Noninvasive Biomarkers For Diagnosis Research Articles

Nonalcoholic Fatty Liver Disease.

Nonalcoholic fatty liver disease (NAFLD), the hepatic manifestation of the metabolic syndrome, is the leading cause of chronic liver disease. Treatments target lifestyle modification and improvement of underlying risk factors. Noninvasive biomarkers for diagnosis and staging of NAFLD and safe, cost-effective treatments for patients with nonalcoholic steatohepatitis (NASH) and/or NASH-related cirrhosis are currently under investigation.

Soluble Tumor Necrosis Factor-α Receptor 2 in Urine Is a Potential Biomarker for Noninvasive Diagnosis of Malaria During Pregnancy.

Background. During pregnancy, the placenta is inaccessible for diagnosis of placental malaria (PM), but soluble tumor necrosis factor-α receptors (sTNFR) are elevated in the plasma of women with PM.Methods. In this study, sTNFR-1 and sTNFR-2 were quantified in urine of pregnant and nonpregnant Cameroonian women who were positive or negative for malaria by blood-smear microscopy.Results. We found that levels of both sTNFR in urine were higher in pregnant compared with nonpregnant women, but malaria-positive pregnant women excreted substantially more sTNFR-1 (P = .005) and sTNFR-2 (P < .001) than malaria-negative pregnant women. The amount of sTNFR-1(rs = 0.784, P < .001) and sTNFR-2 (rs = 0.816, P < .001) in urine correlated with parasitemia, even in afebrile pregnant women. Urine sTNFR-2 predicted maternal malaria with an area under curve of 0.892 (95% confidence interval, .787–.898). At cutoff concentrations of 9.8 ng and 13.6 ng of sTNFR-2 per mL urine, the sensitivity/specificity were 82.6%/87.0% and 78.3%/95.7%, respectively.Conclusions. The sTNFR-2 in noninvasive urine samples may be useful for diagnosis of malaria during pregnancy.

303 Fecal Bacteria Act as Novel Biomarkers for Non-Invasive Diagnosis of Colorectal Cancer

303 Fecal Bacteria Act as Novel Biomarkers for Non-Invasive Diagnosis of Colorectal Cancer

Alu methylation serves as a biomarker for non-invasive diagnosis of glioma.

Current techniques for diagnosing glioma are invasive and do not accurately predict prognosis. We developed a novel, non-invasive liquid chip assay to diagnose glioma and predict prognosis. Using this method, we determined the methylation state of the Alu element in cell-free DNA extracted from the serum of 109 glioma patients. Controls included 56 patients with benign intracranial tumors and 50 healthy subjects. Matched tumor tissues were processed for 36 patients. The cfDNA from glioma patients showed lower levels of Alu methylation than the controls (P<0.01). Alu methylation was also lower in high-grade than low-grade gliomas (P<0.01), indicating that Alu methylation correlates negatively with disease severity. Moreover, Alu methylation correlated positively with survival (P<0.01). These findings suggest high-throughput liquid chip could serve as a non-invasive diagnostic assay for glioma.

Detection of hydrogen cyanide from oral anaerobes by cavity ring down spectroscopy.

Hydrogen cyanide (HCN) has been recognized as a potential biomarker for non-invasive diagnosis of Pseudomonas aeruginosa infection in the lung. However, the oral cavity is a dominant production site for exhaled HCN and this contribution can mask the HCN generated in the lung. It is thus important to understand the sources of HCN production in the oral cavity. By screening of oral anaerobes for HCN production, we observed that the genus of Porphyromonas, Prevotella and Fusobacterium generated low levels of HCN in vitro. This is the first study to show that oral anaerobes are capable of producing HCN in vitro. Further investigations were conducted on the species of P. gingivalis and we successfully detected HCN production (0.9–10.9 ppb) in the headspace of three P. gingivalis reference strains (ATCC 33277, W50 and OMG 434) and one clinical isolate. From P. gingivalis ATCC 33277 and W50, a strong correlation between HCN and CO2 concentrations (rs = 0.89, p < 0.001) was observed, indicating that the HCN production of P. gingivalis might be connected with the bacterial metabolic activity. These results indicate that our setup could be widely applied to the screening of in vitro HCN production by both aerobic and anaerobic bacteria.

Exosomal miRNAs as biomarkers of recurrent lung cancer.

Prognosis of lung cancer still remains grim largely due to recurrence and aggressive metastasis of the disease. In this study, we examined the potential of exosomal miRNAs as biomarkers of recurrent lung cancer. Initially, in vitro miRNA profiles of normal lung (Beas-2b) and lung cancer (H1299) cells and of exosomes isolated from conditioned media were determined. In vivo study involved establishing subcutaneous primary and recurrent lung cancer xenografts in nude mouse model and examining tumor and serum exosomal miRNA alteration in secondary/recurrent lung tumors. A total of 77 miRNAs were observed to be significantly modulated in the H1299 cells (47 miRNA upregulated and 30 downregulated) compared to the Beas-2b cells. The exosomes isolated from conditioned media indicated several miRNAs which were in agreement with cells of origin. A similarity was also observed between miRNAs from serum exosomes and tumors, indicating their origin from the lung tumors. Two miRNAs, miR-21 and miR-155, were found to be significantly upregulated in recurrent tumors compared to primary tumors. These miRNAs were also upregulated in serum exosomes of recurrent tumor-bearing animals versus non-tumor- or primary tumor-bearing animals. Increased expression of the recurrent disease markers were also observed in recurrent tumors compared with primary tumors. Serum exosomes from recurrent tumor mice mirrored its tumor profile in expressing higher levels of these proteins compared with exosomes from primary tumor mice. Our data suggest that exosomal miRNA signatures may be a true representation of a pathological profile of lung cancer; thus, miRNAs could serve as promising biomarkers for non-invasive diagnosis of the disease.

Micronucleus as a Non-invasive Biomarker – A Review

Oral Cancer has a remarkably high incidence worldwide and a significant decrease in its mortality and morbidity rates has been established if it is diagnosed in early stages. There has been always a strong need to develop new, objective, non-invasive methods for its early detection. Micronucleus has come up in the recent past as non-invasive biomarker for diagnosis of not only malignant and pre-malignant lesions but also many other significant diseases. Micronucleus (“MN) is defined as microscopically visible, round or oval cytoplasmic chromatin mass next to the nucleus. Micronuclei Review Article Dev et al.; JAMPS, 6(4): 1-9, 2016; Article no.JAMPS.24136 2 (“MNi”) originate from aberrant mitoses and consist of eccentric chromosomes, chromatid fragments or whole chromosomes that have failed to be incorporated into the daughter nuclei during mitosis. The MN assay has been widely accepted as an in vitro genotoxicity test and a biomarker assay for genotoxic exposure and effect in humans. An attempt has been made to review the related studies, utilizing micronucleus assay of buccal cells as a novel marker of genotoxicity in head and neck region.

Investigation of biomarkers for discriminating breast cancer cell lines from normal mammary cell lines based on VOCs analysis and metabolomics

The aim of this work is to investigate the volatile organic components of human breast cancer/normal cell lines for fingerprinting and exploring potential VOCs biomarkers for noninvasive diagnosis of breast cancer.

MicroRNA-20a in human faeces as a non-invasive biomarker for colorectal cancer.

Detection of microRNA (miRNA) aberrations in human faeces is a new approach for colorectal cancer (CRC) screening. The aim of this study was to characterise miR-20a in faeces as a non-invasive biomarker for diagnosis of CRC. miR-20a expression was significantly higher in the 40 CRC tumours compared to their respective adjacent normal tissues (P = 0.0065). Levels of miR-20a were also significantly higher in faecal samples from CRC patients (P < 0.0001). The area under receiver operating characteristic (AUROC) curve for miR-20a was 0.73, with a sensitivity of 55% and specificity of 82% for CRC patients compared with controls. No significant difference in the level of miR-20a was found between patients with proximal, distal, and rectal cancer. The use of antibiotics did not influence faecal miR-20a levels. miR-20a was selected from an expression microarray containing 667 miRNAs. Further verification of miR-20a was performed in 40 pairs of primary CRC tissues, as well as 595 faecal samples (198 CRCs, 199 adenomas, and 198 healthy controls) using TaqMan probe based quantitative Real-Time PCR (qRT-PCR). Faecal-based miR-20a can be utilised as a potential non-invasive biomarker for CRC screening.

Increased expression of circulating miRNA-93 in women with polycystic ovary syndrome may represent a novel, non-invasive biomarker for diagnosis.

MicroRNAs (miRNA) are a novel class of small noncoding single-stranded RNA molecules that regulate gene expression. There is increasing evidence of their importance in polycystic ovary syndrome (PCOS). The objective was to determine if miRNA-93 and miRNA-223 are differentially expressed in the circulation of women with PCOS compared to age matched women. A case–control study comparing women with PCOS (n = 25) to age and weight matched controls (n = 24) without PCOS was performed. MiRNA-93 and miRNA-223 were determined by total RNA reverse transcription. Both miRNA-93 and miRNA-223 were significantly increased relative to the control group (p < 0.01, p = 0.029 respectively). In both groups there was no correlation of either miRNA-93 or miRNA-223 with insulin, HOMA-IR, HOMA-β or testosterone levels. The area under the receiver operator characteristic curve for miR-223 and miR-93 was 0.66 and 0.72 respectively, suggesting miR-93 is a more efficient biomarker than miR-223 for diagnosis of PCOS. The combination of the two miRNAs together, tested using multiple logistic regression analysis, did not improve the diagnostic potential. In conclusion, circulating miRNA-93 and miRNA-223 were higher in women with PCOS compared to age and weight matched controls independent of insulin resistance and testosterone levels, and miR-93 may represent a novel diagnostic biomarker for PCOS.

Investigation of long noncoding RNAs expression profile as potential serum biomarkers in patients with hepatocellular carcinoma.

There is an increasing interest in using long noncoding RNAs (lncRNAs) as biomarkers in cancer. Predictive biomarkers in hepatocellular carcinoma (HCC) have great benefit in the choice of therapeutic modality for HCC. The aim of this study is to assess lncRNA-urothelial carcinoma associated-1 (lncRNA-UCA1) and WD repeat containing, antisense to TP53 (WRAP53) expression as novel noninvasive biomarkers for diagnosis of HCC in sera of HCC patients compared with chronic hepatitis C virus (HCV) patients and healthy volunteers and to analyze their relationship with respect to the clinicopathologic features. We retrieved HCC characteristic lncRNAs, lncRNA-UCA1 and lncRNA-WRAP53, based on the microarray signature profiling (released by LncRNADisease database). Quantitative reverse-transcriptase polymerase chain reaction assay (RT-qPCR) was then used to evaluate the expression of selected lncRNAs in the serum of 160 participants. Furthermore, in 20 of 82 HCC cases involved in the study, we examined the expression of lncRNA-UCA1 and lncRNA-WRAP53 in 20 HCC tissues and adjacent nontumor tissues and analyzed its correlation with the serum level of these lncRNAs. The prognostic significance of the investigated parameters in HCC patients was explored. We found that lncRNA-UCA1 and lncRNA-WRAP53 were significantly higher in sera of HCC than those with chronic HCV infection or healthy volunteers. Our data suggested that the increased expression of UCA1 and WRAP53 was associated with advanced clinical parameters in HCC. Of note, tissue levels of the chosen lncRNAs strongly correlate with their sera level. The combination of both lncRNAs with serum alpha fetoprotein resulted in improved sensitivity to 100%. The median follow-up period was 21.5months. LncRNA-WRAP53 was significant independent prognostic markers in relapse-free survival. LncRNA-UCA1 and lncRNA-WRAP53 upregulation may serve as novel serum biomarkers for HCC diagnosis and prognosis.

Increased expression of circulating miRNA-93 in women with polycystic ovary syndrome may represent a novel, non-invasive biomarker for diagnosis

MicroRNAs (miRNA) are a novel class of small noncoding single-stranded RNA molecules that regulate gene expression. There is increasing evidence of their importance in polycystic ovary syndrome (PCOS). The objective was to determine if miRNA-93 and miRNA-223 are differentially expressed in the circulation of women with PCOS compared to age matched women. A case-control study comparing women with PCOS (n = 25) to age and weight matched controls (n = 24) without PCOS was performed. MiRNA-93 and miRNA-223 were determined by total RNA reverse transcription. Both miRNA-93 and miRNA-223 were significantly increased relative to the control group (p < 0.01, p = 0.029 respectively). In both groups there was no correlation of either miRNA-93 or miRNA-223 with insulin, HOMA-IR, HOMA-β or testosterone levels. The area under the receiver operator characteristic curve for miR-223 and miR-93 was 0.66 and 0.72 respectively, suggesting miR-93 is a more efficient biomarker than miR-223 for diagnosis of PCOS. The combination of the two miRNAs together, tested using multiple logistic regression analysis, did not improve the diagnostic potential. In conclusion, circulating miRNA-93 and miRNA-223 were higher in women with PCOS compared to age and weight matched controls independent of insulin resistance and testosterone levels, and miR-93 may represent a novel diagnostic biomarker for PCOS.

Tumor-Suppression Mechanisms of Protein Tyrosine Phosphatase O and Clinical Applications.

Tyrosine phosphorylation plays an important role in regulating human physiological and pathological processes. Functional stabilization of tyrosine phosphorylation largely contributes to the balanced, coordinated regulation of protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs). Research has revealed PTPs play an important suppressive role in carcinogenesis and progression by reversing oncoprotein functions. Receptor-type protein tyrosine phosphatase O (PTPRO) as one member of the PTPs family has also been identified to have some roles in tumor development. Some reports have shown PTPRO over-expression in tumors can not only inhibit the frequency of tumor cell division and induce tumor cell death, but also suppress migration. However, the tumor-suppression mechanisms are very complex and understanding is incomplete, which in some degree blocks the further development of PTPRO. Hence, in order to resolve this problem, we here have summarized research findings to draw meaningful conclusions. We found tumor-suppression mechanisms of PTPRO to be diverse, such as controlling G0/G1 of the tumor cell proliferation cycle, inhibiting substrate phosphorylation, down-regulating transcription activators and other activities. In clinical anticancer efforts, expression level of PTPRO in tumors can not only serve as a biomarker to monitor the prognosis of patients, but act as an epigenetic biomarker for noninvasive diagnosis. In addition, the re-activation of PTPRO in tumor tissues, not only can induce tumor volume reduction, but also enhance the susceptibility to chemotherapy drugs. So, we can propose that these research findings of PTPRO will not only support new study ideas and directions for other tumor- suppressors, importantly, but also supply a theoretical basis for researching new molecular targeting agents in the future.

Peripheral biomarkers profile in patients with parkinsonisms

Background: Neurodegenerative diseases are increasing their prevalence in world population, so the search for new diagnostic methods has become an important necessity. Parkinson's disease (PD) as well as other forms of parkinsonisms are classified as protein misfolding diseases and evaluation of proteins like tau, alpha-synuclein (A-syn), Amyloid Beta peptide (AB) and AB precursor protein (ABPP) have been considered as biomarkers. Methods: Three groups of subjects were recruited: PD (n = 30), Parkinson plus (n = 20) and control subjects (n = 20). Complete clinical evaluations including transcranial sonography and olfactory test were made. Blood platelets tau and ABPP were evaluated and A-syn was measured in saliva with Western blot and ELISA assays. Biomarkers profiles in different groups were compared with multivariate analyses. Results: We describe differences in protein profiles, in particular in platelet tau between PD, Parkinson plus and control groups. It is possible to generate and associate peripheral protein profiles to standard diagnostic tests to increase diagnostic accuracy. Conclusion: Peripheral protein profiles may serve as non-invasive biomarkers for diagnosis and follow up in parkinsonisms. This work was funded by FONDECYT 11130233 grant.

Serum angiopoietin-like protein 2 as a potential biomarker for diagnosis, early recurrence and prognosis in gastric cancer patients.

Chronic inflammation of gastric mucosa by Helicobacter pylori infection can initiate gastric carcinogenesis. As angiopoietin-like protein 2 (ANGPTL2) mediates inflammation and inflammation-associated carcinogenesis, we investigated the functional and clinical significance of ANGPTL2 in human gastric cancer (GC). SiRNA knockdown studies were performed for the functional assessment of ANGPTL2 in GC cell lines. ANGPTL2 expression was evaluated immunohistochemically in 192 tissue specimens from GC patients. In addition, we screened serum ANGPTL2 levels from 32 GC patients and 23 healthy controls; and validated these results in 194 serum samples from GC patients and 45 healthy controls by ELISA. ANGPTL2 knockdown caused anoikis and inhibited proliferation, invasion and migration in GC cells. ANGPTL2 expression was upregulated in GC tissues compared to normal gastric mucosa; and high ANGPTL2 expression was significantly associated with tumor progression, early recurrence (P = 0.003) and poor prognosis (P = 0.007). Serum ANGPTL2 in GC patients was significantly higher than for healthy controls (P < 0.05), and accurately distinguished GC patients from healthy control (AUC = 0.865). The validation step confirmed significantly higher serum ANGPTL2 levels in GC patients than healthy controls (P < 0.0001). Receiver operating characteristic curves yielded robust AUC value (0.831) accompanied by high sensitivity (73.0%) and specificity (82.2%) in distinguishing GC patients from healthy controls. High serum ANGPTL2, rather than its expression in matched tissues, was significantly associated with tumor progression, and emerged as an independent marker for recurrence (HR: 5.05, P = 0.0004) and prognosis (HR: 3.6, P = 0.01). Serum ANGPTL2 expression is a potential noninvasive biomarker for diagnosis, early recurrence and prognosis of GC patients.

Urinary Cell-Free DNA Quantification as Non-Invasive Biomarker in Patients with Bladder Cancer

Introduction: Concentration of urinary cell-free DNA (ucfDNA) belongs to potential bladder cancer markers, but the reported results are inconsistent due to the use of various non-standardised methodologies. The aim of the study was to standardise the methodology for ucfDNA quantification as a potential non-invasive tumour biomarker. Material and Methods: In total, 66 patients and 34 controls were enrolled into the study. Volumes of each urine portion (V) were recorded and ucfDNA concentrations (c) were measured using real-time PCR. Total amounts (TA) of ucfDNA were calculated and compared between patients and controls. Diagnostic accuracy of the TA of ucfDNA was determined. Results: The calculation of TA of ucfDNA in the second urine portion was the most appropriate approach to ucfDNA quantification, as there was logarithmic dependence between the volume and the concentration of a urine portion (p = 0.0001). Using this methodology, we were able to discriminate between bladder cancer patients and subjects without bladder tumours (p = 0.0002) with area under the ROC curve of 0.725. Positive and negative predictive value of the test was 90 and 45%, respectively. Conclusion: Quantification of ucf DNA according to our modified method could provide a potential non-invasive biomarker for diagnosis of patients with bladder cancer.

High correlation between 2 flow cytometry platforms in the microparticles analysis using a new calibrated beads strategy

Microparticles (MPs) are potential noninvasive biomarkers for diagnosis or prognosis in pathologic conditions. However, the lack of standardization of the preanalytical and analytical methods leads to a wide variability in MPs results. The recently developed Megamix-Plus beads, a new bead-based standardization tool optimized to specific types of flow cytometers, could help circumvent this problem. The aim of the present study was to determine whether the number of total MPs and platelet-derived MPs (PMPs) is similar using 2 different cytometer platforms calibrated with the Megamix-Plus beads. Blood samples from 65 patients with deep venous thrombosis were collected and processed to obtain platelet poor plasma (PPP). The number of total MPs and PMPs in each PPP sample was measured using 2 flow cytometers. Megamix-Plus side scatter channel beads were used to calibrate the LSRFortessa flow cytometer from Becton Dickinson, whereas Megamix-Plus forward scatter channel beads were applied to the Navios flow cytometer from Beckman Coulter. High correlation of total MPs and PMPs values between the flow cytometers was found (r = 0.908, P < 0.01 and r = 0.910, P < 0.001, respectively). However, the absolute numbers of total MPs and PMPs were significantly higher measured with the Navios flow cytometer compared with the LSRFortessa cytometer. Therefore, both platforms are valid for MPs determination in general, although a similar platform with the same calibration tool could be a better choice for multicenter studies.

Abstract 4930: Next generation sequencing performance for the detection of mutations in plasma cell free DNA

Abstract The identification of mutations in circulating tumor DNA (ctDNA) can serve as a biomarker for non-invasive diagnosis and real time therapeutic monitoring. Although next generation sequencing (NGS) is a promising technology, the intrinsic low abundance of ctDNA in the high background of wild-type cell free DNA (cfDNA) makes the detection and quantification of such mutations in plasma a challenging task. This study aims to measure the performance of NGS analysis when applied to the identification of somatic mutations in plasma samples. Plasma samples from two healthy controls were used to isolate cfDNA. Constitutional genomic DNA from these controls was previously genotyped using the Human OmniExpress BeadChip. A custom multiplex PCR panel was designed to target 420 unique variants. To cover a broad range (0.5%-100%) of minor allele frequencies (MAF), as expected for somatic mutations in the plasma of cancer patients, the cfDNA samples from the two controls were mixed at five different rations (7:25, 1:6, 1:8, 1:20 and 1:100). Because sequence coverage is a key driver of accuracy, 5 different coverage profiles (100x, 500x, 1000x, 2000x and 5000x) were established for each of the cfDNA pools. On total 25 libraries were generated, pooled and sequenced with the Ion PGM system. Ion Reporter software was used for data analysis. The observed MAFs were compared with expected results for all the variants of each cfDNA pool. Median exon sequencing coverage of 133x, 650x, 1312x, 2628x and 5466x was obtained for each of the 5 cfDNA pools, with &amp;gt;99% of the amplicons covered. Overall base substitution and indel detection performance was high (&amp;gt;95% of the variants were detected across the different coverage levels). A direct correlation between expected and observed MAFs for the known variants was observed. For variants present at MAF ≥5%, a sensitivity of 91.4% and 100% was achieved at 100x and ≥500x coverage levels, respectively. For variants with 5% ≤ MAF ≤ 10% at 100x of coverage, the average quality score was &amp;lt;Q20. For variants occurring at low MAF (&amp;lt;5%) the detection sensitivity and the quality score dropped as coverage decreased. At 1000x coverage and above, more than 94% of the variants present at MAF &amp;lt;5% were successfully detected with an average quality score &amp;gt;Q30. Overall, positive predictive value remained high (&amp;gt;98%), with an average of 5 false-positive calls across the full coverage range. To validate our approach we analyzed 10 pairs of primary tumour/plasma samples. All cases carried known mutations of the EGFR gene detected during routine analysis. We were able to detect the corresponding mutation in the plasma samples in all cases. MAF in plasma samples ranged from 3% to 85%. Here we demonstrate that NGS can be used to detect mutations in cfDNA. Our approach with controlled data sets also enabled us to define allele frequency, allele depth, and allele quality score cutoffs for a reliable detection of low MAF variants in ctDNA. Citation Format: Ana Justino, Gabriela Fernandes, Ana Barroso, Barbara Parente, Venceslau Hespanhol, Jose C. Machado, Jose L. Costa. Next generation sequencing performance for the detection of mutations in plasma cell free DNA. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4930. doi:10.1158/1538-7445.AM2015-4930

MiR-15b and miR-21 as Circulating Biomarkers for Diagnosis of Glioma.

Malignant gliomas are lethal primary intracranial tumors. To date, little information on the role of deregulated genes in gliomas have been identified. As the involvement of miRNAs in the carcinogenesis is well known, we carried out a pilot study to identify, as potential biomarkers, differentially expressed microRNAs in blood samples of patients affected by glioma. We studied the miRNAs’ expression, by means of microarray and Real-Time PCR, in 30 blood samples from glioma patients and in 82 blood samples of patients suffering from: (a) various neurological disorders (n=30), (b) primary B-lymphoma of the Central Nervous System (PCNSL, n=36) and (c) secondary brain metastases (n=16). By quantitative real time reverse-transcriptase polymerase chain reaction (qRT-PCR), we identified significantly increased levels of two candidate biomarkers, miR-15b and miR-21, in blood of patients affected by gliomas. ROC analysis of miR-15b biomarker levels allowed to differentiate patients with tumour from patients without glioma. Furthermore, combined expression analyses of miR15b and miR-21 distinguished between patients with and without glioma (90% sensitivity and 100% specificity). In addition, a decrement in the expression levels of miR-16 characterized glioblastomas compared to low grade and anaplastic gliomas. In conclusion, this pilot study suggest that it’s possible to identify the disease state by meaning miR-15b and miR-21 markers in blood, while miR-16 can be used to distinguish glioblastoma from other grade gliomas. They can potentially be used as biomarkers for non-invasive diagnosis of gliomas; further studies are mandatory to confirm our preliminary findings.

Netrin-4 as a biomarker promotes cell proliferation and invasion in gastric cancer.

Gastric cancer (GC) is the second most common cause of cancer-related death with limited serum biomarkers for diagnosis and prognosis. Netrin-4 (Ntn4) is a laminin-related secreted molecule found to regulate tumor progression and metastasis. However, it is completely unknown whether Ntn4 has roles in GC development. Here, we first reported Ntn4 knockdown significantly suppressed cell proliferation and motility, while overexpression or addition of exogenous Ntn4 reversed these effects. In addition, Ntn4 receptor, neogenin (Neo) was also found highly expressed in GC cells and mediated the Ntn4-induced cell proliferation and invasion. Moreover, Ntn4 or Neo silencing decreased the phosphorylation of Stat3, ERK, Akt and p38, indicating multi-oncogenic pathways (Jak/Stat, PI3K/Akt, and ERK/MAPK) were involved in Ntn4-induced effects on the GC cells. Importantly, Ntn4 level was significantly increased in 82 tumor tissues (p = 0.001) and 52 serum samples (p < 0.0001) from GC patients and positively correlated with Neo expression (p = 0.003). Ntn4 expression was negatively correlated with the survival period (p = 0.038), and positively associated with the severity of pathological stages of the tumors (p = 0.008). Taken together, Ntn4 promoted the proliferation and motility of GC cells which was mediated by its receptor Neo and through further activation of multi-oncogenic pathways. Elevated Ntn4 was detected in both tumor tissues and serum samples of GC patients and suggested a relatively poor survival, indicating Ntn4 may be used as a potential non-invasive biomarker for diagnosis and prognosis of GC.