Thesis (Ph.D.)--University of California, San Francisco, 2009. / Source: Dissertation Abstracts International, Volume: 71-02, Section: B, page: . Adviser: Benjamin Cheyette.

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

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2009. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3268. Advisers: Andrew S. Belmont; Jie Chen. Includes bibliographical references (leaves 114-129) Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2009. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3271. Advisers: Andrew S. Belmont; Peter L. Jones. Includes bibliographical references (leaves 70-81) Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006. / Source: Dissertation Abstracts International, Volume: 67-11, Section: B, page: 6160. Adviser: Byron W. Kemper. Includes bibliographical references (leaves 110-130) Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2007. / Source: Dissertation Abstracts International, Volume: 69-02, Section: B, page: 0774. Adviser: Joseph Henry. Includes bibliographical references (leaves 111-128) Available on microfilm from Pro Quest Information and Learning.

C2C12 murine progenitors are a model for transdifferentiation. This project investigated signaling events that regulate this process in culture by monitoring specific markers for transdifferentiation (alkaline phosphatase [ALP] and myogenin for the osteoblastic and myoblaststic fates respectively) in the presence of inducers and inhibitors. Antibodies specific for proteins implicated in signaling were used to monitor the differentiation process. BMP-2 addition caused transdifferentiation to the osteoblastic fate except for a small fraction of cells that may represent the so-called MyoD negative cells or the side population (SP). The timing of short term commitment of C2C12 to osteoblastic transdifferentiation was between 6 to 24h under our culture conditions. BMP-2-induced ALP activity increase and the repression of myogenin expression were not simultaneous. Differentiation as measured by ALP activity may be dependent on the interaction of BMP-2/Smad, p38 MAPK and TGF-beta1 pathways. Smads 1, 5 and/or 8 were almost always found under their phosphorylated form (pSmads) and thus almost invariably located in nuclei suggesting fast nucleoplasmic shuttling from the cytoplasm and nuclear retention of the phosphorylated forms. Phosphorylated forms were also found in the nucleus under proliferative conditions without exogenous BMP-2. In this case, it is suggested that this phosphorylation of Smads may be triggered by the reported autocrine secretion of TGF-beta by the C2C12 cells or by the TGF-beta present in the culture serum.

Hourglass cells (HGCs) are one of three main cell types in the soybean seed coat. We have studied their structure during the early phases of seed coat development, from 9 to 45 days post anthesis (dpa), by four different microscopic techniques. At 9dpa HGCs resemble typical plant cells but from 12-18dpa they under go rapid changes in their internal and external structure. By 18dpa they have assumed the typical hourglass shape with thick cell walls composed of layers of pectic material, intercellular air spaces and large central vacuoles. By 45dpa, all organelles in HGCs have been degraded. Additional experiments have shown that plasmodesmata connect all cell types and that soybean peroxidase is localized to the HGC. These results increase our understanding of the structure and development of the HGC and will be valuable for future studies on protein targeting to components of the endomembrane systems within them.

Multidrug resistance (MDR) commonly occurs during the treatment of cancer. Current research has focused mostly on the role of drug transporters, as the main mechanism of MDR; however, few have demonstrated a definite link between the expression or function of drug transporters and MDR in cancer patients. Anthracyclines such as doxorubicin and epirubicin, autofluoresce and can be monitored by confocal microscopy. Two of the four resistant cell fines generated in our lab: the MCF-7EPI cells and to some extent MCF-7 DOX cells, exhibit a localization defect, whereby epirubicin is localized primarily in the cytoplasm rather than the nucleus. This drug localization defect temporally correlated with the onset of drug-resistance during selection for drug resistance in these cell lines. Consistent with the possible sequestration of drugs into acidic vesicles, acridine orange staining has revealed the presence of aggregates of acidified vesicles in the perinuclear region of MCF-7EPI cells. However, co-localization experiments using a number of intracellular organelle markers determined that epirubicin was localized to lysosomes and not consistently to acidic vesicles. An inhibitor of vacuolar H+ ATPase, was unable to restore the localization of epirubicin to the nucleus. Immunofluorescence using an ABCB1 antibody revealed the localization of ABCB1 predominantly in the plasma membrane and to some extent in the perinuclear region of MCF-7EPI cells. Nevertheless, inhibitors of this transporter failed to restore localization of epirubicin to the nucleus. Taken together, these findings strongly suggest that the acquisition of epirubicin resistance in breast tumour cells may involve the P-glycoprotein independent sequestration of drug into lysosomes. These lysosomes need not be acidic, nor does the removal of acid vesicles by inhibition of vacuolar H+ ATPases block the sequestration of drug into lysosomes.

The development of antiestrogen resistance has been correlated with changes in ERalpha expression/mutation and a rise in NF-kappaB activity. We believe that NF-kappaB is activated in both ER-positive and ER-negative breast cancer cells and that it is attenuated by liganded ERalpha in ER-positive cells by regulating the formation of p50 and p65 complexes. It is possible that mutations in the ER alter its ability to bind and regulate NF-kappaB activity, which allows constitutive activation of NF-kappaB and confers estrogen-independence to these cells. Here, we demonstrate that increased expression of ER in both ER-negative as well as ER-positive cells results in decreased cell viability and decreased NF-kappaB activity. We also confirm a direct interaction between ERalpha and NF-kappaB subunits in vitro. We also demonstrate that NF-kappaB subunits, p65 and p50, are capable of interacting with ERalpha on an ERE in vivo and that this interaction is enhanced by treatment with E2. Moreover we are the first to show that inhibition of NF-kappaB results in increased ER activity, indicating a possible mutual repression between ERalpha and NF-kappaB. Lastly, we demonstrate that treatment with tamoxifen does not have the same inhibitory effects on NF-kappaB as does estrogen. Together, these observations suggest that an interaction between ERalpha and NF-kappaB have a vital role in the development of breast cancer, estrogen-independent growth and resistance to antiestrogens.