Amsterdam UMC Locatie AMC

PhD G. Hamer

Positions

Associate Professor, Research Associate

Main activities

Research

Specialisation

Reproductive Biology

Focus of research

While the genomes present in our somatic cells inevitably disappear upon death, our germ cells can pass on our genes to, in principal, endless generations of offspring. For this reason genome integritity maintenance is differentially regulated in the germline, which includes the preimplantation embryonic stem cells.

The work of Geert Hamer focusses on genome stability maintenance and development of germ cells and human preimplantation embryos. For instance, he and co-workers unravelled the mechanisms that lead to meiotic arrest during human spermatogenesis and recently discovered a miRNA that is specifically secreted by, and aids implantation of, good quality (euploid) human embryos. In addition, one of Geert Hamer's students succeeded to induce spermatogonial differentiation and meiosis in vitro, a technique that is currently explored in many laboratories for fertilty treatment or preservation. However, current results show that meiotic checkpoints, normally required to prevent genomic instability and aneuploidies to be transmitted to the offspring, are not necessarily active in vitro. In vitro generated spermatid-like cells should thus be thoroughly investigated before being considered for clinical use.

Geert Hamer and colleagues were the first the publish the transcriptome of human male germ cells. This study formed the basis of a novel research line that focusses on the role germ cell-specific genes in the development and treatment of cancer. For this research he recently won the prestigious Snoo-award for developmental biology and an Amsterdam Reproduction & Development (AR&D) research grant.

Moreover, Geert Hamer is co-writer of a granted ZonMW Translational Research Program, in which he will be co-promotor and supervisor of a PhD student that will study the influence of different culture media on genome intergrity maintenance and quality of human preimplanation embryo's in an IVF setting.

https://orcid.org/0000-0002-9583-6796

Amsterdam UMC Research Institutes

Amsterdam Reproduction & Development

AMC departments

Reproductive Biology Laboratory

Key publications

Bruggeman Jan Willem, Koster Jan, Lodder Paul, Repping Sjoerd, Hamer Geert Massive expression of germ cell-specific genes is a hallmark of cancer and a potential target for novel treatment development Oncogene 2018;37 (42):5694-5700 [PubMed]
Jan Sabrina Z., Jongejan Aldo, Korver Cindy M., van Daalen Saskia K. M., van Pelt Ans M. M., Repping Sjoerd, Hamer Geert Distinct prophase arrest mechanisms in human male meiosis Development (Cambridge, England) 2018;145 (16) [PubMed]
Zheng Yi, Lei Qijing, Jongejan Aldo, Mulder Callista L., van Daalen Saskia K. M., Mastenbroek Sebastiaan, Hwang Grace, Jordan Philip W., Repping Sjoerd, Hamer Geert The influence of retinoic acid-induced differentiation on the radiation response of male germline stem cells DNA repair 2018;70:55-66 [PubMed]
Verver Dideke E., Hwang Grace H., Jordan Philip W., Hamer Geert Resolving complex chromosome structures during meiosis: versatile deployment of Smc5/6 Chromosoma 2016;125 (1):15-27 [PubMed]
Verver D. E., van Pelt A. M. M., Repping S., Hamer G. Role for rodent Smc6 in pericentromeric heterochromatin domains during spermatogonial differentiation and meiosis Cell death & disease 2013;4:e749 [PubMed]

All Publications

Curriculum Vitae

After obtaining his PhD in Utrecht on DNA damage repair in male germ cells and two research projects, at the Karolinska institute in Stockholm and Biomedicum in Helsinki , Geert Hamer returned to the Netherlands in 2011 to start his own research group in the Reproductive Biology Laboratory of the Center for Reproductive Medicine at the Amsterdam UMC.

The work of Geert Hamer has been paramount in the research on genome stability maintenance and development of germ cells and preimplantation embryos. For instance, he and co-workers unravelled the mechanisms that lead to meiotic arrest during human spermatogenesisand recently discovered a miRNA that is specifically secreted by, and aids implantation of, good quality (euploid) human embryos.Moreover, Geert Hamer and colleagues were the first the publish the transcriptome of human male germ cells. This study formed the basis of a novel research line that focusses on the role of germ cell-specific genes in the development and treatment of cancer.

Geert Hamer is regularly invited as speaker or expert on science symposiums for clinicians or lay-men and on panel discussions and public debates. He is BKO certified and teaches in many courses for medicine, biology or medical biology (undergraduate and PhD) students.

Research programmes

PhD G. Hamer (Promoties)

Faculty
MD R.P. Berkhout
J.W. Bruggeman
MSc S.Z. Jan
MSc Q. Lei
M.A.J. Smits
MSc D.E. Verver
Y. Zheng