Cancer letters
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The various treatments for advanced gastric cancer have limitations and induce only marginal survival benefit. HER-2/neu protein is overexpressed in several types of human cancers and its amplification is associated with poor prognosis. Recombinant humanized anti-HER-2/neu antibody (trastuzumab) not only inhibits the proliferation of HER-2/neu overexpressing tumor cells but also augments the cytotoxicity of concomitant chemotherapeutic agents in metastatic breast cancer. ⋯ After 1-day trastuzumab treatment, the S-phase fraction was decreased by 52 and 70% in YCC-2 and SK-BR-3, respectively. In conclusion, the expressions of HER-2/neu protein in gastric cancer cells are variable, and concomitant treatments of trastuzumab with doxorubicin increase cytotoxicity. This suggests that trastuzumab-based biologic therapy with chemotherapeutic agents can be applied in gastric cancer treatment.
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We examined CYP1A1 (I462V) and GSTM1 null polymorphisms in 200 female cases and 144 female controls selected from a population-based case-control study of lung cancer conducted in northeast China, where the rates of lung cancer among Chinese women are especially high. The CYP1A1 codon 462 point mutation in exon 7 (I462V) causes an Ile-Val substitution near the heme binding site. This mutation correlates with inducibility of aryl hydrocarbon hydrolase (AHH) activity, which activates polycyclic aromatic hydrocarbons (PAHs) in tobacco smoke and in indoor air pollution from coal-burning stoves, a risk factor for lung cancer in this study population. ⋯ The association was more pronounced among non-smokers (OR=3.67; 95% CI, 1.85-7.28) than among smokers (OR=1.74, 95% CI, 0.85-3.54). In contrast, we did not find a significant association with the GSTM1 null genotype. In summary, our case-control study of lung cancer among women in northeast China revealed an elevated risk associated with the CYP1A1 I462V genotype, but no interaction with smoking or indoor air pollution was found.