Fig. 6: SLC7A5 Induces ERBB2 Transcription via ELK1.

A RT-PCR and WB Analysis. The knockout of SLC7A5 significantly inhibited the expression of ERBB2. Line left. HEY, Line right. SKOV3. B RT-PCR Analysis. RT-PCR showed that ELK1 knockdown significantly inhibits SLC7A5-mediated ERBB2 transcription. C Western Blot Analysis. Western blot demonstrated that ELK1 knockdown reverses the increase in ERBB2 protein levels caused by SLC7A5. D Nuclear and Cytoplasmic Fractionation. Nuclear and cytoplasmic fractionation combined with Western blot showed that SLC7A5 overexpression significantly promotes the nuclear translocation of pELK1. E Co-Immunoprecipitation (Co-IP). Co-IP confirmed SLC7A5- ELK1 protein-protein interactions. F Dual Luciferase Reporter Assay. This assay showed that SLC7A5 enhances ELK1 binding to the ERBB2 transcript in a dose-dependent manner. H RT-PCR Analysis. RT-PCR demonstrated that TDE significantly inhibits SLC7A5-mediated ERBB2 protein expression. G Dual Luciferase Reporter Assay. This assay showed that TDE significantly inhibits ELK1 binding to the ERBB2 transcript in a dose-dependent manner. I Chromatin Immunoprecipitation (ChIP) Assay. ChIP analysis showed that TDE significantly inhibits ELK1 binding to the ERBB2 transcript. J Dual Luciferase Reporter Assay. This assay demonstrated that ELK1 binds to the ERBB2 promoter sequence “CCTTCCATC”. Left. Schematic of dual luciferase reporter site mutations. Right. Dual luciferase assay results. K–M Proliferation Assay. TDE significantly mitigates the Olaparib resistance induced by SLC7A5 overexpression. K Edu Assay. L Colony-formation assay. M Cell Viability Test. All in vitro data are derived from at least three independent experiments. Error bars represent standard deviation. Statistical significance is denoted as follows. * = P < 0.05, ** = P < 0.001, *** = P < 0.0001, ns = non-significant compared to normal or control treatment.