Anticancer research

Impact of STAT3 inhibition on survival of osteosarcoma cell lines.

PMID 25368256


Osteosarcoma is often a fatal malignancy. Constitutive STAT3 activation is associated with various human cancers and commonly suggests poor prognosis. We aimed to investigate the effect and potential molecular mechanisms of STAT3 inhibition on osteosarcoma. STAT3 inhibitor S3I-201 was investigated in six osteosarcoma cell lines. Crystal violet colorimetric, clonogenic, cleaved caspase-3 assays and western blot were performed to measure the effect and mechanisms of STAT3 inhibition. All osteosarcoma cell lines expressed phosphorylated STAT3. Anti-proliferative effects of S3I-201 were dose- and time-dependent. S3I-201 also inhibited colony-formation and induced apoptosis through the caspase cleavage pathway. Finally, molecular mechanism studies suggested that down-regulation of STAT3 phosphorylation and downstream STAT3-target genes such as cyclin D1 and survivin may contribute to S3I-201-mediated anti-proliferation and apoptosis. Inhibition of STAT3 signalling suppressed osteosarcoma cell growth and induced apoptosis, and indicated that STAT3 targeted-therapy may have therapeutic potential in osteosarcoma.