@article {Li1129, author = {Mei-Mei Li and Balasubrahmanyam Addepalli and Mei-Juan Tu and Qiu-Xia Chen and Wei-Peng Wang and Patrick A. Limbach and Janine M. LaSalle and Su Zeng and Min Huang and Ai-Ming Yu}, title = {Chimeric MicroRNA-1291 Biosynthesized Efficiently in Escherichia coli Is Effective to Reduce Target Gene Expression in Human Carcinoma Cells and Improve Chemosensitivity}, volume = {43}, number = {7}, pages = {1129--1136}, year = {2015}, doi = {10.1124/dmd.115.064493}, publisher = {American Society for Pharmacology and Experimental Therapeutics}, abstract = {In contrast to the growing interests in studying noncoding RNAs (ncRNAs) such as microRNA (miRNA or miR) pharmacoepigenetics, there is a lack of efficient means to cost effectively produce large quantities of natural miRNA agents. Our recent efforts led to a successful production of chimeric pre-miR-27b in bacteria using a transfer RNA (tRNA){\textendash}based recombinant RNA technology, but at very low expression levels. Herein, we present a high-yield expression of chimeric pre-miR-1291 in common Escherichia coli strains using the same tRNA scaffold. The tRNA fusion pre-miR-1291 (tRNA/mir-1291) was then purified to high homogeneity using affinity chromatography, whose primary sequence and post-transcriptional modifications were directly characterized by mass spectrometric analyses. Chimeric tRNA/mir-1291 was readily processed to mature miR-1291 in human carcinoma MCF-7 and PANC-1 cells. Consequently, recombinant tRNA/mir-1291 reduced the protein levels of miR-1291 target genes, including ABCC1, FOXA2, and MeCP2, as compared with cells transfected with the same doses of control methionyl-tRNA scaffold with a sephadex aptamer (tRNA/MSA). In addition, tRNA-carried pre-miR-1291 suppressed the growth of MCF-7 and PANC-1 cells in a dose-dependent manner, and significantly enhanced the sensitivity of ABCC1-overexpressing PANC-1 cells to doxorubicin. These results indicate that recombinant miR-1291 agent is effective in the modulation of target gene expression and chemosensitivity, which may provide insights into high-yield bioengineering of new ncRNA agents for pharmacoepigenetics research.}, issn = {0090-9556}, URL = {https://dmd.aspetjournals.org/content/43/7/1129}, eprint = {https://dmd.aspetjournals.org/content/43/7/1129.full.pdf}, journal = {Drug Metabolism and Disposition} }