Systematic Review and Meta-analysis of the Prognostic Significance of miRNAs in Melanoma Patients

Circulating microRNAs as diagnostic biomarkers for melanoma: a systematic review and meta-analysis

BACKGROUND

Recent studies have shown that circulating microRNAs (miRNAs) can be used as diagnostic biomarkers for melanoma. This study aimed to evaluate the diagnostic value of circulating miRNAs for melanoma.

METHODS

A comprehensive literature search was conducted and the quality of the included literature was evaluated using QUADAS-2 (Quality Assessment for diagnostic accuracy studies), and the diagnostic accuracy was assessed by pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the curve (AUC). We used Deeks' funnel plot to evaluate publication bias.

RESULTS

The meta-analysis included 10 articles covering 16 studies, and the results showed that circulating miRNAs provide high diagnostic accuracy for melanoma. The overall pooled sensitivity was 0.87 (95% CI: 0.82-0.91), specificity was 0.81 (95% CI: 0.77-0.85), PLR was 4.6 (95% CI: 3.7-5.8), NLR was 0.16 (95% CI: 0.11-0.23), DOR was 29 (95% CI: 18-49), and AUC was 0.90 (95% CI: 0.87-0.92), respectively. Subgroup analysis showed better diagnostic value in miRNA clusters, European population, plasma miRNAs, and upregulated miRNAs compared to other subgroups.

CONCLUSIONS

The results indicated that circulating microRNAs can be used as a non-invasive biomarker for the diagnosis of melanoma.

The Role of Biomarkers in the Diagnosis and Prognosis of Different Stages of Melanoma

Melanoma is a skin cancer arising from melanocytes, the cells responsible for synthesizing melanin pigment, which gives the skin its color. Early diagnosis and treatment of melanoma increase survival rates. Clinical examination and biopsy are the primary tools used to diagnose melanoma. However, distinguishing between pre-malignant melanocytic lesions and early invasive melanoma histopathologically remains challenging. Therefore, additional modalities such as a detailed clinical history, imaging, genetic testing, and biomarkers have been applied to diagnose melanoma. This review discusses the current trends in biomarker advancements over the last 10 years to assist in the early detection and diagnosis of melanoma. Biomarkers such as melanoma-associated antigens (MAAs), S100B, microRNAs (miRNAs), and circulating tumor cells (CTCs) have the potential to aid in the detection, diagnosis, and prognosis of melanoma. However, the application of biomarkers in the diagnosis of melanoma is still evolving.

miRNAs as potential game-changers in melanoma: A comprehensive review

Melanoma is the sixth most frequent malignancy. It represents 1.7% of all cancer cases worldwide. Many risk factors are associated with melanoma including ultraviolet radiation skin phenotype, Pigmented Nevi, Pesticides, and genetic and epigenetic factors. Of the main epigenetic factors affecting melanoma are microribonucleic acids (miRNAs). They are short nucleic acid chains that have the potential to prevent the expression of a number of target genes. They could target a number of genes related to melanoma initiation, stemness, angiogenesis, apoptosis, proliferation, and potential resistance to treatment. Additionally, they can control several melanoma signaling pathways, including P53, WNT/-catenin, JAK/STAT, PI3K/AKT/mTOR axis, TGF- β, and EGFR. MiRNAs also play a role in the resistance of melanoma to essential treatment regimens. The stability and abundance of miRNAs might be important factors enhancing the use of miRNAs as markers of prognosis, diagnosis, stemness, survival, and metastasis in melanoma patients.

Clinical Investigation of Chemotherapeutic Resistance and miRNA Expressions in Head and Neck Cancers: A Thorough PRISMA Compliant Systematic Review and Comprehensive Meta-Analysis

Background: Chemoresistance is a significant barrier to combating head and neck cancer, and decoding this resistance can widen the therapeutic application of such chemotherapeutic drugs. This systematic review and meta-analysis explores the influence of microRNA (miRNA) expressions on chemoresistance in head and neck cancers (HNC). The objective is to evaluate the theragnostic effects of microRNA expressions on chemoresistance in HNC patients and investigate the utility of miRNAs as biomarkers and avenues for new therapeutic targets. Methods: We performed a comprehensive bibliographic search that included the SCOPUS, PubMed, and Science Direct bibliographic databases. These searches conformed to a predefined set of search strategies. Following the PRISMA guidelines, inclusion and exclusion criteria were framed upon completing the literature search. The data items extracted were tabulated and collated in MS Excel. This spreadsheet was used to determine the effect size estimation for the theragnostic effects of miRNA expressions on chemoresistance in HNC, the hazard ratio (HR), and 95% confidence intervals (95% CI). The comprehensive meta-analysis was performed using the random effects model. Heterogeneity among the data collected was assessed using the Q test, Tau², I², and Z measures. Publication bias of the included studies was checked using the Egger's bias indicator test, Orwin and classic fail-safe N test, Begg and Mazumdar rank collection test, and Duval and Tweedie's trim and fill methods. Results: After collating the data from 23 studies, dysregulation of 34 miRNAs was observed in 2189 people. These data were gathered from 23 studies. Out of the 34 miRNAs considered, 22 were up-regulated, while 12 were down-regulated. The TaqMan transcription kits were the most used miRNA profiling platform, and miR-200c was seen to have a mixed dysregulation. We measured the overall pooled effect estimate of HR to be 1.516 for the various analyzed miRNA at a 95% confidence interval of 1.303-1.765, with a significant p-value. The null hypothesis test's Z value was 5.377, and the p-value was correspondingly noted to be less than 0.0001. This outcome indicates that the risk of death is determined to be higher in up-regulated groups than in down-regulated groups. Among the 34 miRNAs that were investigated, seven miRNAs were associated with an improved prognosis, especially with the overexpression of these seven miRNAs (miR15b-5p, miR-548b, miR-519d, miR-1278, miR-145, miR-200c, Hsa- miR139-3p). Discussion: The findings reveal that intricate relationships between miRNAs' expression and chemotherapeutic resistance in HNC are more likely to exist and can be potential therapeutic targets. This review suggests the involvement of specific miRNAs as predictors of chemoresistance and sensitivity in HNC. The examination of the current study results illustrates the significance of miRNA expression as a theragnostic biomarker in medical oncology.

Study on the Mechanism of miR-125b-5p Affecting Melanocyte Biological Behavior and Melanogenesis in Vitiligo through Regulation of MITF

Objective. The goal was to confirm the mechanism by which miR-125b-5p influences melanocyte biological behavior and melanogenesis in vitiligo by regulating MITF. Methods. oe-MITF, sh-MITF, miR-125b-5p mimic, NC-mimic, NC-inhibitor, and miR-125b-5p inhibitor were transfected into cells by cell transfection. Western blotting was used to detect the related protein expression, qRT–PCR was used to detect miR-125b-5p and MITF expression, immunohistochemistry was used to detect the MITF-positive cells in vitiligo patients tissues, and a dual-luciferase reporter system was used to detect the target of miR-125b-5p and MITF. PIG1 and PIG3V cell proliferation by the CCK-8 method, cell cycle progression and apoptosis by flow cytometry, apoptosis was detected by TUNEL, Tyr activity and melanin content were measured using Tyr and melanin content assay kits. Results. Compared with the healthy control group, the expression of miR-125b-5p in the tissues and serum of vitiligo patients was upregulated, and the expression of MITF was downregulated; compared with PIG1 cells, the expression of miR-125b-5p and MITF in the PIG3V group was consistent with the above. Compared with the NC-minic group, the cell proliferation activity of the miR-125b-5p mimic group decreased, apoptosis increased, and the expression levels of melanogenesis-related proteins Tyr, Tyrp1, Tyrp2, and DCT were downregulated. Compared with the NC-inhibitor group, the above indices in the miR-125b-5p inhibitor group were all opposite to those in the miR-125b-5p mimic group. Transfection of oe-MITF into the miR-125b-5p mimic group reversed the effect of the miR-125b-5p mimic, while transfection of sh-MITF enhanced the effect of the miR-125b-5p mimic. Conclusion. miR-125b-5p affects vitiligo melanocyte biological behavior and melanogenesis by downregulating MITF expression.

Mapping Research on miRNAs in Cancer: A Global DataAnalysis and Bibliometric Profiling Analysis

miRNAs biomarkers are emerging as an essential part of clinical oncology. Their oncogenic and tumour suppressor properties playing a role in malignancy has generated interest in their potential for use in disease prognosis. While several studies on miRNA have been carried out across the globe, evaluating the clinical implications of miRNAs in cancer diagnosis and prognosis research has currently not been attempted. A study delineating the area of miRNA research, including the topics presently being focused on, the seminal papers in this field, and the direction of research interest, does not exist. This study aims to conduct a large-scale, global data analysis and bibliometric profiling analysis of studies to evaluate the research output of clinical implications of miRNAs in cancer diagnosis and prognosis listed in the SCOPUS database. A systematic search strategy was followed to identify and extract all relevant studies, subsequently analysed to generate a bibliometric map. SPSS software (version 27) was used to calculate bibliometric indicators or parameters for analysis, such as year and country of affiliation with leading authors, journals, and institutions. It is also used to analyse annual research outputs, including total citations and the number of times it has been cited with productive nations and H-index. The number of global research articles retrieved for miRNA-Cancer research over the study period 2003 to 2019 was 18,636. Between 2012 and 2019, the growth rate of global publications is six times (n = 15,959; 90.71 percent articles) that of 2003 to 2011. (2704; 9.29 per cent articles). China published the most publications in the field of miRNA in cancer (n = 7782; 41%), while the United States had the most citations (n = 327,538; 48%) during the time span. Of these journals, Oncotarget has the highest percentage of article publications. The journal Cancer Research had the most citations (n = 41,876), with 6.20 per cent (n = 41,876). This study revealed a wide variety of journals in which miRNA-Cancer research are published; these bibliometric parameters exhibit crucial clinical information on performance assessment of research productivity and quality of research output. Therefore, this study provides a helpful reference for clinical oncologists, cancer scientists, policy decision-makers and clinical data researchers.

Molecular Investigation of miRNA Biomarkers as Chemoresistance Regulators in Melanoma: A Protocol for Systematic Review and Meta-Analysis

Introduction: Melanoma is a global disease that is predominant in Western countries. However, reliable data resources and comprehensive studies on the theragnostic efficiency of miRNAs in melanoma are scarce. Hence, a decisive study or comprehensive review is required to collate the evidence for profiling miRNAs as a theragnostic marker. This protocol details a comprehensive systematic review and meta-analysis on the impact of miRNAs on chemoresistance and their association with theragnosis in melanoma. Methods and analysis: The articles will be retrieved from online bibliographic databases, including Cochrane Review, EMBASE, MEDLINE, PubMed, Scopus, Science Direct, and Web of Science, with different permutations of ‘keywords’. To obtain full-text papers of relevant research, a stated search method will be used, along with selection criteria. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis for Protocols 2015 (PRISMA-P) standards were used to create this study protocol. The hazard ratio (HR) with a 95% confidence interval will be analyzed using Comprehensive Meta-Analysis (CMA) software 3.0. (CI). The pooled effect size will be calculated using a random or fixed-effects meta-analysis model. Cochran’s Q test and the I2 statistic will be used to determine heterogeneity. Egger’s bias indicator test, Orwin’s and the classic fail-safe N tests, the Begg and Mazumdar rank collection test, and Duval and Tweedie’s trim and fill calculation will all be used to determine publication bias. The overall standard deviation will be evaluated using Z-statistics. Subgroup analyses will be performed according to the melanoma participants’ clinicopathological and biological characteristics and methodological factors if sufficient studies and retrieved data are identified and available. The source of heterogeneity will be assessed using a meta-regression analysis. A pairwise matrix could be developed using either a pairwise correlation or expression associations of miRNA with patients’ survival for the same studies.

Computational and Bioinformatics Methods for MicroRNA Gene Prediction

MicroRNAs (miRNAs) are 20-24-nucleotide-long noncoding RNAs that bind to the untranslated region (3' UTR) of their target mRNAs. The importance of miRNAs in medicine has grown rapidly in the 20 years since the discovery of them. As the regulatory function of miRNAs on biological processes was discovered, they were advocated to play a role in the underlying mechanisms of human pathogenesis. Functional studies have confirmed that miRNAs are promising in preclinical development through deregulation of genes targeted by miRNAs in many cancer cases. In this chapter, we summarize the miRNAs identified for some specific types of cancer and their functions. Besides, miRNAs function as cancer biomarker and their benefits to diagnosis and treatment of cancer are also discussed.

Is miRNA Regulation the Key to Controlling Non-Melanoma Skin Cancer Evolution?

Non melanoma skin cancer (NMSC) is one of the most common types of skin cancer. It has a number of subtypes, which include basal cell carcinoma, cutaneous squamous cell carcinoma and Merkel cell carcinoma. MicroRNAs are short, non-coding RNA (ribonucleic acid) molecules, capable of regulating gene expression at a post transcriptional level. They play a pivotal role in a variety of physiologic cellular functions and pathologies, including malignant diseases. The development of miRNAs represents an important study field, which has been extensively exploited in melanoma for almost a decade with promising results, therefore we consider it a stepstone for further research projects also in non-melanoma skin cancers. The aim of our study was to explore the current literature in order to present the role of the different miRNAs in some of the most frequent types of NMSC pertaining to oncogenesis, evolution and therapy. The most relevant and accurate available data from the literature were evaluated. Our study concluded that there are almost 100 miRNAs which can be upregulated or downregulated and can play a role in oncogenesis. They can be easily identified in circulation, are stable and they can be important diagnosis/prognosis and therapy monitoring markers.

The Prognostic Role of Micro-RNAs in Head and Neck Cancers: An Umbrella Review

We conducted an umbrella review which synthetizes the findings of systematic reviews available in the literature that investigate the prognostic role of miRNAs as potential biomarkers in the field of tertiary prevention of head and neck Cancer (HNC). We selected systematic reviews in English related to HNC, with meta-analysis of observational studies that reported quantitative prognostic measures, hazard ratios (HRs), overall survival (OS) or disease-free survival (DFS). The methodological quality of the included reviews was assessed by using the AMSTAR-2 tool. The most reported miRNAs were the following: miRNA2, Let7 family and miR17, etc. Four out of six reviews particularly emphasized the link between miRNA21 expression and HNC patients. Recently the cumulative effects of sets of miRNAs have been increasingly studied and might be a stronger predictor of survival than single miRNA.

The role of Hypoxia-Inducible Factor-1alpha and its signaling in melanoma

Adaptation to the loss of O2 is regulated via the activity of hypoxia-inducible factors such as Hypoxia-Inducible Factor-1 (HIF-1). HIF-1 acts as a main transcriptional mediator in the tissue hypoxia response that regulates over 1000 genes related to low oxygen tension. The role of HIF-1α in oncogenic processes includes angiogenesis, tumor metabolism, cell proliferation, and metastasis, which has been examined in various malignancies, such as melanoma. Melanoma is accompanied by a high death rate and a cancer type whose incidence has risen over the last decades. The linkage between O2 loss and melanogenesis had extensively studied over decades. Recent studies revealed that HIF-1α contributes to melanoma progression via different signaling pathways such as PI3K/Akt/mTOR, RAS/RAF/MEK/ERK, JAK/STAT, Wnt/β-catenin, Notch, and NF-κB. Also, various microRNAs (miRs) are known to mediate the HIF-1α role in melanoma. Therefore, HIF-1α offers a diagnostic/prognostic biomarker and a candidate for targeted therapy in melanoma.

microRNAs in the Regulation of Melanogenesis

Melanogenesis is the process leading to the synthesis of melanin, the main substance that influences skin color and plays a pivotal role against UV damage. Altered melanogenesis is observed in several pigmentation disorders. Melanogenesis occurs in specialized cells called melanocytes, physically and functionally related by means of autocrine and paracrine interplay to other skin cell types. Several external and internal factors control melanin biosynthesis and operate through different intracellular signaling pathways, which finally leads to the regulation of microphthalmia-associated transcription factor (MITF), the key transcription factor involved in melanogenesis and the expression of the main melanogenic enzymes, including TYR, TYRP-1, and TYRP-2. Epigenetic factors, including microRNAs (miRNAs), are involved in melanogenesis regulation. miRNAs are small, single-stranded, non-coding RNAs, of approximately 22 nucleotides in length, which control cell behavior by regulating gene expression, mainly by binding the 3′ untranslated region (3′-UTR) of target mRNAs. This review collects data on the miRNAs involved in melanogenesis and how these miRNAs can modulate target gene expression. Bringing to light the biological function of miRNAs could lead to a wider understanding of epigenetic melanogenesis regulation and its dysregulation. This knowledge may constitute the basis for developing innovative treatment approaches for pigmentation dysregulation.

Forkhead box F2 as a novel prognostic biomarker and potential therapeutic target in human cancers prone to bone metastasis: a meta-analysis

OBJECTIVE

To undertake a systematic review and meta-analysis to evaluate the prognostic value of Forkhead box F2 (FOXF2) levels in different types of cancers prone to bone metastasis.

METHODS

A systematic search of publications listed in electronic databases (The Web of Science, EMBASE®, PubMed®, PMC, Science Direct and CNKI) from inception to 5 November 2020 was conducted. The hazard ratios (HRs) and 95% confidence intervals (95% CIs) were used to assess the relationship between FOXF2 levels and patient prognosis including overall survival (OS) and disease-free survival (DFS).

RESULTS

Sixteen studies enrolling 8461 participants were included in the meta-analysis. High levels of FOXF2 were a predictor of OS (HR: 0.66; 95% CI 0.51, 0.86) and DFS (HR: 0.60; 95% CI 0.48, 0.76). The trim-and-fill analysis, sensitivity analysis and subgroup analyses stratified by the study characteristics confirmed the robustness of the results.

CONCLUSION

These current findings indicate that high FOXF2 levels could be an indicator of a good prognosis in cancer patients with tumours that are prone to bone metastasis. FOXF2 levels might be a clinically important prognostic biomarker.

Prognostic Value of MicroRNAs in Stage II Colorectal Cancer Patients: A Systematic Review and Meta-Analysis

BACKGROUND

We performed a systematic review and meta-analysis to identify and underline multiple microRNAs (miRNAs) as biomarkers of disease prognosis in stage II colorectal cancer (CRC) patients.

METHODS AND ANALYSIS

This systematic review and meta-analysis study was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The required articles were collected from online bibliographic databases from January 2011 to November 2019 with multiple permutation keywords. Quantitative data synthesis was based on a meta-analysis with pooled data to observe and analyse the outcome measures and effect estimates by using the random effect model. The subgroup analysis was performed from demographic characteristics and the available data.

RESULTS

Eighteen articles were included in this study, 16 of which were incorporated for meta-analysis to examine the stage II CRC prognosis with up- and downregulated miRNA expressions. The pooled hazard ratio (HR) for death in stage II CRC patients was 1.90 (95% confidence interval 1.63-2.211), with a significant p value. A subgroup analysis based on up- or downregulated miRNA expression individually and any deregulated miRNA was also associated with a worse prognosis. The subgroup analysis included parameters such as age, gender, stage II and III combined patients' survival and the repetitive miRNAs (miR21, miR215, miR143-5p, miR106a and miR145) individually.

CONCLUSION

MicroRNAs play a significant role in determining prognosis in stage II CRC patients, with upregulation of miR21, miR215, miR143-5p and miR106a, in particular, portending a worse prognosis. These miRNAs could be considered for further evaluation as biomarkers of prognosis and to guide the decision to administer adjuvant chemotherapy.

miRNA as promising theragnostic biomarkers for predicting radioresistance in cancer: A systematic review and meta-analysis

Radioresistance remains as an obstacle in cancer treatment. This systematic review and meta-analysis aimed to evaluate the association between the expression of miRNAs and responses to radiotherapy and the prognosis of different tumors. In total, 77 miRNAs in 19 cancer types were studied, in which 24 miRNAs were upregulated and 58 miRNAs were downregulated in cancer patients. Five miRNAs were differentially expressed. Moreover, 75 miRNAs were found to be related to radioresistance, while 5 were observed to be related to radiosensitivity. The pooled HR and 95 % confidence interval for the combined studies was 1.135 (0.819-1.574; P-value = 0.4). The HR values of the subgroup analysis for miR-21 (HR = 2.344; 95 % CI: 1.927-2.850; P-value = 0.000), nasopharyngeal carcinoma (HR = 0.448; 95 % CI: 0.265-0.760; P = 0.003) and breast cancer (HR = 1.131; 95 % CI: 0.311-4.109; P = .85) were obtained. Our results highlighted that across the published literature, miRNAs can modulate tumor radioresistance or sensitivity by affecting radiation-related signaling pathways. It seems that miRNAs could be considered as a theragnostic biomarker to predict and monitor clinical response to radiotherapy. Thus, the prediction of radioresistance in malignant patients will improve radiotherapy outcomes and radiotherapeutic resistance.

Prognostic Significance of FOXC1 in Various Cancers: A Systematic Review and Meta-Analysis

BACKGROUND

Forkhead box C1 (FOXC1), a member of the Forkhead box (Fox) transcription factor family, plays an essential role in lymphatic vessel formation, angiogenesis and metastasis. Observational studies examining the relationship between the protein biomarker FOXC1 and breast cancer prognosis have reported conflicting findings. This systematic review and meta-analysis evaluates the prognostic value of the FOXC1 expression in association with patient survival in breast cancer and other types of cancers in order to identify the overall prognostic effectiveness of FOXC1.

METHODS

This study followed the guidelines established in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). We conducted a broad search on the online bibliographic databases EMBASE, PubMed, Science Direct and Scopus, limiting search to publications from 2010 to 2018. The prognostic value was demonstrated by a random effects model meta-analysis using the hazard ratio (HR) with 95% confidence interval (CI) for overall survival (OS) in various cancer patients. The heterogeneity was measured by the I² statistic. Publication bias and quality assessment for the selected articles was performed. Subgroup analysis was conducted based on the data available from the selected articles.

RESULTS

A total of 16 studies met the predefined selection criteria established for our systematic review and meta-analysis, with multiple studies using diverse methodologies and reported on differing clinical outcomes, falling under a common banner of FOXC1 expression and survival in cancer. Overall, we observed a statistically non-significant association between FOXC1 protein expression and patients survival (HR: 1.186 and 95% CI 1.122-1.255, p = 0.000, I² = 88.83%).

CONCLUSION

In summary, FOXC1 protein expression indicated poor survival outcome in various carcinomas, especially in patients with breast cancer, suggesting it as a possible biomarker for the prognosis in multiple carcinomas. Further clinical evaluation and large-scale cohort studies are required to accurately identify its possible clinical utility.

Clinical Theragnostic Potential of Diverse miRNA Expressions in Prostate Cancer: A Systematic Review and Meta-Analysis

Background: Prostate cancer (PrC) is the second-most frequent cancer in men, its incidence is emerging globally and is the fifth leading cause of death worldwide. While diagnosis and prognosis of PrC have been studied well, the associated therapeutic biomarkers have not yet been investigated comprehensively. This systematic review and meta-analysis aim to evaluate the theragnostic effects of microRNA expressions on chemoresistance in prostate cancer and to analyse the utility of miRNAs as clinical theragnostic biomarkers. Methods: A systematic literature search for studies reporting miRNA expressions and their role in chemoresistance in PrC published until 2018 was collected from bibliographic databases. The evaluation of data was performed as per PRISMA guidelines for systematic review and meta-analysis. Meta-analysis was performed using a random-effects model using Comprehensive Meta-Analysis (CMA) software. Heterogeneity between studies was analysed using Cochran’s Q test, I² and the Tau statistic. Quality assessment of the studies was performed using the Newcastle–Ottawa Scale (NOS) for the methodological assessment of cohort studies. Publication bias was assessed using Egger’s bias indicator test, Orwin and classic fail-safe N test, Begg and Mazumdar rank collection test, and Duval and Tweedie’s trim and fill methods. Findings: Out of 2909 studies retrieved, 79 studies were shortlisted and reviewed. A total of 17 studies met our eligibility criteria, from which 779 PrC patients and 17 chemotherapy drugs were examined, including docetaxel and paclitaxel. The majority of the drug regulatory genes reported were involved in cell survival, angiogenesis and cell proliferation pathways. We studied 42 miRNAs across all studies, out of which two miRNAs were found to be influencing chemosensitivity, while 21 were involved in chemoresistance. However, the remaining 19 miRNAs did not appear to have any theragnostic effects. Besides, the prognostic impact of the miRNAs was evaluated and had a pooled HR value of 1.960 with 95% CI (1.377–2.791). Interpretation: The observation of the current study depicts the significance of miRNA expression as a theragnostic biomarker in medical oncology. This review suggests the involvement of specific miRNAs as predictors of chemoresistance and sensitivity in PrC. Hence, the current systematic review and meta-analysis provide insight on the use of miRNA as PrC biomarkers, which can be harnessed as molecular candidates for therapeutic targeting.

The Significance of miRNAs as a Prognostic Biomarker for Survival Outcome in T Cell - Acute Lymphoblastic Leukemia Patients: A Systematic Review and Meta-Analysis

Purpose

T-cell acute lymphoblastic leukemia (T-ALL) affects lymphoid cells. Previous studies have reported that miRNAs play a significant role in T-ALL prognosis and have the potential to function as biomarkers in T-ALL. Therefore, this systematic review and meta-analysis study was designed to evaluate the overall prognostic impact of miRNAs in T-ALL patients.

Methods

Eligible studies published between Jan 2010 and April 2018 were retrieved from online bibliographic databases based on multiple keywords to generate search strings. Meta-analysis was performed using the outcome measure, Hazard Ratio (HR). A survival analysis of all studies was conducted and a subsequent forest plot was generated to evaluate the pooled effect size, across all T-ALL patients. Subgroup analysis was conducted based on demographic characteristics and commonly represented miRNAs among the included studies.

Results

A total of 17 studies were included for systematic review, among which 16 studies were eligible for meta-analysis, which, in total discussed 32 different miRNAs. The mean effect size of HR value was 0.929 (CI 0.878–0984), which indicates a decrease in risk of death by 7.1%. The analysis was based on the random effects model with the heterogeneity measure index (I²) being 84.92%. The pooled effect size (HR) of upregulated and downregulated miRNA expressions on survival outcome in the T-ALL patient was 0.787 (CI 0.732–0.845) and 1.225 (CI 1.110–1.344) respectively. The subgroup analysis was performed based on demographic characteristics (age, gender, lactate dehydrogenase, WBC count) and expression of miR221 and miR46a.

Conclusion

Our systematic review and meta-analysis findings suggest that the overall miRNA expression is potentially associated with a decreased likelihood of death in T-ALL patients. Although our findings are inconclusive, the results point toward miRNA expression allowing for prognostic evaluation of T-ALL patients.

miRNAs in the Diagnosis and Prognosis of Skin Cancer

Skin cancer is, at present, the most common type of malignancy in the Caucasian population. Its incidence has increased rapidly in the last decade for both melanoma and non-melanoma skin cancer. Differential expression profiles of microRNAs (miRNAs) have been reported for a variety of different cancers, including skin cancers. Since miRNAs’ discovery as regulators of gene expression, their importance grew in the field of oncology. miRNAs can post-transcriptionally regulate gene expression, tumor initiation, development progression, and aggressiveness. Nowadays, these short regulatory RNAs are perceived as one of the epigenetic markers for the identification of new diagnostic and/or prognostic molecular markers. Moreover, as miRNAs can drive tumorigenesis, they might eventually represent new therapy targets. Some miRNAs are pleiotropic, such as miR-214, which was found deregulated in several other tumors besides skin cancers. Some others are specific for one or more skin cancer types, like miR-21 and miR-221 for cutaneous melanoma and cutaneous squamous carcinoma or miR-155 for melanoma and cutaneous lymphoma. The goal of this review was to summarize some of the main miRNA detection technologies that are used to evaluate miRNAs in tissues and body fluids. Furthermore, their quantification limits, conformity, and robustness are discussed. Aberrant miRNA expression is analyzed for cutaneous melanoma, cutaneous squamous cell carcinoma (CSCC), skin lymphomas, cutaneous lymphoma, and Merkel cell carcinoma (MCC). In this type of disease, miRNAs are described as potential biomarkers to diagnose early lesion and/or early metastatic disease. In the future, whether in tissue or circulating in body fluids, miRNAs will gain their place in skin cancer diagnosis, prognosis, and future therapeutic targets.

Clinical Theragnostic Relationship between Drug-Resistance Specific miRNA Expressions, Chemotherapeutic Resistance, and Sensitivity in Breast Cancer: A Systematic Review and Meta-Analysis

Awareness of breast cancer has been increasing due to early detection, but the advanced disease has limited treatment options. There has been growing evidence on the role of miRNAs involved in regulating the resistance in several cancers. We performed a comprehensive systematic review and meta-analysis on the role of miRNAs in influencing the chemoresistance and sensitivity of breast cancer. A bibliographic search was performed in PubMed and Science Direct based on the search strategy, and studies published until December 2018 were retrieved. The eligible studies were included based on the selection criteria, and a detailed systematic review and meta-analysis were performed based on PRISMA guidelines. A random-effects model was utilised to evaluate the combined effect size of the obtained hazard ratio and 95% confidence intervals from the eligible studies. Publication bias was assessed with Cochran’s Q test, I² statistic, Orwin and Classic fail-safe N test, Begg and Mazumdar rank correlation test, Duval and Tweedie trim and fill calculation and the Egger’s bias indicator. A total of 4584 potential studies were screened. Of these, 85 articles were eligible for our systematic review and meta-analysis. In the 85 studies, 188 different miRNAs were studied, of which 96 were upregulated, 87 were downregulated and 5 were not involved in regulation. Overall, 24 drugs were used for treatment, with doxorubicin being prominently reported in 15 studies followed by Paclitaxel in 11 studies, and 5 drugs were used in combinations. We found only two significant HR values from the studies (miR-125b and miR-4443) and our meta-analysis results yielded a combined HR value of 0.748 with a 95% confidence interval of 0.508–1.100; p-value of 0.140. In conclusion, our results suggest there are different miRNAs involved in the regulation of chemoresistance through diverse drug genetic targets. These biomarkers play a crucial role in guiding the effective diagnostic and prognostic efficiency of breast cancer. The screening of miRNAs as a theragnostic biomarker must be brought into regular practice for all diseases. We anticipate that our study serves as a reference in framing future studies and clinical trials for utilising miRNAs and their respective drug targets.

Prognostic Value of miRNAs in Head and Neck Cancers: A Comprehensive Systematic and Meta-Analysis

Head and Neck Cancer (HNC) is the sixth most common type of cancer across the globe, with more than 300,000 deaths each year, globally. However, there are currently no standardised molecular markers that assist in determining HNC prognosis. The literature for this systematic review and meta-analysis were sourced from multiple bibliographic databases. This review followed PRISMA guidelines. The Hazard Ratio (HR) was selected as the effect size metric to independently assess overall survival (OS), disease-free survival (DFS), and prognosis. Subgroup analysis was performed for individual highly represented miRNA. A total of 6843 patients across 50 studies were included in the systematic review and 34 studies were included in the meta-analysis. Studies across 12 countries were assessed, with China representing 36.7% of all included studies. The analysis of the survival endpoints of OS and DFS were conducted separately, with the overall pooled effect size (HR) for each being 1.825 (95% CI 1.527–2.181; p < 0.05) and 2.596 (95% CI 1.917–3.515; p < 0.05), respectively. Subgroup analysis was conducted for impact of miR-21, 200b, 155, 18a, 34c-5p, 125b, 20a and 375 on OS, and miR-21 and 34a on DFS. The pooled results were found to be statistically significant for both OS and DFS. The meta-analysis indicated that miRNA alterations can account for an 82.5% decrease in OS probability and a 159.6% decrease in DFS probability. These results indicate that miRNAs have potential clinical value as prognostic biomarkers in HNC, with miR-21, 125b, 34c-5p and 18a, in particular, showing great potential as prognostic molecular markers. Further large scale cohort studies focusing on these miRNAs are recommended to verify the clinical utility of these markers individually and/or in combination.

Diagnostic and prognostic role of HE4 expression in multiple carcinomas: A protocol for systematic review and meta-analysis

BACKGROUND

Human epididymis protein 4 (HE4) protein has garnered a great degree of interest as a complementary biomarker to carbohydrate antigen 125 (CA125), or even as an independent biomarker for monitoring, diagnosis, and prognostication of ovarian cancer. Its use is currently limited to ovarian cancer. Recent studies have suggested that it could also be used in other types of cancers.

METHODS

The Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) guidelines was used to design this meta-analysis protocol. The final study will also be conducted under the PRISMA guidelines for systematic reviews and meta-analyses. The core bibliographic database search will be carried out by 2 reviewers working individually, with each conducting an initial screening based on titles and abstracts. The shortlisted articles will be selected for review and statistical analysis based on predefined inclusion and exclusion criteria. Study characteristics, relevant clinicopathological characteristics and statistical data required for meta-analysis (hazard ratios [HRs] and 95% confidence interval [CIs) will be extracted and compiled into a MS Excel datasheet. Meta-analysis will be performed, using a random-effects model, and the results (pooled HR and 95% CI) will be presented in the form of a forest plot. Publication bias will also be assessed by use of Egger bias indicator test and funnel plot symmetry. If data are insufficient, a narrative line of review will be pursued.

DISCUSSION

HE4 protein has been shown to have great potential for clinical use as a diagnostic and prognostic marker in epithelial ovarian cancer (EOC). However, HE4 is not only limited to expression in ovarian cancer, but is also overexpressed in lung and endometrial cancers. The effectiveness of HE4 as a biomarker in cancers (other than EOC) has not yet been studied in the form of a comprehensive systematic review and meta-analysis. The results of this study should allow for expanded use of HE4 as a multiutility biomarker in multiple cancer types, thereby, elevating HE4's value as a cancer biomarker.

PROSPERO REGISTRATION

CRD42019120326.

miRNA Predictors of Pancreatic Cancer Chemotherapeutic Response: A Systematic Review and Meta-Analysis

BACKGROUND

pancreatic cancer (PC) has increasing incidence and mortality in developing countries, and drug resistance is a significant hindrance to the efficacy of successful treatment. The objective of this systematic review and meta-analysis was to evaluate the association between miRNAs and response to chemotherapy in pancreatic cancer patients.

METHODS

the systematic review and meta-analysis was based on articles collected from a thorough search of PubMed and Science Direct databases for publications spanning from January 2008 to December 2018. The articles were screened via a set of inclusion and exclusion criteria based on the preferred reporting items for systematic review and meta-analysis (PRISMA) guidelines. Data was extracted, collated and tabulated in MS Excel for further synthesis. Hazard ratio (HR) was selected as the effect size metric to be pooled across studies for the meta-analysis, with the random effects model being applied. Subgroup analysis was also conducted, and the presence of publication bias in the selected studies was assessed. Publication bias of the included studies was quantified.

FINDINGS

of the 169 articles screened, 43 studies were included in our systematic review and 13 articles were included in the meta-analysis. Gemcitabine was observed to be the principal drug used in a majority of the studies. A total of 48 miRNAs have been studied, and 18 were observed to have possible contributions to chemoresistance, while 15 were observed to have possible contributions to chemosensitivity. 41 drug-related genetic pathways have been identified, through which the highlighted miRNA may be affecting chemosensitivity/resistance. The pooled HR value for overall survival was 1.603; (95% Confidence Interval (CI) 1.2-2.143; p-value: 0.01), with the subgroup analysis for miR-21 showing HR for resistance of 2.061; 95% CI 1.195-3.556; p-value: 0.09.

INTERPRETATION

our results highlight multiple miRNAs that have possible associations with modulation of chemotherapy response in pancreatic cancer patients. Further studies are needed to discover the molecular mechanisms underlying these associations before they can be suggested for use as biomarkers of response to chemotherapeutic interventions in pancreatic cancer.

Prognostic significance of blood inflammatory biomarkers NLR, PLR, and LMR in cancer-A protocol for systematic review and meta-analysis

BACKGROUND

The neutrophil-lymphocyte-ratio, platelet-lymphocyte-ratio, and monocyte-lymphocyte-ratio have been explored as a simple, inexpensive, and effective method for cancer prognosis. However, there are no studies that have investigated the comparative utility of these markers, in multiple cancers.

METHODS

The preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) guidelines were used to design this meta-analysis protocol. The final study will also be conducted under the PRISMA guidelines for systematic reviews and meta-analyses. The core bibliographic database search will be carried out by 2 reviewers working individually, with each conducting an initial screening based on titles and abstracts. The shortlisted articles will be selected for review and quantitative analysis, based on predefined inclusion and exclusion criteria. Study characteristics, relevant clinicopathological characteristics, and statistical data required for meta-analysis (hazard ratios [HRs] and 95% confidence intervals [CIs]) will be extracted and compiled into a MS Excel datasheet. Meta-analysis will be performed, using a random-effects model, and the results (pooled HR and 95% CI) will be presented in the form of a forest plot. Publication bias will also be assessed by use of Egger bias indicator test and funnel plot symmetry. If statistical data from included studies is insufficient, a qualitative literature review will be pursued.PROSPERO registration: PROSPERO CRD42019121008.

Prognostic miRNA classifiers in t cell acute lymphoblastic leukemia: Study protocol for a systematic review and meta-analysis of observational clinical studies

BACKGROUND

The prognostic value of microRNA (miRNA) expression in T-cell acute lymphoblastic leukemia (T-ALL) has generated significant research interest in recent years. However, most diagnostic and prognostic studies with regards to miRNA expression have been focused on combined B cell and T cell lymphoblastic leukemia. There are very few studies reporting the prognostic effects of miRNA expression on T-ALL. Therefore, a pioneer systematic review and meta-analysis was proposed to explore the possibilities of miRNAs as viable prognostic markers in T-ALL. This study is intended to be useful as a guideline for future research into drug evaluation and targeting miRNA as a biomarker for the treatment and prognosis of T-ALL.

METHODS

The systematic review will be reported according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. The study search will be conducted by using Cochrane, EMBASE, Medline, Science Direct, and SCOPUS bibliographic databases. The reference lists of included studies will be manually searched to further bolster the search results. A combination of keywords will be used to search the databases.

DISCUSSION

To explore the effect of miRNA on prognosis, forest plots will be generated to assess pooled HR and 95% CI. Upregulation, downregulation, and deregulation of specific miRNAs will be individually noted and used to extrapolate patient prognosis when associated with risk factors involved in T-ALL. Subgroup analysis will be carried out to analyze the effect of deregulation of miRNA expression on patient prognosis. A fixed or random-effects model of meta-analysis will be used depending upon between-study heterogeneity. This systematic review and meta-analysis will identify and synthesize evidence to determine the prognosis of miRNA in T-ALL and suggest the possible miRNA from meta-analysis results to predict as a biomarker for further detection and treatment of T-ALL.

Validation of miRNA prognostic significance in stage II colorectal cancer: A protocol for systematic review and meta-analysis of observational clinical studies

BACKGROUND

Advances in early detection and treatment of colorectal cancer (CRC) has seen marked improvements in recent years. However, it is still the third leading cause of cancer-related deaths worldwide. Although there are studies reporting the significance of miRNAs in stage II colorectal cancer, there is no known comprehensive study utilising collective data from multiple published studies. Thus, this study will focus on performing a systematic review and meta-analysis using published data to identify and underline multiple miRNA targets, with regard to disease prognosis in stage II CRC patients.

METHODS

The systematic review will be reported according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines, 2015 statement. The required articles will be obtained via a search of bibliographical databases such as Cochrane Library, EMBASE, MEDLINE, PubMed, and Web of Science. A set of keywords in multiple permutations will be used for the search. The reference lists of included studies will also be manually searched to further increase the robustness of the search results. The systematic review will primarily be done via a literary synthesis.

RESULTS

Quantitative data synthesis will be based on estimated effect across the studies with forest plots generated to observe pooled outcome measures. A fixed or random-effect model of meta-analysis will be used depending upon the heterogeneity observed between studies. Subgroup analysis will be carried out depending on the availability of sufficient clinical data.

CONCLUSION

Based on the systematic review and meta-analysis results of this study, the possible miRNAs could be predicted toward the prognosis of stage II colorectal cancer, and specific miRNAs may perhaps be considered as a biomarker and therapeutic target for this malignancy.

Protective efficacy of liver fluke DNA vaccines: A systematic review and meta-analysis: Guiding novel vaccine development

The immunogenicity and efficacy of Fasciola DNA vaccines have not yet been comprehensively summarised in the form of a systematic review and meta-analysis. Though multiple vaccine studies with respect to Fasciola vaccines exist, the variance in the experimental parameters has made comparison difficult. We conducted a bibliographic database search in Scopus, PubMed, Science Direct, Cochrane Library, EMBASE and Web of Science databases, limited to publications from 1998 to 2017. The key words: Liver fluke, Fasciola hepatica, Fasciola gigantica, DNA vaccination, and immunogenicity were used in combination to form search strings. A total of 4760 studies were identified after initial screening, of which 14 qualified for systematic review and 7 for meta-analysis. The mean Odds Ratio (OR) for all studies was 0.565 (95% confidence interval (CI) of 0.293 to 1.087), which means the percentage of protection in terms of decreased fluke burden in animals vaccinated with DNA vaccines was 43.5%. A moderate protective efficacy was observed for cysteine protease and phosphoglycerate kinase vaccine antigen candidates (pooled OR and 95% CI, [0.542; 0.179-1.721] and [0.616; 0.219-1.735], respectively). Vaccine effectiveness was observed in individual studies and cohorts; however, the overall pooled efficacy for all vaccine candidates was found to be non-significant. Despite multiple individual studies showing promising results for various DNA vaccine candidates against fascioliasis, the pooled studies showed the non-significant effect of the vaccine formulations against fluke burden, and displayed minimal protective efficacy against Fasciola infection. Though promising results are observed in isolated studies, further animal trials with standardised experimental parameters are required to develop new vaccine candidates effective against Fasciola.

Systematic review and meta-analysis of prognostic microRNA biomarkers for survival outcome in nasopharyngeal carcinoma

BACKGROUND

Nasopharyngeal cancer (NPC), despite being one of the most malignant head and neck carcinomas (HNC), lacks comprehensive prognostic biomarkers that predict patient survival. Therefore, this systematic review and meta-analysis is aimed to evaluate the potential prognostic value of miRNAs as prognostic biomarkers in NPC.

METHODS

PRISMA guidelines were used to conduct this systematic review and meta-analysis study. Permutations of multiple "search key-words" were used for the search strategy, which was limited to articles published between January 2012 and March 2018. The retrieved articles were meticulously searched with multi-level screening by two reviewers and confirmed by other reviewers. Meta-analysis was performed using Hazard Ratios (HR) and associated 95% Confidence Interval (CI) of survival obtained from previously published studies. Publication bias was assessed by Egger's bias indicator test and funnel plot symmetry.

RESULTS

A total of 5069 patients across 21 studies were considered eligible for inclusion in the systematic review, with 65 miRNAs being evaluated in the subsequent meta-analysis. Most articles included in this study originated from China and one study from North Africa. The forest plot was generated using cumulated survival data, resulting in a pooled HR value of 1.196 (95% CI: 0.893-1.601) indicating that the upregulated miRNAs increased the likelihood of death of NPC patients by 19%.

CONCLUSION

To our knowledge, this is the first meta-analysis that examines the prognostic effectiveness of miRNAs as biomarkers in NPC patients. We noted that the combined effect estimate of HR across multiple studies indicated that increased miRNA expression in NPC potentially leads to poor overall survival. However, further large-scale prospective studies on the clinical significance of the miRNAs, with sizable cohorts are necessary in order to obtain conclusive results.