miRNA Expression in Senescent and Immortalized BJ fibroblasts

Limited data exists regarding changes of microRNA (miRNA) expression during senescence in human cells and no reports correlate telomerase expression with regulation of senescence-related miRNAs. We used miRNA microarrays to provide a detailed account of miRNA profiles for early passage and senescent human foreskin (BJ) fibroblasts as well as early and late passage immortalized fibroblasts (BJ-hTERT) that stably express the human telomerase reverse transcriptase subunit hTERT. The revelation that miRNA expression changes with extended passaging in BJ-hTERT cells will contribute to a comprehensive understanding of the connections between telomerase expression, senescence and processes of cellular aging. Four samples were assessed for miRNA expression by array: BJ fibroblast early passage, BJ fibroblast senescent, BJ-hTERT early passage, and BJ-hTERT late passage. Total RNA from each sample was arrayed in duplicate and results were compared to expression in early passage BJ fibroblasts. The duplicate sample of early passage BJ cells was not included in the final analysis.