage of ENBD over EBS as the initial PBD for resectable hilar MBO. Although the technical success rate of endoscopic PBD was high, its re-intervention rate was not negligible, and unplanned re-intervention was associated with a poor prognosis in resected hilar MBO.

Gastric Adenocarcinoma of the Fundic Gland Type after Endoscopic Therapy for Metachronous Gastric Cancer.

A 78-year-old man underwent endoscopic submucosal dissection (ESD) for early gastric adenocarcinoma twice in 2009 and 2014. Between the procedures, he successfully completed Helicobacter pylori eradication therapy. In May 2015, upper endoscopy screening showed two elevated lesions on the gastric fundus, and en bloc resection by ESD was performed. We histopathologically diagnosed the patient to have gastric adenocarcinoma of the fundic gland type. In this case, the two lesions of gastric adenocarcinoma of the fundic gland type multifocally developed after ESD for metachronous gastric tubular adenocarcinoma. Furthermore, they appeared in the gastric fundus, where atrophy had been improved due to eradication therapy.

Clinical effectiveness of the pocket-creation method for colorectal endoscopic submucosal dissection.

BACKGROUND AND STUDY AIMS: Endoscopic submucosal dissection (ESD) is a technically advanced procedure for colorectal tumors. Hayashi et al. invented the "pocket-creation method (PCM)," and reported that Is-type lesions with fibrosis could be efficaciously and safely resected. However, only case studies have been published, and there are no previous reports on the usefulness of PCM in colorectal ESD for all lesions, as compared with the conventional method. This study aimed to evaluate the effectiveness and safety of PCM in colorectal ESD. PATIENTS AND METHODS: Ninety-six colorectal tumors were treated: 47 using the PCM and the other 49, considered the control group, using the conventional method. Therapeutic effectiveness and safety were retrospectively assessed. RESULTS: The comparison between the PCM and control groups revealed higher rates of en bloc resection (100 % vs. 88 %, P  = 0.015) and curative endoscopic resection (100 % vs. 84 %, P  = 0.0030) with PCM. There was no significant difference in perforation as an adverse event (AE) between the two groups, though perforation was observed in only 6 % of the control group and none of the PCM group. Compared with the control group, the PCM group had lower incidences of perforation and post-ESD coagulation syndrome, and both AEs were associated with excessive thermal denaturation of the muscle layer (2 % vs. 16 %, P  = 0.018). CONCLUSIONS: This study demonstrated the effectiveness and safety of ESD with PCM for colorectal tumors. Although there is a possible learning curve, PCM enables the endoscopist to safely perform ESD in most cases without encountering the difficulties associated with conventional ESD.

Multimodal Treatment of Vasoactive Intestinal Polypeptide-producing Pancreatic Neuroendocrine Tumors with Liver Metastases.

A 53-year-old man presented with diarrhoea and hypokalaemia and was diagnosed with a neuroendocrine tumour of unknown origin with multiple liver metastases. Somatostatin analogues led to a reduction in the size of the tumours and improvement of his symptoms. However, after several years, the tumours grew in size, and the patient's clinical symptoms recurred. The patient underwent transcatheter arterial embolization (TAE) of the hepatic artery to treat the liver metastases. Immediately after embolization, the symptoms disappeared. Although the patient had an unresectable vasoactive intestinal polypeptide-producing neuroendocrine tumour, the endocrine symptoms were able to be controlled with chemotherapy and TAE, resulting in a long-term survival.

Halofuginone enhances the chemo-sensitivity of cancer cells by suppressing NRF2 accumulation.

The KEAP1-NRF2 system regulates the cellular defence against oxidative and xenobiotic stresses. NRF2 is a transcription factor that activates the expression of cytoprotective genes encoding antioxidative, detoxifying and metabolic enzymes as well as transporters. Under normal conditions, KEAP1 represses NRF2 activity by degrading the NRF2 protein. When cells are exposed to stresses, KEAP1 stops promoting NRF2 degradation, and NRF2 rapidly accumulates and activates the transcription of target genes. Constitutive accumulation of NRF2 via a variety of mechanisms that disrupt KEAP1-mediated NRF2 degradation has been observed in various cancer types. Constitutive NRF2 accumulation confers cancer cells with a proliferative advantage as well as resistance to anti-cancer drugs and radiotherapies. To suppress the chemo- and radio-resistance of cancer cells caused by NRF2 accumulation, we conducted high-throughput chemical library screening for NRF2 inhibitors and identified febrifugine derivatives. We found that application of the less-toxic derivative halofuginone in a low dose range rapidly reduced NRF2 protein levels. Halofuginone induced a cellular amino acid starvation response that repressed global protein synthesis and rapidly depleted NRF2. Halofuginone treatment ameliorated the resistance of NRF2-addicted cancer cells to anti-cancer drugs both in vitro and in vivo. These results provide preclinical proof-of-concept evidence for halofuginone as an NRF2 inhibitor applicable to treatment of chemo- and radio-resistant forms of cancer.

A case report of gastric linitis plastica diagnosed by endoscopic ultrasound-guided fine needle aspiration.

RATIONALE: There is currently no consensus on the ideal method for obtaining deep tissue biopsy material of advanced gastric LP. EUS-FNA has potential as a useful diagnostic method. Thus, we report the case of a 46-year-old male with advanced gastric linitis plastica (LP) who was diagnosed using endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). PATIENT CONCERNS: The patient underwent esophagogastroduodenoscopy (EGD) because of epigastric pain at a local clinic. The gastric fold swelling was pointed out by the EGD and despite the suspected advanced gastric LP, biopsy indicated Group 1. Repeat biopsy did not suggest malignancy. The patient was referred to our institution. DIAGNOSES: Endoscopic ultrasound indicated gastric wall thickening mainly in the greater curvature of the gastric corpus. Low-level echoes were detected throughout the entire gastric wall, and gastric wall layers had been disappeared. EUS-FNA of the gastric wall indicated signet ring cell carcinoma. INTERVENTIONS: As a result of EUS - FNA, it became a policy to administer chemotherapy. In accordance with the patient's wishes, he was referred to another institution for chemotherapy. OUTCOMES: Normal biopsy did not give a definitive pathological diagnosis, and final diagnosis of LP was obtained with EUS-FNA. LESSONS: We expect that EUS-FNA can be utilized as a relatively non-invasive, highly sensitive, and specific pathological diagnostic procedure for advanced gastric LP. EUS-FNA should be considered as one way to obtain a deep tissue biopsy of advanced gastric LP.

Construction of Chiral Tri- and Tetra-Arylmethanes Bearing Quaternary Carbon Centers: Copper-Catalyzed Enantioselective Propargylation of Indoles with Propargylic Esters.

Copper-catalyzed enantioselective propargylation of indoles with propargylic esters and sequential Huisgen cycloaddition with azides lead to the construction of chiral triarylmethanes, bearing a quaternary carbon center, with high to excellent enantioselectivities. The result described herein can be used in the enantioselective preparation of a tetraarylmethane.

Unique cistrome defined as CsMBE is strictly required for Nrf2-sMaf heterodimer function in cytoprotection.

Nrf2-small Maf (sMaf) heterodimer is essential for the inducible expression of cytoprotective genes upon exposure to oxidative and xenobiotic stresses. While the Nrf2-sMaf heterodimer recognizes DNA sequences referred to as the antioxidant/electrophile responsive element (ARE/EpRE), we here define these DNA sequences collectively as CNC-sMaf binding element (CsMBE). In contrast, large and small Maf proteins are able to form homodimers that recognize the Maf recognition element (MARE). CsMBE and MARE share a conserved core sequence but they differ in the 5'-adjacent nucleotide neighboring the core. Because of the high similarity between the CsMBE and MARE sequences, it has been unclear how many target binding sites and target genes are shared by the Nrf2-sMaf heterodimers and Maf homodimers. To address this issue, we introduced a substitution mutation of alanine to tyrosine at position 502 in Nrf2, which rendered the DNA-binding domain structure of Nrf2 similar to Maf, and generated knock-in mice expressing the Nrf2(A502Y) mutant. Our chromatin immunoprecipitation-sequencing analyses showed that binding sites of Nrf2(A502Y)-sMaf were dramatically changed from CsMBE to MARE in vivo. Intriguingly, however, one-quarter of the Nrf2(A502Y)-sMaf binding sites also bound Nrf2-sMaf commonly and vice versa. RNA-sequencing analyses revealed that Nrf2(A502Y)-sMaf failed to induce expression of major cytoprotective genes upon stress stimulation, which increased the sensitivity of Nrf2(A502Y) mutant mice to acute acetaminophen toxicity. These results demonstrate that the unique cistrome defined as CsMBE is strictly required for the Nrf2-sMaf heterodimer function in cytoprotection and that the roles played by CsMBE differ sharply from those of MARE.

Amelioration of inflammation and tissue damage in sickle cell model mice by Nrf2 activation.

Sickle cell disease (SCD) is an inherited disorder caused by a point mutation in the ß-globin gene, leading to the production of abnormally shaped red blood cells. Sickle cells are prone to hemolysis and thereby release free heme into plasma, causing oxidative stress and inflammation that in turn result in damage to multiple organs. The transcription factor Nrf2 (nuclear factor erythroid 2-related factor 2) is a master regulator of the antioxidant cell-defense system. Here we show that constitutive Nrf2 activation by ablation of its negative regulator Keap1 (kelch-like ECH-associated protein 1) significantly improves symptoms in SCD model mice. SCD mice exhibit severe liver damage and lung inflammation associated with high expression levels of proinflammatory cytokines and adhesion molecules compared with normal mice. Importantly, these symptoms subsided after Nrf2 activation. Although hemolysis and stress erythropoiesis did not change substantially in the Nrf2-activated SCD mice, Nrf2 promoted the elimination of plasma heme released by sickle cells' hemolysis and thereby reduced oxidative stress and inflammation, demonstrating that Nrf2 activation reduces organ damage and segregates inflammation from prevention of hemolysis in SCD mice. Furthermore, administration of the Nrf2 inducer CDDO-Im (2-cyano-3, 12 dioxooleana-1, 9 diene-28-imidazolide) also relieved inflammation and organ failure in SCD mice. These results support the contention that Nrf2 induction may be an important means to protect organs from the pathophysiology of sickle cell-induced damage.

Comparison of the usefulness of endoscopic papillary large-balloon dilation with endoscopic sphincterotomy for large and multiple common bile duct stones.

BACKGROUND: Endoscopic sphincterotomy (EST) is currently recognized as the primary endoscopic treatment for common bile duct stones. However, it is difficult to remove multiple (≥ 3) or large (≥ 15 mm) common bile duct stones with EST alone. Recently, EST plus endoscopic papillary large-balloon dilation (EPLBD) was reported to be an effective treatment for such bile duct stones. We compared the results of EST and EST + EPLBD for multiple (≥ 3) or large (≥ 15 mm) stones that were difficult to treat using EST alone. We also compared the complication rates between the techniques. METHODS: Seventy patients with large (largest diameter, ≥ 15 mm) or ≥ 3 common bile duct stones treated in our department between April 2010 and March 2013 underwent EST + EPLBD (n = 34) or EST alone (n = 36). We compared final successful stone removal rates, rates of successful stone removal in the first session, procedure times, status of concurrent mechanical lithotripsy (ML), and complications between the EST + EPLBD and EST groups. RESULTS: The rates of final successful stone removal were similar between the two groups (EST + EPLBD: 100 % vs. EST: 89 %; p = 0.115). The rate of successful stone removal in the first session was significantly higher in the EST + EPLBD group (EST + EPLBD: 88 % vs. EST: 56 %; p = 0.03). Moreover, the procedure time was significantly shorter (EST + EPLBD: 42 min vs. EST: 67 min; p = 0.011) and the rate of ML use was significantly lower in the EST + EPLBD group (EST + EPLBD: 50 % vs. EST: 94 %; p < 0.001). Complications like pancreatitis and bleeding occurred in three patients in the EST + EPLBD group and in 10 patients in the EST group, but the differences were not statistically significant (EST + EPLBD: 9 % vs. EST: 25 %; p = 0.112). CONCLUSIONS: Our results suggest that EST + EPLBD is an effective therapy for patients with difficult-to-treat multiple or large common bile duct stones, because it requires fewer sessions and shorter operative times than EST alone.

Establishment of erythroleukemic GAK14 cells and characterization of GATA1 N-terminal domain.

GATA1 is a transcription factor essential for erythropoiesis and megakaryopoiesis. It has been found that Gata1 gene knockdown heterozygous female (Gata1(G1.05/+)) mice spontaneously develop erythroblastic leukemias. In this study, we have generated a novel Gata1 knockdown erythroblastic cell line, designated GAK14, from the leukemia cells in the Gata1(G1.05/+) mice. Although GAK14 cells maintain immature phenotype on OP9 stromal cells in the presence of erythropoietin and stem cell factor, the cells produce Gr-1-, Mac1-, B220-, CD3e- or CD49b-positive hematopoietic cells when co-cultured with DAS104-8 feeder cells. However, GAK14 cells did not produce erythroid and megakaryocytic lineages, perhaps due to the absence of GATA1. Indeed, GAK14 cells became capable of differentiating into mature erythroid cells when complemented with full-length GATA1 and co-cultured with fetal liver-derived FLS5 stromal cells. This differentiation potential was impaired when GATA1 lacking the N-terminal domain was complemented. The N-terminal domain is known to contribute to the pathogenesis of transient abnormal myelopoiesis and acute megakaryoblastic leukemia related to Down syndrome. These results thus showed that GAK14 cells will serve as a powerful tool for dissecting domain function of GATA1 and that the GATA1 N-terminal domain is essential for the erythroid differentiation of GAK14 cells.