Table 1.
Clinical features of thymomas included in the study.
Table 2.
Primers used to amplify GTF2i and PIK3 genes.
Fig 1.
Primary thymic epithelial cells derived from A, AB and B thymomas. Representative cell cultures derived from patients 3153 (pleural metastasis of A thymoma), 2646 (AB thymoma), 3146 (B2 thymoma) and 3149 (B2/ B3 thymoma). HES (hematoxylin- eosin- saffron) staining were used to characterize the thymic tissues. Thymoma-derived cells were observed daily by phase microscopy and stained for their expression of cytokeratin and vimentin. Nuclei stained with DAPI (blue).
Fig 2.
Mutations in PIK3CA and GTF2i.
PIK3CA and GTF2i have been amplified from total RNA extracted from thymoma, sequenced and compared to reference sequences. A. C/A mutation in exon 2 of PIK3CA in B2/ B3 thymoma #3149. B. T/A mutation in exon 15 of GTF2i in micronodular with lymphoid stroma type A thymoma #3154.
Fig 3.
Activation of the Akt/ mTOR pathway in thymic epithelial tumors.
A. Total and phosphorylated protein expression was analyzed using antibodies directed against total Akt and phosphorylated- Akt (P- Akt) (60 kDa), total mTOR and phosphorylated- mTOR (P- mTOR) (289 kDa), phosphorylated P70S6K (P- P70S6K) (70 kDa) and β-Actin (40 kDa). B. Protein expression (Akt, phospho- Akt, phospho- P70S6K, mTOR, phospho- mTOR) has been measured and expressed as [protein of interest/ actin] relative expression in A (white bars), AB (grey bars) and B (B2 and B2/ B3; black bars) thymomas, thymic carcinoma (TC, hatched bars) or normal thymus (N, dotted bars). Detection have been repeated at least 3 times. Data have been statistically analyzed with an unpaired T test.
Fig 4.
Activation of the Akt/ mTOR pathway in thymoma-derived thymic epithelial cells.
A. Total and phosphorylated protein expression was analyzed using antibodies directed against total Akt and phosphorylated- Akt (phospho- Akt), total mTOR and phosphorylated- mTOR (phospho- mTOR), phosphorylated P70S6K (phospho- P70S6K) and β-Actin in thymic epithelia cells derived from A, AB or B2 thymomas. B. Protein expression has been measured and expressed as [protein of interest/ actin] relative expression in A (white bars), AB (grey bars) and B (B2 and B2/ B3; black bars) thymomas.
Fig 5.
Inhibition of mTOR and phospho-mTOR expression upon rapamycin treatment of thymoma- derived cells.
A. Expression of mTOR and phospho-mTOR proteins in thymoma-derived cells after 48 hours treatment with 100 nM rapamycin (+) or no rapamycin (-). B. Protein expression of mTOR (with bars) and Phospho-mTOR (hatched bars) has been measured and expressed as the ratio of protein expression in [treated/ untreated] cells.
Fig 6.
Proliferation and cell death of TECs upon rapamycin treatment.
1. Proliferation rate has been measured in TECs derived from AB (#3147), B2 (#3146) and B2/ B3 (#3149) thymomas after 24, 48 and 72 hours of culture with 0 nM (○), 10 nM (▲) or 100 nM (●) rapamycin. 2. Cell death was measured by flow cytometry and expressed as percentage of cell death in TECs treated for 24 or 48 hours with 100 nM rapamycin (′) or 10 μM cisplatin (′). Statistical significance (α = 0.05) with t test; ** <0.02; *** < 0.001.