Aberrant expression of oncogenic and tumor-suppressive microRNAs in cervical cancer is required for cancer cell growth

HPV-driven oncogenesis-much more than the E6 and E7 oncoproteins

High-risk human papillomaviruses are well-established drivers of several cancer types including cervical, head and neck, penile as well as anal cancers. While the E6 and E7 viral oncoproteins have proven to be critical for malignant transformation, evidence is also beginning to emerge suggesting that both host pathways and additional viral genes may also be pivotal for malignant transformation. Here, we focus on the role of host APOBEC genes, which have an important role in molecular editing including in the response to the viral DNA and their role in HPV-driven carcinogenesis. Further, we also discuss data developed suggesting the existence of HPV-derived miRNAs in HPV + tumors and their potential role in regulating the host transcriptome. Collectively, while recent advances in these two areas have added complexity to the working model of papillomavirus-induced oncogenesis, these discoveries have also shed a light onto new areas of research that will be required to fully understand the process.

Hsa-miR-194-5p and hsa-miR-195-5p are down-regulated expressed in high dysplasia HPV-positive Pap smear samples compared to normal cytology HPV-positive Pap smear samples

BACKGROUND

The human papillomavirus (HPV) infection may affect the miRNA expression pattern during cervical cancer (CC) development. To demonstrate the association between high-risk HPVs and the development of cervix dysplasia, we examined the expression patterns of hsa-miR-194-5p and hsa-miR-195-5p in Pap smear samples from southeast Iranian women. We compared samples that were HPV-positive but showed no abnormality in the cytological examination to samples that were HPV-positive and had severe dysplasia.

METHODS

Pap smear samples were obtained from 60 HPV-positive (HPV-16/18) patients with histologically confirmed severe dysplasia (cervical intra-epithelial neoplasia (CIN 3) or carcinoma in situ) and the normal cytology group. The expression of hsa-miR-194-5p and hsa-miR-195-5p was analyzed by real-time quantitative PCR, using specific stem-loop primers and U6 snRNA as the internal reference gene. Clinicopathological features were associated with miRNA expression levels. Furthermore, functional enrichment analysis was conducted using in silico tools. The Kaplan-Meier survival method was also obtained to discriminate survival-significant candidate miRNAs in CC, and receiver operating characteristic (ROC) curves were constructed to assess the diagnostic value.

RESULTS

Compared to HPV-positive cytologically normal Pap smear samples, hsa-miR-194-5p and hsa-miR-195-5p relative expression decreased significantly in HPV-positive patients with a severe dysplasia Pap smear. Kaplan-Meier analysis indicated a significant association between the miR-194 decrease and poor CC survival. In essence, ROC curve analysis showed that miR-194-5p and miR-195-5p could serve as valuable markers for the development of cervix dysplasia in individuals who are positive for high-risk HPVs.

CONCLUSIONS

This study revealed that hsa-miR-194-5p and hsa-miR-195-5p may possess tumor suppressor capabilities in the context of cervical dysplasia progression. However, it remains uncertain whether these microRNAs are implicated in the transition of patients with high dysplasia to cervical cancer. We also showed the potential capability of candidate miRNAs as novel diagnostic biomarkers related to cervical dysplasia progression.

Epstein-Barr virus-encoded EBNA2 downregulates ICOSL by inducing miR-24 in B-cell lymphoma

ABSTRACT

Hematological malignancies such as Burkitt lymphoma (BL), Hodgkin lymphoma (HL), and diffuse large B-cell lymphoma (DLBCL) cause significant morbidity in humans. A substantial number of these lymphomas, particularly HL and DLBCLs have poorer prognosis because of their association with Epstein-Barr virus (EBV). Our earlier studies have shown that EBV-encoded nuclear antigen (EBNA2) upregulates programmed cell death ligand 1 in DLBCL and BLs by downregulating microRNA-34a. Here, we investigated whether EBNA2 affects the inducible costimulator (ICOS) ligand (ICOSL), a molecule required for efficient recognition of tumor cells by T cells through the engagement of ICOS on the latter. In virus-infected and EBNA2-transfected B-lymphoma cells, ICOSL expression was reduced. Our investigation of the molecular mechanisms revealed that this was due to an increase in microRNA-24 (miR-24) by EBNA2. By using ICOSL 3' untranslated region-luciferase reporter system, we validated that ICOSL is an authentic miR-24 target. Transfection of anti-miR-24 molecules in EBNA2-expressing lymphoma cells reconstituted ICOSL expression and increased tumor immunogenicity in mixed lymphocyte reactions. Because miR-24 is known to target c-MYC, an oncoprotein positively regulated by EBNA2, we analyzed its expression in anti-miR-24 transfected lymphoma cells. Indeed, the reduction of miR-24 in EBNA2-expressing DLBCL further elevated c-MYC and increased apoptosis. Consistent with the in vitro data, EBNA2-positive DLBCL biopsies expressed low ICOSL and high miR-24. We suggest that EBV evades host immune responses through EBNA2 by inducing miR-24 to reduce ICOSL expression, and for simultaneous rheostatic maintenance of proproliferative c-MYC levels. Overall, these data identify miR-24 as a potential therapeutically relevant target in EBV-associated lymphomas.

Exosomal miRNAs assist in the crosstalk between tumor cells and immune cells and its potential therapeutics

Exosomes are small extracellular vesicles that carry active substances (including proteins, lipids, and nucleic acids) and are essential for homeostasis and signal transmission. Recent studies have focused on the function of exosomal miRNAs in tumor progression. Researchers have expanded the use of exosomes and miRNAs as potential therapeutic tools and biomarkers to detect tumor progression. Immune cells, as an important part of the tumor microenvironment (TME), secrete a majority of exosome-derived miRNAs involved in the biological processes of malignancies. However, the underlying mechanisms remain unclear. Currently, there is no literature that systematically summarizes the communication of exosome-derived miRNAs between tumor cells and immune cells. Based on the cell specificity of exosome-derived miRNAs, this review provides the first comprehensive summary of the significant miRNAs from the standpoint of exosome sources, which are tumor cells and immune cells. Furthermore, we elaborated on the potential clinical applications of these miRNAs, attempting to propose existing difficulties and future possibilities in tumor diagnostics and therapy.

miR-17 ~ 92 suppresses proliferation and invasion of cervical cancer cells by inhibiting cell cycle regulator Cdt2

Cervical cancer (CC) is the 4th most leading cause of death among women worldwide, and if diagnosed in late stages the treatment options are almost negligible. 99% of CC is caused by high-risk human papilloma viruses (HR-HPV). Upon integration into human genome, the encoded viral proteins mis-regulate various onco-suppressors and checkpoint factors including cell cycle regulators. One such protein is cell cycle S phase licensing factor, CDC-10 dependent transcript-2 (Cdt2) which has been reported to be highly upregulated in various cancers including CC. Also, in CC cells, several tumor suppressor miRNAs are suppressed, including miR-17 ~ 92 cluster. In this study, we report that miR-17 ~ 92 directly recruits to 3'UTR of Cdt2 and downregulates this oncogene which suppresses the proliferation, migration and invasion capabilities of the CC cell lines without affecting non-cancerous cells. We further show that suppression of Cdt2 by miR-17 ~ 92, blocks the cancerous cells in S phase and induces apoptosis, eventually leading to their death. Hence, our work for the first time, mechanistically shows how miR-17 ~ 92 could work as tumor suppressor in cervical cancer cells, opening up the potential of miR-17 ~ 92 to be used in developing therapy for cervical cancer treatment.

miRNA-767 and its binding site polymorphism in the mTOR gene act as potential biomarkers for female reproductive cancers

Aims: The present study aimed to understand the relationship between the mTOR gene SNP (rs2536) and reproductive cancer risk. The expression level of miRNA-767 was also assessed. Methods: 700 tumor samples (300 breast, 200 ovarian and 200 cervical cancers), along with adjacent uninvolved control tissue, were used. rs2536 was screened using Tetra-ARMS PCR and expression level of miRNA-767 was assessed using quantitative PCR. Results: The frequency of the homozygous mutant genotype of rs2536 was observed significantly higher in breast (p < 0.04), ovarian (p < 0.005) and cervical (p < 0.003) cancers. Significant downregulation of miRNA-767 was observed in tumors compared with controls. Conclusion: The present study demonstrates that increased mutant frequency of rs2536 and deregulation of miRNA-767 are associated with increased reproductive cancer risk.

MiRNA-146a-A Key Player in Immunity and Diseases

miRNA-146a, a single-stranded, non-coding RNA molecule, has emerged as a valuable diagnostic and prognostic biomarker for numerous pathological conditions. Its primary function lies in regulating inflammatory processes, haemopoiesis, allergic responses, and other key aspects of the innate immune system. Several studies have indicated that polymorphisms in miRNA-146a can influence the pathogenesis of various human diseases, including autoimmune disorders and cancer. One of the key mechanisms by which miRNA-146a exerts its effects is by controlling the expression of certain proteins involved in critical pathways. It can modulate the activity of interleukin-1 receptor-associated kinase, IRAK1, IRAK2 adaptor proteins, and tumour necrosis factor (TNF) targeting protein receptor 6, which is a regulator of the TNF signalling pathway. In addition, miRNA-146a affects gene expression through multiple signalling pathways, such as TNF, NF-κB and MEK-1/2, and JNK-1/2. Studies have been carried out to determine the effect of miRNA-146a on cancer pathogenesis, revealing its involvement in the synthesis of stem cells, which contributes to tumourigenesis. In this review, we focus on recent discoveries that highlight the significant role played by miRNA-146a in regulating various defence mechanisms and oncogenesis. The aim of this review article is to systematically examine miRNA-146a's impact on the control of signalling pathways involved in oncopathology, immune system development, and the corresponding response to therapy.

Micro RNAs as a Diagnostic Marker between Glioma and Primary CNS Lymphoma: A Systematic Review

Differentiating glioma from primary central nervous system lymphoma (PCNSL) can be challenging, and current diagnostic measures such as MRI and biopsy are of limited efficacy. Liquid biopsies, which detect circulating biomarkers such as microRNAs (miRs), may provide valuable insights into diagnostic biomarkers for improved discrimination. This review aimed to investigate the role of specific miRs in diagnosing and differentiating glioma from PCNSL. A systematic search was conducted of PubMed, Scopus, Web of Science, and Embase for articles on liquid biopsies as a diagnostic method for glioma and PCNSL. Sixteen dysregulated miRs were identified with significantly different levels in glioma and PCNSL, including miR-21, which was the most prominent miR with higher levels in PCNSL, followed by glioma, including glioblastoma (GBM), and control groups. The lowest levels of miR-16 and miR-205 were observed in glioma, followed by PCNSL and control groups, whereas miR-15b and miR-301 were higher in both tumor groups, with the highest levels observed in glioma patients. The levels of miR-711 were higher in glioma (including GBM) and downregulated in PCNSL compared to the control group. This review suggests that using these six circulating microRNAs as liquid biomarkers with unique changing patterns could aid in better discrimination between glioma, especially GBM, and PCNSL.

Small RNA Profiling in an HTLV-1-Infected Patient with Acute Adult T-Cell Leukemia-Lymphoma at Diagnosis and after Maintenance Therapy: A Case Study

Small RNAs (sRNAs) are epigenetic regulators of essential biological processes associated with the development and progression of leukemias, including adult T-cell leukemia/lymphoma (ATLL) caused by human T-cell lymphotropic virus type 1 (HTLV-1), an oncogenic human retrovirus originally discovered in a patient with adult T-cell leukemia/lymphoma. Here, we describe the sRNA profile of a 30-year-old woman with ATLL at the time of diagnosis and after maintenance therapy with the aim of correlating expression levels with response to therapy.

JAK/STAT Signaling and Cervical Cancer: From the Cell Surface to the Nucleus

The Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathway constitutes a rapid signaling module from the cell surface to the nucleus, and activates different cellular responses, such as proliferation, survival, migration, invasion, and inflammation. When the JAK/STAT pathway is altered, it contributes to cancer progression and metastasis. STAT proteins play a central role in developing cervical cancer, and inhibiting the JAK/STAT signaling may be necessary to induce tumor cell death. Several cancers show continuous activation of different STATs, including cervical cancer. The constitutive activation of STAT proteins is associated with a poor prognosis and overall survival. The human papillomavirus (HPV) oncoproteins E6 and E7 play an essential role in cervical cancer progression, and they activate the JAK/STAT pathway and other signals that induce proliferation, survival, and migration of cancer cells. Moreover, there is a crosstalk between the JAK/STAT signaling cascade with other signaling pathways, where a plethora of different proteins activate to induce gene transcription and cell responses that contribute to tumor growth. Therefore, inhibition of the JAK/STAT pathway shows promise as a new target in cancer treatment. In this review, we discuss the role of the JAK/STAT pathway components and the role of the HPV oncoproteins associated with cellular malignancy through the JAK/STAT proteins and other signaling pathways to induce tumor growth.

The mechanisms and diagnostic potential of lncRNAs, miRNAs, and their related signaling pathways in cervical cancer

Cervical cancer (CC), the fourth most prevalent type of cancer among women worldwide, is associated with high rates of morbidity and mortality. Due to the long period of latency in CC, most patients are already in the middle to late stages when initially diagnosed, which greatly reduces the clinical cure rate and quality of survival, thus resulting in poor outcomes. In recent years, with continuous exploration in the fields of bioinformatics and molecules, it has been found that ncRNAs, including miRNAs and lncRNAs, without the ability to translate proteins are capable of activating or inhibiting certain signaling pathways by targeting and modulating the level of expression of proteins involved in these signaling pathways. ncRNAs play important roles in assisting with diagnosis, drug administration, and prediction of prognosis during CC progression. As an entry point, the mechanisms of interaction between miRNAs, lncRNAs, and signaling pathways have long been a focus in basic research relating to CC, and numerous experimental studies have confirmed the close relationship of miRNAs, lncRNAs, and signaling pathways with CC development. Against this background, we summarize the latest advances in the involvement of lncRNA- and miRNA-related signaling pathways in the development of CC to provide guidance for CC treatment.

MicroRNAs Improve Cancer Treatment Outcomes Through Personalized Medicine

MicroRNAs (miRNAs) are short non-coding RNAs that repress or degrade mRNA targets to downregulate genes. In cancer occurrence, the expression of miRNAs is altered. Depending on the involvement of a certain miRNA in the pathogenetic growth of a tumor, It may be up or downregulated. The "oncogenic" action of miRNAs corresponds with upregulation, which leads to tumor proliferation and spread meanwhile the miRNAs that have been downregulated bring tumorsuppressive outcomes. Oncogenes and tumor suppressor genes are among the genes whose expression is under their control, demonstrating that classifying them solely as oncogenes or tumor suppressor genes alone is not only hindering but also incorrect. Apart from basic tumors, miRNAs may be found in nearly all human fluids and can be used for cancer diagnosis as well as clinical outcome prognostics and better response to treatment strategies. The overall variance of these tiny noncoding RNAs influences patient-specific pharmacokinetics and pharmacodynamics of anti-cancer medicines, driving a growing demand for personalized medicine. By now, microRNAs from tumor biopsies or blood are being widely investigated as substantial biomarkers for cancer in time diagnosis, prognosis, and, progression. With the rise of COVID-19, this paper also attempts to study recent research on miRNAs involved with deaths in lung cancer COVID patients. With the discovery of single nucleotide polymorphisms, personalized treatment via microRNAs has lately become a reality. The present review article describes the highlights of recent knowledge of miRNAs in various cancers, with a focus on miRNA translational applications as innovative potential diagnostic and prognostic indicators that expand person-to-person therapy options.

Non-coding RNAs and glioma: Focus on cancer stem cells

Glioblastoma and gliomas can have a wide range of histopathologic subtypes. These heterogeneous histologic phenotypes originate from tumor cells with the distinct functions of tumorigenesis and self-renewal, called glioma stem cells (GSCs). GSCs are characterized based on multi-layered epigenetic mechanisms, which control the expression of many genes. This epigenetic regulatory mechanism is often based on functional non-coding RNAs (ncRNAs). ncRNAs have become increasingly important in the pathogenesis of human cancer and work as oncogenes or tumor suppressors to regulate carcinogenesis and progression. These RNAs by being involved in chromatin remodeling and modification, transcriptional regulation, and alternative splicing of pre-mRNA, as well as mRNA stability and protein translation, play a key role in tumor development and progression. Numerous studies have been performed to try to understand the dysregulation pattern of these ncRNAs in tumors and cancer stem cells (CSCs), which show robust differentiation and self-regeneration capacity. This review provides recent findings on the role of ncRNAs in glioma development and progression, particularly their effects on CSCs, thus accelerating the clinical implementation of ncRNAs as promising tumor biomarkers and therapeutic targets.

miR-34a negatively regulates cell cycle factor Cdt2/DTL in HPV infected cervical cancer cells

MicroRNAs have emerged as an important regulator of cell cycle and various other cellular processes. Aberration in microRNAs has been linked with development of several cancers and other diseases but still very little is known about the mechanism by which they regulate these cellular events. High risk human papilloma virus (HR HPV) is the causative agent of 99% of cervical cancer cases which attenuates multiple tumor suppressors and checkpoint factors of the host cell. The viral proteins also stabilize many oncogenic factors, including an essential cell cycle regulator Cdt2/DTL which in turn promotes cell transformation and proliferation. In this study, we report that a micro-RNA, miR-34a by suppressing HPV E6 protein, destabilizes Cdt2/DTL protein level in HPV infected cervical cancer cell lines. Destabilization of Cdt2 stabilizes pro-apoptotic and onco-suppressor proteins like p21 and Set8 and suppresses cell proliferation, invasion and migration capabilities of the HPV positive cervical cancer cells. Overexpression of either HPV E6 or Cdt2 genes along with miR-34a restored back the suppressed proliferation rate. This study is the first-ever report to show that miR-34a regulates cell cycle factor Cdt2 by suppressing viral E6 protein level, thus opening up the possibility of exploring miR-34a as a specific therapy for cervical cancer treatment.

Cervical Cancer Cells-Derived Extracellular Vesicles Containing microRNA-146a-5p Affect Actin Dynamics to Promote Cervical Cancer Metastasis by Activating the Hippo-YAP Signaling Pathway via WWC2

Application of extracellular vesicles (EVs) for cancer treatment has been well-documented. We probed into the potential role of cervical cancer cells-secreted EVs by transferring miR-146a-5p in cervical cancer. After characterization of miR-146a-5p expression in clinical cervical cancer tissue samples, gain- and loss-of-function experiments were implemented to test the effect of miR-146a-5p on the invasion, epithelial-mesenchymal transition (EMT), and anoikis in cervical cancer cells. EVs were isolated from high-metastatic cervical cancer cells, after which their effects on the malignant behaviors of low-metastatic cervical cancer cells were assessed in a co-culture system. Luciferase assay was implemented to validate the putative binding relationship between miR-146a-5p and WWC2, followed by further investigation of downstream pathway (Hippo-YAP). Finally, nude mouse lung metastasis model was developed for in vivo validation. miR-146a-5p was elevated in cervical cancer tissues and high miR-146a-5p expression promoted the metastatic potential of cervical cancer cells through enhancing their invasiveness and anoikis resistance, and inducing EMT. Furthermore, miR-146a-5p carried by EVs secreted by highly metastatic cervical cancer cells could promote the metastasis of low-metastatic cervical cancer cells. Mechanistically, miR-146a-5p targeted WWC2 to activate YAP, by which it inhibited the phosphorylation of cofilin, and promoted the process of cofilin-mediated depolymerization of F-actin to G-actin. In vivo data demonstrated that EVs-carried miR-146a-5p promoted tumor metastasis through the WWC2/YAP axis. Cancer-derived EVs delivered pro-metastatic miR-146a-5p to regulate the actin dynamics in cervical cancer, thereby leading to cancer metastasis. This experiment highlighted an appealing therapeutic modality for cervical cancer.

Expression and role of miR-146a and SMAD4 in placental tissue of pregnant women with preeclampsia

INTRODUCTION

To investigate the expression of miR-146a in severe preeclampsia (PE) and its effect on trophoblast cell proliferation, invasion and apoptosis, as well as its relationship with SMAD4.

MATERIAL AND METHODS

Participants were divided into the severe PE group (n = 30) and the normal group (n = 30). The expression of miR-146a and SMAD4 in placenta tissue was detected by immunohistochemistry, qRT-PCR, and western blot. Trophoblast cell lines HTR-8/SVneo were cultured to detect the expression of miR-146a under the Cobalt chloride (CoCl₂ )-simulated hypoxia. The effects of miR-146a transfection on cell proliferation, invasion, apoptosis, and SMAD4 expression were analyzed.

RESULTS

Compared with the normal group, miR-146a expression was decreased and the protein and mRNA levels of SMAD4 were increased in placenta tissues of the severe PE group. Our in vitro experiments showed that the expression of miR-146a decreased after CoCl₂ treatment. Silencing miR-146a caused increased expression of SMAD4 and decreased expression of VEGF. After transfection with miR-146a inhibitor, compared with the NC group, the invasion and proliferation of HTR-8/Svneo cells were decreased, while the apoptosis was enhanced.

CONCLUSION

The expression of miR-146a decreased in severe PE and was negatively correlated with SMAD4 expression. The expression of miR-146a was inhibited under hypoxia, and the low expression of miR-146a affected the proliferation, invasion, and apoptosis of trophoblast cells.

The Prospective Application of Melatonin in Treating Epigenetic Dysfunctional Diseases

In the past, different human disorders were described by scientists from the perspective of either environmental factors or just by genetically related mechanisms. The rise in epigenetic studies and its modifications, i.e., heritable alterations in gene expression without changes in DNA sequences, have now been confirmed in diseases. Modifications namely, DNA methylation, posttranslational histone modifications, and non-coding RNAs have led to a better understanding of the coaction between epigenetic alterations and human pathologies. Melatonin is a widely-produced indoleamine regulator molecule that influences numerous biological functions within many cell types. Concerning its broad spectrum of actions, melatonin should be investigated much more for its contribution to the upstream and downstream mechanistic regulation of epigenetic modifications in diseases. It is, therefore, necessary to fill the existing gaps concerning corresponding processes associated with melatonin with the physiological abnormalities brought by epigenetic modifications. This review outlines the findings on melatonin’s action on epigenetic regulation in human diseases including neurodegenerative diseases, diabetes, cancer, and cardiovascular diseases. It summarizes the ability of melatonin to act on molecules such as proteins and RNAs which affect the development and progression of diseases.

miR-22-3p and miR-30e-5p Are Associated with Prognosis in Cervical Squamous Cell Carcinoma

Alteration in expression of miRNAs can cause various malignant changes and the metastatic process. Our aim was to identify the miRNAs involved in cervical squamous cell carcinoma (SqCC) and metastasis, and to test their utility as indicators of metastasis and survival. Using microarray technology, we performed miRNA expression profiling on primary cervical SqCC tissue (n = 6) compared with normal control (NC) tissue and compared SqCC that had (SqC-M; n = 3) and had not (SqC-NM; n = 3) metastasized. Four miRNAs were selected for validation by qRT-PCR on 29 SqC-NM and 27 SqC-M samples, and nine metastatic lesions (ML-SqC), from a total of 56 patients. Correlation of miRNA expression and clinicopathological parameters was analyzed to evaluate the clinical impact of candidate miRNAs. We found 40 miRNAs differentially altered in cervical SqCC tissue: 21 miRNAs were upregulated and 19 were downregulated (≥2-fold, p < 0.05). Eight were differentially altered in SqC-M compared with SqC-NM samples: four were upregulated (miR-494, miR-92a-3p, miR-205-5p, and miR-221-3p), and four were downregulated (miR-574-3p, miR-4769-3p, miR-1281, and miR-1825) (≥1.5-fold, p < 0.05). MiR-22-3p might be a metastamiR, which was gradually further downregulated in SqC-NM > SqC-M > ML-SqC. Downregulation of miR-30e-5p significantly correlated with high stage, lymph node metastasis, and low survival rate, suggesting an independent poor prognostic factor.

DNA methylation of miR-138 regulates cell proliferation and EMT in cervical cancer by targeting EZH2

BACKGROUND

Emerging evidence has identified miR-138 as a tumor suppressor that can suppress the proliferation of various cancers. Meanwhile, the cause of abnormal miR-138 expression in cervical cancer remains uncertain. This study clarified the mechanism by which miR-138 regulates proliferation, invasion, metastasis, and EMT in cervical cancer cells.

RESULTS

miR-138 expression in human cervical cancer and adjacent normal tissue was measured using qPCR. SiHa and C33A cells were used to determine the function of miR-138 via miR-138 mimic or inhibitor transfection, followed by wound healing, Cell Counting Kit-8, flow cytometry, and Transwell assays. Epithelial and mesenchymal marker expression was analyzed using Western blotting. DNA methylation in the miR-138 promoter was examined using bisulfite sequencing PCR. The downstream target genes of miR-138 were identified via bioinformatics analysis and luciferase reporter assays. A tumor xenograft model was employed to validate DNA methylation-induced miR-138 downregulation and tumor growth inhibition in cervical cancer in vivo. miR-138 levels were significantly lower in cervical cancer tissues than in adjacent control tissues. Furthermore, lower miR-138 expression and higher CpG methylation in the miR-138 promoter were identified in lymph node-positive metastatic cervical cancer tumors versus that in non-metastatic tumor tissues. Upon miR-138 overexpression, cell proliferation, metastasis, invasion, and EMT were suppressed. miR-138 agomir transfection and demethylating drug treatment significantly inhibited cervical tumor growth and EMT in tumor xenograft models. DNA methylation inhibited miR-138 transcription, and enhancer of zeste homolog 2 (EZH2) downregulation mediated the tumor suppressor function of miR-138 in cervical cancer.

CONCLUSION

We demonstrated that miR-138 suppresses tumor progression by targeting EZH2 in cervical cancer and uncovered the role of DNA methylation in the miR-138 promoter in its downregulation. These findings demonstrated the potential of miR-138 to predict disease metastasis and/or function as a therapeutic target in cervical cancer.

HPV16 and HPV18 Genome Structure, Expression, and Post-Transcriptional Regulation

Human papillomaviruses (HPV) are a group of small non-enveloped DNA viruses whose infection causes benign tumors or cancers. HPV16 and HPV18, the two most common high-risk HPVs, are responsible for ~70% of all HPV-related cervical cancers and head and neck cancers. The expression of the HPV genome is highly dependent on cell differentiation and is strictly regulated at the transcriptional and post-transcriptional levels. Both HPV early and late transcripts differentially expressed in the infected cells are intron-containing bicistronic or polycistronic RNAs bearing more than one open reading frame (ORF), because of usage of alternative viral promoters and two alternative viral RNA polyadenylation signals. Papillomaviruses proficiently engage alternative RNA splicing to express individual ORFs from the bicistronic or polycistronic RNA transcripts. In this review, we discuss the genome structures and the updated transcription maps of HPV16 and HPV18, and the latest research advances in understanding RNA cis-elements, intron branch point sequences, and RNA-binding proteins in the regulation of viral RNA processing. Moreover, we briefly discuss the epigenetic modifications, including DNA methylation and possible APOBEC-mediated genome editing in HPV infections and carcinogenesis.

The Clinical Efficacy of Chemotherapy Combined with Traditional Chinese Medicine in the Treatment of Cervical Cancer and Its Influence on Cellular Immunity, Serum CEA, and TNF-α

BACKGROUND

This study aims to investigate the clinical efficacy of chemotherapy combined with traditional Chinese medicine in patients with cervical cancer and its effect on cellular immunoglobulin, serum sugar chain antigen 125 (CA125), carcinoembryonic antigen (CEA), and tumor necrosis factor-α (TNF-α).

METHODS

Conventional chemotherapy was performed in control and observation groups. Meantime, the observation group received traditional Chinese medicine. Finally, the clinical efficacy, immunoglobulin, serum tumor markers, and serum TNF-α of the two groups were compared.

RESULTS

Compared with the control group, total effective rate in the observation group was increased. After treatment, serum CD8+, TNF-α, CA125, and CEA levels were reduced in the two groups, and the observation group was higher. In the two groups, CD3+ and CD4+ levels were enhanced after treatment, and the observation group was also higher. Compared with the control group, the immunoglobulin IgG, IgA, and IgM levels increased in the observation group. The incidence of adverse reactions in the observation group was reduced compared to the control group.

CONCLUSION

Chemotherapy combined with traditional Chinese can help improve the clinical efficacy and immunity in patients with cervical cancer. Moreover, the safety and feasibility of the treatment method are relatively high.

Versatile role of miR-24/24-1*/24-2* expression in cancer and other human diseases

MiRNAs (miRs) have been proven to be well-validated therapeutic targets. Emerging evidence has demonstrated that intricate, intrinsic and paradoxical functions of miRs are context-dependent because of their multiple upstream regulators, broad spectrum of downstream molecular targets and distinct expression in various tissues, organs and disease states. Targeted therapy has become an emerging field of research. One key for the development of successful miR-based/targeted therapy is to acquire integrated knowledge of its regulatory network and its association with disease phenotypes to identify critical nodes of the underlying pathogenesis. Herein, we systematically summarized the comprehensive role of miR-24-3p (miR-24), along with its passenger strands miR-24-1-5p* (miR-24-1) and miR-24-2-5p* (miR-24-2), emphasizing their microenvironment, intracellular targets, and associated gene networks and regulatory phenotypes in 18 different cancer types and 13 types of other disorders. MiR-24 targets and regulates numerous genes in various cancer types and enhances the expression of several oncogenes (e.g., cMyc, BCL2 and HIF1), which are challenging in terms of druggability. In contrast, several tumor suppressor proteins (p21 and p53) have been reported to be downregulated by miR-24. MiR-24 also regulates the cell cycle and is associated with numerous cancer hallmarks such as apoptosis, proliferation, metastasis, invasion, angiogenesis, autophagy, drug resistance and other diseases pathogenesis. Overall, miR-24 plays an emerging role in the diagnosis, prognosis and pathobiology of various diseases. MiR-24 is a potential target for targeted therapy in the era of precision medicine, which expands the landscape of targetable macromolecules, including undruggable proteins.

5,7,2,5-tetrahydroxy-8,6-dimethoxyflavone up-regulates miR-145 expression and inhibits proliferation of gastric cancer cells

INTRODUCTION

Gastric cancer is a frequently detected malignancy, and its incidence has increased over the past decades in East Asia. The present study investigated the effect of 5,7,2, 5-tetrahydroxy-8,6-dimethoxyflavone (THDMF) on gastric cancer cells and explored the underlying mechanism. The study analysed cell viability changes, apoptotic features, and metastasis potential of treatment with THDMF.

MATERIAL AND METHODS

MTT colorimetric assay was used for measurement of MKN28, MKN45, and GES-1 cell proliferation and flow cytometry for the detection of apoptosis. Transwell and wound healing assays were used to observe the invasion and migration abilities of MKN28 cells. The expression of p21, MMP2/-9, PI3K, and c-Myc proteins was detected by western blotting.

RESULTS

The THDMF treatment significantly (p < 0.05) reduced MKN28 and MKN45 cell proliferation without changing GES-1 cell viability. A significant increase in apoptotic cell population on treatment with THDMF was observed. Treatment of MKN28 cells with THDMF increased the percentage of cells in the G1 phase. Exposure of MKN28 cells to THDMF caused a marked decrease in invasion and migration potential in comparison to control cells. The expression of miR-145 was markedly increased in MKN28 cells on treatment with THDMF. In MKN28 cells expression of c-Myc, PI3K, p-AKT, MMP-2, and MMP-9 was suppressed markedly on exposure to THDMF. The expression of p21 protein in MKN28 cells was markedly promoted on exposure to THDMF.

CONCLUSIONS

THDMF exhibits anti-cancer effect on gastric cancer cells in vitro by activation of cell apoptosis and arrest of cell cycle. In addition, THDMF promoted miR-145 expression and down-regulation of PI3K/AKT signalling pathway in MKN28 cells. Therefore, THDMF may be utilised as a potential novel therapeutic agent for the treatment of gastric cancer.

Cervical Cancer, Papillomavirus, and miRNA Dysfunction

Cervical cancer is the leading cause of death by cancer in women from developing countries. Persistent infection with high-risk human papillomavirus (HPV) types 16 and 18 is a major risk factor for cervical carcinogenesis. Nevertheless, only a few women with morphologic expression of HPV infection progress into invasive disease suggesting the involvement of other factors in cervical carcinogenesis. MicroRNAs (miRNAs) are conserved small non-coding RNAs that negatively regulate gene expression including genes involved in fundamental biological processes and human cancer. Dysregulation of miRNAs has been widely reported in cervical cancer. This work focuses on reviewing the miRNAs affected during the HPV infection process, as well relevant miRNAs that contribute to the development and maintenance of malignant cervical tumor cells. Finally, we recapitulate on miRNAs that may be used to distinguish between healthy individuals from patients with precancerous lesions or cervical tumors.

MicroRNA-214 in Health and Disease

MicroRNAs (miRNAs) are endogenously expressed, non-coding RNA molecules that mediate the post-transcriptional repression and degradation of mRNAs by targeting their 3′ untranslated region (3′-UTR). Thousands of miRNAs have been identified since their first discovery in 1993, and miR-214 was first reported to promote apoptosis in HeLa cells. Presently, miR-214 is implicated in an extensive range of conditions such as cardiovascular diseases, cancers, bone formation and cell differentiation. MiR-214 has shown pleiotropic roles in contributing to the progression of diseases such as gastric and lung cancers but may also confer cardioprotection against excessive fibrosis and oxidative damage. These contrasting functions are achieved through the diverse cast of miR-214 targets. Through silencing or overexpressing miR-214, the detrimental effects can be attenuated, and the beneficial effects promoted in order to improve health outcomes. Therefore, discovering novel miR-214 targets and understanding how miR-214 is dysregulated in human diseases may eventually lead to miRNA-based therapies. MiR-214 has also shown promise as a diagnostic biomarker in identifying breast cancer and coronary artery disease. This review provides an up-to-date discussion of miR-214 literature by describing relevant roles in health and disease, areas of disagreement, and the future direction of the field.

Inflammation and cancer: paradoxical roles in tumorigenesis and implications in immunotherapies

Chronic inflammation caused by persistent infections and metabolic disorders is thought to contribute to the increased cancer risk and the accelerated cancer progression. Oppositely, acute inflammation induced by bacteria-based vaccines or that is occurring after cancer selectively inhibits cancer progression and metastasis. However, the interaction between inflammation and cancer may be more complex than the current explanations for the relationship between chronic and acute inflammation and cancer. In this review, we described the impact of inflammation on cancer on the basis of three perspectives, including inflammation with different durations (chronic and acute inflammation), different scopes (systemic and local inflammation) and different occurrence sequences (inflammation occurring after and before cancer). In addition, we also introduced bacteria/virus-based cancer immunotherapies. We perceive that inflammation may be a double-edged sword with cancer-promoting and cancer-suppressing functions in certain cases. We expect to further improve the understanding of the relationship between inflammation and cancer and provide a theoretical basis for further research on their complex interaction.

Expression profiles of miR-196, miR-132, miR-146a, and miR-134 in human colorectal cancer tissues in accordance with their clinical significance : Comparison regarding KRAS mutation

BACKGROUND

Colorectal cancer (CRC) is among the most widespread malignancies in the world. MicroRNA (miRNA) has been identified as an important modulator of the biological processes of the cells. This group of noncoding RNAs also has a pivotal function in the growth and development of human cancers, including CRC. Among these miRNAs, miR-196, miR-132, miR-146a, and miR-134 have fundamental impacts on the regulation of cancers. The current study aimed to investigate the involvement of these miRNAs in CRC patients.

METHODS

In this study, 50 pairs of tumor and tumor margin samples of CRC patients were investigated to assess the expression levels of miR-196, miR-132, miR-146a, and miR-134 in this cancer. For this purpose, firstly, quantitative real-time PCR (qRT-PCR) was applied. Also, KRAS mutation and clinicopathological characteristics of the CRC patients were analyzed in the study groups.

RESULTS

The findings demonstrated the overexpression of miR-196 (P-value = 0.0045) and miR-146a (P-value = 0.0033) in tumor tissues compared to controls. Conversely, the expression levels of miR-132 (P-value = 0.00032) and miR-134 (P-value < 0.0001) were downregulated in tumor tissues. Also, miR-146a was the only miRNA with significant expression change in the case of the KRAS gene mutation. Interestingly, the expression ratio of these miRNAs was significantly associated with some of the clinicopathological features of the patients, such as lymph node and distant metastases.

CONCLUSION

Our data demonstrated that these miRNAs appear to be promising novel biomarkers for early diagnosis of CRC and may pave the way for the future establishment of novel therapeutic options for CRC.

Cervical cancer development, chemoresistance, and therapy: a snapshot of involvement of microRNA

Cervical cancer (CC) is one of the leading causes of death in women due to cancer and a major concern in the developing world. Persistent human papilloma virus (HPV) infection is the major causative agent for CC. Besides HPV infection, genetic and epigenetic factors including microRNA (miRNA) also contribute to the malignant transformation. Earlier studies have revealed that miRNAs participate in cell proliferation, invasion and metastasis, angiogenesis, and chemoresistance processes by binding and inversely regulating the target oncogenes or tumor suppressor genes. Based on functions and mechanistic insights, miRNAs have been identified as cellular modulators that have an enormous role in diagnosis, prognosis, and cancer therapy. Signatures of miRNA could be used as diagnostic markers which are necessary for early diagnosis and management of CC. The therapeutic potential of miRNAs has been shown in CC; however, more comprehensive clinical trials are required for the clinical translation of miRNA-based diagnostics and therapeutics. Understanding the molecular mechanism of miRNAs and their target genes has been useful to develop miRNA-based therapeutic strategies for CC and overcome chemoresistance. In this review, we summarize the role of miRNAs in the development, progression, and metastasis of CC as well as chemoresistance. Further, we discuss the diagnostic and therapeutic potential of miRNAs to overcome chemoresistance and treatment of CC.

Association between the rs3733846 in the flanking region of miR-143/145 and risk of cervical squamous cell carcinoma

Aim: To investigate the effect of rs3733846 in the flanking region of miR-143/145 on susceptibility to cervical squamous cell carcinoma (CSCC). Materials & methods: We collected venous blood samples from 242 CSCC patients and 250 healthy controls. The rs3733846 polymorphism was genotyped by SnaPshot and Sanger sequencing. The expression of miR-143/145 in CSCC tissues was detected by quantitative real-time PCR. Results: The rs3733846 AG genotype was associated with a decreased risk of CSCC in genetic model (AGvs.AA: adjusted odds ratio [OR]: 0.44; 95% CI: 0.30-0.66; p < 0.001). Patients with the rs3733846 AG/GG genotypes had a reduced risk of developing poorly differential status (OR: 0.57; 95% CI: 0.33-0.98; p < 0.04) and lymph node metastasis (OR: 0.49; 95% CI: 0.26-0.92; p < 0.03). Conclusion: The rs3733846 in the flanking region of miR-143/145 was related to the susceptibility of CSCC.

Role of L1CAM in retinoblastoma tumorigenesis: identification of novel therapeutic targets

The study presented focuses on the role of the neuronal cell adhesion molecule L1 cell adhesion molecule (L1CAM) in retinoblastoma (RB), the most common malignant intraocular childhood tumor. L1CAM is differentially expressed in a variety of human cancers and has been suggested as a promising therapeutic target. We likewise observed differential expression patterns for L1CAM in RB cell lines and patient samples. The two proteases involved in ectodomain shedding of L1CAM (L1CAM sheddases: ADAM10 and ADAM17) were likewise differentially expressed in the RB cell lines investigated, and an involvement in L1CAM processing in RB cells could be verified. We also identified ezrin, galectin-3, and fibroblast growth factor basic as L1CAM signaling target genes in RB cells. Lentiviral L1CAM knockdown induced apoptosis and reduced cell viability, proliferation, growth, and colony formation capacity of RB cells, whereas L1CAM-overexpressing RB cells displayed the opposite effects. Chicken chorioallantoic membrane assays revealed that L1CAM depletion decreases the tumorigenic and migration potential of RB cells in vivo. Moreover, L1CAM depletion decreased viability and tumor growth of etoposide-resistant RB cell lines upon etoposide treatment in vitro and in vivo. Thus, L1CAM and its processing sheddases are potential novel targets for future therapeutic RB approaches.

MicroRNA-155 acts as a diagnostic and prognostic biomarker for oesophageal squamous cell carcinoma

MicroRNA-155 is over-expressed in many human cancers, but researches on its association with malignant oesophageal squamous cell carcinoma (ESCC) are limited. The aim of the present study was to evaluate the potential value of miR-155 as a biomarker for ESCC diagnosis and prognosis. In this study, we found that miR-155 was significantly increased in ESCC tissues compared with the paired adjacent tissues and healthy normal controls (p < .001), according to qRT-PCR, which suggested that miR-155 might act as an oncogene in ESCC. In addition, clinical features such as the depth of tumour invasion, tumour size, and TNM stage were all proved to impact the expression of miR-155 (p < .01). Then, ROC curve analysis, reaching an AUC of 0.870, and a sensitivity and specificity of 83.5% and 77.5%, respectively, revealed that miR-155 was a predictive factor for ESCC. As well, high expression of miR-155 was associated with poor overall survival of the patients (log-rank test, p = .004), according to Kaplan-Meier analysis. MiR-155 might be an independent predictor for overall survival in ESCC patients, manifested by Cox regression analysis (HR = 16.94, 95%CI = 3.33-86.12, p = .001). Taken together, miR-155 could be an independent diagnostic and prognostic biomarker for ESCC.

Angiogenesis-related non-coding RNAs and gastrointestinal cancer

Gastrointestinal (GI) cancers are among the main reasons for cancer death globally. The deadliest types of GI cancer include colon, stomach, and liver cancers. Multiple lines of evidence have shown that angiogenesis has a key role in the growth and metastasis of all GI tumors. Abnormal angiogenesis also has a critical role in many non-malignant diseases. Therefore, angiogenesis is considered to be an important target for improved cancer treatment. Despite much research, the mechanisms governing angiogenesis are not completely understood. Recently, it has been shown that angiogenesis-related non-coding RNAs (ncRNAs) could affect the development of angiogenesis in cancer cells and tumors. The broad family of ncRNAs, which include long non-coding RNAs, microRNAs, and circular RNAs, are related to the development, promotion, and metastasis of GI cancers, especially in angiogenesis. This review discusses the role of ncRNAs in mediating angiogenesis in various types of GI cancers and looks forward to the introduction of mimetics and antagonists as possible therapeutic agents.

Oncogenic HPV promotes the expression of the long noncoding RNA lnc-FANCI-2 through E7 and YY1

Long noncoding RNAs (lncRNAs) play diverse roles in biological processes, but their expression profiles and functions in cervical carcinogenesis remain unknown. By RNA-sequencing (RNA-seq) analyses of 18 clinical specimens and selective validation by RT-qPCR analyses of 72 clinical samples, we provide evidence that, relative to normal cervical tissues, 194 lncRNAs are differentially regulated in high-risk (HR)-HPV infection along with cervical lesion progression. One such lncRNA, lnc-FANCI-2, is extensively characterized because it is expressed from a genomic locus adjacent to the FANCI gene encoding an important DNA repair factor. Both genes are up-regulated in HPV lesions and in in vitro model systems of HR-HPV18 infection. We observe a moderate reciprocal regulation of lnc-FANCI-2 and FANCI in cervical cancer CaSki cells. In these cells, lnc-FANCI-2 is transcribed from two alternative promoters, alternatively spliced, and polyadenylated at one of two alternative poly(A) sites. About 10 copies of lnc-FANCI-2 per cell are detected preferentially in the cytoplasm. Mechanistically, HR-HPVs, but not low-risk (LR)-HPV oncogenes induce lnc-FANCI-2 in primary and immortalized human keratinocytes. The induction is mediated primarily by E7, and to a lesser extent by E6, mostly independent of p53/E6AP and pRb/E2F. We show that YY1 interacts with an E7 CR3 core motif and transactivates the promoter of lnc-FANCI-2 by binding to two critical YY1-binding motifs. Moreover, HPV18 increases YY1 expression by reducing miR-29a, which targets the 3' untranslated region of YY1 mRNA. These data have provided insights into the mechanisms of how HR-HPV infections contribute to cervical carcinogenesis.

Cervical Cancer Diagnosis: Insights into Biochemical Biomarkers and Imaging Techniques

Cervical malignancy is known as one of the important cancers which is originated from cervix. This malignancy has been observed in women infected with papillomavirus who had regular oral contraceptives, multiple pregnancies, and sexual relations. Early and fast cervical cancer diagnosis is known as two important aspects of cervical cancer therapy. Several investigations indicated that early and fast detection of cervical cancer could be associated with better treatment process and increasing survival rate of patients with this malignancy. Imaging techniques are very important diagnosis tools that could be employed for diagnosis and following responses to therapy in various cervical cancer stages. Multiple lines of evidence indicated that utilization of imaging techniques is related to some limitations (i.e. high cost, and invasive effects). Hence, it seems that along with using imaging techniques, finding and developing new biomarkers could be useful in the diagnosis and treatment of subjects with cervical cancer. Taken together, many studies showed that a variety of biomarkers including, several proteins, mRNAs, microRNAs, exosomes and polymorphisms might be introduced as prognostic, diagnostic and therapeutic biomarkers in cervical cancer therapy. In this review article, we highlighted imaging techniques as well as novel biomarkers for the diagnosis of cervical cancer.

MicroRNAs and Long Noncoding RNAs as Novel Therapeutic Targets in Estrogen Receptor-Positive Breast and Ovarian Cancers

Aromatase inhibitors (AIs) such as anastrozole, letrozole, and exemestane have shown to prevent metastasis and angiogenesis in estrogen receptor (ER)-positive breast and ovarian tumors. They function primarily by reducing estrogen production in ER-positive post-menopausal breast and ovarian cancer patients. Unfortunately, current AI-based therapies often have detrimental side-effects, along with acquired resistance, with increased cancer recurrence. Thus, there is an urgent need to identify novel AIs with fewer side effects and improved therapeutic efficacies. In this regard, we and others have recently suggested noncoding RNAs (ncRNAs), specifically microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), as potential molecular targets for utilization in modulating cancer hallmarks and overcoming drug resistance in several cancers, including ER-positive breast and ovarian cancer. Herein, we describe the disruptive functions of several miRNAs and lncRNAs seen in dysregulated cancer metabolism, with a focus on the gene encoding for aromatase (CYP19A1 gene) and estrogen synthesis as a novel therapeutic approach for treating ER-positive breast and ovarian cancers. Furthermore, we discuss the oncogenic and tumor-suppressive roles of several miRNAs (oncogenic miRNAs: MIR125b, MIR155, MIR221/222, MIR128, MIR2052HG, and MIR224; tumor-suppressive miRNAs: Lethal-7f, MIR27B, MIR378, and MIR98) and an oncogenic lncRNA (MIR2052HG) in aromatase-dependent cancers via transcriptional regulation of the CYP19A1 gene. Additionally, we discuss the potential effects of dysregulated miRNAs and lncRNAs on the regulation of critical oncogenic molecules, such as signal transducer, and activator of transcription 3, β-catenin, and integrins. The overall goal of this review is to stimulate further research in this area and to facilitate the development of ncRNA-based approaches for more efficacious treatments of ER-positive breast and ovarian cancer patients, with a slight emphasis on associated treatment–delivery mechanisms.

Identification and Characterization of Osmoregulation Related MicroRNAs in Gills of Hybrid Tilapia Under Three Types of Osmotic Stress

Researchers have increasingly suggested that microRNAs (miRNAs) are small non-coding RNAs that post-transcriptionally regulate gene expression and protein translation in organs and respond to abiotic and biotic stressors. To understand the function of miRNAs in osmotic stress regulation of the gills of hybrid tilapia (Oreochromis mossambicus ♀ × Oreochromis urolepis hornorum ♂), high-throughput Illumina deep sequencing technology was used to investigate the expression profiles of miRNAs under salinity stress (S, 25‰), alkalinity stress (A, 4‰) and salinity-alkalinity stress (SA, S: 15‰, A: 4‰) challenges. The results showed that 31, 41, and 27 upregulated and 33, 42, and 40 downregulated miRNAs (P < 0.05) were identified in the salt stress, alkali stress, and saline-alkali stress group, respectively, which were compared with those in the control group (C). Fourteen significantly differently expressed miRNAs were selected randomly and then validated by a quantitative polymerase chain reaction. On the basis of Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis, genes related to osmoregulation and biosynthesis were enriched in the three types of osmotic stress. In addition, three miRNAs and three predicted target genes were chosen to conduct a quantitative polymerase chain reaction in the hybrid tilapia and its parents during 96-h osmotic stress. Differential expression patterns of miRNAs provided the basis for research data to further investigate the miRNA-modulating networks in osmoregulation of teleost.

Epstein-Barr virus, human papillomavirus and herpes simplex virus 2 co-presence severely dysregulates miRNA expression

This cross-sectional study evaluated the expression of miR-let-7b, miR-21, miR-125b, miR-143, miR-145, miR-155, miR-182, miR-200c, p53 gene, Ki67, SCCA1 and CD4+ T-cell counts among 319 women, to Epstein-Barr virus, human papillomavirus and herpes simplex virus 2 mono-infections and co-infections, using enzyme-linked immunosorbent assay and reverse transcriptase-polymerase chain reaction methods. This study suggests that malignancies associated with viral co-infection could be diagnosed early by monitoring cluster of differentiation 4+ T-cell counts and serum expression of miR-145 and miR-182.

The Association between Five Genetic Variants in MicroRNAs (rs2910164, rs11614913, rs3746444, rs11134527, and rs531564) and Cervical Cancer Risk: A Meta-Analysis

The objective of this study was to conduct a meta-analysis to systematically summarize and investigate the association of miRNA-124 rs531564, miRNA-218 rs11134527, miRNA-146a rs2910164, miRNA-196a2 rs11614913, and miRNA-499 rs3746444 polymorphisms with cervical cancer. A systematic review was performed to identify relevant studies using Embase and PubMed databases. A chi-square-based Q-test combined with the inconsistency index (I 2) was used to check the heterogeneity between studies. A total of six case-control studies on rs2910164 and rs11614913, 4 studies on rs3746444 and rs11134527, and three studies on rs531564 were included. No evidence of association was found between miR-146a rs2910164, miR-196a2 rs11614913, miRNA-499 rs3746444, and miR-218 rs11134527 polymorphisms and cervical cancer risk in all the genetic models. The miR-124 rs531564 polymorphism was associated with a statistically increased risk of cervical cancer in a homozygote model (CC vs. GG: OR = 2.87, 95% CI: 1.40-5.91, P H = 0.887), dominant model (GC/CC vs. GG: OR = 1.38, 95% CI: 1.07-1.80, P H = 0.409), and recessive model (CC vs. GC/GG: OR = 2.26, 95% CI: 1.58-3.23, P H = 0.979). However, this finding should be interpreted with caution for limited samples and heterogeneity. Large-scale and well-designed studies are needed to validate our result.

Downregulation of miR-143/145 Cluster in Breast Carcinoma Specimens: Putative Role of DNA Oncoviruses

Background: The DNA oncoviruses, including human papillomavirus (HPV) and Epstein-Barr virus (EBV) are among the most important infectious agents involved in breast carcinogenesis. These oncoviruses have a broad disrupting effect on cellular miRNAs and their functions, by which they contribute to carcinogenesis. Objectives: In this investigation, we evaluated the correlation between HPV and EBV and the expression level of tumor suppressor miRNAs (miR-143 and 145), clinical outcomes, and their association with stimulating inflammatory cytokines in patients with breast carcinoma. Methods: In our case-control study, 35 cancerous tissues and 35 adjacent non-cancerous tissues were collected from 35 patients. Nested-PCR was set up for the detection of HPV and EBV genomes, and RT-qPCR was used for miRNA expression in the case and control groups. In addition, serum specimens were obtained from all patients (n = 35) and healthy controls (n = 35) to determine the IL-8 serum concentration. Results: We found HPV and EBV in 14.2% (10/70) and 7% (5/70) of all samples, respectively. The distributions of positive samples in the case and control groups were 25.7% (9/35) and 2.9% (1/35) (P = 0.006) for HPV and 11.4% (4/35) and 2.9% (1/35) (P = 0.164) for EBV, respectively. Besides, RT-qPCR showed that miR-143 and miR-145 were significantly downregulated in HPV and EBV-infected cases compared to non-infected ones (P < 0.05). Data also indicated that the promotion of metastasis status was related to miR-143/145 downregulation and HPV infection (P = 0.003). No significant difference was found in serum IL-8 concentration concerning viral infections. Conclusions: Our results suggested the possible involvement of viral infections in breast carcinogenesis and adverse clinical outcomes by downregulating miR-143/145.

Inverse correlation of miR-27a-3p and CDH5 expression serves as a diagnostic biomarker of proliferation and metastasis of clear cell renal carcinoma

BACKGROUND

Cadherin-5 (CDH5) is aberrantly expressed in a variety of human cancers and plays an important role in angiogenesis. The present study provides further insight into the role of miR-27a-3p in the regulation of CDH5 expression in renal clear cell carcinoma (ccRCC).

METHODS

Thedysregulation of CDH5 expression in ccRCC and its association with clinicopathological characteristics were analyzed using the TCGA database. A meta-analysis was performed to verify the alteration of CDH5 expression in ccRCC using the GEO database. Quantitative RT-PCR and immunohistochemical staining were applied to assess the transcriptional and protein levels of CDH5. TargetScan and Tarbase were employed to predict the miRNAs with the potential to target mRNA of CDH5.

RESULTS

The mRNA level of CDH5 in ccRCCwas significantly higher than in normal tissue. CDH5 mRNA expression could therefore serve as a potential diagnostic biomarker for ccRCC (AUC = 0.844). However, the reduced CDH5 transcription levels were significantly correlated with patients in the T3-4 stage, lymph node, and distant metastasis, as well as with a worse clinical outcome. We further observed that CDH5, at the protein level, was almost absent in ccRCC samples. In addition, a few databases screen showed that mir-27a-3p is a highly conserved miRNA targeting CDH5. The expression of mir-27a-3p was significantly elevated in ccRCC tissues in contrast to normal tissues. Importantly, it was positively associated with the T3-4 stage and M stage, respectively, suggesting that the expression level of mir-27a-3p could serve as a diagnostic biomarker for ccRCC (AUC = 0.775).

CONCLUSION

Our data suggest that thereduced translational level of CDH5 in ccRCC was related to the overexpression of mir-27a-3p. The higher mir-27a-3p and lower CDH5 expression significantly correlated with advanced clinical stages for ccRCC patients.

To study the role of pre-treatment microRNA (micro ribonucleic acid) expression as a predictor of response to chemoradiation in locally advanced carcinoma cervix

Background

Concurrent chemoradiotherapy followed by brachytherapy is the standard of care in locally advanced carcinoma cervix. There is no prognostic factor at present to predict the outcome of disease in locally advanced carcinoma cervix.

Aim

Differential expression of microRNAs can be used as biomarkers to predict clinical response in locally advanced carcinoma cervix patients.

Methods

Thirty‐two patients of locally advanced carcinoma cervix with International Federation of Gynecology and Obstetrics Stage IB‐IVA were enrolled from 2017 to 2018. Expression of microRNA‐9 5p, ‐31 3p, ‐100 5p, ‐125a 5p, ‐125b‐5p, and –200a 5p in formalin‐fixed paraffin embedded (FFPE) biopsied tissue were analyzed by real time quantitative reverse transcriptase polymerase chain reaction (RT qPCR). Pretreatment evaluation was done with clinical examination and MRI pelvis. All patients received concurrent chemoradiotherapy followed by brachytherapy. Patients were evaluated for the clinical response after 3 months of treatment, with clinical examination and MRI pelvis scan using RECIST 1.1 criteria. Patients with no residual disease were classified as Complete responders (CR) and with residual or progressive disease were classified as Nonresponders (NR). Results were statistically analyzed using Mann Whiney U test to examine significant difference between the expression of microRNA between complete responders (CR) and nonresponders (NR).

Results

microRNA‐100 5p was upregulated in complete responders (CR) which showed a trend towards statistical significance (p value = 0.05).

Conclusion

microRNA‐100 5p can serve as a potential molecular biomarker in predicting clinical response to chemoradiation in locally advanced Carcinoma cervix. Its role should be further investigated in a larger study population.

Small Non-Coding-RNA in Gynecological Malignancies

Gynecologic malignancies, which include cancers of the cervix, ovary, uterus, vulva, vagina, and fallopian tube, are among the leading causes of female mortality worldwide, with the most prevalent being endometrial, ovarian, and cervical cancer. Gynecologic malignancies are complex, heterogeneous diseases, and despite extensive research efforts, the molecular mechanisms underlying their development and pathology remain largely unclear. Currently, mechanistic and therapeutic research in cancer is largely focused on protein targets that are encoded by about 1% of the human genome. Our current understanding of 99% of the genome, which includes noncoding RNA, is limited. The discovery of tens of thousands of noncoding RNAs (ncRNAs), possessing either structural or regulatory functions, has fundamentally altered our understanding of genetics, physiology, pathophysiology, and disease treatment as they relate to gynecologic malignancies. In recent years, it has become clear that ncRNAs are relatively stable, and can serve as biomarkers for cancer diagnosis and prognosis, as well as guide therapy choices. Here we discuss the role of small non-coding RNAs, i.e., microRNAs (miRs), P-Element induced wimpy testis interacting (PIWI) RNAs (piRNAs), and tRNA-derived small RNAs in gynecological malignancies, specifically focusing on ovarian, endometrial, and cervical cancer.

Integrated bioinformatic analysis of miR-15a/16-1 cluster network in cervical cancer

The miR-15a/16-1 cluster is abnormally expressed in cervical cancer (CC) tissues and plays a vital role in cervical carcinogenesis. We aimed to evaluate the miR-15a/16-1 expression in healthy and cancerous cervical tissues, identify the associated networks, and to test its prognostic significance. miR-15a/16-1-MC expressions were analyzed in TCGA-CESC datasets by UALCAN, GEPIA2, and Datasetviewer. miR-15a/16-1 validated targets were extracted from mirTarBase and in silico functional analysis of the target genes were performed using WebGestalt. The interaction networks were constructed by the miRNet, STRING, and NetworkAnalyst tools. The prognostic significance and metastatic potential of the target genes were predicted using UALCAN and HCMDB. The FDA approved drugs to target miR-15a/16-1 and target gene network in CC were performed using DGIdb, STITCH and PanDrugs. TCGA-CESC and GEO data analysis suggested significant overexpression of miR-15a/16-1 in CC samples. The Kaplan-Meier survival analysis showed that miR-15a and its four target genes (BCL2, CCNE1, NUP50, and RBPJ) influence the overall survival of CC patients. Among the 66 differentially expressed target genes, 12 of them are linked to head, neck, or lung metastasis. Functional enrichment analysis predicted the association of this cluster with p53 signaling, human papillomavirus infection, PI3-AKT signaling pathway, and pathways in cancer. Drug-gene interaction analysis showed 52 potential FDA approved drugs to interact with the miR-15a/16-1 target genes. Nine of the 52 drugs are currently used as a chemotherapeutic agent for the treatment of CC patients. The present study shows that miR-15a/16-1 expression can be used as a clinical marker and target for therapy in CC.

The Role of Non-Canonical Hsp70s (Hsp110/Grp170) in Cancer

Although cancers account for over 16% of all global deaths annually, at present, no reliable therapies exist for most types of the disease. As protein folding facilitators, heat shock proteins (Hsps) play an important role in cancer development. Not surprisingly, Hsps are among leading anticancer drug targets. Generally, Hsp70s are divided into two main subtypes: canonical Hsp70 (Escherichia coli Hsp70/DnaK homologues) and the non-canonical (Hsp110 and Grp170) members. These two main Hsp70 groups are delineated from each other by distinct structural and functional specifications. Non-canonical Hsp70s are considered as holdase chaperones, while canonical Hsp70s are refoldases. This unique characteristic feature is mirrored by the distinct structural features of these two groups of chaperones. Hsp110/Grp170 members are larger as they possess an extended acidic insertion in their substrate binding domains. While the role of canonical Hsp70s in cancer has received a fair share of attention, the roles of non-canonical Hsp70s in cancer development has received less attention in comparison. In the current review, we discuss the structure-function features of non-canonical Hsp70s members and how these features impact their role in cancer development. We further mapped out their interactome and discussed the prospects of targeting these proteins in cancer therapy.

Secondary Structural Model of MALAT1 Becomes Unstructured in Chronic Myeloid Leukemia and Undergoes Structural Rearrangement in Cervical Cancer

Long noncoding RNAs (lncRNAs) influence cellular function through binding events that often depend on the lncRNA secondary structure. One such lncRNA, metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), is upregulated in many cancer types and has a myriad of protein- and miRNA-binding sites. Recently, a secondary structural model of MALAT1 in noncancerous cells was proposed to form 194 hairpins and 13 pseudoknots. That study postulated that, in cancer cells, the MALAT1 structure likely varies, thereby influencing cancer progression. This work analyzes how that structural model is expected to change in K562 cells, which originated from a patient with chronic myeloid leukemia (CML), and in HeLa cells, which originated from a patient with cervical cancer. Dimethyl sulfate-sequencing (DMS-Seq) data from K562 cells and psoralen analysis of RNA interactions and structure (PARIS) data from HeLa cells were compared to the working structural model of MALAT1 in noncancerous cells to identify sites that likely undergo structural alterations. MALAT1 in K562 cells is predicted to become more unstructured, with almost 60% of examined hairpins in noncancerous cells losing at least half of their base pairings. Conversely, MALAT1 in HeLa cells is predicted to largely maintain its structure, undergoing 18 novel structural rearrangements. Moreover, 50 validated miRNA-binding sites are affected by putative secondary structural changes in both cancer types, such as miR-217 in K562 cells and miR-20a in HeLa cells. Structural changes unique to K562 cells and HeLa cells provide new mechanistic leads into how the structure of MALAT1 may mediate cancer in a cell-type specific manner.

MicroRNA-205-5p targets the HOXD9-Snail1 axis to inhibit triple negative breast cancer cell proliferation and chemoresistance

MicroRNA-205 (miR-205) is believed to be related to the progress of tumors. HOXD9 has been proved to be expressed abnormally in several kinds of cancers. However, the role of miR-205 and HOXD9 in breast cancer remains unclear. The biological role of miR-205 in breast cancer cell proliferation and chemoresistance was investigated. The expression of miR-205 in clinical tissues and breast cancer cell lines were analyzed using quantitative real-time PCR test (qRT-PCR). Overexpression and knockdown models of miR-205 were established to study cell proliferation and chemotherapy-resistant. Moreover, the potential relationships between miR-205 and HOXD9/Snail1 were measured using qRT-PCR, western blot, and chemotherapy-resistant study. miR-205 was lowly expressed in breast cancer tissues and cell lines. Overexpression of miR-205 could inhibit cell proliferation and chemotherapy-resistance. Moreover, we proved that miR-205 could target the HOXD9-Snail1 axis to suppress triple negative breast cancer cell proliferation and chemoresistance. The activation of Snail1 gene by HOXD9 was also proved in this study. The present study may provide a novel insight for the therapeutic strategies of breast cancer through targeting miR-205/HOXD9/Snail1.

miR-325-3p Promotes the Proliferation, Invasion, and EMT of Breast Cancer Cells by Directly Targeting S100A2

This study was designed to investigate the precise mechanisms of miR-325-3p/S100A2 axis in breast cancer (BC). In this study, we found that the level of miR-325-3p was dramatically increased in BC tissues and cell lines, and the expression of S100A2 was significantly decreased. Also, the high level of miR-325-3p was closely associated with low expression of S100A2 in BC tissues. Moreover, introduction of miR-325-3p significantly promoted proliferation, invasion, and EMT of BC cells. Bioinformatics analysis predicted that the S100A2 was a potential target gene of miR-325-3p. Luciferase reporter assay demonstrated that miR-325-3p could directly target S100A2. In addition, miR-325-3p overexpression had similar effects with knockdown of S100A2 on BC cells. Overexpression of S100A2 in BC cells partially reversed the promoted effects of miR-325-3p mimic. Overexpression of miR-325-3p promoted cell proliferation, invasion, and EMT of BC cells by directly downregulating S100A2 expression.

Overexpression of microRNA-21 decreased the sensitivity of advanced cervical cancer to chemoradiotherapy through SMAD7

Drug resistance is a major problem in the treatment of advanced cervical cancer. The oncogenic microRNA-21 (miR-21) is involved in drug resistance in various cancers. However, the regulatory role of miR-21 and its target, Smad7 in drug resistance of cervical cancer remains to be elucidated. We compared miR-21 and Smad7 levels in human samples from chemoradiotherapy-resistance cervical cancer (resistant group) and chemoradiotherapy-sensitive cervical cancer (sensitive group) patients. Then, the miR-21 level was manipulated in HeLa and SiHa cervical cancer cells and the Smad7 level was determined by PCR and western blot. We also manipulated miR-21, Smad7 or both in cells, and measured cell viability using cell counting kit-8 method and epithelial-mesenchymal transition (EMT) biomarkers using Western blot. In human samples, resistant group has significantly higher miR-21 and lower Smad7 levels than sensitive group. In-vitro analysis demonstrated downregulated Smad7 after transfection with miR-21 mimics. When cells were transfected with Smad7 inhibitor, we observed increased drug resistance and changed levels of EMT-biomarkers after chemoradiotherapy, suggesting that downregulation of Smad7 decreased the sensitivity through EMT. When the cells were transfected with miR-21 inhibitor alone, we found increased sensitivity to chemoradiotherapy through EMT. However, such effects were attenuated when Smad7 was also downregulated after cotransfection. In summary, we provided clinical and experimental evidence that decreased miR-21 may improve drug resistance through EMT by direct targeting Smad7 in cervical cancer. Our data suggest that miR-21/Smad7 pathway may be an effective target for drug resistance in cervical cancer treatment.