dr. Siebe Loontiens (PhD)

CRIG member
Siebe Loontiens

Molecular biologist - Lab supervisor Molecular Diagnostics UZ Ghent (UZ Ghent)
Principal investigator: prof. Kathleen Claes (PhD) and prof. Nadine Van Roy (PhD)


Research focus

At the platform molecular diagnostics UZ Gent (MDG), novel capture- and amplicon-based next-generation sequencing technologies are being validated for the detection of SNVs, indels, CNVs and fusions in DNA/RNA of tumor tissue, blood or bone marrow samples of cancer patients. The presence of certain genetic defects can help to predict therapy response, can guide the diagnosis and/or can fine tune the prognosis of cancer patients with solid tumors or hematological malignancies.
Using these DNA and RNA-based NGS technologies, MDG collaborates with the pathology department in the further characterization of rare tumor entities and the detection of novel variants and fusions in tumor samples resulting in interesting case reports. Novel technologies including comprehensive genomic profiling, mutation analysis in liquid biopsies using NGS, methylation profiling, homology recombination deficiency testing and optical genome mapping are being explored to implement further in the clinical setting.


I obtained a Master in Biomedical Sciences with a major in Genetics (UGent, 2014).
I immediately became a full-time doctoral fellow (from 2014 until 2019, FWO fellowship) at the lab of Frank Speleman.
In 2017 I did a 6 months internship at the lab of David Langenau, Harvard medical school, Boston. 

Key publications

  • Cell of origin dictates aggression and stem cell number in acute lymphoblastic leukemia. Leukemia. 2018 Aug;32(8):1860-1865. doi: 10.1038/s41375-018-0130-0. Epub 2018 Apr 18. PMID: 29749398.
  • TBX2 is a neuroblastoma core regulatory circuitry component enhancing MYCN/FOXM1 reactivation of DREAM targets. Nat Commun. 2018 Nov 19;9(1):4866. doi: 10.1038/s41467-018-06699-9. PMID: 30451831 
  • ALK positively regulates MYCN activity through repression of HBP1 expression. Oncogene. 2019 Apr;38(15):2690-2705. doi: 10.1038/s41388-018-0595-3. Epub 2018 Dec 11. PMID: 30538293.
  • Purification of high-quality RNA from a small number of fluorescence activated cell sorted zebrafish cells for RNA sequencing purposes. BMC Genomics. 2019 Mar 20;20(1):228. doi: 10.1186/s12864-019-5608-2. PMID: 30894119; PMCID: PMC6425699
  • A novel TLX1-driven T-ALL zebrafish model: comparative genomic analysis with other leukemia models. Leukemia. 2020 Dec;34(12):3398-3403. doi: 10.1038/s41375-020-0938-2. Epub 2020 Jun 26. PMID: 32591643
  • PRL3 enhances T-cell acute lymphoblastic leukemia growth through suppressing T-cell signaling pathways and apoptosis. Leukemia. 2021 Mar;35(3):679-690. doi: 10.1038/s41375-020-0937-3. Epub 2020 Jun 30. PMID: 32606318.
  • PHF6 Expression Levels Impact Human Hematopoietic Stem Cell Differentiation. Front Cell Dev Biol. 2020 Nov 4;8:599472. doi: 10.3389/fcell.2020.599472. PMID: 33251223
  • SOX11 regulates SWI/SNF complex components as member of the adrenergic neuroblastoma core regulatory circuitry. Nat Commun. 2023 Mar 7;14(1):1267. doi: 10.1038/s41467-023-36735-2. PMID: 36882421
  • RRM2 enhances MYCN-driven neuroblastoma formation and acts as a synergistic target with CHK1 inhibition Sci Adv. 2022 Jul 15;8(28):eabn1382. doi: 10.1126/sciadv.abn1382. Epub 2022 Jul 13. PMID: 35857500
  • Therapeutic targeting of LCK tyrosine kinase and mTOR signaling in T-cell acute lymphoblastic leukemia. Blood. 2022 Oct 27;140(17):1891-1906. doi: 10.1182/blood.2021015106. PMID: 35544598
  • RAF1-rearranged Spindle Cell Mesenchymal Tumor With Calcification and Heterotopic Ossification: A Case Report and Review of Literature. Int J Surg Pathol. 2024 Feb;32(1):133-139. doi: 10.1177/10668969231167493. Epub 2023 May 4. PMID: 37141633.
  • High-grade endometrial stromal sarcoma-like' sarcoma in male: Does it exist? A case report and review of the literature. Pathol Res Pract. 2023 Jan;241:154228. doi: 10.1016/j.prp.2022.154228. Epub 2022 Nov 17. PMID: 36455366.
  • Revealing RB1 loss in an emerging entity: report of two cases of PRRX1-rearranged mesenchymal tumours. J Clin Pathol. 2023 Dec 28:jcp-2023-209267. doi: 10.1136/jcp-2023-209267. Epub ahead of print. PMID: 38154915.

Contact & links

  • Lab address: UZ-MRB, Medical Research Building 1 (MRB1), 1st floor, room 110.050, Corneel Heymanslaan 10, 9000 Ghent, Belgium
  • Moleculaire diagnostiek UZ Gent 
  • LinkedIn
  • Member of the Consortium for Sarcoma Research Ghent (ConSaRGhent)
  • Siebe Loontiens is interested to receive invitations for presentations or talks