Pancreatic insulin-producing cells differentiated from human embryonic stem cells correct hyperglycemia in SCID/NOD mice, an animal model of diabetes.

BACKGROUND: Human pancreatic islet transplantation is a prospective curative treatment for diabetes. However, the lack of donor pancreases greatly limits this approach. One approach to overcome the limited supply of donor pancreases is to generate functional islets from human embryonic stem cells (hESCs), a cell line with unlimited proliferative capacity, through rapid directed differentiation. This study investigated whether pancreatic insulin-producing cells (IPCs) differentiated from hESCs could correct hyperglycemia in severe combined immunodeficient (SCID)/non-obese diabetic (NOD) mice, an animal model of diabetes. METHODS: We generated pancreatic IPCs from two hESC lines, YT1 and YT2, using an optimized four-stage differentiation protocol in a chemically defined culture system. Then, about 5-7 × 10(6) differentiated cells were transplanted into the epididymal fat pad of SCID/NOD mice (n = 20). The control group were transplanted with undifferentiated hESCs (n = 6). Graft survival and function were assessed using immunohistochemistry, and measuring serum human C-peptide and blood glucose levels. RESULTS: The pancreatic IPCs were generated by the four-stage differentiation protocol using hESCs. About 17.1% of differentiated cells expressed insulin, as determined by flow cytometry. These cells secreted insulin/C-peptide following glucose stimulation, similarly to adult human islets. Most of these IPCs co-expressed mature ß cell-specific markers, including human C-peptide, GLUT2, PDX1, insulin, and glucagon. After implantation into the epididymal fat pad of SCID/NOD mice, the hESC-derived pancreatic IPCs corrected hyperglycemia for ≥ 8 weeks. None of the animals transplanted with pancreatic IPCs developed tumors during the time. The mean survival of recipients was increased by implanted IPCs as compared to implanted undifferentiated hESCs (P<0.0001). CONCLUSIONS: The results of this study confirmed that human terminally differentiated pancreatic IPCs derived from hESCs can correct hyperglycemia in SCID/NOD mice for ≥8 weeks.

Functional analysis of human cancer-associated genes and their association with the testes and epididymis.

Human cancer-associated UniGene sets (NCBI GeneBank) provide a platform for identifying differentially-expressed genes in human cancers. The present study identified and characterized a set of human cancer-associated genes using the Digital Differential Display (DDD) and functional analysis tools. A total of 1,904 genes were differentially expressed in 15 cancer types, including genes that had been previously shown to be specific in certain human cancers. A total of 274 genes were uniquely expressed in certain cancer types, including 37 genes that were highly expressed in the human testes and epididymis. These genes mainly functioned as ribosomal proteins, enzymes, receptors, secretory proteins and cell adhesion molecules. The most common domains that were encoded by the cancer-associated genes were those of cytochrome P450 CYP2D6, serpin and apolipoprotein A-I. A further gene ontology (GO) enrichment analysis revealed seven major functional clusters, which corresponded to the enriched pathways involved in cancer. The present study provides a source of cancer-associated genes and their functions. The results provide new insights into cancer biology and the involvement of highly-expressed epididymal genes in cancer biomarkers.

A new bioinformatics insight into human cancer-associated proteins.

Cancer is a complex disease caused by multiple factors including genetic mutations, and environmental factors. Cancer-associated proteins are potential biomarkers or targets for diagnostic and therapeutic interventions in cancer. The Universal Protein Resourse (UniPort) is a well-annotated comprehensive resourse for protein sequence records. In the present study, we performed data mining of Uniprot proteins as a proteomic resource. we generated a catalog of 1653 cancer-associated proteins including 344 secretory proteins and 300 cell surface proteins. Integrated bioinformatic analysis including ontological classification, functional enrichment and pathway construction were performed. These proteins could serve as a reference for further studies to discover cancer targets, and the enriched bioinformatic analysis provides new insights into cancer proteomics research.

[Fine mapping of susceptibility genes loci within chromosome 1 in Chinese Han families with type 2 diabetes].

OBJECTIVES: To confirm previous whole-genome scan results of mapping type 2 diabetes susceptibility genes in chromosome 1 in Northern Chinese Han population by conducting a new genome scan with both an enlarged number of type 2 diabetes families and a new set of microsatellite markers. METHODS: A genome scan method was applied. After multiplexed PCR, electrophoreses, genescan and genotyping analysis, size informations for all loci were obtained, and a further study was done using both parametric and non-parametric linkage analysis to calculate the P-values and Z-values of these loci. RESULTS: A total of 34 microsatellite markers distributed within 5 regions along chromosome 1 were surveyed, and 12,000 genotypes were screened. Evidence of linkage with diabetes was identified for 8 of the 34 loci (all the P-values of the 8 loci distributed in 3 regions were lower than 0.05, and the highest Z-value was 2.17). Interestingly, all the 5 markers at the P terminal 1p36.3-1p36.23 region, spanning a long range of 16.9 cM, suggested to be linked with the disease. The results of the other two regions were not consistent with the previous ones. CONCLUSIONS: The study results have confirmed those gained in the previous genome-wide scan. The fact that all 5 loci at the P terminal region displayed linkage with diabetes suggests that more than 1 susceptibility gene may reside in this region.