Tabarestani Sanaz, Ghaderian Sayyed Mohammad Hossein, Rezvani Hamid
Cancer Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran E-mail :
Asian Pac J Cancer Prev. 2015;16(17):7997-8002. doi: 10.7314/apjcp.2015.16.17.7997.
Gene amplification is an important mechanism in the development and progression of cancer. Currently, gene amplification status is generally determined by in situ hybridization (ISH). Multiplex ligation-dependent probe amplification (MLPA) is a PCR-based method that allows copy number detection of up to 50 nucleic acid sequences in one reaction. The aim of the present study was to compare results for HER2, CCND1, MYC and ESR1 gene amplification detected by MLPA with fluorescent in situ hybridization (FISH) and chromogenic in situ hybridization (CISH) as clinically approved methods. Tissue samples of 170 invasive breast cancers were collected. All were ER positive. Tissue samples had previously been tested for HER2 using immunohistochemistry. Amplification of the selected genes were assessed using MLPA, FISH and CISH and results were compared. HER2 MLPA and ISH results were also compared with HER2 immunohistochemistry (IHC) which detects protein overexpression. Amplification of HER2, CCND1, MYC and ESR1 by MLPA were found in 9%, 19%, 20% and 2% of samples, respectively. Amplification of HER2, CCND1, MYC and ESR1 by FISH was noted in 7%, 16%, 16% and 1% of samples, respectively. A high level of concordance was found between MLPA/ FISH (HER2: 88%, CCND1: 88%, MYC: 86%, ESR1: 92%) and MLPA/ CISH (HER2: 84%). Of all IHC 3+ cases, 91% were amplified by MLPA. In IHC 2+ group, 31% were MLPA amplified. In IHC 1+ group, 2% were MLPA amplified. None of the IHC 0 cases were amplified by MLPA. Our results indicate that there is a good correlation between MLPA, IHC and ISH results. Therefore, MLPA can serve as an alternative to ISH for detection of gene amplification.
基因扩增是癌症发生和发展过程中的一种重要机制。目前，基因扩增状态通常通过原位杂交（ISH）来确定。多重连接依赖探针扩增（MLPA）是一种基于PCR的方法，能够在一次反应中检测多达50个核酸序列的拷贝数。本研究的目的是将MLPA检测HER2、CCND1、MYC和ESR1基因扩增的结果与荧光原位杂交（FISH）和显色原位杂交（CISH）这两种临床认可的方法进行比较。收集了170例浸润性乳腺癌的组织样本。所有样本均为雌激素受体（ER）阳性。这些组织样本之前已使用免疫组织化学方法检测过HER2。使用MLPA、FISH和CISH对所选基因的扩增情况进行评估，并比较结果。还将HER2的MLPA和ISH结果与检测蛋白过表达的HER2免疫组织化学（IHC）结果进行了比较。MLPA检测发现，样本中HER2、CCND1、MYC和ESR1的扩增率分别为9%、19%、20%和2%。FISH检测发现，样本中HER2、CCND1、MYC和ESR1的扩增率分别为7%、16%、16%和1%。发现MLPA/FISH（HER2：88%，CCND1：88%，MYC：86%，ESR1：92%）和MLPA/CISH（HER2：84%）之间具有高度一致性。在所有IHC 3+病例中，91%通过MLPA检测为扩增阳性。在IHC 2+组中，31%通过MLPA检测为扩增阳性。在IHC 1+组中，2%通过MLPA检测为扩增阳性。IHC 0病例中无一例通过MLPA检测为扩增阳性。我们的结果表明，MLPA、IHC和ISH结果之间具有良好的相关性。因此，MLPA可作为ISH检测基因扩增的替代方法。
