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.
Ma
Jun
J
Department of Medical Microbiology, Immunology, and Cell Biology, SimmonsCooper Cancer InstituteSouthern Illinois University School of Medicine, Springfield, Illinois 62702.
Yan
Ruilan
R
Department of Medical Microbiology, Immunology, and Cell Biology, SimmonsCooper Cancer InstituteSouthern Illinois University School of Medicine, Springfield, Illinois 62702.
Zu
Xuyu
X
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.
Cheng
Ji-Ming
JM
Division of Hematology/Oncology, Internal Medicine, Southern Illinois University School of Medicine, Springfield, Illinois 62702.
Rao
Krishna
K
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.
Liao
Duan-Fang
DF
Division of Pharmacoproteomics, Institute of Pharmacy and Pharmacology, Nanhua University School of Life Science and Technology, 28 Changshengxi Road, Hengyang, Hunan 421001, China.
Cao
Deliang
D
Department of Medical Microbiology, Immunology, and Cell Biology, SimmonsCooper Cancer InstituteSouthern Illinois University School of Medicine, Springfield, Illinois 62702. Electronic address: dcao@siumed.edu.
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