[Molecular mechanism of reversing metastatic phenotype in human high-metastatic large cell lung cancer cell line L9981 by nm23-H1].
OBJECTIVE
nm23-H1, a tumor metastasis suppressive gene, can reverse tumor metastasis phenotype. But the molecular mechanism of nm23-H1 in inhibiting or reversing metastasis of lung cancer is unclear. This study was to explore the molecular mechanism of nm23-H1 in reversing metastasis phenotype of lung cancer.


METHODS
nm23-H1 gene and pLXSN were separately transfected into human lung cancer cell line L9981. Proliferation of L9981, L9981-pLXSN, and L9981-nm23-H1 cells was detected by MTT assay, cell invasive ability was detected by modified Boyden chamber. Tumorigenesis and experimental lung metastasis were determined in vivo. mRNA and protein levels of beta-catenin, E-Cadherin, CD44S, CD44V6, matrix metalloproteinase-2 (MMP-2), tissue inhibitor of metalloproteinase-1 (TIMP-1), and vascular endothelial growth factor (VEGF) were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot.


RESULTS
(1)Cell proliferation, clone formation, and invasive ability were significantly lower in L9981-nm23-H1 cells than in L9981 cells [(19.5+/-2.9)% vs. 100%, 10.3+/-0.7 vs. 21.7+/-1.3, 31.0+/-3.0 vs. 151.0+/-6.3, P<0.01]. (2) The inhibitory rate of tumorigenesis of nude mice was significantly higher in L8891-nm23-H1 group than in L9981 group (85.6% vs. 0%, P<0.001)u the lung metastatic rate was significantly lower in L9981-nm23-H1 group than in L9981 group (0% vs. 100%, P<0.001). (3)nm23-H1 up-regulated mRNA and protein levels of beta-catenin, E-Cadherin, and TIMP-1, and down-regulated levels of MMP-2, CD44V6, and VEGF (P<0.01). (4) nm23-H1 up-regulated mRNA level of CD44s, protein level of CD44s didn't change (P>0.05).


CONCLUSIONS
nm23-H1 gene can reverse malignant and metastatic phenotype of L9981 cells through regulating the expressions of lung cancer metastasis-related genes.
Che
Guo-Wei
GW
Sichuan Provincial Key Laboratory of Lung Cancer Molecular Biology, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, P.R.China.
Zhou
Qing-Hua
QH
Zhu
Wen
W
Wang
Yan-Ping
YP
Qin
Yang
Y
Liu
Lun-Xu
LX
Chen
Xiao-He
XH
Sun
Yi-Lin
YL
Sun
Ze-Fang
ZF
D000818:Animals; D018287:Carcinoma, Large Cell / Q000235:genetics / Q000378:metabolism / Q000556:secondary*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D054778:NM23 Nucleoside Diphosphate Kinases; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D009368:Neoplasm Transplantation; D009701:Nucleoside-Diphosphate Kinase / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D014162:Transfection
D054778:NM23 Nucleoside Diphosphate Kinases; D012333:RNA, Messenger; C517938:NME1 protein, human; C517939:Nme1 protein, mouse; D009701:Nucleoside-Diphosphate Kinase