Types Of Body Fluids Research Articles

A multi-tissue age prediction model based on DNA methylation analysis

Age related tissue-specific DNA methylation markers have been identified in many studies, which can be used to estimate the chronological age of an unknown biological sample’s donor. However, if these markers have been used on the wrong type of tissue, they will give an inaccurate age estimation. This research has therefore examined HumanMethylation450 (HM450) BeadChip-based profiles retrieved from the NCBI repository, with the aim of identifying a set of universal DNA methylation markers across forensically relevant tissues. By using elastic net regression, it was possible to identify 10 age-related (AR) DNA methylation markers across 41 samples coming from five types of tissue (whole blood, saliva, semen, menstrual blood, and vaginal secretions). The average predictive accuracy of the constructed model based on training data is 3.8 years. In an independent dataset of 24 samples from four types of tissues (blood, saliva, menstrual blood, and vaginal secretions), the mean absolute deviation for the menstrual blood and vaginal fluid is 6.9 years, 5.6 years for buccal swabs, and 7.8 years for blood. The overall multi-tissue accuracy rate based on bootstrap analysis was 7.8 years (95% Confidence Interval 6–9.7 years). The identified multi-tissue age prediction model has the potential to assist forensic investigations without the requirement to identify the sample body fluid type.

Spectral Mining for Discriminating Blood Origins in the Presence of Substrate Interference via Attenuated Total Reflection Fourier Transform Infrared Spectroscopy: Postmortem or Antemortem Blood?

Often in criminal investigations, discrimination of types of body fluid evidence is crucially important to ascertain how a crime was committed. Compared to current methods using biochemical techniques, vibrational spectroscopic approaches can provide versatile applicability to identify various body fluid types without sample invasion. However, their applicability is limited to pure body fluid samples because important signals from body fluids incorporated in a substrate are affected strongly by interference from substrate signals. Herein, we describe a novel approach to recover body fluid signals that are embedded in strong substrate interferences using attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy and an innovative multivariate spectral processing. This technique supported detection of covert features of body fluid signals, and then identified origins of body fluid stains on substrates. We discriminated between ATR FT-IR spectra of postmortem blood (PB) and those of antemortem blood (AB) by creating a multivariate statistics model. From ATR FT-IR spectra of PB and AB stains on interfering substrates (polyester, cotton, and denim), blood-originated signals were extracted by a weighted linear regression approach we developed originally using principal components of both blood and substrate spectra. The blood-originated signals were finally classified by the discriminant model, demonstrating high discriminant accuracy. The present method can identify body fluid evidence independently of the substrate type, which is expected to promote the application of vibrational spectroscopic techniques in forensic body fluid analysis.

Abstract 4439: The urine miRNA transcriptome of prostate cancer is temporally stable and predicts disease aggressivity

Abstract The clinical management of prostate cancer is the most common non-skin male malignancy in the world is hindered by the limitations of current diagnostic and prognostic tests, such as the low specificity of prostate-specific antigen (PSA) testing, low sensitivity of digital rectal examination (DRE) and complications of biopsies. To try to resolve these issues, we evaluated miRNA abundance in the urine of prostate cancer patients. Alterations in miRNA abundance levels have been reported as playing essential roles in the pathogenesis of cancer and is occurred in a tumor phenotype-specific manner (e.g. aggressive and non-aggressive). miRNAs are stable under diverse analytical conditions and can be detected in various types of body fluids including urine. These characteristics make them as promising non-invasive biomarkers. Here, we examined the intra- and inter-individual variance of urine miRNA abundance by investigating longitudinal changes over months to years in a cohort of patients with localized prostate cancer. We observed a large dynamic range of intra-individual variance in miRNA abundances and identified a set of miRNAs that is stable within individuals, and is biased toward specific biological functions including regulation of transmembrane channel activity. We combined this observation with machine-learning techniques to create a predictive model that can identify aggressive prostate cancer. This four miRNAs predictive model was validated in an independent prostate cancer cohort to non-invasively predict high-risk disease. Remarkably it showed comparable performance to the best existing tissue-based prognostic markers. These results demonstrated that non-invasive biomarkers can be developed to precede or supplement tissue-based tests by understanding the intra- and inter-tumoural heterogeneity of the urine miRNA transcriptome. Citation Format: Jouhyun Jeon. The urine miRNA transcriptome of prostate cancer is temporally stable and predicts disease aggressivity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4439. doi:10.1158/1538-7445.AM2017-4439

Direct-STR typing from presumptively-tested and untreated body fluids

Body fluids provide key pieces of information for a forensic investigation. However, sometimes only a small amount of body fluids is found and/or DNA are also degraded by environmental factors at the crime scene. In extreme cases, a forensic analyst may have to decide whether to perform a presumptive test on the stains or proceed straightaway to DNA profiling, which could be wasteful for non-biological stains. Additionally, due to the inefficient DNA extraction process, the amount of DNA may not be enough for STR typing, especially if parts of the evidence had been subjected to presumptive testing. To overcome these problems, we developed a direct PCR method for STR profiling of stains (blood, saliva, and semen) that had been subjected to presumptive tests and also those that had not undergone presumptive tests. Using the optimized protocols, 86 of 90 untreated samples (95.6%) resulted in a full DNA profile. For presumptively-tested samples, both the type of presumptive test used and the surfaces where the stains are deposited affected the quality of the STR profiles. With blood, we obtained full STR profiles from 88% of samples tested with luminol and 78% with Hemastix. The acid phosphatase test for semen and Phadebas test for saliva resulted in full STR profiles from 85% and 73% of samples, respectively. Different substrates also affected the resulting STR profiles, but there was no clear trend based on absorbency or texture. The interactions of types of body fluids, presumptive tests, and substrates must be considered together. Our direct PCR protocol can be used to detect DNA even with 6 months-old biological samples. The benefits of the developed protocol include increasing amount of DNA obtained from evidence, decreasing chances of DNA contamination from complex or lengthy extraction steps, using minimal sample amount for analysis, and most importantly, improving STR profiles. Also, the process could save analysis time and cost due to the omission of DNA extraction and quantification. Our developed method could be beneficial to cases with limited stains available, as forensic analysts can perform indirect presumptive testing on the suspected stains and direct PCR could be carried out from the filter paper used, thus leaving the original stain for subsequent DNA extraction or re-analysis.

Research progress on body fluids microRNAs in the diagnosis of cholangiocarcinoma

The development of cholangiocarcinoma is slow, but its metastasis is extremely quick. When the tumor is found, the patients often have missed optimal operation period, and there is a lack of effective diagnostic indexes at present. In recent years, with the rapid development of molecular biology, studies find that microRNAs (miRNAs) are closely associated with cholangiocarcinoma. Because of miRNAs have great stability in various types of body fluids, so miRNAs in serum/plasma and bile are expected to become potential biomarkers in the diagnosis of cholangiocarcinoma. Key words: MicroRNAs; Bile duct neoplasms; Serum; Plasma; Bile; Diagnosis

Gambaran Sitologi Cairan Peritoneal dan Sinovial Itik Bali (CYTOLOGIC FIGURES OF PERITONEAL AND SYNOVIAL FLUIDS IN BALI DUCKS)

This study aim was to observe cellular composition and morphology in peritoneal and synovial fluids ofbali ducks. This study used 50 ducks, which were composed of 21 males and 29 females aged 8 to 12 weeks.After being declared clinically healthy, the sample ducks were slaughtered and peritoneal fluid specimenfrom the abdominal cavity and the synovial fluid of joints tibiotarsal were collected. Then, in preparationfor the specimen, each of fluid was smeared and stained with Giemsa. Observations were made under amicroscope with a magnification of 1000 times and observations expressed in the average number of cellsper field of view observation. The results showed (duck population that most of the observed sample): inthe peritoneal fluid there was 36% eosinophils observed and 38% had heterophile cells with 0-3 cells perfield of magnification 1000x view. Similarly, 28% ducks had lymphocytes with 13-16 cells, and as much as28% of ducks had macrophage cells with 5- 8 cells in observation . In the synovial fluid, however, 64%sample ducks had monocytes, while 72% having lymphocytes with 1-18 cells each of view field withmagnification 1000x. In addition, in the synovial fluid, as much as 62% of ducks also observed had 1 to 3cells heterophiles and 60% ducks had eosinophils (polimorphonuclear cells) per view field observation.Macrophage cells that were found in the peritoneal fluid were mainly hyper granulated. It can be concludedthat the amount of mononuclear cells in both types of body fluids is likely more dominant compared to thenumber of polymorphonuclear cells.

Characterization of postmortem biochemical changes in rabbit plasma using ATR-FTIR combined with chemometrics: A preliminary study

Postmortem interval (PMI) determination is one of the most challenging tasks in forensic medicine due to a lack of accurate and reliable methods. It is especially difficult for late PMI determination. Although many attempts with various types of body fluids based on chemical methods have been made to solve this problem, few investigations are focused on blood samples. In this study, we employed an attenuated total reflection (ATR)-Fourier transform infrared (FTIR) technique coupled with principle component analysis (PCA) to monitor biochemical changes in rabbit plasma with increasing PMI. Partial least square (PLS) model was used based on the spectral data for PMI prediction in an independent sample set. Our results revealed that postmortem chemical changes in compositions of the plasma were time-dependent, and various components including proteins, lipids and nucleic acids contributed to the discrimination of the samples at different time points. A satisfactory prediction within 48h postmortem was performed by the combined PLS model with a good fitting between actual and predicted PMI of 0.984 and with an error of ±1.92h. In consideration of the simplicity and portability of ATR-FTIR, our preliminary study provides an experimental and theoretical basis for application of this technique in forensic practice.

Novel identification of biofluids using a multiplex methylation sensitive restriction enzyme-PCR system

The identification of a specific body fluid encountered in a forensic investigation can give crucial information. This identification can be aided by methylation profiles based on selected markers specific to a range of biofluids. In this study, the open database of Infinium HumanMethylation450 BeadChip was searched for markers specific for semen, vaginal fluids, saliva, venous blood and menstrual blood. A total of 8 biofluid-specific methylated markers and 2 control markers were combined into a 10-plex methylation sensitive restriction enzyme-PCR (MSRE-PCR) system. Based upon the analysis of 100 DNA samples from these 5 biofluid types, unambiguous results were obtained to identify the body fluid from which it originated. Validation studies of the developed 10-plex MSRE-PCR included sensitivity, reproducibility and mixed body fluids. Co-amplification of the established MSRE-PCR system and the microsatellite loci in AmpFlSTR® MiniFiler™ PCR Amplification Kit was performed to generate both the methylation profile for biofluid type and the miniSTR profile. This allowed human identification and the identification of the body fluid type to be performed in a single reaction. The results of this study displayed the applicability of this 10-plex MSRE-PCR system in forensic science.

Electrochemical Behavior of Cobalt-Chromium Alloy as Biomaterial in Different pH Environments

The paper discusses the electrochemical interactions of Co-Cr alloy with different physiological solutions and organic substances, containing different ions and different pH values, which should play a key role in the materials lifetime. The physical and chemical reactions are numerous and the passivity of the Co-Cr alloy is submitted to the influence of the liquid environment. Some electrochemical investigations were carried out for understanding and predicting the passivity and the corrosion resistance of Co-Cr alloy in three types of simulated body fluids (SBF), namely Fusayama Meyer artificial saliva (pH=5), Hank’s solution (pH=7.4), Ringer's solution (pH=6.6) and citric acid as organic solution. The reason of using another type of environment (other than SBF), such as citric acid is that this medium is a powerful oxidant and has a lower pH value (pH=1.8). This acid environment can influence the state (the formation and growth) of the oxide layer on the surface of the alloy. Research has shown different behavior of the cobalt chromium alloy according to the pH, the chloride content and the oxidizing nature of the environment. Co-Cr alloy biomaterial, immersed in four aqueous media reveals that there are different levels of stabilization of the potential and different current densities depending on the pH value. The Co-Cr alloy biomaterial is very sensitive to localized corrosion (pitting) in Hank solution.

Clinical relevance of circulating cell-free microRNAs in ovarian cancer.

Ovarian cancer is the leading cause of death among gynecologic malignancies. Since ovarian cancer develops asymptomatically, it is often diagnosed at an advanced and incurable stage. Despite many years of research, there is still a lack of reliable diagnostic markers and methods for early detection and screening. Recently, it was discovered that cell-free microRNAs (miRNAs) circulate in the body fluids of healthy and diseased patients, suggesting that they may serve as a novel diagnostic marker. This review summarizes the current knowledge regarding the potential clinical relevance of circulating cell-free miRNA for ovarian cancer diagnosis, prognosis, and therapeutics. Despite the high levels of ribonucleases in many types of body fluids, most of the circulating miRNAs are packaged in microvesicles, exosomes, or apoptotic bodies, are binding to RNA-binding protein such as argonaute 2 or lipoprotein complexes, and are thus highly stable. Cell-free miRNA signatures are known to be parallel to those from the originating tumor cells, indicating that circulating miRNA profiles accurately reflect the tumor profiles. Since it is well established that the dysregulation of miRNAs is involved in the tumorigenesis of ovarian cancer, cell-free miRNAs circulating in body fluids such as serum, plasma, whole blood, and urine may reflect not only the existence of ovarian cancer but also tumor histology, stage, and prognoses of the patients. Several groups have successfully demonstrated that serum or plasma miRNAs are able to discriminate patients with ovarian cancer patients from healthy controls, suggesting that the addition of these miRNAs to current testing regimens may improve diagnosis accuracies for ovarian cancer. Furthermore, recent studies have revealed that changes in levels of cell-free circulating miRNAs are associated with the condition of cancer patients. Discrepancies between the results across studies due to the lack of an established endogenous miRNA control to normalize for circulating miRNA levels, as well as differing extraction and quantification methods, are the pitfalls to be resolved before clinical application. There is still a long way, however, before this can be achieved, and further evidence would make it possible to apply circulating cell-free miRNAs not only as biomarkers but also as potential therapeutic targets for ovarian cancer in the future.

DNA methylation profiling for a confirmatory test for blood, saliva, semen, vaginal fluid and menstrual blood

The ability to predict the type of tissues or cells from molecular profiles of crime scene samples has important practical implications in forensics. A previously reported multiplex assay using DNA methylation markers could only discriminate between 4 types of body fluids: blood, saliva, semen, and the body fluid which originates from female reproductive organ. In the present study, we selected 15 menstrual blood-specific CpG marker candidates based on analysis of 12 genome-wide DNA methylation profiles of vaginal fluid and menstrual blood. The menstrual blood-specificity of the candidate markers was confirmed by comparison with HumanMethylation450 BeadChip array data obtained for 58 samples including 12 blood, 12 saliva, 12 semen, 3 vaginal fluid, and 19 skin epidermis samples. Among 15CpG marker candidates, 3 were located in the promoter region of the SLC26A10 gene, and 2 of them (cg09696411 and cg18069290) showed high menstrual blood specificity. DNA methylation at the 2CpG markers was further tested by targeted bisulfite sequencing of 461 additional samples including 49 blood, 52 saliva, 34 semen, 125 vaginal fluid, and 201 menstrual blood. Because the 2 markers showed menstrual blood-specific methylation patterns, we modified our previous multiplex methylation SNaPshot reaction to include these 2 markers. In addition, a blood marker cg01543184 with cross reactivity to semen was replaced with cg08792630, and a semen-specific unmethylation marker cg17621389 was removed. The resultant multiplex methylation SNaPshot allowed positive identification of blood, saliva, semen, vaginal fluid and menstrual blood using the 9CpG markers which show a methylation signal only in the target body fluids. Because of the complexity in cell composition, menstrual bloods produced DNA methylation profiles that vary with menstrual cycle and sample collection methods, which are expected to provide more insight into forensic menstrual blood test. Moreover, because the developed multiplex methylation SNaPshot reaction includes the 4CpG markers of which specificities have been confirmed by multiple studies, it will facilitate confirmatory tests for body fluids that are frequently observed in forensic casework.

Presence and Persistence of Ebola or Marburg Virus in Patients and Survivors: A Rapid Systematic Review.

BackgroundThe 2013–15 Ebola outbreak was unprecedented due to sustained transmission within urban environments and thousands of survivors. In 2014 the World Health Organization stated that there was insufficient evidence to give definitive guidance about which body fluids are infectious and when they pose a risk to humans. We report a rapid systematic review of published evidence on the presence of filoviruses in body fluids of infected people and survivors.MethodsScientific articles were screened for information about filovirus in human body fluids. The aim was to find primary data that suggested high likelihood of actively infectious filovirus in human body fluids (viral RNA). Eligible infections were from Marburg virus (MARV or RAVV) and Zaire, Sudan, Taï Forest and Bundibugyo species of Ebola. Cause of infection had to be laboratory confirmed (in practice either tissue culture or RT-PCR tests), or evidenced by compatible clinical history with subsequent positivity for filovirus antibodies or inflammatory factors. Data were extracted and summarized narratively.Results6831 unique articles were found, and after screening, 33 studies were eligible. For most body fluid types there were insufficient patients to draw strong conclusions, and prevalence of positivity was highly variable. Body fluids taken >16 days after onset were usually negative. In the six studies that used both assay methods RT-PCR tests for filovirus RNA gave positive results about 4 times more often than tissue culture.ConclusionsFilovirus was reported in most types of body fluid, but not in every sample from every otherwise confirmed patient. Apart from semen, most non-blood, RT-PCR positive samples are likely to be culture negative and so possibly of low infectious risk. Nevertheless, it is not apparent how relatively infectious many body fluids are during or after illness, even when culture-positive, not least because most test results come from more severe cases. Contact with blood and blood-stained body fluids remains the major risk for disease transmission because of the known high viral loads in blood.

Developmental validation studies of epigenetic DNA methylation markers for the detection of blood, semen and saliva samples

Determining the type and origin of body fluids in a forensic investigation can provide important assistance in reconstructing crime scenes. A set of epigenetic markers, ZC3H12D, BCAS4 and cg06379435, have been developed to produce unique and specific patterns of DNA methylation that can be used to identify semen, saliva, and blood, respectively. To ensure the efficacy of these markers, developmental validation studies were performed to determine the conditions and limitations of this new tool for forensic analysis. DNA was extracted from human samples and bisulfite modified using commercial bisulfite modification kits. Specific primers were used to amplify the region of interest and the methylation profile of the CpG sites were determined by pyrosequencing. The percent methylation values at each CpG site were determined in multiple samples and averaged for each tissue type. The versatility of these new markers is presented by showing the results of validation studies on sensitivity, human specificity, stability and mixture resolution. When testing the markers using different organisms, we did obtain positive results for certain non-human primate samples, however, all other tested species were negative. The lowest concentration consistently detected varied from 0.1 to 10ng, depending on the locus, indicating the importance of primer design and sequence in the assay. The method also proved to be effective when inhibitors were present in the samples or when samples were degraded by heat. Simulated case- samples were also tested. In the case of mixtures of different cell types, the overall methylation values varied in a consistent and predictable manner when multiple cell types were present in the same sample. Overall, the validation studies demonstrate the robustness and effectiveness of this new tool for body fluid identification.

The Pig PeptideAtlas: A resource for systems biology in animal production and biomedicine.

Biological research of Sus scrofa, the domestic pig, is of immediate relevance for food production sciences, and for developing pig as a model organism for human biomedical research. Publicly available data repositories play a fundamental role for all biological sciences, and protein data repositories are in particular essential for the successful development of new proteomic methods. Cumulative proteome data repositories, including the PeptideAtlas, provide the means for targeted proteomics, system-wide observations, and cross-species observational studies, but pigs have so far been underrepresented in existing repositories. We here present a significantly improved build of the Pig PeptideAtlas, which includes pig proteome data from 25 tissues and three body fluid types mapped to 7139 canonical proteins. The content of the Pig PeptideAtlas reflects actively ongoing research within the veterinary proteomics domain, and this article demonstrates how the expression of isoform-unique peptides can be observed across distinct tissues and body fluids. The Pig PeptideAtlas is a unique resource for use in animal proteome research, particularly biomarker discovery and for preliminary design of SRM assays, which are equally important for progress in research that supports farm animal production and veterinary health, as for developing pig models with relevance to human health research.

Development of a RNA profiling assay for biological tissue and body fluid identification

Identification of the type of biological tissue or body fluid on forensic samples is no longer limited to conventional biochemical and serological methods. Unlike these methods, RNA profiling allows for ‘multiplexing’, i.e. concurrent detection of several different biological fluids in a single assay, and is capable of distinguishing between a wider range of forensically relevant biological tissues and body fluids. As such, 24 messenger RNAs (mRNA) and 8 micro-RNAs (miRNA) biomarkers previously identified in literature were screened for their specificities towards blood, saliva, and semen. A total of 15 RNA biomarkers were selected, and subsequently incorporated into a multiplex reverse transcription (RT)-PCR assay for RNA profiling. RNA profiling was then accomplished by capillary electrophoresis of the PCR products, to identify positive identifiers specific to each body fluid type. Based on these positive identifiers, the RNA profiling assay successfully distinguished blood, saliva and semen from each other. This study has also demonstrated that mRNA and miRNA biomarkers can be multiplexed (during the reverse transcription and PCR steps) in a single assay for RNA profiling.

Identification of body fluid using tissue-specific DNA methylation markers

Determination of type and origin of body fluids found at crime scenes can provide important clues for forensic investigation. Recently, DNA methylation markers have proved to be a new promising tool for forensic body fluid identification. The goal of this study is to identify CpG sites that display body fluid-specific differentially methylation patterns as DNA methylation markers for forensic purpose. Using pyrosequencing technique, we examined five tissue-specific differentially methylated regions (tDMRs) for the genes BIK, CYTH4, GAS2L1, MDFI, and OSM on five different body fluids (venous blood, saliva, semen, menstrual blood and vaginal). Of the tested tDMRs, four showed different DNA methylation profiles in five body fluids (P<0.05). The differences were unrelated to age and gender of body fluid’s carrier (P>0.05). A body fluid identification assay based on four body fluid-specific DNA methylation markers was set up and evaluated in 40 body fluid samples. The assay could discriminate five body fluids with high sensitivity and specificity. Our results indicated that the set of body fluid-specific CpG sites could become useful DNA markers for forensic analysis of body fluids.

Developed and evaluated a multiplex mRNA profiling system for body fluid identification in Chinese Han population

In forensic casework, identification the cellular origin from a biological sample is crucial to the case investigation and reconstruction in crime scene. DNA/RNA co-extraction for STR typing and human body fluids identification has been proposed as an efficient and comprehensive assay for forensic analysis. Several cell-specific messenger RNA (mRNA) markers for identification of the body fluids have been proposed by previous studies. In this study, a novel multiplex mRNA profiling system included 19 markers was developed and performed by reverse transcription endpoint polymerase chain reaction (RT-PCR). The multiplex combined 3 housekeeping gene markers and 16 cell-specific markers that have been used to identify five types of human body fluids: peripheral blood, semen, saliva, vaginal secretions and menstrual blood. The specificity, sensitivity, stability and detectability of the mixture were explored in our study. Majority of the cell-specific mRNA markers showed high specificity, although cross-reactivity was observed sporadically. Specific profiling for per body fluid was obtained. Moreover, the interpretation guidelines for inference of body fluid types were performed according to the A. Lindenbergh et al. The scoring guidelines can be applied to any RNA multiplex, which was based on six different scoring categories (observed, observed and fits, sporadically observed and fits, not observed, sporadically observed, not reliable, and non-specific due to high input). The simultaneous extraction of DNA showed positive full or partial profiling results of all samples. It demonstrated that the approach of combined STR-profiling and RNA profiling was suitable and reliable to detect the donor and origin of human body fluids in Chinese Han population.

Genome-wide methylation profiling and a multiplex construction for the identification of body fluids using epigenetic markers

The identification of body fluids found at crime scenes can contribute to solving crimes by providing important insights into crime scene reconstruction. In the present study, body fluid-specific epigenetic marker candidates were identified from genome-wide DNA methylation profiling of 42 body fluid samples including blood, saliva, semen, vaginal fluid and menstrual blood using the Illumina Infinium HumanMethylation450 BeadChip array. A total of 64 CpG sites were selected as body fluid-specific marker candidates by having more than 20% discrepancy in DNA methylation status between a certain type of body fluid and other types of body fluids and to have methylation or unmethylation pattern only in a particular type of body fluid. From further locus-specific methylation analysis in additional samples, 1 to 3 CpG sites were selected for each body fluid. Then, a multiplex methylation SNaPshot reaction was constructed to analyze methylation status of 8 body fluid-specific CpG sites. The developed multiplex reaction positively identifies blood, saliva, semen and the body fluid which originates from female reproductive organ in one reaction, and produces successful DNA methylation profiles in aged or mixed samples. Although it remains to be investigated whether this approach is more sensitive, more practical than RNA- or peptide-based assays and whether it can be successfully applied to forensic casework, the results of the present study will be useful for the forensic investigators dealing with body fluid samples.

The landscape of microRNA, Piwi-interacting RNA, and circular RNA in human saliva.

Extracellular RNAs (exRNAs) in human body fluids are emerging as effective biomarkers for detection of diseases. Saliva, as the most accessible and noninvasive body fluid, has been shown to harbor exRNA biomarkers for several human diseases. However, the entire spectrum of exRNA from saliva has not been fully characterized. Using high-throughput RNA sequencing (RNA-Seq), we conducted an in-depth bioinformatic analysis of noncoding RNAs (ncRNAs) in human cell-free saliva (CFS) from healthy individuals, with a focus on microRNAs (miRNAs), piwi-interacting RNAs (piRNAs), and circular RNAs (circRNAs). Our data demonstrated robust reproducibility of miRNA and piRNA profiles across individuals. Furthermore, individual variability of these salivary RNA species was highly similar to those in other body fluids or cellular samples, despite the direct exposure of saliva to environmental impacts. By comparative analysis of >90 RNA-Seq data sets of different origins, we observed that piRNAs were surprisingly abundant in CFS compared with other body fluid or intracellular samples, with expression levels in CFS comparable to those found in embryonic stem cells and skin cells. Conversely, miRNA expression profiles in CFS were highly similar to those in serum and cerebrospinal fluid. Using a customized bioinformatics method, we identified >400 circRNAs in CFS. These data represent the first global characterization and experimental validation of circRNAs in any type of extracellular body fluid. Our study provides a comprehensive landscape of ncRNA species in human saliva that will facilitate further biomarker discoveries and lay a foundation for future studies related to ncRNAs in human saliva.

Circulating Blood-Borne microRNAs as Biomarkers in Solid Tumors.

One of the major challenges in cancer research is the identification of stable biomarkers that could be routinely measured in easily accessible samples. Human blood and other body fluids represent rich sources for the identification of novel biomarkers. It is apparent that the availability of these biomarkers would improve an early detection of asymptomatic disease and the clinical management of cancer. MicroRNAs have been described to be present in various types of body fluids including cell-free serum and plasma. These days, the involvement of microRNAs in molecular pathology of cancer is well established. Moreover, it seems that these molecules could be optimal noninvasive biomarkers owing to their high stability under storage and handling conditions and high sensitivity and specificity in various diseases. To date, more than 100 circulating microRNAs with the potential to serve as novel diagnostic, prognostic, or predictive biomarkers for different types of cancers have been identified, and this number is still increasing. However, there are major discrepancies in the findings by different research groups, and few commonly altered microRNAs have been reported in these studies. Further studies on large cohorts using uniform methodology are warranted to establish the clinical applicability of circulating microRNAs for solid tumors. Here, we summarize the tumor-specific profiles of blood-borne microRNAs and discuss their potential utility for personalized medicine of solid tumors.