Fibulin-5 is down-regulated in urothelial carcinoma of bladder and inhibits growth and invasion of human bladder cancer cell line 5637.
OBJECTIVE
The expression of fibulin-5 was investigated in urothelial carcinomas of bladder and in normal bladder samples. The effects of fibulin-5 on cell proliferation, motility, and invasion were further explored in bladder cancer cell line 5637.


METHODS
The expression of fibulin-5 in 20 bladder carcinoma samples and 7 normal bladder samples were detected by Western blot. Fibuin-5 cDNA was cloned into p-EGFP-N1 vector and transfected into bladder cancer cell line 5637. Growth curves were estimated by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide assay and cell number count. The migration and invasion of the transfected cells and the control cells were measured by Boyden chamber assay.


RESULTS
Compared with 1.16 ± 0.28 in the normal control, the mean ± SD expression of fibulin-5 in low grade tumors and high grade tumors were 0.57 ± 0.32 and 0.44 ± 0.42 (P = 0.002 and P = 0.018, respectively), while the expression in Ta-T1 tumors and T2+ tumors were 0.55 ± 0.31 and 0.49 ± 0.43 (P = 0.002 and P = 0.015, respectively). The differences between low grade and high grade tumors or Ta-T1 and T2+ tumors were not statistically significant (P = 0.362 and P = 0.589, respectively). The growth rate of the fibulin-5 transfected GFP-F5 cells was remarkably reduced than that of the untransfected cells or the empty vector transfected GFP-t cells. Besides, compared with control cells, the GFP-F5 cells showed significant inhibition of cell invasion with slight inhibition of cell migration.


CONCLUSIONS
Fibulin-5 is down-regulated in urothelial carcinoma of bladder and acts as a tumor suppressor gene by inhibiting proliferation and invasion of bladder cancer cells.
Hu
Zheng
Z
Department of Urology, General Hospital of PLA, Beijing, China.
Ai
Qing
Q
Xu
Hua
H
Ma
Xin
X
Li
Hong-Zhao
HZ
Shi
Tao-Ping
TP
Wang
Chao
C
Gong
Dao-Jing
DJ
Zhang
Xu
X
D000368:Aged; D002295:Carcinoma, Transitional Cell / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D002470:Cell Survival; D015536:Down-Regulation; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008297:Male; D008856:Microscopy, Fluorescence; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D014162:Transfection; D001749:Urinary Bladder Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology
D016326:Extracellular Matrix Proteins; C492373:FBLN5 protein, human; D049452:Green Fluorescent Proteins