[Study on enhancing sensitivity of SPC-A1 cells to chemotherapy by Livin isoform-specific gene silencing].
BACKGROUND
As a new member of inhibitor of apoptosis protein(IAP) family,Livin,especially Livin α,is known to be involved in occurrence and development of lung cancer.Livin is an important mechanism of chemotherapy resistance of lung cancer cell.The aim of this study is to set up Livin isoform(α & β)-specific gene silencing system in SPC-A1 cells by gene transfection and RNA interference(RNAi),and to explore the different functions and value of the isoforms in enhancing chemosensitivity of SPC-A1 cells.


METHODS
Livinα+β,Livinα and Livinβ specific siRNA were expressed stably in SPC-A1 cells,respectively.MTT was performed to study sensitivity of the cells to chemotherapy drugs.In vivo experiment was performed to test sensitivity of mouse bearing tumor to cisplatin after gene silencing of Livin.


RESULTS
After silencing of Livinα+β,Livinα and Livinβ genes,sensitivity of SPC-A1 cells to many chemotherapy drugs(including cisplatin,carboplatin,cyclophosphamide and adriblastine) was markedly increased(P < 0.05).Among them,gene silencing of Livinα+β showed the strongest enhancement effect on chemosensitivity of SPC-A1 cells(P < 0.01).Animal experiment showed that tumor inhibition rate of pSilencer-Livinα+β,pSilencer-Livinα and pSilencer-Livinβ groups was 146.1%,130.7% and 110.5%,respectively.


CONCLUSIONS
The results suggest that Livin isoform,especially Livinα+β is hopeful to be a molecular target for increasing sensitivity of lung cancer cell to chemotherapy.Gene silencing may be a new means of gene therapy for non-small cell lung cancer.
Cancer Institute of PLA,Xinqiao Hospital,Third Military Medical University,Chongqing 400037,P.R.China.
Jianguo
J
Sun
Rongxia
R
Liao
Zhengtang
Z
Chen
Zhixin
Z
Wang
Qing
Q
Zhang
Yide
Y
Hu