Targeting heat shock proteins in cancer

Heat shock proteins (HSPs) HSP27, HSP70 and HSP90 are powerful chaperones. Their expression is induced in response to a wide variety of physiological and environmental insults including anti-cancer chemotherapy, thus allowing the cell to survive to lethal conditions. Different functions of HSPs have been described to account for their cytoprotective function, including their role as molecular chaperones as they play a central role in the correct folding of misfolded proteins, but also their anti-apoptotic properties. HSPs are often overexpressed in cancer cells and this constitutive expression is necessary for cancer cells' survival. HSPs may have oncogene-like functions and likewise mediat…

Dose-dependent biphasic leptin-induced proliferation is caused by non-specific IL-6/NF-κB pathway activation in human myometrial cells

Background and Purpose Leptin, an adipokine synthesized by the placenta during pregnancy, has been proposed for the management of preterm labour (PTL), as it is able to prevent in vitro uterine contractility and remodelling associated with labour onset. Another common feature of labour onset is the phenotypic switch of myometrial smooth muscle cells from a proliferative to a hypertrophic state. As proliferative effects have been demonstrated for leptin in other tissues, we aimed to investigate its ability to induce myometrial proliferation and thus to maintain uterine quiescence. Experimental Approach We stimulated human primary myometrial smooth muscle cells with leptin in the presence or …

C-terminal amino acids are essential for human heat shock protein 70 dimerization

The human inducible heat shock protein 70 (hHsp70), which is involved in several major pathologies, including neurodegenerative disorders and cancer, is a key molecular chaperone and contributes to the proper protein folding and maintenance of a large number of protein structures. Despite its role in disease, the current structural knowledge of hHsp70 is almost exclusively based on its Escherichia coli homolog, DnaK, even though these two proteins only share ~50 % amino acid identity. For the first time, we describe a complete heterologous production and purification strategy that allowed us to obtain a large amount of soluble, full-length, and non-tagged hHsp70. The protein displayed both …

Recombinant expression of the N-terminal domain of human T1R2 taste receptor: interaction with brazzein, a sweet-tasting protein

A self-inducible heterologous protein expression system in Escherichia coli

AbstractEscherichia coli is an important experimental, medical and industrial cell factory for recombinant protein production. The inducible lac promoter is one of the most commonly used promoters for heterologous protein expression in E. coli. Isopropyl-β-D-thiogalactoside (IPTG) is currently the most efficient molecular inducer for regulating this promoter’s transcriptional activity. However, limitations have been observed in large-scale and microplate production, including toxicity, cost and culture monitoring. Here, we report the novel SILEX (Self-InducibLe Expression) system, which is a convenient, cost-effective alternative that does not require cell density monitoring or IPTG inducti…

Système d’expression auto-inductible n° 3.026.109

En cours d'enregistrement international N° et date de dépôt : FR1459019 - 2014-09-24 ; n° et date de publication de la demande : FR3026109 - 2016-03-25 (BOPI 2016-12).

Patients with colorectal tumors with microsatellite instability and large deletions in HSP110 T17 have improved response to 5-fluorouracil–based chemotherapy.

Background & Aims Patients with colorectal tumors with microsatellite instability (MSI) have better prognoses than patients with tumors without MSI, but have a poor response to 5-fluorouracil–based chemotherapy. A dominant-negative form of heat shock protein (HSP)110 (HSP110DE9) expressed by cancer cells with MSI, via exon skipping caused by somatic deletions in the T 17 intron repeat, sensitizes the cells to 5-fluorouracil and oxaliplatin. We investigated whether HSP110 T 17 could be used to identify patients with colorectal cancer who would benefit from adjuvant chemotherapy with 5-fluorouracil and oxaliplatin. Methods We characterized the interaction between HSP110 and HSP110DE9 using su…

HSP110 promotes colorectal cancer growth through STAT3 activation.

IF 7.932; International audience; Heat shock protein 110 (HSP110) is induced by different stresses and, through its anti-apoptotic and chaperoning properties, helps cells survive these adverse situations. In colon cancers, HSP110 is abnormally abundant. We have recently shown that colorectal cancer patients with microsatellite instability (MSI) had an improved response to chemotherapy because they harbor an HSP110-inactivating mutation (HSP110DE9). In this work, we used patient biopsies, human colorectal cancer cells grown in vitro and in vivo (xenografts), and intestinal crypts to demonstrate that HSP110 is also involved in colon cancer growth. We showed that HSP110 induces colon cancer ce…

HSP70 sequestration by free α-globin promotes ineffective erythropoiesis in β-thalassaemia

International audience; β-Thalassaemia major (β-TM) is an inherited haemoglobinopathy caused by a quantitative defect in the synthesis of β-globin chains of haemoglobin, leading to the accumulation of free α-globin chains that form toxic aggregates. Despite extensive knowledge of the molecular defects causing β-TM, little is known of the mechanisms responsible for the ineffective erythropoiesis observed in the condition, which is characterized by accelerated erythroid differentiation, maturation arrest and apoptosis at the polychromatophilic stage. We have previously demonstrated that normal human erythroid maturation requires a transient activation of caspase-3 at the later stages of matur…

Nanofitins targeting heat shock protein 110: an innovative immunotherapeutic modality in cancer.

The presence of an inactivating heat shock protein 110 (HSP110) mutation in colorectal cancers has been correlated with an excellent prognosis and with the ability of HSP110 to favor the formation of tolerogenic (M2-like) macrophages. These clinical and experimental results suggest a potentially powerful new strategy against colorectal cancer: the inhibition of HSP110. In this work, as an alternative to neutralizing antibodies, Nanofitins (scaffold ~7 kDa proteins) targeting HSP110 were isolated from the screening of a synthetic Nanofitin library, and their capacity to bind (immunoprecipitation, biolayer interferometry) and to inhibit HSP110 was analyzed in vitro and in vivo. Three Nanofiti…

Molecular Pathways Involved in Prostate Carcinogenesis: Insights from Public Microarray Datasets

PLoS one 7(11), e49831 (2012). doi:10.1371/journal.pone.0049831

XPO1 regulates erythroid differentiation and is a new target for the treatment of β-thalassemia

β-thalassemia major (β-TM) is an inherited hemoglobinopathy caused by a quantitative defect in the synthesis of β-globin chains of hemoglobin, leading to the accumulation of free a-globin chains that aggregate and cause ineffective erythropoiesis. We have previously demonstrated that terminal erythroid maturation requires a transient activation of caspase-3 and that the chaperone Heat Shock Protein 70 (HSP70) accumulates in the nucleus to protect GATA-1 transcription factor from caspase-3 cleavage. This nuclear accumulation of HSP70 is inhibited in human β-TM erythroblasts due to HSP70 sequestration in the cytoplasm by free a-globin chains, resulting in maturation arrest and apoptosis. Like…

Visible photothermal deflection spectroscopy using microcantilevers

International audience; Photothermal deflection spectroscopy based on bi-material cantilevers combines the sensitivity of miniature sensors and the selectivity of optical spectroscopy. In this paper, we report on the photothermal response of the microcantilevers functionalized with nanometer thin organic films in the visible region. Unlike responses in the infrared regime, in the optical region, light absorption by all the cantilever constituents must be considered for extraction of the physical parameters of the organic layer. A model of photothermal deflection for the optical region has been developed for two absorbing layers consisting of a thick metal (>200 nm) and a thin organic film. …

Interaction of the n-terminal domain of human t1r2 taste receptor with brazzein, a sweet-tasting protein

Brazzein is a small (6.5 kDa) sweet-tasting protein originating from the fruit of Pentadiplandra brazzeana, a plant found in West Africa. Brazzein like all classes of sweet compounds is perceived through the activation of the T1R2/T1R3 heterodimeric sweet-taste receptor. T1R2 and T1R3 subunits are members of the small family of class C G-protein coupled receptors (GPCRs). Class C GPCRs possess a large N-terminal domain (NTD) linked to seven transmembrane domain by a cysteine rich domain (CRD). The NTD of T1R2 (T1R2-NTD) has been shown to contain the primary binding site for most of the sweet ligands. However, brazzein has been shown to require CRD of human T1R3 for receptor activation [1]. …

Abstract 1138: The protein disulfide isomerase inhibitor XCE853 inhibits in vitro, ex-vivo and in vivo growth of human tumors

Abstract Protein disulfide isomerase (PDI) is a chaperone protein that regulates oxidative protein folding as well as cell viability. Increased PDI levels have been documented in a variety of human cancers associated with a poor overall survival, including ovarian, prostate, brain and lung cancers. Inhibition of PDI activity leads to apoptosis in cancer, suggesting that PDI is a promising druggable target. XCE853 is a synthetic small molecule displaying an excellent docking with the catalytic domain of the human PDI. XCE853 inhibits in vitro recombinant PDI enzymatic activity. In addition, the proliferation of a large panel of human tumor cells is blocked by XCE853 with IC50s in the nanomol…

Targeting cancer with peptide aptamers

Renaud Seigneuric 1,2 , Jessica Gobbo 1,2 , Pierre Colas 3 , Carmen Garrido 1,2 1 Heat Shock Proteins and Cancer, INSERM, UMR 866 IFR 100, Faculty of Medicine, 7 Boulevard Jeanne D'Arc, 21000 Dijon, France 2 Universite de Bourgogne, Dijon, France 3 CNRS USR 3151, P2I2 Group, Station Biologique, Roscoff, Bretagne, France Received: June 22, 2011; Accepted: June 24, 2011; Published: June 24, 2011; Correspondence: Renaud Seigneuric, email: // // Abstract A major endeavour in cancer chemotherapy is to develop agents that specifically target a biomolecule of interest. There are two main classes of targeting agents: small molecules and biologics. Among biologics (e.g.: antibodies), DNA, RNA but al…

Exosomes in cancer theranostic: Diamonds in the rough

IF 3.306; International audience; During the last 10 years, exosomes, which are small vesicles of 50-200 nm diameter of endosomal origin, have aroused a great interest in the scientific and clinical community for their roles in intercellular communication in almost all physiological and pathological processes. Most cells can potentially release these nanovesicles that share with the parent cell a similar lipid bilayer with transmembrane proteins and a panel of enclosed soluble proteins such as heat shock proteins and genetic material, thus acting as potential nanoshuttles of biomarkers. Exosomes surface proteins allow their targeting and capture by recipient cells, while the exosomes' conte…