Genetic reprogramming of human somatic cells to induced pluripotent stem cells (iPSCs) could offer replenishable cell sources for transplantation therapies. To fulfill their promises, human iPSCs will ideally be free of exogenous DNA (footprint-free), and be derived and cultured in chemically defined media free of feeder cells. Currently, methods are available to enable efficient derivation of footprint-free human iPSCs. However, each of these methods has its limitations. We have previously derived footprint-free human iPSCs by employing episomal vectors for transgene delivery, but the process was inefficient and required feeder cells. Here, we have greatly improved the episomal reprogramming efficiency using a cocktail containing MEK inhibitor PD0325901, GSK3β inhibitor CHIR99021, TGF-β/Activin/Nodal receptor inhibitor A-83-01, ROCK inhibitor HA-100 and human leukemia inhibitory factor. Moreover, we have successfully established a feeder-free reprogramming condition using chemically defined medium with bFGF and N2B27 supplements and chemically defined human ESC medium mTeSR1 for the derivation of footprint-free human iPSCs. These improvements enabled the routine derivation of footprint-free human iPSCs from skin fibroblasts, adipose tissue-derived cells and cord blood cells. This technology will likely be valuable for the production of clinical-grade human iPSCs.

SummaryRecent studies revealed an important role of aquaporins (AQPs) in cell migration and migration-associated cell function such as angiogenesis, wound healing, and neutrophil motility. Migration of tumor cells is a crucial step in tumor invasion and metastasis. In the present study, we investigated the expression of AQP1 in human HT20 colon cancer cells and characterized its function in cell migration. By reverse transcription-polymerase chain reaction (RT-PCR) and immunoblot analysis, expression of AQP1 was identified in HT20 cell lines. Immunofluorescence analysis indicated expression of AQP1 protein in the plasma membrane of HT20 cells. The recombinant adenovirus expressing human AQP1 increased the mRNA and protein expression of AQP1 in HT20 cells. In contrary, the RNA interference vector of AQP1 effectively inhibited the mRNA and protein expression of AQP1 in HT20 cells. Adenovirus-mediated high expression of AQP1 in HT20 cells increased relative plasma membrane water permeability and migration rate in both wound healing and invasive transwell migration assays. In contrary, RNA interference vector-mediated low expression of AQP1 in HT20 cells reduced relative plasma membrane water permeability and migration rate. AQP1 expression induced relocalization of actin protein and activation of RhoA and Rac. In nude mice, AQP1 increased extravasation of HT20 Cells in lung after tail vein injection. The results provided the direct evidence that aquaporin-mediated plasma membrane water permeability plays an important role in colon cancer cell migration and may be associated with colon cancer invasion and metastasis.

Vascular diseases are the most prevalent diseases worldwide. This study intended to analyze peripheral blood miRNA levels and their correlation with NT-pro-BNP and cTN-I in patients with atherosclerosis or pre-atherosclerotic conditions to build a dynamic correlation between vascular diseases and their biomarkers. Serum NT-pro-BNP and cTN-I levels were measured by their respective ELISA kits. The miRNA levels were assayed by quantitative PCR. Unique miRNA signatures were identified for both atherosclerosis and pre-atherosclerosis. The levels of miR-92a, 126, 130a, 222, and 370 levels were decreased in the peripheral blood of pre-atherosclerotic subjects. In atherosclerosis, miR-21, 122, 130a, and 211 were significantly increased whereas miR-92a, 126, and 222 were markedly decreased. Serum levels of NT-pro-BNP and cTN-I correlated with each other and increased with the progression of atherosclerosis. Moreover, the levels of cTN-I and NT-pro-BNP were positively correlated with miR-21 and negatively correlated with miR-126. Integrating specific pattern of miRNA levels with NT-pro-BNP and/or cardiac troponin may improve the diagnosis of cardiovascular diseases.

SummaryThe SET and MYND domain-containing protein 3 (SMYD3) gene was found to encode a novel histone methyltransferase involved in human cancer cells. It could specifically methylate histone H3 at lysine 4 and activate the transcription of a set of downstream genes, including of several oncogenes (e.g., N-Myc, CrkL, Wnt10b, RIZ, and hTERT) and genes involved in the control of cell cycle (e.g., Cyclin G1 and CDK2) and signal transduction (e.g., STAT1, MAP3K11, and PIK3CB). To determine the effects of SMYD3 overexpression on cell transformation, serum dependence and apoptosis sensitivity, we expressed SMYD3 in NIH3T3 cells, and these cells showed several transformed phenotypes as demonstrated by foci formation and colony growth in soft agar. Besides, these transfectants also showed increased serum dependence and depression of sensitivity to apoptosis induced by dexamethasone. These findings lend further understanding to the role of SMYD3 in the genesis of human cancers and might throw light on the development of novel therapeutic approaches to human cancers.2009 IUBMB IUBMB Life, 61(6): 679-684, 2009