Diagnosis of Lung Cancer by SHOX2 Gene Methylation Assay

Abstract

Lung cancer is the most prevalent cancer in the world. Few effective and cheap methods are available so far for early detection and screening of lung cancer. Although histological and cytological examinations are gold standards in lung cancer diagnosis, patients are always at late stages when diagnosis is confirmed. Therefore, new diagnostic methods are needed urgently to increase the early diagnostic rate, enhance the confirmed diagnostic rate, and reduce mortality. The SHOX2 gene methylation assay has become a promising option for the above purposes. It has been shown to enhance the confirmed diagnostic rate of lung cancer in several clinical trials when combined with histological or cytological assays, and has the potential to become an early diagnostic tool. This article reviews the outcome of clinical trials using the SHOX2 gene methylation assay alone or in combination with other examinations, and suggests its future applications and research directions.

An Internal Control for Evaluating Bisulfite Conversion in the Analysis of Short Stature Homeobox 2 Methylation in Lung Cancer

“…This study aimed at designing an IC system for bisulfite-based methylation qPCR assay in order to simultaneously and quantitatively monitor the DNA recovery and bisulfite conversion efficiencies, 2 parameters that are crucial for the accurate quantification of methylated targets. The IC designed here was validated in the context of quantifying the methylation status of SHOX2, known as a valuable biomarker in lung cancer detection (Darwiche et al, 2013;Song et al, 2015). The whole method was then validated on samples from patients with lung cancer and non-cancerous pulmonary diseases.…”

“…Four single-stranded synthetic oligonucleotides were designed, each containing CF sequence derived from the CFF (GRCh37:Chr13,19555120 -19555208) (Holmes et al, 2014), and CpG-containing sequence (named MP-SHOX2) of the SHOX2 promoter (GRCh38:Chr3,158103550 -158103675) (Song et al, 2015). All the cytosines (C) were converted to thymines (T) in two oligonucleotides (named ConIC-Oligos) but not converted in two others (named UnIC-Oligos).…”

“…In the present study, we constructed an internal control (IC) harboring both cytosine-free (CF) and CpG cytosine sequences; the former was derived from CFF while the latter was derived from the SHOX2 gene promoter whose methylation status has been described as a valuable biomarker for lung cancer detection (Darwiche et al, 2013;Song et al, 2015). The IC was mixed with genomic DNA extracted from formalin-fixed, paraffinembedded (FFPE) samples from patients with lung cancer or with non-cancerous pulmonary diseases.…”

P16INK4a gene promoter methylation as a biomarker for the diagnosis of non‐small cell lung cancer: An updated meta‐analysis

“…Promoter methylation of tumor suppressor genes is common in body fluid and can be used as a lung cancer diagnosis method or biomarker. Several studies have evaluated its clinical application with acceptable diagnostic performance and high specificity …”

Diagnostic value of SHOX2 DNA methylation in lung cancer: a meta-analysis

“… 22 – 24 It has been found that the SHOX2 gene includes two large CpG islands, one at the 5′ end, covering a region of approximately 1 kb, the other at the 3′ end, covering approximately 0.5 kb. 25 Studies have revealed that the methylation level of the SHOX2 gene CpG islands was significantly increased in tissues and cells of lung cancer compared with that from normal tissues and cells. 10 – 14 , 17 – 19 Growing evidence suggests that SHOX2 DNA methylation is a promising auxiliary diagnostic biomarker for lung cancer, but with considerable controversial results.…”