A comparative study on regulation of HLA-G expression in bad obstetric history and in head and neck squamous cell carcinoma from Northeast India.

The expression of immunomodulatory molecule HLA-G is tissue restricted with abundant expression in placenta, mediating immune tolerance to fetus. Tumors hijack HLA-G to establish nutrient supply and evade host immune response. 14 base pair Insertion/Deletion polymorphism (rs371194629) and + 3142 G/C SNP (rs1063320) of 3'UTR of HLA-G were investigated in conjunction with miR-148A, miR-152 and HLA-G expression in SAB (Spontaneous abortion) history placenta and HNSCC tumor in a hospital-based case control study. Higher frequency of G allele of rs1063320 was seen in study participants as reported in other global populations. Both miR-148A and miR-152 were downregulated in tumor tissue. Predominance of 14 base pair "IN" allele of rs371194629 was noted in SAB placental tissue (p =<0.0001) with lower expression of HLA-G levels. In conclusion, 14 base pair Insertion/Deletion in linkage with + 3142 G/C SNP was related to lower HLA-G protein expression in SAB tissue, contradictorily HLA-G protein level was manipulated by tumors by suppressing microRNAs.