Overexpression and delocalization of claudin-3 protein in MCF-7 and MDA-MB-415 breast cancer cell lines

Maria C. Todd, Heather M. Petty, Jonathan M. King, Brytanie N. Piana Marshall, Rebecca A. Sheller, Maria E. Cuevas

Research output: Contribution to journalArticlepeer-review

33 Scopus citations


Tumor-specific deregulated expression of claudins, integral membrane proteins found in tight junctions (TJs), has indicated a possible role for TJ disruption in cancer progression. The current study demonstrates the marked overexpression of claudin-3 protein in two breast cancer cell lines of metastatic origin (MCF-7 and MDA-MB-415). Immunofluorescence and differential detergent fractionation analyses revealed that, although claudin-3 was primarily localized at cell junctions, it was also detected intracellularly. Similarly, the siRNA-mediated suppression of claudin-3 did not considerably affect its pattern of subcellular distribution relative to mock-transfected cells. However, there appeared to be a preferential loss of claudin-3 signal in the cytoskeletal fraction. Wound-healing assays were conducted to assess the effect of endogenous overexpression versus siRNA-mediated suppression of claudin-3 on cellular motility in MCF-7 cells. Suppression of claudin-3 protein levels resulted in a marked decrease in the rate of cellular motility relative to mock-transfected cells. These findings suggest that overexpression of claudin-3 may be important in disrupting TJ integrity and thus contribute to enhanced cellular motility, a key component of tumor progression.

Original languageEnglish (US)
Pages (from-to)156-162
Number of pages7
JournalOncology Letters
Issue number1
StatePublished - Jul 1 2015
Externally publishedYes


  • Cell motility
  • Metastasis
  • Tight junctions

ASJC Scopus subject areas

  • Oncology
  • Cancer Research


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