Expression of c-myc, Bmi-1, serum insulin-like growth factor-I and insulin-like growth factor binding protein-3 and their significances in diffuse large B-cell lymphoma

Abstract

Objective To detect the expressions of c-myc, Bmi-1 , serum insulin-like growth factor-Ⅰ (IGF-Ⅰ) and insulin-like growth factor binding protein-3 (IGFBP-3) in diffuse large B-cell lymphoma (DLBCL), and to analyze their relations with clinical stages, efficacy and prognosis. Methods 102 cases of incipient patients with DLBCL and 60 patients or health examination volunteers were chosen as DLBCL group and control group, respectively. Immunohistochemical method was used to detect expressions of c-myc and Bmi-1 in DLBCL wax samples. Chemiluminescence immunoassay method was used to determine the levels of serum IGF-I and serum IGFBP-3. The expression differences of these factors between DLBCL group and control group and their relations with pathological types, clinical stage, IPI and chemotherapy were analyzed. Results The positive rates of c-myc and Bmi-1 were 71.6 % (73/102) and 61.8 % (64/102) in the tissues of DLBCL, respectively. The positive rates of c-myc and Bmi-1 in non-GCB group were higher than those in GCB group [c-myc: 80.0 % (48/60) vs 59.5 % (25/42); Bmi-1: 71.7 % (43/60) vs 50.0 % (21/42)]. With the increase of IPI score, the expressions of c-myc and Bmi-1 were enhanced, but there were no statistical differences between Ⅲ-Ⅳ group andⅠ-Ⅱ group (P> 0.01). The differences of 3-year progression free survival (PFS) rate and 3-year overall survival (OS) rate between c-myc gene or Bmi-1 gene normal and abnormal had statistical significance, and 3-year PFS rate and 3-year OS rate of double-hit of c-myc gene and Bmi-1 were lower. C-myc gene and Bmi-1 gene aberrant were the independent prognosis factors. The levels of serum IGF-Ⅰ and serum IGFBP-3 in DLBCL group were significantly lower than those in the control group (P 0.01). Their levels in stage Ⅳ group or high risk group were significantly lower than those in other groups. Serum IGF-Ⅰ level and serum IGFBP-3 level had no significant differences between the c-myc gene or Bmi-1 gene abnormal group and normal group (P> 0.01), but their levels were lower in both c-myc gene and Bmi-1 gene abnormal group than those in normal group. Conclusions C-myc and Bmi-1 are related with the biological characteristics and prognosis of DLBCL. Serum IGF-Ⅰ level and serum IGFBP-3 level reflect clinical stages of DLBCL and the efficacy in a certain degree. The expressions of c-myc and Bmi-1 have some correlation with the levels of serum IGF-Ⅰ and IGFBP-3 in DLBCL. Key words: Lymphoma, large B-cell, diffuse; C-myc; Bmi-1; Serum insulin-like growth factor-Ⅰ; Serum insulin-like growth factor binding protein-3