title: Adaptor protein CRK induces epithelial-mesenchymal transition and metastasis of bladder cancer cells through HGF/c-Met feedback loop.
abstract: We have previously reported that an adaptor protein CRK, including CRK-I and CRK-II, plays essential roles in the malignant potential of various aggressive human cancers, suggesting the validity of targeting CRK in molecular targeted therapy of a wide range of cancers. Nevertheless, the role of CRK in human bladder cancer with marked invasion, characterized by distant metastasis and poor prognosis, remains obscure. In the present study, immunohistochemistry indicated a striking enhancement of CRK-I/-II, but not CRK-like, in human bladder cancer tissues compared to normal urothelium. We established CRK-knockdown bladder cancer cells using 5637 and UM-UC-3, which showed a significant decline in cell migration, invasion, and proliferation. It is noteworthy that an elimination of CRK conferred suppressed phosphorylation of c-Met and the downstream scaffold protein Gab1 in a hepatocyte growth factor-dependent and -independent manner. In epithelial-mesenchymal transition-related molecules, E-cadherin was upregulated by CRK elimination, whereas N-cadherin, vimentin, and Zeb1 were downregulated. A similar effect was observed following treatment with c-Met inhibitor SU11274. Depletion of CRK significantly decreased cell proliferation of 5637 and UM-UC-3, consistent with reduced activity of ERK. An orthotopic xenograft model with bioluminescent imaging revealed that CRK knockdown significantly attenuated not only tumor volume but also the number of circulating tumor cells, resulted in a complete abrogation of metastasis. Taken together, this evidence uncovered essential roles of CRK in invasive bladder cancer through the hepatocyte growth factor/c-Met/CRK feedback loop for epithelial-mesenchymal transition induction. Thus, CRK might be a potent molecular target in bladder cancer, particularly for preventing metastasis, leading to the resolution of clinically longstanding critical issues.
authors: Department of Cancer Pathology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.|Department of Urology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors: Ryuji
authors: R
authors: Matsumoto
authors: Department of Cancer Pathology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors: Masumi
authors: M
authors: Tsuda
authors: Department of Translational Pathology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors: Lei
authors: L
authors: Wang
authors: Division of Vascular Biology, Hokkaido University IGM Institute for Genetic Medicine Frontier Research Unit, Sapporo, Japan.
authors: Nako
authors: N
authors: Maishi
authors: Department of Urology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors: Takashige
authors: T
authors: Abe
authors: Department of Cancer Pathology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors: Taichi
authors: T
authors: Kimura
authors: Department of Cancer Pathology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors: Mishie
authors: M
authors: Tanino
authors: Department of Translational Pathology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors: Hiroshi
authors: H
authors: Nishihara
authors: Division of Vascular Biology, Hokkaido University IGM Institute for Genetic Medicine Frontier Research Unit, Sapporo, Japan.
authors: Kyoko
authors: K
authors: Hida
authors: Department of Cell Physiology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors: Yusuke
authors: Y
authors: Ohba
authors: Department of Urology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors: Nobuo
authors: N
authors: Shinohara
authors: Department of Urology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors: Katsuya
authors: K
authors: Nonomura
authors: Department of Cancer Pathology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.|Department of Translational Pathology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors: Shinya
authors: S
authors: Tanaka
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D058750:Epithelial-Mesenchymal Transition; D005260:Female; D017228:Hepatocyte Growth Factor / Q000502:physiology*; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D009360:Neoplastic Cells, Circulating; D010766:Phosphorylation; D050737:Proto-Oncogene Proteins c-crk / Q000032:analysis / Q000502:physiology*; D019859:Proto-Oncogene Proteins c-met / Q000502:physiology*; D001749:Urinary Bladder Neoplasms / Q000473:pathology*
chemical_list: C485285:CRK protein, human; C066855:HGF protein, human; D050737:Proto-Oncogene Proteins c-crk; D017228:Hepatocyte Growth Factor; D019859:Proto-Oncogene Proteins c-met
keywords: Bladder cancer; CRK; EMT; c-Met; metastasis