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dc.contributor.authorRodriguez Corrales, Jose Angelen_US
dc.date.accessioned2020-02-13T07:00:47Z
dc.date.available2020-02-13T07:00:47Z
dc.date.issued2018-08-21
dc.identifier.othervt_gsexam:17035en_US
dc.identifier.urihttp://hdl.handle.net/10919/96808
dc.description.abstractCancer, the second leading cause of death worldwide, is characterized by uncontrolled and abnormal cell growth. Even though researchers have made significant progress in its treatment over the past several decades, innovative therapeutic approaches that both improve patient survival and lessen the many debilitating side effects of conventional cancer treatments are vital. Accordingly, we first investigated the mechanism of interaction of a bimetallic complex, Ru(II)-Rh(III), with DNA. Non-covalent binding of Ru(II)-Rh(III) is strong and involves electrostatic and, potentially, groove binding interactions. Ru(II)-Rh(III) photobinds and photocleaves DNA through an O2-independent, metal-center mediated mechanism that could be beneficial in hypoxic tumors. Furthermore, the extent of covalent binding and cleavage of DNA, which inhibit PCR amplification, is dependent upon the strength of the non-covalent interactions. These results suggest that the toxicity of Ru(II)-Rh(III) could be selectively generated in tissues irradiated with light (e.g., a tumor). Secondly, we identified protein combinations selectively present in melanoma, which could be utilized in heteromultivalency. Heteromultivalent scaffolds display higher affinity towards cells that express a protein combination in comparison to those with only one of the proteins, which facilitates cell discrimination. Using an empirically-optimized threshold-based screening method and expression profiles of melanoma patients and normal tissues, we identified surface proteins and protein combinations that are selectively found in melanoma patients and not in normal tissues. After a preliminary validation process using the scientific literature, we used immunofluorescence to confirm differential expression of some of these combinations in established melanoma cell lines in comparison to immortalized keratinocytes controls. Finally, we investigated the resazurin assay, a method used for the evaluation of proliferation and cytotoxicity in more than 2,000 publications. We found that only ~14% of these utilized validated assay conditions, while ~40% failed to report essential analytical parameters needed for their replication. We evaluated assay parameters needed for accurate estimation of cell number in eight cell lines, and found that these are highly variable and independent of tissue type, growth kinetics, and energetic parameters. Furthermore, we obtained some insights into the biochemical reduction of resazurin and proposed minimum reporting standards, along with a sample protocol for assay validation.en_US
dc.format.mediumETDen_US
dc.publisherVirginia Techen_US
dc.rightsThis item is protected by copyright and/or related rights. Some uses of this item may be deemed fair and permitted by law even without permission from the rights holder(s), or the rights holder(s) may have licensed the work for use under certain conditions. For other uses you need to obtain permission from the rights holder(s).en_US
dc.subjectphotodynamic therapyen_US
dc.subjectexcited state reactivityen_US
dc.subjectDNAen_US
dc.subjectheteromultivalencyen_US
dc.subjectmelanomaen_US
dc.subjectcytotoxicityen_US
dc.subjectresazurinen_US
dc.titleEvaluation of potential photodynamic therapy agents and patient-relevant biomarker combinations for the selective targeting of canceren_US
dc.typeDissertationen_US
dc.contributor.departmentChemistryen_US
dc.description.degreePHDen_US
thesis.degree.namePHDen_US
thesis.degree.leveldoctoralen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineChemistryen_US
dc.contributor.committeechairWinkel, Brenda Sophia J.en_US
dc.contributor.committeememberRobertson, John L.en_US
dc.contributor.committeememberFinkielstein, Carla V.en_US
dc.contributor.committeememberDorn, Harry C.en_US


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