Effectiveness of electronic patient reporting outcomes, by a digital telemonitoring platform, for prostate cancer care: the Protecty study.

Research aim and purpose: The benefits of Electronic Patient -Reported Outcomes (e-PRO) for telemonitoring are well established, allowing early detection of illnesses and continuous monitoring of patients. The primary objective of the PROTECTY study was to assess the compliance with patient use of the telemonitoring platform Cureety. An exploratory objective was to assess if the first-month health status is a prognostic factor of progression free-survival (PFS) and overall survival (OS) for prostate cancer patient. Methods: This prospective study was conducted at the Military Hospital Bégin on prostate cancer patients. Patients were allowed to respond to a symptomatology questionnaire based on CTCAE v.5.0, personalized to their pathology and treatment. An algorithm evaluates the health status of the patient based on the reported adverse events, with a classification into 2 different states: Good Health Status (GHS) and Poor Health status (PHS). Results: Sixty-one patients were enrolled between July 1st, 2020 and September 30th, 2021. The median age was 74.0 (range 58.0-94.0). 78% presented a metastatic stage, and the most represented cancer was mHSPC. Overall, 2,457 questionnaires were completed by the patients, 4.0% resulted in a health classification in to monitor or critical state. 87% of patients were classified in the GHS group. The compliance was 72% in the overall population during the first month, 71% in GHS group and 75% in PHS group. The median follow-up was 8 months. PFS at 6 months was 84% in GHS group vs. 57% in PHS group, p = 0.19. OS at 6 months was 98% in GHS group vs. 83% in PHS group, p = 0.31. Conclusions: Our study showed that compliance was satisfactory. The feasibility of remote monitoring for prostate cancer patients means that they should benefit from its implementation. Our study is also the first to assess the correlation between treatment tolerance and survival. The initial results suggest that e-PRO assessment could help identify in the early stages the patients that require further health assessment and potential therapeutic changes. While further follow-up of more patients will be required, our study highlights the importance of e-PRO in cancer patient care.

Endothelin-1, a regulator of angiogenesis in the chick chorioallantoic membrane.

We investigated the angiogenic properties of endothelin-1 (ET-1) using a novel experimental approach involving the constant production and release of ET-1, which was achieved by grafting stably transfected Chinese hamster ovary (CHO) (CHO-ET-1) cell aggregates onto the chorioallantoic membrane (CAM) ectoderm. Macroscopic observation showed that CHO-ET-1 cell aggregates formed highly vascularized nodules surrounded by radially rearranged vessels, with a strong angiogenic response. 5-Bromo-2'-deoxy-uridine (BrdU) studies showed an increase in endothelial cell proliferation in the CAM vasculature around CHO-ET-1 nodules. An angiogenic response was also observed with gelatin sponges containing conditioned medium from CHO-ET-1 cells. The specific involvement of ET-1 in the angiogenic effect mediated by CHO-ET-1 was demonstrated by the reduction or abolition of neovascularized CHO-ET-1 nodules by (1) bosentan, a mixed antagonist of ET(A)/ET(B) receptors, (2) an ET(A) receptor antagonist (Ru69986) and (3) phosporamidon, an inhibitor of endothelin-converting enzyme-1 (ECE-1). We also demonstrated that VEGF was involved in CHO-ET-1-mediated angiogenesis, by using a specific inhibitor of VEGF tyrosine kinase receptor activity (PTK787/ZK 222584), which abolished CHO-ET-1 nodule formation and CAM neovascularization. Thus, our results show that exogenous ET-1 mediates angiogenesis in vivo.

A functional enhanced green fluorescent protein (EGFP)-tagged angiotensin II at(1a) receptor recruits the endogenous Galphaq/11 protein to the membrane and induces its specific internalization independently of receptor-g protein coupling in HEK-293 cells.

The angiotensin II (Ang II) AT(1A) receptor was tagged at its C terminus with the enhanced green fluorescent protein (EGFP), and the corresponding chimeric cDNA was expressed in HEK-293 cells. This tagged receptor presents wild-type pharmacological and signaling properties and can be immunodetected by Western blotting and immunoprecipitation using EGFP antibodies. Therefore, this EGFP-tagged AT(1A) receptor is the perfect tool for analyzing in parallel the subcellular distributions of the receptor and its interacting G protein and their trafficking using confocal microscopy. Morphological observation of both the fluorescent receptor and its cognate Galphaq/11 protein, identified by indirect immunofluorescence, and the development of a specific software for digital image analysis together allow examination and quantification of the cellular distribution of these proteins before and after the binding of different agonist or antagonist ligands. These observations result in several conclusions: 1) Expression of increasing amounts of the AT(1A) receptor at the cell surface is associated with a progressive recruitment of the cytosolic Galphaq/11 protein at the membrane; 2) Internalization of the EGFP-tagged AT(1A) induced by peptide ligands but not nonpeptide ligands is accompanied by a Galphaq/11 protein intracellular translocation, which presents a similar kinetic pattern but occurs predominantly in a different compartment; and 3) This Galphaq/11 protein cellular translocation is dependent on receptor internalization process, but not G protein coupling and signal transduction mechanisms, as assessed by pharmacological data using agonists and antagonists and the characterization of AT(1A) receptor mutants (D(74)N and Delta329) for which the coupling and internalization functions are modified.

Systematic identification of mutations that constitutively activate the angiotensin II type 1A receptor by screening a randomly mutated cDNA library with an original pharmacological bioassay.

The constitutive activation of G-protein-coupled receptors is a major new approach to investigating their physiopathology and pharmacology. A large number of spontaneous and site-directed mutations resulting in constitutive activity have been identified, but systematic mapping of the amino acids involved for a given receptor would be extremely useful for complete elucidation of the molecular mechanisms underlying its activation. We carried out such mapping for the angiotensin II type 1A (AT(1A)) receptor by screening a randomly mutated cDNA library after expressing the mutated clones in eukaryotic cells. To test the AT(1A) mutants generated, we developed an original, specific, and highly sensitive assay based on the properties of CGP42112A. This classical AT(2) agonist is a weak partial agonist of the wild-type AT(1A) receptor and becomes a full agonist for constitutively active AT(1A) mutants, as shown experimentally and in allostery-based theoretical models. Activation of the mutated receptors by CGP42112A was monitored by using the bioluminescent protein aequorin, a very sensitive and specific sensor of intracellular calcium mobilization. The screening of 4,800 clones, providing an exhaustive coverage of all of the mutations generated, led to the identification of 16 mutations in sequences encoding the transmembrane domains that were responsible for high sensitivity to CGP42112A. The constitutive activity was confirmed by agonist-independent production of inositol phosphates, which showed that at least half of the clones had significantly increased basal activity. These data demonstrate that this new type of approach is very efficient for the systematic identification of constitutively active mutants of G-protein-coupled receptors.

Several interesting phenotypes of the AT1 receptor produced by site-directed mutagenesis.

The angiotensin II (AngII) AT1 receptor is a seven-transmembrane domain receptor coupled to a Gq/11 protein and phospholipase C, but also to other G proteins and to several tyrosine kinase pathways. These signaling pathways transduce inside the cells the classical actions of AngII (vasoconstriction, aldosterone secretion, etc.), but also the mitogenic action of this vasoactive peptide. In the past 5 yr, site-directed mutagenesis has elucidated the molecular determinants of the AngII and nonpeptidic analogue-binding sites together with those of G protein interaction. In addition, these studies have demonstrated that modifications of the specific interactions between transmembrane domains are responsible for the activation of the receptor. Therefore, several mutations of these domains are able to block the receptor in active or inactive states. Finally, these mutagenesis studies identify two interesting phenotypes of the AT1 receptor. (1) A carboxy-terminal truncation of the AT1 receptor produces a mutant that is unable to be internalized and desensitized and therefore is functionally hyper-reactive. (2) A replacement of the distal part of the third intracellular loop of the AT1 receptor by the homologous segment of the beta2-adrenergic receptor produces a mutant coupled to both Gq and Gs proteins, which is unable to transduce the mitogenic action of AngII.

Construction, expression and characterization of a soluble form of human endothelin-converting-enzyme-1.

Endothelin-converting-enzyme-1 (ECE-1) belongs to the family of zinc metallopeptidases and is responsible for generating endothelin (ET) peptides from their inactive precursors the big endothelins (bigET). The enzyme is a type II integral membrane protein consisting of a short amino-terminal cytosolic domain of 56 amino acids, a single transmembrane domain and a large putative extracellular domain containing the catalytic site. Recombinant and native ECE-1 are expressed as a dimer. We have constructed a soluble form of ECE, named sECE*, by fusing the cleavable signal peptide of pro-opiomelanocortin in frame to the complete extracellular domain of human ECE-1. Stable expression of this construct in CHO cells resulted in the secretion of a fully active enzyme. In contrast to membrane-bound ECE, sECE* was expressed as a monomer, highly glycosylated, as assessed by gel filtration and Western blot. However, recombinant sECE* converted bigET-1 with similar specific activity as ECE-1a. This activity was completely inhibited by phosphoramidon, but not by thiorphan and captopril. sECE* was active in a broad range of pH, showing an optimum of 6.6-6.8 for bigET-1. Thus, the extracellular domain alone is sufficient for conferring full ECE-1 activity, inhibitors recognition and substrate specificity.

A live-cell assay for studying extracellular and intracellular endothelin-converting enzyme activity.

Endothelin-1 (ET-1) is formed from its precursor preproET-1 via the cleavage of the intermediate bigET-1 by endothelin-converting enzyme (ECE-1). However, the subcellular site at which this step occurs is not clear: It could occur intravesicularly along the secretory pathway or bigET-1 might be released and processed extracellularly. To address this point, we have developed an integrated autocrine system that uses a recombinant Chinese hamster ovary (CHO) luciferase reporter cell line that permanently expresses the human ET(A) receptor. Into these cells we transiently transfected human ECE-1a cDNA, either together with the human preproET-1 cDNA (as an endogenous source of bigET-1), or alone (in which case exogenous bigET-1 was added). Phosphoramidon inhibited the conversion of exogenous bigET-1 (IC50 = 5 to 30 micromol/L) much better than that of endogenous bigET-1 (IC50 > 1 mmol/L). Both conversions showed similar high yields (20% to 100%) that depended on the amount of ECE-1a expressed. Thus, ECE-1a has two equally relevant activities in this recombinant system for CHO cells: (1) an intracellular, probably intravesicular activity, corresponding to the ECE-1a-mediated step of ET-1 biosynthesis and (2) an extracellular activity at the plasma membrane. If this is also the case for endothelial cells, ECE-1a inhibitors would have to cross the plasma and vesicle membranes to be effective. The present system could be useful for screening such inhibitors.