The Role of microRNAs, Long Non-coding RNAs, and Circular RNAs in Cervical Cancer

SPINT1-AS1 Drives Cervical Cancer Progression via Repressing miR-214 Biogenesis

Accumulating evidences have revealed the dysregulated expressions and critical roles of non-coding RNAs in various malignancies, including cervical cancer. Nevertheless, our knowledge about the vast majority of non-coding RNAs is still lacking. Here we identified long non-coding RNA (lncRNA) SPINT1-AS1 as a novel cervical cancer-associated lncRNA. SPINT1-AS1 was increased in cervical cancer and correlated with advanced stage and poor prognosis. SPINT1-AS1 was a direct downstream target of miR-214, a well-known tumor suppressive microRNA (miRNA) in cervical cancer. Intriguingly, SPINT1-AS1 was also found to repress miR-214 biogenesis via binding DNM3OS, the primary transcript of miR-214. The interaction between SPINT1-AS1 and DNM3OS repressed the binding of DROSHA and DGCR8 to DNM3OS, blocked DNM3OS cleavage, and therefore repressed mature miR-214 biogenesis. The expression of SPINT1-AS1 was significantly negatively correlated with miR-214 in cervical cancer tissues, supporting the reciprocal repression between SPINT1-AS1 and miR-214 in vivo. Through downregulating mature miR-214 level, SPINT1-AS1 upregulated the expression of β-catenin, a target of miR-214. Thus, SPINT1-AS1 further activated Wnt/β-catenin signaling in cervical cancer. Functionally, SPINT1-AS1 drove cervical cancer cellular proliferation, migration, and invasion in vitro, and also tumorigenesis in vivo. Deletion of the region mediating the interaction between SPINT1-AS1 and DNM3OS, overexpression of miR-214, and inhibition of Wnt/β-catenin signaling all reversed the roles of SPINT1-AS1 in cervical cancer. Collectively, these findings identified SPINT1-AS1 as a novel cervical cancer-associated oncogenic lncRNA which represses miR-214 biogenesis and activates Wnt/β-catenin signaling, highlighting its potential as prognostic biomarker and therapeutic target for cervical cancer.

Long non-coding RNA MIR200CHG promotes breast cancer proliferation, invasion, and drug resistance by interacting with and stabilizing YB-1

Long non-coding RNAs (lncRNA) have been identified as key regulators of tumorigenesis and development. We aim to explore the biological functions and molecular mechanisms of lncRNA MIR200CHG in breast cancer. We found that MIR200CHG is highly expressed in breast cancer tissues and is related to the tumor size and histopathological grade. In vitro and in vivo experiments confirmed that MIR200CHG can promote breast cancer proliferation, invasion, and drug resistance. MIR200CHG directly binds to the transcription factor Y-box binding protein-1 (YB-1), and inhibits its ubiquitination and degradation. MIR200CHG regulates YB-1 phosphorylation at serine 102, thereby affecting the expression of genes related to tumor cell proliferation, apoptosis, invasion, and drug resistance. Additionally, MIR200CHG partially affects the expression of miR-200c/141-3p encoded by its intron region. Therefore, MIR200CHG can promote the proliferation, invasion, and drug resistance of breast cancer by interacting with and stabilizing YB-1, and has the potential to become a target for breast cancer treatment.

Roles of MicroRNAs in Osteogenesis or Adipogenesis Differentiation of Bone Marrow Stromal Progenitor Cells

Bone marrow stromal cells (BMSCs) are multipotent cells which can differentiate into chondrocytes, osteoblasts, and fat cells. Under pathological stress, reduced bone formation in favour of fat formation in the bone marrow has been observed through a switch in the differentiation of BMSCs. The bone/fat switch causes bone growth defects and disordered bone metabolism in bone marrow, for which the mechanisms remain unclear, and treatments are lacking. Studies suggest that small non-coding RNAs (microRNAs) could participate in regulating BMSC differentiation by disrupting the post-transcription of target genes, leading to bone/fat formation changes. This review presents an emerging concept of microRNA regulation in the bone/fat formation switch in bone marrow, the evidence for which is assembled mainly from in vivo and in vitro human or animal models. Characterization of changes to microRNAs reveals novel networks that mediate signalling and factors in regulating bone/fat switch and homeostasis. Recent advances in our understanding of microRNAs in their control in BMSC differentiation have provided valuable insights into underlying mechanisms and may have significant potential in development of new therapeutics.

miR-17-5p accelerates cervical cancer cells migration and invasion via the TIMP2/MMPs signaling cascade

Cervical cancer (CC) is a common gynecological tumor, ranking second in the female reproductive system tumor. The work aims to study the function of miR-17-5p in the occurrence and pathogenesis of CC. We collected 36 cases of CC tissues for clinical analysis, and two CC cell lines (C33a and HCC94) were obtained for cellular analysis. As expected, the up-regulated miR-17-5p and down-regulated TIMP2 were detected in CC tissues and cell lines by RT-qPCR, in contrast with their normal counterparts. Then, overexpression of miR-17-5p significantly increased the CC cells viability and colonies formation abilities. Moreover, the Transwell analysis revealed that miR-17-5p promoted the capability of invasion and migration. Meanwhile, the expression levels of MMP2 and MMP9 was inhibited by the inhibition of miR-17-5p. The luciferase analysis demonstrated that TIMP2 was the target of miR-17-5p. In addition, cell proliferation, invasion and migration in HCC94 cells were repressed by silencing miR-17-5p, which were reversed by TIMP2 knockdown. In summary, all results indicated that miR-17-5p targeted TIMP2 to modulate CC cells' proliferation, invasion and migration through MMPs signaling pathway; and the miR-17-5p/TIMP2/MMPs signaling pathway had the potential to become a therapeutic target of CC for clinical utilization.

An Overview of the Role of Long Non-Coding RNAs in Human Choriocarcinoma

Choriocarcinoma (CC), a subtype of trophoblastic disease, is a rare and highly aggressive neoplasm. There are two main CC subtypes: gestational and non-gestational, (so called when it develops as a component of a germ cell tumor or is related to a somatic mutation of a poorly differentiated carcinoma), each with very diverse biological activity. A therapeutic approach is highly effective in patients with early-stage CC. The advanced stage of the disease also has a good prognosis with around 95% of patients cured following chemotherapy. However, advancements in diagnosis and treatment are always needed to improve outcomes for patients with CC. Long non-coding (lnc) RNAs are non-coding transcripts that are longer than 200 nucleotides. LncRNAs can act as oncogenes or tumor suppressor genes. Deregulation of their expression has a key role in tumor development, angiogenesis, differentiation, migration, apoptosis, and proliferation. Furthermore, detection of cancer-associated lncRNAs in body fluids, such as blood, saliva, and urine of cancer patients, is emerging as a novel method for cancer diagnosis. Although there is evidence for the potential role of lncRNAs in a number of cancers of the female genital tract, their role in CC is poorly understood. This review summarizes the current knowledge of lncRNAs in gestational CC and how this may be applied to future therapeutic strategies in the treatment of this rare cancer.

N6-Methyladenosine Associated Silencing of miR-193b Promotes Cervical Cancer Aggressiveness by Targeting CCND1

Objective

Cervical cancer is a frequently encountered gynecological malignancy as a major contributor to cancer-related deaths in women. This study focuses on how miR-193b promotes cervical cancer aggressiveness as well as the role of m⁶A in miR-193b silencing.

Methods

Cervical cancer samples and the matching adjacent normal cervical tissues were used to determine the significance of miR-193b in cervical cancer. The CCK-8 assay, cell cycle analysis, qRT-PCR, Western blot assay, IHC, RIP, and xenograft models were utilized to explore the impact of miR-193b in cervical cancer and how m⁶A regulates miR-193b expression. Luciferase reporter assays, qRT-PCR, and Western blotting were enlisted to study the interaction between miR-193b and CCND1.

Results

Our study suggested that lower miR-193b expressions were strongly linked to more advanced cervical cancer stages and the presence of deeper stromal invasion. miR-193b functions as a tumor suppressor that is regulated by m⁶A methylation in cervical tumors. METTL3 modulates miR-193b mature process in an m⁶A-dependent manner. Reintroduction of miR-193b profoundly inhibits tumorigenesis of cervical cancer cells both in vivo and in vitro through CCND1 targeting.

Conclusions

m⁶A associated downregulation of miR-193b promotes cervical cancer aggressiveness by targeting CCND1.

The Emerging Role of Thymopoietin-Antisense RNA 1 as Long Noncoding RNA in the Pathogenesis of Human Cancers

Long noncoding RNAs (lncRNAs) play essential roles in the occurrence and development of multiple human cancers. An accumulating body of researches have investigated thymopoietin antisense RNA 1 (TMPO-AS1) as a newly discovered lncRNA, which functions as an oncogenic lncRNA that is upregulated in various human malignancies and associated with poor prognosis. Many studies have detected abnormally high expression levels of TMPO-AS1 in multiple cancers, such as lung cancer, breast cancer, colorectal cancer (CRC), hepatocellular carcinoma, CRC, gastric cancer, ovarian cancer, thyroid cancer, esophageal cancer, Wilms tumor, cervical cancer, retinoblastoma, bladder cancer, osteosarcoma, and prostate cancer. TMPO-AS1 has been subsequently demonstrated to play a pivotal role in tumorigenesis and progression. The aberrantly expressed TMPO-AS1 acts as a competing endogenous RNA (ceRNA) that inhibits miRNA expression, thus activating the expression of downstream oncogenes. This study comprehensively summarizes the aberrant expressions of TMPO-AS1 as reported in the current literature and explains the relevant biological regulation mechanisms in carcinogenesis and tumor progression. Corresponding studies have indicated that TMPO-AS1 has a potential value as a promising biomarker or a target for cancer therapy.

Competing Endogenous RNAs in Cervical Carcinogenesis: A New Layer of Complexity

MicroRNAs (miRNAs) regulate gene expression by binding to complementary sequences within target mRNAs. Apart from working ‘solo’, miRNAs may interact in important molecular networks such as competing endogenous RNA (ceRNA) axes. By competing for a limited pool of miRNAs, transcripts such as long noncoding RNAs (lncRNAs) and mRNAs can regulate each other, fine-tuning gene expression. Several ceRNA networks led by different lncRNAs—described here as lncRNA-mediated ceRNAs—seem to play essential roles in cervical cancer (CC). By conducting an extensive search, we summarized networks involved in CC, highlighting the major impacts of such dynamic molecular changes over multiple cellular processes. Through the sponging of distinct miRNAs, some lncRNAs as HOTAIR, MALAT1, NEAT1, OIP5-AS1, and XIST trigger crucial molecular changes, ultimately increasing cell proliferation, migration, invasion, and inhibiting apoptosis. Likewise, several lncRNAs seem to be a sponge for important tumor-suppressive miRNAs (as miR-140-5p, miR-143-3p, miR-148a-3p, and miR-206), impairing such molecules from exerting a negative post-transcriptional regulation over target mRNAs. Curiously, some of the involved mRNAs code for important proteins such as PTEN, ROCK1, and MAPK1, known to modulate cell growth, proliferation, apoptosis, and adhesion in CC. Overall, we highlight important lncRNA-mediated functional interactions occurring in cervical cells and their closely related impact on cervical carcinogenesis.

Mechanism of hydrogen on cervical cancer suppression revealed by high‑throughput RNA sequencing

Cervical cancer is considered one of the diseases with the highest mortality among women and with limited treatment options. Hydrogen (H₂) inhalation has been reported to have a variety of tumor-suppressive effects, but the exact mechanism remains unclear. In the present study, HeLa cervical cancer cells and HaCaT keratinocytes treated with H₂, and a HeLa xenograft mouse model subjected to H₂ inhalation were established. TUNEL, Cell Counting Kit-8 and Ki67 staining assays were used to detect cell apoptosis and proliferation. Oxidative stress was determined according to the levels of reactive oxygen species, malondialdehyde and superoxide dismutase. Tumor growth was recorded every 3 days, and the excised tumors were stained with hematoxylin and eosin. High-throughput RNA sequencing and subsequent Gene Ontology (GO) enrichment analysis were performed in HeLa-treated and un-treated HeLa cells. The expression of hypoxia-inducible factor (HIF)-1α and NF-κB p65 was verified by western blotting, immunohistochemistry and reverse transcription-quantitative PCR. The results revealed an increased apoptosis rate, and reduced cell proliferation and oxidative stress in H₂-treated HeLa cells but not in HaCaT cells. Similarly, decreased tumor growth and cell proliferation, and enhanced cell apoptosis were observed in H₂-treated HeLa tumors. RNA sequencing and GO analysis suggest that downregulated HIF1A (HIF-1α mRNA) and RelA (NF-κB p65) levels, and reduced NF-κB signaling were associated with the antitumor effect of H₂. Finally, decreased HIF-1α and NF-κB p65 expression both at the transcriptional and translational levels were observed in H₂-treated HeLa cells and in HeLa-derived tumors. In conclusion, the present study reveals a novel mechanism of H₂ against cervical cancer, which may serve as a potential therapeutic target in clinical practice.

Suppressing long noncoding RNA OGRU ameliorates diabetic retinopathy by inhibition of oxidative stress and inflammation via miR-320/USP14 axis

Long noncoding RNAs (lncRNAs) are important regulators in various diseases including diabetic retinopathy (DR). In this study, DR patients exhibited significantly increased expression of serum LncRNA-OGRU compared with normal individuals. Streptozotocin (STZ)-challenged rats with DR also had higher OGRU expression in retinas than that of the control group, which was confirmed in Müller cells upon high glucose (HG) stimulation. OGRU knockdown remarkably decreased vascular endothelial growth factor (VEGF) and transforming growth factor-β1 (TGF-β1) expression in HG-incubated Müller cells. HG-induced inflammatory response and oxidative stress in vitro were markedly mitigated by OGRU knockdown through restraining IκBɑ/nuclear factor kappa beta (NF-κB) and improving nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathways, respectively. Further studies indicated that OGRU suppression greatly restored miR-320 expression, and a negative correlation between them was detected in DR patients. We also found that miR-320 over-expression considerably restrained TGF-β1 signaling, and hindered inflammation and reactive oxygen species (ROS) production in HG-stimulated Müller cells. Additionally, OGRU knockdown or miR-320 over-expression could dramatically down-regulate ubiquitin-specific peptidase 14 (USP14) expression levels in HG-incubated Müller cells, and miR-320 could directly target USP14. Notably, OGRU/miR-320 axis-mediated TGF-β1 signaling, inflammation and ROS were largely dependent on USP14. Intriguingly, our results showed that USP14 directly interacted with transforming growth factor-beta type 1 receptor (TβR1), and impeded TβR1 ubiquitination and degradation. Furthermore, USP14 could also facilitate IκBɑ deubiquitination and degradation, exacerbating IκBɑ phosphorylation and NF-κB activation. Finally, our in vivo studies confirmed that OGRU knockdown considerably ameliorated DR progression in STZ-challenged rats through mediating the mechanisms observed in vitro. Collectively, these findings implicated that LncRNA-OGRU mediated DR progression through competing for miR-320 to regulate USP14 expression, and thus LncRNA-OGRU/miR-320/USP14 axis may be considered as a therapeutic target for DR treatment.

Silencing of hsa_circ_0009035 Suppresses Cervical Cancer Progression and Enhances Radiosensitivity through MicroRNA 889-3p-Dependent Regulation of HOXB7

Circular RNAs (circRNAs), a novel type of endogenous noncoding RNAs, have been identified as critical regulators in human carcinogenesis. Here, we investigated the precise actions of hsa_circ_0009035 in the progression and radioresistance of cervical cancer (CC). The levels of hsa_circ_0009035, microRNA 889-3p (miR-889-3p), and homeobox B7 (HOXB7) were detected by quantitative real-time PCR (qRT-PCR) or Western blotting. RNase R and actinomycin D assays were used to assess the stability of hsa_circ_0009035. Cell proliferation, cell cycle progression, apoptosis, migration, and invasion were gauged with Cell Counting Kit-8 (CCK-8), flow cytometry, and transwell assays. Cell colony formation and survival were determined by the colony formation assay. Targeted correlations among hsa_circ_0009035, miR-889-3p, and HOXB7 were examined by the dual-luciferase reporter, RNA immunoprecipitation (RIP), or RNA pulldown assay. Animal studies were performed to evaluate the impact of hsa_circ_0009035 on tumor growth. We found that hsa_circ_0009035 was highly expressed in CC tissues and cells, and it was associated with the radioresistance of CC patients. Moreover, the silencing of hsa_circ_0009035 inhibited CC cell proliferation, migration, invasion, and it enhanced apoptosis and radiosensitivity in vitro and weakened tumor growth in vivo. Mechanistically, hsa_circ_0009035 directly targeted miR-889-3p by binding to miR-889-3p, and hsa_circ_0009035 modulated HOXB7 expression through miR-889-3p. HOXB7 was a functional target of miR-889-3p in regulating CC progression and radioresistance in vitro, and hsa_circ_0009035 modulated CC progression and radioresistance in vitro by miR-889-3p. Our current study first identified hsa_circ_0009035 as an important regulator of CC progression and radioresistance at least in part through targeting the miR-889-3p/HOXB7 axis, highlighting its significance as a potential therapeutic target for CC treatment.

Dysregulation of Transcription Factor Networks Unveils Different Pathways in Human Papillomavirus 16-Positive Squamous Cell Carcinoma and Adenocarcinoma of the Uterine Cervix

Squamous cell carcinoma (SCC) and adenocarcinoma (ADC) are the most common histological types of cervical cancer (CC). The worse prognosis of ADC cases highlights the need for better molecular characterization regarding differences between these CC types. RNA-Seq analysis of seven SCC and three ADC human papillomavirus 16-positive samples and the comparison with public data from non-tumoral human papillomavirus-negative cervical tissue samples revealed pathways exclusive to each histological type, such as the epithelial maintenance in SCC and the maturity-onset diabetes of the young (MODY) pathway in ADC. The transcriptional regulatory network analysis of cervical SCC samples unveiled a set of six transcription factor (TF) genes with the potential to positively regulate long non-coding RNA genes DSG1-AS1, CALML3-AS1, IGFL2-AS1, and TINCR. Additional analysis revealed a set of MODY TFs regulated in the sequence predicted to be repressed by miR-96-5p or miR-28-3p in ADC. These microRNAs were previously described to target LINC02381, which was predicted to be positively regulated by two MODY TFs upregulated in cervical ADC. Therefore, we hypothesize LINC02381 might act by decreasing the levels of miR-96-5p and miR-28-3p, promoting the MODY activation in cervical ADC. The novel TF networks here described should be explored for the development of more efficient diagnostic tools.

Urine miRNA signature as a potential non-invasive diagnostic and prognostic biomarker in cervical cancer

MicroRNAs as cancer biomarkers in serum, plasma, and other body fluids are often used but analysis of miRNA in urine is limited. We investigated the expression of selected miRNAs in the paired urine, serum, cervical scrape, and tumor tissue specimens from the women with cervical precancer and cancer with a view to identify if urine miRNAs could be used as reliable non-invasive biomarkers for an early diagnosis and prognosis of cervical cancer. Expression of three oncomiRs (miR-21, miR-199a, and miR-155-5p) and three tumor suppressors (miR-34a, miR-145, and miR-218) as selected by database search in cervical pre-cancer, cancer, and normal controls including cervical cancer cell lines were analyzed using qRT-PCR. The expression of miRNAs was correlated with various clinicopathological parameters, including HPV infection and survival outcome. We observed a significant overexpression of the oncomiRs and the downregulation of tumor suppressor miRNAs. A combination of miR-145-5p, miR-218-5p, and miR-34a-5p in urine yielded 100% sensitivity and 92.8% specificity in distinguishing precancer and cancer patients from healthy controls and it well correlates with those of serum and tumor tissues. The expression of miR-34a-5p and miR-218-5p were found to be independent prognostic factors for the overall survival of cervical cancer patients. We conclude that the evaluation of the above specific miRNA expression in non-invasive urine samples may serve as a reliable biomarker for early detection and prognosis of cervical cancer.

Cervical Cancer Stem-Like Cell Transcriptome Profiles Predict Response to Chemoradiotherapy

Cervical cancer (CC) represents a major global health issue, particularly impacting women from resource constrained regions worldwide. Treatment refractoriness to standard chemoradiotheraphy has identified cancer stem cells as critical coordinators behind the biological mechanisms of resistance, contributing to CC recurrence. In this work, we evaluated differential gene expression in cervical cancer stem-like cells (CCSC) as biomarkers related to intrinsic chemoradioresistance in CC. A total of 31 patients with locally advanced CC and referred to Mário Penna Institute (Belo Horizonte, Brazil) from August 2017 to May 2018 were recruited for the study. Fluorescence-activated cell sorting was used to enrich CD34+/CD45- CCSC from tumor biopsies. Transcriptome was performed using ultra-low input RNA sequencing and differentially expressed genes (DEGs) using Log2 fold differences and adjusted p-value < 0.05 were determined. The analysis returned 1050 DEGs when comparing the Non-Responder (NR) (n=10) and Responder (R) (n=21) groups to chemoradiotherapy. These included a wide-ranging pattern of underexpressed coding genes in the NR vs. R patients and a panel of lncRNAs and miRNAs with implications for CC tumorigenesis. A panel of biomarkers was selected using the rank-based AUC (Area Under the ROC Curve) and pAUC (partial AUC) measurements for diagnostic sensitivity and specificity. Genes overlapping between the 21 highest AUC and pAUC loci revealed seven genes with a strong capacity for identifying NR vs. R patients (ILF2, RBM22P2, ACO16722.1, AL360175.1 and AC092354.1), of which four also returned significant survival Hazard Ratios. This study identifies DEG signatures that provide potential biomarkers in CC prognosis and treatment outcome, as well as identifies potential alternative targets for cancer therapy.

A Timely Review of Cross-Kingdom Regulation of Plant-Derived MicroRNAs

MicroRNAs (miRNAs) belong to a class of non-coding RNAs that suppress gene expression by complementary oligonucleotide binding to the sites in target messenger RNAs. Numerous studies have demonstrated that miRNAs play crucial role in virtually all cellular processes of both plants and animals, such as cell growth, cell division, differentiation, proliferation and apoptosis. The study of rice MIR168a has demonstrated for the first time that exogenous plant MIR168a influences cholesterol transport in mice by inhibiting low-density lipoprotein receptor adapter protein 1 expression. Inspired by this finding, the cross-kingdom regulation of plant-derived miRNAs has drawn a lot of attention because of its capability to provide novel therapeutic agents in the treatment of miRNA deregulation-related diseases. Notably, unlike mRNA, some plant miRNAs are robust because of their 3′ end modification, high G, C content, and the protection by microvesicles, miRNAs protein cofactors or plant ingredients. The stability of these small molecules guarantees the reliability of plant miRNAs in clinical application. Although the function of endogenous miRNAs has been widely investigated, the cross-kingdom regulation of plant-derived miRNAs is still in its infancy. Herein, this review summarizes the current knowledge regarding the anti-virus, anti-tumor, anti-inflammatory, anti-apoptosis, immune modulation, and intestinal function regulation effects of plant-derived miRNAs in mammals. It is expected that exploring the versatile role of plant-derived miRNAs may lay the foundation for further study and application of these newly recognized, non-toxic, and inexpensive plant active ingredients.

Computational Analysis Predicts Hundreds of Coding lncRNAs in Zebrafish

Simple Summary

Noncoding RNAs (ncRNAs) regulate a variety of fundamental life processes such as development, physiology, metabolism and circadian rhythmicity. RNA-sequencing (RNA-seq) technology has facilitated the sequencing of the whole transcriptome, thereby capturing and quantifying the dynamism of transcriptome-wide RNA expression profiles. However, much remains unrevealed in the huge noncoding RNA datasets that require further bioinformatic analysis. In this study, we applied six bioinformatic tools to investigate coding potentials of approximately 21,000 lncRNAs. A total of 313 lncRNAs are predicted to be coded by all the six tools. Our findings provide insights into the regulatory roles of lncRNAs and set the stage for the functional investigation of these lncRNAs and their encoded micropeptides.

Abstract

Recent studies have demonstrated that numerous long noncoding RNAs (ncRNAs having more than 200 nucleotide base pairs (lncRNAs)) actually encode functional micropeptides, which likely represents the next regulatory biology frontier. Thus, identification of coding lncRNAs from ever-increasing lncRNA databases would be a bioinformatic challenge. Here we employed the Coding Potential Alignment Tool (CPAT), Coding Potential Calculator 2 (CPC2), LGC web server, Coding-Non-Coding Identifying Tool (CNIT), RNAsamba, and MicroPeptide identification tool (MiPepid) to analyze approximately 21,000 zebrafish lncRNAs and computationally to identify 2730–6676 zebrafish lncRNAs with high coding potentials, including 313 coding lncRNAs predicted by all the six bioinformatic tools. We also compared the sensitivity and specificity of these six bioinformatic tools for identifying lncRNAs with coding potentials and summarized their strengths and weaknesses. These predicted zebrafish coding lncRNAs set the stage for further experimental studies.

Targeted delivery system using silica nanoparticles coated with chitosan and AS1411 for combination therapy of doxorubicin and antimiR-21

Herein, a novel targeted delivery system was developed for intracellular co-delivery of doxorubicin (DOX) as a chemotherapeutic drug, antimiR-21 as an oncogenic antagomiR. In this system, DOX was loaded into mesoporous silica nanoparticles (MSNs) and chitosan was applied to cover the surface of MSNs. AS1411 aptamer as targeting nucleolin and antimiR-21 were electrostatically attached onto the surface of the chitosan-coated MSNs and formed the final nanocomplex (AACS nanocomplex). The study of drug release was based on DOX release under pH 7.4 and 5.5. Cellular toxicity and cellular uptake assessments of AACS nanocomplex were carried out in nucleolin positive (C26, MCF-7, and 4T1) and nucleolin negative (CHO) cell lines using MTT assay and flow cytometry analysis, respectively. Also, Anti-tumor efficacy of AACS nanocomplex was evaluated in C26 tumor-bearing mice. Overall, the results show that the combination therapy of DOX and antimiR-21, using AACS nanocomplex, could combat the cancer cell growth rate.

Multidimensional Intersection of Nicotine, Gene Expression, and Behavior

The cholinergic system plays a crucial role in nervous system function with important effects on developmental processes, cognition, attention, motivation, reward, learning, and memory. Nicotine, the reinforcing component of tobacco and e-cigarettes, directly acts on the cholinergic system by targeting nicotinic acetylcholine receptors (nAChRs) in the brain. Activation of nAChRs leads to a multitude of immediate and long-lasting effects in specific cellular populations, thereby affecting the addictive properties of the drug. In addition to the direct actions of nicotine in binding to and opening nAChRs, the subsequent activation of circuits and downstream signaling cascades leads to a wide range of changes in gene expression, which can subsequently alter further behavioral expression. In this review, we provide an overview of the actions of nicotine that lead to changes in gene expression and further highlight evidence supporting how these changes can often be bidirectional, thereby inducing subsequent changes in behaviors associated with further drug intake.

The Role of circRNAs in Human Papillomavirus (HPV)-Associated Cancers

Circular RNAs (circRNAs) are a new class of "non-coding RNAs" that originate from non-sequential back-splicing of exons and/or introns of precursor messenger RNAs (pre-mRNAs). These molecules are generally produced at low levels in a cell-type-specific manner in mammalian tissues, but due to their circular conformation they are unaffected by the cell mRNA decay machinery. circRNAs can sponge multiple microRNAs or RNA-binding proteins and play a crucial role in the regulation of gene expression and protein translation. Many circRNAs have been shown to be aberrantly expressed in several cancer types, and to sustain specific oncogenic processes. Particularly, in virus-associated malignancies such as human papillomavirus (HPV)-associated anogenital carcinoma and oropharyngeal and oral cancers, circRNAs have been shown to be involved in tumorigenesis and cancer progression, as well as in drug resistance, and some are useful diagnostic and prognostic markers. HPV-derived circRNAs, encompassing the HPV E7 oncogene, have been shown to be expressed and to serve as transcript for synthesis of the E7 oncoprotein, thus reinforcing the virus oncogenic activity in HPV-associated cancers. In this review, we summarize research advances in the biogenesis of cell and viral circRNAs, their features and functions in the pathophysiology of HPV-associated tumors, and their importance as diagnostic, prognostic, and therapeutic targets in anogenital and oropharyngeal and oral cancers.

Identification and validation of potential mRNA- microRNA- long-noncoding RNA (mRNA-miRNA-lncRNA) prognostic signature for cervical cancer

Cervical cancer is one of the most common causes of cancer deaths in women due to poor prognosis and high mortality rates. A novel mRNA-miRNA-lncRNA signature linked to prognosis of cervical cancer is needed to help clinicians judge the prognosis of individual patients more accurately. On the basis of GEO datasets, a total of 161 upregulated and 242 downregulated DE-mRNAs were identified firstly. Among them, eight potential biomarkers were found to have prognostic values with cervical cancer and miRNAs-lncRNAs related to these biomarkers were then analyzed to create mRNA-miRNA-lncRNA networks in cervical cancer. Moreover, in vitro experiments such as qRT-PCR, western blot and Edu assays were also performed to validate these promising targets. On the basis of these findings, a total of eight mRNA-miRNA-lncRNA subnetworks were finally established as a novel mRNA-miRNA-lncRNA signature and independent prognostic indicator of clinically relevant parameters by ROC analysis, univariate and multivariate Cox regression. Since some work of validation was done, it is believed that this mRNA-miRNA-lncRNA prognostic signature may be applied as a potential clinical judgment to estimate the prognosis of cervical cancer.

LncRNA DLEU2 promotes cervical cancer cell proliferation by regulating cell cycle and NOTCH pathway

Long noncoding RNAs (lncRNAs) are known to play a crucial role in the onset and progression of cervical cancer (CC). Here, the results of RNA microarray and RNA-sequencing dataset analysis showed that lncRNA DLEU2 was significantly upregulated in CC tissues. Clinicopathologic analysis indicated that lncRNA DLEU2 was closely related to tumor topography. Functional experiments and bioinformatics analysis revealed that lncRNA DLEU2 promoted CC cell proliferation and accelerated the cell cycle. Mechanistically, lncRNA DLEU2 promoted the progression of the cell cycle and inhibited the activity of the Notch signaling pathway by inhibiting p53 expression. Additionally, lncRNA DLEU2 probably interacted with ZFP36 Ring Finger Protein (ZFP36) to inhibit the expression of p53. In conclusion, this study revealed the function of lncRNA DLEU2 in CC tumorigenesis, suggesting new therapeutic targets in CC.

The human papillomavirus oncoproteins: a review of the host pathways targeted on the road to transformation

Persistent infection with high-risk human papillomaviruses (HR-HPVs) is the causal factor in over 99 % of cervical cancer cases, and a significant proportion of oropharyngeal and anogenital cancers. The key drivers of HPV-mediated transformation are the oncoproteins E5, E6 and E7. Together, they act to prolong cell-cycle progression, delay differentiation and inhibit apoptosis in the host keratinocyte cell in order to generate an environment permissive for viral replication. The oncoproteins also have key roles in mediating evasion of the host immune response, enabling infection to persist. Moreover, prolonged infection within the cellular environment established by the HR-HPV oncoproteins can lead to the acquisition of host genetic mutations, eventually culminating in transformation to malignancy. In this review, we outline the many ways in which the HR-HPV oncoproteins manipulate the host cellular environment, focusing on how these activities can contribute to carcinogenesis.

Long non-coding RNA BX357664 inhibits gastric cancer progression by sponging miR-183a-3p to regulate the PTEN expression and PI3K/AKT pathway

Lately, long non-coding RNA (lncRNA) is recognized as a key regulator of gastric cancer (GC) which has aroused great interest in the fields of medicine, toxicology, and functional food. Studies related to LncRNA expression microarray data indicate that BX357664 is down-regulated in GC specimens. However, the expression pattern and molecular mechanism of BX357664 in GC have not been studied so far. The purpose of this study was to investigate the expression of lncRNA BX357664 in GC and its function in GC cell lines. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the level of BX357664 in 50 pairs of cancer tissues and adjacent non-cancer tissues collected from GC patients. It was found that BX357664 level was lowered in cancer specimens than adjacent non-cancer tissues and correlated with tumor size and TNM stage. Also, we used cell counting kit 8 (CCK8), cell clone formation assay and transwell assay, which affirmed that up-regulation of BX357664 inhibited the proliferation, migration, and invasion of GC cells, but promoted apoptosis. In the dual-luciferase report analysis, BX357664 acted as a miR-183-3p ceRNA to target and regulate the expression of PTEN and affect the PI3K/AKT pathway. These results indicate that BX357664 can inhibit the proliferation and metastasis of GC through the miR-183-3p/PTEN/PI3K/AKT pathway, which may serve as potential targets for the treatment of GC in the future.

Circular RNAs: A Promising Biomarker for Endometrial Cancer

Endometrial cancer (EC) is one of the most common malignant tumors of the female reproductive tract. EC patients have high morbidity and mortality rates and remain an important cause of cancer-related morbidity and mortality worldwide. More and more studies have shown that a large number of non-coding RNAs (such as microRNAs and long non-coding RNAs) are associated with the occurrence of diseases. Circular RNAs (circRNAs) is an endogenous non-coding RNA. It has a unique covalent structure. Many studies in recent years have found circRNAs differential expression in a variety of tumor tissues compared to matched normal tissues. In endometrial carcinoma, there also are multiple circRNAs differentially expressed and therefore circRNAs perhaps can be used as a diagnostic and prognosis biomarkers of EC. In this review, we described the biogenesis, function and characteristics of circRNAs, and the circRNAs with potential influence and clinical significance on the development of EC were summarized. Adenocarcinoma is the most common form of EC, so this review focuses on endometrioid adenocarcinoma.

Long non‑coding RNA LINC01006 exhibits oncogenic properties in cervical cancer by functioning as a molecular sponge for microRNA‑28‑5p and increasing PAK2 expression

As previously reported, long intergenic non‑protein‑coding RNA 1006 (LINC01006) plays crucial roles in prostate, pancreatic and gastric cancers. However, whether it plays important roles in cervical cancer remains unclear. The present study thus aimed to determine the precise role of LINC01006 in cervical cancer and elucidate its regulatory mechanisms. The expression of LINC01006 in cervical cancer was examined by reverse transcription‑quantitative polymerase chain reaction. Cell proliferation assay, flow cytometric analysis, Transwell migration and invasion assays, and tumor xenograft model experiments were performed to elucidate the roles of LINC01006 in cervical cancer. Bioinformatics analysis, luciferase reporter assay, RNA immunoprecipitation and rescue experiments were performed for mechanistic analyses. The expression of LINC01006 was found to be upregulated in cervical cancer and to be associated with a poor prognosis. The absence of LINC01006 inhibited the proliferation, migration and invasion of cervical cancer cells, whereas it promoted cell apoptosis in vitro. The downregulation of LINC01006 impeded tumor growth in vivo. LINC01006 was verified as an endogenous 'sponge' that competed for microRNA‑28‑5p (miR‑28‑5p), which resulted in the upregulation of the miR‑28‑5p target P21‑activated kinase 2 (PAK2). Rescue experiments revealed that the suppression of miR‑28‑5p expression or the overexpression of PAK2 abrogated the effects of LINC01006 downregulation on malignant cellular functions in cervical cancer. On the whole, the present study demonstrates that LINC01006 exhibits tumor‑promoting functions in cervical cancer via the regulation of the miR‑28‑5p/PAK2 axis. These findings may provide the basis for the identification of LINC01006‑targeted clinical therapy.

Circular RNA circNFATC3 acts as a miR-9-5p sponge to promote cervical cancer development by upregulating SDC2

PURPOSE

Circular RNAs (circRNAs) constitute a class of regulatory RNAs that are thought to play important roles in tumor initiation and progression. Several studies have reported that circRNAs may be involved in various biological processes via networks of competing endogenous RNAs (ceRNAs). However, the regulatory roles and underlying mechanisms of circRNAs in cervical cancer (CC) still largely remain to be resolved.

METHODS

CircNFATC3 (hsa_circ_0005615) expression was assessed in CC cell lines (SiHa, H8) using circRNA microarray analysis, whereas qRT-PCR was used to detect circNFATC3 and miR-9-5p expression in primary human CC tissues and cell lines. The tumor promoting role of circNFATC3 was verified in CC cells using a series of functional assays, and interactions between circNFATC3, miR-9-5p and syndecan-2 (SDC2) were investigated using dual-luciferase reporter assays. SDC2 protein expression was detected using Western blotting and immunohistochemistry. The tumor promoting role of circNFATC3 was confirmed in vivo using a CC xenograft model.

RESULTS

We found that circNFATC3 expression was upregulated in primary CC tissues and positively correlated with CC tumor size and stromal invasion. In addition, we found that exogenous circNFATC3 overexpression enhanced the proliferation, migration and invasion of HeLa cells, while its knockdown reduced the malignancy of SiHa cells. We also found that circNFATC3 may act directly as a miR-9-5p sponge to regulate SDC2 expression and its downstream signaling pathways, thereby enhancing CC development.

CONCLUSION

Our data indicate that circNFATC3 sponges miR-9-5p to regulate SDC2 expression and, thereby, to promote CC tumor development.

Diagnostic, prognostic, and therapeutic significance of long non-coding RNA MALAT1 in cancer

Metastasis Associated Lung Adenocarcinoma Transcript 1 (MALAT1) is a widely studied lncRNA in cancer. Although dispensable for normal physiology, MALAT1 is important for cancer-related pathways regulation. It is localized in the nuclear speckles periphery along with centrally located pre-RNA splicing factors. MALAT1 associated cancer signaling pathways include MAPK/ERK, PI3K/AKT, β-catenin/Wnt, Hippo, VEGF, YAP, etc. Molecular tools such as immunoprecipitation, RNA pull-down, reporter assay, Northern blotting, microarray, and q-RT-PCR has been used to elucidate MALAT1's function in cancer pathogenesis. MALAT1 can regulate multiple steps in the development of tumours. The diagnostic and prognostic significance of MALAT1 has been demonstrated in cancers of the breast, cervix, colorectum, gallbladder, lung, ovary, pancreas, prostate, glioma, hepatocellular carcinoma, and multiple myeloma. MALAT1 has also emerged as a novel therapeutic target for solid as well as hematological malignancies. In experimental models, siRNA and antisense oligonucleotide (ASO) based strategy has been used for targeting MALAT1. The lncRNA has also been targeted for the chemosensitization and radiosensitization of cancer cells. However, most studies have been performed in preclinical models. How the cross-talk of MALAT1 with other signaling pathways affect cancer pathogenesis is the focus of this article. The diagnostic, prognostic, and therapeutic significance of MALAT1 in multiple cancer types are discussed.

CircNEIL3 promotes cervical cancer cell proliferation by adsorbing miR-137 and upregulating KLF12

Background

CircRNAs play crucial roles in multiple tumours. However, the functions of most circRNAs in cervical cancer remain unclear.

Methods

This study collected GSE113696 data from the GEO database to search for differentially expressed circRNAs in cervical cancer. Quantitative reverse transcription PCR was used to detect the expression level of circNEIL3 in cervical cancer cells and tissues. Then, functional experiments in vitro and in vivo were performed to evaluate the effects of circNEIL3 in cervical cancer.

Results

CircNEIL3 was highly expressed in cervical cancer. In vivo and in vitro experiments verified that circNEIL3 enhanced the proliferation capacity of cervical cancer cells. RNA immunoprecipitation, luciferase reporter assay, pull-down assay, and fluorescent in situ hybridization confirmed the interaction between circNEIL3 and miR-137 in cervical cancer. A luciferase reporter assay showed that circNEIL3 adsorbed miR-137 and upregulated KLF12 to regulate the proliferation of cervical cancer cells.

Conclusions

CircNEIL3 is an oncogene in cervical cancer and might serve as a ceRNA that competitively binds to miR-137, thereby indirectly upregulating the expression of KLF12 and promoting the proliferation of cervical cancer cells.

Roles and Mechanisms of the Long Noncoding RNAs in Cervical Cancer

Cervical cancer (CC) continues to be one of the leading causes of death for women across the world. Although it has been determined that papillomavirus infection is one of the main causes of the etiology of the disease, genetic and epigenetic factors are also required for its progression. Among the epigenetic factors are included the long noncoding RNAs (lncRNAs), transcripts of more than 200 nucleotides (nt) that generally do not code for proteins and have been associated with diverse functions such as the regulation of transcription, translation, RNA metabolism, as well as stem cell maintenance and differentiation, cell autophagy and apoptosis. Recently, studies have begun to characterize the aberrant regulation of lncRNAs in CC cells and tissues, including Homeobox transcript antisense RNA (HOTAIR), H19, Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), Cervical Carcinoma High-Expressed 1 (CCHE1), Antisense noncoding RNA in the inhibitors of cyclin-dependent kinase 4 (ANRIL), Growth arrest special 5 (GAS5) and Plasmacytoma variant translocation 1 (PVT1). They have been associated with several disease-related processes such as cell growth, cell proliferation, cell survival, metastasis and invasion as well as therapeutic resistance, and are novel potential biomarkers for diagnosis and prognosis in CC. In this review, we summarize the current literature regarding the knowledge we have about the roles and mechanisms of the lncRNAs in cervical neoplasia.

Circulating miR-15b, miR-34a and miR-218 as promising novel early low-invasive biomarkers of cervical carcinogenesis

Circulating biological markers, such as miRNAs, hold the greatest possibilities to complement tissue biopsy and clinical diagnostic tests. The objective of this study was to evaluate the relative abundance of three circulating miRNAs in serum from 17 HPV16-positive patients with early cervical lesions known as Low-Grade Squamous Intraepithelial Lesions (LSILs). The expression of circulating microRNAs miR-15b, miR-34a and miR-218 in patients with LSILs was compared to 23 HPV-negative individuals showing normal cervical epithelium (healthy women) and 23 Squamous Cell Carcinoma (SCC) samples. The expression levels of miR-15b remained unchanged while those of miRNAs 34a and 218 were relatively high in serum obtained from LSIL patients in comparison with healthy women (results were statistically significant with a p of < 0.01 or < 0.001). According to previous findings, miR-15b was overexpressed and miRNAs 34a and 218 were underexpressed in serum from SCC patients. Additionally, the mRNA expression levels of some selected gene targets were determined [Cyclin D1 (CCND1), Cyclin E1 (CCNE1), B-cell lymphoma 2 (Bcl-2) and MutS homolog 2 (MSH-2)]. All serum results correlated with tissue samples from the same patients. We propose that circulating microRNAs can be valuable as molecular markers for the early follow-up of cervical carcinogenesis risk.

Genome-Wide Analysis of the Expression of Circular RNA Full-Length Transcripts and Construction of the circRNA-miRNA-mRNA Network in Cervical Cancer

Increasing evidence suggests that circular RNA (circRNA) plays an important role in tumorigenesis by regulating gene expression at the transcriptional and post-transcriptional levels. Alternative splicing events permit multiple transcript isoforms of circRNA to be produced; however, changes in the expression of circRNA full-length transcripts in cervical cancer remain unclear. Here, we systematically explored the dysregulation circRNA full-length transcripts and constructed an improved circRNA-miRNA-mRNA regulatory network to provide potential biomarkers and possible treatment targets in cervical cancer. We identified 9359 circular full-length transcripts from RNase R-treated RNA-seq data in cervical cancer, of which 353 circular full-length transcripts were significantly differentially expressed (DE) between the tumor and normal group. A total of 881 DE mRNA transcript isoforms were also identified from total RNA-seq data in cervical cancer, of which 421 (47.8%) transcript isoforms were up-regulated, and 460 (52.2%) transcript isoforms were down-regulated in tumor samples. Two circRNA-miRNA-mRNA competitively regulated networks, including 33 circRNA transcripts, 2 miRNAs, and 189 mRNA transcripts were constructed. Three genes (COPE, RAB3B, and TFPI) in the network were significantly associated with overall survival (P < 0.05), which indicated that these genes could act as prognostic biomarkers for patients with cervical cancer. Our study revealed genome-wide differential expression of full-length circRNA transcripts and constructed a more accurate circRNA-miRNA-mRNA network at the full-length transcript expression level in cervical cancer. CircRNA may thus be involved in the development of cervical cancer by regulating the expression of COPE, RAB3B, and TFPI. However, the specific regulatory mechanism in cervical cancer requires further study.

Novel biomarkers with promising benefits for diagnosis of cervical neoplasia: a systematic review

BACKGROUND

Cervical cancer screening is slowly transitioning from Pappanicolaou cytologic screening to primary Visual Inspection with Acetic Acid (VIA) or HPV testing as an effort to enhance early detection and treatment. However, an effective triage tests needed to decide who among the VIA or HPV positive women should receive further diagnostic evaluation to avoid unnecessary colposcopy referrals is still lacking. Evidence from experimental studies have shown potential usefulness of Squamous Cell Carcinoma Antigen (SCC Ag), Macrophage Colony Stimulating Factor (M-CSF), Vascular Endothelial Growth Factor (VEGF), MicroRNA, p16INKa / ki-67, HPV E6/E7/mRNA, and DNA methylation biomarkers in detecting premalignant cervical neoplasia. Given the variation in performance, and scanty review studies in this field, this systematic review described the diagnostic performance of some selected assays to detect high-grade cervical intraepithelial neoplasia (CIN2+) with histology as gold standard.

METHODS

We systematically searched articles published in English between 2012 and 2020 using key words from PubMed/Medline and SCOPUS with two reviewers assessing study eligibility, and risk of bias. We performed a descriptive presentation of the performance of each of the selected assays for the detection of CIN2 + .

RESULTS

Out of 298 citations retrieved, 58 articles were included. Participants with cervical histology yielded CIN2+ proportion range of 13.7-88.4%. The diagnostic performance of the assays to detect CIN2+ was; 1) SCC-Ag: range sensitivity of 78.6-81.2%, specificity 74-100%. 2) M-CSF: sensitivity of 68-87.7%, specificity 64.7-94% 3) VEGF: sensitivity of 56-83.5%, specificity 74.6-96%. 4) MicroRNA: sensitivity of 52.9-67.3%, specificity 76.4-94.4%. 5) p16INKa / ki-67: sensitivity of 50-100%, specificity 39-90.4%. 6) HPV E6/E7/mRNA: sensitivity of 65-100%, specificity 42.7-90.2%, and 7) DNA methylation: sensitivity of 59.7-92.9%, specificity 67-98%.

CONCLUSION

Overall, the reported test performance and the receiving operating characteristics curves implies that implementation of p16ink4a/ki-67 assay as a triage for HPV positive women to be used at one visit with subsequent cryotherapy treatment is feasible. For the rest of assays, more robust clinical translation studies with larger consecutive cohorts of women participants is recommended.

Immune-Related Four-lncRNA Signature for Patients with Cervical Cancer

Cervical cancer (CC) is a common gynecological malignancy for which prognostic and therapeutic biomarkers are urgently needed. The signature based on immune-related lncRNAs (IRLs) of CC has never been reported. This study is aimed at establishing an IRL signature for patients with CC. A cohort of 326 CC and 21 normal tissue samples with corresponding clinical information was included in this study. Twenty-eight IRLs were collected according to the Pearson correlation analysis between the immune score and lncRNA expression (p < 0.01). Four IRLs (BZRAP1-AS1, EMX2OS, ZNF667-AS1, and CTC-429P9.1) with the most significant prognostic values (p < 0.05) were identified which demonstrated an ability to stratify patients into the low-risk and high-risk groups by developing a risk score model. It was observed that patients in the low-risk group showed longer overall survival (OS) than those in the high-risk group in the training set, valid set, and total set. The area under the curve (AUC) of the receiver operating characteristic curve (ROC curve) for the four-IRL signature in predicting the one-, two-, and three-year survival rates was larger than 0.65. In addition, the low-risk and high-risk groups displayed different immune statuses in GSEA. These IRLs were also significantly correlated with immune cell infiltration. Our results showed that the IRL signature had a prognostic value for CC. Meanwhile, the specific mechanisms of the four IRLs in the development of CC were ascertained preliminarily.

Identification of circ_0085616 as an Upregulated and Oncogenic Circular RNA in Cervical Cancer Via the miR-503-5p-Mediated ATXN7L3 Activation

Background: Increasing evidence enhanced the recognition of circular RNAs (circRNAs) implicated in cancer progression. CircRNA_0085616 (circ_0085616) is a novel circRNA with high expression in cervical cancer (CC); its function and action mechanism are explored during this study. Methods: The measurement of circ_0085616, microRNA-503-5p (miR-503-5p), and Ataxin-7L3 (ATXN7L3) was performed via quantitative real-time polymerase chain reaction. Next, 3-(4,5-dimethylthiazol-2-y1)-2, 5-diphenyl tetrazolium bromide (MTT) and colony formation assays were implemented to analyze the proliferative ability. Cell metastasis was evaluated by using transwell migration and invasion assays. Glycolysis was analyzed by using glucose consumption, lactate and adenosine triphosphate production. Western blot was employed for protein analysis. The target binding was performed by dual-luciferase reporter assay and RNA immunoprecipitation assay. An animal experiment in vivo was conducted by xenografts. Results: Circ_0085616 was heightened and its downregulation blocked cellular proliferation, metastasis, and glycolysis in CC. Then, we found that circ_0085616 had a sponge effect on miR-503-5p and the miR-503-5p inhibitor could ameliorate the effects of circ_0085616 knockdown on CC cells. In addition, miR-503-5p directly targeted ATXN7L3 to obstruct CC cell proliferation, metastasis, and glycolytic process. Further, circ_0085616 could enhance ATXN7L3 by sequestering miR-503-5p, and the miR-503-5p/ATXN7L3 axis was also responsible for circ_0085616 on promoting CC tumorigenesis in vivo. Conclusion: It was obvious that circ_0085616 facilitated the carcinogenic effect on CC via the activation of ATXN7L3 by sponging miR-503-5p. Our study may be likely to provide a novel molecular target for CC therapy.

Long noncoding RNAs (lncRNAs) in cervical carcinogenesis: New molecular targets, current prospects

Aberrant expression of lncRNAs has been seen as a key factor in a wide range of diseases including cancer. The role of lncRNAs in cervical cancer has not been clearly explained, and has been the subject of recent studies. In this review, we have compiled an updated list of previously reported lncRNAs and established a general profile of these transcripts in accordance with the role they play in cervical carcinogenesis. Thus, information here includes the influence of lncRNAs on cervical tumorigenic process through a disturbance of cellular activities. Additionally, we described recent discoveries about how HPV contributes to lncRNAs expression in cervical cancer and we summarized exploratory studies of strategies adopted to modulate the expression levels of lncRNAs to treat cervical neoplasia, by drawing attention to radio and chemo-resistance. Finally, this paper provides a broad overview that sets out new research directions about the role of lncRNAs in cervical cancer.

Protein-Related Circular RNAs in Human Pathologies

Circular RNAs (circRNAs) are a distinct family of RNAs derived from alternative splicing which play a crucial role in regulating gene expression by acting as microRNA (miRNA) and RNA binding protein (RBP) sponges. However, recent studies have also reported the multifunctional potential of these particles. Under different conditions, circRNAs not only regulate protein synthesis, destination, and degradation but can serve as protein scaffolds or recruiters and are also able to produce short peptides with active biological functions. circRNAs are under ongoing investigation because of their close association with the development of diseases. Some circRNAs are reportedly expressed in a tissue- and development stage-specific manner. Furthermore, due to other features of circRNAs, including their stability, conservation, and high abundance in bodily fluids, they are believed to be potential biomarkers for various diseases, including cancers. In this review, we focus on providing a summary of the current knowledge on circRNA-protein interactions. We present the properties and functions of circRNAs, the possible mechanisms of their translation abilities, and the emerging functions of circRNA-derived peptides in human pathologies.

LncRNA MAFG-AS1 Accelerates Cell Migration, Invasion and Aerobic Glycolysis of Esophageal Squamous Cell Carcinoma Cells via miR-765/PDX1 Axis

Background

LncRNA dysregulation is implicated in esophageal squamous cell carcinoma (ESCC) progression; However, the precise role and function of lncRNA MAFG-AS1 in ESCC remains unknown.

Materials and Methods

Expressions of MAFG-AS1, miR-765, PDX1, GLUT1 and LDH-A were detected via qRT-PCR or/and Western blot in ESCC tissues and cell lines. CCK-8, transwell and glycolysis assays were used to investigate the effects of MAFG-AS1 on ESCC cell proliferation, migration, invasion and aerobic glycolysis after knockdown or overexpression of MAFG-AS1, and bioinformatics analyses, RNA pull-down and dual luciferase reporter systems were applied to investigate the interaction between MAFG-AS1, miR-765 and PDX1.

Results

MAFG-AS1 was significantly up-modulated in ESCC tissues and cell lines. MAFG-AS1 significantly accelerated ESCC cell proliferation, migration, invasion and aerobic glycolysis. MAFG-AS1 competitively adsorbed miR-765, while miR-765 negatively modulated the expression of PDX1. miR-765 and PDX1 participated in the promotive effects of MAFG-AS1 on cell migration, invasion and aerobic glycolysis in ESCC cells.

Conclusion

Our research indicates that the MAFG-AS1/miR-765/PDX1 axis accelerates ESCC cell proliferation, migration, invasion and aerobic glycolysis.

Small and Long Non-coding RNAs as Functional Regulators of Bone Homeostasis, Acting Alone or Cooperatively

Emerging knowledge indicates that non-coding RNAs, including microRNAs (miRNAs) and long-noncoding RNAs (lncRNAs), have a pivotal role in bone development and the pathogenesis of bone-related disorders. Most recently, miRNAs have started to be regarded as potential biomarkers or targets for various sets of diseases, while lncRNAs have gained attention as a new layer of gene expression control acting through versatile interactions, also with miRNAs. The rapid development of RNA sequencing techniques based on next-generation sequencing (NGS) gives us better insight into molecular pathways regulated by the miRNA-lncRNA network. In this review, we summarize the current knowledge related to the function of miRNAs and lncRNAs as regulators of genes that are crucial for proper bone metabolism and homeostasis. We have characterized important non-coding RNAs and their expression signatures, in relationship to bone. Analysis of the biological function of miRNAs and lncRNAs, as well as their network, will pave the way for a better understanding of the pathogenesis of various bone disorders. We also think that this knowledge may lead to the development of innovative diagnostic tools and therapeutic approaches for bone-related disorders.

The Role of RNA Splicing Factors in Cancer: Regulation of Viral and Human Gene Expression in Human Papillomavirus-Related Cervical Cancer

The spliceosomal complex components, together with the heterogeneous nuclear ribonucleoproteins (hnRNPs) and serine/arginine-rich (SR) proteins, regulate the process of constitutive and alternative splicing, the latter leading to the production of mRNA isoforms coding multiple proteins from a single pre-mRNA molecule. The expression of splicing factors is frequently deregulated in different cancer types causing the generation of oncogenic proteins involved in cancer hallmarks. Cervical cancer is caused by persistent infection with oncogenic human papillomaviruses (HPVs) and constitutive expression of viral oncogenes. The aberrant activity of hnRNPs and SR proteins in cervical neoplasia has been shown to trigger the production of oncoproteins through the processing of pre-mRNA transcripts either derived from human genes or HPV genomes. Indeed, hnRNP and SR splicing factors have been shown to regulate the production of viral oncoprotein isoforms necessary for the completion of viral life cycle and for cell transformation. Target-therapy strategies against hnRNPs and SR proteins, causing simultaneous reduction of oncogenic factors and inhibition of HPV replication, are under development. In this review, we describe the current knowledge of the functional link between RNA splicing factors and deregulated cellular as well as viral RNA maturation in cervical cancer and the opportunity of new therapeutic strategies.

Targeted Gene Delivery Therapies for Cervical Cancer

Despite being largely preventable through early vaccination and screening strategies, cervical cancer is the most common type of gynecological malignancy worldwide and constitutes one of the leading causes of cancer deaths in women. Patients with advanced or recurrent disease have a very poor prognosis; hence, novel therapeutic modalities to improve clinical outcomes in cervical malignancy are needed. In this regard, targeted gene delivery therapy is presented as a promising approach, which leads to the development of multiple strategies focused on different aspects. These range from altered gene restoration, immune system potentiation, and oncolytic virotherapy to the use of nanotechnology and the design of improved and enhanced gene delivery systems, among others. In the present manuscript, we review the current progress made in targeted gene delivery therapy for cervical cancer, the advantages and drawbacks and their clinical application. At present, multiple targeted gene delivery systems have been reported with encouraging preclinical results. However, the translation to humans has not yet shown a significant clinical benefit due principally to the lack of efficient vectors. Real efforts are being made to develop new gene delivery systems, to improve tumor targeting and to minimize toxicity in normal tissues.