Indoleamine 2,3-dioxygenase expression in gestational trophoblastic disease: implications for development of immunotherapeutic approaches.
OBJECTIVE
To examine the immunoexpression of indoleamine 2,3-dioxygenase (IDO) in gestational trophoblastic neoplasia (GTN), including hydatidiform moles and gestational trophoblastic tumors.


METHODS
GTN cases were identified from a referral center for trophoblastic disease, and sections were immunostained with anti-IDO antibody and classified as positive or negative for trophoblast staining relative to normal chorionic villi.


RESULTS
Fifty-two cases were included: 10 nonmolar hydropic miscarriages (HA), 11 partial moles (PHM), 9 complete moles (CHM), 15 choriocarcinoma cases (CC) and 7 placental site trophoblastic tumors (PSTT). All HA, PHM and CHM demonstrated IDO staining; 2 of 15 CC were strongly positive, 6 demonstrated focal positivity (< 10% of tumor cells), and the remainder were negative. Of the 7 PSTT, only 2 showed focal weak positivity; the others were negative.


CONCLUSIONS
Hydatidiform moles express IDO, but the majority of gestational trophoblastic tumors, despite arising from villous or nonvillous trophoblast, do not express this enzyme, suggesting that IDO-mediated immunoregulation is unlikely to be a major component of the malignant phenotype in these tumors. Immunotherapeutic approaches involving IDO might represent ancillary approaches in a minority of patients with GTN.
Sebire
Neil James
NJ
Trophoblastic Disease Unit, Department of Cancer Medicine, Charing Cross Hospital, London, UK. sebirn@gosh.nhs.uk
Fisher
Rosemary Ann
RA
Williams
Susan
S
Prendergast
George
G
Savage
Philip
P
Seckl
Michael
M
D000328:Adult; D014408:Biomarkers, Tumor; D002822:Choriocarcinoma / Q000201:enzymology / Q000235:genetics; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D031901:Gestational Trophoblastic Disease / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D006801:Humans; D006828:Hydatidiform Mole / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D007150:Immunohistochemistry; D007167:Immunotherapy / Q000379:methods; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D011247:Pregnancy; D014594:Uterine Neoplasms / Q000201:enzymology / Q000235:genetics / Q000473:pathology
D014408:Biomarkers, Tumor; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase