title: Stem cell origin of testicular seminoma.
abstract: BACKGROUND
  A major question concerning cancer is its cells of origin. We hypothesized that distinct cancer subtypes arise from unique cancer-initiating cells. By performing a microarray meta-analysis of seminomas and spermatogonial stem cells, we investigated a putative cell of origin for seminoma.
  
  
  METHODS
  We obtained published microarray data for 6 human adult germ cell lines, 16 embryonic stem cell lines, 3 normal testicular tissue samples, and 40 seminomas from the Gene Expression Omnibus database. By assessing correlations between various tissue microarrays, we determined the number of transitional events and the distance between seminomas and human spermatogonial stem cells.
  
  
  RESULTS
  Our meta-analysis showed that spermatogonial stem cells correlated similarly with seminoma (95% CI of Spearman ρ, 0.33-0.44) and with normal somatic testicular tissue cells (95% CI, 0.39-0.40), which suggests parallel paths of cellular origins.
  
  
  CONCLUSIONS
  Analysis of our results suggests that a unique cancer subtype, namely seminoma, may have originated from an undifferentiated cell with stemness features rather than from a differentiated cell that acquired stemness features.
authors.affiliation: Department of Genitourinary Medical Oncology, University of Texas MD Anderson Cancer Center, Houston, TX.
authors.forename: Avik
authors.initials: A
authors.lastname: Som
authors.forename: Sijin
authors.initials: S
authors.lastname: Wen
authors.forename: Shi-Ming
authors.initials: SM
authors.lastname: Tu
mesh_terms: D002454:Cell Differentiation; D019070:Cell Lineage / Q000235:genetics*; D006801:Humans; D008297:Male; D009373:Neoplasms, Germ Cell and Embryonal / Q000473:pathology*; D018239:Seminoma / Q000473:pathology*; D013234:Stem Cells / Q000473:pathology*; D013736:Testicular Neoplasms / Q000473:pathology*; D046888:Tissue Array Analysis
keywords: Cancer-initiating cells; De-differentiation; Germ cell tumor; Spermatogonial stem cells; Stemness