Performance Evaluation of SHOX2 and RASSF1A Methylation for the Aid in Diagnosis of Lung Cancer Based on the Analysis of FFPE Specimen.

Juanhong Shi,Xia Fang,Bin She,Xuyou Zhu,Xianghua Yi,Long Zhang,Haoyang Zhang,Suxia Zhang,Lichao Fan,Jun Gu,Hongxiu Han,Yuting Liu,Xue Chen

doi:10.3389/fonc.2020.565780

Juanhong Shi, Xia Fang + Show 11 more

Open Access

https://doi.org/10.3389/fonc.2020.565780

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Abstract

Emerging molecular diagnostic methods are more sensitive and objective, which can overcome the intrinsic failings of morphological diagnosis. Here, a RT-PCR-based in vitro diagnostic test kit (LungMe®) was developed and characterized to simultaneously quantify the DNA methylation of SHOX2 and RASSF1A in FFPE tissue specimens. The clinical manifestations were evaluated in 251 FFPE samples with specificity and sensitivity of 90.4 and 89.8%, respectively. Furthermore, the quantitative analysis shows that the degree of SHOX2 methylation was correlated with the stages of lung cancer, but not in the case of RASSF1A. Our observation indicated that the DNA methylation of SHOX2 and RASSF1A may play different roles in cancer development. Comparison of the methylation levels of SHOX2 and RASSF1A between cancer and cancer-adjacent specimens (n = 30), showed they have “epigenetic field defect”. As additional clinical validation, the hypermethylation of SHOX2 and RASSF1A was detected not only in surgical operative specimens, but also in histopathological negative puncture biopsies. SHOX2 and RASSF1A methylation detection can be used to increase sensitivity and NPV, which provide us with a more accurate method of differential diagnosis and are likely to be rapidly applied in clinical examinations.

Highlights

Lung cancer is the leading cause of cancer-related deaths worldwide [1]
In this study, excluding the possible error of sampling by bronchoscopy, we systematically evaluated the ability of LungMe® to diagnose lung cancer in FFPE tissue samples
Our observation indicated that SHOX2 and RASSF1A may play different roles in the process of cancer development

Summary

Introduction

Lung cancer is the leading cause of cancer-related deaths worldwide [1]. Bronchoscopic techniques, sputum cytology, transthoracic needle biopsies, and surgical biopsy have been widely used in the diagnosis of bronchogenic carcinoma [2]. The conventional morphological diagnosis including cytological and histological examination could be severely affected by the quality of specimen and the diagnostic level of the individual pathologist [3, 4]. Among the most promising biomarkers, DNA methylation alterations have emerged as a helpful adjunct in both the diagnosis and staging of lung cancer [5,6,7]. DNA methylation has played a crucial role in the regulation of gene expression, epigenetic changes, and maintenance of cellular identity, occurring frequently in tumorigenesis [8]. The promoter CpG inland hypermethylation may lead to the transcriptional silencing of tumor suppressor genes, and affect the development of carcinogenesis [9]. Previous studies have demonstrated a wide range of DNA methylation abnormalities in lung cancer [5,6,7]

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