Table 2.
Summary of human leukocyte antigen-G evaluations in colorectal cancer and related colonic diseases of the gastrointestinal tract
| Sample type | HLA-Gs | Methods | Disease, n | Relevances | Ref. |
| Tumor DNA | HLA-G | RT-PCR | CRC, n = 39 | HLA-G mRNA was significantly more expressed in CRC (87.2%) than in the extra neoplastic tissue | [24] |
| Tumor tissue | HLA-G | IHC | CRC, n = 201 | HLA-G is over-expressed in primary CRC sites (64.6%), but not in the normal CRC tissues or benign adenomas | [25] |
| Tumor tissue | HLA-G | IHC | UC, n = 24; CD, n = 19 | HLA-G and IL-10 are highly expressed in UC but not in CD tissue biopsies | [154] |
| Tumor tissue | HLA-G | IHC | CRC, n = 60; DA, n = 67; BC, n = 37; AC, n = 52 | HLA-G is over-expressed in 52 % of CRC lesions and also in 79% of PDAs, 76% in BC and 75% AC | [26] |
| Tumor tissue | HLA-G | IHC | CRC, n = 415 | HLA-G is expressed in > 30% of CRC lesions (data summarize published data collected until 2008) | [16] |
| Tumor tissue | HLA-G | IHC | CRC, n = 154 | HLA-G is expressed in > 30% of CRC lesions (data summarize published data collected until 2005) | [17] |
| Serum | sHLA-G | ELISA | CRC, n = 144 | Higher sHLA-G levels in CRC (median 124.3 U/mL) compared to benign colorectal diseases (cut off value 88.6 U/mL). CEA showed less sensitivity e specificity | [27] |
| Plasma | sHLA-G | ELISA | CRC, n = 37 | sHLA-G as a diagnostic biomarker for the detection of early CRC (median 84 U/mL) with respect to BD (median 34 U/mL) | [28] |
| PBMC | sHLA-G | ELISA | HD, n = 30; CD, n = 10; UC, n = 18 | Spontaneous secretion of sHLA-G from cultured PBMCs of CD but not in UC and BD | [161] |
| Secretion of sHLA-G in CD patient cultures and BD but no in UC, after LPS stimulation | |||||
| Plasma and PBMC | HLA-G | ELISA | UC, n = 27; CD, n = 22 | Immunosuppressive therapy decreases sHLA-G hyperproduction in CD and induces its release in UD, in both plasma and in PBMC culture supernatants | [162] |
HLA-G: Human leukocyte antigen-G; sHLA-G: Soluble HLA-G; CRC: Colorectal cancer; UC: Ulcerative colitis; CD: Crohn’s disease; PDA: Pancreatic ductal adenocarcinoma; BC: Biliary cancer; AC: Ampullary cancer; HD: Healthy blood donors; PBMC: Peripheral blood mononuclear cells; IHC: Immunohistochemistry; LPS: Lipopolysaccharide; CEA: Carcinoembryonic antigen; IL: Interleukin; ELISA: Enzyme-linked immunosorbent assay.