title: ER homeostasis and motility of NSCLC cell lines can be therapeutically targeted with combined Hsp90 and HDAC inhibitors.
abstract: OBJECTIVE
  Lung cancer remains the most common cause of cancer-related death in the world for which novel systemic treatments are urgently needed. Protein homeostasis that regulates protein levels and their fold is critical for cancer cell proliferation and survival. A complex network of cellular organelles and signaling cascades is involved in control of protein homeostasis including endoplasmic reticulum (ER). Thus, proteins in control of ER homeostasis are increasingly recognized as potential therapeutic targets. Molecular chaperone heat shock protein 90 (Hsp90) and histone deacetylase (HDAC) play an important role in ER homeostasis. Previous studies demonstrate that Hsp90 and HDAC inhibitors are individually functional against lung cancer. In this work we suggested that combined Hsp90 and HDAC inhibitors may elevate ER stress thereby enhancing the anti non small lung cancer (NSCLC) activity.
  
  
  RESULTS
  Using an in vitro cell line model we demonstrated that 17-DMAG (HSP90 inhibitor) co-administration with PTACH (HDAC inhibitor) caused elevated ER stress (immunoblotting) (more than 110%↑, p < 0.05) accompanied by apoptotic cell death (Annexin V) (7-21%↑, p < 0.05). Moreover, 17-DMAG/PTACH treated cells lost the ability to migrate (scratch test) (57-85%↓ of scratch closure, p < 0.05).
  
  
  CONCLUSIONS
  Our findings provide proof-of-concept that targeting ER homeostasis is therapeutically beneficial in lung cancer cell lines. Indeed, the elevated ER stress caused by 17-DMAG/PTACH combined treatment leads to increased cell death of NSCLC cell lines compared to the application of the drugs separately.
authors: Lung Cancer Research Laboratory, Meir Medical Center, Kfar Saba 44281, Israel. vic.zismanov@clalit.org.il
authors: Victoria
authors: V
authors: Zismanov
authors: Liat
authors: L
authors: Drucker
authors: Maya
authors: M
authors: Gottfried
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D002289:Carcinoma, Non-Small-Cell Lung / Q000503:physiopathology*; D018797:Cell Cycle Proteins / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D018833:Chaperonins / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004721:Endoplasmic Reticulum / Q000187:drug effects* / Q000378:metabolism; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology*; D006706:Homeostasis; D006801:Humans; D015151:Immunoblotting; D008175:Lung Neoplasms / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D015398:Signal Transduction / Q000187:drug effects
chemical_list: C498362:CDC37 protein, human; D018797:Cell Cycle Proteins; D056572:Histone Deacetylase Inhibitors; D018833:Chaperonins