Explore the vast range of titles available.

The small GTPases RalA and RalB are members of the Ras family and activated downstream of Ras. Ral proteins are found in GTP‐bound active and GDP‐bound inactive forms. The activation process is executed by guanine nucleotide exchange factors, while inactivation is mediated by GTPase‐activating proteins (GAPs). RalGAPs are complexes that consist of a catalytic α1 or α2 subunit together with a common β subunit. Several reports implicate the importance of Ral in pancreatic ductal adenocarcinoma (PDAC). However, there are few reports on the relationship between levels of RalGAP expression and malignancy in PDAC. We generated RalGAPβ‐deficient PDAC cells by CRISPR‐Cas9 genome editing to investigate how increased Ral activity affects malignant phenotypes of PDAC cells. RalGAPβ‐deficient PDAC cells exhibited several‐fold higher Ral activity relative to control cells. They had a high migratory and invasive capacity. The RalGAPβ‐deficient cells grew more rapidly than control cells when injected subcutaneously into nude mice. When injected into the spleen, the RalGAPβ‐deficient cells formed larger splenic tumors with more liver metastases, and unlike controls, they disseminated into the abdominal cavity. These results indicate that RalGAPβ deficiency in PDAC cells contributes to high activities of RalA and RalB, leading to enhanced cell migration and invasion in vitro, and tumor growth and metastasis in vivo. Ral is a Ras family small GTPase that have recently been noted as a novel signaling factor that regulates progression of pancreatic ductal adenocarcinoma (PDAC). In this study, by characterizing newly generated RalGAP‐deficient PDAC cells, we first demonstrated that Ral GTPase–activating proteins played a critical role in not only cell migration and invasion in vitro but also tumor growth and metastasis in vivo in PDAC.

The collagen gel droplet-embedded drug sensitivity test (CD-DST) was revealed to be useful for predicting the effect of S-1 adjuvant chemotherapy for pancreatic ductal adenocarcinoma (PDAC). However, collection of an adequate number of PDAC cells is difficult due to the surrounding fibroblasts. Thus, the aim of this study was to discover novel biomarkers to predict chemosensitivity based on the CD-DST results. Proteomics analysis was performed using liquid chromatography tandem mass spectrometry (LC–MS/MS). Candidate proteins were validated in patients with 5-FU CD-DST results via immunohistochemistry (IHC). The relationships between the candidate proteins and the effect of the adjuvant S-1 were investigated via IHC. Among the 2696 proteins extracted by LC–MS/MS, C1TC and SAHH could accurately predict the CD-DST results. Recurrence-free survival (RFS) was significantly improved in the IHC-positive group compared with the IHC-negative group in both factors. The negative group did not show a significant difference from the group that did not receive S-1. The double-positive group was associated with significantly prolonged RFS compared to the no adjuvant chemotherapy group. C1TC and SAHH have been shown to be useful biomarkers for predicting 5-FU sensitivity as a substitute for the CD-DST in adjuvant chemotherapy for PDAC.

BackgroundThe significance of surgical resection in pancreatic ductal adenocarcinoma (PDAC) with positive peritoneal cytology (PPC) is controversial. This study aimed to evaluate whether preceding chemotherapy could be beneficial for patients with PDAC with PPC.MethodsBetween 2017 and 2019, 34 consecutive PDAC patients diagnosed with PPC without distant metastasis were retrospectively reviewed. Twenty-three patients did not receive neoadjuvant treatment (NAT) and 11 received NAT. All patients received systemic chemotherapy after PPC was confirmed, and they underwent surgical resection if PPC turned negative. The treatment course, ratio of conversion surgery (CS), and prognosis were evaluated. Moreover, the prognosis of PPC patients who underwent up-front surgery without NAT between 2003 and 2016 was analyzed as a comparative cohort.ResultsThe median survival time (MST) of the patients without NAT was 31.4 months. CS was performed in 52.2% of the patients. Patients who underwent CS had better prognoses than those who did not undergo CS (p = 0.005). The CS rate was significantly higher in resectable PDAC (78.5%) than in borderline/unresectable PDAC (11.1%) (p = 0.002). The prognosis of patients with resectable PDAC was improved with preceding chemotherapy compared with up-front surgery (MST 13.0 months; p = 0.016). After NAT, the CS rate was low (27.3%), and the MST was only 14.1 months.ConclusionsAs an initial treatment for PDAC patients with PPC, chemotherapy may lead to a favorable prognosis. Especially, resectable PDAC is associated with a greater chance of improved prognosis. Future studies are required to ascertain whether up-front surgery or preceding chemotherapy should be performed for these patients.

The ubiquitin ligase F‐box and WD repeat domain‐containing 7 (FBXW7) is responsible for degrading diverse oncoproteins and is considered a tumor suppressor in many human cancers. Inhibiting FBXW7 enhances the malignant potential of several cancers. In this study, we aimed to investigate the role of FBXW7 in cholangiocarcinoma. We found that FBXW7 expression was associated with clinicopathological outcomes in cholangiocarcinoma patients. Both disease‐free and overall survival were significantly worse in the low‐FBXW7 group than in the high‐FBXW7 group (P = .001 and P < .001, respectively). Multivariate analysis with the Cox proportional hazards model indicated that FBXW7 was the most important independent prognostic factor for disease‐free (P = .006) and overall (P = .0004) survival. We also showed that the two FBXW7 substrates, NOTCH1 and myeloid cell leukemia sequence 1 (MCL1), regulate cholangiocarcinoma progression. Depletion of FBXW7 resulted in NOTCH1 accumulation and increased cholangiocarcinoma cell migration and self‐renewal. Interestingly, when cells were stimulated with cis‐diamminedichloridoplatinum(II) (cisplatin), FBXW7 suppression induced MCL1 upregulation, which reduced the sensitivity of cholangiocarcinoma cells to apoptosis, indicating that FBXW7‐mediated ubiquitylation is context‐dependent. These results indicate that FBXW7 modulates the malignant potential of cholangiocarcinoma through independent regulation of NOTCH1 and MCL1. The ubiquitin ligase FBXW7 is associated with prognostic outcome in cholangiocarcinoma patients. FBXW7 was found to regulate the migration and self‐renewal of cholangiocarcinoma cells through modulation of NOTCH1 as well as CDDP‐induced apoptosis through MCL1 accumulation for the first time in cholangiocarcinoma cells. These findings suggest that FBXW7 modulates the malignant potential of cholangiocarcinoma through two signals, NOTCH1 and MCL1.

Background Loss of expression of the gene ataxia-telangiectasia mutated ( ATM ), occurring in patients with multiple primary malignancies, including pancreatic cancer, is associated with poor prognosis. In this study, we investigated the detailed molecular mechanism through which ATM expression affects the prognosis of patients with pancreatic cancer. Methods The levels of expression of ATM and phosphorylated ATM in patients with pancreatic cancer who had undergone surgical resection were analyzed using immunohistochemistry staining. RNA sequencing was performed on ATM -knockdown pancreatic-cancer cells to elucidate the mechanism underlying the invlovement of ATM in pancreatic cancer. Results Immunohistochemical analysis showed that 15.3% and 27.8% of clinical samples had low levels of ATM and phosphorylated ATM, respectively. Low expression of phosphorylated ATM substantially reduced overall and disease-free survival in patients with pancreatic cancer. In the pancreatic cancer cell lines with ATM low expression, resistance to gemcitabine was demonstrated. The RNA sequence demonstrated that ATM knockdown induced the expression of MET and NTN1. In ATM knockdown cells, it was also revealed that the protein expression levels of HIF-1α and antiapoptotic BCL-2/BAD were upregulated. Conclusions These findings demonstrate that loss of ATM expression increases tumor development, suppresses apoptosis, and reduces gemcitabine sensitivity. Additionally, loss of phosphorylated ATM is associated with a poor prognosis in patients with pancreatic cancer. Thus, phosphorylated ATM could be a possible target for pancreatic cancer treatment as well as a molecular marker to track patient prognosis.

Peritoneal washing cytology (CY) in patients with pancreatic cancer is mainly used for staging; however, it may also be used to evaluate the intraperitoneal status to predict a more accurate prognosis. Here, we investigated the potential of deep learning of CY specimen images for predicting the 1-year prognosis of pancreatic cancer in CY-positive patients. CY specimens from 88 patients with prognostic information were retrospectively analyzed. CY specimens scanned by the whole slide imaging device were segmented and subjected to deep learning with a Vision Transformer (ViT) and a Convolutional Neural Network (CNN). The results indicated that ViT and CNN predicted the 1-year prognosis from scanned images with accuracies of 0.8056 and 0.8009 in the area under the curve of the receiver operating characteristic curves, respectively. Patients predicted to survive 1 year or more by ViT showed significantly longer survivals by Kaplan–Meier analyses. The cell nuclei found to have a negative prognostic impact by ViT appeared to be neutrophils. Our results indicate that AI-mediated analysis of CY specimens can successfully predict the 1-year prognosis of patients with pancreatic cancer positive for CY. Intraperitoneal neutrophils may be a novel prognostic marker and therapeutic target for CY-positive patients with pancreatic cancer.

Stomatin-like protein 2 (SLP-2) is associated with poor prognosis in several types of cancer, including pancreatic cancer (PC); however, the molecular mechanism of its involvement remains elusive. The present study aimed to elucidate the role of this protein in the development of PC. Human PC cell lines AsPC-1 and PANC-1 were transfected by a vector expressing SLP-2 shRNA. Analyses of cell proliferation, migration, invasion, chemosensitivity, and glucose uptake were conducted, while a mouse xenograft model was used to evaluate the functional role of SLP-2 in PC. Immunohistochemical analysis was retrospectively performed on human tissue samples to compare expression between the primary site (n=279) and the liver metastatic site (n=22). Furthermore, microarray analysis was conducted to identify the genes correlated with SLP-2. In vitro analysis demonstrated that cells in which SLP-2 was suppressed exhibited reduced cell motility and glucose uptake, while in vivo analysis revealed a marked decrease in the number of liver metastases. Immunohistochemistry revealed that SLP-2 was increased in liver metastatic sites. Microarray analysis indicated that this protein regulated the expression of glutamine-fructose-6-phosphate transaminase 2 (GFPT2), a rate-limiting enzyme of the hexosamine biosynthesis pathway. SLP-2 contributed to the malignant character of PC by inducing liver metastasis. Cell motility and glucose uptake may be induced via the hexosamine biosynthesis pathway through the expression of GFPT2. The present study revealed a new mechanism of liver metastasis and indicated that SLP-2 and its downstream pathway could provide novel therapeutic targets for PC.

Background Probiotics have been reported to be beneficial for the prevention of postoperative complications and are often used during the perioperative period. Among the probiotic-related adverse events, bacteremia is rare. Here, we report two cases of probiotic-related bacteremia after major hepatectomy for biliary cancer. Case presentation 1 A 74-year-old man was referred to our hospital to be treated for gallbladder cancer. Neoadjuvant chemotherapy, two courses of gemcitabine plus S-1 combination therapy, was administered. Extended right hepatectomy with caudate lobectomy, extrahepatic bile duct resection and biliary reconstruction were performed 3 weeks after chemotherapy. Probiotics, Clostridium butyricum ( C. butyricum ) MIYAIRI 588, were administered 6 days before surgery and continued after surgery. Sepsis of unknown origin occurred 17 days after surgery and developed into septic shock. C. butyricum was detected in blood cultures at postoperative day 26 and 45. After stopping the probiotic agent, C. butyricum was undetectable in the blood cultures. The patient died due to an uncontrollable sepsis 66 days after surgery. Case presentation 2 A 63-year-old man with diabetes mellitus whose past history included total colectomy, papillectomy, and Frey’s operation at the age of 19, 34 and 48, respectively, was referred to our hospital to be treated for perihilar cholangiocarcinoma. Extended left hepatectomy with caudate lobectomy, extrahepatic bile duct resection and reconstruction of bile duct were performed. Probiotics were administered during the perioperative period. Combined probiotics that included lactomin, amylolytic bacillus and C. butyricum , were given before surgery. C. butyricum MIYAIRI 588 was given after surgery. Sepsis occurred 16 days after surgery and developed to respiratory failure 8 days later. Blood culture at postoperative day 25 revealed Enterococcus faecalis and C. butyricum . After the probiotics were stopped at postoperative day 27, C. butyricum was not detected in the blood culture. The general condition improved with intensive care. The patient was transferred to another hospital for rehabilitation at postoperative day 156. Conclusion It should be noted that the administration of probiotics in severe postoperative complications can lead to probiotic-related bacteremia.

Background We aimed to determine whether treatment should be stratified according to 18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) maximum standardized uptake values (SUV max ) in pancreatic ductal adenocarcinoma. Methods Patients who underwent preoperative 18F-FDG PET/CT between 2006 and 2014 ( n  = 138) were stratified into high (≥ 4.85) and low (< 4.85) PET groups. The clinicopathological characteristics and prognostic outcomes were analyzed retrospectively. Results The primary tumor SUV max was positively correlated with preoperative CA19-9 levels ( P  < 0.001). The high PET group failed to achieve postoperative CA19-9 normalization ( P  = 0.014). Disease-specific ( P  < 0.001), recurrence-free ( P  < 0.001), liver recurrence-free ( P  < 0.001), and peritoneal recurrence-free ( P  = 0.020) survivals were significantly shorter in the high PET group. The primary tumor SUV max was an independent predictive risk factor for liver metastasis (hazard ratio 3.46, 95% confidence interval 1.61–7.87; P  = 0.001) and peritoneal recurrence (hazard ratio 3.36, 95% confidence interval 1.18–10.89; P  = 0.023). Conclusions Surgical resection failed to achieve CA19-9 normalization in the high PET group and distant recurrence was frequent. This suggests the potential for residual cancer at distant sites, even after curative resection. Stronger preoperative systemic chemotherapy is preferred for the high PET group patients.