Previously, we reported that retigeric acid B (RB), a natural pentacyclic triterpenic acid isolated from lichen, inhibited cell growth and induced apoptosis in androgen-independent prostate cancer (PCa) cells. However, the mechanism of action of RB remains unclear. In this study, we found that using PC3 and DU145 cells as models, RB inhibited phosphorylation levels of IκBα and p65 subunit of NF...

Introduction: The isotopic compositions of moderately volatile elements like Li, K, Rb may provide key information to further enhance our understanding of the early history of our Solar System (e.g., [1,2]). Here we discuss technical aspects of our efforts to precisely determine the Rb isotopic composition of meteorites and present a hint for a possible nucleosynthetic effect suggested by corre...

PURPOSE Retinoblastoma (RB) is the most common intraocular tumor of early childhood. The early onset of RB, coupled with our previous findings of cancer stem cell characteristics in RB, led us to hypothesize that subpopulations of RB tumors harbor markers and behaviors characteristic of embryonic and neuronal origin. METHODS Our RB sources included: human pathological tissues, and the human R...

The presence of retinoblastoma (RB) protein was evaluated by immunohistochemical staining and correlated with loss of heterozygosity (LOH) at the RB locus in 52 primary epithelial ovarian carcinomas. Forty-eight tumors were informative at the RB locus by molecular genetic analysis. Twenty-five tumors (52%) showed loss of heterozygosity at the RB locus. RB protein expression was found in 23 of t...

We have shown previously that a novel cell cycle-regulated histone H1 kinase activity, retinoblastoma kinase (RbK), associates with and phosphorylates the amino terminus of the Rb protein in G2-M. We have shown also that the amino terminus of p107, a Rb-related protein, does not associate with a similar kinase in vitro or in vivo. Here, we report that a RbK-like kinase associates with the amino...

Unlike lower vertebrates, mammals are unable to replace damaged mechanosensory hair cells (HCs) in the cochlea. Recently, ablation of the retinoblastoma protein (Rb) in undifferentiated mouse HC precursors was shown to cause cochlear HC proliferation and the generation of new HCs, raising the hope that inactivation of Rb in postmitotic HCs could trigger cell division and regenerate functional H...

The retinoblastoma tumor suppressor gene Rb is essential for maintaining the quiescence and for regulating the differentiation of somatic stem cells. Inactivation of Rb in somatic stem cells typically leads to their overexpansion, often followed by increased apoptosis, defective terminal differentiation, and tumor formation. However, Rb's roles in germ-line stem cells have not been explored. We...

BACKGROUND The human retinoblastoma susceptibility gene encodes a nuclear phosphoprotein RB, which is a negative regulator of cell proliferation. The growth suppression function of RB requires an evolutionarily conserved A/B domain that contains two distinct peptide-binding pockets. At the A/B interface is a binding site for the C-terminal trans-activation domain of E2F. Within the B-domain is ...

Abstrad Fundional inadivation of the tumor-suppressing retinoblastoma gene (Rb) is involved in the etiology of many types of human cancers, including hereditary retinoblastomas. The neu gene is a dominant transforming oncogene, and we previously found that the Rb-encoded protein (RB) suppresses neu-induced transformation in NIH3T3 cells by repressing transcription of the neu oncogene. We report...

The purpose of this paper is to introduce and study regular bopen sets (briefly rb-open sets) in topological spaces and obtain some of their properties. We introduce the rb-closure and discuss some basic properties of the rb-closure. Also we study the new concepts of rb-closed spaces by means of filter bases. Mathematics Subject Classification: 54A05, 54A20