弥漫性大B 细胞淋巴瘤组织中miR-448 和KDM2B 的水平表达及临床意义

目的 探讨微小核糖核酸（micro RNA，miR）-448 和赖氨酸特异性脱甲基酶2Blysine(K)-specific demethylase2B，KDM2B] 在弥漫性大B 细胞淋巴瘤（diffuse large B-cell lymphoma，DLBCL）组织中的表达及临床意义。方法 选择2017 年7 月～ 2018 年3 月在达州市中心医院收治的97 例DLBCL 患者作为观察对象，选取同期50 例淋巴结反应性增生 (reactive lymph node hyperplasia，RHL) 组织患者作为对照组，采用实时荧光定量PCR(quantitative real-time PCR,qRT-PCR) 法检测DLBCL 组织与RHL 组织中miR-448 和KDM2B mRNA 表达水平，免疫组织化学染色法检测KDM2B蛋白表达水平，分析miR-448 和KDM2B 表达水平与DLBCL 患者临床病理特征的关系，Pearson 分析miR-448 和KDM2B 表达水平的相关性，Kaplan-Meier 生存分析miR-448 和KDM2B 表达与DLBCL 患者生存率的关系以及COX回归模型分析影响DLBCL 患者预后的影响因素。结果 DLBCL 组织中miR-448 表达水平为0.65±0.08，显著低于对照组的1.04±0.19，差异有统计学意义（t=17.473，P ＜ 0.001）；DLBCL 组织中KDM2B mRNA 表达水平为2.89±0.54，显著高于对照组的0.98±0.21，差异有统计学意义（t=24.058，P ＜ 0.001）；免疫组织化学染色结果显示，与对照组比较，DLBCL 组织中KDM2B 蛋白阳性表达率（72.16% vs 22.00%）显著升高，差异有统计学意义（χ2=33.561，P ＜ 0.001）；miR-448 和KDM2B 表达与Ann Arbor 分期、IPI 评分、Hans 分型有关（χ2=4.227 ～ 12.960，均P ＜ 0.05）；与年龄、性别、LDH 水平、ECOG 评分和有无B 症状无关（χ2=0.072 ～ 3.726，均P ＞ 0.05）；相关性分析显示，miR-448 和KDM2B表达水平呈负相关（r=-0.602，P ＜ 0.001）；Kaplan-Meier 生存分析显示，miR-448 高表达组DLBCL 患者三年累积生存率显著高于miR-448 低表达组患者（55.53% vs 31.38%），差异有统计学意义（χ2=7.434，P=0.006）。KDM2B 阳性表达组DLBCL 患者三年累积生存率显著低于阴性表达组患者（31.73% vs 56.67%），差异有统计学意义（χ2=8.877，P=0.006）；COX多因素分析结果显示，Ann Arbor 分期（95%CI=1.567 ～ 4.012，P=0.005），miR-448（95%CI=2.213 ～ 4.478，P=0.001），KDM2B（95%CI=1.506 ～ 4.554，P=0.003）是影响DLBCL 患者不良预后的独立危险因素。结论 在DLBCL 组织中，miR-448 低表达，KDM2B 高表达，且二者表达与DLBCL 病理特征和患者生存有关，可作为DLBCL患者潜在的预后标志物。

Expression Levels and Clinical Significance of miR-448 and KDM2B in Diffuse Large B-cell Lymphoma Tissues

Objective To investigate the expression and clinical significance of microRNA (miR)-448 and lysine(K)-specific demethylase 2B（KDM2B） in diffuse large B-cell lymphoma (DLBCL) tissues. Methods A total of 97 DLBCL patients who were admitted to Dazhou Central Hospital from July 2017 to March 2018 were selected as the observation object, and 50 patients with reactive hyperplasia of lymph node (RHL) during the same period were selected as the control group.The expression levels of miR-448 and KDM2B mRNA in DLBCL tissues and RHL were detected by quantitative real-time PCR(qRT-PCR), the expression level of KDM2B protein was detected by immunohistochemical staining method, the relationship between the expression levels of miR-448, KDM2B and clinicopathological characteristics in DLBCL patients was analyzed, the relationship between the expression of miR-448, the correlation between the expression levels of miR-448 and KDM2B was detected by Pearson analysis. KDM2B and the survival rate of DLBCL patients was detected by Kaplan-Meier survival analysis ,and COX regression model was used to analyse the influencing factors of prognosis in patients with DLBCL. Results The expression level of miR-448 in DLBCL tissue was 0.65±0.08, which was significantly lower than 1.04±0.19 in the control group, and the difference was statistically significant (t=17.473, P ＜ 0.001). The expression level of KDM2B mRNA in DLBCL tissue was 2.89±0.54, which was significantly higher than 0.98±0.21 of the control group, the difference was statistically significant (t=24.058, P ＜ 0.001).The results of immunohistochemical staining showed that compared with the control group, the positive expression rate of KDM2B protein in DLBCL（72.16% vs 22.00%）tissue was significantly increased, the difference was statistically significant(χ2=33.561, P ＜ 0.001). The expression of miR-448 and KDM2B was related to Ann Arbor staging,IPI score and Hans classification (χ2=4.227 ～ 12.960, all P ＜ 0.05). But not related to age, gender, LDH level, ECOG score, and the presence or absence of B symptom （χ2=0.072 ～ 3.726，all P ＞ 0.05）. Correlation analysis showed that the expression levels of miR-448 and KDM2B were negatively correlated (r=-0.602, P ＜ 0.001). Kaplan-Meier survival analysis showed that the 3-year cumulative survival rate of DLBCL patients in the miR-448 high expression group was significantly higher than that in the miR-448 low expression group (55.53% vs 31.38%),the difference was statistically significant(χ2=7.434, P=0.006). The 3-year cumulative survival rate of DLBCL patients in the KDM2B positive expression group was significantly lower than that in the negative expression group (31.73% vs 56.67%), the difference was statistically significant(χ2=8.877, P=0.006). COX multivariate analysis showed that Ann Arbor staging(95%CI=1.567 ～ 4.012, P=0.005), miR-448(95%CI=2.213 ～ 4.478, P=0.001) and KDM2B (95%CI=1.506 ～ 4.554, P=0.003) were independent risk factors affecting the poor prognosis of DLBCL patients. Conclusion In DLBCL tissues, miR-448 was lowly expressed and KDM2B was highly expressed, and their expressions were related to the pathological characteristics of DLBCL and patient survival, and may serve as potential prognostic markers for DLBCL patients.