title: Autophagy induction by low-dose cisplatin: the role of p53 in autophagy.
abstract: The majority of chemotherapy treatments for lung cancer use cisplatin; however, its use is limited as it has several side-effects. Autophagy (or type II cell death) is an important mechanism by which programmed cell death occurs. The purpose of this study was to determine whether low-dose cisplatin treatment induces autophagy in lung cancer cells. We also examined whether autophagy inhibition results in p53-mediated apoptosis. NCI-H460 (wild-type p53) and NCI-H1299 (null-type p53) cells were treated with 5 or 20 µM cisplatin for 12, 24 or 48 h. An MTT assay was performed to measure the cell viability following cisplatin treatment. To detect cisplatin-induced autophagy, cell morphology (autophagic vacuole) and LC3 localization were examined. The outcome of autophagy inhibition was determined using 3-methyladenine (3-MA) to detect Annexin V (+), propidium iodide (PI) (-) and acridine orange (+) cells by FACS analysis. To determine whether cisplatin induced autophagy, we examined the role of p53 as a cell survival regulator in autophagy. Low-doses of cisplatin (5 µM) induced cell death and this was augmented by 3-MA in both cell lines. Autophagic vacuoles and cytoplasmic LC3 formation was more evident in H460 cells than in H1299 cells. The induction of autophagy by low-dose cisplatin was increased by 2-fold in H460 compared to H1299 cells. However, the tests for apoptosis showed no difference between the 2 cell lines. Following 3-MA pretreatment, cisplatin-induced autophagy was found to be markedly reduced (a 3-fold reduction) in wild-type p53 compared to null-type p53 cells. However, cisplatin-induced apoptosis increased in wild-type p53 compared to null-type p53 cells. Autophagy induction and apoptotic shift after autophagy inhibition may be mediated by p53 activation in lung cancer cells treated with low-dose cisplatin.
authors.affiliation: Department of Internal Medicine, Wonkwang University School of Medicine, Iksan, Jeonbuk, Republic of Korea.
authors.forename: Kyung-Hwa
authors.initials: KH
authors.lastname: Cho
authors.forename: Ji-Hye
authors.initials: JH
authors.lastname: Park
authors.forename: Kang-Beom
authors.initials: KB
authors.lastname: Kwon
authors.forename: Young-Rae
authors.initials: YR
authors.lastname: Lee
authors.forename: Hong-Seob
authors.initials: HS
authors.lastname: So
authors.forename: Kang-Kyoo
authors.initials: KK
authors.lastname: Lee
authors.forename: Sam-Youn
authors.initials: SY
authors.lastname: Lee
authors.forename: Sun-Rock
authors.initials: SR
authors.lastname: Moon
authors.forename: Sei-Hoon
authors.initials: SH
authors.lastname: Yang
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D001343:Autophagy / Q000187:drug effects*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D002945:Cisplatin / Q000494:pharmacology*; D017353:Gene Deletion; D006801:Humans; D008175:Lung Neoplasms / Q000378:metabolism*; D008869:Microtubule-Associated Proteins / Q000096:biosynthesis; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000502:physiology*
chemical_list: D000970:Antineoplastic Agents; C477012:MAP1LC3A protein, human; D008869:Microtubule-Associated Proteins; D016159:Tumor Suppressor Protein p53; C025946:3-methyladenine; D000225:Adenine; D002945:Cisplatin