MicroRNA binding site polymorphism in inflammatory genes associated with colorectal cancer: literature review and bioinformatics analysis

Genetic polymorphism in untranslated regions of PRKCZ influences mRNA structure, stability and binding sites

BACKGROUND

Variations in untranslated regions (UTR) alter regulatory pathways impacting phenotype, disease onset, and course of disease. Protein kinase C Zeta (PRKCZ), a serine-threonine kinase, is implicated in cardiovascular, neurological and oncological disorders. Due to limited research on PRKCZ, this study aimed to investigate the impact of UTR genetic variants' on binding sites for transcription factors and miRNA. RNA secondary structure, eQTLs, and variation tolerance analysis were also part of the study.

METHODS

The data related to PRKCZ gene variants was downloaded from the Ensembl genome browser, COSMIC and gnomAD. The RegulomeDB database was used to assess the functional impact of 5' UTR and 3'UTR variants. The analysis of the transcription binding sites (TFBS) was done through the Alibaba tool, and the Kyoto Encyclopaedia of Genes and Genomes (KEGG) was employed to identify pathways associated with PRKCZ. To predict the effect of variants on microRNA binding sites, PolymiRTS was utilized for 3' UTR variants, and the SNPinfo tool was used for 5' UTR variants.

RESULTS

The results obtained indicated that a total of 24 variants present in the 3' UTR and 25 variants present in the 5' UTR were most detrimental. TFBS analysis revealed that 5' UTR variants added YY1, repressor, and Oct1, whereas 3' UTR variants added AP-2alpha, AhR, Da, GR, and USF binding sites. The study predicted TFs that influenced PRKCZ expression. RNA secondary structure analysis showed that eight 5' UTR and six 3' UTR altered the RNA structure by either removal or addition of the stem-loop. The microRNA binding site analysis highlighted that seven 3' UTR and one 5' UTR variant altered the conserved site and also created new binding sites. eQTLs analysis showed that one variant was associated with PRKCZ expression in the lung and thyroid. The variation tolerance analysis revealed that PRKCZ was an intolerant gene.

CONCLUSION

This study laid the groundwork for future studies aimed at targeting PRKCZ as a therapeutic target.

Significant heightened methylation levels of RUNX3 gene promoter in patients with systemic lupus erythematosus

OBJECTIVE

Researchers are actively investigating new diagnostic and prognostic biomarkers that offer improved sensitivity and specificity for systemic lupus erythematosus (SLE). One area of interest is DNA methylation changes. Previous studies have shown a connection between the RUNX3 gene dysfunction and SLE. In this study, the focus was on examining the methylation level of the RUNX3 promoter in peripheral blood mononuclear cells (PBMCs) of SLE patients and healthy individuals.

METHODS

A total of 80 individuals diagnosed with SLE from Iran, along with 77 healthy individuals, were included. The methylation levels of the RUNX3 gene in the extracted DNA were evaluated using the MethyQESD method. To determine the diagnostic effectiveness of the RUNX3 promoter methylation level, a receiver operating characteristic (ROC) curve was generated.

RESULTS

The methylation of the RUNX3 promoter was found to be significantly higher in patients with SLE compared to healthy individuals (p < .001). This difference in methylation levels was observed between SLE patients and healthy individuals and between SLE patients with renal involvement and those without renal involvement (86.29 ± 10.30 vs 40.28 ± 24.21, p < .001). ROC analyses revealed that the methylation level of the RUNX3 promoter had a diagnostic power of 0.769 [95% CI (0.681-0.814)] for SLE. Additionally, there was a positive correlation between the RUNX3 methylation level and levels of creatinine and C4.

CONCLUSION

The findings of this study emphasize the potential use of RUNX3 methylation levels in PBMCs of SLE patients as biomarkers for diagnosing the disease, predicting renal damage, and assessing disease activity.

Anticancer effect of hUC-MSC-derived exosome-mediated delivery of PMO-miR-146b-5p in colorectal cancer

Antisense oligonucleotide (ASO) is a novel therapeutic platform for targeted cancer therapy. Previously, we have demonstrated that miR-146b-5p plays an important role in colorectal cancer progression. However, a safe and effective strategy for delivery of an ASO to its targeted RNA remains as a major hurdle in translational advances. Human umbilical cord mesenchymal cell (hUC-MSC)-derived exosomes were used as vehicles to deliver an anti-miR-146b-5p ASO (PMO-146b). PMO-146b was assembled onto the surface of exosomes (e) through covalent conjugation to an anchor peptide CP05 (P) that recognized an exosomal surface marker, CD63, forming a complex named ePPMO-146b. After ePPMO-146b treatment, cell proliferation, uptake ability, and migration assays were performed, and epithelial-mesenchymal transition progression was evaluated in vitro. A mouse xenograft model was used to determine the antitumor effect and distribution of ePPMO-146b in vivo. ePPMO-146b was taken up by SW620 cells and effectively inhibited cell proliferation and migration. The conjugate also exerted antitumor efficacy in a xenograft mouse model of colon cancer by systematic administration, where PPMO-146b was enriched in tumor tissue. Our study highlights the potential of hUC-MSC-derived exosomes anchored with PPMO-146b as a novel safe and effective approach for PMO backboned ASO delivery.

Polymorphism rs1057147 located in mesothelin gene predicts lymph node metastasis in patients with gastric cancer

Lymph node metastasis, a crucial factor in the spread of gastric cancer (GC), is strongly associated with a negative prognosis for patients. This study aimed to investigate the association of the mesothelin (MSLN) gene polymorphisms (rs3764247, rs3764246, rs12597489, rs1057147, and rs3765319) with the risk of lymph node metastasis of GC patients in a Chinese Han population. The PCR-LDR genotyping was used to detect the genotypes of MSLN polymorphisms in GC patients with lymph node metastasis (n = 610) or without (n = 356). Our research indicates that certain genetic markers, specifically rs3764247, rs3764246, rs12597489, and rs3765319, do not appear to be linked with an increased risk of lymph node metastasis in GC. However, we did observe that patients with the rs1057147 GA genotype exhibited a higher likelihood of lymph node metastasis in GC when compared to those with the GG genotype (OR = 1.33, 95% CI = 1.01 - 1.76, P = 0.045). Patients with rs1057147 GA + AA genotype were found to have a higher likelihood of lymph node involvement (OR = 1.35, 95% CI = 1.03 - 1.77, P = 0.029) when compared to those with GG genotype in the dominant model. The allelic model revealed that the A allele of rs1057147 exhibited a stronger correlation with lymph node metastasis compared to the G allele (OR = 1.28, 95% CI = 1.02 - 1.60, P = 0.031). In addition, we found that rs1057147 polymorphism revealed a poor prognosis for GC patients with lymph node metastasis. Further stratified analysis revealed that the prognostic effect of rs1057147 was more pronounced in patients with GC who had lymph node metastasis and had a tumor size of 4 cm or greater, as well as more than 2 lymph node metastases. Bioinformatics studies showed that the binding mode of miR-3144-5p or miR-3619-3p to MSLN was altered by the mutation of rs1057147. Our study confirmed the important role of MSLN rs1057147 polymorphism locus in GC lymph node metastases and suggested a potential prognostic factor during GC progression. KEY POINTS: • Rs1057147 GA genotype had an increased risk of lymph node metastasis in gastric cancer. • The A allele of rs1057147 had a stronger association with lymph node metastasis than the G allele. • The binding mode of miR-3144-5p or miR-3619-3p to MSLN was altered by the mutation of rs1057147.

miRNA-binding site polymorphism in IL-15RA gene in rheumatoid arthritis and systemic lupus erythematosus: correlation with disease risk and clinical characteristics

INTRODUCTION/OBJECTIVES

MiRSNPs may interfere with mRNA stability through effects on microRNAs (miRNAs)-mRNA interactions via direct changes in miRNA binding site or effect on the secondary structure of this region and changes in accessibility of this region to miRNAs. Studies have confirmed that an elevated level of interleukin-15 receptor alpha (IL-15RA) has an important role in the pathogenesis of systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). In the present study, for the first time, we aimed to evaluate the possible correlation between a miRSNP, rs2296135, in IL-15RA gene with the risk of SLE and RA.

METHODS

In this case-control study, 100 SLE patients, 100 RA patients, and 110 healthy participants were enrolled to assess rs2296135 genotypes with real-time PCR high-resolution melting method.

RESULTS

According to our findings, AA genotype and A allele of rs2296135 were considerably associated with enhanced risk of RA (for AA genotype, OR = 2.29; 95% CI [1.06-5.02]; for A allele, OR = 1.65; 95% CI [1.10-2.48]). However, this common variant was not significantly correlated with SLE risk in population under study. Stratification analysis in the RA group verified that patients with the A allele had considerably higher serum concentrations of C-reactive protein (CRP) (P < 0.001). In SLE subjects, the frequency of arthritis (P: 0.021) and renal involvement (P: 0.025) in patients with A allele was significantly higher than in other SLE individuals.

CONCLUSION

The current study proposes a substantial association between rs2296135 polymorphism in IL-15RA gene with augmented risk of RA and some clinical characteristics in RA and SLE patients.

Prioritization and Meta-analysis of regulatory SNPs identified IL6, TGFB1, TLR9 and MMP7 as significantly associated with cervical cancer

Cervical cancer is a leading women cancer globally with respect to both incidence and mortality. Its increased risk has been linked with HPV infection and genetic variations like single nucleotide polymorphisms (SNPs). Although, studies have been published which evaluates the effect of SNPs in a few candidate genes, however the role of number of regulatory SNPs (rSNPs) in cervical cancer is not available. As literature evidence has shown that non-coding rSNPs are related with increasing cervical cancer risk, we undertook this study to prioritize the important rSNPs and elucidate their role. A search was conducted in PubMed up to December 2020, which led to the identification of 263 articles and 969 SNPs in the non-coding region. These 969 SNPs were analysed through rSNPBase and RegulomeDB, leading to identification of 105 rSNPs. Afterwards, a regulatory module was constructed using protein-protein interaction data and a hub of highly interacting 23 target genes (corresponding to 34 rSNPs) was identified using MCODE. To further understand the mechanism of action of the 34 rSNPs, their transcription factor information with respect to cervical cancer was retrieved. To evaluate the pooled effect of these prioritized polymorphisms in cervical cancer patients, a meta-analysis was performed on 10,537 cases and 11,252 controls from 30 studies corresponding to 8 rSNPs. It led to identification of polymorphisms in IL6 (rs2069837), TGFB1 (rs1800469), TLR9 (rs187084) and MMP7 (rs11568818) which are significantly (p < 0.05) associated with increased cervical cancer risk at the population level. Overall, the study demonstrates that rSNPs targeting immune and inflammatory genes (IL1B, IL6, IL10, IL18, TGFB1, CCR5, CD40, TLR9, and MMP7) are associated with cervical cancer.

Inflammation, microbiome and colorectal cancer disparity in African-Americans: Are there bugs in the genetics?

Dysregulated interactions between host inflammation and gut microbiota over the course of life increase the risk of colorectal cancer (CRC). While environmental factors and socio-economic realities of race remain predominant contributors to CRC disparities in African-Americans (AAs), this review focuses on the biological mediators of CRC disparity, namely the under-appreciated influence of inherited ancestral genetic regulation on mucosal innate immunity and its interaction with the microbiome. There remains a poor understanding of mechanisms linking immune-related genetic polymorphisms and microbiome diversity that could influence chronic inflammation and exacerbate CRC disparities in AAs. A better understanding of the relationship between host genetics, bacteria, and CRC pathogenesis will improve the prediction of cancer risk across race/ethnicity groups overall.

Association of a miRNA-binding site polymorphism in IL-16 gene with disease risk and clinical characteristics of rheumatoid arthritis and systemic lupus erythematosus

INTRODUCTION

/objectives. Single nucleotide polymorphisms (SNPs) located at the 3'-UTR region of the target genes of microRNAs (miRNAs) can dysregulate their expression via disrupting the binding site of miRNAs. Interleukin-16 (IL-16) is involved in the pathogenesis of rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). In the current study, we assessed the possible association between rs1131445 polymorphism in IL-16 gene with risk and clinical characteristics of RA and SLE in the Iranian population.

METHODS

In this case-control study, 120 patients with RA, 120 patients with SLE, and 120 unrelated healthy subjects were collected to estimate rs1131445 (T > C) polymorphism in IL-16 gene using real-time PCR high-resolution melting (HRM) method.

RESULTS

Our results demonstrated considerable associations between TC genotype and C allele of rs1131445 with enhanced risk of RA (OR_{for TC genotype} = 3.01; 95%CI [1.667-5.526], P < 0.001; OR_{for C allele} = 1.96; 95%CI [1.314-2.941], P < 0.001). Besides, there was a marginal association between CC genotype and increased risk of RA (P: 0.031). However, there was an insignificant correlation between genotypes and allele frequencies of rs1131445 with incidence risk of SLE (P > 0.05). Moreover, stratification analysis indicated that the C allele in rs1131445 was linked with disease activity-associated laboratory parameters such as CRP and ESR in both RA and SLE patients, as well as the higher incidence of neurological symptoms in SLE subjects (P < 0.05).

CONCLUSION

These results proposed a significant association between IL-16 polymorphism and augmented risk of RA and clinical characteristics of RA and SLE.

Impact of miRNA-binding site polymorphisms in STAT3 gene on occurrence and clinical characteristics of systemic lupus erythematosus

BACKGROUND

Signal transducer and activator of transcription 3 (STAT3) is a major regulator of immune response and chronic inflammatory conditions acting through regulation of B cells, T-helper 17 (Th17) cells, and IL-17 production. Previous studies have demonstrated that dysregulation of STAT3 is crucial for SLE pathogenesis and disease severity. It is believed that single nucleotide polymorphisms (SNPs) located at the 3'-UTR sequence of the target genes could dysregulate their expression by disrupting the binding site of miRNAs. In the present study, we assessed the possible association between rs1053005 and rs1053023 SNPs at miRNA binding sites in the STAT3 gene and the risk of SLE in the Iranian population for the first time.

METHODS

112 SLE cases and 120 healthy controls were genotyped for rs1053005 (A>G) and rs1053023 (A>G) polymorphisms in STAT3 using real-time PCR high resolution melting method (HRM).

RESULTS

Our results revealed substantial associations between GG genotype and G allele of rs1053023 with enhanced risk of SLE (OR for GG genotype= 3.13; 95%CI [1.61-6.1], OR for G allele = 2.22; 95%CI [1.51-3.25]). However, no important correlations have been found between rs1053005 polymorphism and SLE susceptibility in this population (p>0.05). Moreover, stratification analysis showed that these polymorphisms are correlated with parameters indicating disease activity and more severe course of the disease. These factors include some laboratory test results and clinical manifestations such as renal involvements.

CONCLUSION

The current study suggests a significant association between STAT3 polymorphisms and augmented risk of SLE, clinical symptoms, disease activity, and severity.

Role of circular RNAs in gastrointestinal tumors and drug resistance

The incidence of gastrointestinal cancers has increased significantly over the past decade and gastrointestinal malignancies now rank among the leading causes of mortality globally. Although newer therapeutic strategies such as targeted therapies have greatly improved patient outcomes, their clinical success is limited by drug resistance, treatment failure and recurrence of metastatic disease. Therefore, there is an urgent need for further research identifying accurate and reliable biomarkers for precise treatment strategies. Circular RNAs (circRNAs) exhibit a covalently closed structure, high stability and biological conservation, and their expression is associated with the occurrence and development of gastrointestinal tumors. Moreover, circRNAs may significantly influence drug resistance of gastrointestinal cancers. In this article, we review the role of circRNAs in the occurrence and development of gastrointestinal cancer, their association with drug resistance, and potential application for early diagnosis, treatment and prognosis in gastrointestinal malignancies. Furthermore, we summarize characteristics of circRNA, including mechanism of formation and biological effects via mRNA sponging, chromatin replication, gene regulation, translational modification, signal transduction, and damage repair. Finally, we discuss whether circRNA-related noninvasive testing may be clinically provided in the future. This review provides new insights for the future development of diagnostics and therapeutics based on circRNAs in gastrointestinal tumors.

Effects of Lipopolysaccharide-Binding Protein (LBP) Single Nucleotide Polymorphism (SNP) in Infections, Inflammatory Diseases, Metabolic Disorders and Cancers

Inflammation, which is induced by the immune response, is recognized as the driving factor in many diseases, including infections and inflammatory diseases, metabolic disorders and cancers. Genetic variations in pivotal genes associated with the immune response, particularly single nucleotide polymorphisms (SNPs), may account for predisposition and clinical outcome of diseases. Lipopolysaccharide (LPS)-binding protein (LBP) functions as an enhancer of the host response to LPS, the main component of the outer membrane of gram-native bacteria. Given the crucial role of LBP in inflammation, we will review the impact of SNPs in the LBP gene on infections and inflammatory diseases, metabolic disorders and cancers.

Strong association of common variants in the miRNA-binding site of NOD2 gene with clinicopathological characteristics and disease activity of systemic lupus erythematosus

INTRODUCTION/OBJECTIVES

Systemic lupus erythematosus (SLE) is a multifactorial systemic autoimmune disease, in which genetic susceptibility plays a pivotal role. The nucleotide oligomerization domain 2 (NOD2) gene is one of the main regulators of chronic inflammatory conditions and could be involved in SLE pathogenesis. Single nucleotide polymorphisms (SNPs) in miRNA binding sites which are located in 3'UTR of the NOD2 gene could be associated with SLE risk by dysregulation of NOD2 expression. In the present study, we assessed the possible association between SNPs rs3135500 and rs3135499 in the NOD2 gene with SLE risk in the Iranian population.

METHODS

A case-control study using 110 SLE patients and 120 control subjects was undertaken to estimate rs3135500 (G > A) and rs3135499 (A > C) genotypes via real-time PCR high-resolution melting method (HRM).

RESULTS

No significant association was observed between allele and genotype frequencies of rs3135500 and rs3135499 polymorphisms and SLE risk in this population (P > 0.05). However, there was an obvious association between rs3135500 (A allele) with laboratory factors that are associated with disease activity (P < 0.05) and some clinical manifestations that are associated with disease severity such as neurological symptoms, skin manifestations, renal involvements, and higher serum concentration of creatinine (P < 0.05). Besides, rs3135499 (C allele) was correlated with renal involvement and also the concentration of creatinine (P < 0.05). Moreover, in the patients group, the risk alleles in these polymorphisms were associated with lower age of onset (P < 0.05).

CONCLUSIONS

Our results suggest a substantial association between NOD2 polymorphisms with clinicopathological characteristics and SLE disease activity. Key Points • Single nucleotide polymorphisms (SNPs) in miRNA binding sites which are located in 3'UTR of the NOD2 gene could be associated with SLE risk by dysregulation of NOD2 expression. • Our results suggested that two miRSNPs (rs3135500 and rs3135499) in the NOD2 gene were meaningfully correlated with clinicopathological characteristics and disease activity of SLE.

A gain-of-function NLRP3 3'-UTR polymorphism causes miR-146a-mediated suppression of NLRP3 expression and confers protection against sepsis progression

Nucleotide-binding domain and leucine-rich repeat (LRR)-containing family protein 3 (NLRP3) regulated the maturation of inflammation-related cytokines by forming NLRP3 inflammasome, which plays pivotal roles in sepsis pathogenesis. In this study, we evaluated the genetic association of NLRP3 polymorphisms with sepsis (640 patients and 769 controls) and characterized the impact of NLRP3 polymorphisms on NLRP3 expression and inflammatory responses. No significant differences were observed in genotype/allelic frequencies of NLRP3 29940G>C between sepsis cases and controls. The G allele was significantly overrepresented in patients with septic shock than those in sepsis subgroup, and the GC/GG genetypes were related to the 28-day mortality of sepsis. Lipopolysaccharide challenge to peripheral blood mononuclear cells showed a significant suppression of NLRP3 mRNA expression and release of IL-1β and TNF-α in CC compared with the GC/GG genotype category. Functional experiments with luciferase reporter vectors containing the NLRP3 3′-UTR with the 29940 G-to-C variation in HUVECs and THP-1 cells showed a potential suppressive effect of miR-146a on NLRP3 transcription in the presence of the C allele. Taken together, these results demonstrated that the 29940 G-to-C mutation within the NLRP3 3′-UTR was a gain-of-function alteration that caused the suppression of NLRP3 expression and downstream inflammatory cytokine production via binding with miR-146a, which ultimately protected patients against susceptibility to sepsis progression and poor clinical outcome.

The Role of non-coding RNAs in colorectal cancer, with a focus on its autophagy

Colorectal cancer (CRC) is one of malignant afflictions burdening people worldwide, mainly caused by shortages of effective medical intervention and poorly mechanistic understanding of the pathogenesis of CRC. Non-coding RNAs (ncRNAs) are a type of heterogeneous transcripts without the capability of coding protein, but have the potency of regulating protein-coding gene expression. Autophagy is an evolutionarily conserved catabolic process in which cytoplasmic contents are delivered to cellular lysosomes for degradation, resulting in the turnover of cellular components and producing energy for cell functions. A growing body of evidence reveals that ncRNAs, autophagy, and the crosstalks of ncRNAs and autophagy play intricate roles in the initiation, progression, metastasis, recurrence and therapeutic resistance of CRC, which confer ncRNAs and autophagy to serve as clinical biomarkers and therapeutic targets for CRC. In this review, we sought to delineate the complicated roles of ncRNAs, mainly including miRNAs, lncRNAs and circRNAs, in the pathogenesis of CRC, particularly focus on the regulatory role of ncRNAs in CRC-related autophagy, attempting to shed light on the complex pathological mechanisms, involving ncRNAs and autophagy, responsible for CRC tumorigenesis and development, so as to underpin the ncRNAs- and autophagy-based therapeutic strategies for CRC in clinical setting.

Regulation of DNA methylation machinery by epi-miRNAs in human cancer: emerging new targets in cancer therapy

Disruption in DNA methylation processes can lead to alteration in gene expression and function that would ultimately result in malignant transformation. In this way, studies have shown that, in cancers, methylation-associated silencing inactivates tumor suppressor genes, as effectively as mutations. DNA methylation machinery is composed of several genes, including those with DNA methyltransferases activity, proteins that bind to methylated cytosine in the promoter region, and enzymes with demethylase activity. Based on a prominent body of evidence, DNA methylation machinery could be regulated by microRNAs (miRNAs) called epi-miRNAs. Numerous studies demonstrated that dysregulation in DNA methylation regulators like upstream epi-miRNAs is indispensable for carcinogenesis; consequently, the malignant capacity of these cells could be reversed by restoring of this regulatory system in cancer. Conceivably, recognition of these epi-miRNAs in cancer cells could not only reveal novel molecular entities in carcinogenesis, but also render promising targets for cancer therapy. In this review, at first, we have an overview of the methylation alteration in cancers, and the effect of this phenomenon in miRNAs expression and after that, we conduct an in-depth discussion about the regulation of DNA methylation regulators by epi-miRNAs in cancer cells.