Differential cytotoxic effects of sodium meta-arsenite on human cancer cells, dental papilla stem cells and somatic cells correlate with telomeric properties and gene expression.

We investigated the effects of sodium meta-arsenite (NaAsO(2)) on human cancer cells (MDA-MB-231, MCF-7 and U-87 MG), dental papilla tissue stem cells (DPSCs) and somatic cells [MRC-5 fetal fibroblasts and adult muscle cells (MCs)] by examining telomeric properties, endogenous reverse transcriptase (RT) activity and the expression of tumorigenesis-linked genes. Half maximal inhibitory concentration (IC(50)) values were higher in DPSCs and MCs, possessing longer telomere lengths when compared to cancer cells. Levels of telomerase and RT activity, and the expression of protein 53 (p53), B-cell lymphoma 2 (BCL2), nuclear factor kappa-light-chain-enhancer of activated B-cells (NFκB), transforming growth factor beta (TGFβ) and vascular endothelial growth factor (VEGF) were significantly lower in cancer cells following sodium meta-arsenite treatment, whereas the effect was absent or marginally detected in DPSCs and somatic cells.

Variation of telomerase activity and morphology in porcine mesenchymal stem cells and fibroblasts during prolonged in vitro culture.

The purpose of this study was to examine the telomerase activity, population doubling time (PDT), morphological alterations, and the cell cycle status with activity of senescence-associated-ß-galactosidase in porcine mesenchymal stem cells (MSCs) and fibroblasts during an extended in vitro culture. MSCs and fibroblasts were isolated from bone marrow and ear skin of a miniature pig, respectively, and cultured up to 20 passages. The analysis was carried out in MSCs and fibroblasts at 1, 5, 10, 15, and 20 passages.

Characterization and comparison of telomere length, telomerase and reverse transcriptase activity and gene expression in human mesenchymal stem cells and cancer cells of various origins.

We have characterized and compared the telomere length, telomerase, reverse transcriptase (RT) activity and expression of genes implicated in cancer and in pluripotency, in human mesenchymal stem cells (MSCs) derived from dental papilla tissue, umbilical cord matrix and adipose tissue and in cancer cells (MDA-MB-231, U-87 MG, and MCF-7). MRC-5 fetal fibroblasts and adult muscle cells were used as somatic cell controls. Telomere length was significantly (P<0.

Comparative analysis of telomere length, telomerase and reverse transcriptase activity in human dental stem cells.

Stem cells from dental tissues have been isolated and established for tooth regenerative applications. However, basic characterization on their biological properties still needs to be investigated before employing them for effective clinical trials. In this study, we compared the telomere length, relative telomerase activity (RTA), and relative reverse transcriptase activity (RRA) as well as the surface antigen profile and mesenchymal differentiation ability in human dental papilla stem cells (DPaSCs), dental pulp stem cells (DPuSCs), and dental follicle stem cells (DFSCs) with mesenchymal stem cells (MSCs) derived from bone marrow.

In vitro development of bovine oocytes reconstructed with round spermatids.

The timing between round spermatid(s) (RS) injection and oocyte activation are critical for spermatid remodeling and embryo development in intracytoplasmic injection of round spermatid (ROSI) procedure. The objective of the present study was to develop an appropriate oocyte activation method for producing developmentally competent bovine embryos reconstructed with RS. Embryos reconstructed by ROSI were compared with three activation treatments for the rates of pronuclear formation, development and ploidy.