Currently, the search for new promising tools of immunotherapy continues. In this regard, microRNAs (miRNAs) that influence immune checkpoint (IC) gene expression in tumor and T-cells and may be important regulators of immune cells are considered. MiRNAs regulate gene expression by blocking mRNA translation. An important feature of miRNA is its ability to affect the expression of several genes simultaneously, which corresponds to the trend toward the use of combination therapy. The article provides a list of miRNAs acting simultaneously on several ICs and miRNAs that, in addition to IC, can regulate the expression of targeted therapy genes. There is dependence of miRNA interactions with IC genes on the type of cancer. The analysis of the accumulated data demonstrates that only about 14% (95% CI: 9.8–20.1%) of the studied miRNAs regulate the expression of specific IC in more than one type of cancer. That is, there is tumor specificity in the miRNA action on ICs. A number of miRNAs demonstrated high efficiency in vitro and in vivo. This indicates the potential of miRNAs as promising agents for cancer immunotherapy. Additional studies of the miRNA–gene interaction features and the search for an optimal miRNA mimic structure are necessary.

To increase the effectiveness of anticancer therapy based on immune checkpoint (IC) inhibition, some ICs are being investigated in addition to those used in clinic. We reviewed data on the relationship between PD-L1, B7-H3, B7-H4, IDO1, Galectin-3 and -9, CEACAM1, CD155, Siglec-15 and ADAM17 expression with cancer development in complex with the results of clinical trials on their inhibition. Increased expression of the most studied ICs—PD-L1, B7-H3, and B7-H4—is associated with poor survival; their inhibition is clinically significant. Expression of IDO1, CD155, and ADAM17 is also associated with poor survival, including gastric cancer (GC). The available data indicate that CD155 and ADAM17 are promising targets for immune therapy. However, the clinical trials of anti-IDO1 antibodies have been unsatisfactory. Expression of Galectin-3 and -9, CEACAM1 and Siglec-15 demonstrates a contradictory relationship with patient survival. The lack of satisfactory results of these IC inhibitor clinical trials additionally indicates the complex nature of their functioning. In conclusion, in many cases it is important to analyze the expression of other participants of the immune response besides target IC. The PD-L1, B7-H3, B7-H4, IDO1 and ADAM17 may be considered as candidates for prognosis markers for GC patient survival.

The receptor for advanced glycation end products (RAGE/AGER) is an important mediator of inflammatory signaling and has been implicated in chronic low-grade inflammation associated with aging. Chronic low-grade inflammation (“inflammaging”) is a characteristic feature of biological aging, providing a rationale for investigating molecular regulators of inflammatory signaling such as RAGE. This study aimed to develop and validate short hairpin RNA (shRNA) constructs suppressing AGER/RAGE in human cell models. Five shRNA constructs targeting human AGER were designed, cloned into pLSL-puro, and verified by Sanger sequencing. Lentiviral vectors were produced in HEK293T cells and used to establish stable HEK293T, 786-O, and human umbilical vein endothelial cell (HUVEC) populations with AGER knockdown. AGER/RAGE expression was assessed by RT-qPCR, Western blotting, and flow cytometry. Silencing efficiency varied with the construct and the cellular model. sh1 produced the strongest suppression of AGER, exceeding 70% in selected models, whereas sh2 was effective in HEK293T and 786-O cells. Reduced RAGE expression was confirmed at the mRNA, protein, and cell-surface levels, identifying sh1 and sh2 as lead candidates. An AGER-focused workflow for lentiviral shRNA construct screening and experimental validation was established, providing a reproducible approach for generating stable cell models with reduced AGER/RAGE expression. Further work is required to confirm isoform specificity, assess off-target effects, and define the functional consequences of RAGE suppression.