MicroRNA‑214 upregulates HIF‑1α and VEGF by targeting ING4 in lung cancer cells

Study on MicroRNAs as Potential Biomarkers of Radon-induced Radiation Damage

ABSTRACT

High concentrations of radon may cause radiation damage to the human body. Finding the biomarkers of radon-induced radiation damage is particularly important for the research and treatment of radon-induced lung cancer. In this study, the expression of γH2AX protein in peripheral blood lymphocytes of miners exposed to high concentrations of radon was detected by flow cytometry. To investigate the possible damage in peripheral blood lymphocytes of miners under a high radon environment, a microRNA (miRNA) microarray technique was used to screen the differentially expressed miRNAs in the peripheral plasma of miners exposed to different concentrations of radon. Prediction of the target genes and the possible biological functions of differentially expressed miRNAs in the peripheral plasma of miners was performed. The results indicated that the relative expression level of γH2AX protein in peripheral blood lymphocytes of miners was significantly higher than that of the control group (P < 0.05). Bioinformatics methods were used to predict the differential expression miRNA chip to screen the target genes of differentially expressed miRNAs and the signaling pathways that may be involved in screening differentially expressed miRNA target genes and to investigate the relationship between some different miRNA target genes and cellular pathways. The analysis of the cellular pathways predicted by differentially expressed miRNAs, including the process of cell cycle, provides new information for the study of miRNAs as potential biomarkers of radon-induced radiation damage in peripheral blood.

[Research Progress in the Role of Hypoxia-Inducible Factor 1 in Altitude Sickness and the Mechanisms Involved]

Individuals who reside at high altitudes for extended periods or those who visit these regions briefly frequently experience high-altitude response, which triggers a series of physiological and pathological changes in the body, ultimately causing altitude sickness. One of the most critical features of high-altitude environments is hypoxia. Recent studies have demonstrated that hypoxia-inducible factor 1 (HIF-1) plays a central role in mediating the body's response to hypoxic conditions at high altitudes. HIF-1, a heterodimeric transcription factor composed of an oxygen-sensitive subunit α (HIF-1α) and a constitutively expressed subunit β (HIF-1β), directly regulates the expression of multiple target genes, thereby modulating various physiological processes essential for cellular adaptation to hypoxia. According to a substantial body of research, aberrant expression of HIF-1 is implicated in the pathogenesis and progression of various diseases, including altitude sickness, cardiovascular disorders, neurological conditions, inflammatory diseases, cognitive impairment, immune dysregulation, and cancer. In this review, we provided an in-depth examination of the structural characteristics and regulatory mechanisms governing HIF-1 expression, discussed its downstream target genes, and highlighted the inhibitors currently under development. Additionally, we summarized the pivotal role and underlying mechanisms of HIF-1 in the development of altitude sickness, particularly its regulatory role in the pathophysiological processes of high-altitude pulmonary edema (HAPE), high-altitude cerebral edema (HACE), and high-altitude pulmonary hypertension (HAPH). Through a thorough examination of the role of HIF-1, we aim to provide a theoretical foundation and potential therapeutic targets for the prevention and treatment of altitude sickness.

The strict regulation of HIF-1α by non-coding RNAs: new insight towards proliferation, metastasis, and therapeutic resistance strategies

The hypoxic environment is prominently witnessed in most solid tumors and is associated with the promotion of cell proliferation, epithelial-mesenchymal transition (EMT), angiogenesis, metabolic reprogramming, therapeutic resistance, and metastasis of tumor cells. All the effects are mediated by the expression of a transcription factor hypoxia-inducible factor-1α (HIF-1α). HIF-1α transcriptionally modulates the expression of genes responsible for all the aforementioned functions. The stability of HIF-1α is regulated by many proteins and non-coding RNAs (ncRNAs). In this article, we have critically discussed the crucial role of ncRNAs [such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), Piwi-interacting RNAs (piRNAs), and transfer RNA (tRNA)-derived small RNAs (tsRNAs)] in the regulation of stability and expression of HIF-1α. We have comprehensively discussed the molecular mechanisms and relationship of HIF-1α with each type of ncRNA in either promotion or repression of human cancers and therapeutic resistance. We have also elaborated on ncRNAs that are in clinical examination for the treatment of cancers. Overall, the majority of aspects concerning the relationship between HIF-1α and ncRNAs have been discussed in this article.

Molecular regulation of hypoxia through the lenses of noncoding RNAs and epitranscriptome

Cells maintain homeostasis in response to environmental stress through specific cell stress responses. Hypoxic stress, well known to be associated with diverse solid tumors, is one of the main reasons for cancer-related mortality. Although cells can balance themselves well during hypoxic stress, the underlying molecular mechanisms are not well understood. The enhanced appreciation of diverse roles played by noncoding transcriptome and epigenome in recent years has brought to light the involvement of noncoding RNAs and epigenetic modifiers in hypoxic regulation. The emergence of techniques like deep sequencing has facilitated the identification of large numbers of long noncoding RNAs (lncRNAs) that are differentially regulated in various cancers. Similarly, proteomic studies have identified diverse epigenetic modifiers such as HATs, HDACs, DNMTs, polycomb groups of proteins, and their possible roles in the regulation of hypoxia. The crosstalk between lncRNAs and epigenetic modifiers play a pivotal role in hypoxia-induced cancer initiation and progression. Besides the lncRNAs, several other noncoding RNAs like circular RNAs, miRNAs, and so forth are also expressed during hypoxic conditions. Hypoxia has a profound effect on the expression of noncoding RNAs and epigenetic modifiers. Conversely, noncoding RNAs/epigenetic modifies can regulate the hypoxia signaling axis by modulating the stability of the hypoxia-inducible factors (HIFs). The focus of this review is to illustrate the molecular orchestration underlying hypoxia biology, especially in cancers, which can help in identifying promising therapeutic targets in hypoxia-induced cancers. This article is categorized under: RNA Turnover and Surveillance > Regulation of RNA Stability RNA in Disease and Development > RNA in Disease RNA Structure and Dynamics > RNA Structure, Dynamics and Chemistry.

miRNA in Molecular Diagnostics

MicroRNAs are a class of small non-coding RNA molecules that regulate gene expression on post-transcriptional level. Their biogenesis consists of a complex series of sequential processes, and they regulate expression of many genes involved in all cellular processes. Their function is essential for maintaining the homeostasis of a single cell; therefore, their aberrant expression contributes to development and progression of many diseases, especially malignant tumors and viral infections. Moreover, they can be associated with certain states of a specific disease, obtained in the least invasive manner for patients and analyzed with basic molecular methods used in clinical laboratories. Because of this, they have a promising potential to become very useful biomarkers and potential tools in personalized medicine approaches. In this review, miRNAs biogenesis, significance in cancer and infectious diseases, and current available test and methods for their detection are summarized.

The Role of Mitochondrial miRNAs in the Development of Radon-Induced Lung Cancer

MicroRNAs are short, non-coding RNA molecules regulating gene expression by inhibiting the translation of messenger RNA (mRNA) or leading to degradation. The miRNAs are encoded in the nuclear genome and exported to the cytosol. However, miRNAs have been found in mitochondria and are probably derived from mitochondrial DNA. These miRNAs are able to directly regulate mitochondrial genes and mitochondrial activity. Mitochondrial dysfunction is the cause of many diseases, including cancer. In this review, we consider the role of mitochondrial miRNAs in the pathogenesis of lung cancer with particular reference to radon exposure.

An integrated in silico analysis highlighted angiogenesis regulating miRNA-mRNA network in PCOS pathophysiology

Background

Polycystic ovary syndrome (PCOS) is a heterogeneous endocrinopathy and a leading cause of anovulatory infertility. Angiogenesis is vital for ovarian folliculogenesis. The expression of angiogenesis-associated genes/proteins is altered in the ovary of PCOS women. However, information on microRNAs (miRNAs) regulating their expression is limited. This study aims to identify dysregulated angiogenesis-related genes in the ovary of women with PCOS, to identify miRNAs regulating them, and to construct a miRNA-mRNA network associated with angiogenesis.

Methods

A comprehensive literature search and reanalysis of seven ovarian GEO microarray datasets were performed to identify differentially expressed angiogenesis-related genes in PCOS. These target genes were used to predict their regulating miRNAs by querying miRNA databases and their expression in the ovary was verified. Panther and STRING database were used for functional enrichment. Gene expression of shortlisted miRNAs was studied in granulosa cells using digital droplet PCR.

Results

The miRNAs expressed in the ovary and potentially targeting dysregulated angiogenesis-related genes in PCOS were identified and those enriched in angiogenesis-related pathways, like VEGF, FGF, PI3K/Akt, Notch signaling, and ECM interaction were shortlisted. Analysis showed PI3K/Akt signaling was the most enriched pathway. MiR-218-5p, miR-214-3p, miR-20a-5p, and miR-140-3p associated with the PI3K/Akt pathway were found to be up-regulated in granulosa cells of women with PCOS.

Conclusions

By in silico analysis, we identified crucial dysregulated angiogenesis-related genes, the miRNA-mRNA interactions, and signaling pathways involved in impaired follicular angiogenesis in PCOS. This work provides a novel insight into the mechanism of aberrant ovarian angiogenesis contributing to PCOS pathophysiology.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10815-022-02396-1.

Dried Blood Specimens as an Alternative Specimen for Immune Response Monitoring During HIV Infection: A Proof of Concept and Simple Method in a Pediatric Cohort

Programs to prevent mother-to-child HIV transmission do not reduce the number of infants exposed during pregnancy and breastfeeding. HIV-exposed but uninfected children (HEU) present higher risk of morbidity and mortality than HIV-unexposed and uninfected children (UU). In this line, the study of immune biomarkers in HIV could improve prediction of disease progression, allowing to diminish comorbidity risk. Dried blood specimens (DBS) are an alternative to serum for collecting and transporting samples in countries with limited infrastructure and especially interesting for groups such as pediatrics, where obtaining a high sample volume is challenging. This study explores the usefulness of DBS for immune profile monitoring in samples from 30 children under clinical follow-up in Kinshasa: 10 HIV-infected (HIV+), 10 HEU, and 10 UU. We have measured the gene expression levels of 12 immune and inflammatory markers (CD14, IL-6, TNFα, HVEM, B7.1, HIF-1α, Siglec-10, IRAK-M, CD163, B7H5, PD-L1, and Galectin-9) in DBS samples by reverse transcription of total RNA and RT-qPCR. Principal component analysis, Kruskal-Wallis test, and Mann-Whitney test were performed in order to study group differences. HIV+ children presented significantly higher levels of seven biomarkers (CD14, IL-6 HVEM, B7.1, Siglec-10, HIF-1α, and CD163) than the UU group. In HEU, we found seven biomarkers significantly elevated (CD14, IL-6, HVEM, B7.1, Siglec-10, HIF-1α, and IRAK-M) vs. UU. Six biomarkers (CD14, IL-6, HVEM, B7.1, Siglec-10, and HIF-1α) showed a significantly higher expression in both HIV+ and HEU vs. UU, with HVEM and CD14 being significantly overexpressed among HIV+ vs. HEU. Our data reveal the utility of DBS for immune response monitoring. Moreover, significant differences in specific biomarker expression across groups strongly suggest the effect of HIV infection and/or HIV exposure on these immune biomarkers' expressions.

AGO2 promotes tumor progression in KRAS-driven mouse models of non-small cell lung cancer

Lung cancer is the deadliest malignancy in the United States. Non-small cell lung cancer (NSCLC) accounts for 85% of cases and is frequently driven by activating mutations in the gene encoding the KRAS GTPase (e.g., KRASG12D). Our previous work demonstrated that Argonaute 2 (AGO2)-a component of the RNA-induced silencing complex (RISC)-physically interacts with RAS and promotes its downstream signaling. We therefore hypothesized that AGO2 could promote KRASG12D-dependent NSCLC in vivo. To test the hypothesis, we evaluated the impact of Ago2 knockout in the KPC (LSL-KrasG12D/+;p53f/f;Cre) mouse model of NSCLC. In KPC mice, intratracheal delivery of adenoviral Cre drives lung-specific expression of a stop-floxed KRASG12D allele and biallelic ablation of p53 Simultaneous biallelic ablation of floxed Ago2 inhibited KPC lung nodule growth while reducing proliferative index and improving pathological grade. We next applied the KPHetC model, in which the Clara cell-specific CCSP-driven Cre activates KRASG12D and ablates a single p53 allele. In these mice, Ago2 ablation also reduced tumor size and grade. In both models, Ago2 knockout inhibited ERK phosphorylation (pERK) in tumor cells, indicating impaired KRAS signaling. RNA sequencing (RNA-seq) of KPC nodules and nodule-derived organoids demonstrated impaired canonical KRAS signaling with Ago2 ablation. Strikingly, accumulation of pERK in KPC organoids depended on physical interaction of AGO2 and KRAS. Taken together, our data demonstrate a pathogenic role for AGO2 in KRAS-dependent NSCLC. Given the prevalence of this malignancy and current difficulties in therapeutically targeting KRAS signaling, our work may have future translational relevance.

Field Cancerization in NSCLC: A New Perspective on MicroRNAs in Macrophage Polarization

Lung cancer is currently the first cause of cancer-related death. The major lung cancer subtype is non-small cell lung cancers (NSCLC), which accounts for approximatively 85% of cases. The major carcinogenic associated with lung cancer is tobacco smoke, which produces long-lasting and progressive damage to the respiratory tract. The progressive and diffuse alterations that occur in the respiratory tract of patients with cancer and premalignant lesions have been described as field cancerization. At the level of tumor cells, adjacent tumor microenvironment (TME) and cancerized field are taking place dynamic interactions through direct cell-to-cell communication or through extracellular vesicles. These molecular messages exchanged between tumor and nontumor cells are represented by proteins, noncoding RNAs (ncRNAs) and microRNAs (miRNAs). In this paper, we analyze the miRNA roles in the macrophage polarization at the level of TME and cancerized field in NSCLC. Identifying molecular players that can influence the phenotypic states at the level of malignant cells, tumor microenvironment and cancerized field can provide us new insights into tumor regulatory mechanisms that can be further modulated to restore the immunogenic capacity of the TME. This approach could revert alterations in the cancerized field and could enhance currently available therapy approaches.

The interplay between HIF-1α and noncoding RNAs in cancer

Hypoxia is a classic characteristic of the tumor microenvironment with a significant impact on cancer progression and therapeutic response. Hypoxia-inducible factor-1 alpha (HIF-1α), the most important transcriptional regulator in the response to hypoxia, has been demonstrated to significantly modulate hypoxic gene expression and signaling transduction networks. In past few decades, growing numbers of studies have revealed the importance of noncoding RNAs (ncRNAs) in hypoxic tumor regions. These hypoxia-responsive ncRNAs (HRNs) play pivotal roles in regulating hypoxic gene expression at the transcriptional, posttranscriptional, translational and posttranslational levels. In addition, as a significant gene expression regulator, ncRNAs exhibit promising roles in regulating HIF-1α expression at multiple levels. In this review, we briefly elucidate the reciprocal regulation between HIF-1α and ncRNAs, as well as their effect on cancer cell behaviors. We also try to summarize the complex feedback loop existing between these two components. Moreover, we evaluated the biomarker potential of HRNs for the diagnosis and prognosis of cancer, as well as the potential clinical utility of shared regulatory mechanisms between HIF-1α and ncRNAs in cancer treatment, providing novel insights into tumorigenicity, which may lead to innovative clinical applications.

Hypoxia: Overview on Hypoxia-Mediated Mechanisms with a Focus on the Role of HIF Genes

Hypoxia represents a frequent player in a number of malignancies, contributing to the development of the neoplastic disease. This review will discuss the means by which hypoxia powers the mechanisms behind cancer progression, with a majority of examples from lung cancer, the leading malignancy in terms of incidence and mortality rates (the frequent reference toward lung cancer is also for simplification purposes and follow up of the global mechanism in the context of a disease). The effects induced by low oxygen levels are orchestrated by hypoxia-inducible factors (HIFs) which regulate the expression of numerous genes involved in cancer progression. Hypoxia induces epithelial-to-mesenchymal transition (EMT) and metastasis through a complex machinery, by mediating various pathways such as TGF-β, PI3k/Akt, Wnt, and Jagged/Notch. Concomitantly, hypoxic environment has a vast implication in angiogenesis by stimulating vessel growth through the HIF-1α/VEGF axis. Low levels of oxygen can also promote the process through several other secondary factors, including ANGPT2, FGF, and HGF. Metabolic adaptations caused by hypoxia include the Warburg effect-a metabolic switch to glycolysis-and GLUT1 overexpression. The switch is achieved by directly increasing the expression of numerous glycolytic enzymes that are isoforms of those found in non-malignant cells.

The Biological and Clinical Relevance of Inhibitor of Growth (ING) Genes in Non-Small Cell Lung Cancer

Carcinogenic mutations allow cells to escape governing mechanisms that commonly inhibit uncontrolled cell proliferation and maintain tightly regulated homeostasis between cell death and survival. Members of the inhibition of growth (ING) family act as tumor suppressors, governing cell cycle, apoptosis and cellular senescence. The molecular mechanism of action of ING genes, as well as their anchor points in pathways commonly linked to malignant transformation of cells, have been studied with respect to a variety of cancer specimens. This review of the current literature focuses specifically on the action mode of ING family members in lung cancer. We have summarized data from in vitro and in vivo studies, highlighting the effects of varying levels of ING expression in cancer cells. Based on the increasing insight into the function of these proteins, the use of ING family members as clinically useful biomarkers for lung cancer detection and prognosis will probably become routine in everyday clinical practice.