Flotillin-1 promotes the progression of hepatocellular carcinoma by activating TFE3-mediated Golgi stress response via inhibition of mTORC1/2

Figure 6 Flotillin-1 regulates Golgi stress homeostasis by inhibiting mechanistic target of rapamycin complex 1/2 and transcription factor E3 nuclear translocation to maintain the proliferation and survival of hepatocellular carcinoma. SNU-387 cells were transfected with short-hairpin RNA-flotillin-1 (FLOT1) and treated with the mechanistic target of rapamycin complex 1/2 inhibitor Torin1. A: CCK-8 assay was used to detect cells viability of SNU-387 cells; B: Cell cycle was measured by flow cytometry; C: Cell invasion and migration ability of SNU-387 cells; D-F: Expressions of FLOT1 and transcription factor E3 mRNA were detected by quantitative reverse transcription polymerase chain reaction with GAPDH as a reference; G: Immunofluorescence staining of Golgi matrix protein 130 and transcription factor E3 expression and localization. Scale bar = 50 μm; H: Apoptosis-related proteins [cleaved-caspase 3 and cleaved-poly(ADP-ribose) polymerase] were detected by western blot. Expressions of FLOT1 total proteins, mechanistic target of rapamycin complex 1/2, and p-S6K-T389 were evaluated using western blot. Values are expressed as mean ± SD (n = 3), comparisons among multiple groups, one-way ANOVA was employed, followed by the LSD test or Tamhane’s T2 test. ^aP < 0.05, ^bP < 0.01. shRNA: Short-hairpin RNA; FLOT1: Flotillin-1; PARP: Poly(ADP-ribose) polymerase; TFE3: Transcription factor E3; mTOR: Mechanistic target of rapamycin; DAPI: 4’-6-diamidino-2-phenylindole; GM130: Golgi matrix protein 130; mTORC1/2: Mechanistic target of rapamycin complex 1/2.