Palbociclib Induces Apoptosis and Modulates Toll-Like Receptor Expression in Lung Adenocarcinoma and Epithelial Cells

The study investigated, the effects of the CDK4/6 inhibitor Palbociclib (PLB) on A549 and Beas-2B cell lines were evaluated. The molecular effects of PLB on cell cycle regulation, apoptosis, and innate immune response were comprehensively investigated. To this end, the mRNA expression levels of CDK4, CDK6, Bax, Bcl-2, Caspase-3, and TLR1-10 genes were analyzed using qRT-PCR, while western blot analysis was used to assess the levels of RB and pRB proteins. In PLB treated groups, a significant decrease in CDK4, CDK6, and Bcl-2 levels was observed, along with an increase in Bax and Caspase-3 expression. Protein analysis revealed a reduction in pRB levels and an increase in RB protein expression. Furthermore, PLB treatment led to a significant upregulation of TLR1-10 gene expression in both cell lines. These findings suggest evidence that PLB not only induces G1 phase arrest and promotes apoptosis but also modulates TLR mediated immune responses. In conclusion, PLB exhibits multifunctional antitumor activities and may represent a promising candidate for immunotherapeutic strategies.