CrkI and CrkII function as key signaling integrators for migration and invasion of cancer cells.
Crk adaptor proteins play an important role during cellular signaling by mediating the formation of protein complexes. Increased levels of Crk proteins are observed in several human cancers and overexpression of Crk in epithelial cell cultures promotes enhanced cell dispersal and invasion, implicating Crk as a regulator of invasive responses. To determine the requirement of Crk for invasive signals, we targeted the CRKI/II gene by RNA interference. Consistent knockdown of CrkI/II was observed with two small interfering RNA targeting sequences in all human cancer cell lines tested. CrkI/II knockdown resulted in a significant decrease in migration and invasion of multiple malignant breast and other human cancer cell lines (MDA-231, MDA-435s, H1299, KB, and HeLa). Moreover, CrkI/II knockdown decreased cell spreading on extracellular matrix and led to a decrease in actin stress fibers and the formation of mature focal adhesions. Using immunohistochemistry, we show elevated CrkI/II protein levels in patients with breast adenocarcinoma. Together, these studies identify Crk adaptor proteins as critical integrators of upstream signals for cell invasion and migration in human cancer cell lines and support a role for Crk in metastatic spread.
Rodrigues
Sonia P
SP
Department of Biochemistry, McGill University, Molecular Oncology Group, McGill University Health Centre, Montréal, Québec, Canada.
Fathers
Kelly E
KE
Chan
Gabriel
G
Zuo
Dongmei
D
Halwani
Fawaz
F
Meterissian
Sarkis
S
Park
Morag
M
D000230:Adenocarcinoma / Q000378:metabolism / Q000556:secondary*; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D002448:Cell Adhesion / Q000502:physiology; D002465:Cell Movement / Q000502:physiology; D006367:HeLa Cells; D006801:Humans; D009361:Neoplasm Invasiveness; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D050737:Proto-Oncogene Proteins c-crk; D034741:RNA, Small Interfering; D015398:Signal Transduction / Q000502:physiology*; D022502:Stress Fibers / Q000378:metabolism
D011518:Proto-Oncogene Proteins; D050737:Proto-Oncogene Proteins c-crk; D034741:RNA, Small Interfering