Rab35 is required for Wnt5a/Dvl2-induced Rac1 activation and cell migration in MCF-7 breast cancer cells.
The small GTPases regulate many major biological processes in both tumorigenesis and tumor progression such as cell survival, actin cytoskeleton organization, cell polarity and movement. Wnt5a, a non-canonical Wnt family member, is implicated in the activation of small GTPases in breast cancer. We previously demonstrated that Wnt5a signaling stimulates the migration of breast cancer cells MDA-MB-231 via activating RhoA. However, we found here that RhoA activation was not enhanced by Wnt5a in breast cancer cells MCF-7. The conflicting results prompted us to further probe novel small GTPases in response to Wnt5a and investigate the mechanisms whereby cell migration is regulated. We showed here that Wnt5a dose dependently activated Dvl2, Rab35 and Rac1 and subsequently promoted the migration of MCF-7 cells, which was, however, abolished by knocking down Wnt5a expression via small interfering RNA (siRNA) transfection. Dvl2 siRNA significantly decreased background and Wnt5a-induced Rab35/Rac1 activation and, consequently, cell migration. Rab35 short hairpin RNA (shRNA) remarkably inhibited background and Wnt5a-induced Rac1 activation and cell migration. Additionally, blockade of Rac1 activation with Rac1 siRNA suppressed background and Wnt5a-induced cell migration. Co-immunoprecipitation and immunofluorescence assays showed that Dvl2 bound to Rab35 in mammalian cells. Taken together, we demonstrated that Wnt5a promotes breast cancer cell migration via the Dvl2/Rab35/Rac1 signaling pathway. These findings implicate Wnt5a signaling in regulating small GTPases, which could be targeted for manipulating breast cancer cell migration.
State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, Jiangsu 210029, PR China.
Yichao
Y
Zhu
Tian
T
Shen
Jiaojing
J
Liu
Jianchao
J
Zheng
Yujie
Y
Zhang
Rui
R
Xu
Chongqi
C
Sun
Jun
J
Du
Yongchang
Y
Chen
Luo
L
Gu
D048868:Adaptor Proteins, Signal Transducing / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D001943:Breast Neoplasms; D002465:Cell Movement; D000072261:Dishevelled Proteins; D005260:Female; D006801:Humans; D047468:Immunoprecipitation; D061986:MCF-7 Cells; D010750:Phosphoproteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D015398:Signal Transduction; D051153:Wnt Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D000071818:Wnt-5a Protein; D020691:rab GTP-Binding Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D020830:rac1 GTP-Binding Protein / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D020742:rhoA GTP-Binding Protein / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; C000606581:DVL2 protein, human; D000072261:Dishevelled Proteins; D010750:Phosphoproteins; D011518:Proto-Oncogene Proteins; D034741:RNA, Small Interfering; C085389:WNT5A protein, human; D051153:Wnt Proteins; D000071818:Wnt-5a Protein; C511183:RAB35 protein, human; D020691:rab GTP-Binding Proteins; D020830:rac1 GTP-Binding Protein; D020742:rhoA GTP-Binding Protein