Journal
PFLUGERS ARCHIV-EUROPEAN JOURNAL OF PHYSIOLOGY
Volume 466, Issue 12, Pages 2323-2338Publisher
SPRINGER HEIDELBERG
DOI: 10.1007/s00424-014-1493-3
Keywords
B7-H4; Mitochondria; PGC1-alpha; cAMP; CREB; Adenocarcinoma
Categories
Funding
- National Research Foundation of Korea (NRF)
- Ministry of Science, ICT & Future Planning of Korea [R13-2007-023-00000-0, 2011-0028925, 2012R1A2A1A03007595]
- Ministry of Education of Korea [2010-0020224]
- National Research Foundation of Korea [2011-0028925] Funding Source: Korea Institute of Science & Technology Information (KISTI), National Science & Technology Information Service (NTIS)
Ask authors/readers for more resources
B7-H4 is a B7 family coregulatory protein that inhibits T cell-mediated immunity. B7-H4 is overexpressed in various cancers; however, the functional role of B7-H4 in cancer metabolism is poorly understood. Because mitochondria play pivotal roles in development, proliferation, and death of cancer cells, we investigated molecular and functional alterations of mitochondria in B7-H4-depleted HeLa cells. In a human study, overexpression of B7-H4 was confirmed in the cervices of adenocarcinoma patients (n = 3) compared to noncancer patients (n = 3). In the cell line model, B7-H4 depletion was performed by transfection with small interfering RNA (siRNA). B7-H4 depletion suppressed oxygen consumption rate, ATP production, and mitochondrial membrane potential and mass and increased reactive oxygen species production. In particular, electron transport complex III activity was significantly impaired in siB7-H4-treated cells. Coincidently, depletion of B7-H4 suppressed major mitochondrial regulators (peroxisome proliferator-activated receptor gamma coactivator 1-alpha [PGC1-alpha] and mitochondrial transcription factor A), a component of oxidative phosphorylation (ubiquinol-cytochrome c reductase core protein 1), and an antiapoptosis protein (Bcl-XL). Mitochondrial dysfunction in siRNA-treated cells significantly augmented oxidative stress, which strongly activated the JNK/P38/caspase axis in the presence of doxorubicin, resulting in increased apoptotic cell death. Investigating the mechanism of B7-H4-mediated mitochondrial modulation, we found that B7-H4 depletion significantly downregulated the cAMP/cAMP response element-binding protein/PGC1-alpha signaling pathway. Based on these findings, we conclude that B7-H4 has a role in the regulation of mitochondrial function, which is closely related to cancer cell physiology and drug sensitivity.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available