Keratins as markers that distinguish normal and tumor-derived mammary epithelial cells

Douglas K. Trask, Vimla Band, Deborah A. Zajchowski, Paul Yaswen, Theodore Suh, Ruth Sager

Research output: Contribution to journalArticlepeer-review

177 Scopus citations


Keratin 5 (K5) mRNA and protein are shown to be expressed in normal mammary epithelial cells in culture and are absent from tumor-derived cell lines. To extend these findings, the full complements of keratins in normal, immortalized, and tumor cells were compared. It is shown here that normal cells produce keratins K5, K6, K7, K14, and K17, whereas tumor cells produce mainly keratins K8, K18, and K19. In immortalized cells, which are preneoplastic or partially transformed, the levels of KS mRNA and protein are lower than in normal cells, whereas the amount of K18 is increased. Thus, K5 is an important marker in the tumorigenic process, distinguishing normal from tumor cells, and decreased K5 expression correlates with tumorigenic progression.

Original languageEnglish (US)
Pages (from-to)2319-2323
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number6
StatePublished - Mar 1990
Externally publishedYes


  • Breast cancer
  • Immortalization
  • Intermediate filaments
  • Tumor and normal antigens

ASJC Scopus subject areas

  • General


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