[Expression and significance of IKBKB in pulmonary adenocarcinoma A549 cells and its cisplatin-resistant variant A549/DDP].
OBJECTIVE
Cisplatin-resistance in Lung cancer cells is widespread in the clinical treatment, seriously affecting the effects of the treatment of lung cancer. Therefore, the research of mechanisms of cisplain-resistance has significant meaning for developing new chemotherapeutic drug and solving the cisplain-resistance in clinic treatment. IKBKB is one of the most important catalytic subunits of IKK complexes. It plays an important regulatory role in activation of NF-κB. The aim of this study is to investigate the differential expression of IKBKB gene in human lung adenocarcinoma cells line A549 and the cisplatin-resistant variant A549/DDP and the mechanisms of cisplain-resistance induced by IKBKB gene.


METHODS
MTT assay was employed to determine the sensitivity of A549 and A549/DDP cells line to cisplatin and the effect of IKBKB gene on A549 cell lines' sensitivity to cisplatin. The mRNA level of IKBKB was determined by real-time PCR. Dual luciferase reporter gene experiment was employed to determine the activity of the NF-κB. Apoptosis rate of lung adenocarcinoma cells was determined by flow cytometry.


RESULTS
Apoptosis rate and IC50 were significantly different in A549 and A549/DDP cells, the expression of mRNA level of IKBKB gene in A549/DDP was significantly higher than that in A549. Compared with control group, IKBKB gene was able to reduce the cisplain sensitivity of A549 cells. After A549 was transfected with pcDNA3.1/IKBKB plasmid, mRNA level of IKBKB was significantly increased, the sensitivity of cisplain was decreased, the IC50 was increased 2.85 fold, the apoptosis rate was decreased 59%, the activity of NF-κB has been greatly increased.


CONCLUSIONS
IKBKB inhibits cisplatin-induced apoptosis via the activation of NF-κB pathway. It will be helpful in the development of new anticancer drug and solving the challenge of cisplatin-resistance.
Tianjin Key Laboratory of Lung Cancer Metastasis and Tumor Microenvironment,  Tianjin Lung Cancer Institute, Tianjin Medical University General Hospital, Tianjin 300052, China.
Kang
K
Qi
Tianjin Key Laboratory of Lung Cancer Metastasis and Tumor Microenvironment,  Tianjin Lung Cancer Institute, Tianjin Medical University General Hospital, Tianjin 300052, China.
Yang
Y
Li
Tianjin Key Laboratory of Lung Cancer Metastasis and Tumor Microenvironment,  Tianjin Lung Cancer Institute, Tianjin Medical University General Hospital, Tianjin 300052, China.
Xuebing
X
Li
Tianjin Key Laboratory of Lung Cancer Metastasis and Tumor Microenvironment,  Tianjin Lung Cancer Institute, Tianjin Medical University General Hospital, Tianjin 300052, China.
Fang
F
Zhang
Tianjin Key Laboratory of Lung Cancer Metastasis and Tumor Microenvironment,  Tianjin Lung Cancer Institute, Tianjin Medical University General Hospital, Tianjin 300052, China.
Yi
Y
Shao
Tianjin Key Laboratory of Lung Cancer Metastasis and Tumor Microenvironment,  Tianjin Lung Cancer Institute, Tianjin Medical University General Hospital, Tianjin 300052, China.
Qinghua
Q
Zhou
D000230:Adenocarcinoma / Q000201:enzymology* / Q000235:genetics / Q000503:physiopathology; D000077192:Adenocarcinoma of Lung; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis; D045744:Cell Line, Tumor; D002945:Cisplatin / Q000494:pharmacology*; D019008:Drug Resistance, Neoplasm; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D051550:I-kappa B Kinase / Q000235:genetics* / Q000378:metabolism; D008175:Lung Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000503:physiopathology; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism
D000970:Antineoplastic Agents; D016328:NF-kappa B; D051550:I-kappa B Kinase; C496560:IKBKB protein, human; D002945:Cisplatin