Inhibition of survivin expression and mechanisms of reversing drug-resistance of human lung adenocarcinoma cells by siRNA.
- Author:
Jing-lei LIU
1
;
Yan WANG
;
Ji JIANG
;
Rui KONG
;
Yan-mei YANG
;
Hong-fei JI
;
Yu-zhi SHI
Author Information
- Publication Type:Journal Article
- MeSH: Adenocarcinoma; drug therapy; pathology; Animals; Apoptosis; Caspase 3; analysis; Cell Line, Tumor; Cisplatin; pharmacology; Cyclin D1; analysis; Drug Resistance, Neoplasm; Female; Humans; Inhibitor of Apoptosis Proteins; Lung Neoplasms; drug therapy; pathology; Male; Mice; Mice, Inbred BALB C; Microtubule-Associated Proteins; antagonists & inhibitors; genetics; Proto-Oncogene Proteins c-bcl-2; analysis; RNA, Messenger; analysis; RNA, Small Interfering; genetics; Vault Ribonucleoprotein Particles; genetics
- From: Chinese Medical Journal 2010;123(20):2901-2907
- CountryChina
- Language:English
-
Abstract:
BACKGROUNDSurvivin, a member of the inhibitor of apoptosis protein (IAP) family, overexpresses in tumor cells and not expresses in terminally differentiated adult tissues. This study aimed to investigate the effects of survivin-specific siRNA on cell proliferation, apoptosis and chemosensitivity to cisplatin in vitro and in vivo and explore the mechanisms about decreasing expression of survivin in reversing cancer cells resistance to chemotherapeutic drug.
METHODSSurvivin-specific siRNA was transfected into A549/DDP cells. The expression of survivin and lung resistance-related protein (LRP) mRNA levels were determined by RT-PCR, chemosensitivity of A549/DDP (cisplatin) cells to cisplatin was determined by MTT assay, and apoptosis and cell cycle were determined by flow cytometry (FCM). The protein expression levels of survivin, LRP, cyclin-D(1), caspase-3 and bcl-2 were determined by Western blotting analyses. The effect of survivin siRNA inhibition on tumor growth was studied in athymic nude mice in vivo.
RESULTSSurvivin-specific siRNA efficiently down-regulated survivin expression. The cell cycle was arrested at G2/M phase, and apoptosis was obviously found. Inhibition of survivin expression could make the IC50 and drug-resistant index of cisplatin decrease, and enhance the cancer cells sensitivity to cisplatin. After transfection by survivin-specific siRNA, expression of LRP and cyclin-D1 were downregulated, caspase-3 expression was upregulated, bcl-2 expression had no obvious change. The animal experiment confirmed knockdown of survivin could inhibit the tumor growth.
CONCLUSIONSSurvivin-specific siRNA can efficiently suppress the expression of survivin, increase apoptosis, inhibit cells proliferation and enhance the chemosensitivity to cisplatin in vitro and in vivo. Suppression of survivin expression helping to reverse drug-resistance may have relationship with downregulation of LRP and upregulation of caspase-3. Anti-tumor strategies based on the inhibition of survivin may be useful in targeting lung adenocarcinomas.
