FIGURE 4.

The lysophosphatidic acid/lysophosphatidic acid receptor5 (LPA/LPAR5) axis activates the PI3K/Akt/mTOR signaling cascade. A, Downregulation of LPAR5 mediated by siRNA decreased phosphorylated Akt levels in CGTH‐W3 and TPC‐1 cells. B, LPA enhanced phosphorylation of Akt and p70S6K in CGTH‐W3 and TPC‐1 cells. Serum‐deprived thyroid cells were treated with LPA (10 μM) for the indicated times. Total Akt and p70S6K protein, as well as their phosphorylated forms were detected using Western blot assay. GAPDH was employed as a loading control. B, LPAR5‐specific inhibitor TC LPA5 4 (5 μM), PI3K inhibitor wortmannin (100 nM), or mTOR inhibitor rapamycin (10 nM) pretreatment for 2 h blocks PI3K/Akt/mTOR signal activation induced by LPA (10 μM) stimulation