Detection of Promoter DNA Methylation in Urine and Plasma Aids the Detection of Non-Small Cell Lung Cancer.

PURPOSE: Low-dose CT screening can reduce lung cancer-related mortality. However, CT screening has an FDR of nearly 96%. We sought to assess whether urine samples can be a source for DNA methylation-based detection of non-small cell lung cancer (NSCLC). EXPERIMENTAL DESIGN: This nested case-control study of subjects with suspicious nodules on CT imaging obtained plasma and urine samples preoperatively. Cases (n = 74) had pathologic confirmation of NSCLC. Controls (n = 27) had a noncancer diagnosis. We detected promoter methylation in plasma and urine samples using methylation on beads and quantitative methylation-specific real-time PCR for cancer-specific genes (CDO1, TAC1, HOXA7, HOXA9, SOX17, and ZFP42). RESULTS: DNA methylation at cancer-specific loci was detected in both plasma and urine, and was more frequent in patients with cancer compared with controls for all six genes in plasma and in CDO1, TAC1, HOXA9, and SOX17 in urine. Univariate and multivariate logistic regression analysis showed that methylation detection in each one of six genes in plasma and CDO1, TAC1, HOXA9, and SOX17 in urine were significantly associated with the diagnosis of NSCLC, independent of age, race, and smoking pack-years. When methylation was detected for three or more genes in both plasma and urine, the sensitivity and specificity for lung cancer diagnosis were 73% and 92%, respectively. CONCLUSIONS: DNA methylation-based biomarkers in plasma and urine could be useful as an adjunct to CT screening to guide decision-making regarding further invasive procedures in patients with pulmonary nodules.

[The Role of Plasma CDO1 Methylation in the Early Diagnosis of Lung Cancer].

BACKGROUND: The incidence and mortality of lung cancer often rank first in all malignant tumors. DNA methylation, as one of epigenetics, often participates in the development and progression of tumors. CDO1 as a tumor suppressor gene always undergoes methylation changes early in tumor development. Therefore, this study aims to discuss the value of CDO1 methylation in the early diagnosis of lung cancer. METHODS: Peripheral blood samples were collected from tumor patients and healthy people. Detection of the methylation level of CDO1 in plasma by sulfite modification and quantitative real-time PCR. RESULTS: The level of gene methylation in peripheral blood of lung cancer patients was significantly higher than that of benign lung disease patients and healthy people. The methylation level of CDO1 was significantly different in the stratified comparison of gender, lymph node metastasis and tumor-node-metastasis (TNM) stage (P<0.05). The sensitivity and specificity of CDO1 were 52.2% and 78.6%, respectively. The overall accuracy of the diagnosis was significantly higher than that of the clinical tumor markers, and the sensitivity of CDO1 to stage I and II patients was the highest (40.8%, 47.1%). In addition, CDO1 could effectively increase the sensitivity of diagnosis in multiple joint examinations. CONCLUSIONS: Detecting the methylation level of CDO1 has a potentially huge advantage for the early diagnosis of lung cancer.

The intervention effect of licorice in d-galactose induced aging rats by regulating the taurine metabolic pathway.

Licorice, an edible and officinal plant material, has attracted considerable attention for its wide range of pharmacological activities. Our previous study showed that licorice can ameliorate cognitive damage and improve oxidative stress and apoptosis in aging rats induced by d-galactose (d-gal). In this study, in order to further explore the changes of the metabolic profile during the aging process and the antiaging mechanism of licorice, the 1H NMR-based metabolomics approach was used to analyze serum and urine samples and identify a potential biomarker in d-gal induced aging rats. The results revealed that the taurine metabolic pathway was significantly correlated with the ageing process in d-gal induced rats. Furthermore, the taurine contents were significantly decreased in both the serum and urine samples of aging rats compared with the controls. At the same time, the levels of cysteine dioxygenase type I (CDO1), cysteine sulfinic acid decarboxylase (CSAD) and glutamate decarboxylase type I (GAD1), which are the key enzymes affecting the synthesis reactions, were decreased in aging rats compared with the controls. After licorice administration, the levels of taurine, CDO1 and CSAD were all significantly increased. These findings firstly demonstrated that the regulation of the taurine metabolic pathway is involved in the anti-aging effect of licorice in d-gal induced aging rats.

Detection of methylated CDO1 in plasma of colorectal cancer; a PCR study.

BACKGROUND: Cysteine biology is important for the chemosensitivity of cancer cells. Our research has focused on the epigenetic silencing of cysteine dioxygenase type 1 (CDO1) in colorectal cancer (CRC). In this study, we describe detection of CDO1 methylation in the plasma of CRC patients using methylation specific PCR (Q-MSP) and extensive analysis of the PCR reaction. METHODS: DNA was extracted from plasma, and analysed for methylation of the CDO1 gene using Q-MSP. The detection rate of CDO1 gene methylation was calculated and compared with that of diluted DNA extracted from "positive control" DLD1 cells. CDO1 gene methylation in the plasma of 40 CRC patients that were clinicopathologically analysed was then determined. RESULTS: (1) The cloned sequence analysis detected 93.3% methylation of the promoter CpG islands of the CDO1 gene of positive control DLD1 cells and 4.7% methylation of the negative control HepG2 CDO1 gene. (2) DLD1 CDO1 DNA could not be detected in this assay if the extracted DNA was diluted ∼1000 fold. The more DNA that was used for the PCR reaction, the more effectively it was amplified in Q-MSP. (3) By increasing the amount of DNA used, methylated CDO1 could be clearly detected in the plasma of 8 (20%) of the CRC patients. However, the percentage of CRC patients detected by methylated CDO1 in plasma was lower than that detected by CEA (35.9%) or CA19-9 (23.1%) in preoperative serum. Combination of CEA/CA19-9 plus plasma methylated CDO1 could increase the rate of detection of curable CRC patients (39.3%) as compared to CEA/CA19-9 (25%). CONCLUSION: We have described detection of CDO1 methylation in the plasma of CRC patients. Although CDO1 methylation was not detected as frequently as conventional tumor markers, analysis of plasma CDO1 methylation in combination with CEA/CA19-9 levels increases the detection rate of curable CRC patients.

Methylated cysteine dioxygenase-1 gene promoter in the serum is a potential biomarker for hepatitis B virus-related hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related mortality worldwide. Epigenetic analysis has attracted increasing attention in the molecular diagnosis of HCC. Cysteine dioxygenase 1 (CDO1) is a key enzyme in the taurine biosynthetic pathway and converts cysteine to cysteine sulfinate. The CDO1 gene is a tumor suppressor gene and is usually silenced by the methylation of its promoter in carcinogenesis. In this study, we evaluated whether the methylation status of CDO1 gene promoter is of diagnostic value for hepatitis B virus (HBV)-related HCC. The CDO1 promoter methylation status was determined in serum samples using methylation-specific polymerase chain reaction (MSP) in a cohort of 123 patients with HBV-related HCC, 28 with liver cirrhosis (LC), 29 with chronic hepatitis B (CHB) and 20 healthy controls. The frequency of the CDO1 promoter methylation in HBV-related HCC (42.3%) was significantly higher than that in LC (14.3%), CHB (6.9%) and healthy controls (0%) (P = 0.006; P < 0.0001; P < 0.0001; respectively). Furthermore, in HCC patients, the frequency of CDO1 promoter methylation was higher in advanced stages (III-IV) (53%) than the early stages (I-II) (20%) (P = 0.001). Evaluation of the CDO1 promoter methylation status in serum, in combination with AFP (> 20 ng/ml), significantly improved the diagnostic value, with sensitivity and specificity of 82.9% and 75.4%, respectively in distinguishing HCC from LC and CHB. In conclusion, methylation status of serum CDO1 gene promoter may be helpful in the diagnosis of HCC and the estimation of the HCC stages.