Thesis (Ph.D.)--Pacific Graduate School of Psychology, 1999. / Source: Dissertation Abstracts International, Volume: 60-05, Section: B, page: 2338. Chair: Catherine Classen.

Thesis (Ph.D.)--University of California, San Francisco, 2008. / Source: Dissertation Abstracts International, Volume: 69-02, Section: B, page: 0841. Adviser: Allan Balmain.

Thesis (Ph.D.)--University of California, San Francisco with the University of California, Berkeley, 2008. / Source: Dissertation Abstracts International, Volume: 69-06, Section: B, page: 3693. Adviser: Daniel Fletcher.

Thesis (Ph.D.)--University of California, San Francisco, 2006. / Source: Dissertation Abstracts International, Volume: 67-08, Section: B, page: 4197. Adviser: Zena Werb.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2008. / Source: Dissertation Abstracts International, Volume: 69-11, Section: B, page: 6636. Adviser: Eric Oldfield. Includes bibliographical references. Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph.D.)--University of California, San Francisco, 2008. / Source: Dissertation Abstracts International, Volume: 69-09, Section: B, page: 5334. Adviser: Thea D. Tlsty.

Thesis (Ph.D.)--University of California, San Francisco, 2010. / Source: Dissertation Abstracts International, Volume: 71-02, Section: B, page: . Adviser: Thea D. Tlsty.

Thesis (Ph.D.)--Fairleigh Dickinson University, 2005. / Source: Dissertation Abstracts International, Volume: 65-04, Section: B, page: 2084. Chairperson: Judith Kaufman. Available also in print.

The work presented herein examines the potential impact of extracellular matrix (ECM) protein-integrin receptor interactions on tumour cell chemotherapeutic sensitivity, proliferation and anchorage-independent growth. First, a screen was performed to assess the impact of ECM proteins on the survival of various tumour cell lines treated with different chemotherapeutic agents, however no significant modulation by ECM was detected. To more specifically understand potential influences of ECM on tumour cell phenotypes, a siRNA approach targeting integrin beta1, an important ECM receptor component, was employed. Integrin beta1 depletion studies conducted in paired cisplatin sensitive and resistant ovarian cancer cells did not support a role for ECM-integrin receptor binding in drug sensitivity. Similarly, reduction of integrin beta1 protein using the siRNA approach did not impact the adhesion or adherent growth of the cancer cell lines studied. However, integrin beta1 was shown to be necessary for the anchorage-independent growth of all tumour cell lines tested in soft agarose colony formation assays. The importance of integrin beta1 for anchorage-independent growth of PC3 cells was further confirmed using both neutralizing antibodies to the receptor subunit and a signaling-impaired splice variant of integrin beta1. Depletion of the integrin ligand, fibronectin, from the tumour cell culture medium similarly reduced soft agarose colony formation, suggesting that ligation of beta1 integrins is necessary for anchorage-independence. Co-immunoprecipitation studies revealed the formation of a de novo interaction between beta catenin and integrin beta1 when tumour cells were transitioned to grow anchorage-independently. These findings suggest a model whereby ligation of the beta1 integrin-containing receptors by soluble fibronectin drives the anchorage-independent growth of tumor cells through a beta catenin signaling pathway.

This thesis explores two questions; how aging of the hematopoietic stem cell (HSC) may contribute to the increase in hematological malignancies with age and secondly, how hematological malignancies can be better treated when they arise. At the intersection of both of these questions is the mitochondrial apoptotic pathway and the tool, BH3 profiling, which measures the mitochondrial priming and anti-apoptotic dependencies within normal and malignant cells. Mitochondrial priming and anti-apoptotic dependencies are measured by assessing the sensitivity of cellular mitochondria to standardized amounts of BH3 peptides derived from the BH3 domains of pro-apoptotic proteins. In our first study, we use BH3 profiling to identify anti-apoptotic dependencies to direct treatment of the anti-apoptotic BCL-2 inhibitor ABT-199 in acute myeloid leukemia (AML). We found that AML blasts are often dependent on the pro-survival protein BCL-2 and the mitochondrial dependence on BCL-2 measured by BH3 profiling correlated with cellular sensitivity to ABT-199. These pre-clinical results showed that ABT-199 was functioning on-target at the mitochondria and that BH3 profiling could be used to identify patients who would be most sensitive to BCL-2 inhibition. Importantly, these results directly led to a Phase II clinical trial of ABT-199 in relapsed/refractory AML patients and BH3 profiling was integrated into the study to test its efficacy as a predictive biomarker. In the clinical trial, we showed that BH3 profiling correlated well with clinical response. Secondly, in our studies of aging in the HSC compartment, we used BH3 profiling to explore how mitochondrial priming is altered during normal hematopoietic differentiation and during differentiation of HSCs isolated from young and old mice. We found that HSCs are less primed than more differentiated progenitor cells and that old HSCs are even less primed than young HSCs which correlates with decreased sensitivity to apoptotic stimuli of old HSCs. These studies expand upon the biological understanding of functional defects of aged HSCs, and showed for the first time in a clinical setting that BH3 profiling may be used successfully to direct treatment of BH3 mimetics in the clinic. / Medical Sciences