Suppression of adenine nucleotide translocase-2 by vector-based siRNA in human breast cancer cells induces apoptosis and inhibits tumor growth in vitro and in vivo.
BACKGROUND
Adenine nucleotide translocator (ANT) 2 is highly expressed in proliferative cells, and ANT2 induction in cancer cells is known to be directly associated with glycolytic metabolisms and carcinogenesis. In addition, ANT2 repression results in the growth arrest of human cells, implying that ANT2 is a candidate for cancer therapy based on molecular targeting.


METHODS
We utilized an ANT2-specific RNA interference approach to inhibit ANT2 expression for evaluating its antitumor effect in vitro and in vivo. Specifically, to investigate the therapeutic potential of ANT2 repression, we used a DNA vector-based RNA interference approach by expressing shRNA to knockdown ANT2 in breast cancer cell lines overexpressing ANT2.


RESULTS
ANT2 shRNA treatment in breast cancer cell line MDA-MB-231 repressed cell growth as well as proliferation. In addition, cell cycle arrest, ATP depletion and apoptotic cell death characterized by the potential disruption of mitochondrial membrane were observed from the ANT2 shRNA-treated breast cancer cells. Apoptotic breast cancer cells transfected with ANT2 shRNA also induced a cytotoxic bystander effect that generates necrotic cell death to the neighboring cells. The intracellular levels of TNFalpha and TNF-receptor I were increased in ANT2 shRNA transfected cells and the bystander effect was partly blocked by anti-TNFalpha antibody. Ultimately, ANT2 shRNA effectively inhibited tumor growth in vivo.


CONCLUSIONS
These results suggest that vector-based ANT2 RNA interference could be an efficient molecular therapeutic method for breast cancer with high expression of ANT2.
Jang
Ji-Young
JY
Department of Pathology, Tumor Immunity Medical Research Center, Cancer Research Institute, Seoul National University College of Medicine, 28 Yongon-dong, Jongno-gu, Seoul 110-799, South Korea.
Choi
Yun
Y
Jeon
Yoon-Kyung
YK
Kim
Chul-Woo
CW
D033742:Adenine Nucleotide Translocator 2 / Q000096:biosynthesis*; D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D001943:Breast Neoplasms / Q000378:metabolism*; D002453:Cell Cycle; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D004195:Disease Models, Animal; D005260:Female; D005822:Genetic Vectors; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D034741:RNA, Small Interfering / Q000378:metabolism*
D033742:Adenine Nucleotide Translocator 2; D034741:RNA, Small Interfering