Figure 4

Western blot analysis of effects of cucurbitacin I on phosphorylation/activation of signaling pathways in human leptomeningeal and meningioma cells. a. Effects of cucurbitacin I on phosphorylation/activation of STAT3, and p44/42MAPK in human leptomeningeal cells. Leptomeningeal cells from 17 (L1) and 20 wk (L2) were treated with serum free media (C), cerebrospinal fluid (CF) without or with cucurbitacin I (Cu) (250 nM) for 72 hrs. Cerebrospinal fluid stimulated STAT3 phosphorylation. Cucurbitacin I had no effect on basal STAT3 phosphorylation but co-administration with cerebrospinal fluid blocked cerebrospinal fluid stimulation of STAT3 phosphorylation in each. b. Effects of cucurbitacin I on phosphorylation/activation of JAK, STAT3, pMEK1/2, p44/42MAPK and mTOR in meningioma cells. WHO grade I (M2 and 3) and (B) WHO grade II (M4 and 5) meningiomas were treated with serum free media (C), cerebrospinal fluid (CF) without or with cucurbitacin I (Cu) (250 nM) for 72 hrs. In the grade I meningiomas, cerebrospinal fluid stimulated phosphorylation of STAT3 and decreased it in MEK1/2. Cucurbitacin I had no effect. In the grade II meningiomas, cerebrospinal fluid stimulated STAT3 phosphorylation in all and reduced phosphorylation of MEK1/2 in all and p44/42MAPK in one. Cucurbitacin reduced basal p44/42 MAPK phosphorylation.