Effects of galectin-3 expression on growth and tumorigenicity of the prostate cancer cell line LNCaP.
BACKGROUND
Galectin-3 is a beta-galactoside-binding vertebrate lectin. In human prostate cancer, galectin-3 expression has been shown to decrease with progression of disease. In the present study, we further investigated the role of galectin-3 in this malignancy by examining the phenotype of galectin-3-transfected prostate cancer cells.


METHODS
Stably transfected galectin-3-expressing cell lines were developed from the prostate cancer cell line LNCaP, which does not constitutively express this molecule. Transfected cells lines were analyzed for alterations in morphology and growth rates, and for ability to form tumors in nude mice.


RESULTS
Morphologically, when compared to the parental LNCaP cells, the galectin-3 transfectants had broader, flatter cell bodies, shorter and less finely branched dendritic processes, and large nuclei with pronounced and often multiple nucleoli. The galectin-3 lines were found to proliferate at a slower rate in vitro than either the vector control-transfected lines or parental LNCaP. When injected subcutaneously in nude mice, four of six galectin-3 lines formed tumors at a slower rate than control lines. Twenty-four tumors that formed from the transfected cell lines were examined by immunohistochemistry for galectin-3 expression. Only one tumor was found to express galectin-3, suggesting that the transfected cells which formed tumors were those which successfully down-regulated galectin-3 expression.


CONCLUSIONS
In contrast to an apparent stimulatory role in some tumor types, galectin-3 is an inhibitory molecule for prostate cancer.
Ellerhorst
Julie A
JA
Department of Molecular and Cellular Oncology, The University of Texas, M.D. Anderson Cancer Center, Houston, Texas 77030, USA. jaellerh@mail.mdanderson.org
Stephens
L Clifton
LC
Nguyen
Thuy
T
Xu
Xiao-Chun
XC
D000818:Animals; D000943:Antigens, Differentiation / Q000235:genetics*; D002455:Cell Division / Q000235:genetics; D037502:Galectin 3; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D010957:Plasmids; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000473:pathology*; D014162:Transfection; D014407:Tumor Cells, Cultured
D000943:Antigens, Differentiation; D037502:Galectin 3