KSHV-encoded miRNAs target MAF to induce endothelial cell reprogramming

A Hansen, S Henderson, D Lagos… - Genes & …, 2010 - genesdev.cshlp.org
A Hansen, S Henderson, D Lagos, L Nikitenko, E Coulter, S Roberts, F Gratrix, K Plaisance
Genes & development, 2010genesdev.cshlp.org
Kaposi sarcoma herpesvirus (KSHV) induces transcriptional reprogramming of endothelial
cells. In particular, KSHV-infected lymphatic endothelial cells (LECs) show an up-regulation
of genes associated with blood vessel endothelial cells (BECs). Consequently, KSHV-
infected tumor cells in Kaposi sarcoma are poorly differentiated endothelial cells, expressing
markers of both LECs and BECs. MicroRNAs (miRNAs) are short noncoding RNA molecules
that act post-transcriptionally to negatively regulate gene expression. Here we validate …
Kaposi sarcoma herpesvirus (KSHV) induces transcriptional reprogramming of endothelial cells. In particular, KSHV-infected lymphatic endothelial cells (LECs) show an up-regulation of genes associated with blood vessel endothelial cells (BECs). Consequently, KSHV-infected tumor cells in Kaposi sarcoma are poorly differentiated endothelial cells, expressing markers of both LECs and BECs. MicroRNAs (miRNAs) are short noncoding RNA molecules that act post-transcriptionally to negatively regulate gene expression. Here we validate expression of the KSHV-encoded miRNAs in Kaposi sarcoma lesions and demonstrate that these miRNAs contribute to viral-induced reprogramming by silencing the cellular transcription factor MAF (musculoaponeurotic fibrosarcoma oncogene homolog). MAF is expressed in LECs but not in BECs. We identify a novel role for MAF as a transcriptional repressor, preventing expression of BEC-specific genes, thereby maintaining the differentiation status of LECs. These findings demonstrate that viral miRNAs could influence the differentiation status of infected cells, and thereby contribute to KSHV-induced oncogenesis.
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