Single Cell Analysis of the Fate of Injected Oncogenic RasV12 Cells in Adult Wild Type Drosophila
Di Chen1, Xiao Lan1, Xiaoming Huang1
1Sino-French Hoffmann Institute, School of Basic Medical Science, State Key Laboratory of Respiratory Disease, Guangzhou Medical University, Guangzhou, China.
Abstract:
We have injected dish-cultured oncogenic RasV12 cells into adult male flies and analyzed by single cell transcriptomics their destiny within the host after 11 days. We identified in the preinjection samples and in the 11-day postinjection samples in all 16 clusters of cells, of which 5 disappeared during the experiment in the host. The other cell clusters expanded and expressed genes involved in the regulation of cell cycle, metabolism, and development. In addition, three clusters expressed genes related to inflammation and defense. Predominant among these were genes coding for phagocytosis and/or characteristic for plasmatocytes (the fly equivalent of macrophages). A pilot experiment indicated that the injection into flies of oncogenic cells, in which two of most strongly expressed genes had been previously silenced by RNA interference, into flies resulted in a dramatic reduction of their proliferation in the host flies as compared to controls. As we have shown earlier, the proliferation of the injected oncogenic cells in the adult flies is a hallmark of the disease and induces a wave of transcriptions in the experimental flies. We hypothesize that this results from a bitter dialogue between the injected cells and the host, while the experiments presented here should contribute to deciphering this dialogue.
Insights
Oncogenic RasV12 cells injected into adult flies were studied using single-cell transcriptomics. Host immune responses, including phagocytosis by plasmatocytes, were observed, and gene silencing reduced tumor cell proliferation.
Area of Science:
- Cell biology
- Genomics
- Immunology
Background:
- Oncogenic mutations drive cancer development.
- Understanding tumor-host interactions is crucial for cancer research.
- Drosophila melanogaster serves as a model organism for studying cancer biology.
Purpose of the Study:
- To investigate the fate and host response to oncogenic RasV12 cells in adult flies.
- To identify cellular and molecular mechanisms governing tumor progression and host defense.
- To explore therapeutic strategies targeting oncogenic cell proliferation.
Main Methods:
- Single-cell transcriptomics to analyze cell populations and gene expression.
- Injection of oncogenic RasV12 cells into adult male flies.
- RNA interference (RNAi) to silence specific genes in oncogenic cells.
Main Results:
- Out of 16 initial cell clusters, 5 disappeared, while others expanded, showing altered gene expression.
- Expanded cell clusters upregulated genes related to cell cycle, metabolism, and development.
- Three clusters exhibited immune and defense gene expression, notably phagocytosis and plasmatocyte markers.
- Silencing key genes in oncogenic cells via RNAi significantly reduced their proliferation in vivo.
Conclusions:
- The host fly mounts an immune response against injected oncogenic cells, involving plasmatocytes.
- Gene silencing strategies can effectively inhibit oncogenic cell proliferation within the host.
- The study provides insights into the complex dialogue between tumor cells and the host immune system.
