Nonsense and missense mutation of mitochondrial ND6 gene promotes cell migration and invasion in human lung adenocarcinoma.
BACKGROUND
Previous study showed that mitochondrial ND6 (mitND6) gene missense mutation resulted in NADH dehydrogenase deficiency and was associated with tumor metastasis in several mouse tumor cell lines. In the present study, we investigated the possible role of mitND6 gene nonsense and missense mutations in the metastasis of human lung adenocarcinoma.


METHODS
The presence of mitND6 gene mutations was screened by DNA sequencing of tumor tissues from 87 primary lung adenocarcinoma patients and the correlation of the mutations with the clinical features was analyzed. In addition, we constructed cytoplasmic hybrid cells with denucleared primary lung adenocarcinoma cell as the mitochondria donor and mitochondria depleted lung adenocarcinoma A549 cell as the nuclear donor. Using these cells, we studied the effects of mitND6 gene nonsense and missense mutations on cell migration and invasion through wounding healing and matrigel-coated transwell assay. The effects of mitND6 gene mutations on NADH dehydrogenase activity and ROS production were analyzed by spectrophotometry and flow cytometry.


RESULTS
mitND6 gene nonsense and missense mutations were detected in 11 of 87 lung adenocarcinoma specimens and was correlated with the clinical features including age, pathological grade, tumor stage, lymph node metastasis and survival rate. Moreover, A549 cell containing mitND6 gene nonsense and missense mutation exhibited significantly lower activity of NADH dehydrogenase, higher level of ROS, higher capacity of cell migration and invasion, and higher pAKT and pERK1/ERK2 expression level than cells with the wild type mitND6 gene. In addition, NADH dehydrogenase inhibitor rotenone was found to significantly promote the migration and invasion of A549 cells.


CONCLUSIONS
Our data suggest that mitND6 gene nonsense and missense mutation might promote cell migration and invasion in lung adenocarcinoma, probably by NADH dehydrogenase deficiency induced over-production of ROS.
Department of Cardiothoracic Surgery, Changhai Hospital, Shanghai, P R China. iamyuanyang@gmail.com.
Yang
Y
Yuan
Department of Medical Imaging, Changhai Hospital, Shanghai, P R China. wangwx@163.com.
Weixing
W
Wang
Department of Cardiothoracic Surgery, Fuzhou General Hospital of Nanjing Command, PLA, Nanjing, China. lihuizhong@gmail.com.
Huizhong
H
Li
Department of Pathology, Changhai Hospital, Second Military Medical University, Shanghai, P R China. yuyongwei@smmu.edu.cn.
Yongwei
Y
Yu
Department of Cardiothoracic Surgery, Changhai Hospital, Shanghai, P R China. taojing1997@163.com.
Jin
J
Tao
Department of Cardiothoracic Surgery, Changhai Hospital, Shanghai, P R China. huangsd@smmu.edu.cn.
Shengdong
S
Huang
Department of Cardiothoracic Surgery, Fuzhou General Hospital of Nanjing Command, PLA, Nanjing, China. zengzhiyong623@sina.com.
Zhiyong
Z
Zeng
D000230:Adenocarcinoma / Q000235:genetics* / Q000556:secondary; D045744:Cell Line, Tumor; D002465:Cell Movement; D018389:Codon, Nonsense; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics* / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D020125:Mutation, Missense; D009245:NADH Dehydrogenase / Q000235:genetics* / Q000378:metabolism; D009361:Neoplasm Invasiveness; D017382:Reactive Oxygen Species / Q000378:metabolism
D018389:Codon, Nonsense; D017382:Reactive Oxygen Species; C507225:MT-ND6 protein, human; D009245:NADH Dehydrogenase