title: Induction of apoptosis by p53, bax, bcl-2, and p21 expressed in colorectal cancer.
abstract: BACKGROUND
  We investigated the influence of genes on the apoptosis of colorectal tumor cells, based on DNA and mRNA kinetics.
  
  
  METHODS
  In 30 colorectal cancer patients, we examined the mRNA expression of p53, bax, bcl-2, and p21(WAF1), and we also investigated the development of tumor cell apoptosis, using a terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick-end labeling (TUNEL) method.
  
  
  RESULTS
  TUNEL-positive cells showed a positive correlation with bax (P = 0.010) and a negative correlation with p21 (P = 0.04). We also investigated the relationship between p53 point mutation, p21 immunostaining degree, and apoptosis, based on DNA ladder expression. A remarkable correlation (P = 0.0090) was found between p21 and apoptosis.
  
  
  CONCLUSIONS
  The present study findings suggest that tumor cell apoptosis is (1) strongly inhibited by p21, (2) induced by bax, and (3) influenced by bcl-2, which, presumably, inhibits tumor cell apoptosis.
authors.affiliation: The Department of Surgery, Tokyo Medical University, Tokyo, Japan. K.Katsu@col.ne.jp
authors.forename: Kenji
authors.initials: K
authors.lastname: Katsumata
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Sumi
authors.forename: Hidenori
authors.initials: H
authors.lastname: Tomioka
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Aoki
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Koyanagi
mesh_terms: D000368:Aged; D017209:Apoptosis / Q000235:genetics*; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology*; D004273:DNA, Neoplasm; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D019254:Genes, bcl-2; D016158:Genes, p53; D006801:Humans; D020287:In Situ Nick-End Labeling; D008297:Male; D008875:Middle Aged; D017354:Point Mutation; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000494:pharmacology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis* / Q000235:genetics / Q000494:pharmacology; D016283:Proto-Oncogene Proteins p21(ras) / Q000096:biosynthesis* / Q000235:genetics / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis* / Q000235:genetics / Q000494:pharmacology; D051028:bcl-2-Associated X Protein
chemical_list: C494826:BAX protein, human; D004273:DNA, Neoplasm; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53; D051028:bcl-2-Associated X Protein; D016283:Proto-Oncogene Proteins p21(ras)