Lysophosphatidic acid induces STAT3 phosphorylation and ovarian cancer cell motility: their inhibition by curcumin.

Lysophosphatidic acid (LPA) is a biolipid that stimulates tumor cell invasion and metastasis. In this report, we determined the role of signal transducers and activators of transcription 3 (STAT3) and the effect of a chemopreventive agent, curcumin, on LPA-induced ovarian cancer cell motility. LPA phosphorylated STAT3 in a dose-dependent manner. Treatment of cells with a JAK/STAT inhibitor, AG490, inhibited LPA-induced cell motility. In contrast, transfection of a constitutively active form of STAT3 induced ovarian cancer cell motility. LPA also stimulated interleukin (IL)-6 and IL-8 secretion, which results in STAT3 phosphorylation. Treatment of the cells with curcumin inhibited LPA-induced IL-6 and IL-8 secretion and STAT3 phosphorylation, leading to blocked ovarian cancer cell motility. Collectively, the present study shows the critical role of STAT3 in ovarian cancer cell motility and that this process can be prevented by curcumin.