Hypoxia inducible BHLHB2 is a novel and independent prognostic marker in pancreatic ductal adenocarcinoma
Hypoxia inducible BHLHB2 is a novel and independent prognostic marker in pancreatic ductal adenocarcinoma
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DOI：
10.1016/j.bbrc.2010.09.070
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发表时间：
2010-10-22
影响因子：
3.1
通讯作者：
Kleeff, Joerg
中科院分区：
文献类型：
--
作者：
Wang, Weibin;Reiser-Erkan, Carolin;Kleeff, Joerg
目的：环磷酸腺苷诱导的碱性螺旋-环-螺旋（bHLH）结构域包含B2类转录因子BHLHB 2的差异表达在一些人类恶性肿瘤。方法：采用定量RT-PCR、半定量免疫组化和免疫印迹分析方法，对10例正常胰腺组织、77例胰腺导管腺癌组织和8株胰腺癌细胞系中BHLHB 2的表达进行分析。使用siRNA转染、缺氧、血清饥饿、用吉西他滨和放线菌素-D诱导凋亡以及侵袭测定进行体外功能实验。使用Kaplan-Meier方法进行生存分析。预后因素采用考克斯比例风险model.Results：BHLHB 2 mRNA和蛋白表达强烈诱导缺氧和血清饥饿胰腺癌细胞系。RNAi沉默BHLHB 2对生长和侵袭没有显著影响，但通过减少caspase-3切割增加了对吉西他滨的凋亡抗性。在BHLHB 2沉默的细胞中，吉西他滨的ED 50从13.95 +/- 1.353增加到38.70 +/- 5.262 nM（p < 0.05）。离体，正常胰腺导管和腺泡细胞中的弱/不存在的核染色被PanIN病变和胰腺癌细胞中的中度至强的核/胞质染色所取代。核BHLHB 2染色弱/缺失的患者的中位生存期显著低于染色强的患者（13个月vs. 27个月，p = 0.03）。多变量分析。结论：缺氧诱导的BHLHB 2表达是胰腺癌患者一种新的独立的预后指标，提示对吉西他滨的化疗敏感性增加。(C)2010年爱思唯尔公司All rights reserved.
Aims: The cyclic adenosine monophosphate-inducible basic helix-loop-helix (bHLH) domain containing class-B2 transcriptional factor BHLHB2 is differentially expressed in a number of human malignancies. In the present study, the expression, regulation, functions and prognostic impact of BHLHB2 in pancreatic cancer were investigated.Methods: Expression analyses were carried out in tissues of the normal pancreas (n = 10) and pancreatic ductal adenocarcinoma (n = 77) as well as in eight pancreatic cancer cell lines using quantitative RT-PCR, semiquantitative immunohistochemistry, and immunoblot analyses. In vitro functional experiments were conducted using siRNA transfection, hypoxia, serum starvation, apoptosis induction with gemcitabine and actinomycin-D, and invasion assays. Survival analysis was performed using the Kaplan-Meier method. Prognostic factors were determined in a multivariable analysis using a Cox proportional hazards model.Results: BHLHB2 mRNA and protein expressions were strongly induced by hypoxia and by serum starvation in pancreatic cancer cell lines. BHLHB2 silencing with RNAi had no significant effects on growth and invasion but increased apoptosis resistance against gemcitabine by reducing caspace-3 cleavage. In BHLHB2 silenced cells the ED50 of gemcitabine increased from 13.95 +/- 1.353 to 38.70 +/- 5.262 nM (p < 0.05). Ex vivo, the weak/absent nuclear staining in normal pancreatic ducts and acinar cells was replaced by moderate to strong nuclear/cytoplasmic staining in PanIN lesions and pancreatic cancer cells. Patients with weak/absent nuclear BHLHB2 staining had significantly worse median survival compared to those with strong staining (13 months vs. 27 months, p = 0.03). In a multivariable analysis. BHLHB2 staining was an independent prognostic factor (Hazard-Ratio = 2.348, 95% CI = 1.250-4.411, p = 0.008).Conclusions: Hypoxia-inducible BHLHB2 expression is a novel independent prognostic marker in pancreatic cancer patients and indicates increased chemosensitivity towards gemcitabine. (C) 2010 Elsevier Inc. All rights reserved.