A novel prognostic signature of chemokines for survival and immune infiltration in kidney renal clear cell carcinoma

Identification of tumor-antigen signatures and immune subtypes for messenger RNA vaccine selection in advanced clear cell renal cell carcinoma

BACKGROUND

Advanced clear cell renal cell carcinoma still lacks reliable diagnostic and prognostic biomarkers. Recently, tumor vaccines targeting specific molecules have been proposed as a promising treatment in mitigating tumor progression, which was rekindled under the background of the COVID-19 pandemic. However, the application of messenger RNA vaccine against advanced clear cell renal cell carcinoma antigens remains stagnant, and no subgroup of patients deemed suitable for vaccination has been extensively studied or validated. Our study aims to explore novel advanced clear cell renal cell carcinoma antigen signatures to select suitable patients for vaccination.

METHODS

Gene expression profiles of advanced clear cell renal cell carcinoma samples and their corresponding clinical data were retrieved from The Cancer Genome Atlas. The least absolute shrinkage and selection operator model was applied to develop signatures to stratify patients with advanced clear cell renal cell carcinoma. Receiver operating characteristic analysis was used to compare the prognostic accuracy of each factor. Tumor Immune Estimation Resource was used to visualize the relationship between the proportion of antigen-presenting cells and the expression of filtered genes. The "CIBERSORT" and "WGCNA" R Packages were employed to ascertain disparities in immune infiltration levels between advanced clear cell renal cell carcinoma subgroups. The Search Tools for the Retrieval of Interacting Genes database and Cytoscape were used to construct the protein-protein interaction network. CCK-8 and colony formation assays were included in the invitro experiment.

RESULTS

In total, 244 potential tumor antigens were identified. Using the least absolute shrinkage and selection operator Cox regression, 21 tumor antigens were selected for developing a risk evaluation signature. The risk score signature can be a useful tool to predict the outcome of advanced clear cell renal cell carcinoma patients. According to the differential clinical, molecular, and immune-related genes, we divided advanced clear cell renal cell carcinoma patients into the immune "cold" subtype and immune "hot" subtype. By developing a logistic score, the immune subtype signature can better distinguish a patient more likely to be immune "cold" subtype or immune "hot" subtype. Interestingly, patients with high risk scores had a higher proportion of immune "hot" subtype than those with a low risk score. Furthermore, the prognostic value was significantly improved when combining risk score and immune subtype. Distinct immune landscapes and signal pathways were observed between different tumor subtypes. Finally, novel tumor antigens related to oxidative stress were identified.

CONCLUSION

The tumor-antigens-based risk score and immune subtype signatures identified potentially effective neo-antigens for advanced clear cell renal cell carcinoma messenger RNA vaccine development, and patients with low risk scores and immune "cold" subtype tumors are more prone to benefit from messenger RNA vaccination. Furthermore, our study highlights the significant role of oxidative stress in determining the efficacy of the messenger RNA vaccine.

CXCL10 Expression in Human Colorectal Cancer Tissue and its Correlation With Serum Levels of CXCL10

BACKGROUND/AIM

CXCL10, a member of the CXC chemokine family, plays a crucial role in immune response by facilitating the chemotaxis of CXCR3-positive immune cells. We examined the expression of CXCL10 to unravel its functional significance in colorectal cancer.

MATERIALS AND METHODS

Bioinformatics analysis was performed to investigate CXCL10 expression and its clinicopathological relevance. Subsequently, we examined the correlation between the serum levels of CXCL10 and its expression within cancer tissues.

RESULTS

Analysis of the TCGA database revealed that elevated CXCL10 expression in CRC tissues correlates with improved long-term survival and is inversely associated with lymph node infiltration and metastasis. Insights from Gene Ontology and Kyoto Encyclopedia of Genes and Genomes further established a connection between increased CXCL10 and co-regulated gene expression with enhanced immune activation and regulation, mediated by the inhibition of the NOD-like receptor signaling pathway. Single-cell analysis pinpointed myeloid cells and macrophages as the primary sources of CXCL10. Immunohistochemical assessments revealed that a subset of cancer cells and macrophages are positive for CXCL10 expression. CXCL10-positive cells are predominantly located at the invasive front of the tumor. Intriguingly, our findings reveal an inverse correlation between serum CXCL10 levels and its expression in cancer tissues.

CONCLUSION

The expression of CXCL10 may play a role in mediating the inflammatory responses at the invasive front in colorectal cancer and is observed to be inversely correlated with serum CXCL10 levels. It is pivotal to elucidate the distinct roles of CXCL10 in colorectal cancer, particularly different functions of cancer-tissue CXCL10 from serum CXCL10.