Functional high-throughput screen identifies microRNAs that promote butyrate-induced death in colorectal cancer cells

Revealing a Novel Methylated Integrin Alpha-8 Related to Extracellular Matrix and Anoikis Resistance Using Proteomic Analysis in the Immune Microenvironment of Lung Adenocarcinoma

Genomic epigenetics of extracellular matrix (ECM) play an important role in lung adenocarcinoma (LUAD). Our study identified a signature of potential prognostic genes associated with ECM and constructed immune risk-related prognosis model in LUAD. We downloaded mRNAs transcriptome data, miRNAs expression data, and clinical patient information for LUAD based on The Cancer Genome Atlas. "Limma, clusterProfiler, ggplot2" R packages and GSEA were used to analyze meaningful genes and explore potential biological function. A competing endogenous RNA network was constructed to reveal the mechanism of ECM-related genes. Combined with clinical LUAD patients' characteristics, univariate and multivariate Cox regression analyses were used to build prognostic immune risk model. Next, we calculated AUC value of ROC curve, and explored survival probability of different risk groups. A total of 2966 mRNAs were differently expressed in LUAD samples and normal samples. Function enrichment analyses proved mRNAs were associated with many tumor pathways, such as cell adhesion, vascular smooth muscle contraction, and cell cycle. There were 18 mRNAs related to ECM receptor signaling pathway, and 7 mRNAs expressions were correlated with EGFR expression, but only 5mRNAs were associated with the long-term prognosis. Based on Integrin alpha-8 (ITGA8) molecule, we identified potential 3 miRNAs from several databases. The promoter of ITGA8 was higher-methylated and lower-expressed in LUAD. And lower-expressed group has poor prognosis for patients. 66 immunomodulators related to ITGA8 were performed to construct immune correlation prediction model (p < 0.05). Comprehensive analyses of ITGA8 revealed it combined focal adhesion kinase to activate PI3K/AKT signaling pathway to influence the occurrence and development of LUAD. A novel immune prognostic model about ITGA8 was constructed and verified in LUAD patients. Combined with non-coding genes and genomic epigenetics, identification of potential biomarkers provided new light on therapeutic strategy for clinical patients.

Crosstalk between non-coding RNAs and programmed cell death in colorectal cancer: implications for targeted therapy

BACKGROUND

Colorectal cancer (CRC) remains one of the most common causes of cancer-related mortality worldwide. Its progression is influenced by complex interactions involving genetic, epigenetic, and environmental factors. Non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), have been identified as key regulators of gene expression, affecting diverse biological processes, notably programmed cell death (PCD).

OBJECTIVE

This review aims to explore the relationship between ncRNAs and PCD in CRC, focusing on how ncRNAs influence cancer cell survival, proliferation, and treatment resistance.

METHODS

A comprehensive literature analysis was conducted to examine recent findings on the role of ncRNAs in modulating various PCD mechanisms, including apoptosis, autophagy, necroptosis, and pyroptosis, and their impact on CRC development and therapeutic response.

RESULTS

ncRNAs were found to significantly regulate PCD pathways, impacting tumor growth, metastasis, and treatment sensitivity in CRC. Their influence on these pathways highlights the potential of ncRNAs as biomarkers for early CRC detection and as targets for innovative therapeutic interventions.

CONCLUSION

Understanding the involvement of ncRNAs in PCD regulation offers new insights into CRC biology. The targeted modulation of ncRNA-PCD interactions presents promising avenues for personalized cancer treatment, which may improve patient outcomes by enhancing therapeutic effectiveness and reducing resistance.

Butyrate Metabolism-Related Gene Signature in Tumor Immune Microenvironment in Lung Adenocarcinoma: A Comprehensive Bioinformatics Study

BACKGROUND

Experimental results have verified the suppressive impact of butyrate on tumor formation. Nevertheless, there is a limited understanding of the hidden function of butyrate metabolism within the tumor immune microenvironment (TIME) of lung adenocarcinoma (LUAD). This research aimed at digging the association between genes related to butyrate metabolism (butyrate metabolism-related genes [BMRGs) and immune infiltrates in LUAD patients.

METHODS

Through analyzing The Cancer Genome Atlas dataset (TCGA), the identification of 38 differentially expressed BMRGs was made between LUAD and normal samples. Later, a prognostic signature made up of nine BMRGs was made to evaluate the risk score of LUAD subjects. Notably, high-risk scores emerged as negative prognostic indicators for overall survival in LUAD subjects. Additionally, BMRGs displayed associations with immunocyte infiltration levels, immune pathway activities, and pivotal prognostic hub BMRGs.

RESULTS

One key prognostic BMRG, PTGDS, exhibited a robust correlation with T cells, the chemokine-related pathway, and the TCR signaling pathway. This study suggests that investigating the interplay between butyrate metabolism and T cells could present a promising novel approach to cancer treatment. OncoPredict analysis further unveiled distinct sensitivities of nine medicine in high- and low-risk groups, facilitating the selection of optimal treatment strategies for individual LUAD patients.

CONCLUSIONS

The study establishes that the BMRG signature serves as a sensitive predictive biomarker, providing profound insights into the crucial effect of butyrate metabolism in the context of LUAD TIME.

miR-181a: regulatory roles, cancer-associated signaling pathway disruptions, and therapeutic potential

INTRODUCTION

microRNA-181a (miR-181a) is a crucial post-transcriptional regulator of many mRNA transcripts and noncoding-RNAs, influencing cell proliferation, cancer cell stemness, apoptosis, and immune responses. Its abnormal expression is well-characterized in numerous cancers, establishing it as a significant genomic vulnerability and biomarker in cancer research.

AREAS COVERED

Here, we summarize miR-181a's correlation with poor patient outcomes across numerous cancers and the mechanisms governing miR-181a's activity and processing. We comprehensively describe miR-181a's involvement in multiple regulatory cancer signaling pathways, cellular processes, and the tumor microenvironment. We also discuss current therapeutic approaches to targeting miR-181a, highlighting their limitations and future potential.

EXPERT OPINION

miR-181a is a clinically relevant pan-cancer biomarker with potential as a therapeutic target. Its regulatory control of tumorigenic signaling pathways and immune responses positions it as a promising candidate for personalized treatments. The success of miR-181a as a target relies on the development of specific therapeutics platforms. Future research on miR-181a's role in the tumor microenvironment and the RNA binding proteins that regulate its stability will help uncover new techniques to targeting miR-181a. Further research into miR-181a serum levels in patients undergoing therapy will help to better stratify patients and enhance therapeutic success.

Current understanding of free fatty acids and their receptors in colorectal cancer treatment

Colorectal cancer (CRC) is one of the leading causes of cancer-related death. Currently, dietary factors are being emphasized in the pathogenesis of CRC. There is strong evidence that fatty acids (FAs) and free FA receptors (FFARs) are involved in CRC. This comprehensive review discusses the role of FAs and their receptors in CRC pathophysiology, development, and treatment. In particular, butyrate and n-3 polyunsaturated fatty acids have been found to exert anticancer properties by, among others, inhibiting proliferation and metastasis and inducing apoptosis in tumor cells. Consequently, they are used in conjunction with conventional therapies. Furthermore, FFAR gene expression is down-regulated in CRC, suggesting their suppressive character. Recent studies showed that the FFAR4 agonist, GW9508, can inhibit tumor growth. In conclusion, natural as well as synthetic FFAR ligands are considered promising candidates for CRC therapy.

Butyrate as a potential therapeutic agent for neurodegenerative disorders

Maintaining an optimum microbial community within the gastrointestinal tract is intricately linked to human metabolic, immune and brain health. Disturbance to these microbial populations perturbs the production of vital bioactive compounds synthesised by the gut microbiome, such as short-chain fatty acids (SCFAs). Of the SCFAs, butyrate is known to be a major source of energy for colonocytes and has valuable effects on the maintenance of intestinal epithelium and blood brain barrier integrity, gut motility and transit, anti-inflammatory effects, and autophagy induction. Inducing endogenous butyrate production is likely to be beneficial for gut-brain homeostasis and for optimal neuronal function. For these reasons, butyrate has gained interest as a potential therapy for not only metabolic and immunological disorders, but also conditions related to the brain, including neurodegenerative diseases. While direct and indirect sources of butyrate, including prebiotics, probiotics, butyrate pro-drugs and glucosidase inhibitors, offer a promising therapeutic avenue, their efficacy and dosage in neurodegenerative conditions remain largely unknown. Here, we review current literature on effects of butyrate relevant to neuronal function, the impact of butyrate in a range of neurodegenerative diseases and related treatments that may have potential for the treatment of neurodegenerative diseases.

Gut microbiome-metabolites axis: A friend or foe to colorectal cancer progression

An expanding corpus of research robustly substantiates the complex interrelation between gut microbiota and the onset, progression, and metastasis of colorectal cancer. Investigations in both animal models and human subjects have consistently underscored the role of gut bacteria in a variety of metabolic activities, driven by dietary intake. These activities include amino acid metabolism, carbohydrate fermentation, and the generation and regulation of bile acids. These metabolic derivatives, in turn, have been identified as significant contributors to the progression of colorectal cancer. This thorough review meticulously explores the dynamic interaction between gut bacteria and metabolites derived from the breakdown of amino acids, fatty acid metabolism, and bile acid synthesis. Notably, bile acids have been recognized for their potential carcinogenic properties, which may expedite tumor development. Extensive research has revealed a reciprocal influence of gut microbiota on the intricate spectrum of colorectal cancer pathologies. Furthermore, strategies to modulate gut microbiota, such as dietary modifications or probiotic supplementation, may offer promising avenues for both the prevention and adjunctive treatment of colorectal cancer. Nevertheless, additional research is imperative to corroborate these findings and enhance our comprehension of the underlying mechanisms in colorectal cancer development.

The potential of short-chain fatty acid epigenetic regulation in chronic low-grade inflammation and obesity

Obesity and chronic low-grade inflammation, often occurring together, significantly contribute to severe metabolic and inflammatory conditions like type 2 diabetes (T2D), cardiovascular disease (CVD), and cancer. A key player is elevated levels of gut dysbiosis-associated lipopolysaccharide (LPS), which disrupts metabolic and immune signaling leading to metabolic endotoxemia, while short-chain fatty acids (SCFAs) beneficially regulate these processes during homeostasis. SCFAs not only safeguard the gut barrier but also exert metabolic and immunomodulatory effects via G protein-coupled receptor binding and epigenetic regulation. SCFAs are emerging as potential agents to counteract dysbiosis-induced epigenetic changes, specifically targeting metabolic and inflammatory genes through DNA methylation, histone acetylation, microRNAs (miRNAs), and long non-coding RNAs (lncRNAs). To assess whether SCFAs can effectively interrupt the detrimental cascade of obesity and inflammation, this review aims to provide a comprehensive overview of the current evidence for their clinical application. The review emphasizes factors influencing SCFA production, the intricate connections between metabolism, the immune system, and the gut microbiome, and the epigenetic mechanisms regulated by SCFAs that impact metabolism and the immune system.

Melatonin, BAG-1 and cortisol circadian interactions in tumor pathogenesis and patterned immune responses

A dysregulated circadian rhythm is significantly associated with cancer risk, as is aging. Both aging and circadian dysregulation show suppressed pineal melatonin, which is indicated in many studies to be linked to cancer risk and progression. Another independently investigated aspect of the circadian rhythm is the cortisol awakening response (CAR), which is linked to stress-associated hypothalamus-pituitary-adrenal (HPA) axis activation. CAR and HPA axis activity are primarily mediated via activation of the glucocorticoid receptor (GR), which drives patterned gene expression via binding to the promotors of glucocorticoid response element (GRE)-expressing genes. Recent data shows that the GR can be prevented from nuclear translocation by the B cell lymphoma-2 (Bcl-2)-associated athanogene 1 (BAG-1), which translocates the GR to mitochondria, where it can have diverse effects. Melatonin also suppresses GR nuclear translocation by maintaining the GR in a complex with heat shock protein 90 (Hsp90). Melatonin, directly and/or epigenetically, can upregulate BAG-1, suggesting that the dramatic 10-fold decrease in pineal melatonin from adolescence to the ninth decade of life will attenuate the capacity of night-time melatonin to modulate the effects of the early morning CAR. The interactions of pineal melatonin/BAG-1/Hsp90 with the CAR are proposed to underpin how aging and circadian dysregulation are associated with cancer risk. This may be mediated via differential effects of melatonin/BAG-1/Hsp90/GR in different cells of microenvironments across the body, from which tumors emerge. This provides a model of cancer pathogenesis that better integrates previously disparate bodies of data, including how immune cells are regulated by cancer cells in the tumor microenvironment, at least partly via the cancer cell regulation of the tryptophan-melatonin pathway. This has a number of future research and treatment implications.

Sodium butyrate supresses malignant human mast cell proliferation, downregulates expression of KIT and promotes differentiation

Sodium butyrate (NaBu) is a class I histone deacetylase inhibitor (HDACi) that can impede the proliferation of transformed cells. Although some HDACi downregulate the expression of the stem cell factor receptor (KIT/CD117), the effect of NaBu on KIT expression and human mast cell proliferation requires further elucidation. In this study, we examined the effects of NaBu on three transformed human mast cell lines, HMC-1.1, HMC-1.2 and LAD2. NaBu (100 µM) inhibited the proliferation and metabolic activity of all three cell lines without significantly affecting their viability, suggesting that although the cells had ceased to divide, they were not yet undergoing apoptosis. Cell cycle analysis using the cell-permeant dye, propidium iodide, indicated that NaBu significantly blocked the cell cycle progression of HMC-1.1 and HMC-1.2 from G1 to G2/M phases. Furthermore, NaBu downregulated the expression of C-KIT mRNA and KIT protein expression in all three cell lines, but this effect was most significant in the HMC-1.1 and HMC-1.2, both of which harbour activating mutations in KIT, which proliferate more rapidly than LAD2. These data support earlier observations showing that human mast cell lines are sensitive to histone deacetylase inhibition. However, our data presents the novel observation that inhibition of cell proliferation by NaBu was not associated with a loss in cell viability but rather an arrest of the cell cycle. Higher concentrations of NaBu led to modest increases in histamine content, tryptase expression, and granularity. In conclusion, NaBu treatment of human mast cell lines led to a modest enhancement of the hallmarks of mature mast cells.