Serine/
threonine protein phosphatase 2A (PP2A) is a
protein that has a wide range of biological functions. As
prostate cancer progresses from
hormone-sensitive
prostate cancer to
castration-resistant
prostate cancer (CRPC), the expression level of PP2A has been found to decrease. The present study aimed to determine the roles that PP2A may play in
prostate cancer and its association with the downstream
factor, X-linked inhibitor of apoptosis (XIAP). First, the
mRNA and
protein expression levels of PP2A in LNCaP, DU145 and PC-3
prostate cancer cell lines were measured. Next, the population of PP2A heterodimers was increased using a PP2A agonist, DT061, in the DU145 and PC-3 cell lines. PP2A expression was then knocked down in the LNCaP cell line. Western blot analysis was performed to determine the association between PP2A, phosphorylated (p)-eukaryotic
initiation factor 4B (
eIF4B) and XIAP. The results revealed that following the increase in PP2A expression, the DU145 and PC-3 cell lines were more sensitive to
docetaxel according to Cell Counting Kit-8 assays and had an increased apoptotic rate as assessed by flow cytometry. Conversely, following the transfection of small interfering (si)PP2A into the LNCaP cell line, the sensitivity to
docetaxel decreased, as well as the apoptotic rate. In addition, following treatment with the PP2A agonist, DT061, PP2A expression was found to be significantly upregulated, while p-eIF4B and
XIAP protein expression levels were significantly downregulated. By contrast, following the transfection of siPP2A into the LNCaP cell line, PP2A
protein expression levels were found to be downregulated, while p-eIF4B and XIAP expression levels were significantly upregulated. In conclusion, by affecting the downstream factor XIAP, PP2A may play a key role in promoting apoptosis and facilitating
docetaxel sensitivity in
prostate cancer cell lines.