Down-Regulation

Publication Title: 
Cancer Research

The vast majority of breast cancers are carcinomas that arise from mammary epithelial cells (MECs). One of the key early events in tumorigenic transformation is the ability of cells to overcome replicative senescence. However, the precise genetic changes that are responsible for this event in MECs is largely unknown. Here, we report that Bmi-1, originally identified as a c-Myc cooperating oncoprotein, can bypass senescence, extend the replicative life span, and immortalize MECs. Furthermore, Bmi-1 was overexpressed in immortal MECs and several breast cancer cell lines.

Author(s): 
Dimri, Goberdhan P.
Martinez, Jose-Luis
Jacobs, Jacqueline J. L.
Keblusek, Petra
Itahana, Koji
Van Lohuizen, Maarten
Campisi, Judith
Wazer, David E.
Band, Vimla
Publication Title: 
Proceedings of the National Academy of Sciences of the United States of America

In investigating the role of metal ions in the pathogenesis of Huntington's disease, we examined the effects of clioquinol, a metal-binding compound currently in clinical trials for Alzheimer's disease treatment, on mutant huntingtin-expressing cells. We found that PC12 cells expressing polyglutamine-expanded huntingtin exon 1 accumulated less mutant protein and showed decreased cell death when treated with clioquinol. This effect was polyglutamine-length-specific and did not alter mRNA levels or protein degradation rates.

Author(s): 
Nguyen, Trent
Hamby, Aaron
Massa, Stephen M.
Publication Title: 
The Journal of Biological Chemistry

Replicative senescence in human fibroblasts is accompanied with alterations of various biological processes, including the impaired function of the proteasome. The proteasome is responsible for the removal of both normal and damaged proteins. Due to its latter function, proteasome is also considered a representative secondary antioxidant cellular mechanism. Nrf2 is a basic transcription factor responsible for the regulation of the cellular antioxidant response that has also been shown to regulate several proteasome subunits in mice.

Author(s): 
Kapeta, Suzanne
Chondrogianni, Niki
Gonos, Efstathios S.
Publication Title: 
Nature

Activating AMPK or inactivating calcineurin slows ageing in Caenorhabditis elegans and both have been implicated as therapeutic targets for age-related pathology in mammals. However, the direct targets that mediate their effects on longevity remain unclear. In mammals, CREB-regulated transcriptional coactivators (CRTCs) are a family of cofactors involved in diverse physiological processes including energy homeostasis, cancer and endoplasmic reticulum stress.

Author(s): 
Mair, William
Morantte, Ianessa
Rodrigues, Ana P. C.
Manning, Gerard
Montminy, Marc
Shaw, Reuben J.
Dillin, Andrew
Publication Title: 
Aging Cell

Dampening of insulin/insulin-like growth factor-1 (IGF1) signaling results in the extension of lifespan in invertebrate as well as murine models. The impact of this evolutionarily conserved pathway on the modulation of human lifespan remains unclear. We previously identified two IGF1R mutations (Ala-37-Thr and Arg-407-His) that are enriched in Ashkenazi Jewish centenarians as compared to younger controls and are associated with the reduced activity of the IGF1 receptor as measured in immortalized lymphocytes.

Author(s): 
Tazearslan, Cagdas
Huang, Jing
Barzilai, Nir
Suh, Yousin
Publication Title: 
PloS One

Although caloric restriction (CR) has been shown to increase lifespan in various animal models, the mechanisms underlying this phenomenon have not yet been revealed. We developed an in vitro system to mimic CR by reducing glucose concentration in cell growth medium which excludes metabolic factors and allows assessment of the effects of CR at the cellular and molecular level.

Author(s): 
Li, Yuanyuan
Tollefsbol, Trygve O.
Publication Title: 
Blood

Although the overproduction of immunoglobulins by short-lived plasma cells accompanying an immune response links with their apoptosis, how long-lived plasma cells adapt to ensure their longevity in this context is obscure. Here, we show that apoptosis signal-regulating kinase 1 (ASK1) contributes to apoptosis of plasma cells because ASK1 activity was induced during differentiation of short-lived plasma cells, and, when produced by ASK1-deficient mice, these cells survived better than those of control mice.

Author(s): 
Lin, Fan-Ru
Huang, Shang-Yi
Hung, Kuo-Hsuan
Su, Shin-Tang
Chung, Cheng-Han
Matsuzawa, Atsushi
Hsiao, Michael
Ichijo, Hidenori
Lin, Kuo-I.
Publication Title: 
Transplantation

Alloantibody can be a major barrier to successful organ transplantation; however, therapy to control antibody production or to alter its impact on the allograft remains limited. The goal of this review is to examine the regulatory steps that are involved in the generation of alloreactive B cells, with a specific emphasis on how known mechanisms relate to clinical situations in transplant recipients. Thus, we will examine the process of activation of mature, naÔve B cells and how this relates to de novo antibody production.

Author(s): 
Stegall, Mark D.
Moore, Natalie
Taner, Timucin
Li, Han
Dean, Patrick G.
Publication Title: 
Nature

Human neurons are functional over an entire lifetime, yet the mechanisms that preserve function and protect against neurodegeneration during ageing are unknown. Here we show that induction of the repressor element 1-silencing transcription factor (REST; also known as neuron-restrictive silencer factor, NRSF) is a universal feature of normal ageing in human cortical and hippocampal neurons. REST is lost, however, in mild cognitive impairment and Alzheimer's disease.

Author(s): 
Lu, Tao
Aron, Liviu
Zullo, Joseph
Pan, Ying
Kim, Haeyoung
Chen, Yiwen
Yang, Tun-Hsiang
Kim, Hyun-Min
Drake, Derek
Liu, X. Shirley
Bennett, David A.
Colai·covo, Monica P.
Yankner, Bruce A.
Publication Title: 
Medical Hypotheses

A considerable amount of evidence is consistent with the proposition that systemic IGF-I activity acts as pacesetter in the aging process. A reduction in IGF-I activity is the common characteristic of rodents whose maximal lifespan has been increased by a wide range of genetic or dietary measures, including caloric restriction. The lifespans of breeds of dogs and strains of rats tend to be inversely proportional to their mature weight and IGF-I levels.

Author(s): 
McCarty, Mark F.

Pages

Subscribe to RSS - Down-Regulation