Advancements in Oncoproteomics Technologies: Treading toward Translation into Clinical Practice

Proteomics continues to forge significant strides in the discovery of essential biological processes, uncovering valuable information on the identity, global protein abundance, protein modifications, proteoform levels, and signal transduction pathways. Cancer is a complicated and heterogeneous disease, and the onset and progression involve multiple dysregulated proteoforms and their downstream signaling pathways. These are modulated by various factors such as molecular, genetic, tissue, cellular, ethnic/racial, socioeconomic status, environmental, and demographic differences that vary with time. The knowledge of cancer has improved the treatment and clinical management; however, the survival rates have not increased significantly, and cancer remains a major cause of mortality. Oncoproteomics studies help to develop and validate proteomics technologies for routine application in clinical laboratories for (1) diagnostic and prognostic categorization of cancer, (2) real-time monitoring of treatment, (3) assessing drug efficacy and toxicity, (4) therapeutic modulations based on the changes with prognosis and drug resistance, and (5) personalized medication. Investigation of tumor-specific proteomic profiles in conjunction with healthy controls provides crucial information in mechanistic studies on tumorigenesis, metastasis, and drug resistance. This review provides an overview of proteomics technologies that assist the discovery of novel drug targets, biomarkers for early detection, surveillance, prognosis, drug monitoring, and tailoring therapy to the cancer patient. The information gained from such technologies has drastically improved cancer research. We further provide exemplars from recent oncoproteomics applications in the discovery of biomarkers in various cancers, drug discovery, and clinical treatment. Overall, the future of oncoproteomics holds enormous potential for translating technologies from the bench to the bedside.

Clinical Application of Mass Spectrometry-Based Proteomics in Lung Cancer Early Diagnosis

The current knowledge on proteomic biomarker analysis for the early diagnosis of lung cancer is summarized, underlining the diversity among the results and the current interest in translating research results into clinical practice. A MEDLINE/PubMed literature search to retrieve all the papers published in the last 10 years is performed. Proteomics studies on lung cancer have gathered evidence on the potential role of biomarkers in early diagnosis. Although promising, none of them have proved to be sufficiently reliable to achieve validation. Future research should evolve toward a multipanel analysis of proteins, considering the possibility that individual biomarkers might not be specific enough to diagnose lung cancer, but could be related to oncological conditions.

Identification of Apolipoprotein C-I Peptides as a Potential Biomarker and its Biological Roles in Breast Cancer

Background

Breast cancer (BC) is one of the most common cancers and is among the main causes of death in females around the world. Although several serum biomarkers have been identified for breast cancer, due to lack of adequate sensitivity and specificity they do not adequately distinguish BC from confounding conditions. New approaches are urgently needed to improve BC detection and treatment.

Material/Methods

Eighty serum samples from 20 healthy individuals and 60 patients with BC (22 triple-negative breast cancer, TNBC; 38 non-triple-negative breast cancer, NTNBC) were included. Protein profiling of serum samples was analyzed using surface-enhanced laser desorption/ionization time-of-flight mass spectroscopy (SELDI-TOF-MS). Candidate biomarkers were purified by SDS-PAGE electrophoresis and identified by MALDI-TOF/TOF.

Results

The candidate biomarker positioned at 6447.9 m/z was significantly decreased in BC patients. Moreover, the expression intensity of the candidate biomarker was weaker in the TNBC and pre-surgery group compared with the NTNBC and post-surgery group. We ultimately identified the biomarker as apolipoprotein C-I (ApoC-I). Furthermore, we found that ApoC-I peptides inhibited proliferation of human breast cancer cells in vitro and suppressed tumor growth in vivo.

Conclusions

These results suggest that ApoC-I peptides may be a potential diagnostic biomarker and therapeutic approach for BC.

Comparative proteomics and global genome-wide expression data implicate role of ARMC8 in lung cancer

BACKGROUND

Cancer loci comprise heterogeneous cell populations with diverse cellular secretions. Therefore, disseminating cancer-specific or cancer-associated protein antigens from tissue lysates could only be marginally correct, if otherwise not validated against precise standards.

MATERIALS AND METHODS

In this study, 2DE proteomic profiles were examined from lysates of 13 lung-adenocarcinoma tissue samples and matched against the A549 cell line proteome. A549 matched-cancer-specific hits were analyzed and characterized by MALDI-TOF/MS.

RESULTS

Comparative analysis identified a total of 13 protein spots with differential expression. These proteins were found to be involved in critical cellular functions regulating pyrimidine metabolism, pentose phosphate pathway and integrin signaling. Gene ontology based analysis classified majority of protein hits responsible for metabolic processes. Among these, only a single non-predictive protein spot was found to be a cancer cell specific hit, identified as Armadillo repeat-containing protein 8 (ARMC8). Pathway reconstruction studies showed that ARMC8 lies at the centre of cancer metabolic pathways.

CONCLUSIONS

The findings in this report are suggestive of a regulatory role of ARMC8 in control of proliferation and differentiation in lung adenocarcinomas.

Serum protein profiles of patients with lung cancer of different histological types

AIMS

To compare serum protein expression profiles between lung cancer patients and healthy individuals, and to examine whether there are differences in serum protein expression profiles among patients with lung cancers of different histological types and whether the characteristic expression of serum proteins may assist in differential diagnosis of various subtypes of lung cancers.

METHODS

Blood samples were collected from 123 lung cancer patients before commencement of treatment who attended Shanxi Cancer Hospital, China, between 2008 and 2013. Blood samples from 60 healthy individuals were also collected in the same period. Serum protein expression profiles were analyzed using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry. The differences in the serum protein spectrums of lung cancer patients with different histological subtypes were analyzed by one-way Analysis of Variance and receiver operating characteristic curves.

RESULTS

A cluster of 48 protein mass-to-change ratio (M/Z) peaks was differentially expressed between sera of lung cancer patients and healthy individuals. The M/Z 1205, 4673, 1429 and 4279 peaks were differentially expressed among patients with lung squamous cell carcinomas, adenocarcinomas and small-cell lung carcinomas.

CONCLUSION

These results reinforce the notion that profiling of serum proteins may be of diagnostic value in lung cancer, and suggest that the differences in serum protein profiles may be useful in differential diagnosis of lung cancers of varying histological subtypes.

Translational Research and Plasma Proteomic in Cancer

Proteomics is a recent field of research in molecular biology that can help in the fight against cancer through the search for biomarkers that can detect this disease in the early stages of its development. Proteomic is a speedily growing technology, also thanks to the development of even more sensitive and fast mass spectrometry analysis. Although this technique is the most widespread for the discovery of new cancer biomarkers, it still suffers of a poor sensitivity and insufficient reproducibility, essentially due to the tumor heterogeneity. Common technical shortcomings include limitations in the sensitivity of detecting low abundant biomarkers and possible systematic biases in the observed data. Current research attempts are trying to develop high-resolution proteomic instrumentation for high-throughput monitoring of protein changes that occur in cancer. In this review, we describe the basic features of the proteomic tools which have proven to be useful in cancer research, showing their advantages and disadvantages. The application of these proteomic tools could provide early biomarkers detection in various cancer types and could improve the understanding the mechanisms of tumor growth and dissemination.

Advances in Proteomic Technologies and Its Contribution to the Field of Cancer

Systematic studies of the cancer genome have generated a wealth of knowledge in recent years. These studies have uncovered a number of new cancer genes not previously known to be causal targets in cancer. Genetic markers can be used to determine predisposition to tumor development, but molecularly targeted treatment strategies are not widely available for most cancers. Precision care plans still must be developed by understanding and implementing basic science research into clinical treatment. Proteomics is continuing to make major strides in the discovery of fundamental biological processes as well as more recent transition into an assay platform capable of measuring hundreds of proteins in any biological system. As such, proteomics can translate basic science discoveries into the clinical practice of precision medicine. The proteomic field has progressed at a fast rate over the past five years in technology, breadth and depth of applications in all areas of the bioscience. Some of the previously experimental technical approaches are considered the gold standard today, and the community is now trying to come to terms with the volume and complexity of the data generated. Here I describe contribution of proteomics in general and biological mass spectrometry in particular to cancer research, as well as related major technical and conceptual developments in the field.

MALDI-TOF MS as evolving cancer diagnostic tool: a review

Recent developments in mass spectrometry have introduced clinical proteomics to the forefront of diseases diagnosis, offering reliable, robust and efficient analytical method for biomarker discovery and monitoring. MALDI-TOF is a powerful tool for surveying proteins and peptides comprising the realm for clinical analysis. MALDI-TOF has the potential to revolutionize cancer diagnostics by facilitating biomarker discovery, enabling tissue imaging and quantifying biomarker levels. Healthy (control) and cancerous tissues can be analyzed on the basis of mass spectrometry (MALDI-TOF) imaging to identify cancer-specific changes that may prove to be clinically useful. We review MALDI-TOF profiling techniques as tools for detection of cancer biomarkers in various cancers. We mainly discuss recent advances including period from 2011 to 2013.