Project description:Drosophila mosaic eye-antennal discs from the listed genotypes generated using the MARCM system were dissected from 3rd instar larvae at day 5 after egg deposition. 20 pairs of discs for the Abrupt and scrib- + Abrupt samples and 50 pairs from FRT control, NACT scrib- +/- BskDN and RasACT scrib- +/- BskDN were used to prepare RNA. Samples were prepared in triplicate, and the RNA isolated using TRIZOL, before being column purified (Qiagen). Probes were hybridized to GeneChip Drosophila 2.0 Genome Arrays (Affymetrix). To compare the expression profile of Abrupt when overexpressed in the eye-antennal discs with tumours formed by Abrupt overexpression in scrib- clones, and to reveal JNK responsive genes in RasV12 (RasACT) scrib- versus NotchICD (NACT) scrib- eye-antennal mosaic discs
Project description:The capacity of tumor cells to maintain continual overgrowth potential has been linked to the commandeering of normal self-renewal pathways. Using an epithelial cancer model in Drosophila we carried out an overexpression screen for oncogenes capable of cooperating with the loss of the epithelial apico-basal cell polarity regulator, scribbled, and identified the cell fate regulator, Abrupt, a BTB-zinc finger protein. Abrupt overexpression alone is insufficient to transform cells, but in cooperation with scrib loss of function, Abrupt promotes the formation of massive tumors in the eye/antennal disc. The steroid hormone receptor coactivator, Taiman (SRC3/AIB1), is known to associate with Abrupt, and Taiman overexpression also drives tumor formation in cooperation with the loss of Scribbled. Expression arrays and ChIP-Seq indicates that Abrupt overexpression represses a large number of genes, including steroid hormone-response genes and multiple cell fate regulators, thereby maintaining cells within an epithelial progenitor-like state. The progenitor-like state is characterised by the failure to express the conserved Eyes absent/Dachshund regulatory complex in the eye disc, and in the antennal disc by the failure to express cell fate regulators that define the temporal elaboration of the appendage along the proximo-distal axis downstream of Distalless. Loss of scribbled promotes cooperation with Abrupt through impaired Hippo signaling, which is required and sufficient for cooperative overgrowth with Abrupt, and JNK signaling, which is required for tumor cell migration/invasion but not overgrowth. These results thus identify a novel cooperating oncogene, mammalian family members of which are also known oncogenes, and demonstrate that epithelial tumors in Drosophila can be characterised by the maintenance of a progenitor-like state. ChIP-Seq of Abrupt, ChIP-Seq of Abrupt (scrib-), Input, Input (scrib-)
Project description:Expressing constitutive active Ras (RasV12) in combination with loss of function mutations in cell polarity determinants such as scrib, dlg or lgl results in large tumors in Drosophila eye imaginal discs. We found that the transcription factor Ets21C critically affects neoplastic growth of RasV12 dlgRNAi tumors. In order better understand this phenomenon, we aimed to identify Ets21C dependent target genes. For this purpose, we did microarrays of RasV12 dlgRNAi tumors that were depleted for Ets21C or overexpressed Ets21C and compared the transcriptional profiles to control tumors.
Project description:The capacity of tumor cells to maintain continual overgrowth potential has been linked to the commandeering of normal self-renewal pathways. Using an epithelial cancer model in Drosophila we carried out an overexpression screen for oncogenes capable of cooperating with the loss of the epithelial apico-basal cell polarity regulator, scribbled, and identified the cell fate regulator, Abrupt, a BTB-zinc finger protein. Abrupt overexpression alone is insufficient to transform cells, but in cooperation with scrib loss of function, Abrupt promotes the formation of massive tumors in the eye/antennal disc. The steroid hormone receptor coactivator, Taiman (SRC3/AIB1), is known to associate with Abrupt, and Taiman overexpression also drives tumor formation in cooperation with the loss of Scribbled. Expression arrays and ChIP-Seq indicates that Abrupt overexpression represses a large number of genes, including steroid hormone-response genes and multiple cell fate regulators, thereby maintaining cells within an epithelial progenitor-like state. The progenitor-like state is characterised by the failure to express the conserved Eyes absent/Dachshund regulatory complex in the eye disc, and in the antennal disc by the failure to express cell fate regulators that define the temporal elaboration of the appendage along the proximo-distal axis downstream of Distalless. Loss of scribbled promotes cooperation with Abrupt through impaired Hippo signaling, which is required and sufficient for cooperative overgrowth with Abrupt, and JNK signaling, which is required for tumor cell migration/invasion but not overgrowth. These results thus identify a novel cooperating oncogene, mammalian family members of which are also known oncogenes, and demonstrate that epithelial tumors in Drosophila can be characterised by the maintenance of a progenitor-like state.
Project description:Drosophila mosaic eye-antennal discs from the listed genotypes generated using the MARCM system were dissected from 3rd instar larvae at day 5 after egg deposition. 20 pairs of discs for the Abrupt and scrib- + Abrupt samples and 50 pairs from FRT control, NACT scrib- +/- BskDN and RasACT scrib- +/- BskDN were used to prepare RNA. Samples were prepared in triplicate, and the RNA isolated using TRIZOL, before being column purified (Qiagen). Probes were hybridized to GeneChip Drosophila 2.0 Genome Arrays (Affymetrix).
Project description:Aim: mRNA profile of larval wing imaginal discs of Drosophila melanogaster to study the cooperation between Notch activation and loss of epithelial polarity (scrib mutation) during neoplastic growth. Results: The combination of Notch activation and scribble mutation (NS) results in mRNA expression changes that, while partly overlapping with Notch only (N), and with scrib mutation only (S), are unique to the combination
Project description:Aim: Su(H) chromatin occupancy profiling by ChIP on larval wing imaginal discs of Drosophila melanogaster to study the cooperation between Notch activation and loss of epithelial polarity (scrib mutation) during neoplastic growth. Results: The combination of Notch activation and scribble mutation (NS) does not lead to a general redeployment of Su(H) binding as compared to individual conditions (Notch only (N), and scrib mutation only (S))
Project description:Expression profiles from Drosophila melanogaster scrib and lgl mutant wing imaginal disc and brain complexes at day 9 after egg deposition (AED) versus wild type at day 5 AED