Generation and characterization of islet cell tumor in pTet-on/pTRE-SV40Tag double-transgenic mice model

Transgenic mouse models of gastric cancer: Pathological characteristic and applications

Transgenic animal models of gastric cancer have high specificity and similar tumor characteristics to human gastric cancer. Current research and application of transgenic animal models of gastric cancer are wide, and several models have been developed. In transgenic animal models of gastric cancer, primary gastric carcinoma can develop spontaneously. These transgenic animal models have been widely used to study the mechanism of gastric cancer development, and have great significance for clinical diagnosis and treatment of gastric cancer. This paper systematically summarizes several different kinds of transgenic animal models and describes the molecular pathogenic mechanisms and pathological characteristics of gastric mucosal lesions in these models as well as their applications.

Molecular profiling of pancreatic neuroendocrine tumors in sporadic and Von Hippel-Lindau patients

PURPOSE

Von Hippel-Lindau (VHL) disease is an inherited syndrome caused by germline mutations in the VHL tumor suppressor gene, predisposing to a variety of neoplasms including pancreatic neuroendocrine tumors (PanNET). In VHL disease, PanNET probably progress according to a specific pathway of carcinogenesis. Our aim was to characterize by molecular quantitative analysis a panel of molecules implicated in the VHL pathway and in tumor progression in the PanNET of patients with VHL.

EXPERIMENTAL DESIGN

The expression of 52 genes was studied by quantitative reverse transcriptase PCR in 18 patients with VHL operated on for PanNET and compared with 16 non-VHL PanNET. The VHL and non-VHL tumors were matched according to their size and cell proliferation. For some genes, we looked for differences in the protein expression in VHL PanNET (n = 31), microadenomas (n = 22), and non-VHL PanNET (n = 16), included in tissue microarray blocks.

RESULTS

Nineteen (36%) genes were significantly upregulated and three (6%) downregulated in VHL PanNET. The upregulated genes were related to (i) hypoxia-inducible factor (HIF) molecules (CA9, HIF2A, and GLUT1), (ii) angiogenesis (CDH5, VEGFR1, EDNRA, ANGPT2, CD34, VEGFR2, VEGFA, and ANGPT1), (iii) the processes of epithelial-mesenchymal transition (VIM) and/or metastasis (LAMA4 and CXCR4), (iv) growth factors and receptors (PDGFB, IRS1, and ERBB1), or (v) cell cycle (CCND1 and CDKN2A). The downregulated genes were related to (i) EMT (OCLN) and (ii) signaling pathways (RPS6KB1 and GADD45B).

CONCLUSION

This study shows that the progression of PanNET in patients with VHL tumors follows a specific pathway and supports that targeting molecules specifically involved may be of therapeutic importance.

Simultaneous detection of multiple transgenes for genetically-modified mouse strains

Recent advances in the genetic manipulation of mice have enabled us to generate transgenic and knockout mice. However, it is not easy to maintain these genetically-modified mice with the high-quality necessary to meet both scientific and legal requirements. RIKEN BRC has collected various transgenic, knockout, and conditional knockout mice. To examine the genetic modifications in these strains quickly and thoroughly, we established a simultaneous PCR test to detect multiple transgenes. We have called this, the "KO-survey". The PCR condition was optimized to detect neo, puro, pgk-neo, lacZ, and HSVtk-neo in set I, and hyg, IRES, cre, flp, and Gfp in set II. This "KO-survey" is useful for providing users with mouse strains of the highest genetic quality and accurate information on their genetic modifications.

SV40 T antigen disrupted the cell metabolism and the balance between proliferation and apoptosis in lens tumors of transgenic mice

PURPOSE

Simian Vacuolating Virus 40 (SV40) T antigen perturbed p53 and RB to cause cell malignant transformation. The purpose of this study was to identify the molecular changes during lens carcinogenesis and cancer progression induced by SV40 T antigen.

METHODS

The different lens lesions of alpha A-crystallin/SV40 T antigen transgenic mice were examined using cDNA microarray, immunohistochemistry and TUNEL to scan the influenced molecules and signal pathways.

RESULTS

There appeared dysplasia, carcinoma in situ, followed by invasion inside or outside eyeball, and final metastasis into lymph node or lung. Cell functions largely changed from such many aspects as cell cycle, cell morphology, cell development, cell-to-cell signaling and so forth since lens carcinogenesis. The significant differences were observed in such signaling pathways as metabolism about carbohydrate, amino acid, nucleotides, Xenobiotics and nitrogen (P < 0.05).The remarkable distinction of cell proliferation and cell death was found after carcinoma began to invade. There was significant alteration in cell growth, cell cycle, cell-to-cell signaling and metabolism since carcinoma invasion outside the eyeball happened. Parafibromin, Stat 1alpha, Mek kinase-1, CK2alpha, GRP78, Arp2 and Apr3 were not expressed in wild-type mice lens, but in others. The proliferative levels of dysplasia, carcinoma in situ and invasive carcinoma inside eyeballs were statistically higher than other groups (P < 0.05). The apoptotic levels of dysplasia were significantly higher than wild-type control (P < 0.05), but lower than the others (P < 0.05).

CONCLUSION

SV40 T antigen remarkably targeted the cell metabolism and disrupted the balance between proliferation and apoptosis during the lens carcinogenesis and following progression.

The genomic revolution and endocrine pathology

The genome has been sequenced. However, the functions of each gene remain to be elucidated through phenotypic analysis. This analysis has been called phenogenomics. That part of phenogenomics related to disease can be called pathogenomics or Genomic Pathology. The initial phases of disease analysis will use genetically modified mice. The proliferation of ambitious programs designed to use mice for phenogenomics has been met with alarm by comparative pathologists who note the lack of qualified genomic pathologists and of training programs in genomic pathology. While endocrine pathology offers a number of excellent examples of the contributions made by pathologists to the scientific literature, it also contains examples of the hazards of working with untrained, unwary personnel.