Publications

Abstract INTRODUCTION Extracellular vesicles (EVs) have been harvested from many plant sources, some of which have anti-cancer effects and some could be used as therapeutic nanodelivery vectors. Hemp plant is a natural source of cannabinoids, of which delta 9-tetrahydroxicannabinol (THC) and cannabidiol (CBD) have proven anti-cancer proprieties. HYPOTHESIS We hypothesized that hemp EVs are enriched in cannabinoids and their application will reduce glioblastoma (GBM) tumor progression. APPROACH EVs were isolated from the hemp plant using ultracentrifugation. Nanotracking analysis, electron microscopy and liquid chromatography tandem mass spectrometry (LC-MS/MS) were utilized to characterize EVs. GBM cell lines were cultured in the neuropshere assay to evaluate hemp EVs anti-glioma effects. Fluorescent-labelled EVs were used to evaluate their brain tissue distribution in orthotopic patient-derived GBM xenografts. RESULTS Hemp EVs have a median diameter of 112.6nm with a typical lipid-bilayer structure. LC-MS/MS have shown that while cannabidiolic, cannabigerolic, and tetrahydroxicannabinolic acids represent 69.1 ± 2.1%, 19.1 ± 1.6%, 6.5 ± 0.54% of the total cannabinoids in hemp EVs, CBD and THC only make 4.75 ± 0.26%, and 0.5 ± 0.3%. Hemp EVs are potent anti-glioma agents with a 7-day LD-50 of 1.04µM and 2.4µM [based on EVs total cannabinoid content] for KR-158 and L0 GBM lines, respectively. Compared to the vehicle, overnight incubation of L0 cells with 1µM hemp EVs significantly reduced GBM cell migration (630.3 ± 61.43 vs 143.7 ± 8.7). Intranasal administration of hemp EVs led to a widespread distribution in tumor bearing brain including GBM tumor core. CONCLUSION Based on these results, hemp EVs with enriched cannabinoid content exert antiglioma effect in-vitro and when delivered intranasally, are widely distributed throughout the brain and within the tumor of PDX animals. Further experiments are ongoing to address the impact of nasally-delivered hemp EVs on tumor progression and compare to the application of purified acidic cannabinoids.

Abstract We previously reported that within the pancreatic ductal adenocarcinoma (PDAC) microenvironment, miR-145 and miR-199a are exclusively expressed in tumor-associated stroma (TAS) cells, but these miRNAs are present in PDAC cells following co-culture with TAS cells. We hypothesized that miRNAs function as paracrine signals via exosomal exchange between TAS cells and adjacent PDAC cells. Primary cultures of human TAS and PDAC cells were employed. Membrane-bound microparticles were isolated from TAS conditioned, serum-free culture media by sequential ultracentrifugation followed by ultrafiltration. Exosomes and microvesicles were then assayed for particle size distribution using nanoparticle tracking analysis and electronic microscopy. miRNA expression levels were determined using quantitative PCR. miRNA transfection was performed with RNAiMax reagents. Cell viability was measured by Alamar Blue. Statistics were performed using Prism 6 software. Following transfection of human TAS cells with cel-miR-39, a nonhuman miRNA, we demonstrated that miRNA exchanges occurred between TAS cells and neighboring PDAC cells via a process that is not dependent upon cell-cell contact. We next confirmed the presence and enrichment of miR-145-5p in TAS-cell-derived exosomes (8-fold higher concentrations in exosomes than parental cells, p<0.05). Feeding of TAS-derived exosomes or transfection of miR-145-5p mimics into PDAC cells led to dose-dependent decreases in PDAC cell viability (p<0.05). Taken together, our data suggest that stroma derived exosomes deliver miRNAs to adjacent PDAC cells and may function as tumor-suppressing paracrine signals in the case of miR-145. This finding provides a potential explanation for the observation that stroma depletion paradoxically accelerates PDAC progression in murine models. Citation Format: Song Han, Sayali Belsare, DongYu Zhang, Mark Beveridge, Carlos Rinaldi, Jose G. Trevino, Thomas D. Schmittgen, Steven J. Hughes. Exosomal delivery of stroma-derived miR-145 inhibits pancreatic cancer cell proliferation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4322. doi:10.1158/1538-7445.AM2017-4322

Abstract MicroRNAs are strongly implicated in such processes as development, carcinogenesis, cell survival, and apoptosis. It is likely, therefore, that they can also modulate sensitivity and resistance to anticancer drugs in substantial ways. To test this hypothesis, we studied the pharmacologic roles of three microRNAs previously implicated in cancer biology (let-7i, mir-16, and mir-21) and also used in silico methods to test pharmacologic microRNA effects more broadly. In the experimental system, we increased the expression of individual microRNAs by transfecting their precursors (which are active) or suppressed the expression by transfection of antisense oligomers. In three NCI-60 human cancer cell lines, a panel of 60 lines used for anticancer drug discovery, we assessed the growth-inhibitory potencies of 14 structurally diverse compounds with known anticancer activities. Changing the cellular levels of let-7i, mir-16, and mir-21 affected the potencies of a number of the anticancer agents by up to 4-fold. The effect was most prominent with mir-21, with 10 of 28 cell-compound pairs showing significant shifts in growth-inhibitory activity. Varying mir-21 levels changed potencies in opposite directions depending on compound class; indicating that different mechanisms determine toxic and protective effects. In silico comparison of drug potencies with microRNA expression profiles across the entire NCI-60 panel revealed that ∼30 microRNAs, including mir-21, show highly significant correlations with numerous anticancer agents. Ten of those microRNAs have already been implicated in cancer biology. Our results support a substantial role for microRNAs in anticancer drug response, suggesting novel potential approaches to the improvement of chemotherapy. [Mol Cancer Ther 2008;7(1):1–9]

Scope High incidence of inflammatory diseases afflicts the increasing aging‐population infringing a great health burden. Dietary flavonoids, including the flavone apigenin, are emerging as important anti‐inflammatory nutraceuticals due to their health benefits, lack of adverse effects and reduced costs. MicroRNAs (miRs) play a central role in inflammation by regulating gene expression, yet how dietary ingredients affect miRs is poorly understood. The aim of this study was to identify miRs involved in the anti‐inflammatory activity of apigenin and apigenin‐rich diets and determine their immune regulatory mechanisms in macrophages and in vivo. Methods and results A high‐throughput quantitative reverse transcriptase PCR screen of 312 miRs in macrophages revealed that apigenin reduced LPS‐induced miR‐155 expression. Analyses of miR‐155 precursor and primary transcript indicated that apigenin regulated miR‐155 transcriptionally. Apigenin‐reduced expression of miR‐155 led to the increase of anti‐inflammatory regulators forkhead box O3a and smooth‐muscle‐actin and MAD‐related protein 2 in LPS‐treated macrophages. In vivo, apigenin or a celery‐based apigenin‐rich diet reduced LPS‐induced expression of miR‐155 and decreased tumor necrosis factor α in lungs from LPS‐treated mice. Conclusion These results demonstrate that apigenin and apigenin‐rich diets exert effective anti‐inflammatory activity in vivo by reducing LPS‐induced expression of miR‐155, thereby restoring immune balance.

Abstract Blacks have higher rates of incidence and mortality of pancreatic cancer compared to Whites and non-White Hispanics. In an effort to identify a biological basis for this disparity, we propose examining the early events in the development of pancreatic cancer. The process by which pancreatic acini transdifferentiate into ductal epithelial cells (i.e. acinar ductal metaplasia or ADM) is one of the earliest events in the development of pancreatic ductal adenocarcinoma. We adapted the classic in vitro ADM assay, by which primary mouse pancreatic acini undergo ADM once plated onto the extracellular matrix matrigel, to an assay to culture and transdifferentiate human pancreatic organoids. We have received normal, human pancreatic acini from pancreatic islet transplantation centers from Black (n=8), White (n=19) and Hispanic (n=16) donors. The gender distribution was 29 males and 14 females. The acinar cells were cultured on matrigel and allowed to undergo ADM over a 5 to 6 day period. The number of ductal epithelial cells were microscopically counted and the rate of transdifferentiation was determined by kinetic modeling of the data. We have successfully cultured and transdifferentiated 40 of 43 human pancreatic acinar cells. Data from our study suggests that females undergo ADM at a faster rate than males and among the different races, the rate of acinar transdifferentiation decreases in the following order Blacks > Whites > non-White Hispanics. In summary, we demonstrate that women and Blacks have the highest rate of pancreatic transdifferentiation. Future studies include sequencing of the RNA isolated from the tissues to identify molecular drivers of acinar transdifferentiation and their impact on health disparities of pancreatic cancer. Citation Format: Alyssa Gosling, Jinmai Jiang, Corey M. Perkins, Yingwei Yao, Thomas D. Schmittgen. Development of an organoid assay for studying racial disparity in pancreatic acinar ductal metaplasia [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-092.

Abstract The PI3K/AKT/mTOR pathway is activated in about 50% of patients with hepatocellular carcinoma (HCC). Allosteric mTOR inhibitors, also known as rapalogs, fail to show any significant clinical utility. In an effort to identify new pathways and compounds to treat advanced HCC, we considered the ATP-competitive mTOR inhibitor INK128. ATP-competitive mTOR inhibitors attenuate both mTORC1 and mTORC2. We evaluated INK128 in sorafenib sensitive and insensitive HCC cell lines, CD44low and CD44high HCC and those cell lines with acquired sorafenib resistance. CD44 was significantly increased in Huh7 cells made resistant to sorafenib. Forced expression of CD44 enhanced cellular proliferation and migration, and rendered the cells more sensitive to the anti-proliferative effects of INK128. INK128 suppressed CD44 expression by blocking phosphorylation of eukaryotic translation initiation factor 4EBP1 in HCC cells while allosteric mTOR inhibitors do not. Moreover, INK128 exhibited potent anti-proliferative and anti-migration effects on the mesenchymal-like HCC cells, CD44high and sorafenib resistant HCC cells compared to the allosteric mTOR inhibitor everolimus. Combination studies of INK128 and sorafenib showed an additive to synergistic anti-proliferative effect in CD44high HCC cells. Our findings suggest that ATP-competitive mTOR inhibitors are effective in treating advanced HCC patients who express CD44, and are insensitive or resistant to sorafenib. It also highlights the potential use of CD44 as a biomarker of response in these patients. Citation Format: Mohamed Badawi, Jihye Kim, Dhruvitkumar Sutaria, Tasneem Motiwala, Ryan Reyes, Nissar Wani, Samson Jacob, Mitch Phelps, Thomas Schmittgen. CD44 positive and sorafenib resistant hepatocellular carcinomas respond to the ATP-competitive mTOR inhibitor INK128 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 141. doi:10.1158/1538-7445.AM2017-141

We demonstrate that antisense to miR-21 and miR-221 results in significant cell killing under various conditions and that antisense oligonucleotides targeted to miRNA represents a potential new therapy for pancreatic cancer.

The in situ detection of microRNAs (miRNAs) has been greatly facilitated by several recent technologic advances. These include the locked nucleic acid (LNA)-modified nucleotide, in situ extension of the mature miRNA, and RT in situ PCR amplification of the pre- and pri-microRNA. Furthermore, marked increases in the sensitivity of automated immunohistochemistry allow for co-localization of a given miRNA and its possible target. Key variables for successful LNA in situ detection of miRNAs include probe concentration, miRNA copy number, and stringency of the hybridization and wash. Success with RT in situ PCR and ultramer extension is highly dependent on adequate protease digestion. The key variables with immunohistochemistry include antibody concentration and pretreatment conditions. With co-labeling, miRNA detection is done first; the antigen can be co-localized if the immunohistochemistry reaction requires pretreatment in either the protease or antigen retrieval.

Aims A population‐based pharmacokinetic (PK) modeling approach (PopPK) was used to investigate the impact of Roux‐en‐Y gastric bypass (RYGB) on the PK of ( R )‐ and ( S )‐carvedilol. We aimed to optimize carvedilol dosing for these patients utilizing a pharmacokinetic/pharmacodynamic (PK/PD) link model. Methods PopPK models were developed utilizing data from 52 subjects, including nonobese, obese, and post‐ RYGB patients who received rac ‐ carvedilol orally. Covariate analysis included anthropometric and laboratory data, history of RYGB surgery, CYP2D6 and CYP3A4 in vivo activity, and relative intestinal abundance of major drug‐ metabolizing enzymes and transporters. A direct effect inhibitory E max pharmacodynamic model was linked to the PK model of ( S )‐ carvedilol to simulate the changes in exercise‐ induced heart rate. Results A 2‐compartmental model with linear elimination and parallel first‐order absorptions best described ( S )‐carvedilol PK. RYGB led to a twofold reduction in relative oral bioavailability compared to nonoperated subjects, along with delayed absorption of both enantiomers. The intestinal ABCC2 mRNA expression increases the time to reach the maximum plasma concentration. The reduced exposure (AUC) of (S)‐carvedilol post‐RYGB corresponded to a 33% decrease in the predicted area under the effect curve (AUEC) for the 24‐hour β‐blocker response. Simulation results suggested that a 50‐mg daily dose in post‐RYGB patients achieved comparable AUC and AUEC to 25‐mg dose in nonoperated subjects. Conclusion Integrated PK/PD modeling indicated that standard dosage regimens for nonoperated subjects do not provide equivalent β‐blocking activity in RYGB patients. This study highlights the importance of personalized dosing strategies to attain desired therapeutic outcomes in this patient cohort.

Abstract Patients with advanced hepatocellular carcinoma (HCC) face a dismal prognosis because of a lack of any effective therapies. To address this situation, we conducted a preclinical investigation of the therapeutic efficacy of oligonucleotides directed against the oncogenic microRNA miR-221, which has been implicated in HCC. Of 9 chemistries evaluated, we determined that a 2′-O-methyl phosphorothioate-modified anti-miR-221 oligonucleotide was most effective at reducing proliferation in vitro. A cholesterol-modified isoform of anti-miR-221 (chol-anti-miR-221) exhibited improved pharmacokinetics and liver tissue distribution compared with unmodified oligonucleotide. Chol-anti-miR-221 significantly reduced miR-221 levels in liver within a week of intravenous administration and in situ hybridization studies confirmed accumulation of the oligonucleotide in tumor cells in vivo. Within the same period, chol-anti-miR-221 reduced tumor cell proliferation and increased markers of apoptosis and cell-cycle arrest, elevating the tumor doubling time and increasing mouse survival. Taken together, our findings offer a preclinical proof of efficacy for chol-anti-miR-221 in a valid orthotopic mouse model of HCC, suggesting that this targeted agent could benefit treatment for patients with advanced HCC. Cancer Res; 71(24); 7608–16. ©2011 AACR.