Functional properties of a Brazilian derived mouse embryonic stem cell line

Pluripotent mouse embryonic stem cells (mESC) are cell lines derived from the inner cell mass of blastocyst-stage early mammalian embryos. Since ion channel modulation has been reported to interfere with both growth and differentiation process in mouse and human ESC it is important to characterize the electrophysiological properties of newly generated mESC and compare them to other lines. In this work, we studied the intercellular communication by way of gap junctions in a Brazilian derived mESC (USP-1, generated by Dr. Lygia Pereira's group) and characterized its electrophysiological properties. We used immunofluorescence and RT-PCR to reveal the presence of connexin 43 (Cx43), pluripotency markers and ion channels. Using a co-culture of neonatal mouse cardiomyocytes with mESC, where the heart cells expressed the enhanced Green Fluorescent Protein, we performed dye injections to assess functional coupling between the two cell types observing dye diffusion. The patch-clamp study showed outward currents identified as two types of potassium currents, transient outward potassium current (Ito) and delayed rectifier outward potassium current (Iks), by use of specific drug blockage. Calcium or sodium currents in undifferentiated mESC were not identified. We conclude that USP-1 mESC has functional Cx43 channels establishing intercellular communication among themselves and with cardiomyocytes and has a similar electrophysiological profile compared to other mESC cell lines

BRCA1 and BRCA1 Genes and Inherited Breast and/or Ovarian Cancer: Benefits of Genetic Testing

The breast cancer associated genes BRCA1 and BRCA2 were discovered in 1994 and 1995 respectively. Since then in addition to our understanding how these proteins function in particular reference to DNA repair, enormous amount of knowledge has been gained regarding genetic epidemiology of inherited breast and ovarian cancer, mutation prevalence among different ethnic groups, presence of founder mutations, varying penetrance, genetic testing and potential management options of mutation carriers. This review will focus on the status of understanding of the role of BRCA1 and BRAC2 mutations among Indian women, structure and biology of these two genes, different methods used for mutation detection and different management options available for BRCA1 and BRCA2 mutation carriers