Gene interactions and pathways from curated databases and text-mining
Br J Dermatol 2009, PMID: 19120326

Suppression of mTOR complex 2-dependent AKT phosphorylation in melanoma cells by combined treatment with rapamycin and LY294002.

Werzowa, J; Cejka, D; Fuereder, T; Dekrout, B; Thallinger, C; Pehamberger, H; Wacheck, V; Pratscher, B

BACKGROUND

Inhibition of mTOR complex 1 (mTORC1) with rapamycin leads to phosphorylation of AKT in some cancer cells, with unknown biological consequences. The role of this phosphorylation in melanoma is unknown, although preliminary clinical data indicate poor activity of rapalogues in melanoma.

OBJECTIVE

We aimed at elucidating the role of AKT phosphorylation after mTORC1 inhibition in melanoma cells.

METHODS

Western blotting, apoptosis assays, cell cycle analyses and viability assays were performed to analyse the effects of rapamycin and LY294002 treatment on melanoma cells. For suppression of mTOR complex 2 (mTORC2) an siRNA directed against rictor was used.

RESULTS

Rapamycin showed limited effects on cell viability but resulted in strong and lasting AKT phosphorylation in melanoma cells. Combined PI3K/mTOR inhibition with LY294002 had pronounced effects on viability but also led to increased AKT phosphorylation after prolonged treatment. In contrast, combination of rapamycin plus LY294002 suppressed AKT phosphorylation. Suppression of AKT phosphorylation did not correlate with decreases in cell viability. Inhibition of mTORC2 led to reduced levels of phosphorylated AKT.

CONCLUSIONS

mTORC1 inhibition with rapamycin and with LY294002 can lead to AKT phosphorylation in melanoma cells via mTORC2. Combination of rapamycin and LY294002 suppresses AKT phosphorylation but without significant effect on treatment efficacy.

Diseases/Pathways annotated by Medline MESH: Melanoma, Skin Neoplasms
Document information provided by NCBI PubMed

Text Mining Data

AKT ⊣ mTORC2: " Inhibition of mTORC2 led to reduced levels of phosphorylated AKT "

Manually curated Databases

No curated data.