RESUMEN
<p><b>OBJECTIVE</b>To investigate the role of mitofusin-2 gene (mfn2) in apoptosis in human breast carcinoma cell line MCF-7 cells after in vitro transfection.</p><p><b>METHODS</b>pEGFP mfn2 was transfected by sofast in vitro. Expression of GFP was observed by Western blot, and the MCF-7 cell proliferation was measured by MTT and cell counting. Apoptosis in MCF-7 cells was observed in annexin-V/PI and chondrosome transmembrane potential of MCF-7 marked in JC-1 by FCM. The Ultrastructure of cells was observed by transmission electron microscopy.</p><p><b>RESULTS</b>The stable expression of GFP in MCF-7 cells was confirmed by Western blot. Mfn2 significantly inhibited cell proliferation, revealed by MTT, and decrease chondrosome transmembrane potential. Exogenous mfn2 gene significantly induced apoptosis. The apoptotic rate was increased from 3.6% to 16.0% (P < 0.05). Mfn2 gene induced break down and loss of mitochondrial cristae, and rarefaction of mitochondrial ground substance. Swollen mitochondria intensely aggregated around the cell nuclei.</p><p><b>CONCLUSION</b>Mfn2 can strongly induce apoptosis in MCF-7 cells, which may be associated with decrease of mitochondrial transmembrane potential.</p>