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:Cancer-driving mutations synergize with inflammatory stress signaling pathways during carcinogenesis. Drosophila melanogaster tumour models are increasingly recognized as models to inform conserved molecular mechanisms of tumorigenesis with both local and systemic effects of cancer. Although initial discoveries of the Toll-NFkB signaling pathway in development and immunity was pioneered in Drosophila, limited information is available for its role in cancer progression. Using a well-studied cooperative RasV12 -driven epithelial-derived tumour model, we here describe functions of Toll- NF-kB signaling in malignant RasV12, scrib- tumors. The extracellular Toll pathway components ModSP and PGRP-SA and intracellular signaling Kinase, Pelle/IRAK, are rate-limiting for tumor growth. The Toll pathway NFkB protein Dorsal, as well as cactus/IkB show elevated expression in tumors with highest expression in invasive cell populations. Oncogenic RasV12, and not loss of scribble, confers increased expression and heterogenous distribution of two Dorsal isoforms, DorsalA and DorsalB in different tumour cell populations. Mechanistic analyses demonstrates that Dorsal, in concert with the BTB-transcription factor Chinmo, drives growth and malignancy by suppressing differentiation, counteracting apoptosis and promoting invasion of RasV12, scrib- tumors.
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