title: Proteomic analysis of novel targets associated with the enhancement of TrkA-induced SK-N-MC cancer cell death caused by NGF.
abstract: Nerve growth factor (NGF) is known to regulate both cancer cell survival and death signaling, depending on the cellular circumstances, in various cell types. In this study, we showed that NGF strongly upregulated the protein level of tropomyosin-related kinase A (TrkA) in TrkA-inducible SK-N-MC cancer cells, resulting in increases in various TrkA-dependent cellular processes, including the phosphorylation of c-Jun N-terminal kinase (JNK) and caspase-8 cleavage. In addition, NGF enhanced TrkA-induced morphological changes and cell death, and this effect was significantly suppressed by the JNK inhibitor SP600125, but not by the phosphatidylinositol 3-kinase (PI3K) inhibitor wortmannin. To investigate novel targets associated with the enhancement of TrkA-induced SK-N-MC cell death caused by NGF, we performed Coomassie Brilliant Blue staining and two-dimensional (2D) proteomic analysis in TrkA-inducible SK-N-MC cells. We identified 31 protein spots that were either greatly upregulated or downregulated by TrkA during NGF treatment using matrix-associated laser desorption/ionization time of flight/time of flight mass spectrometry, and we analyzed the effects of SP600125 and wortmannin on the spots. Interestingly, 11 protein spots, including heterogeneous nuclear ribonucleoprotein K (hnRNP K), lamin B1 and TAR DNA-binding protein (TDP43), were significantly influenced by SP600125, but not by wortmannin. Moreover, the NGF/TrkA-dependent inhibition of cell viability was significantly enhanced by knockdown of hnRNP K using small interfering RNA, demonstrating that hnRNP K is a novel target associated with the regulation of TrkA-dependent SK-N-MC cancer cell death enhanced by NGF.
authors.affiliation: Department of Biochemistry, Gyeongsang National University School of Medicine, Jinju, Republic of Korea.|Institute of Health Sciences, Gyeongsang National University, Jinju, Republic of Korea.
authors.forename: Eun Joo
authors.initials: EJ
authors.lastname: Jung
authors.affiliation: Institute of Health Sciences, Gyeongsang National University, Jinju, Republic of Korea.|Department of Urology, Gyeongsang National University School of Medicine and Gyeongsang National University Hospital, Jinju, Republic of Korea.
authors.forename: Ky Hyun
authors.initials: KH
authors.lastname: Chung
authors.affiliation: Central Instrument Facility, Gyeongsang National University, Jinju, Republic of Korea.
authors.forename: Dong-Won
authors.initials: DW
authors.lastname: Bae
authors.affiliation: Department of Biochemistry, Gyeongsang National University School of Medicine, Jinju, Republic of Korea.|Institute of Health Sciences, Gyeongsang National University, Jinju, Republic of Korea.
authors.forename: Choong Won
authors.initials: CW
authors.lastname: Kim
mesh_terms: D001932:Brain Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D053181:Caspase 8 / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects*; D045744:Cell Line, Tumor; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D020932:Nerve Growth Factor / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects; D040901:Proteomics; D020917:Receptor, trkA / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects
chemical_list: C000611485:NTRK1 protein, human; D020932:Nerve Growth Factor; D020917:Receptor, trkA; D048031:JNK Mitogen-Activated Protein Kinases; D053181:Caspase 8