Incidences of bronchial preneoplastic lesions and LSCC in mice treated with NTCU
or NTCU + LPS and inhibitory effects of DIM on LSCC development. As mouse LSCC does not
form visible solid nodules on the surface of the lung, serial tissue sections were made
from each formalin-fixed lung and 1 in every 20 sections was stained with H&E. To
assess specific effects of the different treatments on each histopathologic stage, all of
the bronchioles in each given slide were counted and grouped into 5 categories based on
normal, hyperplasia, metaplasia, carcinoma in situ (dysplasia was included in this
category), and invasive SCC. The number in each category was then converted into
percentage. *, P < 0.05, compared to NTCU group; *, P < 0.05, compared to
NTCU group; # P < 0.05, NTCU/LPS vs NTCU/LPS/DIM.