Roles moleculaires des proteines de choc thermique dans le fonctionnement des organismes a des temperatures normales et suite a des chocs thermiques; differents genes impliques

The heat-shock proteins

Hydrogels for tissue engineering.

KEGG(Kyoto Encyclopedia of Genes and Genomes)〔和文〕 (特集 ゲノム医学の現在と未来--基礎と臨床) -- (データベース)

Silver staining of proteins in polyacrylamide gels.

Stem cells are defined as cells able to both extensively self-renew and differentiate into progenitors. Research data show that more resistant stem cells than common cancer cells exist in cancer patients.To identify unrecognized differences between cancer stem cells and cancer cells might be able to develope effective classification,diagnose and treat ment for cancer.

Stem Cells,Cancer and Cancer Stem Cells

Crucial prerequisites for the development of safe preclinical protocols in biomedical research are suitable animal models that would allow for human-related validation of valuable research information gathered from experimentation with lower mammals. In this sense, the miniature pig, sharing many physiological similarities with humans, offers several breeding and handling advantages (when compared to non-human primates), making it an optimal species for preclinical experimentation. The present review offers several examples taken from current research in the hope of convincing the reader that the porcine animal model has gained massively in importance in biomedical research during the last few years. The adduced examples are taken from the following fields of investigation: (a) the physiology of reproduction, where pig oocytes are being used to study chromosomal abnormalities (aneuploidy) in the adult human oocyte; (b) the generation of suitable organs for xenotransplantation using transgene expression in pig tissues; (c) the skin physiology and the treatment of skin defects using cell therapy-based approaches that take advantage of similarities between pig and human epidermis; and (d) neurotransplantation using porcine neural stem cells grafted into inbred miniature pigs as an alternative model to non-human primates xenografted with human cells.

The Miniature Pig as an Animal Model in Biomedical Research

Cell biology of hydrogels

Nodular melanoma is one of the most life threatening tumors with still poor therapeutic outcome. Similarly to other tumors, permissive microenvironment is essential for melanoma progression. Features of this microenvironment are arising from molecular crosstalk between the melanoma cells (MC) and the surrounding cell populations in the context of skin tissue. Here, we study the effect of melanoma cells on human primary keratinocytes (HPK). Presence of MC is as an important modulator of the tumor microenvironment and we compare it to the effect of nonmalignant lowly differentiated cells also originating from neural crest (NCSC). Comparative morphometrical and immunohistochemical analysis of epidermis surrounding nodular melanoma (n = 100) was performed. Data were compared to results of transcriptome profiling of in vitro models, in which HPK were co-cultured with MC, normal human melanocytes, and NCSC, respectively. Differentially expressed candidate genes were verified by RT-qPCR. Biological activity of candidate proteins was assessed on cultured HPK. Epidermis surrounding nodular melanoma exhibits hyperplastic features in 90% of cases. This hyperplastic region exhibits aberrant suprabasal expression of keratin 14 accompanied by loss of keratin 10. We observe that MC and NCSC are able to increase expression of keratins 8, 14, 19, and vimentin in the co-cultured HPK. This in vitro finding partially correlates with pseudoepitheliomatous hyperplasia observed in melanoma biopsies. We provide evidence of FGF-2, CXCL-1, IL-8, and VEGF-A participation in the activity of melanoma cells on keratinocytes. We conclude that the MC are able to influence locally the differentiation pattern of keratinocytes in vivo as well as in vitro. This interaction further highlights the role of intercellular interactions in melanoma. The reciprocal role of activated keratinocytes on biology of melanoma cells shall be verified in the future.

/pdf/melanoma-cells-influence-the-differentiation-pattern-of-pk4x0hzuhe.pdf

Melanoma cells influence the differentiation pattern of human epidermal keratinocytes

Proteins C23 and B23 are the major nucleolar silver staining proteins

Summary A method is described for isolation of nucleoli of the Walker tumor and liver in which nuclei were sonicated in a Model DF-101 Raytheon Sonic Oscillator in which the temperature was maintained at 2° C. The medium used for the initial homogenization of the tissue was 0.25 m sucrose containing 0.0033 m CaCl2. This concentration of calcium ion was found to be optimal for the successful release of nucleoli with maximal destruction of nuclei. The volume was maintained at 20 ml., and the time required for destruction of more than 99.8 per cent of the nuclei was 25–40 seconds. The amperage of the output current was 1.0–1.1. Selective centrifugation of the nucleoli of the sonicate was accomplished by initial centrifugation at 2500 × g for 5 minutes followed by rehomogenization of the pellet in 0.88 m sucrose and sedimentation of the nucleoli at 800 × g (1000 × g for the liver) for 15 minutes. A repetition of the last step produced a preparation of nucleoli which was 95–99 per cent pure by direct particle count. For further purification, this preparation was treated either with DNase I or with 2 m NaCl. The content of the nucleic acids and protein in these preparations was determined. Tumor nucleoli purified with DNase contained an average of 1.8 pg. of RNA and 16.1 pg. of protein per nucleolus. Liver nucleoli contained one-sixth the amount of RNA and protein of nucleoli of the Walker tumor. These preparations contained very little DNA. RNA comprised about 10 per cent of the dry weight of nucleoli of both liver and Walker tumor.

https://cancerres.aacrjournals.org/content/canres/23/4_Part_1/510.full.pdf

Karel Smetana

Papers

The Miniature Pig as an Animal Model in Biomedical Research

Cell biology of hydrogels

Melanoma cells influence the differentiation pattern of human epidermal keratinocytes

Proteins C23 and B23 are the major nucleolar silver staining proteins

Quantitative Aspects of Isolation of Nucleoli of the Walker Carcinosarcoma and Liver of the Rat