Neglected Cross-contaminations in Life Sciences and Next Generation Tumor Cell Models
Dr. Wilhelm Dirks (DSMZ, Braunschweig)
Mon, 24.06.2024, 13:00-14:00
Multiscale Imaging Centre (Auditorium), Röntgenstraße 16, 48149 Münster
Everybody interested is welcome! No registration required.

Many of the tumor cell lines that are commonly used in cancer research were established decades ago. These cell lines have been extraordinarily useful for decades in in-vitro experiments to study cancer biology, biochemistry, and drug targets. However, cross-contaminations and genetic drifting had affected reproducibility of scientific data in translational cancer research. Furthermore, conclusions about how in-vitro observations may relate to clinical biology is challenging because cancer cell lines lack the cellular complexity and architecture of human tumors.

Next-generation 3D cell culture models, such as spheroids, conditionally reprogrammed cells (CRC), or induced pluripotent stem cells (iPSCs) and iPSC-derived organoids, offer the possibility to propagate primary normal and cancer cells much closer to their in vivo counterparts and thus represent excellent tools to support precision oncology research. Recent initiatives are addressing the shortcomings of current models by collecting clinical data from patients and, as far as possible, the genomes and transcriptomes of the parent tumors. The first next-gen models have been included in the MuTZ cell bank and will be briefly presented.

The most important criterion for depositing the new models in cell banks is their unlimited and continuous availability. Immortality and senescence are linked to the enzymatic renewal of the chromosome ends (telomeres) in order to overcome the so-called Hayflick limit as a predetermined number of cell divisions. However, determining an existing telomerase activity using techniques from the 1990s is laborious, time-consuming and difficult to reproduce. Therefore, we have developed a non-radioactive, fast and reliable fluorescence telomere repeat amplification protocol (f-TRAP): By combining a fluorescence-labelled oligo-nucleotide telomere bait and subsequent PCR amplification, the detection limit of telomerase activity using capillary electrophoresis is below one telomerase-positive cell out of ten thousand negatives. In view of the increasing research with human pluripotent stem cells, including banking of next-gen tumor models, f-TRAP enables rapid assessment of immortality as a prerequisite for reliable model systems, which the DSMZ is the first global cell bank to introduce in its quality and routine operations.