Molecular epidemiology of plasma oncoproteins in vinyl chloride monomer workers in Taiwan.
OBJECTIVE
To determine the presence of Asp13-p21-ki-ras oncoprotein and p53 oncoprotein in the plasma of vinyl chloride monomer (VCM)-workers in Taiwan.


METHODS
We used enhanced chemiluminescence (ECL) western blotting to detect Asp13-p21-ki-ras and ELISA to detect mutant p53 protein (p53-Ag) and anti-p53 antibodies (p53-Ab) in the plasma of VCM-exposed workers.


RESULTS
Twenty-five out of 251 (10%) VCM-workers were positive for Asp13-p21-ki-ras in plasma, but 0 out of 36 controls were positive. There were 15 out of 95 (15.8%) plasma-positives among the more highly exposed (> 480 ppm-month) workers and 10 out of 156 (6.4%) plasma-positives among the lesser exposed (< or = 480 ppm-month). Compared to the unexposed controls, age and drinking adjusted odds ratios (95% CI) were 1.2 (0.1, 9.8) in the lower exposed workers, and 4.8 (0.8, 28) in the higher exposed workers, and there was a significant linear trend between exposure and plasma positivity (P=0.001). Thirty-three out of 251 (13.2%) VCM-workers were positive for the p53 over-expression (10% with positive p53-Ag and 2.8% with positive p53-Ab). There was a significant association between cumulative VCM exposure concentration and positive p53 expression (P=0.032) among VCM-workers after adjusting for age, hepatitis, drinking and smoking status.


CONCLUSIONS
Asp13-p21-ki-ras oncoprotein and p53 over-expression (p53-Ag or p53-Ab) can be found in the plasma of VCM-workers in Taiwan, and a significant dose-response relationship exists between plasma oncoproteins expression and VCM exposure.
John Luo
Jiin-Chyuan
JC
Department of Public Health, Chang Gung Medical College, 259 Wen-Hua 1st Road, Kwei-Shan, Tao-Yuan, Taiwan ROC.
Cheng
Tsun-Jen
TJ
Du
Chung-Li
CL
Wang
Jung-Der
JD
D000328:Adult; D014408:Biomarkers, Tumor / Q000097:blood; D002273:Carcinogens / Q000009:adverse effects*; D016022:Case-Control Studies; D006801:Humans; D008113:Liver Neoplasms / Q000097:blood / Q000139:chemically induced; D008297:Male; D017720:Molecular Epidemiology; D009154:Mutation; D009784:Occupational Diseases / Q000097:blood* / Q000139:chemically induced; D016273:Occupational Exposure / Q000032:analysis*; D016283:Proto-Oncogene Proteins p21(ras) / Q000097:blood*; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology; D016159:Tumor Suppressor Protein p53 / Q000097:blood*; D014752:Vinyl Chloride / Q000009:adverse effects*
D014408:Biomarkers, Tumor; D002273:Carcinogens; D016159:Tumor Suppressor Protein p53; C501009:HRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras); D014752:Vinyl Chloride