Galectin-3 and L1 retrotransposons in human breast carcinomas.
Galectin-3 is a galactoside binding protein found at elevated levels in a wide variety of neoplastic cells and thought to be involved in cognitive cellular interactions during transformation and metastasis. Previously, we have shown that introduction of human galectin-3 (Mr 31,000) cDNA into the human breast cancer cells BT-549 which are galectin-3 null and non-tumorigenic in nude mice resulted in the establishment of four galectin-3 expressing clones. Three of them acquired tumorigenicity when inoculated in the mammary fat pad of nude mice. Here, we questioned what is the molecular difference between the nude mouse tumorigenic and non-tumorigenic galectin-3 expressing BT-549 cell clones. Differential display analysis and Northern blotting revealed that, unlike the tumorigenic clones, neither the parental cells nor the non-tumorigenic clone expressed a 6.5 Kb transcript. A 607 bp PCR (polymerase chain reaction) product from the differentially displayed mRNA revealed a 93% sequence homology with the human L1 retrotransposon previously suggested to play a role in the pathobiology of some breast cancers. In addition, we show that the two gene products, i.e., galectin-3 and L1, are co-expressed in breast carcinoma specimens and in other nude mouse tumorigenic cell lines.
Tumor Progression and Metastasis Program, Karmanos Cancer Institute, Detroit, MI 48201, USA.
P
P
Nangia-Makker
R
R
Sarvis
D W
DW
Visscher
J
J
Bailey-Penrod
A
A
Raz
F H
FH
Sarkar
D000943:Antigens, Differentiation / Q000032:analysis*; D001483:Base Sequence; D001943:Breast Neoplasms / Q000378:metabolism*; D002277:Carcinoma / Q000378:metabolism*; D005260:Female; D005455:Fluorescent Antibody Technique; D037502:Galectin 3; D006801:Humans; D015151:Immunoblotting; D039841:Leukocyte L1 Antigen Complex; D008562:Membrane Glycoproteins / Q000032:analysis* / Q000235:genetics; D008969:Molecular Sequence Data; D019006:Neural Cell Adhesion Molecules / Q000032:analysis* / Q000235:genetics; D018626:Retroelements; D012689:Sequence Homology, Nucleic Acid; D014407:Tumor Cells, Cultured
D000943:Antigens, Differentiation; D037502:Galectin 3; D039841:Leukocyte L1 Antigen Complex; D008562:Membrane Glycoproteins; D019006:Neural Cell Adhesion Molecules; D018626:Retroelements