title: Aldose Reductase Inhibitor Fidarestat as a Promising Drug Targeting Autophagy in Colorectal Carcinoma: a Pilot Study.
abstract: BACKGROUND
  Colorectal cancer (CRC) is a leading cause of morbidity and mortality worldwide. Targeting autophagic cell death is emerging as a novel strategy in cancer chemotherapy. Aldose reductase (AR) catalyzes the rate limiting step of the polyol pathway of glucose metabolism; besides reducing glucose to sorbitol, AR reduces lipid peroxidation-derived aldehydes and their glutathione conjugates. A complex interplay between autophagic cell death and/or survival may in turn govern tumor metastasis. This exploratory study aimed to investigate the potential role of AR inhibition using a novel inhibitor Fidarestat in the regulation of autophagy in CRC cells.
  
  
  METHODS
  For glucose depletion (GD), HT-29 and SW480 CRC cells were rinsed with glucose-free RPMI-1640, followed by incubation in GD medium+/-Fidarestat (10μM). Proteins were extracted by a RIPA-method followed by Western blotting (35-50 μg of protein; n=3).
  
  
  RESULTS
  Autophagic regulatory markers, primarily, microtubule associated protein light chain (LC) 3, autophagy-related gene (ATG) 5, ATG 7 and Beclin-1 were expressed in CRC cells; glyceraldehyde-3 phosphate dehydrogenase (GAPDH) was used as an internal reference. LC3 II (14 kDa) expression was relatively high compared to LC3A/B I levels in both CRC cell lines, suggesting occurrence of autophagy. Expression of non-autophagic markers, high mobility group box (HMG)-1 and Bcl-2, was comparatively low.
  
  
  CONCLUSIONS
  GD+/-ARI induced autophagy in HT-29 and SW-480 cells, thereby implicating Fidarestat as a promising therapeutic agent for colorectal cancer; future studies with more potent ARIs are warranted to fully dissect the molecular regulatory networks for autophagy in colorectal carcinoma.
authors.affiliation: Research Cell, Department of Research, Amity University Uttar Pradesh, Lucknow, India; University of Texas Medical Branch, Galveston, TX, USA E-mail : drsaumyapandey6@gmail.com; spandey2@lko.amity.edu.
authors.forename: Saumya
authors.initials: S
authors.lastname: Pandey
mesh_terms: D000449:Aldehyde Reductase / Q000037:antagonists & inhibitors*; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D001343:Autophagy / Q000187:drug effects*; D000071186:Beclin-1; D014408:Biomarkers, Tumor / Q000378:metabolism; D045744:Cell Line, Tumor; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D016503:Drug Delivery Systems / Q000379:methods; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005947:Glucose / Q000378:metabolism; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000378:metabolism; D019073:HT29 Cells; D006801:Humans; D048289:Imidazolidines / Q000494:pharmacology*; D008565:Membrane Proteins / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D010865:Pilot Projects
chemical_list: D051017:Apoptosis Regulatory Proteins; C491997:BECN1 protein, human; D000071186:Beclin-1; D014408:Biomarkers, Tumor; D004791:Enzyme Inhibitors; D048289:Imidazolidines; C477012:MAP1LC3A protein, human; D008565:Membrane Proteins; D008869:Microtubule-Associated Proteins; C077139:fidarestat; D000449:Aldehyde Reductase; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D005947:Glucose