title: Frequent microsatellite instability in lung cancer from chromate-exposed workers.
abstract: Although chromium has been the most extensively investigated metal with respect to mutagenicity and carcinogenicity, its genetic effects in humans are only partly understood. Our previous study demonstrated that lung cancer from chromate-exposed workers infrequently (20%) displayed p53 gene mutations as well as a particular mutation pattern. In the present study, we examined the replication error (RER) and loss of heterozygosity (LOH) in 38 lung cancers from 28 chromate-exposed workers (chromate lung cancer group) and in 26 lung cancer patients without chromate exposure (non-chromate lung cancer group), using six microsatellite markers containing CA repeats: D3S647 (3p23), D3S966 (3p21.3), D3S1289 (3p21.1), D5S346 (5q21-q22), D9S161 (9p21), and TP53 (17p13.1). The RER phenotype was defined as the presence of microsatellite instability (MSI) at two or more loci. Thirty (78.9%) of 38 tumors in the chromate lung cancer group exhibited RER. In contrast, only four (15.4%) of 26 tumors in the non-chromate lung cancer group exhibited RER. The frequency of RER in the chromate lung cancer group was significantly higher than that in the non-chromate lung cancer group (P < 0.0001). By contrast, the frequency of LOH at 3p, 5q, 9p, and 17p loci in tumors with chromate exposure was not significantly different from that in tumors without chromate exposure. In the chromate lung cancer group, the period of chromate exposure in workers with RER (24.5 +/- 6.7 yr) was significantly longer than that in workers without RER (17.0 +/- 3.5 yr) (P = 0.0046). In addition, a longer period of chromate exposure was associated with a tendency toward a higher frequency of MSI. This finding suggests that MSI may play a role in chromium-induced carcinogenesis. In addition to our previous study of p53 mutations, the present findings suggest that the carcinogenic mechanism of chromate lung cancer may differ from that of non-chromate lung cancer.
authors.affiliation: Second Department of Surgery, School of Medicine, University of Tokushima, Tokushima, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Hirose
authors.forename: Kazuya
authors.initials: K
authors.lastname: Kondo
authors.forename: Yuji
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Hisashi
authors.initials: H
authors.lastname: Ishikura
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Fujino
authors.forename: Masaru
authors.initials: M
authors.lastname: Tsuyuguchi
authors.forename: Masato
authors.initials: M
authors.lastname: Hashimoto
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Yokose
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Mukai
authors.forename: Tetsurou
authors.initials: T
authors.lastname: Kodama
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Monden
mesh_terms: D000328:Adult; D000368:Aged; D002273:Carcinogens / Q000009:adverse effects*; D002840:Chromates / Q000009:adverse effects*; D004261:DNA Replication; D005260:Female; D005787:Gene Frequency; D005819:Genetic Markers; D006801:Humans; D019656:Loss of Heterozygosity; D008175:Lung Neoplasms / Q000139:chemically induced / Q000175:diagnosis / Q000235:genetics*; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D009784:Occupational Diseases / Q000139:chemically induced / Q000175:diagnosis / Q000235:genetics*; D016273:Occupational Exposure
chemical_list: D002273:Carcinogens; D002840:Chromates; D005819:Genetic Markers