PHLPP2 expression and its clinical significance in multiple myeloma

PH domain leucine-rich repeat protein phosphatase 2 (PHLPP2) is downregulated in most malignant tumors, and can promote tumor development and progression. However, the clinical significance of PHLPP2 in multiple myeloma (MM) has remained elusive. The aim of the present study was to assess the expression and prognostic significance of PHLPP2 in patients with MM. Reverse transcription-quantitative PCR and immunohistochemistry were performed to detect the expression of PHLPP2 in samples from patients with MM and healthy volunteers. The results demonstrated that the mRNA expression levels of PHLPP2 were decreased in plasma and bone marrow samples from 16 patients with MM compared with those from 16 healthy controls. Furthermore, the protein expression of PHLPP2 was significantly different between the patients with MM and controls (P<0.05). This finding was related to the Revised International Staging System (R-ISS) (P=0.028), regardless of sex or age. Furthermore, the expression of PHLPP2 was decreased in the newly diagnosed group compared with that in the effective-treatment group (P=0.0077). In conclusion, the current study demonstrated that PHLPP2 expression is low in MM and decreases with advancing R-ISS stage, indicating that PHLPP2 may inhibit the progression of MM and low expression may be a marker of poor clinical prognosis.