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Updated: Mar 10, 2026
Induction and Diagnosis of Tumors in Drosophila Imaginal Disc Epithelia
Published on: July 25, 2017
The SWI/SNF Complex Protein Snr1 Is a Tumor Suppressor in Drosophila Imaginal Tissues
Gengqiang Xie1, Hanqing Chen2, Dongyu Jia1
1Department of Biological Science, Florida State University, Tallahassee, Florida.
Abstract:
Components of the SWI/SNF chromatin-remodeling complex are among the most frequently mutated genes in various human cancers, yet only SMARCB1/hSNF5, a core member of the SWI/SNF complex, is mutated in malignant rhabdoid tumors (MRT). How SMARCB1/hSNF5 functions differently from other members of the SWI/SNF complex remains unclear. Here, we use Drosophila imaginal epithelial tissues to demonstrate that Snr1, the conserved homolog of human SMARCB1/hSNF5, prevents tumorigenesis by maintaining normal endosomal trafficking-mediated signaling cascades. Removal of Snr1 resulted in neoplastic tumorigenic overgrowth in imaginal epithelial tissues, whereas depletion of any other members of the SWI/SNF complex did not induce similar phenotypes. Unlike other components of the SWI/SNF complex that were detected only in the nucleus, Snr1 was observed in both the nucleus and the cytoplasm. Aberrant regulation of multiple signaling pathways, including Notch, JNK, and JAK/STAT, was responsible for tumor progression upon snr1-depletion. Our results suggest that the cytoplasmic Snr1 may play a tumor suppressive role in Drosophila imaginal tissues, offering a foundation for understanding the pivotal role of SMARCB1/hSNF5 in suppressing MRT during early childhood. Cancer Res; 77(4); 862-73. ©2017 AACR.
Insights
The SWI/SNF complex component Snr1, a homolog of SMARCB1/hSNF5, prevents cancer by regulating signaling pathways. Its absence causes tumor overgrowth, unlike other SWI/SNF members.
Area of Science:
- Cellular Biology
- Cancer Research
- Genetics
Background:
- SWI/SNF chromatin-remodeling complex mutations are common in cancers.
- SMARCB1/hSNF5 is uniquely mutated in malignant rhabdoid tumors (MRT).
- The distinct function of SMARCB1/hSNF5 within the SWI/SNF complex is not well understood.
Purpose of the Study:
- To investigate the tumor-suppressive role of Snr1, the Drosophila homolog of SMARCB1/hSNF5.
- To elucidate the mechanisms by which Snr1 prevents tumorigenesis.
- To understand the differential function of SMARCB1/hSNF5 compared to other SWI/SNF components.
Main Methods:
- Utilized Drosophila imaginal epithelial tissues as a model system.
- Depleted Snr1 and other SWI/SNF complex members to observe phenotypic effects.
- Examined the subcellular localization of Snr1 and its impact on signaling pathways.
Main Results:
- Snr1 depletion led to neoplastic overgrowth in Drosophila tissues, indicating tumor formation.
- Depletion of other SWI/SNF members did not induce similar tumorigenic phenotypes.
- Snr1 was found in both the nucleus and cytoplasm, unlike other SWI/SNF components.
- Tumor progression was linked to aberrant Notch, JNK, and JAK/STAT signaling pathways.
Conclusions:
- Cytoplasmic Snr1 plays a crucial tumor-suppressive role in Drosophila imaginal tissues.
- Snr1 prevents tumorigenesis by maintaining normal endosomal trafficking-mediated signaling.
- These findings provide a basis for understanding SMARCB1/hSNF5's role in suppressing MRT.
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