Laminin gamma2 mediates Wnt5a-induced invasion of gastric cancer cells.
OBJECTIVE
Wnt5a expression stimulates in vitro migration and invasion of cultured gastric cancer cells by an unknown mechanism and is also correlated with aggressiveness of gastric tumors. The aim of this study was to show that Wnt5a is involved in metastasis of gastric cancer cells in vivo and to explore the molecular mechanism by which Wnt5a regulates migration and invasion.


METHODS
In an experimental liver metastasis assay, Wnt5a-knockdown gastric cancer cells were injected into the spleens of nude mice. Microarray analyses were used to compare expression patterns between mouse fibroblast L cells that stably express wild-type and a mutant form of Wnt5a to investigate Wnt5a-dependent gene expression. The expression of genes found to be regulated by Wnt5a was investigated in cultured gastric cancer cells. Immunohistochemical analyses were performed to measure levels of Wnt-regulated gene products in 153 gastric cancer samples.


RESULTS
Knockdown of Wnt5a in gastric cancer cells reduced the number of liver metastases that formed in nude mice. Microarray analyses indicated that Wnt5a activity induced expression of the gene encoding laminin gamma2, a subunit of the epithelial basement membrane protein laminin-5. Wnt5a induced the expression of laminin gamma2 through the activation of protein kinase C and c-Jun-N-terminal kinase. The invasive activity of gastric cancer cells depended on laminin gamma2; Wnt5a expression levels correlated with those of laminin gamma2 in diffuse-scattered type gastric tumor samples from patients.


CONCLUSIONS
Wnt5a contributes to gastric cancer progression by increasing metastatic potential. Wnt5a up-regulates laminin gamma2 to mediate gastric cancer cell aggressiveness.
Yamamoto
Hideki
H
Department of Biochemistry, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan.
Kitadai
Yasuhiko
Y
Yamamoto
Hideki
H
Oue
Naohide
N
Ohdan
Hideki
H
Yasui
Wataru
W
Kikuchi
Akira
A
D000818:Animals; D045744:Cell Line, Tumor; D002465:Cell Movement; D005347:Fibroblasts / Q000378:metabolism; D020869:Gene Expression Profiling / Q000379:methods; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D007797:Laminin / Q000235:genetics / Q000378:metabolism*; D008113:Liver Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000556:secondary; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009154:Mutation; D009361:Neoplasm Invasiveness; D020411:Oligonucleotide Array Sequence Analysis; D011401:Promoter Regions, Genetic; D011493:Protein Kinase C / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction; D013274:Stomach Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D018808:Transcription Factor AP-1 / Q000378:metabolism; D014162:Transfection; D015854:Up-Regulation; D051153:Wnt Proteins / Q000235:genetics / Q000378:metabolism*; D000071818:Wnt-5a Protein
C400567:LAMC2 protein, human; C498522:Lamc2 protein, mouse; D007797:Laminin; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D018808:Transcription Factor AP-1; C085389:WNT5A protein, human; D051153:Wnt Proteins; D000071818:Wnt-5a Protein; C438615:Wnt5a protein, mouse; D011493:Protein Kinase C; D048031:JNK Mitogen-Activated Protein Kinases