PROJECT SUMMARY The high mortality rate in ovarian cancers is explained in part, by late-stage clinical diagnosis where intraperitoneal tumor burden is already prevalent and widespread. Shedding and implantation of transformed secretory cells, originating from the fallopian tube, is considered one of the main initiators of ovarian cancer. During the early stages of this disease, secretory fallopian tube cells gain mutations that support migration (against the direction of fluid flow) to the ends of the fallopian tubes (fimbriae). At the fimbriae, the mutated fallopian tube cells form small early precursor lesions. Both the ovaries and fallopian tubes are suspended within the abdominal cavity, where the environment further exposes early precursor tumor cells to dynamic shear stresses. We therefore hypothesize that the fluidic shear stress stimulates the early precursor lesions in the fallopian tubes and modulates their dissemination to the ovary and peritoneal organs. In order to test this hypothesis, we will utilize microfluidic devices and bioreactors to circulate cell growth medium around transformed human and mouse fallopian tube cell lines that are supported on an agarose-collagen, polysaccharide-protein scaffold. Human immortalized fallopian tube cells with varying degrees of genetic mutation will be probed for changes in cell replication, migration, invasion, cell death, and genetic variation after stimulation of shear stress. Our preliminary data suggests a robust increase in the expression of GPRC5A in fallopian tube secretory epithelial cells (FTSEC) under shear stress stimulation. Therefore, we will validate this discovery in FTSEC cell lines with driver mutations and patient-derived cells, and investigate the GPRC5A molecular pathway and its components that are activated in FTSEC under shear stress stimulation, by utilizing gain-of-function and loss-of-function assays. Shear stressed and static control mutated fallopian tube cells will be tested for stemness and the capacity to initiate tumors in immunodeficient mice. Stimulated transformed fallopian tube cells will also be injected into immunocompromised mice to investigate the cell’s ability to colonize and form tumors. These studies will also be performed in mice with intact immune systems in order to assess whether immune cells impact growth and dissemination. Given that no published studies have yet identified the role of shear stresses in dissemination of early precursor lesions in ovarian cancers, the proposed work can potentially have much broader impact. For example, with our dynamic microfluidic and 3D bioreactor models, mechanotransduction and immunotherapy drugs can be screened for development of effective cancer therapies. The components of the shear stress-induced mechanotransduction that are identified in our proposed work, could also be utilized in early detection of ovarian cancers. As a result, the important role of shear stresses in the fluidic niches of ovarian canc...