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

Background

Membrane-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.

Methods

We 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.

Results

Of 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.

Conclusions

Both 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.

Promotion of DNA repair by nuclear IKKβ phosphorylation of ATM in response to genotoxic stimuli

Ataxia-telangiectasia mutated (ATM) is one of the key molecules involved in the cellular response to DNA damage. A portion of activated ATM is exported from the nucleus into the cytoplasm, where it activates the I kappa B kinase/nuclear factor kappa B (IKK/NF-κB) signaling pathway. It has been thought that activated IKKβ, which is a critical kinase for NF-κB activation, generally resides in the cytoplasm and phosphorylates cytoplasmic downstream molecules, such as IκBα. Here, we identified a new role for IKKβ during the response to DNA damage. ATM phosphorylation in response to alkylating agents consisted of two phases: the early phase (up to 3 h) and late phase (after 6 h). A portion of the activated IKKβ generated during the DNA damage response was found to translocate into the nucleus and directly phosphorylate ATM in the late phase. Furthermore, the phosphorylation of ATM by nuclear IKKβ was suggested to promote DNA repair. In parallel, activated IKKβ induced classical NF-κB activation and was involved in anti-apoptosis. Our findings define the function of IKKβ during the response to DNA damage, which promotes cell survival and DNA repair, and maintains cellular homeostasis.

The relationship between antitumor effects and relative dose intensity of S-1 plus cisplatin treatment for metastatic gastric cancer

BACKGROUND/AIM

S-1 plus cisplatin is the standard first-line chemotherapy for metastatic gastric cancer (MGC) in Japan, but the relationship between dose intensity and antitumor effects remains unclear.

PATIENTS AND METHODS

We retrospectively studied 64 patients who received S-1 plus cisplatin for MGC from January 2006 to December 2010 in two Japanese hospitals.

RESULTS

The median relative dose intensity (RDI) of S-1 plus cisplatin was 87% (range, 59.5%-100%). The cut-off value of RDI of S-1 plus cisplatin was identified to be 80% by a receiver operating characteristic analysis of the tumor response. In the RDI<80% (n=19) and the RDI≥80% (n=45) groups, the response rates were 20.0% and 37.5% (p=0.182), the median survival times were 394 and 376 days (p=0.915), and the median progression-free survival (PFS) was 188 and 170 days (p=0.851), respectively.

CONCLUSION

An appropriate RDI reduction may be permitted for patients with MGC in palliative settings.

Effects of subchronic inhalation exposure to ethyl tertiary butyl ether on splenocytes in mice

Ethyl tertiary-butyl ether (ETBE) is a motor fuel oxygenate used in reformulated gasoline. The current use of ETBE in gasoline or petrol is modest but increasing. To investigate the effects of ETBE on splenocytes, mice were exposed to 0 (control), 500 ppm, 1750 ppm, or 5000 ppm of ETBE by inhalation for 6 h/day for 5 days/wk over a 6- or 13-week period. Splenocytes were harvested from the control and exposed mice, and the following cell phenotypes were quantified by flow cytometry: (1) B cells (PerCP-Cy5.5-CD45R/B220), (2) T cells (PerCP-Cy5-CD3e), (3) T cell subsets (FITC-CD4 and PE-CD8a), (4) natural killer (NK) cells (PE-NK1.1), and (5) macrophages (FITC-CD11b). Body weight and the weight of the spleen were also examined. ETBE-exposure did not affect the weight of the spleen or body weight, while it transiently increased the number of RBC and the Hb concentration. The numbers of splenic CD3+, CD4+, and CD8+ T cells, the percentage of CD4+ T cells and the CD4+/CD8+ T cell ratio in the ETBE-exposed groups were significantly decreased in a dose-dependent manner. However, ETBE exposure did not affect the numbers of splenic NK cells, B cells, or macrophages or the total number of splenocytes. The above findings indicate that ETBE selectively affects the number of splenic T cells in mice.

The effect of omeprazole on gastric myoelectrical activity and emptying

Omeprazole, a proton pump inhibitor, is widely used for the treatment of patients with peptic ulcer, gastroesophageal reflux disease and functional dyspepsia (FD), although some studies have demonstrated that omeprazole delays gastric emptying. The purpose of this study was to investigate the efficacy of omeprazole on gastric motility including gastric myoelectrical activity and gastric emptying. This study was performed on 12 healthy volunteers. Gastric motility was evaluated with cutaneously recorded electrogastrography (EGG) and gastric emptying of semi-solid meals using the (13)C-acetic acid breath test. EGG and gastric emptying were measured before and after treatment with 20 mg omeprazole orally for 7 days. In the fasting state, the percentage of EGG normogastria increased significantly compared to the baseline. No significant changes were observed in other EGG parameters including the percentage of tachygastria and bradygastria in both fasting and postprandial states, and the power ratios between both before and after ingestion of omeprazole. In addition, administrated omeprazole did not show any significant differences in the gastric emptying parameters such as the half emptying time. We conclude that administration of omeprazole did not affect gastric motility but improved gastric myoelectrical activity. These effects of omeprazole may be one of the mechanisms involved in its efficacy in relieving dyspeptic symptoms in FD patients.

A patient with gastric adenosquamous carcinoma with intraperitoneal free cancer cells who remained recurrence-free with postoperative S-1 chemotherapy

The case of a patient with gastric adenosquamous carcinoma with positive cancer cells on intraperitoneal washing cytology (CY1) who achieved a long recurrence-free survival is herein reported. A 74-year-old man was found to have adenosquamous carcinoma of the stomach. Partial gastrectomy was performed, and a pathological examination confirmed a diagnosis of adenosquamous carcinoma with invasion into the serosa and lymph node metastasis. S-1 monotherapy was administered because a cytologic examination revealed that the patient's peritoneal washings were positive for cancer cells. The patient remains alive with no recurrence two years and 10 months after undergoing surgery. Postoperative chemotherapy with S-1 monotherapy is effective for treating adenosquamous carcinoma of the stomach with CY1 and might contribute to long-term survival.

Combination therapy with adalimumab plus intensive granulocyte and monocyte adsorptive apheresis induced clinical remission in a Crohn's disease patient with the loss of response to scheduled adalimumab maintenance therapy: a case report

A 21-year-old Caucasian man with a diagnosis of Crohn's disease (CD) at the age of 14 was admitted to our hospital due to CD flare-up while under scheduled adalimumab (ADA) maintenance therapy. His symptoms remained virtually unchanged following high dose corticosteroid therapy. Seven days later, combination therapy with ADA plus intensive granulocyte/monocyte adsorptive apheresis (GMA) was initiated, which induced clinical remission. Therefore, combination therapy with ADA plus intensive GMA appears to be an effective therapeutic option for patients with severe CD while under scheduled ADA maintenance therapy.

ERas enhances resistance to CPT-11 in gastric cancer

BACKGROUND/AIM

We have reported that embryonic stem cell-expressed Ras (ERas) is expressed in human gastric cancer and is associated with its tumorigenicity. Here, we asked whether ERas plays a role in resistance to chemotherapy in gastric cancer.

MATERIALS AND METHODS

To assess the cytotoxicity of chemotherapeutic agents, ERas-overexpressing human gastric cancer GCIY cells were exposed to anticancer agents, including CPT-11 and inhibitor of mammalian target of rapamycin (mTOR). We also investigated the mechanisms by which ERas induces chemoresistance.

RESULTS

ERas-overexpressing clones were significantly more resistant to CPT-11 than were the control (p<0.001). Administration of rapamycin was significantly cytotoxic to the ERas-overexpressing clones compared with the control (p<0.01). Electrophoresis mobility shift assay revealed that ERas enhanced nuclear factor (NF)-κB activity. PCR array demonstrated that ERas up-regulated several multidrug efflux transporter genes, including ABCG2.

CONCLUSION

ERas induces chemoresistance to CPT-11 via activation of phosphatidylinositol-3 kinase-protein kinase β mTOR pathway and NF-κB, and consequently results in up-regulation of ABCG2.

The role of neuregulin4 and HER4 in gastrointestinal malignant lymphoma

The human epidermal growth factor (EGF) receptor (HER) family consists of four receptors that bind to ligands sharing an EGF-like motif. The HER family of receptor tyrosine kinases and their ligands (EGF family) are known to play a significant role in gastrointestinal cancer. In particular, the EGF receptor, HER1, is one of the main candidates for the molecular-targeted therapy of colon cancer, and HER2 is a candidate for the treatment of gastric cancer which overexpresses HER2. In contrast, the role of the HER and EGF families in malignant lymphoma has not been fully elucidated. In this study, we investigated the expression and function of the HER and EGF families in lymphoma cell lines and tumor samples. Reverse transcription polymerase chain reaction revealed that the ligands for HER1 were mainly expressed in gastric cancer and colon cancer cell lines, but not in lymphoma cell lines. On the other hand, the EGF family member, neuregulin (NRG) 4, was highly expressed in lymphoma cell lines. Immunohistochemical analyses of malignant lymphoma clinical samples revealed that NRG4 and HER4 were mainly expressed in mucosa-associated lymphoid tissue (MALT) and follicular lymphoma. Immunoprecipitation of Raji and Daudi cell lines revealed that recombinant NRG4 induced the tyrosine phosphorylation of HER4. Additionally, recombinant NRG4 activated the proliferation of lymphoma cell lines. These findings suggest that the NRG4-HER4 axis plays a major role in the proliferation of malignant lymphoma cells in the gastrointestinal tract.

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

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.

Metastatic colorectal cancer with severe liver dysfunction successfully treated using FOLFOX therapy

INTRODUCTION

The liver is the most frequent site of metastases from colorectal cancer (CRC), and extensive liver metastases often cause severe secondary liver dysfunction. However, whether chemotherapy for metastatic CRC with severe liver dysfunction offers any clinical benefit is unclear since patients in this setting are typically excluded from clinical trials.

DISCUSSION

We report herein a case of metastatic sigmoid colon cancer with severe liver dysfunction that was successfully treated using infusional 5-fluorouracil, leucovorin, and oxaliplatin (FOLFOX). FOLFOX was effective and well tolerated in the present case, and subsequent addition of bevacizumab to FOLFOX after disease progression was similarly feasible.

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.

A rare case of infectious colitis with ulcers in the cecum caused by Mycobacterium gordonae

A 69-year-old female complained of persistent abdominal pain, and annular ulcers and ulcer scars were detected endoscopically in the cecum. Pathological findings included caseous granulomas with some Langhans giant cells, and Ziehl-Neelsen staining was negative. Mycobacterium gordonae (M. gordonae) was identified by the DNA-DNA hybridization method and culture (Ogawa medium) of biopsy samples from ulcerous cecal lesions. After 6 months of antibiotic therapy, ulcerous cecal lesions were healed, and no acid-fast bacteria were detected by culture of biopsy samples from scar tissue. We believe this is the first report of M. gordonae infection in the alimentary tract.

The effectiveness of packed therapy with three drugs in Helicobacter pylori eradication in Japan

Primary Helicobacter pylori eradication rate using triple therapy (a proton pump inhibitor [PPI] + amoxicillin [AMPC] + clarithromycin [CAM], over 7 days) is showing a declining trend. In this study we report recent eradication rates and have evaluated the usefulness of a pack preparation of three drugs. H. pylori eradication rate was 85.1% (57/67) in 2004 but then fell to 75.2% (79/105) in 2005, 70.1% (68/97) in 2006 and 69.9% (58/83) in 2007. With the introduction of packs (lansoprazole [LPZ] 60 mg, AMPC 1500 mg, CAM 400 mg) the eradication rate recovered to 78.0% (110/141) in 2008. A comparative study in 2008 delineated that the eradication rate in the pack group (88.4%, 38/43) was significantly higher than that of the conventional group (73.5%, 72/98). These results suggest that packs of eradication medicine are useful in increasing eradication success.

Phosphatase and tensin homolog deleted on chromosome 10 regulates sensory cell proliferation and differentiation of hair bundles in the mammalian cochlea

Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a tumor suppressor gene that regulates cell proliferation, differentiation and growth. It regulates neural and glioma stem/progenitor cell renewal and PTEN deletion can drive expansion of epithelial progenitors in the lung, enhancing their capacity for regeneration. Because it is expressed at relatively high levels in developing mammalian auditory hair cells we have analyzed the phenotype of the auditory epithelium in PTEN knock-out mice. PTEN(+/-) heterozygous littermates have only one functional copy of the gene and show clear evidence for haploinsufficiency in the organ of Corti. Auditory sensory epithelial progenitors withdraw from the cell cycle later than in wild-type animals and this is associated with increases in the numbers of both inner and outer hair cells. The cytoskeletal differentiation of hair cells was also affected. While many hair bundles on the hair cells appeared to develop normally, others were structurally disorganized and a number were missing, apparently lost after they had been formed. The results show that PTEN plays a novel role in regulating cell proliferation and differentiation of hair bundles in auditory sensory epithelial cells and suggest that PTEN signaling pathways may provide therapeutic targets for auditory sensory regeneration.

A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects

We previously reported that 2-night/3-day trips to forest parks enhanced human NK activity, the number of NK cells, and intracellular anti-cancer proteins in lymphocytes, and that this increased NK activity lasted for more than 7 days after the trip in both male and female subjects. In the present study, we investigated the effect of a day trip to a forest park on human NK activity in male subjects. Twelve healthy male subjects, aged 35-53 years, were selected after giving informed consent. The subjects experienced a day trip to a forest park in the suburbs of Tokyo. They walked for two hours in the morning and afternoon, respectively, in the forest park on Sunday. Blood and urine were sampled in the morning of the following day and 7 days after the trip, and the NK activity, numbers of NK and T cells, and granulysin, perforin, and granzyme A/B-expressing lymphocytes, the concentration of cortisol in blood samples, and the concentration of adrenaline in urine were measured. Similar measurements were made before the trip on a weekend day as the control. Phytoncide concentrations in the forest were measured. The day trip to the forest park significantly increased NK activity and the numbers of CD16(+) and CD56(+) NK cells, perforin, granulysin, and granzyme A/B-expressing NK cells and significantly decreased CD4(+) T cells, the concentrations of cortisol in the blood and adrenaline in urine. The increased NK activity lasted for 7 days after the trip. Phytoncides, such as isoprene, alpha-pinene, and beta-pinene, were detected in the forest air. These findings indicate that the day trip to the forest park also increased the NK activity, number of NK cells, and levels of intracellular anti-cancer proteins, and that this effect lasted for at least 7 days after the trip. Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity.

Effect of phytoncide from trees on human natural killer cell function

We previously reported that the forest environment enhanced human natural killer (NK) cell activity, the number of NK cells, and intracellular anti-cancer proteins in lymphocytes, and that the increased NK activity lasted for more than 7 days after trips to forests both in male and female subjects. To explore the factors in the forest environment that activated human NK cells, in the present study we investigate the effect of essential oils from trees on human immune function in twelve healthy male subjects, age 37-60 years, who stayed at an urban hotel for 3 nights from 7.00 p.m. to 8.00 a.m. Aromatic volatile substances (phytoncides) were produced by vaporizing Chamaecyparis obtusa (hinoki cypress) stem oil with a humidifier in the hotel room during the night stay. Blood samples were taken on the last day and urine samples were analysed every day during the stay. NK activity, the percentages of NK and T cells, and granulysin, perforin, granzyme A/B-expressing lymphocytes in blood, and the concentrations of adrenaline and noradrenaline in urine were measured. Similar control measurements were made before the stay on a normal working day. The concentrations of phytoncides in the hotel room air were measured. Phytoncide exposure significantly increased NK activity and the percentages of NK, perforin, granulysin, and granzyme A/B-expressing cells, and significantly decreased the percentage of T cells, and the concentrations of adrenaline and noradrenaline in urine. Phytoncides, such as alpha-pinene and beta-pinene, were detected in the hotel room air. These findings indicate that phytoncide exposure and decreased stress hormone levels may partially contribute to increased NK activity.

Processing of high-molecular-weight form adrenocorticotropin in human adrenocorticotropin-secreting tumor cell line (DMS-79) after transfection of prohormone convertase 1/3 gene

Ectopic ACTH-producing tumors preferentially secrete biologically inactive ACTH precursors and ACTH-related fragments. DMS-79 is known to secrete unprocessed high-molecular-weight (HMW) form ACTH. To determine whether prohormone convertase (PC) 1/3 is involved in the abnormal processing of proopiomelanocortin (POMC), we studied whether PC1/3 and 2 genes are expressed in DMS-79, and whether overexpression of PC1/3 gene affects POMC processing pattern. Steady-state mRNA levels of PC1/3 and 2 were determined by real-time RT-PCR. Molecular weights of ACTH-related peptides were determined by chromatographical analyses coupled with ACTH and beta-endorphin (beta-END) radioimmunoassays. PC1/3 gene was transfected into DMS-79 by retrovirus transduction using pMX-IP vector encoding PC1/3 cDNA. The steady-state mRNA levels of PC1/3 and 2 in DMS-79 were lower than those in ACTH-secreting and nonfunctioning pituitary tumors. DMS-79 predominantly secreted HMW form with both ACTH and beta-END immunoreactivities by size-exclusion chromatography. After purification by immunoaffinity chromatography with anti-ACTH antibody, the apparent molecular weight of HMW form ACTH was estimated to be 16 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis with silver staining. After retroviral transfection of PC1/3 cDNA into DMS-79 and puromycin selection, PC1/3 stably-expressing cell line (DMS-79T) secreted two immunoreactive ACTH components, a major one coeluting with ACTH(1-39) and a minor one as a HMW form as well as two beta- END immunoreactive components coeluting with beta-lipotropic hormone and beta-END, respectively. Thus, we have established PC1/3 stably-expressing cell line (DMS-79T) capable of proteolytically processing ACTH precursor molecule(s) into mature ACTH and beta-END.