Yoshikazu Hirata

BCL6 degradation caused by the interaction with the C-terminus of pro-HB-EGF induces cyclin D2 expression in gastric cancers

BCL6 is a transcriptional repressor that has important functions in lymphocyte differentiation and lymphomagenesis, but there have been no reports of BCL6 expression in gastric cancers. In the present study, we investigated the BCL6 function in gastric cancers. Treatment with TPA resulted in BCL6 degradation and cyclin D2 upregulation. This phenomenon was inhibited by the suppression of the nuclear translocation of HB-EGF-CTF (C-terminal fragment of pro-HB-EGF). The HB-EGF-CTF nuclear translocation leads to the interaction of BCL6 with HB-EGF-CTF and the nuclear export of BCL6, and after that BCL6 degradation was mediated by ubiquitin/proteasome pathway. Real-time RT–PCR and siRNA targeting BCL6 revealed that BCL6 suppresses cyclin D2 expression. Our data indicate that BCL6 interacts with nuclear-translocated HB-EGF-CTF and that the nuclear export and degradation of BCL6 induces cyclin D2 upregulation. We performed immunohistochemical analyses of BCL6, HB-EGF and cyclin D2 in human gastric cancers. The inverse correlation between BCL6 and cyclin D2 was also found in HB-EGF-positive human gastric cancers. BCL6 degradation caused by the HB-EGF-CTF also might induce cyclin D2 expression in human gastric cancers. Inhibition of HB-EGF-CTF nuclear translocation and maintenance of BCL6 function are important for the regulation of gastric cancer progression.

Incidence of gastrointestinal bleeding in patients with cardiovascular disease: buffered aspirin versus enteric-coated aspirin

Abstract Objective. Aspirin-induced enteropathy is increasing, but whether the type of aspirin affects the gastrointestinal (GI) bleeding, especially small intestine, is unclear. The incidence of GI bleeding for buffered aspirin and enteric-coated aspirin was evaluated in patients receiving long-term low-dose aspirin (LDA) for cardiovascular (CV) diseases. Methods. This retrospective cohort study assessed overt GI bleeding, decreased hemoglobin levels suspecting small bowel blood loss, and CV death in patients taking LDA for more than 1 year (LDA group) and in patients not taking LDA (control group). The LDA group was divided into two subgroups, patients taking either buffered aspirin (buffered subgroup) or enteric-coated aspirin (enteric subgroup), and their outcomes were compared. Results. A total of 1402 patients (LDA group 701, control group 701; median follow-up duration 1778 ± 747 days) were assessed. The incidences of overt GI bleeding and decreased hemoglobin were 3.9% and 1.4% in LDA group, respectively, significantly higher than the control group (p < 0.01; p < 0.01). In the LDA group, 3% died during the follow-up period. Ten (3.7%) in the buffered subgroup (n = 267) and 17 (3.9%) in the enteric subgroup (n = 434) developed GI bleeding (p = 0.92). One (0.3%) in the buffered subgroup and nine (2%) in the enteric subgroup developed decreased hemoglobin (p = 0.06, log-rank test). Conclusions. The type of aspirin does not affect the incidence of overt GI bleeding and decreased hemoglobin, but enteric-coated aspirin may be associated with an increased incidence of decreased hemoglobin.

TGFβ induces proHB-EGF shedding and EGFR transactivation through ADAM activation in gastric cancer cells

BACKGROUND AND AIMS Transforming growth factor-beta (TGFβ) is known to potently inhibit cell growth. Loss of responsiveness to TGFβ inhibition on cell growth is a hallmark of many types of cancer, yet its mechanism is not fully understood. Membrane-anchored heparin-binding EGF-like growth factor (proHB-EGF) ectodomain is cleaved by a disintegrin and metalloproteinase (ADAM) members and is implicated in epidermal growth factor receptor (EGFR) transactivation. Recently, nuclear translocation of the C-terminal fragment (CTF) of pro-HB-EGF was found to induce cell growth. We investigated the association between TGFβ and HB-EGF signal transduction via ADAM activation. MATERIALS AND METHODS The CCK-8 assay in two gastric cancer cell lines was used to determine the effect for cell growth by TGFβ. The effect of two ADAM inhibitors was also evaluated. Induction of EGFR phosphorylation by TGFβ was analyzed and the effect of the ADAM inhibitors was also examined. Nuclear translocation of HB-EGF-CTF by shedding through ADAM activated by TGFβ was also analyzed. EGFR transactivation, HB-EGF-CTF nuclear translocation, and cell growth were examined under the condition of ADAM17 knockdown. RESULT TGFβ-induced EGFR phosphorylation of which ADAM inhibitors were able to inhibit. TGFβ induced shedding of proHB-EGF allowing HB-EGF-CTF to translocate to the nucleus. ADAM inhibitors blocked this nuclear translocation. TGFβ enhanced gastric cancer cell growth and ADAM inhibitors suppressed this effect. EGFR phosphorylation, HB-EGF-CTF nuclear translocation, and cell growth were suppressed in ADAM17 knockdown cells. CONCLUSION HB-EGF-CTF nuclear translocation and EGFR transactivation from proHB-EGF shedding mediated by ADAM17 activated by TGFβ might be an important pathway of gastric cancer cell proliferation by TGFβ.

Multicenter, prospective trial of white-light imaging alone versus white-light imaging followed by magnifying endoscopy with narrow-band imaging for the real-time imaging and diagnosis of invasion depth in superficial esophageal squamous cell carcinoma.

BACKGROUND Magnifying endoscopy with narrow-band imaging (ME-NBI) has been used to estimate the invasion depth of superficial esophageal squamous cell carcinoma (SESCC), but the real diagnostic power of ME-NBI remains unclear because of few prospective studies. OBJECTIVES To evaluate whether ME-NBI adds additional information to white-light imaging (WLI) for the diagnosis of invasion depth of SESCC. DESIGN Multicenter, prospective trial using real-time imaging and diagnosis. SETTING Seven Japanese institutions. PATIENTS Fifty-five patients with SESCC were enrolled from June 2011 to October 2013, and the results for 49 lesions were analyzed. INTERVENTIONS Patients underwent primary WLI followed by ME-NBI, and reports of primary WLI (WLI alone) were completed before secondary ME-NBI (WLI followed by ME-NBI). To standardize diagnosis among examiners, this trial was started after achievement of a mean κ value≥.6 among 11 participating endoscopists. MAIN OUTCOME MEASUREMENTS Diagnosis of invasion depth by each tool was divided into cancer limited to the epithelium and the lamina propria mucosa and cancer invading beyond the muscularis mucosae (≥T1a-MM) and then collated with the final pathologic diagnosis by an independent pathologist blinded to the clinical data. RESULTS The accuracy of invasion depth in WLI alone and WLI followed by ME-NBI was 71.4% and 65.3% (P=.375), respectively. Sensitivity for ≥T1a-MM was 61.1% for both groups (P=1.000), and specificity for ≥T1a-MM was 77.4% for WLI alone and 67.7% for WLI followed by ME-NBI (P=.375). LIMITATION Open-label trial. CONCLUSIONS ME-NBI showed no additional benefit to WLI for diagnosis of invasion depth of SESCC. (University Hospital Network Clinical Trials Registry number: UMIN000005632.).

Magnifying Chromoendoscopy and Endoscopic Ultrasonography Measure Invasion Depth of Early Stage Colorectal Cancer With Equal Accuracy on the Basis of a Prospective Trial

BACKGROUND & AIMS Magnifying chromoendoscopy (MC) and endoscopic ultrasonography (EUS) are used to estimate the depth of colorectal cancer (CRC) invasion, but it is not clear which procedure is more accurate. We performed a prospective study to compare MC and EUS. METHODS A total of 70 patients with an early stage flat CRC lesion were enrolled at 6 institutions in Japan and randomly assigned to groups assessed by MC followed by EUS or EUS followed by MC. Results from MC and EUS measurements of 66 lesions were included in the final analysis. The invasion depth of each lesion was measured by each procedure and categorized as mucosal to slight submucosal (depth <1000 μm) or deep submucosal (depth ≥ 1000 μm); measurements were compared with the final diagnosis on the basis of the pathology analysis. All participating examiners achieved a mean κ value ≥ 0.6 for both MC and EUS before this trial. RESULTS MC and EUS each measured the depth of lesion invasion with 71.2% accuracy (correctly for 47 of 66 lesions). MC identified lesions with deep submucosal invasion with 74.2% sensitivity and 68.6% specificity, whereas EUS identified them with 67.7% sensitivity and 74.3% specificity. The differences between MC and EUS measurements did not differ significantly. However, MC required significantly shorter observation time than EUS (361.7 ± 164.5 seconds vs 451.2 ± 209.4 seconds, P = .002). CONCLUSIONS MC and EUS are equally accurate in estimating the invasion depth of early stage CRC lesions. However, neither procedure has sufficient diagnostic accuracy to be used as the standard. University Hospital Medical Network Clinical Trials Registry, Number: UMIN 000005085.

Nuclear translocation of the cytoplasmic domain of HB-EGF induces gastric cancer invasion

BackgroundMembrane-anchored heparin-binding epidermal growth factor-like growth factor (proHB-EGF) yields soluble HB-EGF, which is an epidermal growth factor receptor (EGFR) ligand, and a carboxy-terminal fragment of HB-EGF (HB-EGF-CTF) after ectodomain shedding. We previously reported that HB-EGF-CTF and unshed proHB-EGF which has the cytoplasmic domain of proHB-EGF (HB-EGF-C), translocate from the plasma membrane to the nucleus and regulate cell cycle after shedding stimuli. However, the significance of nuclear exported HB-EGF-C in human gastric cancer is unclear.MethodsWe investigated the relationship between intracellular localization of HB-EGF-C and clinical outcome in 96 gastric cancer patients treated with gastrectomy. Moreover, we established stable gastric cancer cell lines overexpressing wild-type HB-EGF (wt-HB-EGF) and mutated HB-EGF (HB-EGF-mC), which prevented HB-EGF-C nuclear translocation after shedding. Cell motility between these 2 gastric cancer cell lines was investigated using a transwell invasion assay and a wound healing assay.ResultsOf the 96 gastric cancer cases, HB-EGF-C immunoreactivity was detected in both the nucleus and cytoplasm in 19 cases (19.8 %) and in the cytoplasm only in 25 cases (26.0 %). The nuclear immunoreactivity of HB-EGF-C was significantly increased in stage pT3/4 tumors compared with pT1/2 tumors (T1/2 vs. T3/4: 11.1 % vs. 36.4 %, P < 0.01). The growth of wt-HB-EGF- and HB-EGF-mC-expressing cells significantly increased compared with control cells, but the growth of HB-EGF-mC-expressing cells was significantly decreased compared with wt-HB-EGF-expressing cells. Gastric cancer cell invasion obviously increased in wt-HB-EGF-expressing cells, but invasion in HB-EGF-mC-expressing cells showed a slight increase compared with control cells. Moreover, wt-HB-EGF overexpression increased the effectiveness of wound healing, but had no significant effect in HB-EGF-mC-expressing cells.ConclusionsBoth the function of HB-EGF as an EGFR ligand and a novel signal for HB-EGF-C nuclear translocation induce gastric cancer growth, whereas HB-EGF-C nuclear translocation independently plays a critical role in gastric cancer invasion. The present study demonstrated that HB-EGF-C nuclear translocation might be crucial in gastric cancer invasion. HB-EGF-C nuclear translocation may offer a prognostic marker and a new molecular target for gastric cancer therapy.

A complicated case of tacrolimus-induced rapid remission after cesarean section in the early third trimester for refractory severe ulcerative colitis flaring in the initial period of gestation.

A 36-year-old woman who had been diagnosed with ulcerative colitis at the age of 17 years was referred to our hospital because of severe abdominal pain and repeated bloody diarrhea that persisted during pregnancy despite combination therapy with high-dose corticosteroids and weekly granulocyte and monocyte adsorptive apheresis (GMA). She underwent combination therapy consisting of high-dose corticosteroids, intensive GMA (two sessions per week) and vancomycin, which was used to eradicate Clostridium difficile, under total parenteral nutrition control until the estimated weight of her fetus reached 1,000 g. This combination therapy was partially successful, resulting in almost complete disappearance of abdominal pain and a marked decrease in stool frequency. However bloody diarrhea persisted and the patient developed anemia and hypoalbuminemia and was unable to prolong her gestation time. Cesarean section was conducted at 28 weeks of gestation without any congenital abnormalities or neurological defects. Oral administration of tacrolimus was begun 7 days after cesarean section, which was followed by rapid induction of remission. Corticosteroids were then gradually tapered off. Tacrolimus is one therapeutic option after cesarean section in pregnant patients who do not respond well to GMA and high-dose corticosteroids for persistent active ulcerative colitis.

Correlation between long-term outcome and steroid therapy in type 1 autoimmune pancreatitis: relapse, malignancy and side effect of steroid

Abstract Objectives. Autoimmune pancreatitis (AIP) responds well to corticosteroid therapy (CST), and CST is essential to induce remission. However, the correlation between long-term outcome and CST has not been evaluated. We aimed to clarify the correlation between long-term outcome of AIP and CST. Material and methods. We retrospectively evaluated relapse, risk of malignancy and side effects of CST by focusing on the correlation with CST in 84 patients with type 1 AIP. Results. The incidence of relapse was 23.8%. The frequency of relapse after CST administration was significantly lower in patients taking CST for >6 months than in those who did not (22% versus 67%; p = 0.036). The incidence of malignancy was 10.7%. The standardized incidence ratio of malignancy was 2.14 [95% confidence interval 0.74–3.54]. There were no significant correlations between development of malignancy and CST. The incidences of total and serious side effects due to CST were 75% and 19.1%, respectively. Relapse was the only significant independent predictive risk factor for serious side effects in a multivariate analysis (odds ratio 4.065; 95% confidence interval 1.125–14.706; p = 0.032). The cumulative dose of corticosteroid was significantly higher in patients with serious side effects than in those without (12,645 mg versus 7322 mg; p = 0.041). Conclusions. CST reduces relapse of AIP. However, CST causes serious side effects, particularly in relapsing patients. Alternative maintenance therapy to prevent relapse is needed.

Combination chemotherapy with cisplatin and gemcitabine in malignant peritoneal mesothelioma

Malignant peritoneal mesothelioma is a rare neoplasm with a rapidly fatal course. The response of this disease to treatment is poor because it tends to be advanced at diagnosis and tends to have inherent resistance to chemotherapeutic treatment. We describe three patients with malignant peritoneal mesothelioma who received combination chemotherapy with cisplatin and gemcitabine. After a histopathological diagnosis of epithelial-type malignant peritoneal mesothelioma, all patients underwent systemic chemotherapy because of the advanced disease stage. Moreover, one patient would have been at high risk of cardiac events, because of congenital heart malformation if complete surgical resection had been performed. This chemotherapy achieved a partial response in two patients, but had no effect in one. Combination chemotherapy with cisplatin and gemcitabine may prove to be one of the recommended treatments for patients with malignant peritoneal mesothelioma in the near future.

Efficacy of Contrast-enhanced Computed Tomography for the Treatment Strategy of Colonic Diverticular Bleeding.

OBJECTIVE Diverticular bleeding is the most common cause of acute lower gastrointestinal bleeding, and its incidence has recently increased. However, the treatment strategy of diverticular bleeding has not yet been established. The aim of the study was to investigate the efficacy of contrast-enhanced computed tomography (CECT) to determine the indication for urgent colonoscopy to achieve hemostasis. METHODS A total of 124 patients diagnosed with diverticular bleeding between 2012 and 2013 in our hospital were analyzed. The clinical behavior, factors related to detecting bleeding diverticula, and risk factors for early rebleeding of diverticular bleeding were evaluated. RESULTS Clinical behavior: Bleeding diverticula were identified in 23 of 124 (19%) patients and most of them (16/23; 70%) were located in the ascending colon. Hemostasis was achieved in all 23 cases, however, six (26%) developed early rebleeding. Factors for detecting bleeding diverticula: In patients in whom extravasation was detected using CECT, the endoscopic detection rate of bleeding diverticula was 60% (12/20), while bleeding diverticula were detected in only 31% (11/35) of patients in whom extravasation was not detected using CECT (p<0.05). The interval between the first hematochezia and colonoscopy in which the bleeding point was detected by colonoscopy (median 23.5 hours) was shorter than that in which bleeding diverticula were not detected (median 43.6 hours) (p<0.01). Risk factors for short term rebleeding: Using a univariate analysis, atherosclerotic comorbidity, anti-inflammatory drugs including low-dose aspirin, antithrombotic agents, vital signs on admission, hemoglobin level on hospitalization, and extravasation on CECT were not found to be significant risk factors. CONCLUSION The finding of extravasation on CECT is the most important factor for identifying and treating bleeding diverticula by colonoscopy. In such cases, urgent colonoscopy is recommended.