Curcumin induces mitochondria pathway mediated cell apoptosis in A549 lung adenocarcinoma cells.
Several studies have shown that curcumin can induce apoptosis and inhibit growth in human tumor cell lines. However, the mechanism is not completely understood yet. The present studies were designed to investigate the effects of curcumin on human A549 lung adenocarcinoma cells lines to better understand its effect on apoptosis and apoptosis-related genes in vitro. Apoptosis induction, mitochondria membrane potential, mitochondria structure, and apoptotic associated gene expression were examined by flow cytometric assay, confocal microscopy, Western blotting and electron microscopy. After treatment with curcumin, percentage of apoptotic cells increased dose- and time-dependently, and morphology observation revealed typical apoptotic features. Our data further indicated that the expression of Bax proteins in A549 cells was increased in a dose-dependent manner, whereas the expression of Bcl-2 was significantly decreased, thus the ratio of Bax/Bcl-2 was increased. The apoptotic process was accompanied by the change of mitochondrial function and structure which led to release of the cytochrome c, and activation of caspase-9 and caspase-3. Furthermore, curcumin also induced a dose-dependent cleavage of PARP. Caspases activation during the course of curcumin-induced apoptosis was additionally confirmed by using a broad-spectrum caspases inhibitor, Z-VAD-fmk. As expected, the inhibitor was able to decrease curcumin-induced apoptosis on A549 cells. These results suggested that mitochondria played an important role in the curcumin-induced apoptosis, and mitochondria membrane potential loss initiated apoptosis via the activation of caspases.
Chen
Qing Yong
QY
Department of Respiratory Disease, The 117th Hospital of PLA, Zhejiang 310013, P.R. China. cqyong117@163.com
Lu
Guo Hua
GH
Wu
Yu Quan
YQ
Zheng
Ying
Y
Xu
Kedi
K
Wu
Li Jun
LJ
Jiang
Zhong Yong
ZY
Feng
Rui
R
Zhou
Jian Ying
JY
D000230:Adenocarcinoma / Q000235:genetics / Q000473:pathology*; D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects* / Q000235:genetics; D015153:Blotting, Western; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D045744:Cell Line, Tumor; D048430:Cell Shape / Q000187:drug effects; D003474:Curcumin / Q000494:pharmacology*; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D045304:Cytochromes c / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics / Q000473:pathology*; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D008928:Mitochondria / Q000187:drug effects* / Q000473:pathology; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D013997:Time Factors; D051028:bcl-2-Associated X Protein / Q000378:metabolism
D000590:Amino Acid Chloromethyl Ketones; D000972:Antineoplastic Agents, Phytogenic; C494826:BAX protein, human; D015853:Cysteine Proteinase Inhibitors; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; D045304:Cytochromes c; D011065:Poly(ADP-ribose) Polymerases; C505407:CASP3 protein, human; C506433:CASP9 protein, human; D053148:Caspase 3; D053453:Caspase 9; D003474:Curcumin