Molecular profiling techniques and bioinformatics in cancer research

Cellular resolution in clinical MALDI mass spectrometry imaging: the latest advancements and current challenges

Mass spectrometry (MS) is the workhorse of metabolomics, proteomics and lipidomics. Mass spectrometry imaging (MSI), its extension to spatially resolved analysis of tissues, is a powerful tool for visualizing molecular information within the histological context of tissue. This review summarizes recent developments in MSI and highlights current challenges that remain to achieve molecular imaging at the cellular level of clinical specimens. We focus on matrix-assisted laser desorption/ionization (MALDI)-MSI. We discuss the current status of each of the analysis steps and remaining challenges to reach the desired level of cellular imaging. Currently, analyte delocalization and degradation, matrix crystal size, laser focus restrictions and detector sensitivity are factors that are limiting spatial resolution. New sample preparation devices and laser optic systems are being developed to push the boundaries of these limitations. Furthermore, we review the processing of cellular MSI data and images, and the systematic integration of these data in the light of available algorithms and databases. We discuss roadblocks in the data analysis pipeline and show how technology from other fields can be used to overcome these. Finally, we conclude with curative and community efforts that are needed to enable contextualization of the information obtained.

Targeting Receptor Kinases in Colorectal Cancer

Colorectal cancer is the third most common malignancy in men and the second most common cancer in women. Despite the success of screening programs and the development of adjuvant therapies, the global burden of colorectal cancer is expected to increase by 60% to more than 2.2 million new cases and 1.1 million deaths by 2030. In recent years, a great effort has been made to demonstrate the utility of protein kinase inhibitors for cancer treatment. Considering this heterogeneous disease is defined by mutations that activate different Receptor Tyrosine Kinases (RTKs) and affect downstream components of RTK-activated transduction pathways, in this review we analyze the potential utility of different kinase inhibitors for colorectal cancer treatment.

Traditional Chinese medicine ZHENG and Omics convergence: a systems approach to post-genomics medicine in a global world

Traditional Chinese medicine (TCM) is a comprehensive system of medical practice that has been used to diagnose, treat, and prevent illnesses for more than 3000 years. ZHENG (also known as "syndrome") differentiation remains the essence of TCM. In China, TCM shares equal status, and integrated with Western medicine in the healthcare system to treat many types of diseases. Yet, compared to biomolecular science and Western medicine, the ZHENG/TCM approach to diagnostics might appear unobjective, but offers at the same time long-standing clinical and phenotypic-rich insights. With the current globalization of life sciences and the arrival of "Big Data" research and development, these two silos of medical lore are rapidly coalescing. The applications of multi-omics strategies to TCM have begun to provide novel insights into the essence and molecular basis of TCM ZHENG. We searched the Chinese electronic databases and PubMed for published articles related to "Omics" and "TCM ZHENG" and observed a dramatic increase in studies over the past few years. In this article, we provide a timely synthesis of the lessons learned, and the emerging applications of omics science in TCM ZHENG research. We suggest that the global health scholarship and the field of "developing world Omics" can usefully draw from TCM, and vice versa.

Application of OMICS technologies in occupational and environmental health research; current status and projections

OMICS technologies are relatively new biomarker discovery tools that can be applied to study large sets of biological molecules. Their application in human observational studies (HOS) has become feasible in recent years due to a spectacular increase in the sensitivity, resolution and throughput of OMICS-based assays. Although, the number of OMICS techniques is ever expanding, the five most developed OMICS technologies are genotyping, transcriptomics, epigenomics, proteomics and metabolomics. These techniques have been applied in HOS to various extents. However, their application in occupational environmental health (OEH) research has been limited. Here, we will discuss the opportunities these new techniques provide for OEH research. In addition we will address difficulties and limitations to the interpretation of the data that is generated by OMICS technologies. To illustrate the current status of the application of OMICS in OEH research, we will provide examples of studies that used OMICS technologies to investigate human health effects of two well-known toxicants, benzene and arsenic.

Quality assessment of microarray data in a multicenter study

Issues implicit in a multicenter microarray study are protocol standardization and monitoring center adherence to established protocols. This study explored the effects of submitting center and sample preservation method on the quality of isolated RNA. In addition, the effects of sample preservation method and laboratory on microarray quality were also examined. Herein we evaluated the contribution of specific technical factors [center, laboratory, and preservation method (frozen/RNAlater)] on quality of isolated RNA, cRNA synthesis products, and reproducibility of gene expression microarray data for independent biologic samples collected in a multicenter microarray study. The Kruskal-Wallis test was used to test for differences owing to submitting center on isolated RNA quality. Mixed effects analysis of variance was used in assessing the impact of laboratory and preservation method on gene expression values for the 12 samples hybridized at 2 independent laboratories (24 GeneChips). One center was found to be in violation of the tissue handling protocol. No significant effect was noted owing to preservation method, which ensured that our tissue handling protocols are working properly. There was a significant laboratory effect with respect to cRNA yield, though this effect did not impact sample quality. We conclude that use of consistent protocols for sample collection, RNA extraction, cDNA/cRNA synthesis, labeling, hybridization, platform, image acquisition, normalization, and expression summaries can yield consistent expression values. Moreover, evaluation of sample quality at various steps in the data acquisition process is an important component of a multicenter study to ensure all participating centers adhere to established protocols.

From bench to bedside: current and future applications of molecular profiling in renal cell carcinoma

Among the adult population, renal cell carcinoma (RCC) constitutes the most prevalent form of kidney neoplasm. Unfortunately, RCC is relatively asymptomatic and there are no tumor markers available for diagnostic, prognostic or predictive purposes. Molecular profiling, the global analysis of gene and protein expression profiles, is an emerging promising tool for new biomarker identification in RCC. In this review, we summarize the existing knowledge on RCC regarding clinical presentation, treatment options, and tumor marker status. We present a general overview of the more commonly used approaches for molecular profiling at the genomic, transcriptomic and proteomic levels. We also highlight the emerging role of molecular profiling as not only revolutionizing the process of new tumor marker discovery, but also for providing a better understanding of the pathogenesis of RCC that will pave the way towards new targeted therapy discovery. Furthermore, we discuss the spectrum of clinical applications of molecular profiling in RCC in the current literature. Finally, we highlight some of the potential challenging that faces the era of molecular profiling and its transition into clinical practice, and provide an insight about the future perspectives of molecular profiling in RCC.