A rare case of resection of a mucinous cystic neoplasm originating from the extrahepatic bile duct with cholangioscopic imaging.

A 29-year-old woman was admitted to our hospital for examination of obstructive jaundice and an extrahepatic bile duct lesion. Contrast-enhanced computed tomography revealed a 20 mm cystic lesion with a thin external capsule in the common hepatic duct. Cholangioscopy revealed translucent oval masses with capillary vessels attached to the bile duct walls. The surface was mostly smooth yet partially irregular with redness, suggesting that the masses were epithelial neoplasms. Histological findings of cholangioscopy-guided targeted biopsies of the mass showed subepithelial spindle cell proliferation with no atypical epithelium. The patient underwent an extrahepatic bile duct resection to confirm the pathological diagnosis. Immunohistochemistry of surgical specimens revealed that the spindle cells were positive for estrogen and progesterone receptors. Finally, the cystic lesion with ovarian-like stroma was diagnosed as a mucinous cystic neoplasm with low-grade intraepithelial neoplasia. This is the first report of cholangioscopic imaging of a biliary mucinous cyctic neoplasm. Cholangioscopic imaging can be helpful in the differential diagnosis of biliary neoplasms and in the determination of treatment strategies.

A case report of carcinoma of the papilla of Vater associated with a hyperplasia-dysplasia-carcinoma sequence by pancreaticobiliary maljunction.

BACKGROUND: Pancreaticobiliary maljunction (PBM) is a known risk factor for biliary tract cancer. However, its association with carcinoma of the papilla of Vater (PVca) remains unknown. We report a case with PVca that was thought to be caused by the hyperplasia-dysplasia-carcinoma sequence, which is considered a mechanism underlying PBM-induced biliary tract cancer. CASE PRESENTATION: A 70-year-old woman presented with white stool and had a history of cholecystectomy for the diagnosis of a non-dilated biliary tract with PBM. Esophagogastroduodenoscopy revealed a tumor in the papilla of Vater, and PVca was histologically proven by biopsy. We finally diagnosed her with PVca concurrent with non-biliary dilated PBM (cT1aN0M0, cStage IA, according to the Union for International Cancer Control, 8th edition), and subsequently performed subtotal stomach-preserving pancreaticoduodenectomy. Pathological findings of the resected specimen revealed no adenomas and dysplastic and hyperplastic mucosae in the common channel slightly upstream of the main tumor, suggesting a PBM related carcinogenic pathway with hyperplasia-dysplasia-carcinoma sequence. Immunostaining revealed positivity for CEA. CK7 positivity, CK20 negativity, and MUC2 negativity indicated that this PVca was of the pancreatobiliary type. Genetic mutations were exclusively detected in tumors and not in normal tissues, and bile ducts from formalin-fixed paraffin-embedded samples included mutated-ERBB2 (Mutant allele frequency, 81.95%). Moreover, of the cell-free deoxyribonucleic acid (cfDNA) extracted from liquid biopsy mutated-ERBB2 was considered the circulating-tumor deoxyribonucleic acid (ctDNA) of this tumor. CONCLUSIONS: Herein, we report the first case of PVca with PBM potentially caused by a "hyperplasia-dysplasia-carcinoma sequence" detected using immunostaining and next-generation sequencing. Careful follow-up is required if pancreaticobiliary reflux persists, considering the possible development of PVca.

Reconsidering resectable oncological conditions in pancreatic tail cancer: A multicenter retrospective study on prognostic factors in pancreatic tail cancer after resection (HOPS Pt-01).

BACKGROUND: Pancreatic tail cancer (Pt-PC) is generally considered resectable when metastasis is absent, but doubts persist in clinical practice due to the variability in local tumor extent. We conducted a multicenter retrospective study to comprehensively identify prognostic factors associated with Pt-PC after resection. METHODS: We enrolled 100 patients that underwent distal pancreatectomy. The optimal combination of factors influencing relapse-free survival (RFS) was determined using the maximum likelihood method (MLM) and corrected Akaike and Bayesian information criteria (AICc and BIC). Prognostic elements were then validated to predict oncological outcomes. RESULTS: Therapeutic interventions included neoadjuvant treatment in 16 patients and concomitant visceral resection (CVR) in 37 patients; 89 patients achieved R0. Median RFS and OS after surgery were 23.1 and 37.1 months, respectively. AICc/BIC were minimized in the model with ASA-PS (≥2), CA19-9 (≥112 U/mL at baseline, non-normalized postoperatively), need for CVR, 6 pathological items (tumor diameter ≥19.5 mm, histology G1, invasion of the anterior pancreatic border, splenic vein invasion, splenic artery invasion, lymph node metastasis), and completed adjuvant treatment (cAT) for RFS. Regarding the predictive value of these 11 factors, area under the curve was 0.842 for 5-year RFS. Multivariate analysis of these 11 factors showed that predictors of RFS include CVR (hazard ratio, 2.13; 95 % confidence interval, 1.08-4.19; p = 0.028) and cAT (0.38, 0.19-0.76; p = 0.006). CONCLUSIONS: The MLM identified certain Pt-PC cases warranting consideration beyond resectable during clinical management. Particular attention should be paid to conditions requiring CVR, even though immortal time bias remains unresolved with adjuvant treatment.

Cancer-associated oxidoreductase ERO1-α promotes immune escape through up-regulation of PD-L1 in human breast cancer.

Many human cancers have been reported to have enhanced expression of the immune checkpoint molecule programmed death-ligand 1 (PD-L1), which binds to programmed cell death-1 (PD-1) expressed on immune cells. PD-L1/PD-1 plays a role in inhibition of antitumor immunity by inducing T cell apoptosis and tolerance. Thus, it is crucial to elucidate mechanisms of PD-L1 expression on cancer cells. ERO1-α is an oxidase located in the endoplasmic reticulum. It is overexpressed in a variety of tumor types and it plays a role in disulfide bond formation in collaboration with PDI. Here, we investigated the influence of ERO1-α on expression of PD-L1 and immune escape. We demonstrated that ERO1-α augmented the expression of PD-L1 via facilitation of oxidative protein folding within PD-L1. In addition, we showed that overexpression of ERO1-α increased HIF-1α protein expression, resulting in an increase of PD-L1 mRNA as well as protein. In clinical cases, we observed that the expression of ERO1-α in triple negative breast cancer was related to the expression of PD-L1. Moreover, apoptosis of Jurkat leukemia T cells, which express PD-1, induced by tumor PD-L1 was inhibited when ERO1-α was depleted. The results suggest that targeting ERO1-α in tumor cells can be a novel approach for cancer immunotherapy. Therefore, the role of ERO1-α in tumor-mediated immunosuppression should be further explored.

Hypoxia augments MHC class I antigen presentation via facilitation of ERO1-α-mediated oxidative folding in murine tumor cells.

To establish an effective cancer immunotherapy, it is crucial that cancer cells present a cancer-specific antigen in a hypoxic area, a hallmark of the tumor microenvironment. Here, we show the impact of hypoxia on MHC class I antigen presentation in vitro and in vivo in murine tumors. Activation of antigen-specific CTLs by tumor cells that had been pre-incubated under a condition of hypoxia was enhanced compared with that by tumor cells pre-incubated under a condition of normoxia. Cell surface expression of MHC class I-peptide complex on the tumor cells was increased under a condition of hypoxia, thereby leading to higher susceptibility to specific CTLs. We show that the hypoxia-inducible ER-resident oxidase ERO1-α plays an important role in the hypoxia-induced augmentation of MHC class I-peptide complex expression. ERO1-α facilitated oxidative folding of MHC class I heavy chains, thereby resulting in the augmentation of cell surface expression of MHC class I-peptide complex under hypoxic conditions. These results suggest that since the expression of MHC class I-peptide complex is augmented in a hypoxic tumor microenvironment, strategies for inhibiting the function of regulatory T cells and myeloid-derived suppressor cells and/or immunotherapy with immune checkpoint inhibitors are promising for improving cancer immunotherapy.

Cancer-associated oxidoreductase ERO1-α drives the production of VEGF via oxidative protein folding and regulating the mRNA level.

BACKGROUND: Endoplasmic reticulum disulfide oxidase 1-α (ERO1-α) is an oxidase that exists in the endoplasmic reticulum and has a role in the formation of disulfide bonds of secreted proteins and cell-surface proteins. Recently, we reported that ERO1-α is present in high levels in various types of tumours, and that ERO1-α is a novel factor of poor prognosis. However, how ERO1-α affects a tumour in vivo and why patients who have a tumour with a high expression level of ERO1-α have a poor prognosis are still unknown. Therefore, to clarify the mechanism, we investigated the effect of ERO1-α on a tumour from the point of view of angiogenesis. METHODS: The effect of ERO1-α on tumour growth and angiogenesis was analysed by using non-obese diabetic-severe combined immunodeficient mice. The production of vascular endothelial growth factor (VEGF) in MDA-MB-231 cells with ERO1-α- overexpression or with ERO1-α knockdown was measured. The role of ERO1-α on VEGF expression was investigated. In triple-negative breast cancer cases, the relationship between expression of ERO1-α and angiogenesis was analysed. RESULTS: We found that the expression of ERO1-α promoted tumour growth in a mouse study and angiogenesis. The effects of ERO1-α on angiogenesis were mediated via oxidative protein folding of VEGF and enhancement of VEGF mRNA expression by using MDA-MB-231. In triple-negative breast cancer cases, the expression of ERO1-α related to the number of the blood vessel. Furthermore, we found that ERO1-α was a poor prognosis factor in triple-negative breast cancer. CONCLUSIONS: Our study has established a novel link between expression of ERO1-α and secretion of VEGF, providing new evidence for the effectiveness of ERO1-α-targeted therapy in patients with ERO1-α-expressed cancer.

Cancer-Associated Oxidase ERO1-α Regulates the Expression of MHC Class I Molecule via Oxidative Folding.

ERO1-α is an oxidizing enzyme that exists in the endoplasmic reticulum and is induced under hypoxia. It reoxidizes the reduced form of protein disulfide isomerase that has oxidized target proteins. We found that ERO1-α is overexpressed in a variety of tumor types. MHC class I H chain (HC) has two disulfide bonds in the α2 and α3 domains. MHC class I HC folding is linked to the assembly of MHC class I molecules because only fully disulfide-bonded class I HCs efficiently assemble with ß2-microglobulin. In this study, we show that ERO1-α associates with protein disulfide isomerase, calnexin, and immature MHC class I before being incorporated into the TAP-1-associated peptide-loading complex. Importantly, ERO1-α regulates the redox state as well as cell surface expression of MHC class I, leading to alteration of susceptibility by CD8(+) T cells. Similarly, the ERO1-α expression within cancer cells was associated with the expression level of MHC class I in colon cancer tissues. Thus, the cancer-associated ERO1-α regulates the expression of the MHC class I molecule via oxidative folding.

Clinical feasibility of laparoscopic lateral pelvic lymph node dissection following total mesorectal excision for advanced rectal cancer.

PURPOSE: To evaluate the technical feasibility, safety and oncological outcomes of laparoscopic lateral pelvic lymph node dissection in patients with advanced low rectal cancer. METHODS: Laparoscopic lateral pelvic lymph node dissection was performed in 18 patients from November 2009 to September 2012. The data regarding the patient demographics, surgical outcomes and short-term oncological outcomes were analyzed. RESULTS: In all 18 patients, the procedures were completed without conversion to open surgery. The mean length of the operation was 603.7 min (473-746 min). The mean number of harvested lateral pelvic lymph nodes was 16.9 (7-27), and five patients (27.8 %) had lymph node metastases. The postoperative mortality and morbidity rates were 0 and 16.7 %, respectively. Three patients developed Grade 2 urinary retention. No local recurrence had developed after a mean follow-up period of 23.6 months. CONCLUSION: Laparoscopic lateral pelvic lymph node dissection is technically feasible, safe and oncologically acceptable within the limitations of the short-term follow-up period.

Continuous monitoring of central venous oxygen saturation predicts postoperative liver dysfunction after liver resection.

BACKGROUND: We examined whether the data obtained by monitoring central venous oxygen saturation (ScvO2) and/or stroke volume variation (SVV) during hepatectomy, as measured with the FloTrac/Vigileo system, can predict postoperative liver dysfunction. METHODS: This study included 33 patients with normal liver function who underwent hepatectomy between December 2007 and August 2010. Baseline ScvO2 and baseline SVV, as control values, were defined as the mean of ScvO2 and SVV, respectively, measured with the FloTrac/Vigileo system before hepatectomy. ScvO2 decrease (ΔScvO2) was defined as the difference between the baseline ScvO2 and the lowest intraoperative ScvO2 and SVV increase (ΔSVV) was defined as the difference between the baseline SVV and the highest intraoperative SVV. Moreover, mean ScvO2 and mean SVV were defined as the means of all ScvO2 and SVV values measured during surgery, respectively. We examined correlations of the new parameters with the highest postoperative values of total bilirubin (T. Bil). RESULTS: The cutoff values for ΔScvO2 and mean SVV for predicting the highest postoperative T. Bil level to be ≥ 3.0 mg/dL with the highest sensitivity and specificity were found to be 10.2% and 13.6%, respectively. The areas under curve in receiver-operating-characteristic analysis of ΔScvO2 and mean SVV were 0.797 and 0.757, respectively, showing significant differences. CONCLUSION: Our results suggest that ΔScvO2 and mean SVV can predict postoperative liver dysfunction. When ΔScvO2 and mean SVV exceed 10.2% and 13.6%, respectively, we advocate that adequate attention be paid to postoperative liver dysfunction, and that early intraoperative general circulatory management measures be implemented as needed.

Human endoplasmic reticulum oxidoreductin 1-α is a novel predictor for poor prognosis of breast cancer.

Human endoplasmic reticulum oxidoreductin 1-α (hERO1-α) is an oxidizing enzyme that exists in the endoplasmic reticulum and its expression is augmented under hypoxia. It regulates a redox state of various kinds of protein through reoxidation of "client" protein disulfide isomerase. Interestingly, although the expression of hERO1-α in normal tissues was comparatively limited, various types of cancer cells expressed it in large amounts. Therefore, we examined the role of ERO1-α in tumor growth using murine breast cancer line 4T1 and found that knockdown of murine ERO1-α inhibited in vivo tumor growth and decreased lung metastasis compared with wild-type 4T1. Moreover, we investigated the relationship between expression of hERO1-α and prognosis in breast cancer patients. Seventy-one patients with breast cancer who underwent surgery between 2005 and 2006 in Sapporo Medical University Hospital (Sapporo, Japan) were analyzed in this study. Significant differences were found between the hERO1-α-positive group (n = 33) and hERO1-α-negative group (n = 38) in nuclear grade (P < 0.001) and intrinsic subtype (P = 0.021) in univariate analysis. More importantly, in multivariate analysis of disease-free survival by Cox regression, expression of hERO1-α was the only independent prognosis factor (P = 0.035). Finally, in univariate survival analysis, patients positive for hERO1-α had significantly shorter disease-free survival and overall survival than those patients negative for hERO1-α. These findings indicate that the expression of hERO1-α in cancer cells is associated with poorer prognosis and thus can be a prognostic factor for patients with breast cancer.

[Human endoplasmic reticulum oxidoreductin 1-like α regulates immune response of cancer cells via modulation of major histocompatibility complex class I expression and oxidation].

The protein human endoplasmic reticulum oxidoreductin 1-like α(hERO1-L α) is a hypoxia-inducible endoplasmic reticulum resident oxidase that regulates the redox state of various proteins via protein disulfide isomerase. The major histocompatibility complex(MHC) class I molecule contains intramolecular disulfide bonds. hERO1-L α is expressed within normoxic cells at very low levels, but may be induced in hypoxic cells such as tumor cells in response to low oxygen availability. We therefore examined whether hERO1-L α affects the oxidation state and expression level of MHC class I in the colon cancer cell line SW480. We generated SW480 cells in which hERO1-L α was overexpressed or knocked down. The surface expression of MHC class I molecule was upregulated in the hERO1-L α-overexpressing SW480 cells and downregulated in the hERO1-L α-knockdown SW480 cells. Moreover, the oxidized form of MHC class I was increased in the hERO1-L α-overexpressing SW480 cells, and the hERO1-L α-knockdown SW480 cells exhibited an impaired response to cytotoxic T lymphocytes. These data suggest that hERO1-L α regulates immune response via modulation of MHC class I expression and oxidation, and that hERO1-L α may act as a new predictive factor for cancer immunotherapy.

Heat-shock proteins as endogenous ligands building a bridge between innate and adaptive immunity.

There has been growing evidence that heat-shock protein (HSP) functions as an endogenous immunomodulator for innate and adaptive immune responses. Since HSPs inherently act as chaperones within cells, passive release (e.g., by cell necrosis) and active release (including release by secretion in the form of an exosome) have been suggested as mechanisms of HSP release into the extracellular milieu. Such extracellular HSPs have been shown to be activators of innate immune responses through Toll-like receptors. However, it has also been suggested that HSPs augment the ability of associated innate ligands such as lipopolysaccharides to stimulate cytokine production and dendritic cell maturation. More interestingly, a recent study has demonstrated that innate immune responses elicited by danger signals were regulated spatiotemporally and that can be manipulated by HSPs, thereby controlling immune responses. We will discuss how spatiotemporal regulation of HSP-chaperoned molecules within antigen-presenting cells affects adaptive immunity via antigen cross-presentation and innate immune responses. Precise analysis of HSP biology should lead to the establishment of effective HSP-based immunotherapy.

Prognostic impact of preoperative the branched-chain amino acid to the tyrosine ratio in hepatocellular carcinoma patients after initial hepatectomy.

INTRODUCTION: The branched-chain amino acid/tyrosine ratio (BTR) reflects the amino acid balance and the severity of liver disease. The aim of the present study was to determine the relationship between BTR and liver function in patients with hepatocellular carcinoma (HCC). Furthermore, we evaluated the clinical usefulness of BTR as a prognostic indicator of disease-free and overall patient survival after initial hepatectomy. METHODS: Between January 2004 and December 2008, 105 consecutive HCC patients who underwent initial hepatectomy were enrolled in this study. The correlation between BTR and preoperative liver functional indicators was evaluated. The cutoff levels of BTR for 2-year survival prediction were evaluated using a dot blot diagram. The patients were divided into high BTR (4.5 or higher) and low BTR (4.4 or lower) groups and these were compared in terms of clinical variables such as liver functional indicators, operative variables, and tumor characteristics. RESULTS: The preoperative BTR level decreased according to the severity of liver disease. BTR was correlated with the albumin, bilirubin, and prealbumin levels, as well as the prothrombin time. Although the preoperative liver function was significantly different between the high BTR and low BTR groups, the operative variables and tumor-related variables were not found to be significantly different. Postoperative complications in the high BTR group were significantly less frequent than in the low BTR group (p = 0.003). Disease-free and overall patient survival in the high BTR group were significantly longer than in the low BTR group (p < 0.001 and p = 0.021, respectively). CONCLUSIONS: BTR reflected the pathological liver background with a high correlation to the other liver functional indicators. BTR is thus considered to be a useful marker to predict postoperative complications, disease-free survival, and overall survival of HCC patients after initial hepatectomy. It is, therefore, a useful indicator of liver function and a predictor for the risk of cancer recurrence and overall survival in HCC patients.