Evaluation of mir-203 Expression Levels and DNA Promoter Methylation Status in Serum of Patients with Endometrial Cancer

Circulating miRNAs as a Tool for Early Diagnosis of Endometrial Cancer-Implications for the Fertility-Sparing Process: Clinical, Biological, and Legal Aspects

This review article explores the possibility of developing an integrated approach to the management of the different needs of endometrial cancer (EC) patients seeking to become pregnant. Life preservation of the woman, health preservation of the baby, a precocious and-as much as possible-minimally invasive characterization of the health and fertility parameters of the patient, together with the concerns regarding the obstetric, neonatal, and adult health risks of the children conceived via assisted reproductive techniques (ART) are all essential aspects of the problem to be taken into consideration, yet the possibility to harmonize such needs through a concerted and integrated approach is still very challenging. This review aims to illustrate the main features of EC and how it affects the normal physiology of pre-menopausal women. We also focus on the prospect of a miR-based, molecular evaluation of patient health status, including both EC early diagnosis and staging and, similarly, the receptivity of the woman, discussing the possible evaluation of both aspects using a single specific panel of circulating miRs in the patient, thus allowing a relatively fast, non-invasive testing with a significantly reduced margin of error. Finally, the ethical and legal/regulatory aspects of such innovative techniques require not only a risk-benefit analysis; respect for patient autonomy and equitable health care access allocation are fundamental issues as well.

Clinical Value and Molecular Function of Circulating MicroRNAs in Endometrial Cancer Regulation: A Systematic Review

This systematic review of literature highlights the different microRNAs circulating in the serum or plasma of endometrial cancer patients and their association with clinical and prognostic characteristics in endometrial cancer. This study also investigates the molecular functions of these circulating microRNAs. According to this systematic review, a total of 33 individual circulating miRs (-9, -15b, -20b-5p, -21, -27a, -29b, -30a-5p, -92a, -99a, -100, -135b, -141, -142-3p, -143-3p, -146a-5p, -150-5p, -151a-5p, -186, -195-5p, -199b, -200a, -203, -204, -205, -222, -223, -301b, -423-3p, -449, -484, -887-5p, -1228, and -1290) and 6 different panels of miRs (“miR-222/miR-223/miR-186/miR-204”, “miR-142-3p/miR-146a-5p/miR-151a-5p”, “miR-143-3p/miR-195-5p/miR-20b-5p/miR-204-5p/miR-423-3p/miR-484”, “mir-9/miR-1229”, “miR-9/miR-92a”, and “miR-99a/miR-199b”) had a significant expression variation in EC patients compared to healthy patients. Also, seven individual circulating miRs (-9, -21, -27a, -29b, -99a, -142-3p, and -449a) had a significant expression variation according to EC prognostic factors such as the histological type and grade, tumor size, FIGO stage, lymph node involvement, and survival rates. One panel of circulating miRs (“-200b/-200c/-203/-449a”) had a significant expression variation according to EC myometrial invasion. Further studies are needed to better understand their function and circulation.

Can miRNAs be useful biomarkers in improving prognostic stratification in endometrial cancer patients? An update review

Endometrial cancer (EC) is the most common gynecological cancer, with annual incidence rates in Western countries ranging between 15 and 25 per 100 000 women. About 15% to 20% of patients with EC have high-risk disease and follow an aggressive clinical course. Unfortunately, the assessment of histologic parameters is poorly reproducible and conventional clinicopathological and molecular features do not reliably predict either the patient's response to the available treatments or the definition of personalized therapeutic approaches. In this context, the identification of novel diagnostic and prognostic biomarkers, which can be integrated in the current classification schemes, represents an unmet clinical need and an important challenge. miRNAs are key players in cancer by regulating the expression of specific target genes. Their role in EC, in association with clinical and prognostic tumor biomarkers, has been investigated but, so far, with little consensus among the studies. The present review aims to describe the recent advances in miRNAs research in EC taking into consideration the current classification schemes and to highlight the most promising miRNAs. Finally, a perspective point of view sheds light on the challenges ahead in the landscape of EC.

Aberrant Telomere Length in Circulating Cell-Free DNA as Possible Blood Biomarker with High Diagnostic Performance in Endometrial Cancer

To investigate the diagnostic performance of relative telomere length (RTL) in cell-free DNA (cfDNA) for endometrioid endometrial cancer (EC). We measured RTL in cfDNA of 40 EC patients (65 ± 12 years) and 31 healthy controls (HC) (63 ± 13 years), excluding in both groups other oncologic and severe non-oncologic diseases to limit confounders. Circulating cfDNA was extracted from serum using the QIAamp DNA Blood Mini kit (Qiagen, Hilden, Germany). After the quantitative real-time polymerase chain reaction, telomere repeat copy number to single-gene copy number ratio was calculated. RTL in cfDNA was found to be significantly lower in EC patients than in HC (p < 0.0001). The diagnostic performance of cfDNA RTL was estimated with receiver operating characteristics (ROC) curve analysis, which showed a diagnostic accuracy for EC of 0.87 (95% CI: 0.79-0.95, p < 0.0001). The cutoff cfDNA RTL value of 2.505 (T/S copy ratio) reported a sensitivity of 80.0% (95% CI: 64.35-90.95) and a specificity of 80.65% (95% CI: 62.53-92.55). Significant differences of RTL among EC stages or grades (p = 0.85 and p = 0.89, respectively) were not observed. Our results suggest that cfDNA RTL analysis may be a diagnostic tool for EC detection since the early stage, whilst its diagnostic performance seems unsatisfactory for cancer progression, staging, and grading. However, further studies are needed to confirm these preliminary findings. In particular, future investigations should focus on high-risk patients (such as those with atypical endometrial hyperplasia) that may benefit from this tool, because TL shortening is not specific for EC and is influenced by other oncologic and non-oncologic diseases.

Diagnostic value of microRNA panel in endometrial cancer: A systematic review

PURPOSE

We conducted a systematic review to evaluate the overall diagnostic accuracy of miRNAs in detecting endometrial cancer.

MATERIALS AND METHODS

A systematic search of Medline, Embase, Cinahl and the Cochrane Controlled Register of Trials was performed to identify studies reporting on the diagnostic value of miRNA in EC patients. Included were diagnostic studies looking at miRNA expression in women diagnosed with endometrial cancer. Two reviewers independently selected studies and assessed quality of studies using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) score system. Data extraction was completed and the vote-counting strategy was used to rank miRNAs.

RESULTS

26 studies were included with a total number of 1,400 EC patients reporting on 106 differentially expressed miRNAs. The most frequently found up-regulated miRNA was miR-205 followed by miR-200c, -223, -182, -183 and -200a. In addition, miR-135b, miR-429, miR-141 and miR-200b were also frequently up-regulated. There was less consensus on down-regulated miRNAs.

CONCLUSIONS

miRNAs yield a promising diagnostic biomarker potential in endometrial cancer, especially miR-205, the miR-200 family and miR-135b, -182, -183 and -223. However, no sufficient high quality data are available to draw hard conclusions. More research is needed to validate the diagnostic potential of these miRNAs in larger studies. In addition, the potential of urine as a non-invasive biofluid should be investigated in more detail.

Overexpression of microRNA-203 can downregulate survivin and function as a potential therapeutic target in papillary thyroid cancer

Papillary thyroid cancer (PTC) is the most common type of thyroid carcinoma. PTC has a considerably high five-year survival rate; however, the possibility of recurrence is also high. Therefore, there is a requirement to clarify the molecular mechanism of PTC to promote understanding regarding the development of the disease and further improve prognosis. A number of studies have demonstrated that microRNAs (miRNAs or miRs) contribute to the progression of PTC. The present study revealed that the expression level of miR-203 was significantly lower in PTC tissues and cell lines compared with in the normal controls. In addition, inhibition of miR-203 was identified to be associated with an overexpression of survivin, which was observed in PTC samples. miR-203 regulates the expression of Bcl-2 via its downstream regulator survivin. Furthermore, the present study identified that inhibition of miR-203 histone acetylation was associated with high expression levels of miR-203 in PTC tissue samples. In summary, the results indicate that miR-203 functions as a biomarker and may serve as a candidate target for the development of novel therapeutic strategies to treat PTC.

Noncoding RNAs in Extracellular Fluids as Cancer Biomarkers: The New Frontier of Liquid Biopsies

The last two decades of cancer research have been devoted in two directions: (1) understanding the mechanism of carcinogenesis for an effective treatment, and (2) improving cancer prevention and screening for early detection of the disease. This last aspect has been developed, especially for certain types of cancers, thanks also to the introduction of new concepts such as liquid biopsies and precision medicine. In this context, there is a growing interest in the application of alternative and noninvasive methodologies to search for cancer biomarkers. The new frontiers of the research lead to a search for RNA molecules circulating in body fluids. Searching for biomarkers in extracellular body fluids represents a better option for patients because they are easier to access, less painful, and potentially more economical. Moreover, the possibility for these types of samples to be taken repeatedly, allows a better monitoring of the disease progression or treatment efficacy for a better intervention and dynamic treatment of the patient, which is the fundamental basis of personalized medicine. RNA molecules, freely circulating in body fluids or packed in microvesicles, have all the characteristics of the ideal biomarkers owing to their high stability under storage and handling conditions and being able to be sampled several times for monitoring. Moreover, as demonstrated for many cancers, their plasma/serum levels mirror those in the primary tumor. There are a large variety of RNA species noncoding for proteins that could be used as cancer biomarkers in liquid biopsies. Among them, the most studied are microRNAs, but recently the attention of the researcher has been also directed towards Piwi-interacting RNAs, circular RNAs, and other small noncoding RNAs. Another class of RNA species, the long noncoding RNAs, is larger than microRNAs and represents a very versatile and promising group of molecules which, apart from their use as biomarkers, have also a possible therapeutic role. In this review, we will give an overview of the most common noncoding RNA species detectable in extracellular fluids and will provide an update concerning the situation of the research on these molecules as cancer biomarkers.

Regulation of collagen type XVII expression by miR203a-3p in oral squamous cell carcinoma cells

Collagen type XVII (COL17) is expressed in various tissues and its aberrant expression is associated with tumour progression. In this study, we investigated the regulation of COL17 expression in oral squamous cell carcinoma (OSCC) using the cell lines NA, SAS, Ca9-22, and Sa3. COL17 was induced upon p53 activation by cisplatin in SAS; however, this effect was more limited in NA and hardly in Ca9-22 and Sa3, with mutated p53. Moreover, COL17 was found to be regulated by miR203a-3p in all cell lines. Our data suggest that COL17 expression in OSCC cell lines is regulated by p53 and miR203a-3p.

Identification of key pathways and genes in endometrial cancer using bioinformatics analyses

Endometrial cancer (EC) is one of the most common gynecological cancer types worldwide. However, to the best of our knowledge, its underlying mechanisms remain unknown. The current study downloaded three mRNA and microRNA (miRNA) datasets of EC and normal tissue samples, GSE17025, GSE63678 and GSE35794, from the Gene Expression Omnibus to identify differentially expressed genes (DEGs) and miRNAs (DEMs) in EC tumor tissues. The DEGs and DEMs were then validated using data from The Cancer Genome Atlas and subjected to gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis. STRING and Cytoscape were used to construct a protein-protein interaction network and the prognostic effects of the hub genes were analyzed. Finally, miRecords was used to predict DEM targets and an miRNA-gene network was constructed. A total of 160 DEGs were identified, of which 51 genes were highly expressed and 100 DEGs were discovered from the PPI network. Three overlapping genes between the DEGs and the DEM targets, BIRC5, CENPF and HJURP, were associated with significantly worse overall survival of patients with EC. A number of DEGs were enriched in cell cycle, human T-lymphotropic virus infection and cancer-associated pathways. A total of 20 DEMs and 29 miRNA gene pairs were identified. In conclusion, the identified DEGs, DEMs and pathways in EC may provide new insights into understanding the underlying molecular mechanisms that facilitate EC tumorigenesis and progression.

Loss of miR-16 contributes to tumor progression by activation of tousled-like kinase 1 in oral squamous cell carcinoma

A different expression signature of miRNA in oral squamous cell carcinoma (OSCC) has been validated. MicroRNA-16 (miR-16) as one of the distinctly dysregulated miRNAs in OSCC, its functional role in progression of OSCC remains not fully clear. Herein, miR-16 expression was significantly lower in OSCC tissues compared to that in adjacent normal tissues (n = 131). A lower level of miR-16 was found to be associated with poor prognosis on a cohort of 131 patients with OSCC, and on an extensive public data (457) from TCGA database. Additionally, expression of TLK1 was significantly higher in OSCC tissues compared to that in adjacent normal tissues, which is negatively correlated with miR-16 expression in OSCC. Bioinformatics analyses exhibited that TLK1 is a potential downstream effector of miR-16 by directly targeting the 3'-untranslated regions (3'-UTR) of mRNA. Forced expression of miR-16 in OSCC cell lines inhibits cell proliferation in vitro, and tumor growth in vivo by inhibition of TLK1. Mechanistically, downregulation of TLK1 by miR-16 enhances higher level of DNA damage leading to a significant increase of G₂/M arrest in SCC9 cells. And, overexpression of TLK1 substantially reduces DNA damage and G₂/M arrest by activation of TLK1-dependent cell cycle checkpoint response. To conclude, miR-16 is downregulated in OSCC and serves as tumor suppressor in OSCC progression by targeting TLK1, which has potential to be the novel therapeutic targets and diagnostic biomarkers for OSCC.

DNMT3A controls miR-200b in cardiac fibroblast autophagy and cardiac fibrosis

AIM AND OBJECTIVE

Regulation of microRNA gene expression by DNA methylation may represent a key mechanism to drive cardiac fibrosis progression. Cardiac fibroblast autophagy is the primary source of cardiac fibrosis, but the mechanisms underlying this process are incompletely understood. Here we found that DNMT3A suppression of the microRNA-200b (miR-200b) through pathway leads to cardiac fibroblast autophagy in cardiac fibrosis.

METHODS

To understand the impact of DNMT3A on miR-200b at cardiac fibrosis, the rat cardiac fibrosis model was established via the abdominal aortic coarctation. Cardiac fibroblasts (CFs) were harvested from SD neonate rats and cultured. The expression of DNMT3A, miR-200b, collagen I was measured by western blotting, immunohistochemistry and qRT-PCR. Gain- or loss-of-function approaches were used to manipulate DNMT3A and miR-200b.

RESULTS

DNMT3A level was upregulated and negatively correlated with miR-200b expression in fibrosis tissues and cardiac fibroblast. We found that autophagy was activated by miR-200b inhibitor and inactivated by miR-200b mimic in the rat cardiac fibroblast. Knockdown of DNMT3A notably increased the expression of miR-200b.

CONCLUSIONS

Taken together, these findings indicate that DNMT3A regulation of miR-200b controls cardiac fibroblast autophagy during cardiac fibrosis and provide a basis for the development of therapies for cardiac fibrosis.