Plasma proteomic analysis of patients with squamous cell carcinoma of the uterine cervix

A novel electrochemical immunosensor for sensitive detection of depression marker Apo-A4 based on bipyridine-functionalized covalent organic frameworks

A novel electrochemical immunosensor for detecting potential depression biomarker Apolipoprotein A4 (Apo-A4) was developed using a multi-signal amplification approach. Firstly, the sensor utilized a modified electrode material, NG-PEI-COF, combining bipyridine-functionalized covalent organic framework (COF) and polyethyleneimine-functionalized nitrogen-doped graphene (NG-PEI), providing high surface area and excellent electron transfer capability for the first-stage amplification in electrical signal conduction. Subsequently, gold nanoparticles (AuNPs) were further electrodeposited onto the electrode, providing good biocompatibility and abundant binding sites for immobilizing the target antigen, thus achieving the second-stage amplification in target recognition and binding. To address the lack of redox properties of the antigen, a tracer probe was formed by loading AuNPs, anti-Apo-A4, and toluidine blue (TB) successively onto COF, leading to the third-stage amplification in signal conversion. The constructed electrochemical immunosensor TB/Ab/AuNPs/COF-Apo-A4/AuNPs/NG-PEI-COF/GCE exhibited excellent detection performance against Apo-A4 with a linear range of 0.01 to 300 ng mL-1 and had a low detection limit of 2.16 pg mL-1 (S/N = 3). In addition, the biosensor had good reproducibility (RSD = 2.31%), stability, and significant anti-interference performance toward other depression biomarkers. The sensor has been successfully used for the quantitative detection of Apo-A4 in serum, providing potential applications for detecting Apo-A4 in the clinic and serving as a reference for constructing sensing methods based on COF.

Precursor carboxy-silica for functionalization with interactive ligands. III. Carbodiimide assisted preparation of immobilized lectin stationary phases for high performance lectin affinity chromatography of sub-glycoproteomics from cancer and disease free human sera

In this study, a precursor carboxy-silica support was demonstrated in the immobilization of two different lectins, namely concanavalin A (Con A) and wheat germ agglutinin (WGA) for use in high performance lectin affinity chromatography (LAC) for the selective capturing and enrichment of glycoproteins from healthy/disease free and cancer human sera. The lectin columns thus obtained (i.e., Con A- and WGA-columns) showed no nonspecific interactions toward some chosen standard glycoproteins and non-glycoproteins. Both columns were shown in sub-glycoproteomics enrichment from human sera including disease free and adenocarcinoma cancer sera. The collected fractions were subjected to LC-MS/MS for identification of the captured glycoproteins, whereby the total number of identified proteins using Con A column from disease-free and cancer sera were 164 and 188, respectively while 133 and 103 proteins were identified in the fractions captured by the WGA column from disease-free and cancer sera samples, respectively. Differentially expressed proteins (DEPs) between the disease free and cancer sera in both the Con A and WGA column fractions were identified via the plot of the abundance vs. the protein ratio whereby the binary logarithm of average intensities of cancer and disease free sera were plotted against the binary logarithm of cancer/disease free sera ratios. The proteins that exhibit log 2 (cancer/healthy) ratio values greater than +2 and less than -2 in both categories are considered as DEPs. Furthermore, for visualization of the data arrangement, Q-Q scatterplot were also used whereby the binary logarithm of cancer serum was plotted against the binary logarithm of disease-free serum for both Con A and WGA. For Con A column, 28 up-regulated and 10 down regulated proteins were identified with a total of 38 DEPs while only two being non-glycoproteins. Furthermore, the up-regulated, and down regulated proteins recorded for WGA column are 14 and 6, respectively, totaling 20 proteins including 3 non-glycoproteins. Some of the non-specific binding to lectin are most likely due to protein-protein interactions.

Comparative Serum Proteome Profiling of Canine Benign Prostatic Hyperplasia before and after Castration

BPH is the most prevalent prostatic condition in aging dogs. Nevertheless, clinical diagnosis and management remain inconsistent. This study employed in-solution digestion coupled with nano-liquid chromatography tandem mass spectrometry to assess serum proteome profiling of dogs with BPH and those dogs after castration. Male dogs were divided into two groups; control and BPH groups. In the BPH group, each dog was evaluated at two time points: Day 0 (BF subgroup) and Day 30 after castration (AT subgroup). In the BF subgroup, three proteins were significantly upregulated and associated with dihydrotestosterone: solute carrier family 5 member 5, tyrosine-protein kinase, and FRAT regulator of WNT signaling pathway 1. Additionally, the overexpression of polymeric immunoglobulin receptors in the BF subgroup hints at its potential as a novel protein linked to the BPH development process. Conversely, alpha-1-B glycoprotein (A1BG) displayed significant downregulation in the BF subgroup, suggesting A1BG's potential as a predictive protein for canine BPH. Finasteride was associated with increased proteins in the AT subgroup, including apolipoprotein C-I, apolipoprotein E, apolipoprotein A-II, TAO kinase 1, DnaJ homolog subfamily C member 16, PH domain and leucine-rich repeat protein phosphatase 1, neuregulin 1, and pseudopodium enriched atypical kinase 1. In conclusion, this pilot study highlighted alterations in various serum proteins in canine BPH, reflecting different pathological changes occurring in this condition. These proteins could be a source of potential non-invasive biomarkers for diagnosing this disease.

Protein Biomarker Discovery Studies on Urinary sEV Fractions Separated with UF-SEC for the First Diagnosis and Detection of Recurrence in Bladder Cancer Patients

Urinary extracellular vesicles (EVs) are an attractive source of bladder cancer biomarkers. Here, a protein biomarker discovery study was performed on the protein content of small urinary EVs (sEVs) to identify possible biomarkers for the primary diagnosis and recurrence of non-muscle-invasive bladder cancer (NMIBC). The sEVs were isolated by ultrafiltration (UF) in combination with size-exclusion chromatography (SEC). The first part of the study compared healthy individuals with NMIBC patients with a primary diagnosis. The second part compared tumor-free patients with patients with a recurrent NMIBC diagnosis. The separated sEVs were in the size range of 40 to 200 nm. Based on manually curated high quality mass spectrometry (MS) data, the statistical analysis revealed 69 proteins that were differentially expressed in these sEV fractions of patients with a first bladder cancer tumor vs. an age- and gender-matched healthy control group. When the discriminating power between healthy individuals and first diagnosis patients is taken into account, the biomarkers with the most potential are MASP2, C3, A2M, CHMP2A and NHE-RF1. Additionally, two proteins (HBB and HBA1) were differentially expressed between bladder cancer patients with a recurrent diagnosis vs. tumor-free samples of bladder cancer patients, but their biological relevance is very limited.

Phaseolus vulgaris Erythroagglutinin (PHA-E)-Positive Ceruloplasmin Acts as a Potential Biomarker in Pancreatic Cancer Diagnosis

Pancreatic cancer (PC) remains one of the top 10 causes of cancer-related death in recent years. Approximately 80% of PC patients are diagnosed at the middle or advanced stage and miss the opportunity for surgery. The demand for early diagnostic methods and reliable biomarkers is increasing, although a number of tumor markers such as CA19-9 and CEA have already been utilized in clinics. In this study, we analyzed the alteration of N-glycan of serum glycoproteins by mass spectrometry and lectin blotting. The results showed that bisecting GlcNAc structures of glycoproteins are significantly increased in PC patients' sera. With Phaseolus vulgaris Erythroagglutinin (PHA-E) lectin that specifically recognizes bisecting GlcNAc N-glycans, the serum glycoproteins bearing bisecting GlcNAc in PC patients' sera were pulled down and identified by nano-LC-MS/MS. Among them, ceruloplasmin (Cp) was screened out with a satisfied sensitivity and specificity in identifying PC from acute pancreatitis patients (AUC: 0.757) and normal healthy persons (AUC: 0.972), suggesting a close association between Cp and PC development and diagnosis. To prove that, the Cp expression in tumor tissues of PC patients was examined. The results showed that Cp was significantly upregulated in PC tissues compared to that in adjacent normal tissues. All these results suggested that PHA-E-positive Cp could be a potential PC-specific glycoprotein marker to distinguish PC patients from acute pancreatitis patients and normal persons.

Evaluation of potential anti-metastatic and antioxidative abilities of natural peptides derived from Tecoma stans (L.) Juss. ex Kunth in A549 cells

Background

Tecoma stans (L.) Juss. ex Kunth is a well-known medicinal plant found in tropical and subtropical regions. It contains a broad range of bioactive compounds that exhibit many biological effects, including antidiabetic, antibacterial, and antioxidative activities. However, the effect of natural peptides from T. stans against cancer progression and free radical production is unknown. This study aims to evaluate the cytotoxic, anti-metastatic, and antioxidative activities of natural peptides from T. stans on A549 cells.

Methods

The natural peptides were extracted from the flower of T. stans using the pressurized hot water extraction (PHWE) method, followed by size exclusion chromatography and solid-phase extraction-C18. The cytotoxic and anti-metastatic effects of natural peptides were evaluated using MTT and transwell chamber assays, respectively. The free radical scavenging activity of natural peptides was determined using ABTS, DPPH, and FRAP assays. The cells were pretreated with the IC₅₀ dosage of natural peptides and stimulated with LPS before analyzing intracellular reactive oxygen species (ROS) and proteomics.

Results

Natural peptides induced cell toxicity at a concentration of less than 1 ng/ml and markedly reduced cell motility of A549 cells. The cells had a migration rate of less than 10% and lost their invasion ability in the treatment condition. In addition, natural peptides showed free radical scavenging activity similar to standard antioxidants and significantly decreased intracellular ROS in the LPS-induced cells. Proteomic analysis revealed 1,604 differentially expressed proteins. The self-organizing tree algorithm (SOTA) clustered the protein abundances into eleven groups. The volcano plot revealed that the cancer-promoting proteins (NCBP2, AMD, MER34, ENC1, and COA4) were down-regulated, while the secretory glycoprotein (A1BG) and ROS-reducing protein (ASB6) were up-regulated in the treatment group.

Conclusion

The anti-proliferative and anti-metastatic activities of natural peptides may be attributed to the suppression of several cancer-promoting proteins. In contrast, their antioxidative activity may result from the up-regulation of ROS-reducing protein. This finding suggests that natural peptides from T. stans are viable for being the new potential anti-cancer and antioxidative agents.

Proteomic Analysis Identifies FNDC1, A1BG, and Antigen Processing Proteins Associated with Tumor Heterogeneity and Malignancy in a Canine Model of Breast Cancer

New insights into the underlying biological processes of breast cancer are needed for the development of improved markers and treatments. The complex nature of mammary cancer in dogs makes it a great model to study cancer biology since they present a high degree of tumor heterogeneity. In search of disease-state biomarkers candidates, we applied proteomic mass spectrometry imaging in order to simultaneously detect histopathological and molecular alterations whilst preserving morphological integrity, comparing peptide expression between intratumor populations in distinct levels of differentiation. Peptides assigned to FNDC1, A1BG, and double-matching keratins 18 and 19 presented a higher intensity in poorly differentiated regions. In contrast, we observed a lower intensity of peptides matching calnexin, PDIA3, and HSPA5 in poorly differentiated cells, which enriched for protein folding in the endoplasmic reticulum and antigen processing, assembly, and loading of class I MHC. Over-representation of collagen metabolism, coagulation cascade, extracellular matrix components, cadherin-binding and cell adhesion pathways also distinguished cell populations. Finally, an independent validation showed FNDC1, A1BG, PDIA3, HSPA5, and calnexin as significant prognostic markers for human breast cancer patients. Thus, through a spatially correlated characterization of spontaneous carcinomas, we described key proteins which can be further validated as potential prognostic biomarkers.

Seminal Plasma and Serum Afamin Levels Are Associated with Infertility in Men with Oligoasthenoteratozoospermia

The plasma glycoprotein afamin has been previously identified as an alternative carrier protein for vitamin E in extravascular fluids such as plasma and cerebrospinal, ovarian follicular, and seminal fluids. However, to date, no study has established a relationship between afamin levels and infertility in women or men. The purposes of our study were (i) to assess the level of afamin in serum and seminal fluids in infertile men compared to healthy controls and (ii) to study the association between polymorphisms in afamin genes and male infertility. This observational, prospective study evaluated the afamin levels in serum and seminal fluids from infertile men (n = 39) and compared them to those in healthy controls (n = 30). We studied the association between single-nucleotide polymorphisms (SNPs) in the 5`-untranslated region (5`-UTR) of the afamin gene and infertility and analyzed a total of 1000 base pairs from the untranslated region of the afamin gene. Subjects with low sperm motility and low sperm concentration had higher median seminal afamin (18.9 ± 2.9 ng/mg of proteins) and serum afamin concentrations (24.1 ± 4.0 ng/mg of proteins) than subjects with normal sperm parameters (10.6 ± 1.4 ng/mg of proteins) (p < 0.02) (15.6 ± 1.4 ng/mg of proteins) (p < 0.002). A total of five different polymorphisms were found, including one deletion and four single-nucleotide polymorphisms (SNPs). A new transversion (A/T) (position 4:73481093) was identified in an oligoasthenoteratozoospermic patient and was associated with high levels of afamin in plasma and seminal fluids. The prevalence of this variant in our study in the case homozygous for TT is 0.985 (98.5%), and in the case heterozygous for TA is 0.015 (1.5%). Our results suggest that genetic variations in afamin might be associated with male infertility. These findings could significantly enhance our understanding of the molecular genetic causes of infertility.

Virtual screening of mutations in antioxidant genes and its putative association with HNSCC: An in silico approach

Abnormalities in the antioxidant pathway are usually associated with inflammatory conditions, followed by tissue damage. Cancer is one such disease where there is a build-up of reactive oxygen species leading to pathological consequences. The present study aims to identify the alteration in genes and proteins associated with the common antioxidant pathways among patients with head and neck squamous cell carcinoma (HNSCC). The study design follows a retrospective approach and employs computational tools to analyse the possible role of genes involved in the anti-oxidation pathways in patients with HNSCC. The TCGA PanCancer Atlas dataset was used for the analysis. The Oncoprint data were analysed further to obtain information on the type of gene alterations encountered in the HNSCC cases. Gene amplification and deletions were commonly observed in genes of the thiol reductase pathway, whereas substitutions leading to missense, frameshifts were found in the other pathways assessed. Gene encoding ceruloplasmin was found to harbor nucleotide variations in about 10 % of the patients with OSCC. An exhaustive knowledge of the molecular genetic mechanisms underlying the pathways identified can open new avenues in selecting candidate genes which can be used as therapeutic targets against HNSCC. The present work identifies and nominates crucial genes from the antioxidant system for further in vitro experiments.

[LC-MS/MS-based screening of new protein biomarkers for cervical precancerous lesions and cervical cancer]

OBJECTIVE

To screen potential plasma protein biomarkers for the progression of cervical precancerous lesions into cervical carcinoma and analyze their functions.

METHODS

Plasma samples obtained from healthy control subjects, patients with low-grade squamous intraepithelial lesion (LSIL), high-grade squamous intraepithelial lesion (HSIL), cervical cancer (CC), and patients with CC after treatment were enriched for low-abundance proteins for liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. The MS data of the samples were analyzed using Discoverer 2.2 software, and the differential proteins (peptide coverage ≥20%, unique peptides≥2) were screened by comparison of LSIL, HSIL and CC groups against the control group followed by verification using target proteomics technology. Protein function enrichment and coexpression analyses were carried out to explore the role of the differentially expressed proteins as potential biomarkers and their pathological mechanisms.

RESULTS

Compared with the control group, both LSIL group and HSIL group showed 9 differential proteins; 5 differentially expressed proteins were identified in CC group. The proteins ORM2 and HPR showed obvious differential expressions in LSIL and HSIL groups compared with the control group, and could serve as potential biomarkers for the progression of cervical carcinoma. The expression of F9 increased consistently with the lesion progression from LSIL to HSIL and CC, suggesting its value as a potential biomarker for the progression of cervical cancer. CFI and AFM protein levels were obviously decreased in treated patients with CC compared with the patients before treatment, indicating their predictive value for the therapeutic efficacy. Protein function enrichment analysis showed that all these differentially expressed proteins were associated with the complement system and the coagulation cascades pathway.

CONCLUSIONS

We identified 5 new protein biomarkers (F9, CFI, AFM, HPR, and ORM2) for cervical precancerous lesions and for prognostic evaluation of CC, and combined detection of these biomarkers may help in the evaluation of the development and progression of CC and also in improving the diagnostic sensitivity and specificity of cervical lesions.

Urine afamin and afamin-creatinine ratio as biomarkers for kidney injury

AIM

The aim of this study was to evaluate the urine afamin (uAFM) and afamin-creatinine ratio (AfCR) levels in patients with glomerulonephritis.

PATIENTS & METHODS

We determined uAFM and AfCR of 247 healthy volunteers and 129 biopsy-proven glomerulonephritis patients.

RESULTS

Analytical evaluation study revealed the assay is a reliable and robust test for measuring uAFM. For reference intervals, uAFM and AfCR values were different significantly between males and females. uAFM and AfCR levels were significantly increased in patients with primary membranous nephropathy, IgA nephropathy and minimal change disease compared with healthy volunteers. uAFM and AfCR were positively correlated with urine albumin and albumin-creatinine ratio, respectively.

CONCLUSION

Our study suggested that uAFM and AfCR may be attractive biomarkers for kidney injury.

Decreased apolipoprotein A4 and increased complement component 3 as potential markers for papillary thyroid carcinoma: A proteomic study

BACKGROUND:

Thyroid carcinomas have comprised the fastest rising incidence of cancer in the past decade. Currently, the diagnosis of thyroid tumors is performed by the fine-needle aspiration biopsy (FNAB) method, which still holds some challenges and limitations, mostly in discriminating malignant and benign lesions. Therefore, the development of molecular markers to distinguish between these lesion types are in progress.

METHODS:

A 2D-PAGE separation of proteins was performed followed by tandem mass spectrometry with the aim of discovering potential serum protein markers for papillary thyroid carcinoma and multinodular goiter. Protein-protein interaction network analysis revealed the most important pathways involved in the progression of papillary thyroid cancer. The enzyme-linked immunosorbent assay method was used to confirm a part of the results.

RESULTS:

The significantly altered proteins included C3, C4A, GC, HP, TTR, APOA4, APOH, ORM2, KRT10, AHSG, IGKV3-20, and IGKC. We also confirmed that increased complement component 3 and decreased apolipoprotein A4 occurred in papillary thyroid cancer. Network investigations demonstrated that complement activation cascades and PPAR signaling might play a role in the pathogenesis of thyroid cancer.

CONCLUSION:

The results demonstrated that serum proteomics could serve as a viable method for proposing novel potential markers for thyroid tumors. Surely, further research must be performed in larger cohorts to validate the results.

Determination of role of ceruloplasmin in oral potentially malignant disorders and oral malignancy-A cross-sectional study

OBJECTIVES

In the process of carcinogenesis, lipid peroxidation and increased oxidative stress lead to changes in certain antioxidants. This study was aimed to assess and co-relate serum levels of ceruloplasmin in oral premalignancies and oral cancer so as to gauge its possible association with the process of carcinogenesis and to determine its role as tumor marker.

MATERIAL AND METHODS

The study population comprised of 300 participants, equally divided into six study groups, that is, oral submucous fibrosis (OSMF), oral leukoplakia (OL), nicotina stomatitis (NS), oral malignancy (OM), controls (C), and healthy controls (HC); 5 ml of blood was collected from ante cubital vein from each participant. The serum was analyzed for ceruloplasmin levels using ERBA CHEM 5 PLUS semiautomated chemistry analyzer and diagnostic kit by turbidimetric immunoassay.

RESULTS

There were total 242 males and 58 females, who were between 18 and 82 years of age, with a mean of 45.31 ± 13.97 years. The serum ceruloplasmin levels were significantly increased in OM, OSMF, OL, and NS groups as compared to C and HC groups (p < .001). No statistically significant difference was found in intragroup analysis of the disease groups (p > .05).

CONCLUSION

Serum ceruloplasmin can be used as diagnostic marker for oral premalignant and malignant lesions.

Afamin promotes glucose metabolism in papillary thyroid carcinoma

Circulating afamin (AFM) concentrations have been investigated as a tumor biomarker in various types of carcinomas. However, suitable cell lines expressing human afamin have not yet been reported and current knowledge of the functions of afamin, particularly at the mechanistic molecular level, is very limited. In the current study, thyroid cancer cell lines 8505c and K1 were used to investigate the potential functions of afamin. AFM over-expression models and vector controls of 8505c (8505c + AFM and 8505c + NC) and K1 (K1 + AFM and K1 + NC) were successfully established by Lenti-LV5-AFM and Lenti-LV5-NC transfection. The change of gene expression was detected by qRT-PCR and western blotting analysis. (18)F-FDG imaging in xenografts model was performed using a micro PET/CT. We found that protein level of GAPDH, GLUT1, HK2, p-AKT, AKT, p-mTOR and PARP1 were up-regulated in K1 + AFM cells when compared to K1 and K1 + NC. While in 8505c, 8505c + NC and 8505c cells, the expression level of these genes were not significantly changed. (18)F-FDG uptake was much higher in K1 + AFM cells when compared to K1 and K1 + NC in vitro and in vivo. In conclusion, afamin could promote glycometabolism by up-regulating the glucose metabolism key enzymes in papillary thyroid carcinoma. These findings reveal new clues of the molecular function of AFM.

Identification of genes containing expanded purine repeats in the human genome and their apparent protective role against cancer

Purine repeat sequences present in a gene are unique as they have high propensity to form unusual DNA-triple helix structures. Friedreich's ataxia is the only human disease that is well known to be associated with DNA-triplexes formed by purine repeats. The purpose of this study was to recognize the expanded purine repeats (EPRs) in human genome and find their correlation with cancer pathogenesis. We developed "PuRepeatFinder.pl" algorithm to identify non-overlapping EPRs without pyrimidine interruptions in the human genome and customized for searching repeat lengths, n ≥ 200. A total of 1158 EPRs were identified in the genome which followed Wakeby distribution. Two hundred and ninety-six EPRs were found in geneic regions of 282 genes (EPR-genes). Gene clustering of EPR-genes was done based on their cellular function and a large number of EPR-genes were found to be enzymes/enzyme modulators. Meta-analysis of 282 EPR-genes identified only 63 EPR-genes in association with cancer, mostly in breast, lung, and blood cancers. Protein-protein interaction network analysis of all 282 EPR-genes identified proteins including those in cadherins and VEGF. The two observations, that EPRs can induce mutations under malignant conditions and that identification of some EPR-gene products in vital cell signaling-mediated pathways, together suggest the crucial role of EPRs in carcinogenesis. The new link between EPR-genes and their functionally interacting proteins throws a new dimension in the present understanding of cancer pathogenesis and can help in planning therapeutic strategies. Validation of present results using techniques like NGS is required to establish the role of the EPR genes in cancer pathology.

Afamin--A pleiotropic glycoprotein involved in various disease states

The human glycoprotein afamin was discovered as the fourth member of the albumin gene family. Despite intense research over the last 20 years, our knowledge of afamin's physiological or pathophysiological functions is still very limited. Circulating afamin is primarily of hepatic origin and abundant concentrations are found in plasma, cerebrospinal, ovarian follicular and seminal fluids. In vitro binding studies revealed specific binding properties for vitamin E. A previously performed analytical characterization and clinical evaluation study of an enzyme-linked immunosorbent assay for quantitative measurement of afamin in human plasma demonstrated that the afamin assay meets the quality specifications for laboratory medicine. Comparative proteomics has identified afamin as a potential biomarker for ovarian cancer and these findings were confirmed by quantitative immunoassay of afamin and validated in independent cohorts of patients with ovarian cancer. Afamin has also been investigated in other types of carcinoma. Most of these studies await further evaluation with validated quantitative afamin assays and require validation in larger patient cohorts. Transgenic mice overexpressing the human afamin gene revealed increased body weight and increased blood concentrations of lipids and glucose. These transgenic mouse data were in line with three large human population-based studies showing that afamin is strongly associated with the prevalence and development of the metabolic syndrome. This review summarizes and discusses the molecular, biochemical and analytical characterization of afamin as well as possible clinical applications of afamin measurement.

Potential predictive plasma biomarkers for cervical cancer by 2D-DIGE proteomics and Ingenuity Pathway Analysis

The current methods available for screening and detecting cervical squamous cell carcinoma (CSCC) have insufficient sensitivity and specificity. As a result, many patients suffered from erroneous and missed diagnosis. Because CSCC is usually asymptomatic at potentially curative stages, identification of biomarkers is an urgent need for the early detection of CSCC. Comparative proteomics based on two-dimensional differential in-gel electrophoresis (2D-DIGE) was employed to quantitatively analyze plasma proteins of healthy Uyghur women and with early stage cervical carcinoma. The 2D-DIGE image were analyzed statistically using DeCyder™ 2D software. The statistical analysis of proteomic data revealed that 43 protein spots showed significantly different expression (ratio > 1.5, P < 0.01). A further identification of these protein spots by MALDI-TOF-MS found out 16 different proteins. Bioinformatic analysis within the framework of Ingenuity Pathway Analysis (IPA(@)) showed that 10 plasma proteins as candidate biomarker were screened, mainly including lipid metabolism-related proteins (APOA4, APOA1, APOE), complement (EPPK1, CFHR1), metabolic enzymes (CP, F2, MASP2), glycoprotein (CLU), and immune function-related proteins (IGK@). Networks involved in lipid metabolism, molecular transport, and small molecule biochemistry were dysfunctional in CSCC. Acute phase response signaling and JAK/Stat signaling and IL-4 signaling, etc., were identified as the canonical pathways that are overrepresented in CSCC. Furthermore, the expression of three proteins (APOA1, APOE, CLU) were validated using ELISA in plasma of patients with different stage cervical lesion. With the combined proteomic and bioinformatic approach, this study was successful in identifying biomarker signatures for cervical cancer and might provide new insights into the mechanism of CSCC progression, potentially leading to the design of novel diagnostic and therapeutic strategies.

Identification of host-immune response protein candidates in the sera of human oral squamous cell carcinoma patients

One of the most common cancers worldwide is oral squamous cell carcinoma (OSCC), which is associated with a significant death rate and has been linked to several risk factors. Notably, failure to detect these neoplasms at an early stage represents a fundamental barrier to improving the survival and quality of life of OSCC patients. In the present study, serum samples from OSCC patients (n = 25) and healthy controls (n = 25) were subjected to two-dimensional gel electrophoresis (2-DE) and silver staining in order to identify biomarkers that might allow early diagnosis. In this regard, 2-DE spots corresponding to various up- and down-regulated proteins were sequenced via high-resolution MALDI-TOF mass spectrometry and analyzed using the MASCOT database. We identified the following differentially expressed host-specific proteins within sera from OSCC patients: leucine-rich α2-glycoprotein (LRG), alpha-1-B-glycoprotein (ABG), clusterin (CLU), PRO2044, haptoglobin (HAP), complement C3c (C3), proapolipoprotein A1 (proapo-A1), and retinol-binding protein 4 precursor (RBP4). Moreover, five non-host factors were detected, including bacterial antigens from Acinetobacter lwoffii, Burkholderia multivorans, Myxococcus xanthus, Laribacter hongkongensis, and Streptococcus salivarius. Subsequently, we analyzed the immunogenicity of these proteins using pooled sera from OSCC patients. In this regard, five of these candidate biomarkers were found to be immunoreactive: CLU, HAP, C3, proapo-A1 and RBP4. Taken together, our immunoproteomics approach has identified various serum biomarkers that could facilitate the development of early diagnostic tools for OSCC.

A1BG and C3 are overexpressed in patients with cervical intraepithelial neoplasia III

The present study aimed to analyze sera proteins in females with cervical intraepithelial neoplasia, grade III (CIN III) and in healthy control females, in order to identify a potential biomarker which detects lesions that have a greater probability of cervical transformation. The present study investigated five sera samples from females who were Human Papilloma Virus (HPV) 16⁺ and who had been histopathologically diagnosed with CIN III, as well as five sera samples from healthy control females who were HPV-negative. Protein separation was performed using two-dimensional (2D) gel electrophoresis and the proteins were stained with Colloidal Coommassie Blue. Quantitative analysis was performed using ImageMaster 2D Platinum 6.0 software. Peptide sequence identification was performed using a nano-LC ESIMS/MS system. The proteins with the highest Mascot score were validated using western blot analysis in an additional 55 sera samples from the control and CIN III groups. The eight highest score spots that were found to be overexpressed in the CIN III sera group were identified as α-1-B glycoprotein (A1BG), complement component 3 (C3), a pro-apolipoprotein, two apolipoproteins and three haptoglobins. Only A1BG and C3 were validated using western blot analysis, and the bands were compared between the two groups using densitometry analysis. The relative density of the bands of A1BG and C3 was found to be greater in all of the serum samples from the females with CIN III, compared with those of the individuals in the control group. In summary, the present study identified two proteins whose expression was elevated in females with CIN III, suggesting that they could be used as biomarkers for CIN III. However, further investigations are required in order to assess the expression of A1BG and C3 in different pre-malignant lesions.

Role of C5b-9 complement complex and response gene to complement-32 (RGC-32) in cancer

Complement system activation plays an important role in both innate and acquired immunity, with the activation of complement and the subsequent formation of C5b-9 terminal complement complex on cell membranes inducing target cell death. Recognition of this role for C5b-9 leads to the assumption that C5b-9 might play an antitumor role. However, sublytic C5b-9 induces cell cycle progression by activating signal transduction pathways and transcription factors in cancer cells, indicating a role in tumor promotion for this complement complex. The induction of the cell cycle by C5b-9 is dependent upon the activation of the phosphatidylinositol 3-kinase (PI3K)/Akt/FOXO1 and ERK1 pathways in a Gi protein-dependent manner. C5b-9 also induces response gene to complement (RGC)-32, a gene that plays a role in cell cycle promotion through activation of Akt and the CDC2 kinase. RGC-32 is expressed by tumor cells and plays a dual role in cancers, in that it has both a tumor suppressor role and tumor-promoting activity. Thus, through the activation of tumor cells, the C5b-9-mediated induction of the cell cycle plays an important role in tumor proliferation and oncogenesis.

Proteomic identification of PKM2 and HSPA5 as potential biomarkers for predicting high-risk endometrial carcinoma

AIM

Endometrial carcinoma (EC) is a common gynecologic malignancy. EC has a favorable prognosis because it is usually diagnosed at an early stage. However, the recurrence rate is high and the prognosis is poor for high-risk EC. Identification of new biomarkers for the prediction of high-risk features will help to guide the treatment and improve the prognosis of patients with EC.

MATERIAL AND METHODS

Differentially expressed proteins among high-risk EC, low-risk EC, and normal endometrial tissues were determined by two-dimensional gel electrophoresis (2-DE) and a liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) proteomics approach. Then, the candidate proteins were examined by immunohistochemical analysis.

RESULTS

Thirteen protein spots were differentially expressed between the high- and low-risk groups, and 25 protein spots were differentially expressed between the high-risk and normal endometrium groups. Twenty-two proteins were identified by MS analysis. PKM2 and HSPA5 were elevated in the high-risk EC tissues compared with both the low-risk EC and normal endometrial tissues. The elevated expression of PKM2 and HSPA5 in high-risk EC tissue was confirmed by immunohistochemical analysis.

DISCUSSION

PKM2 and HSPA5 may play an important role in the progression of EC. These two proteins are potential biomarkers to better predict high-risk EC and thereby guide clinical therapy.

Proteomic analysis of retinopathy-related plasma biomarkers in diabetic patients

Diabetic retinopathy occurs in approximately 25% of patients with type 1 or type 2 diabetes; the disease can cause poor vision and even blindness because high glucose levels weaken retinal capillaries, causing leakage of blood into surrounding areas. We adopted a proteomics-based approach using 2D-DIGE and MALDI-TOF/TOF MS to compare the differential plasma proteome between diabetic retinopathy with significant retinopathy occurrence within 5years after diagnosis of diabetes, and diabetic non-retinopathy without diagnosed retinopathy for more than 10years after diagnosis of diabetes. We identified 77 plasma proteins, which represent 28 unique gene products. These proteins mainly have inflammatory response and coagulation roles. Our approach identified several potential diabetic retinopathy biomarkers including afamin and the protein arginine N-methyltransferase 5, which may be associated with the progression and development of diabetes. In conclusion, we report a comprehensive patient-based plasma proteomic approach to the identification of potential plasma biomarkers for diabetic retinopathy screening and detection.

Serum α1β-glycoprotein and afamin ratio as potential diagnostic and prognostic markers in cholangiocarcinoma

Cholangiocarcinoma (CCA) affects the intra- and extrahepatic bile ducts and is commonly burdened by a late presentation and resulting high mortality rate. Accordingly, finding non-invasive biomarkers with adequate diagnostic/prognostic values is a priority in high-risk populations. In this study, we analyzed proteomes of serum samples from six CCA cases and ten healthy subjects using two-dimensional polyacrylamide gel electrophoresis to identify CCA-associated spots. Thirty-six CCA-associated proteins found in sera were identified by mass spectrometry. α1 β-Glycoprotein (A1BG) and afamin (AFM) were detected consistently at different degrees in CCA sera compared with controls and were validated for their diagnostic and prognostic potential in a larger cohort of 64 patients with CCA, 4 with benign biliary diseases and 20 healthy subjects and compared between pre- and postsurgery serum samples from 26 CCA patients to ascertain a prognostic correlation. A single blot test developed to assess the serum A1BG/AFM ratio could detect CCA cases with 87.5% specificity, 84.4% sensitivity and the levels were significantly higher in CCA compared with controls. A high level of postoperative serum A1BG/AFM ratio was associated with worse outcomes and the infiltration of resection margins. The A1BG/AFM ratio may constitute a novel non-invasive candidate marker to diagnose CCA and its outcomes with high specificity and sensitivity. Prospective studies are awaited to demonstrate the clinical value of this observation.

Nature of light: spectroscopic techniques in obstetrics and gynecology applications

In recent years, advances in spectroscopic techniques led to an increase in their medical applications. In medical sciences, emphasis is increasingly placed on instrumental techniques and accurate, quantitative measurements. It is especially apparent in diagnosis, where imaging techniques and laboratory results have became invaluable and compulsory. Breakthroughs in biochemistry made it possible to characterize physiological processes and living organisms at the molecular level. This led to a proliferation of new methods such as DNA tests and the use of biomarkers in daily clinical practice. Characterization of molecular structure and determination of the composition of a mixture are the fields of analytical chemistry and analytical biochemistry.

The association of a distinct plasma proteomic profile with the cervical high-grade squamous intraepithelial lesion of Uyghur women: a 2D liquid-phase chromatography/mass spectrometry study

OBJECTIVE

To identify plasma protein biomarkers of cervical high-grade squamous intraepithelial lesion (HSIL) of Uyghur women by proteomics approach.

METHODS

Plasma protein samples of Uyghur women with HSIL and chronic cervicitis were analyzed with 2D HPLC followed by detection of target proteins with Linear Trap Quadrupole Mass Spectrometer (LTQ MS/MS).

RESULTS

We detected three upregulated and one downregulated protein peaks representing protein constituents distinguishing HSIL from controls by 2D HPLC, identified 31 target proteins by LTQ MS/MS. Further confirmed analysis with online software IPA® 8.7 and ELISA assay showed APOA1 and mTOR as potential biomarkers.

CONCLUSIONS

A distinct plasma proteomic profile may be associated with HSIL of Uyghur women.

Proteomic identification of plasma biomarkers in uterine leiomyoma

Recent progresses in quantitative proteomics have offered opportunities to discover plasma proteins as biomarkers for tracking the progression and for understanding the molecular mechanisms of uterine leiomyomas. In the present study, plasma samples were analyzed by fluorescence two-dimensional differential gel electrophoresis (2D-DIGE) and differentially expressed proteins were identified by matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). In total, 20 proteins have been firmly identified representing 13 unique gene products. These proteins mainly functioned in transportation (such as apolipoprotein A-I) and coagulation (such as fibrinogen gamma chain). Additionally, our quantitative proteomic approach has identified numerous previous reported plasma markers of uterine leiomyomas such as alpha-1-antitrypsin. On the contrary, we have presented several putative uterine leiomyomas biomarkers including afamin, apolipoprotein A-I, carbonic anhydrase 1, fibrinogen beta chain, fibrinogen gamma chain, gelsolin, hemopexin, leucine-rich alpha-2-glycoprotein, serotransferrin and vitamin D-binding protein which have not been reported and may be associated with the progression and development of the disease. In summary, we report a comprehensive patient-based proteomic approach for the identification of potential plasma biomarkers for uterine leiomyomas. The potential of utilizing these markers for screening and treating uterine leiomyomas warrants further investigations.

Mass spectrometry of peptides and proteins from human blood

It is difficult to convey the accelerating rate and growing importance of mass spectrometry applications to human blood proteins and peptides. Mass spectrometry can rapidly detect and identify the ionizable peptides from the proteins in a simple mixture and reveal many of their post-translational modifications. However, blood is a complex mixture that may contain many proteins first expressed in cells and tissues. The complete analysis of blood proteins is a daunting task that will rely on a wide range of disciplines from physics, chemistry, biochemistry, genetics, electromagnetic instrumentation, mathematics and computation. Therefore the comprehensive discovery and analysis of blood proteins will rank among the great technical challenges and require the cumulative sum of many of mankind's scientific achievements together. A variety of methods have been used to fractionate, analyze and identify proteins from blood, each yielding a small piece of the whole and throwing the great size of the task into sharp relief. The approaches attempted to date clearly indicate that enumerating the proteins and peptides of blood can be accomplished. There is no doubt that the mass spectrometry of blood will be crucial to the discovery and analysis of proteins, enzyme activities, and post-translational processes that underlay the mechanisms of disease. At present both discovery and quantification of proteins from blood are commonly reaching sensitivities of ∼1 ng/mL.

Are serum protein biomarkers derived from proteomic analysis useful in screening for trisomy 21 at 11-13 weeks?

OBJECTIVE

The aim of this study is to identify potential biomarkers for fetal trisomy 21 from previous publications using proteomic techniques and examine the potential value of such biomarkers in early screening for this aneuploidy.

METHODS

This was a case-control study of 25 pregnancies with fetal trisomy 21 and 50 euploid controls undergoing first-trimester screening for aneuploidies by a combination of maternal age, fetal nuchal translucency (NT) thickness and maternal serum free β-human chorionic gonadotrophin (β-hCG) and pregnancy-associated plasma protein-A (PAPP-A). The maternal serum concentrations of afamin, apolipoprotein E, clusterin, ceruloplasmin, epidermal growth factor, fetuin-A, pigment epithelium-derived factor glycoprotein and transthyretin were determined using an ELISA and compared in the euploid and trisomy 21 groups.

RESULTS

In pregnancies with fetal trisomy 21, the median maternal age, fetal NT thickness and serum free β-hCG were increased, whereas serum PAPP-A was decreased. However, there were no significant differences between cases and controls in any of the biomarkers.

CONCLUSION

Proteins identified as potential biomarkers for trisomy 21 using proteomic techniques have not been found to be useful in early screening for this aneuploidy.

Apolipoprotein A1 -75 G/A and +83 C/T polymorphisms: susceptibility and prognostic implications in breast cancer

Apolipoprotein A1 (ApoA1) is the major apoprotein constituent of high-density lipoprotein that can play important roles in tumor invasion and metastasis. In the current report, we evaluated the role of the functional ApoA1 polymorphisms (-75 G/A and +83 C/T) as genetic markers for breast cancer susceptibility and prognosis. We used the polymerase chain reaction and restriction enzyme digestion (RFLP-PCR) to characterize the variations of the ApoA1 gene in 295 unrelated Tunisian patients with breast carcinoma and 197 healthy control subjects. No association was found between the +83 C/T genetic variation in ApoA1 gene and the risk of breast cancer occurrence. The presence of the (+83) T allele appeared however to be associated with an increased risk of lymph node metastasis occurrence (OR = 2.94; P = 0.01). Furthermore, a positive association was found between ApoA1 -75 A allele carriers and breast cancer risk (OR = 1.57; P = 0.02). Regarding prognostic indicators, a significant association was found between ApoA1 (-75) A allele carriers and the premenopausal status of breast cancer patients (OR = 1.73; P = 0.03). Additionally, the presence of the -75 A allele was correlated with the oestrogen receptor status among premenopausal women (OR = 2.45; P = 0.02). This is the first report on the studies of ApoA1 single nucleotide polymorphisms (SNPs) in breast carcinomas. Our data suggest that these genetic variations of ApoA1 may represent a marker for the increased risk of breast cancer.