A New MicroRNA Expression Signature for Cervical Cancer

miR-19-3p Targets PTEN to Regulate Cervical Cancer Cell Proliferation, Invasion, and Autophagy

Background

Cervical cancer is the second most common cancer among women worldwide. Extensive studies have shown that microRNAs (miRNA/miR) can regulate the formation, progression, and metastasis of cancer. The purpose of this study was to investigate the effect of miR-19-3p on the proliferation, invasion, and autophagy of cervical cancer cells and to explore the underlying mechanism.

Methods

SiHa and HeLa cells were transfected with miR-19-3p mimic and inhibitor. miR-19-3p and PTEN expression were detected using real-time quantitative PCR and western blot, respectively. The binding between miR-19-3p and PTEN was predicted using Targetscan7.2 and verified by a dual-luciferase reporter gene assay. The effects of miR-19-3p on cell invasion and proliferation were evaluated by Transwell assays and MTT, respectively. The effect of miR-19-3p on autophagy was observed using fluorescence microscopy.

Results

The expression of miR-19-3p in cervical cancer tissues and SiHa and HeLa cells was significantly upregulated, whereas the expression of PTEN was significantly downregulated. PTEN was one of the direct targets of miR-19-3p. The miR-19-3p mimic significantly reduced the apoptosis rate and autophagy and promoted cell proliferation and invasion of the SiHa and HeLa cells.

Conclusion

In summary, miR-19b-3p can target PTEN to regulate the proliferation, invasion, and autophagy of cervical cancer cells. Our findings indicate the potential of miR-19-3p as a target for cervical cancer treatment in the future.

TCF7L1 Genetic Variants Are Associated with the Susceptibility to Cervical Cancer in a Chinese Population

Background

Cervical cancer (CC) is the second most common tumor in women worldwide. Studies have been accepted that genetic variations play an important role in the development of CC. The aim of this study was to evaluate the impact of TCF7L1 variants on CC risk.

Methods

508 patients of cervical cancer and 497 healthy subjects were recruited to determine the impact of TCF7L1 polymorphisms on CC susceptibility. The associations were investigated by computing odds ratios (ORs) and 95% confidence intervals. The effect of SNP-SNP interactions on CC risk was explored by multifactor dimensionality reduction analysis.

Results

Our study showed that rs11904127 (OR 0.79, p = 0.010) and rs62162674 (OR 0.82, p = 0.044) of TCF7L1 significantly decreased cervical cancer risk. Stratified analysis indicated that rs11904127 and rs62162674 present decreased susceptibility to CC in age > 51 years (OR 0.74, p = 0.019; OR 0.72, p = 0.014, respectively). Haplotype analyses revealed that G_rs2366264T_rs11689667C_rs62162674 has a lower risk to cervical cancer (OR = 0.43, p = 0.018). Besides, there is strong interaction of rs11904127 and rs2366264.

Conclusion

Rs11904127 and rs62162674 in TCF7L1 are related to cervical cancer. We suggest that these variants can be used as prognostic markers for judging the susceptibility to cervical cancer.

miRNAs as biomarkers for early cancer detection and their application in the development of new diagnostic tools

Over the last decades, microRNAs (miRNAs) have emerged as important molecules associated with the regulation of gene expression in humans and other organisms, expanding the strategies available to diagnose and handle several diseases. This paper presents a systematic review of literature of miRNAs related to cancer development and explores the main techniques used to quantify these molecules and their limitations as screening strategy. The bibliographic research was conducted using the online databases, PubMed, Google Scholar, Web of Science, and Science Direct searching the terms "microRNA detection", "miRNA detection", "miRNA and prostate cancer", "miRNA and cervical cancer", "miRNA and cervix cancer", "miRNA and breast cancer", and "miRNA and early cancer diagnosis". Along the systematic review over 26,000 published papers were reported, and 252 papers were returned after applying the inclusion and exclusion criteria, which were considered during this review. The aim of this study is to identify potential miRNAs related to cancer development that may be useful for early cancer diagnosis, notably in the breast, prostate, and cervical cancers. In addition, we suggest a preliminary top 20 miRNA panel according to their relevance during the respective cancer development. Considering the progressive number of new cancer cases every year worldwide, the development of new diagnostic tools is critical to refine the accuracy of screening tests, improving the life expectancy and allowing a better prognosis for the affected patients.

A 70-Gene Signature for Predicting Treatment Outcome in Advanced-Stage Cervical Cancer

Cervical cancer is the fourth most common cancer in women worldwide. The current approaches still have limitations in predicting the therapy outcome of each individual because of cancer heterogeneity. The goal of this study was to establish a gene expression signature that could help when choosing the right therapeutic method for the treatment of advanced-stage cervical cancer. The 666 patients were collected from four independent datasets. The 70-gene expression signature was established using univariate Cox proportional hazard regression analysis. The 70-gene signature was significantly different between low- and high-risk groups in the training dataset (p = 4.24e-6) and in the combined three validation datasets (p = 4.37e-3). Treatment of advanced-stage cancer patients in the high-risk group with molecular-targeted therapy combined with chemoradiotherapy yielded a better survival rate than with only chemoradiotherapy (p = 0.0746). However, treatment of the patients in the low-risk group with the combined therapy resulted in significantly lower survival (p = 0.00283). Functional classification of 70 genes revealed involvement of the angiogenesis pathway, specifically phosphatidylinositol 3-kinase signaling (p = 0.040), extracellular matrix organization (p = 0.0452), and cell adhesion (p = 0.011). The 70-gene signature could predict the prognosis and indicate an optimal therapeutic modality in molecular-targeted therapy or chemotherapy for advanced-stage cervical cancer.

MicroRNA-625-5p Sponges lncRNA MALAT1 to Inhibit Cervical Carcinoma Cell Growth by Suppressing NF-κB Signaling

The exact expression profile and potential involvement of miR-625-5p in the tumor biology of cervical carcinoma are still elusive. In this study, we aimed to analyze the expression status and possible involvements of miR-625-5p in both clinical tissue samples and cell culture of cervical carcinoma. The relative expression levels of miR-625-5p and NF-κB transcript were determined by real-time polymerase chain reaction. Cell proliferation was measured using Cell Counting Kit-8. The protein levels of Cyclin D1, CDK4, NF-κB, and GAPDH were examined by Western blotting. The regulatory effects of miR-625-5p on NF-κB and MALAT1 were interrogated by luciferase reporter assay. We demonstrated that miR-625-5p was downregulated and predicted better survival in cervical carcinoma. Ectopic over-expression of miR-625-5p inhibited cell growth via targeting NF-κB. We further identified MALAT1 as the competitive endogenous long non-coding RNA for miR-625-5p, and over-expression of MALAT1 attenuated the inhibitory effect of miR-625-5p on NF-κB signaling in cervical carcinoma. Our study characterized the suppressive expression of miR-625-5p in cervical carcinoma and unraveled the importance of MALAT1/miR-625-5p/NF-κB signaling in this disease.

Identification and performance evaluation of housekeeping genes for microRNA expression normalization by reverse transcription-quantitative PCR using liquid-based cervical cytology samples

Screening for cervical cancer by cytology has been effective in reducing the worldwide incidence and mortality rates of this disease. However, a number of studies have demonstrated that the sensitivity of conventional cervical cytology may be too low for detection of cervical intraepithelial neoplasias (CIN). Therefore, it is important to incorporate more sensitive molecular diagnostic tests that could substantially improve the detection rates and accuracy for identifying CIN lesions. MicroRNAs (miRNAs) are a class of small non-coding RNAs with the potential to provide robust non-invasive cancer biomarkers for detecting CIN lesions in liquid-based cervical cytology (LBC) samples. At present, there is no consensus on which are the best housekeeping genes for miRNA normalization in LBC. The present study aimed to identify housekeeping genes with consistent and reproducible performance for normalization of reverse transcription-quantitative PCR (RT-qPCR) expression analysis of miRNA using LBC samples. The present study firstly selected six potential candidate housekeeping genes based on a systematic literature evaluation. Subsequently, the expression levels of microRNAs U6, RNU-44, RNU-47, RNU-48, RNU-49 and hsa-miR-16 were measured in 40 LBC samples using RT-qPCR. The stability of each potential housekeeping gene was assessed using the NormFinder algorithm. The results revealed that U6 and RNU-49 were the most stable genes among all candidates requiring fewer amplification cycles and smaller variation across the sample set. However, RNU-44, RNU-47, RNU-48 and hsa-miR-16 stability exceeded the recommended housekeeping value suitable for normalization. The findings revealed that U6 may be a reliable housekeeping gene for normalization of miRNA RT-qPCR expression analysis using LBC samples.

p53-induced long non-coding RNA PGM5-AS1 inhibits the progression of esophageal squamous cell carcinoma through regulating miR-466/PTEN axis

A growing body of evidence suggests that long non-coding RNA (lncRNA) is aberrantly expressed in human cancer and linked to cancer initiation and development. We previously identified Homo sapiens PGM5 antisense RNA 1 (PGM5-AS1) as a novel esophageal squamous cell carcinoma (ESCC)-related lncRNA by performing high-throughput RNA sequencing. However, its clinical implication and biological function in ESCC are still uncharacterized. In the present study, we found that PGM5-AS1 was frequently downregulated in ESCC tissues, plasma, and cell lines, and low PGM5-AS1 expression was positively correlated with poor differentiation, advanced tumor node metastasis (TNM) stage, and lymph node metastasis. Importantly, PGM5-AS1 was identified to be an effective diagnostic and prognostic biomarker for ESCC patients. Functional experiments revealed that exogenous expression of PGM5-AS1 significantly suppressed the proliferation, migration, and invasion of ESCC cells in vitro as well as tumor growth in vivo. Mechanistically, PGM5-AS1 was transcriptionally activated by p53 and it could directly interact with and sequester miR-466 to elevate PTEN expression, thereby inhibiting ESCC progression. Overall, our data indicate that PGM5-AS1 is a novel tumor suppressor in ESCC and restoration of PGM5-AS1 may be a promising avenue for treatment of ESCC patient.

microRNAs: New prognostic, diagnostic, and therapeutic biomarkers in cervical cancer

Cervical cancer is as a kind of cancer beginning from the cervix. Given that cervical cancer could be observed in women who infected with papillomavirus, regular oral contraceptives, and multiple pregnancies. Early detection of cervical cancer is one of the most important aspects of the therapy of this malignancy. Despite several efforts, finding and developing new biomarkers for cervical cancer diagnosis are required. Among various prognostic, diagnostic, and therapeutic biomarkers, miRNA have been emerged as powerful biomarkers for detection, treatment, and monitoring of response to therapy in cervical cancer. Here, we summarized various miRNAs as an employable platform for prognostic, diagnostic, and therapeutic biomarkers in the treatment of cervical cancer.

Reference MicroRNAs for RT-qPCR Assays in Cervical Cancer Patients and Their Application to Studies of HPV16 and Hypoxia Biomarkers

MicroRNA (miRNA) expressions in tumor biopsies have shown potential as biomarkers in cervical cancer, but suitable reference RNAs for normalization of reverse transcription quantitative polymerase chain reaction (RT-qPCR) assays in patient cohorts with different clinicopathological characteristics are not available. We aimed to identify the optimal reference miRNAs and apply these to investigate the potential of miR-9-5p as human papilloma virus (HPV) 16 biomarker and miR-210-3p as hypoxia biomarker in cervical cancer. Candidate reference miRNAs were preselected in sequencing data of 90 patients and ranked in a stability analysis by RefFinder. A selection of the most stable miRNAs was evaluated by geNorm and NormFinder analyses of RT-qPCR data of 29 patients. U6 small nuclear RNA (RNU6) was also included in the evaluation. MiR-9-5p and miR-210-3p expression was assessed by RT-qPCR in 45 and 65 patients, respectively. Nine candidates were preselected in the sequencing data after excluding those associated with clinical markers, HPV type, hypoxia status, suboptimal expression levels, and low stability. In RT-qPCR assays, the combination of miR-151-5p, miR-152-3p, and miR-423-3p was identified as the most stable normalization factor across clinical markers, HPV type, and hypoxia status. RNU6 showed poor stability. By applying the optimal reference miRNAs, higher miR-9-5p expression in HPV16- than HPV18-positive tumors and higher miR-210-3p expression in more hypoxic than less hypoxic tumors were found in accordance with the sequencing data. MiR-210-3p was associated with poor outcome by both sequencing and RT-qPCR assays. In conclusion, miR-151-5p, miR-152-3p, and miR-423-3p are suitable reference miRNAs in cervical cancer. MiR-9-5p and miR-210-3p are promising HPV16 and hypoxia biomarkers, respectively.

MicroRNA-466 inhibits osteosarcoma cell proliferation and induces apoptosis by targeting CCND1

Emerging pieces of evidence indicate that microRNA-466 (miR-466) serves as a tumor suppressor in several human tumors, including colorectal cancer and prostate cancer. However, whether miR-466 is involved in osteosarcoma (OS) progression remains largely unknown. The present study demonstrated that miR-466 was significantly downregulated in OS tissues and cell lines. Furthermore, it was revealed that the expression of miR-466 was negatively correlated with OS severity. Moreover, low miR-466 expression in patients with OS predicted poor prognosis. Through functional experiments, miR-466 overexpression significantly inhibited the proliferation and cell cycle of OS cells while inducing cellular apoptosis. In terms of mechanism, it was revealed that CCND1 was a target of miR-466 in OS cells. miR-466 overexpression suppressed CCND1 expression in OS cells. A reverse association was observed between the expression levels of miR-466 and CCND1 in OS tissues. Furthermore, CCND1 restoration in OS cells significantly rescued the effects of miR-466 on cellular proliferation and apoptosis. Overall, the results of the present study demonstrated that miR-466 suppressed OS progression by targeting CCND1, suggesting that miR-466 may be a promising biomarker and therapeutic target for OS prognosis and treatment.

MicroRNA-466 (miR-466) functions as a tumor suppressor and prognostic factor in colorectal cancer (CRC)

MicroRNAs (miRNAs) have an important role in the regulation of tumor development and metastasis. In this study, we investigated the clinical and prognostic value as well as biological function of miR-466 in colorectal cancer (CRC). Tumor and adjacent healthy tissues were obtained from 100 patients diagnosed with CRC. miR-466 expression was determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR). mRNA and protein levels of cyclin D1, apoptosis regulator BAX (BAX), and matrix metalloproteinase-2 (MMP-2) were analyzed by qRT-PCR and Western blot, respectively, in SW-620 CRC cells transfected with miR-466 mimics or negative control miRNA. Effects of miR-466 on SW-620 cell proliferation, cell cycle and apoptosis, and invasion were investigated using CCK-8 assay, flow cytometry and Transwell assay, respectively. miR-466 expression was significantly downregulated in tumor tissues compared to matched adjacent non-tumor tissues. Low expression of miR-466 was significantly correlated with the tumor size, Tumor Node Metastasis stage, lymph node metastasis, and distant metastasis. The overall survival of CRC patients with low miR-466 expression was significantly shorter compared to high-miR-466 expression group (log-rank test: p = 0.0103). Multivariate analysis revealed that low miR-466 expression was associated with poor prognosis in CRC patients. The ectopic expression of miR-466 suppressed cell proliferation and migration/invasion, as well as induced G0/G1 arrest and apoptosis in SW-620 cells. Moreover, the ectopic expression of miR-466 decreased the expression of cyclin D1 and MMP-2, but increased BAX expression in SW-620 cells. In conclusion, our findings demonstrated that miR-466 functions as a suppressor miRNA in CRC and may be used as a prognostic factor in these patients.

MicroRNAs as markers of progression in cervical cancer: a systematic review

BACKGROUND

Invasive cervical cancer (ICC) is caused by high-risk human papillomavirus types (HR-HPVs) and is usually preceded by a long phase of intraepithelial neoplasia (CIN). Before invasion, (epi) genetic changes, potentially applicable as molecular markers within cervical screening, occur in HPV host cells. Epigenetic alterations, such as dysregulation of microRNA (miRNA) expression, are frequently observed in ICC. The mechanisms and role of miRNA dysregulation in cervical carcinogenesis are still largely unknown.

METHODS

We provide an overview of the studies investigating miRNA expression in relation to ICC progression, highlighting their common outcomes and their weaknesses/strengths. To achieve this, we systematically searched through Pubmed database all articles between January 2010 and December 2017.

RESULTS

From the 24 studies retrieved, miR-29a and miR-21 are the most frequently down- and up-regulated in ICC progression, respectively. Microarray-based studies show a small overlap, with miR-10a, miR-20b, miR-9, miR-16 and miR-106 found repeatedly dysregulated. miR-34a, miR-125 and miR-375 were also found dysregulated in cervical exfoliated cells in relation to cancer progression.

CONCLUSIONS

The pivotal role of miRNAs in ICC progression and initial development is becoming more and more relevant. Available studies are essentially based on convenience material, entailing possible selection bias, and frequently of small size: all these points still represent a limitation to a wide comprehension of miRNAs relevant for ICC. The targeted approach instead of a genome-wide investigation still precludes the identification of all the relevant miRNAs in the process. The implementation of deep sequencing on large scale population-based studies will help to discover and validate the relation between altered miRNA expression and CC progression for the identification of biomarkers. Optimally, once explored on a miRNome scale, small specific miRNA signatures maybe used in the context of screening.

The association between MTHFR polymorphism and cervical cancer

Cervical cancer is an extremely prevalent disease worldwide. The purpose of this study was to illustrate the relationship between methylenetetrahydrofolate reductase (MTHFR) polymorphisms or methionine synthase reductase (MTRR) polymorphisms and cervical cancer. There were 372 women who performed genetic and folic acid assessments. For the MTHFR C677T, there was no significant difference in the distribution of C allele and T allele in the three groups. However, the mutant C allele of MTHFR A1298C was significantly higher in the cancer group than in the normal group. Similarly, the mutant G allele of MTRR A66G was also higher than the normal group. The serum folic acid levels were gradually decreased with the development of cervical lesions. Serum folate levels in 4–9 ng/ml and ≤4 ng/ml were both significantly associated with cervical cancer risk. However, the MTHFR C677T polymorphism was not associated with the risk of cervical cancer or CIN. In contrast, the MTHFR A1298C polymorphism could increase the risk of both cervical cancer and CIN. In addition, the MTRR A66G polymorphism was only associated with the risk of cervical cancer but not CIN.

MicroRNA-466 with tumor markers for cervical cancer screening

Cervical cancer is the second most common cancer in women in the world. In this study, we explore tumor markers and microRNA-466 combination for cervical cancer screening. Tumor markers were measured by the methods of electro-chemiluminescent immunoassay and enzyme immunoassay. The microRNA-466 was performed by quantitative real-time polymerase chain reaction. Among normal group, hyperplasia group and cancer group, the CEA expression levels were 2.26 ng/ml, 3.85 ng/ml and 16.08 ng/ml, respectively. While the CA125 expression levels were 13.61 u/ml, 27.32 u/ml and 44.93 u/ml, respectively. The SCCA expression levels were 13.61 ng/ml, 27.32 ng/ml and 44.93 ng/ml, respectively. The expression levels of tumor markers were all gradually increased with the development of cervical lesions. The expression levels of microRNA-466 in cervical cancers (0.62) were greater than that in normal (0.076) and hyperplasia (0.24). The expression of microRNA-466 was correlated with lymphnode metastasis (P=0.000). There is a lower overall survival rate of patient with large tumor or lymphnode metastasis. Thus, the combination of tumor markers and microRNA-466 can be useful for early detection of cervical cancer and indicators for advanced stage and prognosis of the disease.

A Both-End Blocked Peroxidase-Mimicking DNAzyme for Low-Background Chemiluminescent Sensing of miRNA

G-quadruplex DNAzymes that exhibited peroxidase-like activity have been shown to be appealing reporters for amplified readout of biosensing events simply by their formation or dissociation in the presence of analytes. For low background signaling, the efficient preblock of DNAzymes is critically important. Herein, we report a both-end blocked DNAzyme beacon strategy for chemiluminescent biosensing. The catalytic activity of peroxidase-mimicking DNAzyme can be inactivated fully by fixing both ends of the DNAzyme sequence, and easily recovered via a strand displace reaction between the miRNA and the block DNA. The efficient block and recovery of DNAzymes provide the both-end blocked beacon the highest signal-to-background ratio (over 25) among the reported DNAzymes for amplification-free detection of miRNA. As a result, the beacon allowed detection of subpicomolar miRNA without any labeling and amplification procedures, which is about 40-fold more sensitive than the traditional hairpin fluorescence beacon. Also, it exhibited excellent discrimination ability that can distinguish single-base mismatch miRNA. The simplicity, high sensitivity, and selectivity provided by the beacon make it a promising alternative tool for nucleic acid detection.