Katherine Dai1, Daniel P Radin2, Donna Leonardi1. 1. Bergen County Academies, Hackensack, NJ, United States. 2. Department of Pharmacology, Stony Brook University School of Medicine, Stony Brook, NY, United States. Electronic address: daniel.radin@stonybrookmedicine.edu.
Abstract
BACKGROUND: Despite significant strides in understanding the pathophysiology of non-small cell lung cancer (NSCLC), these neoplasms typically present with intrinsic chemo- and radiotherapeutic resistance. Transcriptomic analyses of patient NSCLC tumors stratified by survival times have identified the PTEN-induced putative kinase 1 (PINK1) as a molecular governor of tumor aggressiveness and patient survival time. PINK1 has been shown to confer neuroprotection in models of Parkinson Disease by ensuring proper mitochondrial turnover (mitophagy), the upkeep of ATP production and sequestering of reactive oxygen species (ROS). METHODS: We utilized an shRNA against PINK1 and the glycolytic inhibitor 3-BP to assess effects on NSCLC viability via MTS cell viability assay. ATP levels, caspase-9 activation, mitophagy and ROS production were determined with standardly available kits. Cytochrome c cellular localization and phosphorylated parkin levels were determined using an ELISA. RESULTS: Our results demonstrate that PINK1 depletion in the NSCLC cell line A549 via shRNA, reduced cancer cell proliferation, increased cell death, reduced ATP production, inhibited mitophagy and increased ROS and caspase-9-dependent apoptosis. PINK1 depleted cells were more susceptible to the glycolytic inhibitor 3-bromopyruvate (3-BP), which further perturbed ATP production. PINK1 depletion and 3-BP synergistically increased ROS production, caspase-9-dependent apoptosis and additively repressed mitophagy. CONCLUSIONS: These results suggest that PINK1 depletion alters energetic metabolism and confers sensitivity to agents that inhibit glycolysis. Targeting accelerated tumor cell metabolism may prove useful in the clinical setting while sparing non-malignant tissue.
BACKGROUND: Despite significant strides in understanding the pathophysiology of non-small cell lung cancer (NSCLC), these neoplasms typically present with intrinsic chemo- and radiotherapeutic resistance. Transcriptomic analyses of patientNSCLC tumors stratified by survival times have identified the PTEN-induced putative kinase 1 (PINK1) as a molecular governor of tumor aggressiveness and patient survival time. PINK1 has been shown to confer neuroprotection in models of Parkinson Disease by ensuring proper mitochondrial turnover (mitophagy), the upkeep of ATP production and sequestering of reactive oxygen species (ROS). METHODS: We utilized an shRNA against PINK1 and the glycolytic inhibitor 3-BP to assess effects on NSCLC viability via MTS cell viability assay. ATP levels, caspase-9 activation, mitophagy and ROS production were determined with standardly available kits. Cytochrome c cellular localization and phosphorylated parkin levels were determined using an ELISA. RESULTS: Our results demonstrate that PINK1 depletion in the NSCLC cell line A549 via shRNA, reduced cancer cell proliferation, increased cell death, reduced ATP production, inhibited mitophagy and increased ROS and caspase-9-dependent apoptosis. PINK1 depleted cells were more susceptible to the glycolytic inhibitor 3-bromopyruvate (3-BP), which further perturbed ATP production. PINK1 depletion and 3-BP synergistically increased ROS production, caspase-9-dependent apoptosis and additively repressed mitophagy. CONCLUSIONS: These results suggest that PINK1 depletion alters energetic metabolism and confers sensitivity to agents that inhibit glycolysis. Targeting accelerated tumor cell metabolism may prove useful in the clinical setting while sparing non-malignant tissue.