Transcription profiling of human cells stably expressing KSHV-encoded MicroRNAs

ABSTRACT: MicroRNAs are 19 to 23 nt RNAs that post-transcriptionally regulate gene expression. Human cells express several hundred miRNAs which regulate important biological pathways such as development, proliferation, and apoptosis. Recently, 12 microRNA genes have been identified within the genome of Kaposi’s sarcoma-associated herpesvirus; however, their functions are still unknown. To identify host cellular genes that may be targeted by these novel viral regulators, we performed gene expression profiling in cells stably expressing KSHV-encoded miRNAs. Data analysis revealed a set of 81 genes whose expression was significantly changed in the presence of miRNAs. While the majority of changes were below 2-fold, eight genes were down-regulated between 4- and 20-fold. We confirmed miRNA-dependent regulation for three of these genes and found that protein levels of thrombospondin 1 (THBS1) were decreased >10-fold. THBS1 has previously been reported to be down-regulated in KS lesions and has known activity as a strong tumor suppressor and anti-angiogenic factor, exerting its anti-angiogenic effect in part by activating the latent form of TGF-b. We show that reduced THBS1 expression in the presence of viral miRNAs translates into decreased TGF-b activity. These data suggest that KSHV-encoded miRNAs may contribute directly to pathogenesis by down-regulation of THBS1, a major regulator of cell adhesion, migration, and angiogenesis. Experiment Overall Design: 293 cells were stably transfected with either a vector expressing 10 KHSV encoded microRNAs or empty vector control. Cells were selected through G418. 4 samples were collected for each cell line and RNA collected for Affymetrix microarray analysis. Results show which transcripts are changed in the presence of KSHV microRNA expression.

ORGANISM(S): Homo sapiens

SUBMITTER: M Cecilia Lopez 

PROVIDER: E-GEOD-7554 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress