PDL1 and KRAS: Immune system evasion and genetic aberrations in cancers

Cancer is a leading global health concern, representing a significant burden on healthcare systems due to its high morbidity and mortality rates. The World Health Organization reports that cancer is the second leading cause of death worldwide, with millions of deaths attributed to this disease annually. The rising incidence of cancer cases necessitates ongoing research and the development of innovative treatment strategies to improve patient outcomes. Among the promising advancements in cancer therapy is immunotherapy, which aims to enhance the ability of immune system to recognize and combat cancer cells. Immune checkpoint inhibitors, such as those targeting the PD-1/PD-L1 pathway, have gained attention for their potential to reactivate T cells and bolster anti-tumor responses. This review focuses on the mechanisms regulating PD-L1 expression and the role of KRAS mutations in tumor progression and immune evasion. PD-L1, a protein that interacts with PD-1 on T cells, plays a crucial role in dampening immune responses, allowing tumors to evade detection and destruction by the immune system. The review discusses various factors influencing PD-L1 expression, including transcriptional regulation by key signaling pathways and the impact of inflammatory cytokines within the tumor microenvironment. Additionally, it highlights how genetic alterations, particularly KRAS mutations, can drive PD-L1 overexpression and contribute to tumor aggressiveness. In conclusion, understanding the complex interplay between PD-L1 expression and KRAS mutations is essential for developing targeted immunotherapies and enhancing precision medicine approaches in oncology. By elucidating these mechanisms, researchers can identify new therapeutic targets and improve treatment strategies, ultimately aiming to enhance patient survival rates and quality of life in cancer care. This review underscores the importance of ongoing research in this area to address the challenges posed by cancer's heterogeneity and resistance to existing therapies.