Targeting SPARC by lentivirus-mediated RNA interference inhibits cervical cancer cell growth and metastasis.
BACKGROUND
Secreted protein acidic and rich in cysteine (SPARC), a calcium-binding matricellular glycoprotein, is implicated in the progressions of some cancers. However, no information has been available to date regarding the function of SPARC in cervical cancer cell growth and metastasis.


METHODS
In this study, we isolated and established high invasive subclones and low invasive subclones from human cervical cancer cell lines HeLa and SiHa by the limited dilution method. Real-time q-RT-PCR, Western Blot and ICC were performed to investigate SPARC mRNA and protein expressions in high invasive subclones and low invasive subclones. Then lentivirus vector with SPARC shRNA was constructed and infected the highly invasive subclones. Real-time q-RT-PCR, Western Blot and ICC were also performed to investigate the changes of SPARC expression after viral infection. In functional assays, effects of SPARC knockdown on the biological behaviors of cervical cancer cells were investigated. The mechanisms of SPARC in cervical cancer proliferation, apoptosis and invasion were also researched.


RESULTS
SPARC was over-expressed in the highly invasive subclones compared with the low invasive subclones. Knockdown of SPARC significantly suppressed cervical cancer cell proliferation, and induced cell cycle arrest at the G1/G0 phase through the p53/p21 pathway, also caused cell apoptosis accompanied by the decreased ratio of Bcl-2/Bax, and inhibited cell invasion and metastasis accompanied by down-regulated MMP2 and MMP9 expressions and up-regulated E-cadherin expression.


CONCLUSIONS
SPARC is related to the invasive phenotype of cervical cancer cells. Knockdown of SPARC significantly suppresses cervical cancer cell proliferation, induces cell apoptosis and inhibits cell invasion and metastasis. SPARC as a promoter improves cervical cancer cell growth and metastasis.
Department of Maternal and Child Health Care, School of Public Health, Shandong University, Jinan 250012, China.
Jie
J
Chen
Dehuan
D
Shi
Xiaoyan
X
Liu
Shuang
S
Fang
Jie
J
Zhang
Yueran
Y
Zhao
D000818:Animals; D017209:Apoptosis / Q000235:genetics; D015820:Cadherins / Q000235:genetics / Q000378:metabolism; D059447:Cell Cycle Checkpoints / Q000235:genetics; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics; D049109:Cell Proliferation; D005260:Female; D015870:Gene Expression; D055785:Gene Knockdown Techniques; D018014:Gene Transfer Techniques; D005822:Genetic Vectors / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D039641:Integrin beta Chains / Q000235:genetics / Q000378:metabolism; D016086:Lentivirus / Q000235:genetics; D051379:Mice; D008819:Mice, Nude; D009362:Neoplasm Metastasis / Q000235:genetics; D015676:Osteonectin; D034622:RNA Interference; D025521:Tumor Suppressor Proteins / Q000235:genetics*; D002583:Uterine Cervical Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*
D015820:Cadherins; D039641:Integrin beta Chains; D015676:Osteonectin; C577241:SPARC protein, human; D025521:Tumor Suppressor Proteins