Elevated Expression of Interleukins in Lung Adenocarcinomas Induced by N‐Nitrosobis(2‐hydroxypropyl)amine in Rats

The expression of interleukins (ILs) in lung adenocarcinomas induced by N‐nitrosobis(2‐hydroxypropyl)amine (BHP) in rats was investigated using a multiprobe RNase protection assay (RPA) followed by densitometric quantification. Male Wistar rats, 6 weeks old, were given 2000 ppm BHP in their drinking water for 12 weeks and maintained without further treatment until they were killed at week 25. Total RNAs were extracted from 14 individual adenocarcinomas and 2 specimens of normal lung tissue of untreated rats. In adenocarcinomas, elevated expression of IL‐1α (6/14), IL‐1β (14/14), IL‐3 (7/14), IL‐4 (11/14), IL‐5 (9/14), IL‐6 (11/14) and IL‐10 (8/14) was observed, compared with normal lung tissues. In contrast, no expression of IL‐2 was detected in any case. The results suggest that preferential expression of these ILs and their complex networks may contribute to the development and progression of lung adenocarcinomas induced by BHP in rats.