Relevance of N-nitrosamines to esophageal cancer in China

Conference · Wed Jan 01 04:00:00 EST 1986 · J. Cell. Physiol., Suppl.; (United States)

OSTI ID:6692019

Lu, S H; Montesano, R; Zhang, M S; Feng, L; Luo, F J; Chui, S X; Umbenhauer, D; Saffhill, R; Rajewsky, M F

Studies on the relevance of the N-nitrosamines to esophageal cancer in China are reviewed. Although a causal association between nitrosamines exposure and esophageal cancer in China has not yet been rigorously established, exposure of Lin-Xian subjects to nitrosamines either directly or as a result of their in vivo formation has been detected in our study. Several N-nitrosamines (NDMA, NDEA, NMBzA, NPyr, NPip, and NSAR) in gastric juice collected from Lin-Xian inhabitants have been detected. A correlation was found between the lesions of esophageal epithelium and the amount of nitrosamines present. In addition, the amounts of N-nitrosamino acids excreted in 24-hr urine of subjects in Lin-Xian were significantly higher than those in Fan-Xian, indicating a higher exposure to N-nitroso compound and their precursors of the inhabitants in the high-risk area. The effect of nitrosamines on human esophagus has been investigated at the cellular levels. The amounts of O/sup 6/-MedG in DNA of esophageal or stomach mucosa of patients from Lin-Xian were higher than that from Europe. The presence of O/sup 6/-MedG in the human fetal esophagus cultured with NMBzA was also detected. These findings indicate that the elevated levels of O/sup 6/-MedG in esophageal DNA could be the result of a recent exposure to N-nitroso compounds or a genetically determined reduced cellular capacity for repair of O/sup 6/-MedG from DNA. The hyperplasia was induced in the esophagus of human fetus that cultured with NMBzA for 2 weeks to 2 months. The intervention studies of esophageal cancer in Lin-Xian have been pursued. Intake of moderate doses of ascorbic acids by Lin-Xian subjects effectively reduced the urinary levels of N-nitrosamino acids to those found in undosed subjects in the low-risk area.

• Research Organization: Cancer Institute, Beijing, China
• OSTI ID: 6692019
• Conference Information: Journal Name: J. Cell. Physiol., Suppl.; (United States) Journal Volume: 4
• Country of Publication: United States
• Language: English

Related Subjects

560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ADDUCTS
AMINES
ASCORBIC ACID
ASIA
BIOLOGICAL EFFECTS
BIOLOGICAL MATERIALS
BIOLOGICAL WASTES
BODY
BODY FLUIDS
CARCINOGENESIS
CHINA
DIGESTIVE SYSTEM
DNA ADDUCTS
ESOPHAGUS
GASTRIC ACID
MATERIALS
NITROSAMINES
NITROSO COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PATHOGENESIS
PATIENTS
URINE
VITAMINS
WASTES