Establishing a panel of pediatric rhabdomyosarcoma tumoroids for drug testing

• Applicant: Dr. Michael Torsten Meister
• Subject Area: Pediatric and Adolescent Medicine ; Hematology, Oncology
• Term: from 2018 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 408083583

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children and adolescents. Despite significant advances in pediatric cancer therapy in general, patients with RMS still have a poor prognosis. Therefore, novel therapeutic approaches are urgently needed for these patients. Development of new treatment options would benefit from appropriate tumor models. There are only a limited number of preclinical models available for RMS. Most studies employ well-characterized RMS cell lines. However, recent studies indicate that these cell lines do not recapitulate the genetic background of RMS tumors found in patients. In order to meet this general need, technology has recently been developed to grow primary samples in vitro so that tumor cells expand over many passages without gaining novel genetic alterations: tumoroids or tumor organoids. Originally developed to grow normal organ tissue, the technology has quickly been adapted to epithelial cancers such as colorectal carcinoma, to allow tumor specimens to form tumor organoids. Transfer to non-epithelial cancer entities such as neuroblastoma has also proved to be an effective way of amplifying primary tumor cells of non-epithelial lineage as tumoroids. Tumoroid culture technology allows the establishment of long-term 3D cultures of patient-derived tissue from many organs with high efficiency. Importantly, studies to date indicate genetic stability and that the genetic background of tumoroids can predict sensitivity to anticancer drugs. The primary objective of the proposed project is to establish and characterize a panel of tumoroid models from pediatric RMS samples in order to generate preclinical models that resemble patient tumors to a higher extent than conventional cell lines. Concomitant to establishment, characterization will be performed via whole-genome-sequencing and RNA-seq as well as histopathologic phenotyping. Genetic stability will be tested via sequencing techniques on a regular basis. Thereafter, drug testing will be performed in these models. We hypothesize that by integrating the data obtained from the characterization of the RMS tumoroids and the drug testing in these models, we will be able to discover novel targetable genetic lesions in the different RMS subtypes and, consequently, to identify targeted – more efficient and less toxic – anticancer agents. Furthermore, this may lead to the identification of molecular markers that improve tumor discrimination at diagnosis and therapeutic risk stratification. In summary, we believe that these studies will serve to gain a deeper understanding in RMS biology and identify suitable anticancer drug treatments for this rare cancer entity in children.

• DFG Programme: Research Fellowships
• International Connection: Netherlands
• Host: Professor Frank Holstege, Ph.D.