Inhibition of Lung Cancer Cell Migration/Invasion by Cell Penetrating Peptides

This proposal examines the hypothesis that inhibition of the morphological alterations obligatory for lung cancer cell (A-549 cells) invasion and proliferation can be achieved using peptide inhibitors specifically designed to abrogate activation of the Ca2+-dependent cysteine protease, calpain II (Cpll), upon which these features of malignancy are contingent. More specifically, it is proposed that blocking Cpll engagement with its regulatory subunit (Rs), endoplasmic reticulum (ER) and/or Golgi apparatus (GA), will block lung cancer cell proliferation and migration (i.e. metastatic potential) and could have significant therapeutic value in adjunctive treatment of these tumors. To investigate this hypothesis 2 Specific Aims are proposed that will: 1) identify amino acids within the Cpll protein that are required for its interactions with the Rs, ER and GA; and 2) develop a cell penetrating peptide (CPP) approach for delivering peptide inhibitors of Cpll-Rs, -ER and/or -GA interactions in these cells. Accordingly, recombinant technologies will be used to mutate key amino acid domains within the Cpll molecule that facilitate CpU interactions with its Rs and organelles. These mutant CpIl structures subsequently will be analyzed for their impact on A-549 cell proliferation, migration and programmed cell death. Information from these studies will be used to develop peptide inhibitors of Cpll activities. The efficacy of these inhibitors will be investigated using a CPP delivery approach to analyze the impact these peptides have on lung cancer cell proliferation, migration and survival. Data accrued from this study should provide insight into the role of Cp in lung cancer cell biology and provide a template for the subsequent design of in vivo models that explore the true therapeutic potential of these inhibitors.