Quantification of Serum Proteins of Metastatic Oral Cancer Patients Using LC-MS/MS and iTRAQ Labeling

Proteomic approaches to assist in diagnosis and prognosis of oral cancer

Introduction: Oral squamous cell carcinoma (OSCC) ranks among the top 10 leading causes of cancer worldwide, with 5-year survival rate of about 50%, high lymph node metastasis, and relapse rates. The OSCC diagnosis, prognosis, and treatment are mostly based on the clinical TNM classification. There is an urgent need for the discovery of biomarkers and therapeutic targets to assist in the clinical decision-making process.Areas covered: We summarize proteomic studies of the OSCC tumor, immune microenvironment, potential liquid biopsy sites, and post-translational modifications trying to retrieve information in the discovery and verification or (pre)validation phases. The search strategy was based on the combination of MeSH terms and expert refinement.Expert opinion: Untargeted combined with targeted proteomics are strategies that provide reliable and reproducible quantitation of proteins and are the methods of choice of many groups worldwide. Undoubtedly, proteomics has been contributing to the understanding of OSCC progression and uncovers potential candidates as biomarker or therapeutic targets. Nevertheless, none of these targets are available in the clinical practice yet. The scientific community needs to overcome the limitations by investing in robust experimental designs to strengthen the value of the findings, leveraging the translation of knowledge, and further supporting clinical decisions.

Metabolic Biomarkers of Squamous Cell Carcinoma of the Aerodigestive Tract: A Systematic Review and Quality Assessment

Introduction. Aerodigestive squamous cell carcinomas (ASCC) constitute a major source of global cancer deaths. Patients typically present with advanced, incurable disease, so new means of detecting early disease are a research priority. Metabolite quantitation is amenable to point-of-care analysis and can be performed in ASCC surrogates such as breath and saliva. The purpose of this systematic review is to summarise progress of ASCC metabolomic studies, with an emphasis on the critical appraisal of methodological quality and reporting.

METHOD

A systematic online literature search was performed to identify studies reporting metabolic biomarkers of ASCC. This review was conducted in accordance with the recommendations of the Cochrane Library and MOOSE guidelines.

RESULTS

Thirty studies comprising 2117 patients were included in the review. All publications represented phase-I biomarker discovery studies, and none validated their findings in an independent cohort. There was heterogeneity in study design and methodological and reporting quality. Sensitivities and specificities were higher in oesophageal and head and neck squamous cell carcinomas compared to those in lung squamous cell carcinoma. The metabolic phenotypes of these cancers were similar, as was the kinetics of metabolite groups when comparing blood, tissue, and breath/saliva concentrations. Deregulation of amino acid metabolism was the most frequently reported theme.

CONCLUSION

Metabolite analysis has shown promising diagnostic performance, especially for oesophageal and head and neck ASCC subtypes, which are phenotypically similar. However, shortcomings in study design have led to inconsistencies between studies. To support future studies and ultimately clinical adoption, these limitations are discussed.

Biomarkers: paving stones on the road towards the personalized precision medicine for oral squamous cell carcinoma

Traditional therapeutics have encountered a bottleneck caused by diagnosis delay and subjective and unreliable assessment. Biomarkers can overcome this bottleneck and guide us toward personalized precision medicine for oral squamous cell carcinoma. To achieve this, it is important to efficiently and accurately screen out specific biomarkers from among the huge number of molecules. Progress in omics-based high-throughput technology has laid a solid foundation for biomarker discovery. With credible and systemic biomarker models, more precise and personalized diagnosis and assessment would be achieved and patients would be more likely to be cured and have a higher quality of life. However, this is not straightforward owing to the complexity of molecules involved in tumorigenesis. In this context, there is a need to focus on tumor heterogeneity and homogeneity, which are discussed in detail. In this review, we aim to provide an understanding of biomarker discovery and application for precision medicine of oral squamous cell carcinoma, and have a strong belief that biomarker will pave the road toward future precision medicine.

Analysis of the plasma proteome using iTRAQ and TMT-based Isobaric labeling

Over the past decade, chemical labeling with isobaric tandem mass tags, such as isobaric tags for relative and absolute quantification reagents (iTRAQ) and tandem mass tag (TMT) reagents, has been employed in a wide range of different clinically orientated serum and plasma proteomics studies. In this review the scope of these works is presented with attention to the areas of research, methods employed and performance limitations. These applications have covered a wide range of diseases, disorders and infections, and have implemented a variety of different preparative and mass spectrometric approaches. In contrast to earlier works, which struggled to quantify more than a few hundred proteins, increasingly these studies have provided deeper insight into the plasma proteome extending the numbers of quantified proteins to over a thousand.

Calcium calmodulin dependent kinase kinase 2 - a novel therapeutic target for gastric adenocarcinoma

Gastric cancer is one of the most common gastrointestinal malignancies and is associated with poor prognosis. Exploring alterations in the proteomic landscape of gastric cancer is likely to provide potential biomarkers for early detection and molecules for targeted therapeutic intervention. Using iTRAQ-based quantitative proteomic analysis, we identified 22 proteins that were overexpressed and 17 proteins that were downregulated in gastric tumor tissues as compared to the adjacent normal tissue. Calcium/calmodulin-dependent protein kinase kinase 2 (CAMKK2) was found to be 7-fold overexpressed in gastric tumor tissues. Immunohistochemical labeling of tumor tissue microarrays for validation of CAMKK2 overexpression revealed that it was indeed overexpressed in 94% (92 of 98) of gastric cancer cases. Silencing of CAMKK2 using siRNA significantly reduced cell proliferation, colony formation and invasion of gastric cancer cells. Our results demonstrate that CAMKK2 signals in gastric cancer through AMPK activation and suggest that CAMKK2 could be a novel therapeutic target in gastric cancer.

Potential biomarkers for oral squamous cell carcinoma: proteomics discovery and clinical validation

Oral squamous cell carcinoma (OSCC) is the worldwide concerned cancer. In spite of the advances in treatment, the 5-year survival rate has only increased subtly during the past two decades, which is largely due to the advanced stages of disease at diagnosis and the frequent development of relapse and second primary tumors. Therefore, the identification of underlying OSCC protein biomarker during cancer initiation and progression could aid the diagnosis and treatment of OSCC. In this review, recent researches on proteomics analysis of tissue, saliva, and serum for early detection and evaluation aggressiveness and occurrence of OSCC were summarized. The emphasis is placed on early detection by tissues, saliva, and serum of patients with histologically defined OSCC patients. Although lots of researches for searching OSCC protein biomarker have done, few common protein biomarkers have been detected. Low-redundant protein in tissues, saliva, and serum from OSCC may more accurately reflected the progression of OSCC, so novel approach for the depth research strategy and the sample choice for proteomics are of importance in OSCC biomarker discovery.

iTRAQ analysis with Paul ion trap-obstacle solved

Mass spectrometers equipped with ion trap analyzers have been significantly improved due to their high performance and wide application area accompanying the low costs of purchase. Despite several advantages, such as reasonable resolution at low cost, high sensitivity, and capability for multistage analysis, ion traps have an important drawback: low mass cutoff during tandem mass spectrometry analysis MS(n). Although the low mass cutoff associated with the ion trap does not seriously obstruct peptide identification, it may cause a serious problem in identification of small molecules (posttranslational modifications, e.g., glycan structures) and quantification of peptides with multiplexed isobaric tag reagents. The presented approach offers the possibility to use isobaric tags for relative and absolute quantification labeling (iTRAQ) for quantitative, proteomic analysis using typical, widely available ion trap devices and manufacturer's software. We have performed series of analyses of standard protein labeled with isobaric tags in various concentration ratios to prove quantitative capabilities of this approach.

Inhibitory effect of the HPV-16mE6δ/mE7/TBhsp70δ vaccine on oral squamous cell carcinoma

AIM

To evaluate the inhibitory effect of a recombinant human papillomavirus (HPV) fusion protein vaccine on oral squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

An animal model of OSCC was established using human peripheral blood lymphocyte reconstituted nonobese diabetic/severe combined immunodeficiency mice. HPV vaccine was subcutaneously injected into mice after tumor establishment. Tumors and spleens were measured, weighed and stained with hematoxylin and eosin. Lymphocyte subpopulations and cytotoxicity were analyzed with flow cytometric and cytotoxic T lymphocyte assay.

RESULTS

The average weight and volume of tumors were significantly lower in the vaccine group than in the control group from day 27. Mice in both groups had high percentages of human CD3+ and CD3+CD8+ T lymphocytes. An elevated percentage of human CD3+CD16+56+ natural killer cells was found in the vaccine group. Moreover, vaccine increased the infiltration of human CD3 and UCHL-1+ cells in tumor tissues and enhanced cytotoxicity.

CONCLUSIONS

The HPV fusion protein vaccine induces tumor cell death, lymphocyte infiltration and therefore suppresses tumor growth and protects against OSCC.

Potential biomarkers in the sera of breast cancer patients from bahawalpur, pakistan

Most of the approximately 90,000 cases of Breast Cancer (BC) documented annually in Pakistan are not diagnosed properly because of lack of suitable markers. We performed serum proteome expression profiling of BC and benign breast disease (BBD) patients with the aim to identify biomarkers that can be helpful for diagnosis and prognosis of the disease. Sera of patients were analyzed by one-dimensional SDS polyacrylamide gel electrophoresis (PAGE). Differentially expressed proteins were subjected to identification through LC-MS/MS analysis. In majority of the BC cases some acute phase proteins (APP) and some complement system components (C3 and C8) containing fractions were up-regulated with the exception of transthyretin (TTR) which was predominantly (68.75%) down-regulated (n = 33/48) in the sera of these patients. Varying expression patterns were observed in BBD patients and healthy controls. These differentially expressed proteins have the potential to serve as diagnostic biomarkers for BC as well as benign breast diseases.