Infrequent mutations of the PPP2R1A and PPP2R1B genes in patients with ovarian cancer.

Protein phosphatase 2, regulatory subunit A, α (PPP2R1A) and β (PPP2R1B) are paralogous subunits of the heterotrimeric protein phosphatase 2 (PP2A) holoenzyme that catalyzes the dephosphorylation of target substrate proteins. Subtype‑specific PPP2R1A mutations have been frequently observed in ovarian and endometrial cancer. Mutations in the paralogous genes were frequently observed in human malignancies. Thus, the present study aimed to analyze the mutation frequencies of the paralogous PPP2R1A and PPP2R1B genes in patients with primary and secondary ovarian cancer. A total of 251 patients with primary (n=234) and secondary (n=17) ovarian cancer were analyzed for the presence of PPP2R1A and PPP2R1B mutations by direct sequencing. For PPP2R1A, a heterozygous, somatic mutation (c.771G>T, p.W257C) was identified in 1 out of 37 patients (2.7%) with primary ovarian endometrioid carcinoma. The mutant sample was that of a 46‑year‑old female, who was also diagnosed with ectopic endometriosis in the benign ovary. No PPP2R1A mutations were detected in the remaining 250 patients with ovarian cancer. For PPP2R1B, no mutations were detected in our samples. The results of this study suggested that PPP2R1A mutations are less common in Chinese patients with ovarian cancer when compared with European and American patients. Furthermore, our study also supported previous observations that PPP2R1B mutations were absent in ovarian cancer, suggesting that PPP2R1B mutations are not actively involved in the pathogenesis of ovarian cancer.