title: Observation of molecular changes of a necrotic tissue from a murine carcinoma by Fourier-transform infrared microspectroscopy.
abstract: OBJECTIVE
  Our purpose is to develop infrared (IR) microspectroscopy as a new optical diagnostic tool to support conventional lightscopic techniques in investigating the viability of carcinoma tissues and to develop its use in the evaluation of the early effects of anticancer therapy by monitoring the IR spectra in the necrotic area.
  
  
  METHODS
  We evaluated the tissue which amassed for 4 weeks after the isotransplantation of mouse squamous cell carcinoma into the thigh of mice. The borders of the necrotic area of frozen tissue specimens were investigated by Fourier-transform IR microspectroscopy and conventional histological staining.
  
  
  RESULTS
  A significantly higher accumulation of cholesterol was observed in the necrotic tissue of a carcinoma. The mechanism of this phenomenon is hitherto unrecognized. We proposed that the accumulated cholesterol may lie extracellularly as a result of the ruptured plasma and internal membranes after the swelling of the necrotic cells brought on by hypoxia. The analysis of the secondary structure of protein revealed that the amounts of beta-sheet increased significantly in striking contrast to the decreasing amounts of alpha-helix in a necrotic area of a carcinoma. It is plausible that this structural conversion of protein was because of lipid-autooxidation products, such as cholesterol oxide but not cholesterol itself, which possesses cell toxicity and could be generated in a necrotic area.
  
  
  CONCLUSIONS
  We conclude that it will be possible to evaluate the efficacy of the clinical treatment of carcinoma by monitoring subtle biological changes of cholesterol absorbance in the early stage of necrosis because of anticancer treatment.
authors.affiliation: Department of Dentistry and Oral Surgery, Fukui Medical University, Matsuoka, Fukui 910-1193, Japan.
authors.forename: Tetsushi
authors.initials: T
authors.lastname: Yamada
authors.forename: Norio
authors.initials: N
authors.lastname: Miyoshi
authors.forename: Toru
authors.initials: T
authors.lastname: Ogawa
authors.forename: Kenichi
authors.initials: K
authors.lastname: Akao
authors.forename: Masaru
authors.initials: M
authors.lastname: Fukuda
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Ogasawara
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Kitagawa
authors.forename: Kazuo
authors.initials: K
authors.lastname: Sano
mesh_terms: D000818:Animals; D001391:Azo Compounds; D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D002784:Cholesterol / Q000378:metabolism; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D009336:Necrosis; D011487:Protein Conformation; D012983:Soft Tissue Neoplasms / Q000473:pathology*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*
chemical_list: D001391:Azo Compounds; D002784:Cholesterol; C009213:Scarlet Red