Development of minimally invasive biomarker assays for early detection and effective clinical management of pancreatic cancer is urgently needed to reduce high morbidity and mortality associated with this malignancy. We hypothesized that if aberrantly expressing microRNAs (miRNA) in pancreatic adenocarcinoma tissues are detected in blood plasma, then plasma profiling of these miRNAs might serve as a minimally invasive early detection biomarker assay for this malignancy. By using a modified protocol to isolate and quantify plasma miRNAs from heparin-treated blood, we show that miRNA profiling in plasma can differentiate pancreatic adenocarcinoma patients from healthy controls. We have profiled four miRNAs, miR-21, miR-210, miR-155, and miR-196a, all implicated in the development of pancreatic cancer with either proven or predicted target genes involved in critical cancerassociated cellular pathways. Of these, miR-155 has recently been identified as a candidate biomarker of early pancreatic neoplasia, whereas elevated expression of miR196a has been shown to parallel progression of disease. The results revealed a sensitivity of 64% and a specificity of 89% with the analyses of plasma levels for this panel of four miRNAs. The area under the receiver operating characteristic curve were estimated at 0.82 and 0.78 without and with leave-one-out cross-validation scheme, respectively. These observations, although a "proof of principle" finding at this time, show the feasibility of developing plasma miRNA profiling as a sensitive and specific blood-based biomarker assay for pancreatic cancer that has the potential of translation to the clinic with additional improvements in the future.

This study was undertaken to provide reference values for relevant parameters of Chinese Reference Man. Eighteen kinds of major organ or tissue samples, including muscle, rib, liver, and so on, were obtained from autopsies of 68 healthy adult men living in four areas of China with different dietary patterns (Hebei, Shanxi, Sichuan, Jiangxi or Jiangsu provinces, including Shanghai City) who had just encountered sudden deaths. At the same time, whole blood samples were collected from 10 volunteers living in each of these areas. The concentrations of 60 elements in these samples were detected by using inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma-atomic emission spectrometry (ICP-AES), neutron activation analysis (NAA), fluorometry (FL), graphite furnace atomic absorption spectrometry (GF-AAS) techniques and necessary quality control (QC) measures. Based on obtained concentrations and reference values of these organ or tissue weights for Chinese Reference Man, the elemental burdens in these organs or tissues were estimated. As a summary report of a series of research studies for Chinese Reference Man, which included three steps (from 1996 to 2006), the concentrations of 60 elements in 18 main organs or tissues were determined and their elemental burdens in the organs or tissues and whole body were estimated. Furthermore, the organ or tissue distributions of some important elements for radiation protection were discussed. These results may provide more reliable and better representative bases than before for establishing related reference values of Chinese Reference Man and revising current reference values of International Commission on Radiological Protection (ICRP) Reference Man. These basic data will also be very valuable for many other applications in radiation protection and other scientific fields.

BackgroundTransforming growth factor (TGF)-β signaling pathway, may act both as a tumor suppressor and as a tumor promoter in pancreatic cancer, depending on tumor stage and cellular context. TGF-β pathway has been under intensive investigation as a potential therapeutic target in the treatment of cancer. We hypothesized a correlation between TGF-βR2/SMAD4 expression in the tumor, plasma TGF-β1 ligand level, genetic variation in TGF-B pathway and prognosis of pancreatic cancer.MethodWe examined TGF-βR2 and SMAD4 protein expression in biopsy or surgical samples from 91 patients with pancreatic ductal adenocarcinoma (PDAC) using immunohistochemistry. Plasma level of TGF-β1 was measured in 644 patients with PDAC using ELISA. Twenty-eight single nucleotide polymorphisms (SNP) of the TGF-β1, TGF-β2, TGF-β3, TGF-βR1, TGF-βR2, and SMAD4 genes were determined in 1636 patients with PDAC using the Sequenom method. Correlation between protein expression in the tumor, plasma TGF-β1 level, and genotypes with overall survival (OS) was evaluated with Cox proportional regression models.ResultsThe expression level of TGF-βR2 and SMAD4 as an independent marker was not associated with OS. However, patients with both low nuclear staining of TGF-βR2 and high nuclear staining of SMAD4 may have better survival (P = 0.06). The mean and median level of TGF-β1 was 15.44 (SD: 10.99) and 12.61 (interquartile range: 8.31 to 19.04) ng/ml respectively. Patients with advanced disease and in the upper quartile range of TGF-β1 level had significantly reduced survival than those with low levels (P = 0.02). A significant association of SMAD4 SNP rs113545983 with overall survival was observed (P<0.0001).ConclusionOur data provides valuable baseline information regarding the TGF-β pathway in pancreatic cancer, which can be utilized in targeted therapy clinical trials. High TGF-β1 plasma level, SMAD4 SNP or TGF-βR2/SMAD4 tumor protein expression may suggest a dependence on this pathway in patients with advanced pancreatic cancer.

PurposeThe study was aimed to evaluate the prognostic or predictive value of serum exosomal microRNAs (miRNAs) for tumor recurrence and response to adjuvant therapy in stage II and stage III colon cancer.Results145 differentially expressed mature miRNAs were identified (P<0.05) and 10 top hits were carried forward in validation test. MiR-4772-3p was significantly under-expressed in 27 patients with recurrence compared to in 57 patients without recurrence (P=0.002). The reduced expression was significantly related to increased risk of tumor recurrence and risk of death. As a predictor for tumor recurrence, ROC analysis revealed the AUC (95% CI) was 0.72 (0.59-0.85, P=0.001) for lower level of miR-4772-3p compared to 0.63 (0.51-0.75, P=0.062) for tumor site and 0.65 (0.51-0.78,P=0.034) for lymph node status. Among 66/84 patients who received FOLFOX adjuvant therapy, 9/10 (90%) patients with a lower level and 10/56 (18%) patients with a higher level of miR-4772-3p had tumor recurrence (P<0.001).Materials and MethodsBlood samples were prospectively collected from84 patients with stage II/III colon cancer after tumor resection and before adjuvant therapy. Serum exosomal miRNA profiles were determined by RNA sequencing. Differentially expressed mature miRNAs were identified between patients with or without tumor recurrence. The top hits were validated in individual RNA samples using quantitative real-time reverse transcription PCR.ConclusionsReduced expression of serum exosomal miR-4772-3p is a prognostic biomarker for tumor recurrence in stage II and stage III colon cancer patients. The predictive value of this marker for response to FOLFOX adjuvant therapy needs further investigation.

Previous studies by us and others have shown a significantly higher level of aromatic DNA adducts in normal adjacent breast tissue samples obtained from breast cancer patients than in those obtained from non-cancerous controls. The increased amount of DNA damage could be related to excess environmental carcinogen exposure and/or genetic susceptibility to such exposure. In the current study, we investigated the relationship between the levels of aromatic DNA adducts in breast tissues and polymorphisms of the drug-metabolizing genes cytochrome P4501A1 (CYP1A1), N-acetyltransferase-2 (NAT2), and glutathione S-transferase M1 (GSTM1), in 166 women having breast cancer. DNA adducts were measured using (32)P-postlabeling and information on smoking status was obtained from medical records. When pooled data of smokers and non-smokers were analyzed by multiple regression analyses, no significant correlation was found between the level of total DNA adducts and age, race, or polymorphisms of CYP1A1, GSTM1, and NAT2. The only significant predictor of the level of DNA adducts in breast tissues was smoking (P = 0.008). When data were analyzed separately in smokers and non-smokers, however, a significant gene-environment interaction was observed. Smokers with CYP1A1*1/*2 or *2/*2 genotypes had a significantly higher level of DNA adducts than those with the CYP1A1*1/*1 genotype. This effect was not seen among non-smokers. There was also a gene-gene interaction, as smokers with combined CYP1A1*1/*2 or CYP1A1*2/*2 genotypes and GSTM1 null had a much higher level of adducts than those with either CYP1A1 or GSTM1 polymorphism. Genetic polymorphisms of CYP1A1 and NAT2 were also significantly correlated with the frequency of certain types of DNA adducts. For example, a bulky benzo[a]pyrene (B[a]P)-like adduct was detected in 26% of the samples, the presence of which was not related to age, race, smoking status, or GSTM1 and NAT2 genotype. However, a significantly higher frequency of the B[a[P-like adduct was found in individuals having CYP1A1*1/*2 or *2/*2 genotypes than in those having the *1/*1 genotype (P = 0.04). In addition, individuals having slow NAT2 alleles had a significantly higher frequency of the typical smoking-related DNA adduct pattern, i.e. a diagonal radioactive zone (DRZ), than others did (P = 0.008). These findings suggest that polymorphisms of CYP1A1, GSTM1, and NAT2 significantly affect either the frequency or the level of DNA adducts in normal breast tissues of women having breast cancer, especially in smokers. Further large-scale studies are required to determine the exact role of these polymorphisms and types of DNA damage in breast cancer susceptibility.