Constitutive Activation of STAT3 Signaling Regulates hTERT and Promotes Stem Cell-Like Traits in Human Breast Cancer Cells
A: Immuno-precipitation with STAT3 antibody revealed that NF-kB and CD44 were bound to STAT3 in MDA-MB-231 cell line. STAT3 pull-down was performed in the cytoplasm and nuclear extracts separately. STAT3 was bound CD44 in the cytoplasm and bound to NF-kB in both cytoplasm and nuclear extracts. B: Pull-down assay with STAT3 antibody showed that STAT3 interaction with NF-kB and CD44 held true in MCF7-HER2. C: Real time PCR data showed that hTERT mRNA expressions were up-regulated in pSTAT3 activated cancer cell lines. MCF7 wild type was used as a control for hTERT mRNA expression of 1 fold. D: Western blot analyses: Up-regulation of hTERT expression was associated with pSTAT3 activation in human breast cancer.