Dendrimer Conjugation Enhances Tumor Penetration and Cell Kill of Doxorubicin in 3D Coculture Lung Cancer Models

Background: Doxorubicin (DOX) is a potent chemotherapeutic widely used for solid tumors (1). Despite high efficacy in 2D cell culture, DOX efficacy does not translate to in vivo lung cancer models (2). Major side effects such as cardiotoxicity may be alleviated with nano-based drug delivery systems (nanoDDS). However, tumor penetration of DOX and DOX-nanoDDS is largely unknown and is an additional barrier to effective clinical therapy (3). Here we describe a nanoDDS capable of enhancing the penetration of DOX. Methods: DOX was conjugated to generation 4 poly(amido-amine) dendrimers through (GFLG) tumor- liable bond. G4SA-GFLG-DOX was synthesized/characterized. spheroids were formed of (A549) lung adenocarcinoma cells and (3T3) fibroblasts. Spheroids were characterized for ECM components with immunohistochemistry. Confocal microscopy was used to evaluate the penetration, internalization, and colocalization of DOX and G4SA-GFLG-DOX. MTT assay and Caspase 3/7 to assess 2D and 3D cytotoxicity. Flow cytometry to determine cells uptake. Results: DOX conjugation to dendrimer resulted in G4SA-GFLG-DOX with ~5.5 DOX, 10±1 nm hydrodynamic diameter, and a -17±3 mV zeta-potential. Spheroids of (A549:3T3) were ECM- rich, developed ECM containing collagen-I, hyaluronan, laminin, and fibronectin. While DOX and G4SA-GFLG-DOX had similar toxicities in 2D model, G4SA-GFLG-DOX demonstrated a 3.1-fold greater penetration into spheroids compared to DOX and correlated to a greater efficacy as measured by caspase 3/7 activity. Also, flow cytometry showed higher uptake of G4SA- GFLG-DOX in cancer cells compared to fibroblasts. Conclusion: The work demonstrates enhanced penetration of DOX, via dendrimer conjugation, into an ECM- rich 3D lung cancer model. The enhanced penetration of G4SA-GFLG-DOX correlated with greater antitumor efficacy. Acknowledgements: We acknowledge partial financial support from the Center for Pharmaceutical Engineering and Sciences - School of Pharmacy at VCU. This study was supported by VCU Quest for Distinction and NSF (DRM #1508363). Microscopy was performed at the VCU Microscopy Facility, supported, in part, by funding from NIH-NCI Cancer Center Support Grant P30 CA016059. RA would like to acknowledge King Faisal University (KFU) and Saudi Arabian Cultural Mission (SACM) for a scholarship.https://scholarscompass.vcu.edu/gradposters/1091/thumbnail.jp

Prefatory Note

The essays in this journal are a collective effort in feminist scholarship. What is feminist scholarship? The intent and focus of feminist scholarship is wonderfully illustrated in a student\u27s response to a handbill taped to my office door that announces: What is Feminism? Come and Find Out. First Feminist Mass Meeting:\u27 On moving closer, one reads: February 17, 1914, 8:00 p.m., People\u27s Institute.” The student commented in astonishment, I didn\u27t know there were feminists in 1914! Without knowing it, the student captured a central aspect of feminist scholarship: feminist scholarship is scholarship that addresses the I didn\u27t knows which surround the life histories and experiences of women who, in any time period, quest after equality

Evolutionary divergence and limits of conserved non-coding sequence detection in plant genomes

The discovery of regulatory motifs embedded in upstream regions of plants is a particularly challenging bioinformatics task. Previous studies have shown that motifs in plants are short compared with those found in vertebrates. Furthermore, plant genomes have undergone several diversification mechanisms such as genome duplication events which impact the evolution of regulatory motifs. In this article, a systematic phylogenomic comparison of upstream regions is conducted to further identify features of the plant regulatory genomes, the component of genomes regulating gene expression, to enable future de novo discoveries. The findings highlight differences in upstream region properties between major plant groups and the effects of divergence times and duplication events. First, clear differences in upstream region evolution can be detected between monocots and dicots, thus suggesting that a separation of these groups should be made when searching for novel regulatory motifs, particularly since universal motifs such as the TATA box are rare. Second, investigating the decay rate of significantly aligned regions suggests that a divergence time of 100 mya sets a limit for reliable conserved non-coding sequence (CNS) detection. Insights presented here will set a framework to help identify embedded motifs of functional relevance by understanding the limits of bioinformatics detection for CNSs.</p

Degenerate flag varieties: moment graphs and Schr\"oder numbers

We study geometric and combinatorial properties of the degenerate flag varieties of type A. These varieties are acted upon by the automorphism group of a certain representation of a type A quiver, containing a maximal torus T. Using the group action, we describe the moment graphs, encoding the zero- and one-dimensional T-orbits. We also study the smooth and singular loci of the degenerate flag varieties. We show that the Euler characteristic of the smooth locus is equal to the large Schr\"oder number and the Poincar\'e polynomial is given by a natural statistics counting the number of diagonal steps in a Schr\"oder path. As an application we obtain a new combinatorial description of the large and small Schr\"oder numbers and their q-analogues.Comment: 25 page

Market access to new anticancer medicines for children and adolescents with cancer in Europe

BACKGROUND AND AIMS: There is an alarming delay in Europe for anticancer medicines becoming accessible for children. Following a paediatric European Union marketing authorisation, national Health Technology Assessment (HTA) agencies evaluate effectiveness, and safety of medicines to support decision on their cost and reimbursement. This study (a SIOPE Access to Medicines project) aimed to evaluate how these HTA evaluations take place for anticancer medicines indicated for paediatric use in Europe and to explore where the delays for market access originate. METHODS: We obtained HTA reports from the public domain for nine European countries for blinatumomab, dinutuximab beta and tisagenlecleucel. We evaluated the time elapsed between marketing authorisation for a paediatric indication and a national HTA decision and the nature of the decision. RESULTS: Out of 23 HTA decisions (four countries without blinatumomab report), 18 were positive, two with restrictions, three negative. For blinatumomab, tisagenlecleucel and dinutuximab beta, the median time to an HTA decision after regulatory approval for paediatric use was 353 days (range 193-751), 141 days (range 77-517) and 515 days (range 0-780), respectively, with variability between countries. Dinutuximab beta and tisagenlecleucel were first introduced in children, but did not result in shorter time to HTA decision. For blinatumomab, marketing authorisation followed 1008 days after the indication in adults, with HTA applications submitted a median of 167 days later, and a recommendation after 145 days. CONCLUSIONS: This study reveals ample variability in HTA decision making in nine European Union countries. Collaboration and alignment of required evidence is needed to facilitate robust scientific HTA assessments, also considering methodological challenges in paediatric oncology