Optimization of protocol for immunofluorescence stain to observe nerve infiltration and regeneration in cancer tissue

Sammanfattning: Background: Neuronal plasticity and regeneration in cancer are understudied aspects of cancer research. Studies have shown that neurogenesis and axonogenesis are associated with cancer progression and metastatic potential. Purpose: The purpose of this project was to optimize an immunofluorescence stain to observe nerve development and regeneration in cancer tissue, with the use of antibodies against neurofilament light chain (Nf-L), growth associated protein 43 (gap-43), and doublecortin X (DCX). Material and method: Staining optimization included evaluations of antigen retrieval, tissue permeabilization, antibody dilution, and duration of primary antibody incubation. The analyses were tested on colorectal- and lung cancer tissues. Results: The detection of Nf-L was not successful in any combination of the analyses or on ether tissue. The staining Gap-43 showed the best results using antigen retrieval with pepsin in HCl and primary antibody dilution 1:500 combined with incubation overnight at 4 °C. Staining for DCX needs more evaluation due to non-specific binding in lung cancer tissue. The stain showed the best results with antigen retrieval performed with pepsin in HCl, primary antibody dilution 1:250 combined with 1 hour incubation at room temperature of the primary antibody. Permeabilization has to some degree shown good results in combination with antigen retrieval with pepsin in HCl. Conclusion: A good protocol was established for Gap-43 detection, but the procedures for Nf-L and DCX detections need to be optimized.