Overexpression and Role of HHLA2, a Novel Immune Checkpoint, in Colorectal Cancer

Abstract

The study aimed to investigate correlations between HHLA2 levels and parameters, including microsatellite instability (MSI) status, CD8+ cells, and histopathological features: budding, tumor-infiltrating lymphocytes (TILs), TNM scale, grading, cytokines, chemokines, and cell signaling moleculesin colorectal cancer (CRC). Furthermore, the immune infiltration landscape and HHLA2-related pathways in colorectal cancer using available online datasets were analyzed. The study included 167 patients diagnosed with CRC. Expression of HHLA2 was detected by immunohistochemistry method (IHC) and enzyme-linked immunosorbent assay (ELISA). The IHC was used to evaluate the MSI and CD8+ status. The budding and TILs were measured using a light microscope. The concentrations of cytokines, chemokines, and cell signaling molecules were measured to analyze the data by the Bio-Plex Pro Human cytokine screening panel, 48 cytokine assay, and principal component analysis (PCA). Geneset enrichment analysis (GSEA) was conducted to identify HHLA2-related pathways. The biological function of HHLA2 was predicted by Gene Ontology (GO). Analysis of the immune infiltration landscape of HHLA2 in colorectal cancer was made by the web-based tool Camoip. High HHLA2 expression was detected in CRC tumor tissues compared to the adjacent noncancerous tissues. The percentage of HHLA2-positive tumors was 97%. GSEA and GO showed that HHLA2 upregulation correlated with cancer-related pathways and several biological functions. Tumor-infiltrating lymphocytes score correlated positively with IHC HHLA2 expression level percentage. There was a negative correlation between HHLA2, anti-tumor cytokines and pro-tumor growth factors. This study provides a valuable insight into the role of HHLA2 in CRC. We reveal the role of HHLA2 expression as well as a stimulatory and inhibitory immune checkpoint in colorectal cancer. Further research may verify the therapeutic values of the HHLA2-KIR3DL3/TMIGD2 pathway in colorectal cancer.

HHLA2 deficiency inhibits pancreatic cancer progression and THP-1 macrophage M2 polarization via EGFR/MAPK/ERK and mTOR/AKT pathway

“…HHLA2 overexpression has been reported to be associated with an increased risk of carcinogenesis. For example, results of a previous study suggested that HHLA2 is up-regulated in gallbladder cancer, and increased expression of HHLA2 may indicate poor prognosis [ 25 ]; moreover, the destiny of CD8 + TILs was also significantly reduced with increased expression of HHLA2 [ 26 ]. In the case of PC, the high expression level of HHLA2 not only reveals the occurrence, development, metastasis, prognosis and immune escape mechanism, but may also suggest that HHLA2 can be used as a potential target for immunotherapy of PC patients [ 27 , 28 ].…”

B7H3 Role in Reshaping Immunosuppressive Landscape in MSI and MSS Colorectal Cancer Tumours

“…The tumours showing nuclear staining for at least 1% of invasive tumour cells were classified as having positive marker staining. The interpretation of immuno-histochemistry testing followed the criteria established by Olave and Graham [ 22 ] and described in our previous articles [ 20 , 23 ]. The MSI status was confirmed if any of the following marker patterns were observed: loss of MLH1 and PMS2, loss of PMS2 alone, loss of MSH2 and MSH6, or loss of MSH6 alone.…”

“…The antigen-antibody complexes were then subjected to staining with 3,3′-diaminobenzidine, which led to their visualization. Lastly, the tissue sections were counterstained with hematoxylin, dehydrated, and covered with coverslips for subsequent analysis, as described in the previous publications [ 20 , 23 ].…”

Advances in Precision Medicine Approaches for Colorectal Cancer: From Molecular Profiling to Targeted Therapies

“…Tumors with high CTLA-4 expression may indicate immune escape mechanisms and a more aggressive phenotype. Clinical trials are exploring the potential benefits of targeting CTLA-4 with immune checkpoint inhibitors to improve treatment outcomes in colorectal cancer patients. , …”

“…Clinical trials are exploring the potential benefits of targeting CTLA-4 with immune checkpoint inhibitors to improve treatment outcomes in colorectal cancer patients. 131,132 The assessment of immune checkpoint markers as prognostic biomarkers also extends to tumor-infiltrating lymphocytes (TILs), which play a crucial role in antitumor immunity. The presence of a higher number of activated cytotoxic T cells among TILs in colorectal tumors is generally associated with a more favorable prognosis, suggesting that an effective immune response is mounted against the cancer.…”