The Role of MicroRNAs in the Metastatic Process of High-Risk HPV-Induced Cancers

MicroRNAs in cancer metastasis: biological and therapeutic implications

Cancer metastasis is the primary cause of cancer-related deaths. The seeding of primary tumours at a secondary site is a highly inefficient process requiring substantial alterations in the genetic architecture of cancer cells. These alterations include significant changes in global gene expression patterns. MicroRNAs are small, non-protein coding RNAs which play a central role in regulating gene expression. Here, we focus on microRNA determinants of cancer metastasis and examine microRNA dysregulation in metastatic cancer cells. We dissect the metastatic process in a step-wise manner and summarise the involvement of microRNAs at each step. We also discuss the advantages and limitations of different microRNA-based strategies that have been used to target metastasis in pre-clinical models. Finally, we highlight current clinical trials that use microRNA-based therapies to target advanced or metastatic tumours.

Interrelation between extracellular vesicles miRNAs with chronic lung diseases

Extracellular vehicles (EVs) are nanoscale lipid bilayer vesicles that carry biologically active biomolecule cargos like proteins, lipids, and nucleic acids (DNA, RNA) outside of the cell. Blood (serum/plasma), urine, and bronchoalveolar lavage fluid are all examples of biofluids from which they may be collected. EVs play a vital role in intracellular communication. The molecular signature of EVs largely depends on the parental cell's status. EVs are classified into two groups, (1) exosomes (originated by endogenous route) and (2) microvesicles (originated from the plasma membrane, also known as ectosomes). The quantity and types of EV cargo vary during normal conditions compared to pathological conditions (chronic inflammatory lung diseases or lung cancer). Consequently, EVs contain novel biomarkers that differ based on the cell type of origin and during lung diseases. Small RNAs (e.g., microRNAs) are transported by EVs, which is one of the most rapidly evolving research areas in the field of EVs biology. EV-mediated cargos transport small RNAs that can result in reprograming the target/recipient cells. Multiple chronic inflammatory lung illnesses, such as chronic obstructive pulmonary disease, asthma, pulmonary hypertension, pulmonary fibrosis, cystic fibrosis, acute lung injury, and lung cancer, have been demonstrated to be regulated by EV. In this review, we will consolidate the current knowledge and literature on the novel role of EVs and their small RNAs concerning chronic lung diseases (CLDs). Additionally, we will also provide better insight into the clinical and translational impact of mesenchymal stem cells-derived EVs as novel therapeutic agents in treating CLDs.

It Takes Two to Tango: A Review of Oncogenic Virus and Host Microbiome Associated Inflammation in Head and Neck Cancer

Simple Summary

Certain viruses, specifically, human papillomavirus (HPV) and Epstein–Barr virus (EBV), have been linked with the development of head and neck cancer. In this study, we review the mechanisms by which (these) viruses lead to cellular transformation and a chronic inflammatory state. Given that the head and neck host a rich microbiome (which itself is intrinsically linked to inflammation), we scrutinize the literature to highlight the interplay between viruses, cellular transformation, inflammation, and the local host microbiome in head and neck cancer.

Abstract

While the two primary risk factors for head and neck squamous cell carcinoma (HNSCC) are alcohol and tobacco, viruses account for an important and significant upward trend in HNSCC incidence. Human papillomavirus (HPV) is the causative agent for a subset of oropharyngeal squamous cell carcinoma (OPSCC)—a cancer that is impacting a rapidly growing group of typically middle-aged non-smoking white males. While HPV is a ubiquitously present (with about 1% of the population having high-risk oral HPV infection at any one time), less than 1% of those infected with high-risk strains develop OPSCC—suggesting that additional cofactors or coinfections may be required. Epstein–Barr virus (EBV) is a similarly ubiquitous virus that is strongly linked to nasopharyngeal carcinoma (NPC). Both of these viruses cause cellular transformation and chronic inflammation. While dysbiosis of the human microbiome has been associated with similar chronic inflammation and the pathogenesis of mucosal diseases (including OPSCC and NPC), a significant knowledge gap remains in understanding the role of bacterial-viral interactions in the initiation, development, and progression of head and neck cancers. In this review, we utilize the known associations of HPV with OPSCC and EBV with NPC to investigate these interactions. We thoroughly review the literature and highlight how perturbations of the pharyngeal microbiome may impact host-microbiome-tumor-viral interactions—leading to tumor growth.

Upregulated miRNAs on the TP53 and RB1 Binding Seedless Regions in High-Risk HPV-Associated Penile Cancer

Cancer development by the human papillomavirus (HPV) infection can occur through the canonical HPV/p53/RB1 pathway mediated by the E2/E6/E7 viral oncoproteins. During the transformation process, HPV inserts its genetic material into host Integration Sites (IS), affecting coding genes and miRNAs. In penile cancer (PeCa) there is limited data on the miRNAs that regulate mRNA targets associated with HPV, such as the TP53 and RB1 genes. Considering the high frequency of HPV infection in PeCa patients in Northeast Brazil, global miRNA expression profiling was performed in high-risk HPV-associated PeCa that presented with TP53 and RB1 mRNA downregulated expression. The miRNA expression profile of 22 PeCa tissue samples and five non-tumor penile tissues showed 507 differentially expressed miRNAs: 494 downregulated and 13 upregulated (let-7a-5p, miR-130a-3p, miR-142-3p, miR-15b-5p miR-16-5p, miR-200c-3p, miR-205-5p, miR-21-5p, miR-223-3p, miR-22-3p, miR-25-3p, miR-31-5p and miR-93-5p), of which 11 were identified to be in HPV16-IS and targeting TP53 and RB1 genes. One hundred and thirty-one and 490 miRNA binding sites were observed for TP53 and RB1, respectively, most of which were in seedless regions. These findings suggest that up-regulation of miRNA expression can directly repress TP53 and RB1 expression by their binding sites in the non-canonical seedless regions.

The E6 and E7 proteins of beta3 human papillomavirus 49 can deregulate both cellular and extracellular vesicles-carried microRNAs

BACKGROUND

The β3 human papillomavirus (HPV)49 induces immortalization of primary keratinocytes through the action of E6 and E7 oncoproteins with an efficiency similar to alpha high risk (HR)-HPV16. Since HR-HPV oncoproteins are known to alter microRNA (miRNA) expression and extracellular vesicle (EV) production, we investigated the impact of HPV49 E6 and E7 proteins on miRNA profile and EV expression, and their involvement in the control of cell proliferation.

METHODS

The miRNA expression was evaluated by a miRNA array and validated by RT-qPCR in primary human keratinocytes immortalized by β3 HPV49 (K49) or α9 HR-HPV16 (K16), and in EVs from K49 and K16. The modulation of miRNA target proteins was investigated by immunoblotting analyses.

RESULTS

By comparing miRNA expression in K49 and K16 and the derived EVs, six miRNAs involved in HPV tumorigenesis were selected and validated. MiR-19a and -99a were found to be upregulated and miR-34a downregulated in both cell lines; miR-17 and -590-5p were upregulated in K49 and downmodulated in K16; miR-21 was downregulated only in K16. As for EV-carried miRNAs, the expression of miR-17, -19a, -21 and -99a was decreased and miR-34a was increased in K49 EVs. In K16 EVs, we revealed the same modulation of miR-19a, -34a, and -99a observed in producing cells, while miR-21 was upregulated. Cyclin D1, a common target of the selected miRNAs, was downmodulated in both cell lines, whereas cyclin-dependent kinase 4 was down-modulated in K49 but upregulated in K16.

CONCLUSION

These data suggest that E6 and E7 proteins of β3 HPV49 and α9 HR-HPV16 affect key factors of cell cycle control by indirect mechanisms based on miRNA modulation.

MicroRNA-92a-3p Enhances Cisplatin Resistance by Regulating Krüppel-Like Factor 4-Mediated Cell Apoptosis and Epithelial-to-Mesenchymal Transition in Cervical Cancer

Recent studies have confirmed the existence and key roles of microRNA (miRNAs) in cancer drug resistance, including cervical cancer (CC). The present study aims to establish a novel role for miR-92a-3p and its associated gene networks in cisplatin (DDP) resistance of CC. First, the disparities in miRNA expression between CC tissues and adjacent normal tissues were screened based on GSE19611 microarray data that retrieved from Gene Expression Omnibus (GEO), and we identified several miRs that were significantly downregulated or upregulated in CC tissues including miR-92a-3p. Moreover, miR-92a-3p was significantly up-regulated in DDP-resistant cells and was the most differently expressed miRNA. Functionally, knockdown of miR-92a-3p increased the sensitivity of DDP-resistant cells to DDP via inhibiting cell proliferation, migration and invasion, and promoting apoptosis. Conversely, overexpression of miR-92a-3p significantly induced DDP resistance in CC parental cells including HeLa and SiHa cells. Moreover, Krüppel-like factor 4 (KLF4) was identified as a direct target of miR-92a-3p, and an obvious inverse correlation was observed between the expression of miR-92a-3p and KLF4 in 40 pairs of cancer tissues. Furthermore, KLF4 knockdown reversed the promoting effect of miR-92a-3p inhibition on DDP sensitivity in DDP-resistant CC cells. Besides, high expression of miR-92a-3p was associated with DDP resistance, as well as a short overall survival in clinic. Taken together, these findings provide important evidence that miR-92a-3p targets KLF4 and is significant in DDP resistance in CC, indicating that miR-92a-3p may be an attractive target to increase DDP sensitivity in clinical CC treatment.

Genetic Predisposition to Persistent Human Papillomavirus-Infection and Virus-Induced Cancers

Human papillomaviruses (HPVs) are the most common sexually transmitted pathogens worldwide and among the more than 200 identified HPV types, approximately 15 high risk (HR-HPV) types are oncogenic, being strongly associated with the development of cervical cancer, anogenital cancers and an increasing fraction of head and neck squamous cell carcinomas (HNSCC). HPV-associated cervix cancer accounts for 83% of HPV-attributable cancers, and more than two-thirds of those cases occur in developing countries. Despite the high frequency of HPV infections, in most cases, the virus is cleared by the host immune response and only a small proportion of infected individuals develop persistent infections that can result in malignant transformation, indicating that other elements, including biological, genetic and environmental factors may influence the individual susceptibility to HPV-associated cancers. Previous studies have quantified that heritability, in the form of genetic variants, common in the general population, is implicated in nearly 30% of cervical cancers and a large number of studies conducted across various populations have identified genetic variants that appear to be associated with genes that predispose or protect the host to HPV infections thereby affecting individual susceptibility to HPV-associated cancers. In this article, we provide an overview of gene association studies on HPV-associated cancers with emphasis on genome-wide association study (GWAS) that have identified novel genetic factors linked to HPV infection or HPV-associated cancers.

Non-Coding RNAs and Reactive Oxygen Species–Symmetric Players of the Pathogenesis Associated with Bacterial and Viral Infections

Infections can be triggered by a wide range of pathogens. However, there are few strains of bacteria that cause illness, but some are quite life-threatening. Likewise, viral infections are responsible for many human diseases, usually characterized by high contagiousness. Hence, as bacterial and viral infections can both cause similar symptoms, it can be difficult to determine the exact cause of a specific infection, and this limitation is critical. However, recent scientific advances have geared us up with the proper tools required for better diagnoses. Recent discoveries have confirmed the involvement of non-coding RNAs (ncRNAs) in regulating the pathogenesis of certain bacterial or viral infections. Moreover, the presence of reactive oxygen species (ROS) is also known as a common infection trait that can be used to achieve a more complete description of such pathogen-driven conditions. Thus, this opens further research opportunities, allowing scientists to explore infection-associated genetic patterns and develop better diagnosis and treatment methods. Therefore, the aim of this review is to summarize the current knowledge of the implication of ncRNAs and ROS in bacterial and viral infections, with great emphasis on their symmetry but, also, on their main differences.

Understanding the Molecular Mechanism of miR-877-3p Could Provide Potential Biomarkers and Therapeutic Targets in Squamous Cell Carcinoma of the Cervix

No therapeutic targets and molecular biomarkers are available in cervical cancer (CC) management. In other cancer types, micro-RNA-877-3p (miR-877-3p) has been associated with events relevant for CC development. Thus, we aimed to determine miR-877-3p role in CC. miR-877-3p levels were examined by quantitative-PCR in 117 cervical lesions and tumors. Effects on CC cell proliferation, migration, and invasion were evaluated upon anti-miR-877-3p transfection. miR-877-3p dependent molecular mechanism was comprehensively explored by proteomics, dual-luciferase reporter assay, western blot, and immunohistochemistry. Cervical tumors expressed higher miR-877-3p levels than benign lesions. miR-877-3p promoted CC cell migration and invasion, at least partly by modulating cytoskeletal protein folding through the chaperonin-containing T-complex protein 1 complex. Notably, miR-877-3p silencing synergized with paclitaxel. Interestingly, miR-877-3p downregulated the levels of an in silico-predicted target, ZNF177, whose expression and subcellular location significantly distinguished high-grade squamous intraepithelial lesions (HSILs) and squamous cell carcinomas of the cervix (SCCCs). Cytoplasmic ZNF177 was significantly associated with worse progression-free survival in SCCC. Our results suggest that: (i) miR-877-3p is a potential therapeutic target whose inhibition improves paclitaxel effects; (ii) the expression and location of its target ZNF177 could be diagnostic biomarkers between HSIL and SCCC; and (iii) cytoplasmic ZNF177 is a poor-prognosis biomarker in SCCC.

Long non-coding RNAs regulate the hallmarks of cancer in HPV-induced malignancies

High-risk human papillomavirus (HPV) is the most frequent sexually transmitted agent worldwide and is responsible for approximately 5% of human cancers. Identifying novel biomarkers and therapeutic targets for these malignancies requires a deeper understanding of the mechanisms involved in the progression of HPV-induced cancers. Long non-coding RNAs (lncRNAs) are crucial in the regulation of biological processes. Importantly, these molecules are key players in the progression of multiple malignancies and are able to regulate the development of the different hallmarks of cancer. This review highlights the action of lncRNAs in the regulation of cellular processes leading to the typical hallmarks of cancer. The regulation of lncRNAs by HPV oncogenes, their targets and also their mechanisms of action are also discussed, in the context of HPV-induced malignancies. Overall, accumulating data indicates that lncRNAs may have a significant potential to become useful tools for clinical practice as disease biomarkers or therapy targets.

miRNA Expression Characterizes Histological Subtypes and Metastasis in Penile Squamous Cell Carcinoma

Although microRNAs are described as promising biomarkers in many tumor types, little is known about their role in PSCC. Thus, we attempted to identify miRNAs involved in tumor development and metastasis in distinct histological subtypes considering the impact of HPV infection. In a first step, microarray analyses were performed on RNA from formalin-fixed, paraffin-embedded tumor (22), and normal (8) tissue samples. Microarray data were validated for selected miRNAs by qRT-PCR on an enlarged cohort, including 27 tumor and 18 normal tissues. We found 876 significantly differentially expressed miRNAs (p ≤ 0.01) between HPV-positive and HPV-negative tumor samples by microarray analysis. Although no significant differences were detected between normal and tumor tissue in the whole cohort, specific expression patterns occurred in distinct histological subtypes, such as HPV-negative usual PSCC (95 differentially expressed miRNAs, p ≤ 0.05) and HPV-positive basaloid/warty subtypes (247 differentially expressed miRNAs, p ≤ 0.05). Selected miRNAs were confirmed by qRT-PCR. Furthermore, microarray data revealed 118 miRNAs (p ≤ 0.01) that were significantly differentially expressed in metastatic versus non-metastatic usual PSCC. The lower expression levels for miR-137 and miR-328-3p in metastatic usual PSCC were validated by qRT-PCR. The results of this study confirmed that specific miRNAs could serve as potential diagnostic and prognostic markers in single PSCC subtypes and are associated with HPV-dependent pathways.

The Role of microRNAs in the Cisplatin- and Radio-Resistance of Cervical Cancer

Cervical cancer is the fourth leading cause of cancer-related death among women worldwide. The chemotherapeutical agent cisplatin, a small platinum-based compound, is considered as the standard therapy for locally advanced cervical cancer or recurrent cancers, sometimes in combination with radiotherapy or other drugs. However, drug resistance and radio-resistance phenomena could reduce the life expectancy of cervical cancer patients. Resistance mechanisms are complex and often involve multiple cellular pathways in which microRNAs (miRNAs) play a fundamental role. miRNAs are a class of endogenous non-coding small RNAs responsible for post-transcriptional gene regulation. Convincing evidence demonstrates that several deregulated miRNAs are important regulators in the onset of drug and radioresistance in cervical cancer, thus underlying their potential applications in a clinical setting. In this review, we summarized the mechanisms by which miRNAs affect both cisplatin and radioresistance in cervical cancer. We also described the regulatory loops between miRNAs and lncRNAs promoting drug resistance. Besides, we reported evidence for the role of miRNAs in sensitizing cancer cells to cisplatin-based chemotherapy, and provided some suggestions for the development of new combined therapies for cervical cancer.

Association of cervicovaginal dysbiosis mediated HPV infection with cervical intraepithelial neoplasia

Cellular transformation to malignancy is a multifactorial process strongly linked with microbiome dysbiosis. The female reproductive tract (FRT) is inhabited by specific Lactobacillus spp which play a significant role in maintaining a homeostatic balance and providing resistance to perturbation. Any imbalance in the resident microbiota of the FRT results in cervicovaginal dysbiosis and increased predisposition to viral and bacterial infections. In the present review, we discuss the critical role played by the cervicovaginal microbiome in maintaining cervicovaginal homeostasis. Loss of the mutualistic relationship between cervicovaginal microbiota and the host leads to increased susceptibility to Human papilloma virus (HPV) infection. HPV in coinfection with Chlamydia trachomatis has been linked with increased risk for cellular transformation. The progression to cervical neoplasia is a multistep process regulated by cellular and epigenetic changes mediated by oncogenes and miRNA. Exosomes derived from the infected cells play an important role in the pathological development and progression to cervical neoplasia as they harbor the regulatory molecules like miRNA, proteins and prooncogenic factors which may facilitate cellular transformation.

Experimental Models for Studying HPV-Positive and HPV-Negative Penile Cancer: New Tools for An Old Disease

Simple Summary

Penile cancer is an uncommon and understudied malignancy that is most commonly diagnosed in developing countries. Therapeutic advances have been slow, in part due to the lack of in vitro and in vivo models for testing new drugs before performing clinical trials. Recently, this difficulty has been partly overcome and multiple new pre-clinical models were reported. These important developments will help develop new therapies for penile cancer patients. The present review summarizes and discusses the available data concerning the pre-clinical models of penile cancer and their uses. Comparisons are drawn between different models, allowing researchers to choose the most adequate setting for their experiments. The remaining gaps in this array of penile cancer models are also discussed, in particular the lack of models for studying metastatic disease and cell lines representing tumors associated with human papillomavirus.

Abstract

Penile cancer is an uncommon malignancy that occurs most frequently in developing countries. Two pathways for penile carcinogenesis are currently recognized: one driven by human papillomavirus (HPV) infection and another HPV-independent route, associated with chronic inflammation. Progress on the clinical management of this disease has been slow, partly due to the lack of preclinical models for translational research. However, exciting recent developments are changing this landscape, with new in vitro and in vivo models becoming available. These include mouse models for HPV⁺ and HPV⁻ penile cancer and multiple cell lines representing HPV⁻ lesions. The present review addresses these new advances, summarizing available models, comparing their characteristics and potential uses and discussing areas that require further improvement. Recent breakthroughs achieved using these models are also discussed, particularly those developments pertaining to HPV-driven cancer. Two key aspects that still require improvement are the establishment of cell lines that can represent HPV⁺ penile carcinomas and the development of mouse models to study metastatic disease. Overall, the growing array of in vitro and in vivo models for penile cancer provides new and useful tools for researchers in the field and is expected to accelerate pre-clinical research on this disease.

Molecular landscape of recurrent cervical cancer

Cervical cancer (CC) is a major gynecological problem in developing and underdeveloped countries. Despite the significant advancement in early detection and treatment modalities, several patients recur. Moreover, the molecular mechanisms responsible for CC recurrence remains obscure. The patients with CC recurrence often show poor prognosis and significantly high mortality rates. The clinical management of recurrent CC depends on treatment history, site, and extent of the recurrence. Owing to poor prognosis and limited treatment options, recurrent CC often presents a challenge to the clinicians. Several in vitro, in vivo, and patient studies have led to the identification of the critical molecular changes responsible for CC recurrence. Both aberrant genetic and epigenetic modifications leading to altered cell signaling pathways have been reported to impact CC recurrence. Researchers are currently trying to dissect the molecular pathways in CC and translate these findings for better management of disease. This article attempts to review the existing knowledge of disease relapse, accompanying challenges, and associated molecular players in CC.

HRRD: a manually-curated database about the regulatory relationship between HPV and host RNA

HPV (Human papilloma virus) is a kind of small double-stranded DNA viruses which is extremely associated with different cancers. The roles HPV plays in the host were gradually identified through the interaction between it (including its early genes) and host RNA. In recent years, increasing numbers of studies in HPV-related cancers have been published showing the relationship between HPV and host RNA. Here, we present a database named HRRD, which contains the regulatory relationship between HPV and RNA (mRNA, miRNA and lncRNA). The information was extracted from 10,761 papers in PubMed (up to December 1st, 2019). In addition, the sequence map of HPV (198 genotypes) is also contained. HRRD was designed as a user-friendly web-based interface for data retrieval. It integrated the information of interaction between HPV and RNA, which reflects the relationship between HPV and host. We hope HRRD will further provide a comprehensive understanding of HPV in carcinogenesis and prognosis. HRRD is freely accessible at www.hmuhrrd.com/HRRD.

Human Papillomavirus 16-Transgenic Mice as a Model to Study Cancer-Associated Cachexia

Cancer cachexia is a multifactorial syndrome characterized by general inflammation, weight loss and muscle wasting, partly mediated by ubiquitin ligases such as atrogin-1, encoded by Fbxo32. Cancers induced by high-risk human papillomavirus (HPV) include anogenital cancers and some head-and-neck cancers and are often associated with cachexia. The aim of this study was to assess the presence of cancer cachexia in HPV16-transgenic mice with or without exposure to the chemical carcinogen 7,12-dimethylbenz(a)anthracene (DMBA). Male mice expressing the HPV16 early region under the control of the cytokeratin 14 gene promoter (K14-HPV16; HPV⁺) and matched wild-type mice (HPV^-) received DMBA (or vehicle) topically over 17 weeks of the experiment. Food intake and body weight were assessed weekly. The gastrocnemius weights and Fbxo32 expression levels were quantified at sacrifice time. HPV-16-associated lesions in different anatomic regions were classified histologically. Although unexposed HPV⁺ mice showed higher food intake than wild-type matched group (p < 0.01), they presented lower body weights (p < 0.05). This body weight trend was more pronounced when comparing DMBA-exposed groups (p < 0.01). The same pattern was observed in the gastrocnemius weights (between the unexposed groups: p < 0.05; between the exposed groups: p < 0.001). Importantly, DMBA reduced body and gastrocnemius weights (p < 0.01) when comparing the HPV⁺ groups. Moreover, the Fbxo32 gene was overexpressed in DMBA-exposed HPV⁺ compared to control mice (p < 0.05). These results show that K14-HPV16 mice closely reproduce the anatomic and molecular changes associated with cancer cachexia and may be a good model for preclinical studies concerning the pathogenesis of this syndrome.

MicroRNA-18a targeting of the STK4/MST1 tumour suppressor is necessary for transformation in HPV positive cervical cancer

Human papillomaviruses (HPV) are a major cause of malignancy worldwide. They are the aetiological agents of almost all cervical cancers as well as a sub-set of other anogenital and head and neck cancers. Hijacking of host cellular pathways is essential for virus pathogenesis; however, a major challenge remains to identify key host targets and to define their contribution to HPV-driven malignancy. The Hippo pathway regulates epithelial homeostasis by down-regulating the function of the transcription factor YAP. Increased YAP expression has been observed in cervical cancer but the mechanisms driving this increase remain unclear. We found significant down-regulation of the master Hippo regulatory kinase STK4 (also termed MST1) in cervical disease samples and cervical cancer cell lines compared with healthy controls. Re-introduction of STK4 inhibited the proliferation of HPV positive cervical cells and this corresponded with decreased YAP nuclear localization and decreased YAP-dependent gene expression. The HPV E6 and E7 oncoproteins maintained low STK4 expression in cervical cancer cells by upregulating the oncomiR miR-18a, which directly targeted the STK4 mRNA 3’UTR. Interestingly, miR-18a knockdown increased STK4 expression and activated the Hippo pathway, significantly reducing cervical cancer cell proliferation. Our results identify STK4 as a key cervical cancer tumour suppressor, which is targeted via miR-18a in HPV positive tumours. Our study indicates that activation of the Hippo pathway may offer a therapeutically beneficial option for cervical cancer treatment.

HPVs are the causative agents of ~5% of human cancers. Better understanding of the mechanisms by which these viruses deregulate cellular signalling pathways may offer therapeutic options for HPV-associated malignancies. The transcription factor YAP is active in cervical cancer but the mechanisms controlling its activation remain unclear. YAP is negatively regulated and sequestered in the cytoplasm through activation of the Hippo pathway. We discovered that expression of the master Hippo kinase, STK4 (also termed MST1), is reduced in HPV positive cervical cell lines and cervical disease samples. Low STK4 levels were maintained by the HPV oncogenes through up-regulation of miR-18a, which targeted the STK4 mRNA 3’UTR. Re-introduction of STK4 or bypassing miR-18a-dependent regulation de-activated YAP-driven transcription and reduced cell proliferation. Thus, our study identifies a novel interplay between HPV oncogenes and the STK4 tumour suppressor and identifies the Hippo pathway as a target for therapeutic intervention in HPV-associated malignancies.

Effects of Wnt/β-Catenin Signal Pathway Regulated by miR-342-5p Targeting CBX2 on Proliferation, Metastasis and Invasion of Ovarian Cancer Cells

Objective

This study aimed to investigate the effect of Wnt/β-catenin signal pathway mediated by miR-342-5p targeting CBX2 gene on the proliferation, metastasis, invasion and apoptosis of ovarian cancer cells, and to explore its related regulatory mechanism.

Methods

Human normal ovarian epithelial cell line IOSE80, human ovarian cancer cell line SKOV3 and OVCAR3 were the subjects. Software were used to predict the binding site of miR-342-5p targeting CBX2 gene. The proliferation rate of ovarian cancer cells was detected by MTT method; the cell viability of each group was observed by colony formation test; the apoptosis of cells in each group was detected by flow cytometry; the invasive ability of cells was determined by transwell test, and the migration ability of cells was detected by scratch test. The mRNA expression levels of miR-342-5p, CBX2, Wnt1, β-catenin, C-myc and Cyclin D1 were measured by qRT-PCR. Also, Western blot was used to determine the protein expression levels of CBX2, Wnt1, β-catenin, C-myc and Cyclin D1.

Results

CBX2 was identified as the target gene of miR-342-5p. MTT test results showed that miR-342-5p could significantly inhibit the proliferation of SKOV3 and OVCAR3 cells, colony formation assay results indicated that the viability of SKOV3 and OVCAR3 cells transfected with miR-342-5p decreased significantly, and flow cytometry results suggested that miR-342-5p could promote the apoptosis of SKOV3 and OVCAR3 cells. Also, the results of transwell showed that miR-342-5p could significantly inhibit the invasive ability of SKOV3 and OVCAR3 cells, and the results of scratch assay suggested that miR-342-5p could significantly inhibit the migration of SKOV3 and OVCAR3 cells. Moreover, qRT-PCR and Western blot results indicated that the mRNA and protein expression levels of CBX2, Wnt1, β-catenin, C-myc and Cyclin D1 decreased in SKOV3 and OVCAR3 cells transfected with miR-342-5p, while the mRNA expression levels of miR-342-5p increased significantly (P<0.05).

Conclusion

MiR-342-5p targeted gene is CBX2, which can significantly reduce the proliferation, invasion, migration and viability of ovarian cancer cell lines SKOV3 and OVCAR3, and promote their apoptosis. The mechanism may be related to the mediation of Wnt/β-catenin signal pathway and down-regulation of the related genes expression.

Role of exosomal microRNAs in lung cancer biology and clinical applications

Exosomes, small extracellular vesicles ranging from 30 to 150 nm, are secreted by various cell types, including tumour cells. Recently, microRNAs (miRNAs) were identified to be encapsulated and hence protected from degradation within exosomes. These exosomal miRNAs can be horizontally transferred to target cells, in which they subsequently modulate biological processes. Increasing evidence indicates that exosomal miRNAs play a critical role in modifying the microenvironment of lung cancers, possibly facilitating progression, invasion, angiogenesis, metastasis and drug resistance. In this review, we summarize the novel findings on exosomal miRNA functions during lung cancer initiation and progression. In addition, we highlight their potential role and challenges as biomarkers in lung cancer diagnosis, prognosis and drug resistance and as therapeutic agents.

MiR-1180 promotes cardiomyocyte cell cycle re-entry after injury through the NKIRAS2-NFκB pathway

Heart failure (HF) is associated with a considerable number of symptoms and significantly impaired health for humans, including reduced quality of life and physical functioning. Previous studies have indicated that miRNAs have important roles in regulating the development of HF. MiR-1180 is involved in the proliferation, migration, invasiveness, and chemoresistance of cancer cells; however, the underlying mechanisms and role of miR-1180 in the functioning of cardiomyocytes remains unclear. In this study, we found that miR-1180 promotes cell activity and cell cycle processes by driving energy generation through NKIRAS2, which declines over time during development. The expression of miR-1180 is down-regulated in cells subjected to hypoxia-reoxygenation, and use of an miR-1180 mimic significantly reduced myocardial injury and cell apoptosis. In addition, miR-1180 regulates the NFκB pathway through NKIRAS2 in cardiomyocytes. These findings suggest that miR-1180 maybe a novel therapeutic target for use in getting cardiomyocytes to re-enter the cell cycle as well as for cardiac repair following myocardial injury.

Hsa_circ_CSPP1/MiR-361-5p/ITGB1 Regulates Proliferation and Migration of Cervical Cancer (CC) by Modulating the PI3K-Akt Signaling Pathway

This study aimed to investigate the regulatory mechanism of circular RNA CSPP1 (hsa_circ_CSPP1) in cervical cancer. Based on GEO database, differentially expressed circRNAs and mRNAs related to cervical cancer were screened out by R software. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and Gene Ontology (GO) term analysis were performed to analyze the functional and pathway enrichment of identified DEGs. In addition, Cytoscape software was used to build interaction network of DEGs. The mRNA expressions were examined by qRT-PCR. Western blot was conducted to view the expression of proteins. Cell proliferation and apoptosis were respectively evaluated using CCK-8 assay and flow cytometry, whereas cell migration abilities were detected by Transwell assay. The relationship among factors was validated by dual-luciferase reporter gene assay. The influence in cervical tumor growth was further verified through nude mouse model in vivo. Hsa_circ_CSPP1 and ITGB1 were high-expressed in cervical cancer, while miR-361-5p was low-expressed. Hsa_circ_CSPP1 knockdown or miR-361-5p overexpression could suppress cervical cancer cell proliferation and migration, whereas promoted cell apoptosis. In addition, further experiments demonstrated that both hsa_circ_CSPP1 and ITGB1 mRNA were targets of miR-361-5p. Repressing hsa_circ_CSPP1 restrained cell viability and mobility and induced apoptosis through sponging miR-361-5p. Meanwhile, miR-361-5p also inhibited cervical cancer tumorigenesis via downregulation of ITGB1. Knockdown of hsa_circ_CSPP1 impeded tumor growth through suppressing the expression of downstream gene ITGB1, PI3K, and Akt. Circular RNA hsa_circ_CSPP1 regulates cell migration and proliferation in cervical cancer through miR-361-5p/ITGB1 in PI3K-Akt signaling pathway.

MiR-34b regulates cervical cancer cell proliferation and apoptosis

Objectives: MiR-34b is a tumour suppressor in different kinds of carcinomas. This study investigated the role of miR-34b in proliferation and apoptosis of cervical cancer. Materials and methods: The expression of miR-34b in 60 cervical cancer patients were quantified by RT-PCR and correlated with their clinicopathological parameters. Besides, there is a significant reverse relationship between miR-43b and TGF-β1 expression in tumour tissues. Cell proliferation and apoptosis was detected by CCK-8 assays and flow cytometry in cell lines transfected with miR-34b mimics. Western blotting, quantitative reverse transcription-PCR (RT-PCR) and luciferase assays were conducted to analyze the regulation of TGF-β1 by miR-34b in cell lines. Results: Here, we found expression of miR-34b to be downregulated in cervical cancer in comparison with the adjacent normal tissues. Expression levels of miR-34b were associated with enhanced malignant potential, such as tumour stage and stromal invasion. The overexpression of miR-34b potently suppressed cell proliferation and induced the apoptosis of cell lines. Conclusions: MiR-34b and TGF-β1 contribute to cervical cancer cell proliferation and apoptosis and are potential targets for cervical cancer therapeutics.

Genome-Wide CpG Island Methylation Profiles of Cutaneous Skin with and without HPV Infection

HPV infection is one of the most commonly transmitted diseases among the global population. While it can be asymptomatic, non-genital HPV infection often gives rise to cutaneous warts, which are benign growths arising from the epidermal layer of the skin. This study aimed to produce a global analysis of the ways in which cutaneous wart formation affected the CpG island methylome. The Infinium MethylationEPIC BeadChip microarray was utilized in order to quantitatively interrogate CpG island methylation in genomic DNA extracted from 24 paired wart and normal skin samples. Differential methylation analysis was carried out by means of assigning a combined rank score using RnBeads. The 1000 top-ranking CpG islands were then subject to Locus Overlap Analysis (LOLA) for enrichment of genomic ranges, while signaling pathway analysis was carried out on the top 100 differentially methylated CpG islands. Differential methylation analysis illustrated that the most differentially methylated CpG islands in warts lay within the ITGB5, DTNB, RBFOX3, SLC6A9, and C2orf27A genes. In addition, the most enriched genomic region sets in warts were Sheffield's tissue-clustered DNase hypersensitive sites, ENCODE's segmentation and transcription factor binding sites, codex sites, and the epigenome sites from cistrome. Lastly, signaling pathway analysis showed that the GRB2, GNB1, NTRK1, AXIN1, and SKI genes were the most common regulators of the genes associated with the top 100 most differentially methylated CpG islands in warts. Our study shows that HPV-induced cutaneous warts have a clear CpG island methylation profile that sets them apart from normal skin. Such a finding could account for the temporary nature of warts and the capacity for individuals to undergo clinical remission.

Relevance function of microRNA-708 in the pathogenesis of cancer

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression post-transcriptionally responsible for regulating >70% of human genes. MicroRNA-708 (miR-708) is encoded in the intron 1 of the Odd Oz/ten-m homolog 4 (ODZ4) gene. Numerous researches have confirmed that the abnormal expressed miR-708 is involved in the regulation of multiple types of cancer. Notably, the expression level of miR-708 was higher in lung cancer, bladder cancer (BC) and colorectal cancer (CRC) cell lines while lower in hepatocellular carcinoma (HCC), prostate cancer (PC), gastric cancer (GC) and so on. This review provides a current view on the association between miR-708 and several cancers and focuses on the recent studies of miR-708 regulation, discussing its potential as an epigenetic biomarker and therapeutic target for these cancers. In particular, the regulated mechanisms and clinical application of miR-708 in these cancers are also discussed.

Altered microRNA processing proteins in HPV-induced cancers

High-risk human papilloma virus (hrHPV) infections are associated with the development of anogenital cancers, in particular cervical cancer, and a subset of head and neck cancers. Previous studies have shown that microRNAs (miRNAs) contribute to the development and progression of HPV-induced malignancies. miRNAs are small non-coding RNAs that exist as multiple length and sequence variants, termed isomiRs. Efficient processing of miRNAs and generation of isomiRs is accomplished by several processing proteins. Deregulation of Drosha, AGO2, and TENT2, among others, has been observed in HPV-induced cancers and was even found at the precancerous stage. This suggests that miRNA processing proteins may be involved during early cancer development and that the generated isomiRs could provide promising biomarkers for early cancer diagnosis.

Monospecific antibody targeting of CDH11 inhibits epithelial-to-mesenchymal transition and represses cancer stem cell-like phenotype by up-regulating miR-335 in metastatic breast cancer, in vitro and in vivo

Background

Metastasis is a leading cause of breast cancer mortality. The induction of epithelial-to-mesenchymal transition (EMT) and complex oncogenic signaling is a vital step in the evolution of highly metastatic and therapeutically-intractable breast cancer; necessitating novel target discovery or development of therapeutics that target metastatic breast cells (MBCs).

Methods

To achieve this, this study employs a combination of in silico bioinformatics analyses, protein and transcript analyses, drug sensitivity assays, functional assays and animal studies.

Results

The present study identified CDH11 as an inductor and/or facilitator of metastatic signaling, and biomarker of poor prognosis in MBCs. Furthermore, we showed that in the presence of CDH11-rich cancer-associated fibroblasts (CAFs), MCF7 and MDA-MB-231 MBC cell lines acquired enhanced metastatic phenotype with increased CDH11, β-catenin, vimentin, and fibronectin (FN) expression. We also demonstrated, for the first time to the best of our knowledge that exposure to anti-CDH11 antibody suppresses metastasis, reduces CDH11, FN and β-catenin expression, and abrogate the cancer stem cell (CSC)-like traits of MBC cells. Interestingly, ectopic expression of miR-335 suppressed CDH11, β-catenin and vimentin expression, in concert with attenuated metastatic and CSC potentials of the MBC cells; conversely, inhibition of miR-335 resulted in increased metastatic potential. Finally, corroborating the in silica and in vitro findings, in vivo assays showed that the administration of anti-CDH11 antibody or miR-335 mimic suppressed tumorigenesis and inhibited cancer metastasis.

Conclusions

These findings validate our hypotheses that miR-335 mediates anti-CDH11 antibody therapy response and that an enhanced miR-335/CDH11 ratio elicits marked suppression of the MBC CSC-like and metastatic phenotypes, thus revealing a therapeutically-exploitable inverse correlation between CDH11-enhanced CSC-like and metastatic phenotype and miR-335 expression in MBCs. Thus, we highlight the therapeutic promise of humanized anti-CDH11 antibodies or miR-335-mimic, making a case for their clinical application as efficacious therapeutic option in patients with MBC.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5811-1) contains supplementary material, which is available to authorized users.

Recent Advances on the Molecular Mechanism of Cervical Carcinogenesis Based on Systems Biology Technologies

Cervical cancer is one of the common malignancies in women worldwide. Exploration of pathogenesis and molecular mechanism of cervical cancer is pivotal for development of effective treatment for this disease. Recently, systems biology approaches based on high-throughput technologies have been carried out to investigate the expression of some genes and proteins in genomics, transcriptomics, proteomics, and metabonomics of cervical cancer. Compared with traditional methods，systems biology technology has been shown to provide large of information regarding prognostic biomarkers and therapeutic targets for cervical cancer. These molecular signatures from system biology technology could be useful to understand the molecular mechanisms of cervical cancer development and progression, and help physicians to design targeted therapeutic strategies for patients with cervical cancer.