Effects of microRNA-29 family members on proliferation and invasion of gastric cancer cell lines.
OBJECTIVE
MicroRNAs have emerged as post-transcriptional regulators that are critically involved in the biologic behavior of cells. This study was designed to investigate the effect of members of the microRNA-29 family on the expression of cell division cycle 42 (Cdc42) and their roles on proliferation, migration, and invasion of gastric cancer cells.


METHODS
We detected microRNA-29s and Cdc42 expression in gastric cancer cells by real-time polymerase chain reaction (PCR) and Western blot analysis. Negative controlled RNA (ncontrol), microRNA-29 family members (microRNA-29a, -29b, and -29c), and Cdc42-specific small interfering RNA (si-Cdc42) were chemically synthesized and transfected into SGC7901 and BGC823 gastric cancer cells, which have a relatively low expression of microRNA-29s and a relatively high expression of Cdc42. The expression of Cdc42 and the phosphorylation of its downstream molecular PAK1 expressions were determined by Western bolt analysis. Cell Counting Kit-8 was used to measure cell proliferation, and wound-healing and invasion assays were used to examine the abilities of migration and invasion.


RESULTS
Similar to si-Cdc42, the ectopic expression of microRNA-29 family members significantly reduced the expression of Cdc42 and its downstream molecular PAK1 phosphorylation levels. Consistently, ectopic expression of microRNA-29s inhibited proliferation and migration in gastric cancer cells. Invasive cell counts of the SGC7901, ncontrol/SGC7901, si-Cdc42/SGC7901, microRNA-29a/SGC7901, microRNA-29b/SGC7901, and microRNA-29c/SGC7901 cell groups were 84.0+/-4.2, 71.7+/-4.6, 16.3+/-3.2, 15.7+/-3.8, 16.3+/-3.0, and 16.7+/-3.1, respectively. The invasive cell counts of the BGC823, ncontrol/BGC823, si-Cdc42/BGC823, microRNA-29a/BGC823, microRNA-29b/BGC823, and microRNA-29c/BGC823 cell groups were 199.0+/-10.5, 146.3+/-9.7, 72.7+/-8.2, 86.7+/-8.5, 86.0+/-8.5, and 73.3+/-8.3, respectively (P<0.05).


CONCLUSIONS
Members of the microRNA-29 family can obviously inhibit cell proliferation, migration, and invasion of gastric cancer cells by targeting Cdc42.
The Laboratory of Signal Transduction & Molecular Targeting Therapy, State Key Laboratory of Biotherapy/Department of Medical Oncology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China.
Nan
N
Lang
Ming
M
Liu
Qiu-Lin
QL
Tang
Xi
X
Chen
Zhen
Z
Liu
Feng
F
Bi
D000818:Animals; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D051379:Mice; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D041681:NIH 3T3 Cells; D009361:Neoplasm Invasiveness; D010766:Phosphorylation; D013274:Stomach Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D014162:Transfection; D020764:cdc42 GTP-Binding Protein / Q000378:metabolism*; D054462:p21-Activated Kinases / Q000378:metabolism
C532045:MIRN29a microRNA, human; D035683:MicroRNAs; C515903:PAK1 protein, human; D054462:p21-Activated Kinases; D020764:cdc42 GTP-Binding Protein