Imprinting of the human RB1 gene is due to the presence of a differentially methylated CpG island (CGI) in intron 2, which is part of a retrocopy derived from the PPP1R26 gene on chromosome 9. The murine Rb1 gene does not have this retrocopy and is not imprinted. We have investigated whether the RB1/Rb1 locus is unique with respect to these differences. For this, we have compared the CGIs from ...

Locally advanced squamous cell carcinoma of the head and neck (SCCHN) that is not associated with human papillomavirus (HPV) has a poor prognosis in contrast to HPV-positive disease. To better understand the importance of RB1 activity in HPV-negative SCCHN, we investigated the prognostic value of inhibitory CDK4/6 phosphorylation of RB1 on threonine 356 (T356) in archival HPV-negative tumor spe...

BACKGROUND Retinoblastoma is the most common intraocular tumor in childhood and mutation in the RB1 gene will trigger the tumorigenesis. So far, a wide range of the mutations along the length of RB1 gene have been reported. However, some could not be detected by common detection methods. In such condition, linkage analysis using microsatellite markers is suggested to trace unknown RB1 mutations...

Retinoblastoma is a non-hereditary as well as an inherited pediatric tumor of the developing retina resulting from the inactivation of both copies of the RB1 tumor suppressor gene. Familial retinoblastoma is a highly penetrant genetic disease that usually develops by carrying germline mutations that inactivate one allele of the RB1 gene, leading to multiple retinoblastomas. However, large and c...

Chemoresistance is a major clinical problem compromising the successful treatment of cancer. One exciting approach is the eradication of cancer stem/tumor-initiating cells (jointly CSCs), which account for tumor initiation, progression, and drug resistance. Here we show for the first time, with mechanism-based evidence, that ginsenoside-Rb1, a natural saponin isolated from the rhizome of Panax ...

Ginsenoside Rb1 shows neuroprotective effects in various neurons, including dopaminergic cells. However, the precise mechanisms of action are uncertain. In this paper, we examine whether Rb1 has a neuroprotective effect on MPP(+)-induced apoptosis and attempt to clarify the signaling pathway in PC12 cells. Apoptosis of PC12 cells was determined by DNA fragmentation assay, the activation of casp...

BACKGROUND Ginsenosides are the principal components responsible for the pharmacological activities of ginseng. Ginsenosides Rg1 and Rb1 are the major compounds recognized as marker substances for quality control of ginseng-based products. These major compounds can be transformed to several pharmacologically active minor ginsenosides by chemical, microbial, and enzymatic means. MATERIALS AND ...

The microglia-mediated inflammatory reaction promotes neuronal damage under cerebral ischemia/hypoxia conditions. We therefore speculated that inhibition of hypoxia-induced microglial activation may alleviate neuronal damage. To test this hypothesis, we co-cultured ginsenoside Rb1, an active component of ginseng, and cortical neurons. Ginsenoside Rb1 protected neuronal morphology and structure ...

The feasible, reliable and selective multi-template molecularly imprinted polymers (MT-MIPs) based on SBA-15 (SBA-15@MT-MIPs) for the selective separation and determination of the trace level of ginsenoside Rb1 (Rb1), ginsenoside Rg1 (Rg1) and notoginsenoside R1 (R1) simultaneously from biological samples were developed. The polymers were constructed by SBA-15 as support, Rb1, Rg1, R1 as multi-...

Previous studies have shown that crude ginseng extracts enhance performance on shock-motivated tasks. Whether such performance enhancements are due to memory-enhancing (nootropic) properties of ginseng, or to other non-specific effects such as an influence on anxiety has not been determined. In the present study, we evaluated both the nootropic and anxiolytic effects of the ginseng saponin Rb1....