Scientists have established a process for identifying biomarkers for the diagnosis of different types of cancer. With the aid of a specific type of infrared (IR) spectroscopy, the researchers applied an automated and label-free approach to detect tumor tissue in a biopsy or tissue sample. Unlike with label-based processes, such as are currently deployed by pathologists, the tissue remains unmodified. This, in turn, facilitates detailed protein analyses in the next step. Studying tissue samples from patients who suffered from lung or pleural cancer, the researchers identified protein biomarkers that are typical of the respective subtype of cancer.
The team of the research consortium has published their report in the journal "Scientific Reports".
For the purpose of the study, the researchers worked with tissue samples of so-called diffuse malignant mesothelioma. They compared two mesothelioma subtypes -- the sarcomatoid and epithelioid type. This type of cancer often scatters into the lung and is usually terminal.
Researchers present a novel approach to spatially resolve the heterogeneity of a tumor in a label-free manner by integrating FTIR imaging and laser capture microdissection (LCM).
FTIR imaging resolves tumor subtypes within tissue thin-sections in an automated and label-free manner with accuracy of about 85% for mesothelioma subtypes. Even in highly heterogeneous tissue structures, the label-free approach can identify small regions of interest, which can be dissected as homogeneous samples using LCM.
Subsequent proteome analysis provides a location specific molecular characterization. Applied to mesothelioma subtypes, authors identify 142 differentially expressed proteins.
The researchers are able to determine which of the more than 2,000 identified proteins in the sarcomatoid mesothelioma are noticeably increased or reduced when compared to the epitheloid mesothelioma. "Consequently, we can determine changes in signal transduction in the cancer cells for each patient individually," explains the author. "This is crucial information for precise therapy."
The thus identified proteins might in future be used as biomarkers, in order to detect the type of cancer in other patients. Researchers studied the correlation of the detected proteins and the biomarkers that are currently used in traditional pathology. The result: the method also identified the five biomarkers which are already used to diagnose the mesothelioma subtypes. "Thereby we have validated our method," explains the author. The researchers also discovered additional biomarkers.
Those biomarkers are yet to be validated with a larger cohort in the next step.
New process for identify cancer biomarkers
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