Down-regulation of beta 3-integrin inhibits bone metastasis of small cell lung cancer

• Published in: Molecular biology reports 2012-03, Vol.39 (3), p.3029-3035
• Main Authors: Li, Na, Zhang, Jian-ping, Guo, Shan, Min, Jie, Liu, Li-li, Su, Hai-chuan, Feng, Ying-ming, Zhang, He-long
• Format: Article
• Language: English
• Subjects: Apoptosis; Bone cancer; Bone tumors; Cell adhesion; Cell migration; Immunofluorescence; Lung cancer; Metastases; Molecular modelling; mRNA; Polymerase chain reaction; siRNA; Tumor cells; Tumors; Western blotting
• ISSN: 0301-4851; 1573-4978
• DOI: 10.1007/s11033-011-1065-y

Bone is one of the most frequent targets of small cell lung cancer (SCLC) metastasis, but the molecular mechanism remains unclear. beta 3-integrin plays an important role in invasion of various kinds of tumors. Yet, its role in bone-metastasis of SCLC is still unknown. In this study, we first examined the expression of beta 3-integrin in SBC-5 and SBC-3 cells by real-time PCR, western blot and immunofluorescence. We found that, compared to none bone-metastatic SBC-3 cells, beta 3-integrin was highly expressed in SBC-5 cells, a specific bone-metastatic SCLC cells line characterized in our previous study. We next constructed beta 3-integrin siRNA and transfected SBC-5 cell line, and found that beta 3-integrin siRNA significantly down-regulated the beta 3-integrin mRNA level and protein expression in SBC-5 cell line. We further found that inhibition of beta 3-integrin significantly reduced tumor cell proliferation and induced apoptosis. In addition, the beta 3-integrin down-regulated cells presented significant decrease in cell adhesion, migration and invasion activity. Our results suggest the beta 3-integrin has an essential effect on tumor cell proliferation and progression, and may be a potential therapeutic target for the prevention of skeletal metastases of lung cancer.