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Fossilized organic remains are important sources of information because they provide a unique form of biological and evolutionary information, and have the long-term potential for genomic explorations. Here we report evidence of protein preservation in a terrestrial vertebrate found inside the vascular canals of a rib of a 195-million-year-old sauropodomorph dinosaur, where blood vessels and nerves would normally have been present in the living organism. The in situ synchrotron radiation-based Fourier transform infrared (SR-FTIR) spectra exhibit the characteristic infrared absorption bands for amide A and B, amide I, II and III of collagen. Aggregated haematite particles (α-Fe 2 O 3 ) about 6∼8 μm in diameter are also identified inside the vascular canals using confocal Raman microscopy, where the organic remains were preserved. We propose that these particles likely had a crucial role in the preservation of the proteins, and may be remnants partially contributed from haemoglobin and other iron-rich proteins from the original blood., Competing Interests: The authors declare no competing financial interests.

Invasive and metastatic cells must cross the basement membrane's extracellular matrix to disseminate to distant sites. Although in the eighties the concept was well established, no easy in vitro functional assay was available. Working in Hynda Kleinman's and George Martin's laboratory at NIH (Bethesda, MD), where the reconstituted basement membrane Matrigel was discovered, I had the intuition that Matrigel coating of migration filters could represent a valid tool to mimic in vitro biological matrix barriers. The "chemoinvasion assay" using Matrigel in Boyden blind-well chambers was developed in 1985-1986 and published in Cancer Research in 1987. It was a rapid and easy tool for studying invasion, a crucial step in cancer metastasis. Since its conception, the assay has been employed for studies on the metastatic process, angiogenesis, and for the screening of drugs that are potentially able to decrease cell invasion. It was adapted to be easily employed as a routine assay and commercialized. In that historical article, we also described the use of thick layers of Matrigel for the study of morphogenesis of invasive cells, a simple and visual assay, adaptable to reproduce collective cell migration in vitro To date, in its diverse optimized variants, the chemoinvasion assay is still widely used, contributing to novel data production. In the era of precision medicine and next-generation sequencing, the cheap, fast, and reproducible chemoinvasion assay may have further developments, including possible applications in the investigations on cancer stem cells, immunity and immune modulators, applications with siRNA silencing, selection of aggressive cell populations, and phenotypes and genetic evaluations. Cancer Res; 76(16); 4595-7. ©2016 AACR.See related article by Albini A et al., Cancer Res 1987;47:3239-45Visit the Cancer Research 75(th) Anniversary timeline., (©2016 American Association for Cancer Research.)

Natural abundances in 13C and 15N of bone collagen are linked to those of the diet. This isotopic signal can thus be linked to the dietary parameters of a given individual, such as the plants at the beginning of his food web and his position in the trophic web. In order to use this approach to study the diet of ancient humans, it is crucial to be sure that the original isotopic abundances of fossil collagen are preserved. This is done by controlling the biochemical purity of the organic matter extracted from fossil bones, and by checking that the isotopic differences observed in modern environments between herbivorous and carnivorous species are indeed measured in the fossil samples. Upper Pleistocene sites with a good isotopic preservation of collagen have been recognized in temperate and arctic environments. The isotopic signatures measured in such sites highlight particularities of the "mammoth steppe" fauna, and improve our knowledge of the diet of Neandertals.

Soil bacteria, which are an always present component of all burial conditions, substantially contribute to the decomposition of bone collagen, i.e. even modifications of preserved bone collagen. Archaeometric data, which were derived from collagen remnants, therefore may always contain diagenetic components which disturb the biological signals and must subsequently be eliminated. To adequately assess probable diagenetic influences one should refer to our model of the biogenic steps of decomposition. The taphonomic experiments and their verifications of archaeological human bones, which were gathered from different origins and of different historical times, were done with histological, biochemical and biophysical methods. Experimentally, as well as through archaeological bone analysis, we were able to identify a "high" molecular product of decomposition, which contains (1) changes in the amino acid composition caused by specific soil conditions and (2) significant deviations of stable nitrogen and carbon isotopes. Due to decomposition procedures, isotope analysis of isolated amino acids indicate rearrangements of collagen fragments.

Favourable burial conditions and self-limiting decomposition processes led to an extraordinarily well molecular preservation of the Mesolithic human skull finds from the Ofnet cave (district Nördlingen, Bavaria). Beyond the extraction of bone collagen, a selection of serum proteins from bone was identified immunologically. Stable carbon and nitrogen isotope ratios from collagen gave clues to dietary behaviour including nursing practices. Diverging results after the application of biochemical protocols (for protein cleaning) and biophysical methods (for stable isotope analysis) are of particular interest: while the first approach failed to quantitatively eliminate anorganic contaminations, the second left some organic, exogenous residues in the samples. Thus, methods for protein extraction must vary according to problem solution and ultimate aim of the study. Taking this into account, application of invasive methods is also encouraged to rare and valuable skeletal finds.

The current state of knowledge about the biosynthesis of the collagen molecule and the stabilization of fibers is reviewed. There have been a number of major breakthroughs during the past 25 years which will be described.