Abstract | OBJECTIVE: To investigate the role of apoptosis stimulating p53 binding protein 2 (ASPP2)-induced p53-dependent and p53-independent autophagy inhibition in apoptosis-promoting function of oxaliplatin (OXA). METHODS: According to different treatments, HCT116(p53(-/-)) cells were divided into 6 groups: rapamycin combined with ASPP2 group, ASPP2 group, p53 group, ASPP2 combined with p53 group, OXA combined with 3-methyladenine (3-MA) group, control group (OXA treatment or starvation without OXA treatment). When the level of apoptosis was detected, green fluorescent protein-advirus (GFP-Ad) group and rapamycin group were supplemented as controls. Cells were transfected with GFP- microtubule-associated protein 1 light chain 3 (GFP-LC3) plasmid, and LC3-expressing cells were calculated under a fluorescent microscope. Expressions of autophagy-related molecules were detected by Western blotting. Cells were subjected to annexin V-FITC/PI staining and apoptosis was assessed by flow cytometry. RESULTS: The 3-MA group showed the same inhibitory ability on autophagy with the ASPP2 group, and both of them were able to promote OXA or starvation-induced apoptosis, but the cell apoptosis rate in the 3-MA group was lower than that of the ASPP2 group. Rapamycin combined with ASPP2 still promoted OXA or starvation-induced apoptosis, and the apoptosis rate was also lower than that of the ASPP2 group. However, rapamycin counteracted effectively the inhibitory effect of ASPP2 on autophagy. CONCLUSION: OXA can induce autophagy of colorectal cancer cells, while ASPP2 over-expression can suppress the OXA-induced autophagy. ASPP2 can promote apoptosis through p53-dependent and p53-independent pathways. The function of ASPP2 promoting cell apoptosis through p53-dependent and p53-independent pathways is not entirely achieved by inhibiting cell autophagy.
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Authors | Bishi Wang, Luxin Qiao, Ying Shi, Xiaokun Feng, Dexi Chen, Hongliang Guo |
Journal | Xi bao yu fen zi mian yi xue za zhi = Chinese journal of cellular and molecular immunology
(Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi)
Vol. 31
Issue 7
Pg. 898-904
(Jul 2015)
ISSN: 1007-8738 [Print] China |
PMID | 26146058
(Publication Type: Journal Article)
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Chemical References |
- Antineoplastic Agents
- Apoptosis Regulatory Proteins
- Organoplatinum Compounds
- TP53BP2 protein, human
- Tumor Suppressor Protein p53
- Oxaliplatin
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Topics |
- Antineoplastic Agents
(pharmacology)
- Apoptosis
(drug effects)
- Apoptosis Regulatory Proteins
(metabolism)
- Autophagy
(drug effects)
- Colonic Neoplasms
(pathology)
- HCT116 Cells
- Humans
- Organoplatinum Compounds
(pharmacology)
- Oxaliplatin
- Tumor Suppressor Protein p53
(deficiency, metabolism)
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