Colorectal Cancer Model in Drosophila melanogaster by Inactivating the Wingless Pathway
Matthew T. Bilotti
Wingless (Wnt) signaling is an important pathway involved in tumorigenesis in colorectal cancer of humans, and can be modeled in Drosophila melanogaster given the conservation of genes and cell biological processes. To understand which components of the Wnt pathway affect growth and patterning, we studied effects of loss of APC specifically in the eye discs using MARCM based approaches. The MARCM approach allows for manipulation of gene expression (both loss- and gain-of-function) in somatic clones. Under wildtype conditions of normal cell growth, the Wnt pathway is kept under check, where a destruction complex (comprising of several proteins like Adenomatous Polyposis Coli (APC), Dishevelled (Dsh), Glycogen Synthase Kinase 3beta (GSK-3beta) and beta-Catenin) prevents nuclear translocation of beta-catenin and promotes its degradation via the ubiquitin/proteasome pathway. However, in the presence of Wnt ligand, signaling is activated and the destruction complex is inhibited. Beta-Catenin then proceeds to the nucleus as a transcription factor to turn on expression of its respective target genes which promotes cell proliferation and survival. We want to examine if loss of APC shows effects on growth and differentiation. In Drosophila, there are two APC family genes, APC and APC2, therefore we devised a strategy to generate double mutant clones wherein the expression of both APC and APC2 is eliminated in the same cells. To do so, we used the eyflp MARCM system to induce APC dysregulation solely in fly larval eye discs. We will study effects of loss of APC on growth, survival and differentiation in the eye discs, with special emphasis on interactions between APC /beta-Catenin with the Hippo pathway. We will use immunohistochemistry to study expression of Wnt target genes in experimental and control samples. We will examine the larval disc phenotypes like effects on differentiation, proliferation or cell death; and survival to adult to understand the interactions between the molecular pathways. We will compare if the interactions observed in the eye imaginal discs are tissue specific by comparing to the effects of loss of APC genes in the brain and intestines in Drosophila.
Primary Advisor's Department
Stander Symposium project, College of Arts and Sciences
United Nations Sustainable Development Goals
Good Health and Well-Being
"Colorectal Cancer Model in Drosophila melanogaster by Inactivating the Wingless Pathway" (2022). Stander Symposium Projects. 2443.