Abstract
Background: Human epidermal growth factor receptor 2(HER2) is one of the driver mutations of lung cancer. This is a rare somatic mutation, 12-bp duplicated insertion is observed the most frequently. It has been reported that anti-HER2 drugs are effective for mutant cases, suggesting the importance of HER2 mutation analysis. Sanger method is not appropriate to detect very low frequency of genetic mutation due to low sensitivity. In contrast, next generation sequencer (NGS) has much higher sensitivity. However, it needs highly specialized equipment, experts and a lot of time to analyze data. We have developed a novel assay using Eprobe-mediated PCR (Eprobe-PCR). This probe is a hybridization-dependent fluorescent oligonucleotide. We evaluated feasibility of Eprobe-PCR for HER2 mutation detection by comparing with Sanger and NGS data.
Methods: We applied genomic DNA from 405 frozen samples of ADC to real-time PCR and melting curve analysis with Eprobe for identification of the 12-bp duplicated insertion. The PCR products were analyzed by Sanger capillary sequencing and HiSeq2500 NGS. From NGS data, we calculated mutation ratio in each specimen.
Results: Eprobe-PCR detected the mutation in 2.47%(10/405), Sanger in 1.98%(8/405), NGS in 3.46%(14/405). According to the NGS results, Eprobe-PCR was able to detect it in the samples that mutation ratio is not less than 1%. There were no false positive results. This method has adequate-sensitivity for determination of HER2-insertion mutation within 2 hours from preparation of reaction mix.
Conclusions: Eprobe-PCR is simple, rapid and highly sensitive. This can lead to be more appropriate molecular targeted therapy for HER2 mutation in lung cancer.
- Copyright ©ERS 2015