Rooney Claire, Geh Catherine, Williams Victoria, Heuckmann Johannes M, Menon Roopika, Schneider Petra, Al-Kadhimi Katherine, Dymond Michael, Smith Neil R, Baker Dawn, French Tim, Smith Paul D, Harrington Elizabeth A, Barrett J Carl, Kilgour Elaine
AstraZeneca, Oncology Innovative Medicines, Alderley Park, Macclesfield, United Kingdom.
AstraZeneca, Personalised Healthcare and Biomarkers Innovative Medicines, Alderley Park, Macclesfield and Melbourn, Cambridge, United Kingdom.
PLoS One. 2016 Feb 23;11(2):e0149628. doi: 10.1371/journal.pone.0149628. eCollection 2016.
FGFR1 amplification occurs in ~20% of sqNSCLC and trials with FGFR inhibitors have selected FGFR1 amplified patients by FISH. Lung cancer cell lines were profiled for sensitivity to AZD4547, a potent, selective inhibitor of FGFRs 1-3. Sensitivity to FGFR inhibition was associated with but not wholly predicted by increased FGFR1 gene copy number. Additional biomarker assays evaluating expression of FGFRs and correlation between amplification and expression in clinical tissues are therefore warranted. We validated nanoString for mRNA expression analysis of 194 genes, including FGFRs, from clinical tumour tissue. In a panel of sqNSCLC tumours 14.4% (13/90) were FGFR1 amplified by FISH. Although mean FGFR1 expression was significantly higher in amplified samples, there was significant overlap in the range of expression levels between the amplified and non-amplified cohorts with several non-amplified samples expressing FGFR1 to levels equivalent to amplified samples. Statistical analysis revealed increased expression of FGFR1 neighboring genes on the 8p12 amplicon (BAG4, LSM1 and WHSC1L1) in FGFR1 amplified tumours, suggesting a broad rather than focal amplicon and raises the potential for codependencies. High resolution aCGH analysis of pre-clinical and clinical samples supported the presence of a broad and heterogeneous amplicon around the FGFR1 locus. In conclusion, the range of FGFR1 expression levels in both FGFR1 amplified and non-amplified NSCLC tissues, together with the breadth and intra-patient heterogeneity of the 8p amplicon highlights the need for gene expression analysis of clinical samples to inform the understanding of determinants of response to FGFR inhibitors. In this respect the nanoString platform provides an attractive option for RNA analysis of FFPE clinical samples.
约20%的肺鳞状非小细胞肺癌（sqNSCLC）中存在成纤维细胞生长因子受体1（FGFR1）扩增，针对FGFR抑制剂的试验通过荧光原位杂交（FISH）筛选出FGFR1扩增的患者。对肺癌细胞系进行了对AZD4547（一种强效、选择性的FGFR1-3抑制剂）敏感性的分析。对FGFR抑制的敏感性与FGFR1基因拷贝数增加有关，但并非完全由其预测。因此，有必要进行额外的生物标志物检测，以评估FGFR的表达以及临床组织中扩增与表达之间的相关性。我们验证了nanoString技术可用于对临床肿瘤组织中包括FGFR在内的194个基因进行mRNA表达分析。在一组肺鳞状非小细胞肺癌肿瘤中，14.4%（13/90）通过FISH检测为FGFR1扩增。虽然扩增样本中的FGFR1平均表达明显更高，但扩增和未扩增队列的表达水平范围存在显著重叠，一些未扩增样本的FGFR1表达水平与扩增样本相当。统计分析显示，FGFR1扩增肿瘤中8p12扩增子（BAG4、LSM1和WHSC1L1）上FGFR1邻近基因表达增加，提示扩增子广泛而非局限，这增加了共依赖的可能性。对临床前和临床样本的高分辨率阵列比较基因组杂交（aCGH）分析支持在FGFR1基因座周围存在广泛且异质性的扩增子。总之，FGFR1扩增和未扩增的非小细胞肺癌组织中FGFR1表达水平的范围，以及8p扩增子的广度和患者内异质性，凸显了对临床样本进行基因表达分析以了解FGFR抑制剂反应决定因素的必要性。在这方面，nanoString平台为福尔马林固定石蜡包埋（FFPE）临床样本的RNA分析提供了一个有吸引力的选择。
