Expression and clinical significance of Rap1GAP in glioma tissues

JI Shiyu; JIANG Guoliang; QI Pingjian; CHEN Yang; SHEN Fengbiao

doi:10.3969/j.issn.1009-0460.2018.12.003

Abstract：Objective To investigate the expression of Rap1 GTPase activating protein (Rap1GAP) in glioma tissues and its relationship with clinicopathological features and prognosis.Methods From January 2011 to December 2016, 79 cases of glioma tissues and 33 cases of normal brain tissues surgical resected and confirmed by pathology were collected.Real-time fluorescence quantitative PCR (QPCR) was used to detect the mRNA level of Rap1GAP in the above tissues.The expression and distribution of Rap1GAP mRNA in different clinicopathological features of glioma (age, sex, pathological type, degree of differentiation, pathological grade, peritumoral edema and depth of invasion) were analyzed.The relationship between Rap1GAP mRNA level and prognosis was analyzed according to follow-up data.Results The mRNA level of Rap1GAP in glioma tissues was 0.172±0.019, lower than 1.068±0.069 in normal brain tissues (P＜0.05). The level and distribution of Rap1GAP mRNA were not correlated with age, sex, peritumoral edema and depth of invasion, but related with pathological type, differentiation degree and pathological grade (P＜0.05). The levels and highexpression rates of Rap1GAP mRNA were lower in glioblastoma, poorly differentiated and gradeⅢ/Ⅳglioma[0.104±0.006 and27.0％ (10/37), 0.099±0.006 and 16.1％ (5/31) and 0.127±0.007 and 39.3％ (22/56) ], respectively.The median overall survival (OS) was 14.5 months in the low-expression group, which was lower than 21.4 months in the high-expression group (P＜0.05). As for glioblastoma, poorly differentiated and gradeⅢ/Ⅳglioma tissues, the median OS was 8.8, 11.2 and 11.5 months in the lowexpression group, lower than 18.2, 19.8 and 19.8 months in the high-expression group (P＜0.05). Conclusion The low expression of Rap1GAP is involved in the occurrence and development of brain glioma, and the poor prognosis of Rap1GAP expression suggests that Rap1GAP may play a role similar to tumor suppressor gene and may be used as a candidate gene for the treatment of brain gliomas.