Fig. 3

CBR4 destabilizes FASN by activating its ubiquitin-proteasome pathway. (A) Proteins that could potentially interact with CBR4 were identified from the STRING database. (B) FASN levels in colorectal cancer (CRC) patients were significantly elevated compared to the control group, as indicated by data from the CPTAC database (p = 6.11443254489116E-20). (C) The protein levels of FASN were assessed across various CRC cell lines and normal cells. (D) The protein levels of FASN were compared between CRC tissues and normal tissues. (E) The protein levels of FASN were evaluated in CRC cases with and without metastasis. (F-G) Immunohistochemical staining of FASN was conducted in CRC tissues, paracancerous tissues, metastatic tumors, and non-metastatic tumors from patients, with a magnification of ×100. (H) Co-immunoprecipitation (Co-IP) analysis demonstrated the interaction between CBR4 and FASN in RKO and SW480 cells. (I-J) Western blot analysis was performed to evaluate FASN levels in RKO and SW480 cells, comparing CBR4 over-expressing groups to control groups, following treatment with CHX (10 µmol/L) and MG132 (10 µmol/L). (K) Co-IP analysis was conducted to assess the interaction between FASN and ubiquitin in CBR4 over-expressing and control groups of RKO and SW480 cells. (L-M) The mRNA and protein levels of FASN were measured in both CBR4 over-expressing and control groups of RKO and SW480 cells