Delloye-Bourgeois Céline, Brambilla Elisabeth, Coissieux Marie-May, Guenebeaud Céline, Pedeux Rémy, Firlej Virginie, Cabon Florence, Brambilla Christian, Mehlen Patrick, Bernet Agnès
Apoptosis, Cancer and Development Laboratory-Equipe labellisée La Ligue, CNRS UMR5238, Université de Lyon, Centre Léon Bérard, Lyon, France.
J Natl Cancer Inst. 2009 Feb 18;101(4):237-47. doi: 10.1093/jnci/djn491. Epub 2009 Feb 10.
Netrin-1 may promote colorectal and breast tumorigenesis, by inhibiting apoptosis induced by its dependence receptors, deleted in colorectal cancer (DCC) and uncoordinated-5-homolog (UNC5H). The status of netrin-1 and its receptors in non-small cell lung cancer (NSCLC) was unknown.
The levels of netrin-1 and its receptors were analyzed in a panel of 92 NSCLC and 25 human lung cancer cell lines by quantitative reverse transcription-polymerase chain reaction and immunohistochemistry. In lung cancer cell lines that express netrin-1, the expression of netrin-1 was inhibited by using small interfering RNA (siRNA), or interference with netrin-1 was performed by treatment with a decoy recombinant DCC ectodomain protein (DCC-5Fbn). Cell death was monitored with a trypan blue exclusion assay or by measuring caspase-3 activity. The effect of netrin-1 interference on tumor growth was analyzed by DCC-5Fbn intratumoral or netrin-1 siRNA intraperitoneal injection in mice engrafted with lung cancer cell lines. All statistical tests were two-sided.
High levels of netrin-1 were found in 43 of the 92 NSCLC tumor samples (47%). Interference with netrin-1 in human lung cancer cell lines was associated with UNC5H-mediated cell death in vitro (percentage of cell death in untreated and in DCC-5Fbn-treated cells = 8% and 26%, respectively, difference = 18%, 95% confidence interval [CI] = 10% to 26%; P = .049) and with lung tumor growth inhibition and/or regression in xenografted nude mice (12 mice in DCC-5Fbn-treated group and 13 mice in control group). Mean volume of control and DCC-5Fbn-treated tumors on day 46 was 489 and 84 mm(3), respectively (difference = 404 mm(3), 95% CI = 145 to 664 mm(3); P < .001).
Almost half of the NSCLC tissue samples examined expressed high levels of netrin-1. Extracellular targeting of the interaction between netrin-1 and UNC5H may be a promising therapeutic approach for NSCLCs that express netrin-1.
Netrin-1可能通过抑制其依赖性受体（在结直肠癌中缺失的基因（DCC）和不协调-5同源物（UNC5H））诱导的细胞凋亡来促进结直肠癌和乳腺癌的发生。Netrin-1及其受体在非小细胞肺癌（NSCLC）中的状态尚不清楚。
通过定量逆转录-聚合酶链反应和免疫组织化学分析了92例NSCLC肿瘤样本和25个人类肺癌细胞系中的Netrin-1及其受体水平。在表达Netrin-1的肺癌细胞系中，使用小干扰RNA（siRNA）抑制Netrin-1的表达，或用诱饵重组DCC胞外域蛋白（DCC-5Fbn）处理干扰Netrin-1。用台盼蓝排斥试验或通过测量caspase-3活性监测细胞死亡。通过在接种肺癌细胞系的小鼠中瘤内注射DCC-5Fbn或腹腔注射Netrin-1 siRNA来分析Netrin-1干扰对肿瘤生长的影响。所有统计检验均为双侧检验。
在92例NSCLC肿瘤样本中的43例（47%）中发现高水平的Netrin-1。在人肺癌细胞系中干扰Netrin-1与体外UNC5H介导的细胞死亡相关（未处理细胞和DCC-5Fbn处理细胞的细胞死亡百分比分别为8%和26%，差异为18%，95%置信区间[CI]=10%至26%；P=0.049），并且与异种移植裸鼠中的肺肿瘤生长抑制和/或消退相关（DCC-5Fbn处理组12只小鼠，对照组13只小鼠）。在第46天，对照组和DCC-5Fbn处理组肿瘤的平均体积分别为489和84mm³（差异=404mm³，95%CI=145至664mm³；P<0.001）。
几乎一半的NSCLC组织样本表达高水平的Netrin-1。对Netrin-1和UNC5H之间相互作用进行细胞外靶向可能是治疗表达Netrin-1的NSCLC的一种有前景的治疗方法。
