microRNA portraits in human vulvar carcinoma

Non-coding RNAs in gynecologic cancer

The term "gynecologic cancer" pertains to neoplasms impacting the reproductive tissues and organs of women encompassing the endometrium, vagina, cervix, uterus, vulva, and ovaries. The progression of gynecologic cancer is linked to various molecular mechanisms. Historically, cancer research primarily focused on protein-coding genes. However, recent years have unveiled the involvement of non-coding RNAs (ncRNAs), including microRNAs, long non-coding RNAs (LncRNAs), and circular RNAs, in modulating cellular functions within gynecological cancer. Substantial evidence suggests that ncRNAs may wield a dual role in gynecological cancer, acting as either oncogenic or tumor-suppressive agents. Numerous clinical trials are presently investigating the roles of ncRNAs as biomarkers and therapeutic agents. These endeavors may introduce a fresh perspective on the diagnosis and treatment of gynecological cancer. In this overview, we highlight some of the ncRNAs associated with gynecological cancers.

MicroRNAs as Potential Biomarkers in Gynecological Cancers

MicroRNAs are non-coding transcripts that, thanks to the ability to regulate the mRNA of target genes, can affect the expression of genes encoding tumor suppressors and oncogenes. They can control many important cellular processes, including apoptosis, differentiation, growth, division, and metabolism. Therefore, miRNAs play an important role in the development of many cancers, including gynecological cancers. Ovarian cancer, endometrial cancer, cervical cancer, and vulvar cancer are the most common cancers in women and are a frequent cause of death. The heterogeneity of the pathogenesis of these gynecological diseases makes the diagnostic process a significant obstacle for modern medicine. To date, many studies have been carried out, in which particular attention has been paid to the molecular pathomechanism of these diseases, with particular emphasis on miRNAs. To date, the changed profile of many miRNAs, which influenced the promotion of proliferation, migration, invasion processes and the simultaneous inhibition of programmed cell death, has been proven many times. Detailed understanding of the molecular effects of miRNAs in the above-mentioned gynecological cancers will enable the development of potential predictive and prognostic biomarkers, as well as the optimization of the diagnostic process.

Circulating Hsa-miR-431-5p as Potential Biomarker for Squamous Cell Vulvar Carcinoma and Its Premalignant Lesions

Vulvar squamous cell carcinoma (VSCC) develops from high-grade squamous intraepithelial lesions (HSIL) and differentiated vulvar intraepithelial neoplasia (dVIN). This study aimed to assess the diagnostic value of circulating hsa-miR-431-5p in vulvar precancers and VSCC. Expression levels of hsa-miR-431-5p were analyzed by quantitative RT-PCR in plasma samples of 29 patients with vulvar precancers (HSIL or dVIN), 107 with VSCC as well as 15 healthy blood donors. We used hsa-miR-93-5p and hsa-miR-425-5p as normalizers. The levels of miR-431-5p were increased in the blood of patients with VSCC compared to those with vulvar precancers. Statistically significant differences in the survival rates (time to progression) were revealed for VSCC patients categorized by miR-431-5p levels. Low levels of circulating miR-431-5p were found to be indicative of unfavorable survival rates. In summary, our data reveal the diagnostic potential of circulating miR-431-5p in patients with vulvar precancers and VSCC.

Lack of Conserved miRNA Deregulation in HPV-Induced Squamous Cell Carcinomas

Squamous cell carcinomas (SCCs) in the anogenital and head and neck regions are associated with high-risk types of human papillomaviruses (HR-HPV). Deregulation of miRNA expression is an important contributor to carcinogenesis. This study aimed to pinpoint commonly and uniquely deregulated miRNAs in cervical, anal, vulvar, and tonsillar tumors of viral or non-viral etiology, searching for a common set of deregulated miRNAs linked to HPV-induced carcinogenesis. RNA was extracted from tumors and nonmalignant tissues from the same locations. The miRNA expression level was determined by next-generation sequencing. Differential expression of miRNAs was calculated, and the patterns of miRNA deregulation were compared between tumors. The total of deregulated miRNAs varied between tumors of different locations by two orders of magnitude, ranging from 1 to 282. The deregulated miRNA pool was largely tumor-specific. In tumors of the same location, a low proportion of miRNAs were exclusively deregulated and no deregulated miRNA was shared by all four types of HPV-positive tumors. The most significant overlap of deregulated miRNAs was found between tumors which differed in location and HPV status (HPV-positive cervical tumors vs. HPV-negative vulvar tumors). Our results imply that HPV infection does not elicit a conserved miRNA deregulation in SCCs.

Could MicroRNAs Be Useful Tools to Improve the Diagnosis and Treatment of Rare Gynecological Cancers? A Brief Overview

Gynecological cancers pose an important public health issue, with a high incidence among women of all ages. Gynecological cancers such as malignant germ-cell tumors, sex-cord-stromal tumors, uterine sarcomas and carcinosarcomas, gestational trophoblastic neoplasia, vulvar carcinoma and melanoma of the female genital tract, are defined as rare with an annual incidence of <6 per 100,000 women. Rare gynecological cancers (RGCs) are associated with poor prognosis, and given the low incidence of each entity, there is the risk of delayed diagnosis due to clinical inexperience and limited therapeutic options. There has been a growing interest in the field of microRNAs (miRNAs), a class of small non-coding RNAs of ∼22 nucleotides in length, because of their potential to regulate diverse biological processes. miRNAs usually induce mRNA degradation and translational repression by interacting with the 3' untranslated region (3'-UTR) of target mRNAs, as well as other regions and gene promoters, as well as activating translation or regulating transcription under certain conditions. Recent research has revealed the enormous promise of miRNAs for improving the diagnosis, therapy and prognosis of all major gynecological cancers. However, to date, only a few studies have been performed on RGCs. In this review, we summarize the data currently available regarding RGCs.

Molecular events in the pathogenesis of vulvar squamous cell carcinoma

Vulvar squamous cell carcinomas (VSCC), which constitute over 90% of vulvar malignancies in adults, are classifiable into 2 subgroups that are mostly clinicopathologically distinct, a classification that is fundamentally based whether or not the tumors are HPV-mediated. In this review, we aim to summarize the recent advances in the understanding of molecular events in the pathogenesis of VSCC, including common and targetable mutations, copy number alterations, epigenetics, noncoding RNAs, and tumor immune microenvironment, which may provide insight into the future management of the disease. These events show substantial differences between the 2 subgroups, although significant areas of overlap exist. Recurrent, driver mutations appear to be substantially more prevalent in HPV(-) VSCC. TP53 mutations are the most common somatic mutations in VSCC overall, and are notably predominant in the HPV(-) VSCC, where 30-88% show a mutation. TP53 mutations are associated with worse patient outcomes, and co-mutations between TP53 and either HRAS, PIK3CA or CDKN2A appear to define subsets with even worse outcomes. A wide variety of other somatic mutations have been identified, including a subset with different mutational frequencies between HPV(+) and HPV(-) VSCC. CDKN2A mutations are common, and have been identified in 21 to 55% of HPV(-) VSCC, and in 2 to 25% of HPV(+) VSCC. Hypermethylation of CDKN2A is the most frequently reported epigenetic alteration in VSCC and the expression of some microRNAs may be associated with patient outcomes. The PTEN/PI3K/AKT/mTOR pathway is commonly altered in HPV(+) VSCC, and is accordingly potentially targetable. HPV-positivity/p16 block expression by immunohistochemistry has been found to be an independent prognostic marker for improved survival in VSCC, and may have some predictive value in VSCC patients treated with definitive radiotherapy. 22-39.3% and 68% of VSCC show EGFR amplification and protein overexpression respectively, although the prognostic and predictive value of an EGFR alteration requires additional study. Recurrent chromosomal gains in VSCCs have been found at 1q, 2q, 3q, 4p, 5p, 7p, 8p, 8q, and 12q, and there may be differential patterns of alterations depending on HPV-status. At least one-third of VSCC patients may potentially benefit from immune checkpoint inhibition therapy, based on a high frequency of PD-L1 expression or amplification, or a high tumor mutational burden. Additional studies are ultimately required to better understand the global landscape of genetic and epigenetic alterations in VSCC, and to identify and test potential targets for clinical application.

miR-100-3p inhibits the adipogenic differentiation of hMSCs by targeting PIK3R1 via the PI3K/AKT signaling pathway

MicroRNAs play an important role in the adipogenic differentiation of human bone marrow mesenchymal stem cells (hMSCs). How miR-100-3p influences such adipogenesis, however, remains uncertain. In this study, hMSC adipogenic differentiation was associated with miR-100-3p downregulation, and overexpressing this miRNA inhibited adipogenesis and the expression of adipogenic marker genes. Through bioinformatics approaches, miR-100-3p can bind the 3'-untranslated region (3'-UTR) of the mRNA encoding phosphoinositide 3-kinase regulatory subunit 1 (PIK3R1) such that miR-100-3p overexpression resulted in significant reductions in PIK3R1 expression. Importantly, overexpressing PIK3R1 was sufficient to reverse the anti-adipogenic effects of miR-100-3p overexpression. PIK3R1 is a critical component of the PI3K/AKT signaling pathway, and miR-100-3p overexpression resulted in reduced AKT phosphorylation in the context of adipogenesis. In addition, the adipogenic differentiation of hMSCs in which miR-100-3p was overexpressed was further enhanced upon treatment with the PI3K/AKT agonist 740Y-P relative to miR-100-3p overexpression alone. Taken together, these findings provide evidence that miR-100-3p inhibits the adipogenic differentiation of hMSCs by targeting PIK3R1 via the PI3K/AKT signaling pathway.

MIR-107, MIR-223-3P and MIR-21-5P Reveals Potential Biomarkers in Penile Cancer

BACKGROUND

Inguinal lymph node involvement is the main prognostic factor in patients with penile cancer. However, there is a lack of marker/s for lymph node metastasis. microRNAs have been investigated as potential markers for prognosis of various types of cancer. Taking this into consideration, our main goal was to determine the association of miR-223-3p, miR-107, and miR-21-5p expression with clinicopathological characteristics, as well as presence of lymph node metastasis in patients with penile cancer.

METHODS

Formalin-fixed paraffin-embedded penile squamous cell carcinoma specimens from 50 patients, at diagnosis and prior to any cancer treatment, were obtained. Tissue samples comprising at least 70% malignant cells and adjacent non-tumor tissues were evaluated by using qRT-PCR for expression level of miR-223-3p, miR-107 and miR-21-5p. Additionally, molecular identification of HPV was performed by PCR, and the expression levels of PTEN were analyzed by immunohistochemistry.

RESULTS

Penile squamous cell carcinoma primary tumors presented higher expression of miR-223-3p, miR-107, and miR-21-5p when compared to non-tumor adjacent tissues. Upregulation of miR-223-3p was associated lymph node metastasis. Higher expression of miR-107 was associated with worsening of prognosis (as observed by histological grade II and III, tumors bigger than 2.0 cm, stage III and IV, and lower disease-free survival). In addition, higher expression of miR-107 and miR-21-5p was correlated to the absence of PTEN protein expression.

CONCLUSIONS

Our data demonstrate that higher expression of miR-223-3p, miR-107, and miR-21-5p is correlated with poor prognosis in penile cancer. The upregulation of these microRNAs potentially affect critical cancer pathways and may be important for the prognosis and response to therapy in penile cancer.

MicroRNAs in Female Malignancies

MicroRNAs (miRNAs) are endogenous 22-nucleotide RNAs that can play a fundamental regulatory role in the gene expression of various organisms. Current research suggests that miRNAs can assume pivotal roles in carcinogenesis. In this article, through bioinformatics mining and computational analysis, we determine a single miRNA commonly involved in the development of breast, cervical, endometrial, ovarian, and vulvar cancer, whereas we underline the existence of 7 more miRNAs common in all examined malignancies with the exception of vulvar cancer. Furthermore, we identify their target genes and encoded biological functions. We also analyze common biological processes on which all of the identified miRNAs act and we suggest a potential mechanism of action. In addition, we analyze exclusive miRNAs among the examined malignancies and bioinformatically explore their functionality. Collectively, our data can be employed in in vitro assays as a stepping stone in the identification of a universal machinery that is derailed in female malignancies, whereas exclusive miRNAs may be employed as putative targets for future chemotherapeutic agents or cancer-specific biomarkers.

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

High-risk human papillomavirus (HPV)-driven cancers represent a major health concern worldwide. Despite the constant effort to develop and promote vaccination against HPVs, there is still a high percentage of non-vaccinated population. Furthermore, secondary prevention programs are not ubiquitous worldwide and not widely followed. Metastatic disease is the cause of the great majority of cancer-associated deaths, making it essential to determine its underlying mechanisms and to identify actionable anti-metastatic targets. Within certain types of cancer (e.g., head and neck), HPV-positive tumors show different dissemination patterns when compared with their HPV-negative counterparts, implicating HPV-related factors in the metastatic process. Among the many groups of biomolecules dysregulated by HPV, microRNAs have recently emerged as key regulators of carcinogenesis, able to control complex processes like cancer metastization. In this review, we present recent data on the role of microRNAs in the metastization of HPV-related cancers and on their possible clinical relevance as biomarkers of metastatic disease and/or as therapeutic targets.

miR‑3147 serves as an oncomiR in vulvar squamous cell cancer via Smad4 suppression

The incidence of vulvar squamous cell carcinoma (VSCC) has increased annually over the last decade. MicroRNAs (miRNAs/miRs) serve an important role in tumor progression and development. Our previous microarray studies have revealed that miR-3147 was overexpressed in VSCC. However, its function and underlying mechanism in VSCC remain unknown. In the present study, it was confirmed by reverse transcription-quantitative polymerase chain reaction that the expression of miR-3147 was markedly upregulated in VSCC tissues. The increased expression of miR-3147 was positively associated with the depth of invasion. The overexpression of miR-3147 resulted in the promotion of vulvar cancer cell proliferation, migration, invasion, G1/S progression and invasion-associated gene expression. miR-3147 may participate in the process of epithelial-mesenchymal transition and reduce the expressions of downstream target genes in the transforming growth factor-β/Smad signaling pathway in A431 cells. The knockdown of Smad4 by small interfering RNA promoted malignant behaviours in A431 cells. In addition, miR-3147 regulated Smad4 by directly binding to its 3′ untranslated region. In conclusion, the results indicated that miR-3147 may serve an oncogenic role in VSCC by targeting Smad4. miR-3147 may represent a novel potential therapeutic target marker for VSCC.

MiR-223-5p works as an oncomiR in vulvar carcinoma by TP63 suppression

MiR-223-5p has been previously mentioned to be associated with tumor metastasis in HPV negative vulvar carcinomas, such as in several other tumor types. In the present study, we hypothesized that this microRNA would be important in vulvar cancer carcinogenesis and progression. To investigate this, we artificially mimicked miR-223-5p expression in a cell line derived from lymph node metastasis of vulvar carcinoma (SW962) and performed in vitro assays. As results, lower cell proliferation (p < 0.01) and migration (p < 0.001) were observed when miR-223-5p was overexpressed. In contrast, increased invasive potential of these cells was verified (p < 0.004). In silico search indicated that miR-223-5p targets TP63, member of the TP53 family of proteins, largely described with importance in vulvar cancer. We experimentally demonstrated that this microRNA is capable to decrease levels of p63 at both mRNA and protein levels (p < 0.001, and p < 0.0001; respectively). Also, a significant inverse correlation was observed between miR-223-5p and p63 expressions in tumors from patients (p = 0.0365). Furthermore, low p63 protein expression was correlated with deeper tumor invasion (p = 0.0491) and lower patient overall survival (p = 0.0494). Our study points out miR-223-5p overexpression as a putative pathological mechanism of tumor invasion and a promising therapeutic target and highlights the importance of both miR-223-5p and p63 as prognostic factors in vulvar cancer. Also, it is plausible that the evaluation of p63 expression in vulvar cancer at the biopsy level may bring important contribution on prognostic establishment and in elaborating better surgical approaches for vulvar cancer patients.

Normalizers for microRNA quantification in plasma of patients with vulvar intraepithelial neoplasia lesions and vulvar carcinoma

The role of circulating microRNAs as a promising tool for diagnosing cancer and monitoring anticancer therapies has been widely studied in the past decades. To date, no suitable reference microRNAs for normalizing quantitative real-time polymerase chain reaction assays has been identified in vulvar intraepithelial neoplasia lesions and vulvar squamous cell carcinoma. The purpose of this study was to select appropriate references for gene expression studies in plasma of patients with these lesions. Expression levels of six microRNAs—hsa-miR-425-5p, hsa-miR-191-5p, hsa-miR-93-5p, hsa-miR-423-5p, hsa-miR-103a-3p, and hsa-miR-16-5p—were analyzed by quantitative reverse transcription polymerase chain reaction in plasma samples obtained from 17 patients with vulvar intraepithelial neoplasia lesion and 27 patients with vulvar squamous cell carcinoma. The expression stability of these candidate normalizers was assayed using geNorm algorithm. hsa-miR-93-5p was revealed as the most stably expressed reference in plasma samples of both vulvar intraepithelial neoplasia lesion and vulvar squamous cell carcinoma patients. The results pointed at hsa-miR-93-5p and hsa-miR-425-5p as microRNAs that retained the greatest robustness in plasma of vulvar intraepithelial neoplasia lesion and vulvar squamous cell carcinoma patients, respectively. Our work is the first report on reference microRNA selection for quantitative real-time polymerase chain reaction applications in vulvar intraepithelial neoplasia lesion and vulvar squamous cell carcinoma. The candidate microRNA stability values for the two types of lesions are provided and might serve for normalization of the future novel microRNA biomarkers in these rare entities.

Modulation of microRNA-mRNA Target Pairs by Human Papillomavirus 16 Oncoproteins

The E6 and E7 proteins are the major oncogenic drivers encoded by high-risk human papillomaviruses (HPVs). While many aspects of the transforming activities of these proteins have been extensively studied, there are fewer studies that have investigated how HPV E6/E7 expression affects the expression of cellular noncoding RNAs. The goal of our study was to investigate HPV16 E6/E7 modulation of cellular microRNA (miR) levels and to determine the potential consequences for cellular gene expression. We performed deep sequencing of small and large cellular RNAs in primary undifferentiated cultures of human foreskin keratinocytes (HFKs) with stable expression of HPV16 E6/E7 or a control vector. After integration of the two data sets, we identified 51 differentially expressed cellular miRs associated with the modulation of 1,456 potential target mRNAs in HPV16 E6/E7-expressing HFKs. We discovered that the degree of differential miR expression in HFKs expressing HPV16 E6/E7 was not necessarily predictive of the number of corresponding mRNA targets or the potential impact on gene expression. Additional analyses of the identified miR-mRNA pairs suggest modulation of specific biological activities and biochemical pathways. Overall, our study supports the model that perturbation of cellular miR expression by HPV16 E6/E7 importantly contributes to the rewiring of cellular regulatory circuits by the high-risk HPV E6 and E7 proteins that contribute to oncogenic transformation.

IMPORTANCE

High-risk human papillomaviruses (HPVs) are the causative agents of almost all cervical cancers and many other cancers, including anal, vaginal, vulvar, penile, and oropharyngeal cancers. Despite the availability of efficacious HPV vaccines, it is critical to determine how HPVs cause cancer, as many people remain unvaccinated and the vaccine does not prevent cancer development in individuals who are already infected. Two HPV proteins, E6 and E7, are the major drivers of cancer development, and much remains to be learned about how the expression of these viral proteins reprograms infected cells, ultimately resulting in cancer development. Small, noncoding human RNAs, termed microRNAs (miRs), regulate gene expression and have been implicated in almost all human cancers, including HPV-associated cancers. Our study provides a comprehensive analysis of how E6 and E7 alter the expression of human miRs and how this potentially impacts cellular gene expression, which may contribute to cancer development.

Design of a miRNA sponge for the miR-17 miRNA family as a therapeutic strategy against vulvar carcinoma

Dysregulation of microRNAs has been studied thoroughly, and has been observed in a variety of tumors including vulvar carcinomas, a rare type of gynecological tumor with increasing incidence. However, very few therapeutic alternatives have reached the clinical setting, and there is an urgent unmet need to develop novel strategies for patients with this tumor type. Thus, a microRNA (miRNA) sponge for the miR-17 miRNA family was designed, synthesized and validated in vitro in order to explore a new therapeutic strategy based on inhibiting this oncogenic miRNA family in vulvar cancer. Members of the miR-17 family were evaluated for expression in a vulvar tumor cell line (SW954) and 20 HPV negative formalin-fixed paraffin-embedded (FFPE) samples by quantitative real-time PCR (qRT-PCR). Six in tandem, bulged sequences that were complementary to these miRNAs were designed, synthesized, cloned, and transfected into SW954 cells. A luciferase reporter assay with a psiCheck2 vector was used to test the specificity of the sponge sequences for miR-17 family miRNA binding. Taqman qRT-PCR was used to test how the sponges affected miRNA expression. In FFPE samples, higher expression of miR-20a and miR-106a correlated with deeper tumor invasion (P = 0.0187 and P = 0.0404, respectively). The luciferase reporter assay validated the specificity of the sponge for miR-17 family members. Using qRT-PCR, we confirmed this specificity with decreased expression in 5 (out of six) miRNAs of the miR-17 family in SW954 cells. Although our results are preliminary, these results demonstrate that these miRNA sponges are potent inhibitors of the miR-17 family of miRNAs in SW954. Therefore, this miRNA-specific sponge may be developed into a novel therapeutic treatment for patients with vulvar cancer.

ET-1 Induced Downregulation of MRP2 via miRNA 133a - A Marker for Tubular Nephrotoxicity?

BACKGROUND

Multiple drug resistance (MDR), known from treating malignant tumors with chemotherapy, increases the efflux of reabsorbed reagents in tumor cells. This mechanism has been reported in the renal proximal tubule and may prevent therapeutic tubular protection in proteinuria. Since endothelin-1 (ET-1), a major component in the urine of proteinuric patients, stimulates proximal tubules, its influence on MDR was analyzed with emphasis on the multidrug resistance-associated protein 2 (MRP2), a prominent transporter in the human proximal tubule and microRNA (miRNA) 133a.

METHODS

ET-1 stimulated, cultured human renal proximal tubule cells (RPTECs), were analyzed via Western blot for the expression of MRP2 and via qRT-PCR for miRNA 133a. For direct interaction between the miRNA 133a and the 3'UTR of MRP2, an immunoprecipitation was performed using FITC-labelled miRNA 133a as capture, followed by MRP2 PCR analysis and Sanger sequencing. Murine Adriamycin nephropathic model and human proteinuric samples showed high levels of miRNA 133a but low levels of MRP2. The increasing miRNA 133a levels were detectable in urine samples of humans and animals.

RESULTS

ET-1 activates the miRNA 133a, which can bind to the 3'UTR of MRP2 and is therefore responsible for the detectable decrease of MRP2.

CONCLUSION

This is the first report to analyze the correlation between ET-1-induced miRNA 133a overexpression in proteinuria resulting in MRP2 downregulation, which is a contributing factor for renal cytotoxicity. The detection of the miRNA 133a in urine samples can be possibly used as a monitor for cytotoxicity.

MiRNA in bladder carcinogenesis: A review

Bladder cancer (BC) is the second urological malignancy in incidence, currently being one of the most neoplasms studied with profile and biology poorly defined. In the world, BC is responsible by about 386000 new cases and 150000 deaths annually with considerable economic impact and high costs for health systems. After its discovery more than 20 years, micro RNAs (miRNAs) have been recognized as molecules that work specifically in post-transcriptional control in majority of eukaryote genomes. MiRNAs are a family of small non-coding RNAs of 19-25 nucleotides in length, expressed in a wide variety of organisms, comprising plants, worms and mammals, including humans. They have a fundamental role in physiological and pathological processes in organs and tissues in a context-dependent manner. This review brings new roles of protective and oncogenic miRNAs linked to carcinogenesis of urothelial carcinoma of the bladder, and associated with behavior of disease. Many studies have demonstrated promising roles of miRNAs working as diagnostic and prognostic biomarkers or involved in target therapies, consolidating miRNAs as crucial players in human cancer. This review allowed a reflection about the true functions of miRNAs in bladder carcinogenesis. Not only by their wide capacities of action, but also by abilities in define the cell date. The future of anti-tumor target therapies will be based not in one, but in groups of miRNAs working together in several steps of carcinogenic process, being able to identify the disease, predicting behavior and effectively treat bladder cancer.