[ST6Gal I siRNA and antisense oligonucleotide-mediated gene silencing lowers the invasiveness potential of colonic carcinoma cells].
OBJECTIVE
To study the effects of small interfering RNA (siRNA) and antisense oligonucleotides (ASOs) targeting ST6Gal I on adhesion and invasiveness of human colonic carcinoma cell line SW480 over-expressing ST6Gal I.


METHODS
siRNA and ASOs targeting ST6Gal I were constructed and transfected into SW480 cells via lipofectmine 2000. SW480 cells were cultured and divided into 7 groups, namely the blank control group, liposome group, siRNA group (transfected with ST6Gal I siRNA), ASO(1) group (transfected with ST6Gal I ASO whose target site is different from the siRNA), ASO(2) group (transfected with ST6Gal I ASO targeting the same site as siRNA), siRNA+ASO(1) group (transfected with siRNA and ASO(1)), siRNA+ASO(2) group (transfected with siRNA and ASO(2)). RT-PCR was used to examine ST6Gal I mRNA expression following the treatment. Flow cytometry was used to examine the amount of alpha2,6-sialylation on SW480 cell surface. SW480 cell adhesion and invasiveness to the extracellular matrix (ECM) were analyzed using CytoMatrix kit and cell invasion assay kit, respectively.


RESULTS
The expression of ST6Gal I mRNA, the amount of alpha2,6-sialylation on the cell surface and cell adhesion and invasion to ECM decreased remarkably in groups siRNA, ASO(1), ASO(2), siRNA+ASO(1) and siRNA+ASO(2), all significantly lower than those of the blank control and liposome groups (all P<0.05), especially in siRNA+ASO(1) group. Significant difference was noted between siRNA+ASO(1) and siRNA groups (P<0.05), but not between siRNA+ASO(2) and siRNA groups, or between blank control and liposome groups (all P>0.05).


CONCLUSIONS
Chemically synthesized specific siRNA targeting ST6Gal I effectively inhibits SW480 cell ST6Gal I expression and leads to diminished cell adhesion and invasiveness to ECM, suggesting a combined effect of siRNA and ASO with different targeting sites.
Yuan
Tian-Hong
TH
Department of Microbiology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu 610041, China. gy.th@163.com
Li
Ming-Yuan
MY
Li
Wan-Yi
WY
Li
Hong
H
Jiang
Zhong-Hua
ZH
D002448:Cell Adhesion; D002465:Cell Movement; D003110:Colonic Neoplasms / Q000235:genetics / Q000473:pathology; D005434:Flow Cytometry; D020868:Gene Silencing; D006801:Humans; D009361:Neoplasm Invasiveness; D016376:Oligonucleotides, Antisense / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012799:Sialyltransferases / Q000235:genetics* / Q000378:metabolism; D014162:Transfection; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase
D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D012799:Sialyltransferases; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase