Biomarkers For Early Cancer Detection Research Articles

Identification of potential serum biomarkers for breast cancer using a functional proteomics technology

BackgroundCancer is a genetic disease; its development and metastasis depend on the function of many proteins. Human serum contains thousands of proteins; it is a window for the homeostasis of individual’s health. Many of the proteins found in the human serum could be potential biomarkers for cancer early detection and drug efficacy evaluation.MethodsIn this study, a functional proteomics technology was used to systematically monitor metabolic enzyme and protease activities from resolved serum proteins produced by a modified 2-D gel separation and subsequent Protein Elution Plate, a method collectively called PEP. All the experiments were repeated at least twice to ensure the validity of the findings.ResultsFor the first time, significant differences were found between breast cancer patient serum and normal serum in two families of enzymes known to be involved in cancer development and metastasis: metabolic enzymes and proteases. Multiple enzyme species were identified in the serum assayed directly or after enrichment. Both qualitative and quantitative differences in the metabolic enzyme and protease activity were detected between breast cancer patient and control group, providing excellent biomarker candidates for breast cancer diagnosis and drug development.ConclusionsThis study identified several potential functional protein biomarkers from breast cancer patient serum. It also demonstrated that the functional proteomics technology, PEP, can be applied to the analysis of any functional proteins in human serum which contains thousands of proteins. The study indicated that the functional domain of the human serum could be unlocked with the PEP technology, pointing to a novel alternative for the development of diagnosis biomarkers for breast cancer and other diseases.

Application of Spectral Crosstalk Correction for Improving Multiplexed MicroRNA Detection Using a Single Excitation Wavelength

MicroRNAs (miRNAs) play crucial roles in the regulation of cellular activities and are next-generation biomarkers for early cancer detection. Simultaneous monitoring of multiplexed miRNA is very important for enhancing the accuracy of cancer diagnostics. Traditional fluorescence methods for multicomponent analysis were usually operated under multiple excitation wavelengths, because spectral crosstalk is very detrimental to detecting accuracy for multicomponent analysis. Herein, we present a fluorescence strategy for multi-miRNAs detection in plasma under a single excitation wavelength. Nucleic acid stain TOTO-1 and three labeled fluorescence dyes Cy3, Cy3.5, and Cy5 emit no fluorescence in their free state. Target miRNA hybridized the auxiliary and probe oligonucleotides into duplex nucleic acid. Intercalation interaction localized TOTO-1 and labeled dyes into the duplex nucleic acid. As a result, TOTO-1 emitted strong fluorescence and efficient Förster resonance energy transfer (FRET) happened. MicroRNAs miRNA-155, miRNA-182, and miRNA-197, which are significant for the early diagnosis of lung cancer, were simultaneously detected as models. Deviations from spectral crosstalk in the presence of other miRNAs were corrected by mathematical methods. Results demonstrated that, after spectra crosstalk corrections, every miRNA at high or low concentration in plasma was determined accurately in the presence of either high or low concentrations of the other two miRNAs. This new multiplexed assay for miRNAs is promising for clinical diagnosis, prognosis, and therapeutic monitoring of early-stage lung cancer.

Microbial Biomarkers for Early Cancer Detection

The human microbiome - the vast amount of microbes that colonize our body - play an important role in maintaining our health. Changes in microbiome composition have been linked to multiple diseases including cancer. Although mechanisms and causalities of these associations still have to be uncovered, microbiome alterations across various stages of disease can be utilized for novel diagnostic and prognostic tests. Research on biomarkers extracted from the gut microbiome has in particular focused on colorectal cancer, where clinical use is already on the horizon. For example, multiple microbial taxonomic markers such as Fusobacterium nucleatum and other oral pathogens have been identified in human feces with potential for non-invasive diagnostics and prognostics. The article summarizes the recent developments, but also limitations and challenges for the development of microbiome-based biomarkers for cancer early detection.

The role of pancreatic cancer-derived exosomes in cancer progress and their potential application as biomarkers.

Pancreatic cancer is one of the most deadly cancers, with dismal prognosis due to its poor early detection rate and high metastatic rate. Thus, elucidation of the molecular mechanisms accounting for its metastasis and discovery of competent biomarkers is required. Exosomes are multivesicular body-derived small extracellular vesicles released by various cell types that serve as important message carriers during intercellular communication. They are also known to play critical roles during cancer-genesis, cancer-related immune reactions, and metastasis. They also possess promising potential as novel biomarkers for cancer early detection. Therefore, extensive studies on pancreatic cancer-derived exosomes are currently being performed because they hold the promising potential of elevating the overall survival rate of patients with pancreatic cancer. In the present review, we focus on the role of exosomes in pancreatic cancer-related immune reactions, metastasis, and complications, and on their potential application as pancreatic cancer biomarkers.

MicroRNA-34a: A Key Regulator in the Hallmarks of Renal Cell Carcinoma.

Renal cell carcinoma (RCC) incidence has increased over the past two decades. Recent studies reported microRNAs as promising biomarkers for early cancer detection, accurate prognosis, and molecular targets for future treatment. This study aimed to evaluate the expression levels of miR-34a and 11 of its bioinformatically selected target genes and proteins to test their potential dysregulation in RCC. Quantitative real-time PCR for miR-34a and its targets; MET oncogene; gene-regulating apoptosis (TP53INP2 and DFFA); cell proliferation (E2F3); and cell differentiation (SOX2 and TGFB3) as well as immunohistochemical assay for VEGFA, TP53, Bcl2, TGFB1, and Ki67 protein expression have been performed in 85 FFPE RCC tumor specimens. Clinicopathological parameter correlation and in silico network analysis have also implicated. We found RCC tissues displayed significantly higher miR-34a expression level than their corresponding noncancerous tissues, particularly in chromophobic subtype. MET and E2F3 were significantly upregulated, while TP53INP2 and SOX2 were downregulated. ROC analysis showed high diagnostic performance of miR-34a (AUC = 0.854), MET (AUC = 0.765), and E2F3 (AUC = 0.761). The advanced pathological grade was associated with strong TGFB1, VEGFA, and Ki67 protein expression and absent Tp53 staining. These findings indicate miR-34a along with its putative target genes could play a role in RCC tumorigenesis and progression.

Metal enhanced fluorescence on super-hydrophobic clusters of gold nanoparticles

We used optical lithography, electroless deposition and deep reactive ion etching techniques to realize arrays of super-hydrophobic gold nanoparticles arranged in a hierarchical structure. At the micro-scale, silicon-micro pillars in the chip permit to manipulate and concentrate biological solutions, at the nano-scale, gold nanoparticles enable metal enhanced fluorescence (MEF) effects, whereby fluorescence signal of fluorophores in close proximity to a rough metal surface is amplified by orders of magnitude. Here, we demonstrated the device in the analysis of fluorescein derived gold-binding peptides (GBP-FITC). While super-hydrophobic schemes and MEF effects have been heretofore used in isolation, their integration in a platform may advance the current state of fluorescence-based sensing technology in medical diagnostics and biotechnology. This scheme may be employed in protein microarrays where the increased sensitivity of the device may enable the early detection of cancer biomarkers or other proteins of biomedical interest.

The Role of Cancer Biomarkers in HIV Infected Hosts.

A higher incidence of cancer has been observed in Human Immunodeficiency Virus (HIV) infected individuals as compared with healthy people of the same age. A complex relationship between HIV-induced immune suppression, chronic antigenic stimulation, and oncogenic virus co-infections may promote carcinogenesis and increase the risk of developing tumors in these patients. Cancers in HIV subjects include the AIDS-defining malignancies (ADMs) and other non-AIDS-defining malignancies (NADMs). Antiretroviral therapy has reduced the incidence of ADMs whereas a concurrent increase of NADMs was observed in the last years. Biomarkers are measurable parameters, characterizing normal or pathogenic processes, which could provide a high potential for risk evaluation and diagnosis of patients. Therefore, the early detection of cancer biomarkers in HIV-positive subjects would be useful to identify patients at most risk of tumor disease development. This review will focus principally on the risk assessment and diagnostic role of several biomarkers of malignancy in HIV patients including cellular and viral biomarkers, cytokines, immune activation molecules and genetic polymorphisms.

ITPKA Gene Body Methylation Regulates Gene Expression and Serves as an Early Diagnostic Marker in Lung and Other Cancers

IntroductionDespite recent advances in cancer therapy, the overall 5-year survival rate of patients with lung cancer remains low. The aim of our study was to search for novel markers for early diagnosis in patients with lung cancer. MethodsComplementary DNA microarray analysis was performed in primary lung adenocarcinomas and cell lines to search for differentially expressed genes, followed by in vivo and in vitro tumorigenic assays to characterize the oncogenic potential of the candidate genes. Gene body methylation was analyzed by 450K methylation array, bisulfite sequencing, and quantitative methylation-specific polymerase chain reaction assays. In silico analysis of The Cancer Genome Atlas data set was also performed. ResultsInositol-trisphosphate 3-kinase A gene (ITPKA), a kinase with limited tissue distribution, was identified as a potential oncogene. We showed that ITPKA expression is up-regulated in many forms of cancers, including lung and breast cancers, and that overexpressed ITPKA contributes to tumorigenesis. We also demonstrated that ITPKA expression is regulated by epigenetic DNA methylation of ITPKA gene body through modulation of the binding of SP1 transcription factor to the ITPKA promoter. ITPKA gene body displayed low or absent levels of methylation in most normal tissue but was significantly methylated in malignant tumors. In lung cancer, ITPKA gene body methylation first appeared at the in situ carcinoma stage and progressively increased after invasion. ConclusionsITPKA is a potential oncogene that it is overexpressed in most tumors, and its overexpression promotes tumorigenesis. ITPKA gene body methylation regulates its expression and thus serves as a novel and potential biomarker for early cancer detection.

Construction of Electrochemical Immunosensing Interface for Multiple Cancer Biomarkers Detection

AbstractThe quick and early detection of cancer biomarkers is crucial for improving resectability rate and reducing mortality rate of cancer treatment. Cancer biomarkers detection with electrochemical assay has attracted considerable attention due to its high sensitivity, rapid response, high efficiency and good specificity. Recent developments of electrochemical immunosensing interface have significantly improved the sensitivity and efficiency by constructing substrates and immunoprobes using hybrid nanomaterials. As is known, electrochemical signal overlapping and sensitivity enhancement are two main challenges in the development of multiplexed electrochemical immunoassay. Many researches have been conducted to solve these problems and have received great progress. Herein, this review describes the recent advances of nanomaterials on the development of the electrochemical immunosensing interface for the detection of multiple cancer biomarkers and provides a perspective in this field.

Amino acid profiling as a method of discovering biomarkers for early diagnosis of cancer.

Cancer is one of the main causes of mortality in the world and its early detection significantly increases chances of patients' survival. High cancer mortality rate is caused mainly by late-stage diagnosis and lack of non-invasive and reliable methods for early diagnosis, such as plasma biomarkers. The incidence of cancers in the world still grows so it is crucial to develop a new, faster, high specificity and more sensitive diagnostic technologies. Several recent researchers indicate amino acids as a potential marker for cancer detection. An ideal cancer biomarker should be characterized by high specificity and sensitivity, reliability, ease of measurement and, what is important, ability to detect disease in its early stage. This study is focused on indicating metabolic amino acid profiling as a method of identifying biomarkers for cancer early detection and screening. Presented results are derived from the most recent studies where patients in early, often asymptomatic stages of disease constituted a large percentage of all the patients and, what is important, where researchers have observed alterations in these patients' amino acid profiles. This review is concentrated on analyzing studies on the most common cancers with high mortality rate. Inventing effective methods of early diagnosis is particularly important in case of such diseases. Research presented in this publication is focused on patients with lung, breast and colon cancer. In all analyzed cases, significant changes in the amino acid profile in cancer patients comparing to healthy controls were observed. This study indicates potential of amino acid profiling as method for early cancer detection.

Graphene: The Missing Piece for Cancer Diagnosis?

This paper reviews recent advances in graphene-based biosensors development in order to obtain smaller and more portable devices with better performance for earlier cancer detection. In fact, the potential of Graphene for sensitive detection and chemical/biological free-label applications results from its exceptional physicochemical properties such as high electrical and thermal conductivity, aspect-ratio, optical transparency and remarkable mechanical and chemical stability. Herein we start by providing a general overview of the types of graphene and its derivatives, briefly describing the synthesis procedure and main properties. It follows the reference to different routes to engineer the graphene surface for sensing applications with organic biomolecules and nanoparticles for the development of advanced biosensing platforms able to detect/quantify the characteristic cancer biomolecules in biological fluids or overexpressed on cancerous cells surface with elevated sensitivity, selectivity and stability. We then describe the application of graphene in optical imaging methods such as photoluminescence and Raman imaging, electrochemical sensors for enzymatic biosensing, DNA sensing, and immunosensing. The bioquantification of cancer biomarkers and cells is finally discussed, particularly electrochemical methods such as voltammetry and amperometry which are generally adopted transducing techniques for the development of graphene based sensors for biosensing due to their simplicity, high sensitivity and low-cost. To close, we discuss the major challenges that graphene based biosensors must overcome in order to reach the necessary standards for the early detection of cancer biomarkers by providing reliable information about the patient disease stage.

Autoantibody recognition mechanisms of p53 epitopes

There is an urgent need for economical blood based, noninvasive molecular biomarkers to assist in the detection and diagnosis of cancers in a cost-effective manner at an early stage, when curative interventions are still possible. Serum autoantibodies are attractive biomarkers for early cancer detection, but their development has been hindered by the punctuated genetic nature of the ten million known cancer mutations. A landmark study of 50,000 patients (Pedersen et al., 2013) showed that a few p53 15-mer epitopes are much more sensitive colon cancer biomarkers than p53, which in turn is a more sensitive cancer biomarker than any other protein. The function of p53 as a nearly universal “tumor suppressor” is well established, because of its strong immunogenicity in terms of not only antibody recruitment, but also stimulation of autoantibodies. Here we examine dimensionally compressed bioinformatic fractal scaling analysis for identifying the few sensitive epitopes from the p53 amino acid sequence, and show how it could be used for early cancer detection (ECD). We trim 15-mers to 7-mers, and identify specific 7-mers from other species that could be more sensitive to aggressive human cancers, such as liver cancer. Our results could provide a roadmap for ECD.

DNA methylation in human papillomavirus-infected cervical cells is elevated in high-grade squamous intraepithelial lesions and cancer.

ObjectiveDNA methylation has been shown to be a potential biomarker for early cancer detection. The aim of this study was to evaluate DNA methylation profiles according to liquid-based Pap (LBP) test results and to assess their diagnostic value in a Korean population.MethodsA total of 205 patients with various Papanicolaou test results were enrolled to this study (negative, 26; atypical squamous cells of undetermined significance, 39; low grade squamous intraepithelial lesion, 44; high grade squamous intraepithelial lesion (HSIL), 48; and cancer, 48). DNA methylation analysis of four genes, ADCYAP1, PAX1, MAL, and CADM1, was performed on residual cervical cells from LBP samples using a quantitative bisulfite pyrosequencing method. To evaluate the diagnostic performance of the four methylated genes for cancer detection, receiver operating characteristic (ROC) curves were drawn. Sensitivities and specificities were also tested at cutoffs determined from the ROC curves.ResultsCervical cancer cells showed dramatically increased methylation levels for the four genes analyzed. ADCYAP1 and PAX1 also trended toward elevated methylation levels in HSIL samples, although the levels were much lower than those in cancer cells. The sensitivities of methylated ADCYAP1, PAX1, MAL, and CADM1 for the detection of cancer were 79.2%, 75.0%, 70.8%, and 52.1%, and the specificities were 92.0%, 94.0%, 94.7%, and 94.0%, respectively. Methylated ADCYAP1 and PAX1 demonstrated relatively better discriminatory ability than did methylated MAL and CADM1 (area under the curves 0.911 and 0.916 vs. 0.854 and 0.756, respectively).ConclusionDNA methylation status, especially in the ADCYAP1 and PAX1 genes, showed relatively good specificity, ranging from 90% to 94%. The possible additive and complementary roles of DNA methylation testing with respect to conventional cervical cancer screening programs will need to be validated in prospective population-based studies.

Methylation of tumor suppressor gene CDH13 and SHP1 promoters and their epigenetic regulation by the UHRF1/PRMT5 complex in endometrial carcinoma

ObjectiveEpigenetic changes in cancer and precancerous lesions could be utilized as biomarkers for cancer early detection. This study aims to investigate the novel biomarkers in endometrial carcinoma, and explore their epigenetic regulation. MethodsMethylation of six tumor suppressor genes (CDH13, SHP1, HIN1, DKK3, CTNNA1 and PCDH8) was evaluated in 155 endometrium samples. Changes of methylation and mRNA expression after treatment with 5-Aza-2′-deoxycytidine (5-Aza-CdR) or/and trichostatin A (TSA) were investigated by MSP and qRT-PCR respectively. Co-immunoprecipitation was used to detect the interactions between UHRF1 and PRMT5 proteins. ResultsCDH13 and SHP1 promoters were highly methylated (81.36% and 86.44%, respectively) in endometrial carcinoma, while CDH13 promoter methylation was also present in complex hyperplasia and atypical hyperplasia (51.72% and 50.00%, respectively). Methylation of CDH13 and SHP1 promoters was associated with age and tumor differentiation or muscular infiltration depth. CDH13 and SHP1 promoters were completely methylated in endometrial carcinoma cell lines and were partially reversed by 5-Aza-CdR or TSA to induce mRNA levels (P<0.01). After combined treatment with these two agents, methylation of CDH13 and SHP1 promoters was completely reversed and expression of their mRNA was significantly increased (P<0.01). Moreover, PRMT5 could bind to UHRF1 and down-regulated by 5-Aza-CdR and/or TSA treatment (P<0.05). ConclusionsOur data demonstrate for the first time that SHP1 methylation has high specificity for diagnosis of endometrial carcinoma, while CDH13 promoter methylation plays a role in the earlier stage. Furthermore, UHRF1 could form a complex with PRMT5 to contribute to the endometrial carcinogenesis.

Particulate matter-induced epigenetic changes and lung cancer.

Lung cancer is the leading cause of cancer death worldwide. Cigarette smoking is the well-known risk factor for lung cancer. Epidemiological studies suggest that air pollution, especially particulate matter (PM) exposure, is associated with increased lung cancer risk and mortality independent of cigarette smoking. English-language publications focusing on PM, epigenetic changes, and lung cancer were reviewed. The epigenome serves as an interface between the environment and the genome. PM is one of the environmental factors that can cause epigenetic changes. The epigenome serves as an interface between the environment and the genome. Some of the epigenetic changes lead to increased disease susceptibility and progression. In cardiovascular disease and asthma, the association between PM exposure and the disease specific epigenetic changes has been identified. In lung cancer, the epigenetic changes in DNA methylation, histone modification and microRNA expression are commonly found, but the specific link between PM exposure and lung cancer remains incompletely understood. The results of epidemiological studies indicate the important effects of PM exposure on lung cancer. PM2.5 is consistently associated with the increased lung cancer risk and mortality. Based on the epidemiological associations between PM exposure and lung cancer, PM-induced epigenetic changes may play important roles in the pathogenesis of lung cancer. In this review, we focus on the current knowledge of epigenetic changes associated with PM exposure and lung cancer. Better understanding of the link between PM exposure and lung cancer at the epigenomic level by comprehensive comparison approach may identify lung cancer early detection biomarkers and novel therapeutic targets.

Aberrant reduction of telomere repetitive sequences in plasma cell-free DNA for early breast cancer detection.

Excessive telomere shortening is observed in breast cancer lesions when compared to adjacent non-cancerous tissues, suggesting that telomere length may represent a key biomarker for early cancer detection. Because tumor-derived, cell-free DNA (cfDNA) is often released from cancer cells and circulates in the bloodstream, we hypothesized that breast cancer development is associated with changes in the amount of telomeric cfDNA that can be detected in the plasma. To test this hypothesis, we devised a novel, highly sensitive and specific quantitative PCR (qPCR) assay, termed telomeric cfDNA qPCR, to quantify plasma telomeric cfDNA levels. Indeed, the internal reference primers of our design correctly reflected input cfDNA amount (R(2) = 0.910, P = 7.82 × 10(-52)), implying accuracy of this assay. We found that plasma telomeric cfDNA levels decreased with age in healthy individuals (n = 42, R(2) = 0.094, P = 0.048), suggesting that cfDNA is likely derived from somatic cells in which telomere length shortens with increasing age. Our results also showed a significant decrease in telomeric cfDNA level from breast cancer patients with no prior treatment (n = 47), compared to control individuals (n = 42) (P = 4.06 × 10(-8)). The sensitivity and specificity for the telomeric cfDNA qPCR assay was 91.49% and 76.19%, respectively. Furthermore, the telomeric cfDNA level distinguished even the Ductal Carcinoma In Situ (DCIS) group (n = 7) from the healthy group (n = 42) (P = 1.51 × 10(-3)). Taken together, decreasing plasma telomeric cfDNA levels could be an informative genetic biomarker for early breast cancer detection.

Label-free capacitance based aptasensor platform for the detection of HER2/ErbB2 cancer biomarker in serum

In this study, a label-free capacitive aptasensor was developed based on capturing of human epidermal growth factor receptor 2 (HER2) protein by anti-HER2 ssDNA aptamers functionalized on interdigitated microelectrodes of capacitor as bio-recognition elements. The aptasensor response was measured by non-Faradaic Impedance Spectroscopy (nFIS) method. Capacitance signal specific to target HER2 protein is based on changes occurred due to charge distribution upon interaction of aptamer–protein molecules against to the applied AC frequency (50–350MHz). HER2 protein in spiked human serum was successfully detected through concentration dependent changes in impedance/capacitance values as a result of the formation of aptamer–HER2 protein complex (0.2–2ngmL−1 of HER2) on capacitor microelectrodes. The label-free capacitive aptasensing is a versatile and promising approach for early detection of cancer biomarkers in dilute human serum and the method potentially be extended to a wide variety of diseases biomarkers.

The Role of miR-21 in Cancer.

MicroRNAs (miRNAs) are small endogenous noncoding RNAs that suppress gene expression at the post-transcriptional level. In the past decade, miRNAs have been extensively studied in a number of different human cancers. MiRNAs have been identified to act both as oncogenes and as tumor suppressors. In addition, miRNAs are associated with the intrinsic resistance of cancer to various forms of therapy, and they are implicated in both tumor progression and metastasis. The characterization of the specific alterations in the patterns of miRNA expression in cancer has great potential for identifying biomarkers for early cancer detection, as well as for potential therapeutic intervention in cancer treatment. In this chapter, we describe the ever-expanding role of miR-21 and its target genes in different cancers, and provide insight into how this oncogenic miRNA regulates cancer cell proliferation, migration, and apoptosis by suppressing the expression of tumor suppressors.

Frequent epigenetic suppression of tumor suppressor gene glutathione peroxidase 3 by promoter hypermethylation and its clinical implication in clear cell renal cell carcinoma.

The goal of this study is to identify novel tumor suppressor genes silenced by promoter methylation in clear cell renal cell carcinoma (ccRCC) and discover new epigenetic biomarkers for early cancer detection. Reactive oxygen species (ROS) is a major cause of DNA damage that correlates with cancer initiation and progression. Glutathione peroxidase 3 (GPX3), the only known extracellular glycosylated enzyme of GPXs, is a major scavenger of ROS. GPX3 has been identified as a tumor suppressor in many cancers. However, the role of GPX3 in ccRCC remains unclear. This study aimed to investigate its epigenetic alteration in ccRCC and possible clinicopathological association. In our study, GPX3 methylation and down-regulation were detected in 5 out of 6 ccRCC cell lines and the GPX3 mRNA and protein expression level in ccRCC tumors was significantly lower than in adjacent non-malignant renal tissues (p < 0.0001). Treatment with 5-Aza-2'-deoxycytidine restored GPX3 expression in ccRCC cells. Aberrant methylation was further detected in 77.1% (162/210) of RCC primary tumors, but only 14.6% (7/48) in adjacent non-malignant renal tissues. GPX3 methylation status was significantly associated with higher tumor nuclear grade (p = 0.014). Thus, our results showing frequent GPX3 inactivation by promoter hypermethylation in ccRCC may reveal the failure in the cellular antioxidant system in ccRCC and may be associated with renal tumorigenesis. GPX3 tumor specific methylation may serve as a biomarker for early detection and prognosis prediction of ccRCC.

AGR3 in breast cancer: prognostic impact and suitable serum-based biomarker for early cancer detection.

Blood-based early detection of breast cancer has recently gained novel momentum, as liquid biopsy diagnostics is a fast emerging field. In this study, we aimed to identify secreted proteins which are up-regulated both in tumour tissue and serum samples of breast cancer patients compared to normal tissue and sera. Based on two independent tissue cohorts (n = 75 and n = 229) and one serum cohort (n = 80) of human breast cancer and healthy serum samples, we characterised AGR3 as a novel potential biomarker both for breast cancer prognosis and early breast cancer detection from blood. AGR3 expression in breast tumours is significantly associated with oestrogen receptor α (P<0.001) and lower tumour grade (P<0.01). Interestingly, AGR3 protein expression correlates with unfavourable outcome in low (G1) and intermediate (G2) grade breast tumours (multivariate hazard ratio: 2.186, 95% CI: 1.008-4.740, P<0.05) indicating an independent prognostic impact. In sera analysed by ELISA technique, AGR3 protein concentration was significantly (P<0.001) elevated in samples from breast cancer patients (n = 40, mainly low stage tumours) compared to healthy controls (n = 40). To develop a suitable biomarker panel for early breast cancer detection, we measured AGR2 protein in human serum samples in parallel. The combined AGR3/AGR2 biomarker panel achieved a sensitivity of 64.5% and a specificity of 89.5% as shown by receiver operating characteristic (ROC) curve statistics. Thus our data clearly show the potential usability of AGR3 and AGR2 as biomarkers for blood-based early detection of human breast cancer.