Correlation of Tissue Distribution of HLA-G and HLA-E and Degree of Tumor Malignancy in Patients with Breast Cancer

Background and Aims: Human leukocyte antigen (HLA) molecules play a substantial role in T Lymphocyte-mediated adaptive immune response. Down-regulation of HLA expression may help the tumor to escape from immune surveillance. This study aimed to evaluate the correlation between HLA-G and HLA-E tissue distribution and the degree of tumor malignancy in human breast tumors. Materials and Methods: This cross-sectional study was conducted on tissue samples of ۱۴۵ patients with breast cancer. The distribution of HLA-G and HLA-E expressions were measured by the immunohistochemistry method. Results: Among ۱۴۵ patients, ۵۱% of tumors did not express HLA-E, and +۱ positive was seen in ۳۶.۶ % of patients. +۲ positive in ۸.۳% and +۳ positive in ۴.۱% of patients. Moreover, ۷۹.۳% of tumors did not express HLA-G, ۱۷.۹% expressed +۱ positive, ۲.۸% expressed +۲ positive, and no patients expressed +۳ positive. Generally, ۲۰.۷% and ۴۹% of patients showed expression of HLA-G and HLA-E, respectively. A significant correlation was seen between the grade of disease and expression of HLA-E (p = ۰.۰۳) and HLA-G (p = ۰.۰۰۱). Moreover, a significant correlation was seen between the simultaneous expression of HLA-G and HLA-E with grade (p = ۰.۰۳, r = ۰.۱۷۶). Conclusion: Significant correlation was seen between the distribution of HLA-G and HLA-E expression with a degree of malignancy. Therefore, these biomarkers’ expression may contribute to the prognosis and progression of breast cancer.

Keywords:

Breast cancer , Tumor malignancy , HLA-E , HLA-G