Search results for "p27"
showing 10 items of 72 documents
HSP27 controls GATA-1 protein level during erythroid cell differentiation.
2010
AbstractHeat shock protein 27 (HSP27) is a chaperone whose cellular expression increases in response to various stresses and protects the cell either by inhibiting apoptotic cell death or by promoting the ubiquitination and proteasomal degradation of specific proteins. Here, we show that globin transcription factor 1 (GATA-1) is a client protein of HSP27. In 2 models of erythroid differentiation; that is, in the human erythroleukemia cell line, K562 induced to differentiate into erythroid cells on hemin exposure and CD34+ human cells ex vivo driven to erythroid differentiation in liquid culture, depletion of HSP27 provokes an accumulation of GATA-1 and impairs terminal maturation. More spec…
Docosahexaenoic acid inhibits cancer cell growth via p27Kip1, CDK2, ERK1/ERK2, and retinoblastoma phosphorylation
2006
Docosahexaenoic acid (DHA), a PUFA of the n-3 family, inhibited the growth of FM3A mouse mammary cancer cells by arresting their progression from the late-G(1) to the S phase of the cell cycle. DHA upregulated p27(Kip1) levels by inhibiting phosphorylation of mitogen-activated protein (MAP) kinases, i.e., ERK1/ERK2. Indeed, inhibition of ERK1/ERK2 phosphorylation by DHA, U0126 [chemical MAPK extracellularly signal-regulated kinase kinase (MEK) inhibitor], and MEK(SA) (cells expressing dominant negative constructs of MEK) resulted in the accumulation of p27(Kip1). MAP kinase (MAPK) inhibition by DHA did not increase p27(Kip1) mRNA levels. Rather, this fatty acid stabilized p27(Kip1) contents…
Activation of MAP kinase p38 is critical for the cell-cycle–controlled suppressor function of regulatory T cells
2007
AbstractRegulatory T cells play an essential role in the control of self-tolerance and processes of adaptive immunity. Tolerogenic IL-10–modulated human dendritic cells (IL-10DCs) induce anergic T cells with strong suppressive properties (iTregs) that inhibit the activation of effector T cells. In this study, we evaluated the interaction between cell-cycle regulation and intracellular signaling in these iTregs. Analysis of signal transduction events revealed a down-regulation of the mitogen-activated protein kinases (MAPKs) Jun N-terminal kinase (JNK) and a nonactivation of extracellular-signal–regulated kinase (ERK) in contrast to a marked activation of p38 MAPK and the p38 effector MAPK-a…
Immunomorphological Pattern of Molecular Chaperones in Normal and Pathological Thyroid Tissues and Circulating Exosomes: Potential Use in Clinics
2019
The thyroid is a major component of the endocrine system and its pathology can cause serious diseases, e.g., papillary carcinoma (PC). However, the carcinogenic mechanisms are poorly understood and clinical useful biomarkers are scarce. Therefore, we determined if there are quantitative patterns of molecular chaperones in the tumor tissue and circulating exosomes that may be useful in diagnosis and provide clues on their participation in carcinogenesis. Hsp27, Hsp60, Hsp70, and Hsp90 were quantified by immunohistochemistry in PC, benign goiter (BG), and normal peritumoral tissue (PT). The same chaperones were assessed in plasma exosomes from PC and BG patients before and after ablative surg…
Chaperone patterns in vernal keratoconjunctivitis are distinctive of cell and Hsp type and are modified by inflammatory stimuli
2016
Background Vernal keratoconjunctivitis (VKC) is a severe ocular allergy with pathogenic mechanism poorly understood and no efficacious treatment. The aims of the study were to determine quantities and distribution of Hsp chaperones in the conjunctiva of VKC patients and assess their levels in conjunctival epithelial and fibroblast cultures exposed to inflammatory stimuli. Methods Hsp10, Hsp27, Hsp40, Hsp60, Hsp70, Hsp90, Hsp105, and Hsp110 were determined in conjunctiva biopsies from nine patients and nine healthy age-matched normal subjects, using immunomorphology and qPCR. Conjunctival epithelial cells and fibroblasts were cultured and stimulated with IL-1β, histamine, IL-4, TNF-α, or UV-…
The expression of HSP27 is associated with poor clinical outcome in intrahepatic cholangiocarcinoma.
2007
Abstract Background The heat shock proteins (HSPs) 27-kDa (HSP27) and 72-kDa (HSP72), are ubiquitous chaperone molecules inducible in cells exposed to different stress conditions. Increased level of HSPs are reported in several human cancers, and found to be associated with the resistance to some anticancer treatments and poor prognosis. However, there is no study of the relationship between HSPs expression and patient's prognosis in intrahepatic cholangiocarcinoma (IHCCA). In this exploratory retrospective study, we investigated the expressions of HSP27 and HSP72 as potential prognostic factors in IHCCA. Methods Thirty-one paraffin-embedded samples were analyzed by immunohistochemical meth…
Overexpression of cyclin D1 and interaction between p27Kip1 and tumour thickness predict lymph node metastases occurrence in lower lip squamous cell …
2005
We have attempted to identify those subgroups of patients most likely to develop lymph node metastases from squamous cell carcinoma of the lower lip (LLSSC). A total of 97 subjects, who did not undergo elective neck dissection, were recruited into the 60-month disease-free survival study. After univariate analysis, tumour size, histological grading, maximal thickness, perineural invasion and immunoreactivity to cyclin D1 and p27Kip1 proteins proved to be significant factors. Tests of the effect of interaction between p27Kip1 LI and tumour thickness yielded that the impact of tumour thickness on the risk of lymph node metastases was modified by the percentage of p27Kip1 positive cells. Subse…
Lack of the Cell-Cycle Inhibitor p27Kip1 Results in Selective Increase of Transit-Amplifying Cells for Adult Neurogenesis
2002
The subventricular zone (SVZ) is the largest germinal layer in the adult mammalian brain and comprises stem cells, transit-amplifying progenitors, and committed neuroblasts. Although the SVZ contains the highest concentration of dividing cells in the adult brain, the intracellular mechanisms controlling their proliferation have not been elucidated. We show here that loss of the cyclin-dependent kinase inhibitor p27Kip1 has very specific effects on a population of CNS progenitors responsible for adult neurogenesis. Using bromodeoxyuridine and [3H]thymidine incorporation to label cells in S phase and cell-specific markers and electron microscopy to identify distinct cell types, we compared th…
Hsp27 and Hsp70 in chronic obstructive pulmonary disease: certainties vs doubts
2015
Dear Editor, We read with great interest the work by Cui et al. (2015) in which they measured the levels of Hsp70 and Hsp27 in plasma and lymphocytes obtained from coal workers (CW) affected by chronic obstructive pulmonary disease (COPD) alone or associated with pneumoconiosis (CWP). They found that Hsp70 levels were higher in plasma of COPD subjects affected by CWP compared to COPD subjects without CWP and to controls. There was no difference in Hsp70 levels between COPD without CWP and controls. Hsp70 levels in lymphocytes did not show differences among the three groups. The authors found lower levels of Hsp27 in plasma from patients when comparing controls to both COPD with and without …
Upregulation of antibody response to heat shock proteins and tissue antigens in an ocular ischemia model.
2011
PURPOSE. The aim of this study was to characterize the serum antibody reactivities occurring after ocular ischemia reperfusion. The time course of serum antibody responses was examined. METHODS. Wistar rats were exposed to transient ocular ischemia by elevating intraocular pressure to 130 mm Hg for 60 minutes. Axonal damage was evaluated on optic-nerve sections 2 and 4 weeks later. Blood samples collected before and several times after ischemia were used for antibody detection via customized protein microarrays. Different tissue antigens, including heat shock proteins (HSPs) and crystallins, were selected based on previous identification of antibody reactivities in studies on ischemic event…