Abstract
<jats:p>In this study, the authors knocked down the MCT-1 gene (Monocarboxylate Transporter-1 gene) to block lactate circulation within the tumor microenvironment. Monocarboxylate transporters -1 and 4 (MCT-1/4) play a pivotal role in maintaining lactate circulation to sustain the growth and development of normoxic and hypoxic cancer cells in the tumor microenvironment. Using <i>In Silico</i> tools and techniques, the five best siRNA -S1, S2, S3, S4 and S5- were screened and designed to target the MCT-1 gene expression. Based on a good docking score and MD simulations, S4 siRNA was selected for further in Vitro studies. For efficient knockdown of the MCT-1 gene, S4 siRNA was formulated into nanoformulation by complexing it with Polyethylenimine (PEI) in 1:1 ratio. The formulation was named as MCT-1 siRNA–PEI polyplex (N:P::1:1). The MCT-1 siRNA–PEI polyplex (N: P::1:1) showed good immunocompatibility and serum stability. The IC50 of MCT-1 siRNA–PEI Polyplex (N: P::1:1) against MCF-7 cells was recorded to be 13.54µl with significant apoptotic potential evident through Acridine Orange/ Ethidium Bromide (AO/Ebtr), 4′,6-diamidino-2-phenylindole (DAPI) and JC1 staining. The effect of MCT-1 siRNA–PEI Polyplex (N: P::1:1) on various checkpoints of central carbon metabolism in cancer and HIF-1 signalling pathway was scrutinised through qRT-PCR followed by Gene Set Enrichment Analysis. The MCF-7 cells were evident for the metabolic stress due to metabolic acidosis and impaired adaptation to hypoxia inducible factor-1 α (HIF-1 α). The cells underwent metabolic reprogramming, upregulating anaerobic glycolysis and glutamine metabolism. Moreover, the cells that could not withstand metabolic stress, even after metabolic rewiring, underwent apoptosis.</jats:p>