Antisense epidermal growth factor receptor transfection impairs the proliferative ability of human rhabdomyosarcoma cells.
Human rhabdomyosarcoma cells express membrane epidermal growth factor receptor (ECF-R), which could confer responsiveness to EGF and transforming growth factor-alpha (TGF-alpha) of autocrine or paracrine origin. To study the role played by this growth factor circuit in the proliferation and differentiation of myogenic neoplastic cells, human rhabdomyosarcoma EGF-R-expressing cells (RD/18 clone) have been transfected with a plasmid containing a fragment of the EGF-R cDNA in the antisense orientation. In vitro growth and differentiative ability were studied on six antisense-transfected clones (AS) in comparison to parental RD/18 cells and to cells transfected with the plasmid containing only the neomycin resistance gene (NEO). A reduced EGF-R membrane expression was found in AS clones by decreased immunofluorescence with an anti-EGF-R monoclonal antibody. All AS transfectants had a greatly impaired proliferative ability, even when cultured in fetal bovine serum-containing medium. Proliferation of AS clones was completely blocked in medium supplemented with 2% horse serum. The differentiation ability of AS clones was heterogeneous, ranging from clones with a percentage of myosin-positive cells higher than controls to clones with a negligible myosin expression. Therefore, the growth impairment determined by the loop interruption is not sufficient to switch on the differentiation program. The role played by EGF-R in the proliferation of human rhabdomyosarcoma cells suggests that this receptor could constitute a target for a therapeutic approach.
De Giovanni
C
C
Cancer Research Institute, University of Bologna, Italy.
Landuzzi
L
L
Frabetti
F
F
Nicoletti
G
G
Griffoni
C
C
Rossi
I
I
Mazzotti
M
M
Scotto
L
L
Nanni
P
P
Lollini
P L
PL
D000818:Animals; D001483:Base Sequence; D002417:Cattle; D002454:Cell Differentiation / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D018076:DNA, Complementary / Q000235:genetics*; D066246:ErbB Receptors / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D006801:Humans; D008969:Molecular Sequence Data; D016376:Oligonucleotides, Antisense / Q000235:genetics*; D012208:Rhabdomyosarcoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D014162:Transfection; D014407:Tumor Cells, Cultured
D018076:DNA, Complementary; D016376:Oligonucleotides, Antisense; D066246:ErbB Receptors