Authors' Affiliation: State Key Laboratory of Molecular Oncology, Cancer Institute and Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China.
Clin Cancer Res. 2013 Nov 1;19(21):5867-78. doi: 10.1158/1078-0432.CCR-12-3753. Epub 2013 Sep 5.
Our aim was to identify frequent genomic aberrations in both esophageal squamous cell carcinoma (ESCC) and esophageal dysplasia and to discover important copy number-driving genes and microRNAs (miRNA) in ESCC.
We conducted array-based comparative genomic hybridization (array CGH) on 59 ESCC resection samples and 16 dysplasia biopsy samples. Expression of genes at 11q13.3 was analyzed by real-time PCR (RT-PCR) and immunohistochemistry (IHC). Integrated analysis was conducted to identify genes or miRNAs with copy number-expression correlations.
Array CGH identified 11 amplifications and eight homozygous deletions in ESCC. Integrated analysis of array CGH data with matched gene expression microarray data showed that 90 overexpressed genes and 24 underexpressed genes were consistent with DNA copy number changes, including 12 copy number-driving miRNAs. In esophageal dysplasia, six gains, four losses, 12 amplifications, and four homozygous deletions were detected. Amplifications of 7p11.2 and 11q13.2-11q13.3 (CCND1) and homozygous deletion at 9p21.3 (CDKN2A) were consistent genomic changes in both dysplasia and carcinoma. ANO1 at 11q13.3 was overexpressed at the mRNA and protein levels in tumors, and higher mRNA expression was correlated with the copy number increase. In particular, ANO1 expression was elevated in moderate dysplasia compared with normal esophageal epithelium. IHC revealed that ANO1 overexpression was positively correlated with lymph node metastasis and advanced clinical stage. Knockdown of ANO1 significantly inhibited the proliferation of KYSE30 and KYSE510 cells.
Copy number aberrations in both esophageal dysplasia and ESCC may be useful as potential biomarkers for early detection. In addition, ANO1 may be a candidate target gene in esophageal tumorigenesis.
本研究旨在鉴定食管鳞癌（ESCC）和食管上皮内瘤变（dysplasia）中常见的基因组异常，并发现 ESCC 中重要的拷贝数驱动基因和 microRNA（miRNA）。
我们对 59 例 ESCC 切除标本和 16 例异型增生活检标本进行了基于阵列的比较基因组杂交（array CGH）分析。通过实时 PCR（RT-PCR）和免疫组织化学（IHC）分析 11q13.3 处基因的表达。通过整合分析鉴定具有拷贝数-表达相关性的基因或 miRNA。
array CGH 在 ESCC 中鉴定出 11 个扩增和 8 个纯合缺失。array CGH 数据与匹配的基因表达微阵列数据的综合分析表明，90 个过表达基因和 24 个低表达基因与 DNA 拷贝数变化一致，包括 12 个拷贝数驱动 miRNA。在食管异型增生中，检测到 6 个增益、4 个缺失、12 个扩增和 4 个纯合缺失。7p11.2 和 11q13.2-11q13.3（CCND1）的扩增和 9p21.3（CDKN2A）的纯合缺失是异型增生和癌中一致的基因组改变。ANO1 在 11q13.3 的 mRNA 和蛋白质水平在肿瘤中均过度表达，较高的 mRNA 表达与拷贝数增加相关。特别是，与正常食管上皮相比，中度异型增生中 ANO1 的表达升高。IHC 显示 ANO1 的过表达与淋巴结转移和临床晚期呈正相关。ANO1 的敲低显著抑制了 KYSE30 和 KYSE510 细胞的增殖。
食管异型增生和 ESCC 中的拷贝数异常可能作为早期检测的潜在生物标志物有用。此外，ANO1 可能是食管肿瘤发生的候选靶基因。
