Caveolin-1 (Cav-1) is a 21 kDa
protein enriched in caveolae, and has been implicated in oncogenic cell transformation,
tumorigenesis, and
metastasis. We explored roles for Cav-1 in
pancreatic cancer (PC) prognostication,
tumor progression, resistance to
therapy, and whether targeted downregulation could lead to therapeutic sensitization. Cav-1 expression was assessed in cell lines, mouse models, and patient samples, and knocked down in order to compare changes in proliferation, invasion, migration, response to
chemotherapy and radiation, and
tumor growth. We found Cav-1 is overexpressed in human PC cell lines, mouse models, and human pancreatic
tumors, and is associated with worse
tumor grade and clinical outcomes. In PC cell lines, disruption/depletion of caveolae/Cav-1 reduces proliferation, colony formation, and invasion. Radiation and
chemotherapy up-regulate Cav-1 expression, while Cav-1 depletion induces both chemosensitization and radiosensitization through altered apoptotic and DNA repair signaling. In vivo, Cav-1 depletion significantly attenuates
tumor initiation and growth. Finally, Cav-1 depletion leads to altered JAK/STAT, JNK, and Src signaling in PC cells. Together, higher Cav-1 expression is correlated with worse outcomes, is essential for
tumor growth and invasion (both in vitro and in vivo), is responsible for promoting resistance to
therapies, and may serve as a prognostic/predictive
biomarker and target in PC.