Induction of apoptosis by p53, bax, bcl-2, and p21 expressed in colorectal cancer.
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.
Katsumata
Kenji
K
The Department of Surgery, Tokyo Medical University, Tokyo, Japan. K.Katsu@col.ne.jp
Sumi
Tetsuo
T
Tomioka
Hidenori
H
Aoki
Tatsuya
T
Koyanagi
Yasuhisa
Y
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
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)