Hyperthermia-driven aberrations of secreted microRNAs in breast cancer in vitro.PURPOSE
 Thereto, the potential influence of the exogenic stimuli hypoxia, acidosis and hyperthermia was investigated in vitro.


 Quantitative analyses of secreted microRNA specimens were performed by RNA isolation from cell culture supernatant and subsequent real-time PCR in cells under physiological versus hypoxic, acidic or hyperthermia conditions.


 The in vitro application of exogenic stimuli hypoxia, extracellular acidosis and hyperthermia caused heterogeneous expression alterations for the investigated secreted miRNA phenotypes.  Most remarkably, hyperthermia triggered a uniform significant down-regulatory effect on the expression levels of the three secreted microRNAs miR-10b, miR-15b and miR-139, respectively.  Hyperthermia-dependent down-regulatory influence on three distinct BC-related microRNAs in vitro generates translational aspects for clinical BC treatment, since the identified microRNAs miR-10b, miR-15b and miR-139 are known to have oncogenic as well as tumour suppressor functions in BC.  However, an evaluation regarding the potential impact of microRNA-related hyperthermia-dependent alterations for innovative BC treatment approaches demands further analysis including in vivo data.
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