Deficiency in hormone-sensitive lipase accelerates the development of pancreatic cancer in conditional KrasG12D mice.

BACKGROUND: Hormone sensitive lipase (HSL) is a neutral lipase that preferentially catalyzes the hydrolysis of diacylglycerol contributing to triacylglycerol breakdown in the adipose tissue. HSL has been implicated to play a role in tumor cachexia, a debilitating syndrome characterized by progressive loss of adipose tissue. Consequently, pharmacological inhibitors of HSL have been proposed for the treatment of cancer-associated cachexia. In the present study we used the conditional KrasG12D (KC) mouse model of pancreatic ductal adenocarcinoma (PDAC) with a deficiency in HSL to determine the impact of HSL suppression on the development of PDAC. METHODS: KC;Hsl+/+ and KC;Hsl-/- mice were fed standard rodent chow for 20 weeks. At sacrifice, the incidence of PDAC was determined and inflammation in the mesenteric adipose tissue and pancreas was assessed histologically and by immunofluorescence. To determine statistical significance, ANOVA and two-tailed Student's t-tests were performed. To compare PDAC incidence, a two-sided Fisher's exact test was used. RESULTS: Compared to KC;Hsl+/+ mice, KC;Hsl-/- mice gained similar weight and displayed adipose tissue and pancreatic inflammation. In addition, KC;Hsl-/- mice had reduced levels of plasma insulin and leptin. Importantly, the increased adipose tissue and pancreatic inflammation was associated with a significant increase in PDAC incidence in KC;Hsl-/- mice. CONCLUSIONS: HSL deficiency is associated with adipose tissue and pancreatic inflammation and accelerates PDAC development in the KC mouse model.

Pancreatic Cyst Disease: A Review.

IMPORTANCE: Cystic lesions of the pancreas are common and increasingly detected in the primary care setting. Some patients have a low risk for developing a malignancy and others have a high risk and need further testing and interventions. OBSERVATIONS: Pancreatic cysts may be intraductal mucinous neoplasms, mucinous cystic neoplasms, serous cystadenomas, solid pseudopapillary neoplasms, cystic variations of pancreatic neuroendocrine tumors, pancreatic ductal adenocarcinomas, or 1 of several types of nonneoplastic cysts. Mucinous (intraductal mucinous neoplasm or mucinous cystic neoplasm) lesions have malignant potential and should be distinguished from serous lesions (serous cystadenomas) that are nearly always benign. Symptomatic patients or those having high-risk features on initial imaging (eg, main pancreatic duct dilatation, a solid component, or mural nodule) require further evaluation with advanced imaging, possibly followed by surgical resection. Advanced imaging includes endoscopic ultrasound with cyst fluid analysis and cytology to confirm the type of cyst and determine the risk of malignancy. Small cysts (size <3 cm) in asymptomatic patients without any suspicious features may be observed with serial imaging because the risk for malignancy is low. CONCLUSIONS AND RELEVANCE: The management of pancreatic cysts requires risk stratification for malignant potential based on the presence or absence of symptoms and high-risk features on cross-sectional imaging. Because pancreatic cysts are becoming more frequently diagnosed, clinicians should have a systematic approach for establishing a diagnosis and determining which patients require treatment.

Intraoperative Laparoscopic Near-Infrared Fluorescence Cholangiography to Facilitate Anatomical Identification: When to Give Indocyanine Green and How Much.

Recent technological advances have enabled real-time near-infrared fluorescence cholangiography (NIRFC) with indocyanine green (ICG). Whereas several studies have shown its feasibility, dosing and timing for practical use have not been optimized. We undertook a prospective study with systematic variation of dosing and timing from injection of ICG to visualization. Adult patients undergoing laparoscopic biliary and hepatic operations were enrolled. Intravenous ICG (0.02-0.25 mg/kg) was administered at times ranging from 10 to 180 minutes prior to planned visualization. The porta hepatis was examined using a dedicated laparoscopic system equipped to detect NIRFC. Quantitative analysis of intraoperative fluorescence was performed using a scoring system to identify biliary structures. A total of 37 patients were enrolled. Visualization of the extrahepatic biliary tract improved with increasing doses of ICG, with qualitative scores improving from 1.9 ± 1.2 (out of 5) with a 0.02-mg/kg dose to 3.4 ± 1.3 with a 0.25-mg/kg dose (P < .05 for 0.02 vs 0.25 mg/kg). Visualization was also significantly better with increased time after ICG administration (1.1 ± 0.3 for 10 minutes vs 3.4 ± 1.1 for 45 minutes, P < .01). Similarly, quantitative measures also improved with both dose and time. There were no complications from the administration of ICG. These results suggest that a dose of 0.25 mg/kg administered at least 45 minutes prior to visualization facilitates intraoperative anatomical identification. The dosage and timing of administration of ICG prior to intraoperative visualization are within a range where it can be administered in a practical, safe, and effective manner to allow intraoperative identification of extrahepatic biliary anatomy using NIRFC.

Pancreatic cancer patients with lymph node involvement by direct tumor extension have similar survival to those with node-negative disease.

BACKGROUND: Lymph node (LN) involvement is a well-known poor prognostic factor in patients with pancreatic ductal adenocarcinoma (PDAC). However, there have been conflicting results on the significance of the mechanism of LN involvement, "direct" tumor invasion versus "metastatic," disease on patient survival. METHODS: Clinicopathologic records from all patients who underwent resection for PDAC from 1990 to 2014 at a single-institution were reviewed. RESULTS: Of the 385 total patients, there was tumor invasion outside of the pancreas in 289 (75.1%) patients. Overall, 239 (62.1%) had node-positive disease: 220 (92.0%) by "metastatic" involvement, 14 (5.9%) by "direct" tumor extension, and five (2.1%) by a mix of "metastatic" and "direct". There were no significant differences in clinicopathologic factors associated with PDAC survival between "metastatic" and "direct" LN patients. The median overall survival for the whole cohort was 31.1 months. Compared to overall survival in patients with LN-negative disease (median 40.7 months), those with LNs involved by "metastatic" spread was significantly shorter (median 25.7 months, P < 0.001), yet "direct" LN extension was similar (median 48.1 months, P = 0.719). CONCLUSIONS: The mechanism of LN involvement affects PDAC prognosis. Patients with LNs involved by direct extension have similar survival to those with node-negative disease.

Management of chronic pancreatitis.

Chronic pancreatitis results from repeated episodes of pancreatic inflammation and associated fibrosis leading to the loss of functional exocrine and endocrine pancreatic function. The disease is manifested by abdominal pain, deterioration in quality of life, food maldigestion and malabsorption, diabetes, and an increased risk for pancreatic adenocarcinoma. This review summarizes the latest evidence on the diagnosis and management of chronic pancreatitis and its manifestations. In particular, this review discusses advances in understanding of the role of genetic disorders in the mechanisms of the disease and surgical options for patients refractory to medical therapy. Furthermore, clinical trials are under way to develop medical therapeutics.

Evidence for activation of mutated p53 by apigenin in human pancreatic cancer.

Pancreatic cancer is an exceedingly lethal disease with a five-year survival that ranks among the lowest of gastrointestinal malignancies. Part of its lethality is attributable to a generally poor response to existing chemotherapeutic regimens. New therapeutic approaches are urgently needed. We aimed to elucidate the anti-neoplastic mechanisms of apigenin-an abundant, naturally-occurring plant flavonoid-with a particular focus on p53 function. Pancreatic cancer cells (BxPC-3, MiaPaCa-2) experienced dose and time-dependent growth inhibition and increased apoptosis with apigenin treatment. p53 post-translational modification, nuclear translocation, DNA binding, and upregulation of p21 and PUMA were all enhanced by apigenin treatment despite mutated p53 in both cell lines. Transcription-dependent p53 activity was reversed by pifithrin-α, a specific DNA binding inhibitor of p53, but not growth inhibition or apoptosis suggesting transcription-independent p53 activity. This was supported by immunoprecipitation assays which demonstrated disassociation of p53/BclXL and PUMA/BclXL and formation of complexes with Bak followed by cytochrome c release. Treated animals grew smaller tumors with increased cellular apoptosis than those fed control diet. These results suggest that despite deactivating mutation, p53 retains some of its function which is augmented following treatment with apigenin. Cell cycle arrest and apoptosis induction may be mediated by transcription-independent p53 function via interactions with BclXL and PUMA. Further study of flavonoids as chemotherapeutics is warranted.

miR-143 decreases COX-2 mRNA stability and expression in pancreatic cancer cells.

Small non-coding RNAs, microRNAs (miRNA), inhibit the translation or accelerate the degradation of message RNA (mRNA) by targeting the 3'-untranslated region (3'-UTR) in regulating growth and survival through gene suppression. Deregulated miRNA expression contributes to disease progression in several cancers types, including pancreatic cancers (PaCa). PaCa tissues and cells exhibit decreased miRNA, elevated cyclooxygenase (COX)-2 and increased prostaglandin E2 (PGE2) resulting in increased cancer growth and metastases. Human PaCa cell lines were used to demonstrate that restoration of miRNA-143 (miR-143) regulates COX-2 and inhibits cell proliferation. miR-143 were detected at fold levels of 0.41 ± 0.06 in AsPC-1, 0.20 ± 0.05 in Capan-2 and 0.10 ± 0.02 in MIA PaCa-2. miR-143 was not detected in BxPC-3, HPAF-II and Panc-1 which correlated with elevated mitogen-activated kinase (MAPK) and MAPK kinase (MEK) activation. Treatment with 10 µM of MEK inhibitor U0126 or PD98059 increased miR-143, respectively, by 187 ± 18 and 152 ± 26-fold in BxPC-3 and 182 ± 7 and 136 ± 9-fold in HPAF-II. miR-143 transfection diminished COX-2 mRNA stability at 60 min by 2.6 ± 0.3-fold in BxPC-3 and 2.5 ± 0.2-fold in HPAF-II. COX-2 expression and cellular proliferation in BxPC-3 and HPAF-II inversely correlated with increasing miR-143. PGE2 levels decreased by 39.3 ± 5.0% in BxPC-3 and 48.0 ± 3.0% in HPAF-II transfected with miR-143. Restoration of miR-143 in PaCa cells suppressed of COX-2, PGE2, cellular proliferation and MEK/MAPK activation, implicating this pathway in regulating miR-143 expression.

Impact of tumor grade on pancreatic cancer prognosis: validation of a novel TNMG staging system.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) patients demonstrate highly variable survival within each stage of the American Joint Committee on Cancer (AJCC) staging system. We hypothesize that tumor grade is partly responsible for this variation. Recently our group developed a novel tumor, node, metastasis, grade (TNMG) classification system utilizing Surveillance Epidemiology and End Results (SEER) data in which the presence of high tumor grade results in advancement to the next higher AJCC stage. This study's objective was to validate this TNMG staging system utilizing single-institution data. METHODS: All patients with PDAC who underwent resection at UCLA between 1990 and 2009 were identified. Clinicopathologic data reviewed included age, sex, node status, tumor size, grade, and stage. Grade was redefined as a dichotomous variable. The impact of grade on survival was assessed by Cox regression analysis. Disease was restaged into the TNMG system and compared to the AJCC staging system. RESULTS: We identified 256 patients who underwent resection for PDAC. Patients with low-grade tumors experienced a 13-month improvement in median survival compared to those with high-grade tumors. On multivariate analysis, tumor grade was the strongest predictor of survival with a hazard ratio of 2.02 (p = 0.0005). Restaging disease according to the novel TNMG staging system resulted in improved survival discrimination between stages compared to the current AJCC system. CONCLUSIONS: We were able to demonstrate that grade is one of the strongest independent prognostic factors in PDAC. Restaging with our novel TNMG system demonstrated improved prognostication. This system offers an effective and convenient way of adding grade to the current AJCC staging system.

Career track of Society of University Surgeons Resident Research Award recipients.

BACKGROUND: The Society of University Surgeons (SUS) has an ongoing competitive funding program to support research training for residents. We sought to determine the career track of award recipients. METHODS: We included in the study SUS resident awardees who completed awards from 1989-2007. Characteristics of awardees and their academic productivity were extracted from curriculum vitae provided by awardees (n = 24), or from online sources (n = 7). RESULTS: Awardees spent an average of 2.7 y (range, 1-4 y) of dedicated research time during residency. Awardees averaged 9.8 publications (range, 1-32), with 5.4 as first author (range, 1-17), with their mentor within 3 y of award completion, with an average maximum impact factor of 5.7. A total of 25 residents (81%) pursued fellowships. At an average follow-up of 11.4 y (range, 4-22 y) from the end of the award and 7.2 y (range, 0-18 y) from end of clinical training, awardees had a Hirsch index of 14.5 (range, 2-48). At the time of the study, 26 awardees (84%) were in academic surgery. Of the 23 awardees who had completed surgical training ≥ 3 y earlier, 11 (48%) received independent research funding, seven of whom (30%) received R01 or equivalent funding. CONCLUSIONS: The SUS resident research awardees had a productive research experience. Although our retrospective study cannot determine causation, the SUS award mechanism delivers on its promise of supporting junior surgeon-scientists who pursue academic careers and establish independent research programs. Further studies are needed to determine how rates of subsequent independent research funding can be improved.

Overexpression of CXCL5 is associated with poor survival in patients with pancreatic cancer.

Epithelial neutrophil-activating peptide-78 (CXCL5), a member of the CXC chemokine family, has been shown to be involved in angiogenesis, tumor growth, and metastasis. The objective of this study was to determine the relationship between CXCL5 expression and tumor progression in human pancreatic cancer and to elucidate the mechanism underlying CXCL5-mediated tumor angiogenesis and cancer growth. We report herein that CXCL5 is overexpressed in human pancreatic cancer compared with paired normal pancreas tissue. Overexpression of CXCL5 is significantly correlated with poorer tumor differentiation, advanced clinical stage, and shorter patient survival. Patients with pancreatic cancer and CXCL5 overexpression who underwent resection of cancer had a mean survival time 25.5 months shorter than that of patients who did not overexpress CXCL5. Blockade of CXCL5 or its receptor CXCR2 by small-interfering RNA knockdown or antibody neutralization attenuated human pancreatic cancer growth in a nude mouse model. Finally, we demonstrated that CXCL5 mediates pancreatic cancer-derived angiogenesis through activation of several signaling pathways, including protein kinase B (Akt), extracellular signal-regulated kinase (ERK), and signal transducer and activator of transcription (STAT) in human endothelial cells. These data suggest that CXCL5 is an important mediator of tumor-derived angiogenesis and that it may serve as a survival factor for pancreatic cancer. Blockade of either CXCL5 or CXCR2 may be a critical adjunct antiangiogenic therapy against pancreatic cancer.

Pathological treatment response has different prognostic implications for pancreatic cancer patients treated with neoadjuvant chemotherapy or chemoradiotherapy.

BACKGROUND: Pathological treatment effect of resected pancreatic adenocarcinoma after neoadjuvant therapy has prognostic implications. The impact for patients who received chemotherapy alone or chemoradiotherapy is not well defined. METHODS: Patients with localized pancreatic adenocarcinoma who had pancreatectomy after neoadjuvant therapy at 3 centers from 2011 to 2017 were retrospectively analyzed. The chemotherapy and chemoradiotherapy groups were evaluated separately. RESULTS: Of 525 patients, 148 received neoadjuvant chemotherapy and 377 received chemoradiotherapy. The chemoradiotherapy group had a better treatment effect (score 0: 10%, score 1: 30%, score 2: 42%, and score 3: 18%) than the chemotherapy group (score 0: 2%, score 1: 8%, score 2: 35%, and score 3: 55%) (P < .001). Median overall survival was similar between the 2 groups (25.8 vs 26.4 months). Median overall survival for score 0/1, 2, or 3 was 72.2, 38.5, and 20.0 months in the chemotherapy group and 37.9, 24.5, and 19.0 months in the chemoradiotherapy group. Score 2 in the chemotherapy group was associated with better overall survival compared to score 3 (adjusted hazard ratio: 0.49, P = .005), whereas only combined score 0/1 reached significance over score 2 for the chemoradiotherapy group (hazard ratio: 0.63, P = .006). CONCLUSION: The prognostic significance of pathological treatment effect for localized pancreatic adenocarcinoma differs for patients receiving neoadjuvant chemotherapy or neoadjuvant chemoradiotherapy.

Evidence for proteotoxicity in beta cells in type 2 diabetes: toxic islet amyloid polypeptide oligomers form intracellularly in the secretory pathway.

The islet in type 2 diabetes mellitus (T2DM) is characterized by a deficit in beta cells and islet amyloid derived from islet amyloid polypeptide (IAPP), a protein co-expressed with insulin by beta cells. It is increasingly appreciated that the toxic form of amyloidogenic proteins is not amyloid but smaller membrane-permeant oligomers. Using an antibody specific for toxic oligomers and cryo-immunogold labeling in human IAPP transgenic mice, human insulinoma and pancreas from humans with and without T2DM, we sought to establish the abundance and sites of formation of IAPP toxic oligomers. We conclude that IAPP toxic oligomers are formed intracellularly within the secretory pathway in T2DM. Most striking, IAPP toxic oligomers appear to disrupt membranes of the secretory pathway, and then when adjacent to mitochondria, disrupt mitochondrial membranes. Toxic oligomer-induced secretory pathway and mitochondrial membrane disruption is a novel mechanism to account for cellular dysfunction and apoptosis in T2DM.

The Effect of Perioperative Blood Transfusion on Long-Term Survival Outcomes After Surgery for Pancreatic Ductal Adenocarcinoma: A Systematic Review.

OBJECTIVE: To evaluate survival outcomes associated with perioperative allogeneic red blood cell transfusion (RBCT) in patients with pancreatic ductal adenocarcinoma undergoing surgery. METHODS: PubMed, Embase, Cochrane, and Web of Science Core Collection were queried for English-language articles until May 28, 2020. Studies evaluating long-term outcomes of RBCT compared with no transfusion in adults with pancreatic ductal adenocarcinoma undergoing pancreatectomy were included. E-value sensitivity analysis assessed the potential for unmeasured confounders to overcome these findings. RESULTS: Of 4379 citations, 5 retrospective cohort studies were included. Three studies reported shorter recurrence-free survival by 1 to 5 months with RBCT. Two studies found shorter disease-specific survival by 5 to 13 months with RBCT. Overall survival was reduced by 5 to 7 months with RBCT in 3 studies. All multivariable findings associated with RBCT could be readily overcome unmeasured confounding on sensitivity analysis. Confounding in baseline characteristics resulted in high risk of bias. CONCLUSIONS: Imprecision, unmeasured confounding, small effect sizes, and overall low quality of the available literature result in uncertainty regarding the effect of transfusion on recurrence-free survival, disease-specific survival, and overall survival in patients undergoing surgery for pancreatic cancer. Randomized trials are needed to determine if there is a causal relationship between transfusion and survival after pancreatic resection.

Direct Effects of Lipopolysaccharide on Human Pancreatic Cancer Cells.

OBJECTIVES: Obesity, a risk factor for pancreatic adenocarcinoma (PDAC), is often accompanied by a systemic increase in lipopolysaccharide (LPS; metabolic endotoxemia), which is thought to mediate obesity-associated inflammation. However, the direct effects of LPS on PDAC cells are poorly understood. METHODS: The expression of toll-like receptor 4, the receptor for LPS, was confirmed in PDAC cell lines. AsPC-1 and PANC-1 cells were exposed to LPS, and differential gene expression was determined by RNA sequencing. The activation of the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway by LPS in PDAC cells was assessed by Western blotting. RESULTS: The expression of toll-like receptor 4 was confirmed in all PDAC cell lines. The exposure to LPS led to differential expression of 3083 genes (426 ≥5-fold) in AsPC-1 and 2584 genes (339 ≥5-fold) in PANC-1. A top canonical pathway affected by LPS in both cell lines was PI3K/Akt/mTOR. Western blotting confirmed activation of this pathway as measured by phosphorylation of the ribosomal protein S6 and Akt. CONCLUSIONS: The exposure of PDAC cells to LPS led to differential gene expression. A top canonical pathway was PI3K/Akt/mTOR, a known oncogenic driver. Our findings provided evidence that LPS can directly induce differential gene expression in PDAC cells.

Persistence of Gender Bias Over Four Decades of Surgical Training.

OBJECTIVE: Female surgeons face gender-specific obstacles during residency training, yet longitudinal data on gender bias experienced by female surgery residents are lacking. We aimed to investigate the evolution of gender bias, identify obstacles experienced by female general surgery residents, and discuss approaches to supporting female surgeons during residency training. METHODS: Between August 2019 and January 2021, we conducted a retrospective cohort study using structured telephone interviews of female graduates of the UCLA General Surgery Residency training program. Responses of early graduates (1981-2009) were compared with those of recent graduates (2010-2020). Quantitative data were compared with Fisher's exact tests and Chi-squared tests. Interview responses were reviewed to catalog gender bias, obstacles experienced by female surgeons, and advice offered to training programs to address women's concerns. RESULTS: Of 61 female surgery residency graduates, 37 (61%) participated. Compared to early graduates (N = 20), recent graduates (N = 17) were significantly more likely to pursue fellowship training (100% vs. 65%, p < 0.01) and have children before or during residency (65% vs. 25%, p = 0.02). A substantial proportion in each cohort experienced some form of gender bias (71% vs. 85%, p = 0.43). Compared to early graduates, recent graduates were significantly less likely to report experiencing explicit gender bias (12% vs. 50%, p = 0.02) but equally likely to report implicit gender bias (71% vs. 55%, p = 0.50). Female graduates across the decades advocated for specific measures to champion work-life balance in residency (51%), strengthen female mentorship (49%), increase childcare support (41%), and promote women into leadership positions (32%). CONCLUSIONS: While having children during residency has become more common and accepted over the decades, female surgery residents continue to experience implicit gender bias in the workplace. Female surgeons advocate for targeted interventions to establish systems for parental leave, address gender bias, and strengthen female mentorship.

Web-based portfolios: a valuable tool for surgical education.

BACKGROUND: Our residency program developed and implemented an online portfolio system. In the present communication, we describe this system and provide an early analysis of its effect on competency-based performance and acceptance of the system by the residents. MATERIALS AND METHODS: To measure competency-based performance, end-of-rotation global evaluations of residents by faculty completed before (n = 1488) and after (n = 697) implementation of the portfolio were compared. To assess acceptance, residents completed a 20-question survey. RESULTS: Practice-based learning and improvement improved following implementation of the portfolio system (P = 0.002). There was also a trend toward improvement in the remaining competencies. In the survey tool (response rate 69%), 95% of the residents agreed that the purpose and functions of the system had been explained to them, and 82% affirmed understanding of ways in which the system could help them, although fewer than half reported that their portfolio had aided in their development of the competencies. All residents appreciated the system's organizational capabilities, and 87% agreed that the portfolio was a useful educational tool. CONCLUSIONS: This web portfolio program is a valuable new instrument for both residents and administrators. Early analysis of its impact demonstrates a positive effect across all competencies, and survey analysis revealed that residents have a positive view of this new system. As the portfolio is further incorporated into the educational program, we believe that our residents will discover new tools to craft a career of genuine self-directed learning.