Upregulation of non-mutated H-ras and its upstream and downstream signaling proteins in colorectal cancer.
We analyzed H-ras protein expression in 38 human colon cancers and the paired normal tissues. H-ras levels were significantly higher in the malignant tumor (average 0.19+/-0.27) than in its normal adjacent tissues (average 0.06+/-0.15) (p<0.05). The H-ras protein expressed in colon carcinomas contained activated form of H-ras without mutation, based on the findings obtained by RBD-binding (ras binding domain of Raf protein) assay and PCR-SSCP analysis. In addition, we found that H-ras expression was higher in female patients than male, and in cancers with distant metastasis compared to those with non-distant metastasis. Good correlation between H-ras expression levels and those of the upstream and downstream signaling proteins of EGFR, MEK and ERK was found, suggesting that H-ras may play a significant role in carcinogenesis of colorectal cancer.
Feng
J
J
Department of Molecular Oncology and Microbiology, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo 113, Japan.
Hua
F
F
Shuo
R
R
Chongfeng
G
G
Huimian
X
X
Nakajima
T
T
Subao
W
W
Tsuchida
N
N
D000368:Aged; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D011905:Genes, ras; D006801:Humans; D008297:Male; D008875:Middle Aged; D015854:Up-Regulation; D018631:ras Proteins / Q000378:metabolism
D018631:ras Proteins