Fig. 4.

Nuclear translocation of PTPN14 is induced under hypoxia and is required for hypoxia-induced drug resistance. PTPN14 mRNA levels (A) and protein levels (B) in HepG2 cells upon sorafenib (5 µM) treatment under hypoxia (2% O₂) for 24 h. C Representative immunofluorescence staining of PTPN14 in HepG2 cells upon sorafenib (5 µM) treatment under normoxia (20% O₂) or hypoxia (2% O₂) for 24 h. Scale bar = 20 μm. D PTPN14 protein levels within the cytoplasm and nucleus under normoxic and hypoxic conditions.E andF. HepG2 cells with stable PTPN14 knockdown (E) and SK-Hep1 cells with PTPN14 stable overexpression (F) were treated with the indicated doses of sorafenib under normoxia or hypoxia for 72 h. Cell viability was calculated by MTT assays. The IC₅₀ values derived from the dose–response curves are presented