Nuclear CSPP1 expression defined subtypes of basal-like breast cancer

Br J Cancer. 2014 Jul 15;111(2):326-38. doi: 10.1038/bjc.2014.297. Epub 2014 Jun 5.


Background: The multi-exon CSPP1 gene, encoding for centrosome and microtubule-associated proteins involved in ciliogenesis and cell division, is a candidate oncogene in luminal breast cancer but expression of CSPP1 proteins remained unexplored.

Methods: CSPP1 gene and protein expression was examined in normal mammary tissue, human breast cancer cell lines, and primary breast cancer biopsies from two patient cohorts. Cell type and epitope-dependent subcellular-specific CSPP1 staining pattern in normal mammary gland epithelium and cancer biopsies were correlated to molecular and clinical parameters.

Results: A novel, nuclear localised CSPP1 isoform was exclusively detected in luminal epithelial cells, whereas cytoplasmic CSPP-L was generally expressed in normal mammary epithelium. Luminal cell-related nuclear CSPP1 expression was preserved in type-matched cell lines and carcinomas, and correlated to gene copy number and mRNA expression. In contrast, basal-like carcinomas displayed generally lower CSPP1 mRNA expression. Yet, a subgroup of basal-like breast carcinomas depicted nuclear CSPP1 expression, displayed luminal traits, and differed from nuclear CSPP1 devoid counterparts in expression of eight genes. Eight-gene signature defined groups of basal-like tumours from an independent cohort showed significant differences in survival.

Conclusions: Differential expression of a nuclear CSPP1 isoform identified biologically and clinically distinct subgroups of basal-like breast carcinoma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Breast Neoplasms / genetics
  • Breast Neoplasms / metabolism*
  • Breast Neoplasms / pathology
  • Cell Culture Techniques
  • Cell Cycle Proteins / biosynthesis*
  • Cell Cycle Proteins / genetics
  • Cell Line, Tumor
  • Cell Nucleus / genetics
  • Cell Nucleus / metabolism
  • Epithelial Cells / metabolism
  • Epithelial Cells / pathology
  • Female
  • Gene Expression
  • Gene Expression Profiling
  • HEK293 Cells
  • Humans
  • Immunohistochemistry
  • MCF-7 Cells
  • Microtubule-Associated Proteins / biosynthesis*
  • Microtubule-Associated Proteins / genetics
  • Neoplasms, Basal Cell / genetics
  • Neoplasms, Basal Cell / metabolism*
  • Neoplasms, Basal Cell / pathology
  • Transfection


  • CSPP1 protein, human
  • Cell Cycle Proteins
  • Microtubule-Associated Proteins