Meta-analysis of HLA-G 14bp insertion/deletion polymorphism and soluble HLA-G revealed an association with digestive cancers initiation and prognosis

Harnessing the potential of HLA-G in cancer therapy: advances, challenges, and prospects

Immune checkpoint blockades have been prized in circumventing and ablating the impediments posed by immunosuppressive receptors, reaching an exciting juncture to be an innovator in anticancer therapy beyond traditional therapeutics. Thus far, approved immune checkpoint blockades have principally targeted PD-1/PD-L1 and CTLA-4 with exciting success in a plethora of tumors and yet are still trapped in dilemmas of limited response rates and adverse effects. Hence, unveiling new immunotherapeutic targets has aroused immense scientific interest in the hope of expanding the clinical application of immune checkpoint blockades to scale new heights. Human leukocyte antigen-G (HLA-G), a non-classical major histocompatibility complex (MHC) class I molecule, is enriched on various malignant cells and is involved in the hindrance of immune effector cells and the facilitation of immunosuppressive cells. HLA-G stands out as a crucial next-generation immune checkpoint showing great promise for the benefit of cancer patients. Here, we provide an overview of the current understanding of the expression pattern and immunological functions of HLA-G, as well as its interaction with well-characterized immune checkpoints. Since HLA-G can be shed from the cell surface or released by various cells as free soluble HLA-G (sHLA-G) or as part of extracellular vesicles (EVs), namely HLA-G-bearing EVs (HLA-GEV), we discuss the potential of sHLA-G and HLA-GEV as predictive biomarkers. This review also addresses the advancement of HLA-G-based therapies in preclinical and clinical settings, with a focus on their clinical application in cancer.

Association of HLA-G 3' untranslated region indel polymorphism and its serum expression with susceptibility to colorectal cancer

Background: Colorectal cancer (CRC) is a significant global health challenge with increasing incidence and mortality rates in developing countries. Genome-wide association studies have identified new low-penetrance genetic variants linked to CRC. This study aimed to explore the relationship between HLA-G polymorphism and serum expression with CRC. Methodology: In a case-control configuration, standard PCR was used for genotyping HLA-G 3' indel polymorphism and ELISA for quantifying soluble HLA-G in plasma. Results: The study revealed a significant association between the rs371194629 deletion allele and CRC, as well as higher soluble HLA-G levels in CRC patients. Conclusion: These findings suggest that HLA-G could be a promising biomarker for CRC, and further research could lead to improved screening and treatment for more personalized care.