Inhibition of growth and induction of apoptosis in human breast cancer by transfection of gef gene.
The gef gene has cell-killing functions in Escherichia coli. To evaluate the feasibility of using this gene as a new strategy for cancer therapy, we transfected it in MCF-7 cells derived from breast cancer (MCF-7TG). The gef gene was cloned in a pMAMneo vector under the control of a mouse mammary tumour virus promoter, inducible by dexamethasone (Dex), and was transfected with liposomes. After selection and induction, expression of the gef gene was confirmed by reverse transcription-polymerase chain reactions (RT-PCR) and Western blot. Cell viability was determined with a haemocytometre and the sulphorodamine B colorimetric assay, and the cell cycle was studied by propidium iodide (PI) staining. Annexin V-FITC and PI assays were used to evaluate apoptosis, which was confirmed by electron microscopy. In comparison with MCF-7 parental cells and MCF-7 cells transfected with an empty vector, MCF-7TG cells induced with Dex showed a significant decrease in proliferation rate, which was associated with evidence of apoptosis. Morphological findings confirmed apoptosis and showed a typical pattern of mitochondrial dilation. Furthermore, the cell cycle was characterised by premature progression from G(1) to S phase and G(2) delay. Our results show that the gef gene was able to decrease proliferation in a breast cancer cell line, and induce apoptosis. These findings suggest that the gef gene is a potential candidate for tumour therapy.
Boulaiz
H
H
Basic Cardiovascular Research Section, Department of Morphological Sciences, School of Medicine, University of Granada, E-18012 Granada, Spain. hboulaiz@ugr.es
Prados
J
J
Melguizo
C
C
García
A M
AM
Marchal
J A
JA
Ramos
J L
JL
Carrillo
E
E
Vélez
C
C
Aranega
A
A
D000818:Animals; D017209:Apoptosis / Q000235:genetics*; D001427:Bacterial Toxins / Q000235:genetics*; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology*; D002453:Cell Cycle; D029968:Escherichia coli Proteins / Q000235:genetics*; D005260:Female; D015316:Genetic Therapy; D006801:Humans; D015674:Mammary Neoplasms, Animal; D008565:Membrane Proteins / Q000235:genetics*; D051379:Mice; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection; D014407:Tumor Cells, Cultured
D001427:Bacterial Toxins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; C071524:HokC protein, E coli