Characterization of human leukocyte antigen-G (HLA-G) expression in endometrial adenocarcinoma.
ABSTRACT The current study sought to determine if endometrial adenocarcinomas express human leukocyte antigen-G (HLA-G), an immune-regulatory protein, and if degree of expression correlates with the stage of carcinoma.
Forty-four primary endometrial adenocarcinomas were tested using immunohistochemical staining with the 4H84 anti-HLA-G monoclonal antibody. Metastatic implants were not included. A subset of 10 samples was tested using RNA in situ hybridization to confirm the presence of HLA-G transcript. Results of staining were analyzed with respect to grade, tumor histology, and stage of disease. Spearman rank correlation was used to assess tumor grade, histology, and disease stage as a function of HLA-G protein staining. Receiver-operator characteristic (ROC) curve analysis was used to determine the feasibility of HLA-G protein staining as a clinical marker for advanced stage disease.
Immunohistochemical staining for HLA-G protein was seen in 55% (24/44) of primary site endometrial adenocarcinomas and localized to glandular but not stromal epithelium. RNA in situ hybridization confirmed the presence of transcript in the majority of samples tested and also localized to glandular epithelium. A significant correlation was seen with increasing HLA-G protein staining and increasing stage of endometrial cancer, P < 0.01. HLA-G was found to be a fair discriminator as a test for metastatic disease with an area under the ROC curve of 0.75 for metastatic versus non-metastatic disease.
HLA-G protein is expressed in a significant number of endometrial adenocarcinomas, in which it is localized to the glandular epithelium. HLA-G may serve as a clinical marker for the preoperative prediction of metastatic endometrial cancer.
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ABSTRACT: Human leukocyte antigen-G (HLA-G) is known to be implicated in a tumor-driven immune escape mechanism in malignancies. The purpose of this study was to investigate HLA-G polymorphism and expression in breast cancer. HLA-G alleles were determined by direct DNA sequencing procedures from blood samples of 80 breast cancer patients and 80 healthy controls. Soluble HLA-G (sHLA-G) was measured by enzyme-linked immunosorbent assay (ELISA) from serum specimens. HLA-G expression in breast cancer lesions was also analyzed by immunohistochemistry staining. The presence of HLA-G 3' untranslated region (UTR) 14-bp sequence was analyzed and found to be associated with reduced risk of breast cancer susceptibility based on HLA-G expression in tissues (P = 0.0407). Levels of sHLA-G were higher in the breast cancer group (median 117.2 U/mL) compared to the control group (median 10.1 U/mL, P<0.001). The area under the receiver operating characteristic curve (AU-ROC) values of sHLA-G for differentiating breast cancer from normal controls and for detecting metastasis from other stages of breast cancer were 0.89 and 0.79, respectively. HLA-G polymorphism and expression may be involved in breast carcinogenesis and sHLA-G concentrations could be used as a diagnostic marker for detecting breast cancer.PLoS ONE 01/2014; 9(5):e98284. · 3.73 Impact Factor
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ABSTRACT: Human leukocyte antigen G (HLA-G) is a non-classical major histocompatibility complex (MHC) class I molecule that, through interaction with its receptors, exerts important tolerogenic functions. Its main physiological expression occurs in placenta where it seems to participate in the maternal tolerance toward the fetus. HLA-G has been studied as a marker of pregnancy complications such as abortion or pre-eclapmsia. Although HLA-G is not expressed in most adult tissues, its ectopic expression has been observed in some diseases such as viral infections, autoimmune disorders, and especially cancer. HLA-G neo-expression in cancer is associated with the capability of tumor cells to evade the immune control. In this review, we will summarize HLA-G biology and how it participates in these physiopathological processes. Special attention will be paid to its role as a diagnostic tool and also as a therapeutic target.Critical Reviews in Clinical Laboratory Sciences 04/2012; 49(3):63-84. · 3.78 Impact Factor
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ABSTRACT: Human leukocyte antigen-G (HLA-G) is a nonclassical HLA class I molecule involved in tumor escape mechanisms. Considering that the HLA-G 14bp insertion/deletion polymorphism is located at the 3' untranslated region (3'UTR) in exon 8, and since it has been associated with the magnitude of HLA-G production, we studied the association of 14bp insertion/deletion polymorphism with the risk of developing hepatocellular carcinoma (HCC). A total of 109 HCC patients followed at the University Hospital, Faculty of Medicine of Ribeirão Preto, São Paulo, Brazil, and 202 healthy controls from the same geographic area were genotyped for the 14bp insertion/deletion polymorphism using polymerase chain reaction (PCR) and polyacrylamide gel electrophoresis. Compared to controls, the frequency of the 14bp deletion allele was overrepresented in HCC patients (65% versus 56%, respectively, P = 0.0326). The 14bp deletion conferred an odds ratio (OR) of 1.46 [95% confidence interval (CI): 1.04-2.05]. Similarly, the deletion/deletion genotype was marginally overrepresented in HCC patients (45% versus 35% in controls, P = 0.0871), conferring an OR of 1.54 (95% CI: 0.96-2.48). The frequencies of the deletion/insertion or insertion/insertion genotypes observed in patients were not statistically different from those observed in controls (P > 0.05). Our results suggest that the 14bp-deletion allele in HLA-G gene is associated with HCC susceptibility in a Brazilian population.Tissue Antigens 03/2013; · 2.93 Impact Factor