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Here we describe a new instrument (SpiderMass) designed for in vivo and real-time analysis. In this instrument ion production is performed remotely from the MS instrument and the generated ions are transported in real-time to the MS analyzer. Ion production is promoted by Resonant Infrared Laser Ablation (RIR-LA) based on the highly effective excitation of O-H bonds in water molecules naturally present in most biological samples. The retrieved molecular patterns are specific to the cell phenotypes and benign versus cancer regions of patient biopsies can be easily differentiated. We also demonstrate by analysis of human skin that SpiderMass can be used under in vivo conditions with minimal damage and pain. Furthermore SpiderMass can also be used for real-time drug metabolism and pharmacokinetic (DMPK) analysis or food safety topics. SpiderMass is thus the first MS based system designed for in vivo real-time analysis under minimally invasive conditions.

Objective: Since European Society for Medical Oncology (ESMO) recommendations and French guidelines, pelvic lymphadenectomy should not be systematically performed for women with early-stage endometrioid endometrial cancer (EEC) preoperatively assessed at presumed low- or intermediate-risk. The aim of our study was to evaluate the change of our surgical practices after ESMO recommendations, and to evaluate the rate and morbidity of second surgical procedure in case of understaging after the first surgery., Methods: This retrospective single-center study included women with EEC preoperatively assessed at presumed low- or intermediate-risk who had surgery between 2006 and 2013. Two periods were defined the times before and after ESMO recommendations. Demographics characteristics, surgical management, operative morbidity, and rate of understaging were compared. The rate of second surgical procedure required for lymph node resection during the second period and its morbidity were also studied., Results: Sixty-one and sixty-two patients were operated for EEC preoperatively assessed at presumed low-or intermediate-risk before and after ESMO recommendations, respectively. Although immediate pelvic lymphadenectomy was performed more frequently during the first period than the second period (88.5% vs. 19.4%; p<0.001), the rate of postoperative risk-elevating or upstaging were comparable between the two periods (31.1% vs. 27.4%; p=0.71). Among the patients requiring second surgical procedure during the second period (21.0%), 30.8% did not undergo the second surgery due to their comorbidity or old age. For the patients who underwent second surgical procedure, mean operative time of the second procedure was 246.1±117.8 minutes. Third operation was required in 33.3% of them because of postoperative complications., Conclusion: Since ESMO recommendations, second surgical procedure for lymph node resection is often required for women with EEC presumed at low- or intermediate-risk. This reoperation is not always performed due to age/comorbidity of the patients, and presents a significant morbidity.

MALDI mass spectrometry imaging (MALDI-MSI) is currently used for clinical applications, such as biomarker identification, particularly for the study of solid tumors. The ability to map specific compounds that have been determined to be biomarkers and therapeutic targets is relevant for the evaluation of the efficacy of targeted therapies. This article describes a new method called Spectro-ImmunoHistoChemistry (SIHC), which combines the use of specific antibodies against markers and mass spectrometric imaging in the MS/MS mode. SIHC is based on direct primary antibody-antigen recognition, trypsin digestion of the antibody overlaying the markers of interest in the tissue section, and MALDI-MSI of the tryptic peptides generated from the antibody. This approach has both clinical and pharmacological applications. First, it can be used as a cross-validation method to monitor the presence specifically of a marker in a tissue section. Second, SIHC could potentially be used as a novel technology for tracking specific antibodies after in vivo injection for anti-cancer treatments. Additionally, SIHC could enable novel clinical applications of MSI, such as monitoring the efficacy of cytotoxic antibody treatments.

Background: Among biomarkers, cancer-antigen 125 (CA-125) is the most studied. We propose an analytical tool to track ovarian carcinoma biomarkers, that is, the MALDI mass spectrometry imaging., Material/methods: Ovarian carcinomas and benign ovaries were directly analyzed by MALDI-TOF-MS. After automatic profiling and mass spectrometry imaging analyses, hierarchical clustering based on principal component analysis in nonsupervised mode was carried out. On the same samples, preparations were performed to investigate peptides, then proteins, followed by high mass proteins, in an automatic profiling to specific signatures for diagnosis. Using tissue bottom-up strategy on tissue digestion, and mass spectrometry imaging after by shotgun sequencing by nalano-LC-IT-MS in MS/MS mode from washing samples from on tissue digested peptides, several biomarkers were found., Results: A list of specific biomarkers from the ovarian carcinoma regions was obtained and classified as proteins associated with cell proliferation, involved in immune response modulation, signaling to the cytoskeleton, and tumor progression. These specific biomarkers were then validated by immunocytochemistry using Tag-mass technology, cell biology, Western blot, and by PCR (using SKOV-3 ovarian epithelial cancer cells). A link between the immune regulation (innate immunity, tolerance) and virus cause is also discussed., Conclusions: From the biomarkers identified, proteins involved in immune response modulation and cell proliferation have been pointed out in this study. Two new markers have been identified using such a strategy, that is, fragment C-terminal of the PSME1 (Reg-Alpha) and mucin-9.

A decade after its inception, MALDI imaging mass spectrometry has become a unique technique in the proteomics arsenal for biomarker hunting in a variety of diseases. At this stage of development, it is important to ask whether we can consider this technique to be sufficiently developed for routine use in a clinical setting or an indispensable technology used in translational research. In this report, we consider the contributions of MALDI imaging mass spectrometry and profiling technologies to clinical studies. In addition, we outline new directions that are required to align these technologies with the objectives of clinical proteomics, including: 1) diagnosis based on profile signatures that complement histopathology, 2) early detection of disease, 3) selection of therapeutic combinations based on the individual patient's entire disease-specific protein network, 4) real time assessment of therapeutic efficacy and toxicity, 5) rational redirection of therapy based on changes in the diseased protein network that are associated with drug resistance, and 6) combinatorial therapy in which the signaling pathway itself is viewed as the target rather than any single "node" in the pathway.