Emerging role of microRNAs and long non-coding RNAs in COVID-19 with implications to therapeutics.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection which is commonly known as COVID-19 (COronaVIrus Disease 2019) has creeped into the human population taking tolls of life and causing tremendous economic crisis. It is indeed crucial to gain knowledge about their characteristics and interactions with human host cells. It has been shown that the majority of our genome consists of non-coding RNAs. Non-coding RNAs including micro RNAs (miRNAs) and long non-coding RNAs (lncRNAs) display significant roles in regulating gene expression in almost all cancers and viral diseases. It is intriguing that miRNAs and lncRNAs remarkably regulate the function and expression of major immune components of SARS-CoV-2. MiRNAs act via RNA interference mechanism in which they bind to the complementary sequences of the viral RNA strand, inducing the formation of silencing complex that eventually degrades or inhibits the viral RNA and viral protein expression. LncRNAs have been extensively shown to regulate gene expression in cytokine storm and thus emerges as a critical target for COVID-19 treatment. These lncRNAs also act as competing endogenous RNAs (ceRNAs) by sponging miRNAs and thus affecting the expression of downstream targets during SARS-CoV-2 infection. In this review, we extensively discuss the role of miRNAs and lncRNAs, describe their mechanism of action and their different interacting human targets cells during SARS-CoV-2 infection. Finally, we discuss possible ways how an interference with their molecular function could be exploited for new therapies against SARS-CoV-2.

GFI1 tethers the NuRD complex to open and transcriptionally active chromatin in myeloid progenitors.

Growth factor indepdendent 1 (GFI1) is a SNAG-domain, DNA binding transcriptional repressor which controls myeloid differentiation through molecular mechanisms and co-factors that still remain to be clearly identified. Here we show that GFI1 associates with the chromodomain helicase DNA binding protein 4 (CHD4) and other components of the Nucleosome remodeling and deacetylase (NuRD) complex. In granulo-monocytic precursors, GFI1, CHD4 or GFI1/CHD4 complexes occupy sites enriched for histone marks associated with active transcription suggesting that GFI1 recruits the NuRD complex to target genes regulated by active or bivalent promoters and enhancers. GFI1 and GFI1/CHD4 complexes occupy promoters that are either enriched for IRF1 or SPI1 consensus binding sites, respectively. During neutrophil differentiation, chromatin closure and depletion of H3K4me2 occurs at different degrees depending on whether GFI1, CHD4 or both are present, indicating that GFI1 is more efficient in depleting of H3K4me2 and -me1 marks when associated with CHD4. Our data suggest that GFI1/CHD4 complexes regulate histone modifications differentially to enable regulation of target genes affecting immune response, nucleosome organization or cellular metabolic processes and that both the target gene specificity and the activity of GFI1 during myeloid differentiation depends on the presence of chromatin remodeling complexes.

ARID3A regulates autophagy related gene BECN1 expression and inhibits proliferation of osteosarcoma cells.

Osteosarcoma (OS) is the most common primary malignant bone tumor which has unclear pathobiology. Hence, enlightening the exact molecular mechanism underlying osteosarcoma progression is crucial for developing new treatment strategies. One member of the ARID family of DNA binding proteins is ARID3A that is implicated in osteosarcoma pathogenesis. ARID3A could bind E2F1 and regulate the transcription of E2F1 targets. At the same time, BECN1 is a well-characterized autophagy regulator gene that is a direct target of E2F1. The present study aimed to investigate the effect of ARID3A on the expression of BECN1 in osteosarcoma cells. First, we determined gene expression levels of ARID3A, BECN1, and E2F1 in U-2 OS by qPCR and confirmed with online datasets from GEO database. In addition, the prognostic value of these genes was also evaluated from Kaplan-Meier plotter database. Next, ARID3A was overexpressed and silenced in order to investigate the effect of ARID3A on BECN1 expression and proliferation of U-2 OS cells. Our results demonstrated that BECN1 was negatively correlated with E2F1 and positively correlated with ARID3A based on initial expression and prognostic effect in OS. Overexpression of ARID3A upregulated BECN1 while silenced ARID3A downregulated BECN1 expression in U-2 OS cells. Additionally, silencing of ARID3A promoted colony formation and proliferation, whereas overexpression of ARID3A suppressed colony formation and proliferation of U-2 OS cells. Taken together, these results indicate that ARID3A could function as tumor suppressor and affect the expression level of BECN1 in U-2 OS cells.

Severe Inflammatory Reactions in Mice Expressing a GFI1P2A Mutant Defective in Binding to the Histone Demethylase KDM1A (LSD1).

GFI1 is a DNA-binding transcription factor that regulates hematopoiesis by repressing target genes through its association with complexes containing histone demethylases such as KDM1A (LSD1) and histone deacetylases (HDACs). To study the consequences of the disruption of the complex between GFI1 and histone-modifying enzymes, we have used knock-in mice harboring a P2A mutation in GFI1 coding region that renders it unable to bind LSD1 and associated histone-modifying enzymes such as HDACs. GFI1P2A mice die prematurely and show increased numbers of memory effector and regulatory T cells in the spleen accompanied by a severe systemic inflammation with high serum levels of IL-6, TNF-α, and IL-1ß and overexpression of the gene encoding the cytokine oncostatin M (OSM). We identified lung alveolar macrophages, CD8 T cell from the spleen and thymic eosinophils, and monocytes as the sources of these cytokines in GFI1P2A mice. Chromatin immunoprecipitation showed that GFI1/LSD1 complexes occupy sites at the Osm promoter and an intragenic region of the Tnfα gene and that a GFI1P2A mutant still remains bound at these sites even without LSD1. Methylation and acetylation of histone H3 at these sites were enriched in cells from GFI1P2A mice, the H3K27 acetylation being the most significant. These data suggest that the histone modification facilitated by GFI1 is critical to control inflammatory pathways in different cell types, including monocytes and eosinophils, and that a disruption of GFI1-associated complexes can lead to systemic inflammation with fatal consequences.

Crosstalk Between MYC and lncRNAs in Hematological Malignancies.

The human genome project revealed the existence of many thousands of long non-coding RNAs (lncRNAs). These transcripts that are over 200 nucleotides long were soon recognized for their importance in regulating gene expression. However, their poor conservation among species and their still controversial annotation has limited their study to some extent. Moreover, a generally lower expression of lncRNAs as compared to protein coding genes and their enigmatic biochemical mechanisms have impeded progress in the understanding of their biological roles. It is, however, known that lncRNAs engage in various kinds of interactions and can form complexes with other RNAs, with genomic DNA or proteins rendering their functional regulatory network quite complex. It has emerged from recent studies that lncRNAs exert important roles in gene expression that affect many cellular processes underlying development, cellular differentiation, but also the pathogenesis of blood cancers like leukemia and lymphoma. A number of lncRNAs have been found to be regulated by several well-known transcription factors including Myelocytomatosis viral oncogene homolog (MYC). The c-MYC gene is known to be one of the most frequently deregulated oncogenes and a driver for many human cancers. The c-MYC gene is very frequently activated by chromosomal translocations in hematopoietic cancers most prominently in B- or T-cell lymphoma or leukemia and much is already known about its role as a DNA binding transcriptional regulator. Although the understanding of MYC's regulatory role controlling lncRNA expression and how MYC itself is controlled by lncRNA in blood cancers is still at the beginning, an intriguing picture emerges indicating that c-MYC may execute part of its oncogenic function through lncRNAs. Several studies have identified lncRNAs regulating c-MYC expression and c-MYC regulated lncRNAs in different blood cancers and have unveiled new mechanisms how these RNA molecules act. In this review, we give an overview of lncRNAs that have been recognized as critical in the context of activated c-MYC in leukemia and lymphoma, describe their mechanism of action and their effect on transcriptional reprogramming in cancer cells. Finally, we discuss possible ways how an interference with their molecular function could be exploited for new cancer therapies.

Long noncoding RNA ERICD interacts with ARID3A via E2F1 and regulates migration and proliferation of osteosarcoma cells.

Long noncoding RNA (lncRNA) dysregulation is known to be taking part in majority of cancers, including osteosarcoma. In one of our previous studies, we showed that lncRNA MEG3 is being regulated by microRNA-664a (miR-664a) suppresses the migratory potential of osteosarcoma cells (U-2OS). We now report a novel lncRNA, namely, ERICD, which is linked to the transcription factor AT-rich interaction domain 3A (ARID3A) in U-2OS cells. We show that ARID3A binds to ERICD and indirectly interacts with each other via the E2F transcription factor 1 (E2F1). Furthermore, small interfering RNA (siRNA)-mediated knockdown of ERICD inhibited cell migration, formation of colonies, and proliferation in U-2OS cells. Overexpression of ARID3A inhibited cell migration, colony formation, and proliferation, whereas siRNA-mediated knockdown of ARID3A promoted cell migration, colony formation, and proliferation. Our findings indicate that ARID3A and lncRNA ERICD have plausible tumor suppressive and oncogenic functions, respectively, in osteosarcoma. Our data demonstrate the converse interaction between ARID3A and lncRNA ERICD that target DNA-binding proteins and dysregulation of their expression through E2F1 augments osteosarcoma progression. The cell rescue experiment also indicated E2F1 to be involved in the regulation of ARID3A and ERICD.

Effects of Moringa oleifera Lam Extract (MOLE) in the heat shock protein 70 expression and germ cell apoptosis on experimentally induced cryptorchid testes of rats.

Moringa oleifera (Moringaceae) is a plant known for having high antioxidant potency, anticancer, hepatoprotective, cardioprotective etc. and many more activities. Besides these, Moringaceae has the potential for attenuating the male sexual dysfunction. Reactive oxygen species/ROS were increased in cryptorchidism and therefore cause infertility by damaging sperm DNA and germ cell apoptosis. There was an increase in heat shock proteins (HSP) in cells, which is affected by heat shock. In the present study, the antioxidant effects of two different doses of M. oleifera Lam Extract (MOLE) on experimentally induced cryptorchid testes of rats was investigated. Forty two male rats (16 days old) were divided into four groups: a normal control group, a cryptorchidism-induced control group and two cryptorchidism-induced groups treated orally with either 400 or 800 mg/kg MOLE for 2 weeks. Our study showed that there were ruptures from interstitial spaces, separation of the germ cells from basal membrane, falling of the germ cells into the lumen, perivascular fibrosis, oedema, increased level of HSP70, apoptosis, malondialdehyde (MDA) and decrease in the level of superoxide dismutase (SOD) after the cryptorchidism. We found that pathological damages, oxidative stress, expression of the HSP70 and germ cell apoptosis were decreased in treated groups with MOLE. In brief, we can say that aqueous extract of M. oleifera reduces the oxidative stress in a unilateral cryptorchidism induced rats, and it might attenuate histopathological damages, HSP expression and germ cell apoptosis.

Inhibition of miR-664a interferes with the migration of osteosarcoma cells via modulation of MEG3.

Osteosarcoma is the most common primary bone tumor in children and adolescents. Understanding the basic molecular mechanisms in developing cancer can be helpful in developing alternative treatment strategies. The relationship between dysregulated non-coding RNAs' (ncRNA) expression level and osteosarcoma was detected. Among those ncRNAs, the expression levels of miR-664a were detected to be upregulated and MEG3 long non-coding RNA levels were detected to be downregulated in osteosarcoma tissue and cell lines. In this study, miR-664a inhibitor was used in order to investigate the changes in the expression levels of MEG3 gene and miR-664a in osteosarcoma cancer cell line (U2-OS) and human osteoblast cell line (hFOB 1.19). According to our results, the expression level of MEG3 gene was increased while the expression level of miR-664a was decreased, as expected. In addition, changes in expression level of MEG3 and miR-644a interferes with the migration of osteosarcoma cells migration speed of osteosarcoma cells. These results are found to be statistically significant (p < 0.05). As a result of this study, it was shown that the upregulated expression of miR-664a could have an inhibitory effect on MEG3 gene expression and migration of osteosarcoma cells.

A novel variable exonic region and differential expression of LINC00663 non-coding RNA in various cancer cell lines and normal human tissue samples.

Long non-coding RNAs (lncRNAs) are found to play crucial roles in several biological processes and have been associated with many complex human diseases including cancers. Several lines of evidences indicate that lncRNAs deregulated in many cancer tissues. In this particular study, differential expression of long intergenic non-coding RNA 663 (LINC00663) was demonstrated in various cancer cell lines and healthy human tissues by using RT-PCR and qPCR methods. While expression level of LINC00663 was most prominent in thyroid gland and uterus, it is least expressed in skeletal muscle tissues. Moreover, LINC00663 was found to be differentially expressed in various cancer cells. Particularly, its expression was highly diminished in DU-145, PC3, HGC-27, CRL-1469, A549, MCF7, and BCPAP cancer cells. Also, LINC00663 expression was most prominent in A172 glioblastoma cells. Additionally, a novel splice variant of LINC00663 RNA was also detected. The sequence and Basic Local Alignment Search Tool (BLAST) analysis results revealed the presence of a novel exonic region between exons 2 and 3. Subsequently, five potential splice variants showing high level of variation have been identified. Secondary structures of these variants with minimum free energy were also demonstrated. Furthermore, putative microRNA (miRNA) binding sites to these variants have been shown. In conclusion, LINC00663 was shown to be differentially expressed in various human tissues and cancer cell lines. Also, LINC00663 undergoes alternative splicing and the novel exonic region alters its secondary structure and its interactions with potential targeting miRNAs. The role of LINC00663 in cancer formation further needs to be investigated with a wide range of studies.

The investigation of miR-221-3p and PAK1 gene expressions in breast cancer cell lines.

The most common malignancy in women is breast cancer. Drug resistance in the treatment of cancer still remains a major clinical concern. Resistance to tamoxifen is seen in half of the recurrences in breast cancer. The anti-estrogen tamoxifen gains agonistic property by transactivating ERα. PAK1-mediated phosphorylation of serine 305 (S305) of ERα leads to resistance to tamoxifen. In our study, PAK1-induced suggestive tamoxifen resistance was designed. According to our hypothesis, phosphorylation of ERα-S305 by PAK1 may be reversed by PAK1 transcriptional inhibition by miR-221-3p due to miR-221-3p targeting the 3' UTR of PAK1. For this purpose, we used Real-time PCR (qRT-PCR) to measure the expression level of miR-221-3p in ER-positive breast cancer cell lines (ZR-75-1, MCF7) and breast epithelial cell line, hTERT-HME1, as control in the laboratory in our department. The increase in the expression of PAK1 depending on miR-221-3p may be related to ZR-75-1 cell line which has invasive characteristic but other two ER+ cancer cell lines, MCF7 and HCC1500, have milder cancer severity. miR-221-3p may have a role on regulation of PAK1 expression because miR-221-3p expression level decreases while PAK1 expression level increases in SKBR3 cell line. miR-221-3p and PAK1 expressions in MDA-MB-231 cell line are higher than that of hTERT-HME1 cell line. This may mean that miR-221-3p has no regulatory effect on of PAK1 expression in this cell line. According to these results, miR-221-3p may give crucial information about molecular mechanism of the disease upon PAK1 activity or different mechanisms with respect to histopathology and severity of breast cancer.

The interrelationship between HER2 and CASP3/8 with apoptosis in different cancer cell lines.

HER2/ErbB2, a known proto-oncogene (also known as HER2, neu), is among the most practiced molecules in the cancer area. Human epidermal growth factor receptor 2 (HER2) is over expressed in approximately 20-30 % of breast cancer tumors and also in a lot of other human cancer types. It is known to be related to the aggressiveness of the disease, increased mortality and higher relapse ratio. The unusual HER2 overexpression is associated with more severe disease characteristics in several cancers. In recent past, there have been remarkable advances in understanding the role of the HER2 gene in cancers. Caspases are well renowned proteases that act as essential initiators and executioners of the apoptotic process. The primary function of HER2 is suppressing apoptosis to enhance cell survival and eventually giving rise to uncontrolled proliferation and tumor growth. The objective of this work was to study the expression levels of HER2 and apoptosis related factors CASP-3 and CASP-8 in several breast and other cancer cell lines and finally to find a meaningful correlation between all these. We summed up by obtaining an increase in expression of HER2 in all cancer cell lines as compared to that of CASP-3 and CASP-8. In summary we conclude that HER2 promotes cell survival by inhibiting apoptosis i.e. by downregulating CASP-3 and CASP-8. This is a novel study comprising the expression study of HER2 and different caspases in different cancer cell lines simultaneously. It is thus expected that this study will aid in better establishment of correlation between HER2 and caspases in different malignancies.

A highly sensitive and specific tetraplex PCR assay for soybean, poultry, horse and pork species identification in sausages: development and validation.

A tetraplex PCR assay was developed for a rapid and reliable identification of horse, soybean, poultry, and pork species in sausages simultaneously. The method merges the use of horse (Equus caballus), soybean (Glycine max), poultry (Gallus gallus), and pork (Sus scrofa) specific primers that amplify small fragments (horse; 85bp, soybean; 100bp, poultry; 183bp and pork; 212bp) of the mitochondrial cyt b, lectin, 12S rRNA and ATPase subunit 6 genes respectively. Good quality DNA was isolated from reference sausage to optimize the assay. Tetraplex analysis of the reference sausage samples showed that the detection limit of the assay was 0.01% for each species. Taken together, all data indicated that this tetraplex PCR assay was a simple, rapid, sensitive, specific, and cost-effective detection method for horse, soybean, poultry, and pork species in commercial sausages.

Expression patterns of miR-221 and its target Caspase-3 in different cancer cell lines.

Caspases are important initiators and most well-known finishers of apoptosis. By changing the death propagation homeostatic equilibrium, their different expression patterns might trigger the progression of hazardous diseases like cancer. miR-221 is an oncogenic miRNA. It is known to have both anti-angiogenic and angiogenic effect. The aim of this work was to compare the expression levels of miR-221 and its target caspase-3 in different cancer cell lines and to find out a relationship between these two. We also tried to establish a prominent relationship between miR-221 and its role in apoptosis by studying their expression levels. Our results indicate that expression of caspase-3 is quite lower as compared to miR-221 expression in all of the selected cancer cell lines. As a result, we conclude that miR-221 may have a crucial role in repressing the expression of caspase-3 which may contribute to a lower apoptotic rate, thus supporting the selection of more aggressive cancer cells. To our knowledge, this is the first study related to the expression levels of caspase-3 and miR-221 in different cell lines at the same time. We expect that our study might pave the way for better understanding the role of miR-221 in apoptotic regulation of caspase-3.