Figure 5.

The expression of p53 is dispensable for the endoplasmic reticulum stress-mediated autophagy-associated cell death of colon cancer cells treated sequentially with CLC and BTZ. HCT-116 or HCT-8 cells were pre-incubated with PTF-α (50 µM) for 1 h. (A and B) Cells in each indicated condition were harvested and blotted with the indicated antibodies. β-actin served as the internal control. (C) Cytosolic and mitochondrial Ca²⁺ levels in HCT-116 cells were determined using Fluo3-AM and Rhod2-AM, respectively. (D) Subcellular distribution of LC3-I/II and LAMP1 in HCT-116 cells. Cells were observed under a confocal microscope (magnification, ×400). Green fluorescence indicates LC3-I/II, and red fluorescence indicates LAMP1. The results are representative of three independent experiments. CLC, celecoxib; BTZ, bortezomib; PFT-α, pifithrin-α; LC3-I/II, microtubule-associated protein 1A/1B-light chain 3; LAMP1, lysosomal-associated membrane protein 1; DMSO, dimethyl sulfoxide control; CHOP, CCAAT-enhancer-binding protein homologous protein; p-, phosphorylated; JNK, c-Jun N-terminal kinase; PARP, poly (ADP-ribose) polymerase.