Citations

AbstractExtracellular vesicles are endogenous biological nanoparticles that have potential for use as therapeutic nanoparticles or as delivery vehicles for therapeutic agents. Milk nanovesicles (MNV) are extracellular vesicles isolated from bovine milk that have been explored for use as delivery vehicles for RNA therapeutics such as small interfering RNA (siRNA). We performed in vivo toxicological studies of MNV or therapeutic MNV (tMNV) loaded with siRNA as a prelude to their clinical use. Development toxicity was assessed in zebrafish embryos. Acute toxicity was assessed in both mice and zebrafish whereas safety, biochemical, histological and immune effects after multiple dosing were assessed in mice. Zebrafish embryo hatching was accelerated with MNV and tMNV. While acute toxicity or effects on mortality were not observed in zebrafish, developmental effects were observed at high concentrations of MNV. There was a lack of discernable toxicity, mortality and systemic inflammatory or immunological responses in mice following administration of either MNVs or tMNVs. The tolerability and lack of discernable developmental or systemic in vivo toxicity support their use as biological nano‐therapeutics. Adoption of a standardized protocol for systematic analysis of in vivo safety and toxicity will facilitate preclinical assessment of EV based formulations for therapeutic use.

AbstractThe role of long noncoding RNAs (lncRNAs) in the epithelial‐mesenchymal transition (EMT) in pancreatic ductal adenocarcinoma (PDAC) is unclear. Some lncRNAs can be transferred by extracellular vesicles (EVs) and have potential as biomarkers. Here, we identify an lncRNA that could serve as a biomarker for PDAC and show the functional roles of the lncRNA. Expression profiling of lncRNAs revealed that highly upregulated in liver cancer (HULC) was highly expressed, and induced, by transforming growth factor‐β in PDAC cells and their EVs. Knockdown of HULC decreased PDAC cell invasion and migration by inhibiting the EMT. Thus, HULC could be transferred by EVs, and promote EMT, invasion, and migration in recipient PDAC cells. To assess the roles of HULC, PDAC cell xenografts in nude mice were established. Knockdown of HULC in PDAC cells implanted in mice inhibited tumor growth. Moreover, microRNA‐133b suppressed PDAC cell invasion and migration by inhibiting the EMT through targeting HULC. Furthermore, serum samples were obtained from 20 PDAC and 22 intraductal papillary mucinous neoplasm (IPMN) patients, as well as 21 healthy individuals. Analysis of serum EV HULC expression by digital PCR showed that HULC expression was significantly increased in PDAC patients compared to healthy individuals or IPMN patients. Additionally, HULC showed good predictive performance for discriminating PDAC, suggesting that the analysis of EV‐encapsulated HULC would contribute to the diagnosis for human PDAC. Extracellular vesicle‐transported HULC promotes cell invasion and migration by inducing the EMT, and microRNA‐133b suppresses the EMT by targeting HULC. Extracellular vesicle‐encapsulated HULC could be a potential circulating biomarker for human PDAC.

AbstractAblation is now recommended by international guidelines for the definitive treatment of hepatocellular carcinoma (HCC). Extensive clinical studies have demonstrated outcomes comparable to surgical resection with shorter hospital stays, decreased costs, and improved quality of life. Successful ablation requires complete treatment of both tumor and margin while preserving critical adjacent structures. HCC exhibits highly variable presentations in both anatomic involvement and biology which have significant implications on choice of ablative therapy. There are now abundant ablation modalities and adjunctive techniques which can be used to individualize ablation and maximize curative results. This article provides a patient-centered summary of approaches to HCC ablation in the context of patient performance, hepatic reserve, tumor phenotype and biology, intra- and extrahepatic anatomy, and ablation technology.

Abstract Direct-acting antivirals (DAA) are now the mainstay of treatment for patients with chronic hepatitis C virus (HCV); however, there is some controversy over whether use of DAAs for HCV, as compared with IFN-based regimens, leads to an increased risk for hepatocellular carcinoma (HCC) development. We investigated the association between use of DAAs and subsequent development of HCC in longitudinal data from patients with HCV from diverse backgrounds (various ages, ethnicities, and geographic regions) across the United States. The design was a retrospective study performed using medical and pharmacy claims from OptumLabs. HCV treatment exposure was categorized as DAA-only, DAA + IFN, any-DAA, or IFN-only. To account for confounding by indication, inverse probability of treatment weighting was performed. Cox proportional hazard models were used to calculate hazard ratios (HR) and 95% confidence intervals (CI). We identified 5,781 patients with HCV with no history of HCC at baseline. Compared with IFN-only regimen, no significant increase in HCC risk was found for use of DAA-only (HR, 1.53; 95% CI, 0.73–3.23), DAA + IFN (HR, 1.02; 95% CI, 0.51–2.06), or any-DAA (HR, 1.04; 95% CI, 0.65–1.65). When stratified by sustained virological response (SVR), we noted a higher HCC risk for DAA-only among patients who achieved SVR post-treatment (HR, 7.53; 95% CI, 1.48–38.34), but the CIs were wide, which might be due to the small sample size of the subgroups. Among those who did not achieve SVR, no association was found for use of DAA-only (HR, 0.59; 95% CI, 0.19–1.91). These findings do not provide compelling evidence for the conception that use of DAAs for HCV is associated with increased risk of HCC development.

Abstract Background: Direct acting antiviral medications (DAA) have become the mainstay for treatment of chronic hepatitis C virus (HCV) infection. However, some studies have suggested an increased risk of HCC development following use of DAAs for HCV compared with use of interferon-based medications (IFN), while other studies, mostly in Veterans Administration population in the United States, did not show an increase in HCC risk after the use of DAA in patients with HCV. To address these conflicting reports, we investigated the association between use of DAA for HCV and subsequent development of HCC in a large, longitudinal data with broad representation of individuals from various ages, ethnicities, and geographic regions across the United States. Methods: A retrospective cohort study was performed using medical and pharmacy claims from the OptumLabs® Data Warehouse. The study included 9,532 incident HCV cases (2010-2016) of ages 18 years or older treated with DAA or IFN and did not have a prior diagnosis of HCC before initiation of the antiviral therapy. The participants were categorized into DAA-only or IFN-only groups. To account for confounding by indication, inverse probability of treatment weighting (IPTW) was performed to ensure balance in sociodemographic and treatment related factors between treatment groups. Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for HCC risk, comparing DAA-only regimen with IFN-only regimen (reference). Results: Median follow-up for the entire study cohort was 1.4 years, with a slightly longer follow-up for individuals in the IFN-only group (1.8 years) than for those in the DAA-only group (1.4 years). One hundred and seventy-one incident HCC cases developed during follow-up, with a higher occurrence of HCC in the DAA-only group (n=155; 11.9 cases per 1,000 person-years) than in the IFN-only group (n=16; 8.3 cases per 1,000 person-years). Compared with IFN-only treatment, use of DAA-only for HCV was not associated with an increase in HCC risk (HR=1.47, 95% CI: 0.89-2.42). Similarly, no association was found between use of DAA-only regimen and HCC risk among individuals with cirrhosis (HR=1.28, 95% CI: 0.71-2.31) or those without cirrhosis (HR =1.80, 95% CI: 0.64-5.03). When stratified by sustained virologic response (SVR), a measure of complete viral clearance, we noted a higher HCC risk associated with DAA-only regimen among individuals with SVR (HR=7.83, 95% CI: 1.54-39.88) and a lower risk for DAA-only regimen among those without SVR (HR=0.12, 95% CI: 0.02-0.95); however, the CIs are substantially wide, reflecting the small numbers in these subgroup analyses. Conclusion: Despite some prior reports of increased risk of HCC development following use of DAA for HCV, this ethnically and geographically diverse study did not find compelling evidence indicating an increased HCC risk associated with use of DAA in patients with HCV when compared with use of IFN. Citation Format: Samuel O. Antwi, Holly K. Van Houten, Lindsey R. Sangaralingham, Tushar Patel. Risk of de novo hepatocellular carcinoma development following use of direct acting antiviral medications for treatment of chronic hepatitis C virus infection [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr LB-150.

Abstract Objectives: Biliary tract cancers (BTCs) comprise the second most common type of hepatobiliary cancer. Given the increase in global BTC incidence, with associated morbidity and mortality, together with the limited therapeutic options, there is increasing interest in strategies for disease prevention. We performed a population-based cohort study to determine the association between low dose aspirin, non-aspirin NSAIDs, statins, metformin, other risk factors and the risk of biliary tract cancer (BTC), while assessing confounding by sex. Methods: We conducted a nationwide Swedish population-based cohort study using the Swedish Prescribed Drug Registry, which virtually completely enumerates use of prescribed medications nationwide since 2005. BTC diagnosis (intrahepatic cholangiocarcinoma [iCCA], extrahepatic cholangiocarcinoma [eCCA] or gallbladder cancer [GBC]) was ascertained from the Swedish Cancer Registry. Age-scaled Cox models, with exposure as time-varying covariates, were used to calculate hazard ratios (HRs), separately for men and women. Results: In the 5.7 million person cohort, the risk of iCCA was significantly lower in men using statins (HR 0.62,95%CI 0.39-1.00,p=0.05), with a non-significant reduction in women. Statin use was associated with a significantly decreased risk of eCCA in both women (HR 0.60,0.38-0.94,p=0.03) and men (HR 0.47,0.28-0.80,p=0.01). Low dose aspirin (HR 0.76,0.60-0.97,p=0.03) was associated with a lower risk of GBC only in women, while statins (HR 0.72,0.55-0.93,p=0.01) showed a significantly decreased risk of GBC in women and a non-significant reduction in men. For all BTC subtypes, combined use of low dose aspirin and statins did not confer additional risk reductions beyond those achieved by statins alone. Male and female users of non-aspirin NSAIDs appeared to be at increased risk of BTC and its subtypes. Metformin did not significantly affect risk of BTC. Conclusion: We performed the largest population-based cohort study evaluating risk and protective factors for BTC. Our results provide strong evidence in favor of the chemopreventive roles of low dose aspirin and statins in a subtype-and sex-specific manner. Individual risk factors contribute to development of BTC subtypes in different magnitudes. If randomized controlled clinical trials validate our findings and provide favorable evidence of the efficacy and safety of these drugs in the prevention of BTCs, our results could potentially be practice-changing, leading to improvements in the outcomes in this population. Citation Format: Lorena Marcano-Bonilla, Cathy D. Schleck, W. Scott Harmsen, Omid Sadr-Azodi, Mitesh J. Borad, Tushar Patel, Gloria M. Petersen, Terry M. Therneau, Lewis R. Roberts, Nele Brusselaers. Associations of aspirin, non-aspirin NSAIDs, statins, and metformin with risk of biliary tract cancer: A Swedish population-based cohort study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 5049.

Hepatocellular carcinoma (HCC) is a leading cause of cancer‐related death worldwide. Although HCC can respond to immune checkpoint inhibitors, such as monoclonal antibodies against programmed death 1 (PD‐1), many patients fail to respond or develop secondary resistance. Activation of Wnt/β‐catenin signaling can contribute to immune evasion. Mutations in β‐catenin are among the most frequent mutations associated with HCC. Thus, our aim was to directly target β‐catenin to enhance the therapeutic response to immune checkpoint inhibition. A synthetic transgenic mouse model of experimental HCC induced by tyrosine‐protein kinase Met/β‐catenin expression and extracellular vesicles (EVs) as a therapeutic delivery agent was used to evaluate the efficacy of directly targeting β‐catenin on the response to anti‐PD‐1. These studies showed that (1) oncogenic β‐catenin could be therapeutically targeted using a biological nanoparticle‐based delivery approach, (2) targeting β‐catenin using small interfering RNA (siRNA) delivered within EVs can reduce tumor growth, and (3) the therapeutic response to anti‐PD‐1 can be enhanced by concomitantly targeting β‐catenin using therapeutic EVs. These preclinical studies establish the efficacy of the use of biological nanoparticles as an endogenous delivery vehicle for therapeutic RNA delivery and support the use of therapeutic strategies targeting tumor‐intrinsic β‐catenin as an adjunct to anti‐PD‐1‐based therapy.Conclusion:Combination therapy with anti‐PD‐1 and β‐catenin siRNA delivered using biological nanoparticles provides an effective strategy for the treatment of HCC. This strategy could be further exploited into targeted approaches for immune potentiation by countering oncogene‐mediated resistance to immunotherapies.

Goal: To investigate associations of prediagnosis and postdiagnosis use of statins and metformin on overall survival of patients with diabetes who later developed HCC. Background: Statins and metformin have received considerable interest as potential chemopreventive agents against hepatocellular carcinoma (HCC) development in individuals with type 2 diabetes mellitus (T2DM); however, their impact on overall survival of patients with T2DM who later develop HCC (diabetic HCC patients) is unclear. Study: Data on 2499 elderly diabetic HCC patients obtained from the SEER-Medicare program (2009 to 2013) were analyzed. Patients were categorized based on use of statins only, metformin only, both, or neither (reference for all comparisons). The patients were further categorized based on: (1) metformin dose: ≤1500 or >1500 mg/d; (2) statins functional form: hydrophilic (pravastatin and rosuvastatin) or lipophilic (atorvastatin, fluvastatin, lovastatin, and simvastatin); (3) statins potency: high (atorvastatin, rosuvastatin, and simvastatin) or low (fluvastatin, lovastatin, and pravastatin); and (4) individual statins type. Multivariable-adjusted hazard ratios (HR) and 95% confidence intervals (CIs) were calculated using Cox proportional hazard models. Results: Prediagnosis use of metformin dose ≤1500 mg/d was associated with lower risk of death after HCC diagnosis in patients with T2DM (HR, 0.72; 95% CI, 0.58-0.91), adjusting for postdiagnosis metformin dose, diabetes severity, Charlson comorbidity index, tumor characteristics, and other relevant factors. No association was found for prediagnosis metformin dose >1500 mg/d or postdiagnosis metformin use. Further, no association was found for either prediagnosis or postdiagnosis statins use. Conclusions: Prediagnosis use of metformin dose ≤1500 mg/d is associated with longer overall survival of elderly diabetic HCC patients.