However, the interaction of programmed cell death 1 (PD-1) and PD-L1-mediated T-cell inhibition is involved in immune evasion in a wide range of solid tumors, including HCC.
Besides oncolytic viruses, vaccines, or immune cell infusions, first results from early-phase clinical trials particularly encourage the use of immune checkpoint inhibitors against PD-1/PD-L1 and CTLA-4 for HCC.
In this study, we investigated the mechanisms by which the chemotherapeutic agent paclitaxel (PTX) induced the expression of B7-H1 immunosuppressive molecules in the human colorectal adenocarcinoma cell line SW480 and the hepatocellular carcinoma cell line HepG2.
We further demonstrated that OPN facilitates chemotactic migration, and alternative activation of macrophages, and promotes the PD-L1 expression in HCC via activation of the CSF1-CSF1R pathway in macrophages.
To better characterise PD-L1 expression in hepatocellular carcinoma (HCC), we analysed its expression patterns in 453 HCC patients by double staining for CD68 and PD-L1 using the Tyramide Signal Amplification Systems combined with immunohistochemistry.
Hence, our observation confirmed that miR-570 works as proliferation and metastatic suppressor in hepatocellular carcinoma cells through directly targeting B7-H1 in hepatocellular carcinoma cell and rationally presents that miR-570 has the potential to be a useful clinical noninvasive diagnostics or predictive marker in human hepatocellular carcinoma.
We found approximately 25% of HCCs to have markers of an inflammatory response, with high expression levels of the CD274 molecule (programmed death-ligand 1) and programmed cell death 1, markers of cytolytic activity, and fewer chromosomal aberrations.
High circulating PD-L1 (HR 0.12, 95%CI 0.16-0.86, p = 0.011) and high circulating Galectin-9 (HR 0.11, 95%CI 0.15-0.85, p = 0.010) levels were both associated with improved HCC-specific survival.
Results of combination treatment with the anti-PD-L1 antibody durvalumab and the anti-CTLA-4 antibody tremelimumab in HCC were presented at the 2017 annual meeting of the ASCO (American Society of Clinical Oncology).
The correlation between paired serum sPD-L1 levels and tumor PD-L1 expression (in resected tissue homogenates) was assessed in a separate group of 20 patients with HBV-related HCC.
Besides, celecoxib treatment increased the infiltration of cytotoxic T lymphocytes (CTLs) and reduced the number of regulatory T cells (Tregs), tumor-associated macrophages (TAMs), and the expression of immune checkpoint PD-L1 in HCC tissues during epirubicin therapy.
Our results suggest that the expression of B7-H1 in hepatocarcimona cells can be initiated by HBx antigen, thus inducing T cell apoptosis and finally potentially facilitates the genesis of HCC.
Furthermore, we performed an extensive immunomonitoring of patients with HCC treated with sorafenib or programmed death (PD)-1/PD-L1 pathway blockade using multiparametric flow cytometry.
High programmed death ligand 1 expression and high frequency of cell cycle regulatory gene alterations were found in the LCC-Null group offering alternative options of targeted therapy.
Additionally, the disruption of PD-1 could protect the GPC3-CAR T cells from exhaustion when combating with native PD-L1-expressing HCC, as the levels of Akt phosphorylation and anti-apoptotic protein Bcl-xL expression in PD-1 deficient GPC3-CAR T cells were significantly higher than those in wild-type GPC3-CAR T cells after coculturing with PLC/PRF/5.
The expression of PD-L1 is associated with the survival time of patients with hepatocellular carcinoma, and the median survival time of patients with high expression of PD-L1 is ten months.