STAT3 is frequently phosphorylated and activated in breast and ovarian cancers, where cytokines and growth factors up-regulate STAT3 and stimulate proliferation.
Signal transducer and activator of transcription 3 (STAT3) is activated in majority of ovarian tumors and confers resistance to cisplatin treatment in patients with ovarian cancer.
Altogether, these findings emphasize the importance of Stat3 in cisplatin resistance in ovarian cancer and provide a further impetus to clinically evaluate biological modifiers that may circumvent cisplatin resistance in patients with chemoresistant ovarian cancer.
Cisplatin-induced CCL5 secretion from CAFs promotes cisplatin-resistance in ovarian cancer via regulation of the STAT3 and PI3K/Akt signaling pathways.
Constitutively activated signal transducer and activator of transcription 3 (STAT3) plays an important role in the formation of many tumors including ovarian cancer.
Hyperactive EGFR signaling through Stat3 and the Jak-Stat3 activity together promote ovarian cancer progression to cisplatin resistance and therefore represent targets for preventing the development of cisplatin resistance and the recurrent disease during cisplatin therapy in ovarian cancer.
In addition, phosphorylated-Stat3 (Tyr705) amounts OC cell invasion and migration, and expression of matrix metalloproteinases (MMP-9 and MMP-2) decreased.
In conclusion, the present study proved for the first time that miR-519a functions as a tumor suppressor by targeting STAT3 in ovarian cancer, suggesting that miR-519a may be a potential biomarker for the diagnosis and treatment of ovarian cancer.
Intriguingly, we demonstrated that M-MDSC could be readily induced by ascitic fluids (AF) from OC patients, which was predominantly dependent on IL-6, IL-10 and STAT3 activation as neutralization of IL-6 and/or IL-10 or inhibition of STAT3 abrogated MDSC's expansion while recombinant IL-6 and IL-10 recapitulated the expansive effect of AF; furthermore, predominantly elevated levels of IL-6 and IL-10 has been noted in the AF which was positively correlated with the abundance of M-MDSC as well as poor prognosis of OC patients.
JAK/STAT3 is one of the major signaling pathways that is aberrantly activated in ovarian cancer and associated with tumor progression and poor prognosis in patients with ovarian cancer.