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

Bioinformatics analysis of the expression and role of microRNA-221-3p in head and neck squamous cell carcinoma

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide, associated with a high rate of morbidity and mortality. However, the target genes of miR-221-3p and the underlying mechanism involved in HNSCC are still not clear. Therefore, in the current study, we studied the role of miR-221-3p in the HNSCC.

METHODS

Tissues collected from 48 control and 21 HNSCC patients were processed to check the differential expression of miR-221-3p by RT-qPCR. Overexpression of microRNA-221-3p (miR-221-3p) is significantly correlated to the onset and progression of HNSCC. We also conducted the meta-analysis of the cancer literature from the cancer genome atlas (TCGA) and the Gene Expression Omnibus (GEO) database to estimate the expression of miR-221-3p in HNSCC. The miR-221-3p target genes in the HNSCC were predicted with the miRWalk and TCGA databases, and functionally annotated via the Gene Ontology. Finally, Spearman's analysis was used to determine the role of the related target genes in important pathways involved in the development of HNSCC.

RESULTS

We observed a significantly higher expression of miR-221-3p in HNSCC compared to the normal with a summary receiver operating characteristic (sROC) of 0.86(95% Cl: 0.83,0.89). The KEGG and GO comprehensive analysis predicted that miR-221-3p might be involved in the development of HNSCC through the following metabolic pathways, viz. Drug metabolism - cytochrome P450 UGT1A7 and MAOB may be important genes for the role of miR-221-3p.

CONCLUSION

Based on bioinformatics analysis, our results indicate that miR-221-3p may be used as a non-invasive and hypersensitive biomarker in the diagnosis. Thus, it can be concluded that miR-221-3p may be an extremely important gene locus involved in the process of the deterioration and eventual tumorigenesis of HNSCC. Hopefully, additional work will validate its usefulness as a target for future clinical research.

Delivery of Peptide Nucleic Acids Using an Argininocalix[4]arene as Vector

The importance of peptide nucleic acids (PNAs) for alteration of gene expression is nowadays firmly established. PNAs are characterized by a pseudo-peptide backbone composed of N-(2-aminoethyl)glycine units and have been found to be excellent candidates for antisense and antigene therapies. Recently, PNAs have been demonstrated to alter the action of microRNAs and thus can be considered very important tools for miRNA therapeutics. In fact, the pharmacological modulation of microRNA activity appears to be a very interesting approach in the development of new types of drugs. Among the limits of PNAs in applied molecular biology, the delivery to target cells and tissues is of key importance. The aim of this chapter is to describe methods for the efficient delivery of unmodified PNAs designed to target microRNAs involved in cancer, using as model system miR-221-3p and human glioma cells as in vitro experimental cellular system. The methods employed to deliver PNAs targeting miR-221-3p here presented are based on a macrocyclic multivalent tetraargininocalix[4]arene used as non-covalent vector for anti-miR-221-3p PNAs. High delivery efficiency, low cytotoxicity, maintenance of the PNA biological activity, and easy preparation makes this vector a candidate for a universal delivery system for this class of nucleic acid analogs.

Lowered Expression of MicroRNAs 221 and 222 Mediate Apoptosis Induced by High Glucose in Human Periodontal Ligament Cells

Impaired periodontal healing is a common complication of diabetes mellitus (DM), frequently related to hyperglycemia. MicroRNAs 221 and 222 have been studied as biomarkers for inflammatory diseases, including diabetes, but their role in the periodontal ligament (PL) is unknown. The effects of high glucose on human PL cells death were studied, as well as the expression of microRNA-221 and microRNA-222, potentially modulated by DM. Cells were obtained from the premolar teeth of young humans and cultured for 7 days under different glucose concentrations (5 or 30 mM). MicroRNAs-221/222 expressions were evaluated by real-time RT-PCR and apoptosis by TUNEL assays. Caspase-3 expression was studied by western blotting and immunocytochemistry. High glucose increased apoptosis and caspase-3 protein expression by about 3×. MicroRNA-221 and microRNA-222 expressions decreased by nearly 40% under high glucose. MicroRNA-221 and microRNA-222 inhibition using antagomiRs increased apoptosis by 2-3×, while the expression of caspase-3, a validated target for these microRNAs, was increased by 50%. The overexpression of both microRNAs using miR mimics in high glucose cells did no effect on apoptosis but increased caspase-3 expression by 30%. In conclusion, high glucose induces apoptosis of human PL cells potentially through a reduction of microRNA-221 and microRNA-222 expression and elevation of caspase-3.

Tumor miRNA expression profile is related to vestibular schwannoma growth rate

OBJECTIVE

Our objective was to investigate if the tumor microRNA (miRNA) expression profile was related to tumor growth rate. Growth-related miRNAs might be potential targets for future therapeutic intervention.

MATERIAL AND METHODS

Tumor tissue was sampled during surgery of patients with a sporadic vestibular schwannoma. Tumor growth rate was determined by tumor measurement on the two latest pre-operative MRI scans. Tumor miRNA expression was analyzed using the Affymetrix Gene Chip® protocol, and CEL files were generated using GeneChip® Command Console® Software and normalized using Partek Genomics Suite 6.5. The CEL files were analyzed using the statistical software program R. Principal component analysis, affected gene ontology analysis, and analysis of miRNA expression fold changes were used for analysis of potential relations between miRNA expression profile and tumor growth rate.

RESULTS AND CONCLUSION

Tumor miRNA expression is related to the growth rate of sporadic vestibular schwannomas. Rapid tumor growth is associated with deregulation of several miRNAs, including upregulation of miR-29abc, miR-19, miR-340-5p, miR-21, and miR-221 and downregulation of miR-744 and let-7b. Gene ontologies affected by the deregulated miRNAs included neuron development and differentiation, gene silencing, and negative regulation of various biological processes, including cellular and intracellular signaling and metabolism.

Benign prostatic hyperplasia treatment using plasmonic nanoparticles irradiated by laser in a rat model

OBJECTIVE

In the current study we have stimulated the efficacy of plasmonic nanoparticles (NPs) by laser hyperthermia to achieve a less invasive method for tumor photothermal therapy of benign prostatic hyperplasia (BPH).

METHODS

The levels of apoptosis on induced BPH in rats were assessed after treatment and revealed and recorded by various assayed. Moreover, the expression of caspases was considered to demonstrate the apoptotic pathways due to laser induced plasmonic NPs.

RESULTS

In the Laser + NPs group prostate size of induced BPH decreased. Laser + NPs also decreased prostate specific antigen in comparison with the BPH groups. Furthermore, Laser + NPs attenuated BPH histopathologic indices in the rats. Laser + NPs induced apoptosis in prostatic epithelial cells via caspase-1 pathway.

CONCLUSIONS

Altogether, the approach and findings from this study can be applied to introduce the laser irritated NPs method as a novel and less invasive therapy for patients suffering from BPH.

Targeting miR‑155‑5p and miR‑221‑3p by peptide nucleic acids induces caspase‑3 activation and apoptosis in temozolomide‑resistant T98G glioma cells

The present study investigated the effects of the combined treatment of two peptide nucleic acids (PNAs), directed against microRNAs involved in caspase‑3 mRNA regulation (miR‑155‑5p and miR‑221‑3p) in the temozolomide (TMZ)‑resistant T98G glioma cell line. These PNAs were conjugated with an octaarginine tail in order to obtain an efficient delivery to treated cells. The effects of singularly administered PNAs or a combined treatment with both PNAs were examined on apoptosis, with the aim to determine whether reversion of the drug‑resistance phenotype was obtained. Specificity of the PNA‑mediated effects was analyzed by reverse transcription‑quantitative polymerase‑chain reaction, which demonstrated that the effects of R8‑PNA‑a155 and R8-PNA-a221 anti‑miR PNAs were specific. Furthermore, the results obtained confirmed that both PNAs induced apoptosis when used on the temozolomide‑resistant T98G glioma cell line. Notably, co‑administration of both anti‑miR‑155 and anti‑miR‑221 PNAs was associated with an increased proapoptotic activity. In addition, TMZ further increased the induction of apoptosis in T98G cells co‑treated with anti‑miR‑155 and anti‑miR‑221 PNAs.

An isothermal electrochemical biosensor for the sensitive detection of microRNA based on a catalytic hairpin assembly and supersandwich amplification

A novel isothermal electrochemical biosensor was proposed for the sensitive detection of microRNA (miRNA) based on the ingenious combination of the target-catalyzed hairpin assembly (CHA) and supersandwich amplification strategies. Since miRNA-221 has been reported to be overexpressed in cancers and has been a potentially useful biomarker for the diagnosis of the related diseases, miRNA-221 was chosen as a model target miRNA. The target miRNA-221 triggered a toehold strand displacement assembly of the two hairpin substrates, which led to the cyclicality of the target miRNA and the CHA products. Subsequently, the CHA products hybridized with a capture probe on the electrode and the exposed stem of the CHA products was further used to propagate the supersandwich. After this, the signal probe was modified with horseradish peroxidase (HRP) to form a supersandwich multiplex HRP-DNA label, which could achieve an amplified electrochemical signal. Using the isothermal dual signal amplification strategies, miRNA-221 as low as 0.6 pM (3σ) could be detected. In addition, this biosensor showed high selectivity and could discriminate miRNA-221 from the homologous miRNAs. Note that human miRNA from cancer cells could also be detected and the results were in excellent agreement with those obtained using qRT-PCR. Given that the biosensor avoided the introduction of nanoparticles, the limitation of using the nanoparticles was overcome. The proposed biosensor has great potential for broad applications in the field of clinical analysis.

Levels of MicroRNA Heterogeneity in Cancer Biology

MicroRNAs (miRNAs) are post-transcriptional regulators of gene expression, involved in the silencing of messenger RNA (mRNA) translation. The importance of miRNA signatures in disease screening, prognosis, and progression of different tumor types and subtypes is increasing. miRNA expression levels change depending on numerous factors. In this review, we are describing the circumstances under which miRNA levels can change, these are named 'levels' of heterogeneity of miRNAs. miRNAs can have oncogenic, tumor suppressive, or both roles depending on tumor type and target mRNA whose translation they silence. The expression levels of a single miRNA may vary across different cancer types and subtypes, indicating that a miRNA signature may be tissue specific. miRNA levels of expression also vary during disease formation and propagation, indicating the presence of a time profile for their expression. The complexity of the miRNA-mRNA interference network mirrors different genetic and epigenetic changes that influence miRNA and mRNA availability to each other, and hence, their binding ability. The potential role of miRNAs as biomarkers is two-fold; first, for monitoring of the phases of cancer pathogenesis, and second, to characterize the particular type/subtype of cancer. It is important that a particular miRNA should be characterized by examining as many types and subtypes of cancers as are available, as well as being extracted from different types of samples, in order to obtain a complete picture of its behavior and importance in the disease pathology.

In Hepatocellular Carcinoma miR-221 Modulates Sorafenib Resistance through Inhibition of Caspase-3-Mediated Apoptosis

Purpose: The aberrant expression of miR-221 is a hallmark of human cancers, including hepatocellular carcinoma (HCC), and its involvement in drug resistance, together with a proved in vivo efficacy of anti-miR-221 molecules, strengthen its role as an attractive target candidate in the oncologic field. The discovery of biomarkers predicting the response to treatments represents a clinical challenge in the personalized treatment era. This study aimed to investigate the possible role of miR-221 as a circulating biomarker in HCC patients undergoing sorafenib treatment as well as to evaluate its contribution to sorafenib resistance in advanced HCC.Experimental Design: A chemically induced HCC rat model and a xenograft mouse model, together with HCC-derived cell lines were employed to analyze miR-221 modulation by Sorafenib treatment. Data from the functional analysis were validated in tissue samples from surgically resected HCCs. The variation of circulating miR-221 levels in relation to Sorafenib treatment were assayed in the animal models and in two independent cohorts of patients with advanced HCC.Results: MiR-221 over-expression was associated with Sorafenib resistance in two HCC animal models and caspase-3 was identified as its target gene, driving miR-221 anti-apoptotic activity following Sorafenib administration. Lower pre-treatment miR-221 serum levels were found in patients subsequently experiencing response to Sorafenib and an increase of circulating miR-221 at the two months assessment was observed in responder patients.Conclusions: MiR-221 might represent a candidate biomarker of likelihood of response to Sorafenib in HCC patients to be tested in future studies. Caspase-3 modulation by miR-221 participates to Sorafenib resistance. Clin Cancer Res; 23(14); 3953-65. ©2017 AACR.

microRNA regulators of apoptosis in cancer

This brief review summarizes our current knowledge on the microRNAs that regulate apoptosis machinery and are potentially involved in the dysregulation or deregulation of apoptosis, a well known hallmark of cancer. microRNAs are critical regulators of the most important cellular processes, including apoptosis. Expression of microRNAs is found to be dysregulated in many malignancies, leading to apoptosis inhibition in cancer, or resistance to current therapies. To date, there are over 80 microRNAs directly involved in apoptosis regulation or dysregulation that can impact cancer detection, initiation, progression, invasion, metastasis or resistance to anti-cancer therapy. Development of microRNA-based therapeutic strategies is now taking shape in the clinic. Thus, these microRNAs represent potential targets or tools for cancer therapy in the future.

Effects of microRNA-221/222 on cell proliferation and apoptosis in prostate cancer cells

OBJECTIVE

To investigate the role of miR-221/222 in cell proliferation and apoptosis in human prostate cancer cells, and examine the effects of miR-221/222 on caspase-10 expression.

METHODS

Prostate cancer cells were transfected with miR-221/222 mimics or inhibitors. Cell proliferation was assessed by MTT assay. The expression levels of miR-221/222 were detected with quantitative real-time PCR. Apoptosis was induced with TNF-α/CHX treatment, and evaluated by Hoechst 33342 staining, propidium iodide (PI) flow cytometric analysis, caspase-3 activity measurement, and Western blot analysis. Luciferase activity assay, quantitative real-time PCR, and Western blot were performed to evaluate the effects of miR-221/222 on caspase-10 expression.

RESULTS

Our results showed that miR-221/222 could promote the proliferation of prostate cancer cells, including LNCaP and PC3 cells. After transfection and apoptosis induction, Hoechst 33342 staining and PI flow cytometric assay showed that apoptosis was dramatically decreased in prostate cancer cells treated with miR-221/222 mimics. Moreover, caspase-3 activity was dramatically decreased, and the cleaved forms of caspase-3 were reduced, in the miR-221/222 mimic-treated group. On the contrary, miR-221/222 knockdown sensitized the prostate cancer cells to TNF-α/CHX-induced apoptosis. In addition, a negative correlation was observed between the expressions of miR-221/222 and caspase-10 in prostate cancer cells. miR-221/222 could repress the expression of caspase-10, which was confirmed by the luciferase reporter assay.

CONCLUSION

miR-221/222 promote cell proliferation and repress apoptosis, through suppressing caspase-10, in prostate cancer cells. Our results provide promising evidence for the miRNA-based therapeutic strategy of prostate cancers.

Downregulation of microRNA‑221 decreases migration and invasion in fibroblast‑like synoviocytes in rheumatoid arthritis

MicroRNAs (miRNAs/miRs) are a group of non-coding RNAs that regulate the activity of target mRNAs and cellular processes, and which have been implicated in the pathogenesis of autoimmune diseases. miR-221 is one of the miRNAs that regulate cell proliferation, invasion and apoptosis in tumors. However, the role of miR-221 in rheumatoid arthritis (RA) remains to be fully elucidated. Therefore, the present study was undertaken to identify the role of miR-221 in RA. The expression of miR-221 in serum and synovial tissues of patients with RA and healthy controls was confirmed by reverse transcription quantitative polymerase chain reaction analysis. The effects of miR-221 on pro-inflammatory cytokines and a chemokine were assessed by ELISA. The effects of miR-221 on cell apoptosis, migration and invasion in fibroblast-like synoviocytes (FLS) were also assessed in vitro. The results showed that miR-221 expression in serum and synovial tissues of patients with RA was higher than that in healthy controls. Downregulation of miR-221 significantly suppressed the expression of pro-inflammatory cytokines and the chemokine, and inhibited FLS cell migration and invasion via inhibiting vascular endothelial growth factor, matrix metalloproteinase (MMP)-3 and MMP-9 expression. In addition, downregulation of miR-221 significantly induced cell apoptosis and decreased survivin and X-linked inhibitor of apoptosis protein expression. These findings indicated that downregulation of miR-221 inhibited the expression of pro-inflammatory cytokines and the chemokine, suppressed FLS cell migration and invasion, and induced cell apoptosis. Therefore, miR-221 is likely to be implicated in RA pathogenesis via these mechanisms, and may be a target for the treatment of RA.

Oncocers: ceRNA-mediated cross-talk by sponging miRNAs in oncogenic pathways

Competing endogenous RNAs (ceRNAs) are RNA transcripts which can communicate with each other by decreasing targeting concentration of micro-RNA (miRNA) with the derepression of other messenger RNAs (mRNAs) having the common miRNA response elements (MREs). Oncocers are ceRNAs taking crucial roles in oncogenic pathways processed in many types of cancer, and this study analyzes oncocer-mediated cross-talk by sponging microRNAs (miRNAs) in these pathways. While doing this, breast, liver, colon, prostate, gastric, lung, endometrium, thyroid and epithelial cancers and melanoma, rhabdomyosarcoma, glioblastoma, acute promyelocytic leukemia, retinoblastoma, and neuroblastoma were analyzed with respect to ceRNA-based carcinogenesis. This study defines, firstly, oncocers in the literature and contains all oncocer-related findings found up to now. Therefore, it will help to increase our comprehension about oncocer-mediated mechanisms. Via this study, a novel perspective would be produced to make clear cancer mechanisms and suggest novel approaches to regulate ceRNA networks via miRNA competition for cancer therapeutics. Graphical Abstract Multiple RNA transcripts have common MREs for the similar miRNA in their 3'-untranslated regions (3'-UTRs). Upregulation of ceRNAs rises the abundance of specific MREs and shifts the miRNA pool distribution, as a result, leading to the increased expression of target mRNA. The depot of genomic mutations and epigenetic alterations changing gene function and expression causes cancers. Herewith, genome-based somatic base-pair mutations, DNA copy number alterations, chromosomal translocation, also transcript fusions, alternative splicing are usually seen in cancer situations. Consequently, such cases causing changed UTR expression in transcripts influence the levels of MRE or present new MREs into the cells. Alterations in MREs of ceRNAs affect the capability of a specific mRNA transcript to attach or titrate miRNAs. As a result, the disturbed ceRNA network can lead to diseases and cancers. As a new term in RNA world, oncocers-the name for ceRNAs taking crucial roles in oncogenic pathways-are processed in many types of cancer, and oncocer-mediated cross-talk are analyzed by sponging miRNAs in these pathways.

Silencing clusterin gene transcription on effects of multidrug resistance reversing of human hepatoma HepG2/ADM cells

Abnormal clusterin (CLU) expression is associated with multidrug resistance (MDR) of hepatocellular carcinoma (HCC). In the present study, the CLU expression was analyzed in human hepatoma cells and chemoresistant counterpart HepG2/ADM cells. Compared with L02 cells, the overexpression of cellular CLU was identified in HepG2, HepG2/ADM, SMMC7721, Hep3B ,and PLC cells and relatively lower expression in Bel-7404, SNU-739, and MHCC97H cells. Specific short hairpin RNAs (shRNAs) to silence CLU gene transcription were designed, and the most effective sequences were screened. After the HepG2/ADM cells transfected with shRNA-1, the inhibition of CLU expression was 73.68 % at messenger RNA (mRNA) level by real-time quantitative RT-PCR with obvious enhancement in cell chemosensitivity, increasing apoptosis induced by doxorubicin using fluorescence kit, and Rh-123 retention qualified with flow cytometry. Knockdown CLU also significantly decreased the drug efflux pump activity through the depression of MDR1/P-glycoprotein (q = 11.739, P < 0.001). Moreover, silencing CLU led to downregulation of β-catenin (q = 13.544, P = 0.001), suggesting that downregulation of CLU might be a key point to reverse multidrug resistance of HepG2/ADM cells.

MicroRNA-221 accelerates the proliferation of laryngeal cancer cell line Hep-2 by suppressing Apaf-1

Laryngeal cancer is one of the most commonly occurring malignant cancers of the head and neck region. In the present study, we investigated the roles of miR-221 in laryngeal squamous cell carcinoma cell line, Hep-2. We examined the function and mechanism of miR-221 in Hep-2 cells using techniques of cell biology and molecular pathology, such as western blotting, quantitative PCR, immunohistochemical staining and flow cytometry. Using a luciferase assay, the apoptotic protease activating factor-1 (Apaf-1) mRNA 3'-UTR was shown to have complementary binding sites using bioinformatics prediction software including TargetScan, PicTar and miRanda. In conclusion, our results showed that miR-221 inhibition caused elevated expression levels of the Apaf-1 apoptotic pathway proteins caspase-3, -8 and -9. miR-221 may therefore be used as a novel therapeutic target for laryngeal cancer.

Computational analysis of 3'UTR region of CASP3 with respect to miRSNPs and SNPs in targetting miRNAs

Apoptosis is a strictly organized course which keeps the healthy survival/death equilibrium. Disregulation in apoptosis may lead autoimmunity or cancer, but increased apoptosis can lead degenerative diseases. Studies during the last several years have identified numerous affected miRNAs in association with apoptosis, their target genes and biological functions, and possible drug interventions. Polymorphisms in miRNA genes or miRNA target sites (miRSNPs) can modify miRNA action. While polymorphisms in miRNA genes are relatively rare, SNPs in miRNA-binding sites in target genes are more frequent. Several studies have shown that SNPs in miRNA target sites enhance or weaken the interaction between miRNA and its target transcripts and are associated with cancers and other diseases. We aimed to identify miRSNPs on executioner caspase, CASP3 gene (caspase-3) and SNPs in miRNA genes targeting 3'UTR of CASP3 and assessing the impact of these miRSNPs and SNPs of miRNA genes targeting 3'UTR of CASP3 with respect to apoptosis. We identified 89 different miRNA binding sites (for 43 different miRNAs) and 16 different SNPs in binding sites of miRNA in the 3'UTR of the CASP3 gene. Also, 2 SNPs (rs372435266 and rs190144655) were found on this miRNA' genomic sequence. One of them crossmatched with a SNP in the 3'UTR of CASP3 that we found formerly. This miRNA was miR-4802-3p. Besides, miR-4802-3p targets three other apoptosis related genes, XIAP, IL1A and SOX2. This means that miR-4802-3p may also have a critical effect on apoptosis via different pathways other than caspase-3. We can therefore conclude that this is the first study proving a strong association between miR-4802-3p and apoptosis upon computational targetting analysis.

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.