Expression patterns of esophageal cancer deregulated genes in C57BL/6J mouse embryogenesis

Downregulation of RPL15 may predict poor survival and associate with tumor progression in pancreatic ductal adenocarcinoma

Early diagnosis and treatment in pancreatic ductal adenocarcinoma (PDAC) is still a challenge worldwide. The poor survival of PDAC patients mainly due to early metastasis when first diagnosed and lack of prognostic biomarker. Ribosomal protein L15 (RPL15), an RNA-binding protein, is a component of ribosomal 60S subunit. It was reported that RPL15 is dysregulated in various type of cancers. However, little is known about the role of RPL15 in PDAC carcinogenesis and progression. Herein, we clarified RPL15 expression status may serve as an independent prognostic biomarker in three independent PDAC patient cohorts. We found that RPL15 was dramatically decreased in PDAC tissues and cell lines. The high expression of RPL15 was inversely correlated with TNM stage, histological differentiation, T classification and vascular invasion. Low expression of RPL15 was significantly associated with poor overall survival of PDAC patients. Furthermore, we demonstrated that the reduction of RPL15 may promote invasion ability of pancreatic cell by inducing EMT process. In conclusion, decreased RPL15 expression is associated with invasiveness of PDAC cells, and RPL15 expression status may serve as a reliable prognostic biomarker in PDAC patients.

Identification of some human genes oppositely regulated during esophageal squamous cell carcinoma formation and human embryonic esophagus development

Here we directly compared gene expression profiles in human esophageal squamous cell carcinomas and in human fetal esophagus development. We used the suppression subtractive hybridization technique to subtract cDNAs prepared from tumor and normal human esophageal samples. cDNA sequencing and reverse transcription polymerase chain reaction (RT-PCR) analysis of RNAs from human tumor and the normal esophagus revealed 10 differentially transcribed genes: CSTA, CRNN, CEACAM1, MAL, EMP1, ECRG2, and SPRR downregulated, and PLAUR, SFRP4, and secreted protein that is acidic and rich in cysteine upregulated in tumor tissue as compared with surrounding normal tissue. In turn, genes up- and downregulated in tumor tissue were down- and upregulated, respectively, during development from the fetal to adult esophagus. Thus, we demonstrated that, as reported for other tumors, gene transcriptional activation and/or suppression events in esophageal tumor progression were opposite to those observed during development from the fetal to adult esophagus. This tumor 'embryonization' supports the idea that stem or progenitor cells are implicated in esophageal cancer emergence.

Transcript profiles of some developmentally important genes detected in bovine oocytes and in vitro-produced blastocysts using RNA amplification and cDNA microarrays

To study the mRNA transcript profiles of some potential candidate developmental genes during bovine oocyte and blastocyst stages, RNA amplification procedures, cDNA microarray of 82 target genes spotted onto glass slide and real-time polymerase chain reaction (PCR) were used. Messenger RNAs were isolated from in vitro-produced bovine matured oocytes and blastocysts. Using equal amounts of input mRNAs but different cycles of amplifications, cDNAs were produced and served as template for RNA amplification by the in vitro transcriptions. After amplification, the RNA yields transcribed from cDNAs of different cycles were evaluated both by hybridization on the cDNA microarrays and by using real-time PCR techniques. The analyses indicated best results from lower amplification cycle templates with consistent signals at hybridization. Generally, the RNA yield was directly proportional to the amplification cycle but inversely related with signal consistency at repeated hybridizations. Using the protocols established, equal amounts of amplified RNA from matured oocytes and blastocysts were hybridized to the array. Analyses of replicated hybridizations indicated that 35 transcripts were differentially expressed. Most of these were not described in previous bovine embryo studies. Independent analyses of 23 transcripts with real-time PCR and unamplified RNA confirmed the results of 22 genes. Moreover, the functional analyses showed various roles related to development. Hence, it is possible to conclude that the genes identified here are potential candidates for characterizing developmental competence, and that the methods established can be used for large-scale gene expression analysis with more comprehensive arrays.

Pancreatic cancer-derived S-100A8 N-terminal peptide: A diabetes cause?

BACKGROUND

Our aim was to identify the pancreatic cancer diabetogenic peptide.

METHODS

Pancreatic tumor samples from patients with (n=15) or without (n=7) diabetes were compared with 6 non-neoplastic pancreas samples using SDS-PAGE.

RESULTS

A band measuring approximately 1500 Da was detected in tumors from diabetics, but not in neoplastic samples from non-diabetics or samples from non-neoplastic subjects. Sequence analysis revealed a 14 amino acid peptide (1589.88 Da), corresponding to the N-terminal of the S100A8. At 50 nmol/L and 2 mmol/L, this peptide significantly reduced glucose consumption and lactate production by cultured C(2)C(12) myoblasts. The 14 amino acid peptide caused a lack of myotubular differentiation, the presence of polynucleated cells and caspase-3 activation.

CONCLUSIONS

The 14 amino acid peptide from S100A8 impairs the catabolism of glucose by myoblasts in vitro and may cause hyperglycemia in vivo. Its identification in biological fluids might be helpful in diagnosing pancreatic cancer in patients with recent onset diabetes mellitus.

Functional network analysis reveals extended gliomagenesis pathway maps and three novel MYC-interacting genes in human gliomas

Gene expression profiling has proven useful in subclassification and outcome prognostication for human glial brain tumors. The analysis of biological significance of the hundreds or thousands of alterations in gene expression found in genomic profiling remains a major challenge. Moreover, it is increasingly evident that genes do not act as individual units but collaborate in overlapping networks, the deregulation of which is a hallmark of cancer. Thus, we have here applied refined network knowledge to the analysis of key functions and pathways associated with gliomagenesis in a set of 50 human gliomas of various histogenesis, using cDNA microarrays, inferential and descriptive statistics, and dynamic mapping of gene expression data into a functional annotation database. Highest-significance networks were assembled around the myc oncogene in gliomagenesis and around the integrin signaling pathway in the glioblastoma subtype, which is paradigmatic for its strong migratory and invasive behavior. Three novel MYC-interacting genes (UBE2C, EMP1, and FBXW7) with cancer-related functions were identified as network constituents differentially expressed in gliomas, as was CD151 as a new component of a network that mediates glioblastoma cell invasion. Complementary, unsupervised relevance network analysis showed a conserved self-organization of modules of interconnected genes with functions in cell cycle regulation in human gliomas. This approach has extended existing knowledge about the organizational pattern of gene expression in human gliomas and identified potential novel targets for future therapeutic development.

Protein expression profiles in pancreatic adenocarcinoma compared with normal pancreatic tissue and tissue affected by pancreatitis as detected by two-dimensional gel electrophoresis and mass spectrometry

Pancreatic cancer is a rapidly fatal disease, and there is an urgent need for early detection markers and novel therapeutic targets. The current study has used a proteomic approach of two-dimensional (2D) gel electrophoresis and mass spectrometry (MS) to identify differentially expressed proteins in six cases of pancreatic adenocarcinoma, two normal adjacent tissues, seven cases of pancreatitis, and six normal pancreatic tissues. Protein extracts of individual sample and pooled samples of each type of tissues were separated on 2D gels using two different pH ranges. Differentially expressed protein spots were in-gel digested and identified by MS. Forty proteins were identified, of which five [i.e., alpha-amylase; copper zinc superoxide dismutase; protein disulfide isomerase, pancreatic; tropomyosin 2 (TM2); and galectin-1] had been associated previously with pancreatic disease in gene expression studies. The identified proteins include antioxidant enzymes, chaperones and/or chaperone-like proteins, calcium-binding proteins, proteases, signal transduction proteins, and extracellular matrix proteins. Among these proteins, annexin A4, cyclophilin A, cathepsin D, galectin-1, 14-3-3zeta, alpha-enolase, peroxiredoxin I, TM2, and S100A8 were specifically overexpressed in tumors compared with normal and pancreatitis tissues. Differential expression of some of the identified proteins was further confirmed by Western blot analyses and/or immunohistochemical analysis. These results show the value of a proteomic approach in identifying potential markers for early diagnosis and therapeutic manipulation. The newly identified proteins in pancreatic tumors may eventually serve as diagnostic markers or therapeutic targets.