A functional screen with metformin identifies microRNAs that regulate metabolism in colorectal cancer cells

Ayla Orang,Amanda L Aloia,Michael Z Michael,Ross A Mckinnon,Saira R Ali,Janni Petersen

doi:10.1038/s41598-022-06587-9

Ayla Orang, Amanda L Aloia + Show 4 more

Open Access

https://doi.org/10.1038/s41598-022-06587-9

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Journal: Scientific Reports	Publication Date: Feb 21, 2022
Citations: 4	License type: open-access

Affiliation: Flinders University, Flinders Medical Centre

Abstract

Metformin inhibits oxidative phosphorylation and can be used to dissect metabolic pathways in colorectal cancer (CRC) cells. CRC cell proliferation is inhibited by metformin in a dose dependent manner. MicroRNAs that regulate metabolism could be identified by their ability to alter the effect of metformin on CRC cell proliferation. An unbiased high throughput functional screen of a synthetic micoRNA (miRNA) library was used to identify miRNAs that impact the metformin response in CRC cells. Experimental validation of selected hits identified miRNAs that sensitize CRC cells to metformin through modulation of proliferation, apoptosis, cell-cycle and direct metabolic disruption. Among eight metformin sensitizing miRNAs identified by functional screening, miR-676-3p had both pro-apoptotic and cell cycle arrest activity in combination with metformin, whereas other miRNAs (miR-18b-5p, miR-145-3p miR-376b-5p, and miR-718) resulted primarily in cell cycle arrest when combined with metformin. Investigation of the combined effect of miRNAs and metformin on CRC cell metabolism showed that miR-18b-5p, miR-145-3p, miR-376b-5p, miR-676-3p and miR-718 affected glycolysis only, while miR-1181 only regulated CRC respiration. MicroRNAs can sensitize CRC cells to the anti-proliferative effects of metformin. Identifying relevant miRNA targets may enable the design of innovative therapeutic strategies.

Highlights

Metformin inhibits oxidative phosphorylation and can be used to dissect metabolic pathways in colorectal cancer (CRC) cells
An unbiased high throughput functional screen was performed to identify miRNA mimics that can enhance the sensitivity of CRC cells to the anti-proliferative effect of metformin
HCT116 cells were treated with a dose of metformin (2.5 mM) equivalent to an IC20, without an enhanced effect on apoptosis (Supplementary Fig. 1)

Summary

Introduction

Metformin inhibits oxidative phosphorylation and can be used to dissect metabolic pathways in colorectal cancer (CRC) cells. MicroRNAs that regulate metabolism could be identified by their ability to alter the effect of metformin on CRC cell proliferation. Experimental validation of selected hits identified miRNAs that sensitize CRC cells to metformin through modulation of proliferation, apoptosis, cell-cycle and direct metabolic disruption. Abbreviations AMP Adenosine monophosphate AMPK AMP-activated protein kinase ATP Adenosine triphosphate CCNB1 Cyclin B1 CDI Coefficient of drug interaction CRC Colorectal Cancer DOCK4 Dedicator of cytokinesis 4 ECAR Extracellular acidification rate EGR3 Early Growth Response 3 EMT Epithelial-to-mesenchymal transition FCCP Carbonyl cyanide-p-trifluoromethoxyphenylhydrazone HIF-1 Hypoxia-inducible factor 1 HOXA16 Homeobox Protein Hox-1B IGF-1R Insulin-like growth factor I receptor IRAK1 Interleukin 1 Receptor Associated Kinase 1 IRS-1 Insulin receptor substrate 1 miRNA MicroRNA mTORC Mechanistic target of rapamycin complex NC Negative control. Despite the development of new targeted therapeutic options, survival outcomes for metastatic CRC remain modest, with lack of response or acquired resistance to therapy leading to treatment failure[2]

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