Inhibition of TGF-beta receptor I by siRNA suppresses the motility and invasiveness of T24 bladder cancer cells via modulation of integrins and matrix metalloproteinase.
BACKGROUND
Urinary bladder transitional-cell carcinoma is still challenging because the mechanisms underlying the tumor progression are still largely unknown. Transforming growth factor beta1 (TGF-beta1) is considered a crucial molecule in the tumorigenesis of urinary bladder carcinoma. Many studies have indicated that it is also associated with epithelial-mesenchymal transition, angiogenesis, migration and metastases in many types of malignant tumors.


METHODS
We blocked the TGF-beta signal pathway in T24 human bladder cancer cells with a siRNA (TsiRNA), which targets the TGF-beta type I receptor and evaluated the effects of TGF-beta1 and TsiRNA on the cell motility and invasiveness by Matrigel migration assay, wound-healing assay and Matrigel invasion assay. RT-PCR and Western blotting analysis were used to examine the effects of TGF-beta1 and TsiRNA on the expression of TGFBRI and genes, which are related to tumor migration and invasion.


RESULTS
While exogenous TGF-beta1 enhanced the migration and invasion of T24 cells, TsiRNA significantly suppressed them. RT-PCR and Western blotting analysis revealed that TsiRNA could downregulate both the expression of alpha3, beta1 and alpha2 integrin subunits and the activity of matrix metalloproteinase 9 enhanced by exogenous TGF-beta1.


CONCLUSIONS
Our study suggested that inhibition of TGF-beta1 signaling pathway by siRNA could be beneficial in the treatment of patients with metastatic bladder cancer.
Li
Yubing
Y
Department of Urology, First Affiliated Hospital, School of Medicine, Zhejiang University, Qingchun Road 79, 310003, Hangzhou, Zhejiang, China.
Yang
Kai
K
Mao
Qiqi
Q
Zheng
Xiangyi
X
Kong
Debo
D
Xie
Liping
L
D002295:Carcinoma, Transitional Cell / Q000235:genetics / Q000473:pathology*; D002465:Cell Movement; D015536:Down-Regulation; D006801:Humans; D016023:Integrins / Q000502:physiology*; D020782:Matrix Metalloproteinases / Q000502:physiology*; D009361:Neoplasm Invasiveness; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors* / Q000235:genetics*; D034741:RNA, Small Interfering / Q000235:genetics / Q000494:pharmacology*; D000077293:Receptor, Transforming Growth Factor-beta Type I; D018125:Receptors, Transforming Growth Factor beta / Q000037:antagonists & inhibitors* / Q000235:genetics*; D015398:Signal Transduction; D014407:Tumor Cells, Cultured; D001749:Urinary Bladder Neoplasms / Q000235:genetics / Q000473:pathology*
D016023:Integrins; D034741:RNA, Small Interfering; D018125:Receptors, Transforming Growth Factor beta; D017346:Protein Serine-Threonine Kinases; D000077293:Receptor, Transforming Growth Factor-beta Type I; D020782:Matrix Metalloproteinases