Human BCAS3 Expression in Embryonic Stem Cells and Vascular Precursors Suggests a Role in Human Embryogenesis and Tumor Angiogenesis

Cancer is often associated with multiple and progressive genetic alterations in genes that are important for normal development. BCAS3 (Breast Cancer Amplified Sequence 3) is a gene of unknown function on human chromosome 17q23, a region associated with breakpoints of several neoplasms. The normal expression pattern of BCAS3 has not been studied, though it is implicated in breast cancer progression. Rudhira, a murine WD40 domain protein that is 98% identical to BCAS3 is expressed in embryonic stem (ES) cells, erythropoiesis and angiogenesis. This suggests that BCAS3 expression also may not be restricted to mammary tissue and may have important roles in other normal as well as malignant tissues. We show that BCAS3 is also expressed in human ES cells and during their differentiation into blood vascular precursors. We find that BCAS3 is aberrantly expressed in malignant human brain lesions. In glioblastoma, hemangiopericytoma and brain abscess we note high levels of BCAS3 expression in tumor cells and some blood vessels. BCAS3 may be associated with multiple cancerous and rapidly proliferating cells and hence the expression, function and regulation of this gene merits further investigation. We suggest that BCAS3 is mis-expressed in brain tumors and could serve as a human ES cell and tumor marker

Screening ethnically diverse human embryonic stem cells identifies a chromosome 20 minimal amplicon conferring growth advantage

The International Stem Cell Initiative analyzed 125 human embryonic stem (ES) cell lines and 11 induced pluripotent stem (iPS) cell lines, from 38 laboratories worldwide, for genetic changes occurring during culture. Most lines were analyzed at an early and late passage. Single-nucleotide polymorphism (SNP) analysis revealed that they included representatives of most major ethnic groups. Most lines remained karyotypically normal, but there was a progressive tendency to acquire changes on prolonged culture, commonly affecting chromosomes 1, 12, 17 and 20. DNA methylation patterns changed haphazardly with no link to time in culture. Structural variants, determined from the SNP arrays, also appeared sporadically. No common variants related to culture were observed on chromosomes 1, 12 and 17, but a minimal amplicon in chromosome 20q11.21, including three genes expressed in human ES cells, ID1, BCL2L1 and HM13, occurred in >20% of the lines. Of these genes, BCL2L1 is a strong candidate for driving culture adaptation of ES cells

Derivation and characterization of two sibling human embryonic stem cell lines from discarded grade III embryos

Human embryonic stem (hES) cells are a valuable tool for studying human development in addition to their potential applications in regenerative medicine and drug discovery. The role of genetic background and epigenetic influences in development as well as in response to external influences such as drugs and therapies is well recognized. The great ethnic diversity in the Indian subcontinent translates to interindividual variability in drug response and disease susceptibility. For these reasons, new hES cell lines representing Indian genetic diversity will be valuable in studies of tissue-differentiation, cellular-function and for aspects of characterization of responses to drugs. We have derived two new hES cell lines, BJNhem19 and BJNhem20 from the inner cell mass (ICM) of discarded grade III human embryos that were not suitable for in vitro fertility treatment. Human leukocyte antigen (HLA) isotype analysis shows that they are genetically distinct from existing hES cell lines. Short tandem repeat (STR) analysis shows that the two cell lines are derived from sibling embryos. These cell lines show an undifferentiated phenotype in culture for more than 65 passages, show normal karyotype and express pluripotency markers such as TRA-1-60, TRA-1-81, stage-specific embryonic antigen-4 (SSEA-4), alkaline phosphatase, DNMT3B, GABRB3, GDF3, OCT4, NANOG, SOX2, TERF1, TDGF, LEFTA, THY1, and REX1. While both cell lines can differentiate into derivatives of all three germ layers in vitro, only BJNhem20 can form teratomas when transplanted into mice. We observe an increased frequency of cardiomyocyte differentiation from BJNhem20 embryoid bodies in feeder-free cultures upon induction with DMSO. Cardiomyocytes purified from such cultures survive and show rhythmic contractions for several weeks in culture. These hES cell lines have been accepted for deposit in the U.K. Stem Cell Bank and will be a useful resource for the international stem cell community