title: Novel markers for differentiation of lobular and ductal invasive breast carcinomas by laser microdissection and microarray analysis.
abstract: BACKGROUND
  Invasive ductal and lobular carcinomas (IDC and ILC) are the most common histological types of breast cancer. Clinical follow-up data and metastatic patterns suggest that the development and progression of these tumors are different. The aim of our study was to identify gene expression profiles of IDC and ILC in relation to normal breast epithelial cells.
  
  
  METHODS
  We examined 30 samples (normal ductal and lobular cells from 10 patients, IDC cells from 5 patients, ILC cells from 5 patients) microdissected from cryosections of ten mastectomy specimens from postmenopausal patients. Fifty nanograms of total RNA were amplified and labeled by PCR and in vitro transcription. Samples were analysed upon Affymetrix U133 Plus 2.0 Arrays. The expression of seven differentially expressed genes (CDH1, EMP1, DDR1, DVL1, KRT5, KRT6, KRT17) was verified by immunohistochemistry on tissue microarrays. Expression of ASPN mRNA was validated by in situ hybridization on frozen sections, and CTHRC1, ASPN and COL3A1 were tested by PCR.
  
  
  RESULTS
  Using GCOS pairwise comparison algorithm and rank products we have identified 84 named genes common to ILC versus normal cell types, 74 named genes common to IDC versus normal cell types, 78 named genes differentially expressed between normal ductal and lobular cells, and 28 named genes between IDC and ILC. Genes distinguishing between IDC and ILC are involved in epithelial-mesenchymal transition, TGF-beta and Wnt signaling. These changes were present in both tumor types but appeared to be more prominent in ILC. Immunohistochemistry for several novel markers (EMP1, DVL1, DDR1) distinguished large sets of IDC from ILC.
  
  
  CONCLUSIONS
  IDC and ILC can be differentiated both at the gene and protein levels. In this study we report two candidate genes, asporin (ASPN) and collagen triple helix repeat containing 1 (CTHRC1) which might be significant in breast carcinogenesis. Besides E-cadherin, the proteins validated on tissue microarrays (EMP1, DVL1, DDR1) may represent novel immunohistochemical markers helpful in distinguishing between IDC and ILC. Further studies with larger sets of patients are needed to verify the gene expression profiles of various histological types of breast cancer in order to determine molecular subclassifications, prognosis and the optimum treatment strategies.
authors: Laboratory of Molecular Pathology, Institute of Pathology, Palacky University, Olomouc, Czech Republic. guliat@gmail.com <guliat@gmail.com>
authors: Gulisa
authors: G
authors: Turashvili
authors: Jan
authors: J
authors: Bouchal
authors: Karl
authors: K
authors: Baumforth
authors: Wenbin
authors: W
authors: Wei
authors: Marta
authors: M
authors: Dziechciarkova
authors: Jiri
authors: J
authors: Ehrmann
authors: Jiri
authors: J
authors: Klein
authors: Eduard
authors: E
authors: Fridman
authors: Jozef
authors: J
authors: Skarda
authors: Josef
authors: J
authors: Srovnal
authors: Marian
authors: M
authors: Hajduch
authors: Paul
authors: P
authors: Murray
authors: Zdenek
authors: Z
authors: Kolar
mesh_terms: D015415:Biomarkers; D001940:Breast / Q000378:metabolism; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology; D015820:Cadherins / Q000235:genetics; D018270:Carcinoma, Ductal, Breast / Q000235:genetics* / Q000473:pathology; D018275:Carcinoma, Lobular / Q000235:genetics* / Q000473:pathology; D024061:Collagen Type III / Q000235:genetics; D016326:Extracellular Matrix Proteins / Q000235:genetics; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007834:Lasers; D042282:Microdissection / Q000379:methods*; D046888:Tissue Array Analysis / Q000379:methods*
chemical_list: C439889:ASPN protein, human; D015415:Biomarkers; C439971:COL3A1 protein, human; C502426:CTHRC1 protein, human; D015820:Cadherins; D024061:Collagen Type III; D016326:Extracellular Matrix Proteins