Interferon-expressing oncolytic adenovirus + chemoradiation inhibited pancreatic cancer growth in a hamster model.

Past clinical trials of adjuvant therapy combined with interferon (IFN) alpha, fluorouracil, cisplatin, and radiation improved the 5-year survival rate of pancreatic ductal adenocarcinoma (PDAC). However, these trials also revealed the disadvantages of the systemic toxicity of IFN and insufficient delivery of IFN. To improve efficacy and tolerability, we have developed an oncolytic adenovirus-expressing IFN (IFN-OAd). Here, we evaluated IFN-OAd in combination with chemotherapy (gemcitabine + nab-paclitaxel) + radiation. Combination index (CI) analysis showed that IFN-OAd + chemotherapy + radiation was synergistic (CI <1). Notably, IFN-OAd + chemotherapy + radiation remarkably suppressed tumor growth and induced a higher number of tumor-infiltrating lymphocytes without severe side toxic effects in an immunocompetent and adenovirus replication-permissive hamster PDAC model. This is the first study to report that gemcitabine + nab-paclitaxel, the current first-line chemotherapy for PDAC, did not hamper virus replication in a replication-permissive immunocompetent model. IFN-OAd has the potential to overcome the barriers to clinical application of IFN-based therapy through its tumor-specific expression of IFN, induction of antitumor immunity, and sensitization with chemoradiation. Combining IFN-OAd with gemcitabine + nab-paclitaxel + radiation might be an effective and clinically beneficial treatment for PDAC patients.

A case of multiple glucagonomas with no clinical manifestations of excess glucagon despite hyperglucagonemia.

Herein we report the case of a patient with multiple glucagonomas that have been precisely described with endoscopic ultrasound. A 36-year-old woman was referred to our hospital for computed tomography investigation of multiple pancreatic masses. Physical examination was unremarkable; on contrast-enhanced computed tomography, mass lesions were evident in the head, body, and tail of the pancreas. The mass in the pancreatic head was poorly demarcated and exhibited a faint contrast effect, the one in the pancreatic body was a cystic lesion, and the one in the pancreatic tail was hypervascular. Blood investigations showed that serum glucagon was abnormally high at 7670 pg/ml; glucose tolerance was not impaired. There was no family history that suggested multiple endocrine neoplasia type 1 or von Hippel-Lindau disease. Endoscopic ultrasound revealed that there were additional masses, which were scattered isoechoic to hyperechoic lesions a few millimeters in size. Ultrasound-guided fine needle biopsy of the lesion in the pancreatic tail resulted in a diagnosis of a neuroendocrine tumor. Based on these pathologic findings, we performed a total pancreatectomy. A large number of nodules with tumor cells were evident in all cut surfaces of the surgical specimen. Immunostaining was positive for chromogranin A and glucagon, and glucagonoma was therefore diagnosed. It is conceivable that attenuated glucagon action could have contributed to the development of the multiple glucagonomas.

Obesity and Pancreatic Cancer: Recent Progress in Epidemiology, Mechanisms and Bariatric Surgery.

More than 30% of people in the United States (US) are classified as obese, and over 50% are considered significantly overweight. Importantly, obesity is a risk factor not only for the development of metabolic syndrome but also for many cancers, including pancreatic ductal adenocarcinoma (PDAC). PDAC is the third leading cause of cancer-related death, and 5-year survival of PDAC remains around 9% in the U.S. Obesity is a known risk factor for PDAC. Metabolic control and bariatric surgery, which is an effective treatment for severe obesity and allows massive weight loss, have been shown to reduce the risk of PDAC. It is therefore clear that elucidating the connection between obesity and PDAC is important for the identification of a novel marker and/or intervention point for obesity-related PDAC risk. In this review, we discussed recent progress in obesity-related PDAC in epidemiology, mechanisms, and potential cancer prevention effects of interventions, including bariatric surgery with preclinical and clinical studies.

Fatty acid binding protein 4 regulates pancreatic cancer cell proliferation via activation of nuclear factor E2-related factor 2.

BACKGROUND: Obesity and diabetes are associated with an increased incidence of pancreatic cancer. Fatty acid binding protein 4 (FABP4), noted to be higher in patients with severe obesity, is linked to the development and progression of several cancers, and its level in the circulation decreases after bariatric surgery. OBJECTIVE: In this paper, we evaluate the role of FABP4 in pancreatic cancer progression. SETTING: University Hospital and Laboratories, United States. METHODS AND RESULTS: When Panc-1 (human) and Pan02 (mouse) pancreatic cancer cells were treated with FABP4 or the-single-point mutant FABP4 (R126Q, fatty acid binding site mutant), only FABP4 stimulated cellular proliferation. The transcriptional activity of nuclear factor E2-related factor 2 (NRF2) was increased in response to FABP4 but not the R126Q. FABP4 treatment also led to downregulation of reactive oxygen species (ROS) activity. Consistent with induced cell propagation by FABP4, the growth of Pan02 tumor was decreased in FABP4-null animals compared with C57BL/6J controls. CONCLUSION: These results suggest that FABP4 increases pancreatic cancer proliferation via activation of NRF2 and downregulation of ROS activity.

Invasion inhibition in pancreatic cancer using the oral iron chelating agent deferasirox.

BACKGROUND: Iron is required for cellular metabolism, and rapidly proliferating cancer cells require more of this essential nutrient. Therefore, iron regulation may well represent a new avenue for cancer therapy. We have reported, through in vitro and in vivo research involving pancreatic cancer cell lines, that the internal-use, next-generation iron chelator deferasirox (DFX) exhibits concentration-dependent tumour-suppressive effects, among other effects. After performing a microarray analysis on the tumour grafts used in that research, we found that DFX may be able to suppress the cellular movement pathways of pancreatic cancer cells. In this study, we conducted in vitro analyses to evaluate the effects of DFX on the invasive and migratory abilities of pancreatic cancer cells. METHODS: We used pancreatic cancer cell lines (BxPC-3, Panc-1, and HPAF II) to examine the efficacy of DFX in preventing invasion in vitro, evaluated using scratch assays and Boyden chamber assays. In an effort to understand the mechanism of action whereby DFX suppresses tumour invasion and migration, we performed G-LISA to examine the activation of Cdc42 and Rac1 which are known for their involvement in cellular movement pathways. RESULTS: In our scratch assays, we observed that DFX-treated cells had significantly reduced invasive ability compared with that of control cells. Similarly, in our Boyden chamber assays, we observed that DFX-treated cells had significantly reduced migratory ability. After analysis of the Rho family of proteins, we observed a significant reduction in the activation of Cdc42 and Rac1 in DFX-treated cells. CONCLUSIONS: DFX can suppress the motility of cancer cells by reducing Cdc42 and Rac1 activation. Pancreatic cancers often have metastatic lesions, which means that use of DFX will suppress not only tumour proliferation but also tumour invasion, and we expect that this will lead to improved prognoses.

Deferasirox, an oral iron chelator, with gemcitabine synergistically inhibits pancreatic cancer cell growth in vitro and in vivo.

OBJECTIVES: Iron is an essential element for cell proliferation and growth processes. We have reported that deferasirox (DFX), an oral iron chelator, showed antiproliferative activity against pancreatic cancer cells. This study aimed to elucidate the effects of combination of gemcitabine (GEM), standard chemotherapy for pancreatic cancer, and DFX in vitro and in vivo. RESULTS: GEM+DFX showed antiproliferative activity and induced apoptosis in pancreatic cancer cells in vitro. GEM+DFX suppressed xenograft tumor growth and induced apoptosis without any serious side effects compared with control, GEM, and DFX (average tumor volume: control 697 mm3 vs GEM 372 mm3, p < 0.05; GEM 372 mm3 vs GEM+DFX 234 mm3, p < 0.05). RRM1 and RRM2 protein levels were substantially reduced by DFX in BxPC-3 in vitro. CONCLUSION: GEM+DFX has significant anticancer effects on pancreatic cancer cell through RR activity suppression. METHODS: BxPC-3, a human pancreatic cancer cell line, was used in all experiments. Cellular proliferation rate was measured using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt assay. Apoptosis was evaluated by flow cytometry and by measuring caspase 3/7 activity with luminescence assay. In the tumor xenografts in nude mice models, when five weeks after engraftment, drug administration began (day 0). After treatment for 21 days, the mice were sacrificed and the tumors were excised. Apoptotic cells in xenografts were evaluated by terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick-end labeling assay. Protein levels of ribonucleotide reductase (RR) subunit 1 (RRM1) and RR subunit 2 (RRM2) in BxPC-3 cells were assessed by western blot in vitro.

Heat Shock Protein 27 Expression in EUS-FNA Samples Can Predict Gemcitabine Sensitivity in Pancreatic Cancer.

BACKGROUND/AIM: Gemcitabine (GEM) sensitivity can help select the appropriate treatment for pancreatic cancer. We examined the association between HSP27 expression and GEM sensitivity. MATERIALS AND METHODS: A total of 19 patients with unresectable pancreatic cancer who underwent endoscopic ultrasonography-guided fine needle aspiration (EUS-FNA) were enrolled and treated with GEM alone. We measured the expression of heat shock protein 27 (HSP27) and phosphorylated HSP27(p-HSP27) in EUS-FNA samples and evaluated the effects of GEM treatment. RESULTS: The rate of GEM resistance was significantly higher in patients who showed overexpression of p-HSP27 (p<0.05). When we set the cut-off p-HSP27 (Ser82) detection rate at 51.6%, the group with a detection rate of >51.6% showed a significantly lower survival rate, and GEM was administered for a shorter period of time (p<0.05). CONCLUSION: It was suggested that the HSP27 expression in EUS-FNA samples was useful for predicting GEM sensitivity.

Side-by-side placement of bilateral endoscopic metal stents for the treatment of postoperative biliary stricture.

Postoperative biliary strictures are usually complications of cholecystectomy. Endoscopic plastic stent prosthesis is generally undertaken for treating benign biliary strictures. Recently, fully covered metal stents have been shown to be effective for treating benign distal biliary strictures. We present the case of a 53-year-old woman with liver injury in which imaging studies showed a common hepatic duct stricture. Endoscopic retrograde cholangiopancreatography also confirmed the presence of a common hepatic duct stricture. Temporally fully covered metal stents with dilated diameters of 6 mm were placed in a side-by-side fashion in the left and right hepatic ducts, respectively. We removed the stents 2 months after their placement. Subsequent cholangiography revealed an improvement in the biliary strictures. Although we were apprehensive about the fully covered metal stents obstructing the biliary side branches, we noted that careful placement of the bilateral metal stents did not cause any complications. Side-by-side deployment of bilateral endoscopic fully covered metal stents can be one of the safe and effective therapies for postoperative biliary stricture.

Deferasirox, a novel oral iron chelator, shows antiproliferative activity against pancreatic cancer in vitro and in vivo.

BACKGROUND: Iron is essential for cell replication, metabolism and growth. Because neoplastic cells have high iron requirements due to their rapid proliferation, iron depletion may be a novel therapeutic strategy for cancer. Deferasirox (DFX), a novel oral iron chelator, has been successful in clinical trials in iron-overload patients and has been expected to become an anticancer agent. However, no studies have investigated the effects of DFX on pancreatic cancer. This study aimed to elucidate the effects of DFX against pancreatic cancer. METHODS: The effects of DFX on cell cycle, proliferation, and apoptosis were examined in three human pancreatic cancer cell lines: BxPC-3, HPAF-II, and Panc 10.05. The effect of orally administered DFX on the growth of BxPC-3 pancreatic cancer xenografts was also examined in nude mice. Additionally, microarray analysis was performed using tumors excised from xenografts. RESULTS: DFX inhibited pancreatic cancer cell proliferation in a dose-dependent manner. A concentration of 10 µM DFX arrested the cell cycle in S phase, whereas 50 and 100 µM DFX induced apoptosis. In nude mice, orally administered DFX at 160 and 200 mg/kg suppressed xenograft tumor growth with no serious side effects (n = 5; average tumor volumes of 674 mm(3) for controls vs. 327 mm(3) for 160 mg/kg DFX, p <0.05; average tumor volumes of 674 mm(3) for controls vs. 274 mm(3) for 200 mg/kg DFX, p <0.05). Importantly, serum biochemistry analysis indicated that serum levels of ferritin were significantly decreased by the oral administration of 160 or 200 mg/kg DFX (n = 5; average serum ferritin of 18 ng/ml for controls vs. 9 ng/ml for 160 mg/kg DFX, p <0.05; average serum ferritin of 18 ng/ml for controls vs. 10 ng/ml for 200 mg/kg DFX, p <0.05). Gene expression analysis revealed that most genes in pancreatic adenocarcinoma signaling, especially transforming growth factor-ß1 (TGF-ß1), were downregulated by DFX. CONCLUSIONS: DFX has potential as a therapeutic agent for pancreatic cancer. Iron depletion was essential for the antiproliferative effect of DFX in a preclinical model, and DFX acted through the suppression of TGF-ß signaling.

Differential diagnosis of benign and malignant branch duct intraductal papillary mucinous neoplasm using contrast-enhanced endoscopic ultrasonography.

AIM: To elucidate the role of contrast-enhanced endoscopic ultrasonography (CE-EUS) in the diagnosis of branch duct intraductal papillary mucinous neoplasm (BD-IPMN). METHODS: A total of 50 patients diagnosed with BD-IPMN by computed tomography (CT) and endoscopic ultrasonography (EUS) at our institute were included in this study. CE-EUS was performed when mural lesions were detected by EUS. The diagnostic accuracy for identifying mural nodules (MNs) was evaluated by CT, EUS, and EUS combined with CE-EUS. In the patients who underwent resection, the accuracy of measuring MN height with each imaging modality was compared. The cut-off values to diagnose malignant BD-IPMNs based on MN height for each imaging modality were determined using receiver operating characteristic curve analysis. RESULTS: Fifteen patients were diagnosed with BD-IPMN with MNs and underwent resection. The remaining 35 patients were diagnosed with BD-IPMN without MNs and underwent follow-up monitoring. The pathological findings revealed 14 cases with MNs and one case without. The accuracy for diagnosing MNs was 92% using CT and 72% using EUS; the diagnostic accuracy increased to 98% when EUS and CE-EUS were combined. The accuracy for measuring MN height significantly improved when using CE-EUS compared with using CT or EUS (median measurement error value, CT: 3.3 mm vs CE-EUS: 0.6 mm, P < 0.05; EUS: 2.1 mm vs CE-EUS: 0.6 mm, P < 0.01). A cut-off value of 8.8 mm for MN height as measured by CE-EUS improved the accuracy of diagnosing malignant BD-IPMN to 93%. CONCLUSION: Using CE-EUS to measure MN height provides a highly accurate method for differentiating benign from malignant BD-IPMN.

Intracellular colocalization of HAP1/STBs with steroid hormone receptors and its enhancement by a proteasome inhibitor.

The stigmoid body (STB) is a cytoplasmic inclusion containing huntingtin-associated protein 1 (HAP1), and HAP1/STB formation is induced by transfection of the HAP1 gene into cultured cells. In the present study, we examined the intracellular colocalization of HAP1/STBs with steroid hormone receptors (SHRs), including the androgen receptor (AR), estrogen receptor, glucocorticoid receptor (GR), and mineralocorticoid receptor, in COS-7 cells cotransfected with HAP1 and each receptor. We found that C-terminal ligand-binding domains of all SHRs had potential for colocalization with HAP1/STBs, whereas only AR and GR were clearly colocalized with HAP1/STBs when each full-length SHR was coexpressed with HAP1. In addition, it appeared that HAP1/STBs did not disrupt GR and AR functions because the receptors on HAP1/STBs maintained nuclear translocation activity in response to their specific ligands. When the cells were treated with a proteasome inhibitor, GR and AR localized outside HAP1/STBs translocated into the nucleus, whereas the receptors colocalized with HAP1/STBs persisted in their colocalization even after treatment with their ligands. Therefore, HAP1/STBs may be involved in cytoplasmic modifications of the nuclear translocation of GR and AR in a ubiquitin-proteasome system.