Expression of bone morphogenetic protein-10 (BMP10) in human urothelial cancer of the bladder and its effects on the aggressiveness of bladder cancer cells in vitro.

BACKGROUND: Bone morphogenetic protein-10 (BMP10), a novel member of the bone morphogenetic protein (BMP) family, has been indicated as a possible tumour suppressor in prostate and breast cancer. However, its role in urothelial tumours remains unknown. In the present study, we examined the role of BMP10 in urothelial cancer cells and the expression of BMP10 in human urethelial cancer of the bladder.
MATERIALS AND METHODS: The expression of BMP10 was examined in human bladder tissues and in the T24 human bladder cancer cell line using immunochemical staining and reverse transcription polymerase chain reaction (RT-PCR), respectively. The biological impact of modifying BMP10 expression, through genetic manipulation, in urothelial cancer cells was evaluated using in vitro models.
RESULTS: mRNA for BMP10 and receptors of BMPs was expressed in T24 cell lines. BMP10 protein expression was observed in normal urothelial and stromal cells, but was found to be decreased in or absent from urothelial cancer cells. The frequency of positive staining in normal tissues (9/9) was significantly higher than that in urothelial cancer tissues (6/15) (p=0.007). T24 cells were transfected with BMP10 expression plasmid. It was further demonstrated that overexpression of BMP10 reduced the growth rate of T24 cells, and markedly reduced the motility, and adhesion of T24 cells in vitro. No significant effects were seen on in vitro invasiveness of T24 cells following BMP10 transfection.
CONCLUSION: Expression of BMP10 protein is reduced in cancer cells of bladder tumours. Overexpression of BMP10 has an inhibitory effect on the growth, adhesion, and migration of bladder cancer cells in vitro. This would suggest a potential tumour suppressor role of BMP10 in bladder cancer.