Direct identification of proteins from T47D cells and murine brain tissue by matrix-assisted laser desorption/ionization post-source decay/collision-induced dissociation

Mass spectrometry MALDI imaging of colon cancer biomarkers: a new diagnostic paradigm

Colorectal cancer (CRC), is the second-leading cause of cancer-related deaths in the USA, affecting both men and women. Current projections show little or no change since the publication of a morbidity and mortality study in 2005. The projected number of new cases for 2008 is 154,000, and the projected number of CRC cancer deaths for 2008 is 53,000. The standard diagnostic paradigm is based on histopathology of either biopsy or surgical specimens. This article suggests a new paradigm for colon cancer diagnosis and staging using matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS or IMS). IMS may identify potential tumors in normal tissue of cancer patients and predict those cancer patients who are at risk for recurrent cancer.

Imaging mass spectrometry: Towards clinical diagnostics

Imaging MS (IMS) has emerged as a powerful tool for biomarker discovery. A key advantage of this technique is its ability to probe the proteome directly from a tissue section with preservation of the spatial relationships of the sample and minimal sample preparation. This allows for direct correlation of protein expression with histology. Here, we present the latest developments in imaging MS and their relevance to clinical mass spectral analysis. IMS allows for high throughput analysis of tissue samples and is fully compatible with biostatistical analysis without prior knowledge of protein expression. Several studies are presented of applications in which direct tissue mass spectral analysis has provided insight into clinical questions not readily available by other means. Examples include the determination of lymph node status from investigation of primary breast tumors, prediction of response of breast tumors to chemotherapy, classification and prediction of progression of lung lesions, and exploration of 'molecular' margins in invasive disease.

MALDI imaging mass spectrometry: molecular snapshots of biochemical systems

Matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) is emerging as a powerful tool for investigating the distribution of molecules within biological systems through the direct analysis of thin tissue sections. Unique among imaging methods, MALDI-IMS can determine the distribution of hundreds of unknown compounds in a single measurement. We discuss the current state of the art of MALDI-IMS along with some recent applications and technological developments that illustrate not only its current capabilities but also the future potential of the technique to provide a better understanding of the underlying molecular mechanisms of biological processes.