Differential effects of Stat3 inhibition in sparse vs confluent normal and breast cancer cells

Aikaterini Anagnostopoulou, Adina Vultur, Rozanne Arulanandam, Jun Cao, James Turkson, Richard Jove, Joon S. Kim, Matthew Glenn, Andrew Hamilton, Leda Raptis

Research output: Contribution to journalArticle

Abstract

The signal transducer and activator of transcription-3 (Stat3) is persistently activated in many cancers such as cancer of the breast and is required for transformation by a number of oncogenes. Signaling through Stat3 is determined by a key phosphorylation at tyr-705. We previously demonstrated that cell-to-cell adhesion brought about through cell aggregation or confluence of cultured cells causes a dramatic increase in Stat3 tyr705 phosphorylation and consequently Stat3 activity in both normal and tumor cells. To examine the role of Stat3 at specific time-points relative to confluence, we used two different approaches of Stat3 inhibition: (1). Introduction of high levels of peptide analogues, which block the Stat3-SH2 domain, to inhibit Stat3 binding to and phosphorylation by growth factor receptors. (2). Treatment with two platinum compounds which bind the Stat3 protein and inhibit its activity without affecting its phosphorylation directly. The results demonstrate that Stat3 downregulation in vSrc transformed NIH3T3 cells or in breast cancer lines harboring activated Src induces apoptosis, which is evident at all densities but is more pronounced at post-confluence. In normal cells on the other hand, Stat3 inhibition at post-confluence caused apoptosis while in sparsely growing cells it induced merely a growth retardation.

Original languageEnglish (US)
Pages (from-to)120-132
Number of pages13
JournalCancer Letters
Volume242
Issue number1
DOIs
StatePublished - Oct 8 2006

Fingerprint

STAT3 Transcription Factor
Breast Neoplasms
Phosphorylation
STAT Transcription Factors
Platinum Compounds
Apoptosis
Cell Aggregation
src Homology Domains
Growth Factor Receptors
Oncogenes
Cell Adhesion
Cultured Cells
Neoplasms
Down-Regulation

Keywords

  • Apoptosis
  • Cell proliferation
  • Cell-to-cell adhesion
  • Neoplastic transformation
  • Peptidomimetics
  • Stat3

ASJC Scopus subject areas

  • Cancer Research
  • Molecular Biology
  • Oncology

Cite this

Anagnostopoulou, A., Vultur, A., Arulanandam, R., Cao, J., Turkson, J., Jove, R., ... Raptis, L. (2006). Differential effects of Stat3 inhibition in sparse vs confluent normal and breast cancer cells. Cancer Letters, 242(1), 120-132. https://doi.org/10.1016/j.canlet.2005.10.047

Differential effects of Stat3 inhibition in sparse vs confluent normal and breast cancer cells. / Anagnostopoulou, Aikaterini; Vultur, Adina; Arulanandam, Rozanne; Cao, Jun; Turkson, James; Jove, Richard; Kim, Joon S.; Glenn, Matthew; Hamilton, Andrew; Raptis, Leda.

In: Cancer Letters, Vol. 242, No. 1, 08.10.2006, p. 120-132.

Research output: Contribution to journalArticle

Anagnostopoulou, A, Vultur, A, Arulanandam, R, Cao, J, Turkson, J, Jove, R, Kim, JS, Glenn, M, Hamilton, A & Raptis, L 2006, 'Differential effects of Stat3 inhibition in sparse vs confluent normal and breast cancer cells', Cancer Letters, vol. 242, no. 1, pp. 120-132. https://doi.org/10.1016/j.canlet.2005.10.047
Anagnostopoulou A, Vultur A, Arulanandam R, Cao J, Turkson J, Jove R et al. Differential effects of Stat3 inhibition in sparse vs confluent normal and breast cancer cells. Cancer Letters. 2006 Oct 8;242(1):120-132. https://doi.org/10.1016/j.canlet.2005.10.047
Anagnostopoulou, Aikaterini ; Vultur, Adina ; Arulanandam, Rozanne ; Cao, Jun ; Turkson, James ; Jove, Richard ; Kim, Joon S. ; Glenn, Matthew ; Hamilton, Andrew ; Raptis, Leda. / Differential effects of Stat3 inhibition in sparse vs confluent normal and breast cancer cells. In: Cancer Letters. 2006 ; Vol. 242, No. 1. pp. 120-132.
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