Table of contentsA standard chronotherapy todayThe mononuclear cell modelTimeThe medicine of Time is (finally) on the rise. Driven by the recognition of the 2017 Nobel Prize (for the discovery of the biological mechanisms of the circadian clock), tools are being developed at high speed to move towards personalized chronomedicine. A team from Chicago from Northwestern University offers in “PNAS” a simple test called “TimeSignature” to determine the biological clock of each individual. This innovative approach is based on a powerful algorithm which allows it to only require two blood samples. Say no to plagiarism. Get a tailor-made essay on “Why violent video games should not be banned”? Get the original essay A standard chronotherapy today For Professor Francis Lévi, pioneer of cancer timing, now coordinator of the associated European laboratory Inserm/ Warwick on the personalization of chronotherapy: “Today, we know how to do group chronotherapy, for example, we know that it is better to give glucocorticoids in the morning, NSAIDs in the afternoon or evening, fluorouracil early in the night, oxaliplatin in the early afternoon or irinotecan in the early evening. from early morning. But what about subjects with altered, decoupled, desynchronized, or even non-existent rhythms? This is the question that tests of this type must answer. There are already many indicators of the human biological clock, e.g. melatonin in the evening or cortisol peak in the morning. But as Étienne Challet, head of the “Circadian clocks and metabolism” team at the Institute of Cellular and Integrative Neuroscience (CNRS/University of Strasbourg), explains: having the phase of an individual, the methods are impractical, with repeated samples. The mononuclear cell model The biological clock is a multi-oscillating system, with a central clock that orchestrates the timing of peripheral clocks. The Chicago researchers used mononuclear cells called PBMCs (peripheral blood mononuclear cells). “These cells have the particularity of having a peripheral clock in phase with the main clock,” explains Étienne Challet. Rosemary Braun's team has successfully developed an algorithm to determine the internal time of an individual from the level of expression of messenger RNA in these cells. » An interesting test but to be validated. Keep in mind: This is just a sample. Get a personalized article now from our expert editors. Get a personalized trial The TimeSignature tool has not yet proven itself, explains Francis Lévi. “The test was developed on healthy subjects,” he explains. It does not take into account inter-patient variability, particularly in sick subjects. No model takes into account individuals with profound destruction of the circadian rhythm. We do not know how tests of this type behave in sick subjects. » For this pioneer who has been working on the subject for more than 30 years, the problem is that of concepts. “These molecular biology papers assume that the clock works for everyone and in the same way,” he continues. However, this is not true. These new data must converge with medical expertise and these tests must be tested prospectively in protocols. "A European project coordinated by Professor Levi is currently testing the combination with biomarkers such as wake/activity rhythm, temperature, sleep, measured continuously using sensors..