Fig. 5: SCARB2 interacts with MYC to disrupt HDAC3-mediated MYC deacetylation.

a MS analyzed the interaction proteins of SCARB2 in HCCLM3 cells. b The interaction between MYC and SCARB2 in HCCLM3 cells was evaluated by Co-IP assays. c CO-IP analysis of SCARB2 and MYC interaction in the cytoplasm, cytomembrance and nucleus of HCCLM3 cells. d Co-localization of MYC/SCARB2 was detected in HepG2 cells with immunostaining. Scale bar, 5 μm. e The interaction between MYC and HDAC3 in CTRL^Cas9 and SCARB2^Cas9 HCCLM3 cells was evaluated by Co-IP assays. f Co-localization of MYC and HDAC3 was detected in CTRL^Cas9 and SCARB2^Cas9 HepG2 cells by immunostaining. Scale bar, 20 μm. g Mapping of MYC regions binding to SCARB2 and HDAC3. Left: deletion mutants of MYC. Right: HEK 293 T cells were cotransfected with the indicated constructs of MYC (GFP tag) and SCARB2 (Myc tag) or HDAC3 (HA tag). Cell extracts were IP with an anti-Myc Ab or anti-HA Ab. h Mapping of SCARB2 regions binding to MYC. HEK 293 T cells were cotransfected with the indicated constructs of SCARB2 (Myc-tagged) and MYC (Flag-tagged). Cell extracts were IP with an anti-Flag. i HCCLM3 cells treated with or without HDAC3 inhibitor (RGFP966 5μM) were analyzed by ChIP with MYC or IgG antibody. ChIP’d DNA was quantified using qPCR for MYC or IgG binding to MYC target genes promoters, CAD, CDK4, LDHA, NCL, PKM2, HES1, or Chr6 (negative control). j Relative cell viabilities of HCCLM3 SCARB2^cas9 cells or HepG2 SCARB2^cas9 cells with overexpression of the indicated genes for the indicated times. k Sphere-forming capacity of HCCLM3 SCARB2^cas9 cells with overexpression of HDAC3 or HDAC3 R265P mutation. b, c, d, e, f, g, h, i, j, k n = 3 biological repeats. Statistical significance was calculated by (i, j, k) two tailed Student’s t test. Data are presented as means ± S.E.M. Source data are provided as a Source Data file.