Collaborative Research: NSF-BSF: Somatic cell adaptation towards immortalization in a marine tunicate

The research investigates how cells from the marine colonial tunicate Botryllus schlosseri evolve when critical molecular networks that control cell growth and programmed cell death are disturbed by either stress or genetic manipulation or a combination thereof. The main question addressed is: What molecular mechanisms constrain cell immortalization?

Immortal cell lines of marine invertebrates have great potential as “bioreactors” for producing pharmaceutical compounds with health benefits, nutraceuticals, anticancer drugs, and other biologically active chemicals. The tunicate B. schlosseri is widely distributed throughout the world and used as a common sentinel species for assessing marine pollution and other anthropogenic impacts on coastal ecosystems.

The research contributes molecular tools that increases the utility of this tunicate for bioindication. Opportunities for cross-disciplinary training, curricular, and professional development are provided to students and researchers at all career stages with emphasis on underrepresented minorities.

The main hypothesis addressed in this project is that specific evolutionary constraints prevent somatic cell immortalization in marine invertebrates and that cell immortalization is facilitated by stress-induced evolution and/or genetic manipulation that removes these constraints. The project investigates the conditions and gene regulatory networks that promote cell proliferation and counteract cellular senescence.

Primary cultures of B. schlosseri hemocytes and epithelial monolayers are exposed to (1) environmental factors (media supplements and attachment substrates), (2) stress-induced evolution, (3) synthetic manipulation of pro- and anti-proliferative genes, and (4) cell fusion technology to increase heritable variation in proteome networks and cellular phenotypes that natural selection can act on. The goal is to a) understand the sequence of molecular events that promotes cell proliferation and inhibits senescence in vitro and b) to generate the first cell line for any marine invertebrate.

This project utilizes systems biology approaches (transcriptomics, proteomics) to characterize how relevant cellular phenotypes (proliferation, senescence) are controlled by gene regulatory networks. Complex datasets are analyzed using network modeling and topological data analysis approaches. Moreover, the extent of mRNA: protein coregulation during transition of cells from in vivo to in vitro contexts provides insight into the degree of non-linearity between mRNA and protein levels of regulation in marine invertebrate cells exposed to environmental stress and synthetic genetic backgrounds.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.