A whole-genome CRISPRa screening metformin resistance related gene in prostate cancer
Ontology highlight
ABSTRACT: Metformin is a classic type II diabetes drug which has possessed anti-tumor properties for various cancers. However, different cancers do not respond to metformin with the same effectiveness or acquire resistance. Thus, searching for vulnerabilities of metformin-resistant prostate cancer is a promising strategy to improve the therapeutic efficiency. A genome-scale CRISPR-Cas9 activation library targeting 23430 genes is conducted to identify the genes that confer resistance to metformin in prostate cancer cells.
Project description:The biguanide metformin has been shown to not only reduce circulating glucose levels but also suppress in vitro and in vivo growth of prostate cancer. However, the mechanisms underlying the anti-tumor effects of metformin in advanced prostate cancers are not fully understood. The goal of the present study was to define the signaling pathways regulated by metformin in androgen-receptor (AR) positive, castration-resistant prostate cancers. Our group used RNA sequencing (RNA-seq) to examine genes regulated by metformin within the C4-2 human prostate cancer cell line. Western blot analysis and quantitative RT-PCR were used to confirm alterations in gene expression and further explore regulation of protein expression by metformin. Data from the RNA-seq analysis revealed that metformin alters the expression of genes products involved in metabolic pathways, the spliceosome, RNA transport, and protein processing within the endoplasmic reticulum. Gene products involved in ErbB, insulin, mTOR, TGF-, MAPK, and Wnt signaling pathways are also regulated by metformin. A subset of metformin-regulated gene products were genes known to be direct transcriptional targets of p53 or AR. Together, our results suggest metformin regulates multiple pathways linked to tumor growth and progression within advanced prostate cancer cells.
Project description:Lung cancer is the leading cause of cancer death worldwide and reports innate and acquired therapeutic resistance to cisplatin. Metformin (MET), an antidiabetic agent with potential antitumor activity, overcomes cisplatin resistance in some cancers through AMPK-dependent and independent mechanisms. MET is a potential treatment in cells with LKB1 mutation, even with the impairment of AMPK and overactivation of mTOR signaling. The present study investigated the role of mTOR signaling and other signaling pathways after MET treatment in control and resistant A549 cells, mapping pathways and possible targets for cisplatin sensitivity induced by metformin.
Project description:Transcriptional profiling of human prostate cancer cell line LNCaP treated with Metformin or AICAR compared to control non-stimulated LNCaP.
Project description:Metformin is the therapy of choice for treating type 2 diabetes and is currently repurposed for a wide range of diseases including aging. Recent evidence implicates the gut microbiota as a site of metformin action. Combining two tractable genetic models, the bacterium E. coli and the nematode C. elegans, we performed C. elegans RNAseq to investigate the role of the metformin sensitive OP50 and metformin resistant OP50-MR E. coli microbiota in the drug effects on the host. Our data suggest an evolutionarily conserved bacterial mediation of metformin effects on host lipid metabolism and lifespan.
Project description:Inflammation, oxidative and dicarbonyl stress play important roles in the pathophysiology of type 2 diabetes. Metformin is the first-line drug of choice for the treatment of type 2 diabetes because it effectively suppresses gluconeogenesis in the liver, however, its “pleiotropic“ effects remain controversial. In the current study, we tested the effects of metformin on inflammation, oxidative and dicarbonyl stress in an animal model of inflammation and metabolic syndrome, the spontaneously hypertensive rat transgenically expressing human C-reactive protein (SHR-CRP). In the SHR-CRP transgenic strain, we found that metformin treatment decreased circulating levels of inflammatory response marker IL6 while levels of human CRP remained unchanged and metformin also significantly reduced oxidative stress (levels of conjugated dienes and TBARS) in the liver while no significant effects were observed in SHR control rats. In addition, in the presence of high human CRP, metformin reduced methylglyoxal levels in left ventricles but not in kidneys. Finally, metformin treatment reduced adipose tissue lipolysis. Possible molecular mechanisms of metformin action studied by gene expression profiling in the liver revealed deregulated genes from inflammatory, insulin signaling, AMP-activated protein kinase (AMPK) signaling and gluconeogenesis pathways. It can be concluded that in the presence of high levels of human CRP metformin protects against inflammation, oxidative and dicarbonyl stress in the heart and ameliorates insulin resistance and dyslipidemia.
Project description:Trans-10, cis-12 conjugated linoleic acid (t10c12 CLA) causes dramatic reductions in white adipose tissue in mice but has had limited effectiveness in humans. Determination of the signaling pathways involved may lead to better regulation of adiposity. T10c12 CLA was found to activate AMP-activating protein kinase (AMPK), a central regulator of cell metabolism. Compound C, a potent inhibitor of AMPK, prevents many of the typical responses to treatments with t10c12 CLA including the integrated stress response (ISR), the inflammatory response, the reduction in key lipogenic transcription factors, and delipidation. Treatment of adipocytes or mice with t10c12 CLA in conjunction with AMPK activator metformin results in more delipidation than treatment with the individual chemicals. Additionally, the combination showed a reduced inflammatory response relative to a t10c12 CLA treatment alone. The combination of t10c12 CLA and metformin, widely used to treat insulin resistance and Type II diabetes, has potential as a treatment for reducing adiposity in humans. Keywords: control/treatment Mouse 3T3-L1 RNA for was isolated from control linoleic acid (LA) and treatment (CLA, CLA+metformin, metformin) samples for analysis on microarrays with three biological reps.
Project description:Metformin is a kind of widely used antidiabetic agent, which regulates glucose homeostasis through inhibiting liver glucose production and increasing glucose uptake in muscle. Recent studies suggest that metformin exhibits anticancer properties in a variety of cancers. Although several antitumor mechanisms have been proposed for metformin action, its mode of action in human liver cancer remains not elucidated. In our study we investigated the underlying molecular mechanisms of metformin’s antitumor effect on Huh-7 cells of hepatocellular carcinoma (HCC) in vitro. RNA sequencing (RNA-seq) was performed to explore the effect of metformin on the transcriptome of Huh-7 cells. The results revealed that 4518 genes (with log2 fold change>1 or < -1, p-adjusted value<0.05) were differentially expressed in Huh-7 cells with treatment of 25mM metformin compared to 0mM metformin including 1812 up-regulated and 2706 down-regulated genes. Gene ontology and KEGG pathway analyses identified 54 classical pathways which were significantly enriched, and 16 pathways are closely associated with cancer, such as cell cycle, DNA replication, ECM-receptor interaction and so on. We selected 11 differentially expressed genes, which are closely associated with HCC to validate their differential expressions through quantitative real-time reverse transcription PCR (qRT-PCR). The result exhibited that the genes of FASN, MCM6, MCM5, MARCKS, FADS2, CXCL1, BMP4, SKP2, KNG1, PCNA were down-regulated and DUSP1 is significantly up-regulated in Huh-7 cells with treatment of 25mM metformin. These differentially expressed genes and pathways might play a crucial part in the antitumor effect of metformin, and might be potential targets of metformin treating HCC. Further investigations are required to evaluate the metformin mechanisms of anti-cancer action in vivo.