Cachexia-related long noncoding RNA, CAAlnc1, suppresses adipogenesis by blocking the binding of HuR to adipogenic transcription factor mRNAs.

Cancer-associated cachexia (CAC) is a devastating syndrome characterized by progressive losses of adipose tissue and skeletal muscle. CAC-related adipose tissue loss (CAL) occurs early and is associated with a shorter survival time. To explore potential regulatory long noncoding RNAs (lncRNAs) of CAL, RNA microarrays were used to analyze the transcriptomes of white adipose tissue from CAC mice vs. control mice. A set of differentially expressed lncRNAs was identified, and among them was CAAlnc1, which suppressed adipogenesis of C3H10 cells as demonstrated by gain-of-function and loss-of-function experiments. RNA immunoprecipitation and pull-down assays revealed Hu antigen R (HuR) was an important binding partner of CAAlnc1. The interaction between CAAlnc1 and HuR blocked the binding of HuR to adipogenic transcription factor mRNAs and further downregulated the expression of these transcription factors. This study generated a list of CAL-related lncRNAs and provided details of a functional lncRNA which may play an important role in CAL.