Heat shock factor 1 regulates hsa-miR-432 expression in human cervical cancer cell line

• Heat shock alters expression of some miRNAs in HeLa cells.
• Putative HSEs are present in upstream sequence of thermally altered miRNAs.
• Heat shock increases occupancy of HSF1 in hsa-miR-432 upstream sequence.
• Ectopic expression of HSF1 increases hsa-miR-432 expression.
• Knockdown of HSF1 inhibits heat shock-driven upregulation of hsa-miR-432 expression.

Heat shock response pathway is a conserved defense mechanism of mammalian cells to maintain protein homeostasis against proteotoxic environmental conditions. This is characterized by robust synthesis of molecular chaperones mostly by stress-induced activation of heat shock factor 1 (HSF1). MicroRNAs (miRNAs) are a family of small non-coding RNAs that negatively regulate expression of protein-coding genes. Here we report altered expression of a set of miRNAs by thermal stress in HeLa cells. We also show that HSF1 regulates hsa-miR-432 expression in heat shock-dependent manner through its cognate binding site present in hsa-miR-432 upstream sequence. Our report uncovers a novel function of HSF1 and indicates involvement of miRNAs in HSF1-mediated protection of cellular proteome.