Furthermore, the effect on the protein expression of multidrug resistance proteins (P-gp and LRP), and the immunomodulatory and synergistic antiapoptotic effect on Lewis lung cancer-bearing C57BL/6J mice were also evaluated.
These results suggest that NNK inhibits IGFBP-3 expression to abrogate anti-tumor actions of the IGFBP-3/IGFBP-3R system in smoking-induced lung cancer.
Immunohistochemical analysis shows that LRP1 is primarily expressed in stromal cells in 94/111 lung cancers, with very little protein found in cancer cells.
LRP mRNA was expressed in all gastric and lung cancer lines, and its level in each cell type was less than two-fold that of HT1080 cells, except for two lung cancer lines.
To extend these findings to further types of human tumours we analysed specimens from 64 patients with primary breast cancer for their individual expression levels of several MDR-associated genes (MDR1, MRP, LRP (lung cancer resistance-related protein), topoisomerase (Topo) II alpha/IIbeta, cyclin A and the PKC isozyme genes (alpha, beta1, beta2, eta, theta, and mu) by a cDNA-PCR approach.