Immunohistochemical expression of RPRM is associated with low expression of proliferation marker Ki67 in patients with breast cancer

Reprimo (RPRM) is a potential p53-dependent tumor suppressor gene, which plays an important role in cell cycle arrest at G(2)/M checkpoint. The aim of this study was to characterize RPRM protein expression in breast cancer tissues and its relation with clinic-pathologic features and proliferation marker protein Ki67. RPRM protein expression was examined by immunohistochemistry in tissue microarray containing 275-breast cancer and 16 normal breast tissues. These cases were classified as negative or positive expression for RPRM expression level with clinic-pathologic variables. The Kaplan-Meier curve was used to estimate survival over time. Positive expression of RPRM was observed in 68.4% (188/275) of tumors and 100% of breast normal tissues (16/16). RPRM expression has a significant relationship with age (P = 0.000). Moreover, positive RPRM expression was significant associated with low expression of proliferation marker protein Ki67; however, survival analysis did not show significant differences. These results suggest that RPRM is not a good prognosis marker but likely had an important role modulating negatively cell proliferation in breast cancer tissues