血清白细胞介素34与肝癌肝移植临床预后的关系及其作用机制

Association of serum interleukin 34 with clinical prognosis in liver cancer transplant recipients and its mechanism of action

背景和目的:肝移植在肝癌的治疗中发挥了越来越重要的作用。目前移植术后肿瘤复发与转移的临床问题尚未解决。本研究旨在分析白细胞介素34(IL-34)表达与肝癌肝移植受者预后、肿瘤复发与转移的关系,并探讨其在肝癌生长和转移中的作用机制。方法:采用酶联免疫吸附试验(ELISA)法检测93例肝癌肝移植受者术前血清中IL-34表达情况,用统计学方法分析IL-34表达与临床病理特征和预后的关系;用受试者工作特征(ROC)曲线分析IL-34检测肿瘤复发和转移的诊断价值。取雄性5~6周龄NOD/SCID小鼠建立人源性肝癌原位移植瘤模型,并随机分为4组,分别腹腔注射不同浓度的IL-34(5、10、35μg/kg)(干预组)及等量生理盐水(对照组),1次/d,共2周。比较10周后各组小鼠总体生存率、移植瘤体积与质量、肺组织转移情况;用Western blot检测各组移植瘤中细胞增殖相关蛋白(Ki-67与PCNA)、肿瘤转移相关蛋白(MMP-2与MMP-9)、上皮-间充质转化(EMT)相关蛋白(E-cadherin、vimentin和snail)的表达。结果:经5年随访,93例肝癌肝移植受者中肿瘤复发27例、转移9例、死亡45例。肿瘤复发和转移患者中IL-34表达水平明显低于肿瘤未复发和未转移患者(均P<0.05);IL-34低表达与肿瘤复发、转移、血管侵犯呈负相关(均P<0.05);IL-34低表达患者5年总体生存率和无瘤生存率明显低于IL-34高表达患者(均P<0.05)。IL-34低表达、肿瘤复发与转移是影响总体生存率的独立危险因素(均P<0.05)。血清IL-34检测肿瘤复发与转移曲线下面积(AUC)分别为0.93与0.79,优于甲胎蛋白(AFP)。与对照组比较,3个IL-34干预组小鼠总体生存率增加,移植瘤体积与重量减少,肺组织转移率和转移灶数量降低,移植瘤中Ki-67、PCNA、MMP-2、MMP-9、vimentin、snail蛋白表达水平降低而E-cadherin表达水平增加,且均呈浓度依赖性(均P<0.05)。结论:血清IL-34低表达与肝癌肝移植受者不良预后、肿瘤复发与转移密切相关。IL-34具有对抗肝癌生长与转移的作用,机制可能与抑制细胞增殖和EMT有关。

Background and Aims:Liver transplantation has become increasingly crucial in treating liver cancer.However,the clinical issue of tumor recurrence and metastasis after transplantation remains unresolved.This study aimed to analyze the relationship between interleukin 34(IL-34)expression and the prognosis,tumor recurrence,and metastasis in liver cancer transplant recipients.It also aimed to explore its role in the growth and metastasis of liver cancer.Methods:The expression of preoperative serum IL-34 of 93 liver cancer transplant recipients was detected using the ELISA method.Statistical methods were used to analyze the relationship between IL-34 expression and clinicopathologic characteristics and prognosis.The diagnostic value of IL-34 in detecting tumor recurrence and metastasis was analyzed using the receiver operating characteristic(ROC)curve.Human hepatocellular carcinoma orthotopic xenograft models were established in male 5-6-week-old NOD/SCID mice,which were randomly divided into four groups and intraperitoneally injected with different concentrations of IL-34(5,10,35μg/kg)or an equal amount of saline(control group)once daily for a total of two weeks.After ten weeks,the overall survival rate,tumor volume and mass,and lung tissue metastasis of the mice in each group were compared.Western blot was used to detect the expression of cell proliferation-related proteins(Ki-67 and PCNA),tumor metastasis-related proteins(MMP-2 and MMP-9),and epithelial-mesenchymal transition(EMT)-related proteins(Ecadherin,vimentin,and snail)in the transplanted tumors of each group.Results:After a 5-year follow-up,among the 93 liver cancer transplant recipients,27 cases experienced tumor recurrence,9 cases experienced metastasis,and 45 cases died.The expression levels of IL-34 in patients with tumor recurrence or metastasis were significantly lower than those without tumor recurrence or metastasis(both P<0.05).Low expression of IL-34 was negatively correlated with tumor recurrence,metastasis,and vascular invasion(all P<0.05).The 5-year overall survival rate and tumorfree survival rate of patients with low IL-34 expression were significantly lower than those with high IL-34 expression(both P<0.05).Low expression of IL-34 and tumor recurrence and metastasis were independent risk factors for overall survival(all P<0.05).The area under the curve(AUC)for serum IL-34 in detecting tumor recurrence and metastasis was 0.93 and 0.79,respectively,superior to AFP.Compared with the control group,the overall survival rate of mice in the three IL-34 intervention groups increased,tumor volume and weight decreased,lung tissue metastasis rate and number of metastatic lesions decreased,and the expression levels of Ki-67,PCNA,MMP-2,MMP-9,vimentin,and snail proteins in the transplanted tumors decreased.In contrast,the expression level of E-cadherin increased,all of which showed a concentration-dependent relationship(all P<0.05).Conclusion:Low expression of serum IL-34 is closely associated with adverse prognosis,tumor recurrence,and metastasis in liver cancer transplant recipients.IL-34 inhibits the growth and metastasis of liver cancer,possibly through the inhibition of cell proliferation and EMT.