Intratubular germ cell neoplasia of the human testis: heterogeneous protein expression and relation to invasive potential.
Testicular germ cell cancer develops from premalignant intratubular germ cell neoplasia, unclassified cells that are believed to arise from failure of normal maturation of fetal germ cells from gonocytes (OCT4(+)/MAGEA4(-)) into pre-spermatogonia (OCT4(-)/MAGEA4(+)). Intratubular germ cell neoplasia cell subpopulations based on stage of germ cell differentiation have been described, however the importance of these subpopulations in terms of invasive potential has not been reported. We hypothesized that cells expressing an immature (OCT4(+)/MAGEA4(-)) germ cell profile would exhibit an increased proliferation rate compared with those with a mature profile (OCT4(+)/MAGEA4(+)). Therefore, we performed triple immunofluorescence and stereology to quantify the different intratubular germ cell neoplasia cell subpopulations, based on expression of germ cell (OCT4, PLAP, AP2γ, MAGEA4, VASA) and proliferation (Ki67) markers, in testis sections from patients with preinvasive disease, seminoma, and non-seminoma. We compared these subpopulations with normal human fetal testis and with seminoma cells. Heterogeneity of protein expression was demonstrated in intratubular germ cell neoplasia cells with respect to gonocyte and spermatogonial markers. It included an embryonic/fetal germ cell subpopulation lacking expression of the definitive intratubular germ cell neoplasia marker OCT4, that did not correspond to a physiological (fetal) germ cell subpopulation. OCT4(+)/MAGEA4(-) cells showed a significantly increased rate of proliferation compared with the OCT4(+)/MAGEA4(+) population (12.8 versus 3.4%, P<0.0001) irrespective of histological tumor type, reflected in the predominance of OCT4(+)/MAGEA4(-) cells in the invasive tumor component. Surprisingly, OCT4(+)/MAGEA4(-) cells in patients with preinvasive disease showed significantly higher proliferation compared to those with seminoma or non-seminoma (18.1 versus 10.2 versus 7.2%, P<0.05, respectively). In conclusion, this study has demonstrated that OCT4(+)/MAGEA4(-) cells are the most frequent and most proliferative cell population in tubules containing intratubular germ cell neoplasia, which appears to be an important factor in determining invasive potential of intratubular germ cell neoplasia to seminomas.
MRC Centre for Reproductive Health, The University of Edinburgh, Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, Scotland, UK.|Edinburgh Royal Hospital for Sick Children, 9 Sciennes Road, Edinburgh, EH9 1LF, Scotland, UK.
Rod T
RT
Mitchell
MRC Centre for Reproductive Health, The University of Edinburgh, Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, Scotland, UK.
Maria
M
Camacho-Moll
MRC Centre for Reproductive Health, The University of Edinburgh, Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, Scotland, UK.
Joni
J
Macdonald
MRC Centre for Reproductive Health, The University of Edinburgh, Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, Scotland, UK.
Richard A
RA
Anderson
Edinburgh Royal Hospital for Sick Children, 9 Sciennes Road, Edinburgh, EH9 1LF, Scotland, UK.
Christopher Jh
CJ
Kelnar
Department of Pathology, Western General Hospital, Crewe Road, Edinburgh, EH4 2XU, Scotland, UK.
Marie
M
O'Donnell
MRC Centre for Reproductive Health, The University of Edinburgh, Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, Scotland, UK.
Richard M
RM
Sharpe
MRC Centre for Reproductive Health, The University of Edinburgh, Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, Scotland, UK.
Lee B
LB
Smith
Department of Pathology, Western General Hospital, Crewe Road, Edinburgh, EH4 2XU, Scotland, UK.
Ken M
KM
Grigor
Edinburgh Royal Hospital for Sick Children, 9 Sciennes Road, Edinburgh, EH9 1LF, Scotland, UK.
W Hamish B
WHB
Wallace
Department of Pathology (LHJL, HS) and Pediatric Urology (KPW), Erasmus MC-University Medical Center Rotterdam, Josephine Nefkens Institute, Room 430b, P.O. Box 1738, 3000 DR Rotterdam, The Netherlands.
Hans
H
Stoop
Department of Pathology (LHJL, HS) and Pediatric Urology (KPW), Erasmus MC-University Medical Center Rotterdam, Josephine Nefkens Institute, Room 430b, P.O. Box 1738, 3000 DR Rotterdam, The Netherlands.
Katja P
KP
Wolffenbuttel
Department of Urology, Western General Hospital, Crewe Road, Edinburgh, EH4 2XU, Scotland, UK.
Roland
R
Donat
MRC Centre for Reproductive Health, The University of Edinburgh, Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, Scotland, UK.
Philippa Tk
PT
Saunders
Department of Pathology (LHJL, HS) and Pediatric Urology (KPW), Erasmus MC-University Medical Center Rotterdam, Josephine Nefkens Institute, Room 430b, P.O. Box 1738, 3000 DR Rotterdam, The Netherlands.
Leendert Hj
LH
Looijenga
D000328:Adult; D000951:Antigens, Neoplasm / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000378:metabolism; D002454:Cell Differentiation; D049109:Cell Proliferation; D002648:Child; D019084:Fluorescent Antibody Technique, Indirect; D018237:Germinoma / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D008297:Male; D009361:Neoplasm Invasiveness; D009363:Neoplasm Proteins / Q000378:metabolism*; D009373:Neoplasms, Germ Cell and Embryonal / Q000378:metabolism* / Q000473:pathology; D012671:Seminiferous Tubules / Q000473:pathology*; D018239:Seminoma / Q000378:metabolism / Q000473:pathology; D013093:Spermatogonia / Q000378:metabolism; D013736:Testicular Neoplasms / Q000378:metabolism* / Q000473:pathology; D013737:Testis / Q000196:embryology; D055815:Young Adult
D000951:Antigens, Neoplasm; D015415:Biomarkers; D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins