TNF-alpha, IL-4R-alpha and IL-4 polymorphisms in mild to severe asthma from Italian Caucasians.

Asthma is a chronic airway inflammatory disease associated with airway hyperresponsiveness which affects subjects with genetic predisposition. An association has been reported between some polymorphisms in various cytokine genes and asthma. Most of them are single nucleotide polymorphisms (SNPs). These polymorphisms are detected in the protein coding sequence or in the promoter region thus influencing cytokine production. We investigated the involvement of SNP mapping in 5 cytokine genes in mild to severe asthmatics of Italian Caucasians. The frequency of alleles and genotypes, relatively to 10 allelic specificities of the cytokine genes, was defined in 57 asthmatics and in 124 control subjects by a Polymerase Chain Reaction-Sequence Specific Primer method. TNF-alpha -308A and TNF-alpha -238A allele frequencies were higher in asthmatics than in controls (p less than 0.001). Significant differences in the frequency of IL-4 -590T allele and of IL-4Ralpha +1902A allele were also detected in asthmatics in comparison with controls (pless than 0.001 and p=0.005, respectively). Similarly, IL-1alpha -889C allele was present in 84.1 percent of asthmatics and in 70.2 percent of controls (p=0.013). Furthermore, the IL-4Ralpha +1902A/A and IL-1alpha -889C/C homozygous conditions and the TNF-alpha -308G/A, TNF-alpha -238G/A, IL-4 -590T/C and IL-10 -1082G/A heterozygous conditions were significantly associated with asthma (p less than 0.05). ACA haplotype of IL-10 was observed only in asthmatic patients. This study reports, for the first time, the frequency of 10 different single nucleotide polymorphisms in 5 cytokine genes in the Italian Caucasians. Furthermore, we also indicate that in our population some single nucleotide polymorphisms are associated with mild to severe bronchial asthma.

An aflatoxin-associated mutational hotspot at codon 249 in the p53 tumor suppressor gene occurs in hepatocellular carcinomas from Mexico.

The p53 tumor suppressor gene is commonly mutated in human hepatocellular carcinoma (HCC). The most frequent mutation in HCC in populations exposed to a high dietary intake of aflatoxin B1 (AFB1) is an AGGarg-->AGTser missense mutation in codon 249 of the p53 gene. We analyzed HCCs from Monterrey, Mexico, for the codon 249ser hotspot mutation. We also analyzed the serum AFB1-albumin adduct levels of the donors and family members to measure the current AFB1 exposure in this population. Moreover, the presence of hepatitis B and/or C viral infection (HBV or HCV) was analyzed serologically in the patients. Tumor cells were microdissected from tissue sections and exon 7 p53 sequences were amplified by polymerase chain reaction from genomic DNA and sequenced directly. The serological tests for anti-p53 antibodies, HBV or HCV were done by ELISA. Immunohistochemical analysis of p53 protein was done using a polyclonal rabbit antiserum (CM-1). Eight of 21 cases were positive by p53 immunohistochemistry. Of the 16 cases sequenced for exon 7 of p53 three codon 249 AGGarg-->AGTser mutations were found. Serum antibodies recognizing p53 protein were found in one of 18 patients. Positive serology for HBV and/or HCV was found in 12 of 20 cases. The serum AFB1-albumin adduct levels in this population ranged from 0.54 to 4.64 pmol aflatoxin/mg albumin. These results indicate that dietary AFB1 and hepatitis viruses are etiological agents in the molecular pathogenesis of HCC in this geographic region of Mexico.

Anti-p53 antibodies in sera of workers occupationally exposed to vinyl chloride.

BACKGROUND: The p53 tumor suppressor gene (also known as TP53) is often mutated in a wide variety of cancers, including angiosarcoma of the liver (ASL). Anti-p53 antibodies have been detected in the sera of patients with leukemia, childhood lymphoma, or cancers such as those of the breast, lung, colon, esophagus, and liver (hepatocellular carcinoma). PURPOSE: The objective of this study was to determine the prevalence and time of appearance of serum anti-p53 antibodies during the pathogenesis of ASL associated with occupational exposure to vinyl chloride. METHODS: Enzyme-linked immunoassay (EIA) was used to detect anti-p53 antibodies in 148 serum samples from 92 individuals occupationally exposed (in France or in Kentucky) to vinyl chloride; 15 of these individuals (six from France and nine from Kentucky) had ASL. A subset of coded EIA-positive and EIA-negative sera was further analyzed for anti-p53 antibodies by immunoblotting and immunoprecipitation. Nucleotide sequence analysis of exons 5-8 of the p53 gene was conducted on ASL DNA from six patients. We tested sera from 31 men who had no occupational exposure to vinyl chloride; they made up the control group. Statistical analyses were done using the Kruskal-Wallis chi-squared approximation and the Wilcoxon two-sample test for normal approximation. All P values result from two-sided tests. RESULTS: Fourteen serum samples (from nine individuals) were positive in the EIA. Five of the 15 individuals with ASL were positive for anti-p53 antibodies by EIA, immunoblotting, and immunoprecipitation: one individual at 11.3 and 10.8 years before diagnosis, another at 4 months before and shortly after diagnosis, and three when diagnosed or shortly thereafter. Four of the 77 vinyl chloride-exposed workers without diagnosed ASL were positive for anti-p53 antibodies; two of the four had symptoms related to vinyl chloride toxicity. Tumors from three of the six vinyl chloride-exposed workers from which sufficient DNA for analysis was obtained had A:T to T:A missense mutations of the p53 gene. Anti-p53 antibodies were detected in two of these individuals. Among the control group, two of 15 serum samples from 15 lung cancer patients and zero of 15 serum samples from control subjects without cancer had anti-p53 antibodies as substantially lower levels than the nine (10%) of 92 vinyl chloride-exposed workers who were positive for anti-p53 antibodies. CONCLUSIONS AND IMPLICATIONS: Serum anti-p53 antibodies can predate clinical diagnosis of certain tumors, such as ASL, and may be useful in identifying individuals at high cancer risk, such as workers with occupational exposure to vinyl chloride.