Relationship between EGFR Promoter Region Methylation and Secondary Resistance Which may be Induced by Geiftinib
10.3779/j.issn.1009-3419.2015.04.04
- VernacularTitle:吉非替尼可能通过EGFR启动子甲基化诱导肺腺癌细胞继发性耐药
- Author:
WANG QILONG
1
;
LI MIN
;
HU CHENGPING
Author Information
1. 中南大学湘雅医院呼吸内科
- Keywords:
Lung neoplasms;
Tyrosine kinase inhibitor;
Secondary resistance;
Epidemal growth factor receptor;
Methylation
- From:
Chinese Journal of Lung Cancer
2015;18(4):193-198
- CountryChina
- Language:Chinese
-
Abstract:
Background and objective Nowadays the secondary resistance of geiftinib in the treatment of lung ad-enocarcinoma is an outstanding problem. hTis research is to explore whether the geiftinib secondary resistance can be induced by geiftinib, to explore whether epidermal growth factor receptor (EGFR) promotor methylation correlate with the geiftinib-resistance in PC9/GR cell lines and to ifnd a new therapeutic target to overcome the geiftinib secondary resistance in lung adenocarcinoma.MethodsIn vitro cultivation of lung adenocarcinoma PC9 cell lines, apply geiftinib on lung adenocarcinoma PC9 cell lines, and improve drug concentration. MTT for test of geiftinib resistance index in PC9 cell and PC9/GR cell. Bisul-ifte sequencing polymerase chain reaction (BSP) and Reverse transcription-polymerase chain reaction (RT-PCR) for detection of EGFR promoter methylation status and mRNA expression.In vitro cultivation of lung adenocarcinoma PC9 cell lines, apply 1 μmol/L 5-Aza-dc on lung adenocarcinoma PC9/GR cell lines for 72 h. MTT method for test of geiftinib resistance index in PC9/GR cell.Results Atfer improving the geiftinib concentration, MTT results showed that half maximal inhibitory concen-tration (IC50) of PC9 cell lines increase from (0.01±0.002) μmol/L to (3.95±0.23) μmol/L (P<0.05). BSP results showed that abnormal methylation sites compared the degree of methylation change: PC9: 59%; PC9/GR: 74% (P<0.05). RT-PCR results showed in PC9/GR cell lines, EGFR mRNA expression quantity increased (P<0.05). Atfer applying 5-Aza-dc on PC9 cell lines, IC50 of PC9/GR decrease from (3.87±0.034) μmol/L to (2.55±0.14) μmol/L.Conclusion The PC9 cell line which is induced by improving geiftinib concentration will be resistant to geiftinib, and the geiftinib-resistant cell line PC9/GR could be built.EGFR gene promoter methylation may be one of the mechanisms for the secondary resistance to geiftinib.
