Fig 2: Interaction between STK25 and STRN. a Subnetworks of striatum interacting phosphatase and kinase complex (STRIPAK) [17]. b Protein networks related to STK25 from String program. c Pearson correlation between STK25 and STRN from GEPIA. d Determining the interaction between STK25 and STRN by Coimmunoprecipitation. e Representative IHC staining images (200×) of STK25 and STRN expression in liver of control and HCC patients, the thick black arrow indicated STK25. f STRN was overexpressed in STK25 knockdown cells, and proteins related to AMPK/ACC signaling pathway were detected by western blot. g Pearson correlation between STRN and AMPK, ACC1, ACLY. h, i Oil Red O test. The red color is intracellular lipid droplets. CON, control. sh, knockdown. flag, overexpression. *, p < 0.05. **, p < 0.01. ***, p < 0.001. Scale bars, 50 μm

Fig 3: STK25 trigger EMT in HCC cells. a Representative western blots and quantification of EMT-related markers in HCC cells. The effect of STK25-silenced was reversed by STRN overexpression in HepG2 and SMMC-7721 cells. The effect of STK25 overexpression was reversed by AMPK agonist in Huh7 cells. b Pearson correlation between STRN and EMT-related makers. c Cellular morphologic change. The sh-STK25 group showed decreased formation of pseudopodia, leading to an elongated, irregular fibroblastoid morphology, HCC cells gathered into clusters and the dissociation decreased. d Representative IHC staining images (200×) of EMT-related markers E-cadherin and N-cadherin in liver of control and HCC patients. e Proposed model of STK25 induced biological function in HCC. STK25 inhibits phosphorylation of AMPK by interacting with STRN, thereby up-regulating the expression of ACC1 and ACLY, and stimulating EMT and lipid energy reserve. E-cad, E-cadherin. N-cad, N-cadherin. VIM, vimentin. CON, control. sh, knockdown. flag, overexpression. Data are expressed as mean ± SD. *, p < 0.05. **, p < 0.01. ***, p < 0.001