S-Space College of Medicine/School of Medicine (의과대학/대학원) Dept. of Medicine (의학과) Theses (Ph.D. / Sc.D._의학과)
In vitro anticancer activity of phosphatidylinositol 3-kinase alpha selective inhibitor BYL719 in head and neck cancer : 두경부 편평세포암 세포주에서 포스파티딜 이노시톨 3 –키나제 알파 특이 억제제의 항암효과
|dc.description||학위논문 (박사)-- 서울대학교 대학원 : 의학과, 2014. 8. 허대석.||-|
|dc.description.abstract||Introduction: Activating mutations of the PIK3CA gene occur frequently in head and neck squamous cell carcinoma. The purpose of this study was to explore the antiproliferative effect of BYL719, a specific inhibitor for phosphatidylinositol 3-kinase (PI3K) p110α, in human head and neck cancer cell lines, as a single agent or in combination with the irreversible EGFR tyrosine kinase inhibitor (TKI), dacomitinib.
Material and Methods: Six head and neck cancer cell lines consisting of 2 PIK3CA mutant cell lines, SNU-1076 and Detroit562 and 4 PIK3CA wild type cell lines, SNU-1066, SNU-1041, FaDu and SCC25, were analysed. The inhibitory effect of BYL719 on cellular proliferation was assessed using the tetrazolium bromide [3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl-tetrazolium bromide] assay. The cell cycle at various concentrations of BYL719 was analyzed by flow cytometry, and the protein expression of downstream molecules determined by Western blot analysis.
Results: The PIK3CA mutant cell lines (SNU-1076 and Detroit562) were more sensitive to BYL719 than the PIK3CA wild type cell lines (SNU-1066, SNU-1041, FaDu and SCC25). Following BYL719 treatment, all PIK3CA wild type cell lines, except the SNU-1066 cell line, exhibited higher IC50 values (1.13, 20.65, 19.67 and 49.30 μM, SNU-1066, SNU-1041, FaDu and SCC25, respectively) compared with the PIK3CA mutant cell lines (6.82 and 1.10 μM, SNU-1076 and Detroit562, respectively). Administration of BYL719 in the PIK3CA mutant cell lines induced cell cycle G0/1 arrest and resulted in increased apoptosis in a dose dependant manner. Furthermore, the administration of BYL719 in the PIK3CA mutant cell lines reduced the level of p-mTOR, p-AKT and p-S6 expression indicating the down regulating of downstream signaling. BYL719 combined with dacomitinib had a synergistic inhibitory effect.
Conclusion: BYL719, PI3K alpha selective blocker, could be a promising treatment for head and neck cancer as a single agent or in combination with dacomitinib. The beneficial effects of BYL719 in in vitro studies for head and neck cancer warrant a further clinical investigation.
MATERIALS AND METHODS 6
Cell lines and culture 6
Mutation analysis for head and neck cancer cell lines 6
Drugs and Reagents 6
Cell growth-inhibition assay 7
Cell cycle analysis 7
Annexin-V assay 7
Western blot analysis and fluorescence in situ hybridization (FISH) 8
Determination of synergism and antagonism 8
Proliferation inhibition activity of BYL719 in head and neck cancer cell lines 9
Apoptotic effect and cell cycle analysis of BYL719 treatment in head and neck cancer cell lines 9
Effect of BYL719 on the PI3K downstream signaling 9
Synergistic effect of BYL719 combined with irreversible EGFR tyrosine kinase inhibitor, dacomitinib 10
FIGURES AND LEGENDS 17
Table 1. Combination index values of concurrent treatment with BYL719 and dacomitinib in head and neck cancer cell lines 17
Figure 1. Antiproliferative activity of BYL719 in various head and neck cancer cell lines. 18
Figure 2. Effects of BYL719 on cell cycle. 19
Figure 3. Western blot analysis for downstream signaling 20
Figure 4. Synergistic interactions between BYL719 and dacomitinib 21
국문 초록 22
|dc.title||In vitro anticancer activity of phosphatidylinositol 3-kinase alpha selective inhibitor BYL719 in head and neck cancer||-|
|dc.title.alternative||두경부 편평세포암 세포주에서 포스파티딜 이노시톨 3 –키나제 알파 특이 억제제의 항암효과||-|
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