Modulation of Ki-67 expression and morphological changes induced by gef gene in MCF-7 human breast cancer cells

Area of Science:

• Oncology
• Molecular Biology
• Gene Therapy

Background:

• Conventional breast cancer treatments face limitations requiring novel therapeutic strategies.
• Suicide gene therapy presents a promising alternative, potentially overcoming issues associated with prodrug-based systems like toxicity and bioavailability.
• The bacterial gef gene offers a prodrug-independent mechanism for inducing cell death, making it a target for gene therapy.

Purpose of the Study:

• To investigate the potential of the gef gene as a novel suicide gene therapy agent for breast cancer.
• To establish and characterize a gef-overexpressing human breast cancer cell line (MCF-7TG).
• To evaluate the gef gene's effect on proliferation and apoptosis in breast cancer cells.

Main Methods:

• Transfection of the gef gene into MCF-7 human breast cancer cells under the control of a pMAMneo promoter to create the MCF-7TG cell line.
• Dexamethasone induction of gef gene expression.
• Assessment of Ki-67 expression as a proliferation marker.
• Annexin-V-FITC and propidium iodide staining to detect apoptosis.
• Confirmation of apoptosis using scanning electron microscopy.

Main Results:

• Dexamethasone induction of gef gene expression in MCF-7TG cells led to a significant decrease in Ki-67 expression.
• Apoptotic cell death was confirmed through annexin-V-FITC and propidium iodide assays.
• Scanning electron microscopy revealed characteristic "craters" on the cell membrane, indicative of apoptosis.

Conclusions:

• The gef gene effectively down-regulates Ki-67 expression and induces apoptosis in a human breast cancer cell line.
• These findings support the potential of the gef gene as a novel therapeutic strategy for breast cancer gene therapy.
• The prodrug-independent nature of the gef gene offers advantages over existing suicide gene therapy approaches.