TY - JOUR
T1 - The Akt inhibitor MK2206 synergizes, but perifosine antagonizes, the BRAFV600E inhibitor PLX4032 and the MEK1/2 inhibitor AZD6244 in the inhibition of thyroid cancer cells
AU - Liu, Ruixin
AU - Liu, Dingxie
AU - Xing, Mingzhao
PY - 2012/2
Y1 - 2012/2
N2 - Purpose: The purpose of the study was to explore optimal combinations of currently actively developed drugs for dually targeting the Ras → Raf → MAPK kinase (MEK) → MAPK/ERK (MAPK) and the phosphatidylinositol 3-kinase/Akt pathways as effective treatments for thyroid cancer. Experimental Design: We tested the combinations of the Akt inhibitors MK2206 or perifosine with the BRAFV600E inhibitor PLX4032 or the MEK1/2 inhibitor AZD6244 in thyroid cancer cells harboring both the BRAFV600E and PIK3CA mutations. Results: We found that MK2206 could potently, when used alone, and synergistically, when combined with either PLX4032 or AZD6244, inhibit thyroid cancer cell growth with all the combination index values lower than 1. Perifosine could potently inhibit thyroid cancer cell growth when used alone, but a strong antagonism occurred between this drug and PLX4032 or AZD6244 in the inhibition of thyroid cancer cell growth with all combination index values higher than 1. Combinations of MK2206 with PLX4032 or AZD6244 dramatically enhanced G1 cell cycle arrest induced by each drug alone. However, G2 cell cycle arrest uniquely induced by perifosine alone and G1 cell cycle arrest induced by PLX4032 or AZD6244 were both reversed by combination treatments, providing a mechanism for their antagonism. All these drugs could correspondingly inhibit the MAPK and phosphatidylinositol 3-kinase/Akt signalings, confirming their expected target effects. Conclusions: We demonstrated, unexpectedly, opposite outcomes of MK2206 and perifosine in their combinational treatments with BRAFV600E/MEK inhibitors in thyroid cancer cells. The data mayhelp appropriate selection of these prominent drugs for clinical trials of combination therapies for thyroid cancer.
AB - Purpose: The purpose of the study was to explore optimal combinations of currently actively developed drugs for dually targeting the Ras → Raf → MAPK kinase (MEK) → MAPK/ERK (MAPK) and the phosphatidylinositol 3-kinase/Akt pathways as effective treatments for thyroid cancer. Experimental Design: We tested the combinations of the Akt inhibitors MK2206 or perifosine with the BRAFV600E inhibitor PLX4032 or the MEK1/2 inhibitor AZD6244 in thyroid cancer cells harboring both the BRAFV600E and PIK3CA mutations. Results: We found that MK2206 could potently, when used alone, and synergistically, when combined with either PLX4032 or AZD6244, inhibit thyroid cancer cell growth with all the combination index values lower than 1. Perifosine could potently inhibit thyroid cancer cell growth when used alone, but a strong antagonism occurred between this drug and PLX4032 or AZD6244 in the inhibition of thyroid cancer cell growth with all combination index values higher than 1. Combinations of MK2206 with PLX4032 or AZD6244 dramatically enhanced G1 cell cycle arrest induced by each drug alone. However, G2 cell cycle arrest uniquely induced by perifosine alone and G1 cell cycle arrest induced by PLX4032 or AZD6244 were both reversed by combination treatments, providing a mechanism for their antagonism. All these drugs could correspondingly inhibit the MAPK and phosphatidylinositol 3-kinase/Akt signalings, confirming their expected target effects. Conclusions: We demonstrated, unexpectedly, opposite outcomes of MK2206 and perifosine in their combinational treatments with BRAFV600E/MEK inhibitors in thyroid cancer cells. The data mayhelp appropriate selection of these prominent drugs for clinical trials of combination therapies for thyroid cancer.
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U2 - 10.1210/jc.2011-1054
DO - 10.1210/jc.2011-1054
M3 - Article
C2 - 22090271
AN - SCOPUS:84863012398
SN - 0021-972X
VL - 97
SP - E173-E182
JO - Journal of Clinical Endocrinology and Metabolism
JF - Journal of Clinical Endocrinology and Metabolism
IS - 2
ER -