Aldo-keto reductase family 1 B10 affects fatty acid synthesis by regulating the stability of acetyl-CoA carboxylase-alpha in breast cancer cells.
Recent studies have demonstrated that aldo-keto reductase family 1 B10 (AKR1B10), a novel protein overexpressed in human hepatocellular carcinoma and non-small cell lung carcinoma, may facilitate cancer cell growth by detoxifying intracellular reactive carbonyls. This study presents a novel function of AKR1B10 in tumorigenic mammary epithelial cells (RAO-3), regulating fatty acid synthesis. In RAO-3 cells, Sephacryl-S 300 gel filtration and DEAE-Sepharose ion exchange chromatography demonstrated that AKR1B10 exists in two distinct forms, monomers (approximately 40 kDa) bound to DEAE-Sepharose column and protein complexes (approximately 300 kDa) remaining in flow-through. Co-immunoprecipitation with AKR1B10 antibody and protein mass spectrometry analysis identified that AKR1B10 associates with acetyl-CoA carboxylase-alpha (ACCA), a rate-limiting enzyme of de novo fatty acid synthesis. This association between AKR1B10 and ACCA proteins was further confirmed by co-immunoprecipitation with ACCA antibody and pulldown assays with recombinant AKR1B10 protein. Intracellular fluorescent studies showed that AKR1B10 and ACCA proteins co-localize in the cytoplasm of RAO-3 cells. More interestingly, small interfering RNA-mediated AKR1B10 knock down increased ACCA degradation through ubiquitination-proteasome pathway and resulted in >50% decrease of fatty acid synthesis in RAO-3 cells. These data suggest that AKR1B10 is a novel regulator of the biosynthesis of fatty acid, an essential component of the cell membrane, in breast cancer cells.
Department of Medical Microbiology, Immunology, and Cell Biology, SimmonsCooper Cancer InstituteSouthern Illinois University School of Medicine, Springfield, Illinois 62702.
Jun
J
Ma
Department of Medical Microbiology, Immunology, and Cell Biology, SimmonsCooper Cancer InstituteSouthern Illinois University School of Medicine, Springfield, Illinois 62702.
Ruilan
R
Yan
Department of Medical Microbiology, Immunology, and Cell Biology, SimmonsCooper Cancer InstituteSouthern Illinois University School of Medicine, Springfield, Illinois 62702; Division of Pharmacoproteomics, Institute of Pharmacy and Pharmacology, Nanhua University School of Life Science and Technology, 28 Changshengxi Road, Hengyang, Hunan 421001, China.
Xuyu
X
Zu
Division of Hematology/Oncology, Internal Medicine, Southern Illinois University School of Medicine, Springfield, Illinois 62702.
Ji-Ming
JM
Cheng
Department of Medical Microbiology, Immunology, and Cell Biology, SimmonsCooper Cancer InstituteSouthern Illinois University School of Medicine, Springfield, Illinois 62702; Division of Hematology/Oncology, Internal Medicine, Southern Illinois University School of Medicine, Springfield, Illinois 62702.
Krishna
K
Rao
Division of Pharmacoproteomics, Institute of Pharmacy and Pharmacology, Nanhua University School of Life Science and Technology, 28 Changshengxi Road, Hengyang, Hunan 421001, China.
Duan-Fang
DF
Liao
Department of Medical Microbiology, Immunology, and Cell Biology, SimmonsCooper Cancer InstituteSouthern Illinois University School of Medicine, Springfield, Illinois 62702. Electronic address: dcao@siumed.edu.
Deliang
D
Cao
D000103:Acetyl-CoA Carboxylase / Q000737:chemistry* / Q000378:metabolism; D000449:Aldehyde Reductase / Q000235:genetics / Q000502:physiology*; D000074408:Aldo-Keto Reductases; D001943:Breast Neoplasms / Q000378:metabolism*; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D020868:Gene Silencing; D006801:Humans; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D025801:Ubiquitin / Q000378:metabolism
D005227:Fatty Acids; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; D025801:Ubiquitin; C120471:AKR1B10 protein, human; D000074408:Aldo-Keto Reductases; D000449:Aldehyde Reductase; D046988:Proteasome Endopeptidase Complex; D000103:Acetyl-CoA Carboxylase