TRAIL-induced apoptosis of hepatocellular carcinoma cells is augmented by targeted therapies

AIM:To analyze the effect of chemotherapeutic drugs and specific kinase inhibitors,in combination with the death receptor ligand tumor necrosis factor-related apoptosis inducing ligand(TRAIL),on overcoming TRAIL resistance in hepatocellular carcinoma(HCC)and to study the efficacy of agonistic TRAIL antibodies,as well as the commitment of antiapoptotic BCL-2 proteins, in TRAIL-induced apoptosis. METHODS:Surface expression of TRAIL receptors (TRAIL-R1-4)and expression levels of the antiapoptotic BCL-2 proteins MCL-1 and BCL-xL were analyzed by flow cytometry and Western blotting,respectively. Knock-down of MCL-1 and BCL-xL was performed by transfecting specific small interfering RNAs.HCC cellswere treated with kinase inhibitors and chemotherapeutic drugs.Apoptosis induction and cell viability were analyzed via flow cytometry and 3-(4,5-Dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. RESULTS:TRAIL-R1 and-R2 were profoundly expressed on the HCC cell lines Huh7 and Hep-G2. However,treatment of Huh7 and Hep-G2 with TRAIL and agonistic antibodies only induced minor apoptosis rates.Apoptosis resistance towards TRAIL could be considerably reduced by adding the chemotherapeutic drugs 5-fluorouracil and doxorubicin as well as the kinase inhibitors LY294002[inhibition of phosphoinositol- 3-kinase(PI3K)],AG1478(epidermal growth factor receptor kinase),PD98059(MEK1),rapamycin(mam- malian target of rapamycin)and the multi-kinase inhibitor Sorafenib.Furthermore,the antiapoptotic BCL-2 proteins MCL-1 and BCL-xL play a major role in TRAIL resistance:knock-down by RNA interference increased TRAIL-induced apoptosis of HCC cells.Additionally, knock-down of MCL-1 and BCL-xL led to a significant sensitization of HCC cells towards inhibition of both c-Jun N-terminal kinase and PI3K.CONCLUSION:Our data identify the blockage of survival kinases,combination with chemotherapeutic drugs and targeting of antiapoptotic BCL-2 proteins as promising ways to overcome TRAIL resistance in HCC.

CTRP3和svacm-1在糖尿病视网膜病变患者血清中的表达水平和临床意义

【目的】探讨血清补体C1q肿瘤坏死因子相关蛋白3(complement-C1q/TNF-ralated 3,CTRP3)、可溶性血管细胞黏附因子-1(soluble vascular cell adhesion molecule 1,sVCAM-1)在糖尿病视网膜病变(diabetic retinopathy,DR)患者血清中表达水平及临床意义。【方法】选取2016年4月至2017年4月我院收治的96例DR患者为研究对象,其中增殖型糖尿病视网膜病变者42例,单纯型糖尿病视网膜病变者54例,同期选取45例单纯糖尿病患者为对照,40例体检健康者为正常对照组(NC),比较4组一般资料、血糖、血脂指标,采用酶联免疫吸附试验检测血清CTRP3、sVCAM-1水平,分析血清CTRP3、sVCAM-1水平与糖尿病视网膜病变患者一般资料、血糖、血脂指标之间的相关性。【结果】4组患者体质指数、病程、收缩压、空腹血糖、餐后2 h血糖(2 hours postprandial plasma glucose,2hPG)、糖化血红蛋白(glycosylated hemoglobin,HbA1c)、总胆固醇、三酰甘油(triglyceride,TG)、低密度脂蛋白胆固醇(low density lipoprotein cholesterol,LDL-C)、胰岛素抵抗指数(homeostasis model assessment for insulin resistance index,HOMA-IR)比较,差异有统计学意义(P<0.05);DR组血清CTRP3水平明显低于NC组,且随着DR病情加重,血清CTRP3水平呈逐级降低趋势,两两比较差异有统计学意义(P<0.05);DR组血清sVCAM-1水平明显高于NC组,且随着DR病情加重,血清sVCAM-1水平呈逐级升高趋势(P<0.05);Pearson相关性分析结果显示,DR患者血清CTRP3水平与HbA1c、TG、LDL-C、HOMA-IR呈明显负相关(r=-0.436、-0.531、-0.540、-0.528,P<0.05),DR患者血清sVCAM-1水平与TG、病程呈明显正相关(r=0.487、0.562,P<0.05)。多因素Logistic回归分析结果显示,病程、收缩压、2hPG、HbA1c及CTRP3、sVCAM-1是DR发生的独立危险因素。【结论】DR患者血清CTRP3水平明显降低,sVCAM-1水平明显升高,与患者血压、血糖、血脂等指标异常密切相关,可能在DR疾病发生及发展过程发挥重要作用,对临床诊断及治疗DR具有一定指导意义。