ABSTRACT
Carcinomas of unknown primary origin constitute 3% to 5% of all newly diagnosed metastatic cancers, with the primary source difficult to classify with current histological methods. Effective cancer treatment depends on early and accurate identification of the tumor; patients with metastases of unknown origin have poor prognosis and short survival. Because miRNA expression is highly tissue specific, the miRNA profile of a metastasis may be used to identify its origin. We therefore evaluated the potential of miRNA profiling to identify the primary tumor of known metastases. Two hundred eight formalin-fixed, paraffin-embedded samples, representing 15 different histologies, were profiled on a locked nucleic acid-enhanced microarray platform, which allows for highly sensitive and specific detection of miRNA. On the basis of these data, we developed and cross-validated a novel classification algorithm, least absolute shrinkage and selection operator, which had an overall accuracy of 85% (CI, 79%-89%). When the classifier was applied on an independent test set of 48 metastases, the primary site was correctly identified in 42 cases (88% accuracy; CI, 75%-94%). Our findings suggest that miRNA expression profiling on paraffin tissue can efficiently predict the primary origin of a tumor and may provide pathologists with a molecular diagnostic tool that can improve their capability to correctly identify the origin of hitherto unidentifiable metastatic tumors and, eventually, enable tailored therapy.
Subject(s)
MicroRNAs/genetics , Molecular Diagnostic Techniques/methods , Neoplasms, Unknown Primary/classification , Neoplasms, Unknown Primary/genetics , Sequence Analysis, RNA/methods , Algorithms , Base Sequence , Biomarkers, Tumor/genetics , Gene Expression Profiling/methods , Gene Expression Regulation, Neoplastic , Humans , Neoplasms, Unknown Primary/diagnosis , Oligonucleotide Array Sequence Analysis/methods , Organ Specificity/genetics , Paraffin EmbeddingABSTRACT
We have developed a fluorescence-based fiber-optical biosensor, which can selectively detect different antibodies in serial at preselected positions inside a single piece of fiber. The fiber is a microstructured polymer optical fiber fabricated from TOPAS cyclic olefin copolymer, which allows for UV activation of localized sensor layers inside the holes of the fiber. Serial fluorescence-based selective sensing of Cy3-labelled α-streptavidin and Cy5-labelled α-CRP antibodies is demonstrated.
Subject(s)
Antibodies/isolation & purification , Biosensing Techniques/methods , Optical Fibers , Carbocyanines/chemistry , Fluorescence , Humans , Polymers/chemistry , Streptavidin/chemistryABSTRACT
We present what is believed to be the first microstructured polymer optical fiber (mPOF) fabricated from Topas cyclic olefin copolymer, which has attractive material and biochemical properties. This polymer allows for a novel type of fiber-optic biosensor, where localized sensor layers may be activated on the inner side of the air holes in a predetermined section of the mPOF. The concept is demonstrated using a fluorescence-based method for selective detection of fluorophore-labeled antibodies.
Subject(s)
Biosensing Techniques , Optics and Photonics , Polymers/chemistry , Alkenes/chemistry , Biocompatible Materials/chemistry , C-Reactive Protein/chemistry , Carbocyanines/chemistry , Fiber Optic Technology , Microscopy, Fluorescence/instrumentation , Microscopy, Fluorescence/methods , Optical Fibers , Polymethyl Methacrylate/chemistry , Streptavidin/chemistry , Ultraviolet RaysABSTRACT
We demonstrate highly efficient evanescent-wave detection of fluorophore-labeled biomolecules in aqueous solutions positioned in the air holes of the microstructured part of a photonic crystal fiber. The air-suspended silica structures located between three neighboring air holes in the cladding crystal guide light with a large fraction of the optical field penetrating into the sample even at wavelengths in the visible range. An effective interaction length of several centimeters is obtained when a sample volume of less than 1 microL is used.
