Expression and exosome incorporation of microRNA by leukemia versus nonmalignant hematopoietic progenitors

Exosomes are paracrine regulators of the tumor microenvironment. However, their complex cargo can hamper an understanding of their specific action in target cells. We therefore sought to identify the changes in exosome miRNA content that occur with malignant transformation by comparing two myeloid cancer cell lines to their nonmalignant predecessors, CD34+ human hematopoietic progenitor cells. We employed microarrays to evaluate which miRNA are present at altered concentrations before and after transformation as well as before and after incorporation into exosomes. This experiment sought to compare the cells and exosomes of CD34+ nonmalignant progenitors to those of malignant myeloid cell lines HL-60 and MOLM-14. Cells were cultured under 1% O2 conditions for 48 hours, after which cells and exosomes were collected, and miRNA was extracted for microarray comparison. Normalization included comparison to the additional MOLM-14 cell and exosome samples grown at 1% O2 in GSE55025 (GSM1328048, GSM1328049, GSM1328044, GSM1328045). The complete_normalized_data.txt contains 16 data columns (12 new samples + 4 re-analyzed data).