Gene expression data from renal preneoplastic lesions

Microarrays were used to analyse gene expression underlying early tumourigenesis in Eker rats. Distinct classes of up- and downregulated genes were identified in different preneoplasic lesion vs. microdissected normal (healthy) renal tubules. Laser capture microdissected renal basophilic atypical tubule (bAT) and basophilic atypical hyperplasia (bAH) and healthy tissue (HT) of 6-months aristolochic acid (AA)- and ochratoxin A (OTA)-treated and control (C) male Eker rats were isolated for RNA extraction and microarray analysis in order to investigate gene expression profiles induced by AA and OTA as well as to differentiate pathways specific for the bAT to bAH progression. Keywords: gene expression study, preneoplasic lesion vs. microdissected normal renal tubules For microdissection of preneoplastic lesions from H&E stained renal cryosections, a PALM laser microdissection and pressure catapulting (LMPC) system (PALM Microlaser GmbH) was used. Atypical tubule (bAT), basophilic atypical hyperplasia (bAH) or healthy tissue (HT) were micodissected separately from each of three replicatemale Eker rats per dose group. Lesions of each type or HT from each individual animal were pooled. RNA isolation from pooled samples and subsequent Affymetrix Rat Genome RAE_230A_2.0 chip hybridization was carried out as previously described (Stemmer et al., Toxicology and Applied Pharmacology(2006) Nov 15;217(1):134-42). Time matched controls for microarrays from lesions of OTA and AA treated rats are specified as C(AA) and C(OTA).