Expression data from Drosophila tumor models

Epithelial tumors can progress from a benign tissue overgrowth (hyperplasia) to a malignant neoplastic tumor, which is characterized by an increase in motility and invasiveness. The Cohen laboratory has developed an epithelial tumor model in which overexpression of the epidermal growth factor receptor gene (EGFR) leads to benign tissue hyperplasia. When combined with other cooperating factors, EGFR overexpression can lead to neoplasia and malignant metastasis. Microarray analysis were performed in normal epithelia, hyperplastic, and neoplastic tumors collected from Drosophila wing imaginal discs to identify genes whose misexpression correlates with tumor progression For each sample, approximately 20 pairs of wing discs were dissected and processed for total RNA extraction and hybridization on Affymetrix microarrays. Four biological replicates were analyzed for each of the five tested conditions: EGFR and EGFR+psqRNAi at 12 hr (E-Ctrl and EP-Ctrl); EGFR and EGFR+psqRNAi samples at day 4 (E-EHT and EP-EHT), and from EGFR+psqRNAi at day 11 of tumor growth (EP-LNT). E-EHT rep1 was discarded from further analysis as preliminary analysis pointed to technical problems.