Conversion surgery for microsatellite instability-high gastric cancer with a complete pathological response to pembrolizumab: a case report.

BACKGROUND: Immune checkpoint inhibitors are reportedly effective in treating microsatellite instability (MSI)-high gastric cancer. There are a few case reports of conversion surgery (CS) with nivolumab but none with pembrolizumab. Herein, we describe a patient with MSI-high gastric cancer who was successfully treated with pembrolizumab and underwent CS with a pathological complete response. CASE PRESENTATION: A 69-year-old man was diagnosed with stage III gastric cancer (T3N2M0) based on contrast-enhanced computed tomography, which revealed a neoplastic lesion and enlarged perigastric lymph nodes in the gastric lesser curvature. The anterior superior lymph node of the common hepatic artery (CHA) was determined to be unresectable due to invasion of the pancreatic head and CHA. Histopathologically, the biopsied tissue showed moderately differentiated adenocarcinoma, then determined to be MSI-high. After three courses of mFOLFOX6 therapy, the patient was diagnosed with progressive disease. Since one course of paclitaxel plus ramucirumab therapy caused grade 3 fatigue, his second-line therapy was switched to pembrolizumab monotherapy. After three courses, the primary tumor and perigastric lymph nodes had shrunk, and it was determined as a partial response. The anterior superior lymph node of the CHA became resectable based on the improvement of infiltration of the pancreatic head and CHA due to shrinkage of the lymph node. Tumor markers remained low; hence, distal gastrectomy plus D2 lymphadenectomy was performed at the end of six courses. Anterior superior lymph node of the CHA was confirmed by intraoperative ultrasonography, and the resection was completed safely. The gross examination of the resected specimen revealed an ulcer scar at the primary tumor site. The histopathological examination showed no viable tumor cell remnants in the primary tumor, which had a grade 3 histological response, and resection margins were negative. The lymph nodes showed mucus retention only in the anterior superior lymph node of the CHA, indicating the presence of metastasis, but no viable tumor cells remained. The patient commenced 6 months of adjuvant pembrolizumab monotherapy 3 months after surgery. Twenty months after surgery, there was no evidence of recurrence. CONCLUSIONS: Conversion surgery following pembrolizumab monotherapy has a potential utility for the treatment of MSI-high gastric cancer.

Conversion surgery for hepatocellular carcinoma with portal vein tumor thrombus after successful atezolizumab plus bevacizumab therapy: a case report.

BACKGROUND: The treatment of hepatocellular carcinoma (HCC) requires diverse and multidisciplinary approaches. In recent years, new agents with good antitumor effects have emerged for systemic chemotherapy, and conversion surgery (CS) after systemic chemotherapy is expected to be an effective treatment strategy for unresectable HCC. We herein report a case of unresectable HCC with portal vein tumor thrombus (PVTT) in which atezolizumab plus bevacizumab therapy induced PVTT regression, followed by CS with R0 resection. CASE PRESENTATION: The patient was a 79-year-old man with S2/S3 HCC who was referred to our department due to tumor re-growth and PVTT after two rounds of transcatheter arterial chemoembolization. The PVTT extended from the left portal vein to the main trunk, and it was determined that the resection of the left portal vein would be difficult to perform with R0 status. Based on the diagnosis of unresectable HCC, treatment with atezolizumab plus bevacizumab was initiated. After two courses of treatment, contrast-enhanced computed tomography showed that the PVTT had regressed to the peripheral side of the left portal vein, and R0 resection became possible. The patient developed grade 3 skin lesions as an immune-related adverse event, and it was determined that the continuation of chemotherapy would be difficult. Four weeks after the second course of atezolizumab plus bevacizumab administration, left lobectomy was performed. Intraoperative ultrasonography was used to confirm the location of the tumor thrombus in the left portal vein during the resection, and a sufficient surgical margin was obtained. The histopathological findings showed that primary tumor and PVTT were mostly necrotic with residues of viable tumor cells observed in some areas. The liver background was determined as A1/F4 (new Inuyama classification). The resection margins were negative, and R0 resection was confirmed. There were no postoperative complications. No recurrence was observed as of five months after surgery. CONCLUSIONS: CS with atezolizumab plus bevacizumab therapy has potential utility for the treatment of unresectable HCC with PVTT.

Relationship between the surgical margin status, prognosis, and recurrence in extrahepatic bile duct cancer patients.

PURPOSE: The purpose of this retrospective study was to evaluate the relationship between the surgical margin status of the bile duct and the prognosis and recurrence of extrahepatic bile duct (EHBD) cancer. METHODS: The clinical data of 100 patients who underwent surgery for EHBD cancer between February 2002 and September 2014 were analyzed. The ductal margin status was classified into the following three categories: negative (D-N), positive with carcinoma in situ (D-CIS), and positive with invasive carcinoma (D-INV). RESULTS: The number of patients with D-N, D-CIS, and D-INV was 69, 16, and 15, respectively. Local recurrence rates of patients with D-CIS (56.3 %) and D-INV (66.7 %) were significantly higher compared to those of patients with D-N (10.1 %; P < 0.001). D-CIS was a significant predictor of shorter recurrence-free survival (RFS). Lymph node metastasis (P = 0.037) and D-INV (P = 0.008) were independent predictors of shorter disease-specific survival (DSS). The prognostic relevance of the ductal margin status was high, particularly in patients without lymph node metastasis. CONCLUSION: The surgical margin status of the bile duct was significantly associated with RFS, DSS, and the recurrence site.

Efficient elimination of pancreatic cancer stem cells by hedgehog/GLI inhibitor GANT61 in combination with mTOR inhibition.

BACKGROUND: Pancreatic cancer is one of the most lethal malignancies. The innovative treatments are required and now the cancer stem cells (CSCs) are expected to be an effective target for novel therapies. Therefore we investigated the significance of hedgehog (Hh) signaling in the maintenance of CSC-like properties of pancreatic cancer cells, in order to discover the key molecules controlling their unique properties. METHODS: Human pancreatic cancer cell lines, Capan-1, PANC-1, MIA PaCa-2 and Capan-1 M9 were used for our experiments in DMEM/F12 medium containing 10 % fetal bovine serum. Sphere formation assay, immunofluorescence staining, flow cytometric analysis and MTT cell viability assay were performed to investigate molecular signals and the efficacy in the treatment of pancreatic cancer cells. RESULTS: Inhibition of the Hh pathway significantly reduced the expression of stem cell marker CD133 and sphere formation, an index of self-renewal capacity, demonstrating the suppression of CSC-like properties. Moreover, the GLI inhibitor GANT61 induced greater reduction in sphere formation and cell viability of pancreatic cancer cells than the smoothened (SMO) inhibitor cyclopamine. This suggests that GLI transcription factors, but not SMO membrane protein, are the key molecules in the Hh pathway. The treatment using GANT61 in combination with the inhibition of mTOR, which is another key molecule in pancreatic CSCs, resulted in the efficient reduction of cell viability and sphere formation of an inhibitor-resistant cell line, showing the strong efficacy and wide range applicability to pancreatic CSC-like cells. CONCLUSIONS: Thus, this novel combination treatment could be useful for the control of pancreatic cancer by targeting pancreatic CSCs. This is the first report of the efficient elimination of pancreatic cancer stem-like cells by the double blockage of Hh/GLI and mTOR signaling.

Clinical significance of serum carbohydrate antigen 19.9 and duke pancreatic monoclonal antigen type 2 for the prediction of hematogenous metastases in patients with pancreatic ducal adenocarcinoma.

OBJECTIVES: The aim of the present study was to investigate the effectiveness of serum carbohydrate antigen (CA) 19.9 and duke pancreatic monoclonal antigen type 2 (DUPAN-2) levels in the prediction of early hematogenous metastases and as indicators of neoadjuvant therapy in patients with pancreatic ductal adenocarcinoma (PDAC). METHODS: Of the 293 enrolled PDAC patients, 61 had hematogenous metastases at the initial evaluation. One hundred and twenty patients without metastases underwent surgical resection. Of the 120 patients who underwent surgical resection, 45 underwent preoperative treatment and 29 developed early hematogenous metastases within 1 year after the surgery. In patients who underwent preoperative therapy, serum CA 19.9 and DUPAN-2 levels were measured within 2 weeks before the preoperative therapy and the subsequent surgery. RESULTS: The elevated serum CA 19.9 and DUPAN-2 levels were significantly associated with hematogenous metastasis at initial evaluation and early hematogenous metastasis after surgery. The rate of early hematogenous metastasis and overall survival (OS) in patients with high CA 19.9 and/or high DUPAN-2 (CA 19.9 > 200 U/mL and/or DUPAN-2 >300 U/mL) were 46.3% and 18 months, respectively, whereas the metastatic rate and OS in patients with low CA 19.9 and DUPAN-2 were 12.7% and 37.5 months, respectively. Furthermore, in patients with high CA 19.9 and/or high DUPAN-2, preoperative therapy significantly reduced the rate of early hematogenous metastasis and prolonged the OS. CONCLUSIONS: Serum CA 19.9 and DUPAN-2 levels are useful predictors of early hematogenous metastasis and indicators for effectiveness of neoadjuvant therapy in PDAC patients.

Preoperative biliary drainage-related inflammation is associated with shorter survival in biliary tract cancer patients.

BACKGROUND: An association between inflammation and patient prognosis has been reported in various types of cancer. The aim of this study was to evaluate the influence of preoperative biliary drainage-related inflammation in patients with biliary tract cancer. METHODS: The clinical data of 97 patients who underwent surgery for extrahepatic bile duct cancer between February 2002 and September 2014 were analyzed, and the prognostic significance of tube-obstructive cholangitis after preoperative biliary drainage and pancreatitis after endoscopic retrograde cholangiopancreatography (ERCP) was evaluated. RESULTS: Eighty-four (86.6 %) of the 97 patients underwent ERCP and preoperative biliary drainage. Tube-obstructive cholangitis occurred in 25 cases and post-ERCP pancreatitis in 8 cases. Collectively, 30 patients experienced preoperative biliary drainage-related inflammation consisting of tube-obstructive cholangitis and/or post-ERCP pancreatitis. Drainage-related inflammation was significant risk factor of postoperative complications (P = 0.006), and significant poor predictors of shorter progression-free survival (P = 0.003) and overall survival (OS; P = 0.006) after surgery. In multivariate analysis, drainage-related inflammation was an independent predictor of shorter OS (hazard ratio, 1.924; P = 0.037) after surgery. CONCLUSION: Preoperative biliary drainage-related inflammation was an independent prognostic factor for shorter OS in biliary tract cancer patients.

CD133 Modulate HIF-1α Expression under Hypoxia in EMT Phenotype Pancreatic Cancer Stem-Like Cells.

UNLABELLED: Although CD133 is a known representative cancer stem cell marker, its function in tumor aggressiveness under hypoxia is not fully known. The aim of this study is to demonstrate that CD133 regulates hypoxia inducible factor (HIF)-1α expression with tumor migration. The CD133⁺ pancreatic cancer cell line, Capan1M9, was compared with the CD133(-) cell line, shCD133M9, under hypoxia. HIF-1α expression levels were compared by Western blot, HIF-1α nucleus translocation assay and real-time (RT)-PCR. The hypoxia responsive element (HRE) was observed by luciferase assay. The migration ability was analyzed by migration and wound healing assays. Epithelial mesenchymal transition (EMT) related genes were analyzed by real-time RT-PCR. HIF-1α was highly expressed in Capan1M9 compared to shCD133M9 under hypoxia because of the high activation of HRE. Furthermore, the migration ability of Capan1M9 was higher than that of shCD133M9 under hypoxia, suggesting higher expression of EMT related genes in Capan1M9 compared to shCD133M9. CONCLUSION: HIF-1α expression under hypoxia in CD133⁺ pancreatic cancer cells correlated with tumor cell migration through EMT gene expression. Understanding the function of CD133 in cancer aggressiveness provides a novel therapeutic approach to eradicate pancreatic cancer stem cells.

Prognostication by inflammation-based score in patients with locally advanced pancreatic cancer treated with chemoradiotherapy.

BACKGROUND: An association between inflammatory/immunonutritional status and patient prognosis has been reported in various types of cancer. The aim of this study was to evaluate the utility of inflammatory/immunonutritional factors as therapeutic predictors for patients with locally advanced pancreatic cancer treated with chemoradiotherapy (CRT). METHODS: Ninety-six patients with histologically proven locally advanced pancreatic adenocarcinoma who underwent CRT were enrolled in this study. We evaluated significance of inflammation-based factors as predictors of therapeutic effect and prognosis. RESULTS: The median progression free survival (PFS) and overall survival (OS) of all patients was 10 and 18 months, respectively. A Glasgow prognostic score (GPS) of 2 and plasma fibrinogen levels ≥ 400 mg/dL were independent predictors of poor PFS and OS. A prognostic nutritional index (PNI) ≥ 45 was a predictor of a significantly better reduction rate of the primary tumor. The prognosis between patients with GPS 0/1 and fibrinogen <400 mg/dL, GPS 2 or fibrinogen ≥400 mg/dL, and GPS 2 and fibrinogen ≥400 mg/dL were significantly different. Patients with GPS 2 and/or plasma fibrinogen ≥ 400 mg/dL had significantly higher incidence of metastasis within 6 months after CRT. CONCLUSIONS: GPS, fibrinogen, PNI are useful therapeutic and prognostic predictors in patients with locally advanced pancreatic cancer treated with CRT.

Assessment of percutaneous laparoscopic ultrasonography-guided core needle biopsy for the advanced diagnosis of unresectable pancreatic cancer.

CONTEXT: Before the initiation of cytotoxic therapy for locally unresectable pancreatic cancer, staging laparoscopy is an important diagnostic method for both the detection of occult small lesions and the extraction of a tumor sample for advanced pathological examination using core needle biopsy (CNB) under laparoscopic ultrasonography (LUS) guidance. OBJECTIVE: This study aimed to evaluate the safety and usefulness of LUS-guided CNB in pancreatic cancer. METHODS: Consecutive patients with locally unresectable pancreatic cancer who underwent staging laparoscopy were retrospectively analyzed. LUS-guided CNB was performed percutaneously under a laparoscopic view. The clinical results of the LUS-guided CNB group and the non-LUS-guided CNB group were compared. RESULTS: Forty-eight patients who underwent staging laparoscopy by LUS-guided CNB or endoscopic ultrasound-guided fine needle aspiration were identified. LUS-guided CNB was performed in 25 patients. The mean tumor size in the LUS-guided CNB group was significantly larger than that in the non-LUS-guided CNB group. No significant difference was observed between the two groups in operating time or bleeding volume. The rates of malignancy diagnosis and histological classification subtyping were significantly higher in the LUS-guided CNB group. Histologically differentiated adenocarcinoma was identified in 15 patients using samples acquired by LUS-guided CNB. There was no uncontrollable bleeding or other complications, and a significant difference in the occurrence of peritoneal dissemination after laparoscopic examination was observed between the two groups. CONCLUSION: LUS-guided CNB enables the safe acquisition of sufficient tissue volumes for certain pathological analyses required to determine treatment strategies for locally unresectable advanced pancreatic cancer.

Pancreaticogastrostomy after Pancreaticoduodenectomy Using Twin Square Wrapping with Duct-to-Mucosa Anastomosis.

BACKGROUND/PURPOSE: This study aimed to evaluate the feasibility and safety of a novel pancreaticogastrostomy technique for diminishing pancreatic fistulas after pancreaticoduodenectomy using gastric wrapping of the pancreatic stump with a twin square-shaped horizontal mattress and a suture fixing the main pancreatic duct to the gastric mucosa anastomosis [twin square wrapping (TSW) method]. METHODS: Fifty-three patients undergoing pancreaticogastrostomy after pancreaticoduodenectomy were included in the study and chronologically divided into a conventional group (n = 32) and a TSW group (n = 21). The perioperative factors and the postoperative outcomes were retrospectively analyzed. RESULTS: The operating time for the pancreatic anastomosis, the total operating time, and the blood loss volume in the TSW group were lower than in the conventional group, but without a statistically significant difference. The TSW group had a significantly lower postoperative white blood cell count and C-reactive protein level, with a reduced intra-abdominal fluid accumulation as assessed by computed tomography on postoperative day 7, had a lower incidence of postoperative complications and pancreatic fistulas, and achieved a shorter duration of drain placement and shorter postoperative hospital stays as compared to the conventional group. CONCLUSIONS: The TSW technique should be considered for reducing pancreatic fistulas by diminishing the postoperative inflammatory response and improving patient outcomes without increasing the operating time.

CD133 facilitates epithelial-mesenchymal transition through interaction with the ERK pathway in pancreatic cancer metastasis.

BACKGROUND: Pancreatic cancer is a lethal disease due to the high incidence of metastasis at the time of detection. CD133 expression in clinical pancreatic cancer correlates with poor prognosis and metastasis. However, the molecular mechanism of CD133-regulated metastasis remains unclear. In recent years, epithelial-mesenchymal transition (EMT) has been linked to cancer invasion and metastasis. In the present study we investigated the role of CD133 in pancreatic cancer metastasis and its potential regulatory network. METHODS: A highly migratory pancreatic cancer cell line, Capan1M9, was established previously. After shRNA was stable transducted to knock down CD133 in Capan1M9 cells, gene expression was profiled by DNA microarray. Orthotopic, splenic and intravenous transplantation mouse models were set up to examine the tumorigenesis and metastatic capabilities of these cells. In further experiments, real-time RT-PCR, Western blot and co-immunoprecipitate were conducted to evaluate the interactions of CD133, Slug, N-cadherin, ERK1/2 and SRC. RESULTS: We found that CD133+ human pancreatic cancer cells were prone to generating metastatic nodules in in vivo models using immunodeficient mice. In contrast, CD133 knockdown suppressed cancer invasion and metastasis in vivo. Gene profiling analysis suggested that CD133 modulated mesenchymal characteristics including the expression of EMT-related genes, such as Slug and N-cadherin. These genes were down-regulated following CD133 knockdown. Moreover, CD133 expression could be modulated by the extracellular signal-regulated kinase (ERK)1/2 and SRC signaling pathways. The binding of CD133 to ERK1/2 and SRC acts as an indispensable mediator of N-cadherin expression. CONCLUSIONS: These results demonstrate that CD133 plays a critical role in facilitating the EMT regulatory loop, specifically by upregulating N-cadherin expression, leading to the invasion and metastasis of pancreatic cancer cells. Our study provides a novel insight into the function of CD133 in the EMT program and a better understanding of the mechanism underlying the involvement of CD133 in pancreatic cancer metastasis.

Gallbladder adenocarcinoma with sarcoid-like reaction in regional lymph nodes: report of a case.

BACKGROUND: Sarcoid-like reaction is often seen in various types of carcinoma, not only in the primary tumor, but also in regional lymph nodes, and can occur at any time, not only at the time of diagnosis, but also after treatment. However, few cases of hepatopancreatobiliary carcinoma, and no cases of gallbladder cancer with sarcoid-like reaction involving the lymph nodes have been described. This report is the first report of a sarcoid-like reaction involving the lymph nodes in a case of gallbladder cancer. CASE PRESENTATION: We encountered a rare case of gall bladder cancer with sarcoid-like reaction in the lymph nodes. Since regional lymph node swelling that was difficult to differentiate from metastasis was found preoperatively, swollen nodes were examined histologically using frozen sections. Based on this histology, the swollen nodes were diagnosed as showing sarcoid reaction and therefore extended lymphadenectomy was avoided. The patient did not receive any adjuvant chemotherapy and has shown no recurrence of disease as of 4 years after surgery. CONCLUSION: Distinguishing between metastasis and sarcoid-like reaction in lymph nodes by preoperative imaging is still difficult. The present case shows that it is important to histologically examine swollen nodes by biopsy or by sampling before deciding on the treatment strategy for gall bladder cancer with swollen lymph nodes.

[Examination of resectable and borderline pancreatic cancer treated with neoadjuvant chemoradiation therapy].

PURPOSE: The purpose of this study was to determine the effect of neoadjuvant chemotherapy( NAC) and chemoradiation therapy( NAC-RT) for the treatment of potentially resectable( PR) and borderline resectable( BR) pancreatic cancer. METHODS: Patients with PR (n=14) and BR (n=13) pancreatic cancer who received NAC (n=15) or NAC-RT (n=12) were enrolled in our study. NAC comprised 2 cycles of S-1 or S-1 plus gemcitabine, and NAC-RT comprised hyperaccelerated radiation therapy and S-1 chemotherapy. RESULTS: According to the Response Evaluation Criteria in Solid Tumors (RECIST), partial response was observed in 10 patients( 37%); stable disease( SD), in 11 patients( 41%); and progressive disease (PD), in 6 patients (22%). The rates of curative surgery in patients with PR and BR pancreatic cancer were 57% and 38%, respectively. Curative surgery was performed in 8 patients with PR pancreatic cancer. Downstaging was observed in 3 patients and upstaging was observed in 1 patient. During the postoperative course, peritoneal dissemination was detected in 2 patients at 4 months after surgery. One patient survived for more than 3 years. Curative surgery was performed in 5 patients with BR pancreatic cancer. Downstaging was observed in 4 patients, and upstaging was observed in 1 patient. During the postoperative course, recurrence was detected in 3 patients and the remaining 2 patients survived with a recurrence-free status. CONCLUSION: The results of the present study indicate that NAC-RT may be useful for the treatment of patients with PR or BR pancreatic cancer. However, this protocol has disadvantages in that the possibility of resectability might be compromised and early recurrence might occur. Thus, this protocol warrants further evaluation.

Interferon-alpha modulates the chemosensitivity of CD133-expressing pancreatic cancer cells to gemcitabine.

Pancreatic cancer is a lethal disease as current chemotherapies with gemcitabine (GEM) are still insufficient. Accumulating evidence suggests that cancer stem cells (CSC) are responsible for chemoresistance and that CD133 is one of the CSC markers in pancreatic cancer. Interferon-alpha (IFN-α), a cytokine with pleiotropic effects, has direct cytotoxic and cytostatic effects on tumor cells. The aim of the present study was to investigate whether IFN-α can modulate the chemosensitivity of a human pancreatic cancer cell line, Capan-1, to GEM. Cell cycles were evaluated for response to GEM with and without IFN-α by BrdU assay. GEM inhibited Capan-1 cell growth in a dose-dependent manner. GEM (IC(50); 100 ng/mL) treatment reduced the number of both CD133(+) and CD133(-) cells in the S phase, induced apoptosis of CD133(-) cells more than that of CD133(+) cells and increased accumulation of CD133(+) cells into the G0/G1 phase. These results infer that CD133(+) cells take shelter into the G0/G1 phase from GEM treatment. IFN-α modulated CD133(+) cells from the G0/G1 phase to the S phase. Consequently, apoptosis was accelerated in both CD133(+) and CD133(-) cells after IFN-α combined with GEM treatment. Furthermore, GEM combined with IFN-α treatment showed a significant tumor suppressive effect in the in vivo study. Importantly, CD133(+) cells showed CSC-like properties, such as generation of spheres, highly invasive ability and high tumorigenesis. These results suggest that IFN-α, as a modulator, could contribute to the treatment of CD133(+) cancer cells and be effective in combined chemotherapies with GEM for pancreatic cancer stem-like cells.

Clinical significance of folate receptor ß-expressing tumor-associated macrophages in pancreatic cancer.

PURPOSE: To examine the appearance and distribution of folate receptor ß-expressing (FRß+) macrophages in the pancreatic tumor microenvironment and their relationship to metastasis and prognosis in pancreatic cancer patients. METHODS: Tumor samples were obtained from 76 patients with pancreatic cancer who underwent curative resection. None of these patients had received any preoperative chemotherapy or radiotherapy. Both FRß+ and tumor-infiltrating (CD68+) macrophages were examined in each tumor specimen by immunohistochemical and immunofluorescence staining using a newly developed anti-human FRß monoclonal antibody and CD68 antibody. The appearance, distribution, expression of vascular endothelial growth factor (VEGF) on FRß-expressing or CD68+ macrophages, and tumor microvessel density (MVD) were assessed. Log rank test and Cox proportional hazard regression were used to investigate the associations among CD68+ or FRß+ macrophages, clinicopathologic factors, and overall survival. RESULTS: FRß+ macrophages were prominent in the perivascular regions of the tumor-invasive front and a specific subset with VEGF expression in the CD68+ macrophages. A high number of FRß+ macrophages showed a positive association with high MVD, a high incidence of hematogenous metastasis, and a poor prognosis in pancreatic cancer patients. CONCLUSIONS: FRß+ macrophages are a novel subset of tumor-associated macrophages in pancreatic cancer and may play an important role in the tumor microenvironment in association with systemic metastasis through the interaction with tumor cells and vessels. FRß+ macrophages may be promising a targeting therapy for pancreatic cancer.

Epithelial-mesenchymal transition and mesenchymal-epithelial transition via regulation of ZEB-1 and ZEB-2 expression in pancreatic cancer.

UNLABELLED: BACKGROUND AND OBJECTIES: Phenotypic plasticity of cancer cells via epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET) is essential for tumor progression and metastasis. METHODS: Tissue samples were obtained from 76 pancreatic head cancers. We assessed the expression of E-cadherin, vimentin, ZEB-1, and ZEB-2 by immunohistochemical and immunofluorescence staining. Next, 147 metastatic lymph nodes from 45 pancreatic cancers with low expression of E-cadherin were obtained and divided into two categories according to the maximum diameter of the metastases: 2 mm or more and less than 2 mm. RESULTS: High expressions of ZEB-1 and ZEB-2 in the primary tumors were significantly associated with repression of E-cadherin (P = 0.0007), and poorer prognosis (P = 0.0322). Forty-three (29.3%) of the 147 metastatic tumors from pancreatic cancers with low expression of E-cadherin showed high E-cadherin expression. Cancer cells in the larger metastases showed high expression of E-cadherin (P = 0.0061) and low expression of ZEB-1 (P = 0.0170) and ZEB-2 (P = 0.0036) compared with those in the smaller metastases. CONCLUSIONS: In primary pancreatic tumors and metastatic lymph nodes, high and low expression of ZEB-1 and ZEB-2 was associated with mesenchymal and epithelial phenotype of cancer cells, respectively.

Successful suppression of endogenous α-1,3-galactosyltransferase expression by RNA interference in pig embryos generated in vitro.

RNA interference (RNAi) technology using small interfering RNAs (siRNA) has been widely used as a powerful tool to knock down gene expression in various organisms. In pig preimplantation embryos, no attempt to suppress the target gene expression with such technology has been made. The purpose of this study is to demonstrate that the RNAi technology is useful for suppression of endogenous target gene expression at an early stage of development in pigs. Alpha-1,3-Galactosyltransferase (α-GalT) is an enzyme that creates the Galα1-3Gal (α-Gal) epitope on the cell surface in some mammalian species, and removal of the epitope is considered to be a prerequisite for pig-to-human xenotransplantation. We decided to suppress the endogenous α-GalT mRNA expression in pig early embryos, since reduction of α-GalT synthesis is easily monitored by cytochemical staining with Bandeiraea simplicifolia isolectin-B(4), a lectin that specifically binds to the α-Gal epitope, and by RT-PCR analysis. Cytoplasmic microinjection of double-stranded RNA and pronuclear injection of an siRNA expression vector into the embryos generated in vitro resulted in a significant reduction in expression of the α-GalT gene and α-Gal epitope in blastocysts, at which stage the α-Gal epitope is abundantly expressed. Somatic cell nuclear transfer of embryonic fibroblasts stably transfected with an siRNA expression vector also led to a significant reduction in the level of α-GalT mRNA synthesis together with decreased amounts of the α-Gal epitope at the blastocyst stage. These results indicate that the RNAi technology is useful for efficient suppression of a target gene expression during embryogenesis in pigs and suggest the possibility of production of siRNA-expressing pigs for use in xenotransplantation.

Effect of postactivation treatment with latrunculin A on in vitro and in vivo development of cloned embryos derived from kidney fibroblasts of an aged Clawn miniature boar.

The objective of this study was to examine the effect of postactivation treatment with latrunculin A (LatA), an actin polymerization inhibitor, on in vitro and in vivo development of somatic cell nuclear transfer (SCNT) embryos derived from kidney fibroblasts of an aged Clawn miniature boar (12 years old). After electric activation, SCNT embryos were treated with 0, 0.5 or 1 µM LatA and cultured in vitro. The rate of blastocyst formation was significantly higher (P<0.05) in SCNT embryos treated with 0.5 µM LatA (38%) than those in control (14%). When cloned embryos treated with 0.5 µM LatA were transferred into the oviducts of two recipient miniature gilts to assess their development in vivo, both recipients became pregnant; one maintained pregnancy to term, and a live piglet (weighing 220 g) was delivered by Caesarean section. The results of this study indicated that the postactivation treatment with LatA was effective in improving in vitro developmental capacity of SCNT miniature pig embryos derived from kidney fibroblasts of an aged animal and that miniature pig cloned embryos treated with LatA had the ability to develop to term.

[A case of pancreatic cancer with liver metastasis controlled effectively by chemotherapy based on chemosensitivity test and stereotactic body radiotherapy].

A 5 5-year-old woman was admitted to our hospital for pancreatic cancer with liver metastasis. We performed pancreatoduodenectomy, D2 dissection, and partial liver resection. Tissue from a resected liver metastasis was submitted to a chemosensitivity test. Based on the test results, we performed systemic chemotherapy with paclitaxel and hepatic artery infusion with gemcitabine for lung and liver metastasis after surgery. Furthermore, we added stereotactic body radiation therapy(SBRT)(48 Gy/4 Fr)for 3 liver metastases that showed enlargement after chemotherapy. Effective control of recurrent tumors was possible for 2 years and 5 month, and she maintained normal daily activities. She died of peritoneal dissemination 3 years and one month after surgery. Combined modality therapy with anticancer agents based on a chemosensitivity test and SBRT may be one useful therapy for pancreatic cancer with distant metastases.

Prognostic relevance of morphological types of intraductal papillary mucinous neoplasms of the pancreas.

OBJECTIVE: The clinicopathological significance of four morphological types of intraductal papillary mucinous neoplasms of the pancreas (IPMNs; gastric, intestinal, pancreatobiliary and oncocytic) was assessed. DESIGN: Retrospective multicentre analysis of 283 surgically resected IPMNs. RESULTS: Of the 283 IPMNs, 139 were of the gastric type, 101 were intestinal, 19 were pancreatobiliary and 24 were oncocytic. These types were significantly associated with clinicopathological factors including sex (p = 0.0032), age (p = 0.00924), ectatic duct size (p = 0.0245), detection of mural nodules (p = 4.09 × 10⁻6), histological grade (p < 2.20 × 10⁻¹6), macroscopic types with differential involvement of the pancreatic duct system (p = 3.91 × 10⁻5), invasive phenotypes (p = 3.34 × 10⁻¹²), stage (p < 2.20 × 10⁻¹6) and recurrence (p = 0.00574). Kaplan-Meier analysis showed significant differences in patient survival by morphological type (p = 5.24 × 10⁻6). Survival rates at 5 and 10 years, respectively, were 0.937 (95% CI 0.892 to 0.984) for patients with gastric-type IPMNs; 0.886 (95% CI 0.813 to 0.965) and 0.685 (95% CI 0.553 to 0.849) for those with intestinal-type IPMNs; 0.839 (95% CI 0.684 to 1.000) and 0.734 (95% CI 0.526 to 1.000) for those with oncocytic-type IPMNs; and 0.520 (95% CI 0.298 to 0.909) and undetermined for those with pancreatobiliary-type IPMNs. Analysis by the Cox proportional hazards model comparing prognostic risks determined by stage and the morphological and macroscopic types indicated that staging was the most significant predictor of survival (p = 3.68×10⁻8) followed by the morphological type (p = 0.0435). Furthermore, the morphological type remained a significant predictor in a subcohort of invasive cases (p = 0.0089). CONCLUSION: In this multicentre retrospective analysis, the morphological type of IPMN appears to be an independent predictor of patient prognosis.