Circulating Methylated XAF1 DNA Indicates Poor Prognosis for Gastric Cancer.

BACKGROUND: Methylated DNA in fluids may be a suitable biomarker for cancer patients. XAF1 has been shown to be frequently down-regulated in human gastric cancer (GC). Here, we investigated if XAF1 methylation in GC could be a useful biomarker. METHODS: Real-time RT-PCR was used to detect XAF1 mRNA expression; immunohistochemistry and western blot were used to examine XAF1 protein expression in GC tissues (n = 202) and their corresponding para-cancerous histological normal tissues (PCHNTs). Real-time methylation specific-PCR was used to investigate XAF1 promoter methylation in the same panel of GC tissues, their PCHNTs and sera. RESULTS: We confirmed frequent XAF1 down-regulation in both mRNA and protein levels in GC tissues as compared to normal controls and PCHNTs. XAF1 hypermethylation was evidenced in 83.2% (168/202) of GC tissues and 27.2% (55/202) of PCHNTs, while no methylation was detected in the 88 normal controls. The methylation level in GC tissues was significantly higher than that in PCHNTs (p<0.05). The hypermethylation of XAF1 significantly correlated with the down-regulation of XAF1 in GC tissues in both mRNA and protein levels (p<0.001 each). Moreover, we detected high frequency of XAF1 methylation (69.8%, 141 out of 202) in the sera DNAs from the same patients, while the sera DNAs from 88 non-tumor controls were negative for XAF1 methylation. The XAF1 methylation in both GC tissues and in the sera could be a good biomarker for diagnosis of GC (AUC = 0.85 for tissue and AUC = 0.91 for sera) and significantly correlated with poorer prognosis (p<0.001). In addition, after-surgery negative-to-positive transition of XAF1 methylation in sera strongly associated with tumor recurrence. CONCLUSIONS: 1) Dysfunction of XAF1 is frequent and is regulated through XAF1 promoter hypermethylation; 2) Detection of circulating methylated XAF1 DNAs in the serum may be a useful biomarker in diagnosis, evaluating patient's outcome (prognosis and recurrence) for GC patients.

Enhanced RegIV expression predicts the intrinsic 5-fluorouracil (5-FU) resistance in advanced gastric cancer.

AIM: RegIV, a member of the Regenerating (REG) gene family, may be a marker for the prediction of resistance to 5-fluorouracil (5-FU)-based chemotherapy. However, the relationship between the intrinsic drug resistance of gastric cancer (GC) cells to 5-FU used alone (single FU) or in multidrug therapeutic regimens (5-FU combinations) and RegIV expression has not been investigated. METHODS: The patient cohort comprised 45 patients with primary GC. The chemoresistance of GC cells to therapeutic regimens consisting of single 5-FU or FU combinations was investigated using the ATP-tumor chemosensitivity assay. The level of RegIV mRNA transcripts was determined by real-time reverse transcriptase-PCR. RegIV expression was evaluated as a novel predictive biomarker for the intrinsic drug resistance of primary GC cells to single 5-FU or 5-FU combinations. RESULTS: Upregulation of RegIV mRNA transcripts was observed in 36 of the 45 tumor specimens and was positively correlated with the invasive depth of the tumor cells (p = 0.000), the clinical stages (p = 0.000) and the in vitro intrinsic drug resistance of primary GC cells to 5-FU (p = 0.000) or 5-FU combinations. CONCLUSION: RegIV mRNA transcript level was strongly associated with the intrinsic resistance of GC cells to single 5-FU or 5-FU combinations, suggesting that RegIV may play an important role in the intrinsic resistance of GC cells to 5-FU and that targeted therapy against the RegIV gene could be applied to overcome 5-FU resistance in the treatment of GC.

Stepwise cumulation of RUNX3 methylation mediated by Helicobacter pylori infection contributes to gastric carcinoma progression.

BACKGROUND: Helicobacter pylori has been recognized as a definite carcinogen for gastric cancer (GC); however, the pathogenesis of H. pylori infection remains unclear. Runt-related transcription factor 3 (RUNX3) is a candidate tumor suppressor gene whose deficiency is causally related to GC. However, in H. pylori infection-associated GC, the role of RUNX3 has not been studied. METHODS: The authors used real-time methylation-specific polymerase chain reaction analysis to determine methylation status of the RUNX3 promoter in a spectrum of gastric lesions, including 220 samples of chronic atrophic gastritis, 196 samples of intestinal metaplasia, 134 samples of gastric adenoma, 102 samples of dysplasia, and 202 samples of GC with paired noncancerous mucosa tissues and corresponding blood specimens. The association of abnormal methylation with precancerous gastric lesions was evaluated along with the association between RUNX3 methylation and H. pylori infection, and the concordance of methylation levels was investigated between serum and tissues. RESULTS: The results indicated that increasing RUNX3 promoter methylation was correlated with distinct stages of GC progression. GC tissues had the highest methylation proportion (75.2%) compared with precancerous gastric lesions, including chronic atrophic gastritis (15.9%), intestinal metaplasia (36.7%), gastric adenoma (41.8%), and dysplasia (54.9%). H. pylori infection, a major risk factor for GC, contributed to the inactivation of RUNX3 in gastric epithelial cells through promoter hypermethylation. The levels of RUNX3 methylation in serum were in significant concordance with the methylation levels observed in GC tissues (P = .887). CONCLUSIONS: The current findings supported RUNX3 methylation as a risk factors for the carcinogenesis of chronic atrophic gastritis with H. pylori infection and indicated that circulating RUNX3 methylation is a valuable biomarker for the detection of early GC.

[Clinicopathologic and prognostic significance of serum levels of cytokines in patients with advanced serous ovarian cancer prior to surgery].

OBJECTIVE: To study the clinicopathologic and prognostic significance of serum levels of six cytokines (IFN-γ, TNF-α, IL-10, IL-5, IL-4, IL-2) in patients with advanced serous ovarian cancer prior to surgery. METHODS: The serum levels of six cytokines were detected in 51 patients with advanced serous ovarian cancer and 46 healthy controls, using cytometric bead arrays. RESULTS: The serum levels of IFN-γ (20.68±11.45), IL-2 (4.54±1.18), IL-4 (5.66±2.25), IL-5 (2.72±0.86) µg/L and IL-10 (5.93±7.92) µg/L were higher (P<0.01, P<0.05) and the serum level of TNF-α (7.53±8.47) was lower (P<0.01) in patients with advanced serous ovarian cancer than those in the healthy controls. The IFN-γ/IL-4 ratio (3.93±2.34) of the patients was lower than that of the controls (P<0.01). Kaplan-Meier analysis revealed that patient's age (P=0.016), menopausal status (P=0.001) and serum IL-10 level (P=0.010) correlated significantly with patient's survival. Cox regression analysis showed that serum IL-2 (P=0.045) and IL-10 levels (P=0.007) were the independent prognostic factors. CONCLUSIONS: Patients with advanced serous ovarian cancer have Th1/Th2 imbalance and immune function disturbance. The age of patients and menopausal status are important prognostic factors. IL-2 and IL-10 level are also independent predictors of survival.

[Study of the metastasis-associated genes and its copy numbers variation in highly metastatic epithelial ovarian cancer].

OBJECTIVE: To investigate the relationship of the metastasis-associated genes and its copy numbers variation in the highly metastatic human epithelial ovarian cancer cell line HO-8910PM. METHODS: The differentially expressed genes and its copy number variation between HO-8910PM cell line and normal ovarian tissues was detected by human genome U133A 2.0 gene chip and human mapping 10K array 2.0 gene chip, and the data was analyzed by bioinformatics. Some of metastasis-associated genes were validated the results of single nucleotide polymorphism (SNP) and cDNA chips by fluorescence in situ hybridization (FISH) and real-time quantitative PCR. RESULTS: Integrate analysis of two gene chips data showed that there were 385 differentially expressed genes in the same and 379 SNP positional point (6 of them, included 2 genes) between HO-8910PM cell line and normal ovarian tissues, these copy number amplification of 379 SNP positional point of chromosome were > or = 3, which had 240, deletion < or = 1 had 139. Chromosome location analysis showed that there were 385 differentially expressed genes located at all chromosomes, and 261 of them (67.8%, 261/385) located at 10 chromosomes, included that 34 (8.8%), 33 (8.6%), 28 (7.3%), 27 (7.0%), 25 (6.5%), 24 (6.2%) of them located at chromosome 3, 2, 9, 10, 1 and 11 respectively, and 23 (6.0%) of them at chromosome 6 and 12 each, 22 (5.7%) of them at chromosome 4 and 5 each. For the function of differentially expressed genes, the results showed that 99 (25.7%) genes belonged to the family of enzymes and their regulators, 54 (14.0%) genes associated with signal transduction, 50 (13.0%) genes associated with nucleic acid binding, and 36 (9.4%) genes associated with protein binding. CONCLUSION: We have demonstrated that there are 4 kinds of differentially expressed genes related to metastasis of ovarian cancer, which belonged to the families enzyme and its regulator, nucleic acid binding, signal transduction and protein binding, and located at chromosome 1, 2, 3, 4, 5, 6, 9, 10, 11 and 12.