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Objective To investigate the methylation status of PCDH8 gene in pancreatic carcinoma.Methods Methylation of PCDH8 gene in 2 samples of normal pancreatic tissues and 6 pancreatic carcinoma cell lines (PANC1, ASPC1, BxPC3, CFPAC, PaTu8988 and SW1990) was detected by the methylationspecific PCR (MSP) method. The expression of PCDH8 mRNA was detected with 5-Aza-2-deoxycytidine (5-Aza-dC) treatment, a kind of DNA methyltransferase (DNMT) inhibitor in 6 pancreatic carcinoma cell lines by real-time-PCR. Results The methylation of PCDH8 gene was not detected in normal tissues, while it was partially methylated in PANC1, BxPC3, CFPAC and it was totally methylated in PaTu8988, ASPC1, SW1990.PCDH8 mRNA was expressed in PANC1, SW1990, PaTu8988 and the relative quantities of mRNA expression (RQ) were 1.576 ± 0.648, 0.013 ± 0.008, 0.002 ± 0.001; PCDH8 mRNA was not expressed in BxPC3,CFPAC, ASPC1. After 5-Aza-dC treatment, PCDH8 mRNA was expressed in PANC1, ASPC1, BxPC3,CFPAC, PaTu8988, SW1990 and the relative quantities of mRNA expression all significantly increased, and they were 7. 463 ± 2.628, 10. 696 ± 1.539, 7.852 ± 2.762,421.815 ± 1.493, 118.595 ± 4.089, 6.690 ±1.884. Conclusions The methylation of PCDH8 gene may be the major mechanism of down-regulated expression of PCDH8 gene in pancreatic carcinoma.
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Objective To investigate the RADIL mRNA expression in pancreatic carcinoma and to evaluate its clinical significance.Methods Fluoesecent quantitative PCR (FQ-PCR) was used to detect the RADIL mRNA expression in 40 patients with pancreatic carcinoma and adjacent tissue and in 5 healthy adult with normal pancreatic tissue and to observe its relationship with clinicopathologic parameters.Results RADIL mRNA was expressed in pancreatic carcinoma and adjacent tissue, as well as normal pancreatic tissue, and the relative expression was 2.263 ± 3.826, 5.425 ± 8.858 and 8.559 ± 4.214, respectively.There was statistically significant difference among the three groups (P ＜0.05 ).RADIL mRNA expression was closely related with the metastasis and differentiation grade ( r = -0.312 and -0.294, P ＜ 0.05 ), however, it was not significantly related to tumor site, tumor size, CA19-9, TNM staging, sex and age.Conclusions RADIL gene may have an inhibitory effect on the pancreatic cancer.
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Objective To investigate the diagnostic value of measurement of SARP2 methylation in peripheral blood for detection of pancreatic cancer in human. Methods Peripheral vein blood of 12 patients with primary pancreatic cancers, 10 patients with chronic pancreatitis and 6 health volunteers were collected. Serum free DNA were extracted from blood samples, and were modified with bisulfate, and SARP2 gene extron 1 were amplified through BSP and sequencing of the production. Results There were 12 patients (83 %) with pancreatic cancer and 10 patients (40%) with chronic pancreatitis had obvious methylation in SARP2 gene in peripheral blood. The rate of CpG methylation in SARP2 gene extron 1 of pancreatic cancer, chronic pancreatitis and health volunteers was 16. 8% , 10. 4% and 2. 2% respectively. There was statistically significant difference among the three groups (P<0.01 or P< 0.05). Conclusions Aberrant methylation of SARP2 gene could be detected in peripheral blood in patients with pancreatic cancer, the detection of SARP2 gene methylation may have potential clinical implication for diagnosis of pancreatic cancer.
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Objective To analyze the differential expression of proteins among patients with pancreatic cancer,chronic pancreatitis and choledocholithiasis in order to find potential biomarkers for diagnosis of pancreatic cancer and to differentiate pancreatic cancer from chronic pancreatitis. Methods The pancreatic juice were connected from 5 pancreatic cancer patients,6 chronic pancreatitis patients and 3 choledocholi-thiasis patients by naso-pancreatic drainage using endoscopic retrograde cholanglopancreatography(ERCP).The proteins in pooled pancreatic juice were separated by two-dimensional gel electrophoresis (2-DE).The differential expression of proteins were analyzed by image analysis software and identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF-MS).Results ①There were 35-200 ml of pancreatic juice collected,and protein concentration were ranged from 0.8 to 4.6 μg/μl.The 2-DE showed that the protein spots in pancreatic cancer,chronic pancreatitis and choledocholithiasis juice were 196±12,209±15 and 199±10,respectively.The matched proteins among three groups all exceeded 75%.②MALDI-TOF-MS revealed that the expression of chain A of a covalent dimer of transthyretin in pancreatic cancer was up-regulated(＞2-fold)while the expressions of chain A of crystal structure of lipid-free human apolipoproteinA-1,chain of human lithostathin and regenerating islet-derived 1 beta precursor were down-regulated. Conclusions Protein spectra are different in patients with pancreatic cancer,chronic pancreatitis and choledocholithiasis.Transthyretin,apolipoproteinA-1,human lithostathin and regenerating islet-derived 1 beta might be the biomarkers of human pancreatic cancer and may be useful in distinguishing pancreatic cancer from chronic panceatitis.
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Objective To assess the methylation patterns in CpG islands of SPARC genes and its relationship with clinicopathological parameters. Methods Bisulfite treatment of genomie DNA and sequencing analysis was used to study methylation patterns in the CpG islands of SPARC genes in fresh tissues from 6 cases of chronic pancreatitis, 6 normal pancreatic tissues, 17 pancreatic adenocarcinoma and the cancer adjacent tissues, as well as 6 normaI blood samples for normal control, and compared the results with clinicopathological parameters. Results WBC DNA showed no methylation of SPARC gene CpG islands. The methylation rates in CpG islands of SPARC genes in pancreatic adenocarcinoma, the cancer adjacent tissues, chronic pancreatitis and normal pancreatic groups (2, 3, 4, 5, 6, 7 CpG sites) were 61.6%, 47.1%, 37.5%, 24.7%, respectively. The methylation rates in CpG islands (1, 8, 9, 10, 11, 12 sites) were 52.0%, 28.7%, 16.7% and 0. The difference were statistically significant between the pancreatic adenocarcinoma and chronic pancreatitis as well as normal pancreas groups (P＜0.001), and the difference were not statistically significant between the pancreatic adenocarcinoma and the cancer adjacent tissues. CpG hypermethylation were not related to risk factors such as smoking, alcohol, history of CP, the tumor size, differentiation and TNM staging, lymph node metastasis. Conclusions CpG in SPARC gene extron 1 was hypermethylated in pancreatic cancer, and this may be an early event in the development of pancreatic cancer.