Searching for combination therapy by clustering methods: Stimulation of PKC in Golgi apparatus combined with hypericin induced PDT

摘要

Cancer cell metabolism is a very attractive target for anticancer treatments. This work focuses on protein kinase C (PKC) signaling in the U87 MG glioma. By means of western blot, fluorescence and time-resolved fluorescence microscopy the correlation between the Golgi apparatus (GA), lysosomes and mitochondria were evaluated. The known regulators of PKC were applied to cancer cells. Phorbol myristate acetate (PMA) was chosen as the activator of PKC. Go6976, hypericin and rottlerin, the inhibitors of PKC alpha and PKC delta were selected as well. Stabilization, destabilization processes occurring in cells allow classification of observations into several groups. Multiple versions of hierarchical cluster analysis have been applied and similarities have been found between organelles and PKC regulators. The method identified GA as an extraordinary organelle whose functionality is significantly influenced by PKC regulators as well as oxidative stress. Therefore, combination therapy has been designed according to the results of the cluster analysis. Furthermore, the efficacy of photodynamic therapy mediated by hypericin, and the consequent apoptosis, was significantly increased during the treatment. To our knowledge, this is the first demonstration of the effectiveness of the clustering in the given area.