Engineering nanomaterials for cancer theranostics

This thesis aims to engineer novel nanomaterial to target receptors on the surface of cancer to diagnose and deliver cytotoxic drugs or siRNA selectively. Receptor-targeting peptides have been relatively unexplored to deliver nanomaterial to cancer. The paucity is due to the challenge associated with the synthesis in assembling the components on a nanomaterial. We developed a universal methodology to overcome the synthetic difficulty and generated a library of peptide-targeted nanomaterial. These materials are targeted towards the following receptors: PD-L1, GRPR, and cMET, which are overexpressed in cancers. In addition, we investigated the diagnostics efficacy of nanomaterials targeted towards PD-L1, and the results showed the unique advantage of these classes of particles to quantify the receptors. Finally, we evaluated the in vitro and in vivo (in GRPR) efficacy of the targeted nanomaterials attached with the Doxorubicin drug in ovarian and hepatocellular cancers. The in vitro results established the superiority of the targeted material over the conventional chemotherapeutics. However, the in vivo evaluation of GRPR targeted nanomaterials showed only moderate efficacy compared with the chemo drug. Importantly, all the animals administered with targeted nanomaterial were healthy and alive at the end of the study; in contrast, all mice administered with doxorubicin succumbed to death. During this study, we gathered that targeted delivery of chemotherapeutics alone might be insufficient to overcome drug resistance and genetic inhibition is imperative. Therefore, we developed another nanomaterial to deliver two siRNAs to co-inhibit drug-resistant proteins and performed preliminary cancer cells. Further studies are warranted to establish this as a therapeutic modality. The experience allowed us to embark on an audacious project wherein we used non-cancer drugs to treat the tumor. Based on the solid scientific rationale, we combined COPD drug and tyrosine kinase inhibitor to treat lung cancer, and the results show benefit. The significance of this study is that the engineered nanomaterial possesses the potential to deliver the drug to cancer, reduce toxicity, and overcome drug resistance; further studies using clinically relevant patient-derived xenograft mouse models help translate the materials to clinics for patient benefits.Includes bibliographical references

Comparative evaluation of micro-tensile bond strength between zirconia core and all-ceramic layering with different surface treatments: an in vitro study

Background: The quest for newer and stronger materials for replacing teeth has resulted in Zirconium oxide\u27s introduction, which possesses excellent mechanical strength and toughness. However, uncertainty exists in the relationship between its bond strength and surface treatment method adopted and the mode of failure at the interface. Aim - The study aimed to evaluate the comparison of micro-tensile bond strength between the zirconia core and all-ceramic layering with different surface treatments and analyse their failure mode by Scanning Electron Microscope (SEM). Materials and methods: Zirconia cores (Ceramill ZI 71 XS) were fabricated by CAD-CAM into discs with 5mm diameter and 3.5mm height. Then the cores were divided into four groups. Among which, Group-I was the control group, and the remaining are surface treated. Group-II specimens were treated with sandblasting, followed by acid etching; Group-III and Group-IV were treated with zirliner and glass beads, respectively. After that, the veneering material (IPS Empress, E.max Ceram Dentin) of 2×2 mm was adhered to the zirconia core and then kept in the ceramic furnace. The specimens were mounted on a Universal Testing Machine, and tensile stress is applied. The obtained data were subjected to One-way ANOVA and Tukey-HSD tests for statistical analyses. Results - The samples treated with sandblasting followed by acid etching showed more micro-tensile bond strength between core and veneer interface. Furthermore, the SEM study revealed a cohesive failure in Group-II, whereas, in Group-I and -III, there was an adhesive failure. Group-IV specimens exhibited a mixed failure. One-way ANOVA showed significant differences (p=0.001) within the groups. In posthoc analysis, Group-III showed significant differences with Groups -I, II, and IV. Conclusion: Increased surface roughness of zirconia obtained by sandblasting with aluminium oxide particles, when coupled along with chemical etching with hydrofluoric acid, enhanced the micro-tensile bond strength between the Y-TZP zirconia core and veneering ceramic

Designing of Accounting Information System for Small and Medium Enterprises: Application of PLS-SEM

Accounting information system is a complex and subjective concept that lacks a comprehensive conceptual framework. Previous AIS studies focused on the context of information system and its benefit. Moreover, the existing studies have revealed contradictory results. Some authors argue that full AIS adoption is necessary for all organizations, regardless their size. Others proposed a reduced level. Nevertheless, they are not precisly  confirmed a subsystems of AIS that  proclaimed as less important for SMEs. In response to this gap, the present study has attempted to design AIS framework for SMEs. As such, this research aims to decompose and identify the important  sub-systems that constitute AIS. To fulfil this purposes, the research employed an exploratory research design that used Partial List Squire-Structural Equation Model. Primary data were collected from eighty SMEs. The study result confirmed that transaction-processing subsystem has the largest importance index followed by reporting subsystem. Even though, internal control is the least important, it was statistically significant in designing of AIS for SME. In the context of reporting, managerial reports (Budget preparation, variance analysis) are more important that financial accounting reports (FSEU). Regarding technology, whether IT is designed as simple as manual system or as complex as EP, its effect on management decision is minimum. Likewise, internal auditing practice of SMEs has very small impact in AIS alignment with accounting information users’ satisfaction. Collectively, the study revailed that all subsystems of AIS are significantly important in the designing of AIS conceptual frame work for SMEs

Manganese-containing Prussian blue nanoparticles for imaging of pediatric brain tumors

Pediatric brain tumors (PBTs) are a leading cause of death in children. For an improved prognosis in patients with PBTs, there is a critical need to develop molecularly-specific imaging agents to monitor disease progression and response to treatment. In this paper, we describe manganese-containing Prussian blue nanoparticles as agents for molecular magnetic resonance imaging (MRI) and fluorescence-based imaging of PBTs. Our core-shell nanoparticles consist of a core lattice structure that incorporates and retains paramagnetic Mn2+ ions, and generates MRI contrast (both negative and positive). The biofunctionalized shell is comprised of fluorescent avidin, which serves the dual purpose of enabling fluorescence imaging and functioning as a platform for the attachment of biotinylated ligands that target PBTs. The surfaces of our nanoparticles are modified with biotinylated antibodies targeting neuron-glial antigen 2 or biotinylated transferrin. Both neuron-glial antigen 2 and the transferrin receptor are protein markers overexpressed in PBTs. We describe the synthesis, biofunctionalization, and characterization of these multimodal nanoparticles. Further, we demonstrate the MRI and fluorescence imaging capabilities of manganese-containing Prussian blue nanoparticles in vitro. Finally, we demonstrate the potential of these nanoparticles as PBT imaging agents by measuring their organ and brain biodistribution in an orthotopic mouse model of PBTs using ex vivo fluorescence imaging

Near infrared navigation system (NAVI) for real time visualization of blood flow

Poster presented at the 2017 Health Sciences Research Day which was organized and sponsored by the University of Missouri School of Medicine Research Council and held on November 9, 2017.Summary: A portable and economical NAVI camera system that can be utilized for intraoperative fluorescence imaging has been fabricated. The NAVI system has been validated by conducting preclinical grafting studies in swine model. Finally, the clinical translational capability of the NAVI imaging system has been established using suitable clinical studies. Future study: The NAVI imaging system is being explored for lymph node imaging and other applications

The emerging role of NG2 in pediatric diffuse intrinsic pontine glioma.

Diffuse intrinsic pontine gliomas (DIPGs) have a dismal prognosis and are poorly understood brain cancers. Receptor tyrosine kinases stabilized by neuron-glial antigen 2 (NG2) protein are known to induce gliomagenesis. Here, we investigated NG2 expression in a cohort of DIPG specimens (n= 50). We demonstrate NG2 expression in the majority of DIPG specimens tested and determine that tumors harboring histone 3.3 mutation express the highest NG2 levels. We further demonstrate that microRNA 129-2 (miR129-2) is downregulated and hypermethylated in human DIPGs, resulting in the increased expression of NG2. Treatment with 5-Azacytidine, a methyltransferase inhibitor, results in NG2 downregulation in DIPG primary tumor cells in vitro. NG2 expression is altered (symmetric segregation) in mitotic human DIPG and mouse tumor cells. These mitotic cells co-express oligodendrocyte (Olig2) and astrocyte (glial fibrillary acidic protein, GFAP) markers, indicating lack of terminal differentiation. NG2 knockdown retards cellular migration in vitro, while NG2 expressing neurospheres are highly tumorigenic in vivo, resulting in rapid growth of pontine tumors. NG2 expression is targetable in vivo using miR129-2 indicating a potential avenue for therapeutic interventions. This data implicates NG2 as a molecule of interest in DIPGs especially those with H3.3 mutation

Eukaryotic Evolutionary Transitions Are Associated with Extreme Codon Bias in Functionally-Related Proteins

Codon bias in the genome of an organism influences its phenome by changing the speed and efficiency of mRNA translation and hence protein abundance. We hypothesized that differences in codon bias, either between-species differences in orthologous genes, or within-species differences between genes, may play an evolutionary role. To explore this hypothesis, we compared the genome-wide codon bias in six species that occupy vital positions in the Eukaryotic Tree of Life. We acquired the entire protein coding sequences for these organisms, computed the codon bias for all genes in each organism and explored the output for relationships between codon bias and protein function, both within- and between-lineages. We discovered five notable coordinated patterns, with extreme codon bias most pronounced in traits considered highly characteristic of a given lineage. Firstly, the Homo sapiens genome had stronger codon bias for DNA-binding transcription factors than the Saccharomyces cerevisiae genome, whereas the opposite was true for ribosomal proteins – perhaps underscoring transcriptional regulation in the origin of complexity. Secondly, both mammalian species examined possessed extreme codon bias in genes relating to hair – a tissue unique to mammals. Thirdly, Arabidopsis thaliana showed extreme codon bias in genes implicated in cell wall formation and chloroplast function – which are unique to plants. Fourthly, Gallus gallus possessed strong codon bias in a subset of genes encoding mitochondrial proteins – perhaps reflecting the enhanced bioenergetic efficiency in birds that co-evolved with flight. And lastly, the G. gallus genome had extreme codon bias for the Ciliary Neurotrophic Factor – which may help to explain their spontaneous recovery from deafness. We propose that extreme codon bias in groups of genes that encode functionally related proteins has a pathway-level energetic explanation

Upfront Biology-Guided Therapy in Diffuse Intrinsic Pontine Glioma: Therapeutic, Molecular, and Biomarker Outcomes from PNOC003

PURPOSE PNOC003 is a multicenter precision medicine trial for children and young adults with newly diagnosed diffuse intrinsic pontine glioma (DIPG). PATIENTS AND METHODS Patients (3-25 years) were enrolled on the basis of imaging consistent with DIPG. Biopsy tissue was collected for whole-exome and mRNA sequencing. After radiotherapy (RT), patients were assigned up to four FDA-approved drugs based on molecular tumor board recommendations. H3K27M-mutant circulating tumor DNA (ctDNA) was longitudinally measured. Tumor tissue and matched primary cell lines were characterized using whole-genome sequencing and DNA methylation profiling. When applicable, results were verified in an independent cohort from the Children's Brain Tumor Network (CBTN). RESULTS Of 38 patients enrolled, 28 patients (median 6 years, 10 females) were reviewed by the molecular tumor board. Of those, 19 followed treatment recommendations. Median overall survival (OS) was 13.1 months [95% confidence interval (CI), 11.2-18.4] with no difference between patients who followed recommendations and those who did not. H3K27M-mutant ctDNA was detected at baseline in 60% of cases tested and associated with response to RT and survival. Eleven cell lines were established, showing 100% fidelity of key somatic driver gene alterations in the primary tumor. In H3K27-altered DIPGs, TP53 mutations were associated with worse OS (TP53mut 11.1 mo; 95% CI, 8.7-14; TP53wt 13.3 mo; 95% CI, 11.8-NA; P = 3.4e-2), genome instability (P = 3.1e-3), and RT resistance (P = 6.4e-4). The CBTN cohort confirmed an association between TP53 mutation status, genome instability, and clinical outcome. CONCLUSIONS Upfront treatment-naïve biopsy provides insight into clinically relevant molecular alterations and prognostic biomarkers for H3K27-altered DIPGs

ONC201 in combination with paxalisib for the treatment of H3K27-altered diffuse midline glioma

Diffuse midline gliomas (DMG), including diffuse intrinsic pontine gliomas (DIPGs), are the most lethal of childhood cancers. Palliative radiotherapy is the only established treatment, with median patient survival of 9-11 months. ONC201 is a DRD2 antagonist and ClpP agonist that has shown preclinical and emerging clinical efficacy in DMG. However, further work is needed to identify the mechanisms of response of DIPGs to ONC201 treatment and to determine whether recurring genomic features influence response. Using a systems-biological approach, we showed that ONC201 elicits potent agonism of the mitochondrial protease ClpP to drive proteolysis of electron transport chain and tricarboxylic acid cycle proteins. DIPGs harboring PIK3CA-mutations showed increased sensitivity to ONC201, while those harboring TP53-mutations were more resistant. Metabolic adaptation and reduced sensitivity to ONC201 was promoted by redox-activated PI3K/Akt signaling, which could be counteracted using the brain penetrant PI3K/Akt inhibitor, paxalisib. Together, these discoveries coupled with the powerful anti-DIPG/DMG pharmacokinetic and pharmacodynamic properties of ONC201 and paxalisib have provided the rationale for the ongoing DIPG/DMG phase II combination clinical trial NCT05009992

The regulatory mechanisms of NG2/CSPG4 expression

Neuron-glial antigen 2 (NG2), also known as chondroitin sulphate proteoglycan 4 (CSPG4), is a surface type I transmembrane core proteoglycan that is crucially involved in cell survival, migration and angiogenesis. NG2 is frequently used as a marker for the identification and characterization of certain cell types, but little is known about the mechanisms regulating its expression. In this review, we provide evidence that the regulation of NG2 expression underlies inflammation and hypoxia and is mediated by methyltransferases, transcription factors, including Sp1, paired box (Pax) 3 and Egr-1, and the microRNA miR129-2. These regulatory factors crucially determine NG2-mediated cellular processes such as glial scar formation in the central nervous system (CNS) or tumor growth and metastasis. Therefore, they are potential targets for the establishment of novel NG2-based therapeutic strategies in the treatment of CNS injuries, cancer and other conditions of these types