This report encompasses a series of multigenic models of colorectal cancer, using combinations of Drosophila genes related to a number of human genes implicated in this disease: human NRAS or KRAS (using an activated form of Dmel\Ras85D), human TP53 (using RNAi-knockdown targeted to Dmel\p53), human APC (using RNAi-knockdown targeted to Dmel\Apc), human PIK3CA (using RNAi-knockdown targeted to Dmel\Pten, a negative regulator of the PIK3 signaling pathway), human PTEN (using RNAi-knockdown targeted to Dmel\Pten), and human SMAD4 (using RNAi-knockdown targeted to Dmel\Med). Multigenic combinations were created in the adult hindgut epithelium using GAL4 driven by the hindgut-specific byn promoter. 32 different combinations that correspond those found in colorectal human tumors have been characterized; mechanisms of drug resistance have been investigated.
A CRISPR-Cas9-based colorectal cancer model uses an ISC-specific driver to express sgRNAs targeting multiple Drosophila genes, Apc, Apc2, p53, Med and Pten, combined with expression of activated Ras85D.
See also human disease model reports for 'colorectal cancer' (FBhh0000178), 'cancer, multiple, RAS-related' (FBhh0000474), 'cancer, multiple, TP53-related' (FBhh0000340), 'cancer, multiple, PIK3C-related' (FBhh0000400), 'familial adenomatous polyposis 1' (FBhh0000135).
[updated May 2023 by FlyBase; FBrf0222196]
Genes recurrently mutated in colon tumors lead to misregulation of five distinct signalling pathways: Wnt, receptor tyrosine kinase/Ras, p53, transforming growth factor-b and PI3K (FBrf0234055).
One to one: 1 human to 1 Drosophila.
Many to many: multiple paralogs and orthologs in both species.
Many to many: multiple paralogs and orthologs in both species.
Many to one: 3 human to 1 Drosophila; additional orthologous human genes are TP63 and TP73.
One to one: 1 human to 1 Drosophila.
Many to one (4 human to one Drosophila); the 4 human genes are PIK3CD, PIK3CB, PIK3CG, and PIK3CA.
High-scoring ortholog of human genes TP53, TP63 and TP73 (1 Drosophila to many human). Dmel\p53 shares 20-24% identity and 36-41% similarity with the human genes.
Ortholog of human genes APC and APC2 (2 Drosophila to 2 human). Dmel\Apc shares 25-26% identity and 37% similarity with both human genes; it lacks a microtubule-binding domain found at the C terminus of the human APC gene.
High-scoring ortholog of human PTEN (1 Drosophila to 1 human); Dmel\Pten shares 39% identity and 55% similarity with the human gene.
High-scoring ortholog of human SMAD4 (1 Drosophila to 1 human); Dmel\Med shares 50% identity and 56% similarity with the human gene.