Figure 5.

Increased susceptibility of platinum-resistant EOC cells mediated by CSN5 deficiency can be partly abrogated by ER stress suppressor. (A, B) Markers of ER stress and apoptosis in immunoblots were analyzed in DDP cells with or without CSN5 inhibition at different doses of cisplatin for 24 h. (C-G) DDP cells with or without CSN5 inhibition exposed to cisplatin were treated with 4-PBA (an ER stress signaling suppressor, 10 μM) or not. Flow cytometry was used to detect and quantify the cellular apoptotic levels. (H) An in vivo xenograft model showed the antagonistic action of 4-PBA on the anti-tumor effects mediated by CSN5 inhibition. (I, J) Tumor weight and volume were analyzed. (K) IHC results exhibited the proliferative marker PCNA, ER stress marker CHOP, and the apoptotic marker Cyt C (Scale bar = 2 mm). (L) The IHC staining intensity was quantified and shown as mean ± SEM.