The present study aimed at investigating the underlying molecular mechanisms for patients following cytokine-induced killer (CIK) therapy, particularly involving the alterations in p53-associated signaling pathways, to elucidate whether CIK therapy serves a function in cancer treatment. Samples of blood were collected from patients with breast cancer prior to and following CIK therapy. Two group samples were used for RNA sequencing (RNA-Seq) to determine the alterations in gene expression levels following CIK therapy and one for the quantitative polymerase chain reaction (qPCR), to analyze the reliability of RNA-Seq results. The genes that may encode proteins associated with p53 pathways were selected and analyzed. The expression levels of 8 genes were analyzed, including tumor suppressor protein 53 (TP53), murine double minute homolog 2 (MDM2), ribosomal protein L11 (RPL11), ribosomal protein S23 (RPS23), sirtuin 1, histone deacetylase 1, tuberous sclerosis complex 1 (TSC1) and mechanistic target of rapamycin (mTOR), and alterations in expression levels following CIK therapy were determined. However, only RPL11 and RPS23 were identified to exhibit marked alterations in expression levels (FDR <0.05), which was considered to be due to individual distinctions. qPCR analysis revealed that the expression levels of the RPL11, TP53 and TSC1 genes were downregulated, and those of the RPS23 and MDM2 genes were upregulated following CIK therapy. Only MDM2 exhibited a marked alteration in the gene expression level following CIK therapy. Alterations in the expression levels of TP53, RPL11 and TSC1 were associated with those of MDM2, RPS23 and mTOR, respectively.