Figure 3. Trametinib and fluvastatin rescue tracheal defects.
(A-A”) btl>control whole larvae (A) and dissected (A’-A”) trachea.
(B-B”) btl>Ras1,PTENi whole larvae have increased fine tracheal branching (B). Dissected btl>Ras1,PTENi trachea displayed thickened tracheal tubes and enlarged cell nuclei (B’-B”).
(C-C”) 1 μM trametinib rescued blt>Ras1,PTENi ectopic fine tracheal branches, tracheal thickening and enlarged cell nuclei.
(D-G) btl>Ras1,PTENi exhibited multiple alterations in anterior sac precursor (ASP) development including ASP absence (D), strong overproliferation (E), mild overproliferation (F), and abnormal shape (G).
(H) Representative btl>Ras1,PTENi ASP rescued by 0.5 μM trametinib + 50 μM fluvastatin.
(I) In btl>Ras1,PTENi animals, 0.5 μM trametinib + 50 μM fluvastatin increased percentage of normal ASPs and lowered percentage of absent and strongly overgrown ASP phenotypes compared to either drug alone.
(J) In btl>Ras1,PTENi animals, ASPs comprised 15% of wing disc volume compared to 3% in control ASPs. 50 μM fluvastatin mildly and 0.5 μM trametinib significantly (p≤0.01) rescued ASP overgrowth. Combining both drugs significantly lowered ASP size compared to trametinib alone (bar, p≤0.05).
(K) Pupal air sacs in whole pupae were visible in btl>control animals in the head (arrowhead) and thorax (arrow).
(L,M) btl>Ras1 or btl>Ras1,PTENi animals exhibited loss of pupal air sacs and gain of abdominal tumors (brackets).
(O,P) 1 μM trametinib rescued pupal air sacs and inhibited abdominal tumors in btl>Ras1 (O) and btl>Ras1,PTENi (P) animals.
(Q) Quantification of 1 μM trametinib rescue of btl>Ras1 (p≤0.01) and btl>Ras1,PTENi (p≤0.001) tumor formation.
(R-T) Dissected btl>Ras1,PTENi pupae had large GFP positive abdominal tumors (R,U) that were MMP1 positive (S). Phosphorylated SRC outlined the pupal casing (T).
(V) 1 μM trametinib consistently rescued formation of pupal abdominal tumors (n=60).
All experiments were performed at 25°C except ASP phenotyping at 27°C.
(Values represent mean ± SEM).