BCKDHB Knockout SK-HEP-1 Polyclonal Cells are a heterogeneous population of human SK-HEP-1 cells with CRISPR/Cas9-mediated disruption of the BCKDHB gene, encoding the beta subunit of the branched-chain alpha-keto acid dehydrogenase (BCKDH) E1 component. This pooled polyclonal product contains diverse loss-of-function mutations, providing a robust model for BCKDH complex deficiency without clonal isolation. Disruption impairs oxidative decarboxylation of branched-chain alpha-keto acids from leucine, isoleucine, and valine catabolism, enabling investigation of branched-chain amino acid (BCAA) metabolism and downstream signaling.
SK-HEP-1 is a human liver adenocarcinoma cell line derived from ascitic fluid of a 52-year-old male. It displays both epithelial and endothelial characteristics, making it a widely used model for hepatic tumor biology and angiogenesis. This background is relevant for metabolic studies because liver cancer cells often rewire BCAA catabolism to support proliferation and anabolism. Introducing a BCKDHB knockout in this setting permits exploration of mitochondrial metabolism and oncogenic signaling interplay.
BCKDHB forms a heterotetramer with BCKDHA as the E1 component of the BCKDH complex, which also includes DBT (E2) and DLD (E3). The complex is the rate-limiting step in BCAA degradation, regulated by BCKDK-mediated inhibitory phosphorylation and PPM1K/PP2Cm-dependent activating dephosphorylation. Upstream factors include branched-chain alpha-keto acids, insulin, and glucocorticoids. Knockout disrupts BCKDH activity, leading to accumulation of branched-chain alpha-keto acids and amino acids. This alters mTORC1 signaling (phospho-S6K1), TCA cycle flux, and acetyl-CoA/succinyl-CoA pools. The BCKDH complex also interfaces with BCAT2, ACADSB, MCCC1, and HMGCL.
In SK-HEP-1 cells, BCKDHB disruption dissects BCAAs?? role in cancer. BCAA catabolism fuels the TCA cycle and modulates mTORC1, a driver of cell growth and angiogenesis. The dual epithelial/endothelial phenotype enables study of BCKDH deficiency effects on tumor metabolism and vascular signaling. The model is relevant to maple syrup urine disease type II, cachexia, and heart failure with BCAA dysregulation, bridging monogenic disorders and metabolic syndromes.
These polyclonal cells support Western blotting and RT-qPCR for BCKDHB validation, BCAA and branched-chain ketoacid quantification, and BCKDH enzymatic assays. 13C-leucine tracing reveals metabolic flux changes, while phospho-S6K1 immunoblotting assesses mTORC1 signaling. Cell proliferation and mitochondrial respiration assays complement phenotypic analysis. Applications include maple syrup urine disease modeling, cancer metabolism and cachexia studies, mitochondrial dysfunction research, and drug screening. Contact Ascent Research for further information.
