DIFFERENCES IN EXPRESSION AND REGULATION BETWEEN TRANSFORMED CELLS OF THE HUMAN GASTRIC CARCINOMA ONCOGENE Ha-ras AND THE UNTRANSFORMED PARENT CELLS

An Ha-ras oncogene was isolated from a cell line of gastric carcinoma called BGE-823 in order to elucidate genetic control and the influence of DNA sequences. The oncogene was cloned and identified as a single nucleotide substitution of thymine for guanine in the 12th codon through the sequencing of its first axon. We compared the differences of expression and regulation between the transformed Ha-ras cells and untransformed parent cells. Data indicated that the expression of Ha-ras in the transformed cells was five-fold higher than in the untransformed cells and that the Ha-ras gene in the former was hypersensitive toward DNase I. In addition, a nuclear protein of 35 kilodaltons bound strongly to the 2.5 Kb fragment located upstream of the 6.6 Kb Ha-ras gene and contained a CC rich region. These results suggest that there might be another mechanism of activation for the ras gene besides point mutation.

IN VIVO COMPARATIVE OBSERVATION ON THE INVASIVENESS OF VARIOUS ORGANS BY DIFFERENT LEUKEMIA CELLS

Using patho-morphological method and transplantation bio-assay, the in vivo invasiveness of leukemia cells is three transplantable mouse T cell leukemia models was comparatively studied. The results showed that the invasion to the liver was consistent, but that to other organs was obviously different. L615 and L7212 leukemia cells preferred to the bone marrow and spleen than to the peritoneum while L7811 leukemia cells were just the opposite. Transplantation bio-assay demonstrated that leukemia cells were present in the bone marrow of L615 mice as early as 6 hours after leukemic cell inoculation, but no leukemia cells was detected in bone marrow of L7811 mice 2 days after inoculation. In the terminal phase, L615 mice bone marrow became filled with leukemia cells, but L7811 mice bone marrow contained only a few leukemia cells. The difference of invasiveness of leukemia cells among organs is probably related to "homing" receptor. The same type of leukemia cells may possess multiple "homing" receptor.

Valproic acid alters differential protein expression in SH-SY5Y cells

This study sought to identify differentially expressed proteins in SH-SY5Y cells treated with valproic acid, using two-dimensional difference gel electrophoresis analysis. Three proteins were unambi-guously identified： the eukaryotic translation initiation factor 4A isoform 1 and ATP6V1B2 protein were downregulated, while the heterogeneous nuclear ribonucleoprotein K was upregulated. Moreover, all three proteins are associated with altered expression due to oxidative stress. Ma-trix-assisted laser desorption/ionization-time of flight mass spectrometry and protein immunoblotting assay confirmed the differential expression of eukaryotic translation initiation factor 4A isoform 1. The results indicate that valproic acid exerts an antioxidation effect by regulating the expression of eukaryotic translation initiation factor 4A isoform 1.

THE STUDY OF DIFFERENCE OF PCNA LABELLED CELL INDEXES BETWEEN ENDOMETRIA OF HUMAN AND MOUSE

40 human endometrial tissues of benign diseases were diviided into 8 groups (phases),and 50 BDF1 mousy endometrial tissues were divided into 5 groups (phases).Immunohistochenical staining was performed to show the PCNA (proliferating cell nuclear antigen)positive cell .In human ,the results suggested that the PCNA layer(48%)of mid-proliferative hpase.The PCNA labelled index was low in superficial epithelium.But in mouse, the results suggested that the Pcna labelled index was the highest(22%)in endometrium of estrus and the labelled cells were distributed mainly in superficial epithelium (60%).The results suggested that times that times and positions of cellular proliferation in endometrial tissues of human and mouse differed greatly.

Design of the sample cell in near-field surface-enhanced Raman scattering by finite difference time domain method

The rational design of the sample cell may improve the sensitivity of surface-enhanced Raman scattering （SERS） detection in a high degree. Finite difference time domain （FDTD） simulations of the configuration of Ag film-Ag particles illuminated by plane wave and evanescent wave are performed to provide physical insight for design of the sample cell. Numerical solutions indicate that the sample cell can provide more ＂hot spots＂ and the massive field intensity enhancement occurs in these ＂hot spots＂. More information on the nanometer character of the sample can be got because of gradient-field Raman （GFR） of evanescent wave. OCIS codes： 290.5860, 240.0310, 240.6680, 999.9999 （surface-enhanced Raman scattering）.

Variations in mesenchymal-epithelial transition-related transcription factors during reprogramming of somatic cells from different germ layers into iPSCs

Introducing a combination of transcription factors such as Oct4,Sox2,Klf4 and c-Myc（OSKM）enables reprogramming which converts somatic cells into induced pluripotent stem cells（i PSCs）（Takahashi and Yamanaka,2006）.i PSCs play an important role in clinical and regenerative medicine because they can be utilized to model a specific disease or differentiate into functional cells for transplantation.Enhancing the efficiency of induction and improving the qualities of iPSCs are constant themes in this field.

The effects of thyroid-stimulating hormone,estradiol and prolactin on sodium/iodide symporter mRNA expression in mouse lactating mammary gland cells under different iodine levels

Objective The present study investigated the sodium/iodide symporter mRNA expression in mouse lactating mammary gland cells under different iodine levels and the effects of thyroid-stimulating hormone(TSH),estradiol(E2)and prolactin(PRL)on NIS mRNA expression in mouse lactating mammary gland cells.