Plasma Mutant-p53 Protein and Anti-p53 Antibody as a Marker: An Experience in Vinyl Chloride Workers in Italy

Vinyl chloride monomer (VCM) induces high occurrence of neural tube defects in embryonic mouse brain during neurulation

The aim of this study was to explore the direct embryonic teratogenicity of vinyl chloride monomer (VCM), especially the toxic effects on the early development of the nervous system and its underlying mechanisms. Pregnant mice at embryonic day 6.5 (E6.5) were injected with different doses of VCM (200, 400 and 600 mg/kg) and embryos were harvested at E10.5. Our results showed that doses higher than 400 mg/kg of VCM increased the incidence of malformed embryos, especially the neural tube defects (NTDs). In addition, high-dose of VCM decreased mitotic figure counts in the neuroepithelium and enhanced the percentage of cells in G0/G1 phase, while they were reduced in S phase. The more VCM was injected into mice, the fewer positive PCNA cells were seen and the more positive TUNEL cells were observed in the neuroepithelium. Moreover, significant increases in the levels of caspase-3 protein were observed in NTD embryos. Our results demonstrate that during early pregnancy, exposure to doses higher than 400 mg/kg of VCM increases the incidence of malformations and particularly the rate of NTDs. High-dose of VCM inhibits the proliferation of neural cells and induces cell apoptosis, leading to an imbalance in the ratio of proliferation and apoptosis. Meanwhile, the apoptosis of neuroepithelial cells might be accelerated by the activation of the caspase-3 pathway, and it might be a reason for NTDs.

Plastics and carcinogenesis: The example of vinyl chloride

The manufacture, use and disposal of various plastics can pose numerous health risks, including the risk of cancer. A model example of carcinogenic risk from plastics is provided by polyvinyl chloride, since it is composed of the known human carcinogen vinyl chloride (VC). In recent years, much has been learned about the molecular biological pathways of VC carcinogenesis. This has led to molecular epidemiologic studies of VC carcinogenesis in exposed human populations which have identified useful biomarkers of exposure, effect and susceptibility for VC. These studies have in turn provided the basis for new molecular approaches for the prevention and treatment of VC cancers. This model could have much wider applicability for many other carcinogenic exposures and many other human cancers.

Serological levels of mutated p53 protein are highly detected at early stages in breast cancer patients

The aim of this study was to compare the sensitivity of the serological level of anti-p53 antibodies in breast cancer patients and to correlate its expression level with patient age, histological stage and grade of tumor differentiation. Total p53 protein expression (mutant and wild-type) was also determined in the breast cancer tissues using immunohistochemistry (IHC). The serological levels of mutant p53 expression were found to be age-dependent, reaching the highest level at 50 years of age. Faint or low detection was observed in patients ≤30 years of age. Anti-p53-antibodies were detected in patients ≤40 and ≥61 years of age. The serological levels of mutant p53 protein were highly detected in all stages of breast cancer, including the early stages. However, anti-p53 antibodies reached a high level of detection only in stage III breast carcinomas. No expression was found in patients with benign breast disease. The detection of p53 mutations was dependent on the grade of tumor differentiation, achieving the highest level in the poorly differentiated breast carcinomas. Results from IHC were highly correlated with serological p53 mutational analysis. Our findings indicate that mutant p53 in serum is a promising novel parameter for the evaluation of cellular biology and the prognosis of breast cancer from its early stages using blood samples. Anti-p53 antibodies were demonstrated to be less sensitive in this study. It is also possible to use the expression of mutant p53 protein as a molecular marker to differentiate benign breast disease from breast carcinoma prior to surgery.

Vinyl chloride and the liver

Vinyl chloride monomer is a known cause of angiosarcoma of the liver. It also has other toxic effects on the liver, and it has recently been suggested that exposure to vinyl chloride also causes hepatocellular carcinoma. However, the data on which this conclusion is based is incomplete. There is inadequate ascertainment of unequivocal diagnoses. In the largest studies lack of data meant that confounding diseases such as viral hepatitis or alcoholic liver disease could not be assessed. At best, the increase in risk is minimal, based on more than 22,000 exposed workers and more than 640,000 person years of observation. However, based on the available data the hypothesis that vinyl chloride causes or contributes to the development of hepatocellular carcinoma remains unproven.

Serum p53 protein and anti-p53 antibodies are associated with increased cancer risk: a case-control study of 569 patients and 879 healthy controls

The aim of this study to determine whether serum p53 protein and antibodies are associated with malignant tumors. A case-control study was conduct in 569 patients with various types of malignant tumors and 879 healthy controls. Serum p53 protein and antibodies were analyzed by enzyme-linked immunosorbent assay (ELISA).The rate of positive p53 protein in patients with various malignant tumors was 4.22% compared with 0.34% in healthy controls (P < 0.001). The rate of anti-p53 antibodies in patients with various malignant tumors was 14.59% compared with 1.02% in healthy controls (P < 0.001). The adjusted odd ratio (OR) for p53 protein was 17.55 (95% CI = 4.98-61.94). The adjusted odd ratio for anti-p53 antibodies was 14.27 (95% CI = 6.75-30.16). The study strongly suggested that serum p53 protein and antibody are associated with increased cancer risk and can be used as early serological markers in the diagnosis of malignancies tumors.