The microRNA-200 family is known to be a master regulator of the epithelial-to-mesenchymal transition, partially through its double-negative feedback loop with the transcriptional repressor Zeb1, yet the mechanisms on how miR-200 controls the invasive phenotype are not fully understood. Recent studies have shown that the miR-200/Zeb1 axis regulates cell-cell and cell-matrix interactions, but it has also been demonstrated that cell-intrinsic changes are insufficient to drive cancer cell invasion, leading us to focus on specific cell-matrix interactions required to activate tumor cell invasion and metastases. We have shown through 3D studies that the Integrin β1-collagen I contact is critical in mediating the invasive phenotype in cells with miR-200 loss or Zeb1 overexpression. Furthermore, those genetic changes enhanced the cells responsiveness to the ECM through the FAK/Src pathway. The importance of this pathway in our Kras and p53 mouse model and in human lung cancer cell lines was further studied using pharmacological inhibitors and an shRNA-based knockdown approach, which exhibited a significant suppression of migration and invasion in Boyden chambers and 3D invasion assays. Furthermore, pharmacological inhibition of Src prevented distant metastases in vivo. We found that miR-200 regulates the activation of the FAK/Src pathway through direct targeting of CRKL, an integrin adaptor molecule. Our studies suggest that CRKL is critical in enhancing the outside-in signaling through Itgβ1 but also involved in the inside-out signaling by maintaining the cell-matrix contact required for continuous cell invasion. Those findings highlight the importance of the ECM composition, in addition to cell-intrinsic changes, that regulate the activation of intracellular signaling pathways required for tumor cell invasion and metastases that allow for targeting at multiple levels.
","abstract_html":"<p>The microRNA-200 family is known to be a master regulator of the epithelial-to-mesenchymal transition, partially through its double-negative feedback loop with the transcriptional repressor Zeb1, yet the mechanisms on how miR-200 controls the invasive phenotype are not fully understood. Recent studies have shown that the miR-200/Zeb1 axis regulates cell-cell and cell-matrix interactions, but it has also been demonstrated that cell-intrinsic changes are insufficient to drive cancer cell invasion, leading us to focus on specific cell-matrix interactions required to activate tumor cell invasion and metastases. We have shown through 3D studies that the Integrin β1-collagen I contact is critical in mediating the invasive phenotype in cells with miR-200 loss or Zeb1 overexpression. Furthermore, those genetic changes enhanced the cells responsiveness to the ECM through the FAK/Src pathway. The importance of this pathway in our Kras and p53 mouse model and in human lung cancer cell lines was further studied using pharmacological inhibitors and an shRNA-based knockdown approach, which exhibited a significant suppression of migration and invasion in Boyden chambers and 3D invasion assays. Furthermore, pharmacological inhibition of Src prevented distant metastases <em>in vivo</em>. We found that miR-200 regulates the activation of the FAK/Src pathway through direct targeting of CRKL, an integrin adaptor molecule. Our studies suggest that CRKL is critical in enhancing the outside-in signaling through Itgβ1 but also involved in the inside-out signaling by maintaining the cell-matrix contact required for continuous cell invasion. Those findings highlight the importance of the ECM composition, in addition to cell-intrinsic changes, that regulate the activation of intracellular signaling pathways required for tumor cell invasion and metastases that allow for targeting at multiple levels.</p>","abstract_has_math":false,"creators":["Ungewiss, Christin"],"institution":null,"degree_name":"Doctor of Philosophy (PhD)","degree_level":"Dissertation (PhD)","degree_discipline":null,"degree_department":null,"school":null,"contributors":["Don Gibbons","Andrew Gladden","Faye Johnson"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2015,"date_issued":"2015-05-01T07:00:00Z","date_published":"2015-05-01T07:00:00Z","updated_at":"2026-07-24T05:50:16Z","subjects":["miR-200","lung cancer","metastases","EMT","Integrin b1","FAK","CRKL","Cancer Biology"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://digitalcommons.library.tmc.edu/utgsbs_dissertations/561","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Don Gibbons","Andrew Gladden","Faye Johnson"]},{"key":"dc:creator","label":"Author","values":["Ungewiss, Christin"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2016-04-30T07:00:00Z"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation (PhD)"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy (PhD)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["miR-200","lung cancer","metastases","EMT","Integrin b1","FAK","CRKL","Cancer Biology"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://digitalcommons.library.tmc.edu/utgsbs_dissertations/561"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The microRNA-200 family is known to be a master regulator of the epithelial-to-mesenchymal transition, partially through its double-negative feedback loop with the transcriptional repressor Zeb1, yet the mechanisms on how miR-200 controls the invasive phenotype are not fully understood. Recent studies have shown that the miR-200/Zeb1 axis regulates cell-cell and cell-matrix interactions, but it has also been demonstrated that cell-intrinsic changes are insufficient to drive cancer cell invasion, leading us to focus on specific cell-matrix interactions required to activate tumor cell invasion and metastases. We have shown through 3D studies that the Integrin β1-collagen I contact is critical in mediating the invasive phenotype in cells with miR-200 loss or Zeb1 overexpression. Furthermore, those genetic changes enhanced the cells responsiveness to the ECM through the FAK/Src pathway. The importance of this pathway in our Kras and p53 mouse model and in human lung cancer cell lines was further studied using pharmacological inhibitors and an shRNA-based knockdown approach, which exhibited a significant suppression of migration and invasion in Boyden chambers and 3D invasion assays. Furthermore, pharmacological inhibition of Src prevented distant metastases in vivo. We found that miR-200 regulates the activation of the FAK/Src pathway through direct targeting of CRKL, an integrin adaptor molecule. Our studies suggest that CRKL is critical in enhancing the outside-in signaling through Itgβ1 but also involved in the inside-out signaling by maintaining the cell-matrix contact required for continuous cell invasion. Those findings highlight the importance of the ECM composition, in addition to cell-intrinsic changes, that regulate the activation of intracellular signaling pathways required for tumor cell invasion and metastases that allow for targeting at multiple levels.
"]},{"key":"dc:title","label":"Title","values":["Microrna-200 Regulates Ecm-Dependent Β1-Integrin/Fak Signaling and Cancer Cell Invasion"]}]}],"canonical_facts":{"dc:contributor":["Don Gibbons","Andrew Gladden","Faye Johnson"],"dc:creator":["Ungewiss, Christin"],"dc:date.available":["2016-04-30T07:00:00Z"],"dc:description.abstract":["The microRNA-200 family is known to be a master regulator of the epithelial-to-mesenchymal transition, partially through its double-negative feedback loop with the transcriptional repressor Zeb1, yet the mechanisms on how miR-200 controls the invasive phenotype are not fully understood. Recent studies have shown that the miR-200/Zeb1 axis regulates cell-cell and cell-matrix interactions, but it has also been demonstrated that cell-intrinsic changes are insufficient to drive cancer cell invasion, leading us to focus on specific cell-matrix interactions required to activate tumor cell invasion and metastases. We have shown through 3D studies that the Integrin β1-collagen I contact is critical in mediating the invasive phenotype in cells with miR-200 loss or Zeb1 overexpression. Furthermore, those genetic changes enhanced the cells responsiveness to the ECM through the FAK/Src pathway. The importance of this pathway in our Kras and p53 mouse model and in human lung cancer cell lines was further studied using pharmacological inhibitors and an shRNA-based knockdown approach, which exhibited a significant suppression of migration and invasion in Boyden chambers and 3D invasion assays. Furthermore, pharmacological inhibition of Src prevented distant metastases in vivo. We found that miR-200 regulates the activation of the FAK/Src pathway through direct targeting of CRKL, an integrin adaptor molecule. Our studies suggest that CRKL is critical in enhancing the outside-in signaling through Itgβ1 but also involved in the inside-out signaling by maintaining the cell-matrix contact required for continuous cell invasion. Those findings highlight the importance of the ECM composition, in addition to cell-intrinsic changes, that regulate the activation of intracellular signaling pathways required for tumor cell invasion and metastases that allow for targeting at multiple levels.
"],"dc:identifier":["https://digitalcommons.library.tmc.edu/utgsbs_dissertations/561"],"dc:subject":["miR-200","lung cancer","metastases","EMT","Integrin b1","FAK","CRKL","Cancer Biology"],"dc:title":["Microrna-200 Regulates Ecm-Dependent Β1-Integrin/Fak Signaling and Cancer Cell Invasion"],"thesis:degree_level":["Dissertation (PhD)"],"thesis:degree_name":["Doctor of Philosophy (PhD)"]},"updated_at":"2026-07-24T05:50:16Z"}