Abstract
Reintroduction of tumor-suppressive microRNA-7-5p (miR-7) that is depleted in non-small cell lung cancer (NSCLC) represents a new therapeutic approach, whereas previous studies mainly used miR-7 mimics chemoengineered in vitro. Here we aim to establish the pharmacological actions and therapeutic potential of novel bioengineered RNA bearing a payload miR-7 (BioRNA/miR-7) molecule produced in vivo. First, through confocal imaging and immunoblot studies, we revealed that BioRNA/miR-7 altered NSCLC cell mitochondrial morphology accompanied by the downregulation of known target genes, epidermal growth factor receptor (EGFR), mitochondrial solute carrier family 25A37 (SLC25A37), and import inner membrane translocase subunit (TIM50). Second, through luciferase reporter and immunoblot studies, we validated mitochondrial acylglycerol kinase (AGK) as a new direct target for miR-7. Third, through real-time live-cell analyses, we revealed BioRNA/miR-7 to modulate mitochondrial respiration and glycolytic capacity. Fourth, live-cell and endpoint viability studies demonstrated that the combination of BioRNA/miR-7 with pemetrexed (PEM) elicited a strong synergistic effect to inhibit NSCLC cell growth, associated with an increased intracellular PEM accumulation, as quantified by a liquid chromatography tandem mass spectrometry method. Finally, through in vivo therapy study using NSCLC patient-derived xenograft mouse model, we demonstrated the efficacy and tolerability of BioRNA/miR-7 monotherapy and combination therapy with PEM to control tumor progression. Our collective works establish a role for miR-7 in NSCLC metabolism and PEM disposition and support our novel, in vivo produced BioRNA/miR-7-5p for molecular pharmacological research. Our findings further illustrate the potential of BioRNA/miR-7 plus PEM combination as a potential treatment to combat NSCLC tumor progression. SIGNIFICANCE STATEMENT: MiR-7 is a tumor-suppressive microRNA depleted in non-small cell lung cancer (NSCLC), and in vitro chemoengineered miR-7 mimics were shown to inhibit tumor growth in NSCLC cell-derived xenograft mice. Here, a novel in vivo bioengineered miR-7 molecule, namely BioRNA/miR-7, was used to effectively control target gene expression and NSCLC cell metabolism. Furthermore, BioRNA/miR-7 was demonstrated to remarkably improve pemetrexed antitumor activity in NSCLC patient-derived tumor mice, supporting the role of miR-7 in NSCLC metabolism and potential for BioRNA/miR-7 to improve NSCLC therapy.