OBJECTIVE: Engulfment and cell motility 1 (Elmo1) has been reported to cooperate 
with dedicator of cytokinesis 1 (Dock180) and to be linked to the invasive 
phenotype of cancer cells through activating small G-protein Rac. We aimed to 
study the role of Elmo1 in the malignant migration of ovarian cancer.
METHODS: Engulfment and cell motility 1 expression was evaluated in specimens 
from 93 patients with serous ovarian cancer (SOC) by immunohistochemical 
staining. Next, Elmo1-RNAi cells were established by validated small 
interference RNAs. Cell proliferation and cell motility were observed and 
compared with Dock180-RNAi cells. To confirm their synergetic contribution to 
forming focal adhesion and activating Rac1, Rac1-GTP level was measured by GST 
pull-down assay and immunofluorescence was used to observe focal adhesion 
formation both in Elmo1-RNAi and Dock180-RNAi cells.
RESULTS: Engulfment and cell motility 1 was mainly overexpressed in high-grade 
SOC tissues. Western blot analysis demonstrated that both Elmo1 and Dock180 
expressions were hampered in Elmo1-RNAi cells. Compared with the negative 
control, decreased colony formation and cell invasion were observed in 
Elmo1-RNAi cells and Dock180-RNAi cells. Consistently, both exhibited reduced 
Rac1-GTP level and inhibited focal adhesion formation.
CONCLUSIONS: Engulfment and cell motility 1 presents with synergetic action in 
helping Dock180 to activate Rac1 and promote cell motility, and thus promote 
untoward expansion and aggressiveness of SOC.