Expression of LAPTM4B in gallbladder carcinoma cells: the role in invasive potential.
OBJECTIVE
It was previously established that LAPTM4B-35 highly expressed in gallbladder carcinoma and being of clinicopathological and prognostic significances. However, expression of LAPTM4B gene in gallbladder carcinoma (GBC-SD), a gallbladder carcinoma cell line, and its role in invasive potential remain unclear.


METHODS
Expression of LAPTM4B in GBC-SD cells was first detected. Plasmids, pcDNA3-AE (containing complete open reading frame of LAPTM4B) and Mock (pcDNA3), were transiently transfected into GBC-SD cells. Invasive phenotypes (migration and invasion) and relative molecules were then shown by transwell assay, crossing river test and Western blot analysis.


RESULTS
Immunocytochemical staining revealed that LAPTM4B-35 positively expressed in cytoplasm of GBC-SD cells. But LAPTM4B-35 expression was obviously weaker in GBC-SD cells than that in BEL-7402 cells (positive control). Besides, cells transfected with pcDNA3-AE presented shorter crossing river time, less migrated and invaded cell numbers, compared with cells transfected with the Mock plasmid and parent cells. Finally, increased expressions of active uPA, MMP-9, pro MMP-2 and active MMP-2 were also observed in cells transfected with pcDNA3-AE.


CONCLUSIONS
Our data suggested that LAPTM4B expressed in GBC-SD cells at a relatively low level. Forced overexpression of LAPTM4B increased invasive potential of GBC-SD cells, through modulating molecules associated with degradation of extracellular matrix.
Zhou
Li
L
Department of General Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences/Peking Union Medical College, Beijing 100730, China.
He
Xiao-Dong
XD
Yu
Jian-Chun
JC
Zhou
Rou-Li
RL
Xiong
Fu-Xia
FX
Qu
Qiang
Q
Rui
Jing-An
JA
D015153:Blotting, Western; D045744:Cell Line, Tumor; D002465:Cell Movement; D015226:Dinucleoside Phosphates / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism; D005706:Gallbladder Neoplasms / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D007124:Immunoenzyme Techniques; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D015513:Oncogene Proteins / Q000235:genetics* / Q000378:metabolism; D016366:Open Reading Frames; D010641:Phenotype; D010957:Plasmids; D018709:Statistics, Nonparametric; D014162:Transfection; D014407:Tumor Cells, Cultured
D015226:Dinucleoside Phosphates; C477083:LAPTM4B protein, human; D008565:Membrane Proteins; D015513:Oncogene Proteins; C009628:uridylyl-(3'-5')-adenosine; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9