Regulation of epidermal growth factor receptor signaling in human cancer cells by microRNA-7

MYC-dependent MiR-7-5p regulated apoptosis and autophagy in diffuse large B cell lymphoma by targeting AMBRA1

Diffuse large B-cell lymphoma (DLBCL) is the leading cause of mortality from invasive hematological malignancies worldwide. MicroRNA-7-5p (miR-7-5p) has been shown to be a tumor suppressor in several types of tumors. However, its role in DLBCL is not fully understood. This study explored the role of miR-7-5p in the progression of DLBCL and pursued the underlying mechanism. Quantitative real-time PCR and transfection of miRNA mimic and inhibitors were used to assess the effects of miR-7-5p on autophagy and apoptosis in SU-DHL-4 and SU-DHL-10 cells. Dual-luciferase reporter assay was used to identify target genes of miR-7-5p. Immunofluorescence, flow cytometry, and western blotting (WB) were performed to explore the underlying mechanism and downstream pathways of miR-7-5p and AMBRA1 in DLBCL cells. MiR-7-5p was upregulated in DLBCL cells. Luciferase reporter assays implicated AMBRA1 as a downstream target of miR-7-5p in DLBCL. WB and flow cytometry showed that an increase in miR-7-5p level and a decrease in AMBRA1 expression led to a decrease in autophagy and apoptosis-related protein expression. Furthermore, miR-7-5p prevented c-MYC dephosphorylation through AMBRA1 downregulation. On the contrary, c-MYC increased the expression of miR-7-5p, thereby establishing positive feedback on miR-7-5p transcription. The addition of hydroxychloroquine, an autophagy inhibitor, reduced autophagy and increased apoptosis in DLBCL cells. In vivo experiments further proved that the increase of miR-7-5p played a regulatory role in the expression of downstream AMBRA1 and c-MYC. These results demonstrate that c-MYC-dependent MiR-7-5p suppressed autophagy and apoptosis by targeting AMBRA1 in DLBCL cells. MiR-7-5p also suppressed autophagy and apoptosis by targeting AMBRA1 in DLBCL cells. Therefore, these data suggest that targeting miR-7-5p may be a promising strategy in DLBCL therapy.

Bioengineered miR-7-5p modulates non-small cell lung cancer cell metabolism to improve therapy

Reintroduction of tumor-suppressive microRNA-7-5p (miR-7) that is depleted in non-small cell lung cancer (NSCLC) represents a new therapeutic approach, whereas previous studies mainly used miR-7 mimics chemoengineered in vitro. Here we aim to establish the pharmacological actions and therapeutic potential of novel bioengineered RNA bearing a payload miR-7 (BioRNA/miR-7) molecule produced in vivo. First, through confocal imaging and immunoblot studies, we revealed that BioRNA/miR-7 altered NSCLC cell mitochondrial morphology accompanied by the downregulation of known target genes, epidermal growth factor receptor (EGFR), mitochondrial solute carrier family 25A37 (SLC25A37), and import inner membrane translocase subunit (TIM50). Second, through luciferase reporter and immunoblot studies, we validated mitochondrial acylglycerol kinase (AGK) as a new direct target for miR-7. Third, through real-time live-cell analyses, we revealed BioRNA/miR-7 to modulate mitochondrial respiration and glycolytic capacity. Fourth, live-cell and endpoint viability studies demonstrated that the combination of BioRNA/miR-7 with pemetrexed (PEM) elicited a strong synergistic effect to inhibit NSCLC cell growth, associated with an increased intracellular PEM accumulation, as quantified by a liquid chromatography tandem mass spectrometry method. Finally, through in vivo therapy study using NSCLC patient-derived xenograft mouse model, we demonstrated the efficacy and tolerability of BioRNA/miR-7 monotherapy and combination therapy with PEM to control tumor progression. Our collective works establish a role for miR-7 in NSCLC metabolism and PEM disposition and support our novel, in vivo produced BioRNA/miR-7-5p for molecular pharmacological research. Our findings further illustrate the potential of BioRNA/miR-7 plus PEM combination as a potential treatment to combat NSCLC tumor progression. SIGNIFICANCE STATEMENT: MiR-7 is a tumor-suppressive microRNA depleted in non-small cell lung cancer (NSCLC), and in vitro chemoengineered miR-7 mimics were shown to inhibit tumor growth in NSCLC cell-derived xenograft mice. Here, a novel in vivo bioengineered miR-7 molecule, namely BioRNA/miR-7, was used to effectively control target gene expression and NSCLC cell metabolism. Furthermore, BioRNA/miR-7 was demonstrated to remarkably improve pemetrexed antitumor activity in NSCLC patient-derived tumor mice, supporting the role of miR-7 in NSCLC metabolism and potential for BioRNA/miR-7 to improve NSCLC therapy.

The role of mir-7-5p in cancer: function, prognosis, diagnosis, and therapeutic implications

One of the important and conserved microRNAs (miRNAs), miR-7-5p, is involved in several pathological mechanisms, including cell proliferation, apoptosis, migration, and metastasis. Dysregulation of this miRNA's expression is correlated with multiple diseases, especially cancer. Its role as a tumor suppressor has been demonstrated in various types of cancer, such as colorectal cancer, lung cancer, bladder cancer, breast cancer, and glioblastoma. Furthermore, several studies have highlighted the prognostic and diagnostic value of this miRNA, which could be valuable for the diagnosis and treatment of certain disorders. We present an overview of the latest findings regarding miR-7-5p's role in the development of cancer, its action mechanisms, and expression, based on in vivo, in vitro, and human research. Additionally, we discuss the function of miR-7-5p as a prognostic biomarker in cancer and explore its potential as a therapeutic target.

miR-191-5p suppresses PRRSV replication by targeting porcine EGFR to enhance interferon signaling

Porcine reproductive and respiratory syndrome virus (PRRSV) is a major thread to the global swine industry, lack of effective control strategies. This study explores the regulatory role of a small non-coding RNA, miR-191-5p, in PRRSV infection. We observed that miR-191-5p significantly inhibits PRRSV in porcine alveolar macrophages (PAMs), contrasting with negligible effects in MARC-145 and HEK293-CD163 cells, suggesting a cell-specific antiviral effect. Further investigation unveiled that miR-191-5p directly targets the porcine epidermal growth factor receptor (EGFR), whose overexpression or EGF-induced activation suppresses type I interferon (IFN-I) signaling, promoting PRRSV replication. In contrast, siRNA-or miR-191-5p-induced EGFR downregulation or EGFR inhibitor boosts IFN-I signaling, reducing viral replication. Notably, this miRNA alleviates the suppressive effect of EGF on IFN-I signaling, underscoring its regulatory function. Further investigation revealed interconnections among miR-191-5p, EGFR and signal transducer and activator of transcription 3 (STAT3). Modulation of STAT3 activity influenced IFN-I signaling and PRRSV replication, with STAT3 knockdown countering EGFR activation-induced virus replication. Combination inhibition of STAT3 and miR-191-5p suggests that STAT3 acts downstream in EGFR's antiviral response. Furthermore, miR-191-5p's broad efficacy in restricting various PRRSV strains in PAMs was identified. Collectively, these findings elucidate a novel mechanism of miR-191-5p in activating host IFN-I signaling to inhibit PRRSV replication, highlighting its potential in therapeutic applications against PRRSV.

MicroRNA as Key Players in Hepatocellular Carcinoma: Insights into Their Role in Metastasis

Liver cancer or hepatocellular carcinoma (HCC) remains the most common cancer in global epidemiology. Both the frequency and fatality of this malignancy have shown an upward trend over recent decades. Liver cancer is a significant concern due to its propensity for both intrahepatic and extrahepatic metastasis. Liver cancer metastasis is a multifaceted process characterized by cell detachment from the bulk tumor, modulation of cellular motility and invasiveness, enhanced proliferation, avoidance of the immune system, and spread either via lymphatic or blood vessels. MicroRNAs (miRNAs) are small non-coding ribonucleic acids (RNAs) playing a crucial function in the intricate mechanisms of tumor metastasis. A number of miRNAs can either increase or reduce metastasis via several mechanisms, such as control of motility, proliferation, attack by the immune system, cancer stem cell properties, altering the microenvironment, and the epithelial-mesenchymal transition (EMT). Besides, two other types of non-coding RNAs, such as long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) can competitively bind to endogenous miRNAs. This competition results in the impaired ability of the miRNAs to inhibit the expression of the specific messenger RNAs (mRNAs) that are targeted. Increasing evidence has shown that the regulatory axis comprising circRNA/lncRNA-miRNA-mRNA is correlated with the regulation of HCC metastasis. This review seeks to present a thorough summary of recent research on miRNAs in HCC, and their roles in the cellular processes of EMT, invasion and migration, as well as the metastasis of malignant cells. Finally, we discuss the function of the lncRNA/circRNA-miRNA-mRNA network as a crucial modulator of carcinogenesis and the regulation of signaling pathways or genes that are relevant to the metastasis of HCC. These findings have the potential to offer valuable insight into the discovery of novel therapeutic approaches for management of liver cancer metastasis.

Non-coding RNAs as therapeutic targets in cancer and its clinical application

Cancer genomics has led to the discovery of numerous oncogenes and tumor suppressor genes that play critical roles in cancer development and progression. Oncogenes promote cell growth and proliferation, whereas tumor suppressor genes inhibit cell growth and division. The dysregulation of these genes can lead to the development of cancer. Recent studies have focused on non-coding RNAs (ncRNAs), including circular RNA (circRNA), long non-coding RNA (lncRNA), and microRNA (miRNA), as therapeutic targets for cancer. In this article, we discuss the oncogenes and tumor suppressor genes of ncRNAs associated with different types of cancer and their potential as therapeutic targets. Here, we highlight the mechanisms of action of these genes and their clinical applications in cancer treatment. Understanding the molecular mechanisms underlying cancer development and identifying specific therapeutic targets are essential steps towards the development of effective cancer treatments.

STR mutations on chromosome 15q cause thyrotropin resistance by activating a primate-specific enhancer of MIR7-2/MIR1179

Thyrotropin (TSH) is the master regulator of thyroid gland growth and function. Resistance to TSH (RTSH) describes conditions with reduced sensitivity to TSH. Dominantly inherited RTSH has been linked to a locus on chromosome 15q, but its genetic basis has remained elusive. Here we show that non-coding mutations in a (TTTG)4 short tandem repeat (STR) underlie dominantly inherited RTSH in all 82 affected participants from 12 unrelated families. The STR is contained in a primate-specific Alu retrotransposon with thyroid-specific cis-regulatory chromatin features. Fiber-seq and RNA-seq studies revealed that the mutant STR activates a thyroid-specific enhancer cluster, leading to haplotype-specific upregulation of the bicistronic MIR7-2/MIR1179 locus 35 kb downstream and overexpression of its microRNA products in the participants' thyrocytes. An imbalance in signaling pathways targeted by these micro-RNAs provides a working model for this cause of RTSH. This finding broadens our current knowledge of genetic defects altering pituitary-thyroid feedback regulation.

Promoter A1312C mutation leads to microRNA-7 downregulation in human non-small cell lung cancer

MicroRNA-7 (miRNA-7, miR-7) is a unique class of tumor suppressors, plays an important role in various physiological and pathological processes including human non-small cell lung cancer (NSCLC). In previous works, we revealed that miR-7 could regulate the growth and metastasis of human NSCLC cells. However, the mechanism of dysregulated miR-7 expression in NSCLC remains to be further elucidated. In this study, based on clinical sample analysis, we found that the downregulated expression of miR-7 was dominantly attributed to the decreased level of pri-miR-7-2 in human NSCLC. Furthermore, there were four site mutations in the miR-7-2 promoter sequence. Notably, among these four sites, mutation at -1312 locus (A → C, termed as A1312C mutation) was dominate, and A1312C mutation further led to decreased expression of miR-7 in human NSCLC cells, accompanied with elevated transduction of NDUFA4/ERK/AKT signaling pathway. Mechanistically, homeobox A5 (HOXA5) is the key transcription factors regulating miR-7 expression in NSCLC. A1312C mutation impairs HOXA5 binding, thereby reducing the transcriptional activity of miR-7-2 promoter, resulting in downregulation of miR-7 expression. Together, these data may provide new insights into the dysregulation of specific miRNA expression in NSCLC and ultimately prove to be helpful in the diagnostic, prognostic, and therapeutic strategies against NSCLC.

Non-coding RNAs as potential therapeutic targets for receptor tyrosine kinase signaling in solid tumors: current status and future directions

This review article presents an in-depth analysis of the current state of research on receptor tyrosine kinase regulatory non-coding RNAs (RTK-RNAs) in solid tumors. RTK-RNAs belong to a class of non-coding RNAs (nc-RNAs) responsible for regulating the expression and activity of receptor tyrosine kinases (RTKs), which play a critical role in cancer development and progression. The article explores the molecular mechanisms through which RTK-RNAs modulate RTK signaling pathways and highlights recent advancements in the field. This include the identification of potential new RTK-RNAs and development of therapeutic strategies targeting RTK-RNAs. While the review discusses promising results from a variety of studies, encompassing in vitro, in vivo, and clinical investigations, it is important to acknowledge the challenges and limitations associated with targeting RTK-RNAs for therapeutic applications. Further studies involving various cancer cell lines, animal models, and ultimately, patients are necessary to validate the efficacy of targeting RTK-RNAs. The specificity of ncRNAs in targeting cellular pathways grants them tremendous potential, but careful consideration is required to minimize off-target effects, the article additionally discusses the potential clinical applications of RTK-RNAs as biomarkers for cancer diagnosis, prognosis, and treatment. In essence, by providing a comprehensive overview of the current understanding of RTK-RNAs in solid tumors, this review emphasizes their potential as therapeutic targets for cancer while acknowledging the associated challenges and limitations.

Involvement of FAM170B-AS1, hsa-miR-1202, and hsa-miR-146a-5p in breast cancer

BACKGROUND

FAM170B-AS1 is usually expressed low in all organs except for testicular tissues. No study was performed to explore its role in breast cancer (BC). Contradictory results were reported about hsa-miR-1202 and hsa-miR-146a-5p in BC.

OBJECTIVE

The present study aimed to explore the involvement of FAM170B-AS1 in BC using bioinformatics predictive tools, followed by a practical validation besides exploring the impact of hsa-miR-1202 and hsa-miR-146a-5p in BC.

METHODS

This study enrolled 96 female patients with BC, 30 patients with benign breast diseases (BBD), and 25 control subjects. The expressions of circulating FAM170B-AS1, hsa-miR-1202, and hsa-miR-146a-5p were quantified using qRT-PCR. These ncRNAs' associations, predictive, and diagnostic roles in BC were statistically tested. The underlying miRNA/mRNA targets of FAM170B-AS1 in BC were bioinformatically predicted followed by confirmation based on the GEPIA and TCGA databases.

RESULTS

The expression of FAM170B-AS1 was upregulated in sera of BC patients and hsa-miR-1202 was upregulated in sera of BBD and BC patients while that of hsa-miR-146a-5p was downregulated in BC. These FAM170B-AS1 was significantly associated with BC when compared to BBD. FAM170B-AS1 and hsa-miR-1202 were statistically associated with the BC's stage, grade, and LN metastasis. FAM170B-AS1 and hsa-miR-146a-5p gave the highest specificity and sensitivity for BC. KRAS and EGFR were predicted to be targeted by FAM170B-AS1 through interaction with hsa-miR-143-3p and hsa-miR-7-5p, respectively. Based on the TCGA database, cancer patients having mutations in FAM170B show good overall survival.

CONCLUSIONS

The present study reported that for the first time, FAM170B-AS1 may be a potential risk factor, predictive, and diagnostic marker for BC. In addition, FAM170B-AS1 might be involved in BC by interacting with hsa-miR-143-3p/KRAS and hsa-miR-7-5p/EGFR through enhancement or repression that may present a new therapeutic option for BC.

Cross-talk between PARN and EGFR-STAT3 Signaling Facilitates Self-Renewal and Proliferation of Glioblastoma Stem Cells

Glioblastoma is the most common type of malignant primary brain tumor and displays highly aggressive and heterogeneous phenotypes. The transcription factor STAT3 has been reported to play a key role in glioblastoma malignancy. Thus, discovering targets and functional downstream networks regulated by STAT3 that govern glioblastoma pathogenesis may lead to improved treatment strategies. In this study, we identified that poly(A)-specific ribonuclease (PARN), a key modulator of RNA metabolism, activates EGFR-STAT3 signaling to support glioblastoma stem cells (GSC). Functional integrative analysis of STAT3 found PARN as the top-scoring transcriptional target involved in RNA processing in patients with glioblastoma, and PARN expression was strongly correlated with poor patient survival and elevated malignancy. PARN positively regulated self-renewal and proliferation of GSCs through its 3'-5' exoribonuclease activity. EGFR was identified as a clinically relevant target of PARN in GSCs. PARN positively modulated EGFR by negatively regulating the EGFR-targeting miRNA miR-7, and increased EGFR expression created a positive feedback loop to increase STAT3 activation. PARN depletion in GSCs reduced infiltration and prolonged survival in orthotopic brain tumor xenografts; similar results were observed using siRNA nanocapsule-mediated PARN targeting. Pharmacological targeting of STAT3 also confirmed PARN regulation by STAT3 signaling. In sum, these results suggest that a STAT3-PARN regulatory network plays a pivotal role in tumor progression and thus may represent a target for glioblastoma therapeutics.

SIGNIFICANCE

A positive feedback loop comprising PARN and EGFR-STAT3 signaling supports self-renewal and proliferation of glioblastoma stem cells to drive tumor progression and can be targeted in glioblastoma therapeutics.

Understanding crosstalk of organ tropism, tumor microenvironment and noncoding RNAs in breast cancer metastasis

Cancer metastasis is one of the major clinical challenges worldwide due to limited existing effective treatments. Metastasis roots from the host organ of origin and gradually migrates to different regional and distant organs. In different breast cancer subtypes, different organs like bones, liver, lungs and brain are targeted by the metastatic tumor cells. Cancer renders mortality to their respective metastasizing sites like bones, brain, liver, and lungs. Metastatic breast cancers are best treated and managed if detected at an early stage. Metastasis is regulated by various molecular activators and suppressors. The conventional theory of 'seed and soil' states that metastatic tumor cells move to tumor microenvironment that has favorable conditions like blood flow for them to grow just like seeds grows when planted in fertile land. Additionally, different coding as well as non-coding RNAs play a very significant role in the process of metastasis by modulating their expression levels leading to a crosstalk of various tumorigenic cascades. Treatments for metastasis is also very critical in controlling this lethal process. Detecting breast cancer metastasis at an early stage is crucial for managing and predicting metastatic progression. In this review, we have compiled several factors that can be targeted to manage the onset and gradual stages of breast cancer metastasis.

Dysregulated miRNAs in recurrent miscarriage: A systematic review

Recurrent miscarriage (RM) is a complex reproductive medicine disease that affects many families. The cause of RM is unclear at this time; however, lifestyle and genetic variables may influence the process. The slight alteration in miRNA expression has enormous consequences for a variety of difficulties, one of which may be RM. The target of this systematic study was to provide a framework of the dysregulated miRNAs in RM. The Prisma guidelines were applied to perform current systematic review pertaining to articles in the seven databases. Thirty-nine papers out of 245 received fulfilled all inclusion requirements. From all the mentioned miRNAs, 40 were up-regulated (65.57 %), whereas 21 were down-regulated (34.43 %). These dysregulated miRNAs contributed to the pathophysiology of RM by influencing key pathways and processes such as apoptosis, angiogenesis, epithelial-mesenchymal transition, and the immune system. Understanding the dysregulation of miRNAs, as well as the pathways and processes that engage these miRNAs and impact disease pathogenesis, may aid in clarifying the unknown underlying mechanisms of RM and the development of novel molecular therapeutic targets and medical domains.

Decoding of miR-7-5p in Colony Forming Unit-Hill Colonies as a Biomarker of Subclinical Cardiovascular Disease-A MERIT Study

Colony forming unit-Hill (CFU-Hill) colonies were established to serve as a sensitive biomarker for vascular health. In animals, the overexpression of miR-7-5p was shown to be pro-atherogenic and associated with increased cardiovascular disease (CVD) risk. In a MERIT study, we aimed to explore the role of miR-7-5p expression in CFU-Hill colonies in type 1 diabetes mellitus (T1DM) and the effect of metformin in subclinical CVD. The expression of miR-7-5p in CFU-Hill colonies in 29 T1DM subjects without CVD and 20 healthy controls (HC) was measured. Metformin was administered to T1DM subjects for eight weeks. MiR-7-5p was upregulated in T1DM whereas metformin reduced it to HC levels. MiR-7-5p was positively correlated with c-reactive protein, and C-X-C motif chemokine ligand 10. The receiver operating characteristic curve revealed miR-7-5p as a biomarker of CVD, and upregulated miR-7-5p, defining subclinical CVD at a HbA1c level of 44.3 mmol/mol. Ingenuity pathway analysis predicted miR-7-5p to inhibit the mRNA expression of Krüppel-like factor 4, epidermal growth factor receptor, insulin-like growth factor 1 receptor, v-raf-1 murine leukemia viral oncogene homolog 1 and insulin receptor substrate ½, and insulin receptor, while metformin activated these miRNAs via transforming growth factor-β1 and Smad2/3. We proved the pro-atherogenic effect of miR-7-5p that maybe used as a prognostic biomarker.

Role of microRNAs in regulation of doxorubicin and paclitaxel responses in lung tumor cells

Lung cancer as the leading cause of cancer related mortality is always one of the main global health challenges. Despite the recent progresses in therapeutic methods, the mortality rate is still significantly high among lung cancer patients. A wide range of therapeutic methods including chemotherapy, radiotherapy, and surgery are used to treat lung cancer. Doxorubicin (DOX) and Paclitaxel (TXL) are widely used as the first-line chemotherapeutic drugs in lung cancer. However, there is a significant high percentage of DOX/TXL resistance in lung cancer patients, which leads to tumor recurrence and metastasis. Considering, the side effects of these drugs in normal tissues, it is required to clarify the molecular mechanisms of DOX/TXL resistance to introduce the efficient prognostic and therapeutic markers in lung cancer. MicroRNAs (miRNAs) have key roles in regulation of different pathophysiological processes including cell division, apoptosis, migration, and drug resistance. MiRNA deregulations are widely associated with chemo resistance in various cancers. Therefore, considering the importance of miRNAs in chemotherapy response, in the present review, we discussed the role of miRNAs in regulation of DOX/TXL response in lung cancer patients. It has been reported that miRNAs mainly induced DOX/TXL sensitivity in lung tumor cells by the regulation of signaling pathways, autophagy, transcription factors, and apoptosis. This review can be an effective step in introducing miRNAs as the non-invasive prognostic markers to predict DOX/TXL response in lung cancer patients.

In silico analysis reveals hypoxia-induced miR-210-3p specifically targets SARS-CoV-2 RNA

Human coronaviruses (HCoVs) until the emergence of SARS in 2003 were associated with mild cold and upper respiratory tract infections. The ongoing pandemic caused by SARS-CoV-2 has enhanced the potential for infection and transmission as compared to other known members of this family. MicroRNAs (miRNA) are 21-25 nucleotides long non-coding RNA that bind to 3' UTR of genes and regulate almost every aspect of cellular function. Several human miRNAs have been known to target viral genomes, mostly to downregulate their expression and sometimes to upregulate also. In some cases, host miRNAs could be sequestered by the viral genome to create a condition for favourable virus existence. The ongoing SARS CoV-2 pandemic is unique based on its transmissibility and severity and we hypothesised that there could be a unique mechanism for its pathogenesis. In this study, we exploited in silico approach to identify human respiratory system-specific miRNAs targeting the viral genome of three highly pathogenic HCoVs (SARS-CoV-2 Wuhan strain, SARS-CoV, and MERS-CoV) and three low pathogenic HCoVs (OC43, NL63, and HKU1). We identified ten common microRNAs that target all HCoVs studied here. In addition, we identified unique miRNAs which targeted specifically one particular HCoV. miR-210-3p was the single unique lung-specific miRNA, which was found to target the NSP3, NSP4, and NSP13 genes of SARS-CoV-2. Further miR-210-NSP3, miR-210-NSP4, and miR-210-NSP13 SARS-CoV-2 duplexes were docked with the hAGO2 protein (PDB ID 4F3T) which showed Z-score values of -1.9, -1.7, and -1.6, respectively. The role of miR-210-3p as master hypoxia regulator and inflammation regulation may be important for SARS-CoV-2 pathogenesis. Overall, this analysis advocates that miR-210-3p be investigated experimentally in SARS-CoV-2 infection.Communicated by Ramaswamy H. Sarma.

EVADR ceRNA transcript variants upregulate WNT and PI3K signaling pathways in SW480 and HCT116 cells by sponging miR-7 and miR-29b

Long noncoding RNAs are cancer regulators and EVADR-lncRNA is highly upregulated in colorectal cancer (CRC). Accordingly, we aimed to functionally characterize the EVADR in CRC-originated cells. Firstly, during the amplification of EVADR full-length cDNA (named EVADR-v1), a novel/shorter variant (EVADR-v2) was discovered. Then, RT-qPCR analysis confirmed that EVADR is upregulated in tumors, consistent with RNA-seq analysis. Interestingly, bioinformatics analysis and dual-luciferase assay verified that EVADR sponges miR-7 and miR-29b. When both EVADR-v1/-v2 variants were overexpressed in SW480/HCT116 cells, miR-7 and miR-29b target genes (involved in the WNT/PI3K signaling) were upregulated. Furthermore, EVADR-v1/-v2 overexpression resulted in elevated PI3K activity (verified by western blotting and RT-qPCR) and upregulation of WNT signaling (confirmed by western blotting, TopFlash assay, and RT-qPCR). Consistently, overexpression of EVADR-v1/-v2 variants was followed by increased cell cycle progression, viability and migration as well as reduced early/late apoptotic rate, and Bax/Bcl2 ratio of the CRC cells, detected by the cell cycle analysis, MTT, wound-healing, Annexin-V/PI, and RT-qPCR methods, respectively. Overall, we introduced two oncogenic transcript variants for EVADR that by sponging miR-7/miR-29b, upregulate WNT and PI3K signaling. Given the crucial role of these pathways in CRC, EVADR may present potential therapy use.

A new paradigm for epidermal growth factor receptor expression exists in PTC and NIFTP regulated by microRNAs

Intoduction

Identification of molecular alterations associated with tumor behavior is necessary to guide clinical management. The 2022 WHO classification has organized the thyroid follicular cell-derived neoplasms into benign, low-risk and high-risk neoplasms, and emphasized the value of biomarkers that may provide differential diagnostic and prognostic information to avoid overtreatment of low risk neoplasms. This work aims to study the epidermal growth factor receptor (EGFR) expression, functional and spatial dynamics in relation to specific miRNAs alterations in papillary thyroid cancer (PTC) and in non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) considered as models of high-risk and low-risk thyroid tumors respectively.

Methods

Primary thyroid cultured cells were used for miRNA gain/loss of function and luciferase reporter assays. Paraffin embedded tissues were used for real time PCR, immuno-fluorescence stain and confocal microscopy experiments.

Results

Our results showed that in PTC, EGFR mRNA is reduced as an effect of miR-146b-5p upregulation. The EGF expression is low and the ERK pathway is inhibited. The EGFR protein high cytoplasmic expression and colocalization with the endosomal/exosomal markers, ALIX and CD63, suggest the occurrence of stress-induced EGFR internalization, accumulation in endosomal vesicles and secretion via exosomes. In NIFTP EGFR transcription is increased in association with downregulation of miR-7-5p and the EGFR/ERK pathway is active indicating dependence on the canonical EGFR pathway for growth.

Conclusion

Downregulation of transcript level along with cytoplasmic accumulation of undegraded protein is a new pattern of EGFR regulation associated with malignancy in thyroid. Further research is needed to elucidate the intracellular trafficking defects responsible for this specific EGFR dynamic in PTC.

MicroRNAs in esophageal squamous cell carcinoma: Application in prognosis, diagnosis, and drug delivery

MicroRNAs (miRNAs) play a vital role in various cell biology processes, including cancer formation. These small non-coding RNAs could function as diagnostic and prognostic markers. They may involve esophageal squamous cell carcinoma (ESCC) and distinctive miRNA expression profiles; they are also known as therapeutic targets in human diseases. Therefore, in this study, the function of miRNAs was reviewed regarding the prognosis and diagnosis of ESCC. The changes in miRNAs before and after cancer therapy and the effects of miRNAs on chemo-susceptibility patterns were also investigated. MiRNA delivery systems in ESCC were also highlighted, providing a perspective on how these systems can improve miRNA efficiency.

Emerging Role of Noncoding RNAs in EGFR TKI-Resistant Lung Cancer

Lung cancer accounts for the majority of malignancy-related mortalities worldwide. The introduction of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) has revolutionized the treatment and significantly improved the overall survival (OS) of lung cancer. Nevertheless, almost all EGFR-mutant patients invariably acquire TKI resistance. Accumulating evidence has indicated that noncoding RNAs (ncRNAs), such as microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs), have a central role in the tumorigenesis and progression of lung cancer by regulating crucial signaling pathways, providing a new approach for exploring the underlying mechanisms of EGFR-TKI resistance. Therefore, this review comprehensively describes the dysregulation of ncRNAs in EGFR TKI-resistant lung cancer and its underlying mechanisms. We also underscore the clinical application of ncRNAs as prognostic, predictive and therapeutic biomarkers for EGFR TKI-resistant lung cancer. Furthermore, the barriers that need to be overcome to translate the basic findings of ncRNAs into clinical practice are discussed.

Glioblastoma microenvironment and its reprogramming by oncolytic virotherapy

Glioblastoma (GBM), a highly aggressive form of brain tumor, responds poorly to current conventional therapies, including surgery, radiation therapy, and systemic chemotherapy. The reason is that the delicate location of the primary tumor and the existence of the blood-brain barrier limit the effectiveness of traditional local and systemic therapies. The immunosuppressive status and multiple carcinogenic pathways in the complex GBM microenvironment also pose challenges for immunotherapy and single-targeted therapy. With an improving understanding of the GBM microenvironment, it has become possible to consider the immunosuppressive and highly angiogenic GBM microenvironment as an excellent opportunity to improve the existing therapeutic efficacy. Oncolytic virus therapy can exert antitumor effects on various components of the GBM microenvironment. In this review, we have focused on the current status of oncolytic virus therapy for GBM and the related literature on antitumor mechanisms. Moreover, the limitations of oncolytic virus therapy as a monotherapy and future directions that may enhance the field have also been discussed.

CircRNA-Associated CeRNAs Regulatory Axes in Retinoblastoma: A Systematic Scoping Review

Retinoblastoma (RB) is one of the most common childhood cancers caused by RB gene mutations (tumor suppressor gene in various patients). A better understanding of molecular pathways and the development of new diagnostic approaches may lead to better treatment for RB patients. The number of studies on ceRNA axes is increasing, emphasizing the significance of these axes in RB. Circular RNAs (circRNAs) play a vital role in competing endogenous RNA (ceRNA) regulatory axes by sponging microRNAs and regulating gene expression. Because of the broadness of ceRNA interaction networks, they may assist in investigating treatment targets in RB. This study conducted a systematic scoping review to evaluate verified loops of ceRNA in RB, focusing on the ceRNA axis and its relationship to circRNAs. This scoping review was carried out using a six-step strategy and the Prisma guideline, and it involved systematically searching the publications of seven databases. Out of 363 records, sixteen articles were entirely consistent with the defined inclusion criteria and were summarized in the relevant table. The majority of the studies focused on the circRNAs circ_0000527, circ_0000034, and circTET1, with approximately two-fifths of the studies focusing on a single circRNA. Understanding the many features of this regulatory structure may help elucidate RB's unknown causative factors and provide novel molecular potential therapeutic targets and medical fields.

miRNAs as therapeutic predictors and prognostic biomarkers of neoadjuvant chemotherapy in breast cancer: a systematic review and meta-analysis

PURPOSE

Accumulating evidence has shown that microRNAs (miRNAs) are promising biomarkers of neoadjuvant chemotherapy (NAC) response in breast cancer (BC). However, their predictive roles remain controversial. Thus, this systematic review and meta-analysis aimed to describe the role of miRNA expression in NAC response and prognosis in BC to increase statistical power and improve translation.

METHODS

A systematic review of electronic databases for relevant studies was conducted following PRISMA guidelines. Data were extracted, collated, and combined by odds ratio (OR) and hazard ratio (HR) with 95% confidence intervals (CIs) to estimate the strength of the associations.

RESULTS

Of the 560 articles screened, 59 studies were included in our systematic review, and 5 studies were included in the subsequent meta-analysis. Sixty of 123 miRNAs were found to be related with NAC response and an elevated baseline miR-7 level in tissues was associated with a higher pathological complete response rate (OR 5.63; 95% CI 2.15-14.79; P = 0.0004). The prognostic value of 39 miRNAs was also studied. Of them, 26 miRNAs were found to be associated with survival. Pooled HRs indicated that patients with increased levels of serum miR-21 from baseline to the end of the second NAC cycle and from baseline to the end of NAC had a worse disease-free survival than those with decreased levels.

CONCLUSION

Our results highlight that a large number of miRNAs have possible associations with NAC response and prognosis in BC patients. Further well-designed studies are needed to elucidate the molecular mechanisms underlying these associations.

Emerging role of lncRNA ELDR in development and cancer

Whole-genome sequencing and transcriptome analysis revealed more than 90% of the human genome transcribes noncoding RNAs including lncRNAs. From the beginning of the 21st century, lncRNAs have gained widespread attention as a new layer of regulation in biological processes. lncRNAs are > 200 nucleotides in size, transcribed by RNA polymerase II, and share many similarities with mRNAs. lncRNA interacts with DNA, RNA, protein, and miRNAs, thereby regulating many biological processes. In this review, we have focused mainly on LINC01156 [also known as the EGFR long non-coding downstream RNA (ELDR) or Fabl] and its biological importance. ELDR is a newly identified lncRNA and first reported in a mouse model, but it has a human homolog. The human ELDR gene is closely localized downstream of epidermal growth factor receptor (EGFR) gene at chromosome 7 on the opposite strand. ELDR is highly expressed in neuronal stem cells and associated with neuronal differentiation and mouse brain development. ELDR is upregulated in head and neck cancer, suggesting its role as an oncogene and its importance in prognosis and therapy. Publicly available RNA-seq data further support its oncogenic potential in different cancers. Here, we summarize all the aspects of ELDR in development and cancer, highlighting its future perspectives in the context of mechanism.

Exosome-mediated miR-7-5p delivery enhances the anticancer effect of Everolimus via blocking MNK/eIF4E axis in non-small cell lung cancer

Everolimus is a kind of mammalian target of rapamycin (mTOR) inhibitors. Activated mitogen-activated protein kinase interacting kinases/eukaryotic translation initiation factor 4E (MNK/eIF4E) axis plays a crucial role in resistance to Everolimus in non-small cell lung cancer (NSCLC). The eIF4E phosphorylation increased by mTOR inhibitors is mainly mediated by MNKs. However, the mechanisms are poorly understood. Recently, extensive reprogramming of miRNA profiles has also been found after long-term mTOR inhibitor exposure. Our previous studies have confirmed that tumor suppressor miR-7-5p is decreased in A549 cells after treatment with Everolimus. Exactly, MNK1 is the target of miR-7-5p. In this study, we investigated the biological functions and potential molecular mechanisms of miR-7-5p in the NSCLC undergoing treatment with Everolimus. We confirmed that Everolimus targeted mTORC1 inducing NSCLC cells to secrete miR-7-5p-loaded exosomes in Rab27A and Rab27B-dependent manners. Loss of intracellular miR-7-5p induced phosphorylation of MNK/eIF4E axis, but a supplement of extra exosomal miR-7-5p could reverse it. Of note, both low expression of miR-7-5p and elevated MNK1 protein were associated with a poor prognosis of NSCLC. Both endogenous miR-7-5p and exo-miR-7-5p enhanced the therapeutic efficacy of Everolimus by inhibiting the proliferation, migration, and metastasis of NSCLC in vitro and in vivo. The combination of miR-7-5p with Everolimus induced apoptosis to exhibit a synergistic anticancer therapeutic efficacy through dual abrogation of MNK/eIF4E and mTOR in NSCLC. In conclusion, Everolimus decreases the intracellular miR-7-5p by releasing of miR-7-5p loaded exosomes from NSCLC cells in Rab27A and Rab27B dependent manners. Either endogenous miR-7-5p or exo-miR-7-5p combined with Everolimus can enhance the anticancer efficacy by targeting MNK/eIF4E axis and mTOR. Besides, both low levels of miR-7-5p and positive expression of MNK1 act as independent poor prognostic biomarkers for NSCLC. Therefore, restoring miR-7-5p carried by exosome may be a promising novel combined therapeutic strategy with Everolimus for NSCLC.

Heat treatment reduced the expression of miR-7-5p to facilitate insulin-stimulated lactate secretion by targeting IRS2 in boar Sertoli cells

Insulin dysfunction of diabetes mellitus (DM) disorders the glucose metabolism in Sertoli cells (SCs), resulting in the impairment of spermatogenesis.Insulin signaling system in Sertoli cells (SCs) plays an important role in regulating lactate secretion. Heat treatment could increase the lactate secretion of boar SCs, but whether heat treatment participates in lactate secretion by improving the sensitivity of insulin is unknown. In the current study, the primary SCs from 21-day-old boar were employed to treat with 100 nM insulin for 24 h or heat treatment (43 °C, 30 min). Heat treatment strengthened the effect of insulin on the effect of lactate secretion. In addition, heat treatment increased the expression of insulin-induced insulin receptor substrate 2 (IRS2), but reduced the expression of miR-7-5p. Using dual luciferase reporter assay and Western blot, the study found that IRS2 is a potential target gene of miR-7-5p. Heat treatment also enhanced the Phosphorylation of insulin-stimulated PI3K/Akt, and increased lactate secretion by promoting the expression of Glucose Transporter 3 (GLUT3), Lactate Dehydrogenase-A (LDHA) and monocarboxylate transporter 1 (MCT1). Furthermore, miR-7-5p inhibitor could partly mimic the effects of heat treatment on lactate production of SCs, indicating that heat treatment improves insulin sensitivity by regulating the expression of miR-7-5p/IRS2/PI3K/Akt. These results reveal a novel miRNA-mediated mechanism of heat treatment on the regulation of lactate metabolism production, and suggest that targeting miR-7-5p is a probably therapeutic method to insulin dysfunction-induced metabolic diseases.

MicroRNA-16 Restores Sensitivity to Tyrosine Kinase Inhibitors and Outperforms MEK Inhibitors in KRAS-Mutated Non-Small Cell Lung Cancer

BACKGROUND

Non-small cell lung cancer (NSCLC) is the leading cause of cancer death worldwide. Chemotherapy, the treatment of choice in non-operable cases, achieves a dismal success rate, raising the need for new therapeutic options. In about 25% of NSCLC, the activating mutations of the KRAS oncogene define a subclass that cannot benefit from tyrosine kinase inhibitors (TKIs). The tumor suppressor miR-16 is downregulated in many human cancers, including NSCLC. The main objectives of this study were to evaluate miR-16 treatment to restore the TKI sensitivity and compare its efficacy to MEK inhibitors in KRAS-mutated NSCLC.

METHODS

We performed in vitro and in vivo studies to investigate whether miR-16 could be exploited to overcome TKI resistance in KRAS-mutated NSCLC. We had three goals: first, to identify the KRAS downstream effectors targeted by mir-16, second, to study the effects of miR-16 restoration on TKI resistance in KRAS-mutated NSCLC both in vitro and in vivo, and finally, to compare miR-16 and the MEK inhibitor selumetinib in reducing KRAS-mutated NSCLC growth in vitro and in vivo.

RESULTS

We demonstrated that miR-16 directly targets the three KRAS downstream effectors MAPK3, MAP2K1, and CRAF in NSCLC, restoring the sensitivity to erlotinib in KRAS-mutated NSCLC both in vitro and in vivo. We also provided evidence that the miR-16-erlotinib regimen is more effective than the selumetinib-erlotinib combination in KRAS-mutated NSCLC.

CONCLUSIONS

Our findings support the biological preclinical rationale for using miR-16 in combination with erlotinib in the treatment of NSCLC with KRAS-activating mutations.

Cardiac expression of microRNA-7 is associated with adverse cardiac remodeling

Although microRNA-7 (miRNA-7) is known to regulate proliferation of cancer cells by targeting Epidermal growth factor receptor (EGFR/ERBB) family, less is known about its role in cardiac physiology. Transgenic (Tg) mouse with cardiomyocyte-specific overexpression of miRNA-7 was generated to determine its role in cardiac physiology and pathology. Echocardiography on the miRNA-7 Tg mice showed cardiac dilation instead of age-associated physiological cardiac hypertrophy observed in non-Tg control mice. Subjecting miRNA-7 Tg mice to transverse aortic constriction (TAC) resulted in cardiac dilation associated with increased fibrosis bypassing the adaptive cardiac hypertrophic response to TAC. miRNA-7 expression in cardiomyocytes resulted in significant loss of ERBB2 expression with no changes in ERBB1 (EGFR). Cardiac proteomics in the miRNA-7 Tg mice showed significant reduction in mitochondrial membrane structural proteins compared to NTg reflecting role of miRNA-7 beyond the regulation of EGFR/ERRB in mediating cardiac dilation. Consistently, electron microscopy showed that miRNA-7 Tg hearts had disorganized rounded mitochondria that was associated with mitochondrial dysfunction. These findings show that expression of miRNA-7 in the cardiomyocytes results in cardiac dilation instead of adaptive hypertrophic response during aging or to TAC providing insights on yet to be understood role of miRNA-7 in cardiac function.

Circular RNA WHSC1 exerts oncogenic properties by regulating miR-7/TAB2 in lung cancer

Circular RNA is a newly discovered member of non‐coding RNA (ncRNA) and regulates the target gene by acting as a micro‐RNA sponge. It plays vital roles in various diseases. However, the functions of circular RNA in non‐small cell lung cancer (NSCLC) remain still unclear. Our data showed that circ‐WHSC1 was highly expressed in NSCLC cells and tissues. Both in vitro and in vivo experiments showed that circ‐WHSC1 promoted NSCLC proliferation. circ‐WHSC1 also promoted the migration and invasion of lung cancer cells. Through bioinformatic analysis and functional experiments, we showed that circ‐WHSC1 could act as a sponge for micro‐RNA‐7 (miR‐7) and regulate the expression of TAB2 (TGF‐beta activated kinase one binding protein two). Inhibition of the circ‐WHSC1/miR‐7/TAB2 pathway could effectively attenuate lung cancer progression. In summary, this study confirmed the existence and oncogenic function of circ‐WHSC1 in NSCLC. The research suggests that the circ‐WHSC1/miR‐7/TAB2 axis might be a potential target for NSCLC therapy.

Characteristics of circRNA and its approach as diagnostic tool in melanoma

One of the most common types of cancer in the world is skin cancer, which has been divided into two groups: non-melanoma and melanoma skin cancer. Different external and internal agents are considered as risk factors for melanoma skin cancer pathogenesis but the exact mechanisms are not yet confirmed. Genetic and epigenetic changes, UV exposure, arsenic compounds, and chemical substances are contributory factors to the development of melanoma. A correlation has emerged between new therapies and the discovery of a basic molecular pattern for skin cancer patients. Circular RNAs (circRNAs) are described as a unique group of extensively expressed endogenous regulatory RNAs with closed-loop structure bonds connecting the 5' and 3' ends, which are commonly expressed in mammalian cells. In this review, we describe the biogenesis of circular RNAs and its function in cancerous conditions focusing on the crosstalk between different circRNAs and melanoma. Increasing evidence suggests that circRNAs appears to be relative to the origin and development of skin-related diseases like malignant melanoma. Different circular RNAs like hsa_circ_0025039, hsa_circRNA006612, circRNA005537, and circANRIL, by targeting different cellular and molecular targets (e.g., CDK4, DAB2IP, ZEB1, miR-889, and let-7 c-3p), can participate in melanoma cancer progression.

MiR-7-5p inhibits thyroid cell proliferation by targeting the EGFR/MAPK and IRS2/PI3K signaling pathways

The aberrant expression of miRNAs is often correlated to tumor development. MiR-7-5p is a recently discovered downregulated miRNA in thyroid papillary carcinoma (PTC). The goal of this project was to characterize its functional role in thyroid tumorigenesis and to identify the targeted modulated pathways. MiR-7-5p overexpression following transfection in TPC1 and HT-ori3 cells decreased proliferation of the two thyroid cell lines. Analysis of global transcriptome modifications showed that miR-7-5p inhibits thyroid cell proliferation by modulating the MAPK and PI3K signaling pathways which are both necessary for normal thyroid proliferation and play central roles in PTC tumorigenesis. Several effectors of these pathways are indeed targets of miR-7-5p, among which EGFR and IRS2, two upstream activators. We confirmed the upregulation of IRS2 and EGFR in human PTC and showed the existence of a negative correlation between the decreased expression of miR-7-5p and the increased expression of IRS2 or EGFR. Our results thus support a tumor-suppressor activity of miR-7-5p. The decreased expression of miR-7-5p during PTC tumorigenesis might give the cells a proliferative advantage and delivery of miR-7-5p may represent an innovative approach for therapy.

The Role of MicroRNAs in Lung Cancer: Implications for Diagnosis and Therapy

Lung cancer is the first cause of cancer death in the world due to its high prevalence, aggressiveness, late diagnosis, lack of effective treatment and poor prognosis. It also shows high rate of recurrence, metastasis and drug resistance. All these problems highlight the urgent needs for developing new strategies using noninvasive biomarkers for early detection, metastasis and recurrence of disease. MicroRNAs (miRNAs) are a class of small noncoding RNAs that regulate gene expression post-transcriptionally. These molecules found to be abnormally expressed in increasing number of human disease conditions including cancer. miRNAs could be detected in body fluids such as blood, serum, urine and sputum, which leads us towards the idea of using them as non-invasive biomarker for cancer detection and monitoring cancer treatment and recurrence. miRNAs are found to be deregulated in lung cancer initiation and progression and could regulate lung cancer cell proliferation and invasion. In this review, we summarized recent progress and discoveries in microRNAs regulatory role in lung cancer initiation and progression. In addition, the role of microRNAs in EGFR signaling pathway regulation is discussed briefly.

Angioregulatory microRNAs in breast cancer: Molecular mechanistic basis and implications for therapeutic strategies

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Cancer-associated angiogenesis is a fundamental process in tumor growth and metastasis.

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Angioregulatory miRNA–target gene interaction is not only involved in sprouting vessels of breast tumors but also, trans-differentiation of breast cancer cells to endothelial cells in a process termed vasculogenic mimicry.

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Successful targeting of tumor angiogenesis is still a missing link in the treatment of Breast cancer (BC) due to the low effectiveness of anti-angiogenic therapies in this cancer.

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Response to anti-angiogenic therapeutics are controlled by a miRNAs, so the identification of interaction networks of miRNAs–targets can be applicable in determining anti-angiogeneic therapy and new biomarkers in BC.

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Angioregulatory miRNAs in breast cancer cells and their microenvironment have therapeutic potential in cancer treatment.

Background

Cancer-associated angiogenesis is a fundamental process in tumor growth and metastasis. A variety of signaling regulators and pathways contribute to establish neovascularization, among them as small endogenous non-coding RNAs, microRNAs (miRNAs) play prominent dual regulatory function in breast cancer (BC) angiogenesis.

Aim of Review

This review aims at describing the current state-of-the-art in BC angiogenesis-mediated by angioregulatory miRNAs, and an overview of miRNAs dysregulation association with the anti-angiogenic response in addition to potential clinical application of miRNAs-based therapeutics.

Key Scientific Concepts of Review

Angioregulatory miRNA–target gene interaction is not only involved in sprouting vessels of breast tumors but also, trans-differentiation of BC cells to endothelial cells (ECs) in a process termed vasculogenic mimicry. Using canonical and non-canonical angiogenesis pathways, the tumor cell employs the oncogenic characteristics such as miRNAs dysregulation to increase survival, proliferation, oxygen and nutrient supply, and treatment resistance. Angioregulatory miRNAs in BC cells and their microenvironment have therapeutic potential in cancer treatment. Although, miRNAs dysregulation can serve as tumor biomarker nevertheless, due to the association of miRNAs dysregulation with anti-angiogenic resistant phenotype, clinical benefits of anti-angiogenic therapy might be challenging in BC. Hence, unveiling the molecular mechanism underlying angioregulatory miRNAs sparked a booming interest in finding new treatment strategies such as miRNA-based therapies in BC.

The impact of microRNAs on myeloid-derived suppressor cells in cancer

Inflammation promotes cancer development. To a large extent, this can be attributed to the recruitment of myeloid-derived suppressor cells (MDSCs) to tumors. These cells are known for establishing an immunosuppressive tumor microenvironment by suppressing T cell activities. However, MDSCs also promote metastasis and angiogenesis. Critically, as small non-coding RNAs that regulate gene expression, microRNAs (miRNAs) control MDSC activities. In this review, we discuss how miRNA networks regulate key MDSC signaling pathways, how they shape MDSC development, differentiation and activation, and how this impacts tumor development. By targeting the expression of miRNAs in MDSCs, we can alter their main signaling pathways. In turn, this can compromise their ability to promote multiple hallmarks of cancer. Therefore, this may represent a new powerful strategy for cancer immunotherapy.

MiR-7 in Cancer Development

MicroRNAs (miRNAs) are short non-coding RNA involved in the regulation of specific mRNA translation. They participate in cellular signaling circuits and can act as oncogenes in tumor development, so-called oncomirs, as well as tumor suppressors. miR-7 is an ancient miRNA involved in the fine-tuning of several signaling pathways, acting mainly as tumor suppressor. Through downregulation of PI3K and MAPK pathways, its dominant role is the suppression of proliferation and survival, stimulation of apoptosis and inhibition of migration. Besides these functions, it has numerous additional roles in the differentiation process of different cell types, protection from stress and chromatin remodulation. One of the most investigated tissues is the brain, where its downregulation is linked with glioblastoma cell proliferation. Its deregulation is found also in other tumor types, such as in liver, lung and pancreas. In some types of lung and oral carcinoma, it can act as oncomir. miR-7 roles in cell fate determination and maintenance of cell homeostasis are still to be discovered, as well as the possibilities of its use as a specific biotherapeutic.

MicroRNA-7a2 Regulates Prolactin in Developing Lactotrophs and Prolactinoma Cells

Prolactin production is controlled by a complex and temporally dynamic network of factors. Despite this tightly coordinated system, pathological hyperprolactinemia is a common endocrine disorder that is often not understood, thereby highlighting the need to expand our molecular understanding of lactotroph cell regulation. MicroRNA-7 (miR-7) is the most highly expressed miRNA family in the pituitary gland and the loss of the miR-7 family member, miR-7a2, is sufficient to reduce prolactin gene expression in mice. Here, we used conditional loss-of-function and gain-of-function mouse models to characterize the function of miR-7a2 in lactotroph cells. We found that pituitary miR-7a2 expression undergoes developmental and sex hormone-dependent regulation. Unexpectedly, the loss of mir-7a2 induces a premature increase in prolactin expression and lactotroph abundance during embryonic development, followed by a gradual loss of prolactin into adulthood. On the other hand, lactotroph development is delayed in mice overexpressing miR-7a2. This regulation of lactotroph function by miR-7a2 involves complementary mechanisms in multiple cell populations. In mouse pituitary and rat prolactinoma cells, miR-7a2 represses its target Raf1, which promotes prolactin gene expression. These findings shed light on the complex regulation of prolactin production and may have implications for the physiological and pathological mechanisms underlying hyperprolactinemia.

LncRNA LINC00240 suppresses invasion and migration in non-small cell lung cancer by sponging miR-7-5p

Background

lncRNAs have important roles in regulating cancer biology. Accumulating evidence has established a link between the dysregulation of lncRNAs and microRNA in cancer progression. In previous studies, miR-7-5p has been found to be significantly down-regulated in mesenchymal-like lung cancer cell lines and directly regulated EGFR. In this work, we investigated the lncRNA partner of miR-7-5p in the progression of lung cancer.

Methods

We investigated the expression of miR-7-5p and the lncRNA after transfection with an miR-7-5p mimics using a microarray. The microarray results were validated using quantitative real time-polymerase Chain Reaction (qRT-PCR). The regulatory effects of lncRNA on miR-7-5p and its target were evaluated by changes in the expression of miR-7-5p after transfection with siRNAs for lncRNA and the synthesis of full-length lncRNA. The effect of miR-7-5p on lncRNA and the miRNA target was evaluated after transfection with miRNA mimic and inhibitor. The role of lncRNA in cancer progression was determined using invasion and migration assays. The level of lncRNA and EGFR in lung cancer and normal lung tissue was analyzed using TCGA data.

Results

We found that LINC00240 was downregulated in lung cancer cell line after miR-7-5p transfection with an miR-7-5p mimic. Further investigations revealed that the knockdown of LINC00240 induced the overexpression of miR-7-5p. The overexpression of miR-7-5p diminished cancer invasion and migration. The EGFR expression was down regulated after siRNA treatment for LINC00240. Silencing LINC00240 suppressed the invasion and migration of lung cancer cells, whereas LINC00240 overexpression exerted the opposite effect. The lower expression of LINC00240 in squamous lung cancer was analyzed using TCGA data.

Conclusions

Taken together, LINC00240 acted as a sponge for miR-7-5p and induced the overexpression of EGFR. LINC00240 may represent a potential target for the treatment of lung cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-020-07755-8.

Long non-coding RNA ELDR enhances oral cancer growth by promoting ILF3-cyclin E1 signaling

Oral squamous cell carcinoma (OSCC) is the sixth most common cancer with a 5-year overall survival rate of 50%. Thus, there is a critical need to understand the disease process, and to identify improved therapeutic strategies. Previously, we found the long non-coding RNA (lncRNA) EGFR long non-coding downstream RNA (ELDR) induced in a mouse tongue cancer model; however, its functional role in human oral cancer remained unknown. Here, we show that ELDR is highly expressed in OSCC patient samples and in cell lines. Overexpression of ELDR in normal non-tumorigenic oral keratinocytes induces cell proliferation, colony formation, and PCNA expression. We also show that ELDR depletion reduces OSCC cell proliferation and PCNA expression. Proteomics data identifies the RNA binding protein ILF3 as an interacting partner of ELDR. We further show that the ELDR-ILF3 axis regulates Cyclin E1 expression and phosphorylation of the retinoblastoma (RB) protein. Intratumoral injection of ELDR-specific siRNA reduces OSCC and PDX tumor growth in mice. These findings provide molecular insight into the role of ELDR in oral cancer and demonstrate that targeting ELDR has promising therapeutic potential.

The role of miR-7 as a potential switch in the mouse hypothalamus-pituitary-ovary axis through regulation of gonadotropins

The hypothalamus-pituitary-ovary (HPO) axis plays fundamental roles in female neuroendocrinology and reproduction. Pituitary gonadotropins are located in the center of this axis. Previous investigation suggested that miR-7 is closely linked with gonadotropins. However, the interaction between miR-7 and the HPO axis remains unclear. This study aims to determine whether and how miR-7 functions in this axis. A mouse ovariectomy model and mouse primary pituitary cells were used in this study. The results showed that miR-7 is localized to gonadotrophs and somatotrophs. miR-7 can inhibit the expression, synthesis and secretion of gonadotropins, but not growth hormones. Gonadotropin-releasing hormone (GnRH) has inhibitory effects on miR-7, while estrogen enhances miR-7 expression. miR-7 is vital for the pathway by which GnRH and estrogen regulate gonadotropins by targeting v-raf-leukemia viral oncogene 1 (Raf1). Together, these results indicate that miR-7 acts as a potential switch in the feedback loop of the HPO axis by regulating gonadotropins.

CircRNA_104889 promotes lung adenocarcinoma cell invasion via sponging miR4458

Background

Lung adenocarcinoma is metastatic cancer with a high mortality rate. Circular RNAs (circRNAs) are a type of noncoding RNA and play a vital role in cancer progression. However, the expression and function of circRNAs in lung adenocarcinoma are still mostly unknown.

Methods

In this study, we screened the differential expression of circRNAs in human bronchial epithelial cells (HBE) and A549 human lung adenocarcinoma cell line (A549) by human circRNA microarray and RT-qPCR. The role of overexpressed circRNA_104889 in A549 cell proliferation, apoptosis, migration, and invasion was studied extensively. Intracellular localization of circRNA_104889 was visualized by FISH assay. MiRNA sponging, ERK1/2 signaling, and caspase-3 expression were analyzed in siRNA-mediated circRNA_104889 knockdowned A549 cells.

Results

CircRNA microarray showed overexpression of circRNA_104889 (> 13-fold) in A459 cells compared to HBE. This finding was further corroborated by the RT-qPCR result. CircRNA_104889 was mainly localized in the cytoplasm of A549 cells. The knockdown of circRNA_104889 in A549 cells by si-RNA mediated RNA interference did not affect cell proliferation and apoptosis but significantly inhibited cell migration and invasion in vitro. Furthermore, knockdown of circRNA_104889 led to an increase of miR4458 expression. Overexpression of miR4458 inhibited A549 cell migration. Both the knockdown of circRNA_104889 and overexpression of miR4458 inhibited the caspase-3 expression and ERK1/2 phosphorylation in A549 cells.

Conclusions

CircRNA_104889 promotes lung adenocarcinoma cell migration and invasion by sponging miR4458 and targeting ERK1/2 signaling and caspase-3 expression.

Imaging Biomarkers of Tumour Proliferation and Invasion for Personalised Lung Cancer Therapy

Personalised treatment in oncology has seen great developments over the last decade, due to both technological advances and more in-depth knowledge of radiobiological processes occurring in tumours. Lung cancer therapy is no exception, as new molecular targets have been identified to further increase treatment specificity and sensitivity. Yet, tumour resistance to treatment is still one of the main reasons for treatment failure. This is due to a number of factors, among which tumour proliferation, the presence of cancer stem cells and the metastatic potential of the primary tumour are key features that require better controlling to further improve cancer management in general, and lung cancer treatment in particular. Imaging biomarkers play a key role in the identification of biological particularities within tumours and therefore are an important component of treatment personalisation in radiotherapy. Imaging techniques such as PET, SPECT, MRI that employ tumour-specific biomarkers already play a critical role in patient stratification towards individualized treatment. The aim of the current paper is to describe the radiobiological challenges of lung cancer treatment in relation to the latest imaging biomarkers that can aid in the identification of hostile cellular features for further treatment adaptation and tailoring to the individual patient’s needs.

High Levels of miR-7-5p Potentiate Crizotinib-Induced Cytokilling and Autophagic Flux by Targeting RAF1 in NPM-ALK Positive Lymphoma Cells

Simple Summary

Anaplastic lymphoma kinase positive anaplastic large cell lymphomas are a pediatric disease, which still needs treatment improvement. Crizotinib was the first ALK-targeted inhibitor used in clinics, but relapses are now known to occur. Current research efforts indicate that combined therapies could represent a superior strategy to eradicate malignant cells and prevent tumor recurrence. Autophagy is a self-digestion cellular process, known to be induced upon diverse cancer therapies. Our present work demonstrates that the potentiation of the crizotinib-induced autophagy flux, through the serine/threonine kinase RAF1 downregulation, drives ALK+ ALCL cells to death. These results should encourage further investigations on the therapeutic modulation of autophagy in this particular cancer settings and other ALK-related malignancies.

Abstract

Anaplastic lymphoma kinase positive anaplastic large cell lymphomas (ALK+ ALCL) are an aggressive pediatric disease. The therapeutic options comprise chemotherapy, which is efficient in approximately 70% of patients, and targeted therapies, such as crizotinib (an ALK tyrosine kinase inhibitor (TKI)), used in refractory/relapsed cases. Research efforts have also converged toward the development of combined therapies to improve treatment. In this context, we studied whether autophagy could be modulated to improve crizotinib therapy. Autophagy is a vesicular recycling pathway, known to be associated with either cell survival or cell death depending on the cancer and therapy. We previously demonstrated that crizotinib induced cytoprotective autophagy in ALK+ lymphoma cells and that its further intensification was associated with cell death. In line with these results, we show here that combined ALK and Rapidly Accelerated Fibrosarcoma 1 (RAF1) inhibition, using pharmacological (vemurafenib) or molecular (small interfering RNA targeting RAF1 (siRAF1) or microRNA-7-5p (miR-7-5p) mimics) strategies, also triggered autophagy and potentiated the toxicity of TKI. Mechanistically, we found that this combined therapy resulted in the decrease of the inhibitory phosphorylation on Unc-51-like kinase-1 (ULK1) (a key protein in autophagy initiation), which may account for the enforced autophagy and cytokilling effect. Altogether, our results support the development of ALK and RAF1 combined inhibition as a new therapeutic approach in ALK+ ALCL.

Curcumin Prevents Brain Damage and Cognitive Dysfunction During Ischemic-reperfusion Through the Regulation of miR-7-5p

OBJECTIVE

This study was to investigate the potential protective effects of curcumin in cerebral ischemia-reperfusion (CIR) and its regulation of miR-7.

METHODS

Rats were occluded by middle cerebral artery occlusion (MCAO) for 1.5 h and reperfused for 2 h to establish a local CIR model. After 24 hours of model establishment, MCAO rats were given curcumin for 3 days by intragastric administration. PC12 cells were cultured for 6 h in oxygen-glucose deprivation medium and then reoxygenated for 24 h to establish an oxygenglucose deprivation/reoxygenation (OGD/R) model. The OGD/R model cells were treated with curcumin for 48 h.

RESULTS

Curcumin inhibited the decrease of miR-7-5p expression and an increase of RelA p65 expression induced by CIR and ODG/R. RelA p65 was a target of miR-7-5p. MiR-7-5p antagonists were able to counteract the effect of curcumin on the expression of RelA p65 in ischemic brain tissue of MCAO rats and OGD/R model cells. Curcumin improved OGD/R-induced inhibition of cell activity, necrosis and apoptosis. Curcumin significantly reduced the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β, reactive oxygen species (ROS) and malondialdehyde (MDA) and increased the activity of superoxide dismutases (SOD) and catalase (CAT) in OGD/R-induced cells. Curcumin may inhibit OGD/R-induced cell damage by regulating miR-7-5p. Curcumin improved cerebral infarction, nerve damage and cognitive dysfunction in rats with CIR, which may be related to the regulation of miR-7-5p/RelA p65 axis.

CONCLUSION

Curcumin exerts cerebral protection by attenuating cell necrosis and apoptosis, inflammatory response and oxidative stress following CIR, which may be related to its regulation of the miR-7/RELA p65 axis.

Identification of Candidate Genes Associated with Charcot-Marie-Tooth Disease by Network and Pathway Analysis

Charcot-Marie-Tooth Disease (CMT) is the most common clinical genetic disease of the peripheral nervous system. Although many studies have focused on elucidating the pathogenesis of CMT, few focuses on achieving a systematic analysis of biology to decode the underlying pathological molecular mechanisms and the mechanism of its disease remains to be elucidated. So our study may provide further useful insights into the molecular mechanisms of CMT based on a systematic bioinformatics analysis. In the current study, by reviewing the literatures deposited in PUBMED, we identified 100 genes genetically related to CMT. Then, the functional features of the CMT-related genes were examined by R software and KOBAS, and the selected biological process crosstalk was visualized with the software Cytoscape. Moreover, CMT specific molecular network analysis was conducted by the Molecular Complex Detection (MCODE) Algorithm. The biological function enrichment analysis suggested that myelin sheath, axon, peripheral nervous system, mitochondrial function, various metabolic processes, and autophagy played important roles in CMT development. Aminoacyl-tRNA biosynthesis, metabolic pathways, and vasopressin-regulated water reabsorption were significantly enriched in the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway network, suggesting that these pathways may play key roles in CMT occurrence and development. According to the crosstalk, the biological processes could be roughly divided into a correlative module and two separate modules. MCODE clusters showed that in top 3 clusters, 13 of CMT-related genes were included in the network and 30 candidate genes were discovered which might be potentially related to CMT. The study may help to update the new understanding of the pathogenesis of CMT and expand the potential genes of CMT for further exploration.

SRCIN1 Regulated by circCCDC66/miR-211 Is Upregulated and Promotes Cell Proliferation in Non-Small-Cell Lung Cancer

The incidence and mortality of lung cancer were extremely high. The present study showed that SRCIN1 was an oncogene in non-small-cell lung cancer (NSCLC). Public dataset analysis showed SRCIN1 was significantly overexpressed in NSCLC samples. Also, we found that NSCLC patients with higher SRCIN1 expression had shorter OS time by analyzing TCGA, Kaplan-Meier Plotter, GSE30219, GSE50081, and GSE19188 databases. Overexpression or knockdown of SRCIN1 significantly induced or reduced A549 and H1299 cell proliferation. Furthermore, we found SRCIN1 was directly targeted by miR-211. Overexpression or knockdown of miR-211 suppressed or induced SRCIN1 levels in NSCLC. Moreover, we found that miR-211 affected NSCLC cell proliferation through SRCIN1. Previous studies demonstrated that circRNAs could act as miRNA sponges in cancer cells. In this study, we showed that knockdown of circCCDC66 induced expression of miR-211. Luciferase assay demonstrated that miR-211 suppressed the activity of luciferase reporter-contained circCCDC66 sequences. Moreover, knockdown of circCCDC66 significantly inhibited SRCIN1 levels in both A549 and H1299 cells. These results showed that circCCDC66 acted as a miRNA sponge to affect the miR-211/SRCIN1 axis. Of note, we for the first time revealed that circCCDC66 suppression reduced cell proliferation by about 65% in A549 and by about 40% in H1299 cells. We thought this study could provide novel potential biomarkers for NSCLC.

Circular RNAs as diagnostic biomarker in pancreatic cancer

Pancreatic cancer is one of the causes of death in the world. Unfortunately, common imaging technologies did not succeed in identifying this disease, and because of the absence of sensitive and specific biomarkers, it is not possible to screen and diagnose the disease. Therefore, this disease is usually diagnosed when patient is at an advanced stage of cancer and has lost the chance of surgery, and routine treatments such as radiotherapy and chemotherapy are not very effective. For this reason, the discovery of new biomarkers to overcome the diagnostic and therapeutic problems of pancreatic cancer is essential. Recently, circular RNAs (circRNAs) have been introduced as a group of noncoding RNAs that can play the role of critical regulators in various human diseases including cancer. A lot of studies revealed that circRNAs can have diverse roles in various cancers, including breast, colorectal, lung, renal, gastric, and hepatocellular carcinoma. The results of these researches have demonstrated that change in circRNAs expression levels in the tumor cells affects carcinogenesis, the stages of progression and metastasis of cancer through various mechanisms. Given that several studies have tested the role of circRNAs in pancreatic cancer, we decided to review the mechanisms proposed in these studies to conclude and summarize the work done in this regard.

UV-type specific alteration of miRNA expression and its association with tumor progression and metastasis in SCC cell lines

PURPOSE

UV exposure is the main risk factor for development of cutaneous squamous cell carcinoma (cSCC). While early detection greatly improves cSCC prognosis, locally advanced or metastatic cSCC has a severely impaired prognosis. Notably, the mechanisms of progression to metastatic cSCC are not well understood. We hypothesized that UV exposure of already transformed epithelial cSCC cells further induces changes which might be involved in the progression to metastatic cSCCs and that UV-inducible microRNAs (miRNAs) might play an important role.

METHODS

Thus, we analyzed the impact of UV radiation of different quality (UVA, UVB, UVA + UVB) on the miRNA expression pattern in established cell lines generated from primary and metastatic cSCCs (Met-1, Met-4) using the NanoString nCounter platform.

RESULTS

This analysis revealed that the expression pattern of miRNAs depends on both the cell line used per se and on the quality of UV radiation. Comparison of UV-induced miRNAs in cSCC cell lines established from a primary tumor (Met-1) and the respective (un-irradiated) metastasis (Met-4) suggest that miR-7-5p, miR-29a-3p and miR-183-5p are involved in a UV-driven pathway of progression to metastasis. This notion is supported by the fact that these three miRNAs build up a network of 81 potential target genes involved e.g. in UVA/UVB-induced MAPK signaling and regulation of the epithelial-mesenchymal transition. As an example, PTEN, a target of UV-upregulated miRNAs (miR-29a-3p, miR-183-5p), could be shown to be down-regulated in response to UV radiation. We further identified CNOT8, the transcription complex subunit 8 of the CCR4-NOT complex, a deadenylase removing the poly(A) tail from miRNA-destabilized mRNAs, in the center of this network, targeted by all three miRNAs.

CONCLUSION

In summary, our results demonstrate that UV radiation induces an miRNA expression pattern in primary SCC cell line partly resembling those of metastatic cell line, thus suggesting that UV radiation impacts SCC progression beyond initiation.