Morphological Changes and Nuclear Translocation of DLC1 Tumor Suppressor Protein Precede Apoptosis in Human Non-Small Cell Lung Carcinoma Cells

Details

• Personal Author:
  Jefferson AM ; Millecchia L ; Popescu NC ; Reynolds SH ; Yuan BZ
• Description:
  We have previously shown that reactivation of DLC1, a RhoGAP containing tumor suppressor gene, inhibits tumorigenicity of human non-small cell lung carcinoma cells (NSCLC). After transfection of NSCLC cells with wild type (WT) DLC1, changes in cell morphology were observed. To determine whether such changes have functional implications, we generated several DLC1 mutants and examined their effects on cell morphology, proliferation, migration and apoptosis in a DLC1 deficient NSCLC cell line. We show that WT DLC1 caused actin cytoskeleton-based morphological alterations manifested as cytoplasmic extensions and membrane blebbings in most cells. Subsequently, a fraction of cells exhibiting DLC1 protein nuclear translocation (PNT) underwent caspase 3-dependent apoptosis. We also show that the RhoGAP domain is essential for the occurrence of morphological alterations, PNT and apoptosis, and the inhibition of cell migration. DLC1 PNT is dependent on a bipartite nuclear localizing sequence and most likely is regulated by a serine-rich domain at N-terminal part of the DLC1 protein. Also, we found that DLC1 functions in the cytoplasm as an inhibitor of tumor cell proliferation and migration, but in the nucleus as an inducer of apoptosis. Our analyses provide evidence for a possible link between morphological alterations, PNT and proapoptotic and anti-oncogenic activities of DLC1 in lung cancer. [Description provided by NIOSH]
• Subjects:
  Irritants Neoplasms Occupational Health Respiratory Tract Diseases Safety
• Keywords:
  Cancer Cell-damage Cell-metabolism Cell-morphology Cellular-function Respiratory-irritants Respiratory-system-disorders
• ISSN:
  0014-4827
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  Maryland ; OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  313
• Issue:
  18
• NIOSHTIC Number:
  nn:20032800
• Citation:
  Exp Cell Res 2007 Nov; 313(18):3868-3880
• Contact Point Address:
  Bao-Zhu Yuan, Laboratory of Molecular Genetics, Toxicology and Molecular Biology Branch, National Institute for Occupational Safety and Health, CDC, Morgantown, WV 26505
• Federal Fiscal Year:
  2008
• NORA Priority Area:
  Manufacturing
• Peer Reviewed:
  True
• Source Full Name:
  Experimental Cell Research
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:edef1ea114668490458c53146478c6019a738665a2c3e72155f0057af8c8800365fb5113e0c2d9ad7d7d5c644cba21dcd18323e75e8751d31e8ddf32d9e352d3
• Download URL:
  https://stacks.cdc.gov/view/cdc/186632/cdc_186632_DS1.pdf
• File Type:
  [PDF - 2.74 MB ]