Recent Articles

: Immune checkpoint inhibitors (ICIs) have changed therapeutic paradigms for patients across multiple cancer types and play an important role. However, due to the complexity and individual differences in immunotherapy, not all patients benefit from immunotherapy. New insights into the role of tumor mutational burden (TMB) suggest that their composition, as well as their functionality, might serve as a biomarker to enable optimal patient selection for current systemic therapies and upcoming treatment options. In this paper, we will review TMB as a biomarker for immunotherapy, assess the efficacy of immunotherapy, present several combinations of biomarkers to improve treatment prediction, and further evaluate the limitations of TMB as a biomarker of immunotherapy for lung cancer. Full article

: Methods: The expression of COL21A1 in different types of tumors and human tissues was analyzed using Gene Expression Profile Interaction Analysis (GEPIA) and the Tumor Immune Assessment Resource website (Timer). The expression of COL21A1 in colon cancer was analyzed based on the Tumor Genome Atlas database (TCGA). The gene co-expression with COL21A1 in colon cancer was analyzed with LinkedOmics database. Gene ontology (GO) and KEGG pathway analyses were performed to explore the functions of COL21A1-related genes. The tumor immune evaluation resource website (TIMER) and TISIDB data were used to investigate the correlation between COL21A1 expression and immune infiltration. Results: COL21A1 expression in colon cancer tissues was significantly lower than that in paracancerous normal tissues. Among the genes co-expressed with COL21A1, the probability of being a low-risk marker for colon cancer was high among the top 50 positively associated genes. GO analysis showed that COL21A1 was mainly involved in the organization of extracellular structures, extracellular regulation of signal transduction, and cyclic nucleotide metabolism. KEGG pathway analysis showed that COL21A1 was significantly associated with the extracellular matrix-receptor interaction pathway and the protein digestion and absorption pathway. The expression level of COL21A1 was positively correlated with the infiltration of such immune cells as mast cells, macrophages, dendritic cells, neutrophils and regulatory T cells. In addition, COL21A1 was positively correlated with the expression of tumor-suppressive immunoregulatory molecules such as TGFB1, CCL11, CX3CR1, CXCL14, CCL14, CCR4 and CD28, and was negatively correlated with the expression of oncogenic immunoregulatory molecules such as CCL5 and CCL15. Conclusion: The expression of COL21A1 was significantly down-regulated in colon cancer tissues. Its down-regulation was correlated with immune cell infiltration and immunomodulatory molecule contents in colon cancer tissues. An in-depth investigation on COL21A1 may be beneficial for the immunotherapy of colon cancer. Full article