Supporting biomarker validation nationally and internationally

Luxembourg as a pioneer in colorectal cancer research

In 2017, Prof. Serge Haan and Dr. Elisabeth Letellier of the Life Sciences Research Unit at the University of Luxembourg identified protein MYO5B as a novel prognostic biomarker for colorectal cancer (CRC), which could help clinicians assess a patient’s risk of relapse and evaluate the need for chemotherapy following surgery. The researchers applied for funding for a proof-of-concept project, supported by IBBL, and were granted a EUR 387,000 financing by the National Research Fund (Fonds National de la Recherche – FNR) to validate the marker and develop a prototype companion diagnostic assay for preliminary clinical use – a project known as MyoRPROG. The assay will be based on a kit that determines the expression of the MYO5B gene. In the context of the project, IBBL will be responsible for the pre-analytical and analytical validation and will perform a clinical verification of the MYO5B biomarker, under the leadership of Biomarker Validation Scientist Dr. Monica Marchese and Chief Scientific Officer Dr. Fay Betsou. The first step entails the validation of the methods initially used by Prof. Haan and Dr. Letellier for the analysis of the expression of MYO5B, as well as an assessment of the pre-analytical factors which could affect the robustness of the biomarker. IBBL has started evaluating two sample types for the extraction of the RNA, namely frozen tissue and formalin-fixed paraffin-embedded (FFPE) tissue, and will compare different RNA quantification techniques to assess which one could provide greater sensitivity in terms of gene expression measurement for the purpose of the kit. During the clinical verification stage, IBBL will collect 150 new tissue samples from stage II CRC patients to carry out a pilot study and verify the performance of the biomarker in clinical sample sets of limited size. “Securing funding for biomarker validation is often challenging, given the associated degree of uncertainty. Being awarded the FNR grant proves that the discovery and validation of biomarkers are a national priority. We are delighted to be supporting local researchers from the initial steps of the funding application to the actual validation, and to contribute to increasing Luxembourg’s visibility in this domain”, states Dr. Marchese.

The international dimension

Dr. Marchese has also been assisting the French National Institute of Health and Medical Research (Institut national de la santé et de la recherche médicale – Inserm) in the first stages of the validation of a promising marker for latent tuberculosis infection (LTBI) – an asymptomatic state of persistent immune response to stimulation by the tuberculosis bacterium. The novel diagnostic biomarker, discovered and patented by Inserm Transfert, is based on the increased secretion of a specific cytokine[1] by a certain type of blood cells in LTBI individuals, in response to an antigen specific for the quiescent state of the Mycobacterium tuberculosis. “The first step we carried out was the ‘feasibility and optimisation’ phase”, explains Dr. Marchese. “Candidate biomarkers often fail in the translation from the ‘bench to the bed’ due to issues related the reproducibility and validation of the methodology used to discover them in the first place. We therefore sought to reproduce on our platform the exact methods that underpinned the discovery of the biomarker”. Through the ‘feasibility’ step, the IBBL team successfully demonstrated the reproducibility of the protocol on two different sample types and, during the ‘optimisation’ step, optimised it for further application in the everyday laboratory routine. “The next phase will entail the pre-analytical and analytical validation to assess the robustness and integrity of the biomarker and evaluate the fitness for purpose of the analytical method used to discover it”, adds Dr. Marchese. There are currently no accurate tests for the diagnosis of LTBI. Although there are assays that are commonly used to diagnose M. tuberculosis, these do not discriminate the active from the latent state of the infection. LTBI individuals have been shown to unequivocally respond to a specific antigen, compared to healthy controls and TB subjects. Therefore, if validated, the biomarker could be translated into a novel assay which would enable the unambiguous distinction of LTBI subjects from patients with active TB and from healthy individuals. One third of the world population being estimated to be infected with LTBI, a novel diagnostic assay could help identify and treat asymptomatic carriers and prevent the reactivation of the bacterium, thus controlling the spread of the disease globally.

[1] Small protein important in cell signaling. Its release has an effect on the behavior of surrounding cells.