Expression of p53 in oral squamous cell carcinoma is associated with the presence of IgG and IgA p53 autoantibodies in sera and saliva of the patients

Identification of salivary autoantibodies as biomarkers of oral cancer with immunoglobulin A enrichment combined with affinity mass spectrometry

Globally, oral cavity squamous cell carcinoma (OSCC) is one of the most common fatal illnesses. Its high mortality is ascribed to the fact that the disease is often diagnosed at a late stage, which indicates an urgent need for approaches for the early detection of OSCC. The use of salivary autoantibodies (autoAbs) as OSCC biomarkers has numerous advantages such as easy access to saliva samples and efficient detection of autoAbs using well-established secondary reagents. To improve OSCC screening, we identified OSCC-associated autoAbs with the enrichment of salivary autoAbs combined with affinity mass spectrometry (MS). The salivary IgA of healthy individuals and OSCC patients was purified with peptide M-conjugated beads and then applied to immunoprecipitated antigens (Ags) in OSCC cells. Using tandem MS analysis and spectral counting-based quantitation, the level of 10 Ags increased in the OSCC group compared with the control group. Moreover, salivary levels of autoAbs to the 10 Ags were determined by a multiplexed bead-based immunoassay. Among them, seven were significantly higher in early-stage OSCC patients than in healthy individuals. A marker panel consisting of autoAbs to LMAN2, PTGR1, RAB13, and UQCRC2 was further developed to improve the early diagnosis of OSCC.

Isotypic analysis of anti-p53 serum autoantibodies and p53 protein tissue phenotypes in colorectal cancer

The presence of IgA- and IgM-specific autoantibody (AAb) isotypes and their relationship to p53 tissue expression patterns are not well understood. This study aims to investigate the clinical utility of the anti-p53 AAb isotypes and tissue positivity in colorectal cancer (CRC). We analysed anti-p53 IgG, IgM, and IgA AAbs in sera of 99 CRC patients and 99 non-cancer control subjects. Corresponding tissue expression of the p53 protein was evaluated by immunohistochemistry (IHC). Anti-p53 AAbs of the IgG isotype were present in the sera of 21 out of 99 patients (21%), while IgM AAbs were observed in 9 (9%) and IgA in 2 (2%) CRC patients. Anti-p53 AAbs of all three isotypes were generally associated with IHC staining indicative of mutated TP53. Seropositive anti-p53 IgM cases in the absence of anti-p53 IgG were linked to wild-type p53. Anti-p53 IgA in the absence of IgG AAbs was detected in two non-cancer controls indicating a potential p53 epitope mimicry. Although seropositivity was not associated with patient survival (P = 0.650), mutant-pattern p53 tissue expression was associated with reduced 5-year overall survival (P = 0.032), however, it was not an independent prognostic marker (Multivariate Cox regression, P = 0.193). In conclusion, immunoglobulin isotyping revealed that anti-p53 IgM and IgA AAbs were predominantly concurrent with anti-p53 serum IgG and the mutant-pattern p53 tissue phenotype. IgM and IgA seropositive cases in absence of anti-p53 IgG were linked to wild-type p53 tissue phenotype indicating early anti-p53 immune responses preceding isotype class-switch (IgM) or p53 antigen mimicry (IgA).

Predictive value of tissue p53 protein expression and serum p53 antibodies in oral potentially malignant disorders: Relative to oral squamous cell carcinoma

Objective

This study aims to assess and report the predictive value of tissue p53 protein expression and serum p53 antibodies as a screening tool for oral potentially malignant disorders (OPMDs) cases with risk of malignant transformation.

Methods

A case–control study was jointly conducted at the Department of Pathology and Oral and Maxillofacial Surgery in several dental institutes in the country from April 2016 to March 2017. A total of 180 eligible subjects (60 cases of OPMDs, 60 cases of oral squamous cell carcinoma, and 60 controls) were included in the study. Tissue p53 immunoreactivity was determined by immunohistochemistry, and serum concentrations of p53 antibodies were determined by enzyme-linked immunosorbent assay. Specimens were collected for laboratory investigations after obtaining written consent from both patients and controls.

Results

Among the study participants, the recorded male to female ratio was close to 2:1, and most participants fell in the age range of 41–60 years and above. Of the 60 cases of OPMDs, the observed tissue p53 immunopositivity was 73.3% (n = 44) while for the p53 antibody, the seropositivity was 96.7% (n = 58). The sensitivity for p53 immunoreactivity was 73%, and specificity was 98.3% between OPMDs and healthy individuals.

Conclusion

The present study provides evidence (for OPMDs) that serum p53 antibodies and p53 immunoreactivity could be used as a sensitivity test and a specific test, respectively, and may contribute to determining the potential of OPMD for malignant transformation risk.

A systematic review of proteomic biomarkers in oral squamous cell cancer

BACKGROUND

Head and neck squamous cell cancer (HNSCC) is the most common cancer associated with chewing tobacco, in the world. As this is divided in to sites and subsites, it does not make it to top 10 cancers. The most common subsite is the oral cancer. At the time of diagnosis, more than 50% of patients with oral squamous cell cancers (OSCC) had advanced disease, indicating the lack of availability of early detection and risk assessment biomarkers. The new protein biomarker development and discovery will aid in early diagnosis and treatment which lead to targeted treatment and ultimately a good prognosis.

METHODS

This systematic review was performed as per PRISMA guidelines. All relevant studies assessing characteristics of oral cancer and proteomics were considered for analysis. Only human studies published in English were included, and abstracts, incomplete articles, and cell line or animal studies were excluded.

RESULTS

A total of 308 articles were found, of which 112 were found to be relevant after exclusion. The present review focuses on techniques of cancer proteomics and discovery of biomarkers using these techniques. The signature of protein expression may be used to predict drug response and clinical course of disease and could be used to individualize therapy with such knowledge.

CONCLUSIONS

Prospective use of these markers in the clinical setting will enable early detection, prediction of response to treatment, improvement in treatment selection, and early detection of tumor recurrence for disease monitoring. However, most of these markers for OSCC are yet to be validated.

Mutations in p53 Gene Exons in a Sample from the South of Spain in Oral Cancer

Background

Cancer is a genetic disease caused by mutations in DNA and epigenetic alterations that control gene expression. The majority of epidermoid carcinomas develop within the fields of epithelial genetic alterations. The mechanisms underlying tumorigenesis of epidermoid carcinoma are as yet unknown; therefore, precise identification of the risk factors is needed. Aim: The main aim of this study is to analyse and identify the emergence of the mutations described in the literature of the p53 gene with regard to the emergence of cancer in a sample of dysplastic and cancerous lesions in oral cavity mucosa in the population of the south of Spain, in order to determine the presence of said mutations and the percentage of them in our population.

Material and Methods

A cross-sectional study was carried out, with a sample size of 22 patients with potentially malignant oral lesions ancillary to biopsy. All were patients, of both sexes, over 18 years of age from the Virgen del Rocío University Hospital with potentially malignant lesions in oral mucosa ancillary to biopsy (leukoplakias, erythroplasias or leukoerythopkias). An anatomopathological study was performed on all the samples and the lesions were divided into three types: low-grade dysplasia, high-grade dysplasia and squamous cell carcinoma. In respect of the genome study process, a complete search or scan for mutations in exons 5, 6, 8 and 9 of the p 53 gene was carried out, given that in the IARC database we observed that the 5 and 6 as well as the 8 and 9 exon sizes can be scanned completely in this way, since they have amplificon sizes of 476 and 445 base pairs respectively.

Results

In the scan for the complete exons 5, 6, 8 and 9 only a single result of interest was found to be described. In patient NBI 57 a change was observed in the TAT triplet by ATT of EXON 6, the change being of the T nucleotide by the A and in both directions both in Forward and Reverse. The exact location in the NCBI is GR Ch 37 p13 on chromosome 17, EXON 6 of the P53 gene and the change is in the C.613 T>A nucleotide; NM_000546.

Conclusions

On reviewing this genetic variant in different scientific databases, such as ENSEMBL among others, in at least 6 different biocomputing tools it is described as a pathogen, therefore we can conclude that it is a pathogenic mutation for this case in particular. The rest of the mutations described in the literature on exons 5, 6, 8 and 9 of the p53 gene have not been found in our sample.

Key words:Oral cancer, p53, Mutations, Exon.

Re-evaluating the clinical significance of serum p53 antibody levels in patients with oral cancer in Japanese clinical practice

TP53 gene mutations can lead to mutant p53 protein accumulation in cancer cells, thereby inducing the production of serum antip53 antibodies (Ap53Ab) in patients with various types of cancer. The aim of the present study was to re-evaluate the clinicopathological and prognostic significance of Ap53Ab using the Ap53Ab ELISA kit, approved by the Japanese Health Insurance System in 2007. Ap53Ab was measured as a tumor marker in 94 patients with oral squamous cell carcinoma (OSCC), by subjecting paraffin-embedded sections obtained from biopsy specimens to immunohistochemical analysis to confirm p53 expression. The associations among Ap53Ab status, p53 expression and clinical significance in OSCC were examined. A total of 23% of the patients were Ap53Ab-positive. Ap53Ab status was found to be significantly associated with p53 expression status in primary tumors (P=0.027), clinical T-category, pathological N-category and pathological stage (P=0.04, P=0.010 and P=0.013, respectively). Kaplan-Meier curve analysis revealed that Ap53Ab status was significantly associated with poor disease-free survival (DFS; P=0.043), and Cox regression analysis revealed that Ap53Ab status was a significant prognostic factor for DFS in patients with OSCC (hazard ratio=2.807; 95% confidence interval: 1.029-7.160; P=0.044). These results suggested that Ap53Ab measurement may reflect the p53 mutation status and an aggressive malignant phenotype, and it may serve as a useful predictive marker candidate for OSCC in clinical practice.

Determination of p53 biomarker using an electrochemical immunoassay based on layer-by-layer films with NiFe2O4 nanoparticles

A disposable electrochemical immunosensors is presented suitable to detect cancer biomarker p53 using screen-printed carbon electrodes modified with a layer-by-layer (LbL) matrix of carboxylated NiFe₂O₄ nanoparticles and polyethyleneimine, onto which anti-p53 antibodies were adsorbed. Under optimized conditions, the immunosensors exhibited high surface coverage and high concentration of immobilized antibodies, which allowed for detection of p53 in a wide dynamic range from 1.0 to 10 × 10³ pg mL^-1, with a limit of detection of 5.0 fg mL^-1 at a working potential of 100 mV vs. Ag/AgCl. The immunosensors also exhibited good selectivity with negligible interference upon incubation in complex matrices containing high concentrations of proteins (i.e., fetal bovine serum and cell lysate). The immunosensor performance is among the best reported in the literature for determination of p53, with the additional advantage of being disposable and operating with low-volume solutions.Graphical abstract Schematic representation of immunosensor fabrication depicting the immobilization of specific antibodies against p53 protein onto the surfaces of disposable printed electrodes modified with films of polyethyleneimine and different concentrations of carboxylated magnetic nanoparticles.

Biochemical analysis of cytokeratin fragment 21-1 concentration and expression of cytokeratin 19 in oral potentially malignant disorders

Introduction

Cytokeratin fragment 21-1 (CYFRA21-1), a constituent of the intermediate filament protein is known to be elevated in cancer. In vitro cleavage of cytokeratin 19 (CK19) protein results in the release of it's fragments into the supernatants of premalignant cell lines. This study was designed with the aim to investigate the concentrations of CYFRA21-1 in serum and saliva of oral potentially malignant disorders (OPMD), to evaluate CK19 expression in tissues of the same patients and to correlate the levels of CYFRA21-1 concentration in serum and saliva with CK19 expression in OPMDs, and to compare it with oral squamous cell carcinoma (OSCC), which was taken as positive control.

Materials and Methods

Concentration of CYFRA21-1 was measured in saliva and serum of 30 OPMD cases with five patients having OSCC using ELISA technique and analysis of CK19 protein expression in the tissue of same patients using immunohistochemical technique was done.

Results

Concentration of CYFRA21-1 in saliva and serum with regard to CK19 protein expression in tissues was significantly higher in control group than in study groups.

Conclusion

CYFRA21-1 can be used as a promising diagnostic molecule and as an adjunctive marker for early detection, disease staging, and monitoring.

Biochemical analysis of oral fluids for disease detection

The field of diagnostics using invasive blood testing represents the majority of diagnostic tests used as part of routine health monitoring. The relatively recent introduction of salivary diagnostics has lead to a major paradigm shift in diagnostic analyses. Additionally, in this era of big data, oral fluid testing has shown promising outcomes in a number of fields, particularly the areas of genomics, microbiomics, proteomics, metabolomics, and transcriptomics. Despite the analytical challenges involved in the interpretation of large datasets generated from biochemical studies involving bodily fluids, including saliva, many studies have identified novel oral biomarkers for diagnosing oral and systemic diseases. In this regard, oral biofluids, including saliva, gingival crevicular fluid (GCF), peri-implant crevicular fluid (PICF), dentinal tubular fluid (DTF), are now attracting increasing attention due to their important attributes, such as noninvasive sampling, easy handling, low cost, and more accurate diagnosis of oral diseases. Recently, the utilization of salivary diagnostics to evaluate systemic diseases and monitor general health has increased in popularity among clinicians. Saliva contains a wide range of protein, DNA and RNA biomarkers, which assist in the diagnosis of multiple diseases and conditions, including cancer, cardiovascular diseases (CVD), auto-immune and degenerative diseases, respiratory infections, oral diseases, and microbial (viral, bacterial and fungal) diseases. Moreover, due to its noninvasive nature and ease-of-adoption by children, it is now being used in mass screening programs, oral health-related studies and clinical trials in support of the development of therapeutic agents. The recent advent of highly sensitive technologies, such as next-generation sequencing, mass spectrometry, highly sensitives ELISAs, and homogeneous immunoassays, suggests that even small quantities of salivary biomarkers are able to be assayed accurately, providing opportunities for the development of many future diagnostic applications (including emerging technologies, such as point-of-care and rapid molecular technologies). The present article explores the omics and biochemical compositions of various oral biofluids with important value in diagnostics and monitoring.

Anti-p53 Autoantibody Detection in Automatic Glass Capillary Immunoassay Platform for Screening of Oral Cavity Squamous Cell Carcinoma

The incidence of oral squamous cell carcinoma (OSCC), which is one of the most common cancers worldwide, has been increasing. Serum anti-p53 autoantibody is one of the most sensitive biomarkers for OSCC. Currently, the most commonly used method on clinical screening platforms is the enzyme-linked immunosorbent assay, owing to its high specificity and repeatability. However, conducting immunoassays on 96-well plates is typically time consuming, thereby limiting its clinical applications for fast diagnosis and immediate prognosis of rapidly progressive diseases. The present study performed immunoassays in glass capillaries of 1-mm internal diameter, which increases the surface to volume ratio of the reaction, to shorten the time needed for immunoassay. The immunoassay was automated while using linear motorized stages and a syringe pump. The results indicated that, when compared with the 96-well plate immunoassay, the glass capillary immunoassay decreased the reaction time from typical 120 min to 45 min, reduced the amount of reagent from typical 50 µL to 15 µL, and required only simple equipment setup. Moreover, the limit of detection for glass capillary anti-p53 autoantibody immunoassay was 0.46 ng mL⁻¹, which is close to the 0.19 ng mL⁻¹ value of the conventional 96-well plate assay, and the glass capillary method had a broader detection range. The apparatus was used to detect the serum anti-p53 autoantibody concentration in clinical patients and compare its results with the conventional 96-well plate method results, which suggested that both of the methods detect the same trend in the relative concentration of serum anti-p53 autoantibody in healthy individuals or patients with OSCC.

A New Approach for the Diagnosis of Systemic and Oral Diseases Based on Salivary Biomolecules

Early diagnosis represents the target of contemporary medicine and has an important role in the prognosis and further treatment. Saliva is a biofluid that generated a high interest among researchers due to its multiple advantages over other body fluids. The multitude of components that can act as biomarkers influenced the existing technologies to develop protocols that could allow saliva to become the new noninvasive diagnostic method. Saliva as a diagnostic tool can bring substantial addition to the diagnostic armamentarium, providing important information about oral and general health. The diagnostic applications of saliva extended and had a rapid evolution due to the advancement in salivaomics. The present review summarizes the latest researches in saliva-related studies and explores the information and correlations that saliva can offer regarding the systemic and oral diseases, highlighting its great potential of diagnosis. It is expected that in the future specific guidelines and results regarding the salivary diagnostics are to be available, together with high-sensitivity and specificity tests for multiple systemic and oral diseases.

Detection of anti-p53 autoantibodies in saliva using microfluidic chips for the rapid screening of oral cancer

Autoantibodies have high specificity and stability and are easy to detect. Anti-p53 autoantibodies can be used as biomarkers for the early detection of oral cancer. However, most studies detected anti-p53 in sera samples. In this study, a microfluidic chip combined with magnetic immunoassay, which can automatically detect the concentration of anti-p53 in saliva, was developed. The use of a micromixer can shorten the immunoassay time: the mixing time of the antigen and antibody can be reduced from the original 60 min off-chip to 20 min, making the total immunoassay time around 60 min. A method of moving magnetic beads and the antibody instead of manipulating fluid was utilized to simplify fluid control and decrease contamination caused by non-specific protein adsorption to the surface of reaction wells. The detection limit of anti-p53 was 4 ng mL⁻¹. In addition, a relative concentration of anti-p53 in the saliva of patients was detected in the chip.

A microfluidic chip with multiple reaction wells is capable of automatically detecting anti-p53 autoantibody in saliva for oral cancer screening.

Proteomics investigation of OSCC-specific salivary biomarkers in a Hungarian population highlights the importance of identification of population-tailored biomarkers

Oral squamous cell carcinoma (OSCC) accounting for about 90% of malignant oral lesions is the 6th most common malignancy worldwide. Diagnostic delay may contribute to dismal survival rate therefore, there is a need for developing specific and sensitive biomarkers to improve early detection. Hungarian population occupies the top places of statistics regarding OSCC incidence and mortality figures therefore, we aimed at finding potential salivary protein biomarkers suitable for the Hungarian population. In this study we investigated 14 proteins which were previously reported as significantly elevated in saliva of patients with OSCC. In case of IL-1α, IL-1β, IL-6, IL-8, TNF-α and VEGF a Luminex-based multiplex kit was utilized and the salivary concentrations were determined. In case of catalase, profilin-1, S100A9, CD59, galectin-3-bindig protein, CD44, thioredoxin and keratin-19, SRM-based targeted proteomic method was developed and the relative amount of the proteins was determined in the saliva of patients with OSCC and controls. After several rounds of optimization and using stable isotope-containing peptides, we developed an SRM-based method for rapid salivary protein detection. The validation of the selected potential biomarkers by ELISA revealed salivary protein S100A9 and IL-6 as useful protein biomarkers for OSCC detection improving the diagnostic accuracy for OSCC in the Hungarian population.A noninvasive diagnostic method to detect biomarkers useful for the early diagnosis of OSCC was developed. This can be an attractive strategy in screening saliva samples collected in a nation-wide multi-centric study in order to decrease morbidity, mortality, to enhance survival rate and to improve quality of life. The heterogeneity of protein biomarkers found in different ethnic groups presented in the literature highlights the importance of identification of population-tailored protein biomarkers.

Ability of salivary biomarkers in the prognostic of systemic and buccal inflammation

Nowadays, there is a growing interest in using saliva as an alternative sample for the diagnosis, prediction and progression of several diseases. It has been established that some molecules found in saliva are related to oral inflammatory processes and systemic health status. Furthermore, it is known that saliva is crucial for the carrying out of different functions in the oral cavity and its role in the local modulation of inflammatory and immune response is being thoroughly studied by the health research community. The aim of this review is to analyze the most important biomarkers which have been utilized in biomedicine during the last two decades in order to establish a correlation between certain specific salivary biomarkers and systemic inflammation. Then, we discuss the utility of total proteins, immunoglobulin A and alpha-amylase as biomarkers for the prognostic of local inflammation after oral surgery.

Key words:Inflammation, salivary biomarkers, systemic disease, buccal surgery, total proteins, inmunoglobulin A, Alpha-amylase.

Detection of inflammatory biomarkers in saliva and urine: Potential in diagnosis, prevention, and treatment for chronic diseases

Inflammation is a part of the complex biological response of inflammatory cells to harmful stimuli, such as pathogens, irritants, or damaged cells. This inflammation has been linked to several chronic diseases including cancer, atherosclerosis, rheumatoid arthritis, and multiple sclerosis. Major biomarkers of inflammation include tumor necrosis factor, interleukins (IL)-1, IL-6, IL-8, chemokines, cyclooxygenase, 5-lipooxygenase, and C-reactive protein, all of which are regulated by the transcription factor nuclear factor-kappaB. Although examining inflammatory biomarkers in blood is a standard practice, its identification in saliva and/or urine is more convenient and non-invasive. In this review, we aim to (1) discuss the detection of these inflammatory biomarkers in urine and saliva; (2) advantages of using salivary and urinary inflammatory biomarkers over blood, while also weighing on the challenges and/or limitations of their use; (3) examine their role(s) in connection with diagnosis, prevention, treatment, and drug development for several chronic diseases with inflammatory consequences, including cancer; and (4) explore the use of innovative salivary and urine based biosensor strategies that may permit the testing of biomarkers quickly, reliably, and cost-effectively, in a decentralized setting.

A review of research on salivary biomarkers for oral cancer detection

Using saliva for disease diagnostics and health surveillance is a promising approach as collecting saliva is relatively easy and non-invasive. Over the past two decades, using salivary biomarkers specifically for early cancer detection has attracted much research interest, especially for cancers occurring in the oral cavity and oropharynx, for which the five-year survival rate (62%) is still one of the lowest among all major human cancers. More than 90% of oral cancers are oral squamous cell carcinoma (OSCC) and the standard method for detection is through a comprehensive clinical examination by oral healthcare professionals. Despite the fact that the oral cavity is easily accessible, most OSCCs are not diagnosed until an advanced stage, which is believed to be the major reason for the low survival rate, and points to the urgent need for clinical diagnostic aids for early detection of OSCC. Thus, much research effort has been dedicated to investigating potential salivary biomarkers for OSCC, and more than 100 such biomarkers have been reported in the literature. However, some important issues and challenges have emerged that require solutions and further research in order to find reliable OSCC salivary biomarkers for clinical use. This review article provides an up-to-date list of potential OSCC salivary biomarkers reported as of the fall of 2013, and discusses those emerging issues. By raising the awareness of these issues on the part of both researchers and clinicians, it is hoped that reliable, specific and sensitive salivary biomarkers may be found soon-and not only biomarkers for early OSCC detection but also for detecting other types of cancers or even for monitoring non-cancerous disease activity.

Salivary diagnostics: a brief review

Early detection of disease plays a crucial role for treatment planning and prognosis. Saliva has great potential as a diagnostic fluid and offers advantage over serum and other biological fluids by an economic and noninvasive collection method for monitoring of systemic health and disease progression. The plethora of components in this fluid can act as biomarkers for diagnosis of various systemic and local diseases. In this review paper, we have emphasized the role of salivary biomarkers as diagnostic tools.

Development of an Au/ZnO thin film surface plasmon resonance-based biosensor immunoassay for the detection of carbohydrate antigen 15-3 in human saliva

OBJECTIVE

To evaluate a novel surface plasmon resonance (SPR) system for the direct measurement of tumor marker carbohydrate antigen 15-3 (CA15-3) in human saliva.

DESIGN AND METHODS

We measured the presence of the tumor marker carbohydrate antigen 15-3 (CA15-3) in human saliva using 2 different surface plasmon resonance (SPR) systems. To compare the sensitivity of an SPR biosensor based on thin-film Au/ZnO and the Biacore SPR system, we prepared CA15-3 samples in saliva and analyzed intensity responses to the samples at various concentrations of CA15-3.

RESULTS

The linear detection range of CA15-3 in human saliva with the SPR system based on thin-film Au/ZnO was 2.5-20 U/mL (the cut-off point in cancer patients is around 4 U/mL). The linear range with the Biacore SPR system was 40-300 U/mL.

CONCLUSIONS

These results show that thin-film Au/ZnO-based SPR systems have higher sensitivity and can be used for measuring the levels of CA15-3 in human saliva without concentrating the samples.

Lessons learned from next-generation sequencing in head and neck cancer

Scientific innovation has enabled whole exome capture and massively parallel sequencing of cancer genomes. In head and neck cancer, next-generation sequencing has granted us further understanding of the mutational spectrum of squamous cell carcinoma. As a result of these new technologies, frequently occurring mutations were identified in NOTCH1, a gene that had not previously been implicated in head and neck cancer. The current review describes the most common mutations in head and neck cancer: TP53, NOTCH1, HRAS, PIK3CA, and CDKN2A. Emphasis is placed on the involved cellular pathways, clinical correlations, and potential therapeutic interventions. Additionally, the implications of human papillomavirus on mutation patterns are discussed.

A review on salivary genomics and proteomics biomarkers in oral cancer

Oral cancer has emerged as an alarming public health problem with increasing incidence and mortality rates all over the world. Therefore, the implementation of newer screening and early detection approaches are of utmost importance which could reduce the morbidity and mortality associated with this disease. Sensitive and specific biomarkers for oral cancer are likely to be most effective for screening, diagnosis, staging and follow-up for this dreaded malignancy. Unlike other deep cancers, oral cancer is located in oral cavity. Hence, the direct contact between saliva and oral cancer lesion makes the measurement of tumor markers in saliva an attractive alternative to serum and tissue testing. The DNA, RNA and protein molecules derived from the living cancer cells can be conveniently obtained from saliva. Thus, salivary biomarkers, a non-invasive alternative to serum and tissue-based biomarkers may be an effective modality for early diagnosis, prognostication and monitoring post therapy status. In the current post-genomic era, various technologies provide opportunities for high-throughput approaches to genomics and proteomics; which have been used to evaluate altered expressions of gene and protein targets in saliva of oral cancer patients. The emerging field of salivary biomarkers has great potentials to prove its clinical significance to combat oral cancer. Hence, we have reviewed importance of several salivary genomics and proteomics biomarkers for oral cancer.

Potential biomarkers in saliva for oral squamous cell carcinoma

Sensitive and reliable early diagnostic markers for oral squamous cell carcinoma (OSCC) remain unavailable. Early identification of recurrence for OSCC is also a challenge. Unlike the other deep cancers, OSCC is located in oral cavity. The DNA, RNA, and protein derived from the living cancer cells and inflammatory cells then can be conveniently obtained from saliva. High-throughput genomic and proteomic approaches have been carried out to identify the potential biomarkers in body fluids such as saliva and blood for diagnosis and prognosis of OSCC. This article reviewed the recently identified biomarkers from saliva for OSCC. In addition, the biomarkers which have been correlated with OSCC tumor malignancy by molecular pathology analysis are also described. Finally, the potential biomarkers that have been demonstrated to associate with the malignant OSCC may be used for salivary screening for high-risk patients are suggested. This article may help to identify the potential biomarkers for screening and the molecular pathology analysis for high-risk patients of OSCC. Effective screening to identify high-risk patients can allow the clinician to provide the appropriate treatment without delay and to reduce the recurrence of OSCC.

Human kallikrein 5: an interesting novel biomarker in ovarian cancer patients that elicits humoral response

INTRODUCTION

Kallikrein-related peptidases are secreted serine proteases that exert stimulatory or inhibitory effects on tumor progression. A recent study demonstrated that kallikrein-related peptidase 5 (KLK5) concentration is elevated in serum of patients with ovarian carcinoma. At the moment, the presence of KLK5 in other ovarian pathological lesions is not clearly determined. Moreover, the possibility of a spontaneous humoral immune response to KLK5 has not been studied yet.

METHODS

In this study, we examined KLK5 levels and antibody (IgG and IgM) response to KLK5 in the serum of 50 healthy women, 50 patients with benign pelvic masses, 17 patients with ovarian borderline tumors, and 50 patients with ovarian carcinomas, using 3 enzyme-linked immunosorbent assay tests available in-house.

RESULTS

At 95% specificity on healthy controls, 52% of patients with ovarian carcinoma showed high serum KLK5 (sKLK5) levels, whereas patients with benign pathological lesions or borderline tumors showed almost undetectable sKLK5 levels. Moreover, sKLK5 levels were positively associated to International Federation of Gynaecologists and Obstetricians stage suggesting a possible role of sKLK5 in ovarian cancer progression. Our results about humoral response showed elevated levels of KLK5-specific antibodies in 20% of patients with benign masses, 26% of patients with borderline tumors, and 36% of patients with ovarian carcinomas when compared with healthy controls. Interestingly, KLK5 antibodies were also found in patients with undetectable sKLK5 levels.

CONCLUSIONS

In conclusion, our results showed that KLK5 is a potential new biomarker to be used in combination with other biomarkers for ovarian cancer detection. Moreover, the existence of KLK5 antibodies suggests that KLK5 might represent a possible target for immune-based therapies.

Detecting tumor-specific autoantibodies for cancer diagnosis: a technology overview

BACKGROUND

Studies on the autoantibody (humoral immune) response to tumor-associated aberrant cellular components have provided critical information about an individual's disease state. Tumor-specific autoantibodies detected in human serum samples are being studied extensively to determine their utility in developing serological diagnostic assays for cancer. The development of accurate panels of diagnostic markers for cancer detection is now being pursued using new technologies and tailored computational methods capable of analyzing data generated from large-scale biomarker discovery projects.

OBJECTIVE

In this technical overview, current methodologies being applied to the identification and characterization of tumor-specific autoantibodies in cancer patients' sera are reviewed.

METHODS

A variety of research approaches are presented that are now being used or have the potential to evaluate large numbers of patient sera for the presence of tumor-specific autoantibodies. Each approach is discussed regarding its primary attributes (advantages and limitations) that could lead to serological diagnostic assays for the early detection of cancer.

CONCLUSION

Preliminary results in the development of serological diagnostic assays have demonstrated that the basic experimental tools to accomplish this goal exist. In the future, autoantibody patterns against tumor-specific proteins may achieve high specificity and sensitivity for diagnosing disease in screening populations. The development of highly accurate reliable assays is a prerequisite for this technology to be integrated into clinically applicable strategies in patient care.

Molecular mechanisms of head and neck cancer

Despite advances in understanding the underlying genetics, squamous cell carcinoma of the head and neck (SCCHN) remains a major health risk and one of the leading causes of mortality in the world. Current standards of treatment have significantly improved long-term survival rates of patients, but second tumors and metastases still remain the most frequent cause of high mortality in SCCHN patients. A better understanding of the underlying genetic mechanisms of SCCHN tumorigenesis will help in developing better diagnostics and, hence, better cures. In this article we will briefly outline the current state of diagnostics and treatment and our understanding of the molecular causes of SCCHN.

The proteomes of human parotid and submandibular/sublingual gland salivas collected as the ductal secretions

Saliva is a body fluid with important functions in oral and general health. A consortium of three research groups catalogued the proteins in human saliva collected as the ductal secretions: 1166 identifications--914 in parotid and 917 in submandibular/sublingual saliva--were made. The results showed that a high proportion of proteins that are found in plasma and/or tears are also present in saliva along with unique components. The proteins identified are involved in numerous molecular processes ranging from structural functions to enzymatic/catalytic activities. As expected, the majority mapped to the extracellular and secretory compartments. An immunoblot approach was used to validate the presence in saliva of a subset of the proteins identified by mass spectrometric approaches. These experiments focused on novel constituents and proteins for which the peptide evidence was relatively weak. Ultimately, information derived from the work reported here and related published studies can be used to translate blood-based clinical laboratory tests into a format that utilizes saliva. Additionally, a catalogue of the salivary proteome of healthy individuals allows future analyses of salivary samples from individuals with oral and systemic diseases, with the goal of identifying biomarkers with diagnostic and/or prognostic value for these conditions; another possibility is the discovery of therapeutic targets.

Salivary mRNA targets for cancer diagnostics

Head and neck squamous cell carcinoma (HNSCC) affects almost 1 million people worldwide per year. Despite therapeutic advances the overall survival rate remains low because diagnosis often occurs only at advanced stages with poor prognosis. Like in most cancers, the implementation of an early detection scheme would have a positive impact on this disease. Similarly, as oral cancer has a very high recurrence rate, the early identification of recurrence or second primary tumors is an important challenge. HNSCC detection is currently based on expert clinical examination of the upper aerodigestive tract and histologic analysis of suspicious areas, but it may be undetectable in hidden sites, and unfortunately visual screening for oral lesions is an often neglected part of dental healthcare. Our group is actively pursuing the assembly of a toolbox for the molecular analysis of oral fluid. Here we present our current status utilizing the salivary transcriptome for oral cancer diagnostics.

Proteomics analysis of cells in whole saliva from oral cancer patients via value-added three-dimensional peptide fractionation and tandem mass spectrometry

Whole human saliva possesses tremendous potential in clinical diagnostics, particularly for conditions within the oral cavity such as oral cancer. Although many have studied the soluble fraction of whole saliva, few have taken advantage of the diagnostic potential of the cells present in saliva, and none have taken advantage of proteomics capabilities for their study. We report on a novel proteomics method with which we characterized for the first time cells contained in whole saliva from patients diagnosed with oral squamous cell carcinoma. Our method uses three dimensions of peptide fractionation, combining the following steps: preparative IEF using free flow electrophoresis, strong cation exchange step gradient chromatography, and microcapillary reverse-phase liquid chromatography. We determined that the whole saliva samples contained enough cells, mostly exfoliated epithelial cells, providing adequate amounts of total protein for proteomics analysis. From a mixture of four oral cancer patient samples, the analysis resulted in a catalogue of over 1000 human proteins, each identified from at least two peptides, including numerous proteins with a role in oral squamous cell carcinoma signaling and tumorigenesis pathways. Additionally proteins from over 30 different bacteria were identified, some of which putatively contribute to cancer development. The combination of preparative IEF followed by strong cation exchange chromatography effectively fractionated the complex peptide mixtures despite the closely related physiochemical peptide properties of these separations (pI and solution phase charge, respectively). Furthermore compared with our two-step method combining preparative IEF and reverse-phase liquid chromatography, our three-step method identified significantly more cellular proteins while retaining higher confidence protein identification enabled by peptide pI information gained through IEF. Thus, for detecting salivary markers of oral cancer and possibly other conditions of the oral cavity, the results confirm both the potential of analyzing the cells in whole saliva and doing so with our proteomics method.

Increased Cyfra 21-1 concentration in saliva from primary oral squamous cell carcinoma patients

BACKGROUND

Saliva is the body fluid in the oral cavity and contacts directly with oral mucosa. As a detective media, it is acceptable and non-traumatic. Cyfra 21-1, being the soluble fragment of cytokeratin 19(CK19), correlates well with oral squamous cell carcinoma (OSCC).

OBJECTIVE

To investigate the saliva Cyfra 21-1 concentrations in OSCC patients and healthy persons, and the correlation between the Cyfra 21-1 concentration in saliva and the CK19 expression in tissue from OSCC patients.

DESIGN

Saliva Cyfra 21-1 concentration was detected by ELISA in 30 OSCC patients and 30 healthy persons; CK19 protein expression and CK19 mRNA level were, respectively, detected by immunohistochemistry and fluorescent real-time RT-PCR in cancerous and paracancerous tissues from 33 OSCC patients.

RESULTS

Saliva Cyfra 21-1 concentration in OSCC patients (85.95+/-78.00 microg/L) was significantly higher than that in healthy persons (42.27+/-40.84 microg/L) (P=0.009); it was also significantly higher in the patients suffering later tumour recurrence (130.95+/-66.38 microg/L) than that in the patients without tumour recurrence (74.84+/-63.45 microg/L) (P=0.023). CK19 protein expression increased significantly in OSCC tissues (P<0.001) with positive rate of 90.9%, CK19 mRNA level in cancerous tissues was 2.21 folds higher than that in paracancerous tissues (P=0.020); significant correlation was found between tissue CK19 protein expression and tissue CK19 mRNA level (P=0.003), and great correlation was found between tissue CK19 protein expression and saliva Cyfra 21-1 concentration (P=0.051).

CONCLUSIONS

The increased CK19 expression in OSCC tissues plays an important role in the increase of saliva Cyfra 21-1 concentration. Potential clinical value of saliva Cyfra 21-1 detection is suggested for OSCC. Further studies are encouraged to reveal the real diagnostic and prognostic value of detecting saliva Cyfra 21-1 concentration for OSCC.

Alteration of saliva and serum concentrations of manganese, copper, zinc, cadmium and lead among career welders

Human saliva offers a unique noninvasive approach for populational study. Purposes of this study were to investigate the feasibility of using saliva manganese (Mn) concentration as a biomarker of Mn exposure among career welders and to study the variations of Mn, copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb) in saliva as affected by the welding profession. Forty-nine male welders, of whom 28 were in the low exposed group and 21 in the high exposed group, were recruited. Control subjects were 33 military soldiers without metal exposure. Ambient Mn levels in breathing zones were 0.01, 0.24 and 2.21mg/m(3) for control, low, and high exposed groups, respectively. Saliva samples were collected to quantify metals by inductive coupled plasma mass spectrometer (ICP-MS). Saliva concentrations of Mn and Cu were significantly higher in welders than in controls (p<0.01); the variation in saliva levels appeared likely to be associated with airborne Mn levels among study populations. Saliva levels of Zn were significantly lower in welders than in controls (p<0.05), while Cd and Pb levels in saliva were unchanged. Significant associations were observed between saliva and serum for Mn (r=0.575, p<0.05) and Cu (r=0.50, p<0.05). Moreover, saliva Mn concentrations were higher among welders with 5-10years of employment than those with less than 5years of employment. Linear regression analysis revealed a significant correlation between saliva Mn and Cu and between saliva Mn and Zn. Taken together, these data suggest that Mn concentrations in saliva appear reflective of welders' exposure to airborne Mn and their years of welding experience, respectively. Elevated Mn levels among welders may alter the homeostasis of Cu and Zn.

[Oral cytology: historical development, current status, and perspectives]

Oral cytology has aroused new interest caused by introduction of the cytobrush as a sampling device and the use of additional analytical methods. By brushing it is possible to reach deeper layers of the oral mucosa where squamous intraepithelial neoplasia (SIN) begins. The biological potential of the oral epithelial cells obtained can be evaluated by the following additional methods: computer-assisted image analysis (OralCDx), DNA cytometry, immunohistochemistry, monolayer cytology, and molecular biological analysis. All of those methods can increase sensitivity (up to 100%) and specificity (up to 100%) of oral brush biopsy. Nevertheless, there are reports that oral epithelial carcinomas were not identified. No comparative study exists allowing conclusions to be drawn about the value of the single methods. Immunocytochemistry with commercial antibodies against laminin-5 is generally available and methodologically easy. Oral brush biopsy as a non invasive diagnostic method can be useful for the early detection of oral mucosal lesions. Positive findings or progression of the lesion despite negative findings are indications to refer the patient to a specialized clinic where a surgical biopsy should be performed, followed by histopathological analysis. Histopathology remains the gold standard for the definitive diagnosis of oral malignant lesions.

Ultrastructural changes of the palatal mucosa following application of 4-nitroquinoline-l-oxide (4NQO) in rats subjected to major salivary gland excision

OBJECTIVE

It has been suggested that saliva exerts a protective role against the carcinogenic effect of various substances in the oral cavity. The objective of this study was to examine the ultrastructural changes of the palatal mucosa caused by the application of 4-nitroquinoline-l-oxide (4NQO) in the presence or absence of saliva.

STUDY DESIGN

Wistar-Furth rats subjected and not subjected to total bilateral excision of the major salivary glands were either painted with an aqueous solution of 4NQO or with propylene glycol only (controls). Two animals of each group were humanely killed periodically. The areas of the palatal lesions were immediately sliced and processed for TEM examination.

RESULTS

Ultrastructurally, the progressive changes to squamous cell carcinoma were observed in the animals painted with 4NQO. In the desalivated animals group, the ultrastructural alterations appeared earlier than in the group with salivary glands.

CONCLUSIONS

Saliva appeared to delay but not hinder tumor induction by 4NQO.

Oral diagnostics for the geriatric populations: current status and future prospects

Because it is a noninvasive technique, there is growing interest in replacing blood with oral-based methods of diagnostics. Oral diagnostics may be used for diagnosis and therapeutic drug monitoring of both oral diseases (eg, caries, periodontal disease,oral lesions, oral cancer) and systemic diseases (eg, infectious diseases, including HIV and AIDS, autoimmune diseases, cancer,and endocrine disorders). The authors address both existing techniques and oral-based diagnostics that will be applicable to the aging population in the future. They also highlight those techniques that are uniquely suited to point-of-care applications.

Detection of telomerase activity in saliva from oral squamous cell carcinoma patients

Tumor markers have been detected in saliva from patients with oral cancers. In order to investigate the expression of telomerase in saliva and its clinical significance. Sixty-two saliva specimens were collected from 32 patients with oral squamous cell carcinoma and 30 normal persons, the telomerase activity was assayed by telomerase PCR-ELISA method. It was detected positively in 75.0% (24/32) of patients with oral squamous cell carcinoma, while it was positive in 6.67% (2/30) of normal persons, the statistical difference was significant with P < 0.001. But the difference of expression of telomerase activity between the patients in clinical early and late stage was not significant with P > 0.05, the same to that between the patients with and without lymph nodes metastasis with P > 0.05. The results suggest that the telomerase in saliva could be used as an assistant marker for oral squamous cell carcinoma, however, a larger study is encouraged to confirm the value of judgement on clinical stage and lymph nodes metastasis.

Molecular markers for diagnosis and prognosis

A plethora of aberrations are associated with progress and outcome for head and neck cancer patients and some have been shown to provide prognostic information independent of the TNM staging system. These findings justify future studies that will harness recent advances in technologies to refine the range of molecular markers available. Important lessons have been learnt during the last two decades, particularly the need to perform multivariate analysis and to combine information derived from several molecular markers. At present the overall evidence is insufficient to alter clinical practice or to consider restricting clinical trials of new adjuvant to subsets of patients, identified on the basis of the use of molecular markers. However, a number of key prospective clinical studies are in progress and we can be optimistic that in the near future clinical research incorporating specific markers may provide new criteria for defining risk of relapse or of developing a new primary tumour, and guide the choice of optimal adjuvant treatment after surgery. The only way to truly validate a marker is to incorporate it into large clinical trials, and it is anticipated that the new treatment options that are on the horizon, that are likely to be an improvement on radiotherapy alone, will provide opportunities to help translate this laboratory research into clinical practice.

Serum protein profiles to identify head and neck cancer

PURPOSE

New and more consistent biomarkers of head and neck squamous cell carcinoma (HNSCC) are needed to improve early detection of disease and to monitor successful patient management. The purpose of this study was to determine whether a new proteomic technology could correctly identify protein expression profiles for cancer in patient serum samples.

EXPERIMENTAL DESIGN

Surface-enhanced laser desorption/ionization-time of flight-mass spectrometry ProteinChip system was used to screen for differentially expressed proteins in serum from 99 patients with HNSCC and 102 normal controls. Protein peak clustering and classification analyses of the surface-enhanced laser desorption/ionization spectral data were performed using the Biomarker Wizard and Biomarker Patterns software (version 3.0), respectively (Ciphergen Biosystems, Fremont, CA).

RESULTS

Several proteins, with masses ranging from 2778 to 20800 Da, were differentially expressed between HNSCC and the healthy controls. The serum protein expression profiles were used to develop and train a classification and regression tree algorithm, which reliably achieved a sensitivity of 83.3% and a specificity of 100% in discriminating HNSCC from normal controls.

CONCLUSIONS

We propose that this technique has potential for the development of a screening test for the detection of HNSCC.

The p53 network in head and neck cancer

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide and, despite advances in treatment, still represents a clinical challenge. Inactivation of one or more components of the p53 network is an extremely common event in human neoplasia. In HNSCC, disabling of p53 occurs in a high proportion of cases by mutation in the p53 gene, but other mechanisms of inactivation, such as the presence of human papillomavirus (HPV) and molecular abnormalities in other components of the pathway, are also recognised. The frequent changes occurring in the p53 pathway in HNSCC imply that molecular genetic and immunocytochemical analysis of this critical tumour suppressor network may be of diagnostic and prognostic utility in the clinical management of HNSCC. Further, these changes also provide targets for the development of novel therapeutic approaches to this increasingly common cancer, in which clinical cure for advanced disease remains an elusive goal.

Serologic analysis of ovarian tumor antigens reveals a bias toward antigens encoded on 17q

We utilized SEREX immunoscreening to identify a set of novel tumor antigens that are associated with human serous ovarian cancer and may prove useful for the early detection and treatment of this disease. Extensive screening with a panel of sera from 25 late-stage ovarian cancer patients against 3 independent cDNA libraries identified a set of 9 antigens that were immunogenic in more than 1 patient and not in a panel of 20-45 normal female serum donors. These antigens include p53, NY-ESO-1, UBQLN1, HOXB6, TOP2A, putative helicase-RUVBL (RUVBL), HMBA-inducible (HEXIM1), DDX5 and HDCMA. Ten of 25 ovarian cancer patients (40%) expressed serum IgG to at least 1 of these antigens, while 14% (4/25) had antibodies to 2 or more antigens. Unexpectedly, 4 antigens identified in this screen, DDX5, HEXIM1, TOP2A and HOXB6, are encoded within a region of 17q that also includes the genes for HER2/neu, Homeobox-B7 and BRCA1. Real-time RT-PCR analysis showed that mRNA for HER2/neu and 3 SEREX-defined antigens, TOP2A, HOXB6 and DDX5, was more abundant in ovarian tumors than most normal tissues, including normal and benign ovarian tissues, suggesting that elevated expression of genes encoded within this region of chromosome 17 is a common event in ovarian tumors. Thus, these abnormal expression patterns combined with the endogenous immune response suggests that these antigens represent potential targets for immunotherapy.