Evaluation of HLA-G, HLA-E, and PD-L1 proteins in oral osteosarcomas.
OBJECTIVE
The aim of this study was to investigate the expression of human leukocyte antigens (HLAs) G and E and programmed death-ligand 1 (PD-L1) in oral osteosarcoma (OO) (n = 13). The relationship between the expression of these molecules and histologic grading and metastasis was also evaluated.


METHODS
HLA-G, HLA-E, and PD-L1 were identified by immunohistochemistry. Samples of normal bone tissue (n = 6) were used as controls. The sections were evaluated using a semiquantitative scoring system with an immunoreactive score, where a score of 0 was considered absent, ≤2 was low, and >2 was high expression.


RESULTS
We identified high expression of HLA-G, HLA-E, and PD-L1 by malignant osteoblastic cells in 69.2% of OO cases, which was statistically higher than that in controls (P < .05). Overexpression of these proteins was identified in 8 of 11 samples of high-grade and 1 of 2 samples of low-grade OO. Additionally, 66.6% of patients with metastases (n = 4) and 71.4% of patients without metastases (n = 5) had high expression of HLA-G, HLA-E, and PD-L1 in tumor samples (P > .05).


CONCLUSIONS
OO had high expression of HLA-G, HLA-E, and PD-L1 irrespective of clinicopathologic parameters, including histologic grading and metastasis.
Department of Stomatology (Oral Pathology), Dental School, Federal University of Goiás, Goiânia, Brazil.
Diego Antonio
DA
Costa Arantes
Department of Stomatology (Oral Pathology), Dental School, Federal University of Goiás, Goiânia, Brazil.
Andréia Souza
AS
Gonçalves
College of Dental Medicine-Illinois, Midwestern University, Downers Grove, IL, USA.
Bruno Correia
BC
Jham
Department of Pathology, School of Medicine, University of Brasília, Brasília, Brazil.
Eliza Carla Barroso
ECB
Duarte
Division of Anatomic Pathology, Araújo Jorge Hospital, Association of Cancer Combat of Goiás, Goiânia, Brazil.
Élbio Candido
ÉC
de Paula
Division of Anatomic Pathology, Araújo Jorge Hospital, Association of Cancer Combat of Goiás, Goiânia, Brazil; Department of Pathology and Medicine Laboratory, Medicine School, Federal University of Goiás, Goiânia, Brazil.
Henrique Moura
HM
de Paula
Department of Stomatology (Oral Pathology), Dental School, Federal University of Goiás, Goiânia, Brazil; Head and Neck Division, Araújo Jorge Hospital, Association of Cancer Combat of Goiás, Goiânia, Brazil.
Elismauro Francisco
EF
Mendonça
Department of Stomatology (Oral Pathology), Dental School, Federal University of Goiás, Goiânia, Brazil. Electronic address: Ali.caba@uol.com.
Aline Carvalho
AC
Batista
D000328:Adult; D000368:Aged; D060890:B7-H1 Antigen / Q000276:immunology*; D014408:Biomarkers, Tumor / Q000276:immunology; D003430:Cross-Sectional Studies; D005260:Female; D059951:HLA-G Antigens / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D006801:Humans; D007150:Immunohistochemistry; D007573:Jaw Neoplasms / Q000276:immunology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D012516:Osteosarcoma / Q000276:immunology* / Q000473:pathology; D000097625:HLA-E Antigens
D060890:B7-H1 Antigen; D014408:Biomarkers, Tumor; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I; D000097625:HLA-E Antigens; C423236:CD274 protein, human