Entwicklung von diagnostischen und prognostischen extrazellulären Matrixmarkern für menschliche Dickdarm- und Bauchspeicheldrüsen-Karzinome
Zellbiologie
Zusammenfassung der Projektergebnisse
Colorectal cancer (CRC) is the third most common malignancy and the fourth leading cause of cancerrelated deaths worldwide. Despite significant treatment advances, the number of patients suffering from CRC is currently still increasing. Although the last two decades yielded tremendous increase in scientific knowledge on the progression of CRC and an avalanche of potential applicable biomarkers were suggested, these studies have not yet successfully been translated to the clinic. Until more effective therapies are available, one strategy for reducing the worldwide CRC mortality is the development of novel screening methods that will result in higher rates of early CRC detection. The extracellular matrix (ECM), a major component of the tumor microenvironment, has been suggested to have major effects on the behavior of tumor and stromal cells, however, the detailed ensemble of ECM and ECM-associated molecules (the ‘matrisome’) in different tumor stages and tumor types is still unknown. To increase the knowledge about the role of ECM components in CRC progression is therefore of utmost importance. The Hynes laboratory used a proteomic-based approach to characterize and understand the ECM composition during human metastatic CRC progression and identified reproducible ECM changes (‘signatures’) characteristic for individual tissues during tumor progression (colon, primary tumor and liver metastasis). The major goal of my postdoctoral study was the translation of these proteomic data from metastatic CRC tumors and their liver metastases, into microscopic screens that are easily applicable in routine pathology. Therefore, I tested and validated a significant number of antibodies specific for the most interesting ECM biomarker candidates and established protocols that allow their reproducible and reliable application in immunohistochemistry (IHC) approaches. Initial screens on formaldehydefixed, paraffin-embedded patient samples helped to refine these antibody panels that are currently being studied on a broader set of well annotated CRC tumors as well as CRC tissue microarrays (TMAs) of various tumor grades. To do this, I have initiated valuable clinical collaborations to be able to validate my IHC stainings in comparison to clinical data in close association with pathologists. This will further help to elucidate the diagnostic and prognostic significance of the identified candidate ECM molecules. The overall goal of my project is to identify specific biomarkers and robust IHC tests that can be widely applied in the course of routine pathological diagnoses, prognoses and the clinical management of CRC. In the future, these findings will hopefully help to define better treatment strategies for patients suffering from CRC. In addition, I started to create recombinant single-domain antibodies, i.e. nanobodies, against the most interesting ECM molecules that I identified in the original antibody screen and aim for their application as new imaging agents to detect residual tumors and occult metastases. Nanobodies are superior to antibodies since they are very small in size, have greater stability, solubility as well as high affinity and specificity towards antigen binding. Therefore, they will subsequently be investigated as ECM target antibody-conjugated therapeutic agents in CRC-bearing mice in vivo in order to proof the nanobodies’ functionality in preclinical models. I am one of ten winners of the ‘SCIENCE with/in/sight 2015’ David H. Koch Institute for Integrative Cancer Research Image Award at MIT (Cambridge, USA) jointly sponsored with the Wellcome Trust (London, UK) – Image name “Gut Instinct: Screening for Signs of Cancer” (opening March 10, 2015) - see http://ki-galleries.mit.edu/2015/rickelt.
Projektbezogene Publikationen (Auswahl)
- The Biology of Cancer: Microenvironment, Metastasis & Therapeutics, May 12 - 16, 2015, Cold Spring Harbor, NY, USA. Poster: Development of diagnostic and prognostic extracellular matrix signatures for human colon carcinoma
Rickelt S, Naba A, Qian Z, Ogino S, Fuchs CS, Tanabe KK and Hynes RO
