LRIG1, a candidate tumour-suppressor gene in human bladder cancer cell line BIU87.
OBJECTIVE
To determine the effects of LRIG1 on the growth, migration and invasion of bladder cancer cells and the mechanisms underlying such effects.


METHODS
The plasmid pLRIG1-green fluorescence protein (GFP) was transfected into BIU87 bladder cancer cells by Lipofectamine2000 (Invitrogen, Groningen, the Netherlands), and the cells that expressed LRIG1 stably were screened out by G418. The changes in LRIG1 and epidermal growth factor receptor (EGFR) protein levels were measured by Western blot; growth curves were estimated by the tetrazolium (MTT) assay; then cell-cell adhesion, cell-matrix adhesion and cell invasion assays were used to measure proliferation, adhesion and invasion in LGIR1-transfected and control cells.


RESULTS
The LRIG1 protein level in pLRIG1-GFP transfected cells was significantly higher than that in control cells, while the EGFR protein level was significantly lower. pLRIG1-GFP transfected cells had less proliferation than control cells. Contrasting with non-LRIG1-transfected cells, the invasion and cell-matrix adhesion ability of pLRIG1-GFP transfected cells decreased markedly, and conversely the homotypic cell-cell adhesion ability was significantly higher.


CONCLUSIONS
LRIG1 might act as a tumour-suppressor gene, participating in negative feedback control of EGFR expression, which inhibits bladder cancer cells from growth, migration and invasion.
Yang
Wei-Min
WM
Department of Urology, TongJi Hospital, TongJi Medical College, HuaZhong University of Science and Technology, Wuhan, Hubei, China. wmyang@tjh.tjmu.edu.cn
Yan
Ze-Jun
ZJ
Ye
Zhang-Qun
ZQ
Guo
Dong-Sheng
DS
D015153:Blotting, Western / Q000379:methods; D002448:Cell Adhesion; D002455:Cell Division; D045744:Cell Line, Tumor; D016147:Genes, Tumor Suppressor / Q000502:physiology*; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D009361:Neoplasm Invasiveness / Q000235:genetics; D009362:Neoplasm Metastasis / Q000235:genetics; D001749:Urinary Bladder Neoplasms / Q000235:genetics* / Q000473:pathology
C484445:LRIG1 protein, human; D008562:Membrane Glycoproteins