scholarly journals Lipoprotein Cholesterols Are Stored in High-Resistant, Metastatic Cancer Cells and Released Upon Stress: Implication for a Mechanism Underlying Hypocholesterolemia in Cancer Patients

2018 ◽  
Author(s):  
Taka Eguchi ◽  
Chiharu Sogawa ◽  
Kisho Ono ◽  
Mami Itagaki ◽  
Masaki Matsumoto
Keyword(s):  
Heat Shock ◽  
Cancer Cells ◽  
Lipid Bilayers ◽  
Metastatic Cancer ◽  
Single Layer ◽  
Cancer Therapies ◽  
Castration Resistant Prostate Cancer ◽  
Heat Shock Stress ◽  
Shock Proteins ◽  
Shock Stress

Resistant cancer often shows a particular secretory trait such as heat shock proteins (HSPs) and extracellular vesicles (EVs), including exosomes and oncosomes surrounded by lipid bilayers. Lipoproteins are biochemical assemblies that transport hydrophobic lipid (a.k.a. fat) molecules in body fluid and are composed of a single-layer phospholipid and cholesterol outer shell, lipids molecules within the particles, and apolipoproteins embedded in the membrane. However, lipoprotein storage and secretion by cancer cells have not well-investigated yet. We found lipoproteins were stored and abundantly secreted by neuroendocrine, castration-resistant prostate cancer (NEPC / CRPC) cells but barely secreted by colon cancer cells and oral squamous cell carcinoma (OSCC) cells. In addition, large EVs (approx. 300 nm diameter) and potential oncosomes were released by CRPC and OSCC cells. Proteomics revealed that CRPC cells secreted EVs enriched with tetraspanins and extracellular matrices which were reduced upon heat shock stress and alternatively lipoproteins and HSPs were secreted upon stress. Heat shock stress triggered secretion of lipoprotein-EV complexes that contained apolipoprotein A, B, C and E. These data suggested that vesicular assembly composed of EVs and lipoproteins enriched with cholesterols and phospholipids may be stored in resistant cancer cells but released upon cell stress that is increased in cancer therapies.

The CRZ-1 Transcription Factor Regulates Hsp 80 Involves in the Acquisition of Thermotolerance, and NCA-2 for Calcium Stress Tolerance in Neurospora Crassa

2021 ◽  
Author(s):  
Avishek Roy ◽  
Ranjan Tamuli
Keyword(s):  
Transcription Factor ◽  
Heat Shock ◽  
Neurospora Crassa ◽  
Stress Condition ◽  
Stress Conditions ◽  
Start Codon ◽  
Expression Levels ◽  
Heat Shock Stress ◽  
Shock Proteins ◽  
Shock Stress

Abstract Heat shock proteins (Hsps) are molecular chaperones and required for survival of organisms under heat stress conditions. In this study, we studied Hsp80, a member of the Hsp90 family, in Neurospora crassa. The expression of hsp80 was severely reduced in the N. crassa calcineurin B subunit RIP-mutant (cnb-1RIP) strains under the heat shock conditions. Furthermore, the expression levels of cnb-1, hsp60, hsp80, and the calcineurin-regulated transcription factor crz-1 were increased, but expression levels were reduced in the presence of the calcineurin inhibitor FK506 under the heat shock stress in the N. crassa wild type. Therefore, the calcineurin-crz-1 signaling pathway transcriptionally regulates hsp60 and hsp80 under the heat shock stress condition in N. crassa. In addition, the transcript levels of trm-9 and nca-2, a Ca2+ sensor and a Ca2+ ATPase, respectively, were increased under the heat shock stress condition. Moreover, the expression of the hsp80, but not the hsp60, was reduced in the Δtrm-9, Δnca-2, and the Δtrm-9 Δnca-2 double mutants. These results suggested that hsp80, trm-9, and nca-2 play a role in coping the heat shock stress in N. crassa. We found that CRZ-1 binds to 5ʹ-CCTTCACA-3ʹ and 5ʹ-AGCGGAGC-3ʹ 8 bp nucleotide sequences, located about 1075 bp and 679 bp upstream of the ATG start codon, respectively, of hsp80. We also found that CRZ-1 binds to an 8 bp nucleotide sequence 5ʹ-ACCGCGCC-3ʹ, located 234 bp upstream of the ATG start codon of nca-2 under Ca2+ stress condition. Thus, cnb-1, hsp60, hsp80, and crz-1 are involved in the heat shock stress response in N. crassa. Moreover, CRZ-1 upregulates the expressions of hsp80 and nca-2 under the heat shock stress and Ca2+ stress conditions, respectively, in N. crassa.

Identification of cis and trans components of a novel heat shock stress regulatory pathway in Saccharomyces cerevisiae

1993 ◽  
Vol 13 (1) ◽  
pp. 248-256
Author(s):  
N Kobayashi ◽  
K McEntee
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Stress Response ◽  
Heat Shock ◽  
Reporter Gene ◽  
Heat Shock Element ◽  
Cis Acting ◽  
Heat Shock Stress ◽  
Specific Complex ◽  
Cis And Trans ◽  
Shock Stress

The stress-responsive DDR2 gene (previously called DDRA2) of Saccharomyces cerevisiae is transcribed at elevated levels following stress caused by heat shock or DNA damage. Previously, we identified a 51-bp promoter fragment, oligo31/32, which conferred heat shock inducibility on the heterologous CYC1-lacZ reporter gene in S. cerevisiae (N. Kobayashi and K. McEntee, Proc. Natl. Acad. Sci. USA 87:6550-6554, 1990). Using a series of synthetic oligonucleotides, we have identified a pentanucleotide, CCCCT (C4T), as an essential component of this stress response sequence. This element is not a binding site for the well-characterized heat shock transcription factor which recognizes a distinct cis-acting heat shock element in the promoters of many heat shock genes. Here we demonstrate the ability of oligonucleotides containing the C4T sequence to confer heat shock inducibility on the reporter gene and show that the presence of two such elements produces more than additive effects on induction. Gel retardation experiments have been used to demonstrate specific complex formation between C4T-containing fragments and one or more yeast proteins. Formation of these complexes was not competed by fragments containing mutations in the C4T sequence nor by heat shock element-containing competitor DNAs. Fragments containing the C4T element bound to a single 140-kDa polypeptide, distinct from heat shock transcription factors in yeast crude extracts. These experiments identify key cis- and trans-acting components of a novel heat shock stress response pathway in S. cerevisiae.

scholarly journals Hsps responsible for apoptosis induction failure in cervical cancer cells upon osthole and tamoxifen treatment

2019 ◽  
Vol 73 ◽  
pp. 563-571
Author(s):  
Joanna Jakubowicz-Gil ◽  
Roman Paduch ◽  
Krystyna Skalicka-Woźniak ◽  
Joanna Sumorek-Wiadro ◽  
Adrian Zając ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Cancer Cells ◽  
Cell Lines ◽  
Tamoxifen Treatment ◽  
Hpv 16 ◽  
Cervical Cancer Cells ◽  
Shock Proteins ◽  
Human Cervical Cancer

Aim: The aim of the present study was to investigate the efficacy of osthole (7-metoxy-8-isopenthenocoumarin) alone and combined with tamoxifen (TAM) in the elimination of human cervical cancer cells via programmed death. The involvement of heat shock proteins, i.e. well-known molecular chaperones, will be investigated. Material/Methods: Three human cervical cancer cell lines, infected with human papilloma virus (HPV), i.e. HeLa (HPV 18), SiHa (HPV 16), and CaSki (HPV 16 and 18), were used in the experiments. After osthole and TAM treatment, cells stained with fluorochromes were analyzed microscopically according to apoptotic, autophagic, and necrotic morphology. Hsp27, Hsp72, and Hsp90 levels were analyzed by immunoblotting. Transfection with specific siRNA was used for blocking of Hsp expression. Results: In the HeLa, CaSki, and SiHa cell lines, osthole and TAM applied alone had no significant effect on cell death induction. This was correlated with an overexpression of heat shock proteins 27, 72, and 90. In the case of a combination of both drugs, the level of apoptosis was elevated only in SiHa cells. Preincubation with osthole followed by TAM addition as well as simultaneous incubation with both drugs was the most effective. This was correlated with the inhibition of Hsp27, Hsp72, and Hsp90 expression. Blocking of Hsp expression with specific siRNA increased the sensitivity of the studied cell lines to the induction of apoptosis, but not to autophagy or necrosis. Conclusions: Our results indicated that the elimination of heat shock proteins from cervical cancer cells sensitized them to initiation of apoptosis after osthole and tamoxifen treatment.

scholarly journals Direct link between metabolic regulation and the heat-shock response through the transcriptional regulator PGC-1α

2015 ◽  
Vol 112 (42) ◽  
pp. E5669-E5678 ◽  
Author(s):  
Neri Minsky ◽  
Robert G. Roeder
Keyword(s):  
Gene Expression ◽  
Stress Response ◽  
Heat Shock ◽  
Metabolic Regulation ◽  
Hormone Receptors ◽  
Transcriptional Networks ◽  
Direct Link ◽  
Heat Shock Stress ◽  
Metabolic Genes ◽  
Shock Stress

In recent years an extensive effort has been made to elucidate the molecular pathways involved in metabolic signaling in health and disease. Here we show, surprisingly, that metabolic regulation and the heat-shock/stress response are directly linked. Peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), a critical transcriptional coactivator of metabolic genes, acts as a direct transcriptional repressor of heat-shock factor 1 (HSF1), a key regulator of the heat-shock/stress response. Our findings reveal that heat-shock protein (HSP) gene expression is suppressed during fasting in mouse liver and in primary hepatocytes dependent on PGC-1α. HSF1 and PGC-1α associate physically and are colocalized on several HSP promoters. These observations are extended to several cancer cell lines in which PGC-1α is shown to repress the ability of HSF1 to activate gene-expression programs necessary for cancer survival. Our study reveals a surprising direct link between two major cellular transcriptional networks, highlighting a previously unrecognized facet of the activity of the central metabolic regulator PGC-1α beyond its well-established ability to boost metabolic genes via its interactions with nuclear hormone receptors and nuclear respiratory factors. Our data point to PGC-1α as a critical repressor of HSF1-mediated transcriptional programs, a finding with possible implications both for our understanding of the full scope of metabolically regulated target genes in vivo and, conceivably, for therapeutics.

scholarly journals The Mitogen-Activated Protein Kinase Slt2 Regulates Nuclear Retention of Non-Heat Shock mRNAs during Heat Shock-Induced Stress

2010 ◽  
Vol 30 (21) ◽  
pp. 5168-5179 ◽  
Author(s):  
Sean R. Carmody ◽  
Elizabeth J. Tran ◽  
Luciano H. Apponi ◽  
Anita H. Corbett ◽  
Susan R. Wente
Keyword(s):  
Heat Shock ◽  
Map Kinase ◽  
Mrna Export ◽  
Mitogen Activated Protein Kinase ◽  
Focus Formation ◽  
Mrna Accumulation ◽  
Heat Shock Stress ◽  
Mitogen Activated Protein ◽  
Nuclear Foci ◽  
Shock Stress

ABSTRACT Cellular adaptation to environmental stress conditions requires rapid and specific changes in gene expression. During heat shock, most polyadenylated mRNAs are retained in the nucleus, whereas the export of heat shock-induced mRNAs is allowed. Although essential mRNA export factors are known, the precise mechanism for regulating transport is not fully understood. Here we find that during heat shock in Saccharomyces cerevisiae, the mRNA-binding protein Nab2 is phosphorylated on threonine 178 and serine 180 by the mitogen-activated protein (MAP) kinase Slt2/Mpk1. Slt2 is required for nuclear poly(A+) mRNA accumulation upon heat shock, and thermotolerance is decreased in a nup42 nab2-T178A/S180A mutant. Coincident with phosphorylation, Nab2 and Yra1 colocalize in nuclear foci with Mlp1, a protein involved in mRNA retention. Nab2 nuclear focus formation and Nab2 phosphorylation are independent, suggesting that heat shock induces multiple cellular alterations that impinge upon transport efficiency. Under normal conditions, we find that the mRNA export receptor Mex67 and Nab2 directly interact. However, upon heat shock stress, Mex67 does not localize to the Mlp1 nuclear foci, and its association with Nab2 complexes is reduced. These results reveal a novel mechanism by which the MAP kinase Slt2 and Mlp1 control mRNA export factors during heat shock stress.

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