Effects of PI3K inhibitor NVP-BKM120 on acquired resistance to gefitinib of human lung adenocarcinoma H1975 cells.
10.1007/s11596-013-1209-5
- Author:
Yi-chen LIANG
1
,
2
;
Hong-ge WU
;
Hong-jian XUE
;
Qing LIU
;
Liang-liang SHI
;
Tao LIU
;
Gang WU
Author Information
1. Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China, francesyichen1@
2. com.
- Publication Type:Journal Article
- MeSH:
Adenocarcinoma;
metabolism;
Aminopyridines;
pharmacology;
Antineoplastic Agents;
pharmacology;
Apoptosis;
drug effects;
Cell Line, Tumor;
Cell Proliferation;
drug effects;
Drug Resistance, Neoplasm;
drug effects;
Humans;
Hypoxia-Inducible Factor 1, alpha Subunit;
genetics;
metabolism;
Lung Neoplasms;
metabolism;
Matrix Metalloproteinase 9;
genetics;
metabolism;
Morpholines;
pharmacology;
Phosphatidylinositol 3-Kinases;
antagonists & inhibitors;
Quinazolines;
pharmacology;
RNA, Messenger;
genetics;
metabolism;
Vascular Endothelial Growth Factor A;
genetics;
metabolism
- From:
Journal of Huazhong University of Science and Technology (Medical Sciences)
2013;33(6):845-851
- CountryChina
- Language:English
-
Abstract:
The effects of class I PI3K inhibitor NVP-BKM120 on cell proliferation, cell cycle distribution, cellular apoptosis, phosphorylation of several proteins of the PI3K/AKT signaling pathway and the mRNA expression levels of HIF1-α, VEGF and MMP9 in the acquired gefitinib resistant cell line H1975 were investigated, and whether NVP-BKM120 can overcome the acquired resistance caused by the EGFR T790M mutation and the underlying mechanism were explored. MTT assay was performed to detect the effect of gefitinib, NVP-BKM120, NVP-BKM120 plus 1 μmol/L gefitinib on growth of H1975 cells. The distribution of cell cycle and apoptosis rate of H1975 cells were examined by using flow cytometry. The mRNA expression levels of tumor-related genes such as HIF1-α, VEGF and MMP9 were detected by using real-time quantitative PCR. Western blotting was used to detect the expression level of phosphorylated proteins in the PI3K/AKT signaling pathway, such as Ser473-p-AKT, Ser235/236-p-S6 and Thr70-p-4E-BP1, as well as total AKT, S6 and 4E-BP1. The results showed that the NVP-BKM120 could inhibit the growth of H1975 cells in a concentration-dependent manner, and H1975 cells were more sensitive to NVP-BKM120 than gefitinib (IC50:1.385 vs. 15.09 μmol/L respectively), whereas combination of NVP-BKM120 and gefitinib (1 μmol/L) did not show more obvious effect than NVP-BKM120 used alone on inhibition of cell growth (P>0.05). NVP-BKM120 (1 μmol/L) increased the proportion of H1975 cells in G0-G1 phase and the effect was concentration-dependent, and 2 μmol/L NVP-BKM120 promoted apoptosis of H1975 cells. There was no significant difference in the proportion of H1975 cells in G0-G1 phase and apoptosis rate between NVP-BKM120-treated alone group and NVP-BKM120 plus genfitinib (1 μmol/L)-treated group or between DMSO-treated control group and gefitinib (1 μmol/L)-treated alone group (P>0.05 for all). It was also found that the mRNA expression levels of these genes were down-regulated by NVP-BKM120 (1 μmol/L), and NVP-BKM120 (1 μmol/L) or NVP-BKM120 (1 μmol/L) plus gefitinib (1 μmol/L) obviously inhibited the activation of Akt, S6 and 4E-BP1 as compared with control group, but single use of gefitinib (1 μmol/L) exerted no significant effect. These data suggested that NVP-BKM120 can overcome gefitinib resistance in H1975 cells, and the combination of NVP-BKM120 and gefitinib did not have additive or synergistic effects. It was also concluded that NVP-BKM120 could overcome the acquired resistance to gefitinib by down-regulating the phosphorylated protein in PI3K/AKT signal pathways in H1975 cells, but it could not enhance the sensitivity of H1975 cells to gefitinib.
