Abstracts Category : Other

Identification of altered cell surface glycoproteins and micropattern assay development in the context of human malignancies

by Jennifer Williams Bergstrom

Metastatic melanoma and relapsed acute T cell lymphoblastic leukemia remain incurabledespite major advancements in our understanding of these cancers. In some ways, thefoundation for a cure has already been laid; many molecular targets for drug developmentare now clearly defined, and recently novel therapeutics have shown promise in theclinical setting. However, this immense progress has not translated into a markedincrease in patient survival. This graduate project focused on two aims, which withfurther research and development may lead to a cure for these cancers. First, thedevelopment of a cellular-based high-throughput synergistic assay was looked at, thatwould allow for rapid screening of multiple drug combinations. Second, cancer-specificalterations in the cell surface high mannose glycoprotein profile were identified in the context of metastatic melanoma and T-ALL cells. The feasibility of these two aims isdemonstrated by existing innovations and research. First, protein microarrays have beendeveloped to isolate and characterize a variety of cell types. Second, growth factors andother molecules have been successfully printed onto these arrays. Third, cancer cells andcancer stem cells have been previously shown to have alterations in their cell surfaceglycome. As part of the first project, micropatterned silane and polyethylene glycol(PEG) coated glass slides were successfully developed, with these modifications acting asa non-fouling surface for cell attachment. On these slides cell-specific antibodies, antiCD3and anti-GD3, were printed and demonstrated successful capture ofT-ALL andmelanoma cell lines, respectively. However, the effectiveness of this cell capture needsfurther improvement, with regards to uniform cell seeding. Future studies will utilizerecently developed epoxide coated slides, which allow for covalent attachment of captureantibodies. Additionally, anti-CD4 antibody will be printed for T-ALL cell capture. Withrespect to the characterization of the cell surface glycome of malignant melanoma and TALLcell lines versus their non- or less-malignant counterparts, we were able to successfully demonstrate that MHC class I and sodium/potassium A TPase proteins weredifferentially glycosylated on both of these diverging cancers. MHC class I hadsignificantly higher expression on high metastatic potential B 16F 10 cells compared toB16FO cells (p-value = 0.014), and in Jurkat cells as compared to normal pan T cells (pvalue= 0.011). Additionally, sodium/potassium ATPase had significantly higherexpression on B16F10 (p-value = 0.028) and Jurkat cells (p-value = 0.013) verses B16F0 and normal T cells, respectively. These proteins, along with other identified highmannose surface proteins are directly linked to cancer cell proliferation promotion.Additionally, the altered glycosylation patterns identified in this graduate project mayhave a direct impact on MHC class I and sodium/potassium A TPase' s roles in cancer cellpromotion. Based on obtainedAdvisors/Committee Members: Peavy, Thomas R..