Postoperative long­term outcomes of acute normovolemic hemodilution in pancreatic cancer: A propensity score matching analysis.

Acute normovolemic hemodilution (ANH) is a useful intraoperative blood conservation technique. However, the impact on long-term outcomes in pancreatic ductal adenocarcinoma (PDAC) remains unclear. The present study investigated the impact of ANH on long-term outcomes in patients with PDAC undergoing radical surgery. Data from 155 resectable PDAC cases were collected. Patients were categorized according to whether or not they had received intraoperative allogeneic blood transfusion (ABT) or ANH. Postoperative complications, recurrence-free survival (RFS) and disease-specific survival (DSS), before and after propensity score matching (PSM), were compared among patients who did and did not receive ANH. A total of 44 patients (28.4%) were included in the ANH group and 30 patients (19.4%) were included in the ABT group; 81 (52.3%) patients, comprising the standard management (STD) group, received neither ANH nor ABT. The ABT group had the worst prognosis among them. Before PSM, ANH was significantly associated with decreased RFS (P=0.043) and DSS (P=0.029) compared with the STD group before applying Bonferroni correction; however, no significant difference was observed after applying Bonferroni correction. Cox regression analysis identified ANH as an independent prognostic factor for RFS [relative risk (RR), 1.696; P=0.019] and DSS (RR, 1.876; P=0.009). After PSM, the ANH group exhibited less favorable RFS [median survival time (MST), 12.1 vs. 18.1 months; P=0.097] and DSS (MST, 32.1 vs. 50.5 months; P=0.097) compared with the STD group; however, these differences were not statistically significant. In conclusion, while ANH was not as harmful as ABT, it exhibited potentially more negative effects on long-term postoperative outcomes in PDAC than STD.

Revealing the role of early peripancreatic bacterial contamination and Enterococcus faecalis in pancreatic fistula development after pancreaticoduodenectomy: Implications for useful antibiotic prophylaxis-An observational cohort study.

BACKGROUND: Peripancreatic bacterial contamination (PBC) is a critical factor contributing to the development of clinically relevant postoperative pancreatic fistula (CR-POPF) following pancreaticoduodenectomy (PD). Controlling pathogenic bacteria is essential in preventing CR-POPF; however, the precise relationship between specific bacteria and CR-POPF remains unclear. This study aimed to investigate the relationship between PBC and CR-POPF after PD, with a focus on identifying potentially causative bacteria. METHODS: This prospective observational study enrolled 370 patients who underwent PD. Microbial cultures were routinely collected from peripancreatic drain fluid on postoperative days (PODs) 1, 3, and 6. Predictive factors for CR-POPF and the bacteria involved in PBC were investigated. RESULTS: CR-POPF occurred in 86 (23.2%) patients. In multivariate analysis, PBC on POD1 (Odds ratio [OR] = 3.59; P = 0.005) was one of the main independent predictive factors for CR-POPF, while prophylactic use of antibiotics other than piperacillin/tazobactam independently influenced PBC on POD1 (OR = 2.95; P = 0.010). Notably, Enterococcus spp., particularly Enterococcus faecalis, were significantly isolated from PBC in patients with CR-POPF compared to those without CR-POPF on PODs 1 and 3 (P < 0.001), and they displayed high resistance to all cephalosporins. CONCLUSIONS: Early PBC plays a pivotal role in the development of CR-POPF following PD. Prophylactic antibiotic administration, specifically targeting Enterococcus faecalis, may effectively mitigate early PBC and subsequently reduce the risk of CR-POPF. This research sheds light on the importance of bacterial control strategies in preventing CR-POPF after PD.

Follicular dendritic cell sarcoma arising from the lymph node of the pancreatic head: a case report with literature review.

A 72-year-old man was referred to our hospital for the examination of a pancreatic head mass. Abdominal computed tomography revealed a contrasted 8-cm-diameter tumor extending from the dorsal pancreatic head to the porta hepatis. The preoperative diagnosis was challenging due to the absence of specific imaging findings and the inability to perform a biopsy. Positron emission tomography/computed tomography and diffusion-weighted imaging suggested a malignant tumor originating from the organs surrounding the pancreatic head. Subtotal stomach-preserving pancreaticoduodenectomy with regional lymph node dissection was performed, as dissection from the pancreatic head proved unfeasible. Pathological examination identified the tumor as an enlarged lymph node consisting of pleomorphic large cells forming clusters, positive for follicular dendritic cell markers cluster of differentiation (CD) 21 and CD23. No evidence of tumor capsule infiltration, other organ infiltration, or metastasis to other lymph nodes was observed. The final diagnosis was nodal follicular dendritic cell sarcoma (FDCS) originating from the pancreatic head lymph nodes. No recurrence occurred at 3 years postoperatively with no postoperative treatment. Intraperitoneal nodal FDCS is extremely rare, and occasionally, it can lead to postoperative recurrence and progression. It is crucial to differentiate neoplastic lymph node enlargement around the pancreatic head from nodal FDCS.

Noninvasive Computed Tomography-Based Deep Learning Model Predicts In Vitro Chemosensitivity Assay Results in Pancreatic Cancer.

OBJECTIVES: We aimed to predict in vitro chemosensitivity assay results from computed tomography (CT) images by applying deep learning (DL) to optimize chemotherapy for pancreatic ductal adenocarcinoma (PDAC). MATERIALS AND METHODS: Preoperative enhanced abdominal CT images and the histoculture drug response assay (HDRA) results were collected from 33 PDAC patients undergoing surgery. Deep learning was performed using CT images of both the HDRA-positive and HDRA-negative groups. We trimmed small patches from the entire tumor area. We established various prediction labels for HDRA results with 5-fluorouracil (FU), gemcitabine (GEM), and paclitaxel (PTX). We built a predictive model using a residual convolutional neural network and used 3-fold cross-validation. RESULTS: Of the 33 patients, effective response to FU, GEM, and PTX by HDRA was observed in 19 (57.6%), 11 (33.3%), and 23 (88.5%) patients, respectively. The average accuracy and the area under the receiver operating characteristic curve (AUC) of the model for predicting the effective response to FU were 93.4% and 0.979, respectively. In the prediction of GEM, the models demonstrated high accuracy (92.8%) and AUC (0.969). Likewise, the model for predicting response to PTX had a high performance (accuracy, 95.9%; AUC, 0.979). CONCLUSIONS: Our CT patch-based DL model exhibited high predictive performance in projecting HDRA results. Our study suggests that the DL approach could possibly provide a noninvasive means for the optimization of chemotherapy.

Differential diagnoses of gallbladder tumors using CT-based deep learning.

Background: The differential diagnosis between gallbladder cancer (GBC) and xanthogranulomatous cholecystitis (XGC) remains quite challenging, and can possibly lead to improper surgery. This study aimed to distinguish between XGC and GBC by combining computed tomography (CT) images and deep learning (DL) to maximize the therapeutic success of surgery. Methods: We collected a dataset, including preoperative CT images, from 28 cases of GBC and 21 XGC patients undergoing surgery at our facility. It was subdivided into training and validation (n = 40), and test (n = 9) datasets. We built a CT patch-based discriminating model using a residual convolutional neural network and employed 5-fold cross-validation. The discriminating performance of the model was analyzed in the test dataset. Results: Of the 40 patients in the training dataset, GBC and XGC were observed in 21 (52.5%), and 19 (47.5%) patients, respectively. A total of 61 126 patches were extracted from the 40 patients. In the validation dataset, the average sensitivity, specificity, and accuracy were 98.8%, 98.0%, and 98.5%, respectively. Furthermore, the area under the receiver operating characteristic curve (AUC) was 0.9985. In the test dataset, which included 11 738 patches, the discriminating accuracy for GBC patients after neoadjuvant chemotherapy (NAC) (n = 3) was insufficient (61.8%). However, the discriminating model demonstrated high accuracy (98.2%) and AUC (0.9893) for cases other than those receiving NAC. Conclusion: Our CT-based DL model exhibited high discriminating performance in patients with GBC and XGC. Our study proposes a novel concept for selecting the appropriate procedure and avoiding unnecessary invasive measures.

Necrotizing pancreatitis complicated by retroperitoneal emphysema: two case reports.

BACKGROUND: Emphysematous pancreatitis is acute pancreatitis associated with emphysema based on imaging studies and has been considered a subtype of necrotizing pancreatitis. Although some recent studies have reported the successful use of conservative treatment, it is still considered a serious condition. Computed tomography (CT) scan is useful in identifying emphysema associated with acute pancreatitis; however, whether the presence of emphysema correlates with the severity of pancreatitis remains controversial. In this study, we managed two cases of severe acute pancreatitis complicated with retroperitoneal emphysema successfully by treatment with lavage and drainage. CASE PRESENTATION: Case 1: A 76-year-old man was referred to our hospital after being diagnosed with acute pancreatitis. At post-admission, his abdominal symptoms worsened, and a repeat CT scan revealed increased retroperitoneal gas. Due to the high risk for gastrointestinal tract perforation, emergent laparotomy was performed. Fat necrosis was observed on the anterior surface of the pancreas, and a diagnosis of acute necrotizing pancreatitis with retroperitoneal emphysema was made. Thus, retroperitoneal drainage was performed. Case 2: A 50-year-old woman developed anaphylactic shock during the induction of general anesthesia for lumbar spine surgery, and peritoneal irritation symptoms and hypotension occurred on the same day. Contrast-enhanced CT scan showed necrotic changes in the pancreatic body and emphysema surrounding the pancreas. Therefore, she was diagnosed with acute necrotizing pancreatitis with retroperitoneal emphysema, and retroperitoneal cavity lavage and drainage were performed. In the second case, the intraperitoneal abscess occurred postoperatively, requiring time for drainage treatment. Both patients showed no significant postoperative course problems and were discharged on postoperative days 18 and 108, respectively. CONCLUSION: Acute pancreatitis with emphysema from the acute phase highly indicates severe necrotizing pancreatitis. Surgical drainage should be chosen without hesitation in necrotizing pancreatitis with emphysema from early onset.

Single-Port Laparoscopic Duodenojejunostomy Employing Semi-Kocherization for a Young Female with Superior Mesenteric Artery Syndrome.

Single-port laparoscopic duodenojejunostomy employing semi-Kocherization performed for a patient with superior mesenteric artery (SMA) syndrome is presented in this report. A 24-year-old woman missed meals due to work pressure, and her body weight decreased from 42 kg to 27 kg within 6 months. After this severe weight loss, she suffered from postprandial abdominal pain. An enhanced computed tomography revealed that the aortomesenteric angle was 11° (narrow), and the distance was short at 4.5 mm. Duodenography also revealed dilatation of the proximal duodenum. These findings led to a diagnosis of SMA syndrome, and we performed single-port laparoscopic duodenojejunostomy. We first dissected the fusion between the duodenum and transverse mesocolon, such as Kocherization, enough to mobilize the duodenum; this procedure was termed semi-Kocherization. A gauze was placed in the dissected space for a landmark from the transverse mesocolon side. We confirmed the gauze at the duodenum's lateral side, then opened the transverse mesocolon, and pulled the duodenum out. We performed side-to-side duodenojejunostomy. The postoperative course was unremarkable, and she gained 4 kg within 2 months of discharge. Semi-Kocherization is shown to be an effective technique to increase duodenal mobility for performing anastomosis, and single-port laparoscopic surgery can reduce wounds and increase cosmesis.

CT-based deep learning enables early postoperative recurrence prediction for intrahepatic cholangiocarcinoma.

Preoperatively accurate evaluation of risk for early postoperative recurrence contributes to maximizing the therapeutic success for intrahepatic cholangiocarcinoma (iCCA) patients. This study aimed to investigate the potential of deep learning (DL) algorithms for predicting postoperative early recurrence through the use of preoperative images. We collected the dataset, including preoperative plain computed tomography (CT) images, from 41 patients undergoing curative surgery for iCCA at multiple institutions. We built a CT patch-based predictive model using a residual convolutional neural network and used fivefold cross-validation. The prediction accuracy of the model was analyzed. We defined early recurrence as recurrence within a year after surgical resection. Of the 41 patients, early recurrence was observed in 20 (48.8%). A total of 71,081 patches were extracted from the entire segmented tumor area of each patient. The average accuracy of the ResNet model for predicting early recurrence was 98.2% for the training dataset. In the validation dataset, the average sensitivity, specificity, and accuracy were 97.8%, 94.0%, and 96.5%, respectively. Furthermore, the area under the receiver operating characteristic curve was 0.994. Our CT-based DL model exhibited high predictive performance in projecting postoperative early recurrence, proposing a novel insight into iCCA management.

Development of a Biomarker-Based Scoring System Predicting Early Recurrence of Resectable Pancreatic Duct Adenocarcinoma.

BACKGROUND: Resectable pancreatic ductal adenocarcinoma (R-PDAC) often recurs early after radical resection, which is associated with poor prognosis. Predicting early recurrence preoperatively is useful for determining the optimal treatment. PATIENTS AND METHODS: One hundred and seventy-eight patients diagnosed with R-PDAC on computed tomography (CT) imaging and undergoing radical resection at Hirosaki University Hospital from 2005 to 2019 were retrospectively analyzed. Patients with recurrence within 6 months after resection formed the early recurrence (ER) group, while other patients constituted the non-early recurrence (non-ER) group. Early recurrence prediction score (ERP score) was developed using preoperative parameters. RESULTS: ER was observed in 45 patients (25.3%). The ER group had significantly higher preoperative CA19-9 (p = 0.03), serum SPan-1 (p = 0.006), and CT tumor diameter (p = 0.01) compared with the non-ER group. The receiver operating characteristic (ROC) curve analysis identified cutoff values for CA19-9 (133 U/mL), SPan-1 (78.2 U/mL), and preoperative tumor diameter (23 mm). When the parameter exceeded the cutoff level, 1 point was given, and the total score of the three factors was defined as the ERP score. The group with an ERP score of 3 had postoperative recurrence-free survival (RFS) of 5.5 months (95% CI 3.02-7.98). Multivariate analysis for ER-related perioperative and surgical factors identified ERP score of 3 [odds ratio (OR) 4.63 (95% CI 1.82-11.78), p = 0.0013] and R1 resection [OR 3.20 (95% CI 1.01-10.17), p = 0.049] as independent predictors of ER. CONCLUSIONS: For R-PDAC, ER could be predicted by the scoring system using preoperative serum CA19-9 and SPan-1 levels and CT tumor diameter, which may have great significance in identifying patients with poor prognoses and avoiding unnecessary surgery.

Intraoperative Allogeneic Red Blood Cell Transfusion Negatively Influences Prognosis After Radical Surgery for Pancreatic Cancer: A Propensity Score Matching Analysis.

OBJECTIVE: We aimed to investigate the real impact of allogeneic red blood cell transfusion (ABT) on postoperative outcomes in resectable pancreatic ductal adenocarcinoma (PDAC) patients. METHODS: Of 128 patients undergoing resectable PDAC surgery at our facility, 24 (18.8%) received ABT. Recurrence-free survival (RFS) and disease-specific survival (DSS), before and after propensity score matching (PSM), were compared among patients who did and did not receive ABT. RESULTS: In the entire cohort, ABT was significantly associated with decreased RFS (P = 0.002) and DSS (P = 0.014) before PSM. Cox regression analysis identified ABT (risk ratio, 1.884; 95% confidence interval, 1.015-3.497; P = 0.045) as an independent prognostic factor for RFS. Univariate and multivariate analysis identified preoperative hemoglobin value, preoperative total bilirubin value, and intraoperative blood loss as significant independent risk factors for ABT. Using these 3 variables, PSM analysis created 16 pairs of patients. After PSM, the ABT group had significantly poorer RFS rates than the non-ABT group (median, 9.8 vs 15.8 months, P = 0.022). Similar tendencies were found in DSS rates (median, 19.4 vs 40.0 months, P = 0.071). CONCLUSIONS: This study revealed certain negative effects of intraoperative ABT on postoperative survival outcomes in patients with resectable PDAC.

Prediction of massive bleeding in pancreatic surgery based on preoperative patient characteristics using a decision tree.

Massive intraoperative blood loss (IBL) negatively influence outcomes after surgery for pancreatic ductal adenocarcinoma (PDAC). However, few data or predictive models are available for the identification of patients with a high risk for massive IBL. This study aimed to build a model for massive IBL prediction using a decision tree algorithm, which is one machine learning method. One hundred and seventy-five patients undergoing curative surgery for resectable PDAC at our facility between January 2007 and October 2020 were allocated to training (n = 128) and testing (n = 47) sets. Using the preoperatively available data of the patients (34 variables), we built a decision tree classification algorithm. Of the 175 patients, massive IBL occurred in 88 patients (50.3%). Binary logistic regression analysis indicated that alanine aminotransferase and distal pancreatectomy were significant predictors of massive IBL occurrence with an overall correct prediction rate of 70.3%. Decision tree analysis automatically selected 14 predictive variables. The best predictor was the surgical procedure. Though massive IBL was not common, the outcome of patients with distal pancreatectomy was secondarily split by glutamyl transpeptidase. Among patients who underwent PD (n = 83), diabetes mellitus (DM) was selected as the variable in the second split. Of the 21 patients with DM, massive IBL occurred in 85.7%. Decision tree sensitivity was 98.5% in the training data set and 100% in the testing data set. Our findings suggested that a decision tree can provide a new potential approach to predict massive IBL in surgery for resectable PDAC.

Eukaryotic initiation factor 2 signaling behind neural invasion linked with lymphatic and vascular invasion in pancreatic cancer.

Perineural invasion (PNI) is a typical poor prognostic factor in pancreatic ductal adenocarcinoma (PDAC). The mechanisms linking PNI to poor prognosis remain unclear. This study aimed to clarify what changes occurred alongside PNI in PDAC. A 128-patient cohort undergoing surgery for early-stage PDAC was evaluated. Subdivided into two groups, according to pathological state, a pancreatic nerve invasion (ne) score of less than three (from none to moderate invasion) was designated as the low-grade ne group. The high-grade (marked invasion) ne group (74 cases, 57.8%) showed a higher incidence of lymphatic metastasis (P = 0.002), a higher incidence of early recurrence (P = 0.004), decreased RFS (P < 0.001), and decreased DSS (P < 0.001). The severity of lymphatic (r = 0.440, P = 0.042) and venous (r = 0.610, P = 0.002) invasions was positively correlated with the ne score. Tumors having abundant stroma often displayed severe ne. Proteomics identified eukaryotic initiation factor 2 (EIF2) signaling as the most significantly enriched pathway in high-grade ne PDAC. Additionally, EIF2 signaling-related ribosome proteins decreased according to severity. Results showed that PNI is linked with lymphatic and vascular invasion in early-stage PDAC. Furthermore, the dysregulation of proteostasis and ribosome biogenesis can yield a difference in PNI severity.

A case report of mucinous adenocarcinoma derived from intra-ampullary papillary-tubular neoplasm with a malignant course.

BACKGROUND: Intra-ampullary papillary-tubular neoplasm (IAPN) has been classified as a Vater papillary tumor. The prognosis of IAPN is generally relatively good. Here, we describe a patient with a mucinous adenocarcinoma cluster in the Vater papilla of IAPN origin. CLINICAL PRESENTATION: The patient was a 66-year-old man who was admitted to our hospital after a diagnosis of pancreatic head carcinoma based on a pancreatic duct dilatation found on abdominal ultrasound. CT showed a 40 mm lesion in the pancreatic head and expansion of the main pancreatic duct to a maximum diameter of 9 mm on the caudal side of the lesion. The extrahepatic bile duct had also expanded to a maximum diameter of 8 mm. PET/CT showed fluorodeoxyglucose (FDG) accumulation of SUVmax 6.02 that corresponded to the tumor in the pancreatic head, though it did not suggest distant metastasis. The patient was diagnosed with pancreatic head carcinoma T3 N0 M0 Stage IIA and underwent a pancreaticoduodenectomy. Pathology indicated that the tumor in the pancreatic head was a benign inflammatory lesion. On the other hand, the papillotubular tumor pervading the lumen in the duodenal papillary common channel met the criteria for IAPN, and a mucinous adenocarcinoma cluster found in the surrounding stroma suggested malignant transformation of IAPN. No metastasis to lymph nodes was demonstrated. With regard to the mucus phenotype of each lesion, the IAPN was MUC2 and MUC5AC positive, while the mucinous adenocarcinoma was MUC2-positive and MUC5AC-negative. In addition, CD10 was negative in both lesions, suggesting that mucus transformation from the gastric type to the intestinal type was a key element. A blood test 10 months after surgery showed increased CA19-9 (105 U/mL) and CEA (7.1 ng/mL). Abdominal CT showed multiple cystoid nodes in the liver, which were diagnosed as multiple liver metastases of mucinous adenocarcinoma transformed from the IAPN. CONCLUSIONS: We reported a case with IAPN that developed in the Vater papilla, which took an extremely malignant course. IAPN generally has a good prognosis, but it is important to understand that a malignant course may occur.

Organ/space infection is a common cause of high output stoma and outlet obstruction in diverting ileostomy.

BACKGROUND: The objectives of this study are to identify causes of high-output stoma (HOS) and outlet obstruction (OO), which are major complications of diverting ileostomy. METHODS: A retrospective analysis was performed in 103 patients who underwent colorectal surgery and diverting ileostomy between December 2015 and November 2018. RESULTS: HOS was found in 32 patients (31.1%) and OO in 19 (18.4%). Organ/space surgical site infection (SSI), anastomotic leakage and OO were significant HOS-related factors in univariate analysis, and OO (odds ratio [OR] 3.39, p = 0.034) was a independent HOS-related factor in multivariate analysis. Organ/space SSI and male were significant OO-related factors in univariate analysis, and organ/space SSI (OR 3.77, p = 0.018) was a independent OO-related factor in multivariate analysis. The white blood cell (WBC) count on postoperative day (POD) 3 was significantly higher in the HOS group compared to the non-HOS group (9765 vs. 8130 /mL, p < 0.05), and the WBC count (9400 vs. 7475 /mL, p < 0.05) and C-reactive protein level (6.01 vs. 2.92 mg/L, p < 0.05) on POD 6 were significantly higher in the OO group compared to the non-OO group. CONCLUSION: Organ/space infection is involved in the common pathology of HOS and OO. Decreased intestinal absorption due to intestinal edema caused by organ/space SSI and relative stenosis at the abdominal wall-penetrating site are major causes of HOS and OO.

[A Case of Non-Resectable Pancreatic Cancer with Multiple Hepatic Metastases Treated with FOLFIRINOX Therapy and Conversion Surgery].

A 50-year-old woman was diagnosed as having pancreatic head cancer with multiple hepatic metastases. FOLFIRINOX therapy was initiated. After completing 18 courses of therapy, partial remission(PR)was achieved based on images, and surgery was then planed. The subtotal stomach-preserving pancreaticoduodenectomy and hepatic S7 partial resection were performed. Macroscopically, complete resection was achieved. Regarding pathological findings of the primary lesion and hepatic metastatic lesions, fibrous formation and hyalinizing condition induced by chemotherapy were noted; moreover, complete disappearance of cancer cells was detected. However, metastasis of poorly differentiated adenocarcinoma was detected in 12b lymph node tissue. One month after the surgery, postoperative adjunctive chemotherapy with S-1 was initiated. However, new hepatic metastasis was detected 3 months after the surgery. Although recurrence treatment was initiated, the disease progressed, and the patient died 11 months after the surgery.

Increase of Tumor Infiltrating γδ T-cells in Pancreatic Ductal Adenocarcinoma Through Remodeling of the Extracellular Matrix by a Hyaluronan Synthesis Suppressor, 4-Methylumbelliferone.

OBJECTIVES: Desmoplastic changes of extracellular matrix (ECM) containing large amounts of hyaluronan (HA) are of interest in chemo- and immunoresistance of pancreatic ductal adenocarcinoma (PDAC). The goal of this study was to evaluate the effects of 4-methylumbelliferone (MU), a selective inhibitor of HA, on ECM and to examine how MU affects adoptive immunotherapy. METHODS: The effect of MU on cell proliferation, HA synthesis and formation of ECM were investigated in four PDAC cell lines. In addition, the cytotoxicity of γδ T-cell-rich peripheral blood mononuclear cells (PBMCs) collected from healthy donors and stimulated with zoledronate and interleukin-2 was examined in the presence of MU. The amount of HA and tumor-infiltrating lymphocytes were also investigated in mice xenograft models. RESULTS: In vitro, 1.0 mM MU inhibited cell proliferation by 45-70% and HA synthesis by 55-80% in all four PDAC cell lines, and enhanced γδ T-cell-rich PBMC-mediated cytotoxicity against PDAC cells. In vivo, MU reduced intratumoral HA and promoted infiltration of inoculated γδ T-cells into tumor tissue, and consequently suppressed tumor growth. CONCLUSIONS: 4-methylumbelliferone may be an effective immunosensitizer against PDAC through induction of structural changes in the ECM.

4-Methylumbelliferone Decreases the Hyaluronan-rich Extracellular Matrix and Increases the Effectiveness of 5-Fluorouracil.

BACKGROUND/AIM: Pancreatic cancer responds poorly to most chemotherapeutic agents. Several studies have reported that hyaluronan (HA)-rich extracellular matrix (ECM) is a biological barrier against chemotherapeutic agents. 4-methylumbelliforone (MU) led to inhibition of HA synthesis and its preservation in ECM, which may enhance 5-fluorouracil (5-FU) cytotoxicity. Thus, new therapy with MU and 5-FU may be developed for pancreatic cancer. MATERIALS AND METHODS: A 5-fluorouracil (5-FU) concentration and 4-methylumbelliferone (MU) dosage was analyzed by high-performance liquid chromatography (HPLC). Change in antitumor efficacy of 5-FU in combination with MU was also examined in vivo and in vitro. RESULTS: Combined 5-FU and MU treatment inhibited cell proliferation better than 5-FU alone; 0.01 mM 5-FU alone decreased cell proliferation by 37.7 %, while 0.01 mM 5-FU with 0.5 mM MU decreased cell proliferation by 57.4%. MU enhanced the intracellular concentration of 5-FU by 47.3% compared to control. Mice tumors treated with 5-FU and MU decreased in size and animal survival was prolonged. Moreover, MU decreased cohesiveness of the intercellular space. CONCLUSION: Combination therapy of 5-FU with MU was effective. A novel therapy can be designed for pancreatic cancer by using ECM modulation.

4-Methylumbelliferone Suppresses Hyaluronan Synthesis and Tumor Progression in SCID Mice Intra-abdominally Inoculated With Pancreatic Cancer Cells.

OBJECTIVES: Pancreatic ductal adenocarcinoma contains large amounts of the glycosaminoglycan hyaluronan (HA), which is involved in various physiological processes. Here, we aimed to clarify the anticancer mechanisms of 4-methylumbelliferone (MU), a well-known HA synthesis inhibitor. METHODS: MIA PaCa-2 human pancreatic cancer cells were used. We evaluated cellular proliferation, migration, and invasion in the presence of MU, exogenous HA, and an anti-CD44 antibody. We also analyzed apoptosis, CD44 expression, and HA-binding ability using flow cytometry. The HA content in tumor tissue was quantified and histopathologically investigated in mice who had been inoculated with cancer cells. RESULTS: In vitro, MU inhibited pericellular HA matrix formation; however, HAS3 mRNA was up-regulated. Treatment with 0.5 mM MU suppressed cellular proliferation by 26.4%, migration by 14.7%, and invasion by 22.7%. Moreover, MU also significantly increased apoptosis. CD44 expression and HA-binding ability were not altered by MU. In vivo, MU suppressed HA accumulation in pancreatic tumors and improved survival times in tumor-bearing mice. CONCLUSIONS: 4-Methylumbelliferone indirectly caused apoptosis in pancreatic cancer cells by inhibiting HA production. 4-Methylumbelliferone may be a promising agent in the treatment of pancreatic cancer.

Antitumor effects of the hyaluronan inhibitor 4-methylumbelliferone on pancreatic cancer.

Hyaluronan (HA) is a major component of the extracellular matrix (ECM), and influences tumor invasion and metastasis. In a previous study, the present authors reported for the first time that 4-methylumbelliferone (MU) inhibited HA synthesis and suppressed tumor growth. However, the localization of HA and the changes in ECM morphology caused by MU in pancreatic cancer remain to be examined in detail. In the present study, the cytotoxicity of MU and its effect on cellular proliferation was evaluated in the human pancreatic cancer cell line MIA PaCa-2. The amount of HA synthesized and the retention of HA around the cells were quantitatively and immunohistochemically analyzed in vitro and in vivo. Structural changes in the ECM in the tumor tissue were investigated using an electron microscope. MU treatment led to a decrease in extracellular HA retention, as evidenced by a particle exclusion assay and immunohistochemical staining. Cell proliferation was suppressed by MU in a dose-dependent manner. The release of lactate dehydrogenase into the culture medium due to damage to the cellular membrane did not increase following MU administration. In tumor-inoculated mice, MU suppressed any increase in tumor volume and decreased the quantity of HA. Electron microscopy revealed that MU attenuated the intercellular space and caused it to be less cohesive. These data indicate that MU inhibits HA synthesis and reduces the amount of HA in the ECM while exhibiting no obvious cytotoxic effect. These findings suggest that MU has potential as a novel therapeutic agent for pancreatic cancer.